Ntn Corporation

Koichi Okada

Hiroaki Ohba

Masatoshi Mizutani

Toru Takahashi

Hisashi Ohtsuki

Takayuki Norimatsu

Kenichi Iwamoto

Takayoshi Ozaki

Eiji Tajima

Katsuyuki Ikei

Hiroyuki Yamada

Koji Sahashi

Takeshi Kanda

Akira Torii

Tetsuya Yamamoto

Shiro Goto

Kenichi Suzuki

Yusuke Makino

Minoru Suzuki

Takahide Saito

Tatsuya Yamasaki

Takashi Koike

Makoto Yasui

Yoshitaka Nagano

Hiroyoshi Ito

Kazuhiko Hozumi

Kenichiro Ito

Isao Hori

Hiroyuki Hakamata

Akio Nakajima

Akiyoshi Nishikawa

Yingjie Zhang

Naoyuki Uchiyama

Hiroshi Bunko

Norihiko Sasaki

Hideo Shinagawa

Kenichi Suzumura

Yutaka Hayashi

A driving device for motors for drive wheels of a vehicle includes a plurality of in-wheel motor assemblies and motor drivers. The motor drivers include a smoothing circuit, an inverter unit to convert the direct current power, inputted through the smoothing circuit, into a three phase alternating current power, an inverter control unit for controlling the inverter unit, and a cooler for cooling the inverter unit. The plurality of the motor drivers are disposed within a single common casing and the plurality of the motor drivers share the smoothing circuit. The inverter control unit of the plurality of the motor drivers is of a control type capable of driving the driving element of the inverter unit according to the PWM scheme and the plurality of the motor drivers have equal cycles of PWM relative to each other and are configured to displace ON and OFF timings of the driving element.

Driving device for motor for drive wheel of vehicle

A slip control device for an electric vehicle which accurately determines slippage occurrence with only a rotation angle sensor for motor rotation control and perform rapid control to eliminate the slippage, is provided. A threshold calculation module () calculates a normal angular acceleration of a motor depending on a manipulation amount of an accelerator to obtain a threshold, and an angular acceleration calculator () differentiates a detection value from a rotation angle sensor () twice to calculate an angular acceleration. A slip determination () determines whether a drive wheel () has slipped, and a torque limitation () limits a torque when a slippage has occurred. The determination () determines the angular acceleration and a threshold. The determination () counts a number of consecutive times it is determined that the threshold is exceeded, and determines that a slippage has occurred, if the number of consecutive times has reached a set value. The limitation () limits a torque developed by a motor unit for a drive wheel laterally opposite to the drive wheel determined as having slipped.

Slip control device for electric vehicle

An angular acceleration monitor may monitor whether or not an angular acceleration of a wheel detected by an angular acceleration detector is equal to or smaller than an acceptable angular acceleration (W) that is calculated with the following formula: W=k1&#xd7;R&#xd7;Tt/m/rwhere k1 is a constant, Tt is a total drive torque that is a sum of drive torques of all motor units that drive wheels of the vehicle, m is vehicle mass, r is tire radius, and R is reduction ratio of a reducer unit interposed between the motor unit and the wheel. A slip-responsive controller causes, if it is determined that the acceptable angular acceleration is exceeded, a motor controller to reduce a drive torque of the motor unit(s).

Electric vehicle control device

To provide a driving device for an in-wheel motor vehicle that can be reduced in size, weight and cost, the driving device for the in-wheel motor vehicle includes a plurality of in-wheel motor assemblies, which are disposed in at least two of a plurality of drive wheels, and a plurality of motor drivers for controlling those in-wheel motor assemblies. Each of the motor drivers includes a smoothing circuit, a control unit, an inverter unit and a cooler for cooling the inverter unit. The plurality of the motor drivers are put together at one location and disposed within the common casing.

Driving device for in-wheel motor vehicles

A cooling structure for an inverter () controls a motor () to drive an automobile. This inverter device () includes a power circuit section () having an inverter () to convert a DC power of a battery () to an AC power for the motor (), and a casing () enclosing the power circuit section (). A fin () is provided in an outer surface of the casing (), a coolant path () for the flow of a cooling medium is provided within the casing () or in the outer surface thereof, and a pump () circulating the cooling medium in the coolant path () is disposed on or in the casing (). With this structure, the flow resistance for cooling the inverter () is reduced to allow the pump () to be downsized and a proper cooling can be accomplished to the amount of heat by the inverter ().

Cooling structure for inverter device

Even when the effective radii of wheels differ from each other because of a change in tire pneumatic pressure, the difference in driving force between left and right drive wheels are substantially zeroed to suppress a turning force to thereby increase the traveling stability. The use is made of a corrector for correcting a command value to be outputted to a drive circuit for an electric drive motor for each of the drive wheels. This corrector receives the steering angle, the respective numbers of revolutions of the drive wheels and an electric drive motor current and corrects with the use of the steering angle as measured with respect to a traveling direction so that command values relative to the drive wheels may have such a relation that the turning force induced in a vehicle as a result of the difference in effective radius between the drive wheels can be suppressed.

Control apparatus and control method for electrically driven vehicle

A vehicle drive motor, capable of efficiently cooling the motor stator without being accompanied by an increase in size, includes a stator having an annular stator core, provided in an inner periphery of a tubular motor casing, and a stator coil provided in the stator core, and a rotor on an inner side of the stator core and rotatable relative to the stator. The motor casing includes an oil supply passage and an oil discharge passage in the motor casing and opening at an inner diametric surface of the motor casing, which are opposite axially to each other. Stator core grooves communicated with the oil supply passage and the oil discharge passage extend axially in an outer diametric surface of the stator core. Accordingly, lubricant oil may flow from the oil supply passage towards the oil discharge passage through the stator core groove.

Vehicle drive motor

To provide a controller apparatus of a type, in which the controller is given the redundancy so that the control of the drive motor can be properly performed at all times when an abnormality such as the failure of the controller occurs, with the reliability consequently increased, a plurality of controllers are provided, each including a power circuit for outputting a drive current for the drive motor and a control circuit, which is a light electric circuit, for controlling the power circuit in response to a motor drive command fed from a higher control. An abnormality determiner is provided for determining an abnormality occurring in the controller then in use according to a prescribed rule and then generating a switching signal. A switch is provided, which is operable in response to the switching signal to change the controller then in a state of functioning relative to the drive motor.

Controller apparatus for electric vehicle

A vehicle wheel bearing apparatus has a wheel hub integrally formed with a peripheral wheel mounting flange at one end and a double row rolling bearing. The double row rolling bearing has an outer member integrally formed with a peripheral body mounting flange and with double row outer raceway surfaces. An inner member, including the wheel hub, is formed with double row inner raceway surfaces each arranged opposite to each of the double row outer surfaces. Double row rolling elements are freely rotatably contained between the double row outer and inner raceway surfaces. The double row rolling bearing is adapted to receive a predetermined preload. A separate outer or inner ring is arranged on at least one of the outer or inner members. A preload varying mechanism is arranged at an abutting portion between the outer and inner members to vary the preload applied to the bearing. The preload varying mechanism can be extended or contracted based on an output signal from a detecting sensor to detect the vehicle running conditions.

Bearing apparatus for a wheel of vehicle

A rotation detecting device that includes an electric power generator having a stator and a rotor, said rotor having a plurality of alternating opposite magnetic poles in a circumferential direction of the rotor, at least a first magnetic sensor mounted on either the stator or a support member for supporting the stator and operable to detect the alternating opposite magnetic poles in the rotor; and an electric power supply circuit for utilizing an electric power generated by the electric power generator as an electric power source for the at least first magnetic sensor.

Rotation detecting device and anti-skid braking system using the same

The device includes a rolling bearing unit supporting a radial load and a magnetic bearing unit supporting an axial load and/or a bearing preload; an electromagnet fitted to a spindle housing so as to confront, on a non-contact basis, a flange shaped thrust plate mounted on a main shaft; a motor rotor of a motor for driving the shaft, and a motor stator opposed to the rotor, the shaft being driven by magnetic or Lorentz forces developed between the rotor and the stator; and a sensor detecting an axial force acting on the bearing unit, and a controller controlling the electromagnet. In this device, the stiffness of a composite spring formed by the bearing unit and a support system for the bearing unit is chosen to be higher than the negative stiffness of a composite spring of a motor part comprised of the electromagnet and the motor.

Motor built-in magnetic bearing device

To provide a wireless sensor system, in which an abnormal power supply in the power supply section can be ascertained, for avoiding a malfunction of the system and accomplishing a stable power supply with reduction of the consumption of a power being transmitted, the wireless sensor system includes wireless sensor units and a sensor signal receiving unit. The wireless sensor units include a sensor section for detecting a detection object, a sensor signal transmitting section for transmitting by wireless a sensor signal from the sensor section, and a power supply section having a power receiving section for receiving a driving power transmitted by wireless. In this system, a power supply monitoring section is provided for monitoring the voltage of the power supply section. The sensor signal receiving unit includes a monitor dependent power control section for regulating the power to be transmitted, depending on a monitored result of the power monitoring section.

Wireless sensor system and wheel support bearing assembly utilizing the same

A rotation transmission device includes a roller clutch unit for selectively engaging an inner member mounted on a rotary shaft with an outer ring through rollers, and an electromagnetic clutch unit for electromagnetically controlling the selective engagement by the rollers. The current until the clutch engages is set so as to correspond to a state in which a maximum current according to the revolving speed is required and is varied according to the revolving speed of the rotary shaft to reduce power consumption and the size of the electromagnetic coil.

Rotation transmission device

A wireless sensor system in which the sensor signal is hardly affected by disturbance and therefore has an increased reliability, which can be constructed light-weight and compact in structure inclusive of the electric power system and in which communication is possible at all times, and a wireless sensor incorporated bearing assembly of a light-weight and compact structure utilizing such wireless sensor system. This wireless sensor system includes a wireless sensor unit and a sensor signal receiving unit. The wireless sensor unit includes a sensor section to detect a target of detection, a digitalizing section to digitalize a sensor signal thereof, and a sensor signal transmitting section.

Wireless sensor system and bearing assembly having built-in wireless sensor

A wireless sensor system of the present invention includes wireless sensor units (A,B) and a sensor signal receiving unit (). The sensor units (A,B) have sensors (A,B), an electric power receiver (A,B) for securing the electric power from an electromagnetic wave of a power feeding frequency fthrough a tuning circuit and a detecting and rectifying circuit, and sensor signal transmitters (A,B) for transmitting the signals outputted from the sensors as a wireless sensor signal of the electromagnetic wave of unique frequencies fand fdifferent from the power feeding frequency f. The sensor signal receiving unit () has an electric power transmitter () for transmitting the electromagnetic wave of the power feeding frequency fto the units (A,B) and a sensor signal receiver () for receiving wireless the sensor signals of the respective frequencies fand ftransmitted from the units (A,B).

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Iwata, Japan

Koichi Okada