GB2609222A

GB2609222A - Vehicle driveline couplings

Info

Publication number: GB2609222A
Application number: GB2110605.9A
Authority: GB
Inventors: Homan Keith; Chetwood Struve Benjamin
Original assignee: Raicam Clutch Ltd
Current assignee: Raicam Clutch Ltd
Priority date: 2021-07-23
Filing date: 2021-07-23
Publication date: 2023-02-01
Also published as: GB202110605D0

Abstract

A vehicle driveline coupling (11, fig 1) connects a clutch driven plate (10) to a drive shaft (12). The coupling (11) comprises a primary hub 14 and an anti-rattle cassette (20) having a secondary hub 21. The primary hub 14 and secondary hub 21 have splines 15, 23 which engage splines (13) on drive shaft (12). The anti-rattle cassette (20) comprises an outer housing 24, 24’encircling the secondary hub 21 and having drive formations 27 for insertion into cooperating drive formations 28 on a main drive flange 16. The outer housing is rotationally biased, via springs 26, relative to the secondary hub 21 to maintain contact between the spline teeth of the primary hub 14 and the drive shaft (12) to reduce spline rattle at idle speeds of the driveline. The secondary hub drive formations are retained in engagement with the drive formations on the main drive flange by locating part of the cassette between the main side plates.

Description

VEHICLE DRIVELINE COUPLINGS

This invention relates to vehicle driveline couplings and in particular to such couplings for coupling a driveline component to a splined drive shaft.

Problems arise with such splined connections as the clearances in such connections can give rise to torsional vibrations at engine idle speeds when both sides of the drive shaft splines tend to tap both sides of the hub splines leading to significant idle rattle.

It is an object of the present invention to provide an improved form of vehicle driveline coupling which at least mitigates this rattle problem and which is compact enough to be easily incorporated into a clutch driven plate assembly.

Thus according to the present invention there is provided a vehicle driveline coupling for coupling a driveline component to an externally splined drive shaft, the coupling comprising an internally splined primary drive hub drivingly connected with a radially outer main drive flange, main outer side plates one on each side of the main drive flange for driving connection with the drive component, main coil springs acting circumferentially between the main drive flange and the main outer side plates to damp torsional vibration occurring in the associated driveline, and an anti-rattle cassette comprising an internally splined secondary hub engageable with the external splines of the drive shaft and an outer housing encircling the secondary hub and having drive formations for insertion into cooperating drive formations on the main drive flange, the outer housing being rotationally biased relative to the secondary hub to maintain contact between the spline teeth of the primary hub and the drive shaft after insertion of the drive shaft through the splines of the secondary and primary hubs to reduce spline rattle at idle speeds of the associated driveline, the secondary hub drive formations being retained in engagement with the drive formations on the main drive flange by holding the cassette captive between the main outer side plates.

Such a coupling arrangement, by maintaining drive transmitting contact with the drive shaft splines at idle speeds, eliminates spline rattle in the connection between the primary drive hub and the splines of the drive shaft. The cassette construction of the coupling can be made particularly compact which allows the cassette to be an integral part of, for example, a clutch drive plate.

The cassette may have an axially central disc which has the secondary hub at its inner periphery and which houses secondary circumferentially acting coil springs which act between the central disc and two secondary outer side plates one on each side of the central disc and which form the outer housing of the cassette.

One of the secondary outer side plates may carry the cassette drive formations in the form of axially projecting drive tabs for insertion into corresponding apertures in the main drive flange.

These drive tabs may have radially extending abutment surfaces which are located by the inside of the adjacent main outer side plate to prevent axial movement of the cassette and ensure continued engagement of the drive formations on the cassette and main drive flange.

External drive teeth on the primary hub may conveniently connect with internal drive teeth on an inner periphery of the main drive flange. This provides an axially compact arrangement for connecting drive between the primary hub and the main drive flange.

The present invention also provides a clutch driven plate assembly including a driveline coupling as described above in which annular clutch surfaces are rotationally connected with the main outer side plates.

The rotational torque applied by the secondary circumferentially acting coil springs is typically 2-3 Nm and remains constant throughout regardless of the coupling being in a static condition or for the complete range of moment of the main drive flange.

The present invention will now be described, by way of example only with reference to the accompanying drawings in which:-Figure 1 shows a perspective view of a clutch drive disc incorporating a vehicle driveline coupling in accordance with the present invention; Figure 2 shows an enlarged view of the central portion of Figure 1 with a main outer side plate removed for clarity; Figure 3 shows a sectional view through part of the central portion of Figure 2; Figure 4 shows an exploded perspective view of the coupling of Figure 1; Figure 5 shows an exploded perspective view of a main drive flange and primary drive hub arrangement used in the driveline coupling of Figure 1, and Figure 6 shows an enlarged exploded perspective view of an anti-rattle cassette used in the coupling of Figure 1, and Figure 7 shows an enlarged end view in the direction of arrow A I n Figure 6.

Referring to the drawings, a vehicle clutch driven plate assembly 10 incudes a vehicle driveline coupling 11 for coupling drive to an associated drive shaft 12 with external splines 13. The coupling has a primary drive hub 14 with internal splines 15 which connect drive to a radially outer main drive flange 16 via inter engaging drive teeth 14a and 16a respectively. Main outer side plates 17,17a lie one on each side of the main drive flange 16 and are connected for driving rotation with friction discs 18 of the clutch drive plate assembly 10. Side plate 17 is directly connected with friction discs 18.

The driveline coupling includes main coil springs 19 which act circumferentially between the main drive flange 16 and the main outer side plates 17, 17a to damp torsional vibration according in the driveline during use of the clutch drive plate 10. The ends of each spring 19 act on the appropriate end of cut outs 16b of flange 16 and appropriate end of cut outs 17' in side plates 17 and 17a to resist relative rotation of the main drive flange16 and the side plates 17,17a in the known manner.

In accordance with the present invention an anti-rattle cassette 20 is provided which has an internally splined secondary hub 21 formed on the inner periphery of an axially central disc 22. The splines 23 of secondary hub 21 engage with the external splines 13 of the drive shaft 12 and the cassette has an outer housing formed by secondary outer side plates 24, 24' which are pinned together by rivets 25 which extend through holes 24a and 24a' in side plates 24, 24' encircling the secondary hub. The rivets 25 pass through circumferentially extending slots 22c in disc 22 to allow relative rotation between side plates 24, 24' and disc 22. The central disc 22 and side plates 24 house secondary circumferentially acting coil springs 26 in cut outs 22b and 24b, 24'b which act between the central disc 22 and two secondary outer side plates 24, 24'. A thin wavy washer 29 with matching holes 29a and cut outs 29b takes up any axial play in the assembly of the cassette on rivets 25.

The side plate 24' has axially projecting drive tabs 27 for insertion into corresponding apertures 28 in the main drive flange 16 so that the secondary springs 26 can rotationally bias the secondary hub 21 relative to the main drive flange 16 to maintain contact between the spline teeth of the primary hub and the drive shaft after insertion of the drive shaft through the splines of the secondary and primary hubs. Typically the secondary springs 26 provide a torque of 2-3 Nm which can be tuned to the specific application. Initially the spline teeth 15 and 23 on the hubs 14 and 21 are not rotational aligned (see Figure 7) but the act of inserting the drive shaft 12 into the hubs 21 and 14 rotates hub 21 in the opposite direction to the intended drive direction of rotation B of the coupling thus loading the springs 26 to provide the rotational bias which maintains the teeth 15 and 23 in contact to reduces spline rattle at idle speeds of the associated driveline.

As can be seen from Figures 3 and 6 of the drawings the drive tabs 27 have radially extending abutment surfaces 27a which are located during assembly of the coupling between the main outer side plates 17, 17a so that the secondary hub drive tabs 27 are retained in engagement with the apertures 28 on the main drive flange with axial movement to the right as viewed in Figure 3 being resisted by side plate 17a thus holding the cassette captive between the main outer side plates.

As can be seen from Figure 3 the coupling has various additional components such as the plastic friction washers 31, 32 and 35 and wavy steel washers 33 and 34 to provide hysteresis in the damping between outer side plates 17, 17a and main drive flange 16. Wavy steel washer 36 also takes up any free play between the main hub 14 and the surrounding components.

This anti-rattle cassette arrangement provides particularly compact construction which allows the cassette to be an integral part of, for example, a clutch driven plate assembly.

Claims

CLAIMS1 A vehicle driveline coupling for coupling a driveline component to an externally splined drive shaft, the coupling comprising an internally splined primary drive hub drivingly connected with a radially outer main drive flange, main outer side plates one on each side of the main drive flange for driving connection with the drive component, main coil springs acting circumferentially between the main drive flange and the main outer side plates to damp torsional vibration occurring in the associated driveline, and an anti-rattle cassette comprising an internally splined secondary hub engageable with the external splines of the drive shaft and an outer housing encircling the secondary hub and having drive formations for insertion into cooperating drive formations on the main drive flange, the outer housing being rotationally biased relative to the secondary hub to maintain contact between the spline teeth of the primary hub and the drive shaft after insertion of the drive shaft through the splines of the secondary and primary hubs to reduce spline rattle at idle speeds of the associated driveline, the secondary hub drive formations being retained in engagement with the drive formations on the main drive flange by holding the cassette captive between the main outer side plates.
2 A coupling according to claim 1 in which the cassette has an axially central disc which has the secondary hub at its inner periphery and which houses secondary circumferentially acting coil springs which act between the central disc and two secondary outer side plates one on each side of the central disc and which form the outer housing of the cassette.
3 A coupling according to claim 2 in which one of the secondary outer side plates carries the cassette drive formations in the form of axially projecting drive tabs for insertion into corresponding apertures in the main drive flange.
4 A coupling according to claim 3 in which the drive tabs have radially extending abutment surfaces which are located by the inside of the adjacent main outer side plate to prevent axial movement of the cassette and ensure continued engagement of the drive formations on the cassette and main drive flange.
A coupling according to any one of claims 1 to 4 in which the external drive teeth on the primary hub connect with internal drive teeth on an inner periphery of the main drive flange.
6 A clutch driven plate assembly including a driveline coupling according to any one of claims 1 to 5 in which annular clutch surfaces are rotationally connected with the main outer side plates.