Abstract: A fluid machine includes an electric motor, a pump, an inverter, and a housing having a motor chamber and an inverter chamber. The housing has a cooling passage having an inverter cooling passage and a motor cooling passage through which cooling fluid flows. After the cooling fluid is introduced to the inverter cooling passage, a flow of the cooling fluid is divided at the inlet into a flow of the cooling fluid flowing through the inverter cooling passage and a flow of the cooling fluid flowing through the motor cooling passage, the flow of the cooling fluid flowing through the inverter cooling passage and the flow of the cooling fluid flowing through the motor cooling passage are joined together at the outlet and discharged from the inverter cooling passage. The inverter cooling passage has a passage expanded portion in which a vortex flow is generated.

Abstract: A roots pump includes a housing, a rotor chamber, a pair of rotary shafts, and a pair of rotors. The rotor chamber includes a rotor chamber peripheral surface facing a pair of distal end portions of each of the rotors. Each of the pair of the distal end portions includes: a pair of rotor peripheral surfaces facing the rotor chamber peripheral surface with a first radial clearance; and a distal end peripheral surface that is formed between the pair of the rotor peripheral surfaces in the rotational direction and faces the rotor chamber peripheral surface with a second radial clearance greater than the first radial clearance. A width of the rotor chamber peripheral surface facing the distal end peripheral surface in the rotational direction is greater than a sum of a pair of predetermined widths of the rotor chamber peripheral surface facing the pair of the rotor peripheral surfaces.

Abstract: A fluid machine includes an electric motor, a pump, an inverter, and a housing having a motor chamber and an inverter chamber. The housing has a cooling passage having an inverter cooling passage and a motor cooling passage through which cooling fluid flows. After the cooling fluid is introduced to the inverter cooling passage, a flow of the cooling fluid is divided at the inlet into a flow of the cooling fluid flowing through the inverter cooling passage and a flow of the cooling fluid flowing through the motor cooling passage, the flow of the cooling fluid flowing through the inverter cooling passage and the flow of the cooling fluid flowing through the motor cooling passage are joined together at the outlet and discharged from the inverter cooling passage. The inverter cooling passage has a passage expanded portion in which a vortex flow is generated.

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 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.

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 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.

Abstract: A motor-driven Roots compressor includes a drive shaft driven by a motor and a driven shaft connected to a drive shaft through a timing gear. A pair of rotors is respectively fixed to the drive shaft and the driven shaft. The rotors are rotated so that the compressor draws and discharges working fluid. The compressor also includes a casing having a plurality of shells which define a motor chamber for accommodating the motor, a gear chamber for accommodating the timing gear and a rotor chamber for accommodating the pair of rotors. A refrigerant passage is formed in at least one of the shells of the motor chamber and the gear chamber for flowing the working fluid therein. At least one of the motor and the timing gear is cooled by the working fluid in the refrigerant passage.

Abstract: A fluid compressor that ensures the discharge of water from a discharge port when water is drawn into or condensed in a pump chamber. The compressor includes a pump chamber for drawing in fluid. The pump chamber includes a bottom part located in a lower portion of the pump chamber. Two rotors arranged in the pump chamber are rotated to compress the fluid in the pump chamber. A discharge port located in the bottom part discharges the compressed fluid out of the pump chamber. The bottom part defines a guide surface formed continuously from the discharge port. The guide surface is sloped downward so that water on the guide surface moves downward to the discharge port due to gravitational force.

Abstract: A fuel cell system includes a fuel cell stack, a hydrogen flowing passage, an air flowing passage and a control valve. At least one of the gas flowing passages includes a bypass, a selecting means, a gas flowing means and a control unit. The bypass allows a gas to flow therethrough so as to detour the fuel cell stack and the control valve. The selecting means selects one of a passage which passes through the fuel cell stack and the bypass. The gas flowing means flows the gas to the bypass. In the control unit, the through passage is selected by the selecting means when the system is operated, The bypass is selected by the selecting means when the operation of the system is stopped. The gas is flowed to the bypass by operating the gas flowing means when the control valve is frozen thereby heating the control valve.