Gm Global Technolgoy Operations, Inc.

Delphi Technologies, Inc.

James Leroy Davison

Albert C Wong

Rick L Lincoln

David R Aden

Thomas C Rytlewski

Tom Cheuk-In Wong

Kenneth P Webber

Johnny M Paris

Carl D Tarum

Rodney M Sanderson

David Fredrick Hammerbacher

James Michael Shea

Ronald Duane Elson

Kevin Mark McClendon

Allan Lee Dickinson

Scott William Clifford

Michael Alan Johnson

James Leibinger

Ali Devrim Can

Henry George Bean

Robert Edward Beyerlein

A vehicular hydraulic system with a pump and first and second hydraulic applications arranged in series. A valve is disposed whereby fluid from the pump flows through an inlet port, primary flow channel and outlet port of the valve to the first hydraulic application. The valve includes a body and a valve member that axially slides within an elongate valve chamber, partitioning the primary flow channel from a low pressure volume. The valve also includes a low pressure port and a bypass port. The bypass port is sealed from fluid communication with the valve chamber in a first position and is in fluid communication with the primary flow channel when the valve member is biased into a second position by a threshold exceeding elevated fluid pressure in the primary flow channel. Fluid discharged from the bypass port is diverted past the first application to the second application.

Vehicular hydraulic system with priority valve

A vehicular hydraulic system having a hydraulic pump and first and second hydraulic applications arranged in series. A dual relief valve defines first and second flow channels, a passageway and a bypass port. The first flow channel is disposed between the hydraulic pump and the first hydraulic application and the second flow channel is disposed between the first hydraulic application and the second hydraulic application. A first valve member controls fluid flow through the passageway and allows fluid flow from the first to the second flow channel through the passageway when fluid pressure within the first flow channel exceeds a first threshold pressure. A second valve member controls fluid flow through the bypass port and allows fluid flow from the second flow channel to a return line through the bypass port when fluid pressure within the second flow channel exceeds a second threshold pressure.

Vehicular hydraulic system with dual relief valve

A vehicular hydraulic system having a pump, first application, pressure-dump valve and second application arranged in series. The pressure-dump valve diverts a portion of the primary fluid flow past the second application when the pressure exceeds a threshold value. A valve member in the pressure-dump valve defines a pressure-reducing orifice that communicates fluid across the valve member. A check valve prevents flow through the pressure-reducing orifice when the pressure in the valve is below the threshold value. When the pressure exceeds the threshold value, fluid flows through check valve and the pressure reducing orifice resulting in the movement of the valve member and exposure of a bypass port thereby diverting a portion of the primary fluid flow past the second application. The check valve may be selectively variable to provide for the adjustment of the threshold value. A priority valve may also be provided upstream of the first application.

Vehicular hydraulic system with pressure dump and relief valve arrangement

A vehicular hydraulic system with a pump and first and second hydraulic applications arranged in series. The fluid upstream of the first application may be elevated to a first threshold pressure value. A pressure-dump valve is disposed downstream of the first application and fluid entering the valve flows through an inlet port, primary flow channel and outlet port of the valve to the second hydraulic application. The valve includes a valve member that axially slides within an elongate valve chamber, partitioning the primary flow channel from a low pressure volume. The valve also includes a low pressure port and a bypass port that diverts fluid past the second application. The valve member is biased into a position wherein fluid is diverted through the bypass port when the pressure in the primary flow channel exceeds a second threshold value. The first threshold value is greater than the second threshold value.

Vehicular hydraulic system with pressure dump valve

A vehicular hydraulic system having a pump, flow-splitting valve, first application and second application arranged in series. The flow-splitting valve diverts a portion of the primary fluid flow to the second application when the pressure exceeds a threshold value. A valve member disposed in the flow-splitting valve defines a pressure-reducing orifice that communicates fluid across the valve member. A one-way relief valve prevents fluid flow through the pressure-reducing orifice when the pressure in the valve is below the threshold value. When the pressure exceeds the threshold value, fluid flows through relief valve and the pressure reducing orifice resulting in the movement of the valve member and exposure of a bypass port to thereby divert a portion of the primary fluid flow to the second application. The relief valve may be selectively variable to thereby provide for the adjustment of the threshold value.

Vehicular hydraulic system with priority valve and relief valve

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.

Hydraulic brake and steering assist system

A hydraulic fluid reservoir for a hydraulic power system includes a reservoir housing having an internal chamber for containing a supply of hydraulic fluid, an outlet for communicating the fluid from the housing to an inlet of a hydraulic pump, and a return flow inlet for receiving a return flow of fluid into the chamber. The reservoir includes a flow diffuser having a diffuser inlet communicating with the return flow inlet for receiving at least a fraction of the return flow into the diffuser. The diffuser has an inner fluid guide wall that is preferably conical which diverges in the downstream direction in order to quiet any turbulence in the flow within the diffuser and to discharge into the bulk of the fluid into the chamber to be deaerated.

Hydraulic pump reservoir having deaeration diffuser

A hydraulic pump includes a housing, a primary discharge outlet, an auxiliary discharge outlet, and a flow control valve for controlling fluid flow from the primary and auxiliary discharge outlets. A first fluid passageway within the housing passes fluid from a first discharge port to the primary discharge outlet, and a second fluid passageway within the housing passes fluid from a second discharge port to a common port of the flow control valve. In a first position, the valve directs fluid from the second discharge port to the primary discharge outlet. In a second position, the valve diverts fluid from the second discharge port to the auxiliary discharge outlet. The valve may be positioned in response to such operating conditions as excessive pressure differential between the high and low-pressure sides, excessive pump rate of rotation (RPM), or excessive rate of fluid flow, among others.

Dual discharge hydraulic pump and system therefor

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. The kinetic energy of the jet stream is converted into fluid pressure in the feeder conduit and in each of the first and the second inlet conduits to suppress cavitation.

Hydraulic system for motor vehicle

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. When the actual flow rate attains a magnitude equal to a desired or scheduled low flow of the flow control valve, the corresponding calibrated position of the tubular sleeve is rigidly captured by friction attributable to the interference fit between the tubular sleeve and the housing.

Demand responsive flow control valve

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. Fluid from the low flow branch dwells in the reservoir for a time duration adequate for natural release therefrom of any entrained gas bubbles.

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. The spherical spring seat is plunged into the stepped bore while the pump is operating to compress the relief valve spring until a reaction force of the relief valve spring on the relief valve element induces a preselected pump relief pressure.

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Freeland, MI, United States of America

James Leroy Davison