Motor-operated compressor

Abstract

An electric compressor includes a main housing including a motor chamber. The motor chamber includes a driving motor. The compressor includes a frame fixed to one end of the main housing, a first scroll supported by one side surface of the frame, and a second scroll provided between the frame and the first scroll. The second scroll, supported by the frame, makes an orbiting motion upon receiving a rotational force from the driving motor. The second scroll also forms a compression chamber with the first scroll and a back pressure space with the frame. A rear cover coupled to the main housing forms a discharge space with the first scroll. A back pressure flow channel extends through the first scroll and the frame to guide a refrigerant and oil from the compression chamber to the discharge and back pressure spaces. The compressor also includes a plurality of decompression portions.

What is claimed is: 
     
         1 . An electric compressor comprising:
 a main housing including a motor chamber;   a driving motor disposed in the motor chamber;   a frame fixed to one end of the main housing;   a first scroll supported by one side surface of the frame;   a second scroll provided between the frame and the first scroll and supported by the frame, the second scroll forming a compression chamber with the first scroll, and forming a back pressure space with the frame, and configured to make an orbiting motion relative to the first scroll when receiving a rotational force from the driving motor to form;   a rear cover coupled to the main housing to support one side surface of the first scroll and forming a discharge space with the first scroll;   a back pressure flow channel extending through the first scroll and the frame and configured to guide a refrigerant and oil discharged from the compression chamber to the discharge space and the back pressure space;   a first decompression portion provided at a first position between the rear cover and the first scroll, the first decompression portion being configured to reduce a pressure of the refrigerant and oil moving from the discharge space toward the back pressure space; and   a second decompression portion provided at a second position between the first scroll and the main housing, the second decompression portion being configured to reduce the pressure of the refrigerant and oil moving to the back pressure space through the first decompression portion.   
     
     
         2 . The electric compressor of  claim 1 , wherein
 a decompression member having a plate-like shape is provided in at least one of the first position and the second position, and   the decompression member includes an inlet communicating with an upstream side back pressure flow channel with respect to a movement path of the refrigerant and oil, an outlet spaced apart from the inlet and communicating with a downstream side back pressure flow channel, and a decompression flow channel connecting the inlet and the outlet, the decompression flow channel being configured to reduce the pressure of the refrigerant and oil moving from the inlet toward the outlet.   
     
     
         3 . The electric compressor of  claim 2 , wherein
 the inlet, the outlet, and the decompression flow channel extend through the decompression member in an axial direction.   
     
     
         4 . The electric compressor of  claim 2 , wherein
 at least any one of the inlet, the outlet, and the decompression flow channel includes a recess formed on one side surface of the decompression member.   
     
     
         5 . The electric compressor of  claim 2 , wherein
 the first decompression member positioned at the first position includes a sealing member having a portion positioned between the main housing and the rear cover.   
     
     
         6 . The electric compressor of  claim 5 , wherein the first decompression member includes a non-metal material. 
     
     
         7 . The electric compressor of  claim 2 , wherein the first decompression member positioned at the first position has an outer diameter smaller than or equal to an outer diameter of the first scroll. 
     
     
         8 . The electric compressor of  claim 2 , wherein a portion of the second decompression member provided at the second position includes a support member positioned between the frame and the second scroll. 
     
     
         9 . The electric compressor of  claim 8 , wherein
 an outer side portion of the second decompression member is fixed between the frame and the first scroll and   an inner side portion of the second decompression member is configured to support the second scroll in an axial direction.   
     
     
         10 . The electric compressor of  claim 1 , wherein
 at least one of the first decompression portion and the second decompression portion is formed as a decompression flow channel having a predetermined cross-sectional area, the decompression flow channel including a recess formed on at least one surface of a respective one of the first position or the second position.   
     
     
         11 . The electric compressor of  claim 1 , wherein
 at least one of the first decompression portion and the second decompression portion is configured as a decompression flow channel formed in a slit shape on a decompression member provided at a respective one of the first position or the second position.   
     
     
         12 . The electric compressor of  claim 1 , further including:
 a discharge passage in the frame, the discharge passage extending between the back pressure space and the motor chamber; and   a third decompression portion provided at the discharge passage, the third decompression portion being configured to lower the pressure of the refrigerant and oil discharged from the back pressure chamber to the motor chamber.   
     
     
         13 . The electric compressor of  claim 12 , wherein
 the third decompression portion includes a decompression member configured as one of an orifice or a decompression valve inserted into the inside of the discharge passage.   
     
     
         14 . The electric compressor of  claim 12 , wherein
 the third decompression portion has a plate-like shape disposed on one side surface of the frame, and the decompression member forming the third decompression portion includes an inlet communicating with the discharge passage, an outlet provided on one side of the inlet and communicating with the motor chamber, and a decompression flow channel connecting the inlet and the outlet, the decompression flow channel being configured to reduce the pressure of the refrigerant and oil moving from the inlet to the outlet.   
     
     
         15 . An electric compressor comprising:
 a main housing including a motor chamber;   a driving motor disposed in the motor chamber;   a frame fixed to one end of the main housing;   a first scroll supported by one side surface of the frame;   a second scroll provided between the frame and the first scroll and supported by the frame, the second scroll forming a compression chamber with the first scroll, and forming a back pressure space with the frame, and configured to make an orbiting motion when receiving a rotational force from the driving motor;   a rear cover coupled to the main housing to support one side surface of the first scroll and forming a discharge space with the first scroll;   a back pressure flow channel extending through the first scroll and the frame and configured to guide a refrigerant and oil discharged from the compression chamber to the discharge space and the back pressure space; and   a plurality of decompression portions provided in the middle of the back pressure flow channel at predetermined intervals and configured to reduce a pressure of the refrigerant and oil moving from the discharge space to the back pressure space through the back pressure flow channel.   
     
     
         16 . The electric compressor of  claim 15 , wherein the plurality of decompression portions have different decompression rates. 
     
     
         17 . The electric compressor of  claim 16 , wherein
 a first decompression portion is provided between the rear cover and the first scroll,   a second decompression portion is provided between the first scroll and the main housing, and   a decompression rate of the first decompression portion is greater than or equal to a decompression rate of the second decompression portion.   
     
     
         18 . The electric compressor of  claim 17 , wherein
 the frame includes a discharge passage extending between the back pressure space and the motor chamber,   the discharge passage further includes a third decompression portion configured to lower the pressure of the refrigerant and oil discharged from the back pressure space to the motor chamber, and   a decompression rate of the third decompression portion is smaller than or equal to a decompression rate of the second decompression portion.   
     
     
         19 . The electric compressor of  claim 15 , wherein the plurality of decompression portions includes an inlet, an outlet, and a decompression flow channel connecting the inlet and the outlet, and the decompression flow channel may extend over an angle of at least 180° in a direction from the inlet to the outlet.