WO2018219398A1

WO2018219398A1 - Slave cylinder and holding clip

Info

Publication number: WO2018219398A1
Application number: PCT/DE2018/100470
Authority: WO
Inventors: Doris Maria Reutter
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2017-05-30
Filing date: 2018-05-17
Publication date: 2018-12-06
Also published as: DE102017111773B3

Abstract

The invention relates to a slave cylinder (1), in particular for a clutch or a braking system of a motor vehicle, wherein the piston (3) can be fastened in an axial direction (102) by means of a holding clip (7), for example for assembly purposes. Said holding clip (7) has a radial section (71), which effects an axial preload on a throw-out bearing (2) of the piston (3). In addition, the radial section (71) can act as a seal for the throw-out bearing (2) by means of a sealing section (73). The holding clip (7) is particularly advantageously produced as a bent sheet-metal part.

Description

NURSING CYLINDER AND HOLDING CLAMP

The invention relates to a slave cylinder, in particular for a clutch or a brake system of a motor vehicle, as well as a retaining clip for a piston of such a slave cylinder. Slave cylinders have a release bearing, which is moved by a displacement of a piston, usually an annular piston, of the slave cylinder. For proper operation of the slave cylinder, the release bearing must be centered during the displacement. This is ensured by a radial force, to which an axial preload acts on the release bearing. This preload leads to a self-centering of the release bearing.

It is known to apply this preload by a plate spring; The plate spring is fixed by a flanged retaining plate. Furthermore, a labyrinth seal is still under the diaphragm spring mounted to protect the release bearing from contamination. This solution according to the prior art requires several items, which is expensive in terms of production of the items and installation in the slave cylinder.

There are still alternative solutions known which, however, require a lot of space axially.

The object of the invention is to provide a slave cylinder, in which a

Self-centering of a release bearing of the slave cylinder is achieved in a manner which is inexpensive in terms of manufacture and installation and also does not take excessive axial space.

This object is achieved by a slave cylinder according to claim 1.

In the slave cylinder according to the invention, the required self-centering is achieved via a retaining clip, which is provided in the slave cylinder to fix a piston of the slave cylinder. According to the invention, the retaining clip has a radial section, by means of which an axial preload on a release bearing of the slave cylinder can be effected. This preload leads to self-centering of the

Release bearing. For example, the axial preload of a tilting of the Release bearing counteract relative to a housing of the slave cylinder. The radial portion of the retaining clip replaces the prior art disc arrays; The diaphragm spring can thus be saved as a separate component.

In one embodiment, the radial portion is formed so that it additionally forms a seal of the release bearing. In this embodiment, the

Labyrinth seal from the prior art saved as a separate component. For this purpose, the radial portion is formed correspondingly extended in the radial direction in the

Compared to a radial section of a retaining clip, which does not have to fulfill this sealing function. The region extending the radial section thus forms a sealing section.

In one embodiment, the retaining clip has at least one axial section through which the piston can be fixed. This corresponds to the function as a retaining clip, the piston should, for example, for installation in a motor vehicle, be fixed in the axial direction. In the ready state, the fixation of the piston is released, so that it can move in the axial direction.

For improved fixation of the piston, a free end of the at least one axial section of the retaining clip is bent like a hook. In order to cooperate with the axial portion of the retaining clip for fixing the piston, at least one recess is provided on the piston, in which the axial portion can engage. If the axial section engages in the recess, the piston is fixed. The at least one axial section may also have a plurality of free ends, which are bent over in the shape of a hook. Likewise, the retaining clip may have a plurality of axial sections.

In embodiments, the retaining clip is annular. The retaining clip may in particular have a plurality of axial sections which are distributed along a circumference of the annular retaining clip. The retaining clip can also be made in one piece, in particular as a

Bent sheet metal part. In this way, the production of the retaining clip is particularly simple. Such a retaining clip represents a single component, which as a retaining clip the Pistons can fix, at the same time causes an axial preload on the release bearing and in embodiments also assumes the role of the labyrinth seal. Thus, the number of components of the slave cylinder is reduced, and the assembly of the

Slave cylinder simplified accordingly. With reference to the accompanying drawings, hereinafter

Invention and its advantages illustrated by the example of embodiments of the invention, without thereby the invention to the specific illustrated

Limiting embodiments.

Figure 1 shows a sectional view of a part of a slave cylinder after the

State of the art.

Figure 2 shows a sectional view of a part of an alternative slave cylinder according to the prior art.

FIG. 3 shows a sectional view of a part of a device according to the invention

Slave cylinder. FIG. 4 shows a sectional view of part of another inventive device

Slave cylinder.

Figure 5 shows an embodiment of a retaining clip according to the invention for a slave cylinder according to the invention.

FIG. 6 shows a further embodiment of a device according to the invention

Retaining clip for a slave cylinder according to the invention.

For identical or corresponding elements, the same reference numerals are used.

Fig. 1 shows a sectional view of a part of a slave cylinder 1 according to the prior art. The slave cylinder 1 has a release bearing 2, which via

Bearing rings 21, 22 and rolling elements 23 has. A labyrinth seal 6 seals the release bearing 2 from. By a plate spring 4, a preload in an axial direction 102 is applied to the release bearing 2. This axial preload acts on a Self-centering of the release bearing 2 in a radial direction 101 out. The

Plate spring 4 is held by a flanged holding plate 5. Furthermore, a part of a housing 1 1 of the slave cylinder 1 is still shown. The release bearing 2 is displaceable by movement of a piston 3 of the slave cylinder 1 in the axial direction 102.

Fig. 2 shows a sectional view of a part of an alternative slave cylinder 1 according to the prior art. The slave cylinder 1 has a release bearing 2, which has bearing rings 21, 22 and rolling elements 23. The release bearing 2 is through

Movement of a piston 3 of the slave cylinder 1 in an axial direction 102 slidably. A labyrinth seal 6 seals the release bearing 2 from. By a plate spring 4, a preload in the axial direction 102 is applied to the release bearing 2. This axial preload acts on a self-centering of the release bearing 2 in a radial direction 101. The plate spring 4 is snapped into a projection 31 on the piston 3. Furthermore, a part of a housing 1 1 of the

Slave cylinder 1 shown.

Fig. 3 shows a sectional view of a part of an embodiment of a

The slave cylinder 1 has a release bearing 2 with bearing rings 21, 22 and rolling elements 23. Portions of a housing 1 1 of the slave cylinder 1 are also shown. By movement of a piston 3 of the slave cylinder 1 in the axial direction 102, the release bearing 2 in the axial direction 102 is movable. According to the invention assumes a specially trained retaining clip 7 for the piston 3 at the same time the function of the plate spring of the prior art, so brings on the axial preload, through which a self-centering of the

Release bearing 2 in the radial direction 101 is effected. For this purpose, the retaining clip 7 according to the invention has a radial portion 71, which

is correspondingly elastic and shaped accordingly to apply the preload. In the embodiment shown, the retaining clip 7 fixes the piston 3 via an axial section 72. The axial section 72 engages with a recess 32 formed in the piston 3; advantageous here is a free end 74 of the axial portion 72 hook-shaped bent, and the hook thus formed engages in the Recess 32 a to fix the piston 3 in the axial direction 102. In the illustrated configuration, with fixed piston 3, the slave cylinder 1 can be handled for assembly, for example, in a motor vehicle. To the

Slave cylinder 1 to make ready after installation, the axial portion 72 is bent in the direction of arrow 103 until the free end 74 is released from the recess 32. Then the piston 3 is movable in the axial direction 102. At a

Embodiment, as shown in Fig. 3, an additional limitation of the displaceability of the release bearing 2 in the radial direction 101 can be achieved in that the bearing ring 22 finally abuts against the axial portion 72 when moving in the radial direction 101. This contributes to the self - centering of the

Release bearing 2 in the radial direction 101 at.

4 shows a sectional view of a part of a further embodiment of a slave cylinder 1 according to the invention. The embodiment is substantially similar to that shown in FIG. 3, in FIG. 3 the majority of the elements also shown in FIG. 4 have already been discussed. Significant difference to shown in Fig. 3

Embodiment is that the radial portion 71 of the invention

Retaining clip 7 is extended and has a sealing portion 73 which is shaped so that the release bearing 2 is sealed by him. The sealing portion 73 thus replaces the labyrinth seal of the prior art. 5 shows an embodiment of a retaining clip 7 according to the invention for a slave cylinder 1 according to the invention (see FIGS. 3 and 4). The retaining clip 7 is annular, in the illustrated embodiment, the radial portion 71 is formed as a closed ring, as is the sealing portion 73. The retaining clip 7 has a plurality of axial portions 72 which are arranged along a circumference of the annular retaining clip 7. A free end 74 of each axial section 72 is bent over in the shape of a hook. The illustrated embodiment of the

Retaining clip 7 corresponds to that shown in Fig. 4. The number of axial sections 72 may be greater or less than the number shown in FIG. It is also conceivable that the axial section is formed as a closed surface. A Retaining clip 7 as shown in Fig. 5 can be made in one piece, preferably as a sheet metal bent part.

FIG. 6 shows a further embodiment of a retaining clip 7 according to the invention for a slave cylinder 1 according to the invention (see FIGS. 3 and 4). The retaining clip 7 is annular, in the embodiment shown, the radial portion 71 is formed as a closed ring. The retaining clip 7 has a plurality of axial sections 72, which along a circumference of the annular

Retaining clip 7 are arranged. In contrast to that shown in Fig. 5

Retaining clip 7, each axial portion 72 a plurality of free ends 74, wherein each free end 74 is bent in a hook shape to engage in a recess 32 in a piston 3 (see Fig. 3 and Fig. 4) of a slave cylinder 1.

LIST OF REFERENCE NUMBERS

1 slave cylinder

2 release bearing

3 pistons

4 plate spring

5 retaining plate

6 labyrinth seal

7 retaining clip

1 1 housing of the slave cylinder

21 bearing ring

22 bearing ring

23 rolling elements

31 lead

32 recess

71 radial section

72 axial section

73 sealing section

74 free end

101 radial direction

102 axial direction

103 arrow

Claims

claims

1. slave cylinder (1) with a retaining clip (7) for fixing a piston (3) of the slave cylinder (1), characterized in that the retaining clip (7) has a radial portion (71) through which an axial preload on a release bearing (2) of the slave cylinder (1) is effected.

2. slave cylinder (1) according to claim 1, wherein the radial portion (71) has a

Seal portion (73) which forms a seal of the release bearing (2).

3. slave cylinder (1) according to one of the preceding claims, wherein the

Retaining clip (7) has at least one axial portion (72) through which the piston (3) is fixable.

4. slave cylinder (1) according to claim 3, wherein a free end (74) of the at least one axial portion (72) is bent hook-shaped.

5. slave cylinder (1) according to claim 4, wherein the at least one axial portion (72) has a plurality of free ends (74) which are bent hook-shaped.

6. slave cylinder (1) according to any one of claims 3 to 5, wherein the retaining clip (7) has a plurality of axial sections (72).

7. slave cylinder (1) according to one of claims 3 to 6, wherein the piston (3) has a recess (32) and the at least one axial portion (72) is provided for fixing the piston (3) in the recess ( 32)

intervene.

8. slave cylinder (1) according to one of claims 1 to 7, wherein the retaining clip (7) is annular.

9. retaining clip (7) for fixing a piston (3) of a slave cylinder (1) in an axial direction (102), characterized by a radial portion (71) through which an axial preload on a release bearing (2) of the slave cylinder (1) is effected.

Retaining clip (7) according to claim 9, wherein the radial portion (71) has a sealing portion (73) adapted to form a seal of the release bearing (2).