JPH0345080U

JPH0345080U -

Info

Publication number: JPH0345080U
Application number: JP10656289U
Authority: JP
Priority date: 1989-09-11
Filing date: 1989-09-11
Publication date: 1991-04-25

Description

[Brief explanation of drawings]

第１図は本考案の一実施例を示す正面図、第２
図は第１図中のロータ本体と速度検出機構との位
置関係を示す説明図、第３図は第２図の動作を示
す説明図、第４図ないし第５図は各々環状小磁石
部の他の例を示す説明図、第６図ないし第８図は
従来例を示す説明図である。１……基板、２……ロータ本体、３……駆動磁
石部、４……回転速度信号形成用の環状小磁石部
、１０……速度検出機構、１１……速度用の信号
検知部材、１２……速度用の信号検出コイル。 Figure 1 is a front view showing one embodiment of the present invention;
The figure is an explanatory diagram showing the positional relationship between the rotor body and the speed detection mechanism in Fig. 1, Fig. 3 is an explanatory diagram showing the operation of Fig. 2, and Figs. 4 and 5 are each annular small magnet part. Explanatory diagrams showing other examples, and FIGS. 6 to 8 are explanatory diagrams showing conventional examples. DESCRIPTION OF SYMBOLS 1...Substrate, 2...Rotor main body, 3...Drive magnet part, 4...Annular small magnet part for forming a rotational speed signal, 10...Speed detection mechanism, 11...Signal detection member for speed, 12 ...Signal detection coil for speed.

Claims

[Claims for Utility Model Registration] A small annular magnet portion for outputting speed signals is provided on the outer periphery of the rotor body, and a drive magnet portion consisting of a plurality of magnets for driving the rotor is provided inside the small annular magnet portion. A brushless motor is equipped with a plurality of drive coils on a substrate side that faces a drive magnet for the rotor and rotatably supports the rotor body. The located annular small magnet part is equally divided into a plurality of parts for a plurality of small magnets, and every other divided area is set to have the same polarity as the polarity of the drive magnet part located on the inner diameter side. A speed detection mechanism is provided outside the rotor corresponding to every other magnetized magnetic pole of the annular small magnetic pole, and this speed detection mechanism is connected to the magnetized magnetic pole of the annular small magnet portion. A signal detection member made of a magnetic material and having an uneven facing surface corresponding to the small magnetic pole, and a signal detection member that converts changes in N and S of magnetic flux detected by this signal detection member into electrical signals and outputs them to the outside. A brushless motor characterized by comprising a single signal detection coil.