Transmission systems may be used to couple the output of a prime mover or power source, for example, an internal combustion engine, to a driven element or device such as wheels or a work implement on a work machine. Transmissions are typically part of a power train that transmits power that may be in the form of torque and/or rotational speed from the power source to the driven element. A continuously variable transmission (CVT) provides an infinite or continuous range of torque-to-speed output ratios with respect to any given input from the power source. In other words, the output of the CVT can be increased or decreased across a continuous range in infinitesimally small increments.
U.S. Pat. No. 8,216,109 issued on Jul. 10, 2012, to Dahl et al. entitled “Torque-Based Control System for a Continuously Variable Transmission” discloses a method of managing the operation of a machine having an operator station with one or more operator interface devices, one or more traction devices and a power train operatively connected to drive at least one of the traction devices. The operator interface devices may include devices for initiating movement of the machine by transmitting signals to a control module. The power train includes a power source, such as an engine, and a transmission unit connected to receive the power output from the power source and transmit the power output to the traction devices. The control module regulates the operation of the transmission unit in response to one or more inputs from the operator interface devices. A first sensor associated with the power source senses an output speed thereof, and a second sensor associated with the transmission unit and/or the traction device senses a travel speed of the machine. The transmission unit may embody a continuously variable transmission. The control module uses information provided by the sensors to control an output torque of the transmission unit that is determined in response to multiple inputs by an operator at the operator interface devices.
USPTO Backgrounds
USPTO Backgrounds