Disk drive in-hub radial-gap spindle motor with coils generating

Details Disk drive in-hub radial-gap spindle motor with coils generating Disk drive in-hub radial-gap spindle motor with coils generating

1997-04-23

1999-07-13

Dougherty, Thomas M.

Electrical generator or motor structure

Dynamoelectric

Rotary

310 68R, 310266, 310268, H02K 100, H02K 112

Patent

active

059231050

ABSTRACT:
An in-hub brushless permanent magnet DC motor has a radial working gap but uses coils wound in the axial direction of the motor. The coils generate fields that interact with the permanent magnet fields across the radial gap. The stator includes a plurality of angularly spaced stator teeth that have faces radially spaced across the gap from the permanent magnet. The stator teeth are connected to the base and extend axially into a cavity within the hub. The permanent magnet is a magnetically-segmented ring magnet located on an outer rim of the hub radially outwardly from the stator teeth. The magnetic flux from the permanent magnet is directed radially across the gap and into the stator teeth. Each stator tooth has an axially oriented post around which is wound a coil that generates an axial field. The axially-oriented part of each coil forms part of the magnetic circuit. The magnetic flux directed radially into each stator tooth is turned axially into the post and through the coil. The axially directed magnetic flux through the coil and post on each stator tooth is redirected from the axial direction to the circumferential direction by a ring magnetic flux guide. The ring flux guide interconnects the stator teeth and forms part of the magnetic circuit. Because the coils are wrapped around axial posts instead of the stator teeth a larger coil volume is obtained which results in higher motor efficiency and reduced heating of the bearing system. The angular spacing between adjacent teeth can be made very small or even eliminated since there is no need to locate a winding device between them as is required in conventional radial-gap motors. This results in a reduction in the motor cogging torque, which in turn allows a higher tooth/pole symmetry leading to better force balance and lower acoustic noise.

REFERENCES:
patent: 2986684 (1961-05-01), Cluwen
patent: 3124733 (1964-03-01), Andrews
patent: 4070319 (1978-01-01), Carel et al.
patent: 4599664 (1986-07-01), Schuh
patent: 4647611 (1987-03-01), Goldstein et al.
patent: 4698542 (1987-10-01), Muller
patent: 4743244 (1988-05-01), LeKhac et al.
patent: 4745345 (1988-05-01), Petersen
patent: 4837474 (1989-06-01), Petersen et al.
patent: 4841393 (1989-06-01), MacLeod et al.
patent: 4858044 (1989-08-01), Crapo
patent: 4891537 (1990-01-01), Shiraki et al.
patent: 4949000 (1990-08-01), Petersen
patent: 5006943 (1991-04-01), Elsasser et al.
patent: 5187006 (1993-02-01), Leighton et al.
patent: 5195002 (1993-03-01), Sakurai
patent: 5257151 (1993-10-01), Cooper et al.
patent: 5296981 (1994-03-01), Ogawa
patent: 5298825 (1994-03-01), Oudet et al.
patent: 5331024 (1994-07-01), Brink et al.
patent: 5352947 (1994-10-01), MacLeod
patent: 5382853 (1995-01-01), von der Heide et al.
patent: 5481143 (1996-01-01), Burdick

Affiliated with

Also associated with

Rating

Disk drive in-hub radial-gap spindle motor with coils generating does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Disk drive in-hub radial-gap spindle motor with coils generating, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Disk drive in-hub radial-gap spindle motor with coils generating will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2278356