JP2006353076A - Rotor manufacturing method, rotor manufactured by this method, and motor using this rotor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotor manufacturing method, a rotor, and a motor that shortens heating time of an adhesive and that prevents permanent magnets from being separated with strong adhesive force even at high speed revolutions. <P>SOLUTION: The rotor manufacturing method adhers the permanent magnets to the outside circumference of iron cores, by applying the adhesive on the outside circumference of the iron core 3 stacked on a rotating shaft 2, arranges a plurality of segmented permanent magnets 4 at equal intervals, presses the permanent magnets 4 to hold them using a non-metal fixing jig 6, arranges high-frequency coils on the outside circumferential surface of the permanent magnets, and heating by induction the permanent magnets and the iron core by feeding a high-frequency current to the high-frequency coil 7. It is more desirable that the temperature difference (T<SB>1</SB>-T<SB>2</SB>) between the temperature of the permanent magnets (T<SB>1</SB>) and that of the iron core (T<SB>2</SB>) is made 10°C or larger when heated by induction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a rotor manufacturing method in which a plurality of permanent magnets are fixed to an outer periphery of a rotor core with an adhesive, a rotor, and a motor thereof.

In a conventional permanent magnet type rotor, a thermosetting adhesive is uniformly applied to the outer peripheral surface of the rotor yoke fitted and fixed to the rotating shaft, and a plurality of permanent magnets are equally spaced on the outer peripheral surface of the yoke. After arranging and fixing, the adhesive is put in a furnace as it is, and the adhesive is heat-cured (see, for example, Patent Document 1). Further, since a strong centrifugal force is generated by high-speed rotation in such a permanent magnet type rotor, a strong adhesive force is required for the adhesive, and a heat-curing type epoxy adhesive is usually used.
JP 2004-236366 A (page 3)

However, in the conventional method, since a large number of rotors are put into the furnace, it takes a long time to heat in order to equalize the temperature inside the furnace. Also, if the heating time is shortened, heating unevenness occurs in the furnace, causing problems such as poor adhesion. Furthermore, since the entire rotor is heated in the furnace, it takes time to cool down, and there is a problem that the product cannot be quickly transferred to the next process and the product is left unsatisfactory.
In furnace heating, both permanent magnets with a coefficient of thermal expansion of nearly zero and iron cores of 1.2 × 10 ⁻⁵ / K are heated to the same temperature. There was also a problem such as being connected to.
The present invention has been made in view of such problems, and a permanent magnet-type rotor capable of efficiently performing adhesion between a permanent magnet and an iron core in a short time and improving the adhesion force, and its An object of the present invention is to provide a manufacturing method and a motor using the rotor.

In order to solve the above problems, the present invention is configured as follows.
The invention according to claim 1 is a method of manufacturing a rotor in which an adhesive is applied to the outer periphery of an iron core laminated on a rotating shaft, and a plurality of segment-shaped permanent magnets are fixed at equal intervals.
The permanent magnet is pressed and held on the outer periphery of the iron core using a non-metallic fixing jig, a high-frequency coil is disposed on the outer peripheral surface of the permanent magnet, and a high-frequency current is passed through the high-frequency coil so that the permanent magnet and the iron core The permanent magnet is adhered to the outer periphery of the iron core.
According to the second aspect of the present invention, the temperature difference (T ₁ −T ₂ ) between the temperature (T ₁ ) of the permanent magnet and the temperature (T ₂ ) of the iron core during the induction heating is set to 10 ° C. or more. Is.
According to a third aspect of the present invention, a through hole is provided in the center of the rotating shaft, and the rotating shaft is water-cooled through a water-cooled pipe therein.
According to a fourth aspect of the present invention, both ends of the rotating shaft are covered with a metal cylinder having a high relative permeability.
The invention according to claim 5 is the manufacture of a rotor manufactured by applying an adhesive to the outer periphery of an iron core laminated on a rotating shaft and fixing a plurality of segment-shaped permanent magnets on the outer periphery at equal intervals. In the method, the permanent magnet is tightly fixed with a cylindrical member having high thermal conductivity, a high frequency coil is disposed on an outer peripheral surface of the cylindrical member, and a high frequency current is passed through the high frequency coil to connect the permanent magnet and the iron core. In this method, the permanent magnet is bonded to the outer periphery of the iron core by induction heating.
The invention described in claim 6 is the one in which the cylindrical member is made of copper and a copper alloy.
In the invention according to claim 7, the surface temperature of the cylindrical member is measured, and the temperature of the metal cylinder surface is uniformly induction-heated by feeding back the temperature to the high frequency power source.
The invention according to claim 8 is a rotor manufactured by using the method for manufacturing a rotor according to claims 1 to 6.
A ninth aspect of the present invention is a motor using a rotor manufactured by the method for manufacturing a motor rotor according to the first to sixth aspects.

According to the first aspect of the present invention, the heating time for curing the adhesive can be shortened by instantaneously heating by high-frequency induction heating, and the cooling time can be reduced by heating only a part rather than the entire rotor. Can also be shortened.
According to the second aspect of the present invention, the difference in thermal expansion between the magnet and the iron core can be reduced by lowering the temperature of the iron core, and the thermal stress of the bonded portion can be lowered, so that a stronger adhesive force can be obtained. As a result, it is possible to manufacture a rotor in which the magnet is difficult to peel off even when the centrifugal force or temperature rises due to high-speed rotation.
According to the third aspect of the present invention, the temperature of the rotating shaft and the iron core can be lowered by passing the water-cooled pipe, and the temperature difference between the magnet and the iron core can be increased.
According to the fourth aspect of the present invention, since the rotating shaft is covered with the metal cylinder having a high relative permeability, the metal tube takes heat for heating the rotating shaft, and the temperature rise of the rotating shaft can be suppressed. The temperature difference of the iron core can be increased.
According to the invention described in claim 5, the inner permanent magnet and the metal cylinder outside the iron core are instantaneously heated to a high temperature during high-frequency induction heating, and can be heated to a uniform temperature by the heat conduction of the metal cylinder. Even in a rotor having a thick iron core and a large number of permanent magnets, a strong adhesive force can be obtained with all the permanent magnets.
According to the invention described in claim 6, by using copper and a copper alloy having a small specific heat and a high thermal conductivity as the material of the metal tube, the entire metal tube can be uniformly heated in a short time by induction heating, And the heat can be quickly transmitted to the permanent magnet.
According to the seventh aspect of the present invention, the surface temperature of each part of the metal cylinder is measured and fed back to the output of the high frequency power source, so that the entire heating temperature can be accurately managed, and the variation and environment of the rotor itself. Even in large rotors with large variations and variations, it is possible to suppress variations in heating temperature and always obtain a strong adhesive force. As a result, it is possible to manufacture a rotor in which the magnet is difficult to peel off even when the centrifugal force or temperature rises due to high-speed rotation.
According to the invention described in claims 8 and 9, since the rotor can be efficiently manufactured in a short time, the manufacturing cost of the motor can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional side view of a permanent magnet rotor bonding apparatus showing Embodiment 1 of the present invention. In the figure, reference numeral 1 denotes a rotor, which is composed of a rotary shaft 2, an iron core 3, and a plurality of segment-shaped permanent magnets 4. 5 is an adhesive, 6 is a fixing jig, and 7 is a high-frequency coil.
Next, a method for manufacturing the rotor will be described.
(1) First, the rotary shaft 2 is press-fitted into the iron core 3, and after washing and drying, the adhesive 5 is applied to the outer periphery of the iron core 3. Note that a silicon steel plate of S60 is used for the material of the iron core 3, and a one-component heat curing type epoxy adhesive is used for the adhesive 5.
(2) Thereafter, a plurality of neodymium-based permanent magnets 4 were pressed against the outer periphery of the iron core 3 at equal intervals, and held by the fixing jig 6 so that the permanent magnets were not displaced. The fixing jig 6 is made of a heat resistant resin containing glass cloth.
(3) The rotor 1 is installed in the high frequency coil 7, and the height is adjusted so that the temperature of each part becomes uniform. As the high-frequency coil 7, a water-cooled copper pipe with φ8 and a two-turn winding with an inner diameter of φ100 was used.
(4) A high frequency current is supplied from a high frequency power source to the high frequency coil 7 to create a dielectric magnetic field, and eddy currents are generated in the rotating shaft 2, the iron core 3 and the permanent magnet 4 which are conductors in the coil, and the conductor itself is directly heated. The high-frequency induction heating was performed at a frequency of 100 kHz and an output of 4 kw, and held for 60 seconds under the condition of an output of 1.8 kw. As a result, the adhesive was cured by the heat of the iron core 3 and the permanent magnet 4, and the rotor 1 was obtained.
As a result of measuring the temperature during heating by attaching a thermocouple to the iron core 3 and the permanent magnet 4 during high frequency induction heating, the temperature of the permanent magnet 4 (T ₁ ) is about 160 ° C. The temperature (T ₂ ) was about 150 ° C. and T ₁ −T ₂ = 10 ° C. This is due to the fact that the permanent magnet 4 is positioned closer to the coil than the iron core 3, and the iron core 3 uses a material that does not easily flow eddy current, such as a silicon steel plate, causing a temperature difference.
The effect of the rotor thus produced was examined. For comparison, a conventional general rotor that was heated in a furnace to cure the adhesive was also added, and a destructive test was performed in which the rotational speed was gradually increased until the permanent magnet 4 was scattered. As a result, it was confirmed that in the rotor of the present invention, the permanent magnets were scattered at substantially the same rotational speed N as that of the conventional rotor, and the same adhesive force was obtained.
In the present invention, it is possible to manufacture a rotor having an adhesive force equivalent to an extremely short time as compared with a method of heating in a furnace. As a result, productivity can be greatly improved and the process can be inlined. Further, since the temperature of the iron core and the rotating shaft is lower, the cooling time can be shortened as compared with furnace heating in which the temperature of the entire rotor is high. Moreover, if a motor is assembled using the rotor of the present invention, a motor with low manufacturing costs can be obtained.

FIG. 2 is a sectional side view of a permanent magnet rotor bonding apparatus showing Embodiment 2 of the present invention. In the figure, 8 is a water-cooled pipe. Other reference numerals are the same as those in the first embodiment.
A through hole having a diameter of 6 is opened in the rotary shaft 2 and a copper water-cooled pipe 8 is passed through the hole.
The method for manufacturing the rotor is the same as that in the first embodiment. That is, heating was performed under high-frequency conditions in the same manner as in Example 1, and the adhesive was cured by the heat of the iron core 3 and the permanent magnet 4, whereby the rotor 1 was manufactured. At that time, water is allowed to flow through the water cooling pipe 8 to cool the rotating shaft 2, and the rotating shaft 2 takes away the heat generated in the iron core 3, thereby suppressing the temperature rise of the iron core 3.
As a result of measuring the temperature during heating by attaching a thermocouple to the iron core 3 and the permanent magnet 4, the temperature (T ₁ ) of the permanent magnet 4 is about 160 ° C., whereas the temperature (T ₂ ) of the iron core 3 is about 125 ° C. The results were: ° C. and T ₁ −T ₂ = 35 ° C.
The effect of the rotor thus manufactured was examined in the same manner as in Example 1.
As a result, it was found that the permanent magnet of the rotor of the present invention was scattered at a rotational speed of 1.35 times that of the conventional permanent magnet of the rotor, and the adhesive force was improved. According manufacturing method of the present invention, the temperature T ₂ of the iron core than the temperature T ₁ of the permanent magnet is lower 35 ° C., the thermal stress is low due to the amount of thermal expansion difference, and strong adhesion can be obtained. Further, since the temperature of the iron core and the rotating shaft is lower, the cooling time can be shortened as compared with furnace heating in which the temperature of the entire rotor is high.

FIG. 3 is a sectional side view of a permanent magnet rotor bonding apparatus according to Embodiment 3 of the present invention. In the figure, 9 is a metal cylinder and 10 is a heat insulating part. Other reference numerals are the same as those in the first embodiment.
The metal cylinder 9 is made of stainless steel and covers the both ends of the rotating shaft 2. The heat insulating portion 10 is obtained by coating the surface portion of the iron core 3 where the metal cylinder 9 is in contact with the iron core 3 with a resin.
The method for manufacturing the rotor is the same as that in the first embodiment. That is, heating was performed under the same high frequency conditions as in Example 1, and the adhesive was cured by the heat of the iron core 3 and the permanent magnet 4 to manufacture the rotor 1. At that time, since the rotary shaft 2 is deprived of heat by the stainless steel metal tube 9 having a high relative magnetic permeability, the temperature rises only due to heat transfer from the iron core 3. Therefore, the temperature rise of the iron core 3 is suppressed by the rotation shaft 2 taking the heat generated in the iron core 3. The heat of the metal cylinder 9 is not transmitted to the iron core 3 in a short time by the heat insulating portion 10.
As a result of measuring the temperature during heating by attaching a thermocouple to the iron core 3 and the permanent magnet 4, the temperature (T ₁ ) of the permanent magnet 4 is about 160 ° C., whereas the temperature (T ₂ ) of the iron core 3 is about 140 ° C. The results were: ° C. and T ₁ −T ₂ = 20 ° C.
The effect of the rotor thus manufactured was examined in the same manner as in Example 1.
As a result, it was found that the permanent magnet of the rotor of the present invention was scattered at a rotational speed 1.2 times that of the conventional permanent magnet of the rotor, and the adhesive force was improved. In the production method of the present invention, the temperature T ₂ of the iron core than the temperature T ₁ of the permanent magnet is lower 20 ° C., the thermal stress is low due to the amount of thermal expansion difference, and strong adhesion can be obtained. Further, since the temperature of the iron core and the rotating shaft is lower, the cooling time can be shortened as compared with furnace heating in which the temperature of the entire rotor is high.

In the present embodiment, the temperature T ₁ of the permanent magnet 4 is set to about 160 ° C. However, the higher the T ₁ , the shorter the heating time because the adhesive cures in a shorter time. Its temperature T ₂ when core 3 is also increased, the thermal stress is increased due to a difference in thermal expansion between the permanent magnet and the iron core, the adhesive force decreases. In addition, when the epoxy adhesive is heated at a high temperature, the adhesive resin is decomposed and foamed, which leads to a decrease in adhesive strength. Therefore, a temperature of about 150 to 160 ° C. is desirable.

FIG. 4 is a side sectional view of the bonding apparatus showing Embodiment 4 of the present invention, and FIG. 5 is a plan view thereof. In the figure, 11 is a cylindrical member.
A method for manufacturing the rotor will be described. First, the rotary shaft 2 is press-fitted into the iron core 3, and after cleaning and drying, the adhesive 5 is applied to the outer periphery of the iron core 3. Note that a silicon steel plate of S60 is used for the material of the iron core 3, and a one-component heat curing type epoxy adhesive is used for the adhesive 5. Further, the iron core 3 having a thickness of 210 mm was used, and 48 permanent magnets 4 mounted on the circumference and 6 stages in the axial direction were used.
Thereafter, 48 neodymium permanent magnets 4 are pressed against the outer periphery of the iron core 3 at equal intervals, and the split cylindrical member 11 having a shape that is in close contact with the outer periphery of the permanent magnet is pressed and fixed. The material of the cylindrical member 11 was oxygen-free copper having a purity of 99.96% or higher. In addition, since this cylindrical member 11 is produced so that it may closely_contact | adhere to the shape of the tile-shaped permanent magnet 4, the role which fixes the position of the permanent magnet 4 and hold | maintains the permanent magnet 4 before adhere | attaching is also simultaneous. Plays.
The rotor 1 is installed in the high frequency coil 7 as it is, and the height is adjusted so that the temperature of each part becomes uniform. As the high-frequency coil 7, a water-cooled copper pipe with φ8 and a six-turn winding with an inner diameter of φ100 was used.
A high frequency current is passed from a high frequency power source to the high frequency coil 7 to create a dielectric magnetic field, and eddy currents are generated in the rotating shaft 2, the iron core 3, the permanent magnet 4 and the cylindrical member 11 which are conductors in the coil, and the conductor itself is directly heated. To do. In addition, the cylindrical member 11 which is the outermost periphery is heated to the highest temperature, and the temperature of the bonding surface of the iron core 3 and the permanent magnet 4 is made uniform by the heat transfer. Here, using a high-frequency induction heating device, heating is performed under the condition that the temperature is raised at a frequency of 100 kHz, an output of 6.2 kw, and held for 60 seconds under the condition of an output of 2 kw, and the adhesive is removed by the heat of the iron core 3 and the permanent magnet 4 The rotor 1 was manufactured by curing.
As a result of measuring the temperature at the time of heating by attaching a thermocouple to each part of the surface of the cylindrical member 11 and the adhesive surface between the iron core 3 and the permanent magnet 4, the temperature of the cylindrical member 11 is 190 ° C. ± 10 ° C. The temperature difference across the cylinder was within 20 ° C. Moreover, the temperature of the bonding surface was 160 ° C. to 175 ° C., and it was confirmed that it was within the heating temperature range of the target adhesive. For comparison, when the non-metallic ceramic jig was used instead of the cylindrical member 11, the temperature difference of the permanent magnet 4 was as large as 35 ° C.

FIG. 6 is a schematic view of a permanent magnet rotor bonding apparatus showing Embodiment 5 of the present invention. In the figure, 12 is a supporting jig, 13 is a thermocouple, 14 is a high-frequency power source, and 15 is a fixing jig.
The rotor has the same configuration as that of the fourth embodiment and is supported by the support jig 12. A thermocouple 13 is attached to the surface of the cylindrical member 11 and the signal is taken into the control circuit of the high-frequency power source 14. Note that the position where the thermocouple 13 is affixed was set to the lowest temperature portion on the surface of the cylindrical member 11 by prior induction heating.
Inductive heating is performed under the same conditions as in Example 1, the temperature at the time of heating is fed back to the high-frequency power source 10 by the thermocouple 13, the output is subtly changed, and the heating temperature is controlled to a constant temperature to make it permanent. The magnet 4 was adhered.
Thus, 20 rotors bonded by temperature feedback and 20 rotors that were not fed back were manufactured as a comparison. The temperature of the rotor thermocouple to which the temperature was fed back was 160 ° C., and the temperature of the rotor thermocouple to which the temperature was not fed back was 156 ° C. to 172 ° C. This is influenced by a change in the room temperature at the time of manufacture and a temperature rise of the support jig 12.
The adhesive force of each of the 20 manufactured rotors was examined by a destructive test in which the rotational speed was gradually increased until the permanent magnets 4 were scattered. While all 20 rotors of the present invention were not broken at the rotation speed N, two of the 20 rotors that were not fed back were broken at the rotation speed N, and one was broken at 0.9N. Thus, the rotor of the present invention can obtain a stable adhesive force.

  By performing heat curing of the adhesive by high frequency induction heating, it is possible to perform magnet bonding in a short time, and therefore, it can be applied to a motor for bonding and fixing other permanent magnets such as a linear motor.

Side sectional view of a permanent magnet rotor adhering device showing Embodiment 1 of the present invention. Side sectional view of a permanent magnet rotor adhering device showing Embodiment 2 of the present invention. Side sectional view of a permanent magnet rotor adhering device showing Embodiment 3 of the present invention. Side sectional view of a permanent magnet rotor adhering device showing Embodiment 4 of the present invention. Plan view in FIG. Schematic of the permanent magnet type rotor bonding apparatus showing Example 5 of the present invention.

Explanation of symbols

1 Rotor 2 Rotating shaft 3 Iron core 4 Permanent magnet (segment type)
DESCRIPTION OF SYMBOLS 5 Adhesive 6 Fixing jig 7 High frequency coil 8 Water cooling pipe 9 Metal cylinder 10 Heat insulation part 11 Cylindrical member 12 Support jig 13 Thermocouple 14 High frequency power supply 15 Fixing jig

Claims (9)

In the manufacturing method of the rotor manufactured by applying an adhesive to the outer periphery of the iron core laminated on the rotating shaft and fixing a plurality of segment-shaped permanent magnets at equal intervals on this,
The permanent magnet is pressed and held on the outer periphery of the iron core using a non-metallic fixing jig, a high-frequency coil is disposed on the outer peripheral surface of the permanent magnet, and a high-frequency current is passed through the high-frequency coil so that the permanent magnet and the iron core The rotor is manufactured by induction heating, and the permanent magnet is bonded to the outer periphery of the iron core. The temperature difference (T ₁ -T ₂ ) between the temperature (T ₁ ) of the permanent magnet and the temperature (T ₂ ) of the iron core during the induction heating is set to 10 ° C. or more. Method of manufacturing the rotor.   3. The method of manufacturing a rotor according to claim 1, wherein a through hole is provided at the center of the rotating shaft, and the rotating shaft is water-cooled through a water-cooled pipe therein.   The method for manufacturing a rotor according to any one of claims 1 to 3, wherein both ends of the rotating shaft are covered with a metal cylinder having a high relative permeability. In the manufacturing method of the rotor manufactured by applying an adhesive to the outer periphery of the iron core laminated on the rotating shaft and fixing a plurality of segment-shaped permanent magnets at equal intervals on this,
The permanent magnet is closely fixed with a cylindrical member having high thermal conductivity, a high frequency coil is disposed on the outer peripheral surface of the cylindrical member, and a high frequency current is passed through the high frequency coil to inductively heat the permanent magnet and the iron core. A method for manufacturing a rotor, wherein the permanent magnet is bonded to the outer periphery of the iron core.   The method for manufacturing a rotor according to claim 5, wherein the cylindrical member is copper and a copper alloy.   The method for manufacturing a rotor according to claim 5 or 6, wherein the surface temperature of the cylindrical member is measured, and the temperature of the metal cylinder surface is uniformly induction-heated by feeding back the temperature to a high frequency power source.   A rotor manufactured using the method for manufacturing a rotor according to claim 1.   A motor comprising a rotor manufactured using the method for manufacturing a rotor according to claim 1.

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