WO2019233520A1

WO2019233520A1 - Slave cylinder with axial play between piston and actuation bearing, actuation device, and clutch system

Info

Publication number: WO2019233520A1
Application number: PCT/DE2019/100458
Authority: WO
Inventors: Michel Jacky; Philippe Wagner
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2018-06-06
Filing date: 2019-05-24
Publication date: 2019-12-12
Also published as: DE102018113399A1

Abstract

The invention relates to a slave cylinder (1) for a clutch actuation device of a motor vehicle, comprising a housing (2), a piston (3) which is movably received in the housing (2), and an actuation bearing (4). The piston (3) is connected to a bearing ring (6) of the actuation bearing (4) in a fixed manner via a holding ring (5), and the holding ring (5) has both a support region (7) lying rigidly against the bearing ring (6) as well as multiple fingers (9) which are pretensioned in the radial direction of the longitudinal axis (8) of the piston (3). The fingers (9) rest against a bevel (10) of the piston (3) such that the piston (3) is pressed against the bearing ring (6) in the axial direction by the radial pretensioning force of the fingers (9). The invention additionally relates to an actuation device for a clutch of a motor vehicle and to a clutch system.

Description

Slave cylinder with axial backlash between piston and actuator;

Actuator and couplers

The invention relates to a slave cylinder for a clutch actuator of a motor vehicle, such as a car, truck, bus or other commercial vehicle, with a housing, a piston slidably received in the housing and an actuating bearing, wherein the piston via a retaining ring slidably connected to a bearing ring of the actuating bearing is. Furthermore, the invention relates to an actuating device for a clutch of a motor vehicle, with this slave cylinder. The invention also relates to a coupling system for a drive train of a motor vehicle, with a clutch and in turn with this actuating device.

Generic slave cylinders are already well known from the prior art. EP 1 937 991 B1 discloses an exemplary slave cylinder with an annular piston bearing axial play.

In some applications, as known from the prior art, a certain axial play between the piston and the actuating bearing is intended to allow the assembly of the actuating bearing or to ensure the further assembly of Neh erzylinders. In the scope of hybrid systems, i. H. Hybrid drive trains, however, have proven to be disadvantageous in motor vehicles because of the requirements for the most accurate possible torque control, if such axial play is present in the slave cylinder. Under certain circumstances, an undefined position of the piston can be generated by the axial play, so that the most accurate possible control of the clutch and thus torque control is relatively difficult or not precise enough to perform.

It is therefore the object of the present invention to remedy the disadvantages known from the prior art and, in particular, to provide a slave cylinder which permits the most precise and traceable adjustment of a clutch. This is inventively achieved in that the retaining ring has both a firmly attached to the bearing ring support region and a plurality of biased in a radial direction of a longitudinal axis of the piston finger, the fingers abut such a slope of the piston that the piston through the radial biasing force of the fingers in an axial direction (the longitudinal axis) is pressed against the bearing ring.

As a result, the actuating bearing and the piston in the axial direction as possible without play into each other in conditioning. The axial play is thereby largely reduced. Also, the structure is as simple as possible implemented by the formation of the retaining ring. The slope of the piston may also be an undercut or the like act, in which snap in the fingers of the retaining ring and thus fixed.

Further advantageous embodiments are claimed with the subclaims and explained in more detail below.

The structure is further simplified if the support region is pressed (directly) against a first disk region of the bearing ring by means of a biasing spring biasing the actuating bearing into a disengaged starting position.

In this context, it is also expedient for the piston to be pressed (directly) against a second disk region of the bearing ring by means of the retaining ring.

A space-saving design of the actuating bearing is also ensured if the first disc region is arranged offset in a radial direction and / or in the axial direction of the longitudinal axis of the piston to the second disc region. If the retaining ring is provided in the axial direction between the support region and the fingers with an annular centering region, which centering region lies radially on the bearing ring (centered), the mounting of the retaining ring is further simplified.

Moreover, it is advantageous if the fingers protrude from an axial end face of the centering region. This results in an even easier producible form of the retaining ring.

It is also advantageous if the bevel is inclined / tapered relative to the longitudinal axis both in the radial direction and in the axial direction. As a result, a particularly easily implementable means is provided, which simultaneously leads to the fact that the retaining ring itself centered relative to the piston or the piston independently centered relative to the actuating bearing.

The piston further preferably directly or indirectly seals a seal sealing a pressure space defined between the piston and the housing.

For indirect recording, it has proven to be useful if a seal carrier, which is further connected to the piston, receives this seal. Furthermore, it is expedient if the seal is received in the axial direction without play on the piston. This further reduces the existing axial play. Alternatively, it is again advantageous, in particular when receiving the seal via the seal carrier, when the seal is accommodated on this piston with play in the axial direction relative to the piston.

The slave cylinder is preferably designed as a concentric slave cylinder.

For improved controllability of the slave cylinder, it is also advantageous if the latter has a sensor device which detects the piston position along a displacement path of the piston. Furthermore, the invention relates to an actuating device for a clutch of a motor vehicle, with a slave cylinder according to the invention according to at least one of the embodiments described above, as well as a donor cylinder operatively connected fluidically to the slave cylinder.

The invention also relates to a clutch system for a drive train of a motor vehicle, with a clutch and with this actuator.

In other words, according to the invention, an axially backlash-free piston bearing connection by means of a biasing ring (retaining ring) is thus realized. It is proposed to remove the axial clearance between a bearing (actuator bearing) and a piston from the CSC (slave cylinder) (to improve the position measurement of the piston) by biasing the preload ring with radially biased fingers between a bearing ring and the retaining ring (retaining ring ) is integrated for the preload spring. During assembly, the piston is pushed out of the pressure chamber in the direction of the bearing until the preloaded fingers of the preload ring snap onto a bevel of the piston and thus firmly fix it to the bearing ring.

The invention will now be explained in more detail with reference to figures, in which context also different embodiments are shown.

Show it:

1 is a longitudinal sectional view of a slave cylinder according to the invention according to a first embodiment, wherein a connection point of a piston on a bearing ring of an actuating bearing is particularly well to recognize

Fig. 2 is a longitudinal sectional view of the slave cylinder of FIG. 1, wherein the

1 is offset relative to the sectional plane of FIG. 1 such that a sensor device detecting the position of the piston can now be detected, 3 is a detail view of the slave cylinder of FIG. 1 in the region of the actuation bearing in longitudinal section,

Fig. 4 is a perspective view of a in Figs. 1 to 3 used holders,

FIGS. 5a to 5c show several longitudinal sections of the slave cylinder of FIGS. 1 to 3 in various assembly steps, wherein in Fig. 5a, the actuating bearing is still arranged in the axial direction relatively displaceable to the piston, in FIG.

5b the actuating bearing with the retaining ring mounted thereon is pushed into the piston so far that several fingers of the retaining ring are biased inwardly in a radial direction to be pushed through an opening of the piston, and FIG. 5c shows the fully assembled position the actuating bearing, in which the fingers are snapped outwards in the radial direction in such a way that they bear against a bevel of the piston in the radial direction under prestress,

Fig. 6 is a longitudinal sectional view of a slave cylinder according to the invention according to a second embodiment, in which a seal of the piston is accommodated on a separate seal carrier, and

Fig. 7 is a longitudinal sectional view of a slave cylinder according to the invention according to a third embodiment, in which a seal receiving the seal carrier is accommodated play on the piston.

The figures are merely schematic in nature and serve only to understand the invention. The same elements are given the same reference numerals. Also, the different features of the various embodiments can be freely combined with each other.

In FIG. 1, a slave cylinder 1 according to the invention can be recognized particularly well in terms of its construction according to a first exemplary embodiment. The slave cylinder 1 is designed as a hydraulic slave cylinder 1. The slave cylinder 1 is also designed as a concentric slave cylinder 1 (CSC). The slave cylinder 1 is used during operation to actuate a clutch (not shown here for the sake of clarity). The slave cylinder 1 is thus part of an actuating device of a clutch in its preferred use / operation. With the slave cylinder 1, a donor cylinder (not shown here for clarity) is hydraulically connected here. The actuator is in turn part of a clutch system in its operation, which also includes a clutch, such as a friction clutch belongs. By means of the slave cylinder 1, an appropriate positioning element for moving the coupling between its engaged and disengaged position is displaced by an actuating bearing 4 of the slave cylinder 1.

The slave cylinder 1 typically has an annular housing 2, within which a piston 3 in the form of an annular piston is displaceably guided along its longitudinal axis 8. The piston 3 forms with the housing 2 a pressure chamber 17, to which pressure chamber 17 is hydraulically connected during operation of the master cylinder. In this embodiment, the piston 3 has an annular base body 19 on which a seal 18 implemented as a sealing ring for sealing the pressure chamber 17 to the environment is accommodated in a region permanently arranged within the housing 2.

The piston 3 is shown in Fig. 3 in its disengaged (initial) position, where in a fixedly attached to the housing 2 stop ring 20 defines that disengaged position of the piston 3 / secures. The stop ring 20 is arranged so that slipping out of the piston 3 is prevented with its seal 18 from the housing 2 out. The piston 3 is biased by means of a trained as a helical compression spring biasing spring 11 in this disengaged position with a certain biasing force. The biasing spring 11 is supported / clamped in the axial direction between the housing 2 and a first bearing ring 6 of the actuating bearing 4. The biasing spring 11 is disposed radially inwardly of the pressure space 17 with respect to the longitudinal axis 8.

With regard to the actuation bearing 4, it can be seen that the first bearing ring 6 is that bearing ring of the actuation bearing 4 which is coupled to the piston 3 so as to be non-displaceable is. A second bearing ring 21 of the actuating bearing 4 is roller-mounted relative to the first bearing ring 6. The actuating bearing 4 is designed as an angular contact ball bearing, so that a plurality of circumferentially distributed, the first bearing ring 6 relative to the second bearing ring 21 roller bearing rolling elements 22 are used as balls. The first bearing ring 6 is formed as a bearing outer ring and the second bearing ring 21 as radially disposed within the first bearing ring 6 bearing inner ring.

According to the invention, a retaining ring 5 is used for backlash-free support of the piston 3 on the part of the first bearing ring 6 in the axial direction. On the one hand, the retaining ring 5 has a support region 7, which is firmly supported on the first bearing ring 6.

On the other hand, the retaining ring 5 a plurality of circumferentially distributed and biased in a radial direction of the longitudinal axis 8 finger 9 (also referred to as tabs / lugs) on which fingers 9 abut such a slope 10 of the piston 3, that the piston 3 through the radial biasing force of the fingers 9 in the axial direction on the first bearing ring 6 is also pressed. The retaining ring 5 is thus designed and inserted as a biasing ring. Thus, the play-free recording of the piston 3 is ensured by the first bearing ring 6.

For the axial fixation of the support region 7 of the retaining ring 5, it is fixed axially in the axial direction between a first disk region 12 (also referred to as the first disk-shaped support region) of the first bearing ring 6 and one end of the biasing spring 11 due to the biasing force of the biasing spring 11 / clamped. In order to achieve the most uniform possible contact / biasing force of the biasing spring 11 on the support region 7, a receiving ring 23 is arranged at the end of the biasing spring 11 and the receiving ring 23 in turn pressed against the support region 7.

A second disk region 13 (also referred to as second disk-shaped support region) of the first bearing ring 6 is formed in the axial direction of the longitudinal axis 8 on a side of the first bearing ring 6 opposite the rolling elements 22 and arranged radially outside the first disk region 12. While the first disk region 12 protrudes inwards in the radial direction, the second disk region 13 protrudes outwardly in the radial direction accordingly. The piston 3 is in axial direction with its radially inwardly projecting thickening region 24 in the axial direction between this second disc portion 13 and the retaining ring 5, that is, the fingers 9, clamped in the axial direction without play.

In conjunction with FIG. 3, the bevel 10 of the piston 3, which is formed on the thickening region 24, namely on a side of the thickening region 24 which is axially remote from the second disk region 13, can also be seen more closely. The bevel 10 is implemented as a conical bearing surface and extends with respect to the central longitudinal axis 8 of the slave cylinder 1 of the piston 3 both obliquely in the axial direction and in the radial direction. Due to the radial pretensioning of the fingers 9 / the bearing of the fingers 9 in the radial outward direction against this bevel 10, the piston 3 is centered automatically relative to the actuating bearing 4.

In turn, the retaining ring 5 is centered / supported on the first bearing ring 6 by means of a centering region 14 formed between the fingers 9 and the support region 7 in the axial direction. The fingers 9 then protrude from an axial end face 15 of the centering region 14 (FIG. 4). FIG. 4 shows that a plurality of fingers 9 are uniformly distributed on the retaining ring 5 in the circumferential direction.

In connection with FIG. 2 it is shown that the slave cylinder 1 has a sensor device 25, which is designed to determine an axial position of the piston 3 during operation of the slave cylinder 1 along its displacement path. FIG. 2 illustrates an engaged position of the piston 3, whereby the piston 3 is pushed into the pressure chamber 17 as far as possible or pushed into the housing 2 and the pressure chamber 17 is minimal in size. The sensor device 25 has a sensor 26 (displacement sensor), which is firmly held on the housing 2 and which detects two targets 27, for example in the form of magnets, mounted on the piston 3 so as to be non-displaceable. This allows a particularly position detection of the piston 3. In conjunction with Figs. 5a, 5b, 5c, an assembly of the actuation bearing 4 on the part of the piston 3 is illustrated by way of example. In a first step according to FIG. 5 a, the actuating bearing 4, whereby the retaining ring 5 is already fixed on the part of the first bearing ring 6, is pushed into the piston 3 in the axial direction. At the same time, so that the piston 3 is not excessively pressed against the housing 2 and thus possibly the seal 18 is damaged, as shown by the arrow 28, in the pressure chamber 17, an artificial pressure, for example by means of an air pressure , so that the piston 3 applies an opposing force. Following this, according to FIG. 5 b, the actuating bearing 4 is pushed further into the piston 3.

For this purpose, the fingers 9 are elastically biased inwards in the radial direction by means of the thickening region 24. After a complete insertion of the actuation bearing 4 into the piston 3, the fingers 9 engage independently behind the thickening region 24 due to their radial preload and thus press the thickening region 24 automatically against the second disc region 13. This is the axial direction play-free recording of the piston 3 implemented.

In conjunction with Figs. FIGS. 6 and 7 illustrate two further exemplary embodiments of the slave cylinder 1 according to the invention, which deviate from the first exemplary embodiment. For brevity, only the differences of these embodiments to the construction of the first embodiment will be described below.

In Fig. 6 it can be seen that the seal 18 of the piston 3 is no longer, as in the first embodiment, received directly on the main body 19 in the axial direction without play, but is indirectly received via a seal carrier 16 on the piston 3. The seal carrier 16 is connected to the main body 19 in the axial direction without further play. The seal carrier 16 also receives the seal 18 in the axial direction without play. In this context, it is particularly advantageous if the seal carrier 16 is made of a different material than the base body 19 and is preferably molded onto it. Thus, a so-called two-cavity injection is preferably realized. In the embodiment of Fig. 7, the seal carrier 16 is made separately from the base body 19 in comparison to the embodiment of Fig. 6 and attached to the base body 19 with a certain play in the axial direction. The seal carrier 16 is attached to the base body 19 via a positive snap connection. The seal carrier 16 in turn receives the seal 18 in the axial direction without play.

In other words, according to the invention a biasing ring 5 with pre-tensioning fingers (finger 9) on the release bearing (actuator bearing 4) between outer ring (first bearing ring 6) and pre-load spring retaining ring (receiving ring 23) attached. During the release bearing assembly, the bearing 4 is held and the piston 3 is pressed with air pressure in the bearing 4. During assembly, the biasing ring 5 is run over by the piston 3 and radially pressed against the bearing 4 (in the elastic range). Once the piston 3 has passed over the biasing ring 5, the biasing fingers 9 jump into the piston incline (slope 10) and press the piston 3 against the outer ring 6. Thus, a constant force between release bearing 4 and piston 3 is shown, for a backlash Connection also ensures at vacuum pressures. The flexibility of the biasing fingers 9 and the bevel 10 on the piston 3 ensure a tolerance compensation and make a bearing mounting under all tolerance cases rather. This solution is in principle intended for a CSC 1 without sealing ring carrier (seal carrier 16), but can also be used in combination with the sealing ring carrier 16 or supporting rings.

Reference number list slave cylinder

casing

piston

operation seat

retaining ring

first bearing ring

support area

longitudinal axis

finger

slope

biasing spring

first disc area

second disc area

centering

front

seal carrier

pressure chamber

poetry

body

stop ring

second bearing ring

rolling elements

receiving ring

thickening area

sensor device

sensor

target

arrow

Claims

claims

1. slave cylinder (1) for a clutch actuation device of a motor vehicle, with a housing (2), in the housing (2) slidably received piston (3) and an actuating bearing (4), wherein the piston (3) via a retaining ring (5) is non-displaceably connected to a bearing ring (6) of the actuating bearing (4), characterized in that the retaining ring (5) has both a fixed to the bearing ring (6) supporting region (7) and a plurality in a radial direction of a longitudinal axis (8) of the piston (3) biased fingers (9), wherein the fingers (9) on a slope (10) of the piston (3) abut, that the piston (3) the radial biasing force of the fingers (9) in an axial direction is pressed against the bearing ring (6).

2. slave cylinder (1) according to claim 1, characterized in that the support region (7) by means of the actuating bearing (4) in a disengaged initial position biasing biasing spring (11) to a first disc region (12) of the bearing ring is pressed.

3. slave cylinder (1) according to claim 1 or 2, characterized in that the piston (3) by means of the retaining ring (5) on a second disc portion (13) of the bearing ring (6) is pressed.

4. slave cylinder (1) according to claim 2 and 3, characterized in that the first disc region (12) in a radial direction and / or in the axial direction of the longitudinal axis (8) of the piston (3) offset from the second disc region (13) is arranged.

5. slave cylinder (1) according to one of claims 1 to 4, characterized in that the retaining ring (5) in the axial direction between the support region (7) and the fingers (9) with an annular centering region (14) is provided, which Centering (14) rests radially from the outside on the bearing ring (6).

6. slave cylinder (1) according to claim 5, characterized in that the fingers (9) protrude from an axial end face (15) of the centering region (14).

7. slave cylinder (1) according to one of claims 1 to 6, characterized in that the slope (10) is inclined relative to the longitudinal axis (8) both in the radial direction and in the axial direction.

8. slave cylinder (1) according to one of claims 1 to 6, characterized in that the piston (3) a between the piston (3) and the housing (2) limited pressure chamber (17) sealing gasket (18) directly or with - absorbs.

9. actuating device for a clutch of a motor vehicle, with a slave cylinder (1) according to at least one of claims 1 to 8 and a fluidly with the slave cylinder (1) operatively connected master cylinder.

10. clutch system for a drive train of a motor vehicle, with a

Coupling and an actuating device according to claim 9.