JPS61195776U

JPS61195776U -

Info

Publication number: JPS61195776U
Application number: JP7454285U
Authority: JP
Priority date: 1985-05-20
Filing date: 1985-05-20
Publication date: 1986-12-06

Description

[Brief explanation of the drawing]

第１図は本考案のブラシレスモータの一実施例
を示す縦断面図、第２図は第１図の駆動用マグネ
ツトの着磁状態を示す図、第３図は第１図の駆動
用マグネツトと第２のセンサーの配置を示す部分
展開斜視図、第４図は第１のセンサーと第２のセ
ンサーからの信号差を得る回路図、第５図は第１
図のブラシレスモータにおける第１、第２のセン
サーからの信号およびそれらの合成信号の波形図
、第６図および第７図は従来のブラシレスモータ
の斜視図およびロータの底面図、第８図は従来の
ブラシレスモータにおいて検出用コイルから得ら
れるパルス信号の波形図である。１，１９……ロータ板、２，２０……駆動用マ
グネツト、３，２１……ロータ、５……パルス信
号発生用マグネツト、６……検出用コイル、８，
１３……磁芯、９……ケース、１１……回転軸、
１４……突極片、１５……駆動コイル、１７……
ステータ、２２……逆磁極部、２３……第１のセ
ンサー（位置検出センサー）、２５……第２のセ
ンサー、２９……比較回路（演算増幅器）。 FIG. 1 is a longitudinal sectional view showing an embodiment of the brushless motor of the present invention, FIG. 2 is a diagram showing the magnetized state of the driving magnet in FIG. 1, and FIG. 3 is a diagram showing the driving magnet in FIG. FIG. 4 is a partially exploded perspective view showing the arrangement of the second sensor, FIG. 4 is a circuit diagram for obtaining a signal difference from the first sensor and the second sensor, and FIG.
Waveform diagrams of the signals from the first and second sensors and their combined signals in the brushless motor shown in the figure; Figures 6 and 7 are a perspective view of a conventional brushless motor and a bottom view of the rotor; and Figure 8 is a conventional brushless motor. FIG. 2 is a waveform diagram of a pulse signal obtained from a detection coil in the brushless motor of FIG. 1, 19... Rotor plate, 2, 20... Drive magnet, 3, 21... Rotor, 5... Pulse signal generation magnet, 6... Detection coil, 8,
13... Magnetic core, 9... Case, 11... Rotating shaft,
14... Salient pole piece, 15... Drive coil, 17...
Stator, 22... Reverse magnetic pole section, 23... First sensor (position detection sensor), 25... Second sensor, 29... Comparison circuit (operational amplifier).

Claims

[Claims for Utility Model Registration] A stator having a drive coil; a rotor rotatably supported by the stator and having a multipolar magnetized annular drive magnet; a plurality of first sensors arranged to detect the rotational position of the rotor; and a plurality of first sensors arranged to detect the rotational position of the rotor. Each of the magnetic poles has a reverse magnetic pole part that is reversely magnetized at the center of the magnetic pole, and a second sensor that detects each magnetic pole including the reverse magnetic pole part is connected to the plurality of first sensors. A brushless motor, characterized in that the brushless motor is attached to the stator at a position where the same magnetic pole as one of the magnets is detected, and facing toward the side where the reverse magnetic pole portion of the driving magnet is formed.