| 摘要 |
A control valve of rotary type controls a flow of hydraulic fluid by relative rotational displacement between a pair of elements (13, 14) of the valve. A C-shaped spring (12) preloads the elements to a neutral position and is resiliently deformed upon movement of the elements from that neutral position. The spring is displaced only in a plane perpendicular to the rotary valve axis, and is constrained against movement out of that plane. In one form, this is achieved by transmitting the spring load through projections consisting of a pair of projections (11, 17) rotatable with one of the valve elements and a further projection (10) rotatable with the other of said elements and disposed axially intermediate said pair of projections. By such means the gap opened by the increasing diameter of the spring as it is deformed does not interfere with the accurate and reliable return of the valve to the neutral position. In another form, the spring is constrained between a snap ring and a shoulder on the valve element 14. <IMAGE> |
