Motor-driven turbo compressor

Abstract

In the compressor of the present invention, an intermediate pressure port through which a first discharge chamber and a first chamber communicate with each other is formed in a front housing. In the front housing, an injection port through which a receiver and a second chamber communicate with each other is formed. An intermediate pressure refrigerant discharged to the first discharge chamber flows into the first chamber through an intermediate pressure port. An injection refrigerant separated by the receiver flows into the second chamber. In the compressor, it is possible to cool an electric motor with the intermediate pressure refrigerant and the injection refrigerant. The intermediate pressure refrigerant and the injection refrigerant circulate through a second suction port as a mixed refrigerant.

1 . A motor-driven turbo compressor used in a refrigeration cycle, comprising:
 a housing;   an electric motor provided in the housing;   a rotating shaft driven to rotate by the electric motor; and   a first impeller and a second impeller arranged on the rotating shaft at an interval in an axial direction of the rotating shaft,   wherein a refrigerant is sucked from a first suction port, compressed by rotation of the first impeller, and discharged to a first discharge chamber provided on a radially outer circumference side of the first impeller, and   wherein the refrigerant through the first discharge chamber is sucked from a second suction port, compressed by rotation of the second impeller, and discharged to a second discharge chamber provided on a radially outer circumference side of the second impeller;   wherein the first impeller, the second impeller, and the electric motor are arranged in the axial direction of the rotating shaft in this order,   wherein a first chamber and a second chamber are formed at both ends in the axial direction of the electric motor in the housing and communicate with each other via a gap in the electric motor, the first chamber is located close to the second impeller in the axial direction of the electric motor, and   wherein an intermediate pressure port is formed in the housing and connects the first chamber and the first discharge chamber; and   wherein an injection port connected to a gas-liquid separator of the refrigeration cycle is formed in the housing and communicates with the second chamber.   
     
     
         2 . The motor-driven turbo compressor according to  claim 1 , wherein
 the electric motor includes a rotor fixed to the rotating shaft and a stator fixed to the housing,   a communication path is formed between the housing and the stator and connects the first chamber and the second chamber in the axial direction, and   a guide wall that guides the refrigerant passed through the intermediate pressure port to the communication path is formed in the housing.   
     
     
         3 . The motor-driven turbo compressor according to  claim 2 , wherein the injection port is configured not to face the communication path. 
     
     
         4 . The motor-driven turbo compressor according to  claim 3 , wherein the injection port extends in a radial direction of the housing. 
     
     
         5 . The motor-driven turbo compressor according to  claim 3 , wherein the injection port is located at a position different from the intermediate pressure port and the communication path around the axis of the rotating shaft. 
     
     
         6 . The motor-driven turbo compressor according to  claim 1 , wherein the second suction port is configured to lead the refrigerant to make contact with the rotating shaft.