JPS6211382U

JPS6211382U -

Info

Publication number: JPS6211382U
Application number: JP10342485U
Authority: JP
Priority date: 1985-07-05
Filing date: 1985-07-05
Publication date: 1987-01-23

Description

[Brief explanation of the drawing]

第１図は本考案の一実施例を示す回転速度検出
装置を備えたブラシレスモータの断面図、第２図
ａは本考案のロータマグネツトの一実施例におけ
る平面図、第２図ｂは同断面図、第３図本考案の
回転速度検知装置の主要部分の裏側より見た平面
図、第４図は従来のブラシレスモータの断面図で
ある。１，２……突出部、３……第１の磁性板、４…
…第３の磁性板、５……検出手段、６……第２の
磁性板、７，１８……ロータヨーク、８，１７…
…ロータマグネツト、１６……固定部、７ａ，７
ｂ……透孔群。 Fig. 1 is a cross-sectional view of a brushless motor equipped with a rotational speed detection device showing an embodiment of the present invention, Fig. 2a is a plan view of an embodiment of the rotor magnet of the invention, and Fig. 2b is the same. FIG. 3 is a cross-sectional view of the main parts of the rotational speed detecting device of the present invention as seen from the back side, and FIG. 4 is a cross-sectional view of a conventional brushless motor. 1, 2... protrusion, 3... first magnetic plate, 4...
...Third magnetic plate, 5...Detection means, 6...Second magnetic plate, 7, 18...Rotor yoke, 8, 17...
...Rotor magnet, 16...Fixed part, 7a, 7
b... Perforation group.

Claims

[Scope of utility model registration request]

A rotor yoke having a first concentric hole group and a second concentric hole group arranged at predetermined intervals on the outer circumference and the inner circumference, and a positive magnetic pole disposed on the rotor yoke in the circumferential direction. a rotor magnet magnetized such that the negative magnetic pole portion and the negative magnetic pole portion are alternately located;
A first magnetic plate is provided on the rotor yoke so as to be connected to one magnetic pole portion of the rotor magnet through a group of through holes, and a first magnetic plate is provided on the rotor yoke so as to be connected to one magnetic pole portion of the rotor magnet through a group of through holes. a second magnetic plate provided on the rotor yoke so as to be connected to the other magnetic pole part; and a third annular magnetic plate held on the fixed part so as to be located between the first and second magnetic pole plates. board and
a detection means for detecting a change in the magnetic flux flowing through the third magnetic plate as a change in voltage, the pair of opposing surfaces of the first and third magnetic plates and the second and third magnetic plates; A rotational speed detection device for a brushless motor, characterized in that a tooth-shaped portion is formed on at least one of a pair of opposing surfaces of the brushless motor.