JPS6245505Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a flat motor.

1 and 2 show a conventional flat motor, in which a self-aligning bearing bracket 32 is press-fitted into the center of a motor case 31.
A self-aligning bearing 33 is disposed in this self-aligning bearing bracket 32 . A lower bearing 35 is press-fitted into the center of a substantially disc-shaped motor yoke 34 , and a terminal block 36 is also attached to this motor yoke 34 . A terminal 37 is press-fitted into the terminal block 36, and a brush 38 is welded to the tip of the terminal 37. Permanent magnets 39 are arranged on the motor yoke 34 at both ends of the terminal block 36 and magnetized with different polarities. Further, in the rotor 40, a segmented coil 41, a cylindrical commutator 42, and a rotor shaft 43 are formed simultaneously. Note that the rectifying action between the brush 38 and the cylindrical commutator 42 is performed within the thickness of the permanent magnet 39.

In such a conventional flat motor, the thickness in the direction of the rotor shaft 43 is the thickness of the motor case 31 and motor yoke 34, the thickness of the permanent magnet 39, and the gap formed between the permanent magnet 39 and the motor case 31. The thickness of the rotor 40 is approximately determined by the thickness of the rotor 40.

This is because when the size of the motor (outer diameter and thickness) is determined by the motor's characteristic specifications, it is inevitably determined to match the rated specifications. When designed to a specification that satisfies the following, the ratio of the thickness of the permanent magnet 39 = Lm and the thickness of the rotor 40 = Lc will be approximately Lm/Lc = 1.5 to 3.0, and the thickness of the permanent magnet 39 will be equal to the thickness of the motor. There is a large proportion of this. Therefore, in the conventional configuration in which the permanent magnet 39 is disposed on the motor yoke 34 and the rotor 40 and the motor case 31 are disposed thereon, there is a limit to how thin the motor can be made. .

This invention was proposed in view of the above points, and its purpose is to divide the permanent magnet into a part placed directly under the rotor and a part placed elsewhere. By making the permanent magnet directly under the rotor thinner without reducing the amount of magnetic flux interlinking with the rotor, it is possible to reduce the thickness of the motor itself in the rotor axial direction as much as possible, making it possible to reduce the thickness of the motor itself in the rotor axial direction. It is an object of the present invention to provide a flat motor that can satisfy the requirements for thinning when applied to the motor.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

In FIGS. 3 to 5, reference numeral 1 denotes a motor case made of magnetic material such as iron pieces, and strip-shaped iron pieces 1a,
1b, and a substantially bottomed semi-cylindrical base portion 1c that covers a rotor 5, which will be described later. A mounting hole 4 is bored in the center of the base 1c for mounting a self-aligning bracket 3 into which a self-aligning bearing 2 is press-fitted.

The substantially disc-shaped rotor 5 includes segment coils 6,
The cylindrical commutator 7 and the rotor shaft 8 are integrally formed.

The motor yoke 9 is made of a magnetic iron plate, and has iron pieces 9a and 9b so as to correspond to the iron pieces 1a and 1b of the motor case 1, and a rotor shaft 8 at the center of a substantially semicircular base 9c. A lower bearing 10 is provided.

Reference numeral 11 denotes a brush stand having a substantially rectangular plan view, and terminals 12 are provided at both longitudinal ends of the brush stand, and brushes 13 are attached to both ends of the terminals 12. Further, a through hole 14 that fits the lower bearing 10 is bored approximately in the center of the brush stand 11 .

The permanent magnets 15 and 16 each have a substantially rectangular plate shape, and each has thick parts 15a and 16a that fit the iron pieces 9a and 9b of the motor yoke 9, and this thick part 1.
5a, 16a, and has thin parts 15b, 16b which partially have a curved peripheral edge that fits the outer periphery of the base 9c of the motor yoke 9, and the thickness L _M of the thick parts 15a, 16a is Thin wall portion 15b,
Thicker than the thickness Lm of 16b, Lm = 1/2L _M ~ 1/3L _M
It is formed to a certain extent. Note that the thick parts 15a and 16a
and the difference in level between the thin wall portions 15b and 16b, that is, L _M −
The distance L _n is formed to be slightly longer than the thickness of the segment coil 6 portion of the rotor 5 . Further, the permanent magnets 15 and 16 are magnetized such that when the thick part 15a and the thin part 16b are set as south poles, the thick part 16a and the thin part 15b are set as north poles.

However, to assemble this, the motor yoke 9
Permanent magnets 15 and 16 are placed on top of the brush stand 1, and the permanent magnets 15 and 16 are arranged in parallel with each other.
1, the lower end of the rotor shaft 8 of the rotor 5 is placed in the lower bearing 10, and the cylindrical commutator 7 is interposed between the brushes 13. After that, the motor case 1 may be placed over the rotor shaft 8.

Considering the flow of magnetic flux in such a flat motor, in Figure 5 B and C, the permanent magnet 1
A magnetic path is formed from the thick parts 15a and 16a of the motor case 1, the rotor 5, and the thin parts 15b and 16b to the motor yoke 9, as shown in FIGS. 1 and 2. Even if the thickness of the permanent magnets (thin wall portions 15b and 16b in the present invention) disposed directly below the rotor is not increased as in the conventional example, the amount of magnetic flux interlinking with the rotor 5 does not change at all. Therefore, in the present invention, the thickness of the permanent magnets directly under the rotor 5, that is, the thin wall portions 15b and 16b, can be reduced, and the motor can be made thinner in the direction of the rotor axis 8 by that amount.

As described above, according to the present invention, plate-shaped permanent magnets each having a thick wall part and a thin wall part are arranged side by side, and a substantially disk-shaped permanent magnet is arranged so that the segment coil is located on the thin wall part. The structure includes a rotor, and a motor case and a motor yoke made of magnetic material above and below the rotor, respectively, so that the thickness of the permanent magnets below the rotor can be reduced without changing the characteristics of the motor. The motor can be made thinner to about 1/2 to 1/3 of the conventional size, and the entire motor can be made thinner in the rotor axis direction, making it possible to apply it to various devices and products.

[Brief explanation of drawings]

1 and 2 show a conventional flat motor; FIG. 1A is a half plan view, FIG. 3 to 5 show an embodiment of the flat motor of the present invention, and FIG. 3 is an exploded perspective view;
FIG. 4A is a perspective view showing the external appearance, FIG. 4B is a perspective view with the motor case removed, FIG. 5A is a plan view, and FIGS. 1...Motor case, 5...Rotor, 6...Segment coil, 9...Motor yoke, 15,1
6...Permanent magnet, 15a, 16a...Thick wall part, 1
5b, 16b... Thin wall portion.

Claims (1)

[Scope of utility model registration request] Thick wall portions 15a, 16a and thin wall portions 15b, 16b
a plate-shaped permanent magnet 15,
16 are arranged side by side, and a substantially disc-shaped rotor 5 is arranged so that the segment coils 6 are located on the thin parts 15b and 16b, and a motor case 1 and a motor case made of a magnetic material are arranged above and below the rotor 5. A flat motor characterized in that motor yokes 9 are arranged respectively.