Torsional damper for a vehicle transmission system

Abstract

A torsional damper for vehicle transmission systems comprises an input element rotationally movable around an axis and exhibiting at least one window comprising two angularly spaced lateral edges and a radially external edge. An output element is rotationally movable around the axis and exhibits at least one window comprising two angularly spaced lateral edges and a radially external edge. An elastic return member capable of being received simultaneously in the window of the input element and the window of the output element generates a force acting against rotation of the output element with respect to the input element. An additional element is rotationally movable around the axis and integral with one of the input element and output element. The additional element exhibits an edge comprising at least one region projecting radially into the window of the input element and output element with which the additional element is integral.

Claims

1. A torsional damper (2) of a friction disk (1) for a clutch for a vehicle transmission system, the torsional damper (2) comprising: an input element (6) rotationally movable around an axis (X) and exhibiting at least one window (15) comprising two angularly spaced lateral edges (20) and a radially external edge (21); an output element (8) rotationally movable around the axis (X) and exhibiting at least one window comprising two angularly spaced lateral edges and a radially external edge, an elastic return member (9) received simultaneously in the at least one window (15) of the input element (6) and in the at least one window of the output element (8) so as to generate a force acting against rotation of the output element (8) with respect to the input element (6); and a support disk (10) rotationally movable around the axis (X) and non-moveably attached to one of the input element (6) and the output element (10), the support disk (10) exhibiting at least one window (17) comprising at least one edge (25), the at least one edge (25) comprising at least one region (30) projecting radially into the at least one window of one of the input element (6) and output element (8) to which the support disk (10) is non-moveably attached, the input element (6) being a web, the output element (8) being two guide washers axially surrounding the web, and the support disk extending radially outwardly from the one of the input element (6) and the output element (10), the support disk (10) supporting at least one friction lining.

2. The torsional damper (2) according to claim 1, wherein the support disk (10) is integral with the input element (6).

3. The torsional damper (2) according to claim 1, wherein the elastic return member (9) is also received radially internally with respect to the at least one edge (25) of the support disk (10).

4. The torsional damper (2) according to claim 3, wherein each angular end of the elastic return member (9) is in contact with a seat (27).

5. The torsional damper (2) according to claim 1, wherein the at least one region (30) of the at least one edge (25) of the support disk (10) is a central region of the at least one edge (25).

6. The torsional damper (2) according to claim 1, wherein the at least one region (30) of the at least one edge (25) of the support disk (10) is rectilinear.

7. The torsional damper (2) according to claim 1, wherein a ratio between an angle (.sub.1) measured from the axis (X) between angular ends of the at least one region (30), and an angle (.sub.2) measured from the axis (X) between angular ends of the at least one edge (25) of the support disk (10) in which the at least one region (30) is configured, is between 0.15 and 0.5.

8. The torsional damper (2) according to claim 1, wherein a maximum distance (D) that the at least one region (30) projects into the at least one window of the one of the input element (6) and output element (8) with which the support disk (10) is integral is at least 0.2 mm.

9. The torsional damper (2) according to claim 1, wherein the support disk (10) is non-moveably connected to one of the input element (6) and the output element (8) by one of rivets (14) and a weld so as to form a rigid connection between the support disk (10) and one of the input element (6) and the output element (8).

10. The torsional damper (2) according to claim 9, wherein the weld is a local weld of a portion of the support disk (10) defined radially internally by the at least one edge (25) of the support disk (10), and a portion of the input element (6) or the output element (8) defined radially externally by the radially external edge of the at least one window of the input element (6) or the output element (8).

11. The torsional damper (2) according to claim 1, wherein: the input element (6) exhibiting a plurality of windows (15) succeeding one another angularly; the output element (8) exhibiting a plurality of windows succeeding one another angularly; and the support disk (10) exhibiting a plurality of windows (17), each window (17) comprising two angularly spaced lateral edges (23) and the at least one edge (25), the at least one edge (25) is a radially external edge (25) in which the at least one region (30) is configured, and wherein each window (17) of the support disk (10) being axially opposite at least a portion of one of the windows of the output element (8) and at least a portion of one of the windows (15) of the input element (6).

12. A friction disk (1) for a clutch, comprising: a hub (3) extending along an axis; a torsional damper (2) according to claim 1; and at least one friction lining (12) carried by the support disk (10) of the torsional damper (2).

13. The torsional damper (2) according to claim 2, wherein the elastic return member (9) also received radially internally with respect to the at least one edge (25) of the support disk (10).

14. The torsional damper (2) according to claim 3, wherein each angular end of the elastic return member (9) is in contact with a seat (27).

15. The torsional damper (2) according to claim 2, wherein the at least one region (30) of the at least one edge (25) of the support disk (10) is a central region of the at least one edge (25).

16. The torsional damper (2) according to claim 3, wherein the at least one region (30) of the at least one edge (25) of the support disk (10) is a central region of the at least one edge (25).

17. The torsional damper (2) according to claim 4, wherein the at least one region (30) of the at least one edge (25) of the support disk (10) is a central region of the at least one edge (25).

18. The torsional damper (2) according to claim 1, wherein the at least one window (17) of the support disk (10) is radially spaced from the axis (X).

19. The torsional damper (2) according to claim 1, wherein the at least one window (17) of the support disk (10), the at least one window (15) of the input element (6) and the at least one window of the output element (8) are radially spaced from the axis (X) and axially spaced from one another.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) A better understanding of the invention will be gained from reading the description below of a non-limiting exemplifying embodiment thereof and from an examination of the attached drawings, in which:

(2) FIG. 1 schematically depicts a disk of a friction disk comprising a damper according to an exemplifying embodiment of the invention;

(3) FIG. 2 is a view, along the axis of the disk, of a region thereof;

(4) FIG. 3 depicts detail III of FIG. 2; and

(5) FIG. 4 depicts a clutch provided with the friction disk and connected to a gearbox.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

(6) FIGS. 1 and 4 depict a friction disk 1 provided for a clutch 4 and equipped with a torsional damper 2 according to an exemplifying embodiment of the invention. This friction disk 1 comprises a hub 3 extending along an axis X. The hub 3 is installed, for example, on a region of an input shaft of a gearbox 5 and is rotationally integral with the input shaft thereof, as shown in FIG. 4.

(7) In known fashion, damper 2 comprises an input element 6 and an output element 8 between which is interposed an elastic return member 9, the latter allowing a limited rotational displacement between the input element 6 and the output element 8. In the example described, the input element 6 is constituted by a web rigidly (i.e., non-moveably) coupled to a support disk 10 for friction linings 12. The support disk 10 constitutes an additional element for damper 2. The web 6 is rigidly (i.e., non-moveably) coupled to the support disk 10, for example, with the aid of rivets 14.

(8) As is evident from FIG. 1, output element 8 is constituted here by two axially offset guide washers arranged axially around web 6. Guide washers 8 are integral and are rotationally fastened on hub 3, for example by means of splines.

(9) In the example considered, damper 2 comprises a plurality of elastic return members 9 succeeding one another angularly, each elastic return element 9 being, in this example, received concurrently in a window 15 configured in web 6, in a window 17 configured in support disk 10, and in a window configured in guide washers 8.

(10) Windows 15 and 17 will now be described in further detail with reference to FIG. 3, in which guide washers 8 are not depicted for reasons of clarity.

(11) Once the web 6 and the support disk 10 have been integrated with the aid of rivets 14, each window 15 of the web 6 is axially and radially opposite the window 17 of the support disk 10. As shown in FIG. 1, each the window 17 of the support disk 10, each window 15 of the input element 6 and each window of the output element 8 is radially spaced from the axis X and axially spaced from one another.

(12) Each window 15 configured in web 6 is delimited on the one hand by: two angularly spaced lateral edges 20, and a radially external edge 21 and a radially internal edge 22.

(13) Radially external edge 21 of a window 15 delimits a strip 16 of the web extending to radially external edge 18 of said web 6. In addition to the use of rivets 14 for rigidly coupling web 6 and support disk 10, each strip 16 of the web can be fastened by local welding to that portion of support disk 10 which is axially and radially opposite the latter.

(14) Each window 17 is delimited on the one hand by: two angularly spaced lateral edges 23, and a radially external edge 25 and a radially internal edge 26.

(15) As is evident from FIG. 2, here the edges of windows 15 and 17 are not rectilinear. In FIG. 2, the edges of window 17 configured in support disk 10 exhibit curved regions. In FIG. 2, radially internal edge 22 of window 15 configured in support disk 10 exhibits a succession of slots.

(16) In the example depicted, radially internal edge 26 of window 17 configured in support disk 10 is, over its entire length, radially behind radially internal edge 22 of window 15 configured in web 6. In other words, edge 22 here projects over its entire length into window 17 configured in support disk 10.

(17) As depicted in FIG. 3, each window 15 configured in web 6 extends over an angular sector, measured from axis X of the hub between two angular ends of radially external edge 21, that is less than the value of the angular sector measured from that same axis X between two angular ends of radially external edge 25 of the opposite window which is configured in support disk 10.

(18) In the example considered, each elastic return member 9 is a spring extending between two angular ends, each angular end coming into abutment against: web 6, support disk 10, and guide washers 8.

(19) In the example of FIG. 2, each angular end of spring 9 comes into contact with a seat 27. When damper 2 is in active, each seat 27 comes into abutment simultaneously against web 6 at a lateral edge 20 of window 15 configured in that web 6, and against guide washers 18 at a lateral edge of the windows configured in those guide washers 18.

(20) As is evident from FIG. 3, radially external edge 25 of window 17 configured in support disk 10 comprises a region 30 projecting radially into window 15 configured in web 6. In the example depicted, region 30 is a central region of radially external edge 25 of window 17 configured in support disk 10. Region 30 here is unique, i.e. outside that region 30, radially external edge 25 of window 17 does not project into window 15 configured in web 6. Region 30 of the example considered is moreover rectilinear. In the example of FIG. 2, the remainder of radially external edge 25 of window 17 is constituted by concave regions 33.

(21) Region 30 has a short length with respect to the total length of radially external edge 25; the ratio here between the angle .sub.1 measured from axis X between the angular ends of said region 30, and the angle .sub.2 measured from that same axis X between the angular ends of radially external edge 25 of window 17 configured in support disk 10, is between 0.15 and 0.5, being in particular between 0.15 and 0.30.

(22) Furthermore, the maximum distance D by which region 30 projects into window 15 configured in web 6 is equal here to at least 0.2 mm. As is evident from FIG. 3, this maximum distance D is measured, between radially external edges 21 and 25 at the center of region 30, orthogonally to said region 30.

(23) When web 6 is rotationally displaced in response to a torque exerted by the combustion engine associated with the transmission system into which friction disk 1 is integrated, that web 6 displaces each elastic return member 9 on which centrifugal forces are exerted. As long as the centrifugal forces remain below a given value, elastic return member 9 does not come into contact with region 30 of radially external edge 25 of the window configured in support 10, which projects into window 15 configured in the web. The presence of regions 30 does not change the functioning of friction disk 1.

(24) When the centrifugal forces exerted on each elastic return member become too large, the elastic return member becomes displaced radially in window 15 until it comes into contact with region 30 of radially external edge 25 of window 17 configured in support disk 10. Thanks to that contact, support disk 10, which is more solid than web 6, absorbs a portion of the centrifugal forces that according to the existing art are applied only onto web 6. Support disk 10 thus plays the part of an additional element of damper 2, reducing the risk of wear on web 6.

(25) The invention is not limited to what has just been described. In other examples that are not depicted, the input element of damper 2 is constituted by guide washers with which support disk 10 is integrated, the output element of damper 2 being constituted by web 6. In this case, region 30 of radially external edge 25 of window 17 configured in support disk 10 projects into the window configured in the guide washer.

(26) In other examples, support disk 10 has no windows, edge 25 then being an edge of that disk 10.

(27) The expression comprising a/an/one must be understood as a synonym of the expression comprising at least a/an/one, unless specified to the contrary.