JP2008289314A - Rotor assembly of embedded magnet-type motor and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently manufacture a rotor core which has a magnet inside and whose length in a rotation axis direction differs in a rotor assembly of an embedded magnet-type motor. <P>SOLUTION: The rotor core 14 is constituted of a plurality of unit rotor cores 16 having the magnets 20 inside. Since lengths in the rotation axis direction of the unit rotor cores 16 are the same, the unit rotor cores 16 can efficiently be manufactured without changing various settings. For manufacturing the rotor core 14 different in the length in the rotation axis direction, only the number of the unit rotor cores 16 which are set in accordance with the lengths of the rotor cores 14 is changed. Thus, the rotor cores 14 can efficiently be manufactured. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rotor assembly of an embedded magnet type motor and a manufacturing method thereof, and more particularly to a structure of a rotor core in which magnets are arranged.

  2. Description of the Related Art Conventionally, there has been known an embedded magnet type motor that includes a magnet inside a rotor and rotates the rotor by an electromagnetic action acting between the rotor and a rotating magnetic field generated by the stator. The rotor of this embedded magnet type motor has a rotor core that is supported by a shaft. The rotor core is formed by laminating steel plates, and the laminated steel plates are provided with holes penetrating therethrough, and magnets are disposed in the holes. Magnets arranged in the holes are fixed with resin to form a rotor assembly.

  Patent Document 1 below shows such a rotor assembly. In this rotor assembly, the mold is adhered to both ends of the laminated steel plates forming the rotor core to seal the hole, and the resin is injected into the gap between the hole and the magnet, so that the resin is filled without leakage, The magnet can be securely fixed in the hole.

JP 2007-68356 A

  In the rotor assembly of the above-mentioned patent document, when a plurality of rotor cores having the same length in the rotation axis direction are manufactured, the work of fixing the magnets in the holes of the stacked steel plates is repeatedly performed, which is efficient. However, in the case where there are many types of lengths of the rotor core in the direction of the rotation axis, the position of the mold that is in close contact with both ends of the laminated steel plates must be changed according to the length of the rotor core. Further, the filling amount of the resin filled in the holes must be changed according to the length of the rotor core.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a rotor assembly of an embedded magnet type motor that can efficiently manufacture a rotor core having magnets therein and having different lengths in the rotation axis direction, and a method for manufacturing the rotor assembly. It is in.

  A rotor assembly of an embedded magnet type motor of the present invention has a unit rotor core that is pivotally supported by a shaft and is formed by laminating steel plates, and the unit rotor core includes a hole that penetrates the laminated steel plates, and the hole. A plurality of unit rotor cores mounted on the shaft to form a rotor core.

  Moreover, the length of the unit rotor core in the rotation axis direction can be made the same.

  The unit rotor core may include at least two unit rotor cores having different lengths in the rotation axis direction.

  Furthermore, the unit rotor core can be arranged with a predetermined angular shift in the circumferential direction with respect to the adjacent unit rotor core.

  The method of manufacturing a rotor assembly for an embedded magnet type motor according to the present invention includes forming a unit rotor core supported by a shaft by laminating steel plates and penetrating the laminated steel plates provided in the unit rotor core. A magnet is fixed to the hole, and a plurality of the unit rotor cores having the magnets are mounted on a shaft to form a rotor core.

  According to the rotor assembly and method for manufacturing the interior magnet type motor of the present invention, it is possible to efficiently manufacture a rotor core having magnets therein and having different lengths in the rotation axis direction.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a rotor assembly of an embedded magnet type motor according to the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a configuration of a rotor assembly 10 of an interior magnet type motor according to the present embodiment. 2 is a cross-sectional view taken along line AA in FIG.

  The rotor assembly 10 includes a shaft 12 and a rotor core 14 that is supported by the shaft 12. The shaft 12 is rotatably supported by a housing (not shown) of an embedded magnet type motor that houses the rotor assembly 10.

  The rotor core 14 is constituted by unit rotor cores 16 stacked in the direction of the rotation axis. The unit rotor cores 16 have the same length a in the rotation axis direction, and the number of unit rotor cores 16 is set according to the length b of the rotor core 14 in the rotation axis direction. The rotor core 14 is formed by mounting the set number of unit rotor cores 16 on the shaft 12 so as to be stacked in the direction of the rotation axis.

  The unit rotor core 16 is formed by laminating steel plates. A steel plate is a disk-shaped magnetic body concentric with a rotating shaft. An opening is provided at the center of the steel plate, and by stacking the steel plates, a hollow hole 24 into which the shaft 12 is fitted is formed. On the other hand, in the vicinity of the outer periphery of the steel plate, four openings are provided at predetermined intervals in the circumferential direction. By laminating the steel plates by aligning the positions of the openings, four holes 18 that penetrate the laminated steel plates in the rotation axis direction are formed. The number of holes 18 that determine the number of rotor poles is an example, and the present invention is not limited to the number of holes 18. A magnet 20 is disposed in each hole 18. The magnet 20 is, for example, a neodymium magnet or a ferrite magnet. The magnet 20 is fixed in the hole 18 by the resin 22. The resin 22 is an epoxy resin having excellent strength such as vibration resistance against rotation of the rotor.

  Next, the manufacturing method of the unit rotor core 16 is demonstrated using figures. FIG. 3 is a cross-sectional view showing a manufacturing state of the unit rotor core 16. FIG. 4 is a perspective view showing the unit rotor core 16. As shown in FIG. 3, in this production, a mold 26 for resin molding is used. The mold 26 is composed of a lower mold 28 having a concave cross section that accommodates laminated steel plates, and an upper mold 30 that is movable with respect to the lower mold 28 in the clamping direction (vertical direction in FIG. 3). Is done. The lower mold 28 has an inner peripheral surface 28a that defines an outer diameter reference of the unit rotor core 16, and the inner peripheral surface 28a has a length corresponding to the length a of the unit rotor core 16 in the rotation axis direction. The upper mold 30 has a cylinder (not shown) that stores the molten resin 22.

  First, a plurality of steel plates are laminated and disposed on the lower mold 28. At this time, each steel plate is restrained from the outer peripheral side by the inner peripheral surface 28a of the lower mold 28, and the center of each steel plate is disposed on the rotation axis. Next, the magnet 20 is inserted into each hole 18 of the laminated steel plates. Then, the upper mold 30 is moved toward the lower mold 28 to perform mold clamping. In the clamped state, the stacked steel plates are held to receive a predetermined pressure in the stacking direction and close the gaps between the steel plates. Thereafter, the resin 22 is injected from the cylinder of the upper mold 30 into a gap between the hole 18 and the magnet 20 disposed therein (hereinafter referred to as a gap in the hole 18). The injected resin 22 is filled in the gaps in the holes 18 and the gaps between the steel plates. By solidifying the filled resin 22, the magnet 20 is fixed in the hole 18, and the steel plate is fixed in a laminated state, whereby the unit rotor core 16 is manufactured. In this embodiment, since the length a of the unit rotor core 16 to be manufactured is the same, the lower mold 28 is not replaced for each unit rotor core 16 and the filling amount of the resin 22 is changed. Nor. Therefore, the operation of fixing the magnet 20 in the hole 18 and fixing the steel plates in a laminated state can be repeatedly performed, and a plurality of unit rotor cores 16 can be efficiently manufactured.

  Next, a method for manufacturing the rotor assembly 10 according to the present invention will be described. The case where the length b of the rotor core 14 in the rotation axis direction is 60 mm and the length a of the unit rotor core 16 in the rotation axis direction is 10 mm will be described. In the rotor assembly 10, the number of unit rotor cores 16 required to constitute the rotor core 14 is six. Six unit rotor cores 16 are fixed to the shaft 12 by interference fit. That is, the unit rotor core 16 is attached to the shaft 12 by press-fitting the shaft 12 into the hollow hole 24 of each unit rotor core 16. At this time, each unit rotor core 16 is disposed on the shaft 12 so that the positions of the magnets 20 of the adjacent unit rotor cores 16 are aligned. As a result, the rotor core 14 having the magnet 20 extending in the rotation axis direction and having a length of 60 mm in the rotation axis direction is formed, and the manufacture of the rotor assembly 10 is completed. When the unit rotor core 16 is fixed to the shaft 12, end plates (not shown) fitted to the shaft 12 can be disposed at both ends of the rotor core 14. By fastening each end plate with a bolt (not shown) penetrating the rotor core 14, the unit rotor core 16 can be reliably fixed to the shaft 12.

  In the rotor assembly 10 of this embodiment, the rotor core 14 is composed of a plurality of unit rotor cores 16, and the unit rotor cores 16 have the same length a in the rotation axis direction. Therefore, as described above, the operation of fixing the magnet 20 in the hole 18 can be repeatedly performed, so that the plurality of unit rotor cores 16 can be efficiently manufactured. Therefore, in order to manufacture the rotor cores 14 having different lengths b in the rotation axis direction, it is only necessary to change the number of the unit rotor cores 16 according to the respective lengths b. As a result, the rotor cores 14 can be manufactured efficiently. can do.

  Next, another embodiment of the rotor assembly 30 will be described with reference to the drawings. FIG. 5 is a side view showing the configuration of another rotor assembly 30. In addition, the same code | symbol is attached | subjected about the same component as the said embodiment, and detailed description is abbreviate | omitted.

  In the rotor assembly 30 of this embodiment, the unit rotor core 16 is disposed with a predetermined angular shift (skew) in the circumferential direction with respect to the adjacent unit rotor core 16. In FIG. 5, one of the magnets 20 fixed to each unit rotor core 16 is indicated by a broken line, and the magnet 20 of the unit rotor core 16 has a predetermined angle in the circumferential direction with respect to the magnet 20 of the adjacent unit rotor core 16. It can be seen that they are arranged with a skew. In this way, by constructing the rotor core 32 by skewing the unit rotor core 16, it is possible to reduce the cogging torque of the motor and reduce the rotation unevenness of the motor. The skew angle formed by the unit rotor cores 16 at both ends of the rotor core 32 and capable of effectively reducing the rotation unevenness of the motor is, for example, the angle of one slot in the stator or half of the angle. Is an angle. Therefore, it is possible to set a predetermined angular deviation between the adjacent unit rotor cores 16 based on these angles.

  In each of the above-described embodiments, the case where the rotor cores 14 and 32 are configured by the unit rotor core 16 that has the same length in the rotation axis direction has been described. The rotor core may be configured by a combination of these unit rotor cores. Thereby, the kind of length of the rotor core in a rotating shaft direction can be increased more. Two or more unit rotor cores having different lengths in the rotation axis direction may be used. Thus, when including the unit rotor core from which the length of a rotating shaft direction differs, the combination of these unit rotor cores is set according to the length of the rotor core in a rotating shaft direction. In this setting, the combination of reducing the total number of unit rotor cores simplifies the configuration of the rotor core, so that the workability can be improved.

  In each of the above-described embodiments, the case where the steel sheet in which the holes 18 are stacked is formed to penetrate in the rotation axis direction is described, but the present invention is not limited to this configuration. If the magnet 20 can be disposed in the hole 18, the steel plate in which the hole 18 is laminated can be obtained even if the hole 18 is formed to penetrate the steel plate laminated in a direction intersecting the rotation axis, for example, in the circumferential direction. It may be formed in a part without penetrating.

It is a perspective view which shows the structure of the rotor assembly of the interior magnet type motor of this embodiment. It is sectional drawing by the AA line of FIG. It is sectional drawing which shows the manufacturing state of a unit rotor core. It is a perspective view which shows a unit rotor core. It is a side view which shows the structure of another rotor assembly.

Explanation of symbols

  10, 30 Rotor assembly, 12 shaft, 14, 32 rotor core, 16 unit rotor core, 18 holes, 20 magnets.

Claims (5)

A unit rotor core that is pivotally supported by the shaft and is formed by stacking steel plates,
The unit rotor core includes a hole penetrating the laminated steel plates, and a magnet fixed in the hole,
A plurality of the unit rotor cores are mounted on the shaft to form a rotor core.
A rotor assembly for an embedded magnet type motor. The rotor assembly for an embedded motor according to claim 1,
The length of the unit rotor core in the rotation axis direction is the same.
A rotor assembly for an embedded magnet type motor. The rotor assembly of an embedded magnet type motor according to claim 1,
The unit rotor core includes at least two unit rotor cores having different lengths in the rotation axis direction.
A rotor assembly for an embedded magnet type motor. The rotor assembly of an embedded magnet type motor according to any one of claims 1 to 3,
The unit rotor core is disposed with a predetermined angular deviation in the circumferential direction with respect to the adjacent unit rotor core.
A rotor assembly for an embedded magnet type motor. A unit rotor core that is pivotally supported by the shaft is formed by laminating steel plates,
A magnet is fixed to a hole provided in the unit rotor core and penetrating the laminated steel plates,
A plurality of the unit rotor cores with the magnets are mounted on a shaft to form a rotor core.
A method of manufacturing a rotor assembly of an embedded magnet type motor.

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