A motor includes a rotor shaft 7 which is fixed in the inside diameter portion of a magnet 6, a first coil 2 which is arranged adjacently to the magnet in the axial direction of the rotor shaft, a first outside magnetic pole portion 1a which is excited by the first coil, is inserted on the inner periphery side of the first coil, and is arranged so as to be opposed to a predetermined angle range of the outer peripheral surface of the magnet with a predetermined gap being provided between the firs...

A motor has a stator substantially encapsulated within a body of thermoplastic material; and one or more solid parts used in the motor either within or near the body. The thermoplastic material has a coefficient of linear thermal expansion such that the thermoplastic material contracts and expands at approximately the same rate as the one or more solid parts. In another aspect, a motor for a hard disc drive comprises at least one conductor, at least one magnet, at least one bearing and a shaft; ...

An end surface portion 8a of a gear housing 8, which is located on a motor unit 2 side of the gear housing 8, is opposed to the motor unit 2 and laterally extends. A brush holder 10 includes a plate portion 13 that is opposed to the end surface portion 8a. A case 15, which receives the control circuit board 14, is formed separately from the plate portion 13. A receiving through hole, through which the circuit board receiver 15 is receivable, is formed in the plate portion 13. The case 15 is cons...

A motor has a board-retaining part that is attached in an opening portion of a gear housing with a circuit board received in the board-installing portion of the gear housing and that restricts the circuit board to move to a counter-insertion side thereof in an insertion direction of the circuit board. The board-retaining part can be attached to any position not to bring that in contact with the cover member in the direction of the center axis. Thus, in a case of installing the circuit board thro...

A motor includes a stator section with a two-phase structure having first and second stator assemblies disposed in an axial direction, and a plurality of pole teeth arranged at an electrical angle of 90 degrees along inner circumferences of the first and second stator assemblies, and a rotor section including a rotation shaft, and first and second permanent magnets that are disposed opposite to and spaced a predetermined gap from the pole teeth and affixed to the rotation shaft with a gap provid...

A motor that can prevent damages on the fluid dynamic bearing. A ball is press-fitted into the end surface of the shaft body, and the ball is disposed in such a manner that the tip portion of the ball comes to the higher position with respect to the end surface of the annular body. When the shaft is at rest, the ball abuts against the upper surface of the counter plate, and the end surface of the annular body is brought into a state of being raised from the upper surface of the counter plate, so...

The electric machine of the present invention comprises a first coil group containing a plurality of coils and a magnet group. The first coil group is classified into M phase sub coil groups, with the coils of the sub coil groups aligned one at a time in sequence at a specified sub coil group interval Dc from the first phase sub coil group to the M-th phase sub coil group. A sub coil group interval Dc is set to a value of K/M times a magnetic pole pitch Pm (K is a positive integer excluding an i...

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 stator formed of a stack of silicon steel sheet members and a winding holder mounted inside the stack of silicon steel sheet members, axles inserted through the stator in four corners, front and back covers respectively covered on the front and back sides of the stator and engaged with the ends of the axles and affixed to the stator with screws, and a rotor supported between the front and back covers and suspending within the stator.

The present invention aims at providing a motor which can stably be mounted on a circuit board when being assembled into an instrument in particular. The motor 1 in accordance with the present invention comprises a motor body A, an output shaft 3 projecting from a front end of the motor body A, and a voltage-supplying terminal 8 provided in the motor body A, the terminal 8 having an elastic force in a direction substantially orthogonal to the output shaft 3 and also having a grounding portion 14...