JP2007236019A - Rotor, its manufacturing method and electric vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotor enhanced in heat dissipation properties of magnets, its manufacturing method and an electric vehicle including the rotor. <P>SOLUTION: The rotor 130 comprises: a rotor core 131 that is fixed to a rotating shaft 120 and has holes 131A; the magnets 132 inserted into the holes 131A; resin parts 133 injected into the holes 131A; and end plates 134, 135 arranged at both ends in the axial direction of the rotor core 131. The magnets 132 and the end plate 135 contact with each other. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a rotor, a manufacturing method thereof, and an electric vehicle, and more particularly, to a rotor excellent in heat dissipation characteristics, a manufacturing method thereof, and an electric vehicle including the rotor.

  In Japanese Patent Laid-Open No. 2002-34187 (Patent Document 1), a permanent magnet is fixed to a rotor core by filling a resin member between a hole provided in the rotor core and a permanent magnet embedded in the hole. A rotor is disclosed.

  Japanese Patent Laid-Open No. 2001-157394 (Patent Document 2) also discloses a rotor in which a permanent magnet is fixed to a rotor core with a resin member, as described above.

  Japanese Patent Laying-Open No. 2000-14062 (Patent Document 3) also discloses a rotor in which a resin material is filled between a cylindrical cover and a permanent magnet.

Japanese Patent Laying-Open No. 2005-94845 (Patent Document 4) discloses a rotor in which a plurality of rod-shaped permanent magnets coated with resin are arranged in the axial direction and embedded in a rotor core.
JP 2002-34187 A JP 2001-157394 A JP 2000-14062 A Japanese Patent Laid-Open No. 2005-94845

  Heat is generated when the rotor rotates. Here, if the heat radiation from the rotor is not sufficiently performed, there may be a problem that the magnetic force of the magnet embedded in the rotor core is reduced by heat. Therefore, it is important to improve the heat dissipation characteristics of the magnet in the rotor. However, Patent Documents 1 to 4 do not disclose a configuration that sufficiently improves the heat dissipation characteristics of the rotor.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a rotor excellent in heat dissipation characteristics of a magnet, a manufacturing method thereof, and an electric vehicle including the rotor.

  A rotor according to the present invention is provided at a rotor core fixed to a rotating shaft and having a hole, a magnet inserted into the hole, a filling portion injected into the hole, and both axial ends of the rotor core. An end plate, and the magnet and the end plate are in contact with each other at at least one of the axial ends of the rotor core.

  In the rotor and the method for manufacturing the same according to the present invention, the “filling portion” means a portion intended to fix the magnet to the rotor core mainly by filling the hole portion instead of bonding. In the rotor according to the present invention, the phrase “the magnet and the end plate are in contact with each other at the axial end portion of the rotor core” is not limited to the case where the magnet and the end plate are completely in contact with each other. This includes the case where a thin film of a filling portion is interposed between them so as not to impair heat transfer.

  According to the said structure, the heat dissipation from a magnet can be improved by making an end plate contact a magnet.

  In the rotor, preferably, a filling portion is interposed between the magnet and the end plate at the axial end portion of the rotor core located on the opposite side of the side where the magnet and the end plate contact.

  According to the above configuration, the axial end face of the magnet is covered with the filling portion, so that the magnet can be prevented from coming off the rotor core even when the rotor receives an impact.

  In the rotor, preferably, the magnet and the end plate are in contact with each other at an axial end portion of the rotor core positioned on the upstream side in the magnet removal direction, and an axial end portion of the rotor core positioned on the downstream side in the magnet removal direction. The filling part is interposed in

  Here, the “extraction direction” means a direction in which the magnet is easily removed. The direction in which the magnet is easily removed is the direction due to the fixing strength of the end plate (for example, the axial end of the rotor core on the side opposite to the rotor core from the axial end of the rotor core positioned on the side where the end plate is more firmly fixed). In the direction toward the motor), the direction due to the mounting direction of the rotating electrical machine (for example, the direction in which the magnet is easily removed when considering a frontal collision or offset collision of the vehicle), and the mounting position of the rotating electrical machine. The direction resulting from the relationship with the device (for example, the direction in which the magnet is easily removed when considering the direction in which the device that moves when the vehicle collides) is included. In addition, the strength of the fixing strength of the end plate may be caused by the fixing method of the end plate, or may be caused by fixing the end plate separately before and after the installation of the magnet and the filling portion. .

  According to the said structure, the heat dissipation from a magnet can be improved, suppressing a magnet falling off from a rotor core more effectively.

  In the above rotor, the end plate is preferably provided with a first end plate provided at one axial end of the rotor core and a weaker strength than the first end plate provided at the other axial end of the rotor core. The magnet and the first end plate are in contact with each other, and the magnet and the second end plate are provided with a filling portion.

  According to the said structure, the heat dissipation from a magnet can be improved, suppressing a magnet falling off from a rotor core more effectively.

  In the rotor, preferably, the filling portion is injected into the hole portion from the opening of the hole portion. As a result, it is not necessary to provide a special hole for filling the filling portion, and the rotor can be downsized.

  The method of manufacturing a rotor according to the present invention includes filling a hole while aligning a step of inserting a magnet into a hole formed in the rotor core and an axial end surface of the magnet in the hole and at least one axial end surface of the rotor core. A step of injecting a material to form a filling portion in the hole, and a step of providing an end plate so as to contact the magnet on the axial end surface of the rotor core aligned with the axial end surface of the magnet.

  According to the said method, a magnet and an end plate can be made to contact. As a result, the heat dissipation characteristics of the magnet are improved.

  In the rotor manufacturing method, preferably, the axial length of the magnet is shorter than the axial length of the rotor core.

  As a result, the axial end surface of the magnet on the side opposite to the side in contact with the end plate can be covered with the filling portion, so that the magnet can be prevented from coming off the rotor core even when the rotor receives an impact. it can.

  The electric vehicle according to the present invention includes the rotor described above or the rotor manufactured by the above-described rotor manufacturing method.

  Thereby, the electric vehicle carrying the rotor with the high heat dissipation characteristic of a magnet is obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the heat dissipation characteristic of the magnet in a rotor can be improved.

  Hereinafter, embodiments of a rotor, a method for manufacturing the same, and an electric vehicle according to the present invention will be described. Note that the same or corresponding parts are denoted by the same reference numerals, and the description thereof may not be repeated.

  FIG. 1 is a diagram schematically showing a configuration of a drive unit to which a rotor according to an embodiment of the present invention is applied. In the example shown in FIG. 1, the drive unit 1 is a drive unit mounted on a hybrid vehicle as an “electric vehicle”, and includes a motor generator 100, a housing 200, a speed reduction mechanism 300, a differential mechanism 400, and a drive shaft. The receiving part 500 is comprised.

  The motor generator 100 is a rotating electrical machine having a function as an electric motor or a generator. The motor generator 100 is a rotary shaft 120 rotatably attached to the housing 200 via a bearing 110, a rotor 130 attached to the rotary shaft 120, and a stator. 140. The stator 140 has a stator core 141, and a coil 142 is wound around the stator core 141. The coil 142 is electrically connected to the power supply cable 600 </ b> A via a terminal block 210 provided in the housing 200. The other end of the power supply cable 600A is connected to the PCU 600. PCU 600 is electrically connected to battery 700 via power supply cable 700A. Thereby, the battery 700 and the coil 142 are electrically connected.

  The power output from the motor generator 100 is transmitted from the speed reduction mechanism 300 to the drive shaft receiving portion 500 via the differential mechanism 400. The driving force transmitted to the drive shaft receiving portion 500 is transmitted as a rotational force to a wheel (not shown) via a drive shaft (not shown), thereby causing the vehicle to travel.

  On the other hand, during regenerative braking of the hybrid vehicle, the wheels are rotated by the inertial force of the vehicle body. Motor generator 100 is driven through drive shaft receiving portion 500, differential mechanism 400, and reduction mechanism 300 by the rotational force from the wheels. At this time, the motor generator 100 operates as a generator. The electric power generated by motor generator 100 is stored in battery 700 via an inverter in PCU 600.

  The feeding cables 600A and 700A are three-phase cables including a U-phase cable, a V-phase cable, and a W-phase cable. Coil 142 includes a U-phase coil, a V-phase coil, and a W-phase coil, and terminals of these three coils are connected to power supply cables 600A and 700A that are three-phase cables.

  The use of motor generator 100 is not limited to a hybrid vehicle (HV), but may be mounted on another “electric vehicle” (for example, a fuel cell vehicle or an electric vehicle).

  FIG. 2 is a plan view of the rotor 130, and FIG. 3 is a longitudinal sectional view of the rotor 130. 2 and 3, the rotor 130 is fixed to the rotating shaft 120 and has a rotor core 131 having a hole 131A, a magnet 132 inserted into the hole 131A and embedded in the rotor core 131, and a hole. The resin part 133 filled between the side surface of 131A and the magnet 132 and end plates 134 and 135 provided on the axial end surface of the rotor core 131 are provided.

  The resin part 133 as the “mold resin part” is configured to include, for example, an epoxy resin. By providing the resin portion 133, the magnet 132 is fixed to the rotor core 131. The resin part 133 fixes the magnet 132 to the rotor core 131 by being mainly filled in the hole part 131 </ b> A rather than being bonded. Therefore, the filling rate of the resin part 133 with respect to the space in the hole 131A is higher than the filling rate of the adhesive when the adhesive is used as the magnet fixing material in the same rotor core. By doing in this way, the magnet 132 can be accurately fixed in the hole 131A. The resin portion 133 is poured into the hole portion 131A from the opening of the hole portion 131A without providing a special hole for resin injection. By doing in this way, size reduction of the rotor 130 can be achieved.

  The metal end plates 134 and 135 are fixed to the rotating shaft 120 and sandwich the rotor core 131 in the axial direction. Here, the end plate 134 is fixed to the rotating shaft 120 by caulking, for example, and the end plate 135 is fixed to the rotating shaft 120 by welding, for example. In other words, the end plate 135 (first end plate) is fixed to the rotating shaft 120 more firmly than the end plate 134 (second end plate).

  The rotor 130 generates heat during rotation, but problems such as a decrease in the magnetic force of the magnet 132 due to heat may occur if heat dissipation from the rotor 130 is not sufficient. Therefore, it is desirable to improve the heat dissipation characteristics of the magnet 132.

  On the other hand, in the present embodiment, the magnet 132 and the end plate 135 are brought into contact with each other at the portion A in FIG. Thereby, heat transfer from the magnet 132 to the end plate 135 is promoted, and the end plate 135 functions as a heat sink. As a result, the heat dissipation characteristics of the magnet 132 are improved, and it is possible to suppress the occurrence of problems such as a decrease in the magnetic force of the magnet 132 when the motor generator 100 is driven.

  By the way, when an impact load is applied to the rotor 130 due to a vehicle collision or the like, if the fixing strength of the magnet 132 is not sufficient, there is a concern that the magnet 132 may come out of the rotor core 131. In the rotor 130, the end plate 135 is fixed to the rotating shaft 120 more firmly than the end plate 134 as described above. Therefore, when an impact load is applied to the rotor 130, the magnet 132 is easily pulled out in the direction of the arrow DR1. In the present specification, the direction of the arrow DR1 in FIG. From the viewpoint of improving the reliability of the rotor 130, it is desirable to take measures to prevent the magnet 132 from coming off in the direction in which the magnet 132 is pulled out (the direction of the arrow DR1).

  On the other hand, in the present embodiment, the end surface 1320 of the magnet 132 is covered with the resin portion 133 on the end plate 134 side. Thereby, since the magnet 132 can be prevented from coming out in the direction of the arrow DR1, the reliability of the rotor 130 with respect to the impact load can be improved.

  Next, a method for manufacturing the rotor 130 described above will be described. FIG. 4 is a flowchart illustrating a method for manufacturing the rotor 130. With reference to FIG. 4, in step 10 (hereinafter abbreviated as S <b> 10), the end plate 135 is firmly fixed to the rotating shaft 120, and the end plate is attached to the rotating shaft 120. The magnet 132 is inserted into the hole 131 </ b> A from the opening on the opposite side of 135. Here, a magnet having a length shorter than the axial length of the rotor core 131 is used as the magnet 132. Next, in S <b> 20, the resin is injected into the hole 131 </ b> A while the magnet 132 in the hole 131 </ b> A is unevenly distributed on one axial end side (end plate 135 side) of the rotor core 131. Thereby, the resin part 133 is formed in the hole part 131A. In S <b> 30, the end plate 134 is provided on the axial end surface of the rotor core 131. Here, the end plate 134 is fixed by a simple method such as caulking. Thereby, the manufacturing method can be simplified and speeded up. Through the above steps, the rotor 130 shown in FIGS. 2 and 3 is obtained. In S10, a jig that closes the hole 131A instead of the end plate 135 may be used. In this case, the jig is removed after the resin is injected, and the end plates 134 and 135 are assembled to the rotor core 131.

  In the above example, the example in which the magnet 132 is in contact with the end plate 135 has been described, but the magnet 132 may be in contact with the end plate 134. Moreover, the magnet 132 may be in contact with only one of the end plates 134 and 135, or may be in contact with both. In addition, the term “contact” as used herein refers not only to the case where the magnet 132 and the end plates 134 and 135 are completely in contact with each other without a gap, but also to the extent that heat transfer is not impaired between the magnet 132 and the end plates 134 and 135. The case where the thin film of the resin part 133 is interposed is also included.

  FIG. 5 is a cross-sectional view showing a modification of the rotor according to the present embodiment. Referring to FIG. 5, magnet 132 may be divided into a plurality of magnets 132A and 132B. Here, in the resin injection step of S20 described above, the magnet 132B located on the upper side is lifted by the flow formed by the resin reflecting off the end plate 135 (or jig) that constitutes the bottom surface of the hole 131A, Resin flows between magnets 132A and 132B. On the other hand, the magnet 132A located on the lower side is not lifted by the above flow. Therefore, the resin hardly flows into the lower surface side of the magnet 132A. Note that the end plate 135 (or jig) serving as the bottom surface of the hole 131A at the time of resin injection is provided with an air vent hole through which air in the hole 131A can be discharged.

  As described above, when the resin part 133 is injected after the magnets 132A and 132B are inserted into the rotor core 131, the inflow of the resin part 133 between the magnets 132A and 132B is promoted, but the magnet 132A and the end plate 135 are injected. The inflow of the resin part 133 to (or the jig) is suppressed. As a result, the contact state between the magnet 132A and the end plate 135 can be maintained.

  FIGS. 6 and 7 are diagrams illustrating the filling rate when a resin and an adhesive are used as the filling material filled in the hole 131A, respectively. When resin is used as the filler, as shown in FIG. 6, the resin portion 133 is formed in the gap in the hole portion 131A with almost no leakage. On the other hand, when the adhesive 133A is used as the filler, the filling rate of the adhesive greatly depends on the viscosity, and the viscosity greatly depends on the production environment. Therefore, as shown in FIG. The gap in the hole 131A is not necessarily filled sufficiently, and the filling rate may be insufficient. Therefore, a high stress may be locally generated in the rotor core 131 due to the centrifugal force when the rotor rotates. Also, depending on the filling rate of the adhesive, it may not be possible to fully expect the effect of preventing the impact load from coming off. Therefore, as a safety measure when the impact load acts in the direction of withdrawal, the end plate as a structure to prevent the magnet from popping out. Is provided. On the other hand, in the rotor according to the present embodiment, the filling rate of the resin portion 133 in the hole 131A is high, and the end surface of the magnet 132 located on the downstream side in the removal direction is covered with the resin portion 133. Therefore, compared to the case where only the end plates 134 and 135 are provided as the pop-out preventing structure, the magnet 132 can be more effectively prevented from coming off.

  In other words, the contents described above are as follows. That is, the rotor 130 according to the present embodiment is fixed to the rotating shaft 120 and has a rotor core 131 having a hole 131A, a magnet 132 inserted into the hole 131A, and “filling” injected into the hole 131A. The resin part 133 as a part and end plates 134 and 135 provided at both ends in the axial direction of the rotor core 131 are provided, and the magnet 132 and the end plate 135 are in contact with each other. On the other hand, a resin portion 133 is interposed between the magnet 132 and the end plate 134 at the axial end portion of the rotor core 131 located on the opposite side of the end plate 135. That is, in the rotor 130, the magnet 132 and the end plate 135 are in contact with each other at the axial end portion of the rotor core 131 located on the upstream side in the removal direction of the magnet 132 (arrow DR1 direction). A magnet 132 and an end plate 134 are interposed with a resin portion 133 at the axial end portion of the rotor core 131 located on the downstream side of the arrow DR1 direction.

  Further, in the rotor manufacturing method according to the present embodiment, as shown in FIG. 4, a step of inserting a magnet 132 having a length shorter than the axial length of the rotor core 131 into the hole 131 </ b> A formed in the rotor core 131 ( S10) and a resin as a “filler” are injected into the hole 131A while aligning the axial end surface of the magnet 132 in the hole 131A with one axial end surface of the rotor core 131, and “filling” is performed in the hole 131A. A step (S20) of forming a resin portion 133 as a portion, and a step (S30) of providing end plates 134 and 135 on the axial end surface of the rotor core 131. In addition, since the magnet 132 can be accurately fixed in the hole 131A by using the resin portion 133 as a fixing material for the magnet 132, noise and vibration are excessively increased even when the end plate 135 is brought into contact with the magnet 132. Is suppressed.

  According to the rotor according to the present embodiment, heat dissipation from the magnet 132 can be improved by bringing the end plate 135 into contact with the magnet 132. Further, the resin portion 133 is interposed between the magnet 132 and the end plate 134 at the downstream end portion in the direction in which the magnet 132 is pulled out (arrow DR1 direction), so that the resin portion 133 covers the axial end surface of the magnet 132. Even when the rotor 130 receives an impact, the magnet 132 can be prevented from coming off the rotor core 131.

  Moreover, according to the method for manufacturing a rotor according to the present embodiment, magnet 132 and end plate 135 can be brought into contact with each other. As a result, the heat dissipation characteristics of the magnet 132 are improved. Further, since the other end surface in the axial direction of the magnet 132 can be covered with the resin portion 133, the magnet 132 can be prevented from coming off the rotor core 131 even when the rotor 130 receives an impact.

  Although the embodiments of the present invention have been described above, the embodiments disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a figure which shows roughly the structure of the drive unit to which the rotor which concerns on one embodiment of this invention is applied. It is a top view of the rotor which concerns on one embodiment of this invention. It is a longitudinal cross-sectional view of the rotor shown by FIG. It is a flowchart explaining the manufacturing method of the rotor which concerns on one embodiment of this invention. It is a longitudinal cross-sectional view of the modification of the rotor which concerns on one embodiment of this invention. It is a figure explaining the filling rate at the time of using resin as a filler. It is a figure explaining the filling rate at the time of using an adhesive agent as a filler.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Drive unit, 100 Motor generator, 110 Bearing, 120 Rotating shaft, 130 Rotor, 131 Rotor core, 131A Hole part, 132 Magnet, 133 Resin part, 134,135 End plate, 140 Stator, 141 Stator core, 142 Coil, 200 Housing, 210 terminal block, 300 speed reduction mechanism, 400 differential mechanism, 500 drive shaft receiving portion, 600 PCU, 600A, 700A power supply cable, 700 battery, 1320 end face.

Claims (8)

A rotor core fixed to the rotating shaft and having a hole;
A magnet inserted into the hole;
A filling portion injected into the hole;
An end plate provided at both ends in the axial direction of the rotor core,
The rotor in which the magnet and the end plate are in contact with each other at at least one of axial end portions of the rotor core.   2. The rotor according to claim 1, wherein the filling portion is interposed between the magnet and the end plate at an axial end portion of the rotor core located on a side opposite to a side where the magnet and the end plate are in contact with each other.   The magnet and the end plate are in contact with each other at the axial end portion of the rotor core located upstream in the magnet removal direction, and at the axial end portion of the rotor core located downstream in the magnet removal direction. The rotor according to claim 2, wherein the filling portion is interposed. The end plate is provided at a first end plate provided at one axial end of the rotor core and at the other axial end of the rotor core, and is fixed with a weaker strength than the first end plate. A second end plate
The magnet and the first end plate are in contact;
The rotor according to claim 2, wherein the magnet and the second end plate interpose the filling portion.   The rotor according to any one of claims 1 to 4, wherein the filling portion is injected into the hole portion from an opening of the hole portion. Inserting a magnet into the hole formed in the rotor core;
Injecting a filler into the hole while aligning the axial end surface of the magnet in the hole with at least one axial end surface of the rotor core to form a filling portion in the hole;
And a step of providing an end plate on the axial end surface of the rotor core aligned with the axial end surface of the magnet so as to contact the magnet.   The rotor manufacturing method according to claim 6, wherein an axial length of the magnet is shorter than an axial length of the rotor core.   An electric vehicle comprising the rotor according to any one of claims 1 to 5 or the rotor manufactured by the method for manufacturing a rotor according to claim 6 or 7.

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