JP6639761B1 - Rotor and motor - Google Patents

Abstract

The rotor (20) includes an iron core (21), a plurality of permanent magnets (22) bonded to a side surface (21a) parallel to a central axis (C) of the iron core (21) by an adhesive layer (23), and an iron core (21). And a cylindrical reinforcing member (24) disposed on the outer surface of the plurality of permanent magnets (22) adhered to the side surface (21a) of (21). The reinforcing member (24) is a fiber-reinforced plastic in which some fibers are oriented in the circumferential direction of the cylindrical shape. The ratio of the elongation at break of the fiber oriented in the circumferential direction of the fiber-reinforced plastic having a cylindrical shape to the elongation at break of the adhesive layer (23) is determined by the thickness of the adhesive layer (23) with respect to the outer diameter (D) of the rotor (20). (T) or less.

Description

  The present invention relates to a rotor, a motor, and a method for manufacturing a rotor, in which a surface of a permanent magnet bonded to an iron core is covered with a fiber-reinforced plastic.

  An SPM (Surface Permanent Magnet) motor having a rotor having a permanent magnet disposed on its surface has a feature that the strong magnetism of the permanent magnet can be efficiently used, the motor torque is linear, and the controllability is excellent. On the other hand, when the rotor is rotated at a high speed, the permanent magnet is scattered by the centrifugal force. Therefore, a method for firmly fixing the permanent magnet to the rotor is required.

  Patent Literature 1 discloses that an iron core in which a permanent magnet is fixed to an outer surface with an adhesive is inserted into a cylindrical fiber reinforced plastic (FRP) for fastening the permanent magnet by press fitting or cold fitting. Are disclosed.

JP 2005-312250 A

  However, in the technique described in Patent Literature 1, there is a possibility that the adhesive may break before the cylindrical fiber-reinforced plastic reaches breakage when the rotor rotates. In this case, there is a problem that the rotor is destroyed because the permanent magnet is peeled off from the iron core and the rotation of the rotor loses balance.

  The present invention has been made in view of the above, and has a rotor that can use a reinforcing member that covers the surface of a permanent magnet as a starting point of destruction before an adhesive that bonds a permanent magnet to an iron core during rotation breaks. The purpose is to gain.

  In order to solve the above-described problems and achieve the object, a rotor of the present invention includes an iron core, a plurality of permanent magnets bonded to a side surface parallel to a central axis of the iron core by an adhesive layer, and a rotor bonded to a side surface of the iron core. And a cylindrical reinforcing member disposed on the outer surface of the plurality of permanent magnets. The reinforcing member is a fiber-reinforced plastic in which some fibers are oriented in the circumferential direction of the cylindrical shape. The ratio of the breaking elongation of the fiber oriented in the circumferential direction of the fiber-reinforced plastic having a cylindrical shape to the breaking elongation of the bonding layer is not more than twice the thickness of the bonding layer with respect to the outer diameter of the rotor. .

  ADVANTAGE OF THE INVENTION According to this invention, there exists an effect that the reinforcing member which covers the surface of a permanent magnet can be set as a starting point of a break before the adhesive which bonds a permanent magnet to an iron core at the time of rotation breaks.

Sectional drawing which shows an example of the structure of the motor concerning embodiment. Sectional drawing which shows an example of the structure of the rotor concerning embodiment. FIG. 2 is an enlarged view of a region including the iron core, the permanent magnet, and the reinforcing member in FIG. 4 is a flowchart illustrating an example of a procedure of a method of manufacturing the rotor according to the embodiment.

  Hereinafter, a rotor, a motor, and a method of manufacturing the rotor according to an embodiment of the present invention will be described in detail with reference to the drawings. The present invention is not limited by the embodiment.

Embodiment.
FIG. 1 is a cross-sectional view illustrating an example of the configuration of the motor according to the embodiment. The motor 1 includes a stator 10 having a cylindrical shape, and a rotor 20 provided inside the stator 10 and rotating around a central axis C of the stator 10. That is, the center axis of the stator 10 and the center axis of the rotor 20 coincide with each other, and the center axis of the stator 10 and the rotor 20 is denoted by C below.

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

  FIG. 2 is a cross-sectional view illustrating an example of the configuration of the rotor according to the embodiment. FIG. 3 is an enlarged view of a region including the iron core, the permanent magnet, and the reinforcing member in FIG. In FIG. 3, the area A in FIG. 2 is enlarged. The rotor 20 includes a polygonal columnar iron core 21, a permanent magnet 22 disposed on each side surface 21 a of the iron core 21 parallel to the central axis C, an adhesive layer 23 for bonding the permanent magnet 22 to each side surface 21 a of the iron core 21, And a reinforcing member 24 that covers the outer surface of the permanent magnet 22 bonded to the iron core 21. Note that the center axis of the iron core 21 coincides with the center axis C of the rotor 20. Hereinafter, the central axis of the iron core 21 is also described as C.

  The iron core 21 has a polygonal column shape extending along the central axis C of the rotor 20. It is desirable that the cross section of the iron core 21 perpendicular to the center axis C has a regular polygon so that the rotor 20 can rotate stably without causing imbalance during rotation. In the example of FIG. 2, the cross section of the iron core 21 perpendicular to the central axis C has a regular hexagon, but may be an arbitrary polygon. Note that this is an example, and the shape of the iron core 21 is appropriately set to a shape that can obtain the magnetism necessary for the rotor 20 and maintain the strength.

  The permanent magnet 22 has a flat surface 22a disposed on the iron core 21 side, a top surface 22b protruding radially outward of the iron core 21, and a side surface 22c connecting 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 surfaces of the permanent magnets 22 bonded to the respective side surfaces 21a of the iron core 21 has a perfect circular shape. That is, the top surface 22b of the permanent magnet 22 has a circular arc shape protruding outward in the radial direction, and the cross section of the permanent magnet 22 perpendicular to the central axis C has a D-shape. Thus, the configuration is such that the distance between the top surface 22b of the permanent magnet 22 of the rotor 20 and the stator 10 does not change when the rotor 20 rotates. The shape of the permanent magnet 22 is not limited to the shape shown in FIG. 2 and may be any shape as long as it can obtain magnetism necessary for operating the motor 1 and can be set as appropriate.

  The adhesive layer 23 bonds 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. For the adhesive layer 23, a material having a larger breaking elongation than the reinforcing member 24 and having a lower elastic modulus than the reinforcing member 24 is selected.

  The reinforcing member 24 covers the outer surface of the permanent magnet 22 bonded to the side surface 21a of the iron core 21, and has a cylindrical shape. The reinforcing member 24 has a smaller breaking elongation than the adhesive layer 23 and is made of a material having a high elastic modulus. In the example of FIG. 2, the reinforcing member 24 is provided in contact with the top surface 22 b of the permanent magnet 22. However, the reinforcing member 24 may be provided at an interval from the top surface 22 b of the permanent magnet 22. . However, in order to exhibit a greater reinforcing effect, it is desirable that the reinforcing member 24 be provided so as to be in contact with the top surface 22b of the permanent magnet 22 in a stationary state.

  An example of the reinforcing member 24 is a fiber-reinforced plastic formed into a cylindrical shape and at least a part of the fiber is circumferentially oriented in the cylindrical shape. The fiber reinforced plastic is composed of fiber and resin, and may optionally contain fillers or additives. The circumferential elastic modulus of the fiber-reinforced plastic in which at least a part of the fibers is oriented in the cylindrical circumferential direction is higher than the circumferential elastic modulus of the cylindrical plastic. For this reason, even if centrifugal force acts on the permanent magnet 22 toward the outside in the radial direction when the rotor 20 rotates, the permanent magnet 22 is suppressed inward in the radial direction by the tensile stress generated in the circumferential direction of the fiber-reinforced plastic. A force is generated, and the permanent magnet 22 can be fixed to the iron core 21.

  In the rotor 20 of the present embodiment, the permanent magnet 22 is adhered to the iron core 21 at the flat surface 22a, and the outside of the permanent magnet 22 is made of a fiber-reinforced plastic in which a part of the fiber is circumferentially oriented in a cylindrical shape. It is configured to be covered by the reinforcing member 24. Therefore, the permanent magnet 22 can be fixed to the rotor 20 without requiring an adhesive force with respect to the moment of inertia generated when the rotation of the rotor 20 accelerates or decelerates.

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

  As described above, the reinforcing member 24 is made of a fiber-reinforced plastic in which at least a part of the fiber is circumferentially oriented in a cylindrical shape. Specifically, as the fiber, a fiber having a larger tensile modulus than stainless steel and a smaller elongation at break than the adhesive layer 23 used is used. The tensile modulus of stainless steel is from 180 GPa to 220 GPa. Since the minimum value of the elongation at break of the material used as the adhesive layer 23 is about 10%, it is desirable to use a fiber having an elongation at break of less than 10%. Examples of such fibers are glass fibers, carbon fibers, SiC fibers, aramid fibers, and boron fibers. Among these, it is desirable to use carbon fibers capable of realizing higher elasticity as the fibers, and among the carbon fibers, those having a higher elastic modulus and a smaller elongation at break are desirable. For example, an anisotropic pitch-based carbon fiber having a tensile modulus of elasticity of 620 GPa, an elongation at break of 0.6% and a tensile strength of 3430 MPa can be used as the fiber. Furthermore, when at least half or more of the fibers of the fiber-reinforced plastic are anisotropic pitch-based carbon fibers, high strength and low elongation at break can be realized. The fiber-reinforced plastic using such anisotropic pitch-based carbon fiber as a fiber has a tensile modulus of 400 GPa or more, a breaking elongation of 0.6%, a tensile strength of 1800 MPa or more, and a high elastic modulus. This is suitable for pressing the permanent magnet 22 inward in the radial direction when the rotor 20 rotates. Further, by orienting the fibers in the circumferential direction of the cylindrical shape, it is possible to realize a fiber-reinforced plastic having high mechanical properties, particularly a high elastic modulus in the circumferential direction of the cylindrical shape.

  Regarding the form of the fiber, it is desirable to use a fiber having a fiber length of 1 mm or more. When a so-called chopped fiber having a fiber length of 1 mm or more and 30 mm or less is used, the destruction of the fiber-reinforced plastic is governed by the strength of the fiber without depending on the resin. It is desirable to use so-called continuous fibers in which the fibers are continuously connected in the circumferential direction, since the strength and elastic modulus of the fiber-reinforced plastic can be increased. As an example, it is desirable that the length of the fiber is equal to or longer than the contour length of the outer surface of the permanent magnet 22 bonded to the iron core 21 in a cross section perpendicular to the central axis C. In addition, the fiber whose fiber length is less than 1 mm cannot make the tensile elastic modulus in the circumferential direction of the cylindrical fiber-reinforced plastic larger than that of stainless steel, or can make the breaking elongation smaller than that of the adhesive layer 23. Not so desirable.

  Regarding the orientation direction of the fibers, it is desirable that the fibers are oriented in the circumferential direction of the cylinder. Generally, the “circumferential direction” refers to a direction at 90 degrees or −90 degrees with respect to the center axis C of the rotor 20. However, in the present embodiment, not only in the case of the direction of 90 degrees or −90 degrees with respect to the central axis C, but also in the range of 90 degrees or −90 degrees with respect to the central axis C in a range where productivity is not impaired. Even if the fiber is inclined, it is treated as if it is oriented in the circumferential direction. In one example, even when the fibers are oriented in a range of 80 degrees to 90 degrees or a range of -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, in manufacturing the rotor 20, the fibers are often arranged so as to intersect the central axis C in a range of 80 to 90 degrees or in a range of -80 to -90 degrees. Further, even if the fibers are arranged on the outer surface of the permanent magnet 22 so as to intersect with the center axis C of the rotor 20 in the range of 80 degrees to 90 degrees or in the range of -80 degrees to -90 degrees, the center axis C This is because the elastic modulus in the circumferential direction can be increased as in the case where the fibers are arranged in the direction of 90 degrees or -90 degrees with respect to For example, in a manufacturing method of winding continuous fibers at a constant feed pitch such as a filament winding method, the fibers intersect with the central axis C in a range of 80 to 90 degrees or in a range of -80 to -90 degrees. Be placed.

  Further, the fibers may be oriented in a plurality of directions so as to have a cylindrical fiber oriented in the circumferential direction and a fiber oriented in another direction intersecting the circumferential direction. An example of a direction intersecting with the circumferential direction is a direction of the central axis C or a direction inclined by 45 degrees with respect to the central axis C. However, when the fibers are oriented in a plurality of directions, the orientation directions of the fibers are set such that the tensile elastic modulus in the circumferential direction of the fiber-reinforced plastic is greater than the tensile elastic modulus of stainless steel. In one example, the circumferential tensile modulus of the fiber reinforced plastic is greater than the tensile modulus of stainless steel by orienting more than half of the total fibers in the circumferential direction of the cylinder, and the reinforcing member 24 is made of stainless steel. In this case, the effect of reinforcing the permanent magnet 22 that cannot be realized is obtained. In addition, since the fibers are oriented in directions other than the circumferential direction, a fiber-reinforced plastic excellent in mechanical properties against stresses other than the circumferential direction can be obtained.

  In the present embodiment, mechanical properties in the circumferential direction that can hold the permanent magnet 22 when the rotor 20 rotates are required. Therefore, an example in which the reinforcing member 24 is made of a fiber-reinforced plastic in which the fibers are all anisotropic pitch-based carbon fibers and the fibers are oriented in a direction of +88 degrees or -88 degrees with respect to the central axis C of the rotor 20. Listed in As described above, since all fibers having high elasticity and small breaking elongation are intentionally oriented in the circumferential direction, the elastic modulus and strength in the circumferential direction are higher, and the amount of movement of the permanent magnet 22 is smaller. Even in this case, the permanent magnet 22 can be held on the iron core 21 by the reinforcing member 24.

  In the above description, a fiber-reinforced plastic using one type of fiber has been exemplified. However, a plurality of fibers, for example, carbon fiber and glass fiber may be combined to form a fiber-reinforced plastic.

  As for the resin of the fiber reinforced plastic, the material is selected so as to give predetermined performance. Resin selected from epoxy resin, vinyl ester, unsaturated polyester, furan, polyurethane, polyimide, polyamide, polyether ether ketone, polyether sulfone, polypropylene, polyester, polycarbonate, acrylonitrile styrene, acrylonitrile butadiene styrene and modified polyphenylene ether Is done. From the viewpoint of the strength and rigidity required for the reinforcing member 24, the resin is preferably an epoxy resin. Further, an additive or a filler may be mixed with the resin so that a predetermined performance is given to the reinforcing member 24.

  The adhesive layer 23 is obtained by curing an adhesive applied between the iron core 21 and the permanent magnet 22. For the adhesive layer 23, a material having a larger breaking elongation than that of the fiber reinforced plastic and a lower elastic modulus than that of the fiber reinforced plastic is selected. As such an adhesive layer 23, an adhesive layer 23 mainly composed of an acrylic resin or an elastomeric adhesive layer 23 is desirable. The adhesive layer 23 mainly composed of an acrylic resin can realize a breaking elongation of 10% or more and 50% or less. The elastomeric adhesive layer 23 can have a larger breaking elongation than the adhesive layer 23 containing an acrylic resin as a main component. From these, since the adhesive layer 23 has a breaking elongation of 10% or more, the breaking elongation of the fiber-reinforced plastic is desirably less than 10%. In addition, among the elastomer-based adhesive layers 23, the thermosetting resin-based elastomer can increase the adhesive strength between the permanent magnet 22 and the iron core 21.

  Examples of the thermosetting resin-based elastomer include those containing a urethane resin, a fluorine resin, a modified silicone resin, or a silicone resin as a main component. Silicone resins have good heat and chemical resistance and can achieve elongation at break of 100% to 690%. Silicone resin is a material that is superior in terms of chemical resistance and oxidative deterioration as compared with other resins, and can increase breaking elongation.

  The adhesive layer 23 mainly composed of an epoxy resin having a breaking elongation of less than 10% breaks before the fiber reinforced plastic breaks. For example, if the adhesive layer 23 of one of the six permanent magnets 22 is broken while the rotor 20 of FIG. 2 is rotating, imbalance occurs and the rotor 20 is destroyed. Therefore, it is desirable to use the adhesive layer 23 having a breaking elongation of 10% or more.

  The adhesive layer 23 containing the above-described main components and having a large breaking elongation, specifically, a breaking elongation value larger than that of the fiber-reinforced plastic, is mixed or dispersed with other components. May be used. As an example, by using an adhesive obtained by dispersing an epoxy resin in a modified silicone resin, it is possible to obtain an adhesive layer 23 having an increased interface adhesive strength. The elongation at break can also be increased by making the adhesive layer 23 porous.

  When the permanent magnet 22 is adhered to the iron core 21 by using the adhesive layer 23 made of such a material, and the outer surface of the permanent magnet 22 is covered with the fiber-reinforced plastic, the adhesive layer until the fiber-reinforced plastic having a small elongation at break is broken. 23 does not break. That is, the breakage of the rotor 20 does not depend on the portion where the strength of the adhesive layer 23 is weak, and the permanent magnet 22 can be fixed to the iron core 21 by utilizing the high circumferential strength of the fiber reinforced plastic. During the rotation of the rotor 20, the centrifugal force acting on the permanent magnet 22 toward the outside of the rotor 20 in the radial direction causes the permanent magnet 22 to be evenly and minutely displaced in the cylindrical radial direction. At this time, the adhesive layer 23 having a larger breaking elongation than the fiber reinforced plastic does not break, and the permanent magnet 22 is pressed against the fiber reinforced plastic. Then, due to the tensile stress generated in the circumferential direction of the fiber reinforced plastic, a force for suppressing the inner side in the radial direction is generated, and the permanent magnet 22 is fixed by the fiber reinforced plastic. Therefore, the permanent magnet 22 is held with higher strength of the fiber reinforced plastic than with the strength of the adhesive layer 23. That is, the holding of the permanent magnet 22 by the adhesive layer 23 is reinforced by the fiber-reinforced plastic.

  Next, the thickness of the adhesive layer 23 will be described. As the thickness of the adhesive layer 23 increases, the adhesive layer 23 does not break until the fiber-reinforced plastic breaks. Even if the permanent magnet 22 moves to the outside in the radial direction of the cylindrical shape due to the centrifugal force, the tensile strain generated in the radial direction of the adhesive layer 23 is kept low, and the destruction of the adhesive layer 23 is avoided. Further, by setting the thickness of the adhesive layer 23 to be equal to or more than a predetermined thickness, 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 bonding layer 23 is reduced, the shear strength of the bonding surface is improved. 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, from a small motor 1 used for a vacuum cleaner or a toy having a rotor 20 having an outer diameter of about 10 mm to a large motor generator used for a power plant having a rotor 20 having an outer diameter of about 4.6 m. Various sizes of rotors 20 are used up to the generator. Those having an outer diameter between them include, for example, a rotor 20 of 25 mm or more and 160 mm or less used for a starter motor of an automobile, a rotor 20 of 80 mm or more and 400 mm or less used for a drive motor of an electric vehicle, NC (Numerical Control). ) There are a rotor 20 of 80 mm or more and 200 mm or less used for a spindle motor of a processing machine, and a rotor 20 of 120 mm or more and 3 m or less used for a wind power generator.

In the present embodiment, the ratio of the elongation at break of the fiber oriented in the circumferential direction of the fiber-reinforced plastic having a cylindrical shape to the elongation at break of the adhesive layer 23 is 2 times the thickness of the adhesive layer 23 with respect to the outer diameter of the rotor 20. Less than double. That is, the relationship between the elongation at break ε _a of the adhesive layer 23 and the elongation at break ε _{f of the} fiber oriented in the circumferential direction of the fiber-reinforced plastic is determined by using the outer diameter D of the rotor 20 and the thickness t of the adhesive layer 23. It is required to satisfy the following expression (1).

If ε _f / ε _a exceeds the upper limit, the centrifugal force acting on the permanent magnet 22 causes the permanent magnet 22 to move outward in the radial direction. However, until the fiber reinforced plastic as the reinforcing member 24 is broken, the adhesive layer 23 does not break. Therefore, the fiber reinforced plastic controls the breaking during rotation. Within the range of the following expression (2), a reinforcing effect when the permanent magnet 22 is held by the fiber-reinforced plastic can be obtained.

More preferably, when ε _f / ε _a satisfies the following expression (3), the reinforcing effect by the fiber-reinforced plastic is obtained.

On the other hand, when ε _f / ε _a is lower than the lower limit, the rotor 20 according to the present embodiment cannot be produced by the filament winding method. Carbon fibers having an elongation at break ε _f of 0.3% or more and 2.4% or less have been put to practical use in industrial applications (for example, FRP Structural Design Handbook, Masashi Uemura et al., Reinforced Plastics Association, 1994; 6-12). Among them, anisotropic pitch-based carbon fibers that can achieve a breaking elongation ε _f of a fiber-reinforced plastic cylindrically oriented fiber in the circumferential direction in a range of 0.3% or more and 1.1% or less are preferable. Here, an example in which an anisotropic pitch-based carbon fiber having a breaking elongation ε _f of 0.3% is used will be described.

Since the elongation at break of the adhesive is various, the lower limit of ε _f / ε _a is examined using various adhesives. The permanent magnet 22 is adhered to the iron core 21 with the following adhesives A, B, C, D, E, F, and G, and anisotropic pitch-based carbon fiber impregnated in resin is applied to the iron core 21 by a filament winding method. A molding test for winding the outer surface of the bonded permanent magnet 22 is performed.
A: Epoxy resin adhesives elongation at break epsilon _a is 5% B: acrylic resin adhesive elongation at break epsilon _a is 10% C: a breaking elongation epsilon _a 50% acrylic resin adhesive D: elongation at break epsilon _a is 100 percent silicone resin adhesive E: breaking elongation epsilon _a is 350% modified silicone resin adhesive F: porous modified silicone resin adhesive moistened with bubbles breaking elongation epsilon _a is 690% G: Porous modified silicone resin adhesive containing bubbles with elongation ε _a of 750%

As a result of the molding test, when the permanent magnets 22 are adhered with the adhesives of A, B, C, D, E, and F, the rotor 20 can be favorably molded by the filament winding method. On the other hand, when the permanent magnet 22 is bonded with the adhesive of G, the permanent magnet 22 falls off from the iron core 21 by the force of winding the fiber, and the rotor 20 is formed by the filament winding method. Can not. From the above, the critical value is obtained when ε _f is 0.3% and ε _a is 690%. That is, when ε _f / ε _a in the following equation (4) is satisfied, the rotor 20 according to the present embodiment can be formed by the filament winding method. Then, equation (1) is derived from equation (2) and equation (4).

If the thickness t of the adhesive layer 23 is too large, the shaft runout generated when the rotation speed of the rotor 20 is accelerated / decelerated becomes large, which may cause contact with the stator 10. Specifically, by setting the ratio of the thickness t of the adhesive layer 23 in the rotor 20 to the outer diameter D of the rotor 20 to 1/150 or less, no further shaft runout occurs. The straight line extending in the radial direction intersects the outer periphery of the rotor 20 at two places, and therefore, the adhesive layer 23 also intersects this straight line at two places. That is, the outer diameter of the rotor 20 includes the thickness of the two adhesive layers 23. For this reason, a relationship such as the following equation (5) is derived. Thereby, the gap between the rotor 20 and the stator 10 in the motor 1 can be narrowed.

From the expressions (1) and (5), the following expression (6) is obtained. That is, the elongation at break ε _a of the adhesive layer 23, the elongation at break ε _{f of the} fiber oriented 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 are expressed by the following equation (6). When satisfied, the above-described configuration of the fiber-reinforced plastic and the adhesive layer 23 can prevent the adhesive layer 23 from being broken before the fiber-reinforced plastic is broken.

  In order that the relationship between the thickness t of the adhesive layer 23 and the outer diameter D of the rotor 20 satisfies the expression (6), the adhesive layer 23 must have at least 1/4600 of the outer diameter D of the rotor 20. The filler having an average particle size of 1/150 or less may be dispersed. Thus, the thickness t of the adhesive layer 23 can be set to be 1/4600 or more and 1/150 or less of the outer diameter D of the rotor 20.

  Next, a method for manufacturing the rotor 20 will be described. FIG. 4 is a flowchart illustrating an example of a procedure of a method of manufacturing the rotor according to the embodiment.

  First, the permanent magnet 22 is bonded to the side surface 21a of the iron core 21 parallel to the central 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 with an adhesive, and the adhesive is cured to form an adhesive layer 23. Thereby, the permanent magnet 22 is bonded to the side surface 21a of the iron core 21 parallel to the central axis C. 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 FIG. 2, since the top surface 22 b of the permanent magnet 22 has an arc shape, the outer surface formed by all the permanent magnets 22 bonded to the iron core 21 in a cross section perpendicular to the central axis C. The contour of the surface has a perfect circle shape. At this time, it is desirable to use an adhesive in which a filler having an average particle diameter of the target thickness is left so that the thickness of the adhesive layer 23 becomes the target thickness. The target thickness is in the range of not less than 1/4600 and not more than 1/150 of the outer diameter D of the rotor 20, as shown in equation (6).

  In one example, an adhesive mainly composed of an acrylic resin or an elastomer is used as the adhesive. As the elastomer-based adhesive, urethane resin, fluorine resin, modified silicone resin, or an adhesive containing silicone resin as a main component is used.

  Next, the fibers are impregnated with an uncured resin (step S12). The fibers may be composed of bundles. In one example, glass fibers, carbon fibers, SiC fibers, aramid fibers, and boron fibers are used as the fibers. In one example, the resin is an epoxy resin, vinyl ester, unsaturated polyester, furan, polyurethane, polyimide, polyamide, polyetheretherketone, polyethersulfone, polypropylene, polyester, polycarbonate, acrylonitrile styrene, acrylonitrile butadiene styrene, and modified polyphenylene. Selected from the group of ethers.

  Thereafter, the fiber impregnated with the uncured resin is directly wound over the entire outer surface of the permanent magnet 22 bonded 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 core 21 to which the permanent magnet 22 is adhered 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 cure the resin. Thereby, as shown in FIG. 2, the cylindrical reinforcing member 24 made of fiber reinforced plastic is formed so as to cover the outer surface of the permanent magnet 22. Thus, the rotor 20 is manufactured.

  In the above steps, a step of processing the outer shape of the iron core 21 to which the permanent magnets 22 are bonded may be provided according to the desired shape. Further, in the technology described in Patent Document 1, the iron core 21 to which the permanent magnet 22 is bonded is fitted into a tubular fiber-reinforced plastic by press-fitting or cold fitting. In press-fitting, the rotor 20 may be damaged by press-fitting, and in cold fit, the rotor 20 may be damaged by heat shock. However, according to the manufacturing method of the present embodiment described above, the possibility of damaging rotor 20 can be reduced. That is, it is possible to provide a method of manufacturing the rotor 20 having excellent productivity.

(Example)
Next, examples will be described. The outer diameter D of the rotor 20 is 40 mm. Elongation at break epsilon _a is 160%, a tensile modulus of the adhesive composed of silicone resin is 45.8MPa is used. Glass beads having an average particle size of 100 μm and a standard deviation of 5 μm are dispersed in the adhesive as a filler. The filler is 2 wt. % Is dispersed in the adhesive. By using this adhesive, the thickness t of the adhesive layer 23 is controlled to 100 μm. Using this adhesive, the permanent magnet 22 is bonded to the side surface 21 a parallel to the central axis C of the iron core 21. The iron core 21 to which the permanent magnet 22 is bonded has a cylindrical shape.

The fiber of the fiber reinforced plastic serving 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 is 600 GPa. This fiber is made into 3000 bundles per bundle. The bundled fibers are impregnated with an uncured resin in which bisphenol A type epoxy and an acid anhydride are mixed at a predetermined ratio. Then, using a filament winding method, the fiber is directly wound around the outer surface of the permanent magnet 22 bonded to the iron core 21 with the bonding layer 23. The winding pitch is 3 mm per winding. Then, the resin is heated in an oven to cure the resin, and the reinforcing member 24 made of fiber-reinforced plastic having a cylindrical shape is formed. The fiber orientation angle is +89 degrees or -89 degrees with respect to the central axis C of the rotor 20. The thickness of the fiber reinforced plastic is 1 mm.

In this case, the elongation at break epsilon _a bonding layer 23, the relationship between the elongation at break epsilon _f of fibers oriented in the circumferential direction of the fiber reinforced plastic cylindrical, represented by the following equation (7).

The ratio between the outer diameter D of the rotor 20 and the thickness t of the adhesive layer 23 is expressed by the following equation (8). Note that, since a radial straight line in a cross section perpendicular to the center axis C of the rotor 20 intersects with the two adhesive layers 23, the equation (8) becomes the following equation (9).

Both ε _f / ε _a obtained by the equation (7) and 2t / D obtained by the equation (9) satisfy the relationship of the above-mentioned equation (6). That is, the fiber-reinforced plastic serves as a starting point of destruction when the rotor 20 rotates, so that the fiber-reinforced plastic has a reinforcing effect of holding 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 filament winding method, the permanent magnet 22 does not fall off, and the structure shown in FIG. 2 can be realized. Further, since a filler having a desired average particle size is dispersed in the adhesive layer 23, the thickness of the adhesive layer 23 can be easily controlled. By manufacturing by a filament winding method, a press-fitting or cold-fitting step is not required, and the rotor 20 can be manufactured by a manufacturing method excellent in productivity.

  The rotor 20 manufactured in this manner was rotated at 23 ° C. under the atmospheric pressure and the number of revolutions was swept at 1000 rpm / min. The rotor 20 was rotated without damage up to 92,000 rpm, and when it reached 93000 rpm, the fiber-reinforced plastic was broken. did.

  The rotor 20 manufactured by this manufacturing method is subjected to thermal stress during molding in a stationary state, but the fiber-reinforced plastic is pulled by intentional pressure as in the case of manufacturing by press-fitting or cold-fitting. Absent. Therefore, the absolute value of the tensile strain in the circumferential direction on the surface of the cylindrical fiber-reinforced plastic becomes 300 με or less. If the absolute value of the tensile strain in the circumferential direction on the surface of the cylindrical fiber-reinforced plastic is larger than 300 με, it is considered that the fiber-reinforced plastic is subjected to thermal stress during molding, as in the case of being manufactured by press-fitting or cold-fitting. Conceivable. That is, a cylindrical fiber-reinforced plastic having an absolute value of tensile strain in the circumferential direction of 300 με or less cannot be manufactured by press-fitting or cold-fitting.

In the present embodiment, the elongation at break ε _a of the adhesive layer 23 is determined in accordance with JIS (Japanese Industrial Standards) K7161-1994 (ISO (International Organization for Standardization) 527-1) or JIS K7127-1999. is there. When the adhesive layer 23, which is a test piece, cannot be manufactured with dimensions conforming to the above-described standard, it may be considered that the measurement is performed by using a similar test piece.

In the present embodiment, the elongation at break ε _f of the fiber is determined according to the method of JIS R 7606-2000. Even when it is necessary to take out the fiber from the fiber reinforced plastic, any of the combustion method, nitric acid decomposition method and sulfuric acid decomposition method described in JIS K 7075-1991 “7. The fiber may be extracted by the principle of any method that does not damage the fiber. Even in the case where the length of the fiber cannot be produced in a size conforming to the above-described standard, the measurement may be performed using a test piece having a similar shape.

Elongation at break epsilon _a and elongation at break epsilon _f of the fibers of the adhesive layer 23 as referred to herein, when the rotor 20 can not know the environmental temperature or even at the time of operation refers to those measured at a temperature of 23 ° C..

According to the embodiment, the rotor 20 is bonded between the iron core 21 and the permanent magnet 22 by the adhesive layer 23 having _a breaking elongation of εa, and is attached to the outer surface of the permanent magnet 22 bonded to the iron core 21. having a cylindrical fiber reinforced plastic having a fiber elongation at break is epsilon _f is wound configuration. In the fiber-reinforced plastic, at least some of the fibers are oriented in the circumferential direction of the cylinder. When the outer diameter of the rotor 20 is D and the thickness of the adhesive layer 23 is t, the adhesive layer 23 and the fiber reinforced plastic satisfying the expression (2) are used. As a result, the fiber-reinforced plastic is broken before the adhesive layer 23 breaks when the rotor 20 rotates. That is, the starting point of the fracture is the fiber reinforced plastic. Therefore, until the fiber reinforced plastic is broken, the reinforcing effect of firmly holding the permanent magnet 22 on the iron core 21 with the fiber reinforced plastic can be obtained.

  Further, by using the adhesive layer 23 and the fiber-reinforced plastic satisfying the expression (4), the fibers are wound around the permanent magnet 22 without falling off by the filament winding method during the manufacture of the rotor 20 by the filament winding method. be able to.

Furthermore, greater than the breaking elongation epsilon _f of fiber-reinforced plastic, adhesive layer 23 of elastomer which can realize 10% or more elongation at break epsilon _a may be used. Further, an adhesive layer 23 having _a breaking elongation εa of 100% or more and 690% or less may be used. With such a configuration, the permanent magnet 22 can be firmly fixed to the iron core 21 with fiber reinforced plastic while the rotor 20 is rotating, and the fiber reinforced plastic can be used as a starting point of destruction. At the same time, the fibers can be wound around the outer surface of the permanent magnet 22 without the permanent magnet 22 falling off during the manufacture of the rotor 20.

  In addition, the thickness t of the adhesive layer 23 is controlled to a desired thickness 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. be able to.

Further, as the fiber reinforced plastic, a carbon fiber reinforced plastic in which at least half of the fibers are anisotropic pitch-based carbon fibers may be used. Alternatively, a carbon fiber reinforced plastic having carbon fibers in which more than half of the fibers are cylindrically oriented in the circumferential direction may be used. Thus, the elongation at break epsilon _f of fibers oriented in the circumferential direction of the fiber reinforced plastic can be realized in a range of 1.1% or less than 0.3%. As a result, the carbon fiber reinforced plastic serves as a starting point of breakage during rotation, and a reinforcing effect of fixing the permanent magnet 22 to the iron core 21 by the carbon fiber reinforced plastic is obtained.

Further, in this embodiment, the bonding the permanent magnet 22 to the core 21 by adhesive layer 23 elongation at break is epsilon _a, elongation at break impregnated with resin is impregnated with resin as a epsilon _f fibers The rotor 20 is manufactured by winding the resin around the surface of the permanent magnet 22 and curing the resin. Thereby, it is possible to suppress damage at the time of manufacturing the rotor 20 as compared with a case where a cylindrical fiber-reinforced plastic is fitted to the iron core 21 to which the permanent magnet 22 is bonded by using a press-fitting or a cold-fitting method. . As a result, the productivity of manufacturing the rotor 20 can be improved as compared with a case where cylindrical fiber-reinforced plastic is fitted into the iron core 21 to which the permanent magnets 22 are bonded by press fitting or cold fitting.

  In the above-described embodiment, the rotor 20 of the motor 1 has been described as an example. However, the present embodiment is not limited to the motor 1 and may be applied to the rotor 20 of the generator. Also in this case, a similar effect can be obtained with a similar configuration.

  The configurations described in the above embodiments are merely examples of the contents of the present invention, and can be combined with another known technology, and can be combined with other known technologies without departing from the gist of the present invention. Parts can be omitted or changed.

  Reference Signs List 1 motor, 10 stator, 10a teeth, 12 windings, 20 rotor, 21 iron core, 21a side surface, 22 permanent magnet, 22a flat surface, 22b top surface, 22c side surface, 23 adhesive layer, 24 reinforcing member.

Claims (10)

Iron core,
A plurality of permanent magnets bonded by an adhesive layer to a side surface parallel to the central axis of the iron core,
A cylindrical reinforcing member disposed on an outer surface of the plurality of permanent magnets bonded to a side surface of the iron core;
With
The reinforcing member is a fiber-reinforced plastic in which some fibers are oriented in the circumferential direction of the cylindrical shape,
The ratio of the elongation at break of the fibers oriented in the circumferential direction of the fiber-reinforced plastic having the cylindrical shape to the elongation at break of the adhesive layer is not more than twice the thickness of the adhesive layer relative to the outer diameter of the rotor. A rotor characterized in that: Wherein a breaking elongation epsilon _a adhesive layer, the relationship between the elongation at break epsilon _f of the fibers oriented in the circumferential direction of the fiber-reinforced plastic having a cylindrical shape, the outer diameter of the rotor is D, the adhesive layer The rotor according to claim 1, wherein the following relationship is satisfied when the thickness of the rotor is t.

  The rotor according to claim 1, wherein the adhesive layer includes an elastomer. The rotor of claim 3 wherein the breaking elongation epsilon _a of the adhesive layer, characterized in that 690% or less than 100%.   The rotor according to any one of claims 1 to 4, wherein the thickness of the adhesive layer is 1/4600 or more and 1/150 or less of the outer diameter of the rotor.   The rotor according to claim 5, wherein the adhesive layer has a filler having an average particle diameter of 1/4600 or more and 1/150 or less of the outer diameter of the rotor.   The rotor according to any one of claims 1 to 6, wherein the fiber reinforced plastic is a carbon fiber reinforced plastic in which half or more of the fibers are anisotropic pitch-based carbon fibers.   The rotor according to any one of claims 1 to 7, wherein at least half of the fibers of the fiber-reinforced plastic are oriented in a circumferential direction of the cylindrical shape.   9. An absolute value of a strain in a circumferential direction of a surface of the fiber-reinforced plastic having the cylindrical shape in a state where the rotor is allowed to stand still is 300 με or less. A rotor according to claim 1. A stator having a cylindrical shape;
The rotor according to any one of claims 1 to 9, wherein the rotor is provided inside the stator so as to be rotatable around a central axis of the stator.
A motor comprising:

Images