JP2015061487A - Process of manufacturing rotor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process of manufacturing a rotor, in which a magnet and such may be easily inserted into a magnet insertion hole, capable of securing a sufficient gap between the magnet and a wall surface of the magnet insertion hole.SOLUTION: The process of manufacturing a rotor includes steps of: cutting one sheet of sheet material to obtain a plurality of spacers 17; pasting the plurality of spacers 17 to a permanent magnet 14; inserting the permanent magnet 14 to which spacers 17 are pasted into a magnet insertion hole 11a; and filling a gap between a wall of the magnet insertion hole 11a and the permanent magnet 14 with a resin 18.

Description

  The present invention relates to a method for manufacturing a rotor.

  Conventionally, an embedded permanent magnet (IPM) rotor in which a permanent magnet is incorporated in a magnet insertion hole formed in a rotor core (rotor core) is known as a rotor (rotor) constituting a rotating electrical machine. It has been. As a method of fixing the magnet inserted into the magnet insertion hole, there is a method of filling a resin (adhesive) in a gap between the magnet and the magnet insertion hole.

  When the rotor rotates at a high speed, the magnet is pressed against the wall surface of the magnet insertion hole with a large centrifugal force, which may cause cracks, cracks, chips, and the like. Therefore, in Patent Document 1, a plurality of guide members affixed to the magnet and an adhesive between the guide members prevent the magnet from directly contacting the wall surface of the magnet insertion hole even when centrifugal force is applied. It is disclosed. The guide member functions as a spacer that secures a gap between the magnet and the wall surface of the magnet insertion hole.

JP 2012-16237 A

  However, the technique described in Patent Document 1 has a problem in that it is inferior in productivity because it is difficult to insert a magnet provided with a guide member and an adhesive into the magnet insertion hole. Therefore, it is conceivable to fill the resin after inserting the magnet and the spacer into the magnet insertion hole.

  However, the gap between the magnet and the wall surface of the magnet insertion hole is as small as about 0.2 mm. Therefore, if the thickness of the spacer is increased in order to ensure a sufficient gap between the magnet and the wall surface of the magnet insertion hole, it becomes difficult to insert the magnet and the spacer. On the other hand, if the spacer is thin, a sufficient gap cannot be secured, and the magnet may come into contact with the wall surface of the magnet insertion hole when the rotor rotates at a high speed. Therefore, it is necessary to set the thickness of the spacer to an appropriate value and keep the variation within a narrow range.

  In view of the above points, the present invention makes it easy to insert a magnet or the like into a magnet insertion hole, and can secure a sufficient gap between the magnet and the wall surface of the magnet insertion hole. It aims at providing the manufacturing method of.

  The present invention is a method for manufacturing a rotor obtained by inserting a magnet into a magnet insertion hole formed in a rotor core, the step of cutting a sheet material to obtain a plurality of spacers, A step of attaching to the magnet, a step of inserting the magnet attached with the spacer into the magnet insertion hole, and a step of filling the gap between the wall surface of the magnet insertion hole and the magnet with resin. To do.

  According to the present invention, the plurality of spacers obtained by cutting from one sheet material are attached to the magnet. One sheet material has a substantially uniform thickness over the whole, and it is easy to manufacture so that the variation in thickness falls within a predetermined narrow range. Therefore, the gap between the magnet and the wall surface of the magnet insertion hole can be made substantially constant.

  In addition, since a predetermined gap is reliably ensured between the spacer and the outer wall on the outer periphery side of the magnet insertion hole depending on the thickness of the spacer, it is possible to reliably fill the gap with resin.

  By the way, when a plurality of spacers are arranged in a row in a direction orthogonal to the resin filling direction, the resin to be filled contacts the plurality of spacers at the same time, so that a large pressure is generated. There is a risk of peeling.

  Therefore, in the present invention, it is preferable that the plurality of spacers are attached to the magnet while being shifted from the filling direction of the resin. In this case, since the resin contacts the spacer with a time difference at the time of resin filling, the magnitude of the generated pressure is suppressed, and the possibility that the spacer is peeled off is reduced.

  In the present invention, it is also preferable that the plurality of spacers have different sizes in the resin filling direction.

  In this case, it becomes possible to flow the resin non-uniformly in a direction orthogonal to the filling direction of the resin. This makes it possible to control the position of the magnet in the circumferential direction of the rotor by moving the magnet in a desired direction in the magnet insertion hole.

  Moreover, in this invention, it is preferable to insert the said magnet in the said magnet insertion hole so that the surface which affixed these spacers may become the outer peripheral side of the said rotor.

  In this case, a predetermined gap is reliably ensured between the outer circumferential side surface of the magnet and the outer circumferential side inner wall surface of the magnet insertion hole depending on the thickness of the spacer, and the gap is filled with resin. Therefore, even if the rotor rotates at a high speed, it is possible to reliably eliminate the possibility that the magnet contacts the wall surface of the magnet insertion hole.

The front view which shows roughly an example of the rotor manufactured using the manufacturing method of the rotor of this invention. II-II sectional view taken on the line of FIG. The figure explaining the position of the spacer affixed on the permanent magnet. The flowchart explaining the manufacturing method of the rotor of this invention. Sectional drawing which shows the structure which fills resin in the clearance gap between a permanent magnet and a magnet insertion hole. The figure explaining the position of the spacer affixed on the permanent magnet based on the deformation | transformation of embodiment. The figure explaining the position of the spacer affixed on the permanent magnet based on other deformation | transformation of embodiment. The figure explaining the position of the spacer affixed on the permanent magnet based on the further another deformation | transformation of the embodiment.

  First, an example of the structure of a rotor (rotor) manufactured using the method for manufacturing a rotor of the present invention will be described.

  As schematically shown in FIGS. 1 and 2, the rotor 10 includes a substantially cylindrical rotor core (rotor core) 11, a boss portion 12 joined to the inner peripheral side of the rotor core 11, and a boss portion 12. And a fixed rod-shaped rotor shaft 13.

  Although not shown, a substantially cylindrical stator (stator) is disposed outside the rotor 10 via a gap. The rotating electrical machine includes the stator and a rotor 10 that is rotatable with respect to the stator.

  A permanent magnet 14 is embedded in a magnet insertion hole (slot) 11a formed in the rotor core 11, and the rotating electrical machine is of an embedded permanent magnet type (IPM: Interior Permanent Magnet). When the rotor shaft 13 functions as an output shaft or an input shaft, the rotating electrical machine is used as an electric motor (motor) or a generator.

  The rotor core 11, the boss portion 12, and the rotor shaft 13 are arranged coaxially, and their axial directions coincide. Hereinafter, these axial directions are referred to as the axial direction of the rotor 10 or simply the axial direction.

  The rotor core 11 is configured by laminating a number of silicon steel plates (electromagnetic steel plates). In the vicinity of the outer periphery of the rotor core 11, a plurality of magnet insertion holes 11a are formed at intervals in the circumferential direction. The magnet insertion hole 11a extends in the axial direction and has a rectangular cross section here.

  A permanent magnet 14 is inserted into each magnet insertion hole 11a. The permanent magnet 14 is a flat plate having a substantially rectangular cross section made of a sintered magnet.

  As shown in FIG. 2, the rotor core 11 is sandwiched between end plates 15 and 16 made of a non-magnetic material at both axial ends. The upper end plate 15 is formed with a resin filling hole 15a communicating with the magnet insertion hole 11a.

  Referring also to FIG. 3, a plurality of spacers 17 are attached to the outer peripheral side surface of the permanent magnet 14. The gap between the outer peripheral side surface of the permanent magnet 14 secured by the thickness of the spacer 17 and the outer peripheral side inner wall surface of the magnet insertion hole 11 a is filled with resin 18. The resin 18 is also filled in the gap between the other surface of the permanent magnet 14 and the other inner wall surface of the magnet insertion hole 11a.

  The plurality of spacers 17 are obtained by cutting out one resin sheet. The resin sheet is made of a heat-resistant resin such as polyphenylene sulfide resin (PPS) or glass fiber resin. When the gap between the permanent magnet 14 and the wall surface of the magnet insertion hole 11a is about 0.2 mm, for example, the thickness of the spacer 17 may be about 0.15 mm.

  The plurality of spacers 17 are attached to the permanent magnet 14 so as to be shifted with respect to the filling direction of the resin 18 indicated by arrows in FIG. The shape of each spacer 17 is a rectangular shape here, but may be an appropriate shape such as a triangle, a pentagon, a polygon with a hexagon, a circle, or an oval. Further, the spacers 17 may have the same shape, different shapes, or different sizes.

  The resin 18 is, for example, a thermoplastic resin such as silicone or epoxy, and is suitably used as an adhesive.

  First, the manufacturing method of the rotor of this invention is demonstrated. Here, the case where the rotor 10 mentioned above is manufactured is demonstrated with reference to FIG. In addition, since processes other than those related to inserting the permanent magnet 14 into the magnet insertion hole 11a are the same as conventionally known processes, description thereof will be omitted.

  First, a step of cutting a sheet material to obtain a plurality of spacers 17 is performed (STEP 1). The cutting method is not particularly limited, and for example, various cutters may be used. In the present invention, a cutter or a cutting method similar to the cutter such as punching is also included in the cutting. Here, the sheet material is formed by laminating a resin layer and an adhesive layer (or an adhesive layer) in layers.

  Next, a step of attaching a plurality of spacers 17 to the permanent magnet 14 is performed (STEP 2). The attaching method is not particularly limited. For example, the surface of the resin layer of the spacer 17 is adsorbed by a pickup nozzle that generates a negative pressure, and the adhering adhesive layer surface of the adsorbed spacer 17 is pressed against the surface of the permanent magnet 14. Good.

  In addition, what is necessary is just to affix the spacer 17 to the permanent magnet 14 with an adhesive agent when the spacer 17 cuts off the sheet | seat material which does not contain an adhesive bond layer.

  Next, a step of inserting the permanent magnet 14 with the plurality of spacers 17 attached into the magnet insertion hole 11a is performed (STEP 3). At this time, the permanent magnet 14 is inserted into the magnet insertion hole 11a so that the surface to which the spacer 17 is attached is on the outer peripheral side.

  Next, a step of filling the resin 18 into the gap between the wall surface of the magnet insertion hole 11a and the permanent magnet 14 is performed (STEP 4). The method for filling the resin 18 is not particularly limited.

  Here, as shown in FIG. 5, the upper mold 21 is installed on the upper surface of the upper end plate 15, and the lower mold 22 is installed on the lower surface of the lower end plate 16. The upper mold 21 is formed with a resin filling hole 21 a communicating with the resin filling hole 15 a of the end face plate 15. Then, the resin 18 that has been heated and softened is filled into the gap between the permanent magnet 14 and the inner wall surface of the magnet insertion hole 11a through the resin filling holes 15a and 21a by a resin injection device (not shown) such as a plunger.

  Finally, the resin 18 is cooled and solidified to solidify the resin 18 and fix the permanent magnet 14 in the magnet insertion hole 11a (STEP 5).

  As described above, the plurality of spacers 17 obtained by cutting from one sheet material are attached to one permanent magnet 14. One sheet material has a substantially uniform thickness over the entire sheet material, and can be easily manufactured so that the variation in thickness is within a predetermined narrow range. Therefore, it becomes possible to easily insert the permanent magnet 14 with the spacer 17 pasted into the gap between the permanent magnet 14 and the wall surface of the magnet insertion hole 11a.

  Further, the thickness of the spacer 17 ensures a predetermined gap between the outer peripheral side surface of the permanent magnet 14 and the outer peripheral side inner wall surface of the magnet insertion hole 11a, and the gap 18 is filled with the resin 18. Therefore, even if the rotor 10 rotates at a high speed, it is possible to reliably eliminate the possibility that the permanent magnet 14 comes into contact with the wall surface of the magnet insertion hole 11a.

  By the way, when the plurality of spacers 17 are arranged in a row in the lateral direction (substantially circumferential direction) with respect to the filling direction of the resin 18, the filled resin 18 contacts the plurality of spacers 17 at the same time. The spacer 17 may be peeled off from the permanent magnet 14 due to this pressure.

  Therefore, in the embodiment, as shown in FIG. 3, the plurality of spacers 17 are arranged with their positions shifted from the filling direction of the resin 18 (the arrow direction in the figure). Therefore, since the resin 18 contacts the spacer 17 with a time difference at the time of resin filling, the magnitude of the generated pressure is suppressed, and the possibility that the spacer 17 is peeled off is reduced. Further, at least the plurality of spacers 17 are not peeled off at the same time. Even if a spacer 17 is peeled off, a gap is secured by another spacer 17, so that there is no significant adverse effect on the filling of the resin 18.

  The interval between the spacers 17 exceeds the interval through which particles having the maximum particle size added to the resin 18 to be filled can pass, and is preferably at least twice the maximum particle size. Thereby, clogging between the spacers 17 can be suppressed, and the filling property of the resin 18 can be improved.

  In addition, the location which affixes the some spacer 17 to the permanent magnet 14 is not limited to what shifted the position with respect to the filling direction of the resin 18, as illustrated in FIG.

  For example, as shown in FIG. 6, the spacer 17 </ b> A may be arranged so as to extend along the filling direction of the resin 18 (the arrow direction in the drawing). In this case, a path through which the resin 18 flows is formed by the spacer 17A, and the resin 18 can be reliably filled to the back of the magnet insertion hole 11a.

  Further, as shown in FIG. 7, a plurality of spacers 17B are arranged on the front side so as to extend along the filling direction of resin 18 (arrow direction in the figure), and on the back side, the lateral direction of these spacers 17B is arranged. A spacer 17 </ b> C extending in the filling direction of the resin 18 may be disposed in the middle. In this case, the resin 18 flowing along the path formed by the front spacer 17C comes into contact with the spacer 17C and a large pressure is generated. Thereby, the permanent magnet 14 is pressed against the outer peripheral side surface of the magnet insertion hole 11a.

  Further, as shown in FIG. 8, a plurality of spacers 17 </ b> D may be arranged unevenly in the left-right direction along the filling direction of resin 18 (arrow direction in the drawing). In this case, the resin 18 flowing along the path formed by the plurality of spacers 17D flows unevenly from side to side, and the permanent magnet 14 is pressed against one side surface in the circumferential direction of the magnet insertion hole 11a. Thereby, it becomes possible to match | position the arrangement position of the circumferential direction of each permanent magnet 14. FIG.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this. For example, the present invention can be applied to any embedded permanent magnet type rotor, such as one having a different cross-sectional shape or arrangement direction of the magnet insertion hole 11a.

  DESCRIPTION OF SYMBOLS 10 ... Rotor, 11 ... Rotor core, 11a ... Magnet insertion hole, 12 ... Boss part, 13 ... Rotor shaft, 14 ... Permanent magnet (magnet) 15, 16 ... End face plate, 15a ... Resin filling hole, 17, 17A- 17D: spacer, 18: resin.

Claims (4)

A method for manufacturing a rotor by inserting a magnet into a magnet insertion hole formed in a rotor core,
Cutting a sheet material to obtain a plurality of spacers;
Attaching the plurality of spacers to the magnet;
Inserting the magnet with the spacer pasted into the magnet insertion hole;
And a step of filling the gap between the wall surface of the magnet insertion hole and the magnet with a resin.   The method for manufacturing a rotor according to claim 1, wherein the plurality of spacers are attached to a magnet while being shifted with respect to a filling direction of the resin.   3. The method for manufacturing a rotor according to claim 1, wherein the plurality of spacers have different sizes in the filling direction of the resin. 4.   The rotation according to any one of claims 1 to 3, wherein the magnet is inserted into the magnet insertion hole so that a surface on which the plurality of spacers are attached is on an outer peripheral side of the rotor. Child manufacturing method.