公开(公告)号：JP2000134982A

公开(公告)日：2000-05-12

申请号：JP30669998

申请日：1998-10-28

Applicant: IBM

Inventor： SHIMIZU YASUHITO ,  KAGAMI NAOYUKI ,  TOKIZONO AKIRA ,  OYAMA AKIHIRO

IPC: H02P1/52 ,  H02P6/06 ,  H02P6/08 ,  H02P6/20

Abstract: PROBLEM TO BE SOLVED: To provide a method for starting a spindle motor and a device utiliz ing it which enables the motor to start well even in the spindle motor having the number of poles and slots in the ratio of 4:3, which is liable to cause a starting failure easily. SOLUTION: This method for starting a spindle motor 1 is intended for the spindle motor 1 having the number of poles and slots in the ratio of 4:3, which is liable to cause a starting failure easily. In this spindle motor 1, the timing of a starting is created by breaking down torque balance between a rotor 2 and a stator 3. In this device, by breaking down torque balance between the rotor 2 and stator 3 at the time of starting, leaving from the magnetic balance can be effected immediately at the time of starting, and the starting failure can be avoided. As a result, in a hard disk drive, too, which uses the spindle motor 1 having the number of poles and slots in the ratio of 4:3, which is liable to cause a starting failure easily, the starting time of the hard disk drive can be shortened. Also, this device is provided with a means which breaks down the torque balance between the rotor 2 and stator 3 in starting to create the timing of a starting.

公开(公告)号：JP2001099147A

公开(公告)日：2001-04-10

申请号：JP27022899

申请日：1999-09-24

Applicant: IBM

Inventor： MATSUZAKI SHINICHI ,  OYAMA AKIHIRO ,  TAKEUCHI KOICHI ,  SATO KIYOSHI

IPC: G11B19/20 ,  F16C19/16 ,  F16C25/08 ,  F16C33/30 ,  H02K5/16 ,  H02K5/173 ,  H02K21/22

Abstract: PROBLEM TO BE SOLVED: To solve a problem that, when a ceramic ball is used as a rolling body of a bearing used in bearing mechanism, an unstable factor such as excessive preload and preload loss is caused so that working temperature condition is limited, since a ceramic member has a low linear expansion coefficient against the other member, although it is desired to use ceramic for durability and vibration resistance. SOLUTION: With respect to a shaft 34 (stainless steel) for retaining inner rings 33a, 34a of a pair of bearings 33, 34, a sleeve 40 (aluminum) is formed of a member having a high linear expansion coefficient to retain outer rings 33b. A change rate of a temperature of a distance X between the outer rings 33b is made to be higher than that of a distance Y between the inner rings 33a, 34a, so that difference of change in dimension of the inner rings 33a, 34b, outer rings 33b, and a rolling body is compensated by difference of change in dimension of a distance between the bearings.