JP2012200087A - Induction motor and rotor used in the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an induction motor which can effectively cool a stator, a rotor and an induction motor body without enlarging the rotor and the induction motor body and to provide the rotor used in the induction motor.SOLUTION: The induction motor 1 includes: a rotor core 41 which integrally rotates with a rotating shaft 2; a pair of end rings 42 which are oppositely arranged on both end sides in a shaft direction of the rotating shaft 2 of the rotor core 41; and a plurality of blade sections 43 which are disposed between an inner diameter of the end ring 42 and an outer diameter of the rotor core 41 so as to project them in a direction of opposite sides of the rotor core 41 from end faces of the end rings 42. At least one blade section 43 is arranged so that an arbitrary projected height from the end face of the end ring 42 becomes the same and an extending direction in the same projected height position is extended in a direction different from a diameter direction of the rotating shaft 2.

Description

  The present invention relates to an induction motor (motor) and a rotor used for the induction motor.

  Conventionally, induction motors are often used as prime movers for various industrial machines. The induction motor has, as basic components, a stator and a rotor, and a housing that houses the rotor and the stator. A rotor used in this induction motor, particularly a squirrel-cage induction motor, includes a rotating shaft, a rotor core in which a plurality of iron cores are stacked around the rotating shaft, and the rotating shaft rotates, and both end portions in the axial direction of the rotating shaft A pair of end rings arranged opposite to each other on the side, and a conductor bar provided to conduct the rotor core and the end ring are provided. In the rotor as described above, a magnetic field is generated in a magnetic gap between the stator and the rotor due to a current flowing through the stator winding provided in the stator, and the generated magnetic field causes the rotor to rotate. Since electromagnetic force is generated in the conductor bar, the rotor core is dragged and configured to rotate. When a magnetic field is generated by passing a current through such a stator winding, the stator winding and the conductor bar generate heat by a loss such as a resistance loss when the current is passed. For this reason, there is a possibility that the rotor body and the induction motor body arranged around the stator body as well as the rotor body and the induction motor body may be damaged and broken due to the temperature rise of the heat generated in the stator winding.

  Therefore, as a device for improving the heat dissipation of the heat generated in the stator main body and the induction motor and in the rotor, for example, in the rotor shown in Patent Document 1, the thickness in the rotation axis direction on the inner diameter side of the end ring is used. A rotor fan that forms a concave curved surface is provided on the end face of the end ring so that the thickness dimension in the rotation axis direction on the outer diameter side is smaller than the dimension. Patent Document 2 discloses a rotor provided with heat radiation fins joined to the end face of a rotor core that protrudes outward from the end face of the end ring in the rotation axis direction. Patent Document 3 discloses a configuration in which a plurality of conductor bars provided so as to conduct the rotor core and the end ring are projected from the end face of the end ring so as to be parallel to the diameter direction of the rotor core. A rotor is disclosed. With such various devices, in the conventional induction motor, the heat radiation area of the rotor is increased to improve the heat radiation performance, and the air inside the induction motor is stirred to improve the cooling performance.

Japanese Patent Laid-Open No. 7-170693 JP-A-6-245447 JP 2000-60045 A

  However, as a recent trend, there is a demand for further improving the cooling effect inside the induction motor and improving the heat dissipation of the rotor without changing the size of a conventionally used induction motor. However, the rotor fan as shown in Patent Document 1 forms a concave curved surface on the end surface of the end ring so as to reduce the thickness dimension in the rotation axis direction from the inner peripheral side to the outer peripheral side of the end ring. It takes time and cost to produce a fan. Further, in the rotors described in Patent Documents 1 to 3, since the rotor fan or the heat radiating fins are provided on both end sides in the axial direction of the rotating shaft, the rotor may be increased in size. The increase in the size of the motor body was incurred.

  Therefore, the present invention has been made paying attention to such a problem, and without increasing the size of the rotor and the induction motor main body, the stator and the rotor, and the induction motor main body are more effective than the conventional one. It aims at providing the induction motor which can be cooled automatically, and the rotor used for the induction motor.

In order to achieve this object, the present invention takes the following measures.
That is, a rotating shaft, a rotor fixed to the rotating shaft, a stator arranged via a rotor and a magnetic gap, a rotating shaft that rotatably supports the rotor and the stator A pair of rotors, the rotor cores rotating integrally with the rotating shaft, and oppositely arranged on both end sides in the axial direction of the rotating shaft of the rotor core. And a plurality of blade portions provided so as to protrude from the end face of the end ring toward the opposite side of the rotor core between the inner diameter of the end ring and the outer diameter of the rotor core. As a result, at least one blade portion of the plurality of blade portions has the same protruding height from the end face of the end ring, and the extending direction at the same protruding height position is the rotation shaft. Extends in a direction different from the diameter direction Is characterized by Te are provided.

  The “arbitrary protruding height position” described here means an appropriate height position protruding from the end face of the end ring disposed on the rotor. Moreover, the “extending direction of the blade portion” refers to the direction of the blade portion that exists from the inner diameter side of the end ring toward the outer diameter side of the rotor core or vice versa, In the present invention, at least one of the plurality of blade portions is present such that the extending direction at the same protruding height position from the end surface of the end ring extends in a direction different from the diameter direction of the rotating shaft. As long as it is provided. In order to have a configuration in which the “blade portion extends in a direction different from the diameter direction of the rotation shaft”, the blade portion has a curved shape along the direction toward the outer diameter side of the rotor core. In addition, it is preferable that the entire or part of the blade portions are configured to have a curved shape or a partial arc shape in a linear shape, a bent shape, or an extending direction thereof. The “extending direction” of the “curved shape” or “partial arc shape” blade refers to the circumferential direction of the shape, and the “straight shape” blade rotates as the name suggests. What is necessary is just to extend in the direction different from the diameter direction of the shaft. A plurality of blade portions may be formed as long as the number of blade portions is one or more as long as the conditions such as the curved shape, the partial arc shape, and the like are satisfied. For the blade material, an appropriate material having conductivity selected from aluminum, copper and the like can be used. Furthermore, in the present invention, a rotating shaft that can rotate in either one direction or forward and backward directions can be applied.

  In the case of the induction motor of the present invention configured as described above, the end rings are arranged opposite to each other on both end sides in the axial direction of the rotating shaft, as in the case of the conventional induction motor, so that the rotor core can be made stronger. Can be fixed. In addition, among the plurality of blade portions provided in the end ring, at least one blade portion extends in a direction in which the extending direction at any same height position from the end surface of the end ring is different from the diameter direction of the rotating shaft. By doing so, when the rotor rotates, the surface area of the blade portion of the rotor can be increased compared to the conventional one. That is, as the surface area of the rotor blades increases, the cooling effect can be improved accordingly. Further, in the induction motor equipped with the rotor of the present invention, the surface area of the blade portion can be increased as compared with the conventional one. Therefore, stirring of the air flow inside the induction motor can be promoted, and the heat of the rotor can be dissipated. And the cooling effect in the stator arranged opposite to the rotor can be enhanced.

  Further, in the induction motor of the present invention, a pair of end rings and a plurality of blade portions that are disposed to face both end portions in the axial direction of the rotating shaft can be integrally formed.

  With this configuration, the rotor includes an end ring that firmly fixes the rotor core, and a plurality of blade portions are formed integrally with the end ring, so that the end ring is integrated with the rotor. By rotating in the direction, the cooling effect of the blade part and the cooling effect of the end ring can be enhanced by the plurality of blade parts stirring the air flow. The “end ring and blade part integrally formed” may be “end ring and blade part integrally formed” or “end ring and blade part rigidly connected”. It may be formed so that it can be handled as a single unit.

  In the induction motor of the present invention, the plurality of blade portions provided in the rotor can be arranged around the central axis of the rotating shaft at an equal angular relationship with respect to the central axis.

  In such a configuration, an air flow passes between the blades and the blades by arranging the blades uniformly with respect to the central axis so as to extend in a direction different from the diameter direction. In this case, since the air flow can be uniformly stirred for all the blade portions, the air flow inside the induction motor can be efficiently stirred.

  In addition, the housing is provided with an intake portion on one side corresponding to the longitudinal direction of the rotation shaft and an exhaust portion on the other side, and a plurality of blade portions are projected from an end ring on at least the intake portion side of the rotor core. Can do.

  With such a configuration, since a plurality of blade portions protrude from the end ring on the intake portion side that takes in at least outside air, there is no need to provide blade portions on both the intake portion side and the exhaust portion side. An increase in size of the child can be prevented.

  Further, the plurality of blade portions may be formed on both the intake portion side and the exhaust portion side end rings.

  If comprised in this way, each blade | wing part is provided in the end ring in the intake part side which takes in external air, and the exhaust part side which discharges internal air to the exterior, Each of these blade | wing parts stirs an air flow Therefore, since the stirring of the air flow can be promoted as compared with the configuration in which the blade portion is provided only on one side, the cooling effect inside the induction motor can be enhanced.

  Or the rotor which concerns on this invention is applied to the induction motor mentioned above, Comprising: Arbitrary protrusion height from the end surface of an end ring is the same at least 1 blade | wing part among several blade | wing parts. The extending direction at the same protruding height position extends in a direction different from the diameter direction of the rotating shaft.

  If comprised in this way, it will become easy to set it as the structure which can increase the surface area of the blade | wing part of a rotor as compared with the conventional structure as mentioned above about the induction motor of this invention. Therefore, the induction motor equipped with the rotor of the present invention can improve the cooling effect inside the stator and the induction motor and the heat dissipation of the rotor than before, so that the air flow inside the induction motor is agitated. In addition, it is possible to obtain all the operational effects obtained in each induction motor described above.

  According to the induction motor according to the present invention, at least one blade portion of the plurality of blade portions has the same arbitrary protruding height from the end face of the end ring, and extends at the same protruding height position. As a result of providing the direction different from the diametrical direction of the rotating shaft, the surface area of the plurality of blade portions provided in the rotor can be increased as compared with the conventional case. Therefore, in the induction motor of the present invention and the rotor applied to the induction motor, the air flow inside the induction motor can be urged to be agitated, so that the heat dissipation of the rotor itself can be improved and the rotor is opposed to the rotor. Thus, the cooling effect of the stators arranged in the same manner can be enhanced. As a result, the efficiency of the induction motor itself is increased by reducing the secondary copper loss due to heat generated in the stator winding, which greatly contributes to the quality improvement as a product.

The schematic diagram which fractured a part of induction motor concerning one embodiment of the present invention. FIG. 1 is a view corresponding to FIG. 1, additionally showing an air flow in the induction motor. The side view which shows the outline of the rotor. The front view which shows the outline of the rotor. The schematic perspective view of the rotor applied to the induction motor. Schematic which fractured | ruptured a part of induction motor which concerns on another embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, because induction motors are robust and inexpensive, they are most often used as prime movers for industrial machines and are synonymous with general-purpose motors. The classification of induction motors can be broadly divided into two types: single-phase motors that are small capacity machines that are often used in home appliances, and three-phase cage types that require good starting characteristics used in special large capacity machines. An induction motor, a winding type induction motor, and the like are known. Most of the induction motors currently used are three-phase squirrel-cage induction motors, and the rotor according to the embodiment of the present invention and the induction motor including the rotor also belong to this category.

FIG. 1 is a schematic view showing a part of an induction motor 1 according to an embodiment of the present invention so as to be broken and visible. Here, the outline of the induction motor 1 will be described with reference to FIG.
The induction motor 1 includes a rotating shaft 2, a stator 3, a rotor 4, and a housing 5.

Next, the main structure of the induction motor 1 will be described with reference to FIG.
The stator 3 used in the induction motor 1 includes a stator core 31 in which a plurality of iron cores are stacked, and a stator winding 32 wound around the stator core 31. The stator core 31 is configured by laminating a plurality of iron cores such as silicon steel plates, and the stator 3 is configured to be provided inside the induction motor 1 via the rotor 4 and a magnetic gap. As shown in FIG. 1, the housing 5 rotatably supports the rotating shaft 2 via a bearing 6 and houses the stator 3 and the rotor 4. The bearing 6 uses a bearing such as a bearing. The housing 5 of the present embodiment includes an intake port 51 and an exhaust port 52 for sucking and exhausting external gas into the induction motor 1.

  The rotor 4 has a shape that is long in one direction along the rotation axis 2, and a pair of rotor cores 41 and a pair of rotor cores 41 that are disposed opposite to each other in the axial direction of the rotation axis 2 of the rotor core 41. A plurality of blades 43 provided to protrude from the end face of the end ring 42 toward the opposite side of the rotor core 41 between the inner diameter of the end ring 42 and the outer diameter of the rotor core 41. It is equipped with. Here, in the present embodiment, the blades 43 provided on the pair of end rings 42 of the rotor 4 include the blades 431 on the intake port 51 side and the blades 432 on the exhaust port 52 side of the housing 5. . The rotor core 41 has a configuration in which a plurality of iron cores such as silicon steel plates are laminated in the axial direction of the rotary shaft 2.

  Here, the principle of generating the rotating magnetic field will be described. First, in the three-phase induction motor 1, three sets of stator windings 32 wound inside the stator 3 are arranged at intervals so that each phase difference is 120 °. When a pulse current having a phase difference is supplied to the stator winding 32 every 120 °, the magnetic field inside the stator winding 32 is generated as if a permanent magnet exists, and the magnetic flux flows. Become. This is the principle of rotating magnetic field generation by the stator winding 32. By this rotating magnetic field, an induced current is generated for the rotor core 41 constituting the rotor 4 provided so as to be opposed to the stator 3 via a magnetic gap. The rotor core 41 is provided with a conductor bar 44 made of aluminum, copper or the like along the longitudinal direction of the rotary shaft 2. The conductor bar 44 includes the rotor core 41 and the end ring 42. It is provided to conduct. The conductor bar 44 provided in the rotor core 41 is excited by the induced current generated in the rotor core 41, and the conductor bar 44 generates a magnetic field that follows the rotating magnetic field generated in the stator 3. Generated for the rotor 4. Therefore, the rotor 4 is rotated by the rotating magnetic field generated in the stator 3 and the magnetic field generated by the conductor bar 44 with respect to the rotor 4.

  Next, the flow of agitation of the air flow in the induction motor 1 will be described with reference to FIG. First, outside air is taken in from an intake port 51 provided in the housing 5 of the induction motor 1. The air flow taken from the intake port 51 flows into a plurality of blades 43 provided on the end ring 42 on the intake port 51 side of the rotor 4. Thereafter, as the rotor 4 rotates, the air around the end ring 42 on the intake port 51 side is agitated by the plurality of blades 43, and the air flowing in from the outside flows from the rotor 4 side to the stator 3 side. Then, after the stator winding 32 provided in the stator 3 is cooled by this air flow, the air flow flows into the exhaust port 52 provided on the opposite side of the housing 5 from the intake port 51 side. Then, the air flow is agitated by the plurality of blades 43 provided on the end ring 42 on the exhaust port 52 side of the rotor 4, and the air flow flows into the exhaust port 52 of the housing 5. 1 Exhausted to the outside.

  The rotor 4 based on the induction motor 1 of this embodiment has the same arbitrary protruding height from the end face of the end ring 42 of at least one blade 431 on the intake port 51 side among the plurality of blades 43 described above, The extending direction at the same protruding height position extends in a direction different from the diameter direction of the rotating shaft 2 (the direction extending from the central axis of the rotating shaft 2 toward the outer peripheral side of the rotor core 41). It is configured as follows. In this embodiment, as an example, the rotor 4 having a curved shape as shown in FIG. 3 and provided with a blade 43 in which the blade 431 on the intake port 51 side is counterclockwise is applied.

  Here, the above-mentioned “extending direction” refers to the direction of the blades 43 extending from the inner diameter side of the end ring 42 toward the outer diameter side of the rotor core 41, and the plurality of blades 43. Among these, at least one blade 431 has the same protruding height protruding from the end face of the end ring 42, and the extending direction of the same protruding height position extends in a direction different from the diameter direction of the rotary shaft 2. It suffices to be provided. In order to be configured so as to “extend in a direction different from the diameter direction of the rotating shaft 2”, the blade 43 has a curved shape along the direction toward the outer diameter side of the rotor core 41, It is preferable that the blades 43 are configured to have a curved shape or a partial arc shape in a linear shape, a bent shape, or in a longitudinal direction. For the material of the blade 43, an appropriate material having conductivity selected from aluminum, copper and the like can be used. Further, of the plurality of blades 43, at least one blade 431 (or blade 432) on the intake port 51 side (or exhaust port 52 side) has a curved shape or the like so as to extend in a direction different from the diameter direction of the rotation shaft 2. A plurality of blades 431 (or blades 432) may be formed as long as the condition that the above is satisfied is satisfied.

  As described above, if the induction motor 1 includes the rotor 4 having the configuration shown in FIGS. 1 to 5, when the rotor 4 rotates, the rotor 4 has at least one blade 431 among the plurality of blades 43. The arbitrary protruding heights protruding from the end face of the end ring 42 are the same, and the longitudinal direction of the same protruding height position is provided so as to extend in a direction different from the diameter direction of the rotary shaft 2. A centrifugal force acts on the air around the child 4 and agitates, whereby an air flow as shown in FIG. 2 can be generated. As a result, the air flow circulates on the side of the stator 3 provided facing the rotor 4 to cool the stator winding 32, and the air flow inside the induction motor 1 can be efficiently stirred. Therefore, a good cooling effect can be obtained.

  Further, in the induction motor 1 of the present embodiment, the rotor 4 includes an end ring 42 that firmly fixes the rotor core 41, and a plurality of blades 43 are formed integrally with the end ring 42. It can be set as the structure which can heighten the cooling effect of the blade | wing 43 and the cooling effect of the end ring 42 by the some blade | wing 43 stirring an air flow.

  Further, as shown in FIG. 3, the plurality of blades 43 provided on the rotor 4 are all arranged around the central axis of the rotary shaft 2 with an equal angular relationship with respect to the central axis. By adopting such a configuration, when the air flow passes between the blades 431 and 431, the air flow can be similarly agitated in a balanced manner with respect to all the blades 43, so that the induction motor 1 The internal air flow can be efficiently stirred. As a result, the air flow can be stirred substantially uniformly as a whole in all the blades 43, so that the temperature rise is made uniform, so that the air flow in the induction motor 1 and the rotor 4 are stirred. It can be set as the structure which can stir the surrounding airflow more efficiently than before.

  Since it is configured in this manner, each blade 43 is provided on the end ring 42 on the side of the intake port 51 for taking in outside air and on the side of the exhaust port 52 for discharging the internal air to the outside. Since the agitation of the air flow is performed, the agitation of the air flow can be promoted more than the configuration in which the blades 43 are provided only on one side, so that the cooling effect inside the induction motor 1 can be enhanced.

  FIG. 6 shows an induction motor 1 ′ and its rotor 4 according to another embodiment of the present invention. The same parts as those in the above-described embodiment are denoted by the same reference numerals in the drawings. In the casing 5 ′ of the induction motor 1 ′ shown in the figure, a space (hereinafter referred to as space A) provided with the rotor 4 and the stator 3, and an outside of the space and the intake port 51 ′. In addition, the partition portion 7 is provided so as to be separated from a space (hereinafter referred to as a space B) provided with the exhaust port 52 ′. In this embodiment, outside air is taken in from an intake port 51 ′ provided in the housing 5 ′ of the induction motor 1, and the air flows only through the space B without passing through the space A, and the exhaust port 52 ′ of the housing 5 ′. It is discharged to the outside again. Therefore, the circulation of the air in the space of the rotor 4 and the stator 3 performs only the circulation of the air in the sealed space B.

  As a result, the cooling in the space B inside the housing 5 ′ partitioned by the partition portion 7 is performed by the outside air taken in from the intake port 51 ′, so that an efficient cooling effect can be obtained. In addition, the circulation of air around the rotor 4 and the stator 3 is performed by using one blade 431 on the intake port 51 ′ side (or one blade 432 on the exhaust port 52 side) among the plurality of blades 43 provided on the rotor 4. ) In the direction in which the arbitrary protruding height protruding from the end face of the end ring 42 provided on the rotor 4 is the same, and the longitudinal direction of the same protruding height position is different from the diameter direction of the rotating shaft 2 Therefore, the air can be efficiently circulated in the sealed space B provided with the stator 3 and the rotor 4.

  As mentioned above, although embodiment of this invention was described, the specific structure of each part is not limited only to embodiment mentioned above. For example, in each of the above-described embodiments, the blades 43 are respectively provided at both ends of the rotor 4 corresponding to both the intake port 51 (51 ′) side and the exhaust port 52 (52 ′) side of the housing 5 (5 ′). In the present invention, the blades 43 can be provided only on the inlet 51 (51 ′) side of the rotor 4. In this case, it is possible to adopt a configuration in which the blades 431 are projected only on the intake port 51 (51 ′) side. In this case, the blades 432 are unnecessary on the exhaust port 52 (52 ′) side, and the rotor 4 Is prevented from becoming large. Moreover, in each said embodiment, the arbitrary protrusion height which protruded from the end surface of the end ring 42 with which all the blade | wings 43 were provided in the rotor 4 is the same, and extension of the same protrusion height position The configuration in which the direction extends in a direction different from the diameter direction of the rotating shaft 2 has been described. However, the effect of the present invention can be obtained with such a configuration for at least one blade 431 (or blade 432). The induction motor 1 to which the rotor 4 according to the present invention is applied is not limited to the three-phase induction motor type as described above, but can be applied to a single-phase induction motor or the like. In addition, the configuration of each part of the rotor 4 and the induction motor 1 can be variously modified without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Induction motor 2 ... Rotating shaft 3 ... Stator 4 ... Rotor 5 ... Housing 6 ... Bearing 7 ... Partition part 31 ... Stator core 32 ... Stator winding 41 ... Rotor core 42 ... End ring 43 ... Multiple Blades (corresponding to "multiple blades" of the present invention)
44 ... Conductor bar 51 ... Inlet (corresponding to "intake part" of the present invention)
52 ... Exhaust port (corresponding to "exhaust part" of the present invention)
431: One blade on the intake port side 432 ... One blade on the exhaust port side A ... A space provided with a rotor and a stator B ... An intake port and an exhaust port outside the space A (the housing 5 side) Space provided

Claims (6)

A rotation axis;
A rotor fixed to the rotating shaft;
A stator disposed via the rotor and a gap;
A housing that rotatably supports the rotating shaft and that houses the rotor and the stator,
In an induction motor comprising:
A rotor core that rotates integrally with the rotary shaft; a pair of end rings that are disposed opposite to both ends of the rotor core in the axial direction of the rotary shaft; and A plurality of blade portions provided between the inner diameter and the outer diameter of the rotor core so as to protrude from the end face of the end ring toward the opposite side of the rotor core,
Arbitrary protruding heights in which at least one blade portion of the plurality of blade portions protrudes from the end face of the end ring is the same, and the extending direction at the same protruding height position is the diameter of the rotating shaft. An induction motor characterized by being provided in a direction different from the direction. The induction motor according to claim 1, wherein the plurality of blade portions are formed integrally with the end ring. 3. The induction motor according to claim 1, wherein each of the plurality of blade portions is arranged around the central axis of the rotating shaft at an equal angular relationship with respect to the central axis. . The housing includes an intake portion on one side corresponding to a longitudinal direction of the rotation shaft and an exhaust portion on the other side, and the plurality of blade portions are provided at least on the end ring on the intake portion side of the rotor. The induction motor according to claim 1, wherein the induction motor is protruded. The induction motor according to claim 4, wherein the plurality of blade portions are formed on both the intake portion side and the exhaust portion side end rings, respectively. A rotation axis;
A rotor fixed to the rotating shaft;
A stator disposed via the rotor and a magnetic gap;
A housing that rotatably supports the rotating shaft and that houses the rotor and the stator,
The rotor applied to an induction motor comprising:
A rotor core that rotates integrally with the rotary shaft; a pair of end rings that are disposed opposite to both ends of the rotor core in the stacking direction; an inner diameter of the end ring; and an outer diameter of the rotor core A plurality of blade portions provided so as to protrude from the end face of the end ring toward the opposite side to the rotor core,
Arbitrary protruding heights from the end face of the end ring are the same in at least one blade portion of the plurality of blade portions, and the extending direction at the same protruding height position is the diameter direction of the rotating shaft A rotor characterized by being provided in a different direction.

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