Patent ID: 8024925
Filing Date: 2011-09-27
Classification: F16H

Abstract:
1. A hydromechanical transmission for outputting a desired torque, comprising: a variable displacement pump configured to be drivingly connected to an engine; a motor drivingly connected to the variable displacement pump; an actuator configured to receive pressure to manage a circuit pressure of the variable displacement pump; and a control module configured to determine the desired torque and to calculate an amount of pressure to apply to the actuator to adjust the variable displacement pump to cause the hydromechanical transmission to output substantially matching the desired torque; and a pressure controlling device communicably coupled to the control module and the actuator and configured to adjust the pressure in the actuator in response to a signal from the control module, wherein the pressure controlling device includes a first pressure controlling valve coupled to the control module and a first side of the actuator, configured to adjust a pressure on a first side of the actuator in response to a first signal and a second pressure-controlling valve coupled to the control module and a second side of the actuator, to adjust a pressure on a second side of the actuator in response to a second signal, and a first pressure sensor connected to an output from the first pressure controlling valve, and a second pressure sensor connected to an output from the second pressure-controlling valve.