JP2009296761A - Rotor and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotor which is easily manufactured while containing a copper bar and an aluminum bar in a slot. <P>SOLUTION: In the rotor 3, a plurality of the slots 11 which are formed so as to be opened at external peripheral sides are formed at the external periphery of a rotor core 7. The copper bar 12 composed of copper or a copper alloy is inserted into and arranged at the depth side of each slot 11, and the aluminum bar 13 formed by aluminum die casting is arranged at the external peripheral side of the copper bar 12. At this time, aluminum system molten metal is fed into the slot 11 also from an opening 11a of the external periphery of the slot 11. At the aluminum die casting of the aluminum bar 13, short-circuiting rings are arranged at axial both ends of the rotor core 7, and the copper bar 12 and the aluminum bar 13 in each slot 11 are electrically connected by the short-circuiting rings. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a rotor having a bar and a short ring and a method for manufacturing the same.

  Generally, a squirrel-cage induction motor is used as a drive source for pumps and fans. A number of bars and short-circuit rings provided on the rotor of the squirrel-cage induction motor are formed by aluminum die casting that is low in cost and excellent in productivity.

  In recent years, in order to increase the rotation efficiency of a squirrel-cage induction motor, a rotor using copper, which has a bar and a short circuit ring, which are more conductive than aluminum, has been considered. For example, it is considered that a cage is configured by combining a copper-based bar and a copper-based short-circuit ring by welding or the like, or a bar and the short-circuit ring are integrally formed by copper die casting. However, the former is inefficient in assembling work, and the latter is poor in productivity because it needs to be heated to a very high temperature, for example, 1000 ° C. or more in order to dissolve copper. Further, when copper die casting, there is a problem that the rotor core constituting the rotor is not practical because it may be distorted by this high heat. Therefore, instead of forming the entire car by welding or copper die casting, a rotor having a car that uses a copper-based material for a part of the car and combines the characteristics of copper and aluminum has been considered.

For example, a fully closed slot is formed on the outer periphery of the rotor core, and a copper-based bar (copper bar) is inserted into the slot from the axial direction. Thereafter, an aluminum-based molten metal is inserted into the slot of the rotor core. A rotor having a structure in which a molten metal is poured from one or both sides in the axial direction, the copper bar is wrapped with aluminum-based molten metal, and a short-circuit ring made of aluminum-based molten metal is formed at both axial ends of the rotor core is conceivable. (For example, refer to Patent Document 1).
JP-A-7-163107

  However, if an attempt is made to manufacture a rotor having a rotor core with a long axial direction with the above configuration, the resistance of the flow of aluminum-based molten metal flowing in the slot increases because the axial direction of the rotor core is long. Supply sufficient amount of aluminum-based molten metal to the end of the copper bar where no pouring is performed when hot water is applied from one side, and to the center of the copper bar when pouring is performed from both sides The aluminum bar having a predetermined shape cannot be formed, and there is a possibility that a predetermined rotation efficiency cannot be obtained.

  An object of the present invention is to provide a rotor capable of satisfactorily producing a slot having a copper bar and an aluminum bar in a slot, and further to provide a rotor capable of reducing torque unevenness and a method for producing the same. It is intended to provide.

  According to a first aspect of the present invention, there is provided a rotor according to the first aspect of the present invention, the rotor core, and a plurality of slots each having a shape that is provided on the outer peripheral portion of the rotor core at a predetermined interval in the circumferential direction, each having an open outer periphery. A copper bar made of copper or a copper alloy inserted and disposed on the back side in each slot, and an aluminum bar provided by aluminum die casting so as to be filled on the outer peripheral side of the copper bar in each slot; The aluminum bar is provided at both ends in the axial direction of the rotor core at the time of aluminum die-casting, and is configured to include the copper bar of each slot and a short-circuit ring that electrically connects the aluminum bar. It is characterized by that.

  In the rotor according to claim 4 of the present invention, the rotor core is formed by laminating a plurality of steel plates, and the laminated steel plates are shifted in the circumferential direction, and the copper bar and the The extending direction of the aluminum bar is inclined with respect to the axial direction of the rotor core.

  The method for manufacturing a rotor according to claim 7 of the present invention is the method for manufacturing a rotor according to claim 4, wherein after inserting the copper bar into each slot of the rotor core, the rotor core is inserted into the rotor core. The steel plates laminated by applying torsional rotation in the circumferential direction are shifted in the circumferential direction to incline the extending direction of the copper bar with respect to the axial direction of the rotor core, and then die cast aluminum The aluminum bar and the short-circuit ring are provided.

  According to the rotor of the first aspect of the present invention, the copper bar is inserted and disposed in the back side of the plurality of slots having an opening on the outer peripheral side, and the aluminum bar is provided on the outer peripheral side of the copper bar by aluminum die casting. In addition, a so-called double squirrel-cage rotor can be formed. The rotor is configured such that current flows mainly to an aluminum bar located on the outer peripheral side of the rotor core at start-up, and flows mainly to a low-resistance copper bar during operation at the rated speed (during continuous operation). As a result, a large starting torque can be obtained by concentrating current on the high resistance aluminum bar at the start, and a low loss rotor can be obtained by current flowing through the low resistance copper bar during operation at the rated speed. Obtainable.

  In this rotor, the aluminum molten metal for forming the aluminum bar is formed not only in the axial direction side of the rotor core but also on the outer peripheral side of the slot of the rotor core at the time of aluminum die casting. Can also be supplied into the slot. In this case, since the aluminum-based molten metal can be supplied from the opening portion of the slot, the copper bar can be easily disposed on the back side of the slot and the aluminum bar can be easily disposed on the outer peripheral side of the copper bar. As a result, compared to the configuration in which the aluminum-based molten metal is supplied only from the axial direction side of the rotor core, the aluminum-based molten metal supplied into the slot can be supplied to the entire slot more uniformly, and the copper can be supplied into the slot. A rotor provided with a bar and an aluminum bar can be manufactured satisfactorily.

  In the rotor according to claim 4 of the present invention, since the extending direction of the copper bar and the aluminum bar is inclined with respect to the axial direction of the rotor core, torque unevenness can be reduced. The rotation can be smoothed.

  According to the method for manufacturing a rotor of claim 7 of the present invention, the steel plate is formed by inserting a copper bar into each slot of the rotor core and then twisting and rotating the rotor core in the circumferential direction thereof. By shifting these in the circumferential direction, the extending direction of the copper bar can be inclined with respect to the axial direction of the rotor core. Then, by forming the aluminum bar in the slot by aluminum die casting, the extending direction of the aluminum bar can be inclined with respect to the axial direction of the rotor core as well as the copper bar. Therefore, the extending direction of the copper bar and the aluminum bar can be easily inclined with respect to the axial direction of the rotor core.

Hereinafter, a first embodiment in which the present invention is applied to a rotor of a squirrel-cage induction motor will be described with reference to FIGS. 1 to 6.
FIG. 2 shows a schematic configuration of the stator 2 of the double squirrel-cage induction motor 1 according to the present embodiment and the rotor 3 positioned on the inner peripheral side of the stator 2.

  The stator 2 is configured by attaching a plurality of coils 5 to a stator core 4. The stator core 4 is formed in a cylindrical shape by laminating a plurality of annular steel plates made of silicon steel plates, and the lamination direction is integrally bound by a rivet (not shown). A plurality of slots 6 for housing the coils 5 are formed on the inner peripheral surface of the stator core 4.

  As shown in FIG. 3, the rotor 3 includes a rotor core 7 formed by laminating a plurality of annular steel plates made of silicon steel plates, and an annular shape provided at both axial ends of the rotor core 7. Short-circuited rings 8 and 8, and a rotating shaft 9 penetrating the central portion of the rotor core 7.

  As shown in FIG. 1, a plurality of rotor cores 7 are formed in the outer peripheral portion at predetermined intervals in the circumferential direction, and in this case, 24 slots 11 are formed. Each slot 11 extends in parallel to the axial direction of the rotor core 7 (rotating shaft 9), and an opening 11a is formed in the slot 11 where the outer periphery side of the rotor core 7 is opened.

  A copper bar 12 made of copper or a copper alloy is inserted and disposed in the back side of each slot 11 (inner peripheral side of the rotor core 7). As shown in FIG. 4, the copper bar 12 is formed by stacking a plurality of copper plates or copper (copper alloy) thin sheets extending in parallel to the axial direction of the rotor core 7. FIG. 4 is a view showing only the rotor core 7 and the copper bar 12 in order to explain the shape of the end 12a of the copper bar 12 (only one end is shown). In this case, six copper plates are used, and the copper bars 12 are configured by superimposing these six copper plates on the circumferential side of the rotor core 7. Further, the end 12a of the copper bar 12 protrudes outward from both axial end portions 7a of the rotor core 7, and half of the overlapped copper plates of the end 12a of the copper bar 12, three in this case The end 12a of the copper plate is bent in one direction (for example, clockwise direction) in the circumferential direction of the rotor core 7, and the end 12a of the remaining half (three in this case) of the copper core is the rotor core. 7 is bent to the other circumferential side (for example, counterclockwise direction side), and the end portions 12a of the copper bars 12 adjacent to each other in the circumferential direction of the rotor core 7 are in contact with each other.

  As shown in FIG. 1, on the outer peripheral side of the copper bar 12 in each slot 11, an aluminum bar 13 made of aluminum and having a bar shape extending in parallel to the axial direction of the rotor core 7 is provided. . Both ends of the aluminum bar 13 are formed integrally with the short-circuit rings 8 and 8 as will be described later.

The short-circuit ring 8 is made of aluminum, and as shown in FIG. 3, a plurality of cooling fins 14 projecting outward in the axial direction are integrally formed on the outer surface of the short-circuit ring 8 in the axial direction.
In the rotor 3 having such a configuration, the short-circuit ring 8, the aluminum bar 13, and the cooling fin 14 are integrally formed by aluminum die casting.

  FIG. 5 shows a mold 15 used for the aluminum die casting. The mold 15 includes a space for accommodating the rotor core 7 in the mold 15 and includes plates 16 and 16 that open on the axial direction side of the rotor core 7. The plate 16 is formed with a cavity 17 for forming the short ring 8 and the cooling fin 14 in the rotor core 7. In addition, runners (flow passages) 18 and 19 are formed in the plate 16 to send aluminum-based molten metal (not shown) from the outside of the mold 15 to the cavity 17.

  A gate (small hole) 20 at the tip of the runner 18 faces a portion 17 a for forming the short-circuit ring in the cavity 17 corresponding to the short-circuit ring 8. On the other hand, the gate 21 of the runner 19 faces the outer peripheral side of the slot 11 of the rotor core 7, specifically, the portion corresponding to the opening 11 a of the slot 11. Although not shown, the runners 19 are formed at 24 locations so as to correspond to the openings 11 a of the slots 11 of the rotor core 7. In FIG. 5, the runner 19 is shown only on one plate 16, but the runner 19 may be formed on the other plate 16 side.

Next, the manufacturing procedure of the rotor 3 will be described with reference to FIGS. 1 and 4 to 6.
First, one end 12a of the copper plate constituting the copper bar 12 is bent, and this copper bar 12 is inserted into each slot 11 of the rotor core 7 as shown in FIG. Insert from the outer periphery. In this case, for example, three of the six copper plates are inserted into each slot 11 in two portions. At this time, the bent end portion 12a of the copper bar 12 is arranged so as to be bent in the circumferential direction of the rotor core 7 as shown in FIG. 4, and as shown in FIG. 6 (b). As described above, the copper bar 12 is arranged on the back side in each slot 11. Further, the other end 12a of the copper bar 12 protruding from the other end 7a of the rotor core 7 is also bent in the circumferential direction of the rotor core 7 so as to be in the state shown in FIG. Thereby, the position shift of the copper bar 12 is prevented. Note that the copper plates may be bonded to each other with an adhesive or the like before inserting the slot 11 so that the copper plates constituting the copper bar 12 do not vary.

  Next, as shown in FIG. 5, the rotor core 7 to which the copper bar 12 is attached is placed at a predetermined position of the mold 15, and an aluminum-based molten metal, in this case, molten aluminum is added to the mold 15. Aluminum die casting is performed by supplying and filling the cavity 17 from the runners 18 and 19. At this time, the aluminum-based molten metal supplied from the runner 18 mainly forms the short-circuit ring 8 and the cooling fin 14.

  Also, the aluminum-based molten metal supplied from the runner 19 flows mainly into the slot 11 of the rotor core 7, and the aluminum bar 13 is formed as shown in FIGS. 1 and 6 (c). In this case, since the aluminum-based molten metal is supplied from the opening 11a of the slot 11, the copper bar 12 is pushed into the back side of the slot 11 and arranged at a predetermined position on the back side. As a result, a sufficient space is generated on the outer peripheral side of the copper bar 12 in the slot 11, and the aluminum-based molten metal is supplied and filled in this space, whereby the aluminum bar 13 having a predetermined shape is formed.

  By such aluminum die-cast molding, the short-circuit ring 8 and the aluminum bar 13 in each slot 11 are integrally formed, and thereby, the copper bar 12 and the aluminum bar 13 in each slot 11 are strengthened by the short-circuit ring 8. In addition to being coupled, they are also electrically connected.

  After the aluminum die casting, the mold 15 is opened, and the rotor core 7 on which the short-circuit ring 8, the copper bar 12, the aluminum bar 13, and the cooling fin 14 are formed is removed. After the rotor core 7 is removed, the rotary shaft 9 is inserted and fixed to the rotor core 7 to complete the manufacture of the rotor 3.

  According to the above configuration, the copper bar 12 is inserted and arranged on the back side of each slot 11 having a shape in which the outer peripheral side of the rotor core 7 is opened, and the aluminum bar 13 is provided on the outer peripheral side of the copper bar 12 by aluminum die casting. A double-cage rotor 3 can be obtained.

  The rotor 3 is configured such that current flows mainly to the aluminum bar 13 positioned on the outer peripheral side of the rotor core 7 at the start, and mainly flows to the low-resistance copper bar 12 during operation at the rated rotational speed (continuous operation). It becomes. As a result, a large starting torque can be obtained by concentrating the current on the high-resistance aluminum bar 13 at the time of starting, and a rotation with a low loss can be achieved by the current flowing through the low-resistance copper bar 12 during operation at the rated speed. Child 3 can be obtained.

  In the rotor 3, the aluminum-based molten metal (in this case, aluminum) for forming the aluminum bar 13 is used not only in the axial direction side of the rotor core 7 but also in the rotor core 7 during aluminum die casting. It is also possible to supply into the slot 11 from the opening 11 a on the outer peripheral side of the slot 11. In this case, since the aluminum-based molten metal can be supplied and filled from the opening 11a of the slot 11, the copper bar 12 is easily disposed on the back side of the slot 11 and the aluminum bar 13 is easily disposed on the outer peripheral side of the copper bar 12. be able to. As a result, compared with the configuration in which the aluminum-based molten metal is supplied and filled only from the axial direction side of the rotor core 7, the aluminum-based molten metal supplied into the slot 11 is supplied and filled to the entire slot 11 without unevenness. Thus, the rotor 3 having the copper bar 12 and the aluminum bar 13 in the slot 11 can be manufactured satisfactorily.

  Further, since the aluminum-based molten metal is also supplied from the opening 11a on the outer peripheral side of the slot 11 of the rotor core 7 at the time of aluminum die casting, the insertion arrangement of the copper bars 12 is insufficient. However, the copper bar 12 can be disposed at a predetermined position of the slot 11 (the back side of the slot 11), so that the aluminum bar 13 formed in the remaining space of the slot 11 also has a predetermined shape. Can do.

  Further, end portions 12a and 12a of the copper bar 12 which protrude outward from the axial end portions 7a and 7a of the rotor core 7 are bent in the circumferential direction of the rotor core 7 and are adjacent to each other in the circumferential direction. Since the 12 end portions 12a are in contact with each other, the current during operation at the rated rotational speed can flow through the low-resistance copper bar 12, whereby the cross-sectional area of the short-circuit ring 8, that is, the short-circuit ring 8 can be reduced.

  Further, since the end portion 12a of the copper bar 12 is positioned inside the short-circuit ring 8, when the aluminum-based molten metal is solidified, the copper bar 12 and the short-circuit ring 8 are firmly bonded, and the copper bar 12 is It can prevent that it remove | deviates from a predetermined position.

  Since the end 12a of the copper bar 12 is bent in the circumferential direction of the rotor core 7 before the aluminum die cast molding, it is possible to prevent the positional deviation in the axial direction of the copper bar 12 in particular. It is possible to prevent the copper bar 12 from being displaced from a predetermined position of the rotor core 7.

Next, a second embodiment of the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected to the same part as the said 1st Embodiment, and the detailed description is abbreviate | omitted.
In the second embodiment, as shown in FIG. 7, the magnetic material is located further on the outer peripheral side of the aluminum bar 13 provided on the outer peripheral side of the copper bar 12 and closes the opening 11 a of the slot 11 of the rotor core 7. In this configuration, a wedge 31 is provided. The magnetic wedge 31 is made of a silicon steel plate or pure iron and has a rod shape extending in the axial direction of the rotor core 7. The magnetic wedge 31 may be formed by kneading a magnetic material such as iron powder and a resin such as an epoxy resin.

A method of attaching the magnetic wedge 31 will be described with reference to FIG.
First, as shown in FIG. 8A, the copper bar 12 is disposed on the back side in each slot 11 as in the first embodiment.
Next, as shown in FIG. 8B, an aluminum bar 13 is formed on the outer peripheral side of the copper bar 12 by aluminum die casting.

  After the aluminum bar 13 is formed, as shown in FIG. 8C, a magnetic wedge 31 is provided by being driven into the outer peripheral portion of the slot 11 of the rotor core 7 by means of a hammer (not shown). Then, the aluminum bar 13 is pushed into the inner peripheral side of the rotor core 7 by the magnetic wedge 31, and the space generated in the aluminum bar 13, for example, the space generated by nests and cracks, decreases.

According to the above configuration, the magnetic wedge 31 is provided on the rotor core 7 so that the magnetic wedge 31 functions as a part of the rotor core 7 and has an operation equivalent to that of a rotor having a fully closed slot. The rotor 3 which has an effect can be obtained.
Further, when a space due to a nest or a crack is generated in the aluminum bar 13, by providing the magnetic wedge 31 in the opening 11a of the slot 11, the space in the aluminum bar 13 can be reduced. The aluminum bar 13 can be obtained, and the fixing strength of the copper bar 12 can be increased, so that the rotor 3 exhibiting a strong and predetermined rotation efficiency can be obtained.

Next, a third embodiment of the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected to the same part as the said 2nd Embodiment, and the detailed description is abbreviate | omitted.
In the third embodiment, instead of the magnetic wedge 31 of the second embodiment, as shown in FIG. 9, a pair of extensions is provided on the outer peripheral portion of the rotor core 41 so as to be positioned on the outer peripheral side of each slot 11. In this configuration, the portion 42 is provided. Each extending portion 42 has a shape in which a part of the rotor core 41 on the opening 11 a side of the slot 11 closes the opening of the slot 11. Specifically, the extending portion 42 has a shape protruding in the circumferential direction from a part of the rotor core 41 located on both sides in the circumferential direction of the opening 11 a of the slot 11, and the tip of the extending portion 42. The portions are formed so as to be substantially in contact with each other at the center of the opening 11 a of the slot 11. Note that the distal end portion of the extending portion 42 is located at a position that does not protrude outward from the outer peripheral surface of the rotor core 41.

A method for manufacturing the rotor 3 using the rotor core 41 in which the extending portion 42 is formed will be described with reference to FIG.
First, as shown in FIG. 10A, the magnetic steel sheet is punched out so that the extending part 42 is formed on the outer peripheral part of the rotor core 41, and the obtained steel sheets are laminated to obtain the rotor core 41.

  Next, as shown in FIG. 10 (b), the tips of the extending portions 42 of the rotor core 41 are positioned outside the outer peripheral surface of the rotor core 41, and the gaps between the tips of the extending portions 42 are set. spread. Thereby, the insertion arrangement of the copper bars 12 and the supply of the aluminum-based molten metal from the outer peripheral side of the rotor core 41 become possible.

  Next, as shown in FIG. 10 (c), the copper bar 12 is arranged on the back side in each slot 11, and then aluminum die casting is performed to form the aluminum bar 13. In this case, the outer peripheral side surface of the aluminum bar 13 may not be flush with the outer peripheral surface of the rotor core 41 and may be slightly swollen.

  Then, after the aluminum die casting, as shown in FIG. 10 (d), each extending portion 42 of the rotor core 41 is placed inside the outer peripheral surface of the rotor core 7 by a punch or the like (not shown). Bend it to the same position as its outer periphery. Then, the aluminum bar 13 is pushed into the inner peripheral side of the rotor core 7, and the space due to the nests and cracks generated in the aluminum bar 13 is reduced.

According to the above configuration, the same effect as that of the second embodiment can be obtained by providing the extended portion 42 in the rotor core 41 and positioning the opening 11 a of the slot 11 so as to be closed.
Moreover, since the extending part 42 is integrally formed with the rotor core 41, the number of parts can be reduced.

Next, a fourth embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same part as the said 1st Embodiment, and the detailed description is abbreviate | omitted.
In the fourth embodiment, as shown in FIG. 11, the shapes of the rotor core 52 and the copper bar 53 constituting the rotor 51 are the same as those of the rotor core 7 and the copper bar 12 of the rotor 3 of the first embodiment. (See FIG. 4).

  In the rotor core 52 of the fourth embodiment, the stacked steel plates are shifted in the circumferential direction, and the extending direction of the copper bar 53 is inclined with respect to the axial direction of the rotor core 52. ing. Although not shown, the laminated steel plates are shifted from each other in the circumferential direction, so that the aluminum bars provided by aluminum die-casting also have an aluminum bar extending direction with respect to the axial direction of the rotor core. In a tilted state.

A method for manufacturing the rotor 51 will be described.
First, as in the first embodiment, after inserting the copper bar 53 into each slot 11 of the rotor core 52, the rotor core 52 is twisted in the circumferential direction thereof. For example, one end side of the rotor core 52 is rotated in the clockwise direction (indicated by an arrow A direction in FIG. 11), and the other end portion of the rotor core 52 is counterclockwise (in FIG. 11). , Indicated by the arrow B direction), and the laminated steel plates are twisted and shifted in the circumferential direction. Then, the axial direction of the rotor core 52 of the slot 11 is inclined with respect to the axial direction of the rotor core 52, and the extending direction of the copper bar 53 is inclined with respect to the axial direction of the rotor core 52.

  Thereafter, when the aluminum bar and the short-circuit ring 8 are formed by aluminum die casting, the extending direction of the aluminum bar is also inclined with respect to the axial direction of the rotor core 52, as with the copper bar 53. Thereby, the rotor 51 in which the extending direction of the copper bar 53 and the aluminum bar is inclined with respect to the axial direction of the rotor core 52 is obtained.

  According to the above configuration, after inserting the copper bar 53 into each slot 11 of the rotor core 52, the rotor steel core 52 is twisted in the circumferential direction to shift the laminated steel plates in the circumferential direction. Thus, the extending direction of the copper bar 53 and the aluminum bar can be easily inclined with respect to the axial direction of the rotor core 52. Since the extending direction of the copper bar 53 and the aluminum bar is inclined with respect to the axial direction of the rotor core 52, torque unevenness during the rotation of the rotor 51 can be reduced, and the rotor 51 can be reduced. Can be rotated smoothly.

  After inserting the copper bar 53, by twisting the rotor core 52, a part of the laminated steel plates, specifically the wall surface forming the slot 11, bites into the copper bar 53. It is possible to prevent 53 from shifting from a predetermined position.

Next, a fifth embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same part as the said 1st Embodiment, and the detailed description is abbreviate | omitted.
In the fifth embodiment, as shown in FIG. 12, the shape of the rotor core 62 constituting the rotor 61 is different from the rotor core 7 of the rotor 3 of the first embodiment (see FIG. 1).

  A fully closed slot 63 whose outer peripheral side is closed is formed between the slots 11 adjacent to each other in the circumferential direction of the rotor core 62. In this case, two fully closed slots 63 are provided at equal intervals between the slots 11 adjacent to each other in the circumferential direction of the rotor core 62. In addition, it is preferable to arrange | position so that the pitch of the circumferential direction of the copper bar 12 may exist 1 or more by one pole. This is because the flow of magnetic flux changes symmetrically with one pole, and if one or more copper bars 12 are not present with one pole, sufficient rotational efficiency may not be obtained.

  In the fully closed slot 63, a second aluminum bar 64 is provided by aluminum die casting. The second aluminum bar 64 is provided in the entire closed slot 63.

A method for manufacturing the rotor 61 will be described.
First, aluminum die casting is performed in a state where the copper bar 53 is inserted into the slot 11 of the rotor core 62 in which the slots 11 and 63 are formed, and the copper bar is not inserted into the fully closed slot 63. In this aluminum die casting, the aluminum-based molten metal supplied into the mold 15 flows into the slot 11, the fully closed slot 63, and the cavity 17 of the short-circuit ring 8, and the (first) aluminum bar 13 and the second Aluminum bar 64 and short-circuit ring 8 are formed. At this time, the supply of the aluminum-based molten metal into the fully closed slot 63 is performed only by flowing from the axial direction of the rotor core 62.

Thereby, the rotor 61 having the second aluminum bar 64 is obtained.
According to the said structure, the rotor 61 provided with the aluminum bars 13 and 64 more than the number of the copper bars 12 can be obtained. Since the rotor 61 having this configuration has many aluminum bars 13 and 64 having excellent starting characteristics, the rotor 61 can be applied to a squirrel-cage induction motor that is frequently started and stopped (starting characteristics are emphasized).

The present invention is not limited to the embodiment described above and shown in the drawings, and the following modifications and expansions are possible.
In the first embodiment, the copper bars 12 whose end portions 12a are not bent are used and inserted into the slots 11 of the rotor core 7 from the axial direction or the outer peripheral direction of the rotor core 7, and then the both ends of the copper bar 12 The portions 12a may be bent in the circumferential direction. Or you may insert the copper bar 12 by which both ends 12a and 12a were bent previously from the outer peripheral direction of the rotor core 7. FIG. Alternatively, after inserting and arranging the copper bar 12 whose end 12a is not bent into the slot 11, a wedge is driven between the copper plates on which the copper bar 12 is overlapped, so that the copper bar 12 is placed in the slot 11. It is also possible to prevent deviation from a predetermined position.

In the rotor 3 of the first embodiment, after the rotating shaft 9 is attached to the rotor core 7, the short-circuit ring 8 may be formed by performing aluminum die casting.
In addition, the number, dimensions, materials, and the like of the above-described components can be changed as appropriate.

The expanded sectional view of the outer peripheral part of the rotor core in the rotor of the 1st Embodiment of this invention Cross section of electric motor Perspective view of rotor with part cut away The perspective view which shows the shape of the edge part of a copper bar Cross section of mold for aluminum die casting It is a figure which shows the manufacturing method of a copper bar and an aluminum bar, (a) is a figure which shows the state before a copper bar is inserted and arranged in a slot, (b) is the state where a copper bar is inserted and arranged in a slot. The figure to show, (c) is the figure which shows the state where the aluminum bar was formed FIG. 1 equivalent diagram showing a second embodiment of the present invention It is a figure which shows the manufacturing method of a copper bar and an aluminum bar, (a) is a figure which shows the state by which the copper bar was inserted and arrange | positioned in a slot, (b) is a figure which shows the state by which the aluminum bar was shape | molded, (c) FIG. 4 is a view showing a state in which a magnetic wedge is provided in the opening of the slot. FIG. 1 equivalent view showing a third embodiment of the present invention The figure which shows the manufacturing method of a copper bar and an aluminum bar, (a) is a figure which shows the state where the extension part before a copper bar was inserted and arranged in a slot was closed, (b) The copper bar was inserted in a slot The figure which shows the state which the extension part before arrangement | positioning opened, (c) is a figure which shows the state by which the copper bar was inserted and arrange | positioned in a slot, and the aluminum bar was shape | molded, (d) is the state of (c) The state which shows the state which extended the extension part FIG. 4 equivalent view showing the fourth embodiment of the present invention FIG. 1 equivalent view showing a fifth embodiment of the present invention

Explanation of symbols

  In the drawings, 3 is a rotor, 7 is a rotor core, 7a is an end, 8 is a short ring, 11 is a slot, 11a is an opening, 12 is a copper bar, 12a is an end, 13 is an aluminum bar, 31 is Magnetic wedge, 41 is rotor core, 51 is rotor, 52 is rotor core, 52a is end, 53 is copper bar, 61 is rotor, 62 is rotor core, 63 is slot, 64 is the second Shows aluminum bar.

Claims (7)

The rotor core,
A plurality of slots provided in the circumferential direction at predetermined intervals in the outer circumferential portion of the rotor core, each having an opening on the outer circumferential side;
A copper bar made of copper or copper alloy inserted and arranged in the back of each slot;
An aluminum bar provided by aluminum die-casting so as to fill the outer peripheral side of the copper bar in each slot;
The aluminum bar is provided at both ends in the axial direction of the rotor core at the time of aluminum die-casting, and is configured to include the copper bar of each slot and a short-circuit ring that electrically connects the aluminum bar. A rotor characterized by that.   The rotor according to claim 1, wherein a magnetic wedge for closing the opening is provided in an opening on an outer peripheral side of the slot.   2. The rotor according to claim 1, wherein a part of the rotor core on the opening side of the slot is positioned so as to close the opening of the slot.   The rotor core is formed by laminating a plurality of steel plates, and the laminated steel plates are shifted from each other in the circumferential direction, and the extending direction of the copper bar and the aluminum bar is the rotor core. The rotor according to claim 1, wherein the rotor is inclined with respect to the axial direction.   The ends of the copper bar that protrude outward from both axial ends of the rotor core are bent in the circumferential direction of the rotor core, and the ends of the copper bars adjacent to each other in the circumferential direction are in contact with each other. The rotor according to claim 1, wherein the rotor is provided. Between the slots adjacent in the circumferential direction of the rotor core, a fully closed slot whose outer peripheral side is closed is formed,
The rotor according to any one of claims 1 to 5, wherein a second aluminum bar is provided in the whole closed slot by the aluminum die casting. In the method of manufacturing the rotor according to claim 4,
After inserting the copper bar into each slot of the rotor core, the copper bars are shifted in the circumferential direction by twisting and rotating the rotor core in the circumferential direction thereof. The rotor manufacturing method is characterized in that the extending direction of the rotor is inclined with respect to the axial direction of the rotor core, and then the aluminum bar and the short-circuit ring are provided by aluminum die casting.

Images