Installation structure for stator core for axial gap motor

Abstract

To provide an installation structure for a stator core for axial gap motors capable of accurately positioning and installing a stator core without adding such a configuration as to may exert an adverse effect on a magnetic circuit to the stator core in the installation structure for the stator core for axial gap motors.SOLUTION: An annular stator core 10 comprises six arcuate split stator teeth 12. On an outer peripheral surface 12a and an inner peripheral surface 12b of each of the split stator teeth 12, tapered parts 13 and 15 are provided in such a manner that a separation interval between an outer peripheral wall part 16a and an inner peripheral wall part 16b of a stator plate 16 becomes wider toward a rotor side. Each of the split stator teeth 12 is loaded onto the stator plate 16 in such a state that the tapered parts 13 and 15 are locked by lock members 18, 20 and 22 which are fixed to the stator plate 16.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an installation structure for a stator core for an axial gap motor, and more particularly to an installation structure for a stator core for an axial gap motor consisting of a plurality of pieces. [Background technology]

[0002] In recent years, the use of axial gap motors, which are capable of being made thinner and have higher output, has been expanding in places where they can replace conventional radial gap motors. An axial gap motor has a structure in which a circular stator core and a rotor that rotates around the axis of the stator core face each other on one or both sides in the axial direction.

[0003] The stator core of an axial gap motor may use a pressed powder core, which involves a process of filling a die with soft magnetic powder and pressurizing it, instead of the electronic steel sheet used in radial gap motors. The use of a pressed powder core increases the freedom of shape, making it possible to configure a good three-dimensional magnetic circuit.

[0004] Fig. 11 shows a stator core disclosed in Patent Document 1. As shown in Fig. 11, stator core 30 is configured by arranging stator teeth 32 divided into a plurality of (six in this example) pieces in an annular shape. A hole 38 is formed in the center of stator core 30, through which the rotating shaft of a rotor is inserted. Each split stator tooth 32 has two teeth 34 protruding toward the rotor. Split stator teeth 32 are fixed to a housing using through holes 36 formed in each split stator tooth 32, and this fixing is performed by using fixing members such as screws in these through holes 36.

[0005] In an axial gap motor, a coil is wound around each tooth portion 34, and magnetic poles are formed on the surfaces of the teeth portion 34. The rotor can be rotated by these magnetic poles and the polarity of a magnet arranged on the rotor. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] WO2020 / 059517 publication Summary of the Invention [Problem to be solved by the invention]

[0007] In the stator core 30 disclosed in Patent Document 1, as described above, the split stator teeth 32 are fixed to the lid of the housing or the stator plate by passing screws through the through holes 36. However, forming the through holes 36 in the stator core 30 is not preferable in consideration of the effect on the magnetic circuit, and reducing the effect of the through holes 36 would result in the stator core 30 becoming larger in size and more complicated.

[0008] In addition, because split stator teeth 32 are dust cores that involve the process of filling a die with soft magnetic powder and pressurizing them as described above, forming holes for screws in split stator teeth 32 and fastening them with screws poses a problem in terms of strength and durability of the split stator teeth due to the brittleness of the material. Another problem is that the number of manufacturing and assembly steps increases.

[0009] Furthermore, in an axial gap motor, the positional relationship between the teeth of the stator core and the magnet of the rotor is important, so it is important to accurately position and fix the stator core to the stator plate, but it is difficult to achieve accurate positioning when fixing the stator core with screws. For example, when creating screw holes for fixing the split stator teeth to the stator plate with screws, if the positions are misaligned, accurate positioning is immediately impossible. Therefore, the inability to achieve accurate positioning also causes the problem that the performance of the axial gap motor cannot be maximized.

[0010] The present invention has been made in consideration of the above problems, and its object is to provide an installation structure for a stator core for an axial gap motor, which can install the stator core in an accurate position without adding any structure to the stator core that would adversely affect the magnetic circuit. [Means for solving the problem]

[0011] In order to achieve the above object, an installation structure of a stator core for an axial gap motor according to one embodiment of the present invention comprises: A stator core installation structure for an axial gap motor includes an annular stator core in which teeth divided into a plurality of pieces are assembled in an annular shape to have a hole in the center, and an annular stator plate having an outer circumferential wall portion and an inner circumferential wall portion at an outer circumferential edge and an inner circumferential edge, respectively, and the annular stator core is provided with a pair of stators each formed by fitting the outer circumferential wall portion and the inner circumferential wall portion of the stator plate, and a rotor is provided between the pair of stators and rotates about an axis centered on the center of the hole, the annular stator core is composed of a plurality of arc-shaped divided stator teeth, and an outer peripheral surface and an inner peripheral surface of each divided stator tooth are provided with tapered portions such that a separation distance between the outer peripheral wall portion and the inner peripheral wall portion of the stator plate becomes wider toward the rotor side, The split stator teeth are mounted on the stator plate with the respective tapered portions locked by locking members fixed to the stator plate.

[0012] According to this configuration, the outer peripheral surface and the inner peripheral surface of each split stator tooth are provided with tapered portions, and the locking member is brought into contact with the tapered portions to restrict the movement of the stator core. That is, the tapered portions are inclined so that the separation distance between the outer peripheral wall portion and the inner peripheral wall portion of the stator plate becomes wider toward the rotor side, and each split stator tooth is locked at the tapered portions by the locking member fixed to the stator plate. This locking can be easily achieved, for example, by the locking member being brought into contact with the tapered portions, and this contact restricts the movement of each split stator tooth toward the rotor side. Furthermore, the locking member is not required to be precisely set in the locking position to be engaged with the tapered portions as long as the tapered portions are present, and the locking member is easily brought into contact with the tapered portions.

[0013] This means that the stator core does not need to have through holes for fixing, so the characteristics of the magnetic circuit are not impaired. Also, the stator core can be fixed more firmly by providing a sufficient number of locking points. Effect of the Invention

[0014] According to the installation structure of the stator core for an axial gap motor of the present invention, it is possible to fix the stator core and accurately position the stator core on the stator plate at the same time without adding any structure that impairs the function of the stator core. It is also possible to simultaneously solve the strength and durability issues that arise when using pressed powder for the stator core, thereby achieving high performance of the axial gap motor. [Brief description of the drawings]

[0015] [Figure 1] 1 is a perspective view showing an embodiment of a stator core installation structure for an axial gap motor according to the present invention; [Diagram 2] FIG. 2 is a plan view of FIG. [Diagram 3] 3 is a cross-sectional view taken along line AA in FIG. 2. [Figure 4] FIG. 4 is a partially enlarged cross-sectional view of FIG. [Diagram 5] 2 is a perspective view of a divided stator tooth of the stator core shown in FIG. 1. [Figure 6] FIG. 2 is a perspective view of the stator plate shown in FIG. [Figure 7] 7 is a cross-sectional view taken along line CC of the stator plate shown in FIG. 6. [Figure 8] 6 shows a cross-sectional view of the split stator tooth shown in FIG. 5 along a line B-B. [Figure 9] FIG. 2 is a perspective view of the arc-shaped fastener shown in FIG. [Figure 10] 10 is a cross-sectional view taken along line DD of the arc-shaped fastener shown in FIG. 9 . [Figure 11] FIG. 2 is an explanatory diagram of a stator core of Patent Document 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a mounting structure for a stator core for an axial gap motor according to the present invention will be described below with reference to the accompanying drawings.

[0017] Fig. 1 is a perspective view of a stator core 10 for an axial gap motor according to this embodiment mounted on a stator plate 16, Fig. 2 is a plan view thereof, and Fig. 3 is a cross-sectional view taken along line AA in the plan view of Fig. 2. Fig. 4 is an enlarged cross-sectional view of a portion of the cross-sectional view of Fig. 3. The stator core 10 is formed in an annular shape with six split stator teeth 12 (described later), and is attached to a stator plate 16 which is also formed in an annular shape by fastening members (described later).

[0018] As shown in the figure, in this embodiment, an annular stator core 10 is formed by six split stator teeth 12. Fig. 5 shows one of these stator teeth 12, each of which is formed in an arc shape when viewed from above, with three teeth portions 14 provided on the upper surface. These split stator teeth 12 are formed by filling a die with soft magnetic powder and applying pressure to the powder, and a coil is wound around each tooth portion 14 and a voltage is applied to form a magnetic circuit.

[0019] A hole 28 is provided in the center of stator core 10, in which the split stator teeth 12 are assembled in a circular ring shape, and the rotation axis of the rotor is positioned at the center of this hole 28. A rotor, not shown, is positioned opposite stator core 10.

[0020] Fig. 6 is a perspective view of stator plate 16, and Fig. 7 is a cross-sectional view taken along line CC thereof. Stator core 10 is fixed onto stator plate 16. As shown in the figure, stator plate 16 is formed in an annular shape and made of a non-magnetic material such as aluminum. An outer peripheral wall portion 16a and an inner peripheral wall portion 16b are formed on the outer peripheral edge and the inner peripheral edge, respectively, and recesses 16c are formed between these walls for mounting split stator teeth 12.

[0021] Fig. 8 is a B-B cross-sectional view of split stator teeth 12 shown in Fig. 5, in which tapered portion 13 is provided on outer peripheral surface 12a, which is the outermost periphery of one of split stator teeth 12. The inclination (angle α°) of tapered portion 13 is such that the separation distance from outer peripheral wall portion 16a of the opposing stator plate 16 becomes wider toward the opposing rotor side (the inclination gradually becomes wider toward the upper side in the drawing). Also, tapered portion 15 is provided on inner peripheral surface 12b, which is the innermost periphery of split stator tooth 12, and the inclination (angle β°) of tapered portion 15 is also such that the separation distance from inner peripheral wall portion 16b of the opposing stator plate 16 becomes wider toward the opposing rotor side (the inclination gradually becomes wider toward the upper side in the drawing).

[0022] Next, a description will be given of how each split stator tooth 12 is attached to recess 16c of stator plate 16 using a locking member. For locking on the inner circumference side, fastening screws 22 shown in Figures 1, 3, and 4 are used. For locking on the outer circumference side, fastening fittings 18, fastening bolts 20, and fastening screws 22 shown in Figures 1, 3, and 4 are used.

[0023] First, split stator teeth 12 are loaded into recesses 16c of stator plate 16, and the tips of fastening screws 22 abut against tapered portions 15 of the loaded split stator teeth 12, thereby locking them on the inner circumferential side. Fastening screws 22 are screwed into fastening screw holes 16e formed in inner circumferential wall portion 16b of stator plate 16, and their tips abut against tapered portions 15. The abutment of fastening screws 22 against tapered portions 15 restricts the movement of split stator teeth 12 upward in FIG.

[0024] That is, the locking structure is formed simply by forming through holes 16e, through which fastening screws 22 are passed, in inner circumferential wall portion 16b of stator plate 16. Then, by passing fastening screws 22 through the locations of inner circumferential wall portion 16b facing tapered portions 13 of split stator teeth 12 and directly abutting their tips against tapered portions 15, movement of each split stator tooth 12 toward the rotor can be restricted, and a stable installation state can be obtained.

[0025] Next, locking on the outer periphery side will be described. First, fastening fitting 18 serving as an intermediate member is fitted into the gap between outer periphery surface 12a of each split stator tooth 12 and outer periphery wall portion 16a of stator plate 16.

[0026] Fig. 9 shows the configuration of this fastener 18, and Fig. 10 shows a DD cross-sectional view of the arc-shaped fastener shown in Fig. 9. The fastener 18 is made of a non-magnetic material such as aluminum, and is formed in an arc shape to fit the gap between the outer peripheral wall portion 16a of the stator plate 16 and the outer peripheral surface 12a of the split stator teeth 12, which is arc-shaped in a plan view, as shown in the figure. What is important is that a tapered portion 19 is provided on an inner peripheral surface 18c of the fastener 18. The inclination of the tapered portion 19 is set so that when the fastener 18 is fitted into the gap between the outer peripheral wall portion 16a of the stator plate 16 and the outer peripheral surface 12a of the split stator teeth 12, the fastener 18 comes into close contact with the tapered portion 13 of the outer peripheral surface 12a of the split stator teeth 12. That is, the inclination (angle γ°) of tapered portion 19 is configured to be substantially equal to the inclination (angle α°) of tapered portion 15 of outer circumferential surface 12a of split stator tooth 12.

[0027] Fastening bolts 20, which are threaded members, penetrate through the fastening fittings 18 and are screwed into the stator plate 16 to be fixed, thereby ensuring a stable contact state of the fastening fittings 18 with the tapered portions 13 of the split stator teeth 12. Therefore, the direction in which the fastening bolts 20 are screwed into the stator plate 16 can be different from the direction in which the fastening fittings 18 contact the tapered portions, expanding the variety of applications of the locking structure using the fastening bolts 20. The locking structure that uses the fastening fittings 18 also accurately restricts the movement of each of the split stator teeth 12 toward the rotor.

[0028] As described above, according to the installation structure of stator core 10 for an axial gap motor according to this embodiment, outer peripheral surface 12a and inner peripheral surface 12b of split stator teeth 12 are provided with tapered portions 13, 15, respectively, in which the separation distance between outer peripheral wall portion 16a and inner peripheral wall portion 16b of stator plate 16 becomes wider toward the rotor side. Therefore, fastening fitting 18 serving as an intermediate member fixed to stator plate 16 by fastening bolt 20 abuts against outer peripheral surface 12a of split stator teeth 12, and the tip of fastening screw 22 similarly fixed to stator plate 16 abuts against inner peripheral surface 12b of split stator teeth 12, thereby obtaining a stable fixed state.

[0029] Therefore, although through holes and recesses for attaching fastening members are formed in stator plate 16, no additional structure is created in stator core 10 itself. In this state, the fastening members are directly or indirectly abutted against tapered portions 13, 15 of split stator teeth 12, so that movement of each split stator tooth 12 toward the rotor is restricted, and adverse effects on the magnetic circuit and other problems that could cause functional degradation are avoided.

[0030] Furthermore, it is possible to accurately position and fix the stator core 10 to the stator plate 16 without adding any structure that impairs the function of the stator core 10. This also achieves high performance of the axial gap motor.

[0031] The present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention. For example, although the number of split stator teeth 12 is six in the above embodiment, the present invention can be applied to configurations with other numbers. [Explanation of symbols]

[0032] 10 Stator core 12 split stator teeth 12a Outer surface 12b Inner surface 13, 15, 19 Tapered section 14 Teeth 16 Stator plate 16a Outer wall 16b Inner peripheral wall 16c Recess 16e Fastening screw hole 16f Fastening bolt hole 18 Arc-shaped fastener 18a Bolt Through Hole 18b Inner surface 18c Outer surface 20 Fastening bolt 22 Fastening screw 28 Rotating shaft hole 30 Stator core of Patent Document 1 32 split stator teeth 34 Teeth 36 Through hole 38 Rotating shaft hole

Claims

1. A stator core installation structure for an axial gap motor includes an annular stator core in which teeth divided into a plurality of pieces are assembled in an annular shape to have a hole in the center, and an annular stator plate having an outer circumferential wall portion and an inner circumferential wall portion at an outer circumferential edge and an inner circumferential edge, respectively, and the annular stator core is provided with a pair of stators each formed by fitting the outer circumferential wall portion and the inner circumferential wall portion of the stator plate, and a rotor is provided between the pair of stators and rotates about an axis centered on the center of the hole, the annular stator core is composed of a plurality of arc-shaped divided stator teeth, and an outer peripheral surface and an inner peripheral surface of each divided stator tooth are provided with tapered portions such that a separation distance between the outer peripheral wall portion and the inner peripheral wall portion of the stator plate becomes wider toward the rotor side, A stator core installation structure for an axial gap motor, characterized in that each of the split stator teeth is loaded onto the stator plate with each tapered portion engaged by a locking member fixed to the stator plate.

2. The locking structure of the split stator teeth by the locking member is as follows:

2. An installation structure for a stator core for an axial gap motor as described in claim 1, characterized in that it is composed of fastening members that, when fastened to the stator plate, are in direct or indirect contact with the tapered portions of the split stator teeth.

3. The structure for locking the split stator teeth by the fastening members is as follows:

3. An installation structure for a stator core for an axial gap motor as described in claim 2, characterized in that it is composed of a screw member that penetrates the inner wall portion of the stator plate from the outside thereof and has a tip that abuts against the tapered portion of the split stator tooth.

4. The structure for locking the split stator teeth by the fastening members is as follows:

3. An installation structure for a stator core for an axial gap motor as described in claim 2, characterized in that it is composed of an intermediate member that is arranged between the outer peripheral wall portion of the stator plate and the tapered portion of the split stator tooth and abuts against the tapered portion, and a screw member that penetrates the intermediate member and is screwed into the stator plate.

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