Patent attributes
A power management system for a surface maintenance machine, such as a street sweeper is disclosed. The system includes a variable speed engine for transporting the surface maintenance machine, a hydraulic pump powered by the engine, a vacuum fan motor powered by the hydraulic pump, an engine speed sensor coupled to the engine, an electric proportional valve coupled between the hydraulic pump and the vacuum fan motor, said valve for selectively restricting a flow rate to the vacuum fan motor, and a control unit operatively coupled to the engine speed sensor and the proportional valve, said control unit receiving engine speed information from the engine speed sensor and communicating a predetermined signal to the proportional valve to control the flow rate to the vacuum fan motor as a function of engine speed. A method of managing engine power from a single-engine street sweeper is also disclosed.