WO2022038031A1 - Drive assembly for a hinged closure element of a motor vehicle - Google Patents

Abstract

The invention relates to a drive assembly for a hinged closure element (2b) of a motor vehicle (2), comprising a drive element (4), more particularly a spindle-based drive element (4) or a gas pressure element, which has a cylinder (6) and a piston (8); wherein the drive element (4) has a first drive connection point (4a), which is connected to the cylinder (6), and a second drive connection point (4b), which is connected to the piston (8), which drive connection points move relative to each other axially during adjustment of the drive element (4) between a retracted position and an extended position; wherein the drive element (4) has a drive spring assembly (9), which has a helical spring (10), which helical spring axially preloads the first drive connection point (4a) relative to the second drive connection point (4b); wherein the drive element (4) has a drive housing (11), which has a housing tube (11a), which housing tube is coaxial with the helical spring (10); and wherein the drive element (4) has a spacer bushing (12), which is coaxial with the cylinder (6), the helical spring (10) being axially supported on the spacer bushing (12). According to the invention, the spacer bushing (12) radially separates the interior of the drive element (4) from the surroundings of the drive element (4) in a first axial segment (x1), at least in the extended position of the drive element (4).

Description

Drive arrangement for a flap of a motor vehicle

The present invention relates to a drive arrangement for a flap, in particular a tailgate, of a motor vehicle according to the preamble of claim 1 and a drive arrangement for a flap, in particular a tailgate, of a motor vehicle according to the preamble of claim 16.

The known prior art (WO2018/141446 A1), on which the invention is based, relates to a drive arrangement for a flap according to the preamble of claim 1 .

The drive arrangement in question is used in the context of the motorized adjustment of any flaps of a motor vehicle. Such flaps can be, for example, tailgates, boot lids, bonnets, luggage compartment floors, but also doors of a motor vehicle. In this respect, the term “flap” is to be understood broadly in the present case.

Such a drive arrangement has a motorized drive in the form of a spindle drive on one side of the tailgate, which has an electric drive unit and a spindle-spindle nut gearing downstream of the electric drive unit in terms of drive technology, with which linear drive movements between a drive connection on the body and a drive connection on the flap side for opening and closing of the flap are generated. In a holding position of the flap, the spindle drive is in an extended position, whereas in a closed position of the flap, the spindle drive is in a retracted position.

Since the weight of the tailgate can be of considerable size, a gas pressure element in the form of a gas spring is arranged separately from the spindle drive on the other side of the flap as a drive element, which is intended to compensate for the weight of the tailgate. As a rule, this is intended to ensure that the tailgate is always in the vicinity of the state of equilibrium or is urged in the opening direction. In such a flap arrangement with a motor drive on the one hand and a non-motor drive element, in particular a gas pressure element, here a gas spring, on the other side of the flap one also speaks of an active/passive system.

It is a challenge to construct the drive element, in particular the gas pressure element, as cost-effectively as possible. For example, the known gas pressure element has a drive spring arrangement with a helical compression spring that axially biases the two drive connections of the gas pressure element against one another. The helical compression spring, which radially surrounds the cylinder-piston unit of the gas pressure element, is itself surrounded by a two-part drive housing. The drive housing has two telescopically guided housing tubes, one housing tube being fixed axially to one drive connection and the other housing tube being fixed axially to the other drive connection. Furthermore, a spacer sleeve is provided, which is arranged between the one drive connection and the helical compression spring within one of the two housing tubes. The many components of this drive element or gas pressure element are associated with increased manufacturing effort and increased manufacturing costs.

The invention is based on the problem of designing and developing the known drive arrangement for a flap in such a way that further optimization is achieved with regard to the challenge mentioned, in particular with regard to the manufacturing complexity and manufacturing costs.

The above problem is solved by the features of the characterizing part of claim 1.

What is essential is the fundamental consideration of dispensing with a housing tube that is axially fixed to this drive connection on that one of the drive connections to which the spacer bush is closest and on which the spacer bush bears in particular. In this axial section of the drive element, in particular the gas pressure element, the spacer sleeve then assumes a housing function. As a result, the drive housing can be simplified and, in particular, reduced to just one housing tube. This housing tube is then preferably axially fixed relative to the one of the drive connections remote from the spacer bushing and in particular fixed axially positively thereto. In this way, the drive spring arrangement can tion or helical spring, namely by said housing tube, are covered radially outwards without the drive spring arrangement requiring a drive housing with two housing tubes for this purpose. In principle, as will be explained later, in another variant a drive housing can also be completely dispensed with.

Specifically, it is proposed that the spacer bushing radially separates the interior of the drive element from the surroundings of the drive element in a first axial section, at least in the extended position of the drive element.

According to the preferred embodiment according to claim 2, in a variant with a drive housing, the housing tube surrounds the helical spring radially over its entire axial extent. The coil spring is thus optimally protected. A further housing tube, which can be telescoped to the existing housing tube, is therefore not required.

Claims 3 and 4 relate to particularly preferred arrangements of the spacer sleeve within the drive assembly. The housing tube with the spacer bushing particularly preferably overlaps in the retracted position of the drive element and in particular also in the extended position of the drive element, as a result of which the interior of the drive arrangement is optimally protected from the environment.

Claim 5 relates to particularly preferred options for arranging the drive element on the motor vehicle.

According to the likewise preferred embodiment according to claim 6, the housing tube is guided radially, in particular on the outside, on the spacer sleeve.

According to the further preferred embodiment according to claim 7, the drive element is a spindle-based drive element, ie a drive element which has a spindle/spindle nut gear. In particular, this drive element is a non-motor drive element. The spindle forms the piston of the cylinder-piston unit of the drive element and a spindle guide tube together with the spindle nut forms the associated gene cylinder. This is therefore a cylinder-piston unit in which the piston has an external thread and the cylinder has a corresponding internal thread provided by the spindle nut.

Claims 8 and 9 relate to a further helical spring as part of the drive spring arrangement, with this helical spring particularly preferably serving as a pop-up spring, which is therefore only active over part of the adjustment of the drive element, in particular only at the beginning of the adjustment from the retracted position. generates an axial preload. This makes it easier to open the flap at the very beginning of the opening process.

Claims 10 to 12 relate to a first joint part which forms the drive connection which is connected to the piston, in particular the spindle. A brake is preferably integrated into this joint part, which brakes the rotational movements of the spindle relative to the first joint part, in particular permanently.

Claims 13 and 14 relate to a second joint part which forms the drive connection which is connected to the cylinder, in particular the spindle guide tube.

Claim 15 defines particularly preferred connection variants which enable an axially fixed connection of the first joint part to the piston or to the spindle and/or an axially fixed connection of the second joint part to the cylinder or spindle guide tube and/or an axially fixed connection of the respective joint part to the spacer bush. Such a connection is in particular a positive, non-positive and/or material connection. A crimped connection, a snap connection, a threaded connection, an adhesive connection and a welded connection, preferably a laser welded connection, are mentioned here merely as examples.

According to a further teaching according to claim 16, which is of independent importance, a drive arrangement for a flap, in particular tailgate, of a motor vehicle is claimed, with at least one drive element, in particular spindle-based drive element or gas pressure element, the drive element having a cylinder-piston unit which one cylinder and one running in the cylinder interior along the cylinder axis has the piston, wherein the cylinder is filled with a fluid, in particular a fluid that is under pressure, the drive element having a first drive connection, which is connected to the cylinder, and a second drive connection, which is connected to the piston an adjustment of the drive element between a retracted and an extended position relative to one another, the drive element having a drive spring arrangement which has a coil spring which is arranged coaxially with the cylinder, radially surrounding it and axially biases the first drive connection relative to the second drive connection , wherein the drive element has no drive housing, wherein the drive element has a spacer bushing, which is arranged coaxially to the cylinder, radially surrounding it and forms or occupies a space, in particular an annular space, which is located axially in an area between one of the drive connections, in particular re the second drive connection, and the helical spring extends, wherein the helical spring is supported axially on the spacer sleeve.

In the variant without a drive housing, it is also proposed that the spacer bush radially separates the interior of the drive element from the area surrounding the drive element in a first axial section, at least in the extended position of the drive element. In this respect, reference may be made to all statements relating to the proposed drive arrangement according to the first teaching.

This variant without a drive housing is particularly suitable for use in the under-roof area of the motor vehicle, as there is no significant risk of moisture or dirt penetrating here. On the other hand, the variant with the drive housing is particularly suitable for arrangement in the water channel on the side of the body opening that can be closed by the flap.

According to the particularly preferred embodiment according to claim 17, the drive element has a spring guide tube. This allows the drive spring arrangement, in particular the helical spring, which preloads the drive connections axially against one another, to be guided radially, which is particularly advantageous if no drive housing is provided. The invention is explained in more detail below with reference to a drawing that merely shows exemplary embodiments. In the drawing shows

1 shows the rear area of a motor vehicle with a proposed drive arrangement for the flap there,

2 shows a sectional view of a drive element of the drive arrangement according to FIG. 1 in the resting state a) after the drive connections have been driven together and b) after the drive connections have been driven apart into their end positions,

3 shows a sectional view of a further exemplary embodiment of a drive element of the drive arrangement according to FIG. 1 in the resting state a) after being driven together and b) after the drive connections have been driven apart into their end positions,

4 shows a perspective view of a drive connection for a drive element according to FIG. 2 or 3 with a brake a) in the installed state of the brake and b) in an exploded view of the brake and

5 shows a sectional view of the other drive connection for a drive element according to FIG. 2 or 3 in a variant without a drive housing a) according to a first exemplary embodiment and b) according to a second exemplary embodiment.

The proposed drive arrangement 1 is used here and preferably for the motorized adjustment of a flap 2b of a motor vehicle 2 by means of a motorized drive 3. The proposed drive arrangement 1 can, in an alternative embodiment, with the provision of at least one non-motorized drive element 4, but also be purely spring-driven or purely manually operable . For example, the proposed drive arrangement 1 can be operated purely by springs if, for example, a gas pressure element in the form of a gas spring is provided as the non-motor drive element 4, or it can be operated purely manually if the non-motor drive element 4 is, for example, a gas pressure element in the form of a gas damper be. A spindle-based drive element 4 can also be provided as a non-motor drive element 4 in particular, which will be explained below. The flap 2b can be adjusted by means of the drive arrangement 1 in an opening direction and/or in a closing direction of the flap 2b.

The flap 2b is here and preferably a tailgate of the motor vehicle 2. The proposed drive arrangement 1 can be used particularly advantageously in the “tailgate” application, since tailgates are comparatively heavy.

In principle, however, the proposed drive arrangement 1 can also be applied to other types of flaps 2b of a motor vehicle 2 . This includes boot lids, front hoods or the like, but also doors. All statements apply accordingly to other flaps 2b.

As FIG. 1 shows, the proposed drive arrangement 1 has here and preferably one, here exactly one, motorized drive 3 . The motor drive 3 is here and preferably a linear drive, in particular a spindle drive.

Furthermore, the proposed drive arrangement 1 has a drive element 4 , in this case precisely one, in particular a non-motor drive element.

According to FIG. 2, the drive element 4 is, for example, a gas pressure element, here and preferably a gas spring, in particular a gas pressure spring. Here, and preferably, the gas spring prestresses the flap 2b in its opening direction. In principle, the gas spring can also be a gas tension spring. It is also conceivable that the gas pressure element is a gas damper, ie has no resilient effect.

In addition, as shown by way of example in FIG. 3 , the drive element 4 , in particular as a non-motor drive element 4 , can be spindle-based. In this case too, the flap 2b can be prestressed in its opening direction or closing direction. In principle, the proposed drive arrangement 1 can also have more than one motorized drive 3 and/or more than one, in particular non-motorized, drive element 4 . In the flap arrangement shown in FIG. 1, which also has the drive arrangement 1 in addition to the flap 2b of the motor vehicle 2, the motorized drive 3 is arranged on a first side of the flap 2b and the drive element 4 on an opposite, second side of the flap 2b.

The motor drive 3, which forms the active side of an active/passive system here, is set up to open and close the flap 2b. For this purpose, the drive 3 has a drive unit (not shown here) with an electric drive motor and optionally one or more other drive components such as an intermediate gear, an overload clutch and/or a brake. The drive unit is here and preferably a likewise not shown linear gear, in particular spindle-spindle nut gear, connected downstream in terms of drive technology, which as gear components has in particular a spindle and a spindle nut which meshes with it. Here and preferably, the spindle is drivingly coupled to the drive unit and is rotated during operation, as a result of which the spindle nut executes a linear movement along the spindle.

The motor drive 3, which has the drive unit and the linear gear, in particular the spindle/spindle nut gear, has a first drive connection 3a, in particular on the spindle side, and a second drive connection 3b, in particular on the spindle nut side, via which the drive 3 is coupled to the motor vehicle 2. Here, and preferably, the drive 3 is coupled to the body 2a of the motor vehicle 2 via the drive connection 3a on the spindle side and to the flap 2b via the drive connection 3b on the spindle nut side. The linear drive movements of the linear gear either drive the drive connections 3a, 3b apart, which corresponds to an adjustment movement of the flap 2b in its opening direction, or drive the drive connections 3a, 3b together, which corresponds to an adjustment movement of the flap 2b in its closing direction. The drive element 4 is to be described in more detail below with reference to the gas pressure element shown as an example in FIG. 2 . The relevant statements also apply equally to the other drive elements 4 described here, in particular also to the spindle-based drive element 4 described below.

The drive element 4 or the gas spring, which here and preferably forms the gas pressure element and which forms the passive side of the active/passive system, does not have its own motor drive, but provides a spring function here. The drive element 4 or the gas spring should absorb part of the weight of the flap 2b and thereby hold the flap 2b, when it is open, in the vicinity of the state of equilibrium or urge it in the opening direction.

The drive element 4, in this case the gas pressure element, has a cylinder-piston unit 5 in a conventional manner with a cylinder 6 that is optionally sealed on the outside and a cylinder interior 7 that runs axially along the cylinder axis A in the interior space 7 that is radially enclosed by the cylinder 6 piston 8 dividing into two compartments 7a, 7b. The piston 8 has a piston rod 8a which runs along the cylinder axis A and is movable relative to the cylinder 6 . The piston rod 8a penetrates, sealingly in the case of the gas pressure element, an axial opening in the cylinder 6, as a result of which a section of the piston rod 8a is arranged in the cylinder interior 7 and another section outside of the cylinder 6. In another, in particular spindle-based, drive element 4 instead of a gas pressure element, the piston rod 8a penetrates the axial opening in the cylinder 6, in particular in a non-sealing manner.

The piston 8 also has a base body 8b on the section of the piston rod 8a arranged in the cylinder interior 7, in particular on its front end, which in particular forms the piston head. Here, the base body 8b preferably has a cross section, based on a section in the radial direction of the cylinder 6, which corresponds to that of the cylinder interior 7. The drive element 4, here the gas pressure element, also has a first drive connection 4a, which is connected to the cylinder 6, and a second drive connection 4b, which is connected to the piston 8. In the case of the gas pressure element, the cylinder 6 is filled with the pressurized fluid in such a way that the two drive connections 4a, 4b are driven apart. The fluid is, in particular, a compressible gas and can optionally, preferably in small amounts, also contain a liquid such as oil, for example to bring about end-position damping and/or lubrication. In the case of another, in particular spindle-based, drive element 4 instead of a gas pressure element, the fluid is in particular not under pressure. The fluid is then preferably air.

In the unloaded state, ie when no external forces are acting on the drive element 4, here the gas pressure element, the two drive connections 4a, 4b are in the maximum spread position shown in FIGS. 1 and 2b). This position of the drive connections 4a, 4b relative to one another also corresponds here and preferably to the holding position of the flap 2b shown in FIG. The drive connection 4a on the cylinder side is coupled to the body 2a of the motor vehicle 2 and the drive connection 4b on the piston side is coupled to the flap 2b. It should be emphasized again that, as explained above, the cylinder 6 can also be pressureless, for example in the case of a gas damper or spindle-based drive element 4 (FIG. 3) instead of a gas spring.

Furthermore, as shown in FIG. 2 for the present exemplary embodiment, the drive element 4, here the gas pressure element, has a drive spring arrangement 9, which has a helical spring 10, optionally also several helical springs. The respective helical spring 10, which is arranged coaxially with the cylinder 6, is in particular a helical compression spring, as is the case here. The coil spring 10 surrounds the cylinder 6 radially. The respective helical spring 10 preferably serves to drive the drive connections 4a, 4b apart, with the helical spring 10 counteracting the piston movement in particular over the entire range of movement of the piston 8, ie over its entire stroke s. In addition, a pop-up spring can also be provided, which only has part of the Hubs s counteracts the piston movement, which will be described below.

The drive element 4, here the gas pressure element, also has a drive housing 11, which has a housing tube 11a, here precisely a housing tube 11a, which is arranged coaxially to the helical spring 10, radially surrounding it. As FIG. 5 shows, however, variants without a drive housing are also conceivable.

A drive housing 11 is, in particular, a housing that radially surrounds at least the component or components that generate the drive force for the drive function, i.e. here the drive spring arrangement 9, and thus forms an outer radial sleeve in this area, which separates the interior of the drive element 4 from the Environment of the drive element 4 separates. A drive housing 11 is advantageous when the drive element 4 is used in the water channel on the side of the body opening that can be closed by the flap 2b. In principle, a variant without a drive housing is also conceivable, which will be explained later.

Furthermore, the drive element 4, here the gas pressure element, has a spacer sleeve 12 which is arranged coaxially to the cylinder 6, radially surrounding it and forms or occupies a space, in particular an annular space. "Forms" in this context means that a free, i.e. not filled, space is created by the spacer bushing 12, whereas "occupies" means that this space is filled by the spacer bushing 12, i.e. the material of the spacer bushing 12 completely fills this space takes. This space, in particular an annular space, extends axially in an area between one of the drive connections 4a, 4b, here the second drive connection 4b, and the helical spring 10. The helical spring 10 is supported axially on the spacer bushing 12, i.e. the spacer bushing 12 takes the Spring force of the coil spring 10 on. Here, and preferably, the helical spring 10 rests directly on the spacer bushing 12 .

The illustrated in the figures and preferred embodiment relates to a drive arrangement 1 for a flap 2b, in particular tailgate, of a motor vehicle 2 with at least one drive element 4, in particular spindle-based drive element 4 or gas pressure element, wherein the drive selement 4 has a cylinder-piston unit 5, which has a cylinder 6, optionally sealed to the outside, and a piston 8 running in the cylinder interior 7 along the cylinder axis A, the cylinder 6 being filled with a fluid, in particular a fluid that is under pressure , wherein the drive element 4 has a first drive connection 4a, which is connected to the cylinder 6, and a second drive connection 4b, which is connected to the piston 8, which change when the drive element 4 is displaced between a retracted and an extended position move axially relative to one another, with the drive element 4 having a drive spring arrangement 9 which has a coil spring 10 which is arranged coaxially with the cylinder 6, radially surrounding it and axially pretensions the first drive connection 4a relative to the second drive connection 4b, the drive element 4 has a drive housing 11, the one, in particular exactly one housing has use tube 11a, which is arranged coaxially to the helical spring 10, radially surrounding it, and wherein the drive element 4 has a spacer bushing 12, which is arranged coaxially to the cylinder 6, radially surrounding it and forms a space, in particular an annular space, or occupies, which extends axially in a region between one of the drive connections 4a, 4b, in particular the second drive connection 4b, and the helical spring 10, the helical spring 10 being supported axially on the spacer bushing 12.

Such a spacer bushing 12 has the fundamental advantage that the available spring installation space is reduced. As a result, the corresponding helical spring 10 can also be made shorter, which in turn offers advantages in terms of packaging sizes and during assembly.

It is now essential that the spacer sleeve 12 radially separates the interior of the drive or gas pressure element 4 in a first axial section Xi from the environment of the drive or gas pressure element 4 at least in the extended position of the drive or gas pressure element 4 .

First of all, it should be emphasized that the spacer bushing 12 must be distinguished from the drive housing 11 . The spacer bushing 12 is a component which is expressly not part of the drive housing 11, ie it does not radially surround the drive spring arrangement 9 providing the drive function, not even just in an axial section. The spacer bushing 12 is a "drive housing tubeless" Component that has no housing tube of the drive housing 11 or forms. Thus, at that one of the drive connections 4a, 4b, to which the spacer bushing 12 is closest and on which the spacer bushing 12 bears in particular, a housing tube that is axially fixed to this drive connection (drive connection 4a in FIG. 2; drive connection 4b in FIG. 3) is applied of the drive housing 11 is omitted.

Here, “axially fixed” means that an axial securing, in particular an axially form-fitting securing, is provided in at least one direction, namely at least in the direction of the nearest drive connection (drive connection 4a in FIG. 2; drive connection 4b in FIG. 3). . The axial securing preferably exists in both directions.

Furthermore, it is here and preferably the case that the spacer sleeve 12 radially surrounds the cylinder 6 only over part of its axial extension, in particular both in the retracted position and in the extended position of the drive element 4 .

According to the proposal, the spacer sleeve 12 is in contact with the surroundings radially on the outside in the aforementioned axial section Xi in the extended position, so it forms the outer surface of the drive element 4 here, in particular the gas pressure element or spindle-based drive element 4, and is therefore not surrounded radially by a housing tube. Thus, the spacer sleeve 12 is the component here that covers the cylinder-piston unit 5, in particular the cylinder 6, radially outwards in the extended position in this axial section Xi. A separate housing tube, which covers the cylinder-piston unit 5, in particular the cylinder 6, in the extended position in this axial section Xi, is omitted. The drive housing 11 thus preferably has only a single housing tube 11a (FIGS. 1 to 4) or even no drive housing at all (FIG. 5). This housing tube 11a is axially fixed here and preferably relative to the one of the drive connections 4a, 4b remote from the spacer bushing 12, in Fig. 2 the second drive connection 4b and in Figs. 3 to 5 the first drive connection 4a, and in particular at this drive connection in both directions axially positively fixed. Here, the spacer bushing 12 preferably has an axial extent that is greater than its inside and/or outside diameter. The spacer bushing 12 is an extruded profile, especially for under-roof applications. For water channel applications, an additional collar can be added to other components for the necessary tightness. Alternatively, there is the option of using an additional sealing cap. In principle, the spacer bushing 12 can be defined as a component that has been cut to length or using standard modular lengths, and has a length that is at least the total stroke of the drive element 4, in particular the gas pressure element or spindle-based drive element 4, if necessary plus a safety measure, for example to implement an overlap with the housing tube 11a in the extended position of the drive element 4.

Here and preferably it is also provided that the housing tube 11a surrounds the coil spring 10 radially over its entire axial extent, at least in the retracted position and in particular also in the extended position of the drive element 4 Housing tube provided that surrounds the coil spring 10 radially. “Telescopic” means that two housing tubes that are guided inside one another can be displaced axially with respect to one another. However, this is not provided here and preferably. In particular, no further housing tube radially surrounding the coil spring 10 is provided.

In the exemplary embodiments shown in the figures and insofar preferred, it is also provided that the spacer sleeve 12, in the retracted position of the drive element 4, in particular the gas pressure element or the spindle-based drive element 4, the interior of the drive or gas pressure element 4 in a second axial section x ₂ radially separates from the surroundings of the drive or gas pressure element 4, preferably that the first axial section Xi is larger than the second axial section x ₂ , more preferably that the second axial section x ₂ forms part of the first axial section Xi.

The second axial section x ₂ of the drive element 4, in particular the gas pressure element or spindle-based drive element 4, corresponds here to an overstroke, ie a part of the total stroke that the drive or gas pressure ckelement can realize in the unassembled state, but which is not run through in the assembled state with intended use and / or assembly-related. The first axial section Xi corresponds at least to the stroke s that the drive or gas pressure element runs through in the mounted state when used as intended, here and preferably plus the said overstroke.

Furthermore, it is preferably provided here that the housing tube 11a in the retracted position of the drive element 4, in particular the gas pressure element or spindle-based drive element 4, overlaps the spacer sleeve 12 radially, in particular on the outside, in a first axial overlapping section yi, preferably that the housing tube 11a in the extended position of the drive or gas pressure element with the spacer sleeve 12 in a second axial overlapping section y2, in particular on the outside, overlaps radially, more preferably that the first axial overlapping section yi is larger than the second axial overlapping section ya, more preferably that the second axial lap portion y ₂ forms part of first axial lap portion yi.

A certain minimum axial overlap between the spacer sleeve 12 and the housing tube 11a is preferably always ensured, ie also in the extended position, so that the helical spring 10 is also completely radially covered in the extended position. As a result, on the one hand, the interior of the drive or gas pressure element 4 is protected from environmental influences such as moisture and dirt, and on the other hand, an operator is prevented from accidentally coming into contact with the helical spring 10 .

The housing tube 11a has in particular a larger diameter than the spacer sleeve 12 and/or is axially movable in particular on the outside of the spacer sleeve 12 and ensures radial guidance of the housing tube 11a. In the state of the art, such a guiding function has always been assumed by the additional housing tube, which is omitted here.

In addition, it is here and preferably provided that the drive element 4, in particular the gas pressure element or spindle-based drive element 4, via the first drive connection 4a with the body 2a of the power vehicle 2 can be or is coupled and that the drive or gas pressure element can be or is coupled via the second drive connection 4b to the flap 2b of the motor vehicle 2, preferably that the spacer sleeve 12 bears against the first drive connection 4a, in particular axially on the first drive connection 4a is fixed. Alternatively, it can be provided that the drive element 4 can be coupled or is coupled to the flap 2b of the motor vehicle 2 via the first drive connection 4a and to the body 2a of the motor vehicle 2 via the second drive connection 4b, preferably that the spacer bushing 12 bears against the second drive connection 4b , is fixed axially in particular on the second drive connection 4b.

Here, and preferably, the spacer bushing 12 transmits the spring force of the coil spring 10 to the first, body-side drive connection 4a. As already explained, here no housing tube is axially fixed relative to this drive connection 4a and/or axially fixed to this drive connection 4a.

Furthermore, it is here and preferably so that the spacer bushing 12 is rotatably mounted relative to this drive connection 4a, so that no torque can be introduced from the coil spring 10 via the spacer bushing 12 into the drive connection 4a. This has the advantage that the screw connection between the drive connection 4a and the cylinder-piston unit 5, in particular the cylinder 6, cannot become loose unintentionally.

It is also claimed that the housing tube 11a is guided radially, in particular on the outside, on the spacer sleeve 12 .

Since no further housing tube is provided to radially support the existing and here only housing tube 11a during the adjustment movements, this function is preferably performed here and preferably by the spacer bushing 12. There is also the possibility of providing ribs radially on the outside of the spacer bushing 12 for improved guidance. These can then interact with corresponding counterparts on the housing tube 11a. Ventilation channels and/or anti-rattle ribs can also be provided radially on the outside of the spacer sleeve 12 . As illustrated in FIGS. 3 to 5, the drive element 4 can also be designed as a spindle-based, in particular non-motorised, drive element 4 instead of a gas pressure element. The drive element 4 then has a spindle-spindle nut gear 13, which has a spindle 14 and a spindle nut 15 meshing therewith as gear components.

The drive element 4 also has a spindle guide tube 16 in which the spindle 14 is guided axially when the drive element 4 is adjusted between the retracted and the extended position, namely via the base body 8b. The spindle nut 15 is arranged axially and non-rotatably on the spindle guide tube 16 .

In this embodiment of the drive element 4, the spindle 14 of the spindle-spindle nut gear 13 forms the piston 8 of the cylinder-piston unit 5. The spindle guide tube 16 together with the spindle nut 15 forms the cylinder 6 of the cylinder-piston unit 5. The spindle 14 is in this case, therefore, a piston 8 provided with an external thread, which is linearly and rotationally movable in an internal thread of the spindle guide tube 16, which is provided by the spindle nut 15.

Here, and preferably, the first drive connection 4a is connected to the spindle guide tube 16 and the second drive connection 4b is connected to the spindle 14 . Basically, according to an alternative embodiment not shown here, it is also conceivable that the first drive connection 4a is connected to the spindle 14 and the second drive connection 4b is connected to the spindle guide tube 16 .

It should be emphasized that the drive element 4 is, in particular, not a motor, ie it does not have a drive motor which is upstream of the spindle-spindle nut gear 13 in terms of drive technology in order to introduce a drive torque into it. In principle, however, it is also quite conceivable to provide the drive element 4 with a drive motor, as was previously described for the optional motorized drive 3 . A spindle-based drive element 4 also enables a good holding effect when the flap 2b is open or a braking effect when it is adjusted via the spindle/spindle nut gear 13 . The spindle-spindle nut gear 13 can be self-locking or non-self-locking.

Here, and preferably, the drive element 4 can be coupled to the body 2a of the motor vehicle 2 via the drive connection 4a on the spindle nut side and to the flap 2b via the drive connection 4b on the spindle side. The spacer bushing 12 and the spindle 14 are here and preferably assigned to the same drive connection 4b, that is to say fixed thereto, and are axially movable with respect to this drive connection 4a.

The spindle 14 is preferably rotatably mounted relative to the associated drive connection 4b. Additionally or alternatively, the spindle nut 15 is preferably non-rotatable relative to the associated drive connection 4a.

It should be emphasized that the following explanations apply not only to a spindle-based drive element 4, as shown in FIGS. 3 to 5, but very generally to a proposed drive element 4, i.e. also to a gas pressure element according to FIG.

As FIG. 3 shows, the drive spring arrangement 9 can also have a further helical spring 17 which is arranged coaxially to the cylinder 6, radially surrounding it and axially prestresses the first drive connection 4a relative to the second drive connection 4b. Here, and preferably, the first helical spring 10 is arranged coaxially to the further helical spring 17, radially surrounding it. The first helical spring 10 therefore acts parallel to the other helical spring 17.

Here, and preferably, the further coil spring 17 keeps the first drive connection 4a opposite the second drive connection 4b only over part of the adjustment of the drive element 4 between the retracted and the extended position, in particular only at the beginning of the adjustment from the retracted position , axially preloaded. The helical spring 17 is in this case designed as a pop-up spring. Preferably, as shown in FIG. 3, the housing tube 11a is also arranged coaxially to the further helical spring 17, radially surrounding it.

The further helical spring 17 is supported here and preferably also axially on the spacer bushing 12, specifically, according to FIG. Here, and preferably, the point at which the first helical spring 10 is axially supported on the spacer bush 12 is closer to the drive connection 4b assigned to the spacer bush 12 than the point at which the further helical spring 17 is axially supported on the spacer bush 12. The “assigned” drive connection means that of the drive connections to which the spacer bushing 12 is closest.

The drive connection 4b, in particular the second drive connection 4b, connected to the piston 8, in particular the spindle 14, is formed here and preferably by a first joint part 18, which forms an articulated connection with a corresponding counter-joint part on the vehicle side. The piston 8, in particular the spindle 14, is axially fixed and in particular rotatable with respect to the first joint part 18.

As illustrated in particular in FIG. 4, a brake 19 is integrated here and preferably in the first joint part 18, which brakes the rotational movements of the spindle 14 relative to the first joint part 18, in particular permanently. Here, and preferably, it is also the case that the brake 19, in particular an optional housing 20 of the brake 19 shown in broken lines in FIG. For the non-rotatable connection, a positive, non-positive and/or material connection, preferably a claw connection (not shown here), can be provided.

The brake 19 is equipped with one or more first friction elements 21 and with one or more second friction elements 22 that interact with them in a frictionally engaged manner, with the friction element or elements 21 being non-rotatable with respect to the spindle 14 and the friction element or elements 22 being non-rotatable with respect to the joint part 18 and/or the to the joint part 18 non-rotatable, optional brake housing 20 are arranged. 4b) shows an exploded view of a corresponding brake 19, which also shows that here the friction elements 21, 22 can be prestressed against one another via an axially acting spring element 23, which is supported on a cover 24 of the brake 19.

It should be emphasized again that such a joint part can be provided not only in a spindle-based drive element 4 as shown in FIGS. 3 to 5, but also in the case of a gas pressure element as shown in FIG. 2 as a drive element 4.

As shown in FIGS. 4a) and b), the first joint part 18 has here and preferably a connection piece 25 for the axially fixed connection to the piston 8, in particular the spindle 14. The connecting piece 25 has a receiving space 26 for the brake 19 here and preferably radially on the inside. In Fig. 4a) the brake 19 is shown in the inserted state, in Fig. 4b) in an exploded view before insertion into the receiving space 26.

4a) further shows that the spindle 14 is rotatably mounted here and preferably in a spindle bearing 27, the spindle bearing 27 bearing against the connection piece 25 in the assembled state. In addition or as an alternative, it is also conceivable for the spindle bearing 27 to be accommodated in the accommodation space 26 . In addition to the connecting piece 25, the joint part 18 also has a joint piece 28, for example a ball socket or a ball head, as shown in FIG. Connection piece 25 and joint piece 28 are in particular configured in one piece.

Here, and preferably, the connection piece 25 also serves to connect to the spacer bushing 12, the connection being in particular a non-rotatable connection.

It is particularly preferred that the spacer bushing 12 rests axially on the connecting piece 25 of the first joint part 18 and/or, as FIGS. 2 and 3 illustrate particularly well, the spacer bushing 12 has a receiving space 26 for the connecting piece radially on the inside 25 and that Connection piece 25 and in particular also the spindle bearing 27 are accommodated in the receiving space 26 .

Fig. 5 shows the other end of the drive element 4 axially opposite the end of the drive element 4 shown in Fig. 4. Here and preferably, the drive connection 4a connected to the cylinder 6, in particular the spindle guide tube 16, in particular the first drive connection 4a, is connected by a second joint part 30 is formed, which forms an articulated connection with a corresponding vehicle-side counter joint part. The cylinder 6, in particular the spindle guide tube 16, is axially fixed to the second joint part 30.

Here, and preferably, the cylinder 6 , in particular the spindle guide tube 16 , is guided in the spacer sleeve 12 such that it can rotate relative to the second joint part 30 and is non-rotatable. However, according to another embodiment not shown here, it is also conceivable for the cylinder 6, in particular the spindle guide tube 16, to be arranged on the second joint part 30 in a rotationally fixed manner. In particular, the cylinder 6 is then guided in the spacer sleeve 12 in a rotatable or non-rotatable manner.

It should be emphasized again that such a joint part can be provided not only in a spindle-based drive element 4 as shown in FIGS. 3 to 5, but also in the case of a gas pressure element as shown in FIG. 2 as a drive element 4.

As shown in FIGS. 5a) and b), the second joint part 30 has here and preferably also a connecting piece 31 for the axially fixed connection to the cylinder 6, in particular the spindle guide tube 16.

The connection piece 31 has here and preferably radially on the inside a receiving space 32 for a connection section 33 of the cylinder 6 , in particular of the spindle guide tube 16 . According to the variants listed in FIG. 5 by way of example and not exhaustively, the connection section 33 of the cylinder 6 , in particular of the spindle guide tube 16 , is received here and preferably in the receiving space 32 in an axially fixed manner. According to Fig. 5a), the cylinder 6 is crimped, for example, with a component, which in turn itself the connecting piece 31 is axially fixed and also non-rotatably connected here. According to FIG. 5 b ), the cylinder 6 is also connected to the connecting piece 31 via a further component in an axially fixed manner and here also in a rotationally fixed manner, this connection being an axial snap connection here, in particular with barbs.

In addition to the connection piece 31 , the joint part 30 also has a joint piece 34 , for example a ball socket or a ball head shown in FIG. 5 . Connection piece 31 and joint piece 34 are in particular configured in one piece.

It should be emphasized at this point that FIG. 5 shows, by way of example, a variant of the drive element 4 without a drive housing. In principle, however, it is also conceivable, as shown in dashed lines in FIG. 5, that the drive element 4 can optionally also be equipped with a drive housing 11 with the housing tube 11a already described. In this case, it is then preferably the case that the connection piece 31 carries the housing tube 11a. The connection piece 31 particularly preferably has a receiving groove 35 radially on the outside, in order to fix the housing tube 11a in an axially fixed manner and, if appropriate, in a rotationally fixed manner. In particular, the housing tube 11a is connected to the connection piece 31 in a sealing manner.

2 to 5 show several axially fixed connections between components of the drive element 4. On the one hand, here and preferably there is an axially fixed connection of the connecting piece 25 of the first joint part 18 with the piston 8, in particular the spindle 14. Additionally or alternatively, there is here and preferably one axially fixed connection of the connecting piece 31 of the second joint part 30 with the cylinder 6, in particular the spindle guide tube 16. The connection is preferably with a radially expanded or narrowed, in particular turned up end section 36 of the cylinder 6, in particular the spindle guide tube 16. Additionally or alternatively here and preferably an axially fixed connection of the connection piece 25, 31 of the respective joint part 18, 30 with the spacer bushing 12.

The respective axially fixed connection is here and preferably a positive, non-positive and/or material connection. A corresponding form-fitting connection binding is preferably a crimp connection or snap connection, in particular with barbs. A corresponding non-positive connection is preferably a threaded connection. A corresponding integral connection is preferably an adhesive or welded connection, for example for fixing the spacer bushing 12 to the first joint part 18. A laser welded connection is particularly preferred as a welded connection.

A positive, non-positive and/or material connection exists in particular directly between, on the one hand, the respective connection piece 25, 31 and, on the other hand, the piston 8, in particular the spindle 14, or directly between, on the one hand, the respective connection piece 25, 31 and, on the other hand, the cylinder 6, in particular the spindle guide tube 16, or directly between the respective connecting piece 25, 31 on the one hand and the spacer bushing 12 on the other.

In addition or as an alternative, it can be provided that there is a positive, non-positive and/or material connection between the respective connection piece 25, 31 on the one hand and another component of the drive element 4 on the other hand. A positive, non-positive and/or material connection can also be formed between the other component on the one hand and the piston 8 on the other, in particular the spindle 14, or between the other component on the one hand and the cylinder 6 on the other hand, in particular the spindle guide tube 16 or be provided between the other component on the one hand and the spacer sleeve 12 on the other hand.

Such another component is, for example, the housing tube 11a, a spring guide tube 37 shown in Fig. 5, a sleeve, in particular with an inner collar, a screw 38 and/or nut 39, a snap ring, in particular a clip-like snap ring, and/or a respective joint part 18, 30 guided end cap, to name just a few examples.

As already mentioned, it is also conceivable for the cylinder 6 , in particular the spindle guide tube 16 , to have a radially widened or narrowed, in particular inverted, end section 36 . The end section 36 is then fixed in particular axially between the respective connection piece 25, 31 on the one hand and the other component on the other hand. Additionally or alternatively, in the case of the cylinder 6, in particular the spindle guide tube 16, it is also conceivable that the respective joint part 18, 30, in particular the connection piece 25, 31, has a radial opening which forms an undercut in the axial direction. During assembly, the radially expanded or narrowed, in particular inverted, end section 36 of the cylinder 6, in particular of the spindle guide tube 16, is then pushed laterally, i.e. radially, into the opening in order to create an axial form fit and thus an axial fixation.

It should be emphasized again that the exemplary embodiments shown in FIGS. 1 to 4 were all described with a drive housing 11, but in principle a variant without a drive housing can also be provided, as illustrated by way of example in FIG. A variant without a drive housing is intended in particular for use in the area under the roof, whereas the variant with a drive housing 11 is intended for use in the water channel on the side of the body opening that can be closed by the flap 2b.

According to a further teaching, which is of independent importance, a drive arrangement 1 is provided for a flap 2b, in particular a tailgate, of a motor vehicle 2, with at least one drive element 4, in particular a spindle-based drive element 4 or gas pressure element, with the drive element 4 having a cylinder-piston Unit 5 has a cylinder 6, optionally sealed to the outside, and a piston 8 running in the cylinder interior 7 along the cylinder axis A, with the cylinder 6 being filled with a fluid, in particular a fluid under pressure, with the drive element 4 having a first drive port 4a, which is connected to the cylinder 6, and a second drive port 4b, which is connected to the piston 8, which move axially relative to one another when the drive element 4 is displaced between a retracted and an extended position, the Drive element 4 has a drive spring arrangement 9 t, which has a helical spring 10, which is arranged coaxially to the cylinder 6, radially surrounding it and axially preloads the first drive connection 4a relative to the second drive connection 4b, the drive element 4 having no drive housing, the drive element 4 having a spacer bushing 12, the coaxial to the cylinder 6, this radial surrounding, and forms or occupies a space, in particular an annular space, which extends axially in an area between one of the drive connections 4a, 4b, in particular the second drive connection 4b, and the helical spring 10, with the helical spring 10 being axially attached to the Spacer 12 is supported. Reference may be made to all statements relating to the proposed drive arrangement 1 according to the first teaching.

In this case, the drive element 4 therefore has no housing that radially surrounds at least the component or components that provide the drive function, ie at least the drive spring arrangement 9 . Accordingly, no housing tube is provided which is arranged coaxially to the helical spring 10, radially surrounding it.

It is also important here that the spacer sleeve 12 radially separates the interior of the drive element 4 from the surroundings of the drive element 4 in a first axial section Xi, at least in the extended position of the drive element 4 .

Finally, as shown in FIGS. 5a) and b), the drive element 4 preferably has a spring guide tube 37 which is arranged coaxially to the cylinder 6 and/or the piston 8, radially surrounding the latter. The helical spring 10 is arranged radially surrounding the spring guide tube 37 .

Here, and preferably, it is also the case that the spring guide tube 37, in particular with a collar 40 on which the helical spring 10 rests axially, is pressed axially against the second joint part 30 by the prestressing of the helical spring 10.

Such a spring guide tube 37 is used, especially in a variant without a drive housing, as shown in Fig. 5, for the radial guidance of the coil spring 10. Such a spring guide tube 37 is not necessary if a housing tube 11a is provided, which then provides the radial guidance for the coil spring 10 can take over.

Claims

- 26 - Claims 1. Drive arrangement for a flap (2b), in particular a tailgate, of a motor vehicle (2) with at least one drive element (4), in particular spindle-based drive element (4) or gas pressure element, the drive element (4) having a cylinder-piston unit (5) having a cylinder (6) and a piston (8) running in the cylinder interior (7) along the cylinder axis (A), the cylinder (6) being filled with a fluid, in particular a fluid under pressure, the drive element (4) has a first drive port (4a), which is connected to the cylinder (6), and a second drive port (4b), which is connected to the piston (8), which change when the drive element (4) is displaced move axially relative to one another between a retracted and an extended position, the drive element (4) having a drive spring arrangement (9) which has a coil spring (10) which is coaxial with the cylinder (6), radially u is arranged and axially prestresses the first drive connection (4a) relative to the second drive connection (4b), the drive element (4) having a drive housing (11) which has one, in particular exactly one, housing tube (11a) which is coaxial to of the helical spring (10), radially surrounding it, and wherein the drive element (4) has a spacer bush (12) which is arranged coaxially with the cylinder (6), radially surrounding it and forming a space, in particular an annular space or occupies which extends axially in an area between one of the drive connections (4a, 4b), in particular the second drive connection (4b), and the helical spring (10), the helical spring (10) being supported axially on the spacer bush (12). , characterized in that the spacer sleeve (12) in any case in the extended position of the drive element (4) the interior of the drive element (4) in a first axial section (xi) radially from the area around the Antr iebelement (4) separates. 2. Drive arrangement according to claim 1, characterized in that, at least in the retracted position and in particular also in the extended position of the drive element (4), the housing tube (11a) surrounds the helical spring (10) radially over its entire axial extent, preferably se that no further housing tube that can be telescoped in relation to the housing tube (11a), in particular no further housing tube at all, surrounds the helical spring (10) radially. 3. Drive arrangement according to claim 1 or 2, characterized in that the spacer bushing (12) in the retracted position of the drive element (4) radially separates the interior of the drive element (4) from the surroundings of the drive element (4) in a second axial section (X2). separates, preferably that the first axial section (xi) is larger than the second axial section (X2), more preferably that the second axial section (x ₂ ) forms part of the first axial section (XT). 4. Drive arrangement according to one of the preceding claims, characterized in that the housing tube (11a) in the retracted position of the drive element (4) with the spacer bush (12) in a first axial overlapping section (yi) radially, in particular on the outside, preferably overlaps, that the housing tube (11a) in the extended position of the drive element (4) overlaps with the spacer sleeve (12) in a second axial overlapping section (y ₂ ) radially, in particular on the outside, more preferably that the first axial overlapping section (yi) is greater than the second axial lap portion (y ₂ ) is, more preferably that the second axial lap portion (y ₂ ) forms part of the first axial lap portion (y. 5. Drive arrangement according to one of the preceding claims, characterized in that the drive element (4) via the first drive connection (4a) to the body (2a) of the motor vehicle (2) and via the second drive connection (4b) to the flap (2b). of the motor vehicle (2) can be or is coupled, preferably that the spacer bushing (12) bears against the first drive connection (4a), in particular that it is axially fixed on the first drive connection (4a), or that the drive element (4) via the first drive connection (4a) can be or is coupled to the flap (2b) of the motor vehicle (2) and via the second drive connection (4b) to the body (2a) of the motor vehicle (2), preferably that the spacer bushing (12) on the second drive connection (4b) rests, in particular on the second drive connection (4b) is fixed axially. 6. Drive arrangement according to one of the preceding claims, characterized in that the housing tube (11a) is guided radially, in particular on the outside, on the spacer bush (12). 7. Drive arrangement according to one of the preceding claims, characterized in that the drive element (4) is a spindle-based, in particular non-motorised, drive element (4) which has a spindle-spindle nut gear (13) which has a spindle (14) as gear components and a spindle nut (15) meshing with it, in that the drive element (4) has a spindle guide tube (16) in which the spindle (14) is axially guided when the drive element (4) is moved between the retracted and the extended position and on which the spindle nut (15) is arranged in an axially fixed and non-rotatable manner, that the spindle (14) of the spindle-spindle nut gear (13) forms the piston (8) of the cylinder-piston unit (5) and that the spindle guide tube (16) together with the spindle nut (15) forms the cylinder (6) of the cylinder-piston unit (5), preferably that the first drive connection (4a) is connected to the spindle guide tube (16) i st and the second drive port (4b) is connected to the spindle (14), or that the first drive port (4a) is connected to the spindle (14) and the second drive port (4b) is connected to the spindle guide tube (16). 8. Drive arrangement according to one of the preceding claims, characterized in that the drive spring arrangement (9) has a further helical spring (17) which is arranged coaxially to the cylinder (6), radially surrounding it and the first drive connection (4a) opposite the second drive connection (4b) axially pretensioned, preferably that the first helical spring (10) is arranged coaxially to the further helical spring (17), radially surrounding it, more preferably that the further helical spring (17) faces the first drive connection (4a). axially preloads the second drive connection (4b) only over part of the adjustment of the drive element (4) between the retracted and the extended position, in particular only at the beginning of the adjustment out of the retracted position. - 29 - 9. Drive arrangement according to Claim 8, characterized in that the further helical spring (17) is supported axially on the spacer bush (12), preferably at an axial distance from the point at which the first helical spring (10) is supported axially on the spacer bush (12). is. 10. Drive arrangement according to one of the preceding claims, characterized in that the piston (8), in particular the spindle (14), connected to the drive connection (4b), in particular the second drive connection (4b), formed by a first joint part (18). which forms an articulated connection with a corresponding counter-joint part on the vehicle side, and that the piston (8), in particular the spindle (14), is axially fixed and in particular rotatable with respect to the first joint part (18), preferably that in the first joint part (18) a brake (19) is integrated, which brakes the rotational movements of the spindle (14) relative to the first joint part (18), in particular permanently, more preferably that the brake (19), in particular a housing (20) of the brake (19), is non-rotatably connected to the first joint part (18), preferably via a positive, non-positive and/or material connection, preferably a claw connection. 11. Drive arrangement according to claim 10, characterized in that the first joint part (18) has a connecting piece (25) for the axially fixed connection to the piston (8), in particular the spindle (14), preferably that the connecting piece (25) radially has a receiving space (26) for the brake (19) on the inside, more preferably that the spindle (14) is rotatably mounted in a spindle bearing (27) and the spindle bearing (27) rests axially on the connecting piece (25) and/or in the receiving space (26) is received. 12. Drive arrangement according to Claim 11, characterized in that the spacer bushing (12) rests axially on the connection piece (25) of the first joint part (18), and/or that the spacer bushing (12) has a receiving space (29) radially on the inside for the Has connecting piece (25) and the connecting piece (25) and in particular the spindle bearing (27) is accommodated in the receiving space (29). - 30 - 13. Drive arrangement according to one of the preceding claims, characterized in that the drive connection (4a) connected to the cylinder (6), in particular the spindle guide tube (16), in particular the first drive connection (4a), is formed by a second joint part (30). which forms an articulated connection with a corresponding counter-joint part on the vehicle side, and that the cylinder (6), in particular the spindle guide tube (16), is axially fixed to the second joint part (30), preferably that the cylinder (6), in particular the spindle guide tube ( 16) is rotatable to the second joint part (30) and is guided in the spacer bushing (12) in a rotationally fixed manner, or that the cylinder (6), in particular the spindle guide tube (16), is arranged in a rotationally fixed manner on the second joint part (30). 14. Drive arrangement according to claim 13, characterized in that the second joint part (30) has a connecting piece (31) for the axially fixed connection to the cylinder (6), in particular the spindle guide tube (16), preferably that the connecting piece (31) radially has a receiving space (32) on the inside for a connection section (33) of the cylinder (6), in particular of the spindle guide tube (16), more preferably that the connection section (33) of the cylinder (6), in particular of the spindle guide tube (16), in is received in an axially fixed manner in the receiving space (32). 15. Drive arrangement according to one of Claims 11 to 13, characterized in that for the axially fixed connection of the connection piece (25) of the first joint part (18) to the piston (8), in particular the spindle (14), and/or for the axially fixed connection of the Connection piece (31) of the second joint part (30) with the cylinder (6), in particular the spindle guide tube (16), preferably a radially widened or narrowed, in particular inverted, end section (36) thereof, and/or for the axially fixed connection of the connection piece (25 , 31 ) of the respective joint part (18, 30) with the spacer bush (12), a positive, non-positive and/or material connection is provided, preferably that the positive connection is a crimp or snap connection and/or the non-positive connection is a Threaded connection and/or the integral connection is an adhesive or welded connection, preferably a laser welded connection. - 31 - 16. Drive arrangement for a flap (2b), in particular tailgate, of a motor vehicle (2) with at least one drive element (4), in particular spindle-based drive element (4) or gas pressure element, the drive element (4) having a cylinder-piston unit (5) having a cylinder (6) and a piston (8) running in the cylinder interior (7) along the cylinder axis (A), the cylinder (6) being filled with a fluid, in particular a fluid under pressure, the drive element (4) has a first drive port (4a), which is connected to the cylinder (6), and a second drive port (4b), which is connected to the piston (8), which change when the drive element (4) is displaced move axially between a retracted and an extended position relative to each other, the drive member (4) having a drive spring assembly (9) comprising a coil spring (10) coaxial with the cylinder (6), radial thereto surrounding, and axially preloads the first drive connection (4a) relative to the second drive connection (4b), the drive element (4) having no drive housing, the drive element (4) having a spacer bushing (12) which is coaxial with the cylinder (6 ), is arranged radially surrounding it and forms or occupies a space, in particular an annular space, which extends axially in an area between one of the drive connections (4a, 4b), in particular the second drive connection (4b), and the helical spring (10). , wherein the helical spring (10) is supported axially on the spacer bush (12), characterized in that the spacer bush (12) at least in the extended position of the drive element (4) the interior of the drive element (4) in a first axial section (xi) radially separated from the environment of the drive element (4). 17. Drive arrangement according to one of the preceding claims, characterized in that the drive element (4) has a spring guide tube (37) which is coaxial with the cylinder (6) and / or piston (8), this radially surrounding, and that the helical spring (10) is arranged radially surrounding the spring guide tube (37), preferably in that the spring guide tube (37), in particular with a collar (40) against which the helical spring (10) bears axially, axially due to the prestressing of the helical spring (10). is pressed against the second joint part (30).