JPH0515104A - Molded motor - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a molded motor in which a ball housing is integrally molded with a stator without creeping even if the ball housing expands due to heat. thing. In a molded motor 10 in which a ball housing 22 for accommodating a ball bearing 32 is integrally molded with a stator 20, an inner peripheral surface of the ball housing 22 forming a space 26 for accommodating the ball bearing 32. The whole 28 has a tapered shape that tapers outwardly in the axial direction, and the ball bearing 32 is further urged outward by the corrugated washer 46 in the axial direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded motor, and more particularly to a molded motor in which a ball housing is integrally molded with a stator.

[0002]

2. Description of the Related Art The structure of a conventional molded motor in which a ball housing is integrally molded with a stator is
Hereinafter, description will be given with reference to FIG.

In the drawing, reference numeral 100 is a stator mold body having a U-shaped cross section, and a donut-shaped stator 103 in which a coil 102 is wound around a stator core 101 is integrally formed by pebbles or sand. It is molded. At the time of molding, one of the stators 103 is molded so as to be closed, and the closed portion is ball housing 104.
And In addition, reference numeral 105 indicates a mold portion.

Inside the stator mold body 100,
A rotor housing space 106 located inside the molded stator 103 and a ball bearing housing space 107 located inside the ball housing 104 are formed.

A rotor 108 formed by winding a coil around a rotor iron core is housed in the rotor housing space 106, and one ball bearing 109 is housed in the ball bearing housing space 107. As is well known, the ball bearing includes an inner ring 110, an outer ring 111, and balls 112 sandwiched between them. The rotor 106 and the ball bearing 109 are coaxially mounted on the output shaft 113.

Reference numeral 114 is another ball bearing supported by a metal bearing bracket 115, and the output shaft 113 is rotatably supported by the ball bearing 114 and the ball bearing 109.

When the molded motor having the above structure is driven, the motor naturally generates heat. Then, the mold portion 10 of the stator mold body 100.
5 and the ball bearing 109 will have heat,
Inflate each.

However, the mold portion 105 and the ball bearing 109 have different degrees of expansion with respect to heat, and the heat of the same temperature causes the mold portion 105 to expand more than the ball bearing 109 made of metal. As a result, the ball bearing storage space 107 also expands (see FIG. 6), and a gap is created between the outer peripheral surface of the ball bearing 109 and the inner peripheral surface of the ball housing 104. In other words, the outer peripheral surface of the ball bearing 109 is separated from the inner peripheral surface of the ball housing 104. The outer ring 111 of the ball housing 104 slips in the ball bearing housing space 107 due to the generation of the air gap and vibration during motor operation, causing so-called creep.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a molded motor that does not cause creep.

[0010]

A molded motor according to the present invention is a molded motor in which a ball housing for housing a ball bearing is integrally molded with a stator, and a space for housing the ball bearing. All or part of the inner peripheral surface of the ball housing is tapered so that the (ball bearing housing space) tapers outward in the axial direction, and the ball bearing is a leaf spring. It is urged outward in the axial direction by urging means such as.

[0011]

In the molded motor of the present invention, the ball bearing arranged in the ball housing is urged axially outward by the urging means, and the outer ring of the ball bearing is pressed against the inner peripheral surface of the ball housing. It is arranged.

Therefore, when the molded motor is driven to generate heat and the ball housing expands, the ball bearings arranged in the ball housing follow the urging force to the inner peripheral surface of the tapered ball housing. Moves axially outward while maintaining the crimped state.
As a result, even if the ball housing expands due to heat,
There is no concern that the outer ring of the ball bearing will separate from the inner peripheral surface of the ball housing, and there is no concern that the outer ring will slip, that is, creep.

[0013]

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

FIG. 1 is a cross-sectional view of a mold motor 10, and reference numeral 12 is a stator mold body having a U-shaped cross section having an opening 14 on one side. The stator mold body 12 is formed by integrally molding a doughnut-shaped stator 20 formed by winding a coil 18 around a stator core 16 with pebbles or sand. When molding
Molding is performed so that one of the stators 20 is closed, and the closed portion serves as the ball housing 22. In addition, reference numeral 24 indicates a mold portion.

A cylindrical ball bearing storage space 26 and a rotor storage space 28 are formed inside the stator mold body 12. Ball bearing storage space 2
6 is provided in the ball housing 22.

The inner peripheral surface 28 of the ball housing 22 forming the ball bearing housing space 26 is tapered so that the ball bearing housing space 26 is tapered outwardly in the axial direction ( See FIG. 2).

Reference numeral 30 is an output shaft. This output shaft 30
At the tip (right end in FIG. 1) of the ball bearing 3
2 is installed. Further, another ball bearing 34 is attached to the substantially central portion of the output shaft 30, and a rotor 36 having a coil wound around a rotor iron core is attached to the ball bearings 32 and 34 substantially in the middle thereof. There is. Note that reference numerals 38 and 40 denote E-shaped stoppers for preventing both ball bearings 32 and 34 from moving in the axial direction. The E-shaped stoppers 38 and 40 are embedded in the output shaft 30 and are embedded in the groove 4 extending in the circumferential direction of the output shaft 30.
It is embedded and fixed in each of 2, 44. A corrugated washer 46 is fixed to the output shaft 30 on the outer side (left side in FIG. 1) of one ball bearing 34.

The output shaft 30 having the above-mentioned components is inserted into the inside of the stator mold body 12 through the opening 14 in the stator mold body 12, and the ball bearing 3 is inserted.
2 is the ball bearing storage space 26, and the rotor 36
Are arranged in the rotor storage space 28, respectively. At this time,
The ball bearing 32 is the ball bearing 32.
The outer surface 33 and the inner surface 23 of the ball housing 22 are arranged with a gap 27 therebetween.

Reference numeral 48 is a metal bearing bracket that closes the opening 14 of the stator mold body 12, and serves to support the ball bearing 34. The bearing bracket 48 has an outer peripheral edge portion 48a.
And is fixed to the stator mold body 12.

In the bearing bracket 48,
In the space 50 formed by the pressing portion 48b that comes into contact with the outer peripheral surface of the ball bearing 34 and presses the outer peripheral surface, and the bent portion 48c that bends inward in the radial direction from the end of the pressing portion 48b, the ball is formed. Bearing 34 is stored,
It is supported by the bearing bracket 48.

When the bearing bracket 48 is fitted into the stator mold body 12, the corrugated washer 46 receives pressure from the bearing bracket 48. The corrugated washer 46 transmits the received pressure to the ball bearing 34, whereby the ball bearing 34 tries to move inward (to the right), but the movement is blocked by the E-shaped stopper 40. The pressure from the bearing bracket 48 is transmitted to the E-shaped stopper 40, and the E-shaped stopper 40 presses the output shaft 30 and further the ball bearing 32 mounted on the tip of the output shaft 30. Become. That is, the corrugated washer 46 causes the ball bearing 32
Will always be urged axially outward.

If the ball bearing 32 is biased as described above, instead of the corrugated washer 46,
A disc spring, a leaf spring or a coil spring may be used.

Therefore, when the motor is driven, the motor generates heat, and the ball bearing 32 and the ball housing 2
If 2 receives the heat, both will try to expand.

However, the expansion of the ball bearing 32 is caused by the expansion of the ball housing 22 which is a part of the mold portion 24.
Is smaller than the expansion of the ball bearing storage space 26, that is, the ball bearing 32 expands and expands in the ball bearing storage space 26 so that the gap 27 is filled with the urging force of the corrugated washer 46. To move axially outward. FIG. 3 shows this state, but the expansion of the ball housing 22 is not shown, and the movement state of the ball bearing 32 is shown so as to be clear.

It should be noted that the ball bearing 32 has a tapered outer edge while moving.
Since it continues to be crimped to the inner peripheral surface 28 of 2, its function,
That is, the function of rotatably supporting the output shaft 30 does not cause any trouble.

As a result, even if the ball housing 22 expands, the ball bearing 32 is firmly supported by the ball housing 22, and the outer ring 56 of the ball bearing 32 separates from the inner peripheral surface 28 of the ball housing 22. No worries, no worries about creep.

In this embodiment, the ball housing 2
Although the entire inner peripheral surface 28 of 2 is tapered, the present invention is not limited to this, and as shown in FIG. 4, a part of the inner peripheral surface 28 ′ of the ball housing 22, that is, the outer ring 56 of the ball bearing 32. The part 29 that contacts the outer peripheral edge may be tapered.

[0028]

According to the molded motor of the present invention, even if the internal ball housing expands due to heat, the ball bearing arranged in the ball housing cannot creep.

[Brief description of drawings]

FIG. 1 is a sectional view of a molded motor showing an embodiment of the present invention.

FIG. 2 is an enlarged view of the vicinity of the ball bearing storage space in the previous figure.

FIG. 3 is a schematic diagram showing a state in which the ball bearing has moved axially outward.

FIG. 4 is an enlarged view of the vicinity of a ball bearing storage space according to another embodiment.

FIG. 5 is a cross-sectional view of a conventional molded motor.

FIG. 6 is an enlarged view of the vicinity of the ball bearing storage space in the previous figure, showing a state where the ball housing is inflated.

[Explanation of symbols]

 10 ...... Molded motor 12 ...... Stator mold body 20 ...... Stator 22 ...... Ball housing 26 ...... Ball bearing storage space 30 ...... Output shaft 46 ...... Corrugated washer

Claims (1)

Claims: What is claimed is: 1. A molded motor comprising a ball housing for housing a ball bearing and a stator integrally molded with the ball housing, wherein a space for housing the ball bearing is axially outside. All or part of the inner peripheral surface of the ball housing is tapered so as to taper toward the outside, and the ball bearing is axially outward by an urging means such as a leaf spring. Molded motor characterized by being urged toward.