JPH07336985A - Motor - Google Patents

Abstract

PURPOSE:To simplify the appearance and reduce the size of a motor by installing in a hollow storing section of an armature holder an FG magnet which rotates in one body with a rotary shaft and an FG coil pattern constituted of a movable board so that they may face each other. CONSTITUTION:A movable flexible printed wiring board 22 consists of a cylinder section 22a which is installed on an inner wall face of a storing section 15a formed in an armature holder 15 and an extended section 22b which is extended outwards from a cutout section 15b of the armature holder 15 along the board. On an inner wall face of the cylinder section 22a, an FG coil pattern 23 is installed. On the other hand, a magnet 27 is so fixed on a rotary shaft 17 as to face the FG coil pattern 23. In such a structure, the FG magnet 27 and the FG coil pattern 23 are not exposed outside a motor 11 and thereby the appearance of the motor 11 can be simplified and at the same time the size of the motor 11 can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric motor, and more particularly to an electric motor in which an FG magnet and an FG coil pattern are arranged to face each other.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 3, a rotating shaft 4 is rotatably held on an inner peripheral surface of a substantially cylindrical bearing holder 1 via a ball bearing 2 and a metal bearing 3, and the bearing holder 1 5 has an armature 5 fixed to the outer peripheral surface thereof, a rotor yoke 7 having a drive magnet 6 fixed to the armature 5 fixed to the rotating shaft 4, and facing an FG coil pattern 9 on a substrate 8 holding the bearing holder 1. FG magnet 10
There is known an electric motor M in which the rotor is fixed to the outer peripheral surface of the rotor yoke 7 (see, for example, Japanese Patent Laid-Open No. 5-30719).

The FG coil pattern 9 detects the rotational position and the number of revolutions of the rotary shaft 4 by the magnetic poles of the FG magnet 10. As such detecting means, the FG magnet 10 is arranged along the axial direction of the rotary shaft 4. In addition to the FG coil pattern facing the
There is a sensor that faces the G magnet.

[0004]

By the way, in the electric motor M configured as described above, the FG magnet 10 facing the FG coil pattern 9 (the same applies when a sensor is used) projects to the outer peripheral surface of the rotor yoke 7. Since it is fixed in this state, not only does it have a complicated structure in appearance, but also the outer diameter of the electric motor M becomes large, so the electric motor M
It was difficult to downsize.

In view of the above situation, it is an object of the present invention to provide an electric motor which has a simple appearance and can be downsized.

[0006]

In order to achieve the object, the present invention provides a drive magnet fixed to a rotor yoke that rotates integrally with a rotary shaft, an armature facing the drive magnet, and an armature. An armature holder that holds and has a hollow storage portion, an FG magnet that is located inside the storage portion and rotates integrally with the rotation shaft, and a cylindrical portion that is installed inside the storage portion so as to face the FG magnet. The gist of the present invention is to provide an FG coil pattern formed of a flexible substrate integrally formed with an extending portion extending from the cylindrical portion and electrically connected to an external power feeding portion. .

[0007]

In such a structure, the drive magnet is fixed to the rotor yoke that rotates integrally with the rotary shaft, and the armature facing the drive magnet is held in the armature holder having a hollow housing portion, and is integrated with the rotary shaft. FG rotating
A magnet is provided in the housing, and the magnet is provided in the housing with the FG coil pattern made of a flexible substrate facing the FG magnet. The magnet extends from the cylinder and is electrically connected to the external power supply unit. The extending portion is integrally formed.

As a result, since the FG magnet is not fixed to the outer peripheral surface of the rotor yoke, the outer diameter of the electric motor can be reduced, resulting in a simple and small electric motor.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the electric motor of the present invention will be described with reference to FIGS.

In FIG. 1, an electric motor 11 has a bottomed cylindrical motor case 12 and an opening 1 of the motor case 12.
A motor chamber 14 is formed by the substrate 13 that closes 2a.

A substantially cylindrical armature holder 15 having a housing portion 15a is fixed to the center of the substrate 13. Also,
The motor case 12 and the armature holder 15 rotatably hold the rotating shaft 17 via bearings 16, 16 such as oil-impregnated bearings and metal bearings. One end of the rotary shaft 17 is projected from the motor case 12 to the outside, and the other end of the rotary shaft 17 is in sliding contact with a thrust bearing 18 fixed to the armature holder 15.

An armature 21 is fixed to the outer peripheral surface of the armature holder 15 and is composed of a stator core 20 having a coil 19 wound around each salient pole. A flexible printed circuit board (hereinafter, referred to as FPC) 22 is held on the inner wall surface of the armature holder 15 forming the storage portion 15a.

As shown in FIG. 2 (A), this FPC 22 has a substantially T-shape in a front view, and as shown in FIG. 2 (B), it is installed in the storage portion 15a in a deformed annular shape. 2C and the cutout portion 15b of the armature holder 15 which is deformed into a substantially L shape as shown in FIG. 2C.
From the base plate 13 to the outside (see FIG. 1). Further, an FG coil pattern 23 is provided on the wall surface that is the inner peripheral surface of the cylindrical portion 22a.

The tip of the extending portion 22b is the motor case 1
The coil pattern 23 is projected from the second hole 12b to the outside, and the coil pattern 23 is electrically connected to the external power feeding portion at the part projected from the hole 12b.

A cylindrical rotor yoke 25 having a bottom is fixed to the rotary shaft 17 via a holder 24 so as to rotate integrally with the rotary shaft 17. A drive magnet 26 facing the armature 21 is fixed to the rotor yoke 25. Further, the FG coil pattern 23 is provided on the rotary shaft 17.
The FG magnet 27 facing the is fixed.

In the above structure, the electric motor 11 can rotate the rotary shaft 17 integrally with the rotor yoke 25 and the FG magnet 27 by the current flowing through the coil 19 and the magnetic force of the drive magnet 26.

At this time, regarding the rotational position and the rotational speed of the rotary shaft 17, the magnetic pole of the FG magnet 27 is set to the FG coil pattern 2.
The electric current is detected by being output to the external power feeding unit via 3, and the current flowing through the coil 19 is controlled according to the rotational position and the rotational speed.

The FPC 22 is inserted into the armature holder 15 from below in FIG. 1 in a state of being deformed into a cylindrical shape having a diameter smaller than the diameter of the accommodating portion 15a, and thereafter, the accommodating portion is returned by the restoring force. It engages with the inner peripheral surface forming 15a and is fixed with an adhesive or the like in this engaged state.

By the way, in the above embodiment, the holder 24
However, the holder portion may be integrally formed with the FG magnet to hold the rotor yoke 25 with the FG magnet.

[0020]

As described above, in the electric motor of the present invention, the drive magnet fixed to the rotor yoke that rotates integrally with the rotating shaft, the armature facing the drive magnet, and the armature are provided. An armature holder that holds and has a hollow storage portion, an FG magnet that is located inside the storage portion and rotates integrally with the rotating shaft, and a cylindrical portion that is located inside the storage portion so as to face the FG magnet. An FG magnet pattern and an FG coil pattern are provided by including an FG coil pattern formed of a flexible substrate integrally formed with an extending portion extending from the cylindrical portion and electrically connected to an external power feeding portion. -Since the battery is not exposed to the outer peripheral part of the electric motor, it can have a simple appearance and
The downsizing of the electric motor can be realized.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a main part of an electric motor according to the present invention.

2A is a front view of a developed state before assembling an FG coil pattern, FIG. 2B is a perspective view of an FG coil pattern assembling state, and FIG. 2C is an assembling of the FG coil pattern. It is a perspective view of a state.

FIG. 3 is a semi-longitudinal sectional view of a main part of a conventional electric motor.

[Explanation of symbols]

 11 ... Electric motor 15 ... Armature holder 15a ... Storage part 17 ... Rotating shaft 21 ... Armature 22 ... Flexible printed wiring board 22a ... Cylindrical part 22b ... Extension part 23 ... FG coil pattern 25 ... Rotor yoke 26 ... Drive magnet 27 ... FG magnet

Claims (1)

[Claims] 1. A drive magnet fixed to a rotor yoke that rotates integrally with a rotating shaft, an armature facing the drive magnet, an armature holder that holds the armature and has a hollow housing portion, An FG magnet located in the housing and rotating integrally with the rotating shaft, a cylindrical portion facing the FG magnet and installed in the housing, and extending from the cylindrical portion to electrically connect to an external power supply unit. An electric motor, comprising: an FG coil pattern formed of a flexible substrate integrally formed with an extending portion to be connected.