Patent ID: 6655233
Filing Date: 2003-12-02
Classification: B60K,B60W,F16H,Y10T

Abstract:
A speed control system for a utility vehicle, comprising:a controller having an input for receiving a selectable set speed signal; an input device responsive to an operator command to select said selectable set speed signal, said input device signal-connected to said input; a variable displacement pump providing a pressurized hydraulic fluid, said pump having an angularly adjustable swashplate, pump displacement set by the angle of the swashplate; a proportional pressure control valve operatively connected to said swashplate to change the angle of said swashplate, said control valve signal-connected to said controller; a hydraulic motor receiving the pressurized hydraulic fluid from the pump to rotate the motor; a part operatively connected for rotation by the hydraulic motor; a rotation sensor arranged to sense rotational speed of said part, said sensor signal-connected to said controller to send a rotational speed signal to said controller; said controller controlling said proportional control valve with a control signal, said controller changing the angular position of said swashplate in response to a difference calculated by said controller between said rotational speed signal and the set speed signal; and an incremental speed switch signal-connected to said controller, each activation of said incremental speed switch causing said controller to increase said set speed signal by an amount that is a function of said set speed signal, said amount being lesser for a range of lesser set speed signals and greater for a range of greater set speed signals.