WO2001044685A2 - Differential - Google Patents

Abstract

The invention relates to a differential for combining two torques (M1, M2), consisting of two simle planetary gears (P1, P2) with sun (16) and planetary elements (15, 18) and ring gears (17, 19).The simple planetary gears (P1, P2) have a common sun wheel shaft (2.1).

Description

 differential

The present invention relates to a CVT belt transmission with power split on two belts, chains or belts with differential for merging the two power flows with the torques M _α and M ₂ , the differential consisting of a sun and two planetary gears meshing with it, which are in engagement with ring gears. The differential can be switched via a switching device, so that the ratio of the torques Mi and M _{2 can be the} same or different in accordance with the translations provided by the differential.

In Lechner, Naunheimer (vehicle transmission, Springer Verlag ISBN-3-540-57423-9, page 145, picture 6.35) is a CVT Belt transmission with power split and downstream planetary gear differential shown. The disadvantage of this solution is the maximum torque specified by the one belt. The torques are not evenly distributed among the power branches because of the reactive power flows, so that in certain driving areas the almost complete engine torque has to be transmitted through the one belt.

A metal band is also required for small vehicles in order to be able to transmit sufficient torque. Since the coefficients of friction between the metal band and the adjusting discs are low, the discs have to be applied with high forces and therefore with high energy expenditure. Such CVT transmissions have poor efficiency.

A continuously variable automatic transmission is also described, for example, in EP 0 309 427 AI. There are corresponding pressure cylinders on the drive and output shafts, which adjust the V-belts in a double-belt drive accordingly by applying pressure. The disadvantage here is that a plurality of actuating cylinders have to be provided in a complex manner in order to continuously adjust the two belts. A differential function for merging the two torques is not described.

The present invention has for its object to provide a differential of the type mentioned, which eliminates the disadvantages mentioned and with which very high torques can be achieved with a large spread in the belt area of the CVT continuously variable transmission. For this purpose, the differential should also be one Have switching device that ensures different switching positions with short switching times.

To solve this problem, the simple planetary gears have a common sun gear shaft.

In addition, such a transmission should be built to save space and be inexpensive to manufacture. Furthermore, a dynamic acceleration process should be carried out without interrupting the tractive force.

In the present invention, with regard to the belt area of the continuously variable transmission, in particular by arranging individual pulley elements of pulleys, at least one belt can be moved continuously with respect to the pulley by means of only one actuating element in order to produce a stepless torque transmission without interrupting the tractive force.

In particular, this solution offers adjustment options for adjacent belts on the individual pulleys, which can also be adjusted separately by means of a locking device. It should also be within the scope of the present invention that a plurality of pulleys and belts are provided in parallel on the input and / or output shaft, so that a further division of the line flow is still possible.

In this way, differently determinable power flows of the two pulleys between the input shaft and the output shaft can be generated, which are brought together again in the differential. This creates a continuously variable, in particular dry running belt transmission, preferably for front / transverse installation, in which very high engine torques are permitted in very wide gear ratios.

Another advantage is the use of dry-running belts, which results in very low losses when hydraulic actuators are not used. As an alternative to hydraulics, e.g. B. electromechanical linear actuators can be used.

In particular, by forming a differential consisting of two simple planetary gears with a common sun, different torque ratios can be realized in different switching positions.

With the appropriate wiring, a first input torque can be introduced into the differential via a drive sleeve. This drive sleeve is with the

Planet carrier of the planets of the first planetary stage connected. The second input moment is initiated via the common sun. In this switching position, the two input torques are finally brought together in the ring gear of the first planetary stage, which is connected to the planetary gear carrier of the planets of the second planetary stage in a particularly space-saving manner. The second stage planet carrier is also the output shaft. In this switch position, the planets and the non-switched ring gear of the second planetary stage rotate freely. In a second switching position, the switching sleeve is switched and a first torque is introduced via the ring gear of the second planetary stage. The second input torque introduced via the sun and the input torque via the shift sleeve are brought together in the planet gear carrier of the second planetary stage and passed on to the output. The drive sleeve does not remain switched in this second switching position and the ring gear and the planets of the first planetary stage rotate freely.

In an intermediate position, in which neither the drive sleeve nor the shift sleeve are switched, the overall transmission ratio can be changed when the vehicle or the output shaft are stationary. This is an important function after braking hard.

Further advantages, features and details of the invention result from the following description of preferred exemplary embodiments and with reference to the drawing; this shows in

Figure 1 is a plan view of a continuously variable automatic transmission according to the invention in a starting and reverse gear position with subsequent differential;

Figure 2 is a plan view of the continuously variable automatic transmission in a first driving range;

Figure 3 is a plan view of a continuously variable automatic transmission according to Figures 1 and 2 in another driving range, in particular overdrive;

Figure 4 is a plan view of a further embodiment of a continuously variable automatic transmission with subsequent differential in a geared-neutral position when moving forward or backward;

FIG. 5 shows a top view of the continuously variable automatic transmission according to FIG. 4 in a main driving area;

FIG. 6 is a top view of the continuously variable automatic transmission according to FIG. 4 in an overdrive.

According to FIG. 1, a continuously variable automatic transmission Ri according to the invention has at least one drive shaft 1 and one output shaft 2. In the preferred embodiment, input shaft 1 and output shaft 2 are arranged parallel to one another. In the preferred performance example sit on the drive shaft 1 and output shaft 2 two pulleys 3.1 and 3.2 each, the first two pulleys 3.1 arranged on the drive shaft 1 and the output shaft 2 being connected to each other via a belt 4 and the second two pulleys 3.2 being connected to one another by a belt 5.

The individual pulleys 3.1, 3.2 are preferably divided into individual pulley elements 6.1 to 6.4, the pulley 3.1 being formed from the pulley element 6.1 which is fixedly connected with respect to the drive shaft 1 and a further pulley element 6.2 which can be moved axially on the drive shaft 1. The pulley 3.2 on the drive shaft 1 consists of the two disk elements 6.3, 6.4, both of which are axially movable on the drive shaft 1. The disk elements 6.2 to 6.4 are arranged on the drive shaft 1 in a rotationally fixed but axially movable manner.

The pulley elements 6.2, 6.3 of the two adjacent pulleys 3.1, 3.2 are preferably firmly connected to one another, but can be moved axially relative to the drive shaft 1. The outermost pulley element 6.4 is assigned an actuating device 7.1 which, by appropriate pressurization, pressurizes the individual pulley elements 6.2 to 6.4 against the pulley element 6.1 fixed on the drive shaft 1 in order to achieve different transmission ratios of the belts 4, 5 by correspondingly moving the different pulley elements 6.2 to 6.4 to generate according to the CVT principle or to the required

To generate belt tension. The pulleys 3.1, 3.2 of the output shaft 2 are also in disk elements in the manner described above

6.1 to 6.4 divided, the pulley elements 6.1, 6.2 forming the pulley 3.2 and the pulley elements 6.3, 6.4 forming the pulley 3.1.

It is also important in the present invention that between the two pulleys 3.1, 3.2

Axial bearing 8 is arranged, which different rotational speeds of the adjacent pulleys 3.1,

3.2 or adjacent disc elements 6.2, 6.3 compensated or compensated.

A further special feature of the present invention is that the individual pulley elements 6.3, 6.4, in particular the pulley 3.1 of the output shaft 2, are axially movable thereon and rotatable relative to the output shaft 2 and are connected in a rotationally rigid manner to a second drive shaft 9.

A torque Mi, which is transmitted via the belt 4, is derived separately via an output sleeve 9 independently of a torque M _{2 of} the output shaft 2 and transmitted to the shift sleeve 12 of a shifting device 13.

In contrast, the pulley 3.2 is non-rotatably on the output shaft 2, the pulley element 6.2 being axially movable but non-rotatably connected to the drive shaft 2.

An actuating device 7.2 is assigned to the disk element 6.4 of the output shaft 2 and applies pressure to the individual disk elements 6.4, 6.3 and 6.2 to generate the required belt pretension in order, if necessary, to carry out a basic setting, adjustment or fine adjustment of a translation, in particular of the belts 4, 5 or to generate the different transmission ratios of the belts 4, 5.

Another advantage of the present invention is that only one actuating device 7.1 or 7.2 has to be assigned to the drive shaft 1 and / or the output shaft 2, in particular to the disk element 6.1, in order to move the remaining disk elements 6.2 to 6.4 axially.

A torque M is introduced via the drive shaft 1 and distributed to the two pulleys 3.1, 3.2, with a distribution or power split of the individual torques M _x , M ₂ on the drive shaft 2, in particular on its pulleys 3.2, 3.1.

According to FIG. 1, a switching device 13 is switched via the shift sleeve 12, the torque M _{i # being} transferable to the differential 10 via a drive sleeve 14. The torque M _x is transmitted to a planet carrier 14.1 of corresponding planets 15 which are in engagement with a sun 16.

The torque M _{2 of} the output shaft 2 is transmitted directly to the sun 16 via a sun gear shaft 2.1 and is introduced into the sun 16.

The planet 15 sit in a ring gear 17, which transmits the torque M ₂ to the planet carrier 14.1 of the output planet 18. The output planets 18 are preferably also spaced apart from the sun 16 the planet 15. The ring gear 17 is connected to the planet carrier 14.2 of the output planet 18. The output planet 18 are in engagement with an output ring gear 19.

The output torque M _ab is generated in the switching position shown by combining the moments Mi, M ₂ in the ring gear 17.

At the same time, the output ring gear 19 is connected to a switching sleeve 20 which leads into the area of the switching device 13. By means of the shift sleeve 12, either the shift sleeve 20 or the drive sleeve 14 can be put into operation to switch on the torque Mi.

Idle switching of the shift sleeve 12, the switching device 3 between the drive sleeve 14 and the shift sleeve 20 is also possible.

In the present case, the torque M _x of the

Output shaft 2 is transmitted directly to the drive sleeve 14, from there it is introduced into the planet 15 via the planetary gear carrier 14.1 and transmitted to the planet carrier 14.2 via their common ring gear 17. The torque M ₂ , which is applied to the sun 16, is also introduced into the planet 15. In this switching position, the ratio of the torques Mi and M ₂ is preferably approximately 3: 1.

In the exemplary embodiment of the present invention according to FIG. 2, both belts 4, 5 are approximately the same

Height of the pulleys 3.1, 3.2 arranged both on the drive 1 and on the output shaft 2, so that the Speeds of the pulleys 3.1, 3.2 are approximately the same.

It is also crucial in the present invention that the two given torques Mi, M ₂ , on the one hand from the output shaft 2 and from the output sleeve 9 into a differential 10 via a switching device 13, and there via corresponding planetary gears Pi, P ₂ to a common one Powertrain are transmitted.

In particular, by means of the corresponding actuating device 7.1, the disk elements 6.2 to 6.4 can be moved, as shown in FIGS. 1, 2 and 3, so that different, infinitely variable gear ratios and gear ratios can be set.

In this way, the torques Mi, M ₂ and the speeds can be set continuously and arbitrarily on the drive train.

In the exemplary embodiment of the present invention according to FIG. 2, a further shift position is shown, in which the torque M _{x is} transmitted directly to the shift sleeve 20 via the shift sleeve 12 and passed to the drive ring gear 19. The torque M _{2 of} the output shaft 2 is also transmitted directly to the sun 16, as in FIG. 1.

The output planets 18 are also directly connected to the sun 16, so that, in corresponding size ratios, a torque M _x approximately equal to the torque M ₂ , which is transmitted directly to the sun 16, for a common output torque M ^ can be merged with the torque M ₂ in the planet carrier 14.2.

In the exemplary embodiment of the present invention according to FIGS. 4 to 6, a continuously variable automatic transmission R ₂ is shown, in which, in particular, a locking device 11 is assigned to the drive shaft 1, which in particular ensures that the disk elements 6.2, 6.3 can be fixed in a releasable manner.

In particular, by defining the pulley elements 6.2, 6.3, a selectable gear ratio of the pulley 3.1 and / or 3.2 can be set and defined.

After, for example, the disk elements 6.1, 6.2 have been fixed against axial movement with respect to the drive shaft 1 in a desired ratio, the disk element 6.4 can be moved relative to the fixed disk element 6.3 by means of the actuating element 7.1. In this way, a second translation stage can be regulated and controlled continuously compared to the first defined translation stage.

In FIG. 4, the disk elements 6.2 and 6.3 are axially locked in a first position by the locking device 11. The belt 4 remains in the position shown and the belt 5 is adjusted in the direction of the arrow with increasing driving speed from the illustrated starting position (geared-neutral).

In Figure 5, the belts 4 and 5 have the same position and the locking device 11 gives the pulleys 6.2 and 6.3 axially free. The belts are adjusted in parallel in the direction of the arrow with increasing speed.

In order to further increase the spread of the transmission, there is the possibility shown in FIG. 6 of locking the disk elements 6.2 and 6.3 in a further position of the locking device 11. The belt 4 remains in the position shown and the belt 5 is adjusted in the direction of the arrow with increasing driving speed ,

Position Number List

Claims

P atent claims 1. Differential for combining two torques (Mi, M ₂ ), consisting of two simple planetary gears (Pi, P ₂ ) with the elements sun (16), planets (15, 18) and ring gears (17, 19), characterized, that the simple planetary gears (P , P ₂ ) have a common sun gear shaft (2.1). 2. Differential to combine two torques (Mi, M ₂ ), consisting of two simple planetary gears (Pi, P ₂ ) with the elements sun (16), planets (15, 18) and ring gears (17, 19), characterized in that a first drive torque (Mi) either on the planet gear carrier (14.1) of the planet (15) of first simple planetary gear (Pi) or on the ring gear (19) of the second simple planetary gear (T ₂ ) and that a second torque (M ₂ ) is introduced on the sun gear shaft (2.1) and the output with the torque (M _ab ) on Planetary gear carrier (14.2) of the planet (18) of the second simple planetary gear (P ₂ ) takes place. 3. Differential according to claim 1 or 2, characterized in that a sun (1) is provided on the sun gear shaft (2.1), which meshes with the planets (15 and 18). 4. Differential according to at least one of claims 1 to 3, characterized in that the ring gear (17) of the first simple planetary gear (P _x ) is connected to the planetary gear carrier (14.2) of the planet (18) of the second simple planetary gear (P ₂ ). 5. Differential according to at least one of claims 1 to 4, characterized in that the planet (18) is designed as a step planet. 6. Differential according to at least one of claims 1 to 5, characterized in that a first torque (Mi) can be transferred via a switching device (13) either to the planetary gear carrier (14.1) of the planet (15) or to an output ring gear (19). 7. Differential according to at least one of claims 1 to 6, characterized in that in a first switching position with the same torque ratios, the torque (M _i7 M ₂ ) and a transmission of the torque (Mi) to the output ring gear (19) can be set. 8. Differential according to at least one of claims 1 to 7, characterized in that in a second switching position, the first torque (Mi) is transferred to the planet gear carrier (14.1) in a ratio of approximately % to approximately Ä of the torque (M ₂ ) to the sun (16). 9. Differential according to at least one of claims 1 to 8, characterized in that the planets (15) and the Output planets (18) are arranged next to each other on the sun (16), the output planets (18) being guided in the output ring gear (19) and this via a Switching sleeve (20) can be connected to a switching device (13). 10. Differential according to at least one of claims 1 to 9, characterized in that a second torque (M ₂ ) is applied directly to the in a further switching position Output ring gear (19) is transferable and the torque (M ₂ ) is applied directly to the sun (16), and to the Output planet (18) the torques (Mi, M ₂ ) can be brought together. 11. Continuously variable automatic transmission with at least one input (1) and output shaft (2), on which a plurality of pulleys (3.1, 3.2), each consisting of two disc elements (6.1 to 6.4), are arranged to accommodate at least two belts (4, 5). are, characterized in that a disk element (6.1) is connected in a rotationally fixed manner to the drive (1) and output shaft (2), the remaining disk elements (6.2 to 6.4) being arranged to be axially movable. 12. Continuously variable automatic transmission with at least one input (1) and output shaft (2), on which a plurality of pulleys (3.1, 3.2), each consisting of two disc elements (6.1 to 6.4), are arranged to accommodate at least two belts (4, 5). are, characterized in that at least one axially movable disk element (6.2, 6.3) is axially releasable, in particular axially fixable, relative to the drive (1) and/or output shaft (2) in at least one determinable position. 13. Continuously variable automatic transmission with at least one drive (1) and output shaft (2), on which a plurality of pulleys (3.1, 3.2) consisting of two pulley elements (6.1 to 6.4) for receiving at least two belts (4, 5 ) are arranged, characterized in that at least one axial bearing (8) is arranged between two adjacent pulleys (3.1, 3.2) of the output shaft (2). 14. Continuously variable automatic transmission with at least one input (1) and output shaft (2), on which a plurality of pulleys (3.1, 3.2), each consisting of two disc elements (6.1 to 6.4), are arranged to accommodate at least two belts (4, 5). are, characterized in that on the output shaft (2) a belt pulley (3.1) is axially movable and rotatable relative to the output shaft (2), and possibly the second belt pulley (3.2) is non-rotatable and axially movable in connection with the output shaft (2). stands. 15. Continuously variable automatic transmission with at least one input (1) and output shaft (2), on which a plurality of pulleys (3.1, 3.2), each consisting of two disc elements (6.1 to 6.4), are arranged to accommodate at least two belts (4, 5). are, characterized in that the disk elements (6.4) on the drive (1) and / or output shaft (2) are assigned at least one actuating element (7.1, 7.2) for axial displacement or prestressing. 16. Continuously variable automatic transmission according to at least one of claims 2 to 11, characterized in that at least one disk element (6.1) is rotationally fixed to the drive shaft (1) is connected, with the subsequent ones Disc elements (6.2 to 6.4) can be moved axially on the Drive shaft (1) and the two middle ones are arranged Pulley elements (6.2, 6.3) of adjacent pulleys (3.1, 3.2) are firmly connected to one another. 17. Continuously variable automatic transmission according to at least one of claims 11 to 16, characterized in that the drive shaft (1) and / or the output shaft (2) is assigned a locking device (11) for fixing the at least one disk element (6.2, 6.3) against axial movement is . 18. Continuously variable automatic transmission according to claim 17, characterized in that the locking device (11) secures the two disc elements (6.2, 6.3) adjacent pulleys (3.1, 3.2) are axially releasably locked in at least one specific selectable position relative to the drive shaft (1). 19. Continuously variable automatic transmission according to at least one of claims 11 to 18, characterized in that a first belt (4) on the first pulley (3.1) of the drive shaft (1) with a first pulley (3.1) of the output shaft (2) and a second Belt (5) on a second pulley (3.2) of the drive shaft (1) is in engagement with a second pulley (3.2) of the output shaft (2). 20. Continuously variable automatic transmission according to at least one of claims 11 to 19, characterized in that the first belt pulley (3.1) is axially movable on the output shaft (2) and is rotatably mounted relative to it. 21. Continuously variable automatic transmission according to at least one of claims 11 to 20, characterized in that the first pulley (3.1) of the output shaft (2) consists of two pulley elements (6.3, 6.4), the second pulley (3.2) of the output shaft (2) is connected to it in a rotationally fixed manner and a pulley element (6.2) adjacent to the pulley (3.1) is assigned to the output shaft (2) in an axially movable manner. 22. Continuously variable automatic transmission according to at least one of claims 13 to 21, characterized in that between the two adjacent disk elements (6.2 and 6.3) on the output shaft (2) of the adjacent pulleys (3.1, 3.2) there is at least one axial bearing (8) for balancing is arranged at different speeds. 23. Continuously variable automatic transmission according to at least one of claims 15 to 22, characterized in that the actuating device (7.1, 7.2) is connected to the outermost disk element (6.4) of the drive (1) and / or output shaft (2) for axially moving the disk elements (6.4 to 6.2) attacks. 24. Continuously variable automatic transmission according to at least one of claims 11 to 23, characterized in that a torque (Mi) of the first belt pulley (3.1) of the output shaft (2), independent of that applied to the output shaft (2) by the second belt pulley (3.2) transmitting torque (M ₂ ) can be transferred to a differential (10) for combining different torques (M _x , M ₂ ). 25. Continuously variable automatic transmission according to claim 24, characterized in that the torque (Mi) can be transferred via an output sleeve (9) to a switching sleeve (12) or to a first element of a switching device (13). 26. Continuously variable automatic transmission according to at least one of claims 11 to 25, characterized in that the torque (Mi) can be transferred to a drive sleeve (14) or a switching sleeve (20) via a multi-plate clutch. 27. Continuously variable automatic transmission according to claim 26, characterized in that the multi-plate clutch is designed electromechanically.