JPH0548060B2 - - Google Patents

Description

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

Conventional Structure and Problems There are two 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 8 shows an example of this.
A stator 4 is formed by integrally molding and fixing the coil 2 with a molded resin 3 around which the winding 2 is wound. on the other hand,
The rotor 5 is fixed to a rotating shaft 6, and bearings 7a and 7b supporting this rotating shaft 6 are mounted on brackets 8a and 8.
b are press-fitted into the pilot parts 4a, 4b provided on the stator 4, and then mounted, and retaining rings 9a, 9b are mounted on the shaft 6 from both outsides of the bearings 7a, 7b.

When assembled in this way, suppose a force F ₁ is applied to the shaft 6 from the right side, and the force F ₁ is transmitted to the bearing 7a via the retaining ring 9a, then to the bracket 8a, and finally to the stator. The end face of the spigot part of No. 4 is pushed with a force of F ₁ '. 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 the pullout load is not 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 7a and 7b are installed after the brackets 8a and 8b are installed.
It becomes impossible to assemble a and 7b integrally with the rotor 5 in advance. Therefore, the assembly work becomes complicated. Also, there must be play between the inner shaft and outer bracket with the bearing as the center.
Slippage occurs between these three components during rotation, resulting in the bracket or shaft cleaving.
Due to the reliability of the product, it could not be used as a general electric motor.

FIG. 9 shows another example. The stator 4 is formed similarly to the previous example. On the other hand, the rotor 5 is assembled in advance by attaching retaining rings 9a, 9b to its shaft 6, and furthermore, bearings 7a, 7b are attached and fixed to the outside of the retaining rings 9a, 9b. Then, it is held on the spigot parts 4a, 4b of the stator by brackets 8a, 8b,
The bolts 11a and 11b are tightened and fixed to the nuts 10a and 10b embedded during stator molding.

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 a direction that attempts to separate the bracket on the opposite side of the force from the stator. It is.

Therefore, a fixing force sufficient to withstand this is required for fixing the brackets 8a, 8b and the stator 4.

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 need to worry about reliability such as cleavage of the bearing part.
Also, partial assembly can be used for assembly, making it much more efficient.

However, with this configuration, it is necessary to embed the nuts 10a and 10b, which takes time and effort during molding, and
In order to ensure the pull-out strength after embedding the nuts 10a, 10b, the nuts 10a, 10b must be embedded with a certain thickness, and the molding thickness l must be increased accordingly. Furthermore, winding 2 and nut 10
It is also necessary to provide a sufficient insulation distance between a and 10b. On the other hand, the heads of the bolts 11a, 11b for tightening and fixing the brackets 8a, 8b protrude on both sides of the motor end face, making it difficult to install the motor.

As an example of the second method, it is possible to fix the bracket only by pressing force into the spigot part of the stator or by using adhesive in combination, but this is because the dimensions of the spigot part change due to thermal expansion. This method is difficult to adopt because there is a risk that the interference will become smaller and the pull-out load will decrease.

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 rotor 5 is also assembled in the same manner as the example shown in FIG. 9, and is held in the spigot portions 4a, 4b of the stator by brackets 8a, 8b.

Here, in order to prevent the brackets 8a, 8b from coming off or coming off, retaining ring grooves 12a, 12b are provided by cutting or the like in the portions of the pilot parts 4a, 4b corresponding to the outside of the brackets 8a, 8b. The retaining rings 13a and 13b are inserted into these grooves using their spring force.

In this structure, the bracket 8a,
This is to prevent 8b from coming off, and usually at least 2~
3mm is required, and the width of the retaining ring grooves 12a and 12b
t _S (usually 1.5 to 2 mm) and bracket plate thickness t _B (usually 1
~1.5mm), the distance L from the stator end face to the bracket contact surface due to the mold is t + t _S
+t _B , usually (2-3) + (1.5-2) + (1-1.5) =
4.5-6.5mm is required. This ratio was a major obstacle when designing a thin molded motor with a small axial length. Also, retaining ring groove 12
Since insertion is not possible unless there is a slight gap between the width _tS of a and 12b and the thickness of the retaining rings 13a and 13b, create a gap by making _tS slightly larger than the thickness of the retaining rings 13a and 13b. However, after assembly, due to this gap, it is unavoidable that the brackets 8a and 8b vibrate in the axial direction, and in order to prevent this, the retaining ring 13
Corrugated washers 14a, 14b are inserted between a, 13b and brackets 8a, 8b. Therefore, the retaining rings 13a, 13b must be inserted and mounted while pushing the corrugated washers 14a, 14b, making it extremely difficult.

Furthermore, since the brackets 8a and 8b are rotatable within the stator spigots, they rotate at a very low speed together with the rotor 5 due to vibrations, etc., and it is expected that an accident will occur in which the resin spigot parts are scraped.

On the other hand, when looking at the radial dimension for machining the retaining ring grooves 12a and 12b, the distance l ₁ (normally
1.5mm) and provide a spigot part, and it is necessary to further carve the required depth l ₂ (usually 1.5mm) from the spigot part for the retaining ring grooves 12a and 12b.
It is necessary to ensure a resin wall thickness of at least 3 mm from the inner diameter surface of the stator. Therefore, electrical components such as stator windings and lead connections cannot be placed in this 3 mm portion, which is also a constraint in motor design.

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.

Composition of the Invention The present invention provides a plurality of stators having openings between the core end face and the stator end face on the inner diameter face of a stator in which a stator core and a winding are integrally molded with resin. A notch in the axial direction is provided, and a groove substantially concentric with the inner diameter surface is provided at a position where the width of the groove includes the end face on the iron core side of the notch, and the outer peripheral projection of the bracket and the bracket pressing projection of the bracket pressing spring are provided. are integrally inserted into the notch and inserted into the groove by twisting in the circumferential direction, while the rotation preventing protrusion of the bracket presser spring slides on the end face of the stator by the twisting. By moving the bracket and dropping it into the notch, the stator, bracket, and bracket presser spring are integrally fixed and prevented from rotating.

DESCRIPTION OF EMBODIMENTS The present invention will be described in detail below using an example in which the present invention is applied to a toroidal winding motor in which a yoke is wound in each slot of a stator core.

FIG. 1 is a side view of an embodiment of the present invention, and FIG.
The figure is a sectional view taken along the line A-O-B in FIG. 1.
FIG. 3 is a sectional view taken along line A--C in FIG. 2. Fig. 4 is a perspective view of the stator with the bracket and presser spring attached, and Fig. 5 a, b, c
6 is a perspective view of an example of a presser spring, and FIG. 6 is a perspective view of a bracket.

In the figure, a stator core 1 has toroidal windings 2 wound around the yoke portions of each slot, and a stator 4 is formed by resin molding.

The rotor 5 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, in the spigot part of the inner diameter surface of the stator 4,
A plurality of notches 4d are provided in the axial direction along the inner diameter surface. A groove 4c having a width L is provided substantially concentrically with the inner diameter surface so as to include the core side end surface of the notch 4d. The cutout portion 4d can be provided by simultaneous molding during molding. On the other hand, the outer circumferential surface 8c of the bracket 8 is a fitting part with the spigot part, and the same number of protrusions 8 are provided at the same position and in the same number as the notches 4d on the stator inner diameter surface, and are slightly smaller than the size of the notches 4d and are easy to insert.
Provide d. The projection 8d projects in the axial direction from the outer circumferential surface 8c, and its end surface is brought into contact with the core side wall surface of the groove 4c. Further, the presser spring 12 has the same number of protrusions 12d on the outer periphery of the ring-shaped disc 12a at the same positions as the notches 4d, similar to the bracket.
At least one anti-rotation protrusion 12f is provided in the middle between each protrusion 12d, and a plurality of protrusions 12e for pushing the bracket are provided on the inner periphery. To assemble these, insert the bracket 8 into the stator 4, further insert the presser spring 12, and rotate it to the right or left as shown by the arrow in Fig. 4 while pushing the protrusion 12d of the presser spring 12 in the axial direction. , the protrusion 8d of the bracket 8 and the protrusion 12d of the presser spring 12
into the groove. The axial cross section of the notch 4d immediately before rotation after inserting the bracket 8 and the presser spring 12 is as shown in FIG.

At this time, since the tip of the detent protrusion 12f is bent toward the stator side from the surface of the ring-shaped disk portion 12a of the presser spring 12, the tip of the detent protrusion 12f is bent toward the stator end surface. It is shaped like a push button. In this state, when the bracket 8 and the presser spring 12 are twisted together in order to be inserted into the groove 4c, the rotation preventing protrusion 12f slides on the end face of the stator, and the twist angle becomes equal to the angle between the notches 4d. When it becomes about 1/2,
It falls into the notch 4d and hits the wall of the notch, preventing further rotation. Moreover, if the tip of the rotation stopper protrusion 12f is shaped as shown in FIG.
There is no fear that the edge of the tip will hit and damage the end face of the stator as in the above example.

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

(1) The bracket can be fixed with one touch,
Assembly is easy and the process can be streamlined.

(2) Compared to the adhesive method, the bracket 8 can be disassembled.

(3) No insert parts are required during molding,
The molding process can be streamlined.

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

(5) By the first method, there is extremely less concern about the occurrence of cleaves between the bearing, bracket, and shaft, and quality is improved.

(6) Compared to the method of providing a retaining ring groove and fixing with a retaining ring, the L dimension is smaller (approximately 4 to 5 mm) and a thinner motor can be obtained.

(7) Compared to methods that use retaining rings, internal parts such as windings can be placed as deep as the retaining ring groove.
Pre-mold work such as wiring connections becomes easier and more streamlined.

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

As described above, the present invention can greatly improve the bracket fixing structure, which was a major drawback of conventional molded motors, by rotating and inserting the bracket and presser spring into the bracket mounting groove as one unit. It is something.

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 it is of course applicable to any molded motor having a bracket, regardless of the winding method or shape. It is.

[Brief explanation of the drawing]

FIG. 1 is a side view of a molded motor according to an embodiment of the present invention, FIG. 2 is a sectional view taken along line A-O-B in FIG. 1, and FIG. 3 is a cross-sectional view taken along line A-O-C in FIG. 1. FIG. 4 is a perspective view of the bracket according to the present invention in an assembled state. FIGS. 5 a, b, and c are perspective views of an example of the presser spring according to the present invention. FIG. Fig. 7 is an enlarged sectional view of the main part immediately before the bracket is fixed, Fig. 8 is a sectional view of a molded motor showing a conventional bracket mounting structure, and Figs. 9 and 10 are another conventional bracket. FIG. 3 is a cross-sectional view of the molded motor showing the mounting structure. DESCRIPTION OF SYMBOLS 1...Stator core, 2...Winding, 3...Mold resin, 4...Stator, 4c...Groove, 4d...Notch, 5...Rotor, 6...Shaft, 7... bearing, 8
... Bracket, 12 ... Presser spring, 12a ...
Ring-shaped disc, 12d...protrusion, 12e...protrusion, 12f...rotation stopper protrusion.

Claims (1)

[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 plurality of protrusions on the outer periphery that rotatably supports the rotor via a bearing. and a bracket holding spring having a plurality of protrusions for holding the bracket and at least one protrusion for preventing rotation on the outer periphery, and a bracket holding spring having a plurality of protrusions for holding the bracket and at least one protrusion for preventing rotation on the outer periphery between the core end face and the stator end face on the inner diameter surface of the stator. , a stator end face and an inner diameter face are provided with openings and a plurality of axial notches, and a groove substantially concentric with the inner diameter face is provided at a position where the groove width includes the end face of the notch on the iron core side. , the outer circumferential protrusion of the bracket and the outer circumferential protrusion for holding down the bracket of the presser spring are inserted through the notch and slid together in the circumferential direction within the groove, and the rotation preventing protrusion slides on the stator end face. and falls into the notch,
A molded motor in which the stator, the bracket, and the presser spring are integrally fixed and are prevented from rotating.