| 摘要 |
The present invention relates to a field element that mitigates stress concentration in a coupling part. A field element core (1) includes field magnet through holes (41, 42) and coupling part (11). The field magnet through holes (41, 42) are circularly disposed in a peripheral direction (92) around a predetermined direction (91) and are adjacent to each other in the peripheral direction (92) to form a set. The field magnet through holes (41, 42) forming the same pair both extend along a given direction (94) that is defined for each pair, when viewed from the predetermined direction (91). The coupling part 11 is provided between the field magnet through holes (41, 42) forming the same set and has ends (412, 422) as lateral surfaces (111, 112), respectively. The entire lateral surfaces (111, 112) of the coupling part (11) are curved to form a concave shape. Specifically, viewed from the predetermined direction (91), only at a given position (r13) between both ends of the lateral surface (111), a tangent (t(r13)) of the lateral surface (111) extends along an extending direction (93) of the coupling part (11). The same holds true for the lateral surface (112). |
