Abstract: A hydraulic device includes an internally toothed stator formed by a one-piece homogeneous body having a continuous inner wall defining a series of circumferentially spaced arcuate recesses each of which is dimensioned to receive a radially and circumferentially shiftable roller vane. The continuous inner wall further includes a series of radially oriented notches which are disposed between the arcuate recesses and which serve to make portions of the stator wall defining the arcuate recesses resiliently deflectable as a function of the forces applied to the rollers vanes. Further, the notches direct fluid flow to and from expanding and contracting fluid pockets defined between the roller vanes and the teeth of an externally toothed rotor located within the stator.

Abstract: A hydraulic motor includes an elongated output member which is supported for rotational movement about a central axis thereof. The output member is driven by a gerotor gearset which includes an outer member having internal teeth which mesh with external teeth on an inner member. The inner member is fixed against movement and the teeth on the inner and outer members define a series of expansible and contractable fluid pockets. The outer member orbits and rotates as a result of fluid being directed into certain of the fluid pockets to expand same and fluid is directed from contracting pockets. A tubular member drivingly connects the outer member and output member and transmits driving torque to the output member. The tubular member is connected in a 1:1 rotational driving relationship with the outer member and output member.

Abstract: The present invention relates to a hydrostatic controller for controlling fluid flow to a device such as a steering cylinder for a vehicle. The controller comprises a gerotor gearset. The gerotor gearset includes a rotor and a stator which define expanding and contracting fluid pockets upon relative rotational and orbital movement therebetween. A control valve forms a part of the hydrostatic controller and the control valve includes a valve spool which is movable upon an input signal thereto to direct fluid to the device which is controlled by the hydrostatic controller and to receive return fluid from that device. In addition, the control valve spool in cooperation with the housing therefor functions as the commutator valve for the gerotor gearset for directing fluid to and from the expanding and contracting pockets of the gerotor gearset.