Abstract: A centrifugal compressor has a housing assembly and an impeller rotatably connected to the housing assembly. Gas introduced into the housing assembly by rotation of the impeller is compressed at least by centrifugal force. One aspect of the present invention is that the impeller includes an inducer portion having a pressure surface and a suction surface and a hole extending between the pressure surface and the suction surface. Another aspect of the present invention is that the centrifugal compressor includes a diffuser located downstream of the impeller, a volute in communication with an outlet of the diffuser, and a reflux passage connecting the diffuser with the volute for returning part of gas in the volute to the diffuser.

Abstract: A centrifugal compressor has a housing assembly and an impeller rotatably connected to the housing assembly. Gas introduced into the housing assembly by rotation of the impeller is compressed at least by centrifugal force. One aspect of the present invention is that the impeller includes an inducer portion having a pressure surface and a suction surface and a hole extending between the pressure surface and the suction surface. Another aspect of the present invention is that the centrifugal compressor includes a diffuser located downstream of the impeller, a volute in communication with an outlet of the diffuser, and a reflux passage connecting the diffuser with the volute for returning part of gas in the volute to the diffuser.

Abstract: In a region where heat deformation of a movable scroll spiral wall and/or a fixed scroll spiral wall for a scroll type compressor is relatively large, a relieving part is formed for relieving the heat deformation of the movable scroll spiral wall and/or the fixed scroll spiral wall in at least a part of at least one of an outer circumferential wall of the movable scroll spiral wall and an inner circumferential wall of the fixed scroll spiral wall, which corresponds to the outer circumferential wall of the movable scroll spiral wall.

Abstract: In a region where heat deformation of a movable scroll spiral wall and/or a fixed scroll spiral wall for a scroll type compressor is relatively large, a relieving part is formed for relieving the heat deformation of the movable scroll spiral wall and/or the fixed scroll spiral wall in at least a part of at least one of an outer circumferential wall of the movable scroll spiral wall and an inner circumferential wall of the fixed scroll spiral wall, which corresponds to the outer circumferential wall of the movable scroll spiral wall.

Abstract: A scroll type compressor includes a housing, a movable scroll member, a plurality of compression chambers, a discharge port, a communication passage and a relief valve. The communication passage interconnects each intermediate compression chamber with the discharge port. The communication passage has a first portion and a second portion. The first portion extends from the first intermediate compression chamber and the second portion extends from the second intermediate compression chamber. The first portion and the second portion meet at a meeting point on the way in the communication passage before reaching the discharge port. The relief valve is placed between the meeting point and the discharge port inclusive of the meeting point in the communication passage. The relief valve opens the communication passage when the pressure in the first and the second intermediate pressure chambers is higher than the pressure in the discharge port.

Abstract: A scroll type compressor includes a housing, a movable scroll member, a plurality of compression chambers, a discharge port, a communication passage and a relief valve. The communication passage interconnects each intermediate compression chamber with the discharge port. The communication passage has a first portion and a second portion. The first portion extends from the first intermediate compression chamber and the second portion extends from the second intermediate compression chamber. The first portion and the second portion meet at a meeting point on the way in the communication passage before reaching the discharge port. The relief valve is placed between the meeting point and the discharge port inclusive of the meeting point in the communication passage. The relief valve opens the communication passage when the pressure in the first and the second intermediate pressure chambers is higher than the pressure in the discharge port.