Abstract: A rotary shaft is rotatable relative to a motor rotor. A first end face of the motor rotor is exposed to the outside of a stator. A hammer portion is provided at the first end face. The hammer portion is configured to be movable as the motor rotor rotates. A collision portion rotating integrally with the rotary shaft is configured to collide with the hammer portion. The allowance space between the collision portion and the hammer portion allows the hammer portion to be move relative to the collision portion. Therefore, the electric pump is capable of detaching a rotor from a pump chamber without increasing the size of the pump.

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: Provided is a backup line allocation apparatus that determines which fail lines, in a memory provided with a plurality of backup lines, to allocate the backup up lines to, comprising a bit counting section that, for each fail bit contained in each fail line, counts a number of orthogonal fail bits, which is a number of fail bits in a fail line that includes the each fail bit and has an orientation that differs from the orientation of the each fail line, and stores the number of orthogonal fail bits associated with the each fail bit; a weight calculating section that calculates a weighting coefficient for each fail line based on the number of orthogonal fail bits of the fail bits contained in the each fail line, and stores the weighting of the each fail line; and an allocating section that determines which of the fail lines to allocate the backup lines to, based on the relative sizes of the weighting coefficients calculated by the weight calculating section.

Abstract: A variable displacement rotary pump includes a main pump unit, an auxiliary pump unit, a discharge passage, a bypass passage, a suction passage, a check valve and a control valve. The suction passage is in communication with the discharge passage through the bypass passage and a second discharge port. The check valve is disposed in the discharge passage for preventing fluid in a first discharge port of the main pump unit from flowing into the bypass passage. The control valve is operable for opening and closing the bypass passage. When the control valve opens the bypass passage and the check valve closes the discharge passage, flow rate of the fluid discharged from the discharge passage is reduced. A throttle passage is provided in the bypass passage or the control valve for regulating flow of the fluid in early phase of operation of the control valve to open the bypass passage.

Abstract: The variable displacement gear pump for a loading system in an industrial vehicle has main and sub gear pump portions, suction, discharge and bypass passages, and check and opening valves. The main gear pump portion has main drive and driven gears, and has suction and discharge side spaces. The sub gear pump portion has sub drive and driven gears, and has suction and discharge side spaces. The bypass passage returns hydraulic fluid in the discharge-side space of the sub gear pump portion to the suction passage. The check valve prevents hydraulic fluid in the discharge-side space of the main gear pump portion from flowing to that of the sub gear pump portion. The opening valve is used for opening and closing the bypass passage, and closes the bypass passage due to a pressure in a discharge conduit of the loading system increased by the load applied to the loading system.

Abstract: A hydraulic system that can implement effective practical use of energy is provided. A hydraulic system according to the present invention has a hydraulic pump driven by a hydraulic pump motor, a loading cylinder and a power steering cylinder which are driven by pressure oil supplied from the hydraulic pump, and power supply means for supplying power to the hydraulic pump motor. The power supply means comprises a stack of a fuel cell, a fuel supply passage for supplying hydrogen gas to the stack, fuel circulating passages in which a hydrogen pump for joining unreacted hydrogen gas discharged from the stack into the fuel supply passage to circulate hydrogen gas is disposed, and a regenerator which is driven by pressure oil to generate rotational force. The hydrogen pump is rotationally driven by the regenerator.

Abstract: It is intended to provide a fuel cell system more capable of exhibiting effects of downsizing and reduction in weight. The fuel cell system of this invention has a stack and a regenerator that are provided in parallel to an air compressor. An air supply passage to which an air discharged from the air compressor is supplied and an air discharge passage for discharging an unreacted air to the downstream are connected to the stack. A regeneration air supply passage to which the air discharged from the air compressor is supplied and a regeneration air discharge passage for discharging the air to the downstream are connected to the regenerator. A fuel pump has a structure that the fuel pump is rotatively driven by the regenerator.

Abstract: A fuel cell system which can exhibit a better result of a reduction in size and weight is provided. The fuel cell system of the present invention comprises a stack of fuel cells which generate electricity by receiving a supply of hydrogen gas and air, a fuel supply passage for supplying hydrogen gas to the stack, a fuel circulation and supply passage and a fuel circulation and discharge passage equipped with a fuel pump for causing any unreacted hydrogen gas discharged from the stack to join the fuel supply passage and be circulated, a cooling water pump for supplying cooling water to the stack, and a regenerator driven by the cooling water supplied from the cooling water pump for generating a rotary force. The hydrogen pump is adapted to be driven for rotation by the regenerator.

Abstract: A variable displacement type gear pump has gear chambers, one of which is a specific gear chamber. A suction passage is formed in the housing so as to communicate with suction-side spaces. An outlet passage communicates with discharge-side spaces. A return passage returns the fluid discharged to the discharge-side space of the specific gear chamber to the suction passage. The return passage communicates with the suction passage at a confluence portion located upstream side of the suction-side space. An opening and closing valve opens the return passage in a small displacement operational state. A check valve is located between the discharge-side space of the specific gear chamber and the outlet passage for preventing the fluid discharged from the gear chamber other than the specific gear chamber from flowing into the discharge-side space of the specific gear chamber in the small displacement operational state.

Abstract: In a variable displacement type gear pump, each of a main gear pump portion and a sub gear pump portion has a drive gear, a driven gear engaging with the drive gear, and an urging portion applying radial load to the drive and driven gears. A bypass passage returns fluid in a discharge-side space of the sub gear pump portion to a suction passage. An opening and closing valve opens the bypass passage in a small displacement operational state. A drive shaft supports the main drive gear and the sub drive gear. A driven shaft supports the main driven gear and the sub driven gear. The drive gears and the driven gears are rotated in accordance with a rotation of the drive shaft. The drive and driven shafts transmit the radial load in the main gear pump portion to the sub gear pump portion in the small displacement operational state.

Abstract: A roots-type fluid machine including a set of rotors and a rotor housing is disclosed. The rotor housing accommodates the rotors and has a suction space. The set of rotors mesh with each other and rotate in the rotor housing so that fluid is drawn into the suction space and discharged from the rotor housing. Each of the set of rotors includes a tooth having a twisted portion and a different shape variation portion. The twisted portion has a twist angle that changes linearly or non-linearly about a rotation axis of the corresponding rotor with respect to the variation of the position in the direction of the axis. The different shape variation portion has a twisted angle that changes by a smaller degree than the variation of the twist angle of the twisted portion.

Abstract: A composite fluid machine has a first and a second fluid delivering mechanisms. The first fluid delivering mechanism includes an accommodation chamber, a movable body, and a suction space. The movable body is accommodated in the accommodation chamber.. The suction space is defined by the accommodation chamber and the movable body. The suction space is connected to the inlet, and the flow rate of the fluid introduced into the suction space is displaced. The movable body performs a suction movement and a discharge movement.. The second fluid delivering mechanism is combined with the first fluid delivering mechanism and is located upstream of the first fluid delivering mechanism to deliver the fluid to the suction space of the first fluid delivering mechanism.. Lobes of helical roots rotors are twisted in a respective direction around the rotational axis.

Abstract: A roots pump including a pair of multi-lobe rotors is disclosed. The pair of rotors each include a first straight portion and a second straight portion. The first straight portion is provided on one of end portions of the rotary shaft of the rotor in an axial direction to extend straight along the axial direction. The straight portion is provided on the other one of the end portions to extend straight along the axial direction. The phases of the first straight portion and the second straight portion are displaced along the circumferential direction of the associated rotary shaft. Each of the pair of rotors further includes a coupling portion, which couples the first straight portion and the second straight portion. The coupling portions of the pair of rotors are engaged with each other to suppress fluid leakage between the pair of rotors.

Abstract: A centrifugal compressor for compressing gas has a casing, a rotary shaft, an impeller, a diffuser, a first scroll, a second scroll, a first passage, a second passage, and a switching member. The rotary shaft is supported by the casing. The impeller is rotatably fixed to the rotary shaft, and sends the gas radially outward to a flow path downstream thereof. The diffuser is formed around the impeller. The first scroll is formed around the diffuser. The second scroll is formed between the diffuser and the impeller. The first passage is formed from the impeller to the first scroll through the diffuser. The second passage is formed from the impeller to the second scroll. The switching member switches the flow path between the first passage and the second passage by opening and closing the diffuser.

Abstract: A Roots pump has a driving shaft press fitted into a driving rotor, and a driven shaft press fitted into a driven shaft. A driving timing gear is located between an electric motor and the driving rotor. The driving rotor has a driving assist shaft that projects in a direction opposite to the driving timing gear. The specific gravity of the material of the driving assist shaft is less than the specific gravity of the material of the driving rotary shaft. A driven rotor has a driven assist shaft that projects in a direction opposite to a driven timing gear. The specific gravity of the material of the driven assist shaft is less than the specific gravity of the material of the driven rotary shaft.

Abstract: A driving timing gear is located between an electric motor and a driving rotor with respect to an axial direction of a driving shaft. A first bearing is located on the same side of the driving rotor as the driving timing gear. The driving shaft has a rotor attaching end. The rotor attaching end is a free end that is located on the same side of the first bearing as the driving rotor. A weight is at a portion of the driving rotor that is close to the driving timing gear with respect to the axial direction of the driving shaft. Another weight is located at a portion of a driven rotor that is closer to a driven timing gear.

Abstract: A hydrogen circulation pump including a liquid receptacle arranged in a discharge pipe extending upward from a housing or a discharge port arranged in the housing. The liquid receptacle extends along the entire circumference of the inner surface of the discharge pipe or the discharge port. Fine holes far circulating unreacted gas are formed in a bottom portion of the liquid receptacle. A water repellent film formed from a water repellent material is arranged on an upper surface of the bottom portion of the liquid receptacle.

Abstract: A roots type fluid machine includes a housing, a pair of parallel rotary shafts and two-lobe rotors. Each rotor includes two lobe portions and two well portions. Each lobe portion has a profile of convex arc with a radius R and each well portion has a profile of concave arc which is an envelope of the convex arc of the lobe portion. The rotor has a configuration defined by a curve which includes the convex arc, the concave arc and further an involute curve with a base radius r between the convex and concave arcs. The base radius r is set in a range L/(2?{square root over ( )}2)<r<0.3(?{square root over ( )}2)L where distance between axes of the rotary shafts is L, and the radius R is set in a range {(?{square root over ( )}2)/16}?L<R<{(27?5?{square root over ( )}2)/56}L.

Abstract: A roots compressor has a housing, a rotary shaft, a rotor and a layer. The housing defines a pump chamber, a suction port and a discharge port. The suction port and the discharge port adjoin to the pump chamber. The rotary shaft is rotatably supported by the housing. The rotor is connected to the rotary shaft and contained in the pump chamber. Fluid introduced into the pump chamber through the suction port is discharged to the outside of the pump chamber through the discharge port by rotation of the rotor which is driven through the rotary shaft. The layer is formed on an inner peripheral surface of the housing, which defines the pump chamber. The layer is thinner from a side adjacent to the suction port toward a side adjacent to the discharge port in circumferential direction of the housing.

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.