JPS58144553A - Motor - Google Patents

Abstract

PURPOSE:To obtain a motor which can reduce its size and its cost of a drive system with large bending rigidity by mounting bearings between the inner periphery of a motor housing and the outer periphery of an armature which is secured to a rotational shaft. CONSTITUTION:Bearings 8, 8 are mounted between the inner periphery of a motor housing 7 and the outer periphery of an armature 2 which is secured to a rotational shaft 1, and the armature 2 is rotatably supported in the motor housing 7. For example, the armature 2 which is secured to the shaft 1 is composed of a laminated core 3, a coil 4 wound in the slit of the core 3 and rigid holders 5, 6 which hold the core 3 between the holders 5 and 6. Radial bearings 8, 8 of one side shield are respectively mounted between the outer peripheries of the rigid holders 5, 6 of the armature 2 and the inner periphery of the motor housing 7 to rotatably support the armature 2, and a commutator 10 is provided outside from the bearing 8 of one end of the holder 5.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a motor suitable for a drive system in which a large bending load is applied to the rotating shaft of the motor.

For example, when using a motor as a drive source for a drive system that may be subjected to a relatively large bending load (radial load), such as the rotation axis of a robot arm, prepare a motor that has bending properties that can withstand the bending load. There is a need to.

However, commonly used motors have a structure in which the rotating shaft of the armature (rotor), that is, the entire output shaft of the motor, is rotatably supported within the motor housing by, for example, a radial ball bearing. Low bending rigidity.

This is because in order to increase the magnetic flux density of the motor's armature, the inner hole of the armature, that is, the hole where the entire output shaft is attached, becomes smaller, and the radial ball bearing that supports the entire output shaft of the momentum motor also needs to be smaller. Therefore, the bending rigidity had to be reduced.

Therefore, when using such a conventional motor in a drive system that is subjected to a bending load as described above, for example, a shaft with a diameter larger than that of the output shaft is connected to the output shaft of the motor. is carried by a large-diameter radiano ball bearing, for example, in a column attached to the motor housing, to prevent large bending loads from being applied to the output shaft of the motor.

However, in such a method, the connecting portion becomes longer in the direction of the output shaft of the motor, which makes it difficult to completely downsize the drive system, and there is also the problem of high costs due to the large number of parts.

The present invention has been made in view of the above-mentioned points, and it is an object of the present invention to provide a motor that has excellent bending rigidity, and can also reduce the size and cost of the drive system.

Therefore, the motor according to the present invention has a bearing installed between the inner periphery of the motor housing and the outer periphery of the armature fixed to the rotating shaft, so that the electric motor is rotatably supported within the motor housing. It's all about achieving.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

The figure is a longitudinal sectional view of a motor showing an embodiment of the present invention.

In the figure, an armature (rotor) 2 fixed around a rotating shaft 1 of a motor is connected to an iron core 3 in which a large number of thin-walled iron pieces are laminated and fixed, and the armature (rotor) 2 is installed at regular intervals around the entire circumference of the iron core 3. The coil 4 is wound around a slit, and a rigid holder 5.6 holds the iron core 3 around which the coil 4 is wound.

In addition, the iron core 6. Coil 4. The surfaces of the rigid holders 5 and 6 are insulated, and the coils 4 are hardened with resin.

Between the outer periphery of the rigid holder 5.6 in the armature 2 and the inner periphery of the motor housing 7, there are single-sided shielded radial ball bearings 8, 8, which are rolling bearings, respectively.
The armature 2 is rotatably supported within the motor housing 7.

Note that the shield surfaces of the radial ball bearings 8.8 are oriented in the directions of arrows A and B, respectively.

A commutator 10 is fixed to one end of the rigid holder 5 via an epoxy resin layer 9, and each commutator piece 11 of the commutator 10 has an inner part inside the rigid holder 5 and the resin layer 9, respectively. One end of each coil 4 that is completely wound around the iron core 1 is soldered.

A brush rocker 13 is attached to the entire motor housing 7 so that the brush 12 is in sliding contact with the commutator piece 11 of the commutator 10.

Incidentally, the brush 12 is arranged around the commutator 10 with, for example, 120 brushes.
A total of three of them are arranged at each time, and each of them is pressed against the commutator piece 11 by the biasing force of a spring 15 adjusted by an adjustment screw 14.

Further, in the figure, 16 is a permanent magnet that is a stator, and 17 is a motor end cover.

According to this embodiment, the armature 2 has a rotary shaft 1 like the conventional one.
Since the motor is supported by radial ball bearings 8, 8 with a diameter larger than the diameter of the ball bearing supporting the motor, the bending rigidity is much lower than that of a conventional motor. The motor can now rotate without any problem.

In addition, since the commutator 10 and the brush 12 are all disposed at the motor end outside the radial ball bearing 8, the commutator 10
And the maintenance of the brush 12 is not only facilitated, but also
Since there is no iron core 6° coil 4 and permanent magnet 16 between the radial ball bearings 8, 8, which will not cause any problem even if grease leaks, in order to sufficiently lubricate the radial ball bearings 8, 8, a large amount of grease should be applied to both. Can be filled.

In addition, in the above embodiment, an example was described in which a radial ball bearing 8.8 was used as a rolling bearing, but the invention is not limited to this, and radial roller bearings may be fully installed, or the rotating shaft 1 may be equipped with a radial ball bearing 8.8. If a large thrust load is also applied, angular ball bearings or taber roller bearings may be used.

As described above, in the motor according to the present invention, all nine roller bearings are installed between the outer periphery of the armature and the inner periphery of the motor housing, and the rollers are rotatably supported within the armature and the motor housing. Not only does this increase the bending rigidity, but it also eliminates the need for a special mechanism to handle the bending load applied to the rotating shaft, which is required in the past. Is it possible to make the drive system as short as possible and downsize the drive system that incorporates the motor? You can also measure it.

[Brief explanation of the drawing]

The figure is a longitudinal sectional view of a motor showing an embodiment of the present invention. 1... Rotating shaft 2... Armature 3... Iron core 4... Coil 5.6... Rigid body holder 7... Motor housing 8... Radial pole bearing 10... Commutator 11・Commutator piece 12・
・Brush 13... Brush rocker 16... Permanent magnet -7=

Claims (1)

[Claims] 1. A motor characterized in that a bearing is fully mounted between the inner circumference of a motor housing and the outer circumference of an armature fixed to a rotating shaft, so that the armature is rotatably supported within the motor housing.