JPS5924623B2 - Ultra-thin coreless DC motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coreless DC motor, and particularly to the arrangement and connection of rotor coil windings of a thin coreless DC motor.

Conventionally, the rotor coil of this type of motor is a coil wound into a thin plate, with two parts overlapping each other, that is, each coil has n-pole coils arranged so that they overlap diagonally when viewed from the thickness direction. This makes it difficult to assemble the coil, and the thickness of the entire assembled rotor coil is more than three times the thickness of the individual coils, so the stator magnetic poles that sandwich the rotor coil are The air gap between them must also be large.

If the air gap between the magnetic poles is large, it is difficult to obtain a sufficient magnetic flux density within the air gap, making it difficult to realize a high-performance motor.

The present invention provides an effective means for eliminating the above-mentioned drawbacks, which consists of connecting in series two coils each having a thickness approximately half that of the conventional coil for each pole. These coils are placed on the same plane symmetrically about the rotor axis, and the magnetic pole coil is created as a single pole coil, instead of stacking diagonally when viewed from the coil thickness direction as in the past. By shifting the n-pole coils by 360°/n and superimposing them and fixing them, the total thickness of the rotor coil can be made relatively thin while having the same number of turns as the conventional coil.

Accordingly, the air gap between the stator magnetic poles can be kept small, and the purpose is to maintain a high magnetic flux density in the air gap without increasing the thickness of the entire motor, thereby achieving a high-performance motor.

The present invention will be explained in detail below with reference to the drawings.

[FIG. 1] A is a plan view of an embodiment of a conventional rotor coil, and b is a side view thereof.

A rotor coil 1 is fixed around the rotor shaft 2, and the terminal of each of these coils is connected to a commutator 3 fixed to the rotor shaft 2.

[Fig. 2] shows the method of connecting the rotor coil of [Fig. 1].

Dotted lines 4a and 4b indicate the positions of the stator permanent magnets, with magnetic flux flowing vertically upward at 4a and vertically downward from the paper surface at 4b.

Now, if a current is applied to one side of the commutator 3b by the brush and a negative pole to the commutator piece 3d, the current will flow as follows: commutator piece 3b → coil 1b → commutator piece 3c → coil 1c → commutator Piece 3d→, and the commutator piece 3
It is divided into the following paths: b → coil 1a → commutator piece 3a → coil 1e → commutator piece 3e → coil 1d → commutator piece 3d.

As shown by the arrows in [Figure 2], the coil current on the stator magnet 4a flows outward from the rotor axis, and the coil current on the magnet 4b flows inward, and the coils move clockwise due to the direction of the magnetic field and current. generates rotational force.

[Fig. 3] is a wiring diagram of the rotor coil of the present invention.

The stator magnet 12a is shown upward from the paper surface, and the stator magnet 12b is
The magnetic flux flows downward from the paper surface.

Now, from the brush to the commutator piece 11b, the positive pole commutator piece 11
If a negative current is applied to d, the current flows as follows: commutator piece 11b → coil 10b → coil 10b' → commutator piece 11c → coil 10c → coil 10c' → commutator piece 1
1d, and the path of commutator piece 11b → coil 10 a' → coil 10a → commutator piece 11a → coil 10e' → coil 10e → commutator piece 11e → coil 10d' → coil 10
It separates into a path from d to commutator piece 11d.

Then, as shown by the arrows in [Fig. 3], all the coil currents on the stator magnet 12a are directed outward from the rotor axis, and all the coil currents on the stator magnet 12b are directed inward [Fig. 2]
Similarly, a rotational force is generated in the clockwise direction.

[Fig. 4] shows an embodiment of the rotor coil connection method [Fig. 3] according to the present invention.

[FIG. 4) As shown in the side view of b, the coils 10a and 10a' are connected in series and are connected as one pole coil on the same plane, and the coils 10b and 10b' are connected in series, and the coils 10c and 10c are connected in series.
j coils 10d and 10d' and coils 10e and 10e'
are combined in the same way, and the respective coils are stacked one on top of the other, shifted by 360°/n, or by 720° since there are five poles in this example, and connected to the commutator 11 as shown in FIG. 3, and the rotor shaft 13 is fixed to constitute the rotor coil 10.

As described above, in the present invention, two plate-shaped coils are divided into symmetrical positions on the same plane with respect to the rotor axis, and the coils connected in series are used as one pole coil. Because it has a structure in which other coils are stacked on top of each other, (1) it is easier to assemble (2) ■If the number of turns of the pole coil is the same as before, the thickness of the entire rotor coil can be made thinner. Along with this, the stator grinding stone can also be made thinner, making it possible to realize an ultra-thin motor.

(3) The rotational torque generated at one point in the coil will always generate the same rotational torque at a point that is symmetrical about that point and the rotor axis, so the rotational force of the rotor is well balanced when the rotor rotates. There is less vibration.

This is a big effect that can be obtained.

[Brief explanation of the drawing]

[FIG. 1] A is a plan view of an embodiment of a conventional rotor coil, b is a side view thereof, and FIG. 2 is a diagram showing the connection method of FIG. 1. [Fig. 3] shows a method of connecting a rotor coil according to the present invention, and [Fig. 4] shows an embodiment thereof, and a shows a plan view or a side view. 1.10... Rotor coil, 2.13...
...Rotor shaft, 3, 11... Commutator, 4a, 4
b and 12a. 12b...Stator magnet.

Claims (1)

[Claims] 1. A thin disc-shaped air-core coil rotor, a stator permanent magnet that applies a magnetic field so as to sandwich the disc-shaped coil rotor above and below,
In the coil rotor, the coil for one pole has two plate-shaped air-core coils connected in series on the same plane and centered on the rotor axis. Arrange the left and right points symmetrically as
An ultra-thin coreless DC motor characterized by having a coil rotor in which n poles of coils (where n is an integer of 5 or more) are stacked and fixed while being shifted by 360°/n.