Compressor

Abstract

A compressor, comprising: a housing (101) provided with a rotor accommodating cavity (105) and an exhaust cavity (180); and a pair of screw rotors (110) at least partially located in the rotor accommodating cavity (105), a compression accommodating cavity (150) being formed between teeth of the pair of screw rotors (110) and the housing (101), and the pair of screw rotors (110) having a suction end (112) and an exhaust end (113), wherein the housing (101) further comprises an unloading channel (208) and a connecting channel (308), the unloading channel (208) is provided with an unloading channel inlet (216) and an unloading channel outlet (217), the unloading channel inlet (216) can be communicated with the compression accommodating cavity (150) through the connecting channel (308), and the unloading channel outlet (217) is communicated with a suction side of the compressor; and an unloading device (109) configured to controllably open or close the connecting channel (308), such that the compression accommodating cavity (150) can be controllably communicated with or disconnected from the connecting channel (308). The compressor can reduce the load upon startup.

1 . A compressor, comprising:
 a housing having a rotor accommodating cavity and an exhaust cavity, wherein the housing further comprises an unloading channel and a connecting channel, and the unloading channel has an unloading channel inlet and an unloading channel outlet;   a pair of screw rotors at least partially located in the rotor accommodating cavity, wherein a compression accommodating cavity is formed between teeth of the pair of screw rotors and the housing, the pair of screw rotors have a suction end and an exhaust end, the unloading channel inlet is in communication with the compression accommodating cavity through the connecting channel, and the unloading channel outlet is in communication with a suction side of the compressor; and   an unloading device configured to controllably open or close the connecting channel, such that the compression accommodating cavity is controllably communicated with or disconnected from the connecting channel.   
     
     
         2 . The compressor of  claim 1 , wherein:
 the unloading device is configured to open the connecting channel at startup of the compressor to open the unloading channel inlet of the unloading channel and establish communication between the compression accommodating cavity and the suction side of the compressor.   
     
     
         3 . The compressor of  claim 1 , wherein:
 the housing further comprises an unloading device accommodating cavity and a cover, a proximal end of the unloading device accommodating cavity forms the connecting channel, and a distal end of the unloading device accommodating cavity is closed by the cover.   
     
     
         4 . The compressor of  claim 3 , wherein:
 the unloading device accommodating cavity has an unloading device accommodating cavity opening, and an area of the unloading device accommodating cavity opening is larger than an area of the unloading channel inlet.   
     
     
         5 . The compressor of  claim 4 , wherein:
 the exhaust end of the pair of screw rotors has an exhaust end surface, the unloading device accommodating cavity opening, the unloading channel inlet, and the exhaust end surface are in a common plane, and the unloading device accommodating cavity opening is configured to simultaneously overlap at least a part of the unloading channel inlet and at least a part of the exhaust end surface.   
     
     
         6 . The compressor of  claim 3 , wherein:
 the unloading device comprises a piston movable in the unloading device accommodating cavity and an elastic device configured to provide an elastic force, wherein the unloading device is configured, in response to a pressure on the piston that is less than the elastic force of the elastic device, to move the piston away from the unloading channel inlet and to thereby open the connecting channel, and the unloading device is configured, in response to the pressure on the piston being greater than the elastic force of the elastic device to close the unloading channel inlet via the piston and to thereby close the connecting channel, wherein the pressure is provided by gas exhaust pressure of the compressor.   
     
     
         7 . The compressor of  claim 6 , wherein:
 the piston has a head and a body, wherein a diameter of the head is greater than a diameter of the body, the unloading device accommodating cavity has a first section and a second section, wherein a diameter of the second section is less than a diameter of the first section, the first section is close to the cover, and the head is accommodated in the first section and forms a seal with an inner wall of the first section; and   one end of the elastic device abuts against a step surface formed by the first section and the second section, another end of the elastic device abuts against the head of the piston, wherein the elastic device is configured to provide the elastic force to bias the piston away from the unloading channel inlet to open the connecting channel, and the head of the piston is configured to be subjected to the pressure to bias the piston towards the unloading channel inlet to close the connecting channel.   
     
     
         8 . The compressor of  claim 4 , wherein:
 the unloading device accommodating cavity is communicated with the exhaust cavity of the compressor through a connecting passage, and a throttling element is disposed along the connecting passage.   
     
     
         9 . The compressor of  claim 8 , wherein:
 a buffer device is disposed along the connecting passage, and the buffer device is arranged between the unloading device accommodating cavity and the throttling element.   
     
     
         10 . The compressor of  claim 8 , wherein:
 the cover is provided with a cover channel, and the cover channel forms the throttling element.   
     
     
         11 . The compressor of  claim 9 , wherein:
 the throttling element and the buffer device are disposed in the housing.   
     
     
         12 . The compressor of  claim 4 , wherein:
 the housing has a housing fitting surface disposed facing an exhaust end surface of the exhaust end of the pair of screw rotors, an exhaust port is disposed on the housing fitting surface, and in a radial direction, a distance extends between the unloading device accommodating cavity opening and the exhaust port.   
     
     
         13 . (canceled)