WO2007137939A1

WO2007137939A1 - Clutch release bearing comprising an adjusting ring

Info

Publication number: WO2007137939A1
Application number: PCT/EP2007/054688
Authority: WO
Inventors: Ludwig Winkelmann
Original assignee: Schaeffler Kg
Priority date: 2006-05-26
Filing date: 2007-05-15
Publication date: 2007-12-06
Also published as: BRPI0711746A8; BRPI0711746A2; DE102006024486A1

Abstract

The invention relates to a clutch release bearing (1, 25) which comprises an adjusting ring (2, 26), a non-rotating bearing ring (4), a rotating bearing ring (3) and rolling elements (5) between the bearing rings (3, 4). The invention is characterized in that the rotating bearing ring (3) rotates in relation to the non-rotating bearing ring (4) about an imaginary axis of rotation (7, 27) of the clutch release bearing (1, 25), the adjusting ring (2, 26) is associated with a first concave section (8, 29), the rotating bearing ring (3) is associated with a second concave section (10, 31), the second concave section (10, 31) is in contact (9, 33) with the first concave section (8, 29), the concave sections (8, 10), in the point of contact (9, 33), have matching geometrical shapes, the rotating bearing ring (3) is pivotally supported on the first concave section (8, 29) in the point of contact (9, 33), the rotating bearing ring (3) and the adjusting ring (2, 26) both rotate about the axis of rotation (7, 27) and the contact (9) has a sliding layer between the concave sections (8, 10).

Description

Name of the invention

Clutch release bearing with an adjustment ring

description

Field of the invention

The invention relates to a clutch release bearing with an adjusting ring, with a non-rotating bearing ring, with a rotating bearing ring and with rolling elements between the bearing rings, wherein

the rotating bearing ring rotates relative to the non-rotating bearing ring about an imaginary rotational axis of the clutch release bearing,

the adjustment ring is assigned a first dome section,

the rotating bearing ring is assigned a second calotte section,

the second dome portion in contact with the first

Is calotte section,

the dome sections in contact correspond geometrically with each other,

the rotating bearing ring is pivotally supported on the first calotte section on the contact, the rotating bearing ring and the adjusting ring rotate together about the axis of rotation and the contact has a sliding layer between the Kalottenabschnitten.

Background of the invention

Such a clutch release bearing is described in EP 1 647 731 A2. The adjusting ring has on the surface of an outwardly curved Kugelkalottenabschnitts on a sliding coating made of plastic. The dome portion on the adjusting ring engages in an inwardly curved dome portion on the inner ring. The inner shape of the concave Kalottenabschnitts on the inner ring corresponds to the convex outer shape of the Kalottenabschnitts on the adjustment, so that the inner ring to the outer ring is pivotally articulated.

A sliding coating between the Kalottenabschnitten reduces the friction during normal operation significantly, but is for continuous operation, especially in transmissions with dual clutch at operating temperatures above 180 ⁰ C and short-term temperature intervals up to 220 ⁰ C prone or not suitable. A designed on the life of the clutch layer of plastic must be relatively thick walls due to the low wear resistance and the lubricating properties and the resulting erosion, especially when the articulated compound runs almost or completely unlubricated dry. Thick-walled plastic layers, however, adversely affect the stiffness of the axially loaded with release forces Kupplungsausrücklagers and require relatively much axial space.

Summary of the invention

The object of the invention is therefore to provide a self-adjusting clutch release bearing, which meets the requirements of low axial space, high axial load, dry running and the requirements for operation at high operating temperatures. This object is achieved according to the characterizing part of claim 1, characterized in that the sliding layer is formed on a sintered material.

Sintered materials are pulverulent or fine-grained substances or mixtures of pulverized substances which are produced by pressure and temperatures below the melting point by sintering = compression. The starting materials of the sintered component or the sintered layer are metal powders or non-metallic starting materials such as ceramics. The materials are sometimes very hard mixtures of metals and oxides, carbides or borides. Sinteraluminum, for example, contains finely divided oxide and is used because of its higher heat resistance for thermally stressed parts.

Important properties of the sintered material include not only the strength, but also the density and pore size. Pores are small open to the surface chambers or cavities in the material, which are networked together depending on the design of the material. The associated material property is the porosity, the ratio of the volume of all cavities .DELTA.V of a porous solid to its outer volume V. It is therefore a measure of how much space fills the actual solid due to its grain size or solid structure within a certain volume or which cavities it has in this. The pores are usually filled with air or, as provided by one embodiment of the invention, at least partially or completely filled with lubricants and / or lubricants, at least in the surface layer. The pore volume represents, in addition to the degree of crosslinking of the pores, the most important factor of the permeability (permeability) or partial permeability. The porosity is usually denoted by the formula letter Φ and in percent Φ = (ΔV: V) ^x 100 or as fraction (fractions of 1 =% / 100) and.

As a contact is the area, the area, are the surface portions and in the worst case, the line sections are to be understood, at which the two Kalottenabschnitte abut each other, slide against each other or act in any other way. An example of a sinterable material which can be used for the invention is a material of the designation "Sint - C10" made of steel with a mass fraction of approximately 1.5% copper and with a porosity of 15 +/- 2.5%, which has a density of about 6.4 to 6, 8 g / cm ³ .

The clutch release bearing according to the invention can form a layer on either the inwardly curved and / or, as one embodiment of the invention, at the edge of the outwardly curved first dome portion at least in the region in contact with the dome portion inwardly curved made of sintered material. Alternatively, one or both are dome sections or quite partially made of sintered material. Alternatively, a one-piece made of sintered material adjustment ring is provided. Sintered parts can be produced very accurately, so that in the last-mentioned case, machining of a setting ring produced by sintering can be dispensed with.

Embodiments of the invention provide that at least the porous and at least partially permeable surface of the sintered material is impregnated, filled or impregnated at the contact with lubricants. The lubricants are liquid or solid. Lubricants are, for example, synthetic oils with working ranges at operating temperatures up to 250 ° or graphite, lubricants with emergency running properties such as copper, brass or bronze. It is also conceivable that the sintered material itself contains these solid lubricants such as graphite. The oils are stored in the pores of the material and are discharged into the contact during operation by leakage or by elastic deformations by pressure from actuating forces to the surface.

A further embodiment of the invention provides that a sliding material is integrated into the pores of the edge layer of at least one, in particular of the dome section on the adjusting ring. This sliding material is preferably a plastic with sliding properties, such as polytetrafluoroethylene (PTFE). The plastic will expand at operating temperatures and / or in contact swell with lubricants and thus pressed into the frictional contact there as a sliding material to reduce the friction between the friction partners.

The advantage of the invention lies in the fact that the friction-reducing de or sliding-promoting arrangement hardly takes up axial space, since the lubricants or lubricants are stored for the most part in the pores of one of the Kalottenabschnitte and not applied as a layer on the surface. The stiffness of the clutch release bearing at high loads is not affected by this arrangement. The friction-reducing measures are very resistant to high temperatures, since lubricating and / or sliding materials can be selected due to the thin sliding film in frictional contact for the temperature resistance and not for mechanical strength properties.

With a further embodiment of the invention it is provided that either the sintered material of the Kalottenabschnitts or only the surface of the Kalottenabschnitts of sintered bronze, preferably with sintered bronze balls. Conceivable is the use of sintered bronzes or graphite-containing sintered bronzes with densities of 6.0 to 7.7 g / cm ³ and with porosities of 15 to 25 +/- 2.5%, for example, the material designation A50 (A51), B50 (B51) or C50 (C51).

In the case where a layer of sintered bronze is applied, the substrate is either steel or another sintered material. On steel, the sintered layer is pressed on, rolled, rolled or applied in a materially cohesive manner. The two-component sintered material is preferably produced by sintering. Polytetrafluoroethylene (PTFE) is preferably integrated in the pores of the sintered bronze. The layer thicknesses of the sintered bronze layer according to the invention, are about 0.2 to 0.35, preferably 0.3 mm thick, therefore require little axial space, thus have little effect on the axial stiffness of the clutch release bearing and are temperature resistant.

Brief description of the drawings The invention will be explained in more detail with reference to embodiments. Show it:

1 shows a clutch release bearing in a longitudinal section along the axis of rotation of the clutch release bearing,

Figure 2 is a greatly enlarged partial view of the adjustment of the

Clutch release bearing according to FIG. 1 in the same longitudinal section,

3 is a simplified representation of the structure of a sliding layer on the edge of the sliding layer of the adjusting ring of FIG. 2, in which the longitudinal section is greatly enlarged and not to scale.

Figure 4 shows the simplified representation of the structure of an alternative to Figure 3 edge layer of an adjustment ring of Figure 2, in the longitudinal section greatly enlarged and not to scale and

Figure 5 shows a further clutch release bearing in a longitudinal section along the axis of rotation of the clutch release bearing.

Detailed description of the drawing

1 shows a clutch release bearing 1 with an adjusting ring 2, a rotating bearing ring 3 and a non-rotating bearing ring 4. The rotating bearing ring 3 is an inner bearing ring 21 which acts via the adjusting ring on a clutch spring, not shown, and this together with the adjustment ring 2 is rotated about the axis of rotation 7. The non-rotating bearing ring 4 is an outer bearing ring 22, acting on the release elements not shown axially. Between the trained as Schrägschulterringen bearing rings 3 and 4 rolling elements 5 are arranged. The rolling elements 5 are in a cage. 6 held.

In the ideal state, the axis of rotation 7 of the clutch release bearing 1 and the center axis 19 of the adjusting ring 2 or the axis of rotation 7 of the bearing are concentric with one another. In constructional offset of clutch and release bearing 1, however, these can be inclined to each other by angle α. This inclination is compensated by means of the articulated interaction of the rotating bearing ring 3 with the adjusting ring 2. For this purpose, the adjusting ring 2 a Kalottenabschnitt 8, which is in one piece - in this case - formed einmaterialig with the Einstellring 2. The surface of the dome section 8 is convexly curved and engages in a corresponding concave dome section 10 on the rotating bearing ring 3 and is pivotable on the contact 9 = at the contact zone to this. The concave calotte section 10 is formed in one piece with the rotating bearing ring 3 and can also be formed separately from it on a support ring of the rotating bearing ring 3.

FIG. 2 shows a detail of the item adjusting ring 2, whose main body 11 is made of either steel or alternatively a sintered material, e.g. made of sintered steel. The edge layer 12 of the adjusting ring 2, which is curved on the outside in the manner of a spherical segment with the dome section 8, is made of a sintered material at least in the contact zone with the dome section 10. The pores 13 and 15 of the sintered materials 16 and 18 are, as shown with the embodiments of Figures 3 and 4, partially formed directly on the surface 14 of the Kalottenabschnitts 8 and opened to the outside or are cavities 20 under the surface 14th

The pores 13 in the sintered material 16 according to FIG. 3 are partially crosslinked with one another and filled with plastic, for example with PTFE. The sintered material 16 is in this case, for example, sintered bronze on the carrier material / the base body 17 made of sintered steel or steel.

In the pores 15 of the embodiment of Figure 4 are in the edge layer of the adjusting ring 2 of the sintered material 18 made of steel, for example with a synthetic oil or oil filled with fluoride additives.

Figure 5 shows another embodiment of a clutch release bearing 25 with an adjustment ring 26, a rotating bearing ring 3 and a non-rotating bearing ring 4. The rotating bearing ring 3 is an outer bearing ring 23 which acts via the adjusting ring 26 on a clutch spring, not shown, and in common with this rotated with the adjusting ring 26 about the rotation axis 27. The non-rotating bearing ring 4 is an inner bearing ring 24, acting on the not further shown release elements, such as a piston of a hydraulic release device axially. Between the trained as Schrägschulterringen bearing rings 3 and 4 rolling elements 5 are arranged. The rolling elements 5 are held in a cage 6.

In the ideal state, the axis of rotation 27 of the clutch release bearing 25 and the center axis 28 of the adjusting ring 26 or the axis of rotation 27 are concentric with each other. In constructional offset of clutch and release bearing 25, however, they can be inclined to each other by angle α. This inclination is compensated for by means of the articulated interaction of the rotating bearing ring 3 with the adjusting ring 26. For this purpose, the adjusting ring 26 has a calotte 29, which is applied in this case as a layer 30 on the adjusting ring 26. The layer 30 is very thin in the original and not drawn to scale in FIG. The surface of the Kalottenabschnitts 29 is concave. In the Kalottenabschnitt 29 engages a corresponding convex Kalottenabschnitt 31 on the rotating bearing ring 3 and is at the contact 33 = at the contact zone to this pivotable. The convex dome portion 31 is integrally formed with the rotating bearing ring 3 and can also be formed separately from this on a support ring of the rotating bearing ring 3.

The main body 32 of the adjusting ring 26 is made of steel. The sliding layer 30 on the adjusting ring 26 is curved with the Kalottenabschnitt 29 spherical segment-shaped and at least in the contact zone 33 to the Kalottenabschnitt 31 of a sintered material 16. The pores of the sintered material, as in the Representation of Figure 3, for example, filled with PTFE and the sintered material 16 is for example made of sintered bronze or, as in the example of Figure 4, filled with a synthetic oil or with fluoride additives.

LIST OF REFERENCE NUMBERS

Clutch release bearing 30 Sliding layer

Adjusting ring 31 Kalottenabschnitt rotating bearing ring 32 body non-rotating bearing ring 33 contact

rolling elements

Cage

axis of rotation

calotte

Contact

calotte

body

boundary layer

pore

surface

pore

Sintered material

body

Sintered material

mid-axis

Cavity inner bearing raceway outer raceway outer raceway inner raceway

Clutch

adjustment

axis of rotation

mid-axis

calotte

Claims

claims

1. Clutch release bearing (1, 25) with an adjusting ring (2, 26), with a non-rotating bearing ring (4), with a rotating bearing ring

(3) and with rolling elements (5) between the bearing rings (3, 4), wherein

the rotating bearing ring (3) relative to the non - rotating bearing ring (4) about an imaginary axis of rotation (7, 27) of the

Clutch release bearing (1, 25) rotates,

the adjusting ring (2, 26) is associated with a first calotte section (8, 29),

a second dome section (10, 31) is associated with the rotating bearing ring (3),

the second dome portion (10, 31) is in contact (9, 33) with the first dome portion (8, 29),

the dome sections (8, 10) in the contact (9, 33) correspond geometrically to one another,

- The rotating bearing ring (3) on the first dome portion (8, 29) on the contact (9, 33) is pivotally supported,

the rotating bearing ring (3) and the adjusting ring (2, 26) rotate together about the axis of rotation (7, 27)

and the contact (9) has a sliding layer between the dome sections (8, 10), characterized in that the sliding layer is formed on a sintered material (16, 18).

2. clutch release bearing according to claim 1, characterized in that the first Kalottenabschnitt (8, 29) at least on the contact (9, 33) of the sintered material (16, 18).

3. clutch release bearing according to claim 1, characterized marked, that the adjusting ring (2) is integral with the first dome portion (8) of the sintered material (18).

4. clutch release bearing according to claim 1, characterized in that the sintered material (16, 18) is a metallic Sinterwerk- material.

5. clutch release bearing according to claim 1, characterized in that the surface (14) of the sintered material (16, 18) on the contact (9, 33) is porous and at least in the porous surface (14) at least one of the Kalottenabschnitte ( 8, 10, 29, 31) a lubricant is introduced.

6. clutch release bearing according to claim 5, characterized in that the lubricant is a solid lubricant.

7. clutch release bearing according to claim 5, characterized in that the lubricant is an oil.

8. A clutch release bearing according to claim 1, characterized in that the surface (14) of the sintered material (16) of at least one of the ball sections (8, 10, 29, 33) at least at the contact (9) is porous and at least in the pores ( 13) at the surface che (14) of the sintered material (16) a sliding material is integrated.

9. clutch release bearing according to claim 8, characterized in that the sliding material is a plastic.

10. clutch release bearing according to claim 9, characterized in that the plastic is a polytetrafluoroethylene (PTFE).

1 1. A clutch release bearing according to claim 1, characterized marked, that the sintered material (16) is made of sintered bronze balls.

12. A clutch release bearing according to claim 1 1, characterized in that at least the first dome portion has a base body (17, 32) as a carrier material for the sintered bronze balls up.

13. Clutch release bearing according to claim 12, characterized in that the base body (17) is made of a further sintered material (18).

14 clutch release bearing according to claim 1 1, characterized in that the sliding layer (30) is a porous coating of the sintered bronze balls.

15. clutch release bearing according to claim 14, characterized in that in the pores at least partially polytetrafluoroethylene (PTFE) is integrated.

16. Clutch release bearing according to claim 1, characterized marked, that the rotating bearing ring (3) an inner bearing ring (21) and the non-rotating bearing ring (4) is an outer bearing ring (22).

17. Clutch release bearing according to claim 1, characterized in that the rotating bearing ring (3) is an outer bearing ring 23 and the non-rotating bearing ring (4) is an inner bearing ring (24).