Self-reinforcing friction clutch having leaf springs

Abstract

A friction clutch includes an axis of rotation, a disk spring, a plurality of leaf springs, a clutch cover and a pressure plate. The disk spring is for engaging the friction clutch. The disk spring includes tongues. The plurality of leaf springs is axially fixed to the tongues. The pressure plate is axially displaceable relative to the clutch cover and attached to the clutch cover in a torsion-resistant manner by the plurality of leaf springs.

Claims

1. A friction clutch comprising: an axis of rotation; a disk spring for engaging the friction clutch, the disk spring comprising tongues; a plurality of leaf springs axially fixed to the tongues; a clutch cover; and a pressure plate, axially displaceable relative to the clutch cover and attached to the clutch cover in a torsion-resistant manner by the plurality of leaf springs, wherein: the pressure plate comprises cams; the disk spring is supported on the cams in a tiltable manner for engaging and disengaging the friction clutch; and the leaf springs are arranged within the cams in a radial direction.

2. The friction clutch of claim 1, wherein the pressure plate is attached to the clutch cover at a certain relief angle.

3. The friction clutch of claim 1, further comprising a thrust piece, wherein: the plurality of leaf springs comprises: a clutch-cover-side group of leaf springs; and a pressure-plate-side group of leaf springs connected to the clutch-cover-side group of leaf springs by the thrust piece; and the tongues are received in the thrust piece in an axially fixed manner.

4. The friction clutch of claim 3, wherein: the thrust piece comprises: a first thrust-piece disk; and a second thrust-piece disk connected to the first thrust-piece disk; and the tongues are arranged axially between the first thrust-piece disk and the second thrust-piece disk.

5. The friction clutch of claim 3, wherein the thrust piece is arranged to actuate the disk spring to displace the pressure plate.

6. The friction clutch of claim 3, wherein: each one of the clutch-cover-side group of leaf springs is attached to the clutch cover at a first end and to a first attachment on the thrust piece at a second end; and each one of the pressure-plate-side group of leaf springs is attached to the pressure plate at a third end and to a second attachment on the thrust piece at a fourth end.

7. The friction clutch of claim 6, wherein the first attachment and the second attachment are each arranged axially between the pressure plate and the clutch cover.

8. The friction clutch of claim 6 wherein: each one of the clutch-cover-side group of leaf springs extends from the first end to the second end in a first circumferential direction; and each one of the pressure-plate-side group of leaf springs extends from the third end to the fourth end in the first circumferential direction.

9. The friction clutch of claim 6, wherein: each one of the clutch-cover-side group of leaf springs extends from the first end to the second end in an axial direction at a maximal first angle with respect to a circumferential direction; each one of the pressure-plate-side group of leaf springs extends from the third end to the fourth end in the axial direction at a maximal second angle with respect to the circumferential direction; and the maximal first angle and the maximal second angle are equal.

10. A friction clutch comprising: a rotational axis; a clutch cover; a pressure plate rotationally fixed and axially displaceable relative to the clutch cover; a disk spring disposed axially between the clutch cover and the pressure plate and comprising a tongue; a first leaf spring comprising a first end axially fixed relative to the tongue and a second end fixed to the clutch cover; and a second leaf spring comprising a third end axially fixed relative to the tongue and rotationally fixed relative to the first end, and a fourth end fixed to the pressure plate.

11. The friction clutch of claim 10 wherein: the first leaf spring extends in a first rotational direction from the first end to the second end; and the second leaf spring extends in the first rotational direction from the third end to the fourth end.

12. The friction clutch of claim 10, wherein: the pressure plate comprises a plurality of cams circumferentially disposed about the rotational axis; and the disk spring is arranged to pivot on the plurality of cams to displace the pressure plate and engage the friction clutch.

13. The friction clutch of claim 12 further comprising a thrust piece: axially fixed relative to the tongue; and fixed to the first end and the third end.

14. The friction clutch of claim 13 wherein the first leaf spring, the second leaf spring, and the thrust piece are all disposed radially within the plurality of cams.

15. The friction clutch of claim 13 wherein the thrust piece is fixed to the first end by a first rivet and to the third end by a second rivet, circumferentially offset from the first rivet.

16. The friction clutch of claim 13 further comprising a hub axially fixed to the thrust piece for axially displacing the thrust piece to engage the friction clutch.

17. The friction clutch of claim 13 wherein the thrust piece comprises: a first thrust piece disk disposed on a first axial side of the tongue; and a second thrust piece disk disposed on a second axial side of the tongue, opposite the first axial side.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The disclosure and the technical field are explained in more detail below with reference to the figures. It should be noted that the disclosure is not intended to be restricted by the exemplary embodiments shown. In particular, unless explicitly stated otherwise, it is also possible to extract partial aspects of the substantive matter explained in the figures and to combine it with other elements and findings from the present description and/or figures. In particular, it should be noted that the figures and, in particular, the ratios illustrated are merely schematic. Identical reference signs denote identical objects, which means that explanations from other figures may be used in a supplementary manner, where appropriate. In the figures:

(2) FIG. 1 shows a friction clutch, additionally with counter-plate and clutch disk in a view along the axis of rotation;

(3) FIG. 2 shows the friction clutch according to FIG. 1 in a side view in section;

(4) FIG. 3 shows the friction clutch according to FIG. 1 in a view along the axis of rotation;

(5) FIG. 4 shows the friction clutch according to FIG. 3 in a side view in section;

(6) FIG. 5 shows the friction clutch according to FIGS. 3 and 4 in a side view in section in traction mode;

(7) FIG. 6 shows a detailed view of FIG. 5;

(8) FIG. 7 shows the friction clutch according to FIGS. 3 and 4 in a side view in section in coasting mode; and

(9) FIG. 8 shows a detailed view of FIG. 7.

DETAILED DESCRIPTION

(10) FIG. 1 shows a friction clutch 1 additionally with a counter-plate 28 and clutch disk 29 in a view along the axis of rotation 27. FIG. 2 shows the friction clutch 1 according to FIG. 1 in a side view in section. FIGS. 1 and 2 are described together below.

(11) The friction clutch 1 additionally has a counter-plate 28, wherein the pressure plate 6 is provided for pressing the clutch disk 29 with friction fit between the counter-plate 28 and the pressure plate 6.

(12) The friction clutch comprises a disk spring 2, a clutch cover 3 (here screwed to the flywheel and the counter-plate 28) and a pressure plate 6, which is capable of limited displacement in the axial direction 4 and is attached to the clutch cover 3 in a torsion-resistant manner by leaf springs 5, wherein the leaf springs 5 are attached to tongues 7 of the disk spring 2 in a fixed manner in the axial direction 4.

(13) The leaf springs 5 extend between a first end 14, 17 and a second end 15, 18, at least in a circumferential direction 20, 21 (ref. FIGS. 3, 5, 6) and in an axial direction 4. The leaf springs 5, in the radial direction 8, are arranged within pressure plate cams 9 on which the disk spring 2 is supported in a tiltable manner for engaging and disengaging the friction clutch 1 (i.e. for displacement of the pressure plate 6 in the axial direction 4).

(14) The leaf springs 5, here the second ends 15, 18 of the leaf springs 5 in each case, are connected to the tongues 7 of the disk spring 2 in a fixed manner via the thrust piece 13 in the axial direction 4 in order to exert a force on the tongues 7 of the disk spring 2 which engages the friction clutch 1 in the traction mode 31 of the internal combustion engine (accelerating torque is transmitted via the clutch cover 3 to the pressure plate 6 and the counter-plate 28 and, from these, to the clutch disk 29) and to exert a force on the tongues 7 of the disk spring 2 which disengages the friction clutch 1 in the coasting mode 30 of the internal combustion engine (clutch cover 3 is driven by the clutch disk 29).

(15) The torsion-resistant attachment of the pressure plate 6 to the clutch cover 3 is realized at a certain relief angle 10.

(16) In the illustrated exemplary embodiment, a friction clutch 1 is shown with a tensioned disk spring 2, which is actuated by the gearbox input shaft 36.

(17) FIG. 3 shows the friction clutch 1 according to FIG. 1 in a view along the axis of rotation 27. FIG. 4 shows the friction clutch 1 according to FIG. 3 in a side view in section. In contrast to FIGS. 1 and 2, at least the counter-plate 28 and the clutch disk 29 are not illustrated here. Please refer to the embodiments in FIGS. 1 and 2.

(18) The direction of rotation 33 of the clutch cover 3 and the braking direction 34 of the pressure plate 6 are illustrated. The friction clutch is in traction mode 31 (ref. FIGS. 5 and 6). The braking direction 34 (illustrated in FIG. 4) of the pressure plate 6 extends into the plane of the drawing, the direction of rotation 33 extends out of the plane of the drawing.

(19) FIG. 5 shows the friction clutch 1 according to FIGS. 3 and 4 in a side view in section in traction mode 31. FIG. 6 shows a detailed view of FIG. 5. Please refer to the embodiments in FIGS. 1 to 4.

(20) Two groups 11, 12 of leaf springs 5 are provided, namely clutch-cover-side (first group 11) and pressure-plate-side (second group 12) leaf springs 5, which are connected to one another via a thrust piece 13 in which the tongues 7 of the disk spring 2 are received in an axially fixed manner.

(21) A pressure-plate-side thrust piece (second thrust-piece disk 25) is provided here, which is attached to the pressure plate 6 in a torsion-resistant manner via (a) pressure-plate-side (second group 12 of) leaf springs 5, and a clutch-cover-side thrust piece (first thrust-piece disk 24), which is attached to the clutch cover 3 in a torsion-resistant manner via (a) clutch-cover-side (first group 11 of) leaf springs 5.

(22) The leaf springs 5 of the first group 11 are attached by a first end 14 to the clutch cover 3 and by a second end 15 to a respective first attachment 16 on the thrust piece 13. The leaf springs 5 of a second group 12 are attached by a first end 17 to the pressure plate 6 and by a second end 18 to a respective second attachment 19 on the thrust piece 13.

(23) The first attachments 16 and the second attachments 19 are arranged between the pressure plate 6 and the clutch cover 3 in the axial direction 4.

(24) Each leaf spring 5 of the first group 11 extends from the first end 14 to the second end 15 in a first circumferential direction 20 and each leaf spring 5 of the second group 12 extends from the first end 17 to the second end 18 in an aligned first circumferential direction 20.

(25) The leaf springs 5 of the first group 11 extend in the axial direction 4 between the first end 14 and the second end 15, at a maximal first angle 22 with respect to a circumferential direction 20, 21, and the leaf springs 5 of the second group 12 extend in the axial direction 4 between the first end 17 and the second end 18, at a maximal second angle 23 with respect to a circumferential direction 20, 21, wherein the first angle 22 and the second angle 23 are the same size.

(26) The thrust piece 13 comprises a first thrust-piece disk 24 and a second thrust-piece disk 25, which are connected to one another via rivets 35, wherein the tongues 7 of the disk spring 2 are arranged 4 between the first thrust-piece disk 24 and the second thrust piece disk 25 in the axial direction.

(27) The leaf springs 5 are connected to the thrust piece 13 or the respective thrust-piece disk 24, 25 via rivets 35, specifically via the rivets 35 which are provided for connecting the thrust-piece disks 24, 25 to one another.

(28) The disk spring 2 can be actuated for the displacement of the pressure plate 6 via the thrust piece 13. The thrust piece 13 is connected to a hub 26, on which the thrust-piece disks 24, 25 are arranged in an axially fixed manner. The thrust piece 13 (and via the thrust piece 13, the disk spring 2) can therefore be actuated via the hub 26.

(29) In the illustrated traction mode 31, the clutch cover 3 pulls on the thrust piece 13 in the first circumferential direction 20 (see direction of force 32 and direction of rotation 33, in the direction out of the plane of the drawing) via the first group 11 of leaf springs 5. The thrust piece 13 simultaneously pulls the pressure plate 6 via the second group 12 in the first circumferential direction 20 (or brakes the pressure plate 6 in the second circumferential direction 21, braking direction 34).

(30) The angles 22, 23 of the leaf springs 5 are selected such that they act preferably equally and oppositely. In the illustrated traction mode 31, the generated axial forces of the leaf springs 5 act in the same axial direction 4 and push the clutch further closed, i.e. exert a self-reinforcing force in the engagement direction (see arrows pointing to the thrust piece 13 in the axial direction 4). In coasting mode (see FIGS. 7 and 8), the generated axial forces of the leaf springs 5 likewise act in the same direction and pull the friction clutch 1 open, i.e. disengage the friction clutch 1.

(31) The pressure plate 6 introduces its torque via leaf springs 5 (second group 12 of leaf springs 5) into the thrust piece 13 (second thrust-piece disk 25) located below the pressure plate 6, i.e. on the pressure plate side, with reference to the accompanying figures. This torque is introduced via the rivets 35 of the leaf spring rivet arrangement on the pressure-plate side into the thrust piece 13 (first thrust-piece disk 24) on the coupling-cover side, which is arranged below the disk spring 2 with reference to the accompanying figures. This thrust piece 13 (first thrust-piece disk 24) is fastened to the coupling cover 3 via coupling-cover-side leaf springs 5 (first group 11 of leaf springs 5).

(32) FIG. 7 shows the friction clutch 1 according to FIGS. 3 and 4 in a side view in section in coasting mode 30. FIG. 8 shows a detailed view of FIG. 7. FIGS. 7 and 8 are described together below. Please refer to the embodiments in FIGS. 5 and 6.

(33) In the illustrated coasting mode 30, the clutch cover 3 is pulled by the thrust piece 13 in the second circumferential direction 21 (see direction of force 32, braking direction 34, in the direction out of the plane of the drawing, and direction of rotation 33, in the direction into the plane of the drawing) via the first group 11 of leaf springs 5. The thrust piece 13 is simultaneously pulled by the pressure plate 6 in the second circumferential direction 21 via the second group 12. In coasting mode 30 the generated axial forces of the leaf springs 5 (see arrows pointing to the thrust piece 13 in the axial direction 4) likewise acting in the same direction and pull the friction clutch 1 open, i.e. disengage the friction clutch 1.

REFERENCE NUMERALS

(34) 1 Friction clutch 2 Disk spring 3 Clutch cover 4 Axial direction 5 Leaf spring 6 Pressure plate 7 Tongue 8 Radial direction 9 Pressure plate cam 10 Relief angle 11 First group 12 Second group 13 Thrust piece 14 First end (first group) 15 Second end (first group) 16 First attachment 17 First end (second group) 18 Second end (second group) 19 Second attachment 20 First circumferential direction 21 Second circumferential direction 22 First angle 23 Second angle 24 First thrust-piece disk 25 Second thrust-piece disk 26 Hub 27 Axis of rotation 28 Counter-plate 29 Clutch disk 30 Coasting mode 31 Traction mode 32 Direction of force 33 Direction of rotation 34 Braking direction 35 Rivet 36 Gearbox input shaft