IMPROVEMENTS IN AND RELATING TO VISCOUS FLUID COUPLING DEVICES

摘要

A fluid coupling contains a working fluid and includes a rotatable driving member (11), which is mounted for co-axial rotation within a working chamber (26) forming part of a rotatable driven member (12). A valve plate (42) is mounted within the driven member (12) for rotation therewith and divides the driven member (12) into the working chamber (26) and a fluid reservoir (40). A rotary valve member (46) controls the flow of working fluid between the fluid reservoir (40) and the working chamber (26) through a valve port (44) in the valve plate (42). The valve plate (42) is carried by a valve shaft (56) mounted co-axially with the driven member (12). A temperature responsive bi-metal coil (64), mounted externally of and co-axially with the driven member, has its inner end (85) fixed for rotation with the valve shaft (56) and its outer end (78) resiliently fixed for rotation with the driven member (12). In order to reduce wear and fretting of the valve shaft, the outboard end of the valve shaft (56) is journalled in a bearing member (60) supported by a bracket member (72) fixed to the exterior face (70) of the external wall (55) of the driven member (12) for co-axial rotation therewith. The outer end (78) of the coil is embraced by an elastomeric sleeve (82) which is received in a recess (80) in the driven member (12) and the inner end (85) of the coil is received in a slot (88) in the valve shaft (56).