| 摘要 |
PROBLEM TO BE SOLVED: To suppress deterioration in motor characteristics due to temperature rises even if an R-TM-B permanent magnet having inferior temperature characteristic is employed by increasing the permeance coefficient at the operating point of a ring magnet as the temperature rises. SOLUTION: When a radial anisotropic ring magnet 4 and a rotor core 3 with shaft are bonded through a buffer layer (thickness: 20-1000μm) 6, the radial anisotropic ring magnet 4 shrinks in the inner radial direction and the rotor core 3 expands in the outer radial direction. Consequently, the thickness of buffer layer 6 decreases and the permeance coefficient increases at the operating point of ring magnet 4 constituting the rotor 2. The radial anisotropic ring magnet 4 comprises an R-TM-B based magnet (R is one or more than one kind of rare earth elements, e.g. Nd and Dy including Y, TM is Fe or an alloy principally comprising the elements of Fe and Co, and B is boron element). This structure can suppress deterioration of motor characteristics due to temperature rise. |
