Scroll compressor

Abstract

A scroll compressor includes a drive shaft that has a first oil flow passage extending axially on a shaft center of a main shaft and having an inflow hole opening in an upper end surface of an eccentric shaft, and a second oil flow passage extending axially at a periphery of the first oil flow passage and having an annular cross-section. The second oil flow passage forms at least part of an oil supply path in which oil that has been transported by the pump is supplied to at least a sliding portion between a boss portion and the eccentric shaft. A third oil flow passage is formed in which oil that has flowed out from the sliding portion to the chamber is sent to the inflow hole of the first oil flow passage. The first oil flow passage forms at least part of an oil drainage path.

1 . A scroll compressor comprising:
 a casing, a bottom portion of the casing having a storage portion configured to store oil;   an electric motor accommodated in the casing;   a drive shaft configured to be driven by the electric motor, the drive shaft having a main shaft and an eccentric shaft provided at an upper end of the main shaft;   a compression mechanism coupled to the drive shaft, the compression mechanism having
 a movable scroll that has a boss portion with the eccentric shaft fitted thereto and 
 a fixed scroll that meshes with the movable scroll; and 
   a housing disposed below the compression mechanism and fixed to the casing, the housing including a chamber that accommodates the boss portion,   a lower end of the main shaft being provided with a pump configured to transport oil of the storage portion,   the drive shaft having
 a first oil flow passage that extends on a shaft center of the main shaft in an axial direction of the drive shaft and that has an inflow hole opening in an upper end surface of the eccentric shaft, and 
 a second oil flow passage that extends at a periphery of the first oil flow passage in the axial direction and that has an annular cross-section, 
   the second oil flow passage forming at least part of an oil supply path in which oil that has been transported by the pump is supplied to at least a sliding portion between the boss portion and the eccentric shaft,   a third oil flow passage being formed in which oil that has flowed out from the sliding portion to the chamber is sent to the inflow hole of the first oil flow passage, and   the first oil flow passage forming at least part of an oil drainage path in which oil that has flowed in through the inflow hole is returned to the storage portion.   
     
     
         2 . The scroll compressor according to  claim 1 , wherein
 the drive shaft has a vertical hole that extends in the axial direction and that opens at at least an upper end of the drive shaft,   a pipe is disposed on a shaft center of the drive shaft in the vertical hole and extends in the axial direction,   the first oil flow passage is formed in an inside of the pipe, and   the second oil flow passage is formed between an inner peripheral surface of the vertical hole and an outer peripheral surface of the pipe.   
     
     
         3 . The scroll compressor according to  claim 2 , wherein
 an annular upper cover closes a gap between
 an inner peripheral surface of an upper end portion of the vertical hole and 
 an outer peripheral surface of an upper end portion of the pipe. 
   
     
     
         4 . The scroll compressor according to  claim 2 , wherein
 the vertical hole passes through the drive shaft in the axial direction,   a lower cover closes a lower end of the vertical hole, and   the lower cover includes a through passage that causes a discharge side of the pump and the second oil flow passage to be in communication with each other.   
     
     
         5 . The scroll compressor according to  claim 2 , wherein
 a connection member has a connecting port and an internal flow passage, the connecting port being connected to a lower end of the pipe, and the internal flow passage extending from the connecting port outwardly in a radial direction, and   a peripheral wall of the vertical hole in the drive shaft has an outflow hole in communication with the internal flow passage.   
     
     
         6 . The scroll compressor according to  claim 1 , wherein
 the housing is provided with a first bearing that supports the main shaft, and   the drive shaft is provided with a first oil supply hole extending from the second oil flow passage outwardly in a radial direction and through which oil is supplied to the first bearing.   
     
     
         7 . The scroll compressor according to  claim 6 , wherein
 a support has a second bearing that supports a lower portion of the main shaft, and   the drive shaft is provided with a second oil supply hole extending from the second oil flow passage outwardly in the radial direction and through which oil is supplied to the second bearing.   
     
     
         8 . The scroll compressor according to  claim 1 , wherein
 the third oil flow passage is formed in an inside of the movable scroll, and   an outflow port of the third oil flow passage and the inflow hole of the first oil flow passage overlap each other in the axial direction.   
     
     
         9 . The scroll compressor according to  claim 1 , wherein
 a concave portion is formed on an upper end surface of the eccentric shaft, and   the inflow hole of the first oil flow passage is formed at a bottom of the concave portion.   
     
     
         10 . The scroll compressor according to  claim 3 , wherein
 the vertical hole passes through the drive shaft in the axial direction,   a lower cover closes a lower end of the vertical hole, and   the lower cover includes a through passage that causes a discharge side of the pump and the second oil flow passage to be in communication with each other.   
     
     
         11 . The scroll compressor according to  claim 3 , wherein
 a connection member has a connecting port and an internal flow passage, the connecting port being connected to a lower end of the pipe, and the internal flow passage extending from the connecting port outwardly in a radial direction, and   a peripheral wall of the vertical hole in the drive shaft has an outflow hole in communication with the internal flow passage.   
     
     
         12 . The scroll compressor according to  claim 4 , wherein
 a connection member has a connecting port and an internal flow passage, the connecting port being connected to a lower end of the pipe, and the internal flow passage extending from the connecting port outwardly in a radial direction, and   a peripheral wall of the vertical hole in the drive shaft has an outflow hole in communication with the internal flow passage.   
     
     
         13 . The scroll compressor according to  claim 2 , wherein
 the housing is provided with a first bearing that supports the main shaft, and   the drive shaft is provided with a first oil supply hole extending from the second oil flow passage outwardly in a radial direction and through which oil is supplied to the first bearing.   
     
     
         14 . The scroll compressor according to  claim 3 , wherein
 the housing is provided with a first bearing that supports the main shaft, and   the drive shaft is provided with a first oil supply hole extending from the second oil flow passage outwardly in a radial direction and through which oil is supplied to the first bearing.   
     
     
         15 . The scroll compressor according to  claim 4 , wherein
 the housing is provided with a first bearing that supports the main shaft, and   the drive shaft is provided with a first oil supply hole extending from the second oil flow passage outwardly in a radial direction and through which oil is supplied to the first bearing.   
     
     
         16 . The scroll compressor according to  claim 5 , wherein
 the housing is provided with a first bearing that supports the main shaft, and   the drive shaft is provided with a first oil supply hole extending from the second oil flow passage outwardly in a radial direction and through which oil is supplied to the first bearing.   
     
     
         17 . The scroll compressor according to  claim 2 , wherein
 the third oil flow passage is formed in an inside of the movable scroll, and   an outflow port of the third oil flow passage and the inflow hole of the first oil flow passage overlap each other in the axial direction.   
     
     
         18 . The scroll compressor according to  claim 3 , wherein
 the third oil flow passage is formed in an inside of the movable scroll, and   an outflow port of the third oil flow passage and the inflow hole of the first oil flow passage overlap each other in the axial direction.   
     
     
         19 . The scroll compressor according to  claim 4 , wherein
 the third oil flow passage is formed in an inside of the movable scroll, and   an outflow port of the third oil flow passage and the inflow hole of the first oil flow passage overlap each other in the axial direction.   
     
     
         20 . The scroll compressor according to  claim 5 , wherein
 the third oil flow passage is formed in an inside of the movable scroll, and   an outflow port of the third oil flow passage and the inflow hole of the first oil flow passage overlap each other in the axial direction.