Sleeve for rotor, rotor of rotating electrical machine, and method for manufacturing rotor of rotating electrical machine

Abstract

Provided are a rotor sleeve that is less affected by the operating conditions and installation conditions of a rotating electrical machine and can stably rotate a rotor, a rotor of a rotating electrical machine, a method for manufacturing the rotor sleeve, and a method for manufacturing the rotor of a rotating electrical machine. 【Solution means】The rotor sleeve 1 is a rotor sleeve 1 used for a rotor 10 of a rotating electrical machine having a permanent magnet 2, a shaft 3 provided on the end side of the permanent magnet 2, and a rotor sleeve 1 in which the permanent magnet 2 and the shaft 3 are disposed inside. The rotor sleeve 1 has a cylindrical shape with a constant inner diameter and outer diameter, and includes a first cylindrical portion 4 made of metal in which the permanent magnet 2 is disposed inside, and a second cylindrical portion 5 made of fiber-reinforced plastic having a cylindrical shape with a constant inner diameter and in which the first cylindrical portion 4 is disposed inside. The thickness of the second cylindrical portion 5 is larger than the thickness of the first cylindrical portion 4 over the entire length from one end to the other end in the length direction of the first cylindrical portion 4 and the second cylindrical portion 5.

Description

Technical Field

[0001] The present invention relates to a sleeve for a rotor, a method for manufacturing a rotor of a rotating electrical machine, and a rotating electrical machine having the rotor. Ta and

Background Art

[0002] A rotating electrical machine includes a rotor around a shaft, and the rotor has a rotating shaft and permanent magnets. A cylindrical member (also called a sleeve) is installed on the outer periphery of the permanent magnets so that the permanent magnets do not scatter during rotation.

[0003] In Patent Document 1 below, a first cylindrical member and a second cylindrical member are provided around a magnetic body, which is a permanent magnet, and a shaft member. The first cylindrical member is, for example, stainless steel, and the second cylindrical member is, for example, a titanium alloy or a carbon fiber reinforced material. The second cylindrical member is overlapped on the radially outer side of the first cylindrical member, and the thickness of the second cylindrical member is thinner than the thickness of the cylindrical main body portion of the first cylindrical member.

[0004] Further, in Patent Document 2 below, the rotor includes a permanent magnet, a metal protective sleeve, and a CFRP shrink ring. The permanent magnet is fitted on the outer periphery of the rotating shaft and has a frustoconical cylindrical shape with a taper on the inner and outer peripheral portions over the entire axial length. The protective sleeve has a taper on the inner periphery corresponding to the outer periphery of the permanent magnet and has a taper or a cylindrical surface on the outer periphery. The shrink ring has the protective sleeve provided on the inner peripheral surface, and the shape of the inner periphery is a taper or a cylindrical surface corresponding to the outer periphery of the protective sleeve.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] As in Patent Documents 1 and 2 described above, there is a technique of applying a fiber-reinforced plastic such as a carbon fiber reinforcing material to a rotor sleeve in order to reduce the weight and improve the strength of the rotor.

[0007] However, in Patent Document 1, the first cylindrical member has low strength, the second cylindrical member has high strength, and the thickness of the first cylindrical member is thicker than that of the second cylindrical member. Therefore, under conditions where the rotating electrical machine is used at ultra-high speed for a long period with heat cycles, creep deformation occurs in the first cylindrical member of the rotor disclosed in Patent Document 1, and the clamping force for holding the permanent magnet inside decreases.

[0008] Also, in Patent Document 2, in the example where the shrink ring made of CFRP is tapered (Figure 1), the strength on the thin side (i.e., the large-diameter side of the rotating shaft) is low, so the clamping force of the magnet by the shrink ring is weak. Therefore, when the rotating electrical machine is used at ultra-high speed for a long period with heat cycles, this rotor may break starting from the thin side of the shrink ring.

[0009] Furthermore, in Patent Document 2, in the example where the shrink ring is cylindrical (Figure 3), similar to the example of the tapered shape in Figure 1, the inner peripheral surface of the metal protective sleeve, the inner and outer peripheral surfaces of the permanent magnet, and the outer peripheral surface of the rotating shaft are necessarily tapered, and each component has a shape with a different diameter in the length direction. Therefore, there is a difference in the linear expansion coefficient inside each component. Therefore, when the rotating electrical machine is used at ultra-high speed for a long period with heat cycles, displacement is likely to occur at the fitting portions between the components. For example, when there is a temperature change and it rotates at high speed, while the thick side of the component does not deform, the thin side may expand in diameter.

[0010] Furthermore, parts having a tapered shape like those of Patent Document 2 require taper processing for manufacturing, and there is a problem that the processing is laborious and costly. In addition, not only is it necessary to adjust the taper angle of each part, but if there is a deviation in the angle, the parts cannot be properly combined with each other, so the assembled rotor is likely to become unbalanced. Therefore, the rotor of Patent Document 2 is difficult to apply to a rotating electrical machine that rotates at ultra-high speed.

[0011] In a rotating electrical machine that operates at ultra-high speed while undergoing heat cycles in a range from lower than normal temperature to higher than normal temperature over a long period, in particular, the sleeve that doubles the arrangement of parts is highly likely to undergo creep deformation. As a result, there has been a problem that the clamping force of the magnet by the sleeve is impaired and the rotational balance of the rotor is disrupted.

[0012] The present invention has been made in view of such circumstances, and a sleeve for a rotor, a rotor of a rotating electrical machine, and a manufacturing method of a rotor of a rotating electrical machine that are less affected by the operating conditions and installation conditions of the rotating electrical machine and can stably rotate the rotor. Ta and and aims to provide a manufacturing method of a rotor of a rotating electrical machine.

Means for Solving the Problems

[0013] In order to solve the above problems, the sleeve for a rotor, the rotor of a rotating electrical machine, and the manufacturing method of the rotor of a rotating electrical machine of the present invention employ the following means. That is, the rotor sleeve according to the present invention is a rotor sleeve used for a rotor of a rotating electrical machine having a permanent magnet, a shaft provided on an end side of the permanent magnet, and a rotor sleeve in which the permanent magnet and the shaft are disposed inside, and has a cylindrical shape with a constant inner diameter and outer diameter, and the permanent magnet is disposed inside such that an outer surface of the permanent magnet contacts an inner surface, and includes a first cylindrical portion made of a metal excluding a shape memory material, and a second cylindrical portion made of a fiber-reinforced plastic having a cylindrical shape with a constant inner diameter and having the first cylindrical portion disposed inside such that an outer surface of the first cylindrical portion contacts an inner surface, and a thickness of the second cylindrical portion is larger than a thickness of the first cylindrical portion over the entire length from one end to the other end of the first cylindrical portion and the second cylindrical portion. く, the first cylindrical portion is arranged in a state of being press-fitted inside the second cylindrical portion It is characterized by this.

[0014] The rotor of the rotating electrical machine according to the present invention includes the above-described rotor sleeve, a permanent magnet disposed inside the first cylindrical portion of the rotor sleeve, and a shaft disposed inside the first cylindrical portion of the rotor sleeve and provided on an end side of the permanent magnet. , the permanent magnet is arranged in a state of being press-fitted inside the first cylindrical portion .

[0015] In the above invention, the axial lengths of the first cylindrical portion and the second cylindrical portion may be longer than the axial length of the permanent magnet.

[0016] The present invention Reference example of A method for manufacturing a rotor sleeve according to the present invention is a method for manufacturing a rotor sleeve used for a rotor of a rotating electrical machine having a permanent magnet, a shaft provided on an end side of the permanent magnet, and a rotor sleeve in which the permanent magnet and the shaft are disposed inside, and includes a first press-fitting step of press-fitting a first cylindrical portion made of a metal having a cylindrical shape into a second cylindrical portion made of a fiber-reinforced plastic having a cylindrical shape, and a thickness of the second cylindrical portion is larger than a thickness of the first cylindrical portion, and before the first press-fitting step, an outer diameter of the first cylindrical portion is larger than an inner diameter of the second cylindrical portion, and by the first press-fitting step, the first cylindrical portion is disposed inside the second cylindrical portion such that an outer surface of the first cylindrical portion contacts an inner surface of the second cylindrical portion.

[0017] The manufacturing method of a rotor of a rotating electrical machine according to the present invention is a manufacturing method of a rotor of a rotating electrical machine having a permanent magnet, a shaft provided on an end side of the permanent magnet, and a rotor sleeve in which the permanent magnet and the shaft are disposed inside, and includes a first press-fitting step of press-fitting a first cylindrical portion made of metal having a cylindrical shape into an inside of a second cylindrical portion made of fiber-reinforced plastic having a cylindrical shape, and a second press-fitting step of press-fitting a cylindrical permanent magnet into an inside of the first cylindrical portion disposed inside the second cylindrical portion. A thickness of the second cylindrical portion is larger than a thickness of the first cylindrical portion. Before the first press-fitting step, an outer diameter of the first cylindrical portion is larger than an inner diameter of the second cylindrical portion. By the first press-fitting step, the first cylindrical portion is disposed inside the second cylindrical portion such that an outer surface of the first cylindrical portion contacts an inner surface of the second cylindrical portion. Before the second press-fitting step, an outer diameter of the permanent magnet is larger than an inner diameter of the first cylindrical portion disposed inside the second cylindrical portion. By the second press-fitting step, the permanent magnet is disposed inside the first cylindrical portion such that an outer surface of the permanent magnet contacts an inner surface of the first cylindrical portion.

[0018] In the above invention, a ratio (δ2 / δ1) of a second interference (δ2), which is a difference between an outer diameter of the permanent magnet before the second press-fitting step and an inner diameter of the first cylindrical portion disposed inside the second cylindrical portion, to a first interference (δ1), which is a difference between an outer diameter of the first cylindrical portion before the first press-fitting step and an inner diameter of the second cylindrical portion, is 0.8 or more and 1.6 or less. a certain 。

[0019] In the above invention, values of the first interference (δ1) and the second interference (δ2) may be the same.

Effect of the Invention

[0020] According to the present invention, it is less susceptible to the influence of operating conditions and installation conditions of the rotating electrical machine, and the rotor can be stably rotated.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0022] As shown in FIG. 1, a rotor 10 of a rotating electrical machine according to an embodiment of the present invention includes a rotor sleeve (hereinafter referred to as "sleeve") 1, a permanent magnet 2, and a shaft 3 provided on the end side of the permanent magnet 2. The rotor 10 is a component installed in a rotating electrical machine and is installed together with a stator in the housing of the rotating electrical machine.

[0023] The permanent magnet 2 is cylindrical and is arranged inside the sleeve 1 so that the outer peripheral surface contacts the inner peripheral surface of the sleeve 1. The permanent magnet 2 and the sleeve 1 are arranged coaxially. The length of the permanent magnet 2 is shorter than the length of the sleeve 1, the permanent magnet 2 is arranged substantially at the center of the sleeve 1, and the ends of the permanent magnet 2 are located inside the sleeve 1.

[0024] The shaft 3 is cylindrical and is arranged inside the sleeve 1 so that the outer peripheral surface contacts the inner peripheral surface of the sleeve 1. The shaft 3 is arranged coaxially with the permanent magnet 2 and the sleeve 1. In the rotor 10, two shafts 3 are provided, and the two shafts 3 are respectively arranged at the ends on both sides of the permanent magnet 2, and the ends of the shaft 3 and the ends of the permanent magnet 2 are in contact inside the sleeve 1.

[0025] The sleeve 1 includes a first cylindrical portion 4 made of metal and a second cylindrical portion 5 made of fiber-reinforced plastic, and the first cylindrical portion 4 is arranged inside the second cylindrical portion 5. The axial lengths of the first cylindrical portion 4 and the second cylindrical portion 5 are longer than the axial length of the permanent magnet 2.

[0026] The first cylindrical portion 4 is made of a metal such as stainless steel and has a cylindrical shape with a constant inner diameter and outer diameter. Accordingly, unlike the case where the cylindrical member made of metal has a tapered shape, the pressing force can be made uniform over the length direction. The permanent magnet 2 is disposed inside the first cylindrical portion 4 such that the outer surface of the permanent magnet 2 contacts the inner surface thereof.

[0027] The second cylindrical portion 5 is made of a fiber-reinforced plastic such as CFRP (carbon fiber reinforced plastic) and has a cylindrical shape with a constant inner diameter and outer diameter. Accordingly, unlike the case where the cylindrical member made of fiber-reinforced plastic has a tapered shape, the pressing force can be made uniform over the length direction. The first cylindrical portion 4 is disposed inside the second cylindrical portion 5 such that the outer surface of the first cylindrical portion 4 contacts the inner surface thereof.

[0028] The thickness of the second cylindrical portion 5 is larger than the thickness of the first cylindrical portion 4 over the entire length direction from one end to the other end of the first cylindrical portion 4 and the second cylindrical portion 5. Accordingly, the first cylindrical portion 4 can be surely fixed inside by the pressing force of the second cylindrical portion 5 made of fiber-reinforced plastic. Unlike the present embodiment, when the thickness of the cylindrical portion made of fiber-reinforced plastic disposed outside is smaller than the thickness of the cylindrical portion made of metal disposed inside, the pressing force is weak, and thus creep deformation is likely to occur under the conditions where the rotating electric machine is used at a super high speed for a long period with heat cycles. In contrast, in the present embodiment, creep deformation can be suppressed even under such conditions.

[0029] Next, with reference to FIGS. 2 and 3, a method for manufacturing the rotor sleeve 1 and a method for manufacturing the rotor 10 will be described. First, in order to manufacture the sleeve 1, the first cylindrical portion 4 made of metal and the second cylindrical portion 5 made of fiber-reinforced plastic are separately manufactured (step S11).

[0030] Then, as shown in Fig. 3(A), a metal first cylindrical portion 4 having a cylindrical shape is press-fitted into the inside of a second cylindrical portion 5 made of fiber-reinforced plastic having a cylindrical shape (first press-fitting step) (step S12). Specifically, a lubricant such as molybdenum disulfide lubricant is applied to the surface of the first cylindrical portion 4, and the first cylindrical portion 4 is press-fitted into the inside of the second cylindrical portion 5 by a press.

[0031] Before the first press-fitting step, the outer diameter of the first cylindrical portion 4 disposed inside is larger than the inner diameter of the second cylindrical portion 5 disposed outside. That is, the first cylindrical portion 4 and the second cylindrical portion 5 are manufactured so as to have an interference δ2 (second interference), which is the difference between the outer diameter of the first cylindrical portion 4 and the inner diameter of the second cylindrical portion 5 before the first press-fitting step.

[0032] By the first press-fitting step, the first cylindrical portion 4 is disposed inside the second cylindrical portion 5 so that the outer surface of the first cylindrical portion 4 contacts the inner surface of the second cylindrical portion 5. The interference δ2 (second interference) is set to a value that can appropriately press-fit the metal first cylindrical portion 4 into the inside of the fiber-reinforced plastic second cylindrical portion 5. Thereby, the sleeve 1 according to the present embodiment is manufactured.

[0033] Next, as shown in Fig. 3(B), a cylindrical permanent magnet 2 is press-fitted into the inside of the sleeve 1 manufactured above, that is, the inside of the first cylindrical portion 4 disposed inside the second cylindrical portion 5 (second press-fitting step) (step S13). Specifically, a lubricant such as molybdenum disulfide lubricant is applied to the surface of the permanent magnet 2, and the permanent magnet 2 is press-fitted into the inside of the first cylindrical portion 4 of the sleeve 1 by a press.

[0034] Before the second press-fitting step, the outer diameter of the permanent magnet 2 disposed inside is larger than the inner diameter of the first cylindrical portion 4 in a state where it is disposed inside the second cylindrical portion 5. That is, the permanent magnet 2, the first cylindrical portion 4, and the second cylindrical portion 5 are manufactured so as to have an interference δ1 (first interference), which is the difference between the outer diameter of the permanent magnet 2 before the second press-fitting step and the inner diameter of the first cylindrical portion 4 in a state where it is disposed inside the second cylindrical portion 5.

[0035] In the second press-fitting process, the permanent magnet 2 is disposed inside the first cylindrical portion 4 such that the outer surface of the permanent magnet 2 contacts the inner surface of the first cylindrical portion 4. The interference δ1 (first interference) may be a value commonly used when press-fitting the permanent magnet into the sleeve.

[0036] Finally, as shown in FIG. 3(C), the shaft 3 having a cylindrical shape is press-fitted into the inside of the first cylindrical portion 4 in a state where the permanent magnet 2 is disposed inside the first cylindrical portion 4 of the sleeve 1 (step S14). The shaft 3 is press-fitted into each of the end portions on both sides of the permanent magnet 2. Thereby, the rotor 10 according to the present embodiment is manufactured.

[0037] Next, the interference set for each member for the above-described press-fitting will be described. The ratio (δ2 / δ1) of the interference δ2, which is the difference between the outer diameter of the permanent magnet 2 before the second press-fitting process and the inner diameter of the first cylindrical portion 4 in a state where it is disposed inside the second cylindrical portion 5, to the interference δ1, which is the difference between the outer diameter of the first cylindrical portion 4 before the first press-fitting process and the inner diameter of the second cylindrical portion 5, is desirably 0.8 or more and 1.6 or less. In particular, it is even better that the values of the interference δ1 and the interference δ2 are the same (δ2 / δ1 = 1.0). The reason is as follows.

[0038] After manufacturing the sleeve 1 and further manufacturing the rotor 10, a creep test was performed on the rotor 10. The creep test was performed under the conditions of 150°C for 72 hours. The wall thickness of the first cylindrical portion 4 was set to a plurality of values, and the values of the interference δ1 and the interference δ2 were each set to a plurality of values to manufacture a plurality of types of rotors 10, and a creep test was performed on each rotor 10. Then, the permanent magnet 2 was removed, and the inner diameter of the metal first cylindrical portion 4 was measured. And the change amount of the inner diameter of the first cylindrical portion 4 before and after the creep test was calculated.

[0039] As a result, as shown in Fig. 4, regardless of the wall thickness of the first cylindrical portion 4 and the absolute values of the tightening margins δ1 and δ2, when the ratio (δ2 / δ1) of the tightening margin δ2 to the tightening margin δ1 is 0.8 or more and 1.6 or less, the change amount of the inner diameter of the first cylindrical portion 4 before and after the creep test becomes relatively small. In particular, when the ratio (δ2 / δ1) of the tightening margin δ2 to the tightening margin δ1 is 1.0, the change amount of the inner diameter of the first cylindrical portion 4 before and after the creep test becomes the minimum.

[0040] That is, regardless of whether the creep test is carried out, when the ratio (δ2 / δ1) of the tightening margin δ2 to the tightening margin δ1 is within the above-mentioned range, it can be said that the metal first cylindrical portion 4 is deformed within the elastic region without plastic deformation. Therefore, even when the rotor 10 is used under severe conditions such as high temperature, the tightening force of the sleeve 1 on the permanent magnet 2 can be maintained. On the other hand, when the ratio (δ2 / δ1) of the tightening margin δ2 to the tightening margin δ1 is less than 0.8 or exceeds 1.6, since the change amount of the inner diameter of the first cylindrical portion 4 before and after the creep test is relatively large, there is a possibility that the tightening force of the sleeve 1 on the permanent magnet 2 becomes relatively low.

Description of Reference Numerals

[0041] 1: Sleeve for Rotor (Sleeve) 2: Permanent Magnet 3: Shaft 4: First Cylindrical Portion 5: Second Cylindrical Portion 10: Rotor

Claims

1. A rotor sleeve for use in a rotor of a rotating electric machine, the rotor sleeve including a permanent magnet, a shaft provided on an end side of the permanent magnet, and a rotor sleeve in which the permanent magnet and the shaft are disposed, a first cylindrical portion made of a metal other than a shape memory material, the first cylindrical portion having a cylindrical shape with a constant inner diameter and an outer diameter, the permanent magnet being disposed inside the first cylindrical portion so that the outer surface of the permanent magnet is in contact with the inner surface of the first cylindrical portion; A second cylindrical portion made of fiber reinforced plastic, the second cylindrical portion having a cylindrical shape with a constant inner diameter, the first cylindrical portion being disposed inside the second cylindrical portion so that the outer surface of the first cylindrical portion is in contact with the inner surface of the second cylindrical portion; Equipped with The thickness of the second cylindrical portion is greater than the thickness of the first cylindrical portion over the entire length direction from one end to the other end of the first cylindrical portion and the second cylindrical portion, A rotor sleeve, characterized in that the first cylindrical portion is press-fitted into the second cylindrical portion.

2. A rotor sleeve according to claim 1 ; a permanent magnet disposed inside the first cylindrical portion of the rotor sleeve; a shaft disposed inside the first cylindrical portion of the rotor sleeve and provided on an end side of the permanent magnet; Equipped with The rotor of the rotating electric machine, wherein the permanent magnet is arranged in a press-fit state inside the first cylindrical portion.

3. The rotor for a rotating electric machine according to claim 2 , wherein an axial length of the first cylindrical portion and the second cylindrical portion is longer than an axial length of the permanent magnet.

4. A manufacturing method of a rotor for a rotating electric machine having a permanent magnet, a shaft provided on an end side of the permanent magnet, and a rotor sleeve in which the permanent magnet and the shaft are disposed, comprising the steps of: a first press-fitting step of press-fitting a first cylindrical portion made of metal and having a cylindrical shape into a second cylindrical portion made of fiber-reinforced plastic; a second press-fitting step of press-fitting a cylindrical permanent magnet into the first cylindrical portion while the permanent magnet is disposed inside the second cylindrical portion; Equipped with The thickness of the second cylindrical portion is greater than the thickness of the first cylindrical portion, Before the first press-fitting step, an outer diameter of the first cylindrical portion is larger than an inner diameter of the second cylindrical portion, the first cylindrical portion is disposed inside the second cylindrical portion such that an outer surface of the first cylindrical portion is in contact with an inner surface of the second cylindrical portion by the first press-fitting step; Before the second press-fitting step, an outer diameter of the permanent magnet is larger than an inner diameter of the first cylindrical portion when the permanent magnet is disposed inside the second cylindrical portion, The second press-fitting step places the permanent magnet inside the first cylindrical portion such that an outer surface of the permanent magnet is in contact with an inner surface of the first cylindrical portion, A manufacturing method for a rotor for a rotating electric machine, characterized in that a ratio (δ2 / δ1) of a second interference (δ2), which is the difference between the outer diameter of the first cylindrical portion and the inner diameter of the second cylindrical portion before the first press-fitting process, to a first interference (δ1), which is the difference between the outer diameter of the permanent magnet before the second press-fitting process and the inner diameter of the first cylindrical portion when disposed inside the second cylindrical portion, is 0.8 or greater and 1.6 or less.

5. 5. The method for manufacturing a rotor for a rotating electric machine according to claim 4, wherein the first interference (δ1) and the second interference (δ2) have the same value.

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