Title:
【発明の名称】スピンドルモータ
Document Type and Number:
Japanese Patent JP2826156
Kind Code:
B2
Abstract:
A spindle motor for high speed hand tools is disclosed. The spindle motor includes a rotor (28) and a sleeve (21) that is journaled about the rotor (28). A pressure generating mechanism creates sufficient air pressure in a clearance (52) between the rotor (28) and the sleeve (21) to form a pressurized air film in the clearance (52) when the spindle motor is in normal operation. A plurality of armature coils (27) and a plurality of magnetic sensors (31) for detecting magnetism of magnetic poles in the rotor (28) are provided on the outer surface of the sleeve (21). The rotor (28) has a field magnet (13) with multiple magnetic poles. The sleeve (21) is formed of a ceramic material whose dielectric constant is 10 or lower. The pressurized air film created by the pressure generating mechanism is sufficient to radially supports the rotor (28) so that the rotor (28) does not significantly contact the sleeve (21) during normal operation of the spindle motor. The armature coils (27) cooperate with the field magnet (13) to rotate the rotor (28) by the magnetic interaction between magnetic fields formed by the armature coils (27) and the poles of the field magnet (13). The excitation of the armature coils (27) is controlled at least in part by signals provided by the magnetic sensors (31).
Inventors:
YAHIRO HIROKAZU
SHIRAKI MANABU
SHIRAKI MANABU
Application Number:
JP6518290A
Publication Date:
November 18, 1998
Filing Date:
March 15, 1990
Export Citation:
Assignee:
IBIDEN KK
International Classes:
F16C17/10; F16C32/04; F16C33/10; F16C35/08; F16C32/00; F16C39/06; H02K3/46; H02K5/128; H02K5/16; H02K7/09; H02K21/14; H02K29/08; (IPC1-7): H02K21/14; F16C32/00; F16C32/04; F16C35/08
Domestic Patent References:
| JP3256546A | ||||
| JP33629A | ||||
| JP6158853U | ||||
| JP62154413U |
Attorney, Agent or Firm:
Hironobu Onda