JP2006109676A - Rotor and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotor which can be reduced in the eccentricity of a permanent magnet and can be enhanced in the fracture resistance of the permanent magnet. <P>SOLUTION: The rotor comprises an inner cylinder 2 having protruded stripes 21 on the outer peripheral part, an outer cylinder 3 which is loosely fitted to the outer periphery of the inner cylinder 2 and covers the permanent magnet 4 with respect to the inner cylinder 2, a cushioning layer 5 composed of a silicon synthetic resin which is filled between the inner cylinder 2 and the outer cylinder 3 and holds the permanent magnet 4, and a support cylinder 1 which is fitted in the inside of the inner cylinder 2 so that it can be freely inserted and detached to integrally rotate with the inner cylinder 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electric motor rotor and a method of manufacturing the same.

  The electric motor includes a rotor having a magnet holding cylinder and a permanent magnet arranged on the outer periphery of the magnet holding cylinder, and a stator arranged on the outer periphery of the permanent magnet. However, the electric motor has a problem that the rotor is easily decentered with respect to the stator, the rotor is easily inclined with respect to the stator, and eddy current loss of the permanent magnet portion easily occurs. There has been a problem that the permanent magnet breaks due to thermal deformation of the permanent magnet portion.

As a rotor for reducing eccentricity and inclination of a rotor, a rotor having a cylindrical permanent magnet and a special rubber buffer layer coupled to the inside of the permanent magnet is known (for example, see Patent Document 1). ing.
Further, as a rotor for reducing eddy current loss in a permanent magnet portion, a rotor having an insulating layer between a plurality of cylindrical permanent magnets (see, for example, Patent Document 2) is known.
Further, as a rotor capable of preventing thermal destruction, a rotor in which a cylindrical permanent magnet is loosely fitted in a magnet holding cylinder, and the permanent magnet is bonded to the magnet holding cylinder with a silicon-based adhesive (for example, Patent Documents) 3) is known.
JP 2001-327105 A Japanese Patent Laid-Open No. 08-163801 Japanese Patent Laid-Open No. 08-154351

  However, in the case of a rotor configured as in Patent Document 1, when it is used in an electric motor of an electric power steering device that requires high torque at low speed and is expected to be relatively high temperature, There is a problem that the permanent magnet is easily cracked by heat.

  Further, in the case of the rotor configured as in Patent Document 2, when employed in the electric motor of the electric power steering apparatus, the rotor is deformed by heat, the insulating layer is pressed by the deformed portion, and is permanently There is a problem that the magnet is easily cracked.

  Moreover, in the rotor comprised like patent document 3, since a cylindrical single permanent magnet is used, there exists a problem that a permanent magnet is huge and manufacture of a permanent magnet is difficult. .

  As the electric motor of the electric power steering apparatus in which the electric motor is used for steering assistance, the magnet holding cylinder of the rotor is integrally coupled in the middle of the steering shaft, and the rotational force of the electric motor is obtained without passing through the reduction mechanism. When configured to transmit directly to the steering shaft, high torque is required at low speed rotation, but since the electric motor is disposed in the passenger compartment, the electric motor can be increased in the radial direction so that high torque can be obtained. If the rotor of the electric motor is regarded as a simple cylinder, generally the inertia of the cylinder is proportional to the square of the outer diameter D and the mass M, and in the electric power steering device, the outer diameter D is large. Since the inertia term increases and the return characteristics of the steering wheel deteriorate due to the diameter increase, it is required to install advanced correction control or correction mechanism, which increases the cost and is allowed on the vehicle side. That to cause the installation on the interference of the volume margin beyond peripherals, it is difficult mounting to the vehicle body when it is not possible to adopt the configuration is likely to occur. When the hollow cylinder is used to reduce the inertia when the diameter is increased, the inertia is indicated by the sum of the square of the outer diameter D and the square of the inner diameter d of the hollow cylinder. Since it is proportional, the rotor itself can be reduced in weight by merely thinning the cylinder with the inner diameter d by the axial length L, but it cannot always be reduced more than the inertia at the time of the cylinder. In order to cope with many cases as described above, the electric motor is required to be elongated in the axial direction to obtain a high torque.

Here, there is a magnetization orientation direction as a feature of the generation of the permanent magnet. The orientation direction of magnetization is a predetermined magnetization direction (generally referred to as N pole or S pole) by applying a two-dimensional or three-dimensional magnetization magnetic field from the outside to a composition structure in a permanent magnet called a magnetic domain. It is determined by being magnetized in the direction).
Permanent magnets whose magnetization orientation directions are determined are often shipped in a non-magnetized state, which is magnetized or demagnetized according to the specifications of the user of the permanent magnet.

  When a permanent magnet whose magnetization orientation direction has been determined is magnetized, it is likely to be magnetized as a property of magnetization orientation (hereinafter referred to as the easy axis of magnetization, and in many cases almost coincides with the direction of magnetic force in the production of permanent magnets. ) And the direction in which magnetization is difficult (hereinafter referred to as the hard axis), and in many cases, the direction perpendicular to the direction of the magnetic force is pointed out in the production of the permanent magnet, which is almost equal to the lamination direction and the circumferential direction of the permanent magnet. Many).

The thermal expansion coefficients of the easy magnetization axis and the hard magnetization axis generally have positive values, but rare earth permanent magnets such as neodymium-iron-boron systems often have negative values for the hard magnetization axis. When the permanent magnets are stacked and disposed without gaps on the motor shaft, the permanent magnets expand in the motor axial direction and circumferential direction at low temperatures, and the residual stress etc. in the permanent magnet and the axial direction and circumferential direction of the permanent magnet There is a problem that it is damaged due to a synergistic effect with the arrangement relationship.
When a rare earth-based permanent magnet such as the neodymium-iron-boron system is laminated on the motor shaft, a predetermined gap for avoiding damage is created by some method, or sufficient for expansion and contraction of the motor shaft and the permanent magnet. A high-performance adhesive that has high reversibility that can be followed and that satisfies the specified durability specifications for the surrounding environmental characteristics (humidity, oil resistance, temperature, salt resistance, etc.), and sufficient performance as an adhesive is required. It is necessary to provide an adhesive layer width.

  However, by providing a predetermined gap for avoiding breakage of the adhesive layer and the permanent magnet, the outer circumference of the permanent magnet and the motor shaft or Since the various geometrical intersections (coaxiality, roundness, cylindricity, etc.) with respect to the steering shaft need to be set gently for various reasons such as cost, the eccentricity of the rotor itself increases as a result. In the electric power steering apparatus having the above, there is a problem that pulsation torque increases and steering feeling deteriorates.

In particular, in the ambient environment characteristics, the recent general temperature guarantee range required for the electric power steering apparatus is about −40 ° C. to + 85 ° C. in the vehicle interior, but in the engine room for substantial durability guarantee. -40 ° C to + 125 ° C are often required, including those mounted on the board, and there are parts that must cover up to -55 ° C to + 180 ° C specifications for each part. There is a case where it is necessary to withstand a temperature change of ° C or more for an extremely long time.
Based on these circumstances, if the axial length is increased to obtain high torque, the amount of mechanical torsion of the rotor increases, resulting in driver discomfort (feeling that a spring is interposed on the steering shaft). ), The steering of the electric power steering apparatus is performed while considering a balance of quality, performance, and cost with respect to the dimensional change of the temperature expansion and contraction while maintaining a predetermined rigidity in the entire rotor. Responding to the deterioration of feeling is a major design issue.

  As described above, as the axial length of the electric motor increases, it becomes difficult to manufacture the rotor permanent magnet and the rotor, and the permanent magnet is liable to break due to thermal deformation.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a rotor that can reduce the eccentricity of the rotor and can improve the breakage resistance of the permanent magnet. It is an object of the present invention to provide a manufacturing method capable of easily manufacturing a rotor having a relatively long axial length while maintaining a predetermined amount of rigidity.

  The rotor according to the first invention is a rotor in which a plurality of permanent magnets are arranged around a magnet holding cylinder, wherein the magnet holding cylinder is loosely fitted to an inner cylinder and an outer periphery of the inner cylinder, An outer cylinder that covers the permanent magnet between the inner cylinder and a buffer layer that holds the permanent magnet between the inner cylinder and the outer cylinder.

  The rotor according to a second aspect of the present invention is characterized in that, in the first aspect of the present invention, the rotor includes a support cylinder that is detachably fitted inside the inner cylinder and rotates integrally with the inner cylinder.

  A method for manufacturing a rotor according to a third aspect of the present invention includes a step of temporarily fixing a plurality of annular permanent magnets to an outer peripheral portion of an inner cylinder, a step of loosely fitting a plurality of outer cylinders around the outer periphery of the permanent magnet, Disposing an annular plate having a through-hole penetrating in the plate thickness direction and facing a space between the inner cylinder and the outer cylinder between the adjacent outer cylinders, and separating the outer cylinder in the central axis direction; and It includes a step of supplying a buffer material melted into a space between the cylinder and the outer cylinder to form a buffer layer, and a step of removing the annular plate.

  According to the first invention, since the permanent magnet is disposed between the inner cylinder and the outer cylinder and is held between the inner cylinder and the outer cylinder by the buffer layer, the eccentricity of the permanent magnet can be reduced, and the permanent magnet is resistant to breakage. In addition, it is possible to reduce the damage of the permanent magnet due to heat. In addition, since the plurality of permanent magnets are formed integrally with the inner cylinder, the outer cylinder, and the buffer layer, it can be easily incorporated into the electric motor.

  According to the second invention, since the inner cylinder including the permanent magnet can be inserted into and removed from the support cylinder, the replacement of the permanent magnet portion can be simplified, and the support cylinder only needs to support the inner cylinder. The rotor structure does not depend on the shape of the support cylinder, and it is possible to give the support cylinder a high degree of design freedom that is difficult to provide with a conventional rotor structure such as providing an impact absorbing mechanism in the support cylinder.

  According to the third invention, a plurality of permanent magnets and outer cylinders are provided, and the permanent magnets and outer cylinders can be integrated with one inner cylinder. Therefore, a rotor having a relatively long axial length can be easily manufactured.

Hereinafter, the present invention will be described in detail with reference to the drawings showing embodiments thereof.
Embodiment 1
1 is a schematic perspective view showing the structure of a rotor according to the present invention, FIG. 2 is an enlarged sectional view taken along line II-II in FIG. 1, FIG. 3 is an enlarged sectional view taken along line III-III in FIG. (A) and (b) are perspective views of the permanent magnet.

  The rotor includes a cylindrical support cylinder 1, a metal inner cylinder 2 that is externally fitted to the support cylinder 1, and a metal outer cylinder 3 that is loosely fitted around the outer circumference of the inner cylinder 2. And a plurality of permanent magnets 4 disposed between the inner cylinder 2 and the outer cylinder 3 and a buffer layer 5 for holding the permanent magnet 4 between the inner cylinder 2 and the outer cylinder 3.

  The inner cylinder 2 is made of a pipe made of metal such as aluminum, and is formed with an annular ridge 21 that protrudes radially outward from a plurality of positions separated in the central axis direction.

  The permanent magnet 4 has a curved substantially rectangular parallelepiped shape as shown in FIG. 4 (a). However, the permanent magnet 4 may have a non-curved substantially rectangular parallelepiped shape as shown in FIG. Not. Grooves 41 that engage with the ridges 21 are provided on one surface of the permanent magnet 4. The grooves 41 are arranged at a plurality of circumferential positions of the inner cylinder 2 along the ridges 21. By combining, the position of the permanent magnet 4 with respect to the inner cylinder 2 is determined. A first non-permanent magnet part a is provided between the permanent magnets 4 in the circumferential direction position, and a second non-permanent magnet part b is provided between the permanent magnets 4 in the central axis direction position.

  The buffer layer 5 is made of a silicon-based synthetic resin material having extensibility and excellent heat resistance, etc., and is filled in the space between the inner cylinder 2 and the outer cylinder 3 in a molten state and solidifies by being solidified. The magnet 4 is wrapped and formed so as to hold the permanent magnet 4 in a buffered manner.

  The outer cylinder 3 is made of a pipe made of a metal such as aluminum, and is formed in a size that is loosely fitted around the outer periphery of the permanent magnet 4 arranged at a plurality of circumferential positions along the ridges 21. The portions corresponding to the first and second non-permanent magnet portions a and b are squeezed into the concave stripes to prevent the position of the permanent magnet 4 from being displaced.

  The rotor configured as described above is manufactured by inserting the inner cylinder 2 into an upright columnar jig, loosely fitting the outer cylinder 3 around the outer periphery of the inner cylinder 2, and the inner cylinder 2 and the outer cylinder. By inserting a plurality of permanent magnets 4 between the cylinders 3 and engaging the grooves 41 of the permanent magnets 4 with the ridges 21 of the inner cylinder 2, the position of the permanent magnets 4 is determined, and then the inner cylinder 2 and the outer The space between the cylinders 3 is filled with molten silicon-based synthetic resin material, and the synthetic resin material is solidified to form a buffer layer 5, and the buffer layer 5 holds each permanent magnet 4. And the location corresponding to the 1st and 2nd non-permanent magnet parts a and b in the outer cylinder 3 is caulked into the recesses to prevent the positional displacement of the permanent magnet 4, and the inner cylinder 2 and the plurality of permanent magnets 4. The buffer layer 5 and the outer cylinder 3 are integrated. Thus, since the permanent magnet part is integrated, the assembly | attachment to an electric motor can be performed easily. Moreover, since the permanent magnet 4 is held by the buffer layer 5 between the inner cylinder 2 and the outer cylinder 3 which are concentric, the eccentricity of the permanent magnet 4 can be reduced, and the damage resistance of the permanent magnet 4 is improved. Furthermore, since the permanent magnet 4 has a stretchability and is held by the buffer layer 5 made of a silicon-based synthetic resin material having excellent heat resistance, the permanent magnet 4 can be prevented from being damaged by heat. .

  FIG. 5 is a schematic diagram showing a configuration of an electric power steering apparatus in which an electric motor having a rotor according to the present invention is incorporated. The assembly of the permanent magnets 4 manufactured as described above is externally fitted and fixed to the support cylinder 1 having magnetism so as to be a detachable element. For example, the support cylinder 1 is integrally coupled to the rotor in the middle of the steering shaft 10 in the electric power steering apparatus. In FIG. 5, reference numeral 11 denotes a steering wheel connected to the upper end of the steering shaft 10, 12 denotes a motor housing that rotatably supports the rotor, 13 denotes a stator fixed inside the motor housing 12, and 14 denotes a steering shaft 10. An intermediate shaft that is interlocked and connected to the lower end of the intermediate shaft via a universal shaft joint, 15 is a pinion that the transmission shaft is interlocked and connected to the lower end of the intermediate shaft, and 16 is a rack shaft that has rack teeth that mesh with the pinion 15.

Embodiment 2
FIG. 6 is a schematic perspective view showing the configuration of the second embodiment. Instead of equalizing the circumferential positions of the permanent magnets 4 arranged at a plurality of positions in the central axis direction of the inner cylinder 2 as in the first embodiment, the rotor of the permanent magnets 4 arranged at the positions in the central axis direction is used. The circumferential positions are alternately changed (see FIG. 6), and the first non-permanent magnet portions a and, consequently, the caulking portions of the outer cylinder 3 are alternately changed. The shape of the longitudinal side surface and the shape of the transverse plane are shown in FIG. 3 is the same as FIG. 3 and manufactured in the same manner as in the first embodiment.
Since other configurations and operations are the same as those in the first embodiment, the same reference numerals are given to the same configurations, and detailed descriptions and descriptions of the operations and effects are omitted.

Embodiment 3
FIG. 7 is a schematic perspective view showing the configuration of the third embodiment, FIG. 8 is a perspective view of the inner cylinder 2, and FIG. 9 is a perspective view of the permanent magnet 4. In this rotor, a plurality of cylindrical permanent magnets 4 are held between the inner cylinder 2 and the outer cylinder 3 by the buffer layer 5 instead of using the permanent magnet 4 having a substantially rectangular parallelepiped shape as in the first and second embodiments. Is.

  In the third embodiment, the inner cylinder 2 made of a metal pipe such as aluminum is formed with spiral ridges 22 protruding radially outward across both ends.

  The permanent magnet 4 has a cylindrical shape slightly larger in diameter than the inner cylinder 2, and a spiral groove 42 that engages with the spiral protrusion 22 is provided on both ends of the inner periphery 2. The inner cylinder 2 is disposed at a plurality of positions in the central axis direction, and the groove 42 is engaged with the ridge 22 to determine the position of the permanent magnet 4 with respect to the inner cylinder 2. It is comprised so that the magnet part c can be performed.

  In the outer cylinder 3 made of a metal pipe such as aluminum, a portion corresponding to the third non-permanent magnet portion c is crimped into a concave line, and the displacement of the permanent magnet 4 is prevented.

  In the manufacture of the rotor configured as in the third embodiment, the inner cylinder 2 is inserted into an upright columnar jig, and a plurality of permanent magnets 4 are inserted into the outer side of the inner cylinder 2. The permanent magnet 4 can be inserted along the ridge 22 by engaging the groove 42 with the ridge 22 and turning it, and is stopped at the interval of the third non-permanent magnet portion c. Next, the outer cylinder 3 is loosely fitted around the outer periphery of the permanent magnet 4, and the space between the inner cylinder 2 and the outer cylinder 3 is filled with the molten silicon-based synthetic resin material, and the synthetic resin material is solidified. A buffer layer 5 is formed, and the buffer layer 5 holds each permanent magnet 4 in a buffering manner. And the location corresponding to the 3rd non-permanent magnet part c in the outer cylinder 3 is crimped by the groove, and the position shift of the permanent magnet 4 is prevented, and the inner cylinder 2, the plurality of permanent magnets 4, the buffer layer 5 and The outer cylinder 3 is integrated. Since other configurations and operations are the same as those in the first embodiment, the same reference numerals are given to the same configurations, and detailed descriptions and descriptions of the operations and effects are omitted.

Embodiment 4
10 is a schematic perspective view showing the configuration of the fourth embodiment, FIG. 11 is an enlarged sectional view taken along line XI-XI in FIG. 10, FIG. 12 is an enlarged sectional view taken along line XII-XII in FIG. It is a top view of a board. In this rotor, instead of using the rectangular parallelepiped permanent magnet 4 as in the first and second embodiments, a plurality of cylindrical permanent magnets 4 are held by the buffer layer 5 between the inner cylinder 2 and the plurality of outer cylinders 3. It is a thing.

  In the fourth embodiment, an adhesive is applied to the outer peripheral portion of the inner cylinder 2 made of a metal pipe such as aluminum at a plurality of positions separated in the central axis direction.

  The permanent magnet 4 has a cylindrical shape slightly larger in diameter than the inner cylinder 2, is fitted around the outer periphery of the inner cylinder 2, and is temporarily fixed by the adhesive.

  The outer cylinder 3 is formed to have a length substantially equal to that of the permanent magnet 4. An annular plate 6 is disposed between each outer cylinder 3 and each permanent magnet 4, and each outer cylinder 3 and each permanent magnet 4 is connected to the inner cylinder 2. It is spaced apart in the direction of the central axis.

  The annular plate 6 is formed of a disc having an inner diameter substantially the same as that of the inner cylinder 2 and having an outer diameter larger than that of the outer cylinder 3, and a slit 61 is provided in a part of the circumferential direction. The diameter can be increased by 61. Further, a through-hole 62 a that penetrates in a plate thickness direction at a plurality of circumferential positions and faces a first space between the permanent magnet 4 and the outer cylinder 3, and a second space between the permanent magnet 4 and the inner cylinder 2 And a through-hole 62b facing the surface.

In the manufacture of the rotor configured as in the fourth embodiment, an inner cylinder 2 whose outer peripheral portion is coated with an adhesive is inserted into an upright cylindrical jig, and the outer side of the inner cylinder 2 is inserted. The permanent magnet 4 is inserted, the permanent magnet 4 is temporarily fixed to the inner cylinder 2 with the adhesive, the outer cylinder 3 is loosely fitted around the outer periphery of the permanent magnet 4, and the outer cylinder 3 is annularly formed outside. The plate 6 is inserted. And the permanent magnet 4, the outer cylinder 3, and the annular plate 6 are inserted in order. In this case, the annular plate 6 is interposed between the adjacent permanent magnets 4 and between the adjacent outer cylinders 3, and the through hole 62 a on the outer diameter side of the annular plate 6 is formed in the first space between the permanent magnet 4 and the outer cylinder 3. At first, the first space between each permanent magnet 4 and each outer cylinder 3 communicates with a through hole 62a on the outer diameter side. Similarly, the through hole 62b on the inner diameter side of the annular plate 6 faces the second space between the permanent magnet 4 and the inner cylinder 2, and the second space communicates with the through hole 62b on the inner diameter side. Next, the melted silicon-based synthetic resin material is filled into the second space between the inner cylinder 2 and the permanent magnet 4 and the first space between the permanent magnet 4 and the outer cylinder 3. The synthetic resin material supplied to the second space passes through the through hole 62b on the inner diameter side of the annular plate 6, passes through the temporary fixing adhesive, and is filled into each second space. The synthetic resin material supplied to the spaces is filled in the first spaces through the through holes 62 a on the outer diameter side of the annular plate 6. A buffer layer 5 is formed by solidifying the filled synthetic resin material, and the buffer layer 5 holds each permanent magnet 4 and each outer cylinder 3. Next, the inner cylinder 2, the plurality of permanent magnets 4, the buffer layer 5, and the plurality of outer cylinders 3 are integrated by pulling each annular plate 6 radially outward and breaking and removing the annular plate 6. An annular groove is formed between the permanent magnets 4 and between the outer cylinders 3.
Since other configurations and operations are the same as those in the first embodiment, the same reference numerals are given to the same configurations, and detailed descriptions and descriptions of the operations and effects are omitted.

Embodiment 5
FIG. 14 is a schematic perspective view showing the configuration of the fifth embodiment. This rotor uses the annular plate 6 of the fifth embodiment instead of the configuration in which the portion corresponding to the first non-permanent magnet portion a in the outer cylinder 3 is crimped to the concave shape as in the first embodiment. After forming the buffer layer 5, the annular plate 6 is pulled outward in the radial direction, and the annular plate 6 is broken and removed to form an annular groove d in the first non-permanent magnet portion a (between the permanent magnets 4). It is comprised as follows.

In the fifth embodiment, the inner cylinder 2 and the permanent magnet 4 are those of the first embodiment, the outer cylinder 3 and the annular plate 6 are those of the fourth embodiment, and the space between the inner cylinder 2 and the outer cylinder 3. A melted silicon-based synthetic resin material is filled in, and the synthetic resin material is solidified to form a buffer layer 5, and the buffer layer 5 holds each permanent magnet 4. And the location corresponding to the 2nd non-permanent magnet part b in the outer cylinder 3 is crimped by the concave stripe, the position shift of the permanent magnet 4 is prevented, and further, each annular plate 6 is pulled radially outward, By destroying and removing the annular plate 6, the inner cylinder 2, the plurality of permanent magnets 4, the buffer layer 5 and the plurality of outer cylinders 3 are integrated, and an annular groove d is formed between the permanent magnets 4 and between the outer cylinders 3. Has been.
Since other configurations and operations are the same as those of the first and fourth embodiments, the same reference numerals are given to the same configurations, and the detailed description and description of the operations and effects are omitted.

Although the rotor according to the embodiment described above includes the support cylinder 1, the support cylinder 1 is eliminated and the inner cylinder 2, the outer cylinder 3, the permanent magnet 4, and the buffer layer 5 are provided. Also good.
In the embodiment described above, a plurality of permanent magnets 4 are arranged between the inner cylinder 2 and the outer cylinder 3 in the central axis direction. One magnet 4 may be provided.
The rotor according to the present invention is incorporated in a brushless type electric motor, but may be incorporated in a brush type electric motor.

It is a typical perspective view which shows the structure of the rotor which concerns on this invention. It is an expanded sectional view of the II-II line of FIG. It is an expanded sectional view of the III-III line of FIG. It is a perspective view of the permanent magnet of the rotor which concerns on this invention. It is a mimetic diagram showing the composition of the electric power steering device with which the electric motor which has the rotor concerning the present invention was built. It is a typical perspective view which shows the structure of Embodiment 2 of the rotor which concerns on this invention. It is a typical perspective view which shows the structure of Embodiment 3 of the rotor which concerns on this invention. It is a perspective view of the inner cylinder of the rotor which concerns on this invention. It is a perspective view of the permanent magnet of the rotor which concerns on this invention. It is a typical perspective view which shows the structure of Embodiment 4 of the rotor which concerns on this invention. It is an expanded sectional view of the XI-XI line of FIG. It is an expanded sectional view of the XII-XII line | wire of FIG. It is a top view of the annular plate of the rotor which concerns on this invention. It is a typical perspective view which shows the structure of Embodiment 5 of the rotor which concerns on this invention.

Explanation of symbols

1 support cylinder 2 inner cylinder (magnet holding cylinder)
3 Outer cylinder (magnet holding cylinder)
4 Permanent magnet 5 Buffer layer 6 Annular plate 62a, 62b Through hole

Claims (3)

  In a rotor formed by arranging a plurality of permanent magnets around a magnet holding cylinder, the magnet holding cylinder is loosely fitted around an inner cylinder and an outer periphery of the inner cylinder, and the permanent magnet is interposed between the inner cylinder and the inner cylinder. And a buffer layer for holding the permanent magnet between the inner cylinder and the outer cylinder.   The rotor according to claim 1, further comprising a support cylinder that is fitted in and removable from the inside of the inner cylinder and rotates integrally with the inner cylinder. A step of temporarily fixing a plurality of annular permanent magnets to the outer peripheral portion of the inner cylinder, a step of loosely fitting a plurality of outer cylinders around the outer periphery of the permanent magnet, and a penetrating through the plate in the plate thickness direction. A step of disposing an annular plate having a through hole facing the space between the cylinders between the adjacent outer cylinders to separate the outer cylinders in the direction of the central axis, and a buffer melted in the space between the inner cylinder and the outer cylinder A method of manufacturing a rotor, comprising: supplying a material to form a buffer layer; and removing the annular plate.

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