VERTEILERVENTIL FUER EINE INNENACHSIGE KREISKOLBENMASCHINE.

摘要

A rotary fluid pressure device is provided of the type including a gerotor gear set (17) including an orbiting and rotating star (27) providing output torque by means of a main drive shaft (41). The device includes a valve housing section including a relatively thicker outer housing (61) and a relatively thinner inner housing (73) press-fit within the outer housing with an interference fit causing a preload force equal to the equivalent force of a predetermined fluid pressure, to avoid expansion of the spool bore (81). Disposed within the spool bore is a spool valve (55) which is relatively solid and able to withstand the predetermined fluid pressure without collapse of the spool valve. The spool valve defines axial slots (93) and (95) communicating by means of passages (97 and 99) with pressure-balancing recesses (101 and 103), whereby the valve spool is axially pressure balanced. The motor has improved volumetric efficiency, as well as improved mechanical efficiency.