Abstract: A hydraulic flow control valve assembly comprises an inlet port for input fluid flow from a pump, a first outlet port for output fluid flow to a power steering unit, a second-outlet port for output fluid flow to an accumulator of a braking system, and an excess flow port for output fluid flow to other services or a tank. A flow control valve controls the fluid flow from the inlet port to the outlet ports and the excess flow port, and a load sensing port communicates a load-dependent pressure signal from the power steering unit to the valve so as to provide priority fluid flow to the power steering unit. A pilot valve is provided for cutting off the load-dependent pressure signal when the pressure within the accumulator falls below a predetermined value so as to provide for fluid flow from the valve to the accumulator, and in addition a pressure difference sensing arrangement communicates the pressure difference across a restrictor to the valve so as to provide fluid flow to the accumulator.

Abstract: A rotary positive displacement hydraulic machine such as a gear pump or motor, comprises a housing defining two mutually intersecting parallel working chambers, two meshing rotors mounted for rotation in the two chambers, respectively, and two bearing supports at opposite ends of the parallel chambers and each supporting bearings in which the two rotors are journalled for rotation. The housing is open at one or both ends. The or each open end of the housing has a hollow, non-circular spigot which is received in a recess of matching non-circular shape defined by a continuous flange projecting from a peripheral region of a respective bearing support in a direction parallel to the axes of rotation of the meshing rotors and which is surrounded by a shoulder extending from the spigot to the peripheral edge of the housing, so that the or each open end of the housing is supported by its bearing support against outwards movement in a plane transverse to the axes of rotation of the meshing rotors.

Abstract: A hydrostatic transmission for a vehicle, such as a commercial walk-behind mower, comprises a fixed displacement pump, first and second reversible hydraulic motors for driving first and second ground engageable wheels, respectively, of the vehicle, and first and second spool valves for controlling hydraulic fluid flow from the fixed displacement hydraulic pump to the first and second hydraulic motors, respectively. The transmission may have a further fixed displacement hydraulic pump arranged in tandem with the first mentioned pump, a fluid pressure operated device and a third spool valve movable between a first position in which hydraulic fluid from the further pump is supplied to the pressure operated device and a second position in which hydraulic fluid from the further pump is supplied to the first and second spool valves to supplement hydraulic fluid from the first mentioned hydraulic pump.

Abstract: The retarder is installed adjacent a railway track for reducing the speed of a wagon rolling along the track and additionally has the capability of boosting the speed of a wagon. The retarder includes a hydraulic unit having a portion adapted to be deflected out of the path of a wheel of the wagon when directly or indirectly engaged by the wheel before returning to its original position. The unit has adjustable hydraulic damping capable of resisting such deflection to retard the wagon, and a wagon speed responder for adjusting the hydraulic damping of the unit to retard a wagon travelling at high speed.

Abstract: A rotary drive mechanism comprises an hydraulic motor, a shaft rotatable by the hydraulic motor, a cutting blade (or fan impeller) connected to the shaft, and a bearing assembly supporting the shaft. The bearing assembly comprises a bearing housing, a plain journal bearing mounted in the housing, and a plain thrust bearing integral with the journal bearing also mounted in the housing.