Patent ID: 8720197
Filing Date: 2014-05-13
Classification: E02F,F15B

Abstract:
1. A hydraulic system with hydraulic fluid flow management, comprising at least one actuator system, a boost system for accepting or supplying fluid from or to the at least one actuator system, and a controller; the actuator system including a hydraulic actuator to and from which hydraulic fluid is supplied and returned in opposite directions to operate the actuator in opposite directions, a bi-directional pump operable in one direction for supplying pressurized fluid from a first inlet/outlet port to the hydraulic actuator for operating the actuator in one direction, and operable in a second direction opposite the first direction for supplying pressurized fluid from a second inlet/outlet port to the hydraulic actuator for operating the actuator in a direction opposite the first direction, and an electric bi-directional pump drive for driving the bi-directional pump in either direction; the boost system including a boost pump for supplying fluid to a fluid make-up/return line that selectively is in fluid communication with one of the inlet/outlet ports of the bi-directional pump when the other of the inlet/output ports is supplying pressurized fluid to the hydraulic actuator, and an electric boost pump drive for driving the boost pump; and the controller including at least one logic device for controlling operation of the electric bi-directional pump drive and the boost pump drive, the logic device controlling the boost pump drive being configured to control operation of the boost pump drive based on at least one of (a) a speed at which the bi-directional drive is commanded to operate, (b) a load acting on the electric bi-directional pump drive, (c) hydraulic line losses in the actuator system, (d) a commanded acceleration of the bi-directional drive, and (e) combinations of two or more thereof.