JP2013220004A - Induction motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an induction motor that uses a rotor having a plurality of secondary conductors and that is effectively cooled with a coolant.SOLUTION: An induction motor 1 has a stator 10, a rotor 20, a rotating shaft 30, and end plates 40. The rotor 20 has a rotor core 21, a plurality of secondary conductors 22, and end rings 25 that are disposed on axial end surfaces of the rotor core 21. The rotating shaft 30 has an oil passage 31 and oil discharge ports 32. The oil discharge ports 32 are positioned between the respective end surfaces of the rotor core 21 and respective end surfaces of the end rings 25, extend in a radial direction of the rotating shaft 30, and connect the oil passage 31 and an outer circumferential surface of the rotating shaft 30. The end plates 40 are fixedly mounted on the rotating shaft 30 at positions in contact with the respective axial end surfaces of the end rings 25, and define oil accumulation sections Re together with the surfaces of the end rings 25. Oil discharged through the oil discharge ports 32 is accumulated in the oil accumulation sections Re and comes into contact with the surfaces of the end rings 25.

Description

  The present invention relates to an induction motor using a rotor having a plurality of secondary conductors.

  Conventionally, in the field of rotating electrical machines, the inventions described in Patent Document 1 and Patent Document 2 are known as inventions for cooling the rotating electrical machines. In the inventions described in Patent Document 1 and Patent Document 2, in order to cool a so-called IPM (Interior Permanent Magnet) motor, the end of the permanent magnet exposed at the rotor core end of the rotor is used as a refrigerant. By supplying cooling oil, the end of the permanent magnet is cooled.

JP 2006-006091 A JP 2009-027836 A

  Here, the inventions described in Patent Document 1 and Patent Document 2 are both inventions that have been made for IPM motors, and are predicated on circumstances specific to IPM motors. For example, in the case of an IPM motor, most of the permanent magnets to be cooled by the cooling oil are covered with the rotor core, and only the end face of the permanent magnet is exposed at the axial end face of the rotor core. Can be mentioned. In other words, in the case of the IPM motor, the portion that comes into contact with the supplied cooling oil and is directly cooled is limited to a limited portion, that is, the end face of the permanent magnet. Based on the premise of such restrictions, the IPM motor is efficiently cooled by the cooling oil.

  In this regard, in an induction motor using a rotor having a plurality of secondary conductors (for example, a squirrel-cage rotor or a wound rotor), the induction motor needs to be cooled. A technique for efficiently cooling an induction motor with a refrigerant (cooling oil) is desired.

  The present invention relates to an induction motor using a rotor having a plurality of secondary conductors, and provides an induction motor that can be efficiently cooled by a refrigerant.

  An induction motor according to an aspect of the present invention includes a rotating shaft rotatably disposed, a rotor core fixed to the rotating shaft, and a plurality of rotor motors that are distributed in the circumferential direction of the rotor core and extend in the rotating shaft direction. A secondary conductor, an end connecting portion connecting the end portions of the secondary conductor located on the end face side of the rotor core in the axial direction of the rotating shaft, and at least one side with respect to the axial direction of the rotating shaft An induction motor comprising: a rotor having an end plate fixed to a rotating shaft; and a stator on which a coil is wound and having a coil end portion of the coil on an axial end portion side of the rotating shaft, The end-entangled portion protrudes from the end surface of the rotor core in the axial direction and is configured to have an annular shape surrounding the periphery of the rotation shaft. The rotation shaft extends along the axial direction of the rotation shaft, and the refrigerant flows therethrough. Possible With respect to the refrigerant flow path and the axial direction of the rotating shaft, the outer circumferential surface of the rotating shaft extends in the radial direction of the rotating shaft at a position between at least one end surface of the rotor core and the end surface of the end entangled portion. A refrigerant discharge port that communicates with the refrigerant flow path, and is partitioned by a surface of the end plate that faces the end surface of the rotor core and an outer surface of the end tanged portion, and is discharged from the refrigerant discharge port It has the refrigerant | coolant retention part which retains.

  The induction motor includes a rotating shaft, a rotor core, an end tangle, a rotor having an end plate and a plurality of secondary conductors, and a stator. And the rotating shaft has the refrigerant | coolant flow path extended along the axial direction of a rotating shaft, and a refrigerant | coolant discharge port. In the induction motor, the refrigerant discharge port extends in the radial direction of the rotating shaft and communicates with the outer peripheral surface of the rotating shaft and the refrigerant channel, so that the refrigerant in the refrigerant channel is in contact with the rotor and the rotating shaft. The refrigerant is discharged from the refrigerant discharge port toward the outside of the rotation shaft by the centrifugal force accompanying the rotation. Here, the end entangled portion protrudes from the end surface of the rotor core in the axial direction, and is configured to have an annular shape surrounding the rotation shaft, and the end plate is at least one side with respect to the axial direction of the rotation shaft. And fixed to the rotating shaft. The refrigerant discharge port is formed at a position between at least one end surface of the rotor core and the end surface of the end entangled portion with respect to the axial direction of the rotation shaft, and the refrigerant retention portion is formed on the end plate. Since it is configured to be partitioned by the surface facing the end surface of the rotor core and the outer surface of the end-entangled portion, the refrigerant discharged from the refrigerant discharge port is discharged into the refrigerant retention portion and stays in the refrigerant retention portion. It will be. As a result, according to the induction motor, the refrigerant that has been discharged from the refrigerant discharge port is retained in the refrigerant retention part, so that the end connection part that constitutes the refrigerant retention part for a sufficient period of time to cool the end connection part and the like. Thus, the refrigerant can be brought into contact with the outer surface of the steel plate, so that the end entangled portion can be efficiently cooled. Moreover, since the end part is connected to the ends of the plurality of secondary conductors, the induction motor can efficiently cool the plurality of secondary conductors.

  An induction motor according to another aspect of the present invention is the induction motor according to claim 1, wherein the end portion includes an uneven portion that increases a volume of the refrigerant that is retained in the refrigerant retention portion. It has on the surface of an end part.

  In the induction motor, the volume of the refrigerant staying in the refrigerant staying portion can be increased by having the uneven portion on the surface of the end junction. Moreover, the said uneven | corrugated | grooved part also fulfill | performs the function to lengthen the period for which the refrigerant | coolant discharged from the refrigerant | coolant discharge port retains in a refrigerant | coolant retention part. Therefore, according to the induction motor, the end junction can be further efficiently cooled by the refrigerant, and the plurality of secondary conductors can also be efficiently cooled.

  An induction motor according to another aspect of the present invention is the induction motor according to claim 2, wherein the uneven portion is separated from the end surface of the rotor core in the axial direction of the rotation shaft. It is comprised by the several step part formed in the position spaced apart from the outer peripheral surface of this.

  In the induction motor, by forming the concavo-convex portion with a plurality of step portions, the volume of the refrigerant staying in the refrigerant staying portion is increased and the period in which the refrigerant stays in the refrigerant staying portion is lengthened. Can do. Therefore, according to the induction motor, the end junction can be further efficiently cooled by the refrigerant, and the plurality of secondary conductors can also be efficiently cooled.

  An induction motor according to another aspect of the present invention is the induction motor according to claim 2, wherein the concavo-convex portion is formed by forming a plurality of island-shaped protrusions on the outer surface of the end junction portion. It is characterized by being.

  In the induction motor, by forming the concavo-convex portion by forming a plurality of island-shaped protrusions on the outer surface of the end-entangled portion, the volume of the refrigerant staying in the refrigerant staying portion is increased, and The period during which the refrigerant stays in the refrigerant retention part can be lengthened. Therefore, according to the induction motor, the end junction can be further efficiently cooled by the refrigerant, and the plurality of secondary conductors can also be efficiently cooled.

  An induction motor according to another aspect of the present invention is the induction motor according to any one of claims 1 to 4, wherein the refrigerant retention portion and the outside of the rotor are communicated to each other in the refrigerant retention portion. It has the communicating path for making the refrigerant | coolant flow out of the said rotor outside.

  In the induction motor, a communication path communicates the refrigerant retention part and the outside of the rotor. Here, the refrigerant is discharged to the refrigerant retention portion via the refrigerant discharge port extending in the radial direction of the rotation shaft. Since the refrigerant that has accumulated in the refrigerant retention part can flow out of the rotor via the communication path, the refrigerant in the refrigerant retention part can be circulated at any time. As a result, according to the induction motor, the end junction and the plurality of secondary conductors can be efficiently cooled by the refrigerant in the refrigerant retention part.

  An induction motor according to another aspect of the present invention is the induction motor according to claim 5, wherein the communication path is formed by a hole penetrating the end plate along the axial direction of the rotation shaft. It is characterized by being.

  In the induction motor, the communication path is formed by a hole penetrating the end plate along the axial direction of the rotation shaft. Here, the refrigerant is discharged to the refrigerant retention portion via the refrigerant discharge port extending in the radial direction of the rotation shaft. That is, in the induction motor, the flow direction of the refrigerant when it is discharged into the refrigerant retention part and the flow direction of the refrigerant when it flows out of the refrigerant retention part can be made different. Sufficient retention can be achieved.

  An induction motor according to another aspect of the present invention is the induction motor according to claim 5 or 6, wherein the induction motor is disposed at an opening edge of the communication path in the refrigerant retention portion, and the rotation of the rotor. It has the valve body which obstruct | occludes the said communicating path by the centrifugal force accompanying.

  In the induction motor, the valve body is disposed at an opening edge of the communication path in the refrigerant retention portion, and the valve body closes the communication path by a centrifugal force accompanying the rotation of the rotor. Here, in the induction motor, when the rotor rotates at a high speed, heat generation in the plurality of secondary conductors and the short-circuit portion is reduced. Further, the refrigerant scattered from the communication path to the outside of the rotor is scattered at a high speed as the rotor rotates at a high speed, and may adversely affect components such as a coil end portion. In this regard, according to the induction motor, when the rotor rotates at a high speed, the valve body closes the communication path due to the centrifugal force accompanying the high speed rotation. Parts can be prevented from being damaged.

It is sectional drawing which shows schematic structure of the induction motor which concerns on 1st Embodiment. It is an external appearance perspective view which shows schematic structure of the rotor of an induction motor. It is a partial top view of a rotor which shows the composition of the end ring concerning a 1st embodiment. It is a fragmentary sectional view which shows the structure of the rotor of the induction motor which concerns on 2nd Embodiment. It is a partial top view of a rotor which shows the structure of the end ring which concerns on 2nd Embodiment. It is a fragmentary sectional view which shows the structure of the rotor of the induction motor which concerns on 3rd Embodiment. It is a partial top view of a rotor which shows the structure of the end ring which concerns on 3rd Embodiment. It is a fragmentary sectional view which shows the structure of the rotor of the induction motor which concerns on 4th Embodiment. It is a fragmentary sectional view showing the composition of the rotor of the induction motor concerning a 5th embodiment. It is a fragmentary sectional view showing the composition of the rotor of the induction motor concerning a 6th embodiment. It is a fragmentary sectional view showing the composition of the rotor of the induction motor concerning a 7th embodiment.

  Hereinafter, an embodiment (first embodiment) in which an induction motor according to the present invention is embodied in an induction motor 1 will be described in detail with reference to the drawings.

(First embodiment)
First, a schematic configuration of the induction motor 1 according to the first embodiment will be described in detail with reference to FIGS. The induction motor 1 according to the first embodiment is a squirrel-cage three-phase induction motor, and includes a stator 10 that generates a rotating magnetic flux by a three-phase alternating current, a rotor 20 that is configured as a squirrel-cage rotor, A rotation shaft 30 configured as a rotation center and a pair of end plates 40 disposed on the axial end surface of the rotor 20 are provided.

  In the induction motor 1, the rotating magnetic flux generated from the stator 10, which will be described later, and the induced current generated in the secondary conductor 22 of the rotor 20 configured as a squirrel-cage rotor are linked to each other to rotate the rotor 20. Force is generated. In such an induction motor 1, heat is generated in each secondary conductor 22 when an induced current flows.

  In the induction motor 1, the stator 10, the rotor 20, the rotating shaft 30, and the end plate 40 described above are accommodated inside a case (not shown), and an oil pump (not shown) is contained in the case. ) Is connected. The oil pump is constituted by an inscribed gear pump having an inner rotor and an outer rotor. By driving the oil pump, an oil passage 31 formed in an inner peripheral portion of a rotating shaft 30 described later, an oil discharge port 32, and the The oil corresponding to the “refrigerant” in the present embodiment is circulated through the inside of the case (see FIG. 1). In the course of being circulated by the oil pump, the oil cools the induction motor 1 housed in the case and lubricates a drive transmission mechanism (for example, a gear mechanism) in the induction motor 1.

  Next, the configuration of the stator 10 constituting the induction motor 1 will be described. The stator 10 is fixed inside the case, and includes a substantially cylindrical stator core 11 and a coil wound around the stator core 11. The stator core 11 is configured by laminating a plurality of electromagnetic steel plates. The stator core 11 has a plurality of slots (not shown) that are distributed in the circumferential direction and extend in the axial direction, and a coil made of a conductor is wound around the slots. In the present embodiment, the stator 10 is configured as a stator used for the induction motor 1 driven by a three-phase alternating current, and includes a U-phase, a V-phase, and a W-phase three-phase coil. And the part which protrudes in the axial direction both sides of the stator core 11 among each coil is made into the coil end part 12. FIG.

  Next, the configuration of the rotor 20 in the induction motor 1 according to the first embodiment will be described in detail with reference to FIGS. The rotor 20 is configured as a squirrel-cage rotor, and is rotatably supported around the axis of the rotary shaft 30 on the radially inner side of the stator 10 described above. As shown in FIGS. 1 to 3, the rotor 20 is joined to a cylindrical rotor core 21, a plurality of secondary conductors 22 distributed in the circumferential direction of the rotor core 21, and both axial ends of the secondary conductor 22. And an end ring 25.

  The rotor core 21 is configured in a cylindrical shape so as to surround the rotating shaft 30 by laminating a plurality of plates made of electromagnetic steel plates, and is fixed to the rotating shaft 30. Further, the outer peripheral surface of the rotor core 21 is opposed to the above-described inner peripheral surface (the surface on the rotating shaft 30 side) of the stator 10 with a space therebetween. The rotor core 21 is provided with a plurality of secondary conductors 22 so as to surround the rotating shaft 30.

  The plurality of secondary conductors 22 are formed in a solid bar shape from copper, and are distributed at equal intervals along the circumferential direction of the rotor core 21. As shown in FIG. 1, each secondary conductor 22 is arranged so as to extend in a straight line along the axial direction of the rotor core 21. Further, the length dimension of each secondary conductor 22 is formed substantially equal to the axial dimension of the rotor core 21.

  The end ring 25 is a member called a short-circuited ring or an end-ring ring, and is formed in an annular shape from copper like the secondary conductor 22. The end ring 25 is disposed along both end faces of the rotor core 21 in the axial direction of the rotating shaft 30 and is joined to the end of each secondary conductor 22. Thereby, each secondary conductor 22 is short-circuited by being joined to the pair of end rings 25. The end ring 25 is formed with an annular step portion 25A corresponding to the concavo-convex portion in the present invention. This configuration will be described in detail later.

  Next, the configuration of the rotating shaft 30 in the induction motor 1 according to the first embodiment will be described in detail with reference to the drawings. The rotating shaft 30 is rotatably supported by a case (not shown) via a bearing on both axial sides of the induction motor 1. An oil flow path 31 and an oil discharge port 32 are formed inside the rotary shaft 30. The oil flow path 31 is a flow path that extends in the axial direction along the axis of the rotary shaft 30 and flows down the oil circulated by the oil pump described above.

  The oil discharge port 32 is a discharge port that discharges oil in the oil passage 31 from the rotation shaft 30 toward the outside as the rotor 20 and the rotation shaft 30 rotate. The oil discharge port 32 communicates with the oil flow path 31 and is formed so as to extend radially outward from the oil flow path 31 and open to the outer peripheral surface of the rotary shaft 30. The oil discharge port 32 is formed at a position outside the axial end face of the rotor core 21 and inside the axial end face of the end ring 25 in the axial direction of the rotary shaft 30.

  The end plate 40 is formed in a substantially disc shape from aluminum, a sintered material, a cold-rolled steel plate, or the like, and is disposed to balance the weight of the rotor 20 in the induction motor 1. The end plate 40 is fixed to the rotary shaft 30 so as to come into contact with the axial end surface of the end ring 25 on the axially outer side than the axial end surface of the rotor core 21. Thereby, the end plate 40 forms an oil retention portion Re described later by cooperating with the axial end surface of the rotor core 21 and the surface of the end ring 25 (see FIG. 1).

  Further, in the end plate 40, a plurality of communication passages 41 are formed so as to surround an insertion portion of the rotary shaft 30 in the end plate 40 (see FIG. 2). As shown in FIG. 1, the communication passage 41 passes through the end plate 40 along the axial direction and communicates with the oil retention portion Re.

  Next, the cooling structure of the induction motor 1 will be described with reference to the drawings. In the following description, the flow direction of oil as a refrigerant is referred to as “oil flow direction D”, and is illustrated using arrows.

  As the oil pump is driven, oil is supplied from one end side of the rotating shaft 30 to an oil passage 31 formed inside the rotating shaft 30. When the induction motor 1 is driven, the oil supplied to the oil passage 31 is axially moved along the inner peripheral surface of the oil passage 31 due to the centrifugal force accompanying the rotation of the rotor 20 and the rotating shaft 30 (see FIG. 1) (from left to right). Further, at the connection portion between the oil flow path 31 and the oil discharge port 32, the oil is directed from the oil flow path 31 to the outer side in the radial direction of the rotation shaft 30 due to the centrifugal force accompanying the rotation of the rotor 20 and the rotation shaft 30. Will move. Accordingly, the oil in the vicinity of the connection portion between the oil flow path 31 and the oil discharge port 32 is discharged toward the outside of the rotating shaft 30 through the oil discharge port 32.

  Here, as described above, the oil discharge port 32 is formed at a position outside the axial end surface of the rotor core 21 and inside the axial end surface of the end ring 25 in the axial direction of the rotating shaft 30. Has been. Accordingly, the oil discharged from the oil discharge port 32 is discharged toward the surface of the end ring 25 on the rotating shaft 30 side (hereinafter referred to as an inner side surface) and reaches the oil retaining portion Re. As a result, the oil stays in the oil retaining portion Re while being in contact with the surface of the end ring 25 that constitutes the oil retaining portion Re, and then out of the oil retaining portion Re through the communication path 41 of the end plate 40. leak. In addition, since the said oil can contact with the coil end part 12 of the stator 10 after flowing out of the oil retention part Re via the communicating path 41, the coil of the stator 10 can also be cooled.

  As a result, in the induction motor 1, the end ring 25 connected to the secondary conductor 22 that is the heat generating portion is directly cooled by the oil while the oil that is the refrigerant stays in the oil retention portion Re. And the rotor 20 can be efficiently cooled.

  Here, when the oil enters the gap formed between the outer peripheral surface of the rotor core 21 and the inner peripheral surface of the stator 10, resistance to the rotation of the rotor 20 is caused by the viscosity of the oil, and the induction motor 1 may cause energy loss. In this regard, in the induction motor 1, the oil is discharged from the oil discharge port 32 to the oil retention portion Re and flows out from the oil retention portion Re through the communication path 41. That is, the discharged oil does not directly reach the gap formed between the outer circumferential surface of the rotor core 21 and the inner circumferential surface of the stator 10, and the oil can be prevented from entering the gap. . Thereby, according to the said induction motor 1, the increase in the energy loss in the induction motor 1 can be suppressed.

  Next, the configuration of the end ring 25 according to the first embodiment will be described in detail with reference to FIGS. 1 and 3. The end ring 25 according to the first embodiment has an annular step portion 25 </ b> A that is an example of the concavo-convex portion in the present invention on the axial end surface and the inner side surface.

  As shown in FIG. 1, the annular step portion 25 </ b> A is configured in a stepped shape including a plurality of steps in the axial section of the rotating shaft 30. FIG. 3 is a partial plan view of the rotor 20 viewed from the axial direction with the end plate 40 omitted, and as shown in FIG. 3, the plurality of stepped portions constituting the annular stepped portion 25 </ b> A are provided on the end ring 25. The step portion is concentric with the center of the ring and has a different diameter, and has an end surface at a position farther away from the end surface in the axial direction of the rotor core 21 as it is located on the radially outer side of the end ring 25.

  According to the induction motor 1 according to the first embodiment, as can be seen from FIGS. 1 and 3, by forming the annular step portion 25 </ b> A in the end ring 25, the oil constituted by the end ring 25 and the end plate 40. While increasing the volume of the retention part Re, it is possible to lengthen the period during which oil stays in the oil retention part Re. As a result, a sufficient period of contact between the oil, which is the refrigerant, and the end ring 25 can be ensured, and the contact area between the oil and the end ring 25 can be increased. 25 can be cooled. Further, according to the induction motor 1 according to the first embodiment, each secondary conductor 22 connected to the end ring 25 can be efficiently cooled by cooling the end ring 25 efficiently.

  Furthermore, since the secondary conductor 22 and the end ring 25 are cooled, with respect to the constituent material of the induction motor 1, it is possible to suppress a decrease in yield strength due to a temperature rise. Therefore, the induction motor 1 according to the first embodiment has a high rotational speed. It can correspond to.

  And since the end ring 25 can be formed by cutting, die casting or press lamination, the annular step portion 25A can be easily formed with respect to the end ring 25, and without complicated processes, Cooling efficiency with oil can be increased.

(Second Embodiment)
Next, an embodiment (second embodiment) different from the above-described first embodiment will be described in detail with reference to FIGS. 4 and 5. The induction motor 1 according to the second embodiment has the same basic configuration as the induction motor 1 according to the first embodiment, and the configuration of the end ring 25 is different. Therefore, the description regarding the same structure as 1st Embodiment is abbreviate | omitted.

  As shown in FIGS. 4 and 5, in the induction motor 1 according to the second embodiment, the end ring 25 has a large number of protrusions 25 </ b> B on the inner side surface thereof. The large number of protrusions 25B correspond to the uneven portions and the island-shaped protrusions in the present invention, and are formed by applying a texture to the inner side surface of the end ring 25. In FIG. 4, the shape of the plurality of protrusions 25B is omitted, and FIG. 5 is exaggerated.

  According to the induction motor 1 according to the second embodiment, the volume of the oil retaining portion Re configured by the end ring 25 and the end plate 40 by forming a large number of protrusions 25B on the inner side surface of the end ring 25. Can be increased, and the period during which the oil stays in the oil retaining portion Re can be lengthened. As a result, a sufficient period of contact between the oil, which is the refrigerant, and the end ring 25 can be ensured, and the contact area between the oil and the end ring 25 can be increased. 25 can be cooled. Further, according to the induction motor 1 according to the second embodiment, each secondary conductor 22 connected to the end ring 25 can be efficiently cooled by cooling the end ring 25 efficiently.

  Further, by cooling the secondary conductor 22 and the end ring 25, it is possible to suppress a decrease in yield strength due to a temperature rise with respect to the constituent material of the induction motor 1, and therefore the induction motor 1 according to the second embodiment has a high rotational speed. It can correspond to.

  Since the end ring 25 can be formed by cutting, die casting, or press lamination, a large number of protrusions 25B can be easily formed on the end ring 25 without complicated processes. The cooling efficiency with oil can be increased.

(Third embodiment)
Next, an embodiment (third embodiment) different from the above-described first embodiment and second embodiment will be described in detail with reference to FIGS. The induction motor 1 according to the third embodiment has the same basic configuration as the induction motor 1 according to the first embodiment and the second embodiment, and the configurations of the end ring 25 and the end plate 40 are different. To do. Therefore, the description regarding the same structure as 1st Embodiment and 2nd Embodiment is abbreviate | omitted.

  As shown in FIGS. 6 and 7, in the induction motor 1 according to the third embodiment, the end ring 25 has a plurality of concave portions 25C corresponding to the concave and convex portions in the present invention on the inner side surface and the axial end surface thereof. doing. On the inner side surface of the end ring 25, each recess 25 </ b> C is formed in a groove shape on the outer side in the radial direction of the end ring 25. The outermost portion of the concave portion 25C in the radial direction is formed to a position that is radially outward of the end plate 40, and the concave portion 25C is interrupted so that the groove hits the wall at that position. On the end surface in the axial direction of the end ring 25, the plurality of recesses 25 </ b> C extend along the radial direction of the end ring 25 and are formed in a groove shape on the end surface side of the rotor core 21.

  And the end plate 40 which concerns on 3rd Embodiment is the structure similar to the end plate 40 which concerns on 1st Embodiment mentioned above except the point where the some communication path 41 is not formed. Also in the third embodiment, the end plate 40 is fixed to the rotary shaft 30 so as to be in contact with the axial end surface of the end ring 25 on the axially outer side than the axial end surface of the rotor core 21. . Thus, the end plate 40 forms an oil retention portion Re by cooperating with the axial end surface of the rotor core 21 and the surface of the end ring 25 (see FIG. 6).

  Here, in 3rd Embodiment, several recessed part 25C formed in the axial direction end surface of the end ring 25 is extended along the radial direction of the end ring 25, and is dented in groove shape at the rotor core 21 end surface side. Therefore, by fixing the end plate 40 so as to be in contact with the end surface of the end ring 25 in the axial direction, each recess 25C and the surface of the end plate 40 extend radially from the oil retaining portion Re to the outside. A flow path is formed as a communication path that communicates the retention portion Re with the outside. The flow path constituted by the recess 25C and the end plate 40 functions as a flow path through which oil flows out from the oil retention part Re, like the communication path 41 in the first and second embodiments.

  According to the induction motor 1 according to the third embodiment, by forming the plurality of recesses 25C in the end ring 25, the volume of the oil retaining portion Re configured by the end ring 25 and the end plate 40 is increased, The period during which oil stays in the oil retaining portion Re can be extended. As a result, a sufficient period of contact between the oil, which is the refrigerant, and the end ring 25 can be ensured, and the contact area between the oil and the end ring 25 can be increased. 25 can be cooled. In addition, according to the induction motor 1 according to the third embodiment, each secondary conductor 22 connected to the end ring 25 can be efficiently cooled by cooling the end ring 25 efficiently.

  Furthermore, since the secondary conductor 22 and the end ring 25 are cooled, with respect to the constituent material of the induction motor 1, it is possible to suppress a decrease in yield strength due to a temperature rise. Therefore, the induction motor 1 according to the present embodiment has a high rotational speed. Can respond.

  And since the end ring 25 can be formed by cutting, die casting, or press lamination, a plurality of concave portions 25C can be easily formed on the end ring 25, and without complicated processes, Cooling efficiency with oil can be increased.

(Fourth embodiment)
Next, an embodiment (fourth embodiment) different from the first to third embodiments described above will be described in detail with reference to FIG. The induction motor 1 according to the fourth embodiment has the same basic configuration as the induction motor 1 according to the first to third embodiments, and the configurations of the end ring 25 and the end plate 40 are different. To do. Therefore, the description regarding the same structure as 1st Embodiment-3rd Embodiment is abbreviate | omitted.

  The end ring 25 according to the fourth embodiment has the same configuration as that of the end ring 25 according to the first to third embodiments, except that the uneven portion in the present invention is not formed. Further, the end plate 40 according to the fourth embodiment has the same configuration as the end plate 40 according to the third embodiment. And in 4th Embodiment, the end plate 40 is being fixed to the rotating shaft 30 in the position spaced apart from the axial direction end surface of the end ring 25 to the axial direction outer side. And the said end plate 40 forms the oil retention part Re by cooperating with the axial direction end surface of the rotor core 21, and the surface of the end ring 25 (refer FIG. 8). Therefore, also in the fourth embodiment, the oil discharged from the oil discharge port 32 stays in the oil retaining portion Re and comes into contact with the surface of the end ring 25 constituting the oil retaining portion Re.

  As described above, since the end plate 40 is fixed at a position spaced apart from the axial end surface of the end ring 25 by a predetermined distance outward in the axial direction, the oil in the oil retaining portion Re is removed from the axial end surface of the end ring 25. And flows out of the oil retaining portion Re through a gap as a communication path formed between the end plate 40 and the surface.

  According to the induction motor 1 according to the fourth embodiment, the oil retaining portion Re is configured by the end ring 25 and the end plate 40, so that a sufficient period of contact between the oil as the refrigerant and the end ring 25 is ensured. Therefore, the end ring 25 can be cooled more efficiently. In addition, according to the induction motor 1 according to the fourth embodiment, each secondary conductor 22 connected to the end ring 25 can be efficiently cooled by cooling the end ring 25 efficiently.

  Furthermore, since the secondary conductor 22 and the end ring 25 are cooled, with respect to the constituent materials of the induction motor 1, it is possible to suppress a decrease in yield strength due to a temperature rise. Therefore, the induction motor 1 according to the fourth embodiment has a high rotational speed. It can correspond to.

(Fifth embodiment)
Next, an embodiment (fifth embodiment) different from the first to fourth embodiments will be described in detail with reference to FIG. The induction motor 1 according to the fifth embodiment has the same basic configuration as the induction motor 1 according to the first to fourth embodiments, and the configurations of the end ring 25 and the end plate 40 are different. To do. Therefore, the description regarding the same structure as 1st Embodiment-4th Embodiment is abbreviate | omitted.

  The end ring 25 according to the fifth embodiment has the same configuration as that of the end ring 25 according to the first to third embodiments except that the uneven portion in the present invention is not formed. Further, the end plate 40 according to the fifth embodiment is formed in an annular shape having a slightly smaller diameter than the inner diameter of the end ring 25. In the fifth embodiment, the end plate 40 is fixed at a position where the end surface on the inner side in the axial direction is axially inner than the end surface in the axial direction of the end ring 25 and does not block the oil discharge port 32. And the said end plate 40 forms the oil retention part Re by cooperating with the axial direction end surface of the rotor core 21, and the surface of the end ring 25 (refer FIG. 9). Therefore, also in the fifth embodiment, the oil discharged from the oil discharge port 32 stays in the oil retaining portion Re and comes into contact with the surface of the end ring 25 constituting the oil retaining portion Re.

  As described above, since the end plate 40 is formed in an annular shape having a slightly smaller diameter than the inner diameter dimension of the end ring 25, the oil in the oil retaining portion Re is separated from the outer diameter side surface of the end plate 40 and the end plate 40. It flows out of the oil retention part Re through a gap formed between the inner side surface of the ring 25.

  According to the induction motor 1 according to the fifth embodiment, the oil retaining portion Re is configured by the end ring 25 and the end plate 40, thereby sufficiently securing a period in which the oil that is the refrigerant and the end ring 25 are in contact with each other. Therefore, the end ring 25 can be cooled more efficiently. In addition, according to the induction motor 1 according to the fifth embodiment, each secondary conductor 22 connected to the end ring 25 can be efficiently cooled by cooling the end ring 25 efficiently.

  Furthermore, since the secondary conductor 22 and the end ring 25 are cooled, with respect to the constituent material of the induction motor 1, it is possible to suppress a decrease in yield strength due to a temperature rise. Therefore, the induction motor 1 according to the fifth embodiment has a high rotational speed. It can correspond to.

(Sixth embodiment)
Next, an embodiment (sixth embodiment) different from the first to fifth embodiments described above will be described in detail with reference to FIG. The induction motor 1 according to the sixth embodiment has the same basic configuration as the induction motor 1 according to the first to fifth embodiments, and the configuration of the end ring 25 and the end plate 40, and The difference is that a valve body 50 is disposed in the oil retention part Re. Therefore, the description regarding the same structure as 1st Embodiment-5th Embodiment is abbreviate | omitted.

  As shown in FIG. 10, the end ring 25 according to the sixth embodiment has a valve body arrangement portion 26 on the end surface in the axial direction of the end ring 25. The valve element arranging portion 26 is formed as an annular concave portion in which the end surface in the axial direction of the end ring 25 is recessed along the inner diameter side edge of the end ring 25. The said valve body arrangement | positioning part 26 is comprised so that the cyclic | annular valve body 50 can be accommodated in the inside, and has 26 A of inclined surfaces in the outer-diameter side. 26 A of inclined surfaces incline so that it may be located in the radial direction outer side of the end ring 25 toward the rotating shaft 30 axial direction end part side.

  In the sixth embodiment, the end plate 40 is fixed to the rotary shaft 30 at a position spaced apart from the axial end face of the end ring 25 by a predetermined distance outward in the axial direction. And the said end plate 40 forms the oil retention part Re by cooperating with the axial direction end surface of the rotor core 21, and the surface of the end ring 25 (refer FIG. 10). Therefore, also in the sixth embodiment, the oil discharged from the oil discharge port 32 stays in the oil retaining portion Re and comes into contact with the surface of the end ring 25 constituting the oil retaining portion Re.

  In the sixth embodiment, the end surface of the end ring 25 in the axial direction and the surface of the end plate 40 are separated by a predetermined distance in the axial direction, and the oil retaining portion Re and the outside of the rotor 20 communicate with each other. Therefore, in the sixth embodiment, the communication path 41 is formed by the axial end surface of the end ring 25 and the space of the surface of the end plate 40.

  The valve body 50 according to the sixth embodiment is a so-called O-ring that is a ring made of a rubber wire. The thickness of the wire constituting the valve body 50 is larger than the distance between the axial end surface of the end ring 25 and the end plate 40 surface. Further, the valve body 50 is configured as an annular ring having substantially the same diameter as the inner diameter of the end ring 25, and is disposed in the valve body arrangement portion 26 described above.

  In addition, as a material of the valve body 50, a nitrile rubber, a styrene rubber, a silicone rubber, a fluorine rubber, etc. can be used, and it determines suitably according to the use environment of the said valve body 50. FIG. For example, when the rotor 20 rotates at a predetermined number of revolutions or more and the communication passage 41 is closed by the valve body 50, the communication passage 41 is closed by the centrifugal force accompanying the rotation of the rotor 20 a predetermined number of times. The material of the valve body 50 is determined as a material having such deformation characteristics (elasticity).

  In the induction motor 1 according to the sixth embodiment, when the rotor 20 rotates about the rotation shaft 30, centrifugal force associated with the rotation of the rotor 20 acts on the valve body 50 arranged in the valve body arrangement portion 26. To do. As described above, since the valve body 50 is made of rubber, the valve body 50 is deformed so as to become a larger-diameter ring by the centrifugal force accompanying the rotation of the rotor 20, and the inside of the valve body arrangement portion 26 is formed. Move to the outer diameter side. Since the centrifugal force accompanying the rotation of the rotor 20 increases as the rotor 20 rotates at a higher speed, the valve body 50 is positioned on the outer diameter side of the valve body arranging portion 26 as the rotation speed of the rotor 20 increases. It moves toward the inclined surface 26A.

  As described above, the inclined surface 26A is inclined so as to be positioned on the radially outer side of the end ring 25 toward the axial end portion of the rotating shaft 30, so that the valve body 50 moves along the inclined surface 26A. To do. And in 6th Embodiment, since the communicating path 41 is comprised by the space between the axial direction end surface of the end ring 25, and the surface of the end plate 40, the valve body 50 is the rotor 20 above predetermined rotation speed. Rotates and moves along the inclined surface 26A, the communication path 41 is closed (see FIG. 10).

  According to the induction motor 1 according to the sixth embodiment, the oil retaining portion Re is configured by the end ring 25 and the end plate 40, thereby sufficiently securing a period in which the oil as the refrigerant and the end ring 25 are in contact with each other. Therefore, the end ring 25 can be cooled more efficiently. Further, according to the induction motor 1 according to the sixth embodiment, each secondary conductor 22 connected to the end ring 25 can be efficiently cooled by cooling the end ring 25 efficiently.

  Furthermore, by cooling the secondary conductor 22 and the end ring 25, it is possible to suppress a decrease in yield strength due to a temperature rise with respect to the constituent material of the induction motor 1, and therefore the induction motor 1 according to the sixth embodiment has a high rotational speed. It can correspond to.

  Here, in the induction motor 1, when the rotor 20 rotates at a high speed, heat generation in the plurality of secondary conductors 22 and the end rings 25 is reduced. Further, the oil scattered from the communication path 41 to the outside of the rotor 20 may be scattered at a high speed as the rotor 20 rotates at a high speed, and may adversely affect structural components such as the coil end portion 12.

  In this regard, according to the induction motor 1 according to the sixth embodiment, when the rotor 20 rotates at a high speed at a predetermined rotation speed or higher, the communication path 41 communicating with the oil retention part Re is configured as an O-ring. It is closed by the valve body 50. In this regard, according to the induction motor 1, when the rotor 20 rotates at a high speed, the valve body 50 closes the communication path 41 due to the centrifugal force accompanying the high speed rotation. Therefore, the induction motor 1 according to the sixth embodiment. According to this, it is possible to reduce pump loss and to prevent damage to components (for example, the coil end portion 12) due to oil splashes.

(Seventh embodiment)
Next, an embodiment (seventh embodiment) different from the first to sixth embodiments will be described in detail with reference to FIG. The induction motor 1 according to the seventh embodiment has the same basic configuration as the induction motor 1 according to the first to sixth embodiments, and the configuration of the end ring 25 and the end plate 40, and The difference is that a valve body 50 is disposed in the oil retention part Re. Therefore, the description regarding the same structure as 1st Embodiment-5th Embodiment is abbreviate | omitted.

  The end ring 25 according to the seventh embodiment has the same configuration as the end ring 25 according to the first to sixth embodiments, except that the concave and convex portion and the valve element arrangement portion 26 in the present invention are not formed. is there. Further, the end plate 40 according to the seventh embodiment is fixed to the rotary shaft 30 so as to be in contact with the axial end surface of the end ring 25 as in the first embodiment. As a result, the end plate 40 cooperates with the axial end surface of the rotor core 21 and the surface of the end ring 25 to form an oil retention portion Re described later (see FIG. 11).

  In the end plate 40 according to the seventh embodiment, as in the first embodiment, a plurality of communication paths 41 are formed so as to surround the insertion portion of the rotating shaft 30 in the end plate 40 (see FIG. 11). . The communication passage 41 passes through the end plate 40 along the axial direction, and communicates with the oil retaining portion Re and the outside of the rotor 20.

  As shown in FIG. 11, the valve body 50 according to the seventh embodiment includes an adhering portion 51 and a blocking film 52 that are disposed inside the oil retention portion Re and are formed into an annular plate shape by rubber. Has been. The fixing portion 51 is fixed to the surface of the end plate 40 on the inner diameter side of the opening edge of each communication passage 41 formed in the end plate 40. The blocking film 52 is integrally formed with the fixing portion 51 by rubber, and is formed in a thin film shape that extends in the axial direction into the oil retention portion Re. Furthermore, the distal end portion of the blocking membrane 52 is formed with a thickness greater than that of the membrane portion (see FIG. 11).

  In addition, as a material of the valve body 50, a nitrile rubber, a styrene rubber, a silicone rubber, a fluorine rubber, etc. can be used, and it determines suitably according to the use environment of the said valve body 50. FIG. For example, when the communication path 41 is closed by the valve body 50 when the rotor 20 rotates at a predetermined rotational speed or more, the material of the valve body 50 is a centrifugal force accompanying the rotation of the rotor 20 a predetermined number of times. Thus, the material is determined to have a deformation characteristic (elasticity) that closes the communication path 41 by the blocking film 52.

  In the induction motor 1 according to the seventh embodiment, when the rotor 20 rotates about the rotation shaft 30, centrifugal force associated with the rotation of the rotor 20 acts on the valve body 50 arranged in the valve body arrangement portion 26. To do. As described above, the closing membrane 52 of the valve body 50 is made of rubber, and the distal end portion thereof is formed with a thickness larger than that of the membrane portion. Therefore, the distal end of the closing membrane 52 is caused by the centrifugal force accompanying the rotation of the rotor 20. The portion is deformed so as to move toward the outer diameter side in the oil retention portion Re. And since the centrifugal force accompanying the rotation of the rotor 20 increases as the rotor 20 rotates at a high speed, the tip portion of the blocking film 52 is located in the oil retention part Re when the rotation speed of the rotor 20 exceeds a predetermined speed. It will be in close contact with the outer diameter side surface.

  Therefore, when the rotor 20 rotates at a high speed, as shown by a broken line in FIG. 11, the rotor 20 is closed via the space in which the closing film 52 of the valve body 50 communicates with the oil discharge port 32 and the communication passage 41. The oil retention part Re is partitioned in a part communicating with the outside. That is, since the flow of oil discharged from the oil discharge port 32 is blocked by the blocking film 52, according to the induction motor 1 according to the seventh embodiment, the oil flows outside the rotor 20 via the communication path 41. Will not flow into

  According to the induction motor 1 according to the seventh embodiment, the oil retaining portion Re is configured by the end ring 25 and the end plate 40, thereby sufficiently ensuring a period in which the oil as the refrigerant and the end ring 25 are in contact with each other. Therefore, the end ring 25 can be cooled more efficiently. Further, according to the induction motor 1 according to the seventh embodiment, each secondary conductor 22 connected to the end ring 25 can be efficiently cooled by cooling the end ring 25 efficiently.

  Furthermore, since the secondary conductor 22 and the end ring 25 are cooled, it is possible to suppress a decrease in yield strength due to a temperature rise with respect to the constituent material of the induction motor 1. Therefore, the induction motor 1 according to the seventh embodiment has a high rotational speed. It can correspond to.

  Here, in the induction motor 1, when the rotor 20 rotates at a high speed, heat generation in the plurality of secondary conductors 22 and the end rings 25 is reduced. Further, the oil scattered from the communication path 41 to the outside of the rotor 20 may be scattered at a high speed as the rotor 20 rotates at a high speed, and may adversely affect structural components such as the coil end portion 12.

  In this regard, according to the induction motor 1 according to the seventh embodiment, when the rotor 20 rotates at a high speed equal to or higher than a predetermined rotation speed, the oil with respect to the communication passage 41 is blocked by the blocking film 52 of the valve body 50 in the oil retention part Re. Is interrupted. In this regard, according to the induction motor 1, when the rotor 20 rotates at a high speed, the closing film 52 of the valve body 50 closes the communication path 41 due to the centrifugal force accompanying the high speed rotation. According to the induction motor 1, it is possible to reduce pump loss and prevent damage to components due to oil splashes.

  In addition, according to the induction motor 1 according to the seventh embodiment, when the rotor rotates at a lower speed than the predetermined rotation speed, the flow of oil when discharged from the oil discharge port 32 to the oil retention part Re. The direction of the oil and the flow direction of the oil when it flows out of the oil retaining part Re via the communication passage 41 can be made different, so that the oil can be sufficiently retained in the oil retaining part Re, and more The end ring 25 and the plurality of secondary conductors 22 can be efficiently cooled.

  Although the present invention has been described based on the embodiments, the present invention is not limited to the above-described embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. For example, in the embodiment described above, the induction motor 1 is a cage induction motor using a cage rotor, but is not limited to this mode. That is, the present invention can also be applied to a winding induction motor using a winding rotor. In this case, like the end ring 25 in the above-described embodiment, the coil end portion in the wound rotor protrudes along the axial direction from the end surface in the axial direction of the rotor core 21 and surrounds the rotary shaft 30. It is desirable that it is formed.

  In the above-described embodiment, the secondary conductor 22 and the end ring 25 are made of copper, but are not limited to this mode. The secondary conductor 22 and the end ring 25 can be formed of other conductors such as aluminum.

  In the above-described embodiment, the annular step portion 25A, the plurality of protrusions 25B, and the plurality of recesses 25C corresponding to the uneven portion in the present invention are formed only on the surface of the end ring 25. Is not to be done. For example, in addition to the surface of the end ring 25, it may be formed on the surface of the end plate 40 constituting the oil retaining portion Re. Moreover, you may form the structure which concerns on the uneven | corrugated | grooved part in this invention only in the surface of the end plate 40 which comprises the oil retention part Re. In the above-described embodiment, the end plate 40, the oil discharge port 32, the annular step portion 25A, the protrusion portion 25B, and the recess portion 25C as the concavo-convex portions are provided on both sides in the axial direction of the rotor 20. You may provide only.

DESCRIPTION OF SYMBOLS 1 Induction motor 10 Stator 20 Rotor 21 Rotor core 22 Secondary conductor 25 End ring 25A Annular level | step difference part 30 Rotating shaft 31 Oil flow path 32 Oil discharge port 40 End plate 41 Communication path Re Oil retention part

Claims (7)

A rotating shaft rotatably disposed;
A rotor core fixed to the rotating shaft, a plurality of secondary conductors distributed in the circumferential direction of the rotor core and extending in the rotating shaft direction;
An end portion connecting the end portions of the secondary conductors located on the end face side of the rotor core in the axial direction of the rotating shaft; and
A rotor having an end plate fixed to the rotary shaft on at least one side with respect to the axial direction of the rotary shaft;
A stator having a coil wound thereon and a stator having a coil end portion of the coil on the axial end portion side of the rotating shaft,
The end portion is
It protrudes in the axial direction from the end surface of the rotor core, and is configured in an annular shape surrounding the periphery of the rotating shaft,
The rotation axis is
A refrigerant flow path extending along the axial direction of the rotating shaft and capable of circulating a refrigerant;
With respect to the axial direction of the rotating shaft, at a position between at least one end surface of the rotor core and the end surface of the end entangled portion, it extends in the radial direction of the rotating shaft, and the outer peripheral surface of the rotating shaft, the refrigerant flow path, And a refrigerant discharge port that communicates,
An induction motor characterized in that it has a refrigerant retention part that is partitioned by a surface of the end plate that faces the end face of the rotor core and an outer surface of the end entanglement part and in which the refrigerant discharged from the refrigerant discharge port stays. The induction motor according to claim 1,
The end portion is
An induction motor having an uneven portion that increases a volume of the refrigerant staying in the refrigerant staying portion on a surface of the end portion. An induction motor according to claim 2, wherein
The uneven portion is
An induction motor comprising a plurality of step portions formed at positions spaced apart from the outer peripheral surface of the rotating shaft as the distance from the end surface of the rotor core increases in the axial direction of the rotating shaft. An induction motor according to claim 2, wherein
The uneven portion is
An induction motor comprising a plurality of island-shaped protrusions formed on the outer surface of the end entanglement portion. An induction motor according to any one of claims 1 to 4,
An induction motor having a communication path for communicating the refrigerant retaining portion and the outside of the rotor and allowing the refrigerant in the refrigerant retaining portion to flow out of the rotor. An induction motor according to claim 5, wherein
The communication path is
An induction motor characterized in that the end plate is formed by a hole penetrating along the axial direction of the rotating shaft. The induction motor according to claim 5 or 6,
Disposed at the opening edge of the communication path in the refrigerant retention portion;
An induction motor having a valve body that closes the communication path by centrifugal force accompanying rotation of the rotor.

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