JPS6345831Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a brushless motor for video discs, and by fitting and fixing the rotor yoke and the turntable mounting base or turntable, the rotation of the drive magnet fixed to the inner peripheral surface of the rotor yoke is controlled. The purpose of this is to control the position in the axial direction, improve assembly efficiency, reduce the cost of the rotor yoke, and improve the concentricity of the rotor yoke with respect to the rotation axis.

The configuration of a conventional brushless motor for video discs is shown in FIG. In Fig. 1, the rotor assembly includes a rotating shaft 1, a turntable mounting base 2 made of a non-magnetic material fixed to the rotating shaft 1, a drive magnet 4 magnetized perpendicularly to the rotating shaft 1, and a speed detection unit. The stator assembly consists of a rotor yoke 3 to which a speed detection magnet 8 is fixed, and the stator assembly includes bearings 13 and 1 that rotatably support the rotating shaft 1.
4, a bracket 7 to which the bearings 13 and 14 are press-fitted, a stator winding 6 and a stator yoke 5 for generating force between the drive magnet 4, and a flange 9 for attaching the motor to the chassis. It consists of a printed circuit board 10 for mounting a position detection element and for speed detection.

In the conventional configuration described above, the drive magnet 4 is a protrusion 1 provided at a predetermined position on the rotor yoke 3.
2, the rotor yoke 3 is fixed to the rotor yoke 3 with its position regulated in the direction of the rotating shaft by the rotor yoke 3, and the rotor yoke 3 is fixed to the turntable mounting base 2 by screws or screws so that it is concentric with the rotating shaft 1 or the rotating shaft hole 1a. Fixed. As described above, according to the conventional configuration, the rotor yoke 3 and the turntable mounting base 2 must be fitted with a predetermined gap, and although high accuracy is required for each fitting part, This causes deterioration of mechanical precision, such as eccentricity of the rotor yoke 3 with respect to the center of the rotating shaft 1. Furthermore, it is necessary to provide a protrusion 12 on the rotor yoke 3 for regulating the position of the drive magnet 4, which complicates the shape of the rotor yoke 3 and causes waste in terms of manufacturing and cost of the rotor yoke 3.

The present invention solves the above-mentioned conventional drawbacks, and an embodiment thereof will be described below with reference to FIG. 2. Note that explanations of parts or parts that are the same as those of the conventional example will be omitted. In the present invention, as shown in FIG. 2, a rotor yoke mounting and drive magnet position regulating support part 17 extending in the axial direction is provided on a turntable mounting base 16 made of a non-magnetic material.
The inner circumferential surface 15a of the rotor yoke 15 is
7 by press-fitting, and is in contact with an end surface 17b perpendicular to the outer peripheral surface 17a of the support portion 17, that is, perpendicular to the rotation axis 1, to define the position of the drive magnet 4 in the rotation axis direction. It is then glued and fixed. Therefore, the turntable mounting base 16 is press-fitted to the rotor yoke 15, and the outer circumferential surface 17a of the support portion 17 formed on the turntable mounting base 16 is
By using this as the reference position for adhering the drive magnet 4, (a) the protrusion 12 of the rotor yoke 3 is not required to define the axial position of the drive magnet 4, so manufacturing costs (processing costs and mold costs) can be reduced. Can be reduced.

(b) Since the end surface 17b in contact with the drive magnet 4 is made of a non-magnetic material, efficiency can be improved by reducing leakage magnetic flux.

(c) Turntable mounting base 16 and rotor yoke 1
Since the rotor 5 is press-fitted, the eccentricity of the rotor yoke 15 with respect to the rotating shaft 1 can be improved, thereby improving mechanical properties.

This produces effects such as It should be noted that this invention is applicable not only to the turntable mounting base 16 but also to the turntable mounting base 16.
The present invention can also be applied to a turntable (not shown) integrated with the present invention, and the same effects as in the above embodiment can be produced.

As is clear from the above explanation, the present invention press-fits the turntable mounting base to the rotor yoke,
By using one end of the turntable mounting base as the reference position for adhesion of the drive magnet, (a) simplification of configuration and reduction of manufacturing costs (processing costs + mold costs) (b) improvement of motor efficiency ( c) It has great practical effects such as improved mechanical properties (eccentricity, balance, etc.).

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional brushless motor for driving a turntable, and FIG. 2 is a sectional view of an embodiment of the present invention. 1... Rotating shaft, 4... Drive magnet, 5...
Stator yoke, 6...Stator winding, 15...
Rotor yoke, 16... Turntable mounting plate,
17...Support part, 17a...Outer peripheral surface of support part, 1
7b... end face of support section,... rotor assembly,...
...Stator assembly.

Claims (1)

[Scope of utility model registration request] A drive magnet magnetized in a direction perpendicular to the rotating shaft, a rotor yoke, a turntable mounting base made of a non-magnetic material or a rotor assembly having the turntable, and arranged facing the drive magnet with a predetermined gap maintained in the radial direction. a stator assembly having a stator winding and a stator yoke;
A supporting part for attaching a rotor yoke and regulating the position of a drive magnet is formed on the turntable mounting base or the turntable, and the outer peripheral surface of the supporting part and the inner surface of the rotor yoke are fitted and fixed, and the outer peripheral surface of the supporting part is fixed. A brushless motor in which a drive magnet is adhesively fixed to a rotor yoke with an end face of the drive magnet in contact with an end face perpendicular to the rotor yoke.