Abstract: A fluid machine includes a plurality of fluid dynamic plain bearings supporting a rotating member. The fluid dynamic plain bearings each include: a top foil; a bump foil; and a bearing housing. The top foil has a bearing surface that has one end portion and the other end portion in a circumferential direction of the bearing surface. The top foil has a fixed end and a free end respectively formed at the one end portion and the other end portion. A movement of the free end in an axial direction of the rotating member is regulated by a regulating member. A clearance through which a fluid flows is formed between the fixed end and the free end. The free end has a discharge passage through which a foreign substance contained in the fluid is discharged from the clearance. The discharge passage is formed through the free end.

Abstract: A foil bearing includes a bearing housing, a top foil, a bump foil, and two retaining portions. A holding groove is formed in the inner circumferential surface of the bearing housing to extend in an axial direction. The top foil and the bump foil each include an insertion plate portion, which is inserted into the holding groove and extends in the axial direction. Each of the retaining portions includes a facing surface that faces the insertion plate portion in the axial direction. In the axial direction, the distance between the facing surfaces of the two retaining portions is longer than the length of the insertion plate portion. At least one of the insertion plate portions includes a bent plate portion that is bent to contact the facing surface.

Abstract: A foil bearing includes a bearing housing, a top foil, and a bump foil. The bump foil has: a first portion, a second portion, and a third portion disposed at least between the first portion and the second portion and configured to come in contact with the top foil. The top foil applies a load to the second portion with displacement of the top foil in a radially outward direction of the bearing housing. The third portion is not in contact with the top foil when the load is equal to or lower than a predetermined load, and is in contact with the top foil with elastic deformation of the second portion when the load is higher than the predetermined load. The first portion is in surface contact with the inner peripheral surface.

Abstract: A turbo fluid machine includes a rotary shaft configured to rotate in one rotational direction, and a thrust foil bearing that includes: a plurality of bump foils each having a corrugated shape and a plurality of top foils each having a bearing surface that faces a thrust collar. Each bump foil is divided into an outer peripheral foil and an inner peripheral foil in a radial direction of the rotary shaft. Ridges on the outer peripheral foil are inclined in the other rotational direction of the rotary shaft while extending from an edge of the outer peripheral foil adjacent to an inner peripheral side toward an outer peripheral side, and the ridges on the inner peripheral foil are inclined in the other rotational direction while extending from an edge of the inner peripheral foil adjacent to the outer peripheral side toward the inner peripheral side.

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 turbo fluid machine includes a rotating member having a bearing-contact surface; an operating part configured to rotate together with the rotating member to compress and discharge a fluid; a housing accommodating the rotating member and the operating part; and a foil bearing having a bearing surface that faces the bearing-contact surface and supporting the rotating member such that the rotating member is rotatable relative to the housing. At least one of the bearing-contact surface or the bearing surface has thereon a coating layer. The coating layer comprises polyamide-imide serving as a binder resin and molybdenum disulfide serving as a solid lubricant. A mass ratio of molybdenum disulfide to polyamide-imide is 0.42 or more.

Abstract: A turbo fluid machine includes a rotary shaft configured to rotate in one rotational direction, and a thrust foil bearing that includes: a plurality of bump foils each having a corrugated shape and a plurality of top foils each having a bearing surface that faces a thrust collar. Each bump foil is divided into an outer peripheral foil and an inner peripheral foil in a radial direction of the rotary shaft. Ridges on the outer peripheral foil are inclined in the other rotational direction of the rotary shaft while extending from an edge of the outer peripheral foil adjacent to an inner peripheral side toward an outer peripheral side, and the ridges on the inner peripheral foil are inclined in the other rotational direction while extending from an edge of the inner peripheral foil adjacent to the outer peripheral side toward the inner peripheral side.

Abstract: A turbo fluid machine includes a rotary shaft configured to rotate in one rotational direction, and a radial foil bearing. The radial foil bearing includes: a bump foil formed of an elastic thin plate having a corrugated shape. The bump foil is divided into first and second foil portions located respectively on one side and on the other side in an axial direction of the rotary shaft. Ridges on the first foil portion are inclined in the other rotational direction of the rotary shaft while extending from an edge of the first foil portion adjacent to the other side toward the one side in the axial direction. The ridges on the second foil portion are inclined in the other rotational direction of the rotary shaft while extending from an edge of the second foil portion adjacent to the one side toward the other side in the axial direction.

Abstract: A fluid machine includes a rotating body, an operation body rotated integrally with the rotating body, a housing, hydrodynamic plain bearings rotatably supporting the rotating body relative to the housing, and a cooling passage arranged in the housing. The hydrodynamic plain bearings each include a resin coating layer at a portion that is opposed to the rotating body. The hydrodynamic plain bearings include at least one combination of hydrodynamic plain bearings. Each combination includes an upstream hydrodynamic plain bearing and a downstream hydrodynamic plain bearing located at different positions in a direction in which the fluid flows through the cooling passage. The coating layer of the upstream hydrodynamic plain bearing has a lower hardness than the coating layer of the downstream hydrodynamic plain bearing.

Abstract: A pump for a fuel cell includes a pump portion, a motor, a controller, a housing, and a temperature detector. The controller executes an activation control and a sensorless vector control. In the activation control, the controller executes a cold activation mode process when the outside air temperature is less than or equal to a set temperature. In the cold activation mode process, the controller executes at least one of increasing a value of an activation current supplied to the motor relative to when a normal activation mode process is executed or setting a supply duration of the activation current to the motor to be longer than that of when the normal activation mode process is executed.

Abstract: A fluid machine includes a rotating body, an operation body rotated integrally with the rotating body, a housing, hydrodynamic plain bearings rotatably supporting the rotating body relative to the housing, and a cooling passage arranged in the housing. The hydrodynamic plain bearings each include a resin coating layer at a portion that is opposed to the rotating body. The hydrodynamic plain bearings include at least one combination of hydrodynamic plain bearings. Each combination includes an upstream hydrodynamic plain bearing and a downstream hydrodynamic plain bearing located at different positions in a direction in which the fluid flows through the cooling passage. The coating layer of the upstream hydrodynamic plain bearing has a lower hardness than the coating layer of the downstream hydrodynamic plain bearing.

Abstract: A pump for a fuel cell includes a pump portion, a motor, a controller, a housing, and a temperature detector. The controller executes an activation control and a sensorless vector control. In the activation control, the controller executes a cold activation mode process when the outside air temperature is less than or equal to a set temperature. In the cold activation mode process, the controller executes at least one of increasing a value of an activation current supplied to the motor relative to when a normal activation mode process is executed or setting a supply duration of the activation current to the motor to be longer than that of when the normal activation mode process is executed.

Abstract: A fuel cell system includes a fuel cell stack, a hydrogen supply source, a hydrogen flow passage, a hydrogen recirculation passage, and a hydrogen circulation pump configured to recirculate emission gas containing hydrogen from the fuel cell stack through the hydrogen recirculation passage. The hydrogen circulation pump includes a pump body, a motor, and a housing. The housing internally includes a merge portion that merges the hydrogen recirculation passage with the hydrogen flow passage. The hydrogen flow passage includes a bypass passage that bypasses the merge portion by branching from a portion of the hydrogen flow passage between the hydrogen supply source and the merge portion. The hydrogen flow passage or the bypass passage includes an open degree control valve configured to control a flow rate of hydrogen flowing through the hydrogen flow passage and the bypass passage.

Abstract: A hydrogen circulation pump includes a pump body, a motor, a driver, and a housing. The housing internally includes a hydrogen recirculation passage connecting the pump body to a fuel cell stack, a hydrogen supply passage through which hydrogen is supplied from a hydrogen supply source to the fuel cell stack, and a partition wall that defines an accommodation chamber accommodating the driver. The hydrogen supply passage includes a merge portion where the hydrogen supply passage merges with the hydrogen recirculation passage. The hydrogen supply passage is arranged in the housing such that heat is exchanged at an upstream side of the merge portion through the partition wall between the driver and the hydrogen in the hydrogen supply passage.

Abstract: A compressor includes a compression mechanism drawing in, compressing and discharging fluid and a housing accommodating therein the compression mechanism. The housing has therein a discharge chamber into which the fluid compressed by the compression mechanism is discharged. A silencing and cooling device is provided in the discharge chamber to cool the fluid discharged in the discharge chamber and reduce pressure fluctuation. A dispersion wall is provided in the discharge chamber on downstream side of the discharge chamber that is opposite from an inflow port with respect to flowing direction of the discharged fluid. The dispersion wall is disposed to cover a part of the silencing and cooling device and cover at least a part of the inflow port.

Abstract: An air compressor includes a compression mechanism for compressing intake air and discharging the compressed air, and an intake chamber portion through which intake air is introduced into the compression mechanism. The intake chamber portion has an inlet of intake air and an outlet connected to the compression mechanism. The intake chamber portion is integrated with the compression mechanism. The intake chamber portion has therein a partition wall extending in the direction from the inlet toward the outlet to form plural flow passages in the intake chamber portion. The plural flow passages have different flow path lengths and connect between the inlet and the outlet.

Abstract: A compressor has a housing which includes a compression mechanism for compressing and then discharging sucked air, and an intercooler core for cooling the discharged air and mitigating a pressure fluctuation thereof. The housing has a cylinder block integrally formed so as to include a rotor chamber which accommodates the compression mechanism, a silencing and cooling chamber which accommodates the intercooler core, and a discharge hole which provides communication between the rotor chamber and the silencing and cooling chamber.

Abstract: A compressor includes a compression mechanism drawing in, compressing and discharging fluid and a housing accommodating therein the compression mechanism. The housing has therein a discharge chamber into which the fluid compressed by the compression mechanism is discharged. A silencing and cooling device is provided in the discharge chamber to cool the fluid discharged in the discharge chamber and reduce pressure fluctuation. A dispersion wall is provided in the discharge chamber on downstream side of the discharge chamber that is opposite from an inflow port with respect to flowing direction of the discharged fluid. The dispersion wall is disposed to cover a part of the silencing and cooling device and cover at least a part of the inflow port.

Abstract: A roots type fluid machine includes suction and discharge ports, rotary shafts and a pair of rotors. The rotor has a number n of lobe and valley portions with apex and bottom ends. The lobe portions are located on imaginary lines extending radially from an axis of the rotary shaft. The outer surface of each one of the rotors is generated by rotating an outline of the rotor including an arc and involute and envelope curves around and moving the outline in the direction of the axis. The arc has a radius R and a center located on the imaginary line. The involute curve is formed by an imaginary base circle having a radius r and a center located on the axis. The envelope curve is formed by an arc having a radius R. The number n is four or more. A torsional angle ? is over 360/n degrees.

Abstract: An electric pump for supplying a hydrogen gas to a fuel cell includes a rotary shaft rotatably inserted through an electric motor, a transmitting member provided on one of an outer peripheral surface of the rotary shaft and an inner peripheral surface of the electric motor so as to be rotatable therewith, and a groove formed in the other of the outer peripheral surface of the rotary shaft and the inner peripheral surface of the electric motor for the transmitting member to be inserted therein. The groove transmits a rotary torque of the electric motor to the rotary shaft by contacting an inner surface of the groove and the transmitting member and has an opening width along a rotary direction of the rotary shaft which is larger than the width of the transmitting member. The groove and the transmitting member produce an impact torque when the electric pump is started.