JP2002142402A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reliable and inexpensive motor having insulating properties, drip-proofness, and a long life. SOLUTION: The motor is provided with rubber insulators 8 on the surfaces opposed to a stator assembly 2 and the engaging surfaces of bracket portions 3 and 4 that are engaged with the stator assembly 2 and hold a rotor assembly 5 provided with ball bearings 6 and 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improving the reliability of a motor.

[0002]

2. Description of the Related Art In recent years, robots as industrial equipment, N
In C machine tools, semiconductor devices, and the like, higher performance, higher function, and smaller size have been developed, and various demands have been made on electric motors mounted as drive sources.

[0003] For this reason, the specification required for the motor is becoming severer due to the decrease in the mounting space allowed for the motor and the deterioration of the use environment of the motor, and it is required to ensure reliability including life.

[0004] In addition, since equipment equipped with a motor is exported, it is necessary to obtain safety standards for the motor to which the motor is to be exported. Has become important.

[0005] In order to cope with these problems, generally, means such as molding the stator portion with an insulating resin material is employed.

[0006]

However, in the conventional method of molding the stator portion, a high molding pressure is applied to the stator winding during molding, so that the yield is poor and the reliability of the molded product cannot be ensured. There was a problem.

Further, since the use environment of the electric motor is deteriorated, it is necessary to secure the drip-proof property of the electric motor, and it is necessary to provide a sheet-like packing at the joint between the stator and the bracket or to apply a liquid gasket.

In order to ensure the life of the motor,
It was necessary to ensure the life of the bearing, and in particular, to prevent creep of the ball bearing.

As described above, in order to ensure the reliability such as insulation, drip-proof, and life, separate measures are required for each of them, resulting in an increase in cost and a problem that the assembling work becomes complicated. .

An object of the present invention is to solve such a conventional problem, and an object of the present invention is to provide a small-sized and inexpensive motor having high insulation properties, drip-proof property and long life.

[0011]

In order to solve the above-mentioned problems, an electric motor according to the present invention comprises a stator having a winding and a rotor having a ball bearing engaged with the stator. A bracket portion for holding the assembly portion, and a rubber-like insulator on a surface of the bracket portion facing the stator portion and an engagement surface thereof.

Further, the bracket has a notch at an opening end for holding the ball bearing, and an insulator is provided up to the notch.

[0013]

In order to solve the above-mentioned problems, an electric motor according to a first aspect of the present invention has a stator having a winding and a rotor having a ball bearing engaged with the stator. Since the bracket portion holding the assembly portion and the rubber-like insulator on the facing surface and the engagement surface of the bracket portion facing the stator portion are provided, the insulator allows the stator winding and the bracket portion to be separated from each other. The insulation can be ensured, and the drip-proof property of the engagement surface between the bracket portion and the stator portion can be secured. Further, since insulation and drip-proofing can be easily performed by the same assembling work without adding a process, costs can be reduced by reducing man-hours.

Further, the motor according to the second aspect of the present invention has a notch at an open end for holding the ball bearing of the bracket, and an insulator is provided up to the notch, so that the outer periphery (outer ring) of the ball bearing is provided. The insulator abuts against the ball bearing to prevent creep of the ball bearing.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) In FIG. 1, 1 is an electric motor,
Reference numeral 2 denotes a stator portion having windings, 3 and 4 denote bracket portions, 5 denotes a rotor portion having ball bearings 6 and 7, 8 denotes an elastic rubber-like insulator, and the bracket portion 3 and the bracket portion 4 are arranged so as to integrally cover the facing surface 9 and the engaging surface 10 of the stator portion 2.

First, the ball bearing 6 of the rotor section 5 is assembled to the stator section 2 in a state of being housed in the bearing holding section of the bracket section 3. Next, the ball bearing 7 on the opposite side is assembled so as to be housed in the bearing holding portion of the bracket portion 4. As a result, the stator section 2 is sandwiched between the bracket section 3 and the bracket section 4, and the bracket section 3, the stator section 2, and the bracket section 4
Are fixed by penetrating bolts into the holes provided in each of them. Thereby, the rotor part 5 becomes rotatable.

As described above, the insulation between the winding of the stator portion 2 and the bracket portions 3 and 4 can be secured by the insulator 8 on the facing surface 9, and the insulator 8 on the engagement surface 10 prevents the engagement portion from drip-proof. Performance can be secured.

FIG. 2 is a perspective view of the inside of the bracket portion 3, in which a rubber-like insulator 8 is applied to a facing surface 8 and an engaging surface 9 of the bracket portion 3 facing the stator portion 2. There is no need to mold the stator portion or cover the stator with an insulating cap to insulate the windings.

Further, it is not necessary to add a packing for securing the drip-proof property or apply a liquid gasket, so that the material cost can be reduced and the number of assembling steps can be reduced. In addition, by integrating the bracket portion 3 and the insulator 8, stable quality can be ensured while minimizing the axial dimension.

(Embodiment 2) In Embodiment 2, a notch is provided at the opening end of the bearing holding portion of one of the brackets for the sake of explanation, and this embodiment can be carried out with both brackets.

In FIG. 3, four notches 4a are provided at the opening end of the bearing holding portion of the bracket portion 4. The notch 4a is filled with the rubber-like insulator 8 so as to contact the outer periphery of the ball bearing.

The insulator 8 is rubbery and elastic, and contacts the outer periphery of the ball bearing at the notch 4a to prevent creep.

The insulator may be coated with a liquid rubber, or may be obtained by press-molding the rubber.

As described above, the insulator can ensure the drip-proof performance and prevent the ball bearing from creeping while ensuring the insulation performance, thereby securing the life of the ball bearing, thereby improving the reliability (shaft). A small motor (thin in the direction) can be provided at low cost.

[0026]

As is clear from the above embodiment, according to the first aspect of the present invention, the insulation performance and the drip-proof performance can be ensured by the same insulator, and the assembling work can be facilitated.

According to the second aspect of the present invention, since the creep of the ball bearing can be prevented, the life of the ball bearing can be ensured.

As described above, if the insulator of the present invention is used,
There is an effect that an insulating property, drip-proof property and long life can be secured, and a highly reliable electric motor can be provided at a small size and at low cost.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an electric motor according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a bracket portion according to the first embodiment of the present invention.

FIG. 3 is a perspective view of a bracket according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Motor 2 Stator part 3, 4 Bracket part 4a Notch part 5 Rotor part 6, 7 Ball bearing 8 Insulator 9 Opposing surface 10 Engagement surface

Claims (2)

[Claims] 1. A stator portion having a winding, a bracket portion engaged with the stator portion to hold a rotor assembly portion having a ball bearing, and a stator portion of the bracket portion facing the stator portion. An electric motor comprising a surface and a rubber-like insulator on an engagement surface. 2. The electric motor according to claim 1, wherein the bracket has a notch at an opening end for holding the ball bearing, and an insulator is provided up to the notch.