GB2202909A

GB2202909A - Clutch alignment device and the use thereof

Info

Publication number: GB2202909A
Application number: GB08706681A
Authority: GB
Inventors: John Frederick Bray
Original assignee: Quinton Hazell Automotive Ltd
Current assignee: Quinton Hazell Automotive Ltd
Priority date: 1987-03-20
Filing date: 1987-03-20
Publication date: 1988-10-05
Also published as: GB8706681D0

Abstract

A clutch alignment device comprising a clutch spine location bush 20. Fig 4, having deformable radial vanes 28 which are adapted to be compressible and removably locatable within any one of a series of varying diameter spline bores 34, Fig 1, of a clutch driven plate 14 of a friction clutch 2, the bush 20 having a longitudinal hole 24 therethrough, a shaft 38 on which the bush is mounted, and means for centralising the shaft 38 relative to a flywheel 6 of the friction clutch 2. The bush includes a tube 22 and a flange 26, the vanes being of rubber or plastics material. A pilot bearing location bush 36 is mounted on the distal end of the shaft 38 and constitutes the centralising means. <IMAGE>

Description

CLUTCH ALIGNMENT DEVICE AND THE USE THEREOF.

The present invention relates to a clutch alignment device and to a method of assembling a friction clutch employing the clutch alignment device.

When assembling a friction clutch to a vehicle, it is necessary to centralise the clutch driven plate relative to the flywheel before the clutch cover assembly is bolted into postiton. Such centralisation is required in order that the gearbox first motion shaft can be passed through the clutch and can engage the pilot bearing in the flywheel without causing any damage to the clutch driven plate.

A known tool for centralising the clutch driven plate comprises a series of cylindrical collars of increasing diameter, each of which is adapted to fit within the clutch driven plate spline bore of a respective diameter. The selected collar of appropriate size is slidably mounted on a shaft on which is threadably engaged a pilot bearing collar of appropriate size. An alternative tool employs a tapered collar which is locatable in the spline bore of the clutch driven plate.

The known tools suffer from the disadvantage that it is necessary to have a number of collars corresponding to the number of different spline bores of clutches which may be assembled by a particular mechanic, so that the tools consist of a large number of individual parts. In addition, when a different dimensioned spline bore is introduced onto the market a new collar is also required.

Furthermore, since each set of collars includes a number of collars, it is often the case that the one collar which is required by the mechanic has become separated from the set.

The present invention relates to a clutch alignment device which can be employed with a variety of sizes of clutch driven plate spline bores.

Accordingly, the present invention provides a clutch alignment device comprising a clutch spline location bush having a deformable portion which is adapted to be compressible and removably locatable within any one of a series of varying diameter spline bores of a clutch driven plate of a friction clutch, the bush having a longitudinal hole therethrough, a shaft on which the bush is mounted about the longitudinal hole, and means for centralising the shaft relative to a flywheel of the friction clutch.

The present invention further provides a method of assembling a friction clutch, which method includes the steps of: (a) removably locating a deformable portion of a clutch spline location bush in the spline bore of a clutch drive plate of the friction clutch, the deformable portion being compressed thereby to be locatable within the spline bore and the clutch spline loction bush having a longitudinal hole therethrough which is aligned with the axis of the clutch driven plate when the clutch spline location bush is located in the spline bore; (b) mounting the bush on a shaft about the longitudinal hole; (c) centralising the shaft relative to a flywheel of the friction clutch thereby to centralise the clutch driven plate relative to the flywheel;; (d) assembling together in coaxial relation a clutch cover, a clutch pressure plate, the clutch driven plate and the flywheel while the clutch driven plate is centralised as aforesaid; and (e) withdrawing the clutch spline location bush, the shaft and the means for centralising from the assembled friction clutch.

An embodiment of the present invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a section through a part of a vehicle friction clutch driving assembly showing how a clutch alignment device of the present invention is employed to align a clutch driven plate with a gearbox shaft pilot bearing which is located in a flywheel; Figure 2 is a section, similar to Figure 1, of the vehicle friction clutch after assembly in accordance with the method of the present invention with the gearbox shaft being aligned with the clutch driven plate.

Figure 3 is an end view of a multi-vaned bush for use in aligning a clutch driven plate with a pilot bearing of a gearbox shaft in accordance with the present invention; Figure 4 is a section on line A-A through the multi-vaned bush of Figure 3; and Figure 5 is an end view of the multi-vaned bush of the Figure 3 when fitted into the bore of a clutch driven plate.

Referring to Figure 1, there is shown a friction clutch 2 for a vehicle during assembly of the friction clutch 2 employing a clutch alignment device 4 of the present invention. The assembly is carried out when the friction clutch 2 is fitted to the vehicle. The friction clutch 2 comprises a flywheel 6 having a flywheel hub 8 in which is located a pilot bearing 10 for receiving an end of a gearbox first motion shaft (not shown). A clutch pressure plate 12 is coaxially spaced from the flywheel 6 in known manner. A clutch driven plate 14 which is mounted on a central splined hub 16 is positioned between the clutch pressure plate 12 and the flywheel 6. A diaphragm spring 18 engages the clutch pressure plate 12 in known manner.

Prior to assembly, the clutch pressure plate 12/diaphragm spring 18 assembly, clutch driven plate 14 and flywheel 6 are separate. In order to assemble the clutch 2, it is necessary to assemble those components together and ensure that they are coaxially located along a single axis along which the gearbox first motion shaft is to be disposed. In accordance with the present invention, this is achieved by locating the hub 16 of the clutch driven plate 14 on a clutch spline location bush 20. The clutch spline location bush 20, which is shown in greater detail in Figures 3 and 4, consists of a cylindrical tube 22 which has a central bore 24 and at one end thereof an annular flange 26. A plurality of vanes 28 extend radially away from the cylindrical tube 22. In the illustrated embodiment, twelve vanes 28 are employed, although this number may be varied as desired.The vanes 28 are equally spaced from each other. Each vane 28 is rectangular in shape and one major rectangular edge 30 is connected to the cylindrical tube 22 and the other major rectangular edge 32 extends parallel to the axis of the tube 22. Each vane 28 is not connected directly to the annular flange 26 and each longitudinal edge of each vane 28 is a free edge. The vanes 28 are made of an elastically deformable resilient material such as a plastics or rubber material. If desired, the whole of the clutch spline location bush 20 may be made of such a material, with the vanes 28 being integral with the cylindrical tube 22 and the annular flange 26.

The undeformed diameter of the vaned-portion of the bush 20 is greater than that of the splined bore 34 of the hub 16 of the clutch driven plate 14. Accordingly, in order to locate the vane-portion of the bush 20 it is necessary to twist the bush 20 into the splined bore 34 thereby to deform the vanes 20 by pushiny the edges 32 of the vanes 28 radially inwardly and circumferentially and thereby to reduce the diameter of the vane-portion of the bush 20 until it is equal to that of the splined bore 34 so that the bush vaned-portion of the bush 20 can be slid into the splined bore 34. The edges 32 of the vanes 28 engage the splines of the splined bore 34. Figure 5 is an end view of the bush 20 in its deformed configuration showing the circumferentilly-deformed vanes 28 with the vaned-portion having a reduced diameter compared to that in the undeformed configuration.

The annular flange 26 of the bush 20 is disposed on that side of the clutch driven plate 14 which is remote from the flywheel 6.

A pilot bearing location bush 36, which consists of a cylindrical tube having an external diameter which is substantially the same as that of the internal diameter of the pilot bearing 10, is positioned in the pilot bearing 10. The pilot bearing location bush 36 is mounted by a snap fit on a shaft 38 which in the assembled configuration extends away from and coaxially with the flywheel 6.

The diameter of the shaft 38 is slightly less than the diameter of the central bore 24 of the clutch spline location bush 20 so as to permit the clutch spline location-bush 20 to be slid freely up and down the shaft 38 but as to permit substantially no relative radial movement between the clutch spline location bush 20 and the shaft 38. The clutch spline location bush 20, upon which the clutch driven plate 14 is located, is slid onto the shaft 38 and pushed towards the flywheel 8 until the friction surface 40 of the clutch driven plate 14 engages the flywheel 6. The clutch pressure plate 12/diaphragm spring 18 assembly is located over the clutch driven plate 14 and is fixed to the flywheel 6, thereby loosely sandwiching the clutch driven plate 14 between the clutch pressure plate 12 and the flywheel 6.The clutch driven plate 14 is still supported by the bush 20 on the shaft 38 which ensures that the centre of the clutch driven plate 14 is aligned with that of the flywheel 6.

A cover 41 is then bolted in position over the clutch pressure plate 12/diaphragm spring 18 assembly thereby clamping the clutch driven plate 14 firmly between the clutch pressure plate 12 and the flywheel 6. In the clamped position, the clutch driven plate 14 is centralised with the centre of rotation of the flywheel 6 since the clutch alignment device 4 has ensured that throughout the assembly operation the bush 20 has supported the clutch driven plate 14 on the shaft 38 which is mounted along the axis of the flywheel 6.

The clutch alignment device 4 is then withdrawn from the friction clutch 2 by pulling the bush 20 out of the splined bore 34 and by removing the pilot bearing location bush 36 from the pilot bearing 10 of the flywheel 6.

As is shown in Figure 2, the gearbox first motion shaft 42 is inserted into the friction clutch 2 when bolting the gearbox into position to the vehicle. The gearbox first motion shaft 42 passes through the clutch cover 44, on which is mounted the clutch release mechanism 46, through the gearbox shaft bearing 48, through the diaphragm spring 18, and through the splined bore 34 of the central hub 16 of the clutch driven plate 14. The end of the gearbox first motion shaft 42 is engaged in the pilot bearing 10.

The clutch alignment device of the present invention permits the clutch driven plate to be clamped on centre with the flywheel so as to permit the gearbox first motion shaft to be passed through the friction clutch and engage the driven plate centre spline and the pilot bearing.

This centralisation ensures that the gearbox can be fitted to the friction clutch in the vehicle since the gearbox first motion shaft can reliably be engaged with the pilot bearing. This centralisation also reduces the danger of damage to the clutch driven pl ate.

The clutch alignment device of the preferred embodiment of the present invention provides an advantage over the known devices in that the spline bore location bush is radially deformable and consequently can be fitted into a variety of diameters of spline bore of clutch driven plates. Accordingly, only one clutch alignment device is required for a number of different clutches. This leads to a reduction of cost when compared to the known systems described above since those systems require a series of spline bore collars of varying diameters. Also, the clutch alignment device is very convenient to use since the mechanic does not initially have to select a bush of the appropriate size when fitting a particular clutch since the single spline bore location bush can be used for a range of sizes of spline bores.

Claims

CLAIMS:

1. A clutch alignment device comprising a clutch spline location bush having a deformable portion which is adapted to be compressible and removably locatable within any one of a series of varying diameter spline bores of a clutch driven plate of a friction clutch, the bush having a longitudinal hole therethrough, a shaft on which the bush is mounted about the longitudinal hole, and means for centralising the shaft relative to a flywheel of the friction clutch.

2. A clutch alignment device according to Claim 1, wherein the clutch spline location bush includes a cylindrical tube which defines the longitudinal hole and the deformable portion comprises a plurality of radially outwardly extending vanes of elastically deformable material which are connected to the cylindrical tube.

3. A clutch alignment device according to Claim 2, wherein the deformable portion comprises twelve vanes.

4. A clutch alignment device according to Claim 2 or Claim 3, wherein the clutch spline location bush further comprises a transverse annular flange at one end thereof.

5. A clutch alignment device according to any foregoing claim, wherein the means for centralising comprises a pilot bearing location bush which is carried on an end of the shaft and is adapted to be centrally located in a pilot bearing of the flywheel.

6. A clutch alignment device substantially as hereinbefore described with reference to the accompanying drawings.

7. A method of assembling a friction clutch, which method includes the steps of: (a) removably locating a deformable portion of a clutch spline location bush in the spline bore of a clutch driven plate of the friction clutch, the deformable portion being compressed thereby to be locatable within the spline bore and the clutch spline loction bush having a longitudinal hole therethrough which is aligned with the axis of the clutch driven plate when the clutch spline location bush is located in the spline bore; (b) mounting the bush on a shaft about the longitudinal hole; (c) centralising the shaft relative to a flywheel of the friction clutch thereby to centralise the clutch driven plate relative to the flywheel;; (d) assembling together in coaxial relation a clutch cover, a clutch pressure plate, the clutch driven plate and the flywheel while the clutch driven plate is centralised as aforesaid; and (e) withdrawing the clutch spline location bush, the shaft and the means for centralising from the assembled friction clutch.

8. A method according to Claim 7 wherein the clutch spline location bush includes a cylindrical tube which defines the longitudinal hole and the deformable portion comprises a plurality of radially outwardly extending vanes of elastically deformable material which are connected to the cylindrical tube.

9. A method according to Claim 8 wherein the clutch spline location bush further comprises a transverse annular flange at that end thereof which is in use positioned on that side of the clutch driven plate which is remote from the flywheel.

10. A method according to any one of Claims 7 to 9 wherein the shaft is centralised relative to the flywheel by locating a pilot bearing location bush, which is carried on one end of the shaft, centrally in a pilot bearing of the flywheel.

11. A method according to Claim 10 herein the pilot bearing location bush is attached to the shaft by a snap-fit.

12. A method of assembling a friction clutch substantially as hereinbefore described with reference to the accompanying drawings.