Nippon Densan Corporation

Kuniyasu Iwazaki

Kihachiro Ohta

Noriaki Hishida

Masanobu Chuta

Yuji Morioka

A spindle motor having a housing, a hub member rotatable relative to the housing, a bearing means disposed between the housing and the hub member, a rotor magnet mounted on the hub member, and a stator disposed in a facing relationship with the rotor magnet. The hub member includes a supporting wall portion, which cooperates with the stator to constitute an air seal structure. A magnetic fluid seal means is provided at a position outward of the bearing means, and includes a conductive plate for grounding static electricity. The bearing means is comprised of a radial ball bearing, which includes certain improvement.

Motor

A spindle motor having a housing, a hub member rotatable relative to the housing, a bearing disposed between the housing and the hub member, a rotor magnet mounted on the hub member, and a stator disposed in a facing relationship with the rotor magnet. The hub member includes a supporting wall portion, which cooperates with the stator to constitute an air seal structure. A magnetic fluid seal is provided at a position outward of the bearing, and includes a conductive plate for grounding static electricity. The bearing is comprised of a radial ball bearing, which includes certain improvement.

Spindle motor with the stator core supported by a resin member

A spindle motor having a shaft member secured to a fitting member, a rotary member which is rotatable relatively to the shaft member, a rotor magnet fitted to the rotary member in such a manner that the rotor magnet confronts the rotor magnet and a stator, wherein a pair of inner annular grooves are formed in the shaft member, a pair of outer annular grooves are formed in the rotary member and a plurality of ball members are accommodated in ball-accommodating space defined by these annular grooves. A spindle motor having a fitting member having a hollow cylindrical portion, a shaft member which is rotatable relatively to the fitting member, a rotary member secured to the shaft member, a rotor magnet fitted to the rotary member and a stator disposed in such a manner that the stator confronts the rotor magnet, wherein a pair of inner annular grooves are formed in the shaft member, a pair of outer annular grooves are formed in the inner surface of the cylindrical portion and a plurality of ball members are accommodated in a ball-accommodating space defined by these annular grooves.

Spindle motor

A spindle motor comprising a fixed shaft member, a hub member rotatably supported by the fixed shaft member through bearings, and a magnetic-fluid type sealing mechanism arranged between the fixed shaft member and the hub member. The magnetic-fluid type sealing mechanism has a rotary member mounted on the hub member, a stationary member mounted on the fixed shaft member, and a magnetic fluid holding device for holding a magnetic fluid. The magnetic fluid holding is secured to the annular mounting portion of the stationary member. The magnetic fluid holding device and the annular portion of the rotary member cooperate with each other in holding the magnetic fluid therebetween. The fixed shaft member has an axially extending locating recess or projection, while the stator and the circuit assembly have locating projections or recesses for cooperation with the locating recess or projection of the fixed shaft member so as to set the stator and the circuit assembly in a predetermined angular positional relationship to each other. The fixed shaft member is provided with a stopper projection, and an urging device for urging the stator and the circuit assembly towards the stopper projection is provided, so that the stator and the circuit assembly are held at predetermined axial positions on the fixed shaft member by cooperation between the stopper projection and the urging means.

Growing community of inventors

Kyoto, Japan

Kuniyasu Iwazaki