Cylindrical member, cylindrical member with tapered part, surface magnet-type motor, and method for manufacturing surface magnet-type motor

Abstract

This cylindrical member (1) is formed of fiber-reinforced plastic satisfying the relationship shown in Expression 2 when a stress vector is defined as σ, a strain vector is defined as ε, a shear stress is defined as τ, a shear strain is defined as γ, and an i-row j-column component of an in-plane stiffness matrix Q is defined as component Q ij , and a stress-strain relational expression in an XY plane is represented as shown in Expression 1 in a Cartesian coordinate system O-XYZ in which an intermediate position in the thickness direction of a microelement (10) of the cylindrical member (1) is defined as an origin O, a tangential direction of the cylinder is defined as an X-axis, a direction parallel to the axial direction of the cylinder is defined as a Y-axis, and a radial direction of the cylinder is defined as a Z-axis.

Description

Cylindrical member, cylindrical member with tapered portion, surface magnet motor, and method for manufacturing surface magnet motor

[0001] The present disclosure relates to a cylindrical member made of fiber-reinforced plastic, a cylindrical member with a tapered portion, a surface magnet motor using the cylindrical member, and a method for manufacturing the surface magnet motor.

[0002] Conventionally, cylindrical members made of fiber-reinforced plastics (FRP) have been known. For example, Patent Document 1 discloses a rotor using a cylindrical rotor body made of fiber-reinforced plastic. The rotor is configured such that a hub, which serves as a core, is press-fitted with an interference fit into the inner diameter side of the rotor body. The rotor generates tension in the circumferential direction of the rotor body, generating frictional force at the contact surface between the rotor body and the hub. This prevents the rotor body from slipping relative to the hub during rotation.

[0003] Japanese Patent Application Laid-Open No. 2002-95208

[0004] However, in order to press-fit the hub into the inner diameter side of the rotor body with an interference, as in the rotor of Patent Document 1, a large press-fitting force is required, and large-scale equipment is needed to generate that press-fitting force.

[0005] The present disclosure has been made in consideration of the above, and aims to obtain a cylindrical member that can reduce the press-fitting force of a core portion that is pressed into the inner diameter side of the cylindrical member.

[0006] In order to solve the above-mentioned problems and achieve the object, the cylindrical member according to the present disclosure is a cylindrical member having an origin O at the intermediate position in the thickness direction of a minute element of the cylindrical member, an orthogonal coordinate system O-XYZ in which the tangential direction of the cylinder is the X axis, a direction parallel to the axial direction of the cylinder is the Y axis, and a radial direction of the cylinder is the Z axis, where σ is the stress vector, ε is the strain vector, τ is the shear stress, γ is the shear strain, and the i-th row / j-th column component of the in-plane stiffness matrix Q is the component Q ｉｊ When the stress-strain relationship in the XY plane is expressed as shown in Equation 1, the component is characterized by being made of fiber-reinforced plastic for which the relationship shown in Equation 2 holds.

[0007] The cylindrical member according to the present disclosure has the effect of reducing the press-fitting force of the core portion that is press-fitted into the inner diameter side of the cylindrical member.

[0008] 9 is an enlarged view of a virtual cut of part X shown in FIG. 9.

[0033] FIG. 10 is a schematic diagram of an example of a manufacturing method of a cylindrical member according to the second embodiment.

[0034] FIG. 11 is a cross-sectional view of a method of evaluating the "torsion-expansion characteristics" of a cylindrical member according to the second embodiment.

[0035] FIG. 12 is a cross-sectional view of a method of evaluating the "torsion-expansion characteristics" of a cylindrical member according to the second embodiment.

[0036] FIG. 13 is a cross-sectional view of a method of manufacturing a surface permanent magnet motor using a cylindrical member with a tapered portion according to the third embodiment.

[0037] FIG. 14 is a cross-sectional view of a cylindrical member with a tapered portion according to the third embodiment.

[0038] FIG. 15 is a cross-sectional view of a cylindrical member with a tapered portion according to the third embodiment.

[0039]

[0009] Hereinafter, a cylindrical member, a cylindrical member with a tapered portion, a surface magnet motor, and a method for manufacturing a surface magnet motor according to embodiments of the present disclosure will be described in detail with reference to the drawings.

[0010] First embodiment. Figure 1 is a perspective view showing a cylindrical member according to a first embodiment. In Figure 1, a Cartesian coordinate system O-XYZ is defined to indicate the material direction, which is the direction for defining the characteristics of the cylindrical member 1. The Cartesian coordinate system O-XYZ is a coordinate system in which, considering an infinitesimal element 10 of the cylindrical member 1, the origin O is the midpoint of the infinitesimal element 10 in the thickness direction, the tangential direction of the cylinder is the X axis, the direction parallel to the axial direction P of the cylinder is the Y axis, and the radial direction of the cylinder is the Z axis. Furthermore, the torsional moment M applied to the cylindrical member 1 is Ｔ The direction of the right-hand thread is defined as the positive direction, with respect to the axis of the cylinder.

[0011] The cylindrical member 1 is made of fiber-reinforced plastic, in which reinforcing fibers are solidified with resin. Reinforcing fibers can be, for example, carbon fiber or glass fiber, as well as organic fibers such as para-aramid fiber or polyester fiber. Resins can be thermosetting resins such as epoxy resin, unsaturated polyester resin, and epoxy acrylate resin, as well as thermoplastic resins such as polyamide, polypropylene, polyethylene, polystyrene, polyethylene terephthalate, polycarbonate, polyether ether ketone, and polyphenylene sulfide. Fibers can be continuous or discontinuous, such as those formed by injection molding or compression molding. In the Cartesian coordinate system O-XYZ, the cylindrical member 1 is an anisotropic material. According to Reference 1 (Japan Society of Mechanical Engineers, Mechanical Engineering Handbook, DVD-ROM Edition, Alpha 3, Material Mechanics (First Edition), Maruzen (2014), Section 12.4, pp. 160-163), the stress-strain relationship in the XY plane can be expressed by Equation (1.1).

[0012]

[0013] In equation (1.1), {σ} is the stress vector in the XY plane, {ε} is the strain vector in the XY plane, and [Q] is the in-plane stiffness matrix. The reason why the subscripts of the components in the third row and third column of equation (1.1) are 6 instead of 3 is because, as shown in Reference 1, the three-dimensional stress-strain relationship equation has been reduced to a two-dimensional form, and the same notation is used in the equations shown below. Solving equation (1.1) for {ε} gives equation (1.2), and ε xcan be expressed by equation (1.3).

[0014]

[0015]

[0016] In formula (1.3), [Q] ｉｊ －１ is the ij component of the inverse matrix of [Q]. Here, the shear stress τ ｘｙ If only σ ｘ = σ ｙ = 0), we obtain equation (1.4).

[0017]

[0018] Here, [Q] １６ －１ Specifically, this is written as equation (1.5).

[0019]

[0020] detQ is the determinant of the matrix [Q] and is expressed by equation (1.6).

[0021]

[0022] Here, the cylindrical member 1 according to the first embodiment is characterized in that it satisfies the formula (1.7).

[0023]

[0024] By satisfying the formula (1.7), the cylindrical member 1 has the following characteristics: That is, the cylindrical member 1 is subjected to a torsional moment M Ｔ When applied, the cylindrical member 1 is subjected to shear stress τ ｘｙ occurs, but from equation (1.7), [Q] １６ －１ Since ≠0, the shear stress τ ｘｙ Therefore, the normal strain ε calculated by equation (1.4) ｘ In the Cartesian coordinate system O-XYZ, ε ｘ is the circumferential strain of the cylindrical member 1 and indicates the amount of deformation in the radial direction. [Q] １６ －１ If θ is greater than 0, a torsional moment MＴ By adding the shear stress τ ｘｙ >0, so ε ｘ >0, and the cylindrical member 1 expands in the radial direction. １６ －１ <0, a torsional moment M Ｔ Adding this, the shear stress τ ｘｙ >0, so ε ｘ <0, and the cylindrical member 1 contracts in the radial direction, but the torsional moment M Ｔ Applying a force in the opposite direction causes radial expansion.

[0025] Here, the torsional moment M Ｔ Consider an index for evaluating the amount of radial expansion when a torsional moment M is applied to the cylindrical member 1. In the following explanation, the amount of radial expansion is referred to as the "torsion-expansion characteristic." Ｔ The amount of deformation when the torsional moment M is applied depends on the diameter and thickness of the cylindrical member 1. Therefore, in order to evaluate the amount of radial expansion, Ｔ The shear stress τ generated by ｘｙ Equation (1.4) is the shear stress τ ｘｙ This is an equation that expresses the relationship between strain and [Q] １６ －１ is an evaluation index for the "torsion-expansion characteristics."

[0026]

[0027] From the formulas (1.4) and (1.5), when comparing cylindrical members 1 with the same inner diameter and the same thickness, the larger the value obtained by the formula (1.8), the greater the torsional moment M Ｔ In the cylindrical member 1 according to the first embodiment, the value of the right side of the formula (1.8) is preferably 0.002 [1 / GPa] or more, more preferably 0.005 [1 / GPa] or more, and even more preferably 0.01 [1 / GPa] or more. Note that 1 / GPa, which is the unit of the above value, is the reciprocal of GPa, and 1GPa=10 ９ N (Newton) / m ２(square meters).

[0028] Next, a surface permanent magnet (SPM) 100 equipped with a cylindrical member 1 according to the first embodiment will be described with reference to Figures 2 and 3. Figure 2 is a perspective view showing the surface permanent magnet motor equipped with a cylindrical member according to the first embodiment. Figure 3 is a front view of the surface permanent magnet motor equipped with a cylindrical member according to the first embodiment as viewed from the axial direction.

[0029] As shown in FIGS. 2 and 3, the surface permanent magnet motor 100 includes the cylindrical member 1 having the above-described configuration, and a rotor core 3 press-fitted into the inner diameter side of the cylindrical member 1.

[0030] The rotor core 3 includes a shaft 30, an iron core 31, permanent magnets 32, a spacer 33, and a high-conductivity member 34. The shaft 30 is concentrically fitted inside the cylindrical iron core 31. The permanent magnets 32 are spaced apart along the circumferential direction on the outer circumferential surface of the iron core 31. The number of poles of the permanent magnets 32 is not limited to the four poles shown in the figure and can be freely set. Spacers 33 are disposed between adjacent permanent magnets 32. The high-conductivity member 34 is disposed on the outer circumferential surfaces of the permanent magnets 32 and the spacer 33 to reduce rotor loss. The high-conductivity member 34 may be disposed over the entire outer circumferential surfaces of the permanent magnets 32 and the spacer 33, or may be disposed over a portion of the outer circumferential surfaces of the permanent magnets 32 and the spacer 33. The cylindrical member 1 is attached to the outer circumferential surface of the high-conductivity member 34. The cylindrical member 1 is a sleeve for fixing the permanent magnets 32.

[0031] Next, a method for manufacturing the surface permanent magnet motor 100 equipped with the cylindrical member 1 according to the first embodiment will be described with reference to Figures 4 and 5. Figure 4 is an explanatory diagram showing a method for manufacturing the surface permanent magnet motor equipped with the cylindrical member according to the first embodiment. As shown in Figure 4, in the manufacturing method for the surface permanent magnet motor 100, first, a torsional moment M is applied to the cylindrical member 1. Ｔ The cylindrical member 1 is subjected to a torsional moment M Ｔ Next, when a torsional moment M is applied to the cylindrical member 1, it expands in the radial direction. ＴWhile maintaining the state in which the torsional moment M is applied, the rotor core 3 is press-fitted into the inner diameter side of the cylindrical member 1. After the rotor core 3 is press-fitted into the inner diameter side of the cylindrical member 1, the torsional moment M Ｔ The load is removed. As a result, the cylindrical member 1 contracts in the radial direction, but because the rotor core 3 restrains the cylindrical member 1 in the radial direction, tension is generated in the circumferential direction. As a reaction to this tension, a distributed load acts in the radial direction on the outer circumferential surface of the rotor core 3. This distributed load acts in a direction that prevents the permanent magnets 32 from separating from the iron core 31 due to centrifugal force when the surface permanent magnet motor 100 rotates.

[0032] 5 is an explanatory diagram showing a manufacturing method of a plurality of surface permanent magnet motors equipped with cylindrical members according to the first embodiment. As shown in FIG. 5, in the manufacturing method of the surface permanent magnet motor 100, it is also possible to fit a plurality of rotor cores 3 into one cylindrical member 1. The torsional moment M Ｔ While maintaining the applied state, a plurality of rotor cores 3 are press-fitted into the inner diameter side of the cylindrical member 1. At this time, each rotor core 3 is arranged so that adjacent rotor cores 3 do not come into contact with each other in the cylindrical axial direction X. After all rotor cores 3 are press-fitted into the inner diameter side of the cylindrical member 1, the torsional moment M of the cylindrical member 1 is applied. Ｔ Then, the cylindrical member 1 is cut to match the axial length of each rotor core 3, thereby forming a plurality of surface permanent magnet motors 100 at once.

[0033] As described above, in the cylindrical member 1 according to the first embodiment, in an orthogonal coordinate system O-XYZ in which the origin O is the intermediate position in the thickness direction of the infinitesimal element 10 of the cylindrical member 1, the tangential direction of the cylinder is the X axis, the direction parallel to the axial direction of the cylinder is the Y axis, and the radial direction of the cylinder is the Z axis, the stress vector is σ, the strain vector is ε, the shear stress is τ, the shear strain is γ, and the i-th row and j-th column component of the in-plane stiffness matrix Q is the component Q ｉｊ When the stress-strain relationship in the XY plane is expressed as shown in the above formula (1.1), the material is fiber reinforced plastic for which the relationship shown in the above formula (1.7) holds.

[0034] Therefore, the cylindrical member 1 according to the first embodiment is subjected to a torsional moment M Ｔ When a torsional moment M is applied, not only shear deformation but also radial expansion of the cylindrical member 1 occurs, so that the press-fitting force of the rotor core 3, which is press-fitted into the inner diameter side of the cylindrical member 1, can be reduced. Furthermore, after the rotor core 3 is fitted into the cylindrical member 1, the torsional moment M Ｔ When the pressure is released, the cylindrical member 1 attempts to return from the expanded state to its original state, generating a circumferential tension due to the restoring force. Therefore, when the surface permanent magnet motor 100 rotates, the permanent magnet 32 ​​can be prevented from separating from the iron core 31 due to centrifugal force.

[0035] Second Embodiment Next, a cylindrical member 2 according to a second embodiment will be described. Fig. 6 is a perspective view showing the cylindrical member according to the second embodiment. Fig. 7 is a plan view of the cylindrical member according to the second embodiment as seen from the cylindrical axial direction. Fig. 8 is an enlarged view of part VIII shown in Fig. 7.

[0036] 6, an orthogonal coordinate system O-XYZ is defined to indicate the material direction, which is the direction for defining the characteristics of the cylindrical member 2. The orthogonal coordinate system O-XYZ is a coordinate system in which, considering an infinitesimal element 20 of the cylindrical member 2, the origin O is the middle position in the thickness direction of the infinitesimal element 20, the tangential direction of the cylinder is the X axis, the direction parallel to the axial direction P of the cylinder is the Y axis, and the radial direction of the cylinder is the Z axis. Furthermore, the torsional moment M applied to the cylindrical member 2 Ｔ The direction of the right-hand thread is defined as the positive direction, with respect to the axis of the cylinder.

[0037] As shown in FIGS. 6 to 8 , the cylindrical member 2 according to the second embodiment has a configuration including a plurality of cylindrical fiber-reinforced plastic layers (hereinafter referred to as FRP layers 21). Adjacent FRP layers 21 are bonded together. Bonding by adhesive, for example, can be used as a bonding method. When the cylindrical member 2 is manufactured by, for example, a sheet winding method, all layers are wound around a mandrel and laminated, and curing and bonding between adjacent FRP layers 21 are performed simultaneously. Alternatively, the cylindrical member 2 can be manufactured by a method in which only some adjacent FRP layers 21 out of all the FRP layers 21 are integrally molded in advance and then bonded together using an epoxy adhesive, an acrylic adhesive, or the like.

[0038] The joining method is not limited to the above-described configuration. Each FRP layer 21 is composed of reinforcing fibers, some or all of which are continuous and oriented in at least one direction, and resin, and different reinforcing fibers and resins can be combined in each layer. Reinforcing fibers can be, for example, carbon fiber or glass fiber, or organic fibers such as para-aramid fiber or polyester fiber. Resins can be thermosetting resins such as epoxy resin, unsaturated polyester resin, and epoxy acrylate resin, as well as thermoplastic resins such as polyamide, polypropylene, polyethylene, polystyrene, polyethylene terephthalate, polycarbonate, polyether ether ketone, and polyphenylene sulfide.

[0039] 6, the fiber direction of the FRP layer 21 (the tangential direction on the cylinder) is defined as the L direction, and the direction perpendicular to the L direction is defined as the T direction. The L direction is represented by the counterclockwise rotation angle θ from the X axis of the Cartesian coordinate system O-XYZ. The total number of FRP layers 21 is defined as N, and the layers are referred to, starting from the inner circumferential surface, as the first layer, second layer, ..., kth layer, ..., Nth layer. If the L direction of the kth layer is defined as θk, then the relationship between the resultant force and strain in the XY plane of the cylindrical member 2 can be expressed by Equation (2.1) according to the classical lamination theory described in Reference 1.

[0040]

[0041] Here, {N}={N ｘ N ｙ Nｘｙ} Ｔ is the resultant force vector. ｘ ε ｙ gamma ｘｙ} Ｔ is the strain vector. Also, the component A of the in-plane stiffness matrix [A] ｉｊ is expressed by equation (2.2).

[0042]

[0043] Here, as shown in FIG. ｋ is the Z coordinate of the boundary on the radial side of the kth layer. ｉｊ ) ｋ is the component Q (bar) of the stress-strain relation of the kth layer ｉｊ (i, j = 1, 2, 6), and is specifically given by equation (2.3). Note that Q(bar) is Q with a bar above it.

[0044]

[0045] In formula (2.3), Q １１ , Q ２２ , Q １２ , Q ６６ is expressed by equation (2.4).

[0046]

[0047] In formula (2.4), E Ｌ is the tensile modulus of elasticity in the L direction of the kth layer, E Ｔ is the tensile modulus of the kth layer in the T direction, ν ＬＴ is the Poisson's ratio in the LT direction of the kth layer, G ＬＴ is the shear modulus in the LT direction.

[0048] Solving equation (2.1) for {ε} gives equation (2.5), which in turn gives equation (2.6).

[0049]

[0050]

[0051] In formula (2.6), [A] ｉｊ －１is the ij component of the inverse matrix of [A]. Here, the resultant shear force N ｘｙ If only ｘ = N ｙ = 0), we obtain equation (2.7). [A] １６ －１ is expressed by equation (2.8).

[0052]

[0053]

[0054] In equation (2.8), detA is the determinant of the matrix [A] and is expressed by equation (2.9).

[0055]

[0056] The cylindrical member 2 according to the second embodiment is characterized in that it satisfies formula (2.10).

[0057]

[0058] By satisfying the formula (2.10), the cylindrical member 2 has the following characteristics. That is, the cylindrical member 2 is subjected to a torsional moment M Ｔ When applied, the cylindrical member 2 is subjected to a shear force N ｘｙ occurs, but from equation (2.10), [A] １６ －１ Since ≠0, the resultant shear force N ｘｙ Therefore, the normal strain ε calculated by equation (2.7) ｘ In the Cartesian coordinate system O-XYZ, ε ｘ is the circumferential strain of the cylindrical member 2, and indicates the amount of deformation in the radial direction. [A] １６ －１ If θ is greater than 0, a torsional moment M Ｔ Adding this, the resultant shear force N ｘｙ >0, so ε ｘ >0, and the cylindrical member 2 expands in the radial direction. １６ －１ <0, a torsional moment M Ｔ Adding this, the resultant shear force N ｘｙ >0, so εｘ <0, and the cylindrical member 2 contracts in the radial direction, but the torsional moment M Ｔ Applying a force in the opposite direction causes radial expansion.

[0059] Here, N ｘｙ is the shear stress τ of each FRP layer 21 ｘｙ is integrated in the thickness direction, so N ｘｙ Dividing this by the thickness t of the cylindrical member 2 gives the formula (2.11), and the average shear stress τ (bar) ｘｙ If we define １２ A ２６ -A １６ A ２２ ) can be used as an evaluation index for the "torsion-expansion properties." Note that τ (bar) is τ with a bar above it.

[0060]

[0061]

[0062]

[0063] From equation (2.12), when comparing cylindrical members 2 of the same dimensions, the larger the value obtained from equation (2.13), the greater the torsional moment M Ｔ In the cylindrical member 2 according to the second embodiment, the value of the right-hand side of the formula (2.13) is preferably 0.002 [1 / GPa] or more, more preferably 0.005 [1 / GPa] or more, and even more preferably 0.01 [1 / GPa] or more. The unit of the above value, 1 / GPa, is the reciprocal of GPa, and 1GPa=10 ９ N (Newton) / m ２ (square meters).

[0064] Next, a specific example of the cylindrical member 2 according to the second embodiment will be described with reference to Fig. 6, Fig. 9, and Fig. 10. Fig. 9 is a perspective view showing a specific example of the cylindrical member according to the second embodiment. Fig. 10 is an enlarged view showing a virtual cutaway of the X portion shown in Fig. 9.

[0065] Table 1 shows the material, thickness, and fiber direction of each FRP layer 21 in the cylindrical member 2. Table 2 shows the material constants and physical properties of Material A shown in Table 1, which is a unidirectional reinforced prepreg material made of high-strength PAN-based carbon fiber and epoxy resin. PAN (Polyacrylonitrile) is polyacrylonitrile.

[0066]

[0067]

[0068] In the cylindrical member 2 shown in Tables 1 and 2, t / |detA|×|A １２ A ２６ -A １６ A ２２ When calculating |, we get equation (2.14).

[0069]

[0070] As shown in FIG. 6, the diameter of the central part of the cylindrical member 2 is D ｍ , torsional moment M Ｔ Diameter D ｍ The expansion amount of ΔD ｍ Then, the average shear stress τ (bar) ｘｙ can be approximately calculated as in equation (2.15).

[0071]

[0072] In addition, if the circumferential length of the central part of the plate thickness of the cylindrical member 2 is L and the amount of expansion of the circumferential length L is ΔL, then, as shown in equation (2.16), the amount of diameter expansion ΔD ｍ is expressed as equation (2.17).

[0073]

[0074]

[0075] In equation (2.17), the torsional moment M Ｔ is 500 Nm (Newton meters), diameter D ｍ When is 100 mm, the diameter expansion amount ΔD ｍ can be calculated as 0.119 mm.

[0076] Next, a description will be given of different specific examples of the cylindrical member 2 according to the second embodiment. Table 3 shows the material, thickness, and fiber direction of each FRP layer 21 in the cylindrical member 2. Table 4 shows the material constants and physical properties of Material B shown in Table 3, which is a unidirectional reinforced prepreg material made of high-modulus pitch-based carbon fiber and epoxy resin.

[0077]

[0078]

[0079] If the FRP layer 21 has a large elastic modulus, the tension of the cylindrical member 2 increases after it is attached to the outer circumferential surface of the rotor core 3, and this generates a force that prevents the permanent magnets 32 from separating or scattering from the cylindrical member 2 due to the centrifugal force caused by the high-speed rotation of the surface magnet motor 100. For this reason, high-elasticity pitch-based carbon fiber is desirable as the fiber used for the FRP layer 21. Furthermore, the tensile modulus of elasticity of the fiber in the fiber direction is desirably 300 GPa or more. In such a cylindrical member 2, the parameter t / |detA|×|A １２ A ２６ -A １６ A ２２ Calculating | gives equation (2.18).

[0080]

[0081] In addition, in equation (2.17), the torsional moment M Ｔ is 500 Nm (Newton meters), diameter D ｍ When is 100 mm, the diameter expansion amount ΔD ｍ can be calculated as 0.113 mm.

[0082] Next, a manufacturing method of the cylindrical member 2 according to the second embodiment will be described with reference to FIG. 11 . FIG. 11 is an explanatory diagram schematically illustrating an example of a manufacturing method of the cylindrical member according to the second embodiment. When the resin is a thermosetting resin, manufacturing methods of the cylindrical member 2 include a sheet winding method and a filament winding method. As shown in FIG. 11 , the sheet winding method involves pre-impregnating unidirectionally oriented continuous fibers with resin, winding the semi-cured prepreg 22 around a cylindrical or columnar mandrel 23, and then curing it. The filament winding method involves impregnating a fiber tow with a liquid pre-cured thermosetting resin, winding it around a mandrel, and then curing it. Another manufacturing method of the cylindrical member 2 when the resin is a thermoplastic resin is the automated tape placement (ATP) method. The ATP method involves winding and bonding a tape- or sheet-like substrate, which is made of unidirectionally oriented continuous fibers pre-impregnated with resin, around a mandrel jig while applying heat and pressure. The method for manufacturing the cylindrical member 2 is not limited to the sheet winding method, the filament winding method, or the ATP method, and other methods may be used.

[0083] Next, a method for evaluating the "torsion-expansion characteristics" of the cylindrical member 2 will be described with reference to Fig. 12 and Fig. 13. Fig. 12 is a perspective view showing a method for evaluating the "torsion-expansion characteristics" of a cylindrical member according to the second embodiment. Fig. 13 is a cross-sectional view showing a method for evaluating the "torsion-expansion characteristics" of a cylindrical member according to the second embodiment. As shown in Figs. 12 and 13, strain gauges 200 are bonded to the outer peripheral surface and the inner peripheral surface of the cylindrical member 2. The strain gauges 200 detect a torsional moment M Ｔ Circumferential normal strain ε when ｘ The strain measurement direction of the strain gauge 200 is the circumferential direction of the cylindrical member 2. The number of measurement points of the strain gauge 200 is not limited to two points as shown in FIG. 13, and may be one or more points. Circumferential normal strain ε ｘcan be calculated from equations (2.16) and (2.17) using the following equation (2.19): By comparing the value calculated using equation (2.19) with the measurement value of the strain gauge 200, the "torsion-expansion characteristics" can be evaluated.

[0084]

[0085] Furthermore, even in the cylindrical member 2 of this embodiment 2, a surface magnet motor 100 can be formed in which the rotor core 3 is pressed and fitted into the inner diameter side of the cylindrical member 2 based on the manufacturing method of the surface magnet motor 100 described above.

[0086] As described above, the fiber reinforced plastic forming the cylindrical member 2 according to the second embodiment is composed of a plurality of FRP layers 21 in which some or all of the fibers are continuous fibers, and the resultant vector of the FRP layers 21 is defined as N, and the i-th row and j-th column component of the equivalent in-plane stiffness matrix A calculated by the classical lamination theory is defined as component A ｉｊ When the resultant force-strain relationship in the XY plane is expressed as shown in the above formula (2.1), component A ｉｊ is expressed as shown in the above formula (2.2), and the fiber direction of the FRP layer 21 is defined as the L direction, the direction perpendicular to the L direction is defined as the T direction, and the L direction is expressed as a counterclockwise rotation angle θ from the X axis. The component Q shown in the above formula (2.2) ｉｊ (bar) is expressed as shown in the above formula (2.3) and formula (2.4), and is formed so that the relationship shown in the above formula (2.10) holds.

[0087] Therefore, the cylindrical member 2 according to the second embodiment is subjected to a torsional moment M Ｔ When a torsional moment M is applied, not only shear deformation but also radial expansion of the cylindrical member 2 occurs, so that the press-fitting force of the rotor core 3, which is press-fitted into the inner diameter side of the cylindrical member 2, can be reduced. Furthermore, after the rotor core 3 is fitted into the cylindrical member 2, the torsional moment M Ｔ When the pressure is released, the cylindrical member 2 attempts to return from the expanded state to its original state, generating a circumferential tension due to the restoring force. Therefore, when the surface permanent magnet motor 100 rotates, the permanent magnet 32 ​​can be prevented from separating from the iron core 31 due to centrifugal force.

[0088] Third Embodiment Next, a tapered cylindrical member 4 according to the third embodiment and a surface permanent magnet motor 100 manufactured using the tapered cylindrical member 4 will be described. FIG. 14 is an explanatory diagram showing a method for manufacturing a surface permanent magnet motor using the tapered cylindrical member according to the third embodiment. As shown in FIG. 14 , the tapered cylindrical member 4 according to the third embodiment includes a straight body portion 41 made of the cylindrical member 1 of the first embodiment or the cylindrical member 2 of the second embodiment, and a cylindrical tapered portion 42 connected to one end of the straight body portion 41 in the cylindrical axis direction X and having an inner diameter that expands along the cylindrical axis direction X from the end connected to the straight body portion 41. The rotor core 3 of the surface permanent magnet motor 100 is press-fitted into the straight body portion 41. Therefore, it is sufficient that at least the straight body portion 41 satisfies formula (1.7) or formula (2.10). Note that the tapered portion 42 may also satisfy formula (1.7) or formula (2.10). The cylindrical portion 41 and the tapered portion 42 are integrally formed. The tapered portion 42 is provided for attaching a twisting jig 51b, which will be described later.

[0089] When the body portion 41 corresponds to the cylindrical member 2 of the second embodiment, the cylindrical member 4 with a tapered portion is manufactured by, for example, a sheet winding method. In this case, a mandrel having the outer diameter shape of the body portion 41 and a mandrel having an outer diameter shape corresponding to the inner diameter of the tapered portion 42 is combined, and semi-cured prepregs are wound and stacked around the combined mandrel, and adjacent prepregs in the stacking direction are simultaneously cured and bonded. In this way, the cylindrical member 4 with a tapered portion having the body portion 41 and the tapered portion 42 can be formed.

[0090] FIG. 15 is a cross-sectional view of a tapered cylindrical member according to the third embodiment, cut in the axial direction of the cylinder. As shown in FIG. 15 , a reinforcing doubler 43a is provided on the outer peripheral surface of the straight body portion 41 near the opening of the cylinder. Furthermore, a reinforcing doubler 43b is provided on the outer peripheral surface of the tapered portion 42 near the opening of the cylinder. As a result, the thickness of the straight body portion 41 and the tapered portion 42 near the cylindrical opening where the doubler 43a and the doubler 43b are provided is thicker than the thickness of the portions without the doubler 43a and the doubler 43b. The doubler 43a and the doubler 43b can be formed, for example, by increasing the number of prepregs used in the sheet winding method during manufacturing. Alternatively, the doubler 43a and the doubler 43b can be formed by adhesively bonding separately manufactured cylindrical members to the outer peripheral surfaces of the straight body portion 41 and the tapered portion 42. The doublers 43a and 43b do not need to satisfy formula (1.7) or formula (2.10), and any material can be selected. Taking processability into consideration, cloth material can also be used on the surface of the doublers 43a and 43b. The tapered cylindrical member 4 is not limited to a configuration in which doublers are provided on the body portion 41 and the tapered portion 42, and may be configured such that a doubler is provided on at least one of the body portion 41 and the tapered portion 42.

[0091] The tapered portion 42 has a plurality of taper angles that gradually increase along the cylindrical axis direction X from one end connected to the straight body portion 41. The tapered portion 42 shown in FIG. 15 includes, for example, a first tapered portion 44 connected to the straight body portion 41 and having a taper angle θ1, and a second tapered portion 45 having a taper angle θ2 larger than the taper angle θ1. For example, the taper angle θ1 of the first tapered portion 44 is 1°, 2°, or 5°. For example, the taper angle θ2 of the second tapered portion 45 is 10°, 20°, 30°, or 45°. The taper angle θ1 of the first tapered portion 44 and the taper angle θ2 of the second tapered portion 45 are not limited to the above angles, and may be any angle as long as the taper angle θ1 is smaller than the taper angle θ2. Furthermore, the tapered portion 42 is not limited to a configuration having two taper angles θ1 and θ2, but may be a configuration having one taper angle, or a configuration having three or more taper angles.

[0092] Furthermore, the doubler 43b provided in the tapered portion 42 is not provided in a portion of the first tapered portion 44 close to the straight body portion 41, but is provided continuously over a part of the first tapered portion 44 and the entire area of ​​the second tapered portion 45. Preferably, the doubler 43b is provided in the first tapered portion 44 so as to have a portion a having the same thickness as the straight body portion 41, a portion b having the same thickness as the second tapered portion 45 where the doubler 43b is provided, and a portion c where the thickness changes continuously therebetween. If the taper angle of the tapered portion 42 of the cylindrical member 4 with a tapered portion is large, the torsional moment M Ｔ When a stress is applied, highly specific stress occurs at the joint between the body portion 41 and the tapered portion 42, and the joint can become the starting point of fracture. The tapered cylindrical member 4 according to the third embodiment has a first tapered portion 44 with a small taper angle, which can suppress the specific stress at the joint between the body portion 41 and the tapered portion 42. Furthermore, the tapered cylindrical member 4 is provided with doublers 43b in a part of the first tapered portion 44 and in the second tapered portion 45, which can improve the strength of the tapered portion 42. As a result, even when highly specific stress occurs at the joint between the first tapered portion 44 and the second tapered portion 45, the tapered cylindrical member 4 can suppress fracture at the joint.

[0093] Next, a manufacturing method of a surface permanent magnet motor 100 using the cylindrical member 4 with a tapered portion according to the third embodiment will be described. As shown in FIG. 15 , a cylindrical twisting jig 51a is provided inside the cylindrical body portion 41. A cylindrical twisting jig 51b is provided inside the cylindrical body portion 42. The twisting jig 51a provided inside the cylindrical body portion 41 is arranged so that at least a portion thereof faces the doubler 43a provided on the outer circumferential surface, and is fastened and fixed together with the doubler 43a and the cylindrical body portion 41 by bolts 52a. Fastening the portion where the doubler 43a is provided by the bolts 52a can alleviate stress concentration due to bolt fastening. The twisting jig 51b provided inside the cylindrical body portion 42 is arranged so that at least a portion thereof faces the doubler 43b provided on the outer circumferential surface of the second tapered portion 45, and is fastened and fixed together with the doubler 43b and the second tapered portion 45 by bolts 52b. Fastening the portion where the doubler 43b is provided with the bolt 52b can alleviate stress concentration due to bolt fastening. Here, the inner diameter of the twisting jig 51b provided inside the cylindrical interior of the tapered portion 42 is set to be larger than the outer diameter of the rotor core portion 3, so that the rotor core portion 3 can pass through the cylindrical interior of the twisting jig 51b. Note that the twisting jigs 51a, 51b are not limited to being fixed to the cylindrical interior of the straight body portion 41 and the cylindrical interior of the tapered portion 42, but may also be fixed to the outer peripheral surfaces of the straight body portion 41 and the tapered portion 42. Furthermore, the means for fixing the twisting jigs 51a, 51b to the straight body portion 41 and the tapered portion 42 may be, for example, a method of bonding using an adhesive such as an epoxy adhesive or an acrylic adhesive, a method of fixing by friction, or a combination of these methods with bolt fastening.

[0094] In the manufacturing method of the surface permanent magnet motor 100, the twisting jigs 51a and 51b on both sides are gripped, and as shown in FIG. 14, a torsion moment M is applied to the twisting jigs 51a and 51b. Ｔ By applying the torsional moment M Ｔ The torsional moment M is transmitted to the cylindrical member 4 with the tapered portion, causing the straight body portion 41 to expand in the radial direction. ＴWhile maintaining the state in which the torsional moment M is applied, the rotor core 3 is inserted from the inner diameter side of the twisting jig 51b fixed to the tapered portion 42 and press-fitted into the inside of the straight body portion 41. In the tapered cylindrical member 4, the inner diameter of the twisting jig 51b fixed to the tapered portion 42 is larger than the outer diameter of the rotor core 3, so that the rotor core 3 can be mounted inside the cylindrical member 4 with the tapered portion without interference between the rotor core 3 and the twisting jig 51b. After the rotor core 3 is fitted inside the straight body portion 41, the torsional moment M applied to the twisting jig 51a and the twisting jig 51b is applied to the rotor core 3. Ｔ When the load is removed, tension is generated in the circumferential direction of the tapered cylindrical member 4. A reaction to this tension causes a distributed load to act in the radial direction on the outer circumferential surface of the rotor core 3. This distributed load acts in a direction that prevents the permanent magnets 32 from separating from the iron core 31 due to centrifugal force when the surface permanent magnet motor 100 rotates. Then, the twisting jigs 51a and 51b are removed from the tapered cylindrical member 4. The tapered portion 42 is then cut off from the straight body portion 41, thereby completing the surface permanent magnet motor 100.

[0095] 16 is an explanatory diagram showing a method for manufacturing a plurality of surface permanent magnet motors using a cylindrical member with a tapered portion according to the third embodiment. As shown in FIG. 16, in the manufacturing method for the surface permanent magnet motor 100, it is also possible to fit a plurality of rotor cores 3 into one cylindrical member 4 with a tapered portion. A torsional moment M Ｔ By applying the torsional moment M Ｔ The torsional moment M is transmitted to the cylindrical member 4 with the tapered portion, causing the straight body portion 41 to expand in the radial direction. Ｔ While maintaining the state in which the torsional moment M is applied, the rotor core parts 3 are inserted from the inner diameter side of the twisting jig 51b fixed to the tapered part 42 and press-fitted into the straight body part 41. At this time, each rotor core part 3 is positioned so that adjacent rotor core parts 3 do not come into contact with each other in the cylindrical axial direction X. After all rotor core parts 3 are fitted into the straight body part 41, the torsional moment M applied to the twisting jig 51a and the twisting jig 51b is ＴThen, the twisting jigs 51a and 51b are removed from the cylindrical member 4 with tapered portions. After that, the cylindrical member 4 with tapered portions is cut to match the axial length of each rotor core portion 3, thereby forming multiple surface permanent magnet motors 100 at once.

[0096] As described above, the cylindrical member 4 with a tapered portion according to the third embodiment includes the straight body portion 41 made of a cylindrical member corresponding to the cylindrical member 1 of the first embodiment or the cylindrical member 2 of the second embodiment, and the cylindrical tapered portion 42 connected to one end of the straight body portion 41 in the cylindrical axis direction X and expanding along the cylindrical axis direction X. That is, the straight body portion 41 is formed so that the relationship shown in the above formula (1.7) or formula (2.10) holds.

[0097] Therefore, the cylindrical member 4 with the tapered portion according to the third embodiment has a torsional moment M Ｔ When a shear moment M is applied, not only shear deformation but also radial expansion occurs in the straight body portion 41, so that it is possible to reduce the press-fitting force of the rotor core portion 3 that is press-fitted into the inner diameter side of the straight body portion 41. Furthermore, in the cylindrical member 4 with a tapered portion, the inner diameter of the twisting jig 51b fixed to the tapered portion 42 is larger than the outer diameter of the rotor core portion 3, so that the rotor core portion 3 can be mounted inside the cylindrical member 4 with a tapered portion without interference between the rotor core portion 3 and the twisting jig 51b. Furthermore, after the rotor core portion 3 is fitted into the straight body portion 41, the torsional moment M Ｔ When the expansion is released, tension is generated in the circumferential direction due to the restoring force generated when the body portion 41 tries to return from the expanded state to its original state. Therefore, when the surface permanent magnet motor 100 rotates, the permanent magnet 32 ​​can be prevented from separating from the iron core 31 due to centrifugal force.

[0098] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or different embodiments may be combined with each other. It is also possible to omit or modify parts of the configurations as long as they do not deviate from the gist of the invention.

[0099] 1, 2 Cylindrical member, 3 Rotor core, 4 Cylindrical member with tapered portion, 10, 20 Microelements, 21 FRP layer, 22 Prepreg, 23 Mandrel, 30 Shaft, 31 Iron core, 32 Permanent magnet, 33 Spacer, 34 High conductivity member, 41 Straight body portion, 42 Tapered portion, 43a, 43b Doubler, 44 First tapered portion, 45 Second tapered portion, 51a, 51b Twisting jig, 52a, 52b Bolt, 100 Surface magnet type motor, 200 Strain gauge, θ1, θ2 Taper angle.

Claims

1. In the Cartesian coordinate system O-XYZ, where the origin O is the midpoint in the thickness direction of the infinitesimal element of the cylindrical member, the tangential direction of the cylinder is the X axis, the direction parallel to the axial direction of the cylinder is the Y axis, and the radial direction of the cylinder is the Z axis, the stress vector is σ, the strain vector is ε, the shear stress is τ, the shear strain is γ, and the i-th row and j-th column component of the in-plane stiffness matrix Q is the component Q. ｉｊ When the stress-strain relationship in the XY plane is expressed as shown in Equation 1, the structure is made of fiber-reinforced plastic, for which the relationship shown in Equation 2 holds. A cylindrical member characterized by: [Equation 1] [Equation 2]

2. The component Q ｉｊ The following relationship holds true for 2. The cylindrical member according to claim 1. [Equation 3]

3. The component Q ｉｊ The following relationship holds true for 2. The cylindrical member according to claim 1. [Equation 4]

4. The component Q ｉｊ The following relationship holds true for 2. The cylindrical member according to claim 1. [Equation 5]

5. The fiber reinforced plastic is composed of a plurality of fiber reinforced plastic layers, some or all of which are made of continuous fibers, The resultant force vector of the fiber reinforced plastic layer is defined as N, and the i-th row and j-th column component of the equivalent in-plane stiffness matrix A calculated by the classical lamination theory is defined as component A ｉｊ When the resultant force-strain relationship in the XY plane is expressed as shown in Equation 6, the component A ｉｊ is expressed as shown in Equation 7, and the fiber direction of the fiber reinforced plastic layer is the L direction, the direction perpendicular to the L direction is the T direction, and the L direction is expressed as a counterclockwise rotation angle θ from the X axis. ｉｊ (bar) is expressed as shown in Equation 8 and Equation 9, and is formed so that the relationship shown in Equation 10 holds.

2. The cylindrical member according to claim 1. [Equation 6] [Equation 7] In Equation 7, the component Q ｉｊ (bar) is the stress-strain relationship in the kth layer of the fiber-reinforced plastic layer, z ｋ is the Z coordinate of the boundary on the radial side of the kth layer. [Equation 8] [Equation 9] In Equation 9, E Ｌ is the tensile modulus of elasticity in the L direction of the kth layer, E Ｔ is the tensile modulus of the kth layer in the T direction, ν ＬＴ is the Poisson's ratio in the LT direction of the kth layer, G ＬＴ is the shear modulus in the LT direction. [Equation 10]

6. Component A ｉｊ Regarding the thickness of the cylinder, the following relationship holds:

6. The cylindrical member according to claim 5. [0011]

7. Component A ｉｊ Regarding the thickness of the cylinder, the following relationship holds:

6. The cylindrical member according to claim 5. [0012]

8. Component A ｉｊ Regarding the thickness of the cylinder, the following relationship holds:

6. The cylindrical member according to claim 5. [0013]

9. A part of the fibers of the fiber reinforced plastic has a tensile modulus of elasticity in the fiber direction of 300 GPa or more.

6. The cylindrical member according to claim 5.

10. Some of the fibers of the fiber-reinforced plastic are carbon fibers.

10. The cylindrical member according to claim 9.

11. A straight body portion made of the cylindrical member according to any one of claims 1 to 10; a cylindrical tapered portion connected to one end side of the straight body portion in the cylindrical axial direction, the inner diameter of which increases along the cylindrical axial direction from the one end side connected to the straight body portion. A cylindrical member with a tapered portion.

12. The tapered portion has a plurality of taper angles that increase stepwise along the cylindrical axis direction from one end side connected to the straight body portion.

12. The cylindrical member with a tapered portion according to claim 11.

13. At least one of the straight body portion and the tapered portion has a portion where a reinforcing doubler is provided and the plate thickness is increased.

12. The cylindrical member with a tapered portion according to claim 11.

14. The thickness of the tapered portion includes a portion that changes continuously along the cylindrical axial direction.

14. The cylindrical member with a tapered portion according to claim 13.

15. A cylindrical member according to any one of claims 1 to 10; a rotor core portion press-fitted into the inner diameter side of the cylindrical member, A surface magnet motor characterized by:

16. A method for manufacturing a surface permanent magnet motor according to claim 15, applying a torsional moment to the cylindrical member; a step of press-fitting a rotor core into an inner diameter side of the cylindrical member while maintaining a state in which a torsional moment is applied to the cylindrical member; and a step of press-fitting the rotor core into the inner diameter side of the cylindrical member, and then removing the torsional moment from the cylindrical member. A method for manufacturing a surface magnet motor.

17. The rotor cores are press-fitted into the inner diameter side of the cylindrical member, After removing the torsional moment from the cylindrical member, the cylindrical member is cut to fit the length of each of the rotor core portions.

17. The method for manufacturing a surface permanent magnet motor according to claim 16.

18. A method for manufacturing a surface permanent magnet motor using the cylindrical member with a tapered portion according to claim 11, comprising the steps of: a step of fixing a twisting jig to the body portion and the tapered portion; applying a torsional moment to the twisting jig and transmitting the torsional moment to a cylindrical member with a tapered portion; a step of inserting a rotor core portion from the tapered portion side while maintaining a state in which a torsional moment is applied to the cylindrical member with a tapered portion, and press-fitting the rotor core portion into the inner diameter side of the straight body portion; and a step of press-fitting the rotor core into the inner diameter side of the straight body portion, and then removing the torsional moment from the cylindrical member with the tapered portion. A method for manufacturing a surface magnet motor.

19. a plurality of rotor core portions are press-fitted into the inner diameter side of the straight body portion; The method further includes a step of cutting the cylindrical portion to match the length of each of the rotor core portions after removing the torsional moment from the cylindrical member with tapered portion.

19. The method for manufacturing a surface permanent magnet motor according to claim 18.

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