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: 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 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: A magnetic sensor that is inexpensive and suppresses changes in offset voltage caused by wear. The magnetic sensor includes magnetoresistance elements having electrical resistances that change in accordance with magnetism changes. The magnetic sensor detects magnetism based on changes in the electrical resistances. The magnetoresistance elements are covered by a protective film. Part of the protective film is etched and eliminated to form a recess.

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 magnetic sensor that is inexpensive and suppresses changes in offset voltage caused by wear. The magnetic sensor includes magnetoresistance elements having electrical resistances that change in accordance with magnetism changes. The magnetic sensor detects magnetism based on changes in the electrical resistances. The magnetoresistance elements are covered by a protective film. Part of the protective film is etched and eliminated to form a recess.

Abstract: A compressor includes a housing member having a through hole. The compressor includes a conductive portion through which external electricity is supplied to a motor mechanism. The conductive portion has a lead extending from the motor mechanism, and a connector terminal. The connector terminal is connected to the lead to permit the external electricity to be conducted to the lead. The connector terminal is attached to the through hole such that a joint between the lead and the connector terminal is located in the through hole to face inward of the housing member. A viscoelastic insulating material fills the through hole. Therefore, the compressor ensures reliable insulation of the terminal from a housing member.

Abstract: A vibration actuator comprising a drive section having a coil placed in a cavity of a magnetic circuit, a vibrator driven by the drive section, a spacer made such that its end portion supports a peripheral edge portion of the vibrator, and an external plate member for covering the other end portion of the spacer. A closed space defined by the vibrator, the spacer and the external plate member is constructed as an acoustic space based on the Helmholtz's resonance principle. A mobile communication terminal contains the vibration actuator in its housing.

Abstract: In a vibration actuator having a magnetic circuit component (10) and a coil (17) arranged in a gap (14) which is made at one side of the magnetic circuit in a predetermined direction, a space defining member (31, 32, 19) defines an accommodation space (34) to accommodate the magnetic circuit component and the coil. A supporting unit (16,18) supports the magnetic circuit component and the coil so that they are separately movable in the predetermined direction. The space defining member has a sound release hole (33) faced to the other side of the magnetic circuit component in the predetermined direction.

Abstract: In an antenna assembly (10) including a whip antenna (1, 9) provided with a stopper (5) of a conductive material at a lower end of the whip antenna, a helical antenna (2) provided with a conductive sleeve (6) mounted on a top end of the whip antenna, and a holder (4) of a conductive material for slidably holding the whip antenna, each of the stopper, the conductive sleeve, and the holder is of a light metal having a specific gravity not greater than 3 g/cm3. The holder is electrically connected to the stopper when the whip antenna is in an extended position. The holder is electrically connected to the conductive sleeve when the whip antenna is in a retracted position. The light metal may includes at least one of aluminum and magnesium. Alternatively, the light metal essentially consists of 0.4% or less Si, 0.7% or less Fe, 5.0-6.0% Cu, 0.30% or less Zn, 0.2-0.6% Bi, 0.2-0.6% Pb, and the balance Al in weight.