GB2163223A - Multi-plate clutch in compressor assembly - Google Patents

Abstract

A clutch-driven air compressor assembly has a housing 1 including compressor crankshaft 7 the driven end of which engages through splines 20 with the inner plates 21 of a spring-applied multiplate clutch and also rotatably supports the inner end of a drive, part 15 of which engages with the cage 23 of the clutch. The pressure of the springs 26 causing the plates to be engages is opposed by a fluid pressure operable release piston which acts between the housing 1 and the cage 23. The input shaft 11 is mounted on bearings 12, 16 and the crankshaft 7 in a bearing 18. <IMAGE>

Description

SPECIFICATION Compressor Assembly This invention relates to a compressor assembly and relates especially to a compressor assembly having a rotary member driven through a clutch.

In the Specification of United Kingdom Patent Application No. 8331 867 there is described an air compressor having a rotary member driven through a clutch and wherein there is provided enhanced support length for an input shaft for the clutch.

The present invention seeks to provide an alternative and yet further improved compressor driven through a clutch.

According to the invention there is provided a compressor assembly including a housing having an input shaft rotatably supported in a first bearing in the housing a second bearing rotatably supporting an inner end of the shaft in relation to the driven end of a compressor shaft said input shaft having a part rotationally coupled to a cage of a multiplate clutch through which said compressor shaft is driveable, resilient thrust means acting between said cage and said engaging means in a sense to engage the clutch and release means operable between the cage and the housing in a sense to oppose the thrust means.

In order that the invention may be more clearly understood and readily carried into effect the same will be further described by way of example with reference to the accompanying drawing the single figure of which illustrates part of an air compressor according to the invention. Referring to the drawing the compressor has a cast metal housing in the form of a combined crankcase and cylinder denoted by reference 1 the cylinder being provided with a valve plate 2 containing the necessary valves co-operating with a cylinder head 3 with suitable inlet and output ports the details of which are of,no consequence in relation to the present invention and may be of a suitable construction.The compressor is provided with a piston 4 and a connecting rod 5 for effecting reciprocation of the piston 4 in the bore 6 of the cylinder by virtue of rotation of a crankshaft 7 the free end of which runs in a bush 8 in an end plate 9 on one end of the crankcase. The other end of the crankcase is provided with a generally cylindrical integrally cast extension 10 which houses a clutch assembly via which the crankshaft is driven by a rotatable input shaft portion 11 which runs in a taper roller bearing 1 2 captive in a further end plate 1 3 on this end of the housing. The outer end of the shaft 11 is provided with a keyway 1 4 and suitable fixing means (not shown) for mounting coupling means for engagement with a gear train of an internal combustion engine for driving the compressor.The input shaft 11 is integral with an input part 1 5 of a multi-plate clutch and being coaxial with the crankshaft 7 of the compressor.

The inner end of the input shaft 11 is carried in a ball bearing 1 6 which is itself captive in a recess 1 7 formed in the inner drive end 1 9 of the crankshaft 7 which is carried in a further larger ball bearing 1 8 captive in the crankcase. The driven end 1 9 of the crankshaft is further externally splined at 20 for keyed engagement with four driven plates 21 of a multiplate clutch on one side of 1 5 interleaved with drive plates 22. These drive plates 22 and member 1 5 are rotationally located within a cylindrical clutch cage by virtue of ears formed on the peripheries of 1 5 and 22 engaging with axial slots of 23.Cage 23 is provided with an inwardly projecting flange 24 between which and the other side of 1 5 a cage 25 carrying equi-spaced springs 26 is located. The reaction to the clutch springs acting through the interleaved clutch plates is provided by an annular member spotwelded to the inner surface of the inner end of the clutch cage 23. The release mechanism for the clutch comprises an annular piston 28 provided with seals and whilst having a rotationally locating projection 32 engageable with a recess of the housing, is axially moveable in a fluid cylinder 29 under the effect of an air pressure signal applied at a port 30 in the end plate 1 3. The piston acts through the intermediary of a suitable clutch thrust bearing cage 31 to apply a clutch release force to the flange 24 of the cage.

In use, the Compressor assembly may be bolted to the crankcase of the engine of a vehicle and the shaft 11 is continuously directly gear driven by the engine.

The port 30 is connected to a governor responsive to the pressure in a reservoir to be charged with compressed air by the compressor. Alternatively, the compressor may if desired be mounted separately from the engine for belt driving or otherwise. In operation of the assembly, in the absence of a suitable compressed air signal at the control port 30 from a governor or control valve, the clutch assembly will be in the engaged condition and therefore full drive torque will be applied from the input shaft 11 through the clutch assembly to the crankshaft 1 9 of the compressor for charging compressed air storage reservoirs.Upon attainment of a first predetermined compressed air pressure in the reservoirs, the governor or control valve will provide a pressure signal via the passage 30 to the release piston 28 which, reacted by the bearing 12, will be urged right wards to compress the disc springs 26 and quickly release the clutch. The compressor will then stop until the controlling pressure signal in passage 27 is again removed to re-engage the clutch. During the released condition of the clutch, any tendency for rotation of the piston 22 will be prevented by locating projection 32 which holds the piston 22 in a given position in relation to the end plate 1 3.

When the pressure in the storage reservoirs falls again below a second relatively lower pressure value the signal pressure at port 30 is rapidly removed whereby the clutch reengages to reinstate the charging mode.

In order to enhance the support length, if required, for the drive shaft 11, the axial depth of the recess 1 7 in the inner end of crankshaft 1 9 may be increased in order to accommodate a larger input shaft and to permit the bearing 16 to be located within the plane of action of the bearing 1 8.

Claims (5)

1. A compressor assembly including a housing having an input shaft rotatably supported in a first bearing in the housing a second bearing rotatably supporting an inner end of the shaft in relation to the driven end of a compressor shaft said input shaft having a part rotationally coupled to a cage of a multiplate clutch through which said compressor shaft is driveable, resilient thrust means acting between said cate and said engaging means in a sense to engage the clutch and release means operable between the cage and the housing in a sense to oppose the thrust means.

2. A compressor assembly as claimed in claim 1 wherein said second bearing is carried in a recess of the driven end of the compressor shaft.

3. A compressor assembly as claimed in claim 1 or 2 wherein said release means comprises a fluid pressure operable annular piston sealingly moveable in an end cover of the housing which carries said first bearing.

4. A compressor assembly as claimed in claim 1, 2 or 3 said release means acting on said cage through a thrust bearing.

5. A compressor assembly substantively as described herewith reference to the accompanying drawling.