Abstract: By controlling an amount of preload applied to a rolling bearing that supports a spindle in accordance with the change of state of the spindle in actual machining, the rotation of the spindle is controlled in an optimal state, and the service life of the bearing is extended while the required stiffness of the spindle is ensured. When a corrected preload amount falls outside a range of a preload as a controllable region, the corrected preload amount is corrected so as to fall within the range of the preload. That is, an actually controlled preload is regulated to fall within the preset range of preload. Therefore, it is possible to ensure the stiffness of the rolling bearing or prevent heating and excessive increase in contact pressure of the rolling bearing.

Abstract: A current command value computing section includes an integration control computing section. Based on an integration of the steering torque ?, the integration control computing section computes a steering torque integration control amount Iint*, which is a compensation component for increasing the assist force. The integration control computing section functions as a determining device that determines whether the vehicle is traveling forward in a straight line. When the determining device determines that the vehicle is traveling forward in a straight line, the integration control computing section outputs the steering torque integration control amount Iint* to an adder. The current command value computing section superimposes the steering torque integration control amount Iint* on a basic assist control amount Ias* computed by a basic assist control section, and outputs the obtained value, as a current command value Iq* corresponding to a target assist force, to an output section.

Abstract: A motor control device of the present invention includes: target electric current value setting units (15 and 16) that set target electric current values that should be supplied to a motor (1), basic voltage value computing units (511, 521, 51a, and 52a) that compute basic voltage values for driving the motor, a rotation angle speed computing unit (23) that computes a rotation angle speed of the motor, correction value computing units (50, 512, 515, 516, 522, 525, and 526) that compute correction values for correcting the basic voltage values based on motor electric current values and a rotation angle speed of the motor, correcting units (513 and 523) that obtain voltage command values by correcting the basic voltage values by the correction values computed by the correction value computing units, and a driving unit (13) that drives the motor by using voltage command values.

Abstract: A tapered roller bearing according to the invention is such that when an arithmetical mean roughness as a surface roughness of a large end face of a tapered roller is ?1 and an arithmetical mean roughness as a surface roughness of a large rib surface of an inner ring is ?2, ?1 is 0.04 ?m or larger, and a composite roughness that is expressed by a square root of a sum of a squared value of ?1 and a squared value of ?2 is 0.17 ?m or smaller. Raceway surfaces of an outer ring and the inner ring and a rolling contact surface of the tapered roller are crowned, and a total crowning amount is set to 50 ?m or larger, an outer ring crowning rate is set to 40% or larger, and a roller crowning rate is set to 20% or smaller.

Abstract: Plate-shaped projections are provided on a front insulator in such a manner as to project towards a front housing. In addition, projecting pieces are provided on a surface of each projection which confronts an inner circumferential surface of a stator housing. The projecting pieces are provided on each projection in such a manner as to form three rows which are parallel to an inner circumferential direction of the stator housing. Spaces between the respective rows constitute guide paths by which the transition wirings which connect between the coils are disposed on the projection in such a manner as to be spaced apart from each other.

Abstract: A power transmission chain includes a plurality of links aligned in a chain travel direction and a coupling member that includes a first power transmission member and a second power transmission member. The first power transmission member includes an opposing portion that opposes the corresponding second power transmission member and contacts the corresponding second power transmission member on a contact portion that undergoes displacement in association with a change of a bending angle between corresponding links in a contact state including at least one of rolling contact and sliding contact. The opposing portion includes an arc-shaped portion having a predetermined radius of curvature and a rate-of-change increasing portion. The arc-shaped portion includes a portion that forms the contact portion when the bending angle is equal to or greater than zero and equal to or smaller than a predetermined boundary angle.

Abstract: A roller bearing assembly is provided which is adapted to enhance lubrication performance for preventing seizure and for reducing frictional torque during rotation. The roller bearing assembly includes an inner ring (1), an outer ring (2) and a roller (3) rollably interposed between these inner and outer rings. The inner ring (1) is formed with a rib (4) making contact with a greater end face (7) of the roller (3) for guiding the rolling motion of the roller (3). A recess (5) is formed centrally of the greater end face (7) of the roller (3). A stopper member (6) for preventing oil invasion is fitted in the recess (5) of the roller (3).

Abstract: There is provided a controller for a steering device that makes it possible to prevent sudden ceasing of steering assisting power by effectively utilizing an auxiliary power source. An electric power steering device that generates steering assist force by a motor includes a battery for supplying electric power to the motor, an auxiliary power source that supplies the motor with electric power, and a control circuit for controlling a power supply to the motor. In the event of a breakdown of the battery, the control circuit adjusts a power supply to the motor from the auxiliary power source according to an amount of energy remaining in the auxiliary power source so as to reduce steering assist force.

Abstract: A multilayer circuit board in which wirings are arranged so that the inductance thereof is reduced. A ground wiring and a power source wiring which are provided in a multilayer circuit board are arranged so that most of the wirings are superposed vertically along a direction of a longer side of the circuit board, and since currents flow in an opposite direction to each other in the portions which are superposed, magnetic fields generated by the currents so flowing are canceled by each other. Similarly, a W-phase wiring, a V-phase wiring and a W-phase wiring are also arranged so that the wirings are partially superposed along their longer side direction vertically, and magnetic fields generated by currents flowing in the portions which are superposed vertically are canceled by one another. By this, the inductance of the wirings can be reduced by increasing a mutual inductance between these wirings.

Abstract: In a tapered roller bearing, LWR/DW is in the range of 1.1 to 1.7 where LWR represents a roller effective length of tapered rollers and DW represents a roller mean diameter of tapered rollers. RCO/LRO is 30 to 150, and RCI/LRI is 50 to 260 where RCO represents a crowning radius of an outer ring, LRO represents a raceway length of the outer ring, RCI represents a crowning radius of an inner ring and LRI represents a raceway length of the inner ring. The following expressions are satisfied: 20°???30°, and ??0.87??0.334?BK???0.87??0.167, where ? represents a raceway angle of the outer ring, ? represents a roller angle of the tapered rollers, and BK represents a rib angle of a large rib portion of the inner ring.

Abstract: A pulser ring and a second seal ring are separately formed. When a multipolar magnetic rotor of the pulser ring is bonded to an outer circumferential face of an outer cylindrical portion of an annular core portion, the multipolar magnetic rotor is opposed to a magnetic sensor in the radial direction. Due to the above structure, the multipolar magnetic rotor can be strongly supported by an outer cylindrical portion of the annular core portion. Therefore, even when a rotary centrifugal force is given to the multipolar magnetic rotor, it can not be swung in the radial direction. Accordingly, an interval of the multipolar magnetic rotor and the magnetic sensor in the radial direction, which are opposed to each other, can be maintained constant irrespective of an intensity of the centrifugal force.

Abstract: In an electric power steering system, an ECU 11 includes two independent microcomputers 17a, 17b that serve as motor control signal generators, and the microcomputers 17a, 17b perform the same current feedback computation. Switching arms 20a, 20b that constitute a driving circuit 18 operate independently of each other, based on motor control signals generated by the corresponding microcomputers 17a, 17b. Each of the microcomputers 17a, 17b determines whether an absolute value of a current deviation of an actual current I (I1, I2) from a current command value exceeds a predetermined threshold value. If the current deviation exceeds the threshold value, it is determined that an abnormality occurs in the system.

Abstract: A motor control signal output unit of an electric power steering system includes a feedback gain calculation unit (52), and a feedback control unit executes a feedback control with the use of a proportional gain (Kp) and an integral gain (Ki) that are calculated by the feedback gain calculation unit (52). The feedback gain calculation unit (52) sets the feedback gains to large values (Kp=P0, Ki=I0) when the absolute value of an assist gradient (?) is equal to or smaller than a predetermined value (?0) (|?|??0). On the other hand, when the absolute value of the assist gradient (?) exceeds the predetermined value (A) (|?|>?0), the feedback gain calculation unit (52) sets the feedback gains to small values (Kp=p1, Ki=I1:P1<P0, I1<I0).

Abstract: A motor controller and an electric power steering system including the motor controller are provided. The motor controller has a microcomputer. When the on time of one of the lower potential-side FETs corresponding to the respective phases in a drive circuit becomes shorter than the detection time for detecting the phase current value, the microcomputer estimates the phase current value of the electric current undetectable phase based on the phase current values of the two phases other than the electric current undetectable phase corresponding to the relevant FET (blind estimation). When electric current detection is performed in the blind estimation, motor control signals are output, by which the switching state of the switching arm of the electric current undetectable phase is maintained and the power loss caused by the switching operation of the FETs in the two phases other than the electric current undetectable phase is compensated for.

Abstract: A planet gear mechanism 19 interposed between a steering 2 and steerable wheels 4L and 4R is interposed. A torque controlling motor 25 for controlling a torque acting on the steering 2 and a transmission-rate varying motor 20 for driving the planet gear mechanism 19 are arranged coaxially (on an axial A) with the planet gear mechanism 19. This eliminates the need for arranging each motor 20 and 25 on the both ends of the axis A to face each other, and also reduces a space occupied by the motors 20 and 25 with respect to a radial direction of the axis A. As a result, reduction in the size of an apparatus can be achieved.

Abstract: A rolling bearing apparatus is provided that rotatably supports a cam shaft in a cylinder head of an engine. The rolling bearing apparatus includes a plurality of rolling elements; a cage that positions the rolling elements so as to be spaced at regular intervals from each other in a circumferential direction and that retains the rolling elements in a freely rotatable manner; a shell-type outer ring configured to receive the rolling elements and the cage and having a raceway surface of the rolling elements at an inner side thereof; and an outer ring fastening member formed of a material having almost the same thermal expansion coefficient as the shell-type outer ring and having a press-fit portion press-fitted to the shell-type outer ring.

Abstract: In the present cage, both pillar portions which face each other in a circumferential direction of a pocket have a plurality of bent portions which are alternately bent in a width direction, and each bent portion is provided with roller stopping portions protruding into the pocket. The bent portions are formed in a curved cross-sectional shape. Tip portions of the bent portions in the thickness direction of the cage are formed in a cross-sectional shape that becomes narrower toward the tips, and the tip portions are drawn in a state where they protrude into the pocket by plastic deformation working, thereby forming the roller stopping portions.

Abstract: A tangential grinding resistance measuring method includes obtaining an abrasive grain section area which is at a predetermined infeed depth from the highest top surface of abrasive grains on a grinding wheel; calculating the tangent of a half vertex angle of a conical model for cutting edges of the abrasive grains which model takes the abrasive grain section area as its bottom surface and the predetermined depth as its height; setting grinding parameters; and calculating a tangential grinding resistance from the grinding parameters and the tangent.

Abstract: A differential case for a vehicle and a differential device for a vehicle supplying sufficiently lubrication oil to a gear peripheral portion as a supported portion of a pinion gear in order to prevent a bonding of the gear peripheral portion of the pinion gear. The differential case or the differential device for the vehicle comprises a pair of pinion gear supporting portions (10, 11) supporting slidably a pair of pinion gears (3, 4), and a lubrication oil introducing portion (7, 8) provided around a peripheral portion of the pair of pinion gears (3, 4) to introduce lubrication oil into a clearance between sliding faces of the pair of pinion gears (3, 4) and pinion gear supporting faces (10a, 11a, 10b, 11b) of the pair of pinion gear supporting portions (10, 11).

Abstract: A motor control unit controls a motor including a rotor and a stator facing the rotor. A current drive unit drives the motor at an axis current value of a rotating coordinate system that rotates in accordance with a control angle that is a rotational angle used in a control. An addition angle calculation unit calculates an addition angle to be added to the control angle. A control angle calculation unit obtains, at every predetermined calculation cycle, a present value of the control angle by adding the addition angle that is calculated by the addition angle calculation unit to an immediately preceding value of the control angle. An angular speed calculation unit calculates an angular speed of the rotor. An addition angle correction unit corrects the addition angle based on the angular speed calculated by the angular speed calculation unit. A filtering unit filters the angular speed calculated by the angular speed calculation unit.