Oshkosh Corporation
Mixer drum drive with variable displacement motor

Abstract:

A vehicle includes an engine, a drum, a drum drive system, and a control system coupled to the engine and the drum drive system. The drum drive system includes a pump and a motor. The pump is mechanically coupled to the engine and configured to pump a fluid through a hydraulic system. The pump has a variable pump displacement. The motor is fluidly coupled to the pump by the hydraulic system and positioned to drive the drum to agitate the drum contents. The motor has a variable motor displacement. The control system is configured to receive pressure data indicative of a pressure of the fluid within the hydraulic system, reduce the variable motor displacement in response to the pressure of the fluid being less than a threshold system pressure, and reduce a speed of the engine based on the reduction of the variable motor displacement.