TWI659590B - Stator engagement structure - Google Patents

Abstract

A stator fixing structure is used to solve the problem of instability of conventional combination. The system includes: a base; a shaft tube provided on the base; a silicon steel sheet group tightly coupled to the outer peripheral wall of the shaft tube; and an insulating sleeve group coupled to the silicon steel sheet group, the insulation sleeve group having A through hole is sleeved on the shaft tube, and an accommodation gap is formed between the inner peripheral wall of the through hole and the outer peripheral wall of the shaft tube. The accommodation gap forms an accommodation space, and the bottom of the accommodation space The abutment end has a minimum gap between the abutment end and the outer peripheral wall of the shaft tube, and the minimum gap is less than or equal to the accommodation gap.

Description

Stator fixing structure

The invention relates to a stator, in particular to a stator fixing structure in which a silicon steel sheet, an insulating sleeve and a shaft tube are combined.

The conventional motor or cooling fan is provided with a stator, and the stator is tightly coupled to the outer wall of a shaft tube with a silicon steel sheet group, or a gap is left between the silicon steel sheet group and the shaft tube, and the gap is The adhesive is coated to make the silicon steel sheet group adhere to the shaft tube to prevent the silicon steel sheet group from falling off the shaft tube.

However, since the silicon steel sheet group of the stator is generally made of a metal material, when the silicon steel sheet group of the stator is tightly coupled to the outside of the shaft tube, the silicon steel sheet group is likely to compress the shaft tube excessively, thereby causing the shaft The deformation of the tube affects the service life of the conventional motor or cooling fan, and because the shaft tube is generally made of plastic, the plastic material has a larger expansion coefficient than the metal material, making the plastic material easily affected by temperature changes and affecting the dimensional stability. And further, the bonding stability between the silicon steel sheet group and the shaft tube is poor; or, when a gap is left between the silicon steel sheet group and the shaft tube, and the gap is coated with an adhesive, the silicon steel sheet During the process of assembling the sleeve on the outer peripheral wall of the shaft tube, the adhesive will be squeezed to cause the adhesive to flow downwards, which will affect the bonding stability.

In view of this, the conventional stator fixing structure still needs to be improved.

In order to solve the above problems, the present invention provides a stator fixing structure, which is a stator fixing structure with better combined stability.

The following directional or similar terms of the present invention, such as "front", "rear", "upper (top)", "lower (bottom)", "inside", "outside", "side", etc., are mainly related to With reference to the directions of the accompanying drawings, each directivity or its approximate terms are only used to assist in explaining and understanding the embodiments of the present invention, and are not intended to limit the present invention.

The stator fixing structure of the present invention includes: a base; a shaft tube provided on the base; a silicon steel sheet group tightly coupled to the outer peripheral wall of the shaft tube; and an insulating sleeve group coupled to the silicon steel sheet group The insulation sleeve group has a through hole, which is sleeved on the shaft tube. An accommodation gap is formed between the inner peripheral wall of the through hole and the outer peripheral wall of the shaft tube. The accommodation gap forms an accommodation space. The bottom of the accommodating space has an abutting end, and there is a minimum gap between the abutting end and the outer peripheral wall of the shaft tube, and the minimum gap is less than or equal to the accommodating gap.

The stator fixing structure of the present invention includes: a base; a shaft tube provided on the base, the shaft tube having a joint end surface; a silicon steel sheet group tightly coupled to the outer peripheral wall of the shaft tube; and an insulation sleeve Group, combined with the silicon steel sheet group, the insulating sleeve group has a through hole, and the through hole is sleeved on the shaft tube; wherein a receiving gap is formed between a coupling end surface of the shaft tube and an inner peripheral wall of the through hole, The accommodating gap forms an accommodating space. The bottom of the accommodating space has an abutting end. There is a minimum gap between the abutting end and the insulating sleeve group, and the minimum gap is smaller than the accommodating gap.

According to this, the stator fixing structure of the present invention utilizes a minimum gap between the abutting end of the bottom of the accommodation space and the outer peripheral wall of the shaft tube or the insulation sleeve, and the minimum gap is less than or equal to the accommodation gap The adhesive that flows downward due to the compression can be stored in the accommodating space, so that the shaft tube and the insulating sleeve can also be bonded to each other by the adhesive, thereby improving the shaft tube and the silicon steel. The bonding stability between the sheet group and the lower insulation sleeve is stable.

The insulating sleeve group has an upper insulating sleeve and a lower insulating sleeve, and the accommodating space is formed in the lower insulating sleeve. In this way, it has the effect of combining the shaft tube with the lower insulation sleeve.

The shaft tube has an enlarged diameter section, one end of the enlarged diameter section forms a first shoulder, and the silicon steel sheet group is positioned at the first shoulder. In this way, the The effect of the axial movement of the shaft tube.

The upper insulating sleeve has a first through hole, the lower insulating sleeve has a second through hole, and the first through hole and the second through hole are sleeved on the shaft tube. In this way, the system has the effect of being easy to combine.

The second through hole has a minimum inner diameter, and the minimum inner diameter is greater than or equal to the maximum outer diameter of the enlarged diameter section. In this way, it has the effect that the lower insulation sleeve can be easily combined with the outer peripheral wall of the shaft tube.

The silicon steel sheet group has a perforation, the silicon steel sheet group has a perforation, and the perforation is sleeved on the outer peripheral wall of the shaft tube. In this way, the system has the effect of easy assembly.

The minimum gap is much smaller than the receiving gap, so that the abutting end of the bottom of the receiving space is closer to the outer peripheral wall of the shaft tube. In this way, it has the effect of preventing the adhesive from flowing out.

The shaft tube is made of plastic material. In this way, the system has the effect of being easily combined with the insulation set.

The shaft tube and the insulating sleeve are made of the same material. In this way, it has the effect of bonding the shaft tube and the insulating sleeve with an adhesive.

Wherein, the accommodating space has an axial height a, and an end face of the lower insulation sleeve and the shaft tube is combined with an axial height h, and (1/5) h ≦ a ≦ (9/10) h. In this way, the system has the effect that sufficient adhesive can be injected without overflowing.

The bottom of the accommodating space is inclined. In this way, it has the effect of ensuring that the adhesive is accommodated in the accommodating space.

Wherein, the second through hole is formed with a reaming hole below the bottom of the accommodating space, and an outer expanding guide angle is formed between the reaming hole and the shaft tube. In this way, it has the effect of making the lower insulation sleeve easier to be sleeved on the outer peripheral wall of the shaft tube.

The accommodating space is used for accommodating the adhesive. In this way, it has the effect of adhering the shaft tube to the insulating sleeve.

Wherein, the adhesive is an adhesive used in combination of a plastic material and a plastic material. In this way, it has the effect of making the shaft tube and the insulation sleeve easy to adhere.

Wherein, the accommodating space is a ring groove shape. In this way, the system has the effect of a large bonding area.

The accommodating space is a plurality of spaced grooves. In this way, the system has the effect of concentrating the bonding surface.

The accommodation gap is tapered from top to bottom, so that the bottom is the abutting end. In this way, it has the effect of making the adhesive stuck in the minimum gap and solidified and stored in the accommodating space.

Wherein, the accommodation gap is tapered from top to bottom, or is formed at an equal distance and then tapered, so that the bottom is the abutting end. In this way, it has the effect of making the adhesive stuck in the minimum gap and solidified and stored in the accommodating space.

1‧‧‧ base

2‧‧‧ shaft tube

21‧‧‧Expansion section

211‧‧‧first shoulder

22‧‧‧Combined face

23‧‧‧accommodation space

24‧‧‧ bottom

24a‧‧‧adjacent end

3‧‧‧ Silicon steel sheet set

31‧‧‧perforation

4‧‧‧ Insulation Kit

4a‧‧‧Upper insulation sleeve

4b‧‧‧Lower insulation sleeve

40‧‧‧through hole

40a‧‧‧First through hole

40b‧‧‧Second through hole

40b’‧‧‧ Reaming

41‧‧‧accommodation space

41’‧‧‧ trench

42‧‧‧ bottom

42a‧‧‧adjacent end

D1‧‧‧Maximum outer diameter

D2‧‧‧minimum inner diameter

α‧‧‧ Outer divergence angle

a‧‧‧ the axial height of the accommodation space

h‧‧‧ the axial height of the end face of the lower insulation sleeve and the shaft tube

f‧‧‧Receiving gap

g‧‧‧Minimum clearance

Figure 1: An exploded perspective view of the first embodiment of the present invention.

FIG. 2 is a combined sectional view of the first embodiment of the present invention.

Figure 3: A partially enlarged view of Figure 2.

Figure 4: Another aspect of the bottom of the second embodiment of the present invention.

Figure 5: Another aspect of the accommodation space of the first embodiment of the present invention.

Fig. 6 is a partially enlarged sectional view of a third embodiment of the present invention.

Fig. 7 is a partially enlarged sectional view of a fourth embodiment of the present invention.

Fig. 8 is a partially enlarged sectional view of a fifth embodiment of the present invention.

Fig. 9 is an assembled sectional view of a sixth embodiment of the present invention.

Fig. 10: A partially enlarged view of Fig. 9.

In order to make the above and other objects, features, and advantages of the present invention more comprehensible, the following describes the preferred embodiments of the present invention and the accompanying drawings in detail, as follows: Please refer to FIG. The first embodiment of the stator fixing structure of the present invention includes a base 1, a shaft tube 2, a silicon steel sheet group 3, and an insulation sleeve group 4. The shaft tube 2 is disposed on the base 1, and the silicon steel The sheet group 3 is coupled to the outer peripheral wall of the shaft tube 2, and the insulating sleeve group 4 is coupled to the silicon steel sheet group 3.

Please refer to Figures 1 and 2. The shaft tube 2 is set at the center of the base 1. The shaft tube 2 is made of plastic material, and the shaft tube 2 can be used to install the shaft tube internal components, and the shaft tube internal components. It can be various related components (such as bearings, wear plates, retaining rings or positioning rings) that can be installed on the shaft tube 2 and provide different functions. In addition, the shaft tube 2 has an enlarged diameter section 21, and the enlarged diameter A first shoulder 211 is formed at one end of the segment 21, and the enlarged diameter segment 21 has a maximum outer diameter D1.

Please refer to FIGS. 1 and 2. The silicon steel sheet group 3 is tightly coupled to the outer peripheral wall of the shaft tube 2 and is positioned at the first shoulder 211 of the enlarged diameter section 21. The silicon steel sheet group 3 has a The perforation 31 is sleeved on the outer peripheral wall of the shaft tube 2.

Please refer to Figs. 1, 2, and 3, the insulating sleeve group 4 is combined with the silicon steel sheet group 3, and the through hole 40 of the insulating sleeve group 4 is sleeved on the shaft tube 2. The insulation sleeve group 4 and the shaft tube 2 It is made of the same material. In particular, the insulating sleeve group 4 can be formed by integrally overmolding the silicon steel sheet group 3, or the upper and lower insulating sleeves can be separately combined with the silicon steel sheet group 3, In this embodiment, the insulating sleeve group 4 has an upper insulating sleeve 4a and a lower insulating sleeve 4b. The upper insulating sleeve 4a has a first through hole 40a, and the lower insulating sleeve 4b has a second through hole 40b. The first through hole 40a and the second through hole 40b are sleeved on the shaft tube 2 and are respectively disposed on the upper and lower ends of the silicon steel sheet group 3 and clamped and fixed the silicon steel sheet group 3 and below the insulating sleeve group 4. The insulation sleeve 4b is positioned at the enlarged diameter section 21, and an accommodation gap f is formed between an inner peripheral wall of the second through hole 40b and an outer peripheral wall of the enlarged diameter section 21, and the accommodation gap f forms an accommodation space 41, In addition, the bottom 42 of the accommodating space 41 has an abutting end 42a, and an abutting end 42a has an outermost wall between the abutting end 42a and the outer peripheral wall of the shaft tube 2. The small gap g is smaller than the receiving gap f, so that the abutment end 42 a of the bottom 42 of the receiving space 41 is closer to the outer peripheral wall of the shaft tube 2.

Please refer to Figs. 1, 3, and 5. The accommodating space 41 has a ring groove shape as shown in Fig. 1, or the accommodating space 41 may also be a plurality of spaced-apart grooves 41 'as shown in Fig. 5. The accommodating space 41 is used for accommodating an adhesive, and the adhesive is preferably an adhesive for combining a plastic material with a plastic material. The accommodating space 41 has an axial height a, and the lower insulation. The end face of the sleeve 4b combined with the shaft tube 2 has an axial height h, and (1/5) h ≦ a ≦ (9/10) h, so that sufficient adhesive can be injected and not overflow. In addition, the The bottom 42 of the lower insulation sleeve 4b in the accommodating space 41 is horizontal and straight as shown in FIG. 3 and can be used to receive the adhesive.

Please refer to FIGS. 2 and 3, wherein the second through hole 40b has a minimum inner diameter D2, the minimum inner diameter D2 is greater than or equal to the maximum outer diameter D1 of the enlarged diameter section 21, and the second through hole 40b A reaming hole 40b 'is formed below the bottom 42 of the accommodating space 41, and an outer expanding guide angle α is formed between the reaming hole 40b' and the shaft tube 2. Thus, during assembly, the lower insulating sleeve 4b It can be set on the outer peripheral wall of the shaft tube 2 more easily.

Please refer to FIG. 3. According to the foregoing structure, when the silicon steel sheet group 3 is set on the outer peripheral wall of the shaft tube 2, the adhesive applied on the outer peripheral wall of the shaft tube 2 will flow down to the container due to extrusion. The clearance gap f is designed to make the abutment end 42a of the bottom 42 of the accommodation space 41 closer to the outer peripheral wall of the shaft tube 2 by the minimum gap g being much smaller than the accommodation gap f. Downstream adhesive is stored in the accommodating space 41, so that the shaft tube 2 and the lower insulation sleeve 4b can also be bonded to each other by the adhesive, and since the shaft tube 2 and the insulation sleeve group 4 are both plastic Made of material, so it can provide a better bonding effect, thereby improving the bonding stability between the shaft tube 2, the silicon steel sheet group 3 and the lower insulation sleeve 4b. In particular, when the minimum When the inner diameter D2 is equal to the maximum outer diameter D1 of the enlarged diameter section 21, the minimum gap g approaches zero, thereby allowing the adhesive to be stored in the accommodating space 41.

Please refer to FIG. 4, which is a second embodiment of the stator fixing structure of the present invention. The second embodiment of the invention is substantially the same as the first embodiment described above. The main difference is that the bottom 42 of the accommodating space 41 of the second embodiment of the present invention is as shown in FIG. 4 in an inclined plane. . Therefore, when the silicon steel sheet group 3 is set on the outer peripheral wall of the shaft tube 2, the adhesive applied on the outer peripheral wall of the shaft tube 2 will flow down to the accommodation gap f due to extrusion, which is inclined. The bottom 42 can further prevent the adhesive from flowing out, ensuring that the adhesive is stored in the accommodating space 41, so that the shaft tube 2 and the lower insulating sleeve 4b can be adhered to each other by the adhesive, thereby improving the The coupling stability between the shaft tube 2, the silicon steel sheet group 3, and the lower insulation sleeve 4b.

Please refer to FIG. 6, which is a third embodiment of the stator fixing structure of the present invention. The third embodiment of the present invention is substantially the same as the first embodiment described above. The main difference is that the minimum gap g is smaller than the capacity. A clearance f is formed, and the accommodation clearance f is tapered from top to bottom, so that the bottom 42 is the abutting end 42a, and the abutting end 42a does not contact the outer peripheral wall of the shaft tube 2. As a result, when the silicon steel sheet group 3 is set on the outer peripheral wall of the shaft tube 2, the adhesive applied on the outer peripheral wall of the shaft tube 2 will flow downward due to extrusion, and flow through the accommodation gap f to At the minimum gap g, the adhesive will be stuck in the minimum gap g and solidified and stored in the accommodating space 41, so that the shaft tube 2 and the lower insulating sleeve 4b can be bonded to each other by the adhesive, and This can improve the bonding stability between the shaft tube 2, the silicon steel sheet group 3, and the lower insulation sleeve 4b.

Please refer to FIG. 7, which is a fourth embodiment of the stator fixing structure of the present invention. The fourth embodiment of the present invention is substantially the same as the first embodiment described above. The main difference is that the minimum gap g is equal to the capacity. The clearance gap f is formed at an equal distance from the top to the bottom, so that the bottom 42 is the abutting end 42a, and the abutting end 42a does not contact the outer peripheral wall of the shaft tube 2. As a result, when the silicon steel sheet group 3 is set on the outer peripheral wall of the shaft tube 2, the adhesive applied on the outer peripheral wall of the shaft tube 2 will flow downward due to extrusion, and flow through the accommodation gap f to The minimum gap g is solidified and stored in the accommodating space 41, so that the shaft tube 2 and the lower insulating sleeve 4b can be adhered to each other by the adhesive, thereby improving the shaft tube 2, the silicon steel sheet group 3 Bonding stability with the lower insulation sleeve 4b.

Please refer to FIG. 8, which is a fifth embodiment of the stator fixing structure of the present invention. The fifth embodiment of the present invention is substantially the same as the first embodiment described above. The main difference is that this embodiment is constituted by the shaft tube. The outer peripheral wall of 2 is changed to form an accommodating space 23. Specifically, the shaft tube 2 has a joint end surface 22, and the insulating sleeve 4b under the insulating sleeve group 4 is sleeved on the outer peripheral wall of the joint end surface 22. An accommodating gap f is formed between the combining end surface 22 and the lower insulation sleeve 4b, and the accommodating gap f forms the accommodating space 23. The bottom 24 of the accommodating space 23 has an abutting end 24a, and the abutting end 24a and the There is a minimum gap g between the lower insulation sleeves 4b, and the minimum gap g is far smaller than the accommodation gap f, whereby the adhesive flowing downward due to the compression can be stored in the accommodation space 23, so that the shaft tube The bonding end surface 2 of 2 and the lower insulating sleeve 4b can be adhered to each other by the adhesive, thereby improving the bonding stability between the shaft tube 2, the silicon steel sheet group 3 and the lower insulating sleeve 4b.

Please refer to FIGS. 9 and 10, which are the sixth embodiment of the stator fixing structure of the present invention. The sixth embodiment of the present invention is substantially the same as the fifth embodiment described above. The main difference is that the minimum gap g is less than The accommodating gap f is formed at an equal distance from the top to the bottom, and then is tapered. The accommodating gap f may also be tapered from the top to the bottom, so that the bottom 24 is the abutment. The end 24a, by which, when the silicon steel sheet group 3 is set on the outer peripheral wall of the shaft tube 2, the adhesive applied on the outer peripheral wall of the shaft tube 2 will flow downward due to extrusion and pass through the accommodation gap. When f flows to the minimum gap g, the adhesive will be stuck in the minimum gap g and solidified and stored in the accommodating space 23, so that the joint end surface 22 of the shaft tube 2 and the lower insulation sleeve 4b can borrow the same. Adhesives are bonded to each other, thereby improving the bonding stability between the shaft tube 2, the silicon steel sheet group 3, and the lower insulation sleeve 4b.

In summary, the stator fixing structure of the present invention utilizes a minimum gap between the abutting end of the bottom of the accommodation space and the outer peripheral wall of the shaft tube or the lower insulation sleeve, and the minimum gap is less than or equal to the capacity The design of the gap can allow the adhesive flowing downwards due to the compression to be stored in the accommodating space, so that the shaft tube and the lower insulating sleeve can also be adhered to each other by the adhesive. This can improve the bonding stability between the shaft tube, the silicon steel sheet group, and the lower insulation sleeve.

Although the present invention has been disclosed using the above-mentioned preferred embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make various changes and modifications to the above embodiments without departing from the spirit and scope of the present invention. The technical scope protected by the invention, so the scope of protection of the present invention shall be determined by the scope of the appended patent application.

Claims (29)

A stator fixing structure includes: a base; a shaft tube provided on the base; a silicon steel sheet group tightly coupled to the outer peripheral wall of the shaft tube; and an insulating sleeve group coupled to the silicon steel sheet group, the The insulating sleeve group has a through hole, which is sleeved on the shaft tube. An accommodation gap is formed between the inner peripheral wall of the through hole and the outer peripheral wall of the shaft tube. The accommodation gap forms an accommodation space. The bottom of the accommodation space has an abutment end, and there is a minimum gap between the abutment end and the outer peripheral wall of the shaft tube, and the minimum gap is less than or equal to the accommodation gap. The stator fixing structure according to item 1 of the scope of the patent application, wherein the insulation sleeve group has an upper insulation sleeve and a lower insulation sleeve, and the accommodation space is formed in the lower insulation sleeve. The stator fixing structure according to item 2 of the scope of the patent application, wherein the shaft tube has an enlarged diameter section, one end of the enlarged diameter section forms a first shoulder, and the silicon steel sheet group is positioned on the first shoulder. The stator fixing structure according to item 3 of the scope of patent application, wherein the upper insulating sleeve has a first through hole, the lower insulating sleeve has a second through hole, the first through hole and the second through hole sleeve Set on the shaft tube. The stator fixing structure according to item 4 of the scope of patent application, wherein the second through hole has a minimum inner diameter, and the minimum inner diameter is greater than or equal to the maximum outer diameter of the enlarged diameter section. The stator fixing structure according to item 1 of the scope of the patent application, wherein the silicon steel sheet group has a perforation, and the perforation is sleeved on the outer peripheral wall of the shaft tube. According to the stator fixing structure described in item 1 of the patent application scope, wherein the minimum gap is much smaller than the accommodation gap, so that the abutting end of the bottom of the accommodation space is closer to the outer peripheral wall of the shaft tube. The stator fixing structure according to item 1 of the scope of patent application, wherein the shaft tube is made of plastic material. The stator fixing structure according to item 1 of the scope of patent application, wherein the shaft tube and the insulation sleeve are made of the same material. The stator fixing structure according to item 2 of the scope of the patent application, wherein the accommodating space has an axial height a, and the end surface where the lower insulation sleeve is combined with the shaft tube has an axial height h, and (1/5 ) h ≦ a ≦ (9/10) h. The stator fixing structure according to item 2 of the scope of patent application, wherein the bottom of the accommodation space is inclined. The stator fixing structure according to item 4 of the scope of the patent application, wherein the second through hole is formed with a reaming hole below the bottom of the accommodation space, and an outer expanding guide angle is formed between the reaming hole and the shaft tube. . The stator fixing structure according to item 1 of the patent application scope, wherein the accommodating space is used for accommodating the adhesive. The stator fixing structure according to item 13 of the scope of the patent application, wherein the adhesive is an adhesive used for combining a plastic material with a plastic material. The stator fixing structure according to item 1 of the scope of patent application, wherein the accommodation space is a ring groove shape. The stator fixing structure according to item 1 of the patent application scope, wherein the accommodation space is a plurality of spaced apart grooves. The stator fixing structure according to item 1 of the scope of patent application, wherein the accommodation gap is tapered from top to bottom, so that the bottom is the abutting end. A stator fixing structure includes: a base; a shaft tube provided on the base, the shaft tube having a joint end surface; a silicon steel sheet group tightly coupled to the outer peripheral wall of the shaft tube; and an insulating sleeve group, Combined with the silicon steel sheet group, the insulating sleeve group has a through hole, and the through hole is sleeved on the shaft tube; wherein a receiving gap is formed between a coupling end surface of the shaft tube and an inner peripheral wall of the through hole, and the container The receiving gap forms an accommodating space. The bottom of the accommodating space has an abutting end, and there is a minimum gap between the abutting end and the insulating sleeve group, and the minimum gap is smaller than the accommodating gap. The stator fixing structure according to item 18 of the scope of patent application, wherein the accommodation gap is tapered from the top to the bottom or is formed at an equal distance and then is tapered, so that the bottom is the abutting end. The stator fixing structure according to item 18 of the scope of the patent application, wherein the insulation sleeve group has an upper insulation sleeve and a lower insulation sleeve, and the accommodation space is formed in the lower insulation sleeve. According to the stator fixing structure described in claim 18, wherein the shaft tube has an enlarged diameter section, one end of the enlarged diameter section forms a first shoulder, and the silicon steel sheet group is positioned on the first shoulder. The stator fixing structure according to item 20 of the scope of patent application, wherein the upper insulating sleeve has a first through hole, the lower insulating sleeve has a second through hole, the first through hole and the second through hole sleeve Set on the shaft tube. The stator fixing structure according to item 18 of the scope of patent application, wherein the silicon steel sheet group has a perforation, and the perforation is sleeved on the outer peripheral wall of the shaft tube. The stator fixing structure according to item 18 of the patent application scope, wherein the shaft tube is made of plastic material. The stator fixing structure according to item 18 of the scope of the patent application, wherein the shaft tube and the insulating sleeve are made of the same material. The stator fixing structure according to item 20 of the scope of patent application, wherein the accommodating space has an axial height a, and a joint end surface of the lower insulation sleeve and the shaft tube has an axial height h, and (1/5 ) h ≦ a ≦ (9/10) h. The stator fixing structure according to item 22 of the scope of the patent application, wherein the second through hole is formed with a reaming hole below the bottom of the accommodation space, and an outer expanding guide angle is formed between the reaming hole and the shaft tube. . The stator fixing structure according to item 18 of the scope of patent application, wherein the accommodating space is used for accommodating the adhesive. The stator fixing structure according to item 28 of the scope of application for a patent, wherein the adhesive is an adhesive for the combination of a plastic material and a plastic material.