Abstract: An improved hydraulically assisted braking and steering system of a vehicle having a hydraulic pump communicating with a hydraulic steering assist device and including a hydraulic brake assist device coupled in series between the pump and the steering assist device includes the provision of a flow splitter which operates to reduce the interdependence of the hydraulic brake and steering assist devices on the flow of fluid from the pump. The flow splitter communicates with the outlet of the pump and the inlet of the brake assist device and is operative when the back pressure from the brake assist device exceeds a predetermined control value to divert a fraction of the flow of fluid around the brake assist device directly to the steering assist device, thereby providing sufficient flow to operate both the brake and steering assist devices within their normal design limits, rather than having the brake assist device starve the steering assist device when under heavy load.

Abstract: An improved hydraulically assisted braking and steering system of a vehicle having a hydraulic pump communicating with a hydraulic steering assist device and including a hydraulic brake assist device coupled in series between the pump and the steering assist device includes the provision of a flow splitter which operates to reduce the interdependence of the hydraulic brake and steering assist devices on the flow of fluid from the pump. The flow splitter communicates with the outlet of the pump and the inlet of the brake assist device and is operative when the back pressure from the brake assist device exceeds a predetermined control value to divert a fraction of the flow of fluid around the brake assist device directly to the steering assist device, thereby providing sufficient flow to operate both the brake and steering assist devices within their normal design limits, rather than having the brake assist device starve the steering assist device when under heavy load.

Abstract: A hydraulic system for a motor vehicle having a first flow circuit for steering power assist and a second flow circuit for a radiator cooling fan. The first flow circuit includes a reservoir, a power steering pump connected to the reservoir through a first inlet conduit and a first return conduit, a steering assist fluid motor, and a first flow control valve. The second flow circuit includes the aforesaid reservoir, a second pump connected to the reservoir through a second inlet conduit and a second return conduit, a second fluid motor for the radiator cooling fan in the second return conduit, and a second flow control valve. Fluid in the first return conduit is conducted into the reservoir substantially without turbulence. Fluid in the second return conduit is conducted into the reservoir as a jet stream aimed at a submerged passage in a venturi tube. The submerged passage communicates with a feeder conduit between the reservoir and each of the first and the second inlet conduits.

Abstract: A demand responsive flow control valve including a housing in a fluid conduit between a pump and a motor vehicle power steering gear, a flow control orifice in the fluid conduit, and a valve pintle supported on the housing for linear translation. An inboard stop on the housing engageable by the valve pintle defines an active position of the valve pintle, obstructing the flow control orifice and reducing the effective area of the latter. The inboard stop is a tubular sleeve interference fitted in a bore in the housing. The position of the tubular sleeve on the housing corresponding to the active position of the valve pintle is established by inducing linear translation of the tubular sleeve into the bore in the housing as a unit with the valve pintle while monitoring the corresponding flow rate through the fluid conduit.

Abstract: A motor vehicle hydraulic system including a power steering pump, a reservoir, a steering assist fluid motor, and a second fluid motor for a radiator cooling fan. A flow control valve remote from the power steering pump divides the total fluid flow from the power steering pump into a high flow branch and a low flow branch. Fluid circulates in the low flow branch at a substantially constant flow rate for a proportional control valve for the steering assist fluid motor and returns to the reservoir through an unrestricted tubular boss on the reservoir. Fluid in the high flow branch issues as a jet stream from a nozzle on the reservoir into a venturi passage submerged in fluid in the reservoir. The venturi passage is connected to an inlet port of the power steering pump. The jet stream aspirates fluid from the reservoir into the venturi passage. The kinetic energy of the jet stream is converted into superatmospheric pressure at the inlet port of the power steering pump to suppress cavitation.

Abstract: A hydraulic pump having a flow control valve for recirculating a fraction of the discharge of a rotating group of the pump and an externally adjustable pressure relief valve. The flow control valve includes a cylindrical bore in a housing of the pump, a discharge passage intersecting the bore, a recirculation passage intersecting the bore, and a valve spool slideable in the bore. A valve body on the housing closes an open end of the cylindrical bore and cooperates with the valve spool in defining a spring chamber connected to the discharge passage. A spring in the spring chamber biases the valve spool to a position corresponding to zero recirculation. The relief valve includes a stepped bore in the valve body, a valve seat in the stepped bore, a valve element, a spring biasing the valve element against the valve seat, and a spherical metal spring seat interference fitted in the stepped bore.