Abstract: A sun gear is supported by an eccentric portion of a rotor via a bearing and rotatable eccentrically to the rotor axis. A ring gear includes inner teeth via which the ring gear is meshed with outer teeth of the sun gear. An output shaft is located adjacent to the sun gear in the axial direction. A fitted portion of the output shaft is loosely fitted to a fitting portion of the sun gear to transfer rotation of the sun gear to the output shaft. The bearing has a center position located in a fitting overlap region between the fitting portion of the sun gear and the fitted portion of the output shaft in the axial direction and/or located in a gear overlap region between the outer teeth of the sun gear and the inner teeth of the ring gear which are meshed with the outer gear.

Abstract: A shift-by-wire (SBW) device includes a capacitor, which stores electric power. When an abnormality occurs in a battery or an electric power supply system, an actuator of the SBW device receives electric power from the capacitor and changes a shift range of an automatic transmission to a P range at least once. Furthermore, when a lever of a P range releasing arrangement is operated, the P range of the automatic transmission is released.

Abstract: A reference position detecting apparatus includes an electric motor and a motor control unit. The electric motor includes a plurality of first coils and a plurality of second coils. The electric motor further includes a rotor that rotates when at least one of the plurality of first coils and the plurality of second coils is supplied with electricity. The motor control unit controls electricity supplied to either one of the plurality of first coils and the plurality of second coils to rotate the rotor to a limit position in a movable range of an object.

Abstract: A sun gear is supported by an eccentric portion of a rotor via a bearing and rotatable eccentrically to the rotor axis. A ring gear includes inner teeth via which the ring gear is meshed with outer teeth of the sun gear. An output shaft is located adjacent to the sun gear in the axial direction. A fitted portion of the output shaft is loosely fitted to a fitting portion of the sun gear to transfer rotation of the sun gear to the output shaft. The bearing has a center position located in a fitting overlap region between the fitting portion of the sun gear and the fitted portion of the output shaft in the axial direction and/or located in a gear overlap region between the outer teeth of the sun gear and the inner teeth of the ring gear which are meshed with the outer gear.

Abstract: At an initial drive operation after turning on of an electric power source, an ECU sequentially changes each current exciting phase among multiple phases through one complete cycle at a predetermined time schedule, so that a rotational position of a rotor and the corresponding exciting phase coincide with each other at some timing during the initial drive operation, and thereby the rotor is rotated. The ECU counts the A-phase signal and the B-phase signal during the rotation of the rotor in the initial drive operation and learns a relationship among a count value of the A-phase signal and the B-phase signal, a rotational position of the rotor and each exciting one of the plurality of phases at an end of the initial drive operation. When the ECU determines that a result of the learning is erroneous, the ECU re-executes the learning by re-executing the initial drive operation.

Abstract: A rod-lock mechanism is provided in an automatic transmission for a vehicle. The rod-lock mechanism has an engaging pin which will be engaged with a rod when the rod is in its initial position, so as to hold the rod in its initial position. The rod-lock mechanism further has an electric actuator for driving the engaging pin when electric power is supplied, so that the engaging pin is brought out of engagement from the rod. A forced parking current supply unit controls electric power supply to the electric actuator. When the electric power is supplied to the electric actuator, the rod is moved in a direction of a parking position to bring a vehicle into a parking condition.

Abstract: In an electric motor of an SBW actuator, a rotor shaft is rotated upon energization of the motor. A rotor core is rotated integrally with the rotor shaft. A resilient member enables tilting or decentering of the rotor shaft upon application of a decentering force on the rotor shaft. A stator core contacts the rotor core when the rotor shaft is tilted or decentered.

Abstract: A shift-by-wire control system includes a parking lock device that brings an output shaft of an automatic transmission device to a lock state when a range switching unit switches to the P-range. The parking lock device brings the output shaft to a lock-release state when the range switching unit switches to another shift range. An electric motor actuates the range switching unit and the parking lock device in accordance with an instruction of an operator. A manual device transmits manual operation force of the operator to the parking lock device when the electric motor stops. The manual device includes a one-way transmission unit permitting transmission of the manual operation force in a direction toward the lock state, and prohibiting transmission of the manual operation force in a direction toward the lock-release state.

Abstract: An electric motor drives and rotates a rotor shaft, and a speed reducer reduces speed of rotation of the rotor shaft and outputs the rotation. A shaft is fixed to a front housing. A turning member is meshed with an external teeth member provided to an output shaft of the speed reducer and is supported to be able to rotate around an axis line of the shaft. A turning angle sensor senses a turning angle of the turning member by sensing a magnetic field corresponding to a turning angle of a magnet section provided to the turning member. An outer wall of a cup is fixed to the turning member, and an inner wall of the cup is fitted to a ball bearing. A plate is provided slidably between a bottom outer wall surface of the cup and an end surface of the front housing around the shaft.

Abstract: A shift range switching apparatus connects with a motor for switching a shift range of an automatic transmission. The shift range switching apparatus includes a switching unit that is operated by the motor for switching the shift range. The shift range switching apparatus further includes a control unit that outputs a driving current to the motor for switching the shift range to one of a P range, an R range, an N range, and a D range. The control unit controls the driving current at one of a plurality of set values in accordance with a switching pattern of the shift range. The switching pattern may be defined by a combination of two of the P range, the R range, the N range, and the D range.

Abstract: A shift range switching device is provided to a shift-by-wire system for an automatic transmission device. The shift range switching device includes a range switching unit for switching a shift range of the automatic transmission device between a P range and the other range. The shift range switching device further includes an actuator including an electric motor and a reduction device. The reduction device transmits driving force of the electric motor to the range switching unit for actuating the range switching unit as instructed. The reduction device has a variable reduction ratio. The reduction device transmits the driving force in switching of the shift range from the P range to the other range at a reduction ratio, which is greater than a reduction ratio in switching of the shift range from the other range to the P range.

Abstract: A reference position detecting apparatus includes an electric motor and a motor control unit. The electric motor includes a plurality of first coils and a plurality of second coils. The electric motor further includes a rotor that rotates when at least one of the plurality of first coils and the plurality of second coils is supplied with electricity. The motor control unit controls electricity supplied to either one of the plurality of first coils and the plurality of second coils to rotate the rotor to a limit position in a movable range of an object.

Abstract: A shift range switching apparatus includes an automatic transmission that includes a shift range switching device having a control rod for switching an actual shift range corresponding to rotation angle of the control rod. The shift range switching apparatus further includes an electric actuator that includes an output shaft connecting with the control rod. The electric actuator switches the actual shift range by rotating the control rod via the output shaft. The shift range switching apparatus further includes an assembly regulating device that allows the electric actuator to be detachable from and attachable to the automatic transmission when the actual shift range of the shift range switching device is set at a specific shift range.

Abstract: A reference position detecting apparatus includes an electric motor and a motor control unit. The electric motor includes a plurality of first coils and a plurality of second coils. The electric motor further includes a rotor that rotates when at least one of the plurality of first coils and the plurality of second coils is supplied with electricity. The motor control unit controls electricity supplied to either one of the plurality of first coils and the plurality of second coils to rotate the rotor to a limit position in a movable range of an object.

Abstract: A thin plate 80x forming a stator tooth 80 has two convex portions 83 on each of side faces 80b, 80c. Four convex portions 83 are a sharpened convex portion 83a of which a tip portion has a thickness thinner than a thickness of the thin plate 80x. When a bobbin 81 wound with an exciting coil 22 is press-fitted around the stator tooth 80, four lines of convex portions formed by laminating the thin plates 80x cut in an inner wall of the bobbin 81, the strength for fixing and holding the bobbin 81 can be increased in a radial, lamination and rotating directions, so that the position of the bobbin 81 assembled in a right position can be maintained.

Abstract: At an initial drive operation after turning on of an electric power source, an ECU sequentially changes each current exciting phase among multiple phases through one complete cycle at a predetermined time schedule, so that a rotational position of a rotor and the corresponding exciting phase coincide with each other at some timing during the initial drive operation, and thereby the rotor is rotated. The ECU counts the A-phase signal and the B-phase signal during the rotation of the rotor in the initial drive operation and learns a relationship among a count value of the A-phase signal and the B-phase signal, a rotational position of the rotor and each exciting one of the plurality of phases at an end of the initial drive operation. When the ECU determines that a result of the learning is erroneous, the ECU re-executes the learning by re-executing the initial drive operation.

Abstract: A brushless synchronous motor includes a stator having a plurality of phase coils, a rotor disposed opposite the stator, a magnetic sensor for detecting a rotation angle of the rotor, a power supply circuit connected to the phase coils, a control circuit for controlling the power supply circuit so that the motor rotates synchronously. In the above motor, a circuit board includes a wiring circuit connecting the phase coils with the power supply circuit, and the magnetic sensor is directly fixed to the circuit board so that dimensional variation of the magnetic sensor relative to the stator can be minimized.

Abstract: In an electric motor of an SBW actuator, a rotor shaft is rotated upon energization of the motor. A rotor core is rotated integrally with the rotor shaft. A resilient member enables tilting or decentering of the rotor shaft upon application of a decentering force on the rotor shaft. A stator core contacts the rotor core when the rotor shaft is tilted or decentered.

Abstract: A reference position detecting apparatus includes an electric motor and a motor control unit. The electric motor includes a plurality of first coils and a plurality of second coils. The electric motor further includes a rotor that rotates when at least one of the plurality of first coils and the plurality of second coils is supplied with electricity. The motor control unit controls electricity supplied to either one of the plurality of first coils and the plurality of second coils to rotate the rotor to a limit position in a movable range of an object.

Abstract: A rod-lock mechanism is provided in an automatic transmission for a vehicle. The rod-lock mechanism has an engaging pin which will be engaged with a rod when the rod is in its initial position, so as to hold the rod in its initial position. The rod-lock mechanism further has an electric actuator for driving the engaging pin when electric power is supplied, so that the engaging pin is brought out of engagement from the rod. A forced parking current supply unit controls electric power supply to the electric actuator. When the electric power is supplied to the electric actuator, the rod is moved in a direction of a parking position to bring a vehicle into a parking condition.