TWI747266B - Rotor and motor - Google Patents

Abstract

The invention provides a rotor (20) which includes: an iron core (21); a plurality of permanent magnets (22) which are attached to a side surface (21a) of the iron core (21) parallel to the central axis (C) by an adhesive layer (23); and a barrel-shaped reinforcing member (24) which is arranged on the outer surface of the plurality of permanent magnets (22) that have been attached to the side surface (21a) of the iron core (21). The reinforcing member (24) is a fiber reinforced plastic in which a part of fibers are oriented in the circumferential direction of the barrel shape. The ratio of the breaking elongation rate of the fibers oriented in the circumferential direction of the fiber reinforced plastic having a barrel shape to the breaking elongation rate of the adhesive layer (23) is less than twice the ratio of the thickness (t) of the adhesive layer (23) to the outer diameter (D) of the rotor (20).

Description

Rotor and motor

The present invention relates to a method for manufacturing a rotor, a motor, and a rotor that uses a fiber reinforced plastic (FRP) to cover the surface of a permanent magnet attached to an iron core.

The SPM (Surface Permanent Magnet) motor system with permanent magnets arranged on the surface has the following characteristics: it can efficiently use the strong magnetic force of the permanent magnets and the linearity of the motor torque (motor torque) Good and excellent controllability. On the other hand, when the rotor is rotated at a high speed, the permanent magnets will scatter due to centrifugal force. For this reason, a fixing method for firmly fixing the permanent magnet to the rotor is required.

Patent Document 1 discloses a rotor manufactured by the following method: a permanent magnet is fixed on the outer surface of the iron core with an adhesive, and the iron core is inserted into the cylindrical shape used to fasten the permanent magnet by press-fitting or cold sleeve. The fiber reinforced plastic.

[Prior Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent Application Publication No. 2005-312250

However, in the technique described in Patent Document 1, there is a possibility that the adhesive may break before the cylindrical fiber-reinforced plastic is broken when the rotor rotates. In this case, there will be the following problems: the permanent magnet is peeled off from the iron core, and the rotation of the rotor is out of balance, whereby the rotor will be damaged.

The present invention was developed in view of the above-mentioned problems, and its purpose is to obtain a rotor that can use the reinforcing member covering the surface of the permanent magnet as the starting point of failure before the adhesive that adheres the permanent magnet to the core during rotation is broken.

In order to solve the above-mentioned problems and achieve the objective, the rotor of the present invention is provided with: an iron core; a plurality of permanent magnets, which are adhered to the side surface of the iron core parallel to the central axis by bonding layers; and a cylindrical reinforcing member, which is It is arranged on the outer surface of a plurality of permanent magnets attached to the side of the iron core. The reinforcing member is a fiber-reinforced plastic in which a part of the fibers are aligned in the circumferential direction of the cylindrical shape. The ratio of the elongation at break of the fibers aligned in the circumferential direction of the fiber-reinforced plastic having a cylindrical shape to the elongation at break of the adhesive layer is less than twice the thickness of the adhesive layer relative to the outer diameter of the rotor.

According to the present invention, it is possible to use the reinforcing member covering the surface of the permanent magnet as the starting point of damage before the adhesive of the permanent magnet is attached to the iron core during rotation.

1: Motor

10: Stator

10a: tooth

12: Coil

20: Rotor

21: iron core

21a: side

22: permanent magnet

22a: flat surface

22b: Top surface

22c: side

23: Next layer

24: Reinforcement member

A: area

C: Central axis

D: Outer diameter

t: thickness

ε _a : The elongation at break of the adhesive layer

ε _r : the elongation at break of the fiber

Fig. 1 is a cross-sectional view showing an example of the configuration of the motor of the embodiment.

Fig. 2 is a cross-sectional view showing an example of the configuration of the rotor of the embodiment.

Figure 3 is an enlarged view of the area including the iron core, permanent magnets, and reinforcing members of Figure 2.

Fig. 4 is a flow chart showing an example of the sequence of the manufacturing method of the rotor of the implementation type.

Hereinafter, the rotor, the motor, and the method of manufacturing the rotor according to the embodiment of the present invention will be described in detail based on the drawings. Furthermore, the present invention is not limited by this embodiment.

[Implementation Type]

Fig. 1 is a cross-sectional view showing an example of the configuration of the motor of the embodiment. The motor 1 includes a stator 10 and a rotor 20, the stator 10 has a cylindrical shape, and the rotor 20 is provided inside the stator 10 and rotates around the central axis C of the stator 10 as a center. In other words, the central axis of the stator 10 is consistent with the central axis of the rotor 20, and the central axes of the stator 10 and the rotor 20 are marked as C below.

The stator 10 has a plurality of teeth 10a protruding inward, and a coil 12 wound around the teeth 10a. The rotor 20 has a cylindrical shape extending along the central axis C. As shown in FIG. The rotor 20 is arranged with a gap between the rotor 20 and the stator 10.

Fig. 2 is a cross-sectional view showing an example of the configuration of the motor of the embodiment. Figure 3 is an enlarged view of the area including the iron core, permanent magnets, and reinforcing members of Figure 2. In Figure 3, the area A of Figure 2 is enlarged and displayed. The rotor 20 has: a polygonal columnar iron core 21; permanent magnets 22 arranged on each side 21a of the iron core 21 parallel to the central axis C; and a bonding layer 23 that connects the permanent magnets 22 to each side 21a of the iron core 21; And the reinforcing member 24 covers the outer surface of the permanent magnet 22 attached to the iron core 21. Furthermore, the central axis of the iron core 21 is consistent with the central axis C of the rotor 20. Hereinafter, the central axis of the iron core 21 is also marked as C.

The iron core 21 has a polygonal column shape extending along the central axis C of the rotor 20. The cross section of the core 21 perpendicular to the central axis C preferably has a regular polygonal shape, so that the rotor 20 can rotate stably without unbalance. In the example of FIG. 2, although the cross section of the core 21 perpendicular to the central axis C has a regular hexagon, it can be any polygonal shape. Furthermore, this is an example, and the shape of the core 21 can be appropriately set to a shape that can obtain the magnetic force required for the rotor 20 and can maintain the strength.

The permanent magnet 22 has a flat surface 22a which is arranged on the side of the core 21; a top surface 22b which is convex toward the radially outer side of the core 21; and a side surface 22c which connects the flat surface 22a and the top surface 22b. The permanent magnets 22 are arranged on the side surface 21 a of the iron core 21 at equal intervals along the circumferential direction of the rotor 20. In the example of FIG. 2, the outline connecting the outer side surfaces of the permanent magnets 22 adhered to the respective side surfaces 21a of the iron core 21 is a perfect circle shape. In other words, the top surface 22b of the permanent magnet 22 has an arc shape convex toward the radially outer side, and the cross section of the permanent magnet 22 perpendicular to the central axis C has a D-shape. Thereby, when the rotor 20 rotates, the distance between the top surface 22b of the permanent magnet 22 of the rotor 20 and the stator 10 does not change. Furthermore, the shape of the permanent magnet 22 is not limited to the shape shown in FIG. 2, but As long as the shape obtains the magnetic force required for operating the motor 1, it can be appropriately set.

The subsequent layer 23 is connected between the flat surface 22 a of the permanent magnet 22 and the side surface 21 a of the iron core 21, and fixes the permanent magnet 22 to the iron core 21. Then, the layer 23 is selected from a material having a greater elongation at break than the reinforcing member 24 and a lower elastic modulus than the reinforcing member 24.

The reinforcing member 24 covers the outer surface of the permanent magnet 22 attached to the side surface 21a of the core 21, and has a cylindrical shape. The reinforcing member 24 is made of a material having a lower elongation at break than the adhesive layer 23 and a higher elastic modulus than the adhesive layer 23. In the example of FIG. 2, although the reinforcing member 24 is provided in contact with the top surface 22b of the permanent magnet 22, the reinforcing member 24 may be arranged at an interval with respect to the top surface 22b of the permanent magnet 22. However, in order to exhibit a greater reinforcement effect, it is preferable to install the reinforcement member 24 in a manner such that the top surface 22b of the permanent magnet 22 is in contact with the top surface 22b of the permanent magnet 22 in a static state.

An example of the reinforcing member 24 is a fiber-reinforced plastic formed into a cylindrical shape and at least one part of the fiber is distributed in the circumferential direction of the cylindrical shape. Fiber-reinforced plastics are composed of fibers and resins, and fillers or additives can also be appropriately blended. The elastic modulus in the circumferential direction of the fiber-reinforced plastic that distributes one part of the fiber in the circumferential direction of the cylindrical shape becomes higher than the elastic modulus of the cylindrical plastic in the circumferential direction. Therefore, when the rotor 20 rotates, even if centrifugal force acts on the permanent magnet 22 toward the outer side in the radial direction, tensile stress generated in the circumferential direction of the fiber-reinforced plastic will cause the permanent magnet 22 to be pressed into the radial direction. With the force of the inner side, the permanent magnet 22 can be fixed to the iron core 21.

The rotor 20 of this embodiment has the following configuration: the permanent magnet 22 is connected to the iron core 21 with a flat surface 22a, and the reinforcing member 24 covers the outer side of the permanent magnet 22, and the reinforcing member 24 is distributed by a part of the fiber to the cylinder It is composed of fiber-reinforced plastic in the circumferential direction of the shape. For this reason, the permanent magnet 22 can be fixed to the rotor 20 even if no adhesive force is required with respect to the moment of inertia generated when the rotation of the rotor 20 is accelerated or decelerated.

Next, the materials of the adhesive layer 23 and the fiber reinforced plastic used in this embodiment will be described.

As described above, the reinforcing member 24 is composed of fiber reinforced plastic that aligns at least a part of the fibers in the circumferential direction of the cylinder. Specifically, as the fiber system, a fiber having a tensile modulus of elasticity larger than that of stainless steel and a lower elongation at break than the adhesive layer 23 used is used. The tensile elastic modulus of stainless steel is 180GPa to 220GPa. Since the minimum elongation at break of the material used as the adhesive layer 23 is about 10%, it is preferable to use fibers having an elongation at break of less than 10%. Examples of such fibers are glass fiber, carbon fiber, SiC (silicon carbide) fiber, aramid fiber, and boron fiber. Even here, it is preferable to use carbon fiber that can achieve higher elasticity as the fiber, and even among carbon fibers, it is preferable to still have a higher elastic modulus and a lower elongation at break. For example, anisotropic pitch-based carbon fiber having a tensile elastic modulus of 620 GPa, an elongation at break of 0.6%, and a tensile strength of 3430 MPa can be used as the fiber. Moreover, when at least half of the fibers of the fiber reinforced plastic are anisotropic pitch-based carbon fibers, high strength and low elongation at break can be achieved. Fiber-reinforced plastics using such anisotropic pitch-based carbon fibers as fibers have a tensile modulus of 400GPa or more, an elongation at break of 0.6%, a tensile strength of 1800MPa or more, and a high modulus of elasticity, so it is suitable When the rotor 20 rotates, the permanent magnet The iron 22 is pressed against the inner side in the radial direction. In addition, by aligning the fibers in the circumferential direction of the cylindrical shape, it is possible to realize a fiber-reinforced plastic with higher mechanical properties and particularly a higher modulus of elasticity in the circumferential direction of the cylindrical shape.

Regarding the form of the fiber, it is preferable to use fibers having a fiber length of 1 mm or more. In the case of using so-called chopped fibers with a fiber length of 1 mm or more and 30 mm or less, the destruction of fiber reinforced plastics does not depend on the resin but is dominated by the strength of the fiber. In the case of using so-called continuous fibers in which the fibers are elongated in the circumferential direction, it is preferable because the strength and elastic modulus of the fiber-reinforced plastic can be improved. As an example, the length of the fiber is preferably greater than the length of the contour of the outer surface of the permanent magnet 22 attached to the iron core 21 in a cross-section perpendicular to the central axis C. Furthermore, for fibers with a fiber length of less than 1 mm, the circumferential tensile modulus of the cylindrical fiber reinforced plastic cannot be made larger than that of stainless steel, or the elongation at break cannot be made smaller than that of the adhesive layer 23. , So bad.

Regarding the orientation direction of the fibers, it is preferable that the fibers are aligned in the circumferential direction of the cylinder. Generally speaking, the “circumferential direction” refers to a direction that is 90 degrees or -90 degrees with respect to the central axis C of the rotor 20. However, in this embodiment, it does not only refer to the case where the direction is 90 degrees or -90 degrees with respect to the central axis C, and the fiber is 90 degrees or 90 degrees from the central axis C within the range that does not hinder productivity. The -90-degree tilt is still handled as an alignment in the circumferential direction. In one example, even if the fibers are aligned in the range of 80 degrees to 90 degrees or -80 degrees to -90 degrees with respect to the central axis C, they are treated as being arranged in the circumferential direction. This is because when the rotor 20 is manufactured, when there are many fibers, they are arranged in a crosswise manner within a range of 80 degrees to 90 degrees or a range of -80 degrees to -90 degrees with respect to the central axis C. Moreover, this is because even in the range of 80 degrees to 90 degrees with respect to the central axis C of the rotor 20, or -80 Arranging the fibers on the outer surface of the permanent magnet 22 in a crossing manner within the range of -90 degrees, it will still be the same as arranging the fibers in the direction of 90 degrees or -90 degrees with respect to the central axis C, which can be improved Because of the modulus of elasticity in the circumferential direction. For example, in a manufacturing method in which continuous fibers are wound with a fixed feed pitch, such as the filament winding method, it is in the range of 80 to 90 degrees with respect to the central axis C. The fibers are arranged in a crossing manner within or within the range of -80 degrees to -90 degrees.

In addition, the fibers may be aligned in a plurality of directions so that fibers aligned in the circumferential direction of the cylindrical shape and fibers aligned in other directions crossing the circumferential direction. An example of the direction intersecting the circumferential direction is the direction of the central axis C or the direction inclined by 45 degrees with respect to the central axis C. However, when the fibers are aligned in multiple directions, the orientation direction of the fibers is set in such a way that the tensile elastic modulus of the fiber reinforced plastic in the circumferential direction becomes larger than the tensile elastic modulus of stainless steel. In one example, by aligning more than half of the entire fiber in the circumferential direction of the cylinder, the circumferential tensile modulus of the fiber-reinforced plastic becomes larger than the tensile modulus of stainless steel. The reinforcing effect of the permanent magnet 22 cannot be achieved when the reinforcing member 24 is made of stainless steel. In addition, since the fibers are also aligned in directions other than the circumferential direction, a fiber-reinforced plastic with excellent mechanical properties can be obtained even with respect to stresses other than the circumferential direction.

In this embodiment, the mechanical characteristics that can maintain the circumferential direction of the permanent magnet 22 when the rotor 20 rotates are obtained. Here, the case where all the fibers are anisotropic pitch-based carbon fibers, and a fiber reinforced plastic whose fiber orientation is +88 degrees or -88 degrees with respect to the central axis C of the rotor 20 is taken as an example to constitute the reinforcing member 24 . In this way, since all the fibers with high elasticity and low elongation at break are deliberately oriented in the circumferential direction, even the elastic modulus in the circumferential direction The number and strength will become higher, and the permanent magnet 22 has a smaller amount of movement, the permanent magnet 22 can still be held on the iron core 21 by the reinforcing member 24.

In addition, in the above description, although a fiber reinforced plastic using one type of fiber has been exemplified, it is also possible to combine a plurality of fibers such as carbon fiber and glass fiber as the fiber reinforced plastic.

The resin of the fiber reinforced plastic is selected in a way that imparts a predetermined performance. The resin is from epoxy resin, vinyl ester, unsaturated polyester, furan, polyurethane, polyimide, Polyamide, polyetheretherketone, polyether sulfone, polypropylene, polyester, polycarbonate, acrylonitrile-styrene, Choose from the group of acrylonitrile-styrene, acrylonitrile-butadiene-styrene and modified polyphenylene ether. From the viewpoint of the strength and rigidity obtained by the reinforcing member 24, the resin is preferably an epoxy resin. In addition, it is also possible to incorporate additives or fillers into the resin in a manner to impart predetermined performance to the reinforcing member 24.

The adhesive layer 23 is obtained by curing the adhesive applied between the iron core 21 and the permanent magnet 22. For the layer 23, a material having a greater elongation at break than fiber reinforced plastic and a lower modulus of elasticity than fiber reinforced plastic is selected. As such an adhesive layer 23, the adhesive layer 23 which has an acrylic resin as a main component, or the adhesive layer 23 of an elastomer (elastomer) type is preferable. The adhesive layer 23 with acrylic resin as the main component can achieve a breaking elongation of 10% or more and 50% or less. The adhesive layer 23 of the elastic system can be compared with acrylic resin as the main The adhesive layer 23 of the composition further increases the elongation at break. According to these, since the adhesive layer 23 has an elongation at break of 10% or more, the elongation at break of the fiber reinforced plastic is preferably less than 10%. Furthermore, even in the adhesive layer 23 of the elastic system, the thermosetting resin-based elastomer can still strengthen the adhesive force with the permanent magnet 22 and the iron core 21.

As the thermosetting resin-based elastomer, an elastomer having a urethane resin, a fluororesin, a modified silicone resin, or a silicone resin as a main component is exemplified. Silicone resin has good heat resistance and chemical resistance, and can achieve 100% to 690% elongation at break. Compared with other resins, silicone resin is a material that is superior in terms of chemical resistance and oxidative degradation, and can increase the elongation at break.

Furthermore, the adhesive layer 23 with epoxy resin with an elongation at break of less than 10% as the main component will break before the fiber reinforced plastic reaches failure. For example, when the rotor 20 in FIG. 2 is rotating, when the adhesive layer 23 of one permanent magnet 22 among the six permanent magnets 22 is broken, an imbalance will occur and the rotor 20 will be damaged. For this reason, it is preferable to use the adhesive layer 23 having an elongation at break of 10% or more.

Furthermore, as long as it has the above-mentioned main components and increases the elongation at break, specifically, as long as the elongation at break is larger than that of the fiber reinforced plastic, the adhesive layer 23 mixed or dispersed with other components may also be used. As an example, by using an adhesive in which an epoxy resin is dispersed in a modified silicone resin, an adhesive layer 23 with an increased interface strength can be obtained. Moreover, even if the adhesive layer 23 is formed into a porous shape, the elongation at break can be increased.

When the permanent magnet 22 is bonded to the iron core 21 with the adhesive layer 23 of such a material, and the outer surface of the permanent magnet 22 is covered with fiber reinforced plastic, it will be bonded until the fiber reinforced plastic with a small elongation at break breaks. The layer 23 will not break. In other words In other words, the damage of the rotor 20 does not depend on the weaker part of the adhesive layer 23, but the higher strength of the fiber reinforced plastic in the circumferential direction can be effectively used to fix the permanent magnet 22 to the iron core 21. When the rotor 20 rotates, the permanent magnet 22 will move toward the outer side of the rotor 20 in the radial direction and the centrifugal force acting on the permanent magnet 22 will be evenly and slightly displaced in the cylindrical radial direction. At this time, the adhesive layer 23 having a greater elongation at break than the fiber reinforced plastic will not be damaged, and the permanent magnet 22 will be pressed against the fiber reinforced plastic. Then, the tensile stress generated in the circumferential direction of the fiber-reinforced plastic generates a force that is pressed into the radial inner side, whereby the permanent magnet 22 is fixed by the fiber-reinforced plastic. For this reason, the permanent magnet 22 is not so much maintained by the strength of the adhesive layer 23 as it is maintained by the higher strength of the fiber reinforced plastic. In other words, the permanent magnet 22 held by the adhesive layer 23 is reinforced by the fiber reinforced plastic.

Next, the thickness of the adhesive layer 23 will be described. The thicker the thickness of the adhesive layer 23 is, the less the adhesive layer 23 will be damaged until the fiber reinforced plastic is destroyed. Even if the permanent magnet 22 receives the centrifugal force and moves toward the radially outer side of the cylindrical shape, the radial tensile strain generated in the adhesive layer 23 is still suppressed to a low level, and the damage of the adhesive layer 23 is avoided. In addition, by setting the thickness of the adhesive layer 23 to be greater than or equal to the thickness determined in advance, impact resistance is added to the adhesive layer 23. Specifically, when the thickness of the adhesive layer 23 is 0.05 mm or more, the adhesive layer 23 has impact resistance.

On the other hand, when the thickness of the adhesive layer 23 is reduced, the shear strength of the adhesive layer will increase. Specifically, it is known that when the thickness of the adhesive layer 23 is 0.5 mm or less, the shear strength is improved.

The outer diameter of the rotor 20 is set according to the target motor 1 or generator. For example, rotors 20 of various sizes are used between a small motor 1 and a large generator. The type of motor 1 is used in a vacuum cleaner or toy with a rotor 20 having an outer diameter of about 10mm. This large generator is used in a power plant with a rotor 20 having an outer diameter of about 4.6m. . Among these rotors with outer diameters, there are, for example, a rotor 20 of 25mm or more and 160mm or less used in the starter motor of an automobile, and a rotor of 80mm or more and 400mm or less used in the drive motor of an electric vehicle. 20. Rotor 20 of 80mm or more and 200 or less used in NC (Numerical Control) processing machine spindle motor, rotor 20 of 120mm or more and 3m or less used in wind power generator, etc.

In this embodiment, the ratio of the elongation at break of the fibers aligned in the circumferential direction of the fiber-reinforced plastic having a cylindrical shape to the elongation at break of the adhesive layer 23 is the ratio of the thickness of the adhesive layer 23 to the rotor 20 Less than twice the outer diameter. _{In other words, the relationship between the elongation at break ε a of the} adhesive layer 23 and the elongation at _{break ε f} of the fibers aligned in the circumferential direction of the fiber reinforced plastic is based on the outer diameter D of the rotor 20 and the thickness t of the adhesive layer 23 To find that satisfies the following mathematical formula (1).

When ε _f /ε _a exceeds the upper limit, although the permanent magnet 22 will move toward the outer side in the radial direction due to the centrifugal force acting on the permanent magnet 22, until the fiber reinforced plastic as the reinforcing member 24 is broken, the layer 23 does not Will destroy. For this reason, fiber-reinforced plastic will dominate the destruction during rotation. The reinforcing effect when the permanent magnet 22 is held by the fiber reinforced plastic is obtained within the range of the following mathematical formula (2).

It is better to obtain the reinforcing effect by the fiber reinforced plastic when _{ε f} /ε _{a satisfies the following mathematical formula (3).}

On the other hand, when ε _f /ε _{a is} lower than the lower limit, the rotor 20 of this embodiment cannot be produced by the silk-wound blanking method. Carbon fiber systems with a breaking elongation ε _f of 0.3% or more and 2.4% or less are practically used in industrial applications (e.g., FRP Structural Design Handbook, Masuji Uemura, etc., Reinforced Plastics Association, 1994, p. 6-12 ). _{In particular, it is preferably an anisotropic pitch-based carbon fiber that can realize the elongation at break ε f} of the fibers aligned in the circumferential direction of the cylindrical shape of the fiber-reinforced plastic within a range of 0.3% or more and 1.1% or less. Here, the series takes the case of anisotropic pitch-based fibers with a _{breaking elongation ε f of 0.3% as an example.}

Since the elongation at break of the adhesive varies, various adhesives are used to investigate the lower limit of _{ε f} /ε _a. The following forming test was performed: the permanent magnet 22 was adhered to the core 21 with the following adhesives A, B, C, D, E, F, and G, and the anisotropic pitch-based carbon fiber impregnated in the resin was wound by winding The silk blank method is used to coil the outer surface of the permanent magnet 22 attached to the iron core 21.

A: Epoxy resin adhesive with elongation at break ε _{a of 5%}

B: Acrylic resin adhesive with elongation at break ε _{a of 10%}

C: Acrylic resin adhesive with 50% elongation at break ε _a

D: Silicone resin adhesive with 100% elongation at break ε _a

E: Modified silicone resin adhesive with elongation at break ε _{a of 350%}

F: The elongation at break ε _a is 690% porous modified silicone resin adhesive containing bubbles

G: The elongation at break ε _a is 750% porous modified silicone resin adhesive containing bubbles

As a result of the molding test, when the permanent magnet 22 is bonded with the adhesives of A, B, C, D, E, and F, the rotor 20 can be excellently molded by the wire-wound blanking method. On the other hand, when the permanent magnet 22 is bonded with the G adhesive, the permanent magnet 22 will fall off from the core 21 due to the force when the fiber is wound, and the rotor 20 cannot be formed by the wire-wound blanking method. According to the above situation, when ε _f is 0.3% and ε _a is 690%, it becomes a critical value. _{In other words, when ε f} /ε _{a of the} following mathematical formula (4) is satisfied, the rotor 20 of the present embodiment can be formed by the wire-wound blanking method. Then, formula (1) is derived from formula (2) and formula (4).

When the thickness t of the adhesive layer 23 is excessively thick, the shaft runout (shaft runout) generated during acceleration and deceleration of the rotation speed of the rotor 20 will increase, and contact with the stator 10 may be induced. Specifically, the ratio of the thickness t of the adhesive layer 23 in the rotor 20 to the outer diameter D of the rotor 20 is set to 1/150 or less in advance, so that no more serious shaft runout will occur. The straight line extending in the direction intersects the outer circumference of the rotor 20 at two places, so the subsequent layer 23 will also intersect the straight line at two places. In other words, the outer diameter of the rotor 20 contains two Follow the thickness of layer 23. For this reason, the relationship as shown in the following mathematical formula (5) is derived. Thereby, the gap between the rotor 20 and the stator 10 in the motor 1 can be narrowed.

The following mathematical formula (6) is obtained by mathematical formula (1) and mathematical formula (5). That is, the elongation at break ε _{a of the adhesive layer 23, the elongation at break ε f} of the fiber weave aligned in the circumferential direction of the fiber reinforced plastic, the thickness t of the adhesive layer 23 and the outer diameter D of the rotor 20 satisfy the mathematical formula (6) In the case of the relationship, the above-mentioned composition of the fiber reinforced plastic and the adhesive layer 23 can be used to avoid the adhesive layer 23 from being broken before the fiber reinforced plastic is destroyed.

Furthermore, in order for the relationship between the thickness t of the adhesive layer 23 and the outer diameter D of the rotor 20 to satisfy the mathematical formula (6), it is only necessary to have an average particle diameter of 1/4600 or more and 1/150 or less of the outer diameter D of the rotor 20 What is necessary is to disperse the filler in the adhesive layer 23. Thereby, the thickness t of the adhesive layer 23 can be 1/4600 or more and 1/150 or less of the outer diameter D of the rotor 20.

Next, the manufacturing method of the aforementioned rotor 20 will be described. Fig. 4 is a flowchart showing an example of the sequence of the manufacturing method of the rotor of the implementation type.

First, the permanent magnet 22 is bonded to the side surface 21a of the core 21 parallel to the center axis C via the bonding layer 23 (step S11). Specifically, the side surface 21a of the iron core 21 parallel to the central axis C and the flat surface 22a of the permanent magnet 22 are bonded by an adhesive, and the adhesive is hardened to form the adhesive layer 23. Thereby, the permanent magnet 22 will be attached to the iron core parallel to the central axis C 21 of the side 21a. In addition, permanent magnets 22 are arranged at equal intervals on the side surface 21 a of the iron core 21 along the circumferential direction of the rotor 20. As shown in Figure 2, since the top surface 22b of the permanent magnet 22 has an arc shape, in a cross section perpendicular to the central axis C, the outer surface formed by all the permanent magnets 22 attached to the iron core 21 The outline has a perfect circle shape. At this time, it is preferable to use an adhesive in which a filler having an average particle diameter becomes the target thickness, so that the thickness of the adhesive layer 23 becomes the target thickness. As shown in the mathematical formula (6), the target thickness is within the range of 1/4600 or more and 1/150 or less of the outer diameter D of the rotor 20.

In one example, as the adhesive system, an adhesive having an acrylic resin as a main component is used, or an adhesive of an elastic system is used. As the adhesive of the elastic system, an adhesive mainly composed of urethane resin, fluororesin, modified silicone resin or silicone resin is used.

Next, the fiber is impregnated with uncured resin (step S12). The fiber may also be composed of bundles. In one example, glass fiber, carbon fiber, SiC fiber, amide fiber, and boron fiber are used as the fiber system. Also, in one example, the resin system used is from epoxy resin, vinyl ester, unsaturated polyester, furan, polyurethane, polyimide, polyamide, polyether ether ketone, polyether stubble, Choose from the group of polypropylene, polyester, polycarbonate, acrylonitrile-styrene, acrylonitrile-styrene, acrylonitrile-butadiene-styrene and denatured polyphenylene ether.

After that, the fiber impregnated with uncured resin is directly wound around the entire outer surface of the permanent iron core 22 attached to the iron core 21 (step S13). Next, the resin impregnated in the fiber wound around the permanent magnet 22 is cured (step S14). In one example, the iron core 21 to which the permanent magnet 22 is followed and the fiber is wound around the outer surface of the permanent magnet 22 is heated by a heating device such as an oven to harden the resin. Take this, as shown in Figure 2, to make the fiber The cylindrical reinforcing member 24 made of reinforced plastic is formed in such a way that the outer surface of the permanent magnet 22 is covered. The rotor 20 is manufactured by the above.

Furthermore, in the above-mentioned process, a process of processing the outer shape of the iron core 21 to which the permanent magnet 22 has been attached can also be provided in accordance with the target shape. In addition, in the technique described in Patent Document 1, the core 21 to which the permanent magnet 22 is attached is embedded in a cylindrical fiber reinforced plastic by press-fitting or cold fitting. In terms of press-in, there is a possibility that the rotor 20 may be damaged due to the press-in force, and in terms of the cold jacket, there is a possibility that the rotor 20 may be damaged due to heat shock. However, according to the above-mentioned manufacturing method of this embodiment, the possibility of damage to the rotor 20 can be reduced. In other words, it is possible to provide a method of manufacturing the rotor 20 with excellent productivity.

(Example)

Next, the embodiment will be described. The outer diameter D of the rotor 20 is 40 mm. Use an adhesive composed of silicone resin with a breaking elongation ε _a of 160% and a tensile elastic modulus of 45.8 MPa. In the adhesive, glass beads having an average particle diameter of 100 μm and a standard deviation of 5 μm are dispersed as a filler. The filler is dispersed in the adhesive at a ratio of 2wt.%. By using this adhesive, the thickness t of the adhesive layer 23 is controlled to 100 μm. This adhesive is used to bond the permanent magnet 22 to the side surface 21a of the iron core 21 parallel to the central axis C. The iron core 21 to which the permanent magnet 22 is next has a cylindrical shape.

The fiber-reinforced plastic fiber used as the reinforcing member 24 is one kind, and is a continuous fiber of anisotropic pitch-based carbon fiber. The elongation at break ε _f of the fiber is 0.6%, and the tensile modulus of elasticity is 600 GPa. This fiber was formed into a bundle of 3000 fibers. In addition, an uncured resin is impregnated into the bundled fibers, and the uncured resin is obtained by mixing bisphenol A epoxy and acid anhydride in a predetermined formulation. Then, the fiber is directly wound on the outer surface of the permanent magnet 22 after the iron core 21 is adhered to the iron core 21 with the adhesive layer 23 by using the silk blanking method. The pitch of the winding feed hole is set to 3mm for each coil. After that, it is heated in an oven to harden the resin, thereby forming a reinforcing member 24 composed of a cylindrical fiber reinforced plastic. The orientation angle of the fibers is +89 degrees or -89 degrees with respect to the central axis C of the rotor 20. The thickness of fiber reinforced plastic is 1mm.

In this case, the relationship between the elongation at break ε _{a of the adhesive layer 23 and the elongation at break ε f} of the aforementioned fibers aligned in the circumferential direction of the cylindrical fiber reinforced plastic is expressed by the following formula (7) Express.

In addition, the ratio of the outer diameter D of the rotor 20 to the thickness t of the adhesive layer 23 is expressed by the following mathematical formula (8). Furthermore, since the radial line system of the cross section perpendicular to the central axis C of the rotor 20 intersects the two adhesive layers 23, the equation (8) becomes the following equation (9).

_{The ε f} /ε _a obtained by the mathematical formula (7) and the 2t/D obtained by the mathematical formula (9) all satisfy the relationship of the above-mentioned mathematical formula (6). In other words, since the fiber reinforced plastic becomes the starting point of damage when the rotor 20 rotates, the fiber reinforced plastic will obtain the reinforcing effect of keeping the permanent magnet 22 on the outer periphery of the iron core 21. At the same time, when the rotor 20 is manufactured by the silk-wound blanking method, the permanent magnet 22 does not fall off, and the structure shown in FIG. 2 can be realized. In addition, since fillers having a desired average particle diameter are dispersed in the adhesive layer 23, the thickness of the adhesive layer 23 can be easily controlled. It is manufactured by the silk-wound blanking method, thereby eliminating the need for press-fitting or cold-sleeve processes, and the rotor 20 can be manufactured by a manufacturing method with excellent productivity.

When the rotor 20 manufactured in this way is rotated at 23°C under atmospheric pressure, and the number of rotations is scanned at 1000 rpm/min, it will rotate without damage until 92000 rpm, and when the fiber-reinforced plastic has reached 93000 rpm Will be destroyed.

Although the rotor 20 manufactured by this manufacturing method receives thermal stress during molding in a static state, the fiber reinforced plastic is not subject to deliberate pressure as in the case of manufacturing by press-fitting or cold jacketing. And be stretched. For this reason, the absolute value of the tensile strain in the circumferential direction of the surface of the cylindrical fiber-reinforced plastic becomes 300 με or less. Furthermore, when the absolute value of the circumferential tensile strain on the surface of the cylindrical fiber-reinforced plastic is greater than 300με, it can be considered that it will be molded as in the case of press-fitting or cold sleeve manufacturing. When receiving thermal stress. In other words, the cylindrical fiber reinforced plastic whose absolute value of the tensile strain in the circumferential direction is 300με or less cannot be manufactured by press-fitting or cold jacketing.

In this embodiment, the elongation at break ε _a of the adhesive layer 23 is based on JIS (Japanese Industrial Standards; Japanese Industrial Standards) K7161-1994 (ISO: International Organization for Standardization; International Organization for Standardization) 527-1) or JIS K7127 -1999 is calculated based on it. In the case where the adhesive layer 23 as a test piece cannot be produced in a size based on the above-mentioned specifications, even if it is measured using a test piece of a similar shape, it can be considered to be equivalent.

Furthermore, in this embodiment, the elongation at break ε _f of the fiber is determined based on the method of JIS R 7606-2000. Even if it is necessary to take out the fiber from the fiber reinforced plastic, it is only necessary to follow the combustion method, the nitric acid decomposition method, and the sulfuric acid decomposition method described in JIS K 7075-1991 "7. Measurement of the quality of carbon fiber". The principle of any one of the methods of damaging the fiber is to extract the fiber. Even if the length of the fiber cannot be made according to the size based on the above specifications, it can still be measured with a test piece of similar shape.

The adhesive layer referred to rupture elongation ε _a and 23 fibers of elongation ε _f, refers to the ambient temperature during operation of the rotor 20 is measured, or in a case where the ambient temperature is not known at 23 The temperature measured in ℃.

According to the embodiment, the rotor 20 has the following structure: the iron core 21 and the permanent magnet 22 are connected by _{the adhesive layer 23 whose fracture elongation becomes ε a} , and the permanent magnet 22 connected to the iron core 21 is wound on the outer surface There are cylindrical fiber reinforced plastics with fibers whose elongation at break becomes ε _f. In the fiber reinforced plastic, at least a part of the fibers are aligned in the circumferential direction of the cylinder. When the outer diameter of the rotor 20 is set to D and the thickness of the adhesive layer 23 is set to t, the adhesive layer 23 and the fiber reinforced plastic satisfying the mathematical formula (2) are used. Thereby, the fiber reinforced plastic will be damaged before the adhesive layer 23 breaks when the rotor 20 rotates. That is, the starting point of destruction will become fiber reinforced plastic. Therefore, during the period until the fiber-reinforced plastic is destroyed, the reinforcing effect of using the fiber-reinforced plastic to firmly hold the permanent magnet 22 on the iron core 21 can be obtained.

In addition, by using the adhesive layer 23 and the fiber reinforced plastic that satisfy the mathematical formula (4), it is possible to wind the fiber between the permanent magnet 22 without falling off by the silk-wound blanking method in the manufacture of the rotor 20 around.

And more, it can also be used to implement than the fiber-reinforced plastic elongation ε _f of greater than 10% of the elongation at break ε _a of the elastomeric adhesive layer 23. _{In addition, the adhesive layer 23 having a} breaking elongation ε a of 100% or more and 690% or less can also be used. With such a configuration, it is possible to firmly fix the permanent magnet 22 to the core 21 with the fiber reinforced plastic while the rotor 20 is rotating, and the fiber reinforced plastic can be used as the starting point of damage. At the same time, the permanent magnet 22 can be wound around the outer surface of the permanent magnet 22 without falling off during the manufacture of the rotor 20.

In addition, by using an adhesive in which a filler having an average particle diameter of 1/4600 or more and 1/150 or less of the outer diameter D of the rotor 20 is dispersed, the thickness t of the adhesive layer 23 can be controlled to a desired thickness.

Furthermore, as fiber-reinforced plastic, carbon fiber-reinforced plastic in which more than half of the fiber is anisotropic pitch-based carbon fiber can also be used. Alternatively, a carbon fiber reinforced plastic in which more than one half of the fiber has carbon fibers aligned in the circumferential direction of the cylinder can also be used. _{With this, the elongation at break ε f} of the fibers aligned in the circumferential direction of the fiber reinforced plastic can be achieved within the range of 0.3% or more and 1.1% or less. As a result, the carbon fiber reinforced plastic will become the starting point of destruction during rotation, and the reinforcing effect of the permanent magnet 22 being fixed to the iron core 21 by the carbon fiber reinforced plastic is obtained.

Further, in the present embodiment patterns, the system to be the elongation at break ε _a of adhesive layer 23 and then the permanent magnet 22 to core 21, so that the resin has an elongation at break of the impregnated fibers to be impregnated with a resin is wound on ε _f The surface of the permanent magnet 22, and the resin is hardened to manufacture the rotor 20. Thereby, compared to the case where the cylindrical fiber reinforced plastic is embedded in the iron core 21 to which the permanent magnet 22 is adhered by the method of press-fitting or cold jacketing, the damage of the rotor 20 during manufacturing can be suppressed. As a result, the productivity of manufacturing the rotor 20 can be improved compared to the case where the cylindrical fiber reinforced plastic is embedded in the iron core 21 to which the permanent magnet 22 is adhered by press-fitting or cold jacketing.

Furthermore, in the foregoing embodiment, although the rotor 20 of the motor 1 has been cited as an example, this embodiment is not limited to the motor 1 and can also be applied to the rotor 20 of a generator. In this case, the same effect can be obtained with the same composition.

The configuration shown in the above embodiment is an example of the content of the present invention, which can be combined with other known technologies, and part of the configuration can be omitted or changed without departing from the gist of the present invention.

20: Rotor

21: iron core

21a: side

22: permanent magnet

22a: flat surface

22b: Top surface

22c: side

23: Next layer

24: Reinforcement member

A: area

C: Central axis

D: Outer diameter

t: thickness

Claims (10)

A rotor with: core; A plurality of permanent magnets are bonded to the side surface of the iron core parallel to the central axis by bonding layers; and The reinforcing member of the cylindrical shape is arranged on the outer surface of the plurality of permanent magnets attached to the side surface of the iron core; The aforementioned reinforcing member is a fiber-reinforced plastic in which a part of the fiber is aligned in the circumferential direction of the aforementioned cylindrical shape; The ratio of the elongation at break of the fibers aligned in the circumferential direction of the fiber reinforced plastic having the cylindrical shape to the elongation at break of the adhesive layer is twice the thickness of the adhesive layer relative to the outer diameter of the rotor the following. The rotor described in the first item of the scope of patent application, wherein the relationship between the elongation at break ε _{a of the adhesive layer and the elongation at break ε f} of the fibers aligned in the circumferential direction of the fiber-reinforced plastic having a cylindrical shape, When the outer diameter of the rotor is set to D and the thickness of the aforementioned adhesive layer is set to t, the relationship of the following mathematical formula is satisfied, [Number 1]

. The rotor described in item 1 or item 2 of the scope of patent application, wherein the adhesive layer includes an elastomer. In the rotor described in item 3 of the scope of patent application, the elongation at break ε _{a of the} aforementioned adhesive layer is 100% or more and 690% or less. The rotor described in item 1 or item 2 of the scope of patent application, wherein the thickness of the adhesive layer is 1/4600 or more and 1/150 or less of the outer diameter of the rotor. In the rotor described in item 5 of the scope of patent application, the adhesive layer has a filler having an average particle size of 1/4600 or more and 1/150 or less of the outer diameter of the rotor. For the rotor described in item 1 or item 2 of the scope of patent application, the aforementioned fiber reinforced plastic is carbon fiber reinforced plastic in which more than half of the aforementioned fibers are anisotropic pitch-based carbon fibers. The rotor described in item 1 or item 2 of the scope of patent application, wherein more than half of the fibers of the fiber reinforced plastic are aligned in the circumferential direction of the cylindrical shape. The rotor described in item 1 or item 2 of the scope of the patent application, wherein the absolute value of the circumferential strain of the surface of the fiber reinforced plastic having the cylindrical shape is 300 με or less when the rotor is in a static state. A motor with: The stator has a cylindrical shape; and The rotor described in item 1 or item 2 of the scope of patent application is rotatably installed on the inner side of the stator with the center axis of the stator as the center.

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