JPS63117645A - Motor - Google Patents

Abstract

PURPOSE:To improve the accuracy of assembling the rotor by forming the pole part of a rotor of a plastic magnet, providing a pin at the outer periphery of the magnet, and forming a hole at a position opposed to the pin. CONSTITUTION:Toothlike projections 4 are formed on the outer periphery of a plastic magnet 3 attached to a shaft 1, and a pin 5 projected axially is provided on the projections 4 to be displaced at 1/4 pitch with respect to the pitch of the projections 4. The core 2 is engaged with the shaft 1, and the magnet 3 is mounted on the outer periphery of the core 2. The magnet 3 is associated by oppositely disposing the back surface and the front surface so that the pin 5 is engaged with a hole 6, and inverting them at 180 deg. to engage the pin 5 with the hole 6.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to an electric motor having a structure in which a magnetic rotor can be manufactured at low cost.

"Prior Art" In electric motors in which the magnetic poles of a magnet rotor are formed by protrusions, a large number of protrusions are formed in the circumferential direction, so the rotor is generally formed in the same way as a gear.

When the rotor is formed into such a gear shape, molding is advantageous in manufacturing.

Therefore, it is generally convenient to mold and manufacture the magnet using a plastic magnet, and then it is assembled by being fixed to the yoke using a method such as gluing.

However, if the gear-shaped magnet is composed of one piece, the gear-shaped protrusion can be accurately obtained with molding precision, but if two gear-shaped magnets are provided on the same axis, two pieces It is necessary for the protrusions of the magnets to maintain accurate mutual positional relationship.

Since such accurate positional relationship of the protrusions is determined during the assembly process, such as adhesion, it is necessary to use accurate jigs and to be extremely careful during assembly.

"Problems to be Solved by the Invention" In particular, when two magnets are assembled so that they are unevenly distributed at a half-pitch, the pitch cannot be obtained accurately and the assembly must be performed patiently using a jig. had.

The present invention was made in view of these circumstances.
The purpose of the present invention is to obtain an electric motor equipped with a magnetic rotor that can be assembled accurately and inexpensively.

"Embodiment" The present invention will be described based on an embodiment shown in the drawings. FIG. 1 is a front view of a main part showing a part of a rotor of an electric motor according to an embodiment of the present invention, and FIG. , its vertical sectional view, 3rd
The figure is a front view of the main parts showing the assembled state.

In FIG. 1, an electric motor L'l[l has an iron core 2 on a shaft 1, and a gear-shaped magnet 3 is attached to the outer diameter side of the iron core 2.

On the outer diameter side of the magnet 3, there is a gear-shaped projection 4.
A large number of pins 5 are formed, and pins 5 are provided at positions B that are unevenly distributed in the circumferential direction by 1/4 pitch with respect to the pitch A of the protrusions 4.

A large hole 6 into which the pin 5 fits is formed at a position opposite to the pin 5 in the radial direction.

In general, the magnet 3 is a radially anisotropic plastic magnet made of samarium cobalt,
Made by molding.

In FIG. 2, two identical magnets 3 are mounted on the iron core 2 so as to face each other, and the pins 5 are configured to fit into the holes 6.

In FIG. 3, when the pin 5 is fitted into the hole 6, the protrusion 4
/2 pitch is unevenly distributed.

In such a configuration, the iron core 2 is fitted onto the shaft 1, and the iron core 2 is fitted onto the shaft 1.
Attach magnet 3 to the outer periphery of.

Then, the magnet 3 is assembled by turning the back side and the front side upside down so that the pin 5 fits into the hole 6, and then turning it over 180 degrees so that the pin 5 and the hole 6 fit together.

By assembling in this manner, the opposing magnets 3 are accurately positioned, and the precision of the rotor can be improved.

Moreover, by fitting and connecting the pin 5 and the hole 6,
Not only can the positional relationship be assembled with high accuracy, but also the bonding force can be obtained.
Even when a binder such as an adhesive is used, it is highly effective as an auxiliary means until the binder hardens, making assembly easier.

Since such a magnet 3 is made of a plastic magnet, it can be easily manufactured by molding and can be manufactured at an extremely low cost.

Moreover, even though parts of the same shape are combined, the pitch of the protrusions can be accurately unevenly distributed, and this advantageous aspect in assembly is greatly reflected in the manufacturing cost and assembly accuracy.

"Effects of the Invention" According to the present invention, the rotor can be assembled with good accuracy, so a high-performance electric motor can be constructed.Moreover, since the assembly is easy, the motor can be constructed at a low cost. becomes possible, and the effect is extremely large.

[Brief explanation of the drawing]

FIG. 1 is a front view of a main part showing a part of a rotor of an electric motor according to an embodiment of the present invention, FIG. 2 is a longitudinal sectional view thereof, and FIG. 3 is a front view of a main part showing an assembled state. . 2... Iron core, 3... Magnet, 4... Protrusion, 5... Pin, 6... Hole, A, B... Pitch.

Claims (1)

[Claims] In an electric motor equipped with a rotor in which magnetic poles are formed by protrusions on the outer diameter side, the magnetic pole part of the rotor is formed of a plastic magnet, and the pins protrude in the axial direction and are unevenly distributed in the circumferential direction by 1/4 pitch with respect to the pitch of the protrusions. What is claimed is: 1. An electric motor comprising: a hole into which a pin fits at a radially opposite position facing the pin;