Caterpillar Inc.

Moses Imo Akpan

Gang Victor Wen

Edward William Mate

Steven Edward Johnson

Michael D Hudson

Sudarshan Maiyur

Dennis Ray Barber

John J Kaufman

Eric P Jakubiak

Scott D Vollmer

Susan E Bieker

A hydraulic circuit includes: a priority valve including a first position and a second position where: the first position includes a first fluid passage and a fixed bypass orifice connected to the first fluid passage; the second position includes a second fluid passage and a variable bypass orifice connected to the second fluid passage. The hydraulic circuit further includes: a first fluid line fluidly connecting the priority valve and a first machine component; a second fluid line fluidly connecting the priority valve and a second machine component; a check valve placed between the priority valve and the second machine component and fluidly connecting the priority valve and the second machine component; an oil passage on the priority valve fluidly connected to one or more machine components other than the first and second machine components; one or more actuators connected to the priority valve; and a control valve communicatively connected to the one or more actuators connected to the priority valve.

Brake charge valve with set minimum fixed hydro-mechanical pressure by-pass function

A main valve and method assembling for use on a machine is disclosed. The main valve may comprise a body, a free wheeling valve, a bypass valve, a flow divider valve, a free wheeling pilot valve, and a flow divider bypass pilot control valve. Each valve may be disposed inside the body. The body may define a plurality of ports and channels between the valves. The free wheeling valve may be operable between a free wheeling mode and a drive assist mode. The bypass valve may have a flow dividing mode that permits fluid communication between the free wheeling valve and the flow divider valve, and a bypass mode that permits fluid communication between the free wheeling valve and first and second bypass channels.

Flow divider free wheeling valve

A hydraulic fan circuit is provided. The hydraulic fan circuit includes a tank, a motor having a fluid inlet and a fluid outlet and a pump to draw fluid at a low pressure from the tank and discharge the fluid at elevated pressures to the motor via the fluid inlet. The hydraulic fan circuit further includes a directional control valve disposed between the fluid outlet of the motor and the tank. The directional control valve is operable to move between a flow blocking position and a flow passing position. Further, the directional control valve is configured to reduce a positive speed of the motor below a lowest positive speed attainable through control of pump output. Furthermore, the hydraulic fan circuit includes a pressure control circuit configured to provide a pilot fluid flow at varying pressure to move the directional control valve.

Hydraulic system having low speed operation

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Channahon, IL, United States of America

Moses Imo Akpan