Caterpillar Inc.

Andrew Kleitsch

John Cody Vacca

Pengfei Ma

Jason Brinkman

Daniel T Mather

Michael D Hudson

Mikhail A Sorokin

Carl McIlheran

Derek W Holmes

A system for stabilizing pressure fluctuations in a hydraulic line of a hydraulic circuit includes a hydraulic vessel coupled to the hydraulic line; a separator element disposed within the vessel to define a first fluid chamber and a second fluid chamber within the vessel; and a relief valve disposed in communication with the second fluid chamber of the vessel. The vessel includes a first fluid receivable in the first fluid chamber from the hydraulic line and a second fluid that is disposed within the second fluid chamber. The separator element is moveable within the vessel in response to a volume change of the first fluid received from the hydraulic line. The relief valve is configured to selectively release the second fluid from the vessel in response to a pressure of the first fluid exceeding a pre-determined amount of pressure within the hydraulic vessel.

System for stabilizing pressure fluctuations in a hydraulic line of a hydraulic circuit

An IMV circuit includes a set of IMVs, an IMV resolver, an on/off bypass valve, and a bypass valve. The set of IMVs is fluidly coupled to an actuator to independently control a flow of a hydraulic fluid to the actuator. The IMV resolver is configured to receive a first pressure signal and a second pressure signal and output a third pressure signal. The on/off bypass valve is configured to control the flow of the hydraulic fluid to the set of IMVs in response to the third pressure signal. The bypass valve is fluidly coupled to a hydraulic fluid supply conduit downstream of an IMV circuit supply. The bypass valve is fluidly coupled to the IMV resolver and is configured to reduce the flow of hydraulic fluid through the hydraulic fluid supply conduit in response to an increase in pressure in the third pressure signal.

Independent metering valve priority in open center hydraulic system

A relief valve in a hydraulic system in a machine selectively sends pressurized oil to both a brake cooling apparatus and a cylinder used to hoist a load. A relief valve lowers pressure spikes in a brake cooling line by dumping fluid in a brake cooling line to tank responsive to a pressure spikes at the head end of the cylinder during hoisting or other transitions in the hydraulic system. Reducing the pressure spikes in the brake cooling line improves reliability of the brake cooling apparatus by protecting seals from undue stresses.

Hydraulic system with an unloading valve

An independent metering valve circuit includes an actuator, a set of independent metering valves, an independent metering valve pre-compensator, an inverse resolver, and a signal conditioning element. The set of independent metering valves are fluidly coupled to the actuator and configured to independently control a flow of a hydraulic fluid to the actuator. The independent metering valve pre-compensator is configured to control the flow of the hydraulic fluid to the set of independent metering valves. The inverse resolver is configured to receive a first pressure signal from the independent metering valve circuit and a second pressure signal from a load-sense hydraulic system and output a third pressure signal. The signal conditioning element is configured to receive the third pressure signal and output a forth pressure signal configured to control a pump fluidly coupled to the load-sense hydraulic system and the independent metering valve circuit.

Hydraulic system including independent metering valve with flowsharing

A wheel housing for a vehicle, such as a truck. The wheel housing includes a rotatable hub and stationary axle housing disposed within the hub. A wet brake assembly is disposed between the axle housing and the hub. The wet brake assembly includes a disc stack, which includes a plurality of friction plates that are coupled for rotation with the hub and that are separated from each other by a plurality of separator plates that remain stationary with the axle housing. The disc stack is cooled by coolant or oil that flows through a closed circuit. During a braking event, pressure spikes in the coolant circuit are alleviated by the placement of a compressible accumulator in the outlet passageway of the coolant circuit.

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Shorewood, IL, United States of America

Andrew Kleitsch