Hybrid cooling systems for hermetic motors

A hermetic motor for a compressor of a heating, ventilating, air conditioning, and refrigeration (HVAC&R) system, comprising:

• a stator configured to cause rotation of a rotor that drives the compressor, wherein a vent slot is defined through a central portion of the stator to fluidly couple a radially outward surface of the stator to an annular gap defined between the stator and the rotor;
• a sleeve circumferentially surrounding a portion of the radially outward surface of the stator;
• and
• a motor housing disposed around the stator and the sleeve, wherein the motor housing defines:
• a first annulus and a second annulus each adjacent to the sleeve, wherein the first annulus and the second annulus are each configured to direct a respective liquid flow through the sleeve to the stator;
• and
• an annular chamber adjacent to the sleeve, wherein the annular chamber is axially positioned between the first annulus and the second annulus, and wherein the annular chamber is configured to direct a vapor flow from the annular chamber, through the sleeve and the vent slot, and into the annular gap.

A heating, ventilating, air conditioning, and refrigeration (HVAC&R) system, comprising:

• a main refrigerant circuit comprising a compressor, a condenser, an expansion device, and an evaporator coupled in series, wherein a high pressure side of the main refrigerant circuit is defined between an outlet of the compressor and an inlet of the expansion device;
• a motor configured to drive the compressor;
• and
• a hybrid cooling system, comprising:
• a cooling refrigerant circuit configured to direct a vapor flow from the high pressure side of the main refrigerant circuit to the motor, direct a liquid flow from the condenser to the motor, and direct warmed refrigerant from the motor to the evaporator;
• and
• a housing of the motor defining a first annulus, a second annulus, and an annular chamber axially positioned between the first annulus and the second annulus, wherein the first annulus and the second annulus are each configured to receive the liquid flow from the cooling refrigerant circuit and direct the liquid flow to a stator of the motor, and wherein the annular chamber is configured to receive the vapor flow from the cooling refrigerant circuit and direct the vapor flow to a gap between the stator and a rotor of the motor.