Arrangement of annular piston and grooved sealing ring for slave cylinders of clutch actuation devices

Abstract

Arrangement of a ring piston (5) and a groove seal ring (6) for the master cylinder of clutch actuating devices, wherein the ring piston (5) and the groove seal ring (6) have at least one pair consisting of an annular recess and a complementary annular projection in their axially facing end regions, which engages form-fittingly in the recess to hold the ring piston and the groove seal ring together without play, wherein the groove seal ring (6) has at least one annular recess (10) opening in the axial direction towards the ring piston (5), which is formed between two radially spaced annular projections (11, 12) of the groove seal ring (6) engaging in annular recesses (14, 15) in the ring piston (5), and an annular projection (13) of the ring piston (5) complementary to the at least one annular recess (10) in the groove seal ring (6) engages form-fittingly in the recess (10) in the groove seal ring (6),characterized in that an annular sealing ring carrier (7) is provided between the annular piston (5) and the grooved sealing ring (6), and the sealing ring carrier (7) is in contact with the annular projections (11, 12) of the grooved sealing ring (6) and the annular piston (5).

Description

[0001] The invention relates to an arrangement comprising an annular piston and a grooved sealing ring for slave cylinders of clutch actuating devices, wherein the annular piston and the grooved sealing ring have, in their axially mutually facing end regions, at least one pair consisting of an annular recess and a complementarily shaped annular projection which engages positively in the recess in order to hold the annular piston and the grooved sealing ring together without play.

[0002] Such an arrangement comprising an annular piston and grooved sealing ring is known, for example, from DE 10 2013 214 370 A1. In the known arrangement, in the end region of the annular piston axially facing the grooved sealing ring, there is an annular recess opening towards the grooved sealing ring. This recess is formed between two radially spaced annular projections, one of which is arranged on the radial outer side of the annular piston and the other projection on the radial inner side of the annular piston. Each of these projections has an annular rib with a rounded tip. The tips of these ribs face one another in the radial direction and enclose a section of the recess between them, which has a smaller radial width than the section of the recess adjoining the base of the recess and the section of the recess adjoining the opening of the recess.A base of the grooved sealing ring, shaped complementarily to the recess in the annular piston, engages positively with the recess in the annular piston. A seal carrier comprising a radially outer ring part and a radially inner ring part is connected to the grooved sealing ring and bears against the end region of the annular piston comprising the annular recess and the annular projections of the annular piston. The outer ring part and the inner ring part of the seal carrier each bear against a sealing neck of the grooved sealing ring arranged between the seal base and a pair of V-shaped diverging sealing lips of the grooved sealing ring.

[0003] During operation of the clutch actuation device, the annular piston is exposed to strong transverse forces, which, in the known arrangement, can lead to deformation of the annular piston in its end region and / or to tilting of the annular piston, whereby the required clearance between the annular piston and the grooved sealing ring is no longer guaranteed, at least under vacuum. An arrangement comprising an annular piston and a grooved sealing ring according to the preamble of claim 1 is known from DE 10 2009 021 346 A1. Further prior art is disclosed in JP 2011-179 666 A and US Pat. No. 4,821,627 A.

[0004] The object of the invention is to at least partially overcome the disadvantages known from the prior art and, in particular, to design the arrangement of annular piston and grooved sealing ring of the type mentioned at the outset in such a way that no gap is formed between the annular piston and the grooved sealing ring during operation, even under vacuum.

[0005] The object of the invention is achieved in that the groove sealing ring has at least one annular recess opening in the axial direction towards the annular piston, which is formed between two radially spaced annular projections of the groove sealing ring engaging in annular recesses in the annular piston, and an annular projection of the annular piston complementarily shaped to the at least one annular recess in the groove sealing ring engages in this recess in the groove sealing ring in a form-fitting manner.

[0006] The annular piston of the arrangement according to the invention has increased stability, which prevents transverse forces acting on the annular piston during operation from deforming the annular piston in its end region to such an extent that a gap could form between the annular piston and the grooved sealing ring. As a result, zero play between the annular piston and the grooved sealing ring is guaranteed, even under vacuum.

[0007] Preferably, the annular projection of the annular piston widens conically toward its free end. While the conical widening of the annular projection of the annular piston toward its end can be realized by various cross-sectional shapes of the projection, a dovetail is preferred as the cross-sectional shape of the projection.

[0008] Instead of providing the annular projection as a single piece on the annular piston, the annular projection can also be divided into a radially outer annular projection and a radially inner annular projection by an annular groove opening towards the groove sealing ring, and a further projection of the groove sealing ring, shaped complementarily to the annular groove, can engage positively in the annular groove.

[0009] The annular groove between the two projections of the annular piston and the further projection of the grooved sealing ring can each have parallel side walls. However, it is also possible for the annular groove to widen conically toward its opening, and then for the further projection of the grooved sealing ring to taper conically toward its free end. In both cases, the radially inner annular projection and the radially outer annular projection of the annular piston can widen conically toward their respective free ends, whereby the conical widening of the respective projection can be symmetrical or asymmetrical.

[0010] The division of the annular projection on the annular piston into a radially outer and a radially inner annular projection by means of an annular groove facilitates the creation of a dovetail geometry of the projection, as this allows the wall thickness to be made more constant over the entire component.

[0011] According to the invention, an annular seal carrier is provided between the annular piston and the grooved sealing ring. The seal carrier engages the annular projections of the grooved sealing ring and the annular piston. In the event of a vacuum during operation of the assembly, the seal carrier wedges the grooved sealing ring onto the annular piston. A radially inner annular part of the seal carrier presses against the radially inner projection of the grooved sealing ring, and a radially outer annular part of the seal carrier presses against the radially outer projection of the grooved sealing ring.

[0012] The invention also relates to an annular piston for slave cylinders of clutch actuation devices. This annular piston has an end region provided with at least one annular recess and at least one annular projection, located between a radial outer side of the annular piston and a radial inner side of the annular piston, which end region can be positively connected to an end region of a grooved sealing ring. The piston is characterized in that the annular piston has, in its end region, two radially spaced annular recesses, between which an annular projection is arranged, one of the recesses being arranged on the radial outer side of the annular piston and the other recess being arranged on the radial inner side of the annular piston.

[0013] The annular projection of the annular piston can widen conically toward its free end, for example, in the shape of a dovetail. In a modification of the annular piston, the annular projection can be divided by an annular groove into a radially outer projection and a radially inner projection. This modification facilitates demolding of the annular piston produced by casting.

[0014] Another subject of the invention is a grooved sealing ring for annular pistons of slave cylinders of clutch actuation devices. This grooved sealing ring has an end region provided with at least one annular recess and at least one annular projection, located between a radial outer side and a radial inner side of the grooved sealing ring, which end region can be positively connected to an end region of an annular piston. The grooved sealing ring is characterized in that the end region of the grooved sealing ring has two radially spaced annular projections, between which an annular recess is arranged, one of the projections being arranged on the radial outer side and the other projection on the radial inner side of the grooved sealing ring.

[0015] The features listed individually in the patent claims can be combined with one another in any technologically reasonable manner and can be supplemented by explanatory facts from the description and details from the figures, whereby further embodiments of the invention are shown.

[0016] The invention and the technical environment are explained in more detail below with reference to the figures. The figures show particularly preferred embodiments, to which the invention is not limited, however. It should be noted in particular that the figures, and in particular the proportions shown, are only schematic. Like reference numerals denote like objects. They show: Fig. 1 a partial section through the housing of a slave cylinder of a clutch actuation device with an arrangement of annular piston and grooved sealing ring which is axially displaceable in the annular space of the cylinder housing according to a first example, Fig. 2 a similar partial section through the housing of a slave cylinder of a clutch actuating device with a modified arrangement of annular piston and grooved sealing ring, axially displaceable in the annular space of the cylinder housing, according to a second example; and Fig. 3 a similar partial section through the housing of a slave cylinder of a clutch actuating device with a further modified arrangement of annular piston and grooved sealing ring according to a third example, which is axially displaceable in the annular space of the cylinder housing.

[0017] First, the Fig. 1 is described in more detail. The slave cylinder 1 of an actuating device (not shown in detail) of a clutch for motor vehicles, in particular a dual clutch, has an annular housing 2 in which an annular space 3 is located. The slave cylinder 1 has a geometric axis 4 which is surrounded by the housing 2. In the annular space 3 there is an axially displaceable arrangement consisting of an annular piston 5 and a grooved sealing ring 6 which is connected to the annular piston 5 without play. A seal carrier 7, which has a radially outer annular part 8 and a radially inner annular part 9, is arranged between the annular piston 5 and the grooved sealing ring 6.

[0018] The grooved sealing ring 6 has, in an end region facing the annular piston 5, an annular recess 10 which opens in the axial direction towards the annular piston 5 and is formed between two radially spaced, annular projections 11, 12 of the grooved sealing ring 6. The annular recess 10 in the grooved sealing ring 6 tapers conically symmetrically in the axial direction towards its opening. In an end region of the annular piston 5 facing the grooved sealing ring 6 there is an annular projection 13 which widens conically towards its free end. The annular projection 13 of the annular piston 5 and the annular recess 10 in the grooved sealing ring 6 have a complementary shape, and the annular projection 13 of the annular piston 5 engages positively in the annular recess 10 in the grooved sealing ring 6. The cross-sectional shape of the annular projection 13 of the annular piston 6 can be described as dovetail-shaped.

[0019] In the end region of the annular piston 5, on its radial outer side and on its radial inner side, there is an annular recess 14, 15 with a V-shaped cross section, wherein the radially outer recess 14 is partially delimited by the radially outer side wall of the projection 13 of the annular piston 5 and the radially inner recess 15 is partially delimited by the radially inner side wall of the projection 13 of the annular piston.

[0020] The radially outer annular projection 11 of the groove sealing ring 6 engages in the radially outer recess 14 in the annular piston 5, and the radially inner projection 12 of the groove sealing ring 6 engages in the radially inner recess 15 in the annular piston 5.

[0021] The radially outer ring part 8 of the seal carrier 7, which bears against the radially outer projection 11 of the grooved sealing ring 6, wedges the radially outer projection 11 with the annular piston 5, and the radially inner ring part 9 of the seal carrier 7, which bears against the radially inner projection 12 of the grooved sealing ring 6, wedges the radially inner projection 12 of the grooved sealing ring 6 with the annular piston 5. Both ring parts 8, 9 of the seal carrier 7 also bear against the annular piston 5.

[0022] The grooved sealing ring 6 has two V-shaped, spread sealing lips 16, 17, of which the radially outer sealing lip 16 rests against the radially outer inner wall of the housing 2, and the radially inner sealing lip 17 rests against the radially inner inner wall of the housing 2. Between the two sealing lips 16, 17 is an annular groove 19 that opens into a pressure chamber 20 connected to a hydraulic line (not shown). The annular piston 5 has an extension 18, via which it is connected in a known manner to the clutch actuation device (not shown), which can be, for example, the release bearing of a dual clutch.

[0023] With reference to Fig. A second example is described in section 2. It includes a modification of the Fig. 1 shown arrangement of ring piston and groove sealing ring, where in Fig. 2 the same reference numbers as in Fig. 1 for those parts of the modified arrangement which correspond to corresponding parts of the Fig. 1 are the same or similar.

[0024] Instead of a single projection 13 widening conically towards its free end, the Fig. 1 shown arrangement are in the Fig. 2, two annular projections 21, 22 are provided on the annular piston 5, each of the projections 21, 22 widening conically towards its respective free end. The two annular projections 21, 22 are radially spaced from one another by an annular groove 23. The radially outer projection 21 engages in a form-fitting manner in a complementarily shaped annular recess in the end region of the grooved sealing ring 6 facing the annular piston 5, and the radially inner projection 22 engages in a form-fitting manner in a complementarily shaped annular recess in the end region of the grooved sealing ring 6 facing the annular piston 5. The grooved sealing ring 6 has an annular projection 24 which is directed axially between the two annular projections 11 and 12 and which engages in a form-fitting manner in the annular groove 23 in the annular piston 5. The annular groove 23 and the further projection 24 each have parallel side walls.The seal carrier 7 is again located between the annular piston 5 and the grooved sealing ring 6 in the same way as in . Fig. 1 shown arrangement.

[0025] A third example is in Fig. 3, where Fig. 3 the same reference numbers as in Fig. 2 for those parts of the further modified arrangement which correspond to corresponding parts of the Fig. 2 are the same or similar.

[0026] The Fig. The arrangement of annular piston 5 and grooved sealing ring 6 shown in Figure 3 differs from that shown in Fig. 2 shown arrangement only in that the annular groove 23 of the Fig. 3, widens conically symmetrically towards its opening. The further projection 24 of the arrangement shown in Fig. 3 shown arrangement is to the annular groove 23 of the in Fig. 3 shown arrangement. Accordingly, the further projection 24 of the Fig. 3 shown arrangement conically symmetrical towards its free end. As a result, the projection 24 of the Fig. 3 shown arrangement into the annular groove 23 of the Fig. 3. The two projections 21, 22 of the Fig. 3, engage in complementary recesses in the groove sealing ring 6. Each of the projections 21, 22 has parallel side walls. However, they can also widen conically towards their free ends. Also in the arrangement shown in Fig. In the arrangement shown in Figure 3, the seal carrier 7 is arranged between the annular piston 5 and the grooved sealing ring 6. List of reference symbols 1 slave cylinder 2 housings 3 annular space 4 axis 5 ring pistons 6 Groove seal 7 Seal carrier 8 Radial outer ring part 9 Radial inner ring part 10 Annular recess 11 Annular projection 12 Annular projection 13 Annular projection 14 Annular recess 15 Annular recess 16 Sealing lip 17 Sealing lip 18 Extension 19 grooves 20 printing room 21 Radial outer projection 22 Radial inner projection 23 Ring groove 24 further lead

Claims

[1] Arrangement comprising annular piston (5) and grooved sealing ring (6) for slave cylinders of clutch actuating devices, wherein the annular piston (5) and the grooved sealing ring (6) have, in their axially mutually facing end regions, at least one pair consisting of an annular recess and a complementarily shaped annular projection which engages positively in the recess in order to hold the annular piston and the grooved sealing ring together without play, wherein the grooved sealing ring (6) has at least one annular recess (10) opening in the axial direction towards the annular piston (5), which is formed between two radially spaced annular projections (11, 12) of the grooved sealing ring (6) engaging in annular recesses (14, 15) in the annular piston (5), and an annular projection (13) of the annular piston which is complementarily shaped to the at least one annular recess (10) in the grooved sealing ring (6) (5) engages positively in the recess (10) in the groove sealing ring (6),, characterized by that an annular sealing ring carrier (7) is provided between the annular piston (5) and the grooved sealing ring (6) and the sealing ring carrier (7) is in contact with the annular projections (11, 12) of the grooved sealing ring (6) and the annular piston (5). [2] Arrangement according to claim 1, characterized by that the annular projection (13) of the annular piston (5) widens conically towards its free end. [3] Arrangement according to claim 1, characterized by that the annular projection (13) of the annular piston (5) is divided into two by an annular groove (23) opening towards the groove sealing ring (6) into a radially outer annular projection (21) and a radially inner annular projection (22), and a further annular projection (24) of the groove sealing ring (6) which is shaped complementarily to the annular groove (23) engages in the annular groove (23) in a form-fitting manner. [4] Arrangement according to claim 3, characterized bythat the annular groove (23) of the annular piston (5) and the further projection (24) of the groove sealing ring (6) each have parallel side walls. [5] Arrangement according to claim 3, characterized by that the annular groove (23) of the annular piston (5) widens conically towards its opening and the further projection (24) of the groove sealing ring (6) tapers conically towards its free end. [6] Arrangement according to one of claims 3 to 5, characterized by that the radially inner annular projection (22) and the radially outer annular projection (21) of the annular piston (5) each widen conically towards their respective free ends. [7] Arrangement according to claim 4, characterized by that the radially inner annular projection (22) and the radially outer projection (21) of the annular piston (5) each widen conically asymmetrically towards their respective free ends.

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