DE102019101437A1 - Slave cylinder for a clutch release mechanism - Google Patents

Abstract

The invention relates to a slave cylinder (1) for a clutch release mechanism, comprising a housing (10) in which an annular fluid chamber (18) is formed, and an annular piston (20) which is displaceably arranged in the fluid chamber (18), wherein the piston (20) consists of a sliding sleeve (22), a seal carrier (24) and a seal (26), characterized in that the seal carrier (24) is connected to the sliding sleeve (22) by an eccentric hook connection (30), which has play in the axial direction.

Description

The invention relates to a slave cylinder for a clutch release mechanism, having a housing in which an annular fluid chamber is formed, and an annular piston which is arranged displaceably in the fluid chamber, the piston consisting of a sliding sleeve, a seal carrier and a seal.

The slave cylinder serves to transfer a friction clutch in the drive train of a motor vehicle from the engaged, ie unactuated, position to the disengaged, ie actuated position. For this purpose, the fluid chamber is connected via a line to a master cylinder, in which an actuating force (for example from a clutch pedal) is converted into a fluid pressure.

The housing of the slave cylinder is usually attached to a clutch or transmission bell. When the pressure in the fluid chamber is increased, a release bearing attached to the piston is pressed against a diaphragm spring of the clutch, which can thereby be converted from a form closing the clutch into a form in which the clutch is open.

When the clutches are not actuated, slight vibrations can be exerted on the release bearing and from there on the piston. If the release bearing were rigidly connected to the seal via the sliding sleeve and the seal carrier, these vibrations would lead to the seal being moved in the axial direction within the housing. These frequent movements, even if they each have only a very small stroke, lead to increased wear on the seal.

The object of the invention is to provide a slave cylinder in which premature wear of the seal due to vibrations of the clutch and the release bearing is prevented.

To achieve this object, it is provided in a slave cylinder of the type mentioned at the outset that the seal carrier is connected to the sliding sleeve by an eccentric hook connection which is subject to play in the axial direction. The invention is based on the basic idea of providing an axial play between the seal carrier and the sliding sleeve, so that although the sliding sleeve moves when the release bearing vibrates, the seal carrier and thus the seal are not displaced in the axial direction. The eccentric hook connection has the particular advantage that it can be installed very simply by the sliding sleeve and the seal carrier being joined together outside the housing in a direction perpendicular to their central axes and then being pushed into the fluid chamber. In this state, the two components are guided at least on an inner sleeve of the housing, so that they can no longer move in the radial direction relative to one another. Accordingly, the hook connection can no longer be released. Although the hook connection is eccentric, i.e. it only extends over part of the circumference (or in other words: represents an imbalance), the sliding sleeve and the seal carrier are reliably locked together in the axial direction, since the maximum tensile loads on the hook connection are not so great than the uneven application of force could be a problem.

The hook connection preferably has at least one rigid hook which has an engagement section which extends in the radial direction and engages in a groove. The hook can be rigid, since it does not have to be deformed when the sliding sleeve is mounted on the seal carrier.

According to one embodiment of the invention, the hook connection has a single hook, which is designed concentrically around the central axis and extends around a maximum of 180 °. This shape of the hook ensures that the sliding sleeve and the seal carrier are automatically aligned relative to each other when they are assembled together.

If the hook connection has a circumferential groove, there is the advantage that the sliding sleeve and the seal carrier do not have to have a defined position in the circumferential direction relative to one another when they are assembled.

According to an alternative embodiment, it is provided that the hook connection has a plurality of individual hooks which are arranged at a distance from one another. This design is advantageous from a manufacturing point of view.

The hook connection can have several individual grooves that are assigned to the individual hooks. This can prevent the sliding sleeve and the seal carrier from rotating relative to one another in the assembled state.

In particular, three hooks can be provided, each of which has an inner guide surface which is flat, the two outer guide surfaces being parallel to one another. This makes it possible to manufacture the seal carrier and the sliding sleeve in an injection mold, which does not require a slide.

According to the invention, the at least one hook is arranged on the seal carrier and the at least one groove in the sliding sleeve. This makes it possible to design the sliding sleeve with a slightly smaller diameter, so that a support ring for the release bearing can be easily mounted on it.

According to the invention, the same material is used for the seal carrier and the sliding sleeve, in particular a rigid plastic, preferably PPA. This is possible because the sliding sleeve and the seal carrier do not have to be elastically deformed when they are assembled together.

The axial play of the eccentric hook connection is of the order of 0.2 to 0.5 mm, in particular approximately 0.3 mm. It has been found that even this slight play is sufficient to decouple the seal from vibrations of the clutch and the release bearing.

• - 1 einen Querschnitt durch einen Nehmerzylinder gemäß einer ersten Ausführungsform;
• - 2 das Detail X von 1, wobei das Spiel zwischen den Stirnflächen der Schiebehülse und des Dichtungsträgers zu sehen ist;
• - 3 das Detail von 2, wobei der Dichtungsträger gegen die Schiebehülse geschoben ist, sodass das Spiel zwischen den Stirnflächen der Schiebehülse und des Dichtungsträgers beseitigt ist;
• - 4 die Schiebehülse des Nehmerzylinders von 1 in einer ersten perspektivischen Ansicht;
• - 5 die Schiebehülse von 4 in einer zweiten perspektivischen Ansicht;
• - 6 den Dichtungsträger des Nehmerzylinders von 1 in einer ersten perspektivischen Ansicht;
• - 7 den Dichtungsträger von 6 in einer zweiten perspektivischen Ansicht;
• - 8 in einer Seitenansicht die Schiebehülse und den Dichtungsträger während der Montage;
• - 9 in einer perspektivischen Ansicht die Schiebehülse und den Dichtungsträger während der Montage;
• - 10 den montierten Kolben des Nehmerzylinders gemäß der ersten Ausführungsform;
• - 11 einen Querschnitt durch einen Nehmerzylinder gemäß einer zweiten Ausführungsform;
• - 12 das Detail X von 11, , wobei das Spiel zwischen den Stirnflächen der Schiebehülse und des Dichtungsträgers zu sehen ist;
• - 13 das Detail von 12, wobei der Dichtungsträger gegen die Schiebehülse geschoben ist, sodass das Spiel zwischen den Stirnflächen der Schiebehülse und des Dichtungsträgers beseitigt ist;
• - 14 die Schiebehülse des Nehmerzylinders von 11 in einer ersten perspektivischen Ansicht;
• - 15 die Schiebehülse von 14 in einer zweiten perspektivischen Ansicht;
• - 16 den Dichtungsträger des Nehmerzylinders von 11 in einer ersten perspektivischen Ansicht;
• - 17 den Dichtungsträger von 16 in einer zweiten perspektivischen Ansicht;
• - 18 in einer Seitenansicht die Schiebehülse und den Dichtungsträger während der Montage;
• - 19 in einer perspektivischen Ansicht die Schiebehülse und den Dichtungsträger während der Montage; und
• - 20 den montierten Kolben des Nehmerzylinders gemäß der zweiten Ausführungsform.

The invention is described below with reference to embodiments which are illustrated in the accompanying drawings. In these show:

• - 1 a cross section through a slave cylinder according to a first embodiment;
• - 2nd the detail X from 1 , wherein the game between the end faces of the sliding sleeve and the seal carrier can be seen;
• - 3rd the detail of 2nd , wherein the seal carrier is pushed against the sliding sleeve, so that the play between the end faces of the sliding sleeve and the seal carrier is eliminated;
• - 4th the sliding sleeve of the slave cylinder from 1 in a first perspective view;
• - 5 the sliding sleeve from 4th in a second perspective view;
• - 6 the seal carrier of the slave cylinder from 1 in a first perspective view;
• - 7 the seal carrier of 6 in a second perspective view;
• - 8th in a side view the sliding sleeve and the seal carrier during assembly;
• - 9 in a perspective view, the sliding sleeve and the seal carrier during assembly;
• - 10th the assembled piston of the slave cylinder according to the first embodiment;
• - 11 a cross section through a slave cylinder according to a second embodiment;
• - 12th the detail X from 11 ,, The game between the end faces of the sliding sleeve and the seal carrier can be seen;
• - 13 the detail of 12th , wherein the seal carrier is pushed against the sliding sleeve so that the play between the end faces of the sliding sleeve and the seal carrier is eliminated;
• - 14 the sliding sleeve of the slave cylinder from 11 in a first perspective view;
• - 15 the sliding sleeve from 14 in a second perspective view;
• - 16 the seal carrier of the slave cylinder from 11 in a first perspective view;
• - 17th the seal carrier of 16 in a second perspective view;
• - 18th in a side view the sliding sleeve and the seal carrier during assembly;
• - 19th in a perspective view, the sliding sleeve and the seal carrier during assembly; and
• - 20 the assembled piston of the slave cylinder according to the second embodiment.

In the 1 to 10th is a slave cylinder 1 shown according to a first embodiment. It is a central releaser with a central axis M.

The slave cylinder 1 has a housing 10th on that a mounting flange 12th , an inner sleeve 14 and an outer sleeve 16 having. Between the inner sleeve 14 and the outer sleeve 16 an annular space is formed, which is connected to a "floor" (in 1 on the right side) by the material of the housing 10th is closed. A piston is displaceable in the annular space 20 (please refer 10th ) arranged.

Thus the annular space constitutes an annular fluid chamber 18th represents, an access opening is not shown here. If the fluid chamber 18th is filled with fluid and the pressure in the fluid chamber is increased, the piston 20 to the left (related to 1 ) acted upon.

The fluid chamber can in particular be a hydraulic chamber, and in particular hydraulic fluid can be used as the fluid.

The housing is usually an injection molded part made of plastic.

The piston has a sliding sleeve 22 , a seal carrier 24th and a seal 26 on (see also 2nd ). The seal 26 seals the fluid chamber 18th and is in a circumferential groove on the seal carrier 24th clipped in. The seal carrier in turn is with the sliding sleeve 22 connected, and the sliding sleeve 22 carries on from the seal carrier 24th a release bearing on the opposite side 28 . The release bearing 28 has an outer ring 29 that can act on a diaphragm spring of a friction clutch.

The connection between the sliding sleeve 22 and the seal carrier 24th is subject to play in the axial direction, as in particular by comparing the 2nd and 3rd you can see. In 2nd are the sliding sleeve 22 and the seal carrier 24th shown in an "exploded" state in which a game S between the sliding sleeve 22 and the seal carrier 24th you can see. This state corresponds to the normal state when the clutch is not actuated. Small vibrations from the outer ring 29 of the release bearing 28 on the sliding sleeve 22 transmitted, cause the sliding sleeve 22 slightly further into the case 10th is pushed in or pulled out again. This little relative movement between the sliding sleeve 22 and the seal carrier, however, find "within" the game S instead of; the seal carrier 24th with the seal 26 is not shifted in the axial direction. As a result, these vibrations do not cause the seal to wear 26 .

In 3rd is the piston 20 shown in a state in which the clutch is actuated and consequently the seal 26 and the seal carrier 24th to the left in the axial direction. It can be seen that there is no more play between the seal carrier 24th and the sliding sleeve 22 is present and accordingly the sliding sleeve is pushed from the seal carrier to the left.

The play in the axial direction is of the order of maximum 0.5 mm. A common value is 0.3 mm.

The sliding sleeve 22 and the seal carrier 24th are in the axial direction by means of an eccentric hook connection 30th connected with each other. This will be explained in particular using the 4th to 7 explained.

The sliding sleeve 22 has four grooves 32 on, each have a flat bottom and are aligned at an angle of 90 ° relative to each other. Accordingly, the bottom of each groove 32 at an angle of 90 ° to the bottom of the adjacent groove 32 aligned.

In the area of each groove 32 is the front wall 34 the sliding sleeve 22 each with a flattening 36 provided so that the groove 32 , viewed from the side of the seal carrier 24th , represents an undercut with constant depth.

Although only three grooves 32 needed to make the hook connection is the sliding sleeve 22 with four grooves 32 Mistake. This facilitates assembly since there is more than one relative position in which the hook connection can be made.

The seal carrier 24th is with three hooks 40 provided, which are arranged in the circumferential direction at an angular distance of 90 ° to each other. Every hook 40 is designed so that it fits into one of the grooves 32 the sliding sleeve 22 with an engagement section extending in the radial direction 41 can engage, with each hook an internal guide surface 42 which is flat and flattened 36 the front wall 34 the sliding sleeve 22 opposite.

The hook connection 30th is eccentric because of the hook 40 not evenly along the circumference of the seal carrier 24th are distributed, but are in a sector that extends over 180 ° (if you click on the center of the hook 40 turns off). The guide surfaces of the two opposing hooks 40 are aligned parallel to each other.

Since the hook connection is eccentric, the sliding sleeve can 22 and the seal carrier 24th are assembled to each other by pushing the sliding sleeve from the side of the "missing" hook into the three hooks 40 is inserted. This is in the 8th and 9 to see, the in 8th drawn arrows represent the relative movement. By moving in the radial direction, the in 10th shown state reached, in which the sliding sleeve 22 using the three hooks 40 in the axial direction with the seal carrier 24th paired (including the game S ).

In the in 10th shown state is the piston 20 in the housing 10th inserted, then the sliding sleeve 22 and the seal carrier 24th on the inner sleeve 14 be guided and centered. This prevents them from being able to move relative to one another in the radial direction, which means the hook connection 30th would be solved again.

Because the hook 40 do not need to be elastically deformed when the sliding sleeve 22 and the seal carrier 24th assembled to each other, the two components can be rigid. For example, PPA can be used as the material.

In the 11 to 20 a second embodiment is shown. The same reference numerals are used for the components known from the first embodiment, and reference is made to the above explanations in this regard.

The main difference between the first and the second embodiment is that in the second embodiment a single hook 40 is used, which is curved and extends over a range of about 180 °. There is a circumferential groove on the side of the sliding sleeve 32 used, the bottom of which is annular.

Because the catch 40 only on one half of the face of the seal carrier 24th is the hook connection 30th eccentric.

The assembly of sliding sleeve 22 and seal carrier 24th to each other is done in the same manner as in the first embodiment (see the 18th and 19th ). In contrast to the first embodiment, no specific positioning of the sliding sleeve in the circumferential direction has to be maintained in the second embodiment in order to catch the hook 40 to allow in the groove 32 intervene.

The sliding sleeve is also used in the second embodiment 22 and the seal carrier 24th secured to each other once they are on the inner sleeve 14 are arranged.

Claims (10)

Slave cylinder (1) for a clutch release mechanism, comprising a housing (10) in which an annular fluid chamber (18) is formed, and an annular piston (20) which is slidably arranged in the fluid chamber (18), the piston (20 ) consists of a sliding sleeve (22), a seal carrier (24) and a seal (26), characterized in that the seal carrier (24) is connected to the sliding sleeve (22) by an eccentric hook connection (30) in the axial direction is playful. Slave cylinder after Claim 1 , characterized in that the hook connection (30) has at least one rigid hook (40) which has an engagement section (41) which extends in the radial direction and engages in a groove (32). Slave cylinder after Claim 1 or Claim 2 , characterized in that the hook connection (30) has a single hook (40), which is designed concentrically around the central axis (M) and extends by max. 180 ° circumferential. Slave cylinder after Claim 3 , characterized in that the hook connection (30) has a circumferential groove (32). Slave cylinder after Claim 1 or Claim 2 , characterized in that the hook connection (30) has a plurality of individual hooks (40) which are arranged at a distance from one another. Slave cylinder after Claim 5 , characterized in that the hook connection (30) has a plurality of individual grooves (32) which are assigned to the individual hooks (40). Slave cylinder after Claim 5 or Claim 6 , characterized in that three hooks (40) are provided, each having an inner guide surface (42) which is flat, the two outer guide surfaces (42) being parallel to one another. Slave cylinder according to one of the preceding claims, characterized in that the at least one hook (40) is arranged on the seal carrier (24) and the at least one groove (32) in the sliding sleeve (22). Slave cylinder according to one of the preceding claims, characterized in that the same material is used for the seal carrier (24) and the sliding sleeve (22), in particular a rigid plastic, preferably PPA. Slave cylinder according to one of the preceding claims, characterized in that the play (S), viewed in the axial direction, is of the order of magnitude of 0.2 to 0.5 mm, in particular approximately 0.3 mm.

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