Abstract: A motor 1 according to an embodiment of the present disclosure includes a rotor 10 configured to freely rotate around a rotation axis AX; and a stator 20 arranged inside the rotor 10 and including a stator unit 21 of a claw-pole type, the stator unit including a winding wire 212 that is annularly wound around the rotation axis AX and a stator core 211 provided so as to surround the winding wire, wherein the stator 20 includes an inner space 24A around the rotation axis AX and in communication with an outer side of the rotor 10, such that heat can be radiated to the inner space 24A.

Abstract: A power steering device includes an oil-hydraulic pump, an electric motor to drive the pump, an inverter, a control valve, a power cylinder to produce a steering assist, and a control unit to control the drive signal of the inverter. The control valve includes a pump port supplied with oil from the pump, a first and second cylinder ports connected to first and second cylinder chambers on sides of the piston, and a discharge port. Communication between the first cylinder port and the pump port and communication between the second cylinder port and the discharge port, and communication between the first cylinder port and the discharge port and communication between the second cylinder port and the pump port are established in steered status in the other direction. Communication among the pump port and first and second cylinder ports, and isolation of the discharge port from the pump port and first and second cylinder ports are established when the control valve is in neutral status.

Abstract: A power steering device includes an oil-hydraulic pump, an electric motor to drive the pump, an inverter, a control valve, a power cylinder to produce a steering assist, and a control unit to control the drive signal of the inverter. The control valve includes a pump port supplied with oil from the pump, a first and second cylinder ports connected to first and second cylinder chambers on sides of the piston, and a discharge port. Communication between the first cylinder port and the pump port and communication between the second cylinder port and the discharge port, and communication between the first cylinder port and the discharge port and communication between the second cylinder port and the pump port are established in steered status in the other direction. Communication among the pump port and first and second cylinder ports, and isolation of the discharge port from the pump port and first and second cylinder ports are established when the control valve is in neutral status.

Abstract: Capacitors act as bootstrap capacitors of a high side control circuits. The capacitors are charged in a period in which all of high arm switching devices are non-conductive, so-called in a precharge period. When any of U-phase current, V-phase current and W-phase current is smaller than a negative predetermined value (when an absolute value is larger), it is judged which is the largest value. The low arm switching device is turned on only for a phase corresponding to the current of the largest value and the low arm switching devices of other phases are turned off.

Abstract: A pump driving apparatus has a characteristic changing section which receives a set pressure, a set flowing amount, a set horse power, and a DC voltage of the converter section as input, outputs modified values of pressure, flowing amount, and horse power, and supplies the modified values to the horse power command generation section. Therefore, the motor can be driven to suit the change in power voltage so that the motor capacity can be utilized sufficiently.

Abstract: An oil pressure unit includes an inverter arranged to supply electric power to a motor; a load sensor arranged to detect a load of the oil pressure pump; a rotation sensor arranged to detect a rotation speed of the motor; a current command value calculation part configured to calculate a current command value so that a deviation between a speed command value representing a target rotation speed of the motor and a rotation speed of the motor converges to zero; a correction part configured to correct the current command value based on the load of the oil pressure pump; and a control signal generation part configured to output a control signal to the inverter based on a corrected current command value.

Abstract: Capacitors act as bootstrap capacitors of a high side control circuits. The capacitors are charged in a period in which all of high arm switching devices are non-conductive, so-called in a precharge period. When any of U-phase current, V-phase current and W-phase current is smaller than a negative predetermined value (when an absolute value is larger), it is judged which is the largest value. The low arm switching device is turned on only for a phase corresponding to the current of the largest value and the low arm switching devices of other phases are turned off.

Abstract: Resistance of the coil of a DC motor is calculated by using the motor current and the motor voltage, and the coil temperature is estimated by using the resistance-temperature characteristics of the coil.

Abstract: An apparatus for warm up control of an autonomous inverter-driven hydraulic unit has a warm up control section and a switch section. The warm up control section performs a predetermined process using a current speed and current pressure as input information and outputs a first switch command. The switch section is controlled by the first switch command so as to control on/off of power supplied to a fan motor. The apparatus causes an oil temperature to quickly rise to a level where a hydraulic unit driven by a hydraulic pump can work in an optimum condition.

Abstract: Resistance of the coil of a DC motor is calculated by using the motor current and the motor voltage, and the coil temperature is estimated by using the resistance-temperature characteristics of the coil.

Abstract: An apparatus for warm up control of an autonomous inverter-driven hydraulic unit has a warm up control section and a switch section. The warm up control section performs a predetermined process using a current speed and current pressure as input information and outputs a first switch command. The switch section is controlled by the first switch command so as to control on/off of power supplied to a fan motor. The apparatus causes an oil temperature to quickly rise to a level where a hydraulic unit driven by a hydraulic pump can work in an optimum condition.

Abstract: A pump driving apparatus has a characteristic changing section which receives a set pressure, a set flowing amount, a set horse power, and a DC voltage of the converter section as input, outputs modified values of pressure, flowing amount, and horse power, and supplies the modified values to the horse power command generation section. Therefore, the motor can be driven to suit the change in power voltage so that the motor capacity can be utilized sufficiently.

Abstract: Output currents from a superconducting quantum interference device which corresponds to magnetic flux guided thereto are compared with a predetermined value which corresponds to a magnetic flux locking point so as to detect a direction of shift with respect to the magnetic flux locking point. A shift quantity is judged to determine whether or not it is large based upon a history of the shift direction. A variation value component of an estimate feedback quantity is varied by taking this history into consideration. The estimate feedback quantity is used to guide magnetic flux for compensating for variation in the magnetic flux which is guided to the superconducting quantum interference device.