DE102006024084A1 - Clutch - Google Patents

Abstract

Clutch release bearing, which by means of a thrust washer (10, 24) in contact with spring tongues (2, 3, 4) of a plate spring, wherein circumferentially on the thrust washer (10, 24) arranged distributed ribs (8, 25) positively in slots (7, 23) between immediately circumferentially adjacent to each other of the spring tongues (2, 3, 4) engage.

Description

Field of the invention

The The invention relates to a clutch release bearing, by means of a Thrust washer in contact with spring tongues of a plate spring, wherein circumferentially distributed on the thrust washer arranged ribs form-fitting in radial gaps between immediately circumferentially adjacent to each other engage the spring tongues.

Background of the invention

Of the Positive connection between the thrust washer and the spring tongues of the diaphragm spring the clutch prevents circumferential relative movements around the Rotation axis between the spring tongues and the thrust washer and prevents slippage between the diaphragm spring and the on the Disc spring acting bearing ring of the clutch release bearing.

slippage occurs in the clutch especially in new vehicles in contact between disc spring and thrust washers on when the thrust washer made of plastic. This especially affects self-centering release bearings detrimental to the self-centering effect of these bearings. The disadvantages are noises and premature wear.

A clutch release bearing of the generic type is in a with DE 37 43 853 A1 published application of the applicant described. DE 37 43 853 A1 describes a clutch release bearing, which is arranged on a sliding sleeve and having two concentrically arranged races. Rolling elements are arranged between the races. At the plate spring facing the end face of the inner ring a thrust washer between the inner ring and the spring tongues is arranged. The thrust washer is provided with radially extending ribs. In each case one of the ribs engages positively in each case a slot between two adjacent spring tongue ends.

To at the time when the invention described in the "Summary of the Invention" section There was a lack of knowledge and approaches to sizing Ribs. Too high or otherwise insufficiently dimensioned ribs caused increased for a long time Effort in the assembly of the release bearing to the clutch, as the thrust washer twisted against the suspensions as long had to be until each rib was opposite one of the slots. Furthermore, the ribs jammed in the operation of the vehicle the dedicated endeavor of the clutch release bearing itself to the axis of rotation to center the clutch. This resulted in particular in the retraction phase of the new vehicle forced forces on the ribs. These constraints led to that sounds and also not premature wear in the desired Scope were avoidable as well as partial breakage of the diaphragm spring tongues and thus led to premature failure.

Summary of the invention

The The object of the invention is therefore to provide a clutch release bearing to create, which can be easily assembled, the contact washer free of premature wear and the quiet about the entire service life of the clutch works.

These The problem is solved according to the characterizing part of claim 1. The Clutch, the means of a thrust washer in contact with spring tongues of a Belleville spring is, has a thrust washer, on the circumference distributed on the thrust washer one, two or more ribs arranged are. The invention is applicable to all common types of clutch release bearings applicable, the one with a clutch actuator spring pressure loaded thrust washer exhibit. These are e.g. the self-centering clutch release bearing, with which radial axial offset between the axis of rotation of the clutch release bearing and the axis of rotation of the clutch is compensated. That's it too self-centering and at the same time self-adjusting clutch release bearing, the except the aforementioned axial offset also tilting and inclinations the above-mentioned axes articulate each other.

Under Ribs are all protrusions protruding from a surface, which are suitable in at least one slot between two directly circumferentially mutually adjacent to the spring tongues of the plate spring form-fitting intervene. It is conceivable that several radially in a row aligned and thereby radially separated projections in one common slot or of several of the projections each in one engages other of several of the slots. Preferably, however, are radially to the axis of rotation of the clutch release bearing to and from this provided away-oriented ribs, one of which in a engages at least two of the slots.

The ribs are from the thrust washer away in the radial and / or axial direction or in directions that are predetermined by axial and radial directional vectors simultaneously - are, however, preferably aligned in axial direction with the axis of rotation of the clutch release bearing rectified direction. The ribs protrude from the surface of the thrust washer and thus protrude beyond this. Alternatively, the ribs are in a forehead side circumferential groove or similar end-side recesses of the thrust washer and thus protrude beyond the bottom of the recess / groove, but optionally not alternatively also from the circumferential groove / recess over the surface of the thrust washer also.

in the Meaning of the invention is under "form-fitting in Slots intervene " releasable with positive locking Understand game interference. Between each of the form-fitting in one of the slots engaging ribs and at least one of the on the slot circumferentially opposite spring tongues at least in the circumferential direction or tangential direction a movement play educated. When the motion play in the slot between a is formed of the spring tongues and the rib, the rib abuts the opposite On spring tongue. If the rib in the slot at intervals too engages both spring tongues, the movement is the sum of the two distances from the rib to the respective spring tongue.

The Rib is thus in the slot between the opposite Spring tongues so flexibly limited that, especially in new vehicles, first between the spring tongues and the bearing ring of the release bearing Slip can occur. However, this slippage is in the size of the movement game and thus small, barely noticeable and thus not promoting wear.

The Invention allows the force-free self-centering of the clutch release bearing, if the respective rib even with extreme deviations of the dimensions, the Mold and the position of the components of the clutch from the setpoint not can jam in the slot. An embodiment of the invention therefore provides that the measure of Movement is at least as large as a maximum sum out of itself possibly also influencing largest dimensional, shape and position deviations of assemblies and components of the clutch assembly from the setpoint, directly or from those vectors with the measure tangential or circumferentially rectified as well as structurally or structurally are interconnected and the immediate impact on the relationship from slit width and position to rib width and position in Slot have.

These largest sum is from the extreme values of deviations of the individual dimensions and dimensional chains etc. and is the biggest negative or positive value from the largest and Minimum values, which in the slot at the most unfavorable dimensional, positional or form deviations from the set point between rib and slot leads. The Deviations result from the permissible individual deviations known to the experts and as allowed Tolerances specified deviations up (+) or down (-) of nominal size (nominal size = nominal value) together, the for the manufacture of the parts and the assembly of the assembly required are. This concerns for example the dimensions of the Individual parts, such as width and height, the distances of the Individual parts of each other and the distances of reference points or Layers or straights, such as distances from the axis of rotation, the deviations of shapes, such as allowed Deviations from the ideal flatness or cylindricity etc ..

In the largest sum also deviations in position of assemblies, such as the deviations of Position and alignment Center axis of the coupling to the position and Alignment of the axis of rotation of the clutch release bearing, which by self-centering and / or the self-adjusting action of the clutch release bearing is to compensate.

• – die größten Abweichungen der Position der Radialrippe an der Anlaufscheibe, der Position der Rippen an der Anlaufscheibe zueinander und der Position der jeweiligen Rippe zur Rotationsachse des Kupplungsausrücklagers,
• – die größten Abweichungen der zumindest mit dem Maß des Bewegungsspiels gleichgerichteten gerichteten Abmessungen der Rippe, beispielsweise die der Rippenbreite
• – die größten Abweichungen von der Position der Federzungen zueinander und zur Rotationsachse des Kupplungsausrücklagers und
• – die größten Abweichungen wenigstens der mit dem Maß gleich gerichteten Abmessungen der Federzungen

vom Nennmaß an der Stelle, an der das Bewegungsspiel zwischen der jeweiligen Rippe und den Federzungen im Schlitz am kleinsten ist. Kleiner darf das kleinste Bewegungsspiel in einem der Schlitze nicht sein.Important influencing factors on the movement play in the concrete case of the clutch arrangement are:

• The greatest deviations of the position of the radial rib on the thrust washer, the position of the ribs on the thrust washer relative to one another and the position of the respective rib relative to the rotational axis of the clutch release bearing,
• - The largest deviations of the rectified at least with the degree of movement directed dimensions of the rib, for example, the rib width
• - The largest deviations from the position of the spring tongues to each other and the axis of rotation of the clutch release bearing and
• - The largest deviations at least the dimensions of the spring tongues with the same dimensions

from the nominal size at the point where the play of movement between the respective rib and the spring tongues in the slot is the smallest. Smaller may not be the smallest movement game in one of the slots.

• – die Form- und Lageabweichungen der Federzungen vom Sollwert,
• – die engste mit dem Bewegungsspiel gleichgerichtete Breite b_min des Schlitzes sowie
• – die Abweichungen t der Teilung T vom Sollwert, mit denen die Rippen bzw. Federzungen umfangsseitig zueinander angeordnet sind,

berücksichtigt sind.The width a _{max of} the respective rib and the deviations in shape and position from the predetermined desired values in any slot provided for the engagement are preferably dimensioned such that even with extreme radial displacement x _{max of} the rotational axis of the release bearing to the center axis of the Clutch,

• - the shape and position deviations of the spring tongues from the nominal value,
• - The narrowest with the movement play rectified width b _{min of} the slot as well
• - The deviations t of the pitch T from the setpoint, with which the ribs or spring tongues to are arranged on the catch side,

are considered.

Under the term division is the relation to understand, with the ribs or the spring tongues relative to a according to mathematical definition full angle of 360 ° on the Scope of a whole circle distributed and thus arranged to each other are. An embodiment of the invention provides, for example, a Thrust washer three pieces the ribs in front, with even division T = 3 × 120 ° on the circumference are distributed. The radially outgoing from the axis of rotation and rectified with the radially aligned longitudinal axis of the respective rib imaginary graduation planes / longitudinal axes the radially extending straight ribs in this case are thus mutually inclined by 120 °. In this case, a pitch error of t = (+/-) 0.5 ° is conceivable, such that the angle at which the graduation planes are inclined to each other are also 199.5 ° or 120.5 ° can be.

In the movement play is also changes while considered the coupling operation. Such changes are for example the thermal expansion of individual components, swelling or shrinking and aging of Material, in particular the plastic of the thrust washer and the Wear the Components.

A preferred embodiment of the invention provides that the movement play is at least two tenths of a millimeter larger than the sum of the deviations from the dimensional, shape and bearing of the components. By the above measures, even with extreme radial displacement x _max the axis of rotation of the release bearing is secured to the axis of rotation of the clutch that the ribs in the respective slot does not jam.

The Clutch let yourself mount undirected with regard to the position of the ribs. In that case, in which the respective one of the ribs during assembly is not one of Slits opposite stands, but on a spring tongue between two adjacent slots rests, the ribs and the slots twist at the latest at the first actuation the rotating clutch with slip a short distance against each other until the ribs face the slots and form-fitting in engage the respective slot. A too long rib leaves in the Usually a non-directional mounting not to, because of the axial space in the clutch assembly for it not available stands. A relatively high rib claimed on a newly mounted Clutch, if this rests on the spring tongue and not in one Slot is immersed, first at least a portion of the axial space more, the rib high is. It is also conceivable that the spring tongue, on which the high rib rests more einfedert, as the other spring tongues. When the rib at least at the portion which intervenes between the spring tongues, is too high leads this often also to cancel the ribs due to the initial slip until the Engage ribs in the slots.

The Clutch according to the invention are also applicable in clutches with disc springs, where narrow Slots provided between some of the adjacent spring tongues and wide between other adjacent spring tongues Slits are formed. The width of the ribs and thus the movement play is adapted according to an embodiment of the invention the wider slots designed. The ribs in this case are wider than the narrow ones Slots so that the ribs are not in the narrow slots but just dive into the wide slots. In the case where the respective ribs during assembly of the clutch release bearing not facing one of the wide slits, but at one Spring tongue abuts between two adjacent slots or one facing the narrow slots, The ribs and slots twist at the latest at the first actuation of the rotating clutch with slip a short distance against each other until the ribs face the slots and form-fitting in engage the respective slot. Also in this case is from construction space technical establish the height the ribs as low as possible to keep.

A Embodiment of the invention provides that the optimum height of the rib at least at the portion of the rib, the form-fitting in dips the slot, 0.2 times as high as the height with the same height possible smallest dimension of the spring tongues, at least at the contact. This place is usually the sheet thickness of the spring tongues on the contact.

The materials of the thrust washer are preferably plastics, such as plastics, which can be used even at operating temperatures up to 160 ° C the environment of the clutch release bearing. These are, for example, polytetrafluoroethylene (PTFE) and polyaryl ether ketones (PAEK). Also used are polyamides such as PA46 CF30, partially aromatic polyamides such as polyphthalamide (PPA), polyhexamethylene terephthalamide (PA6T), polyhexamethylene isophthalamide (PA6T / 6I), polyhexamethylene adipamide (PA6T / 66, PA6T / 6I / 66), poly-methylpentamethylene terephthalamide (PA6T / MPMDT) with friction- and wear-reducing and strength-enhancing additives. Aggregates are, for example, carbon fibers or aramid fibers, which are added, for example, with a weight fraction of 20% to 30% or 1% to 15% of the material. Other additives are solid lubricants such as molybdenum disulfide together or as an alternative to graphite or together or as an alternative to PTFE or polyphenylene sulfone (PPSo2, Ceramer), which are added, for example, depending on the additive in proportions by weight of 1% to 5%, or to 15% or 30%.

Further Embodiments and embodiments The invention will be described below.

Brief description of the drawings

It demonstrate:

1 a plate spring of an otherwise not shown coupling arrangement in a main view of the spring tongues of the plate spring,

2 an embodiment of a self-centering clutch release bearing for contact with a plate spring after 1 in a main view of the thrust washer of the clutch release bearing,

3 after the clutch release bearing 2 in a partial section along the line III-III,

4 a further embodiment of a self-centering clutch release bearing in a main view of the thrust ring of the clutch release bearing,

5 after the clutch release bearing 4 in a partial section along the line IV-IV,

6 a representation of possible dimensional and position deviations on a model of an engagement of ribs in slots of a diaphragm spring, not shown,

Detailed description of the drawing

1 shows a plate spring 1 with spring tongues 2 . 3 and 4 , The spring tongues 2 . 3 and 4 are arranged circumferentially adjacent to each other. Two each of the directly adjacent spring tongues 2 . 3 or 4 are circumferentially by one slot 5 . 6 or 7 separated from each other. The slots 7 are wider than the slots with the tangential maximum width b _1min 5 or 6 the width b _2min .

In each case one of the slots 7 is one rib each 8th dipped in a positive fit. Every single rib 8th indicates contact with the rib 8th tangentially the maximum width a _max and is wider than the maximum width b _{2min of} the slot 5 and also the slot 6 so that the ribs are immersed 8th in the slots 5 respectively. 6 not possible. The slots 7 at the narrowest point of the slot 7 where the contact with the diaphragm spring 1 is, that's where the ribs are 8th intervene, with the minimum width b _1min but wider than the ribs 8th around the width a _{max can be} maximally wide, so that the ribs 8th in the slot 7 intervention. Ribs 8th grab in the slot 7 with the motion play S, which is the sum of the distances S ₁ and S ₂ . The minimum width b _1min is therefore at least the sum of a _max plus the required movement _clearance S _min . In other words, in the design of the width a _{max of} the rib, the minimum width of the slot and the minimum necessary play S _min must be considered: a _max = b _{1 min} - S _min .

As with 1 and in particular with 2 are shown are three pieces of ribs 8th with uniform pitch T = 3 × 120 ° to each other circumferentially on a thrust washer 10 distributed, that is, the straight longitudinal axes 8a the radially aligned ribs 8th meet on the axis of rotation 11 of the clutch release bearing 12 and are each inclined at 120 ° to each other.

How out 3 by a rib 8th it can be seen, stand the three pieces of ribs 8th in a circumferential groove 9 from the surface of the groove bottom 9a the circumferential groove 9 and axially over the circumferential groove 9 out of the thrust washer 10 out. The circumferential groove 9 is frontally on the thrust washer 10 educated.

The bent ends 33 the spring tongues 2 . 3 or 4 of which in 3 only one can be seen lying in the circumferential direction on both sides of the ribs 8th at the bottom of the groove 9a adapted to the shape of the bent ends.

The thrust washer 10 is the front side of an inner ring 13 attached and has an edge for it 14 on, the front flange 13a of the inner ring 13 outside includes. The thrust washer 10 is for example on the inner ring 13 pressed on, with this snapped or connected in any other suitable manner form-fitting or positive-locking or glued to this, welded or otherwise materially connected.

Between the inner ring 13 and an outer ring 15 are balls 16 arranged. The balls 16 are in a cage 17 guided. The outer ring 15 is by means of a spring 18 elastic against an axial flange 19a a sliding sleeve 19 biased.

The sliding sleeve 19 has fasteners 19b for fixing an actuating element, not shown, by means of which axial forces on the sliding sleeve 19 be applied so that the sliding sleeve 19 and thus the clutch release bearing 12 over the outer ring 15 against the spring tongues 2 . 3 and 4 is moved and the spring tongues 2 . 3 and 4 thereby spring down.

Radial offset x between the axis of rotation 11 of the clutch release bearing 12 and the axis of rotation 20 The coupling, not shown, to each other when rotating the inner ring 13 with radial movements of the outer ring 15 axially by the offset x on the axial flange 19a centered ( 3 ) to the axis of rotation 11 and the rotation axis 20 are concentric with each other. Therefore, the distance H between the inner diameter of the outer ring 15 and the sliding sleeve 19 greater than x.

• – die maximal zulässige Abweichung der Position der Rippe 8, wie zum Beispiel die Abweichung ΔA vom Nennmaß des senkrechten Abstandes A zur Rotationsachse 11,
• – die mit dem Bewegungsspiel tangential gleichgerichteten Vektoren der Abweichungen von den Nennmaßen der Position der Rippen 8 an der Anlaufscheibe zueinander, wie zum Beispiel die zulässige Abweichung t von der Teilung T (Teilungsfehler t), bzw. die Abweichungen Δα_R vom Sollwinkel α_R mit dem die Längsachsen 8a zur Vertikalen geneigt sind,
• – die Abweichungen x_t von der Position der jeweiligen Rippe zur Drehachse 20,
• – die größte zulässige Abweichungen Δa vom Nennmaß a der Breite a_max = a + Δa der jeweiligen Rippe 8 oder anderer mit dem Bewegungsspiel tangential gleichgerichteten gerichteten Abmessungen der jeweiligen Rippe 8 sowie
• – die mit dem Bewegungsspiel tangential gleichgerichteten Vektoren der größten bzw. kleinsten zulässigen Abweichungen vom Nennmaß Positionen b_min und α_F der Federzungen 2, 3 bzw. 4 zueinander und zur Rotationsachse 11 des Kupplungsausrücklagers 12.

The center of the axial disc 10 lies on the axis of rotation 11 so that the offset x _max (see 6 ) may result in a radial displacement of the position of one of the ribs 8th maximum by the offset x _max in the slot 7 can lead to other ribs 8th to partial radial displacements x _r in the slot 7 and leads to tangential displacements x _t . The tangential displacements x _t are to be considered in the movement play S _min . The radial displacements x _r are by longitudinal movements in the slot 7 balanced. In the game of play, further consideration must be given ( 6 ):

• - the maximum permissible deviation of the position of the rib 8th , such as the deviation .DELTA.A from the nominal dimension of the vertical distance A to the axis of rotation 11 .
• - The vectors of the deviations from the nominal dimensions of the position of the ribs which are tangentially rectified with the movement play 8th on the thrust washer to each other, such as the allowable deviation t of the pitch T (pitch error t), and the deviations Δα _R from the target angle α _R with the longitudinal axes 8a inclined to the vertical,
• The deviations x _t from the position of the respective rib to the axis of rotation 20 .
• The largest permissible deviations Δa from the nominal dimension a of the width a _max = a + Δa of the respective rib 8th or other with the movement play tangentially rectified directed dimensions of the respective rib 8th such as
• - The tangentially rectified vectors of the largest or smallest permissible deviations from the nominal dimension positions b _min and α _{F of} the spring tongues 2 . 3 respectively. 4 to each other and to the axis of rotation 11 of the clutch release bearing 12 ,

The 4 and 5 show a further embodiment of a self-centering clutch release bearing 21 in contact with spring tongues 22 is. Three of the circumferentially mutually adjacent spring tongues 22 are indicated by a broken line. Between two directly mutually arranged spring tongues 22 are slots 23 educated. The slots 23 are identical to each other in the embodiment, so that they all have the same tangentially directed width b _min . The clutch release bearing 21 has a thrust washer 24 on. From the face flat flat thrust washer are axially ribs 25 in the slots 23 interlock positively.

The thrust washer 24 made of plastic, which can also be provided with an insert made of sheet metal as reinforcement, is frontally on an inner ring 26 firmly. For this purpose, the thrust washer 24 inside snap elements 27 on, with the inner ring 26 engage behind axially. Between the inner ring 26 and an outer ring 28 are balls 29 arranged. The balls 29 are in a cage 30 guided. The outer ring 28 is by means of a spring 31 elastic against an axial flange 32a a sliding sleeve 32 biased.

1

Belleville spring

2

spring tongue

3

spring tongue

4

spring tongue

5

slot

6

slot

7

slot

8th

rib

8a

longitudinal axis

9

circumferential groove

9a

groove base

10

thrust washer

11

axis of rotation

12

Clutch

13

inner ring

13a

flange

14

edge

15

outer ring

16

roll

17

Cage

18

feather

19

sliding sleeve

19a

axial flange

20

axis of rotation

21

Clutch

22

spring tongue

23

slot

24

thrust washer

25

rib

26

inner ring

27

snap element

28

outer ring

29

Bullet

30

Cage

31

feather

32

sliding sleeve

32a

axial flange

33

The End a spring tongue

Claims (6)

Clutch release bearing, which by means of a thrust washer ( 10 . 24 ) in contact with spring tongues ( 2 . 3 . 4 ) is a plate spring, wherein circumferentially on the thrust washer ( 10 . 24 ) distributed ribs ( 8th . 25 ) in slots ( 7 . 23 ) between immediately circumferentially adjacent to the spring tongues ( 2 . 3 . 4 ), characterized in that between each of the form-fitting in one of the slots ( 7 . 23 ) engaging ribs ( 8th . 25 ) and at least one of the slots ( 7 . 23 ) circumferentially opposed spring tongues ( 2 . 3 . 4 ) at least in the circumferential direction a movement play is formed around which the rib ( 8th . 25 ) ( 8th . 25 ) in the slot ( 7 . 23 ) between the opposing spring tongues ( 2 . 3 . 4 ) is limited mobility. Clutch release bearing according to claim 1, characterized in that the degree of movement play is at least as large as a rectified with the motion game largest possible sum of dimensional, shape and position deviations arising from the largest possible deviations: - the position of the rib ( 8th . 25 ) on the thrust washer ( 10 . 24 ), the position of the ribs ( 8th . 25 ) on the thrust washer ( 10 . 24 ) to each other and the position of the respective rib ( 8th . 25 ) to the rotation axis ( 11 ) of the clutch release bearing ( 12 . 21 ), - the at least dimensionally rectified directed dimensions of the rib ( 8th . 25 ), - the position of the spring tongues ( 2 . 3 . 4 ) to each other and to the axis of rotation ( 11 ) of the clutch release bearing ( 12 . 21 ) and - at least the same dimensions of the spring tongues ( 2 . 3 . 4 ) of the nominal size at the point where the movement between the respective ribs ( 8th . 25 ) and the spring tongues ( 2 . 3 . 4 ) in the slot ( 7 . 23 ) is the smallest. Clutch according to claim 2, characterized in that the movement play least is two-tenths of a millimeter larger, as the sum of the deviation. Clutch release bearing according to claim 1, characterized in that the ribs ( 8th . 25 ) are radially aligned. Clutch release bearing according to claim 1, characterized in that the ribs ( 8th . 25 ) end face of the thrust washer ( 10 . 24 ) are formed. Clutch release bearing according to claim 1, characterized in that the height of the rib ( 8th . 25 ) at least at the portion of the rib ( 8th . 25 ), the form-fitting in the slot ( 7 . 23 ) is immersed, at least 0.2 times as high as the possible with the height possible possible smallest dimension of the spring tongues ( 2 . 3 . 4 ) at the point where the section with the height in the slot ( 7 . 23 immersed).