Abstract An electric motor is mounted in a hermetic casing. There is a supply of a mixture containing a refrigerant and a lubricating oil in the lower portion of the casing. A flow passage extends from the upper portion of the casing to the inlet of a screw type compressor, the output of which is discharged to a condenser. There is a flow passage from the condenser to the motor casing and a float operated valve to maintain the mixture in the motor casing at a preselected level. A pump is employed to discharge the mixture through a line to the motor bearings and shaft seal. A branch line is connected to the pump discharge line for discharging a metered flow of the mixture into the passage leading to the intake of the screw compressor to insure a sufficient supply of oil to the compressor when the motor is operating under light load.
Apparatus for cooling an electric motor of the type having a casing, a stator and rotor arranged within the casing, and bearing and seal means supporting the rotor, including: sump means within the casing adapted to hold a supply of liquid refrigerant and lubricant, first conduit means extending from the sump to the portions of the motor requiring cooling and lubrication, pump means within the sump to pump liquid refrigerant and lubricant through the first conduit means, second conduit means extending from the casing to the sump, a condenser positioned in the second conduit means to condense vaporized refrigerant for return to the sump, a compressor positioned in the second conduit means ahead of the condenser to draw gaseous refrigerant with entrained lubricant from the casing and compress the refrigerant and to move the refrigerant through the conduit to the condenser, and means communicating with the first conduit means so as to be subject to pressure developed by the sump to provide liquid refrigerant and lubricant from the sump into the second conduit ahead of the compressor to provide lubrication for the compressor.
Claim 2
Dependent Claim
183 words
Apparatus for cooling an electric motor of the type having a casing, a stator and rotor arranged within the casing, and bearing and seal means supporting the rotor, including: sump means within the casing adapted to hold a supply of liquid refrigerant and lubricant, first conduit means extending from the sump to the portions of the motor requiring cooling and lubrication, pump means within the sump to pump liquid refrigerant and lubricant through the first conduit means, second conduit means extending from the casing to the sump, a condenser positioned in the second conduit means to condense vaporized refrigerant for return to the sump, a compressor positioned in the second conduit means ahead of the condenser to draw gaseous refrigerant with entrained lubricant from the casing and compress the refrigerant and to move the refrigerant through the conduit to the condenser, and means communicating with the first conduit means so as to be subject to pressure developed by the sump to provide liquid refrigerant and lubricant from the sump into the second conduit ahead of the compressor to provide lubrication for the compressor.