GB2210674A

GB2210674A - Pulley mounting device

Info

Publication number: GB2210674A
Application number: GB8823115A
Authority: GB
Inventors: Peter Alexander Schneider; Kurt Hiestermann
Original assignee: Volkswagen AG
Current assignee: Volkswagen AG
Priority date: 1987-10-03
Filing date: 1988-10-03
Publication date: 1989-06-14
Anticipated expiration: 2008-10-03
Also published as: JPH01116378A; FR2621367A1; GB2210674B; GB8823115D0

Abstract

A device for fixing a pulley (2) on a shaft is described. In order to ensure simple axial adjustment of the pulley, a substantially radially extending flange part (6) of the pulley (2) is provided with ramp faces (8), which are uniformly distributed about its periphery, extend in the peripheral direction and have an axial slope, on which faces a fastening disc (10), which can be rigidly connected to the shaft and which has corresponding counter-faces (14), is slidably adjustable and can be detachably fixed in individual positions. <IMAGE>

Description

DESCRIPTION PULLEY MOUNTING DEVICE The present invention relates to pulley mounting devices and more particularly to a mounting device for axial adjustment of a pulley on a shaft.

A pulley, provided for a belt drive, is usually rigidly mounted upon a shaft, for example the drive shaft of a secondary drive of a internal combustion engine, by a flange or hub. However, it often happens that there is a large axial offset between the individual pulleys of such a belt drive, which pulleys are connected to one another by the belt in a part of a drive and this offset is unacceptable, particularly in cases where the belt is formed by a so-called ribbed Vbelt (poly-V-belt). It is, however, expensive to axially adjust each pulley individually by placing spacers and the like underneath, and furthermore this adjustment makes assembly more difficult.

It is thus an object of the present invention to provide a device for mounting a pulley on a shaft, which device allows simple axial adjustment to be made to compensate for axial offset.

According to the present invention there is provided a device for axially adjusting the mounting of a pulley on a shaft, comprising a substantially radially extending flange portion forming part of the pulley, a plurality of ramp faces provided on the flange portion, distributed uniformly about its periphery extending in the peripheral direction and having an axial slope, and on which ramp faces a fastening disc adapted to be rigidly connected to the shaft and having corresponding counter-faces, is slidingly adjustable and releasably securable thereto.

In one embodiment, a plurality of ramp faces is provided on the pulley, which ramp faces extend at an angle to the peripheral plane and on which a fastening disc, which is directly connected to the shaft, can be slidably rotated relative to the pulley and detachably mounted in various positions. As a result of this rotation of the fastening disc relative to the pulley on the inclined ramp faces, an axial adjustment of the pulley is obtained relative to the fastening disc forming the holding surface, so that any axial offset occurring between the individual pulleys of the belt drive can readily be compensated.

A specific embodiment of the invention will now be described by way of example only with reference to the accompanying drawings, in which: Fig. 1 is a longitudinal section through a pulley mounting device according to the invention; and Fig. 2 is a view of the pulley mounting device as seen from the front end of the mounting device.

Referring to the drawings, the pulley mounting device as a whole is designated 1, and comprises a pulley 2, a fastening disc 10 and a holding ring 20, which are connected to one another by clamping screws 17. The outer periphery of the pulley 2 is provided with a ring part 3 for holding the belt (not shown), which is formed by a ribbed V-belt, and is connected by way of a substantially radially extending edge bar 4 to a drum part 5, which extends substantially concentrically with respect to the ring part 3. The drum part 5 merges into a substantially radially directed flange part 6, on which ramp faces 8 are formed, which are uniformly distributed about its periphery and which are axially inclined with respect to the peripheral direction.The end regions of the three ramp surfaces 8 provided in this case about the periphery are connected by way of connecting rods 9 to the ends of-the respective adjacent ramp faces. Each ramp face 8 has a longitudinal slot 7, which extends in the peripheral direction. The entire pulley 2 is advantageously made by forming from a sheet steel material.

In order to rigidly fasten the pulley to the shaft (not shown), for example the drive shaft of a secondary or auxiliary drive of an internal combustion engine, the inner periphery of the fastening disc 10 is provided with a plurality of fastening holes 11, which are uniformly distributed about its periphery, for mounting it upon a flange on the drive shaft. The fastening disc 10 may, of course, be connected to the drive shaft in a different way, for example by shrinking a hub part, which is mounted on the fastening disc, onto the drive shaft. The inner periphery of the fastening disc 10 is provided with a bore 12 for mounting the fastening disc on the drive shaft (not shown).

In the region of its outer periphery, the fastening disc 10 has bearing shoes 13, which are provided on the side facing the flange part 6 of the pulley with counter-faces 14 matching the ramp faces 8. Each bearing shoe 13 also has an axially directed through bore 15, through which a clamping screw 17 extends, whose head is held in a recess 16 on the front end of the fastening disc 10.

Radially directed spokes 18 are provided on the fastening disc 10 between the bearing shoes 13 and are held by their outer periphery with a small amount of play in the drum part 5 of the pulley 2, hence providing radial fixing of the pulley 2 with respect to the fastening disc 10 for assembly.

The clamping screws 17 held in the through bores 15 of the bearing shoes 13 engage through the longitudinal slots 7 in the ramp faces 8 of the flange part 6 and each of them is held in a thread 22 of a lock nut 19 on the side of the flange part 6 remote from the fastening disc 10. The lock nuts 19, three of which are provided on the periphery in this case, are connected to one another by way of connecting rods 23, thus forming a holding ring 20. Single lock nuts may, however, also of course be provided. The front end of the lock nuts 19 facing the flange part 6 of the pulley 2 are provided in turn with a bearing surface 21, which is adapted to the slope of the ramp faces 8, so that the holding ring 20 may be disposed parallel to the fastening disc 10 in a plane which is perpendicular to the longitudinal axis of the pulley 2.

The pulley is mounted on the drive shaft in such a way that the unit 1, comprising the pulley 2, the fastening disc 10, the clamping screws 17 and the holding ring 20, is initially pre-assembled, wherein the clamping screws 17 are tightened only to the extent that they still permit relative rotation between the fastening disc 10 and the pulley 2. Subsequently, the fastening disc 10 is first rigidly fixed on the drive shaft, for example by using fastening screws, which engage through the fastening holes 11 and can be anchored to a fixing flange of the drive shaft. By rotating the pulley 2 with respect to the fastening disc 10, which is now axially fixed, the axial position of the pulley 2 can now be fixed within an axial adjustment range determined by the slope of the ramp faces 8 and the length of the longitudinal slots 7. This is done when possible, so that all the pulleys of the belt drive are disposed in a common plane which is perpendicular to the shaft axes. Following adjustment of the pulley 2, the clamping screws 17 are tightened so that the adjusted axial position of the pulley is secured.

The invention thus offers the opportunity for simple, axial adjustment of a pulley during assembly, so that even large axial offsets inside the pulley can be compensated. The invention can also be used to carry out subsequent adjustment or readjustment of the pulley.

Claims

1. A device for axially adjusting the mounting of a pulley on a shaft, comprising a substantially radially extending flange portion forming part of the pulley, a plurality of ramp faces provided on the flange portion, distributed uniformly about its periphery extending in the peripheral direction and having an axial slope, and on which ramp faces a fastening disc adapted to be rigidly connected to the shaft and having corresponding counter-faces, is slidingly adjustable and releasably securable thereto.

2. A device as claimed in claim 1, in which each ramp face has a longitudinal slot extending in the peripheral direction, through which slot a clamping screw engages, for connecting the fastening disc to a lock nut.

3. A device as claimed in claim 2, in which the lock nuts are connected by connecting rods, which extend in the peripheral direction, to form a continuous holding ring.

4. A device as claimed in claim 1 or 2, in which the pulley is produced in one piece with a ring part and the flange part which is provided with the ramp faces, by forming from a sheet steel material.

5. A device as claimed in claim 1 or 2, in which the fastening disc is provided with bearing shoes, which have the counter-faces, and with spokes which are disposed between the bearing shoes and provide fixing inside the pulley.

6. A device for axially adjusting the mounting of a pulley on a shaft, substantially as herein described, with reference to, and as illustrated in, the accompanying drawings.