Electric-motor pump unit for use in hydraulic arrangement, has oil heat exchanger cooling pressurizing medium, as air flow stands in heat exchange with pressurizing medium volume flow flowing through oil heat exchanger

摘要

The unit has an electric motor (4) i.e. asynchronous variable-speed electric motor, for driving a hydro pump (2) e.g. interior gear pump, and a fan (36). The fan produces air flow (38), which cools the electric motor. An oil heat exchanger (32) cools a pressurizing medium, as the air flow stands in heat exchange with the pressurizing medium volume flow flowing through the oil heat exchanger. The speed of the electric motor is adjustable by a frequency inverter (20), which controls the speed for regulating pressure.