Angle detecting device and servo apparatus using same

Patent metadata

Field	Value
Publication number	US-9770668-B2
Application number	US-201514709911-A
Country	US
Kind code	B2
Filing date	May 12, 2015
Priority date	May 13, 2014
Publication date	Sep 26, 2017
Grant date	Sep 26, 2017

Abstract

An angle detecting device includes a rotatably supported magnet, and a magnetic sensor disposed opposite to the magnet. An output of the magnetic sensor is changed based on a magnetic flux change due to a rotation of the magnet. The magnet is disposed such that a distance between the magnetic sensor and the magnet is changed by the rotation of the magnet.

First claim

What is claimed is:

1. An angle detecting device comprising:
a magnet attached to a rotatable shaft, the magnet having a circular plate shape and an even thickness, wherein the magnet is inclined with respect to a plane perpendicular to an axial direction of the rotatable shaft; and
a magnetic sensor disposed opposite to the magnet,
wherein an output of the magnetic sensor is changed based on a magnetic flux change due to a rotation of the magnet and to a change in a distance between the magnetic sensor and a point on a circumference of the magnet closest to the magnetic sensor,
wherein the magnet is magnetized to have two poles symmetrical with respect to a linear line passing through a center of the circular plate,
wherein the magnet is inclined along a boundary line of the two poles, and
wherein, in the magnet, one end of the boundary line is farthest from the magnetic sensor and the other end of the boundary line is closest to the magnetic sensor in the axial direction.

2. The angle detecting device of claim 1 , wherein the magnetic sensor includes a Hall element and an amplifying circuit.

3. A servo apparatus comprising:
an angle detecting device;
a motor;
a speed reducer connected to the motor, the speed reducer serving to reduce a speed of an output of the motor;
an output shaft connected to the speed reducer and the angle detecting device; and
a control unit configured to compare an output of the angle detecting device with a control signal inputted from an outside and to control rotation of the motor such that a difference between the output of the angle detecting device and the control signal becomes zero,
wherein the angle detecting device comprises:
a magnet attached to a rotatable shaft, the magnet having a circular plate shape and an even thickness, wherein the magnet is inclined with respect to a plane perpendicular to an axial direction of the rotatable shaft; and
a magnetic sensor disposed opposite to the magnet,

wherein an output of the magnetic sensor is changed based on a magnetic flux change due to a rotation of the magnet and to a change in a distance between the magnetic sensor and a point on a circumference of the magnet closest to the magnetic sensor,
wherein the magnet is magnetized to have two poles symmetrical with respect to a linear line passing through a center of the circular plate,
wherein the magnet is inclined along a boundary line of the two poles, and
wherein, in the magnet, one end of the boundary line is farthest from the magnetic sensor and the other end of the boundary line is closest to the magnetic sensor in the axial direction.

Assignees

• Futaba Denshi Kogyo Kk

Inventors

• Tsuchiya Hiroyuki
• Konishi Ippei

Classifications

• A63H30/04

  using wireless transmission · CPC title

• A63H27/02 Primary

  Model aircraft · CPC title

• G05D3/14

  using an analogue comparing device · CPC title

• G01D5/145

  influenced by the relative movement between the Hall device and magnetic fields (see G01R33/06) · CPC title

• G01D5/14

  influencing the magnitude of a current or voltage · CPC title