TW202203557A - Motor component and magnet fixing method capable of fixing a magnet to a predetermined position of a slit hole with good positional accuracy - Google Patents

Abstract

The present invention provides a motor component capable of fixing a magnet to a predetermined position of a slit hole with good positional accuracy, with the adhesive for fixing the magnet to the predetermined position of the slit hole being difficult to ooze out to the part outside the predetermined position. A rotor 3 or a stator 2 of a motor 1, that is, the motor component, includes a slit hole 10 extending parallel to the rotation axis O of the rotor 3, a magnet 6 inserted into the slit hole 10, and a resin sheet 7 for bonding the magnet 6 to the slit hole 10. The slit hole 10 includes a first surface 10A on which a positioning portion 11 for limiting the position of the magnet 6 is provided, and a second surface 10C on the opposite side of the first surface 10A. The magnet 6 is abutted against the first surface 10A, and the resin sheet 7 is disposed between the magnet 6 and the second surface 10C.

Description

Motor parts and magnet fixing method

The present invention relates to a motor part and a magnet fixing method suitable for the motor part.

As a method of fixing magnets to the rotor core or stator core of a motor, transfer mold molding is known, that is, forming a slit hole larger than the magnet in the rotor core or the like, inserting the magnet, and filling the gap with a thermosetting resin to fix the magnet. In this method, the smaller the gap between the slit hole and the magnet, the more difficult it is for the resin to flow, and the easier it is for unfilled parts to occur. Every time the design of the motor is changed, the transfer molding die is produced, which increases the cost.

Therefore, Patent Document 1 proposes a heating foam sheet for bonding a magnetic member of a motor, which is formed into a sheet shape using a resin composition containing a foaming agent, and is formed in a sheet shape by interposing a magnetic field between a housing hole of a rotor core for a motor and a magnetic field. It heats and foams in the state in the clearance gap of a member, and the thickness increases, and it adheres to the magnetic member on one surface side, and adheres to the receiving hole on the other surface side. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2007-174872

[Problems to be Solved by Invention]

However, the heating foam sheet for motor magnetic member bonding disclosed in Patent Document 1 is wound around the entire circumference of the magnetic member. Since the storage hole and the magnetic member do not directly contact each other, it is difficult to fix the magnetic member to the storage hole with good positional accuracy. In addition, since the heating foam sheet for bonding a motor magnetic member expands in all directions, it is difficult to leave a space only at a predetermined portion of the housing hole.

Therefore, an object of the present invention is to provide a magnet that can be fixed to a predetermined position of a slit hole with good positional accuracy, and an adhesive that fixes the magnet to the predetermined position of the slit hole is unlikely to ooze out to a predetermined position. Motor parts and a magnet fixing method suitable for the motor parts. [means to solve the problem]

A motor part of one aspect of the present invention is a rotor or a stator of a motor. The motor parts include a slit hole extending parallel to the rotation axis of the rotor, a magnet inserted into the slit hole, and a resin sheet for adhering the magnet to the slit hole. The slit hole includes a first surface on which a positioning portion for regulating the position of the magnet is provided, and a second surface on the opposite side of the first surface. The magnet is in contact with the first surface, and the resin sheet is disposed between the magnet and the second surface.

According to this aspect, since the magnet is in direct contact with the first surface of the slit hole in which the positioning portion is provided, the magnet can be fixed with good positional accuracy. The resin sheet is arranged between the magnet and the second surface, but is not arranged at other locations. Even if the resin sheet swells, it is difficult to ooze out to parts other than between the magnet and the second surface.

A magnet fixing method according to one aspect of the present invention is a method of fixing a magnet using a resin sheet in a slit hole provided in a rotor core or a stator core of a motor. The slit hole includes a first surface and a second surface opposite to the first surface. The magnet fixing method includes: inserting the magnet into the slit hole, and first heating (mainly heating) the resin sheet disposed between the second surface of the slit hole and the magnet, so that the resin sheet is expanded and the magnet is pressed against the magnet. connected to the first surface, and the magnet is abutted to the second surface. It further includes: before inserting the magnet into the slit hole, the resin sheet is subjected to a second heating (preheating) at a lower temperature than the normal heating, and the preheated resin sheet is attached to the magnet or the slit hole.

According to this aspect, the resin sheet is temporarily fixed to the second surface of the magnet or the slit hole by generating the adhesive force by preheating. Since the resin sheet can be correctly arranged between the magnet and the second surface, when the resin sheet is expanded by the main heating, the resin sheet is less likely to ooze out to a portion other than between the magnet and the second surface.

In the above-mentioned form, the resin sheet may include a pair of release liners covering both surfaces of the resin sheet. Before inserting the magnet into the slit hole, one of the release liners may be peeled off from the resin sheet, and the other release liner may be pressed to attach the resin sheet to the magnet. Alternatively, before inserting the magnet into the slit hole, one of the release liners may be peeled off from the resin sheet, and the other release liner may be pressed to attach the resin sheet to the second surface.

According to this aspect, the resin sheet can be temporarily fixed to the magnet or the slit hole by pressing the release liner without being in direct contact with the resin sheet to which the adhesive force has been generated by preheating. It is difficult for impurities such as dust to adhere to the resin sheet. [Inventive effect]

According to the present invention, it is possible to provide a motor component and a magnet fixing method suitable for the motor component, capable of fixing a magnet to a predetermined portion of a slit hole with good positional accuracy, and fixing the magnet to a predetermined portion of the slit hole. It is difficult for the adhesive to ooze out to areas other than specified.

Preferred embodiments of the present invention will be described with reference to the accompanying drawings. In addition, in each figure, the member which attached|subjected the same code|symbol includes the same or the same structure. Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing an example of a motor according to an embodiment of the present invention.

As shown in FIG. 1 , a motor (electric motor) 1 includes a stator (stator) 2 , a rotor (rotator) 3 , and a casing and bearings not shown. The motor 1 is connected to, for example, an external drive unit or the like. The drive unit rotates the rotor 3 relative to the stator 2 by supplying electric power to the motor 1 and controlling the timing of supplying the electric power.

The stator 2 includes a stator core (stator core) 20 . The rotor 3 includes a rotor core (rotor core) 30 . In the following description, the stator iron core 20 and the rotor iron core 30 may be collectively referred to as motor iron cores (iron cores) 20 and 30 . The motor iron core 20 and the motor iron core 30 are formed by laminating, for example, electromagnetic steel sheets punched by a die. The material of the motor iron core 20 and the motor iron core 30 is not limited to the laminated electromagnetic steel sheet, and may be a single electromagnetic steel sheet or a powder magnetic core or the like.

The structure of the motor 1 may be an inner rotor type or an outer rotor type. In the illustrated example, the motor 1 is of an inner rotor type, the rotor core 30 is formed in a substantially cylindrical shape, and the stator core 20 is formed in a substantially cylindrical shape larger than the rotor core 30 by one turn. When the motor 1 is configured as an outer rotor type, the stator core 20 may be formed into a substantially cylindrical shape, and the rotor core 30 may be formed into a substantially cylindrical shape larger than the stator core 20 .

In the illustrated example, the stator core 20 includes a back yoke portion 21 formed in a substantially cylindrical shape, and a plurality of tooth portions 22 protruding from the back yoke portion 21 toward the rotor 3 . The front end of the tooth portion 22 faces the rotor 3 with a slight air gap.

In the illustrated example, the stator 2 includes a plurality of winding wires 4 in addition to the stator core 20 . The respective winding wires 4 are electromagnetic wires (wires for winding wires) such as enameled wires wound around the bobbin 5 or the like, and are connected to each other to generate a magnetic field. The bobbin 5 is formed of an insulating material, and is fitted to the teeth portion 22 .

In the illustrated example, the rotor 3 includes, in addition to the rotor core 30 , the magnets 6 fixed in the slit holes 10 of the rotor core 30 . The structure of the stator 2 and the rotor 3 is not limited to the example shown in figure. For example, the winding wire 4 may be formed on the rotor core 30 , and the slit hole 10 may be formed on the stator core 20 , so that the magnet 6 is fixed to the slit hole 10 .

Hereinafter, referring to FIGS. 2 to 9 , the motor core 20 , the slit hole 10 of the motor core 30 , and a method of fixing the magnet 6 to the slit hole 10 will be described in detail. In addition, in the case where the slit holes 10 are formed in the stator core 20 , the slit holes 10 having substantially the same shape as in the case where the slit holes 10 are formed can also be formed in the rotor core 30 in substantially the same order. Since the magnets 6 are fixed, the slit holes 10 of the rotor core 30 shown in FIG. 1 will typically be described in detail, and the overlapping descriptions of the case where the slit holes 10 are formed in the stator core 20 will be omitted.

FIG. 2 is a cross-sectional view showing the rotor core 30 shown in FIG. 1 . As shown in FIG. 2 , a plurality of slit holes 10 are formed in the rotor core 30 . The number and arrangement of the slit holes 10 are not limited to the illustrated example. Each slit hole 10 extends parallel to the rotation axis O of the rotor 3 . The slit hole 10 penetrates the electromagnetic steel sheet constituting the rotor core 30 in the thickness direction. In the illustrated example, the rotor core 30 is formed with a small-diameter tenon hole 31 . A rod-shaped tenon is inserted into the tenon hole 31 to prevent positional displacement of the laminated electromagnetic steel sheets.

FIG. 3 is an enlarged cross-sectional view of the slit hole 10 shown in FIG. 1 . As shown in FIG. 3 , the magnet 6 is fixed to the slit hole 10 using the resin sheet 7 . In the example shown in the figure, the cross section of the magnet 6 is formed in a substantially rectangular bar shape, and includes a third surface 6A, a fourth surface 6C on the opposite side of the third surface 6A, and a space between the third surface 6A and the fourth surface 6C. Connected end face 6B, end face 6D. The cross section of the magnet 6 is not limited to the illustrated example. For example, it may be an arc shape, a substantially trapezoidal shape, or other shapes.

The slit hole 10 includes a first surface 10A, a second surface 10C opposite to the first surface 10A, and an end surface 10B and an end surface 10D connecting the first surface 10A and the second surface 10C. In the following description, the direction from one end surface (for example, end surface 10B) toward the other end surface (for example, end surface 10D) may be referred to as the longitudinal direction of the cross section of the slit hole 10 .

On the first surface 10A, a positioning portion 11 for regulating the position of the magnet 6 is formed in the longitudinal direction of the cross section of the slit hole 10 . In the illustrated example, the positioning portion 11 is formed as a recessed portion having a shape similar to the third surface 6A, the end surface 6B, and a part of the end surface 6D of the magnet 6 . The positioning portion 11 may also be a convex portion abutting against the magnet 6 .

The inner wall surface 10A, the inner wall surface 10B, the inner wall surface 10C, and the inner wall surface 10D of the slit hole 10 surround the magnet 6 from all directions without interruption. Specifically, the first surface 10A of the slit hole 10 faces the third surface 6A of the magnet 6 , and the positioning portion 11 directly abuts the third surface 6A. The second surface 10C faces the fourth surface 6C with a gap therebetween. The end surface 10B faces the end surface 6B with a gap therebetween. The end surface 10D faces the end surface 6D with a gap therebetween.

The resin sheet 7 is disposed between the second surface 10C of the slit hole 10 and the fourth surface 6C of the magnet 6 , adheres the second surface 10C and the fourth surface 6C, and presses the magnet 6 toward the positioning portion 11 . The outer shape of the resin sheet 7 is formed to have substantially the same width and length as the fourth surface 6C of the magnet 6 .

FIG. 4 is a perspective view showing the resin sheet 7 before being attached to the magnet or the slit hole. In the illustrated example, the resin sheet 7 includes a release liner 8 covering both surfaces 7A and 7C. The resin sheet 7 is formed into a sheet shape using a resin composition containing a foaming agent, and is foamed by heating in a state of being disposed between the slit hole 10 and the magnet 6, and the thickness increases, which is one of them. 7A is bonded to the magnet 6 and the other side 7C is bonded to the adhesive of the slit hole 10 .

From the viewpoint of adhesiveness and heat resistance, the base resin of the resin composition is preferably a thermosetting resin such as epoxy resin. A thermoplastic resin may be used as long as it is a material capable of withstanding the heat generated by the motor 1 . The foaming agent to be blended in the resin composition is preferably a foaming agent that generates gas at a temperature near the softening point of the base resin of the resin composition. The foaming agent may be an inorganic foaming agent, an organic foaming agent, or a thermally expandable microcapsule. Various additives, stabilizers, etc. can also be added to the resin composition as needed.

5 and 6 are diagrams for explaining an example of the magnet fixing method of the present invention. In order to fix the magnet 6 to the slit hole 10 of the motor iron core 20 and the motor iron core 30 , first, the resin sheet 7 is preheated (second heating) (step S11 ), and one of the release liners 8 is peeled off (step S12 ). In addition, the preheating may be before peeling off the release liner 8 or after peeling the release liner 8 .

In the preheating, the resin sheet 7 is heated at a temperature lower than the temperature of the main heating (first heating) for foaming the foaming agent. An example of the preheating temperature is about 60% of the main heating temperature in degrees Celsius. For example, when the base resin of the resin composition of the resin sheet 7 is an epoxy resin having a softening point of 180° C. to 200° C., in the main heating, the resin sheet 7 is heated at 200° C. or lower (for example, 180° C.) In the preheating, the resin sheet 7 is heated at 80°C to 130°C (for example, 100°C).

Next, the resin sheet 7 with the adhesive force generated by preheating is attached to the fourth surface 6C of the magnet 6 (step S13 ). The release liner 8 remaining on the resin sheet 7 is peeled off (step S14 ), and the magnet 6 is inserted into the slit hole 10 . Using the positioning portion 11 , the magnet 6 and the resin sheet 7 are arranged at a predetermined portion (the second surface 10C) of the slit hole 10 (step S15 ), and the main heating is performed to expand the resin tape 7 , and the magnet 6 is fixed to the slit hole 10 (step S16). Thereby, motor components, such as the rotor 3 shown in FIG. 1, can be obtained.

7 and 8 are diagrams illustrating another example of the magnet fixing method of the present invention. First, the resin sheet 7 is preheated (step S21 ), and one of the release liners 8 is peeled off (step S22 ). The steps up to this point are the same as the method shown in FIG. 5 . In the method shown in FIGS. 7 and 8 , the preheated resin tape 7 is attached to the second surface 10C of the slit hole 10 (step S23 ), and a release liner is removed from the resin tape in the slit hole 10 . 7 is peeled off (step S24).

When the magnet 6 is inserted into the slit hole 10 in the state where the resin tape 7 is attached, and the fourth surface of the magnet is attached (step S25 ), the main heating is performed to expand the resin tape 7 and the magnet 6 is fixed to the slit hole 10 (step S26 ), the motor components such as the rotor 3 shown in FIG. 1 can be obtained similarly to the method shown in FIGS. 5 and 6 .

The above-described embodiments are intended to facilitate understanding of the present invention, and are not to be construed to limit the present invention. Each member included in the embodiment and its arrangement, material, condition, shape, size, etc. are not limited to the examples, and can be appropriately changed. In addition, the configurations shown in the different embodiments can be partially replaced or combined with each other.

For example, in the case of using the resin tape 7 having sufficient adhesive force at room temperature, preheating can be omitted, and the resin tape 7 can be directly attached to the magnet 6 or the slit hole 10 at room temperature. For example, in the case of using the resin tape 7 that is hard at room temperature, the magnet 6 can be inserted into the slit hole 10 to form a gap between the second surface 10C of the slit hole 10 and the fourth surface 6C of the magnet 6 A resin sheet 7 is inserted into it.

In the embodiment described so far, the resin sheet 7 of the magnet 6 is pressed along the thickness direction of the magnet 6, that is, the short side direction intersecting with the long side direction of the cross section of the slit hole 10, and the magnet 6 is fixed to the slit hole 10. Slit hole 10. The direction in which the resin sheet 7 presses the magnet 6 is not limited to the thickness direction of the magnet 6 . Although not shown, the positioning portion 11 may be provided on any end face (eg, the end face 10B) of the slit hole 10 , and the resin sheet may be inserted into any other end face (eg, the end face 10D), so that the resin sheet is formed along the The magnet 6 is pressed in the longitudinal direction of the slit hole 10 .

Alternatively, as shown in FIG. 9 , in addition to the resin sheet 7 arranged on the fourth surface 6C, a resin sheet 7 ′ formed of the same material as the resin sheet 7 may be arranged on the end face 6B and the end face 6D. When the resin sheet is arranged on the three surfaces 6B, 6C, and 6D, the resin sheet 7 and the resin sheet 7 ′ are integrally formed and the resin sheet having a U-shaped (U-shaped) cross section may be attached to the magnet 6 or the magnet. Slit hole 10.

1: Motor (electric motor) 2: Stator (Stator) 3: Rotor (rotator) 4: reel 5: bobbin 6: Magnets 6A: The third side 6C: Fourth side 6B, 6D: end face 7, 7': resin sheet (resin tape) 7A, 7C: Both sides 8: Release liner 10: Slit hole 10A: The first side (inner wall) 10C: The second side (inner wall) 10B, 10D: end face (inner wall) 11: Positioning part 20: stator core (motor core) 21: Back yoke 22: Teeth 30: rotor core (motor core) 31: Mortise hole O: Rotation axis S11～S16, S21～S26: Steps

FIG. 1 is a cross-sectional view showing an example of a motor according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing the rotor core shown in FIG. 1 . FIG. 3 is an enlarged cross-sectional view of the slit hole shown in FIG. 1 . FIG. 4 is a perspective view showing a resin sheet before being attached to a magnet or a slit hole. FIG. 5 is a diagram illustrating an example of the magnet fixing method of the present invention. FIG. 6 is a flowchart illustrating an example of the magnet fixing method of the present invention following FIG. 5 . FIG. 7 is a diagram illustrating another example of the magnet fixing method of the present invention. FIG. 8 is a flowchart illustrating another example of the magnet fixing method of the present invention following FIG. 7 . FIG. 9 is a cross-sectional view showing a modification of the resin sheet shown in FIG. 3 .

6: Magnets

6A: The third side

6C: Fourth side

6B, 6D: end face

7: Resin sheet

7A, 7C: Both sides

10: Slit hole

10A: The first side

10C: Second side

10B, 10D: end face

11: Positioning part

Claims (4)

A motor part, which is the rotor or stator of a motor, comprising: a slit hole extending parallel to the rotation axis of the rotor; a magnet inserted into the slit hole; and a resin sheet, adhering the magnet to the slit hole, and The slit hole includes a first surface on which a positioning portion for regulating the position of the magnet is provided, and a second surface on the opposite side of the first surface, the magnet is in contact with the first surface, and The resin sheet is arranged between the magnet and the second surface. A magnet fixing method is a method of fixing the magnet by using a resin sheet in a slit hole provided in a rotor iron core or a stator iron core of a motor, The slit hole includes a first surface and a second surface opposite to the first surface, The method includes: inserting the magnet in the slit hole, and By first heating the resin sheet disposed between the second surface of the slit hole and the magnet, the resin sheet is expanded and the magnet is brought into contact with the first surface, and adhering the magnet to the second surface; and It further includes: before inserting the magnet into the slit hole, the resin sheet is heated at a lower temperature than the first heating for a second time, and the second heated resin sheet is attached to the the magnet or the slit hole. The magnet fixing method of claim 2, wherein the resin sheet includes a pair of release liners covering both sides of the resin sheet, and Before inserting the magnet into the slit hole, one of the release liners is peeled off from the resin sheet, and the other release liner is pressed to attach the resin sheet to the magnet . The magnet fixing method as claimed in claim 2, wherein the resin sheet includes a pair of release liners covering both sides of the resin sheet, and Before inserting the magnet into the slit hole, one of the release liners is peeled off from the resin sheet, and the other of the release liners is pressed to attach the resin sheet to the first two sides.

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