Abstract: A compressor suction pipe includes a bent portion at least including a first pipe segment on the most upstream side with respect to flow of a fluid to be compressed, a second pipe segment connected to a suction side of a compressor and extending in a direction different from the extension direction of the first pipe segment, and a third pipe segment disposed between the first pipe segment and the second pipe segment and extending in a direction different from the extension directions of the first and second pipe segments, and at least one partition extending at least from an intermediate portion of the first pipe segment at least to an intermediate portion of the second pipe segment in the bent portion and dividing an interior of the bent portion. The partition extends in a direction intersecting a virtual plane including an incircle that touches an axis of the first pipe segment on an upstream side of a downstream end of the first pipe segment and touches an axis of the second pipe segment.

Abstract: A centrifugal compressor includes a rotary shaft; a hollow casing; a first-stage inlet guide vane; a first-stage impeller; a diffuser; a return flow channel; return vanes; a second-stage inlet guide vane; and a second-stage impeller. The return vanes are arranged at predetermined intervals in a circumferential direction of the rotary shaft and a vane angle of each return vane is changed in a region from a leading edge, at which the fluid is introduced, to a predetermined position and the vane angle is maintained constant in a region from the predetermined position to a trailing edge, at which the fluid is discharged, in terms of meridian plane distance in a direction from the leading edge to the trailing edge.

Abstract: A centrifugal compressor includes a rotary shaft; a hollow casing; a first-stage inlet guide vane; a first-stage impeller; a diffuser; a return flow channel; return vanes; a second-stage inlet guide vane; and a second-stage impeller. The return vanes are arranged at predetermined intervals in a circumferential direction of the rotary shaft and a vane angle of each return vane is changed in a region from a leading edge, at which the fluid is introduced, to a predetermined position and the vane angle is maintained constant in a region from the predetermined position to a trailing edge, at which the fluid is discharged, in terms of meridian plane distance in a direction from the leading edge to the trailing edge.

Abstract: Provided are an inlet guide vane and a centrifugal compressor such that air can be caused to efficiently flow in with use of a simple shape. The inlet guide vane is disposed upstream of an impeller in a flow path of a centrifugal compressor. The inlet guide vane has: a plate-shaped plate section that is disposed in the flow path; and a rotation part that causes the plate section to rotate along an axis of rotation aligned with the radial direction of a rotary shaft of the centrifugal compressor. In a cross-section orthogonal to the axis of rotation of the rotation part, the plate section has, at the leading edge thereof on the upstream side of the flow path, a bent part that is tilted with respect to the other portions.

Abstract: A compressor suction pipe includes a bent portion at least including a first pipe segment on the most upstream side with respect to flow of a fluid to be compressed, a second pipe segment connected to a suction side of a compressor and extending in a direction different from the extension direction of the first pipe segment, and a third pipe segment disposed between the first pipe segment and the second pipe segment and extending in a direction different from the extension directions of the first and second pipe segments, and at least one partition extending at least from an intermediate portion of the first pipe segment at least to an intermediate portion of the second pipe segment in the bent portion and dividing an interior of the bent portion. The partition extends in a direction intersecting a virtual plane including an incircle that touches an axis of the first pipe segment on an upstream side of a downstream end of the first pipe segment and touches an axis of the second pipe segment.

Abstract: An inlet guide vane includes vane main bodies (42) having a pressure surface (S1) and a suction surface (S2) which extend along a radial-direction axial line (Ar). Each of the pressure surface (S1) and the suction surface (S2) has a blade-shaped surface along a surface of an imaginary blade shape (Pv) having a blade-like cross-sectional shape. At least one of the pressure surface (S1) and the suction surface (S2) has a thin portion-forming surface (St) which recedes toward an inside of the imaginary blade shape (Pv) more than the surface of the imaginary blade shape (Pv).

Abstract: A return flow channel formation part that comprises a casing (28) and a plurality of return vanes (38). The casing (28) comprises a return bend part (36) and a return flow channel (33) that has a straight flow channel (37). The straight flow channel (37) includes a hub side wall surface (W1), a shroud side wall surface (W2), and an intermediate intake port (41) that is formed in one radial-direction portion of the shroud side wall surface (W2). The angle of inclination of the hub side wall surface (W1) and/or the shroud side wall surface (W2) with respect to the radial direction in a cross-section that includes an axis line (Ar) changes at the intermediate intake port (41).

Abstract: Provided are an inlet guide vane and a centrifugal compressor such that air can be caused to efficiently flow in with use of a simple shape. The inlet guide vane is disposed upstream of an impeller in a flow path of a centrifugal compressor. The inlet guide vane has: a plate-shaped plate section that is disposed in the flow path; and a rotation part that causes the plate section to rotate along an axis of rotation aligned with the radial direction of a rotary shaft of the centrifugal compressor. In a cross-section orthogonal to the axis of rotation of the rotation part, the plate section has, at the leading edge thereof on the upstream side of the flow path, a bent part that is tilted with respect to the other portions.

Abstract: A compressor (2) characterized by being equipped with: a rotary shaft (12); multiple impellers attached to the rotary shaft; a main flow path that guides a fluid from the prior-stage impeller to the latter-stage impeller; a chamber (31) that forms a circle centered around the axial line and connects to the main flow path; a suction nozzle (32) that guides the fluid from the outer circumferential side toward the inner circumferential side in the chamber; multiple movable vanes provided in the main flow path at intervals in the circumferential direction of the axial line and capable of moving and thereby adjusting the flow volume of the fluid passing through the main flow path; and a drive mechanism (42) that is provided at one side in the circumferential direction of the suction nozzle (32) within the chamber (31), and that changes the angle of the multiple movable vanes.

Abstract: A turbo refrigerator includes a centrifugal compressor configured to compress a refrigerant by rotation of an impeller having a plurality of blades, a condenser configured to cool the compressed refrigerant, a first expansion valve and a second expansion valve connected in series and configured to decompress the refrigerant from the condenser to form two phases of a gas and a liquid, an evaporator configured to evaporate the refrigerant from the second expansion valve, an economizer disposed between the first expansion valve and the second expansion valve and configured to separate the refrigerant into two phases of a gas and a liquid, and an introduction path configured to allow the gas phase separated from the refrigerant in the economizer to flow between a front edge and a rear edge of a blade in a main flow channel between the neighboring blades of the impeller.

Abstract: A compressor (2) characterized by being equipped with: a rotary shaft (12); multiple impellers attached to the rotary shaft; a main flow path that guides a fluid from the prior-stage impeller to the latter-stage impeller; a chamber (31) that forms a circle centered around the axial line and connects to the main flow path; a suction nozzle (32) that guides the fluid from the outer circumferential side toward the inner circumferential side in the chamber; multiple movable vanes provided in the main flow path at intervals in the circumferential direction of the axial line and capable of moving and thereby adjusting the flow volume of the fluid passing through the main flow path; and a drive mechanism (42) that is provided at one side in the circumferential direction of the suction nozzle (32) within the chamber (31), and that changes the angle of the multiple movable vanes.

Abstract: A terminal crimping method and a crimping tool are provided, thereby suppressing the generation of friction at an anvil and a crimper and also suppressing the generation of an upthrust portion at the upper part of a wire barrel to which a conductor of a covered electrical wire is crimped. The crimping tool includes an anvil having a placement groove on which a female-type terminal is mounted, and a crimper that crimps a conductor barrel of the female-type terminal mounted on the anvil. The placement groove includes a first pressing portion that presses the effective crimping portion and a second pressing portion that presses the extension, and the bottom surface of the second pressing portion is formed as an inclined surface expanding and opening toward a receptacle side.

Abstract: A terminal crimping method and terminal crimping device in which friction between an anvil and a crimper is suppressed and a projection is prevented from being formed above a wire barrel where core wires of an electric cable are crimped. The terminal crimping device (40) has the anvil (41) having a placement groove (43) in which a terminal (10) is placed and also has the crimper (42) for pressing the wire barrel (31) of the terminal (10) placed on the anvil (41). The placement groove (43) has a first pressing section (43a) for pressing an effective crimping section (31a) and also has a second pressing section (43bg) for pressing an extension section (31b). The bottom surface of the second pressing section (43b) is formed as a slope surface expanding toward the receptacle (20).

Abstract: A turbo-type compressor having an improved performance which may be produced without increasing its size or cost, and the performance of a refrigeration unit is also improved when it is provided with such a turbo-type compressor.