JPS603652Y2 - small dc motor - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a small DC motor in which a rotation transmission member is inserted and fixed between a drive rotor and a rotation detector to extract driving force.

Conventionally, when a motor is used, driving force is extracted from an output shaft protruding from a motor case.

For example, when the motor is used as a capstan direct drive motor for a cassette deck, etc.
Since the output shaft is dedicated to the capstan shaft, a separate reel drive motor is used to drive the rotation of the reel stand where other tape winding is performed, and these motors are expensive motors such as brushless motors and coreless motors. has been done.

In addition, as shown in Fig. 1, the above brushless motor has an output shaft 5.
A rotating member 91 made of yoke material is fixed to the rotating member 9.
A rotor yoke 5 to which a driving annular permanent magnet 6 is fixed.
2 is fixed and facing the stator coil 7.

Since a rotation detector such as a frequency generator is placed above the rotating member, leakage magnetic flux from the driving annular permanent magnet 6 affects the output of the frequency generator through the rotating member made of yoke material in contact with the rotor yoke. giving.

In view of the above-mentioned points, an object of the present invention is to provide a small-sized DC motor that extracts a second driving force from an output shaft other than a portion protruding from a motor case.

A feature of the present invention is that a rotation transmission member is inserted and fixed to the output shaft between the drive rotor and the rotation detector.

Hereinafter, the present invention will be explained with reference to illustrated embodiments.

As shown in Figure 2, a small DC motor has multiple support columns 11 on a support plate 1.
is fixed with caulking etc.

A stator yoke 2 and a printed wiring board 3 are fixed to the other end of the support column 11 with screws 12.

A through hole is formed in the center of the support plate 1, and the holder 4
is fixed by caulking, and a through hole is formed in the stator yoke 2 below the center of the holder 4, into which a thrust bearing 41 is fitted.

The holder 4 has recessed portions 4a and 4b on the upper and lower sides, respectively.
A through hole 4C connecting the concave portions is bored.

Bearing metal 42.4 is provided in each of the concave portions 4a and 4b.
3 are fitted, and the output shaft 5 is pivotally supported by the bearing metals 42 and 43 and the thrust bearing 41.

A host portion 51 made of a non-magnetic material is fixed to the lower end of the output shaft 5.

A rotor yoke 52 is fixed to the host portion by caulking.

The rotor yoke 52 is formed into a downward dish shape, and a driving annular permanent magnet 6 is fixed to the lower surface of the rotor yoke 52.
A driving rotor is constituted by the driving annular permanent magnet 6 and the driving annular permanent magnet 6.

A stator coil 7 is disposed on the stator yoke 2 below the permanent magnet 6.

The driving annular permanent magnet 6 has multiple N and S poles magnetized on its lower surface.

A pulley 8 is fixed above the host portion 51 and constitutes a rotation transmission member made of a non-magnetic material either integrally or separately.

A rotating member 91 of the magnetic rotation detector 9 is fixed to the output shaft 5 above the pulley 8 .

Above the rotating member 91, a fixing member 92 for a magnetic rotation detector 9 such as a frequency generator is mounted on the support plate 1 or the holder 4.
is fixed.

A disk-shaped magnetic shield plate may be inserted into the upper surface of the rotation transmission member.

When the above-mentioned small DC motor is used in a cassette deck, the support plate 1 is fixed to the chassis of the deck, or the chassis also serves as a support plate to which the support 11 is fixed and the output shaft 5 is inserted.

Next, a belt 81 is hung around the pulley 8 of the rotation transmission member, and the stator yoke 2 and printed wiring board 3 are fixed with screws 12 and assembled.

The tip of the output shaft 5 is used as a capstan shaft, the belt 81 is stretched between other pulleys and reel stands (not shown), and the tape is fed at a constant speed at the tip of the output shaft. Rotation is transmitted to the reel stand by the pulley and belt of the rotation transmission member, and the tape is wound up.

Since the present invention is configured as described above, the rotation transmission member comprising the pulley is inserted and fixed to the output shaft between the rotor yoke, the driving rotor of the driving annular permanent magnet, and the magnetic rotation detector. As a result, a space is created between the driving annular permanent magnet and the magnetic rotation detector, and a rotation transmission member made of a non-magnetic material is inserted into this space, so that the leakage magnetic flux of the permanent magnet is transferred to the magnetic rotation detector. Since it does not adversely affect the rotation characteristics, more accurate rotation characteristics can be obtained.

Furthermore, when attached to a cassette deck, a single motor with high-precision rotation characteristics can rotate the capstan shaft and the reel stand, improving the wow and fluff characteristics of the deck and reducing motor costs. It is possible to provide a small DC motor that exhibits excellent effects.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional side view of a conventional brushless small DC morph, and FIG. 2 is a partially sectional side view of the small DC motor of the present invention. 1...Support plate, 2...Stator yoke,
3...Printed wiring board, 4...Holder, 41...Thrust bearing, 42.43...
... Bearing metal, 5 ... Output shaft, 51 ...
...Hoss part, 52...Rotor yoke, 6...
...Annular permanent magnet for driving, 6,52...Rotor for driving, 7...Stator coil, 8...
・Rotation transmission member (pulley), 81...Belt, 9...Magnetic rotation detector, 91...
Rotating member, 92... Fixed member.

Claims (1)

[Scope of utility model registration request] In a small DC motor in which a drive rotor and a magnetic rotation detector are fixed to an output shaft, a rotation transmission member is inserted and fixed between the drive rotor and the rotation detector, and the output shaft is connected to the output shaft by the one motor. A small DC motor that extracts two driving forces from the tip and the rotation transmission member.