JPS6284372U - - Google Patents

Description

[Brief explanation of the drawing]

Figures 1 to 3 are diagrams showing an embodiment of the brushless electric motor according to this invention, and Figure 1 is a longitudinal sectional view;
Figure 2 is a plan layout of the stator and the first stator coil, Figure 3 is an illustration of torque ripple, and Figures 4 to 6.
The figures show a conventional surface-to-face type brushless electric motor, in which Fig. 4 is a longitudinal cross-sectional view, Fig. 5 is a planar arrangement of stator coils, Fig. 6 is a magnetization state diagram of rotor permanent magnets, Figures 7 and 8 are diagrams showing a conventional brushless electric motor with an outer rotor with an iron core, in which Figure 7 is a longitudinal sectional view, Figure 8 is a plan view of the stator and permanent magnets, and Figure 9 is a diagram showing the arrangement of the stator and permanent magnets. is an explanatory diagram of torque ripple in a conventional brushless electric motor. In the figure, 1 is a substrate, 6 is a rotor, 7 is a first permanent magnet, 8 is a first stator coil, 11 is a stator,
11a is a pole piece, 12 is a second stator coil, 13
is the second permanent magnet. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims for Utility Model Registration] (1) A plate-shaped rotor pivotally supported on a substrate, and a rotor fixed to the circumferential surface of the rotor facing the substrate and magnetized with alternately different poles. 1 permanent magnet, a plurality of first stator coils provided opposite to the first permanent magnet and fixed on the substrate, and a plurality of first stator coils fixed on the substrate and extending radially. a stator around which two stator coils are wound; and a second permanent magnet arranged opposite to the pole pieces of the stator, fixed to the rotor, and alternately magnetized with different poles; A brushless electric motor in which the center line of the first stator coil and the center line of the pole piece of the stator are shifted by a predetermined angle. (2) The brushless electric motor according to claim 1, wherein the shift angle is 30 electrical degrees when the ratio of the number of coils to the number of permanent magnets corresponding to the coils is 3:2. (3) The brushless electric motor according to claim 1, wherein the shift angle is 15 electrical degrees when the ratio of the number of coils to the number of permanent magnets corresponding to the coils is 3:4.