Abstract: A fuel cell centrifugal compressor includes: an impeller including a hub and blades; and a shroud. A smaller one of angles formed by each blade and a meridian surface is a blade angle. An absolute value of the blade angle on a hub-side of the blade is local minimum between hub-side front and rear edges of the blade. An absolute value of the blade angle on a shroud-side of the blade is local minimum between shroud-side front and rear edges of the blade. The hub-side of the blade is constantly less than or equal to the shroud-side of the blade in absolute value of the blade angle between the hub-side front and rear edges. The shroud-side rear edge is less than the shroud-side front edge in absolute value of the blade angle. The hub-side rear edge is greater than the hub-side front edge in absolute value of the blade angle.

Abstract: A turbo fluid machine includes a partition wall separating an inside of a housing into a compression space and a bearing space; and a foil bearing. The partition wall includes a support part having an end face raised toward a thrust collar in an axial direction. The support part has a groove formed in the end face and radially extending to an outer peripheral surface of the support part. Top foils of the foil bearing each have one surface facing the thrust collar and the other surface elastically supported by corresponding one of bump foils of the foil bearing. The foil bearing is mounted on the end face such that a position of the groove corresponds to a position of a gap between the bump foils and a position of a gap between the top foils and such that the groove faces the thrust collar in the axial direction.

Abstract: A fuel cell centrifugal compressor includes: an impeller including a hub and blades; and a shroud. A smaller one of angles formed by each blade and a meridian surface is a blade angle. An absolute value of the blade angle on a hub-side of the blade is local minimum between hub-side front and rear edges of the blade. An absolute value of the blade angle on a shroud-side of the blade is local minimum between shroud-side front and rear edges of the blade. The hub-side of the blade is constantly less than or equal to the shroud-side of the blade in absolute value of the blade angle between the hub-side front and rear edges. The shroud-side rear edge is less than the shroud-side front edge in absolute value of the blade angle. The hub-side rear edge is greater than the hub-side front edge in absolute value of the blade angle.

Abstract: An oil passage of a centrifugal compressor includes a first oil passage that communicates with an oil pan and a speed increaser chamber to supply oil to a speed increaser and the seal. A second oil passage communicates with the speed increaser chamber. A third oil passage extends upward in a gravitational direction from an end of the second oil passage. A fourth oil passage extends in a horizontal direction and causes the oil pan and an end of the third oil passage to communicate with each other. A pressure relief passage that communicates with an outside is arranged in at least one of a portion of the fourth oil passage through which a gas layer passes and a portion of the oil pan in which the gas layer is stored.

Abstract: A centrifugal compressor includes a low-speed shaft, an impeller, a speed increaser, a housing, a separation wall, a shaft insertion hole, a seal member, an oil pan, an oil supply passage, an oil return passage, and a pressure reduction passage. The impeller is integrally rotated with a high-speed shaft. The housing has therein an impeller chamber accommodating the impeller and a speed increaser chamber accommodating the speed increaser. The centrifugal compressor includes a bypass passage having a first end communicating with the speed increaser chamber and a second end communicating with the oil pan.

Abstract: A centrifugal compressor includes a partition wall that is arranged between a ring member and the bottom of a main body in a speed-increaser chamber. The centrifugal compressor further includes an introduction passage that guides oil in a stirring region to a storage region. The stirring region includes a region between the partition wall and the ring member in the speed-increaser chamber. The storage region includes a region between the partition wall and the bottom of the main body in the speed-increaser chamber. The oil that has been stirred by rotation of the ring member collides the inner circumferential surface of a speed increaser housing before flowing toward the partition wall. The oil is then guided to the storage region via the introduction passage. Since the oil stored in the storage region is unlikely to be stirred by rotation of the ring member, only a small amount of oil is stirred by the ring member.

Abstract: A centrifugal compressor includes a partition wall that is arranged between a ring member and the bottom of a main body in a speed-increaser chamber. The centrifugal compressor further includes an introduction passage that guides oil in a stirring region to a storage region. The stirring region includes a region between the partition wall and the ring member in the speed-increaser chamber. The storage region includes a region between the partition wall and the bottom of the main body in the speed-increaser chamber. The oil that has been stirred by rotation of the ring member collides the inner circumferential surface of a speed increaser housing before flowing toward the partition wall. The oil is then guided to the storage region via the introduction passage. Since the oil stored in the storage region is unlikely to be stirred by rotation of the ring member, only a small amount of oil is stirred by the ring member.

Abstract: A centrifugal compressor includes a low-speed shaft, an impeller, a speed increaser, a housing, a separation wall, a shaft insertion hole, a seal member, an oil pan, an oil supply passage, an oil return passage, and a pressure reduction passage. The impeller is integrally rotated with a high-speed shaft. The housing has therein an impeller chamber accommodating the impeller and a speed increaser chamber accommodating the speed increaser. The centrifugal compressor includes a bypass passage having a first end communicating with the speed increaser chamber and a second end communicating with the oil pan.

Abstract: An oil passage of a centrifugal compressor includes a first oil passage that communicates with an oil pan and a speed increaser chamber to supply oil to a speed increaser and the seal. A second oil passage communicates with the speed increaser chamber. A third oil passage extends upward in a gravitational direction from an end of the second oil passage. A fourth oil passage extends in a horizontal direction and causes the oil pan and an end of the third oil passage to communicate with each other. A pressure relief passage that communicates with an outside is arranged in at least one of a portion of the fourth oil passage through which a gas layer passes and a portion of the oil pan in which the gas layer is stored.

Abstract: A centrifugal compressor includes a rotary shaft, an electric motor, which has a rotor, a tubular boss, through which the rotary shaft extends, and a radial bearing. The rotor has a rotor end face, which is an end face in an axial direction of the rotary shaft. The boss has a boss end face, which is an end face in the axial direction of the rotary shaft. The rotor end face and the boss end face face each other in the axial direction of the rotary shaft. A thrust bearing is arranged between the rotor end face and the boss end face to receive thrust force generated by rotation of the impeller.

Abstract: In a compressor of the present invention, an intermediate pressure port through which a first discharge chamber and a motor chamber communicate with each other is formed in a front housing. A refrigerant having an intermediate pressure is discharged to the first discharge chamber. Consequently, it is possible to guide the refrigerant having the intermediate pressure in the first discharge chamber to the motor chamber, and cool an electric motor, which generates heat during actuation, with the refrigerant having the intermediate pressure. In the compressor, a first impeller and a second impeller are disposed such that large diameter portions of the first impeller and the second impeller face each other. The second impeller is smaller in diameter than the first impeller.