Browsing by Author "KO, D"

Now showing 1 - 2 of 2

ANALYSIS AND TESTING OF MAGNETIC BEARING WITH PERMANENT-MAGNETS FOR BIAS
(1994-12-01)
LEE, AC
;
HSIAO, FZ
;
KO, D
;
交大名義發表
;
機械工程學系
Active magnetic bearings constructed with electromagnets only are usually bulky and power-consuming This shortcoming can be remedied by adopting permanent magnets as the source of bias flux. Satisfactory results achieved by using rare-earth permanent magnets substantiate the feasibility of using permanent magnet bias in magnetic bearings. In this paper, an analytic model for permanent-magnet-biased magnetic bearings is presented. The static characteristics of a prototype are tested and compared with values estimated using this model. Manufacturing the prototype and subsequent testing offer some technological information which is important for future improvements.
PERFORMANCE LIMITS OF PERMANENT-MAGNET-BIASED MAGNETIC BEARINGS
(1994-12-01)
LEE, AC
;
HSIAO, FZ
;
KO, D
;
交大名義發表
;
機械工程學系
An active magnetic bearing with electromagnets only is unavoidably bulky and power-consuming. These shortcomings can be remedied by using permanent magnets as the source of bias flux. Unlike the hybrid magnetic bearings with the same flux path for both permanent magnets and electromagnets, so-called coplanar PEMBs, a noncoplanar PEMB with permanent magnets located between two sets of electromagnets, which are placed around the periphery of the shaft, cannot be regarded as equivalent to a pure electromagnet magnetic bearing. This paper analyzes the performance limits, such as maximum static bearing force, force slew rate, displacement sensitivity, and dynamic load capacity, of the non-coplanar PEMBs. We also campare the characteristics of this type of magnetic bearing to the co-plane PEMBs and point out their differences. Investigation of these performance limits enable better utilization of permanent-magnet-biased magnetic bearings and offer useful guidelines for the design of this type of magnetic bearing.