JPS6022439A - Molded motor - Google Patents

Abstract

PURPOSE:To improve the bracket fixing structure by mounting a retaining spring on the radial surface of a stator by utilizing the lining force of the spring. CONSTITUTION:A stator core 1 and a winding 2 are integrally molded with resin with a stator 4, a rotor 5 disposed in the stator 4, a bracket 8 rotatably supported through a bearing 7 to the rotor 5, and a retaining spring 14 mounted on the radial surface of the stator 4 are provided. A stepped part is formed due to the radial difference between the end face of the core 1 of the bore of the stator 4 and the end face of the stator 4, the end face of the bracket 8 is contacted with the stepped part, and a spring 14 is mounted on the radial surface of the stator 4 at the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a bracket fixing structure for a molded motor.

Conventional Structure and Problems There are two possible methods for fixing the bracket of the molded motor, which can be broadly classified based on the direction of the force applied to the bracket.

Figure 1 shows an example of this.
The stator 4 is formed by wrapping and integrally molding and fixing with mold resin 3. On the other hand, the rotor 5 is fixed to the rotating shaft 6, and bearings 71L and 7bld support the rotating shaft 6.
, plug 7) 8N, 8b is press-fitted into the pilot part 4L, 4b provided on the stator 4, and then installed, and its bearing 71L,
The retaining ring sa and 9b are attached to the shaft 6 from the side oblique side of 7b.

3°2゛When assembled in this way, if we consider a case where the force F1 of the arrow arrow is applied to the shaft 6 from the right side, the force F1fd and the force 9
The force is transmitted to the bearing 7fL via a, and further to the bracket 81L, and finally pushes the end face of a part of the spigot of the stator 4 with a force of y,/. In the case of force in the opposite direction, the same procedure can be followed. This method is often used in pulley motors, conveyor rollers, etc. because no load is applied to the bearing or bracket on the opposite side to the direction in which the force is applied. However, with this method, the bearings 71L and 7b are installed after the brackets 81L and 8b are installed, so the bearing 71L
.

7b cannot be assembled together with the rotor 6 in advance. Therefore, the assembly work becomes complicated.

In addition, the inner shaft and outer bracket must be loosely mated with each other around the bearing, and slippage may occur between these three parts during rotation, resulting in creep of the bracket or shaft. Due to the reliability of the product, it could not be used as a general electric motor.

FIG. 2 shows another example. The stator 4 is formed similarly to the previous example. On the other hand, the rotor 5 has retaining rings ga and gb attached to its shaft 6, and bearings 7&, 7b on the outside thereof.
is installed and fixed, and assembled in advance. Then, the spigot parts 4a, 4b of the stator are fixed by the brackets 8a, 8b.
10J 1
The tightening is fixed by 111L and 11b (pol for 0b).

This method is generally adopted, and the basic difference from the previous example is that the force F1 applied to shaft 1 is transmitted in the direction that attempts to separate the bracket on the opposite side from the side to which the force is applied from the stator. be.

Therefore, the adhesion force for brackets 8N and 8 is sufficient to withstand it.
This is required for fixing b and stator 4 together.

On the other hand, compared to the previous example, since the shaft 6 and the bearings 7a and 7b can be integrated by press fitting, there is no concern about reliability such as creep in the bearing part.

Partial assembly is used for assembly, making it much more efficient.

However, with this configuration, it is necessary to embed the nuts 101L and 10b, which takes time and effort during molding.
In order to ensure strength when removing L and IQb after embedding, it is necessary to embed the oak (1 QIL, 10 t) with a certain degree of twisting, and the forming depth L is required to be correspondingly large. Furthermore, winding 2 and oak) 101L.

It is also necessary to provide a sufficient insulation distance between the 1ob and the 1ob.

On the other hand, the heads of the pins 11fL and 11b that tighten and fix the platen) 8J and 8b protrude from both sides of the motor end face, obstructing the motor installation.

As another example of the second method, it is possible to fix the bracket only by pressing force into a part of the stator's spigot, or by using adhesive in combination, but this is because the dimensions of the part of the spigot are due to thermal expansion. This method is difficult to adopt for molded motors because there is a risk that the interference will become smaller and the load will decrease when the load changes.

Furthermore, as another example of the second method, there is a structure shown in FIG. The stator 4 is formed similarly to the previous example.

On the other hand, the first rotor 5 is also assembled in the same manner as the example shown in FIG.
, platen) 81L, 8b, and is held in the stator pilot parts 4a, 4b in 6 pages. Here, in order to prevent the platen) 81L, 8b from coming off or coming off, the platen) 8J of the above-mentioned inlet part 41L, 4b.
A retaining ring groove 12&, 12b is formed by cutting on the outside of the retaining ring 8b, and a retaining ring 131L is attached to this groove.
, 13b are inserted using their spring force.

In this structure, the brackets 8&,
This is to prevent the retaining ring groove 12a from coming off, and usually requires at least 2 to 3 screws.

12b width ts (usually 1.5-2111M) and bracket Ba.

When adding the plate thickness ta (usually 1 to 1.6 mm) of 8b.

The length L from the stator end face to the bracket contact face due to molding is 1 + 18 + 1. Usually (2 to 3), this was a major obstacle when designing small thin motors.

Also, retaining ring groove 12! L, 12b width 1B and stopper 131
There is a slight gap between the thickness of L113b: Since it cannot be inserted without leaving a gap, insert ts into the retaining ring 13.
It is slightly larger than the thickness of a, 1a, and b to provide a gap, but after 1 assembly, this gap will be used for brackets 81L and 8.
It is unavoidable that b vibrates in the axial direction.

To prevent this, retaining rings 13a, 13b and platinum)
Wave washer 14 & between 8J 8b.

14b. For that purpose, retaining ring 13 &.

13b must be inserted and mounted while pushing the wave washers 141L and 14b, which is extremely difficult.

Furthermore, since the platen (81L, 81) is freely rotatable within the stator spigot, it is expected that it will rotate at an extremely low speed together with the rotor 6 due to vibrations, etc., and an accident may occur in which part of the resin spigot is scraped.

On the other hand, looking at the radial dimension for machining the retaining ring grooves 12a and 12b, from the inner diameter surface of the stator, the platen) 8J
Secure the hole 11 (usually 1.6 mm) necessary for abutment of 8b, provide a part of the spigot, and insert the retaining ring groove 1 from the spigot part.
It is necessary to further cut down the required depth M (usually 1.511) for 2&, 12b, and it is necessary to ensure a resin thickness of at least 3 g from the inner diameter surface of the stator. Therefore, it is not possible to arrange electrical components such as the stator winding and the solar connection section in this 3 m long section, and this is also a constraint on the motor design.

Furthermore, considering the manufacturing method of the molded motor, it is extremely difficult to provide the retaining ring grooves 12+1, 12b by molding during resin molding, and it is usually not possible to obtain them by machining such as cutting after molding is completed. However, it also had the disadvantage of increasing the number of manufacturing steps.

OBJECTS OF THE INVENTION The present invention belongs to the second type of bracket mounting structure, and aims to take advantage of its advantages while correcting its disadvantages.

Structure of the Invention The present invention provides a stepped portion due to a difference in inner diameter between the core end surface of the stator inner diameter surface and the stator end surface, and the end surface of the bracket is applied to this stepped portion, and a presser is placed on the outside of the stator inner diameter surface. 〇9 Page 〇Explanation of Embodiment The details of the present invention will be described below using an example of application to a toroidal winding motor in which a yoke of each slot of a stator core is wound. Explain.

FIG. 4 is a side view of the embodiment of the present invention, and FIG. 6 is a side view of the embodiment of the present invention.
It is a cross-sectional view taken along the Mu B line in the figure. FIG. 6 is a perspective view of the presser spring. FIG. 7 shows an example of the cross-sectional shape of the presser spring.

In the figure, a stator core 1 has toroidal windings 2 wound around the yoke portions of each slot, and is integrally molded with mold resin 3 to form a stator 4. The rotor 6 is disposed inside the stator 4 with a bearing 7 mounted on its shaft 6, and is rotatably held by the stator 4 from both sides by brackets 8. Here, the bracket 8 is inserted into the spigot part 4a of the inner diameter surface of the stator 4, and a presser spring 14 is attached from the outside. The presser spring 14 has a shape as shown in the perspective view of FIG. 6, and its outer peripheral surface is provided with sawtooth-like unevenness 16 as shown in FIG. To install the retainer spring 14, just as when installing a regular C-type retaining ring, hook a jig (not shown) into the spring hole 16, retract it in the direction of the arrow, and tighten the stator spigot part. 4a, remove the jig, and fix it to the spigot part 4a using the force exerted by the spring in the outer diameter direction. Since the outer periphery of the spring is provided with sawtooth-like unevenness 16, the tip thereof partially bites into the inner diameter surface of the spigot to prevent the spring 14 from coming off.

The shape of the inner diameter surface of the stator at the part where the spring 14 is attached may be such that the bracket insertion inner diameter and the spring attachment inner diameter are the same plane as shown in FIG. Even if the insertion inner diameter is larger than the insertion inner diameter, the effect remains the same.

With the above configuration, the following effects can be obtained compared to the conventional example.

(1) Bracket fixing can be done with one touch, which simplifies assembly and streamlines the process.

(2) The bracket can be disassembled compared to the adhesive method.

(3) No insert parts are required during molding, streamlining the molding process.

11ba' (4) Since no insert parts are required, a product can be obtained that is thinner and has improved insulation reliability.

(5) Bearings and brackets from the first method above.

There is no need to worry about creep occurring between the shafts, resulting in improved quality.

(6) Compared to the method of providing a retaining ring groove and fixing with a retaining ring,
5 dimensions are smaller (about 4 to 5 questions), and a thinner motor can be obtained.

(7) Compared to the method of using a retaining ring with a retaining ring groove,
Four internal components such as windings can be placed to the depth of the retaining ring groove, making pre-mold work such as wire connection easier and more streamlined.

(8) Compared to the method of providing retaining ring grooves, the man-hours for groove machining can be omitted, and quality defects such as damage to internal windings due to groove machining are eliminated, resulting in a molded motor with stable quality. It will be done.

(9) As in the first example, there is no change in the fixing strength of the bracket due to expansion and contraction of a part of the inlet, and stable fixation of the bracket can be achieved.

Effects of the Invention As described above, the present invention greatly improves the bracket fixing structure, which was a major drawback of conventional molded motors, by attaching the presser spring to the inner diameter surface of the stator using the internal tension of the presser spring. It is something that can be improved.

Although the present invention has been described as an embodiment in which the winding is a toroidal winding, the present invention is not limited to this, and the winding method can be applied to any molded motor having a bracket.

Of course, it can be applied regardless of the shape.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a molded motor showing a conventional bracket mounting structure, FIGS. 2 and 3 are cross-sectional views of a molded motor showing another conventional bracket mounting structure, and FIG. 4 is a cross-sectional view of a molded motor showing a conventional bracket mounting structure. FIG. 6 is a sectional view taken along the Mu B line in FIG. 4, FIG. 6 is a perspective view of a bracket presser spring according to the present invention, and FIG. 7 is a side view of a presser spring according to the present invention. An example of a sectional view, FIG. 8 is a sectional view of a main part in another embodiment of the present invention. 13 l knee i 1... Stator core, 2... Winding wire, 3...
...Mold resin, 4...Stator, 6.
...Rotor, 6...Axis, 7...
Bearing, 8...Bracket, 14...Pressure spring, 16...Irregularities. Name of agent: Patent attorney Toshio Nakao and 1 other person 1st
Figure 2 Figure 3 Figure 5 Figure 6 Figure 7 Figure 8

Claims (4)

[Claims] (1) A stator in which a stator core and a winding are integrally molded with resin, a rotor disposed within the stator, and a rotor rotatable through a bearing to form a text and a stator end face. A molded motor in which a stepped portion with a different inner diameter is provided in between, the end face of the bracket is placed against this stepped portion, and a presser spring is attached to the inner diameter surface of the stator outside of the stepped portion. (2) The molded motor according to claim 1, wherein the inner diameter of the stator at the portion where the bracket is attached and the inner diameter of the stator at the portion where the presser spring is attached are equal and concentric. (3) The inner diameter of the stator where the presser spring is attached is larger than the inner diameter of the stator where the bracket is attached. 2. The motor according to claim 1, which is concentric and concentric. (4) The molded motor according to claim 1, wherein the outer diameter surface of the presser spring is provided with unevenness having a sawtooth cross-section.