GB2094910A

GB2094910A - Clutch release assembly including a gear pump for circulating cooling oil

Info

Publication number: GB2094910A
Application number: GB8207588A
Authority: GB
Original assignee: Fichtel and Sachs AG
Current assignee: ZF Sachs AG
Priority date: 1981-03-17
Filing date: 1982-03-16
Publication date: 1982-09-22
Also published as: IT8253067V0; IT8267333A0; GB2094910B; SE8201615L; SE450409B; FR2502272A1; IT1155638B; DE3110256A1

Abstract

The axially displaceable release bearing (7, 15) of a clutch (1), especially a multiple disc clutch, comprises a releaser element (7) rotating together with the clutch (1) and a releaser element (15) stationary in relation thereto. An internal gear pump (11) delivers a current of cooling oil into the clutch (1). The internal gear pump comprises an annular, internally toothed outer gear wheel (5) and an externally toothed inner gear wheel (6) arranged therein. The outer gear wheel (5) and the inner gear wheel (6) are mounted rotatably in a housing (12, 13), mounted on the releaser element (15), of the internal gear pump (11) such that the pump moves axially with the release bearing. The outer gear wheel (5) additionally carries an external toothing (10) which meshes with an external toothing (9) of the rotating releaser element (7). In further embodiments the toothing (10) may be centrally positioned on gear wheel (5) with locating rings on either side for radial location of the wheel (5) in the housing (12, 13). Alternatively toothing (10) may be full width with locating sleeves on either side of the meshing with toothing (9). <IMAGE>

Description

SPECIFICATION Clutch assembly The invention relates to a clutch having a gear pump for cooling agent, for example an oil-cooled multiple disc clutch.

A cooling oil gear pump is known for example from U.S. P.S. No. 3,249,189, in which the axes of rotation for the gear wheels are arranged parallel and radially outside the drive-input shaft and the transmission of the drive movement takes place through an entraining sleeve which is connected fast in rotation with the releaser elements of the clutch, at the same time transmits the release movement and is provided on the external circumference with a toothing concentric with the drive-output shaft. Here the cooling oil gear pump is secured internally to the clutch housing and comprises a gear wheel with appropriately large axial extent, in which there engages the toothing of the entraining sleeve which is connected fast in rotation with the spring tongues of the diaphragm spring and accompanies the release movement of the releaser system.

Now it is the problem of the present invention to produce a cooling oil gear pump which is easy to produce and accommodate without great expense and the drive of which is made as simple and durable as possible.

The formation of the cooling agent pump as internal gear pump or crescent type pump results in a very compact form of construction. Due to the formation of the external circumference of the outer gear wheel of this crescent-type pump with a toothing it is possible for the otherwise necessary intermediate gear wheel to be eliminated without replacement. Due to the arrangement of the cooling agent pump on the release system no relative movement occurs between the individual gear wheels during the operation of release of the clutch, and due to the formation of one part of the release system at the same time as the one part of the pump housing, the fitting of the pump is greatly simplified and adjustment during the fitting operation becomes unnecessary.

The invention will now be explained in greater detail by reference to the examples of embodiment as represented in the accompanying drawings, wherein:- FIGURE 1 shows the section along the line I1--II in Figure 2 through a multiple disc clutch with crescent-type pump arranged in the release system; FIGURE 2 shows the view in the direction "A" in Figure 1; FIGURES 3 to 6 show different embodiments of the toothing on the outer wheel of the crescent type pump.

In the drawings, Figure 1 shows the section Il-Il through a multiple disc clutch with cooling oil pump arranged in the clutch release system.

The multiple disc clutch 1 is here of the usual construction type and its construction is not to be discussed further here. The multiple disc clutch 1 is provided with a diaphragm spring 1 7 the spring tongues 8 of which engage, in their radially inner region, for rotation-fast connection, in a toothing 20 of the entraining sleeve 7, which is at the same time part of the release system of the multiple disc clutch and is mounted through balls 1 6 rotatably in relation to a relase bush 1 5. The release bush 1 5 is here guided displaceably in the axial direction by means of a sliding sleeve 22, for example on a drive-output shaft 2 or on a tube arranged concentrically with the latter.For the transmission of the release movement from a release fork 14 to the spring tongues 8 an entraining sleeve 7 is provided with a circlip 21 on the side of the spring tongues 8 facing the multiple disc clutch 1. The entraining sleeve 7, rotating with the diaphragm spring 17, has in the region between the balls 1 6 and the spring tongues 8 an external toothing 9 which engages in a corresponding external toothing 10 of an annular outer gear wheel 5 of an internal gear pump or crescent-type pump 11, the outer gear wheel 5 and an inner gear wheel 6, arranged in and meshing with the outer gear wheel 5, of the crescent-type pump 11 being guided about their rotation axes 3 and 4 both in a housing 13 and in a bearing cover 12.This bearing cover 1 2 is made in one piece with the release bush 1 5. The housing 13 is disengageably connected with the bearing cover 12 through screws 25.

Figure 2 reproduces the view as seen in the direction "A" in Figure 1. It shows the crescenttype pump 11 from the side of the housing 13, which is detachably secured through the screws 25 to the bearing cover 12 of the release bush 1 5.

A suction pipe 23 leads into the pump and the outiet opening 24 is open in the direction towards the observer. The entraining sleeve 7-engages with its toothing 9 in the toothing 10 of the outer wheel 5 and thus drives the pump.

The operation of the crescent-type pump is as follows: The multiple disc clutch 1 rotates constantly with the internal combustion engine (not shown) during its operation. Thus the spring tongues 8 of the diaphragm spring 17, through the toothing 20, entrain the entraining sleeve 7 which, through its toothing 9 and the toothing 10 of the outer gear wheel 5, drives the crescent-type pump 11. This drive is maintained even when the multiple disc clutch 1 is disengaged or engaged, since the entraining sleeve is at the same time part of the release system and almost constitutes the inner race of the release bearing. During the release and engagement operations the entire crescent-type pump 11 moves with the releaser bush 1 5 correspondingly to and fro in the axial direction.

In this movement the engagement between the toothing 9 and the toothing 10 does not vary. The oil sucked in through the suction pipe at "B" is pumped as indicated by the arrow "C" through the outlet opening 24 into the region of the,multiple disc clutch 1 and there arrives, due to centrifugal force, into the region of the friction faces. In the embodiment of the crescent-type pump 11 according to Figure 1, the outer gear wheel 5 is provided with a toothing 10 which is made slightly wider than the toothing 9 of the entraining sleeve 7. However the outer gear wheel 5 is made substantially wider in the axial direction than the region of the toothing 10, so that the outer gear wheel is rotatably mounted and guided, in the region outside its toothing 10, by means of its external circumference directly in the housing 1 3.

The outer gear wheel 5 in known manner, by an internal toothing, entrains the inner gear wheel 6 by its external toothing and together with this inner gear wheel forms a crescent-type pump 11.

Figure 3 shows a form of embodiment of an outer gear wheel 5 in which this wheel has an external toothing 10 which is arranged approximately in the middle of the outer gear wheel 5. To both sides of the toothing 10 the outer gear wheel 5 is provided with a smaller diameter on which, on each side, a bearing ring 1 8 is fitted. This bearing ring 1 8 serves for the guidance of the outer wheel 5 in the housing 1 3 in the radial direction.

Figure 4 shows a further variant of the outer gear wheel 5. In this embodiment the external toothing 10 is fitted laterally on the outer gear wheel 5 and the outer gear wheel is reduced in diameter outside its toothing 10.

In Figures 5 and 6 the outer gear wheel 5 is provided with an external toothing 10 which extends over the whole width of the outer gear wheel. Such a toothing is especially simple to produce and it is readily possible to mount and guide the outer gear wheel 5 directly with the crown circle diameter of the toothing 10 in a corresponding bore of the housing 13. However, as may be seen especially from Figure 5, it can also be provided that on each of the two sides of the toothing 9 of the entraining sleeve 7 a ring 19 is fitted which forms an unbroken circumferential surface for the mounting of the outer gear wheel 5 in the housing 13.

Claims

1. Clutch assembly having a disc clutch, an axially displaceable clutch release system (7, 1 5) which comprises a first release element (7) rotatable together with the clutch (1) and a second release element (1 5) fixed in relation said first element and an internal gear pump (11) (e.g.

a crescent-type pump) for preparing a covering agent having a housing (12, 13) an annular, internally toothed outer gear wheel (5) and an externally toothed inner gear wheel (6) arranged therein, the outer gear wheel (5) and the inner gear wheel (6) being rotatably mounted in said housing carried by the second release element (15), said outer gear wheel (5) additionally carrying an external toothing (10) which meshes with the external toothing (9) of the first rotating release element (7).

2. Clutch according to Claim 1, characterised in that the inner gear wheel (6) of the internal gear pump (11) meshes with the outer gear wheel (5) on the side of the axis (3) of rotation of the latter remote from the rotating release element.

3. Clutch according to Claim 1 , characterised in that the housing (12, 13) of the internal gear pump (11) is made substantially in two parts and in that one of the housing parts (12) and the stationery release element (15) are connected in one piece with one another.

4. Clutch according to Claim 3, characterised in that the releaser (7, 1 5) is formed as a rolling bearing releaser the rotating release element (7) and the release element (15) stationary in relation thereto of which are integrally provided with tracks for rolling bodies (16), and in that the rotating releaser element is formed as a sleeve (7) the external circumference of which is integrally provided with the external toothing (9).

5. Clutch according to Claim 3, characterised in that the stationary releaser element is formed as an axially displaceably guided bush (15).

6. Clutch according to Claim 3, characterised in that the housing part (12), which is integrally connected with the stationary release element (1 5), is formed as a cover for a housing part (13) enclosing the outer gear wheel (5).

7. Clutch according to Claim 6, characterised in that the inner gear wheel (6) carries bearing journals axially on both sides and is mounted in both housing parts (12, 13).

8. Clutch according to Claim 1, characterised in that the external toothing (9) of the rotating release element (7) is narrower in the axial direction than the outer gear wheel (5).

9. Clutch according to Claim 8, characterised in that the external toothing (10) of the outer gear wheel (5) is narrower in the axial direction than its external periphery and in that the external periphery, at least on one axial side of the external toothing (10), possesses a bearing face for the rotatable mounting of the outer gear wheel (5) in the housing (12, 13).

1 0. Clutch according to Claim 9, characterised in that the diameter of the bearing face of the outer gear wheel (5) is smaller than the crown circle diameter of its external toothing (10).

11. Clutch according to Claim 9, characterised in that the outer gear wheel (5) carries bearing rings (18) axially beside its external toothing (10).

12. Clutch according to Claim 8, characterised in that the external toothing (10) of the outer gear wheel (5) extends over the whole axial width of its external periphery.

13. Clutch according to Claim 12, characterised in that at least one bearing ring (19) is pushed on to the external toothing (10) of the outer gear wheel (5).

14. Clutch assembly substantially as described with reference to the accompanying drawings.