JP2018068012A - Manufacturing method of rotor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress unevenness of magnetic resistance and torque, and a noise deterioration in a rotor.SOLUTION: In a manufacturing method of a rotor disclosed in the specification, a rotor has a rotor core in which a plurality of steel plates are laminated and which has an insertion hole, a magnet inserted into the insertion hole, and resin filling material filled in the insertion hole. The insertion hole is larger than a sectional size of the magnet in a larger range than a magnet length in a lamination direction. In the steel plates of both ends in the lamination direction of the rotor core, a projection portion extending from an edge of the insertion hole is provided. At least one of the projection portions of both ends is provided in a range not interrupting passage of the magnet. The manufacturing method of a rotor has an insertion step and a filling step. In the insertion step, the magnet is inserted into the insertion hole of the rotor core. In the filling step, when viewed from the lamination direction, the magnet is arranged so that the projection portion of the steel plates of both ends and the magnet are overlapped at least partially and the filling material is filled in the insertion hole.SELECTED DRAWING: Figure 2

Description

  The technology disclosed in this specification relates to a method of manufacturing a rotor of a motor.

  Conventionally, a motor in which a magnet and a filler are inserted into a rotor core is known (for example, Patent Document 1). The rotor core of Patent Document 1 has an insertion hole in which a magnet is disposed. The insertion hole is closed at both ends of the rotor core. The rotor core is divided into two at the center in the axial direction. In the manufacturing method of the rotor of the motor of patent document 1, the rotor core divided | segmented into two from the both sides of the magnet is engage | inserted, and a rotor core is connected. Small holes that lead to the insertion holes are provided at both ends of the rotor core, resin is filled from the small holes, and the magnet is fixed in the insertion holes.

JP2015-226368A

  In the method for manufacturing a rotor described in Patent Document 1, magnets are inserted into the divided rotor cores, and then the divided rotor cores are connected. If the divided insertion holes of the rotor core are displaced at the connection locations, problems such as variations in magnetic resistance, variations in torque, and deterioration in noise may occur. When connecting a rotor core with a magnet inserted, it is expensive to accurately align and connect the insertion holes of the divided rotor core. A manufacturing method in which a magnet is inserted into a completed rotor core is desirable. However, when providing a through-hole through which a magnet is inserted in the rotor core, it has been necessary to attach a cover plate (end plate) for preventing popping out at both ends of the rotor core into which the magnet has been inserted. It was. If a rotor can be completed by inserting a magnet after manufacturing a rotor core without requiring a cover plate, the rotor can be manufactured at low cost.

  In the rotor manufacturing method disclosed in the present specification, the rotor is a rotor core in which a plurality of steel plates are stacked, the rotor core having an insertion hole formed so as to penetrate along the stacking direction, and the rotor core is inserted into the insertion hole. And a resin filler filled in the insertion hole. The insertion hole provided in each of the plurality of steel plates is larger than the cross-sectional size of the magnet in a range larger than the length of the magnet along the stacking direction. The steel plates at both ends in the stacking direction of the rotor core are provided with protrusions extending from the edge of the insertion hole. At least one of the projecting portions at both ends is provided in a range that does not hinder the passage of the magnet. The method for manufacturing a rotor includes an insertion step and a filling step. In the insertion step, a magnet is inserted into the insertion hole of the rotor core. In the filling step, the filler is filled in the insertion hole while arranging the magnets so that the protruding portions of the steel plates on both ends overlap at least part of the magnets when viewed from the stacking direction. According to the rotor manufacturing method of this embodiment, the magnet can be inserted after the rotor core is completed first. Moreover, the magnet can be prevented from jumping out without requiring an end plate.

  Details and further improvements of the technology disclosed in this specification will be described in detail in the section of Detailed Description.

It is a schematic plan view of the rotor manufactured by the manufacturing method of a present Example. It is sectional drawing of the cross section A1 in FIG. It is an expanded sectional view of the cross section B1 in FIG. It is an expanded sectional view of the cross section B2 in FIG. It is a flowchart of the manufacturing method of a rotor. It is sectional drawing of the rotor core formed by laminating | stacking several steel plates. It is sectional drawing of the rotor core in the state where the magnet was inserted in the insertion hole. It is sectional drawing of the rotor core of a state with which an insertion hole is filled with a filler. It is an expanded sectional view of section B1 (Drawing 2) in the state where a filler is filled up with an insertion hole.

  FIG. 1 is a schematic plan view of a rotor 10 manufactured by the manufacturing method of this embodiment. FIG. 2 is a cross-sectional view of a cross section A1 in FIG. FIG. 2 shows a cross section passing through the center of the rotor 10 shown in FIG. 1 and parallel to the axial direction of the rotor 10. In FIGS. 1 and 2 and subsequent figures, the XYZ axes are defined. The XYZ axes shown in each figure are correlated with each other. The Z axis is an axis parallel to the axis of the rotor 10. The Y axis is an axis orthogonal to the Z axis and parallel to the cross section A1. The X axis is an axis orthogonal to the Y axis and the Z axis. Hereinafter, the direction parallel to the Z axis is also simply referred to as “axial direction”, and the direction of the straight line parallel to the XY plane is also simply referred to as “radial direction”.

  The rotor 10 is one of the parts constituting the motor. As shown in FIG. 2, the rotor 10 includes a shaft 20, a rotor core 30, a plurality of magnets 50, and a filler 60. The shaft 20 is an axis of the rotor 10 that is a rotating body. As shown in FIGS. 1 and 2, the shaft 20 has a substantially cylindrical shape. A part of the shaft 20 projects in a radial direction from a circular cylinder having a perfect cross section. As shown in FIG. 1, the shaft 20 is formed with a key groove 21 that is recessed inward in the radial direction from a circular cylinder having a perfect cross section.

  As shown in FIGS. 1 and 2, the rotor core 30 has a cylindrical shape formed around a positioning hole 38 into which the shaft 20 is inserted. As shown in FIG. 2, the rotor core 30 is formed by laminating a plurality of steel plates 70 along the axial direction. As shown in FIG. 1, the rotor core 30 has a key portion 39 that engages with the key groove 21 of the shaft 20 on the outer peripheral portion of the positioning hole 38. The shaft 20 is fixed to the rotor core 30 by the engagement of the key groove 21 and the key portion 39.

  As shown in FIGS. 1 and 2, near the outer diameter of the rotor core 30, sixteen insertion holes 40 penetrating along the lamination direction of the steel plates 70, which is the axial direction, are formed. A magnet 50 is inserted into each of the 16 insertion holes 40. Specifically, the rotor core 30 is formed with two insertion holes 40 per pole, and 16 insertion holes 40 corresponding to a total of eight poles are formed. The filler 60 is a thermosetting resin. The magnet 50 inserted into each of the 16 insertion holes 40 is fixed by a filler 60 filled in the insertion hole 40. As shown in FIG. 2, all the magnets 50 are fixed to the outside in the radial direction in the insertion holes 40 in which the magnets 50 are inserted. Since FIG. 1 is a schematic plan view, for convenience, FIG. 1 shows a plan view of the insertion hole 40 as a rectangle. Strictly speaking, the shape of the insertion hole 40 in the XY plane has a substantially rectangular shape. These shapes are combined.

  As shown in FIG. 2, the rotor core 30 includes, in the axial direction, a central steel plate 31 located in the central portion, a first end steel plate 32 located in the negative direction of the Z axis, and a positive direction of the Z axis. And a second end steel plate 33 positioned. The insertion hole 40 includes a central hole 41 formed in the central steel plate 31, a first end hole 42 formed in the first end steel plate 32, and a second end formed in the second end steel plate 33. It is divided into part holes 43. As shown in FIG. 2, the cross-sectional area of the central hole 41, the cross-sectional area of the first end hole 42, and the cross-sectional area of the second end hole 43 are different. The central hole 41, the first end hole 42, and the second end hole 43 are formed in this order so that the cross-sectional area increases. Specifically, the cross-sectional area of the first end hole 42 is smaller than the cross-sectional area of the central hole 41, and the first protrusion 72 protrudes inward in the radial direction. In addition, the cross-sectional area of the second end hole 43 is larger than the cross-sectional area of the central hole 41, and the second protrusion 73 has a cross-sectional area of the second end hole 43 over the entire collection of the second end holes 43. It is formed small by projecting in the radial direction to be reduced.

  FIG. 3 is an enlarged sectional view of a section B1 in FIG. 4 is an enlarged sectional view of a section B2 in FIG. As shown in FIGS. 2 and 3, the magnet 50 is fixed to the radially outer side of the central hole 41. As shown in FIGS. 2 and 4, the cross-sectional area of the first end hole 42 is larger than the cross-sectional area of the magnet 50. In FIG. 4, in order to clearly show the difference in the presence or absence of the first protrusion 72, the radially outer surface of the central hole 41 with which the magnet 50 is in contact is shown as a straight line L <b> 1. As shown in FIG. 2, the sectional area of the second end hole 43 is smaller than the sectional area of the magnet 50. Since the length in the stacking direction of the central steel plate 31 having a cross-sectional area larger than the cross-sectional area of the magnet 50 is larger than the length in the stacking direction of the magnet 50, the magnet 50 includes the first protrusion 72 and the axial direction. The second protrusion 73 may be disposed between the second protrusion 73 and the second protrusion 73.

  FIG. 5 is a flowchart of the method for manufacturing the rotor 10. In order to manufacture the rotor 10 described above, first, a plurality of steel plates 70 to be the basis of the rotor core 30 are laminated (step S11). FIG. 6 is a cross-sectional view of the rotor core 30 formed by laminating a plurality of steel plates 70. As shown in FIG. 6, the laminated steel plates 70 have different shapes depending on which of the central steel plate 31, the first end steel plate 32, and the second end steel plate 33 is configured.

  Next, an insertion step is performed in which the magnet 50 is inserted into the center hole 41 along the axial direction in each of the insertion holes 40 of the rotor core 30 (step S13 in FIG. 5). FIG. 7 is a cross-sectional view of the rotor core 30 in a state where the magnet 50 is inserted into the insertion hole 40. As shown in FIG. 7, the first protrusion 72 is smaller than the cross-sectional area of the magnet 50 inserted into the insertion hole 40, and thus does not hinder the insertion of the magnet 50 into the insertion hole 40. When the magnet 50 is inserted into the insertion hole 40, the positioning of the magnet 50 in the radial direction is not performed.

  Next, a filling process for filling each of the insertion holes 40 of the rotor core 30 with the filler 60 is performed (step S15 in FIG. 5). FIG. 8 is a cross-sectional view of the rotor core 30 in a state where the insertion hole 40 is filled with the filler 60. FIG. 9 is an enlarged cross-sectional view of the cross section B1 (FIG. 2) in a state where the insertion hole 40 is filled with the filler 60. As shown in FIG. 8, in the filling step, the magnet 50 is pressed outward in the radial direction so that the magnet 50 is disposed between the first protrusion 72 and the second protrusion 73 in the stacking direction. In addition, the filler 60 is filled in the direction of the flow 60F indicated by the arrow. In other words, in the filling process, the first protrusion 72 and the second protrusion 73 formed on the steel plates 70 at both ends overlap with at least a part of the magnet 50 when viewed from the stacking direction. The filler 60 is filled in the insertion hole 40. When the filling process is performed, the rotor core 30 is completed.

  Next, the shaft 20 is inserted and fixed to the completed rotor core 30 (step S17 in FIG. 5). As shown in FIG. 1, the key portion 39 of the shaft 20 is engaged with the key portion 39 of the rotor core 30, and the shaft 20 is fixed to the rotor core 30, thereby completing the rotor 10.

  As described above, the rotor core 30 of the rotor 10 manufactured by the manufacturing method of the present embodiment includes the insertion hole 40 formed so as to penetrate along the stacking direction of the steel plates 70. A magnet 50 is inserted into the insertion hole 40 and filled with a resin filler 60. The length in the stacking direction of the central steel plate 31 having a cross-sectional area larger than that of the magnet 50 is larger than the length of the magnet 50 in the stacking direction. The first end steel plate 32 has a first protrusion 72 that reduces the cross-sectional area of the first end hole 42, and the second end steel plate 33 includes a first cross-sectional area that reduces the cross-sectional area of the second end hole 43. Two protrusions 73 are provided. The 1st protrusion part 72 is formed in the range which does not prevent insertion of the magnet 50 inserted in the insertion hole 40. FIG. The method for manufacturing the rotor 10 includes an insertion process in which the magnet 50 is inserted into the insertion hole 40 of the rotor core 30. Moreover, this manufacturing method is a filler so that the 1st protrusion part 72 and the 2nd protrusion part 73 which were formed in the steel plate 70 of both ends seeing from the lamination direction, and at least one part of the magnet 50 may overlap. 60 has a filling step in which the insertion hole 40 is filled. Therefore, in the manufacturing method of the rotor 10 of the present embodiment, the magnet 50 can be inserted into the insertion hole 40 formed in the already completed rotor core 30, so compared with the manufacturing method in the case of joining the divided rotor cores 30, The insertion hole 40 is not displaced. Thereby, the problem of the dispersion | variation in the magnetic resistance in the rotor 10, the dispersion | variation in a torque, and the deterioration of a noise can be suppressed. Further, the rotor 10 manufactured by the manufacturing method of the present embodiment can prevent the magnet 50 from jumping out without a cover plate or the like mounted outside the steel plates 70 at both ends in order to prevent the magnet 50 from jumping out. Therefore, the rotor 10 can be manufactured at low cost. Further, in the rotor 10 of the present embodiment, the magnet 50 is fixed to the outer side in the radial direction in the insertion hole 40, and therefore receives a force in the outer side in the radial direction by centrifugal force when the rotor 10 rotates. Furthermore, it is difficult to jump out of the insertion hole 40.

  In the said Example, although the 1st end hole 42 and the 2nd end hole 43 which were formed of the some steel plate 70 demonstrated about an example of a different shape, the 1st end hole 42 and the 2nd end hole 43 were demonstrated. The shape of can be variously modified. For example, the first end hole 42 and the second end hole 43 may have the same shape, and the magnet 50 may be inserted through the second end hole 43. Further, the number of stacked steel plates 70 that form the first end hole 42 is different from the number of stacked steel plates 70 that form the second end hole 43, and the length of the first end hole 42 in the stacking direction is the second. The length of the end hole 43 in the stacking direction may be different. The first end hole 42 and the second end hole 43 have a first protrusion 72 and a second protrusion 73 that reduce the cross-sectional area of the center hole 41, and the center hole 41 is stacked. The shape of the steel plate 70 forming the first end hole 42 and the second end hole 43 can be changed within a range in which the length in the direction is larger than the length in the stacking direction of the magnets 50.

  In the above embodiment, an example of the insertion hole 40 formed in the rotor core 30 and the magnet 50 inserted into the insertion hole 40 has been described. However, with regard to the number of insertion holes 40 formed in the rotor core 30 and the poles of the magnet 50, Various modifications are possible. The number of insertion holes 40 formed in the rotor core 30 may be 15 or less, or 17 or more. Moreover, the magnet 50 inserted in the insertion hole 40 may not be a total of 8 poles.

  In the above embodiment, an example of the fixing method between the rotor core 30 and the shaft 20 has been described, but a known technique can be applied to the fixing method between the rotor core 30 and the shaft 20.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

DESCRIPTION OF SYMBOLS 10 ... Rotor 20 ... Shaft 21 ... Key groove 30 ... Rotor core 31 ... Central part steel plate 32 ... First end steel plate 33 ... Second end steel plate 38 ... Positioning hole 39 ... Key part 40 ... Insertion hole 41 ... Central part hole 42 ... first end hole 43 ... second end hole 50 ... magnet 60 ... filler 60F ... filler flow 70 ... steel plate 72 ... first protrusion 73 ... second protrusion L1 ... straight line

Claims (1)

A rotor core in which a plurality of steel plates are laminated, the rotor core having an insertion hole formed so as to penetrate through the lamination direction, a magnet inserted into the insertion hole, and a resin made into the insertion hole A method of manufacturing a rotor comprising:
The insertion holes provided in each of the plurality of steel plates are larger than the cross-sectional size of the magnet in a range larger than the length of the magnets along the stacking direction, and the steel plates at both ends of the rotor core in the stacking direction. Is provided with a protrusion extending from the edge of the insertion hole, and at least one of the protrusions at both ends is provided in a range that does not hinder the passage of the magnet,
The manufacturing method includes:
An insertion step of inserting the magnet into the insertion hole of the rotor core;
And a filling step of filling the insertion hole with the filler while arranging the magnet so that at least a part of the magnet overlaps the protruding portion of the steel plate at both ends when viewed from the stacking direction. .

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