A pump apparatus includes a motor unit and a pump unit. The motor unit includes a cylindrical yoke housing and a rotor accommodated in the yoke housing. A rotary shaft of the rotor is supported by a first bearing and a second bearing. In a direction from a bottom wall of the yoke housing toward an opening of the yoke housing, the first bearing, an armature, a commutator, and a second bearing are arranged in this order on the rotary shaft. A base plate is attached to the opening of the yoke housi...

A motor having a fluid dynamic bearing generating a fluid dynamic pressure by forming an oil gap between a rotor and a stator such that oil is accommodated in the oil gap, and a first and second air dynamic bearing generating an air dynamic pressure by forming an air gap between the rotor and the stator such that air is introduced into the air gap. The fluid dynamic bearing generates a fluid dynamic pressure by forming an oil gap between an axial hole of a sleeve and a shaft such that oil is acc...

Bearings for rotatably supporting a rotor are disposed on an inner side of a hollow cylindrical portion of the rotor which is disposed in a rotating magnetic field formed by a group of stator windings and on an outer periphery of which magnetic poles for generating torque are arranged, thereby shortening the axial length of the rotor and making a motor compact. A motor of the invention includes: a stator in which a plurality of split cores with windings wound therearound are arranged in an annul...

A motor includes a rotor and a stator. A shaft of the rotor is received in a sleeve. A face of the sleeve and a face of the shaft, that are opposed to each other, form a bearing supporting the rotor in a rotatable manner relative to the stator. A sleeve-retaining portion that retains the sleeve has a bottom portion opposed to an axial end of the sleeve. A magnet holder is arranged in the bottom portion to accommodate an attracting magnet magnetically attracting the axial end of the shaft. The ma...

A motor includes a drive circuit for driving a rotor by controlling a current applied to an armature winding of a stator, and a capacitor for smoothing a voltage supplied to the armature winding and/or a capacitor for smoothing a supply voltage from outside on a same board. The board and the stator are integrally molded in using resin. Prior to the molding, capacitors are sealed inside a cylindrical metal case with a closed top face by rubber, and a pair of lead terminals protrude outside throug...

According to the disclosed motor, since the motor includes a rotor in which a plurality of core pieces and magnets are alternately arranged in the circumferential direction, magnetic flux of the magnets is prevented from flowing between the core pieces neighbored with each other in the circumferential direction and the leakage of the magnetic flux can be minimized. Since identical polarities of the magnets neighbored with each other in the circumferential direction face each other, the magnetic ...

In a motor, an sensor magnet is attached to a shaft and three Hall sensors for detecting the position of the sensor magnet are mounted on a circuit board. By using neodymium-iron-boron base rare earth magnet having radial anisotropy as a sensor magnet, the detection accuracy for the position of a field magnet via the sensor magnet by the Hall sensor can be improved.

A motor includes a stator and a rotor rotated due to the interaction between the rotor and the stator. Since overhangs are protruded only from the circumference of a rotor core of the rotor facing the stator in the axial direction, manufacturing costs for improving performance and core loss of the stator are minimized. Additionally, since the rotor core is manufactured by iron powder metallurgy, the rotor core is conveniently designed.

A motor includes a bearing receiving the shaft end of a rotor. a bearing holder provided with a through hole into which the bearing is inserted, a spring member which is disposed on one end side of the bearing holder and provided with a plate spring part which urges the bearing in the through hole toward the shaft end of the rotor shaft, four engaging recessed parts formed at four portions on an outer peripheral side face of the bearing holder, and four engaging pawl parts formed in the spring m...

A motor may include a rotor provided with a permanent magnet, a stator whose inner peripheral face faces an outer peripheral face of the permanent magnet, a first radial bearing fixed to an end portion on an output side of the stator for rotatably supporting the rotor shaft on an output side, a second radial bearing rotatably supporting the rotor shaft on an opposite output side, a spring member which is disposed between the first radial bearing and an end face on the output side of the rotor fo...