JPH0578178U - Ultra high speed motor rotor - Google Patents

Abstract

(57) [Summary] [Structure] A cylindrical core 31 having an outer diameter larger than the outer diameter of the shaft 4, and a plurality of slots 32 which are opened only at both end faces of the core 31 and penetrate through in the axial direction. A plurality of axially extending rotor bars 5 formed by die-casting of aluminum, copper or an alloy thereof and ring-shaped short-circuiting of the rotor bars 5 provided on both end surfaces of the iron core portion 31 simultaneously with the rotor bars 5 by die-casting. The short-circuit ring 6, the outer periphery of the short-circuit ring 6 and the outer periphery of both ends of the rotor bar 5 are pressed from the outer peripheral direction, and the strength is higher than the strength of the iron core portion 31 between the rotor bar 5 and the outer peripheral surface of the iron core portion 31. It is a rotor of an ultra-high speed motor including a holding portion 72. [Effect] The strength of the both ends of the rotor bar and the part that presses the outer peripheral side of the short-circuit ring has been increased, so even if a large centrifugal force acts due to high speed rotation, the deformation does not increase, and stable ultra-high speed rotation is obtained. It is possible to provide a super high speed rotation motor that can be used.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rotor of a motor that rotates at an extremely high speed.

[0002]

[Prior Art]

 Conventionally, as a rotor for an ultra-high speed motor with a peripheral speed of the rotor exceeding 200 m / sec, a rotor bar formed by die-casting aluminum, copper or an alloy thereof in a plurality of axial directions on the iron core, and a rotor bar A solid rotor having a ring-shaped short-circuit ring is used. In this case, the temperature of the short-circuit ring rises due to the heat generated by the rotor, and the strength of the short-circuit ring is reduced. Therefore, a steel holding ring is provided on the outside of the short-circuit ring in the axial direction, a can is closely attached to the outer circumference of the rotor to cover it, and the ring and the can are welded by an electron beam or the like to form the short-circuit ring, the rotor bar, and the iron core. Japanese Patent Application Laid-Open No. 1-264550 and Japanese Patent Application Laid-Open No. 2-119557 have been disclosed in which they are joined to form an integral body and have strength to withstand centrifugal force.

[0003]

[Problems to be solved by the device]

 However, in the structure in which the outer circumference of the short-circuit ring, the rotor bar, and the iron core is pressed by the thin can, the can cannot withstand the centrifugal force of the short-circuit ring and the rotor bar in the case of ultra-high speed rotation, and the central part of the can However, there are drawbacks such as swelling and loss of balance, and contact with the stator core leading to damage. An object of the present invention is to provide a rotor for a high-speed motor that has a structure that can sufficiently withstand the centrifugal force of a short-circuit ring or a rotor bar and that can achieve stable ultra-high speed rotation.

[0004]

[Means for Solving the Problems]

 The present invention is a rotor for an ultra-high-speed motor that is composed of a solid rotor having a plurality of axially extending rotor bars and a short-circuit ring that short-circuits both ends of the rotor bar. And a plurality of axially extending cores formed by die-casting of aluminum, copper, or an alloy in a plurality of axially penetrating slots that open only at both end faces of the core. A rotor bar, a short-circuit ring provided on both end surfaces of the iron core portion and short-circuiting the rotor bar formed in a ring shape by die casting at the same time as the rotor bar in a ring shape, and an outer circumference of the short-circuit ring and an outer circumference of both end portions of the rotor bar. And a pressing portion having a strength higher than the strength of the iron core portion between the rotor bar and the outer peripheral surface of the iron core portion. Those were. In particular, the radial thickness of the pressing portion is equal to or greater than the radial thickness between the outer circumference of the rotor bar and the outer circumference of the iron core portion.

[0005]

[Action]

 The mass of the short-circuit ring is larger than the mass of the rotor bar, the centrifugal force acting on the short-circuit ring is larger than the centrifugal force acting on the rotor bar, and the presser ring that presses the outer peripheral surface of the short-circuit ring from the outer peripheral direction or the presser part provided on the iron core part. Centrifugal force, which is larger than that in the central part of the core, acts on the core, but the radial thickness of the retainer is the same as or thicker than the radial thickness between the outer circumference of the rotor bar and the outer circumference of the core. Since the strength is high, even if a large centrifugal force is applied by ultra-high speed rotation, the radial deformation of the pressing part does not become large, and the balance is not lost.

[0006]

【Example】

The present invention will be described with reference to the embodiments shown in the drawings. FIG. 1 is a side sectional view showing an embodiment of the present invention, in which a stator 2 having a stator coil 21 wound therein is fixed to the inside of a ring-shaped frame 1, and a rotor 3 and a shaft 4 are provided inside the stator 2 through a gap. It is formed and arranged integrally. The rotor 3 includes a cylindrical iron core portion 31 having an outer diameter larger than that of the shaft 4. A plurality of slots 32, which are open at both end surfaces of the iron core portion 31 and do not open on the outer periphery of the iron core portion 31, are provided at equal intervals in the circumferential direction and penetrate through the slots 32. Alternatively, a plurality of rotor bars 5 extending in the axial direction are formed by die casting of the alloy, and a short-circuit ring 6 that short-circuits both ends of the rotor bar 5 is formed. On both sides of the iron core portion 31, a cup-shaped holding ring 7 made of steel, which is the same material as the iron core portion 31 for pressing both ends of the short-circuit ring 6 and the rotor bar 5 from the outer peripheral direction, is provided. The outer diameter of the pressing ring 7 is the same as the outer diameter of the iron core portion 31, or is larger than the outer diameter of the iron core portion 31 and smaller than the inner diameter of the stator 2, and has a hole for shrink fitting the inner diameter to the outer circumference of the shaft 4. A disk-shaped collar portion 71 and a holding portion 72 having a hole that fits into the outer shape D ₁ of the short-circuiting ring 6 after turning shown in FIG. 3B are provided. As shown in FIGS. 2 (a) and 2 (b), the processing procedure of the rotor 3 is such that the slots 32 are machined on both end surfaces of the iron core portion 31 and the circles connecting the outer peripheral sides of the slots 32 are substantially the same. And a ring-shaped charging groove 33 having an inner peripheral surface concentric with the outer peripheral surface of the iron core portion 31 is provided by machining or the like, and aluminum or copper or A plurality of axially extending rotor bars 5 are formed by die casting of the alloy, and short-circuit rings 6 that short-circuit both ends thereof in a ring shape are formed. After that, as shown in FIGS. 3A and 3B, the outer diameter of the short-circuit ring 6 and the outer diameter D ₁ of both ends of the rotor bar 5 become smaller than the diameter D _{2 of the} circle connecting the outer circumferences of the rotor bars 5. As described above, S is cut from both ends of the iron core portion 31 and turned. By processing as described above, the inner diameter of the pressing portion 72 of the pressing ring 7 becomes smaller than the diameter of the circle connecting the outer peripheries of the rotor bars 5, and the thickness t ₁ of the pressing portion 72 of the pressing ring 7 becomes smaller. Is thicker than the radial thickness t ₂ between the outer circumference of the rotor bar 5 and the outer circumference of the iron core portion 31. With such a holding ring 7, the collar portion 71 is fitted onto the outer periphery of the shaft 4 by shrink fitting so that the end surface of the holding portion 72 is in contact with the end surface of the iron core portion 31, and the outer diameter of the short-circuit ring 6 and the rotor bar 5 are fitted. Both ends of the are pressed from the outer peripheral direction. Therefore, since the rotor bar 5 is contained in the slot 32 that does not open to the outer periphery of the iron core portion 31, the radial deformation is suppressed by the outer peripheral portion 34 of the iron core portion 31 even when a large centrifugal force is applied. Further, the short-circuit ring 6 is also pressed against the radial deformation by the pressing ring 7. Further, the mass of the short-circuit ring 6 is larger than that of the rotor bar 5, the centrifugal force acting on the short-circuit ring 6 is larger than the centrifugal force acting on the rotor bar 5, and the pressing ring 7 is subjected to a centrifugal force larger than that of the iron core 31. However, the radial thickness of the pressing portion 72 of the pressing ring 7 is thicker than the radial thickness between the outer circumference of the rotor bar 5 and the outer circumference of the iron core portion 31, and the strength thereof is higher, so that it is large due to the ultra-high speed rotation. Even if centrifugal force is applied, the radial deformation of the pressing ring 7 does not increase. FIG. 4 shows another embodiment, in which a gap G is provided between the end surface 73 of the stepped ring 73 between the collar portion 71 of the pressing ring 7 and the pressing portion 72 and the end surface of the short-circuiting ring 6, and the iron core portion 31 and the rotor bar 5. The difference in the amount of expansion in the axial direction is released to prevent deformation of the short circuit ring 6 and the rotor bar 5. Further, the collar portion 71 of the presser ring 7 is provided with a vent hole 74 penetrating in the axial direction, the presser portion 72 is penetrated in the radial direction, and a gap G is formed between the step end face 73 and the end face of the short-circuit ring 6. A ventilation hole 75 communicating with each other is provided. Therefore, the rotation of the rotor 3 produces cooling air passing through the ventilation hole 74, the gap G, and the ventilation hole 75, so that the cooling effect of the short-circuit ring 6 can be enhanced.

[0007]

[Effect of the device]

 As described above, according to the present invention, the strength of the die bar formed at both ends of the rotor bar and the portion that presses the outer peripheral side of the short-circuit ring is increased. There is an effect that it is possible to provide an ultra-high-speed rotation motor that can obtain stable ultra-high-speed rotation without increasing the size.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment of the present invention.

FIG. 2 is a side view and a front view of a rotor of the present invention during processing.

FIG. 3 is a side view and a front view of the rotor of the present invention during processing.

FIG. 4 is a side sectional view showing another embodiment of the present invention.

[Explanation of symbols]

 2 Stator 3 Rotor 31 Iron core part 32 Slot 33 Insertion groove 4 Shaft 5 Rotor bar 6 Short-circuit ring 7 Presser ring 71 Collar part 72 Presser part 74, 75 Vent hole

Continuation of front page (72) Inventor Noriaki Iwabuchi No. 2 Kurosaki Shiroishi, Hachimannishi-ku, Kitakyushu, Fukuoka Prefecture Yasukawa Electric Co., Ltd.

Claims (5)

[Scope of utility model registration request] 1. A rotor for an ultra-high speed motor comprising a solid rotor including a plurality of axially extending rotor bars and a short-circuit ring having both ends short-circuited in a ring shape, the rotor having an outer diameter larger than the outer diameter of the shaft. A cylindrical iron core part, a plurality of axially extending rotor bars formed by die casting of aluminum or copper or an alloy thereof in a plurality of axially penetrating slots opened only at both end faces of the iron core part, and A short-circuit ring that short-circuits the rotor bar formed in a ring shape by die casting at the same time as the rotor bar on both end surfaces of the iron core portion in a ring shape, and the outer circumference of the short-circuit ring and the outer circumferences of both ends of the rotor bar from the outer peripheral direction And a pressing portion having a strength higher than the strength of the iron core portion between the rotor bar and the outer peripheral surface of the iron core portion. An ultra-high-speed motor rotor characterized by. 2. The pressing portion is provided on a pressing ring that is in contact with the axial end surface of the short-circuit ring and is fitted to the shaft, and the outer diameter of the pressing portion is larger than the outer diameter of the iron core portion.
The rotor for an ultra high speed motor according to claim 1, wherein an inner diameter is formed smaller than a diameter of a circle connecting the outer circumference of the rotor bar. 3. The pressing portion is provided at both ends of the iron core portion, and an outer diameter of the pressing portion is larger than an outer diameter of the iron core portion.
The rotor for an ultra high speed motor according to claim 1, wherein an inner diameter is formed smaller than a diameter of a circle connecting the outer circumference of the rotor bar, and pressing rings are provided in contact with both end surfaces of the iron core portion. 4. The rotor for an ultra-high speed motor according to claim 2, wherein an axial gap is provided between the pressing ring and the short-circuit ring. 5. The ultra-high speed motor according to claim 4, wherein the holding ring is provided with a ventilation hole penetrating in the axial direction and communicating with the gap, and a ventilation hole penetrating in the radial direction and communicating with the gap. Rotor.