Patent ID: 7086241
Filing Date: 2006-08-08
Classification: B60H

Abstract:
1. A power unit for a refrigeration system for use in a land transport vehicle having an engine for propelling the land transport vehicle and a power take off from the engine, the refrigeration system having a compressor for compressing a refrigerant and an evaporator which is cooled by the compressed refrigerant, the power unit comprising: a pump adapted for pumping hydraulic fluid, automatically adjusting the pressure of said hydraulic fluid in substantial compensation for changes in engine speed, and connecting to the power take off for driving said pump; a hydraulic compressor motor for driving the compressor in response to receiving hydraulic fluid from said pump; and a hydraulic circuit for conducting said hydraulic fluid from said pump to said compressor motor and for conducting said hydraulic fluid from said compressor motor back to said pump, said hydraulic circuit including a temperature control portion having a heat exchanger and adapted for diverting at least a portion of said hydraulic fluid through said heat exchanger in response to a temperature indication indicating the temperature of said fluid, in such manner as to provide for at least one of (a) reducing the temperature of said fluid where the temperature is too high, and (b) increasing the temperature of said fluid where the temperature is too low.