Caterpillar Inc.

Aaron Benjamin Crabtree

Brian Eugene Lister

Michael David Beyer

Gaurav Vasudeva

Konrad Garrett

Jeremiah C Johnson

Russell Ross Henderson

Christopher W Pruess

Abdul Karim Maoued

A system including a gearbox and a hydraulic machine connected by a working fluid circuit. The gearbox including a gearbox housing having first and second gearbox fluid passages integrated into the gearbox housing. The hydraulic machine including a case having first and second hydraulic machine fluid passages, the first and second hydraulic machine fluid passages being integrated into the case. A set of rotating elements enclosed within the case. The first gearbox fluid passage and the first hydraulic machine fluid passage align to form a feed passage to conduct fluid at a first pressure from a first source to the set of rotating elements. The second gearbox fluid passage and the second hydraulic machine fluid passage align to form a charge passage to conduct fluid at a second pressure from a second source to the set of rotating elements. The first pressure being less than the second pressure.

Cooling scheme for hydrostatic transmission

A transmission for a machine is disclosed. The transmission may comprise a first torque path for transmission of torque from an input shaft to an output shaft, and a single clutch element along the first torque path. The transmission may further comprise a clutch actuator configured to actuate engagement of the clutch element, and a clutch pressure control (CPC) valve configured to permit a flow of hydraulic fluid to the clutch actuator when in an open position to cause the clutch actuator to actuate engagement of the clutch element. The transmission may further comprise a FMR valve having a failure position obstructing flow of the hydraulic fluid from the CPC valve to the clutch actuator when the CPC valve is in the open position. The FMR valve actuated by pilot pressure from a CPC valve that controls actuation of other clutch elements that are not on the first torque path.

Clutch hydraulic control circuit with a pilot operated failure mode response valve

A transmission for a machine is disclosed. The transmission may comprise a torque path providing a path for transmission of torque from an input shaft to an output shaft, and a single clutch element along the torque path. The transmission may further comprise a clutch actuator configured to actuate engagement of the clutch element, and a clutch pressure control (CPC) valve configured to permit a flow of hydraulic fluid to the clutch actuator through a control pressure line when in an open position to cause the clutch actuator to actuate engagement of the clutch element. The transmission may further comprise a failure mode response (FMR) valve in the control pressure line between the CPC valve and the clutch actuator. The FMR valve may have a failure position obstructing flow of the hydraulic fluid from the CPC valve to the clutch actuator when the CPC valve is in the open position.

Machine transmission with clutch element hydraulic control

A controller is provided for varying gear ratios in a transmission system including at least one planetary gear train disposed within a housing. The controller includes a ratio control gear set, a ratio control pump, and a relief valve. The ratio control gear set includes a sun gear, a planet carrier, and a ring gear. The planet carrier is configured to rotatably connect to an output shaft of an engine. The ring gear is configured to mesh with a sun gear of the planetary gear train. The ratio control pump includes a body configured to rigidly connect to the housing, and a rotor rigidly coupled to the sun gear of the ratio control gear set. The rotor is configured to co-act with the body to pump fluid. The relief valve is configured to restrict fluid egress from the ratio control pump.

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Metamora, IL, United States of America

Aaron Benjamin Crabtree