GB2315110A

GB2315110A - Clutch plate

Info

Publication number: GB2315110A
Application number: GB9713912A
Authority: GB
Inventors: Theodor Gassmann
Original assignee: GKN Viscodrive GmbH
Current assignee: GKN Viscodrive GmbH
Priority date: 1996-07-11
Filing date: 1997-07-02
Publication date: 1998-01-21
Anticipated expiration: 2017-07-02
Also published as: GB2315110B; GB9713912D0; JPH1068427A

Abstract

A torsionally damped clutch plate in which a carrier ring 16 carrying friction linings 17, 18 is secured to a damper housing 4, which contains a damping plate 2 and a viscous fluid, by cooperating engaging means which are provided directly on the carrier ring 16 and the damper housing 4 and which comprise circumferentially disposed tooth or tongue formations 22, (32, 35, Fig 2), (42, Fig 3), (52, 55, Fig 4) and complementary receiving formations 21, 24, (31, 34, Fig 2), (41, Fig 3), (51, 54, Fig 4).

Description

Title: CLUTCH PLATE Description of Invention This invention relates to a clutch plate for torsionally-damped transmission of torque; comprising a hub adapted to be connected to an input shaft of a drive unit; at least one damping plate connected thereto and rotationally fast therewith; a damper housing with a carrier ring attached thereto for carrying friction linings; the damper housing enclosing the damping plate and being sealed relative to the damping plate or the hub to contain a damping fluid; with the damping plate and the damper housing rotationally resiliently supporting one another and being rotatable relative to one another to a limited extent damped by said fluid.

A clutch plate of the above described type is known from DE-4416012-A1. A similar clutch plate is described in JP-60-192126-A. With such clutch plates according to the state of the art, the carrier ring is riveted to the damper housing, with the rivets simultaneously serving to connect the damping housing halves. With damper housings of said type enclosing a damping fluid, this type of riveted connection leads to sealing problems because of the need for bores through which the rivets extend.

DE-3903652-A1 proposes a clutch plate with a vibration damper which is provided with a spring-loaded friction device with dry friction at the friction faces. Friction lining carriers of the clutch plate are riveted by hollow rivets to a cover plate of the vibration damping housing, such hollow rivets being formed out of the material of the cover plate.

From DE-3817954-A1 there is known a hydraulic friction damper with a clutch plate attached thereto. A cover plate of the damper housing provided for receiving a viscous medium is provided with rivet projections by means of which a friction lining carrier is riveted on.

DE-3203648 proposes a torsion damping device with an attached friction disc, of which the former comprises a housing consisting of two dish members which are welded together. The friction disc is fixed by rivets which are drawn out of the material of one of the dish members and inserted through bores in the friction disc.

It is the object of the present invention to provide a clutch plate of the kind herein first set forth, which permits a cost-effective and practical connection between the damper housing and the carrier ring, which avoids riveted connections and prevents leakages.

The objective is achieved in that the carrier ring is secured to the damper housing entirely by cooperating engaging means which are provided directly on the carrier ring and on the damper housing and support one another in the circumferential direction, and which comprise circumferentially disposed tooth or tongue formations and complementary receiving formations.

There is thus provided a construction which, because of the elimination of rivet bores and rivets, makes it possible to manage with a minimum of parts and machining operations. The means used are practically neutral in terms of costs, because both the damper housing and the carrier ring may be pressed sheet-metal parts which can easily be provided with the necessary formations.

The damper housing is thus advantageously composed of two disc-shaped sheet metal dishes which are welded to one another at the circumference.

Furthermore, the sheet metal dishes, on their insides, may be provided with cylindrical formations which may form sealing faces relative to the hub. It is clear that a housing produced in this way can easily be provided with form-fitting engaging means without incurring any additional costs.

In a first embodiment the outer circumferential contour of the damper housing and the carrier ring, on its inside, may be provided with tooth formations and complementary tooth-receiving formations which form-fittingly engage with one another. The elements may be axially slid into engagement with one another, and in at least one direction, it is possible to provide effective axial stop means.

There is no need for any additional reciprocal fixing means.

To modify the above embodiment, it is proposed that the tooth formations and the complementary tooth-receiving formations may provide for a circumferential play relative to one another, with compression springs disposed in spaces affording the circumferential play. In addition to the production related advantages, such an embodiment has the function of providing an additional torsional resilience with a low damper and spring stiffness to avoid any gearbox rattling during idling. Respective rotational stops can be provided by the compression springs themselves, which become solid to constitute stops, or by further tooth formations which do not have associated pressure springs and abut before the compression springs become solid.

In the two above mentioned embodiments, the tooth formations of the damper housing can also form rotational stops in the housing interior relative to the at least one damping plate, whose circumference is then provided with corresponding counterformations.

According to a further possible embodiment it is proposed that on the outer circumference of the damper housing or on the inner circumference of the carrier ring, there may be provided circumferential slots into which there are form-fittingly inserted tongue formations of the respective other one of the components in the circumferential direction, which tongue formations are securingly bent at their ends. In this way it is possible to give the damper housing a completely rotationally symmetrical shape, which simplifies the shape of the pressing tools and renders production even cheaper.

To modify the above design, it is proposed that on the outer circumference of the damper housing or on the inner circumference of the carrier ring, there may be provided circumferential slots which, with provision for circumferential play, are engaged by tongue formations of the respective other one of the components, with compression springs disposed in spaces affording the circumferential play. The design is as simple as the one described in the preceding paragraph and again, by using springs with a low stiffness, it is possible to avoid any gearbox rattle during idling.

Examples of the above described embodiments of the invention will be described below with reference to the accompanying drawings, wherein: Figure 1 shows a first embodiment of a clutch plate having tooth formations, in a partial plan view partly in section, and in a longitudinal section; Figure 2 illustrates a second embodiment of clutch plate, with tooth formations and further with an outer idling stage, in a plan view and in a longitudinal section; Figure 3 shows a third embodiment of clutch plate, with slot and tongue connecting means, in a plan view and in a longitudinal section; Figure 4 shows a fourth embodiment of clutch plate, with slot and tongue connecting means and further with an idling stage, in a plan view and in a longitudinal section.

The four embodiments of clutch plate have certain parts in common with one another, and such parts are identified by the same reference numerals throughout. Those common parts will initially be described with reference to all the drawings.

Both the cross-section (on the left) and the axial section (on the right) show a hub 1 with a damping plate 2 connected thereto. The hub has a splined bore with internal toothing 3 for being secured to a driveshaft. The damping plate 2 is enclosed by a damper housing 4 consisting of two annular sheet metal dish parts 5, 6, which, on their outer circumferences, are connected to one another by a weld 7 and which, on their inner circumferences, comprise cylindrical spigots 8, 9 which form sealing faces for annular seals 10, 11 positioned on the hub 1. The damping plate 2 is provided with windows 12 into which there are inserted helical springs 13. The helical springs 13 are enclosed by pocket-shaped formations 14, 15 in the housing halves 5, 6. When the damping plate 2 and damper housing 4 move rotationally relative to one another, respective one ends of the helical springs 13 are supported on the windows and the other ends on the pockets, thus building up returning forces to resist such movement. The damper housing 4 is surrounded by a carrier ring 16 which is substantially annular and planar, and to which friction linings 17, 18 are secured by rivets 19 which extend through rivet bores 20 in the carrier ring 16. The interior of the damper housing 4 is filled with a viscous fluid, such as, and preferably, silicone oil. The identifiable gaps between the damping plate 2 and the inner walls of the damper housing 4 form shear gaps in which the fluid shears, so that relative torsional vibration processes between the hub 1 and the carrier ring 16 are greatly damped.

The carrier ring 16 and the damper housing 4 are connected to one another by form-fitting engaging means which will be described below.

The details described so far are all common to the various embodiments referred to, even if some of the details can only be seen in the partial section to Figure 1.

Figure 1 shows an embodiment wherein the damper housing 4, on its outer circumference, is provided with tooth-receiving formations 21 which, in the circumferential direction, are form-fittingly engaged by inwardly directed tooth formations 22 of the carrier ring 16. Furthermore, between the tooth formations 22, the carrier ring is provided with centring portions 23 which are in contact with the outer circumferential face of the damper housing 4. As can be seen in the axial section, the carrier ring 16 is fitted by sliding on to the damper housing 4 entirely axially, without there existing a relative axial securing connection. Inside the tooth-receiving formations 21, opposite circumferentially-facing faces thereof form rotational stops cooperating with recesses 24 in the damper plate 2 to limit relative angular movement therebetween. The possible relative angles of rotation between the damping plate 2 and the housing 4 have been given the reference symbols az and 4.

Figure 2 shows an embodiment wherein the carrier ring 16 is provided with inner tooth formations 32, 35 in two different shapes which engage outer tooth-receiving formations 31, 34 of the damper housing 4. The formations mentioned engage one another with circumferential play. Between each tooth formation 35 and its receiving formation 34, there are arranged compression springs 36, 37 which by resisting relative circumferential movement form an idling damper acting against gearbox rattle. The angle of relative circumferential movement between the carrier ring 16 and the damper housing 4 is limited by the tooth engaging means 31, 32 which permit relative angles of rotation a1, . All remaining details are identical to those of Figure 1 to which reference is hereby made.

In the embodiment of Figure 3, the inner circumference of the carrier ring 16 is provided with circumferential slots 41, through which tongue formations 42 which are provided on the damper housing 4 extend and are securingly bent at their free ends after passing through said slots. The tongues 42 are formed out of the housing half 6 so as to be integral therewith. The circumferential slots 41 and the tongue formations 42 provide a form-fitting non-rotating connection between the carrier ring 16 and the damper housing 4.

In Figure 4, the inner circumference of the carrier ring 16 is provided with first circumferential slots 51 and second circumferential slots 54 which are respectively engaged with circumferential play by first tongue formations 52 and second tongue formations 55 provided on the outside of the damper housing 4.

The tongue formations are formed out of the housing half 6 so as to be integral therewith. Between each slot 54 and tongue 55 there are arranged compression springs 56, 57 which, together, form an idling damper to avoid gearbox rattle during idling. The maximum permissible rotation between the carrier ring 16 and the damper housing is determined by the circumferential slots 51 and the tongues 52 which permit relative angles of rotation al, o2 until said slots and tongues contact one another.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

1. A clutch plate for torsionally damped transmission of torque; comprising a hub adapted to be connected to an input shaft of a drive unit, at least one damping plate connected thereto and rotationally fast therewith, a damper housing with a carrier ring attached thereto for carrying friction linings; the damper housing enclosing the damping plate and being sealed relative to the damping plate or the hub to contain a damping fluid; with the damping plate and the damper housing resiliently supporting one another rotationally and being rotatable relative to one another to a limited extent damped by said fluid, wherein the carrier ring is secured to the damper housing entirely by cooperating engaging means which are provided directly on the carrier ring and on the damper housing and support one another in the circumferential direction, and which comprise circumferentially disposed tooth or tongue formations and complementary receiving formations.

2. A clutch plate according to Claim 1, wherein the damper housing comprises two disc-shaped sheet metal dishes which are welded to one another at the circumference.

3. A clutch plate according to Claim 1 or Claim 2 wherein the sheet metal dishes are provided with internally cylindrical formations which form sealing faces relative to the hub.

4. A clutch plate according to any one of the preceding claims wherein the outer circumferential contour of the damper housing and the inside of the carrier ring are provided with said cooperating engaging means in the form of teeth and tooth-receiving formations which form-fittingly engage with one another.

5. A clutch plate according to any one of Claims 1 to 3, wherein the outer circumferential contour of the damper housing and the inside of the carrier ring are provided with said cooperating engaging means in the form of teeth and tooth-receiving formations which engage one another with circumferential play therebetween, with compression springs disposed in spaces affording the circumferential play.

6. A clutch plate according to any one of Claims 1 to 3, wherein on the outer circumference of the damper housing or on the inner circumference of the carrier ring, there are provided circumferential slots into which there are formfittingly inserted tongue formations of the respective other one of the components, which tongue formations are bent for securement.

7. A clutch plate according to any one of Claims 1 to 3, wherein on the outer circumference of the damper housing or on the inner circumference of the carrier ring, there are provided circumferential slots which, with provision for circumferential play, are engaged by tongue formations at the respective other one of the components, with compression springs disposed in spaces affording the circumferential play.

8. A clutch plate substantially as hereinbefore described with reference to any of the accompanying drawings.

9. Any novel feature or novel combination of features described herein and/or in the accompanying drawings.