GB746549A - Improvements in compressor units for refrigeration systems - Google Patents

Abstract

746,549. Refrigerating. GENERAL MOTORS CORPORATION. March 11, 1954 [April 1, 1953], No. 7050/54. Class 29. [Also in Group XXVI] A compressor unit for refrigeration systems has a valve responsive to a predetermined pressure of the compressed refrigerant to artificially overload the compressor unit to initiate operation of an overload responsive device to stop the motor driving the compressor. A sealed casing 44 encloses an electric motor 50 with a driving shaft 46 on which is mounted an eccentric 48 of a rotary compressor having a sliding abutment 37. The refrigerant returns by pipe 20 to the suction port 22, is compressed and discharged at port 38 via a pipe 40 through a heat exchanger 42 into the interior of the casing 44, from which it is delivered by a pipe to the rest of the refrigeration system. When the compressed refrigerant in casing 44 reaches a predetermined pressure the valve 60 opens and allows the compressed refrigerant to pass into the suction space 64 so overloading the motor 50 which causes a current overload protector 30, as described in Specification 620,890, [Group XXXVII], to stop'the motor. The refrigerator system comprises the compressor unit 10, a condensor 12, a restrictor tube 16, a coil evaporator 14, and a plate evaporator 18 which has a thermostat bulb 24 connected to a pressure-operated switch 26 to control the motor. If air leaks into the system causing moisture to freeze in the tube 16 and block it the pressure in the system increases and the overload protector 30 stops the motor.