WO2017050330A1

WO2017050330A1 - Clutch transmitter with radially nested seals, (double) clutch with clutch transmitter, and powertrain

Info

Publication number: WO2017050330A1
Application number: PCT/DE2016/200424
Authority: WO
Inventors: Julien Oster; Thomas Niesen; Jérémy Keller; Kirill PROKHOROV
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2015-09-25
Filing date: 2016-09-07
Publication date: 2017-03-30
Also published as: EP3353443A1; DE102016216987A1; DE112016004328A5; CN108026985A; CN108026985B

Abstract

The invention relates to a clutch transmitter (1) for a clutch of a motor vehicle, comprising a piston (5) which can be attached to a mechanical actuating element (2) and which is mounted in a housing (6) in an at least axially movable manner back and forth. The piston (5) adjoins a high-pressure chamber (7) with a size that is changed by the piston upon moving. Two seals (10) are provided between the piston (5) and the housing (6). One seal seals the high pressure chamber (7) provided for receiving hydraulic fluid in a fluid-tight manner as a primary seal (11), and the one seal (10) is arranged radially within the other seal (10). The invention also relates to a clutch comprising such a clutch transmitter (1).

Description

Clutch sender with radially nested seals, (double) clutch with clutch sender and drive train

The invention relates to a clutch transmitter for a (double / single) clutch of a motor vehicle, such as a car, a truck or other commercial vehicle, with an attachable to a mechanical actuator piston, at least axially movable in a housing back and is mounted movable, wherein the piston adjoins a size-changing during movement of the high-pressure chamber, further between the piston and the housing preferably two separate voneinan- separate seals are present, one of which as a primary seal the high pressure chamber prepared for receiving hydraulic fluid seals fluid-tight.

Different hydraulic clutch master cylinders (CMC, clutch master cylinder) for conventional disengagement systems are already known from the prior art. In this area, the invention is to settle. In particular, in the partial region of the seal assembly, the invention is.

According to the current state of the art, clutch master cylinder or clutch master can be divided into two categories, namely in such coupling, in which seals are mounted in the housing, so standing seals are used, and on the other hand, those in which the seals are arranged relatively movable, eg. are fixed to the piston.

From DE 103 27 437 A1, for example, a hydraulic system with upright seals is known. The system disclosed therein comprises a master cylinder with a housing and a piston arranged axially displaceably in it. The piston limits a filled with a hydraulic fluid pressure chamber. Upon actuation of the master cylinder by means of a piston rod acting on the piston, the piston is displaced axially, whereby the hydraulic fluid is pressurized. Between the housing and the piston at least one sealant is arranged. There is a slave cylinder and a pressure medium line connecting the individual areas. As particularly disclosed in this earlier patent application that the piston is made of a thermosetting plastic. Furthermore, two seals are used, which are mounted in the housing. On the one hand a primary seal and on the other hand a secondary seal is used. The primary seal and the secondary seal are arranged in a substantially cylindrical rear housing part of the housing.

A characteristic of a sender with standing seals is that the seals are fixed on the housing, i. are attached. A sealing lip of the respective seal is in contact with the moving piston and is stuck when the CMC is actuated. Since the piston is made of materials that are optimized for sliding and noise, usually made of a polymer material such as duroplastic, this type of master cylinder shows extremely favorable behavior in terms of friction and noise.

In particular, such an optimized piston material allows the use of, for example, ethylene-propylene-diene rubber (EPDM) as the sealing material. Although moderate in terms of noise and friction, this material offers advantages in terms of media compatibility with different fluids, such as different brake fluids.

In addition to encoders with permanently mounted seals in the housing, encoders with moving seals are also known. Characteristic for a transmitter with moving seals here is that the seals are fixed / fastened on the piston. Their sealing lips are in contact with the housing and move along the housing wall when the CMC is actuated with the piston and seal dynamically to the environment. It is advantageous to use the two seals differently, namely as a primary and secondary seal.

This arrangement of a primary seal has the great advantage that reduces the pressurized surface of the housing during actuation. This allows the CMC to realize a low volume uptake. Also, such a clutch encoder / clutch master cylinder is inexpensive to produce. Furthermore, a resulting from the internal pressure occurring in the high-pressure chamber expansion of the housing during operation is minimized, since the high-pressure space reduced by the retraction of the piston into the housing and the movable primary seal is tracked, whereby a smaller and smaller area of the housing is exposed to the high internal pressure. This is basically understood by a low volume intake. In addition to the disadvantages mentioned, however, the existing two concepts also have other disadvantages. Thus, the type with upright seals, so with seals that are set in the housing, just the disadvantage of a high volume consumption. During the actuation of the piston, that area which is subjected to high pressure from the inside does not just decrease, as is the case with the second concept, that is, the concept with movable seals. Due to the seal arrangement, the entire pressure chamber of the housing remains under pressure over the entire stroke, which leads to a higher volume intake of the master cylinder.

But also the donors with moving seals have disadvantages, especially in terms of media compatibility over the life cycle of the product. Also, an incompatibility with various brake fluids and their components is observed, which leads to the fact that it comes to leaks in the system over time. In addition, depending on the brake fluid, this type of master cylinder tends to generate a high level of noise and, in particular, squeaking noises occur due to stick-slip effects.

However, it is the object of the present invention to avoid the disadvantages of both systems and to combine their advantages. In particular, a good media compatibility with low noise is to be achieved. Also, a clutch encoder should be inexpensive to produce and remain tight over a long life.

The aim of the new development is, inter alia, to develop a novel sealing arrangement that limits the noise level upwards, ensures the sealing function with different brake fluids over the lifetime, especially in terms of media compatibility, and ensures low volume consumption. It could also be briefly summarized that the advantages of the two known solutions, without combining the known disadvantages is the goal, in particular a robust one Design with low noise emission at the same time, high media compatibility and low volume consumption at the same time.

This object is achieved in a generic device according to the invention by the fact that one seal is arranged radially within the other seal.

Advantageous embodiments are claimed in the subclaims and are explained in more detail below.

So it is advantageous if one seal is the primary seal and the other seal is formed as a secondary seal. The secondary seal is not designed to seal against high pressure, but only to seal against low pressure, such as ambient (air) pressure +/- (15% to) 20% designed / prepared / dimensioned. In this way, a particularly dense system can be achieved and leakage can be avoided.

In order to achieve a well-functioning system, it is advantageous if the primary seal and / or the secondary seal on the one hand in contact with the housing and on the other hand in contact with the piston stand / stand. A compact system can be achieved.

In order to integrate the advantages of upright seals, it is advantageous if the primary seal and / or the secondary seal are fixedly mounted on the housing and slidably abut the surface of the piston, such as with (each) a sealing lip ,

For the overall structure, it is beneficial if the two seals are arranged concentrically to each other. It is also advantageous if the housing and the piston, and a closure sleeve are arranged concentrically in addition to the two seals, in particular to these seals are arranged concentrically. An advantageous embodiment is also characterized in that the piston is designed as an annular piston with an inner surface and an outer circumferential surface, wherein one of the seals on the inner surface and one of the seals on the outer circumferential surface sealingly abuts, such as with an elastic sealing lip or a Dichtkuppe.

For the fatigue strength, it is beneficial if the primary seal is made of a reinforcement of the sealing material in comparison less elastic material, such as metal or plastic, held in the form and / or position. The elastic mate- rial of the primary seal can be positively and / or non-positively attached to the reinforcement.

It is expedient if the piston is guided to be retractable in a secondary space formed by a double wall of the housing. Such a clutch encoder then builds particularly short in the axial direction.

In order to keep manufacturing costs low, it is advantageous if the piston is made of plastic, such as a thermoset, molded / formed / procured. In particular, a tough or less brittle material can be used, or a treatment of the piston to make the piston less brittle.

If the high-pressure space is formed / arranged / defined within the piston, the internal pressure acting on the housing can be reduced. The lifetime increases among other things.

Further, it is advantageous if the high-pressure chamber on the one hand by a wall and a bottom of the piston and on the other hand by a plug and / or the housing, and the primary seal is completed / limited. It is expedient if the wall / wall has a constant thickness in the axial direction and / or in the circumferential direction. An advantageous exemplary embodiment is characterized in that the high-pressure space is arranged / positioned between a secondary pressure area or a fluid outlet and the actuating element. In order to use the space optimally, it is advantageous if, in the actuated state of the clutch transmitter, the high-pressure chamber is present or arranged predominantly or completely (almost) within the housing.

Bleeding and filling / topping up can be reached skilfully if a secondary suction and bleeding pipe leads away / goes off / branches off from the secondary pressure area.

An efficient interaction of the individual components can be achieved if the high-pressure chamber is in fluid communication with the fluid outlet.

If a pre-pressure valve is arranged in the fluid outlet, then vibrations can be efficiently damped.

It is advantageous if the admission pressure valve is designed as an "anti-vibration unit" (AVU) or "tingling filter", different from a peak torque limiter (PTL), in order to dampen vibrations.

The invention ultimately also relates to a clutch, such as a single or double clutch for a drive train of a motor vehicle, with a clutch transmitter according to the invention.

In the foreground of the invention therefore is a seal assembly in the master cylinder. The construction of the CMC is based on two main features. On the one hand, the two seals, ie the primary seal and the secondary seal, are installed vertically and concentrically in the housing. In particular, they are concentric with each other and arranged to the piston and the housing. The primary seal sits in the interior of the piston and seals the high-pressure chamber. The secondary seal contacts the outer surface of the piston and seals against the environment. Furthermore, the piston is designed as an annular piston and consists of sliding and friction-optimized material, for example. Plastic such as thermosetting plastic. The inner area acts as a "moving" pressure chamber and seals against the high pressure with the aid of the primary seal, which allows for low volume absorption Leakage of the operating medium, such as a brake fluid, to the outside, especially in the environment, is avoided.

The design has the following features:

The piston is designed as an annular piston. The interior of the piston serves as a high pressure space, i. The piston is loaded from the inside to pressure. The outside area is used as a contact surface for the secondary seal. The seal is guided through a reinforcement and centered. This has the advantage that the piston moves backlash to the primary seal.

The primary seal sits statically in / on the housing. The dynamic side / sealing lip of the seal seals against the piston. The secondary seal also sits statically in / on the housing and concentric with the primary seal.

With the help of this seal design and the material used, a robust, brake fluid-resistant and low-noise generating master cylinder is provided, the volume of which remains at a low level.

In other words, in the present invention, the advantages of the standing seals, which are so firmly in the housing, and those of the moving seals, so those that move on the piston, united, to the resulting noise in the operation of the encoder to reduce. Also, disadvantages in terms of life of the seals are reduced. In summary, therefore, a piston is provided which is designed as an annular piston. This piston is made of duroplastic. The primary seal sits on a housing extension located inside the ring piston. The secondary seal is located concentrically outside the primary seal within the housing and seals towards the piston. The interior of the piston thus serves as a movable pressure chamber. A noise-optimized slave cylinder with concentric primary and secondary seal is the result.

The invention will be explained in more detail with the aid of a drawing. Two different embodiments are shown. Show it:

Fig. 1 shows a coupling sensor according to the invention in only partially gezeem

Longitudinal section, wherein the piston is in an unactuated state, Fig. 2 shows the clutch transmitter of Fig. 1, but with the piston actuated in one

Position, ie the CMC is in the actuated state,

Fig. 3 shows a variant of a clutch sender, with inserted pre-pressure valve / anti-vibration unit (AVU) / Kribbelfilter, and

4 shows an enlargement of the region IV from FIG. 3.

The figures are in part merely schematic in nature and are only for understanding the invention. The figures relate to longitudinal sections, ie those sections which run along the longitudinal axis through the coupling transmitter, in particular along a rotation axis through the piston. Identical elements are provided with the same reference numerals. The features of the individual embodiments can also be combined with each other. So they are interchangeable.

In Fig. 1, an inventive coupling sensor 1 is shown. The clutch encoder 1 is used in a single or double clutch. It is for use in a motor vehicle, such as a car, a truck or other commercial vehicle intended. The clutch encoder 1 is connected to a mechanical actuator 2, such as a rod 3. The rod 3 is surrounded by a bellows 4. The rod 3 is connected to a piston 5. The piston 5 is mounted axially movable in a housing 6. Inside the piston 5, a high-pressure chamber 7 is present.

The piston 5 is designed as an annular piston and has a bottom 8 and a cylindrical wall 9. Between the piston 5 and the housing 6, two seals 10 are present. The one seal 10 is a primary seal 1 1. The other seal 10 is a secondary seal 12. The primary seal 1 1 is made of elastic material, as well as the secondary seal 12. For the two seals 10, the same material can be used. At least the primary seal 1 1 is flanked by a reinforcement 13 and supported.

The high pressure space 7 is filled with hydraulic fluid, such as a liquid, such as oil, in particular mineral oil or a brake fluid. The clutch transmitter 1 can also be referred to as a brake transmitter. Of course, the use as a clutch or brake is possible.

The piston is surrounded by a closure sleeve 14. The closure sleeve 14 engages in an undercut region 15 of the housing 6. A collar 16 of the closure sleeve 14 engages behind the undercut region 15 or engages in this. The housing 6 has a double wall region 17. The double wall region 17 is formed as a nozzle 18, in which the piston 5 end facing a through hole 19 is introduced, in which a plug 20 is inserted. The plug 20 in turn has a passage opening 21. Through this passage opening 21, high-pressure fluid can pass through and cause an adjusting movement of another component.

The housing 6 with the nozzle 18 defines an annular gap region 22 which is in fluid communication with a suction and vent pipe 23. The two seals 10 each have sealing lips 24. The annular gap region 22 also defines a secondary pressure region 25. While the piston 5 is made of duroplastic, the housing is made of polyamide, in particular of PA66 with or without a glass fiber reinforcement. When using a glass fiber reinforcement, the weight percentage is 35% or 43%. From the same or similar material, the closure sleeve 14 is made. There are also retaining clips used.

While in FIG. 1 the piston 5 is still maximally removed from an outlet-side end of the housing 6, it is approached significantly closer in FIG. 2, and shown in the maximum retracted position. The high-pressure chamber 7 in the actuated state is thus substantially smaller than the high-pressure chamber 7 in the unactuated state. In forming the high-pressure space 7 within the annular piston, the internal pressure load of the housing 6 is greatly reduced and lowered (almost) to zero.

The use of a prefilter / Kribbelfilters / anti-vibration unit (AVU) 26 between see the outlet end of the housing 6 and the piston 5 is shown in Figs. 3 and 4 shown. Although there is no more plug 20 available, but additionally usable. This component acts as a damper element that dampens vibrations 6.

The thickness of the wall 9 of the piston 5 is marked with the reference numeral 27. The thickness is constant in the axial and radial directions. In the Fign. 3 and 4, the fluid outlet is also marked with the reference numeral 28.

List of references Clutch transmitter

actuator

pole

bellow

piston

casing

High-pressure chamber

ground

wall

poetry

primary seal

secondary seal

reinforcement

closing sleeve

Undercut region

collar

Doppelwandungsbereich

Support

Through Hole

Plug

Through opening

Ring gap region

Suction and vent pipe

sealing lip

Secondary pressure area / Secondary pressure chamber Pre-pressure valve / AVU / Kribbelfilter

thickness

fluid outlet

Claims

claims

1 . Clutch sender (1) for a clutch of a motor vehicle, with a piston (5) which can be attached to a mechanical adjusting element (2), which is mounted so that it can move back and forth in a housing (6) at least in an axially movable manner, the piston (5) being attached to this during movement, size-changing high-pressure chamber (7) is adjacent, wherein between the piston (5) and the housing (6) two seals (10) are present, of which as a primary seal (1 1) the prepared for receiving hydraulic fluid high-pressure chamber (7) fluid-tight seals, characterized in that the one seal (10) is arranged radially within the other seal (10).

Second clutch transmitter (1) according to claim 1, characterized in that the one seal (10) is the primary seal (1 1) and the other seal (10) as a secondary seal (12) is formed.

3. clutch transmitter (1) according to claim 1 and / or 2, characterized in that the primary seal (1 1) and / or the secondary seal (12) on the one hand in contact with the housing (6) and on the other hand in contact with the piston (5 ) stands / stand.

4. clutch transmitter (1) according to one of claims 1 to 3, characterized in that the primary seal (1 1) and / or the secondary seal (12) fixed to the housing (6) is / are mounted and on the surface of the piston (5 ) Slidably abuts / abut.

5. clutch transmitter (1) according to one of claims 1 to 4, characterized in that the two seals (10) are arranged concentrically to each other.

6. clutch transmitter (1) according to one of claims 1 to 5, characterized in that the piston (5) is designed as an annular piston with an inner surface and an outer circumferential surface, wherein one of the seals (10) on the inner surface and one of the seals (10 ) sealingly abuts against the outer circumferential surface.

7. clutch transmitter (1) according to one of claims 1 to 6, characterized in that the primary seal (1 1) of a reinforcement (13) is held to her in comparison less elastic material in the form and / or position.

8. clutch transmitter (1) according to one of claims 1 to 7, characterized in that the piston (5) in a through a double wall of the housing (6) formed secondary pressure region (25) is guided retractable.

9. clutch transmitter (1) according to one of claims 1 to 8, characterized in that the piston (5) is formed of plastic.

10. Coupling for a drive train of a motor vehicle, with a coupling transmitter (1) according to one of the preceding claims.