Stator auxiliary groove structure and stator

Abstract

Provide a stator auxiliary groove structure and a stator. 【Solution means】The stator auxiliary groove structure optimizes the auxiliary groove 13 disposed at the end facing the gap of the stator pole teeth. In particular, the auxiliary groove is divided into a groove opening 131 formed at the tooth tip 125 of the end facing the gap of the tooth portion 121 of the pole tooth, a first groove region 132 located in the tooth portion, and a second groove region 133 between the groove opening and the first groove region. The maximum width of the first groove region is larger than the maximum width of the second groove region, and the maximum width of the groove opening is smaller than or equal to the maximum width of the second groove region. The structure in which the groove opening is smaller than the maximum groove width of the first groove region reduces the possibility that the resin present in the auxiliary groove falls out after filling.

Description

Technical Field

[0001] The present invention relates to a motor, and more particularly to a stator auxiliary groove structure and a stator having a plurality of stator auxiliary grooves.

Background Art

[0002] By means of a technical means of providing a notch groove at the tip of the stator teeth of a motor, the air gap permeance distribution in the tip region is changed, and a modulation and cancellation effect on the harmonics of the cogging torque is produced, thereby reducing the cogging torque and torque ripple, obtaining an effect of suppressing electromagnetic vibration and noise, which is a technical means adopted in the motor technology field.

[0003] The effects of the change in the air gap permeance distribution due to the notch groove shapes at the tips of different stators are also different, which also affects the effects after the optimization of the motor structure. For example, in Patent Document 1, by using an arc-shaped groove bottom, the concentration of eddy currents is prevented, aiming at reducing local overheating and material fatigue. However, due to the adoption of a gradually expanding taper shape at the groove opening, resin dropout is likely to occur after resin injection. Furthermore, in various notch groove shapes at the tips of the stator teeth disclosed in Patent Document 2, there are also drawbacks such as easy resin dropout.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Therefore, the main object of the present invention is to provide a stator auxiliary groove structure that reduces the possibility of resin falling out of the auxiliary grooves under the resin injection structure of the motor.

Means for Solving the Problem

[0006] Therefore, in order to achieve the above object, the stator auxiliary groove structure provided by the present invention optimizes the auxiliary groove disposed at the end facing the gap of the stator pole teeth. In particular, the auxiliary groove is divided into a groove opening formed at the tooth tip portion of the end facing the gap of the tooth portion of the pole teeth, a first groove region located in the tooth portion, and a second groove region between the groove opening and the first groove region. The maximum width of the first groove region is larger than the maximum width of the second groove region, and the maximum width of the groove opening is smaller than or equal to the maximum width of the second groove region. The structure in which the groove opening is smaller than the maximum groove width of the first groove region reduces the possibility that the resin present in the auxiliary groove falls out after filling.

[0007] Furthermore, the groove wall of the first groove region presents a major arc shape, is adjacent to both sides of one end of the second groove region through two end points of the arc respectively, and the outer angle between the tangent at one end point of the arc of the groove wall of the first groove region and the adjacent groove wall of the second groove region is 120 degrees to 152 degrees. Thus, the groove wall of the first groove region can be aligned with the resin in the auxiliary groove to provide better support, enhance the fixing effect of the resin, and reduce the possibility of the resin falling out.

[0008] Another object of the present invention is to effectively reduce torque by the stator auxiliary groove structure. To achieve this object, the shape of the auxiliary groove can satisfy any of the following formulas.

[0009]

Number

[0010] In the above formulas, L1 is the maximum value of the width of the first groove region, L2 is the maximum value of the width of the second groove region, and L3 and L4 divide the depth of the auxiliary groove into a first depth portion (L3) and a second depth portion (L4) with the geometric center of the second groove region as a virtual division point. The first depth portion is from the division point to the groove opening position, and the second depth portion is from the division point to the groove bottom wall of the auxiliary groove.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0012] Hereinafter, several preferred embodiments of the present invention will be specifically described with reference to the drawings.

[0013] First, please refer to FIG. 1. In a preferred embodiment of the present invention, the stator auxiliary groove structure is provided at the end surface of each of the plurality of pole teeth 12 protruding on the annular stator yoke 11 facing the gap, and can be provided on all or part of the pole teeth according to the actual product requirements. The plurality of pole teeth 12 are respectively connected to the stator yoke 11 via the tooth roots, and are arranged radially around the center of curvature of the stator yoke 11.

[0014] For the sake of convenience of explanation, the present invention will first explain the stator auxiliary groove structure using a single pole tooth 12 shown in FIG. 2. The stator auxiliary groove structure includes the pole tooth 12 and an auxiliary groove 13.

[0015] Referring to FIG. 1 in combination, the pole tooth 12 is used for providing a motor coil winding, includes a tooth portion 121 having an appropriate length, and is connected to the stator yoke 11 through a tooth root 122 at one end of the long axis. The length direction is defined as the long axis. The first side 123 and the second side 124 are on opposite sides, located on both sides of the long axis of the tooth portion 121. The width direction W is defined between the first side 123 and the second side 124, and the distance between the first side 123 and the second side 124 is defined as the tooth width t of the tooth portion 121. The tooth tip portion 125 is located at an end facing the gap at the other end of the long axis of the tooth portion 121.

[0016] The auxiliary groove 13 is recessed inward from the tooth tip portion 125 and provided in the tooth portion 121, so that a groove opening 131 is formed on the tooth tip portion 124, and is divided into a first groove region 132 and a second groove region 133 according to the size of the groove width in the width direction W. The second groove region 133 is interposed between the groove opening 131 and the first groove region 132. The maximum groove width L2 of the first groove region 132 in the width direction W is made larger than the maximum groove width L1 of the second groove region 133 in the width direction W. The maximum groove width and the minimum groove width of the second groove region 133 shown in FIG. 2, and the maximum groove width and the minimum groove width of the groove opening 131 are all the same. However, this is only a specific realizable example of the present invention and is not used with the intention of limiting the present invention.

[0017] By restricting the groove width of the groove opening 131 to be narrower than the groove width of the first groove region 132, after filling the motor stator with insulating resin, the resin filled in the groove is restricted by the small opening and is less likely to fall out, so that the occurrence of resin shedding can be prevented.

[0018] Furthermore, when the resin 14 in the groove is heated and deformed, in order to prevent the generation of cracks due to stress concentration, in the present embodiment, as shown in FIG. 3, the groove wall of the first groove region 132 is formed in a convex arc shape, and both ends of the arc are connected to both sides of one end of the second groove region 133, thereby increasing the area for supporting the resin. In particular, in the portion of the first groove region 132 adjacent to the second groove region 133, when the resin 14 is heated and expands through the arc surface, the deformation pressure is dispersed, the stress of the resin in the adjacent portion is reduced, and cracks in the resin 14 are avoided. Furthermore, as shown in the example of FIG. 4, the arc of the first groove region 132 can be a circular arc, a combined arc or an elliptical arc, and the external angle θ between the tangent line at one end point of the arc of the groove wall of the first groove region 132 and the adjacent groove wall of the second groove region 133 is set to 120 degrees to 152 degrees. The so-called combined arc is a smooth curve formed by connecting two circular arcs in the same tangent direction.

[0019] In the effect of reducing cogging torque, in the present embodiment, the groove width L2 in the first groove region 132 of the auxiliary groove 13 and the groove width L1 of the second groove region 133 satisfy the following formula (I), and the groove width of the groove opening 131 is smaller than or equal to one-third of the tooth width.

[0020]

Equation

[0021] Taking the geometric center of the first groove region 132 as the division point d, the groove depth of the auxiliary groove 13 is divided into a first depth part L3 and a second depth part L4. The first depth part L3 is the distance from the division point d to the groove opening 131, and the second depth part L4 is the distance from the division point d to the groove bottom wall 134 of the auxiliary groove, and the following formulas II and III are satisfied.

[0022]

Equation

[0023] Please continue to refer to FIG. 5. In a preferred embodiment of the present invention, when the shape of the auxiliary groove 13 satisfies the conditions of L1 = 0.5 mm, X1 = 0.85, Y1 = 1, L = 0.5, and θ = 146°, the cogging torque achieved is 6.6 mNm, which has a remarkable cogging torque reduction effect compared with 8.25 mNm achieved in Patent Document 1 of the prior art and 13.23 mNm achieved in Patent Document 2.

[0024] In addition to the shape of the auxiliary groove under the above specific conditions, the present invention can also have other different embodiments as shown in the following table. Number 1 is the specific numerical value of the above embodiment, and numbers 2 and below are those of other possible embodiments.

[0025]

Table 1

[0026] Obviously, in other embodiments of the present invention, under different conditions, the achieved cogging torque reduction effect is also remarkable. For example, in No. 3 of the above table, when the shape of the auxiliary groove satisfies L1 = 0.5 mm, X1 = 0.85, Y1 = 0.5, L = 0.5, and θ = 146°, the achieved cogging torque is 4.7 mNm, which is better than the above. As described in the above table, in other possible embodiments, since the angle range of the outer corner θ is 120° - 146°, the cogging torque can be effectively reduced. In addition, although the angle range of the outer corner θ is 146° - 152° and is not described in the above table, structurally, the object and effect of the present invention can be fully achieved.

[0027] In addition to the structure in which a single auxiliary groove is provided on a single pole tooth disclosed in the above embodiment example, a plurality of auxiliary grooves may be provided on a single pole tooth. For example, as shown in FIG. 6, two auxiliary grooves 13a that are symmetric and have the same shape and size may be provided on a single tooth portion 121a. Or, as shown in FIG. 7, two auxiliary grooves 13b and 13c that are symmetric but have different shapes and / or sizes may be provided on a single tooth portion 121b. Both can achieve the effect of reducing the cogging torque.

[0028] Furthermore, with respect to the entire stator, in addition to the plurality of auxiliary grooves being selectively provided in some or all of the pole teeth, different types of auxiliary grooves can be regularly combined and used, such as arranging single-groove types and double-groove types alternately or separately. These are other embodiments in which the present invention can be implemented.

Explanation of Signs

[0029] 11 Stator yoke 12 Pole teeth 121 121a 121b Tooth part 122 Tooth root 123 First side 124 Second side 125 Tooth tip 13 13a 13b 13c Auxiliary groove 131 Groove opening 132 First groove region 133 Second groove region 134 Groove bottom wall 14 Resin d Split point L1 Groove width of the first groove region L2 Groove width of the second groove region L3 First depth part L4 Second depth part t Tooth width W Width direction θ Outer angle

Claims

1. a tooth portion (121) having a predetermined length; a first side (123) and a second side (124) located on both sides of the long axis of the tooth portion (121), the width direction (W) being defined between the first side (123) and the second side (124), and the distance between the first side (123) and the second side (124) being defined as a tooth width (t); a tooth tip portion (125) located at one end of the long axis of the tooth portion (121); An auxiliary groove (13) formed in the tooth tip (125) to form a groove opening (131); A stator auxiliary groove structure comprising: The auxiliary groove (13) further comprises a first groove region (132) and a second groove region (133) interposed between the groove opening (131) and the first groove region (132), and in the width direction (W): The maximum width of the first groove region (132) is greater than the maximum width of the second groove region (133); The maximum width of the groove opening (131) is equal to or smaller than the maximum width of the second groove region (133); The groove wall of the first groove region (132) has a major arc shape, and is adjacent to both sides of one end of the second groove region (133) via two end points of the arc, respectively; The external angle between a tangent at one end point of the arc of the groove wall of the first groove region (132) and an adjacent groove wall of the second groove region (133) is 120 degrees to 152 degrees. A stator auxiliary groove structure characterized by:

2. The stator auxiliary groove structure of claim 1, wherein the minimum width and the maximum width of the second groove region (133) are the same.

3. 2. The stator auxiliary groove structure according to claim 1, wherein the maximum width of the groove opening (131) is equal to or less than one-third of the tooth width (t).

4. 2. The stator auxiliary groove structure of claim 1, wherein the maximum width of the second groove region (133) is greater than one-third of the maximum width of the first groove region (132).

5. The auxiliary groove (13) has a depth, and is defined with the geometric center of the arc of the first groove region (132) as a dividing point (d), and the depth is from the dividing point (d) to the groove opening (131) as a first depth part (L ３ ), and from the dividing point (d) to the groove bottom wall (134) of the auxiliary groove (13) as a second depth part (L ４ ), and the first depth part (L ３ ) is made larger than or equal to the second depth part (L ４ ). The stator auxiliary groove structure according to claim 1.

6. The value of the second depth part (L ４ ) is half of the value of the first depth part (L ３ ), and the auxiliary stator groove structure according to claim 5.

7. The value (L ４ of the second depth part (L ４ and the maximum value (L ２ of the width of the first groove region (132) both satisfy the following formula. The stator auxiliary groove structure according to claim 5. 【Number 1】

8. 8. The stator auxiliary groove structure of claim 1, 5, 6 or 7, wherein the arc of the first groove region (132) is a circular arc, a compound arc or an elliptical arc.

9. 8. The stator auxiliary groove structure according to claim 1, wherein the auxiliary grooves (13) are plural and arranged symmetrically on the tooth portion (121), and the groove openings (131) formed on the tooth tip portions (125) are not connected to each other.

10. The structure of the stator auxiliary groove according to claim 8, wherein the number of the auxiliary grooves (13) is plural, they are symmetrically arranged on the tooth portion (121), and the groove openings (131) formed on the tooth tip portion (125) are not communicated with each other.

11. A stator yoke (11), The structure of the stator auxiliary groove according to claim 1, which is arranged at equal intervals from each other and fixed to the stator yoke (11) through the tooth roots (122) at the other ends of the major axes of the plurality of tooth portions (121), A plurality of coil windings respectively wound on each of the tooth portions (121), An insulating resin filled in the space of the plurality of auxiliary grooves (13) between the tooth portions (121) A stator comprising.

Images