HK1178235B - A wear adjuster for a brake caliper of a disk brake of a rail vehicle and a disk brake - Google Patents

Description

Wear adjuster for a brake caliper of a disc brake for a rail vehicle and disc brake

Technical Field

The invention relates to a wear adjuster for a brake caliper of a disc brake of a rail vehicle and to a disc brake for a rail vehicle.

Background

In compact brake caliper units, the wear of the brake linings and the brake disk is automatically compensated for by lengthening or shortening the push rod adjuster or the pull rod adjuster. The lengthening or shortening of the actuator is achieved by a screw drive as a nut-spindle system. In order to be able to achieve as large an adjustment as possible in a single operation, the thread is constructed with a very large pitch. The thread is thus non self-locking. One of the screw drive components, for example the nut, is held in a rotationally fixed manner, while the other screw drive component, for example the spindle, is mounted rotatably.

The control mechanism rotates an adjusting lever with a freewheeling mechanism (e.g., a sleeve freewheeling mechanism), which in turn drives the spindle or the nut or rotates it, so that the actuator is extended, for example, in the case of a push-rod actuator. For adjustment, the adjusting lever is therefore actuated by means of a pressure lever with a ball head engaging in a ball cage of the adjusting lever. The screw rod rotates along with the sleeve type one-way clutch mechanism pressed in the adjusting rod. Here the disc spring one-way clutch mechanism is slipped in the free-running direction.

If the push rod releases the actuating lever again when the brake is released, the actuating lever is rotated back again by the restoring spring into its initial position, in which it rests against a rigid stop of the actuator housing. The sleeve-type one-way clutch mechanism is now rotated in the free-running direction, at which time the lead screw is prevented from co-rotating by the coil spring of the coil spring one-way clutch mechanism. The adjustment process is terminated when the adjusting lever comes into abutment against a stop of the adjuster housing or when an axial force is formed in the adjuster (for example when the linings come into abutment against the brake disk) which the control mechanism of the adjuster can no longer overcome.

In the push-rod adjuster, the rotation of the lead screw-nut mechanism, for example, in the direction to shorten the push-rod adjuster is prevented by a wound spring one-way clutch mechanism between the lead screw and the adjuster housing. In addition to the one-way clutch mechanism of the adjusting element, the spiral spring one-way clutch mechanism also forms a further or second one-way clutch mechanism. When the adjusting element is rotated back into its initial position by the force of its return spring or when a high tensioning force and thus a high torque are applied to the spindle on braking, the rotatable spindle is held in its position by the wrap spring freewheel.

EP0732247B1 of the generic type describes a strut adjuster for a brake caliper of a brake disk of a rail vehicle, wherein, according to fig. 3, a nut is fixed in a rotationally fixed manner in the right wear adjuster housing (reference numeral 22) and a spindle is rotatably mounted in a guide tube connected to the left wear adjuster housing (reference numeral 21). Furthermore, there is a spiral spring freewheeling mechanism which is locked in the direction of rotation of the spindle opposite to the wear adjustment and which runs freely in the opposite direction of rotation, by means of which the spindle can be coupled to a separate guide tube which is fixed in the left-hand wear adjuster housing. The spiral spring of the spiral spring freewheeling mechanism is radially surrounded by a left-hand wear adjuster housing, which also accommodates the adjusting rod (reference numeral 24) and its sleeve freewheeling mechanism. The axial force which is applied to the push rod adjuster during a braking operation and shortens it is supported in the force transmission flow from the anti-rotation nut through the adjusting rod to the spindle in the left wear adjuster housing. The adjustment accuracy is thereby influenced not only by the thread friction of the thread drive but also by the friction state between the adjustment lever and the left-hand wear adjuster housing or between the adjustment lever and the spindle.

EP0699846B1, which is also of the same type, describes a disk brake for rail vehicles, having a brake caliper and an automatic wear adjuster. In the embodiment described here as a push rod adjuster, the adjusting rod is formed by an adjusting sleeve with an external toothing. A one-way clutch mechanism is pressed into the adjusting sleeve. The toothed segment of the adjusting sleeve engages with a toothed segment of the adjusting sleeve, by means of which the adjusting sleeve is rotated by means of a lever against the force of a return spring. The nut is driven by the one-way clutch mechanism, so that the pressure bar adjuster is prolonged. According to fig. 2, the spindle is mounted in a non-rotatable manner in the left-hand wear adjuster housing and the nut is mounted in a rotatable manner in the right-hand wear adjuster housing. By means of the cup spring one-way clutch mechanism, the rotatable nut can be fixed in a radially inner tube piece (reference numeral 39), which is connected to the right-hand wear adjuster housing. Furthermore, the tubular housing part (reference numeral 30) of the right wear adjuster housing encloses the cup spring freewheeling mechanism.

In the case of the push rod adjusters of the prior art, each of the at least one wear adjuster housings is designed in multiple parts and in particular in a double-tube manner, in that the cup springs of the cup spring freewheel interact with a separate tube connected to the respective wear adjuster housing, and in that the cup spring freewheel is radially surrounded by a tubular projection of the wear adjuster housing. However, such double-tube wear adjuster housings lead to a certain expenditure in terms of production and assembly or disassembly for maintenance purposes.

Furthermore, the space requirement for the disk spring one-way clutch mechanism for connecting the separate tube to the associated wear adjuster housing is reduced, so that the disk spring in the prior art described has to be fastened to the non-rotatable separate tube by means of a hook. However, such a hook has an adverse effect on the switching accuracy of the cup spring one-way clutch mechanism and thus on the adjustment accuracy of the wear adjuster. In addition, a separate step for manufacturing the hook is required in manufacturing.

Disclosure of Invention

In contrast, the object of the invention is to improve a wear adjuster of the type mentioned above such that it can be produced in a simple manner and at the same time has a high degree of adjustment accuracy.

The invention relates to a wear adjuster for a brake caliper of a disc brake of a rail vehicle, comprising:

a) a threaded drive as a threaded part having a spindle and a nut which can be screwed onto the spindle, wherein one threaded part and an adjusting element for rotationally driving the threaded part in a wear adjustment direction are rotatably mounted in a first wear adjuster housing, while the other threaded part is non-rotatably mounted in a second wear adjuster housing,

b) a disc spring one-way clutch mechanism which locks in a rotational direction of a rotatable threaded member opposite to a wear adjustment and freely runs in an opposite rotational direction, by which the rotatable threaded member can be coupled with a non-rotatable member, characterized in that,

c) the non-rotatable component is formed directly by the first wear adjuster housing, and the rotatable threaded component is supported on the first wear adjuster housing by a disc spring one-way clutch mechanism or a disc spring without intervening additional components.

The invention provides that the non-rotatable component is formed directly by the first wear adjuster housing. The expression "directly" here means that the rotatable threaded part can be supported on the first wear adjuster housing directly, i.e. without intermediate provision of further components, such as tubes, by means of a cup spring one-way clutch or cup spring. In this case, the first wear adjuster housing is, for example, of one-piece design, wherein no components, such as projections or tubes, which are of separate design, are fastened to the first wear adjuster housing and are in the force transmission flow when the wear adjuster must support axial forces which act in the direction of shortening the wear adjuster.

The term "first" wear adjuster housing refers to a housing part of the wear adjuster, which is hinged to one caliper lever of the brake caliper, and the term "second" wear adjuster housing refers to a housing part, which is hinged to the other caliper lever. In the customary practice in the technical field, the first wear adjuster housing is often referred to as the "housing", while the second wear adjuster housing is often referred to as the "yoke".

This makes it possible to dispense with the double-tube construction of the first wear adjuster housing of the prior art, in particular to dispense with the possible separate guide tube fastened to the first wear adjuster housing, as a result of which the number of components of the wear adjuster and thus the production and assembly costs are advantageously reduced.

Furthermore, the cup spring of the cup spring one-way clutch acts on the active surface of the rotatable threaded part on the one hand and on the active surface which is formed on the outer surface of the first wear adjuster housing on the other hand, in order to prevent the rotatable threaded part from rotating by a frictional or frictionally engaged connection with the non-rotatable threaded part and no longer on the active surface of a separate tube which is arranged inside the first wear adjuster housing. This results in an advantageous position condition. In particular, more space is available for the cup spring of the cup spring one-way clutch, as a result of which the longitudinal extent of the cup spring in the axial direction of the wear adjuster can be increased. Since more screws can then act on the active surface of the first wear adjuster housing or the non-rotatable threaded part, the frictional engagement of the cup spring one-way clutch mechanism and thus the force transmission is improved. While the hook for fixing the coil spring can be omitted. This measure in turn has a favorable effect on the switching accuracy of the cup spring one-way clutch mechanism and thus on the adjustment accuracy of the wear adjuster. In this case, the force transmission in the cup spring freewheeling mechanism can take place exclusively by frictional engagement between the spiral of the cup spring and the assigned active surface on the first wear adjuster housing or on the rotatable threaded part.

The cup spring of the cup spring one-way clutch particularly preferably interacts in a friction-locking manner with the radially outer active surface forming the outer surface of the first wear adjuster housing on the one hand and with the radially outer active surface of the rotatable threaded part or of the element rotating together with the rotatable threaded part on the other hand. In other words, the active surface for the disk spring already forms part of the outer surface of the first wear adjuster housing, without the disk spring having to be surrounded by further tubes or housing sections. The "active surface" here refers to the surface of the relevant component on which the spiral of the disk spring acts from the radial outside in order to form a frictional engagement between the disk spring and the relevant component.

In order to protect the threaded drive, the cup spring one-way clutch, and other components of the wear adjuster, for example, from dirt and moisture, the cup spring of the cup spring one-way clutch, viewed in the radial direction, is surrounded only by a bellows which is elastic in the axial direction of the wear adjuster and which is fastened at one end to the first wear adjuster housing and at the other end to the second wear adjuster housing. The cup spring one-way clutch and the cup spring are preferably arranged between two connection points of the bellows on the wear adjuster housing, viewed in the axial direction.

When the disc spring has the correct minimum length achieved by the measures according to the invention, the disc spring can couple the active surface of the first wear adjuster housing with the active surface of the rotatable threaded part or of the element rotating together with the rotatable threaded part only by means of a frictional lock, without the need for a form-locking hook. As described above, the omission of the hook for the cup spring has a favorable effect on the switching accuracy of the cup spring one-way clutch mechanism and thus on the adjustment accuracy of the wear adjuster. In particular, wear of the active surface or of the disk spring can be avoided in that no distortion of the disk spring with locally large stress peaks occurs as a result of the free movement of the disk spring in the axial direction.

According to one refinement, the rotatable threaded part or the element rotating together with the threaded part has an end face directed in the axial direction, which is in contact with a corresponding end face of the first wear adjuster housing in order to support the axial forces acting on the wear adjuster. In this case, therefore, the axial force transmission flow is transmitted directly from the second wear adjuster housing into the first wear adjuster housing, for example, via the thread part which is held in a rotationally fixed manner and the thread part which is screwed thereto and is prevented from rotating by the cup spring one-way clutch mechanism, on two end faces which are in contact with one another. The pressure acting on the wear adjuster and introduced via the caliper lever is therefore introduced directly and without detour (Umweg) via the adjusting lever, for example in EP0732247B1, into the first wear adjuster housing, so that the friction conditions of the adjusting lever can no longer influence the adjustment accuracy. In particular, the separation gap below the spiral spring freewheeling mechanism is closed by this force transmission flow.

The rotatable threaded part of the screw drive is preferably designed as a threaded spindle, while the non-rotatable threaded part is designed as a nut. In this case, a clutch sleeve as a co-rotating element can be coupled to the spindle, forming an operating surface for operating the cup spring of the cup spring one-way clutch on its radial outer circumferential surface. The clutch sleeve is then, for example, rotatably mounted in the first wear adjuster housing. The clutch sleeve is necessary because the spindle is arranged inside the nut and the spiral spring is arranged radially outside, the rotational movement of the spindle having to be transmitted radially outwards.

According to one alternative, the rotatable threaded part is formed by a nut and the non-rotatable threaded part is formed by a lead screw. In this case, for example, the contact surface of the cup spring for contacting the cup spring one-way clutch is formed directly on the radially outer circumferential surface of the nut, since the nut is already arranged radially on the outside.

The invention also comprises in particular a disc brake for a rail vehicle, which disc brake comprises a wear adjuster as described above. The details will be given in the following description of the embodiments.

Drawings

Embodiments of the invention are illustrated in the drawings and further described in the following description. In the drawings:

fig. 1 shows a plan view of a disk brake of a rail vehicle with a strut adjuster having a brake caliper as a wear adjuster according to a preferred embodiment of the invention;

FIG. 2 shows a partially cut-away view of the brake caliper of FIG. 1;

FIG. 3 shows a cross-sectional view of a strut adjuster of the disc brake of FIG. 1;

FIG. 4 shows a cross-sectional view along line IV-IV of FIG. 3, showing an adjustment member supported in the adjuster housing by a sleeve-type one-way clutch mechanism in its initial position;

FIG. 5 shows the adjustment element of FIG. 4 in a loaded position beyond an initial position;

FIG. 6 shows an enlarged partial view of FIG. 5;

FIG. 7 shows the adjustment element of FIG. 4 in a position corresponding to the maximum adjustment displacement of the strut adjuster of FIG. 3;

FIG. 8 shows a cross-sectional view of another embodiment of the strut adjuster;

FIG. 9 shows a cross-sectional view of the strut adjuster of FIG. 3 in an extended state;

fig. 10 shows a cross-sectional view of another embodiment of the plunger regulator.

Detailed Description

Fig. 1 and 2 show a disk brake 100 for a wheel set, in particular a laterally displaceable wheel set, of a rail vehicle, having an eccentrically driven brake caliper 7, the two caliper levers 6, 8 of which are coupled at one end to a brake shoe 15 and at the middle region to a brake force motor 14. The brake disk 1 is only partially shown as a shaft disk.

The two sides of the two-sided caliper lever 6 of the brake caliper 7 are coupled on the brake housing 2 at a connection point 10, which can be regarded as holding a space fixed, rotatably about a rotational axis by means of a bolt 9. The other lever 8 is rotatably connected to the brake housing 2 at a connection point 10 by a bolt 9, the bolt 9 being mounted on the brake housing 2 so as to be rotatable about a rotational axis parallel to the rotational axis and carrying eccentrically a parallel-axis bolt projection 11, on which the lever 8 is mounted.

From the bolt 9, a pivot arm 12 projects, the piston rod of the brake cylinder being articulated at the end thereof as a force output 13 of a brake force motor 14. The two caliper levers 6 and 8 are connected at one end to a brake shoe 15 which can be pressed against the brake disk 1, and at the other end to a wear adjuster 16, in this example a strut adjuster, which connects the two caliper levers and is connected in a rotatable manner at connection points 17, 18, 19 and 20. The push rod adjuster 16 or its adjuster housing is provided for its connection with bearings 21 and 22 extending between the two sides 4 and 5 of the clamping levers 6 and 8. These bearings are also referred to below as first or second wear adjuster housings 21, 22.

When a pressure medium is applied to, for example, a pneumatic brake motor 14, the force output mechanism 13 rotates the pivot arm 12, so that the connecting point 20 of the caliper lever 8 with the strut adjuster 16, due to the eccentric arrangement of the bolt projection 11, rotates the brake pad 15 in the direction of pressing the brake disk 1. The structure and principle of the eccentric tensioning of brake caliper 7 therefore correspond to the structure and principle according to EP0732247a2 already mentioned above. After the brake pads 15 associated with the caliper lever 8 have been brought into contact with the brake disk 1, the caliper lever 8 is rotated about its connection point 18 with the brake pads 15, and the connection point 19 of the lever 16 and the caliper lever 6 is rotated about the connection point 10 via the connection point 20, so that the brake pads 15 come into contact with the brake disk 1.

The strut adjuster 16 increases its length according to the wear of the brake pad 15. For this purpose, the push rod adjuster has an adjusting lever 24, which is mounted on a first wear adjuster housing 21 associated with the clamping lever 6 so as to be rotatable about a longitudinal axis 25 of the push rod adjuster 16. The pin-like stop section 23 of the adjusting rod 24 is pressed into its initial position by means of a return spring 26 mounted on the first wear adjuster housing 21 and pressed against a stop 37 shown in fig. 3 to 8.

As shown in fig. 3, the extended spindle 27, which is secured against rotation by the preloaded toothing 53, is held in the second wear adjuster housing 22 so as to be non-rotatable and axially immovable coaxially with the longitudinal axis 25. In contrast, the adjusting nut 31 screwed to the threaded spindle 27 is rotatably mounted on the first wear adjuster housing 21. The spindle 27 and the adjusting nut together form a screw drive of the push rod adjuster 16.

The adjusting nut 31 can be connected in a rotationally fixed manner to the first wear adjuster housing 21 via a clutch with a helical spring 28 or a helical spring freewheeling mechanism 29. On the other hand, the adjustment nut 31 is driven by the adjustment lever 24 in the extending direction of the strut adjuster 16 through the sleeve type one-way clutch mechanism 38. The principle construction and operation of such a wear adjuster with two unidirectional rotating clutches or flywheels is well known and therefore need not be described in all detail. However, other embodiments of the wear adjuster, such as a tie rod adjuster, can also be used, wherein it is only important that the wear adjuster has an adjusting element corresponding to the adjusting rod 24. In the exemplary embodiment shown in fig. 3, the spindle 27 is mounted in a non-rotatable manner in the second wear adjuster housing 22, whereas the adjusting nut 21 is mounted in a rotatable manner in the first wear adjuster housing 21. The adjusting nut 31 can be rotated in one direction by the adjusting lever 24 with the sleeve-type one-way clutch 38, in which direction the strut adjuster 16 is extended for wear adjustment. However, embodiments according to EP0732247a2, for example, are also conceivable in which the spindle 27 is rotatably driven by the adjusting lever 24, while the adjusting nut 31 is mounted in a non-rotatable manner, as will be explained in the exemplary embodiment according to fig. 10.

The spring 28 supports a torque which is generated by the axial force acting on the push rod adjuster 16 and which is applied directly by the adjusting nut 31, which is prevented from rotating in the process, on a radially outer active surface 54 of the first wear adjuster housing 21, which active surface at the same time forms the outer surface of the first wear adjuster housing 21. The radially outer contact surface 54 is preferably formed here on a tubular projection 57, which is integral with the first wear adjuster housing 21.

In fig. 3, the rotatable adjusting nut 3 preferably also has an active surface 55 for the cup spring 28, i.e., some of the coils of the cup spring can act on this active surface and other coils of the cup spring act on an active surface 54 of the first wear adjuster housing 21, in order to prevent rotation of the adjusting nut 31 and thus shortening of the push rod adjuster 16 by reducing the diameter of the cup spring 28 when loaded axially. The cup spring 28 of the cup spring one-way clutch couples the active surface 54 of the first wear adjuster housing 21 to the active surface of the adjusting nut 31 only by frictional engagement, while the use of form-locking structures, such as hooks, is dispensed with.

In order to protect the screw drives 27, 31, the cup spring freewheel 29 and other components from dirt and moisture, the cup spring 28 of the cup spring freewheel 29, viewed in the radial direction, is only surrounded by a bellows 56 which is elastic in the axial direction of the push rod adjuster 16 and which is fastened, for example, by a tension ring, on one end side to the first wear adjuster housing 21 and, on the other end side, to the second wear adjuster housing 22.

The adjusting nut 31 has an end face 58 pointing in the axial direction, which comes into contact with a corresponding end face 59 of the first wear adjuster housing 21 in order to support the axial forces acting on the push rod adjuster 16. The axial force transmission flow is thus transmitted directly and instantaneously into the first wear adjuster housing 21, for example from the second wear adjuster housing 22 via the spindle 27, which is held fixed there, and the adjusting nut 31, which is screwed to the spindle and is prevented from rotating by the cup spring freewheel 29, on two end faces 58, 59 that are in contact with one another.

Fig. 9 shows the strut adjuster of fig. 3 in the extended state, i.e. the adjusting nut 31 is driven by the adjusting rod 24 in a direction of rotation on the spindle 27, which extends the strut adjuster 16 in order to automatically adjust the worn brake shoes 15. The cup spring one-way clutch 29 is free to run, i.e. the cup spring 28 is disengaged from the engagement surface 54 or 44 with the diameter of the cup spring 28 enlarged, so that the adjusting nut 31 can rotate freely in the direction of wear adjustment. As shown, the bellows 56 elastically deforms as the strut adjuster 16 is extended because the two wear adjuster housings 21, 22 move away from each other.

Fig. 10 shows a further exemplary embodiment of the push rod adjuster 16, in which the rotatable threaded part of the screw drive is formed by the spindle 27 and the non-rotatable threaded part of the screw drive is formed by the adjusting nut 31. At this time, the clutch sleeve 60, which is a rotationally fixed element, is rotationally coupled to the spindle 27, and an operating surface 55 for operating the cup spring 28 of the cup spring one-way clutch 29 is formed on a radially outer circumferential surface of the clutch sleeve. The clutch sleeve 60 is then mounted, for example, rotatably together with the spindle 27 in the first wear adjuster housing 21, and the adjusting nut 31 is held in the second wear adjuster housing 22 in a rotationally fixed manner. In this case, the clutch sleeve 60 surrounds at least one section of the threaded spindle 27 which is directed toward the first wear adjuster housing 21, and the clutch sleeve 60 is connected to the adjusting rod 24 via the sleeve-type freewheel 38. If the push rod adjuster 16 is subjected to an axial load, the end face 58 of the clutch sleeve 60 also bears against the corresponding end face 59 of the first wear adjuster housing 21 or its projection 57.

For wear adjustment, the adjusting sleeve 24 drives the spindle 27, likewise via the sleeve-type freewheel 38 and the clutch sleeve 60, in order to unscrew the spindle from the adjusting nut 31, in order to extend the push rod adjuster 16. The cup spring freewheeling mechanism 29 is now free to run, i.e. the helix of the cup spring 28 is disengaged from the active surface 54 or 55 with the diameter of the cup spring 28 being enlarged, so that the spindle 27 can rotate freely in the wear adjustment direction. Conversely, rotation of the lead screw 27 in the opposite direction is prevented by the coil spring one-way clutch mechanism 29 which acts as a lock.

A control rod 32 extends between the two sides 4 and 5 of the jaw lever 6, the rounded rearward end of which is supported in a bearing recess on the free end of the adjusting lever 24. The control rod 32 is therefore connected to the adjusting rod 24 via the connecting point 33. But the operating lever 24 is not shown in fig. 2. The control rod 32 is bent in its central region toward the outside of the brake caliper in order to avoid collisions with other components, in particular with the brake force motor 14. The likewise rounded end of the front side of the control rod 32 is supported in a bearing recess of the swivel lever 35, not visible here, as shown in fig. 2. The double-armed swivel lever 35 is rotatably mounted in its central region at a hinge point 36 and has a free leg 35 a. The functional principle of the engagement of the swivel lever 35 with an adjoining component is described in detail in EP0732247a 2.

As shown in fig. 2, the free end 35a of the swivel lever 35 is opposite the lever element 45 on the brake disk side at a distance s, forming the lost motion device 44. The lever 45 is configured as an extension of the swivel arm 12. The distance s corresponds to the distance traveled by the end of the lever 45 when the two brake pads 15 are still resting against the brake disk 1 without clamping force, starting from a disk brake released with the correct release stroke. When the brake is applied, the lever 45 rests against the side leg 35a of the swivel lever 35.

Starting from an excessive release travel of the disc brake, for example due to wear of the brake pads, during the brake application process, the release overtravel is initially overcomeIn its further movement, the lever 45 carries the leg 35a with the rotation of the rotary lever 35 until the brake comes into contact, the control rod 32 is moved in the direction of the adjusting lever 24 and the push rod adjuster 16 is actuated at this point. The front end of the control rod 32 on the brake side can therefore be connected by the connecting point 46 surrounding the swivel lever 35Connected to the force output 13 of the brake force motor 14.

In a development of the embodiment, on the brake caliper, the caliper lever can be centrally articulated on a lever adjuster 16 which can be actuated in the shortening direction of the lever adjuster by means of an adjusting lever 24. The wear adjuster 16 may be of any construction, and as mentioned above, the wear adjuster need only have an adjustment lever. The fastening of the brake caliper to spatially fixed components, in particular to the vehicle frame or the bogie frame, can be effected at the connection points of the different connection points 10. The brake caliper unit can be designed in such a way that the brake housing can be omitted. The tensioning of the brake caliper 7 can also take other forms and can be effected in one of a number of known ways, for example by means of brake cylinders connected directly to the caliper levers 6, 8 or by means of brake cylinders connected to the caliper levers 6, 8 by means of a lever mechanism.

The length of the strut adjuster 16 can therefore be adjusted as a function of the stroke of the brake force motor by means of a control mechanism which acts with a control rod 32 on the adjusting rod 24 of the strut adjuster 16. As shown in fig. 3 to 8 in particular, the actuating rod 24 is supported in the actuator housing or the bearing part 21 of the push rod actuator 16 by means of a sleeve-type freewheeling mechanism 38 and in the non-actuating initial position the pin-shaped stop section 23 is acted upon by the return spring 26 against the stop 37 of the bearing part 21 or the cover 21a of the bearing part 21. This state is shown in particular in fig. 4, in which fig. 4 the adjusting lever 24 is in its spring-loaded initial position.

The stop 37 for the adjusting element 24 in its initial position comprises at least one element 39 which is elastic in the stop direction, preferably a compression spring. The compression spring 39 is prestressed, wherein the prestressing force of the compression spring is greater than the force of the restoring spring 26, which acts on the adjusting lever 24 against the stop 37. The compression spring 39 is positioned in the support 21 or in its cover 21a in such a way that the adjustment lever 24 rests on it when the adjustment lever is rotated into its initial position due to the force of the return spring 26. Since the pretensioning force of the pretensioned compression spring 39 is greater than the force of the restoring spring 26, a defined initial position of the adjusting lever 24 is ensured.

The compression spring 39 is accommodated in particular in a cylindrical recess 40 of the bearing part 21 of the plunger regulator 16 or its cover 21a and is supported there with both ends under tension, said compression spring 39 contacting the regulating rod 24 via a pressure piece 41 which is supported in the recess 40 so as to be displaceable in the stop direction, as is best shown in fig. 4 and 6. The pressure element 41 is prevented from coming out of the recess 40, for example by an expansion ring 42 which is inserted into a radially inner annular groove of the recess 40 in the cover 21a, or the pretensioning of the compression spring 39 is produced as a result. In particular, the pressure element 41 is pressed axially by the compression spring 39 under pretension against a stop formed in the recess 40, which is formed here by an expansion ring 42. As can be easily imagined from fig. 4, the compression spring 39, the pressure piece 41 and the return spring 26 can be simply mounted thanks to the cover 21 a.

Thus, the return spring 26, here preferably a conical spring, holds the adjusting lever 24 in its initial position. The adjusting lever 24 bears against a pressure element 41 which is mounted in a displaceable manner in a recess 40, which is embodied as a blind hole, for example, in the bearing part 21 and can be displaced against the preloaded compression spring 39. As shown in fig. 4, 5 and 7, in addition to the stop 37 associated with the initial position of the actuating lever 24 and together with the compression spring 39, a further stop is provided in the bearing part 21 or its cover 21a, against which the actuating lever 26 rests with a further pin-shaped stop section 49 against the action of the return spring when the push-lever actuator 16 has set the maximum actuating travel. This state is shown in fig. 7.

When the disc spring 28 of the disc spring one-way clutch mechanism 29 has large elastic deformation, the compression spring 19 is over-pressurized as shown in fig. 5 and 6. The torque acting on the adjusting lever 24 and thus on the sleeve freewheel 38 is now limited to the torque or force introduced into the sleeve freewheel 38 by the compression spring 39. The pressure element 41 is now displaced a distance into the recess or blind hole 40 when the compression spring 39 is elastically deformed, as shown in fig. 6, and is lifted off the expansion ring 42, which otherwise forms a stop for the pressure element 42 in the initial position.

Therefore, if the disc spring one-way clutch mechanism 29 allows a certain rotation of the adjustment nut 31 in the shortening direction due to elastic elongation under load, the adjustment lever 24 can follow the rotation against the force of the compression spring while the pressure member 41 moves linearly (see fig. 6). The sleeve-type freewheel 38 is loaded only by a torque, which is determined by the spring force of the compression spring 39 and the distance of the line of action of the spring force from the axis of rotation of the adjusting nut 31, which is coaxial with the longitudinal axis 25.

According to a further embodiment shown in fig. 8, the compression spring 39 and the pressure element 41 are held inside a hollow screw 51, which is screwed from the outside into a through-hole 52 of the support element 21, which is designed as a threaded hole. In this case, the elastic stop 37 can be retrofitted in a simple manner to an already existing push rod adjuster 16. The structure and the operating principle of the elastic stop 37 are otherwise the same as in the case described in the preceding exemplary embodiments. Likewise, the embodiment according to fig. 8 omits the cover 21a of the embodiment according to fig. 4 to 6.

According to a further exemplary embodiment, which is not shown here, the elastic element may not form the compression spring 39, but may be formed as an arbitrary elastic element. In particular, an elastomer designed as a conical spring, designed as a vulcanized or separately arranged or supported with the regulator housing or support 21, is conceivable.

Likewise, embodiments of the spring element as a section integral with the support 21, which section, due to the special geometry, has a higher elasticity than the region of the support 21 adjoining it, are also conceivable. In this case, the higher flexibility or elasticity therefore results not from the lower material stiffness but from the lower stiffness compared to the adjoining region of the support 21 due to the geometry of the stop 37.

List of reference numerals

1 brake disc

2 brake housing

6 pliers pole

7 brake caliper

8 clamp rod

9 pin bolt

10 connecting part

11 cotter projection

12 rotating arm

13 power output mechanism

14 braking force motor

15 brake pad

16 compression bar adjuster

17 attachment site

18 attachment site

19 connection site

20 attachment site

21 first wear adjuster housing

21a cover

22 second wear adjuster housing

23 abutting section

24 adjusting rod

25 longitudinal axis

26 return spring

27 leading screw

28 coil spring

29 coil spring one-way clutch mechanism

31 adjusting nut

32 control rod

33 connecting part

35 rotating lever

35a end portion

36 hinge part

37 stop

38 sleeve type one-way clutch mechanism

39 compression spring

40 recess

41 pressure piece

42 expansion ring

43 stop

44 lost motion device

45 lever member

46 connection site

49 stop segment

51 hollow bolt

52 through hole

53 tooth system

54 acting surface

55 acting surface

56 corrugated pipe

57 projection

58 end face

59 end face

60 Clutch sleeve

100 disc brake

Claims (11)

1. A wear adjuster (16) for a brake caliper (7) of a disc brake (100) of a rail vehicle, having:

a) a screw drive as a threaded part having a spindle (27) and a nut (31) that can be screwed onto the spindle, wherein one of the threaded parts (27; 31) and an adjusting element (24) for rotationally driving the threaded part in a wear adjusting direction is rotatably supported in the first wear adjuster housing (21), while the other threaded part (27; 31) is mounted in a non-rotatable manner in the second wear adjuster housing (22),

b) a coil spring one-way clutch mechanism (29) which is axially movable along a rotatable threaded member (27; 31) is locked in a rotational direction opposite to the wear adjustment and is free to run in the opposite rotational direction, by means of which the rotatable threaded part can be coupled with the non-rotatable part, characterized in that,

c) the non-rotatable part is formed directly by the first wear adjuster housing (21), on which the rotatable threaded part is supported by a wrap spring one-way clutch or wrap spring without further intermediate components.

2. A wear adjuster according to claim 1, characterized in that the cup spring (28) of the cup spring freewheel (29) cooperates in a friction-locking manner, on the one hand, with a radially outer active surface (54) which forms the outer surface of the first wear adjuster housing (21) and, on the other hand, with a radially outer active surface (55) of the rotatable screw part (27; 31) or of an element (60) which rotates together with the rotatable screw part.

3. Wear adjuster according to claim 2, characterized in that the cup spring (28) of the cup spring freewheel (29) is surrounded, viewed in the radial direction, only by a bellows (56) which is fixed on one end side to the first wear adjuster housing (21) and on the other end side to the second wear adjuster housing (22).

4. A wear adjuster according to claim 2, characterized in that the disc spring (28) couples the active surface (54) of the first wear adjuster housing (21) with the active surface (55) of the rotatable threaded part (27; 31) or of the element (60) rotating together with the rotatable threaded part only by means of a friction fit.

5. A wear adjuster according to claim 1, characterized in that the rotatable threaded part (27; 31) or the element (60) rotating therewith has an end face (58) directed in the axial direction, which end face is in contact with a corresponding end face (59) of the first wear adjuster housing (21) for supporting the axial forces acting on the wear adjuster (16).

6. A wear adjuster according to any one of claims 1-5, wherein the rotatable threaded part of the screw drive is a lead screw (27) and the non-rotatable threaded part is a nut (31).

7. Wear adjuster according to claim 6, characterized in that the threaded spindle (27) is coupled with a clutch sleeve (60) as a co-rotating element, on the radial outer circumferential surface of which an active surface (55) for the action of a cup spring (28) of a cup spring one-way clutch mechanism (29) is formed.

8. The wear adjuster according to claim 7, characterized in that the clutch sleeve (60) is rotatably mounted coaxially to the spindle (27) in the first wear adjuster housing (21).

9. A wear adjuster according to any one of claims 1-5, wherein the rotatable threaded part is a nut (31) and the non-rotatable threaded part is a lead screw (27).

10. A wear adjuster according to claim 9, wherein the active surface (55) of the cup spring (28) for acting on the cup spring one-way clutch mechanism (29) is formed directly on the radially outer circumferential surface of the nut (31).

11. Disc brake, characterized in that it comprises a wear adjuster according to one of claims 1 to 10.