JP5541577B2 - Cage rotor and electric motor - Google Patents

Description

  The present invention relates to a cage rotor and an electric motor using the same.

  As this type of squirrel-cage rotor, for example, the following Patent Document 1 has been proposed. The cage rotor described in Patent Document 1 includes a rotor core, a heat radiating portion (duct plate) sandwiched between the rotor cores, and a shaft inserted through the center of the rotor core and the heat radiating portion. ing.

  The heat dissipating part is composed of two disk-shaped duct plates, and the first notch directed radially outward is formed on the radially inner end side of one duct plate, that is, on the shaft side. The second notch is formed on the radially outer end side of the other duct plate, and a communicating portion where both notches are overlapped in the axial direction of the shaft is located at a position near the radial center of the heat radiating portion. Is formed.

  According to the above configuration, the air that has reached the first notch from the shaft side (heated air) changes its direction in the axial direction so as to pass through the communicating portion, reaches the second notch, and then the heat radiating portion from the second notch. Is discharged outward in the radial direction. The cage rotor is cooled by the air flow.

JP-A-9-191617

  In the squirrel-cage rotor, the flow of air outward in the radial direction of the heat radiating portion is changed in the axial direction at the communicating portion and then again outward in the radial direction. However, when the air flow direction is changed in the axial direction, there is a problem that the air is stopped and the heat dissipation efficiency is lowered accordingly.

  In view of the above problems, an object of the present invention is to provide a squirrel-cage rotor and an electric motor that can suppress a decrease in heat dissipation efficiency by smoothing the flow of air.

  A squirrel-cage rotor according to the present invention includes a plurality of rotor cores, a disk-shaped heat dissipation portion sandwiched between the rotor cores, and a shaft inserted through the center of the rotor core and the heat dissipation portion. An axial groove is formed on at least a surface of the shaft extending from the rotor core to the heat radiating portion, the heat radiating portion having a flat disk surface having a flat disk surface, and the groove on the disk surface. A guide wall member that guides air that moves radially outward from the groove in the circumferential direction in a region corresponding to the radially outward direction, and a guide that is spaced apart and radially outward of the guide wall member It is characterized by comprising a discharge wall member for forming a discharge path for discharging air guided in the circumferential direction by the wall member to the outside of the disk body in the radial direction.

  In the above configuration, the guide wall member guides the air directed radially outward of the disk body from the groove of the shaft in the circumferential direction along the disk surface, and the air guided in the circumferential direction is the circumferential direction of the guide wall member Radiating outwardly from the end, moving along the flat disk surface, moving the discharge path formed by the discharge wall member further radially outward along the disk surface And the cage rotor is cooled.

  In the cage rotor of the present invention, the grooves are intermittently formed in the circumferential direction on the surface of the shaft, the guide wall member is intermittently disposed in the circumferential direction of the disk surface, and the discharge wall member is disposed on the entire disk surface. By disposing intermittently in the circumferential direction over the circumference, it is possible to adopt a configuration in which the discharge path is intermittently provided in the circumferential direction of the disk surface.

  In the above configuration, the guide wall member in the region corresponding to the radially outward direction of each groove guides the air from the groove of the shaft to the radially outward direction of the disk body in the circumferential direction along the disk surface. The air guided in the direction is directed radially outward from the circumferential end of each guide wall member, that is, between adjacent guide wall members along the disk surface, and is discharged by the discharge wall member. The path further moves radially outward along the disk surface and is discharged from the heat radiating portion, thereby cooling the cage rotor.

  In this case, the guide wall members are not only arranged adjacent to each other in the circumferential direction on the same circumference, but are also displaced in the radial direction alternately if they are in a region corresponding to the radially outward direction of each groove. This includes cases where

  In the squirrel-cage rotor of the present invention, it is possible to adopt a configuration in which a space between the guide wall member and the discharge wall member serves as a diffusion region that diffuses the air before reaching the discharge path. The air that has reached the diffusion region is diffused in the diffusion region, the heat of the air is made uniform, and the air is discharged from the heat radiating portion to cool the cage rotor.

  In the squirrel-cage rotor of the present invention, the disc body is a disc surface having a flat surface on both sides, and the guide wall member and the discharge wall member are on the disk surfaces on both sides and are formed integrally with the disc body. Can be adopted.

  According to this configuration, heat is radiated from both sides of the disc body, and the structure of the heat radiating portion is simplified correspondingly by integrating the guide wall member, the discharge wall member and the disc body.

  The electric motor of the present invention is characterized in that any one of the above cage rotors is provided.

  In the squirrel-cage rotor of the present invention and the electric motor including the same, the guide wall member guides the air that is directed radially outward of the disk body from the groove of the shaft in the circumferential direction along the disk surface, and is guided in the circumferential direction The air thus moved moves outward from the circumferential end of the guide wall member in the radial direction of the disk surface, and moves radially outward in the discharge path formed on the disk surface by the discharge wall member. Since the air is discharged from the heat radiating portion, the air flow is smooth, the decrease in heat radiating efficiency is suppressed, and the cage rotor can be reliably cooled.

1 is an overall schematic side cross-sectional view of an electric motor including a cage rotor according to an embodiment of the present invention as a component. It is a YY direction arrow half sectional view in FIG. It is a perspective assembly drawing which shows the structure of the same cage rotor. It is a front view of the thermal radiation part of the same cage rotor. It is a front view of the thermal radiation part which concerns on another embodiment.

  Hereinafter, an example in which a cage rotor according to an embodiment of the present invention is used as a component of an electric motor will be described with reference to FIGS. 1 to 4. As shown in FIG. 1, the electric motor 1 includes a housing 2, a stator 3, and a squirrel-cage rotor (hereinafter simply referred to as a rotor) 4, and includes a cooling structure.

  The housing 2 is formed in a columnar shape having an internal mounting space 2C from a cylindrical outer wall body 2A and a side wall body 2B that closes open portions on both sides of the outer wall body 2A. A suction fan section 5 that is rotated by a motor (not shown) is installed on both longitudinal sides of the upper portion of the outer wall body 2A, and cooling air K sucked from the suction ports 51 of each suction fan section 5 is used as an internal mounting space. A suction port 21 for introduction into 2C from both sides in the longitudinal direction of the housing 2 is formed in the upper part of the outer wall body 2A.

  The stator support member 6, the stator 3, and the rotor 4 are mounted between the suction space 22 that is a region corresponding to the suction port 21 in the internal mounting space 2 </ b> C of the housing 2.

  The stator support member 6 is formed in a cylindrical shape so that the stator 3 can be fitted therein, and is fixed to the inner peripheral surface of the outer wall body 2A. The stator support member 6 is divided in the longitudinal direction and is provided as a pair, and an air exhaust path serving as a discharge means described later is formed between the stator support members 6.

  The stator 3 is wound around the stay 32 (see FIG. 2) provided on the inner peripheral surface of the stator core 31, a cylindrical stator core 31 that is fitted into the stator support member 6. And the coil 33 formed. The stator core 31 is composed of a plurality of (in this case, two) block bodies integrated by overlapping a plurality of silicon steel plates. Between the stator cores 31, a wind exhaust path serving as a discharge means described later is formed.

  The rotor 4 is inserted inward in the radial direction of the stator 3 via an annular gap G, and is provided so as to be rotatable about an axis 4 a with respect to the stator 3. The gap G is sealed at both ends in the longitudinal direction. A plurality of rotors 4, in this case, three rotor cores 41, a plurality of rotor cores 41 interposed between the rotor cores 41, in this case, two heat radiation portions 42 (also referred to as ducts), a rotation A shaft 43 inserted through the center of the core 41 and the heat radiating portion 42, an electric conductor (cage-shaped conductor) 44 embedded so as to pass through the rotor core 41 and the heat radiating portion 42, and the electric conductor 44 are electrically connected. And a short-circuit ring (also referred to as an end ring) 45 connected to the.

  Each rotor core 41 is composed of a plurality of (in this case, three) block bodies integrated by overlapping a plurality of silicon steel plates. Each rotor core 41 is formed in a hollow cylindrical shape in which a center hole 41a through which the shaft 43 is inserted is formed at the center in the radial direction. In each rotor core 41, electric conductor insertion holes 41 b are formed intermittently (at equal intervals) in the circumferential direction over the entire circumferential direction near the outer peripheral end. The electric conductor insertion hole 41b is formed as a long hole having a radially outer portion larger in diameter than the radially inner portion (the direction along the radial direction is the longer diameter), and all have the same shape.

  As shown in FIGS. 2 to 4, the heat radiating portion 42 is formed in a disk shape having the same diameter as the rotor core 41, and integrally includes a disk main body 421, a guide wall member 422, and a discharge wall member 423. The rotor core 41 is sandwiched from both sides in the axial direction (longitudinal direction). Since each heat radiating part 42 has the same configuration, the description of one heat radiating part 42 will be mainly substituted for FIG. 4 below.

  The disk main body 421 is formed in an annular shape having a center hole 421a through which the shaft 43 is inserted at the center in the radial direction, and both surfaces (front surface and rear surface) are flat disk surfaces 421b. In the disk main body 421, an electric conductor insertion hole 42b having the same position and shape as the electric conductor insertion hole 41b of the rotor core 41 is intermittently provided in the circumferential direction over the entire circumferential direction near the outer peripheral end (such as (Interval).

  The guide wall member 422 is an arcuate wall member disposed concentrically with the center hole 42a, and has an inner arc surface 422a and an outer arc surface 422b, and is slightly radially outside the center hole 42a. It is disposed in the opposite position and is formed integrally with each disk surface 421b. The guide wall members 422 are intermittently arranged at equal intervals in the circumferential direction. Between the guide wall members 422 adjacent in the circumferential direction, as will be described later, there is an escape portion 421c through which the air K from the shaft 43 side further escapes radially outward.

  The discharge wall member 423 is a member for forming a discharge path 90 through which the air K guided radially outward from the escape portion 421c is further discharged radially outward of the disc body 421. Each discharge wall member 423 is integrally raised from the disk surface 421b so as to be an surrounding wall that surrounds the electric conductor insertion hole 42b at the periphery. Accordingly, a large number of discharge wall members 423 are intermittently formed in the circumferential direction over the entire circumferential direction near the outer peripheral end of each disk surface 421b.

  Further, since the electric conductor insertion hole 42b is formed as a long hole having a radially outer portion larger in diameter than the radially inner portion, the discharge wall member 423 also has the electric conductor insertion hole 42b. It is a Go wall with a shape corresponding to. Since the electric conductor insertion holes 42b are arranged at equal intervals in the circumferential direction, the discharge wall members 423 are also arranged at equal intervals in the circumferential direction.

  In each discharge wall member 423, the circumferential intervals between the side walls 4231 and 4232 facing each other in the circumferential direction are narrowed toward the inner side in the radial direction. This is because the radially outer portion of the electrical conductor insertion hole 42b is formed as a long hole having a larger diameter than the radially inner portion, and the discharge wall member 423 has the electrical conductor insertion hole 42b around it. This is because it is a Go wall that surrounds the border.

  Then, in the relationship between one discharge wall member 423 and the discharge wall member 423 adjacent to this in the circumferential direction, the side surface 4231a of one side wall 4231 of one discharge wall member 423 and the other side surface of the adjacent discharge wall member 423. The distance between 4232a is equally spaced in the radial direction.

  The radially inner end surface 423a of the discharge wall member 423 is formed as a curved surface having a small curvature and is on a virtual circle concentric with the center hole 42a. Further, the radially outer end surface 423b of the discharge wall member 423 protrudes slightly radially outward from the outer peripheral surface 421d of the disc body 421, and is formed into a curved surface having a smaller curvature than the radially inner end surface 423a. And it is on a virtual circle concentric with the central hole 42a.

  Since the discharge wall member 423 is in a position corresponding to the front and back surfaces of the both disk surfaces 421b, the discharge wall members 423 of the both disk surfaces 421b are continuous over the both disk surfaces 421b at the radially outer end surface 423b portion. ing. The diameter of the imaginary circle connecting the radially outer end surfaces 423b is set to be substantially equal to the diameter of the rotor core 41.

  The discharge path 90 is formed by the side surfaces 4231a and 4232a of the discharge wall members 423 adjacent in the circumferential direction, and the disk surface 421b in the area between them. Therefore, the discharge path 90 is in the radial direction with the center hole 42a as the center. The outer peripheral surface 421d of the disc main body 421 is formed to be a concave surface that is recessed toward the center in the radial direction of the disc main body 421 between the radial outer end surfaces 423b of the discharge wall members 423.

  The distance between the upper end surface 422c of the guide wall member 422 and the upper end surface 423c of the discharge wall member 423 from the disk surface 421b (that is, the height of the guide wall member 422 and the discharge wall member 423 from the disk surface 421b) is set equal. ing. Thus, since the upper end surface 422c of the guide wall member 422 and the upper end surface 423c of the discharge wall member 423 are separated from the disk surface 421b, when the heat radiating portion 42 is sandwiched between the rotor cores 41, In the heat radiating portion 42, not the disk surface 421 b but the upper end surface 422 c of the guide wall member 422 and the upper end surface 423 c of the discharge wall member 423 are in contact.

  Since the guide wall member 422 is in the vicinity of the center hole 42a, and the discharge wall member 423 is near the outer peripheral end of the disk surface 421b, the guide wall member 422 and the discharge wall member 423 are spaced apart in the radial direction. ing. In the disk surface 421b, an area surrounded by an imaginary circle formed by continuing the outer circular arc surface 422b of the guide wall member 422 and an imaginary circle formed by continuing the radial inner end surface 423a of the discharge wall member 423. Is used as the diffusion region 7 for diffusing the air K.

  The electric conductor insertion hole 42b is filled with molten aluminum as the electric conductor 44 and solidified in a rod shape by being solidified. The short-circuit ring 45 is formed to have substantially the same diameter as the rotor core 41 and is provided integrally with the rotor core 41 so as to be electrically connected to the electric conductor 44. The short ring 45 is also formed of a conductive material.

  The shaft 43 is inserted so that a middle portion in the axial direction is fitted into the rotor core 41 and the center holes 41 a and 42 a of the heat radiating portion 42. End portions 431 on both sides of the shaft 43 protrude outward in the axial direction from the short-circuit ring 45, and each end portion 431 is rotatably supported on the side wall body 2 </ b> B of the housing 2 via a bearing 433.

  In the shaft 43, an introduction groove 432 (corresponding to the “groove” of the present invention) is formed on the surface of the region inserted through the rotor core 41 and the heat radiating portion 42 and the portion extending from the region to both sides in the axial direction. . The introduction grooves 432 are formed along the axial direction of the shaft 43, and a plurality (in this case, four) are formed intermittently (equally spaced) apart from the circumferential direction of the shaft 43. The cross-sectional shape of the introduction groove 432 is not specific, and in this case, it is formed in a substantially rectangular cross section.

  Each end 432 a of the introduction groove 432 is located at an axially outer position than the axial end of the rotor 4. That is, each end portion 432 a communicates with the suction space 22, and the space that communicates directly (substantially) with the suction space 22 is only the end portion 432 a of the introduction groove 432. The end portion 432a of the introduction groove 432 is formed on an inclined surface facing the axis 4a of the shaft 43 so that air can be easily introduced into the introduction groove 432.

  The guide wall member 422 of the heat radiating portion 42 is located at a location corresponding to the radially outer side of the introduction groove 432, and the circumferential length of the guide wall member 422 is set longer than the circumferential length of the introduction groove 432. Has been. That is, the guide wall member 422 covers the entire region where the circumferential length of the introduction groove 432 is projected outward in the radial direction.

  The cooling structure includes a suction fan unit 5 and a discharge structure 9 that discharges the cooling air K sucked from the suction fan unit 5 from the suction space 22 to the outside of the housing 2. As shown in FIGS. 1 and 2, the discharge structure 9 includes the introduction groove 432, the heat radiating portion 42, the gap G, a gap space 92 between the stays 32, a first exhaust path 93, and a second exhaust path described later. 94, and a third exhaust passage 95.

  The first air exhaust passage 93 is a space between the stator cores 31 and is formed in an annular space. The second air exhaust passage 94 is a space between the stator support members 6 and is formed in an annular space. The third air exhaust path 95 is an opening formed in a part of the outer wall 2 </ b> A of the housing 2.

  Both the first air exhaust passage 93 and the second air exhaust passage 94 are disposed at the center position in the longitudinal direction of the housing 2. The second air exhaust passage 94 has a larger radial width and a longer longitudinal length than the first air exhaust passage 93. The clearance space 92 between the stays 32, the first air exhaust passage 93, and the second air exhaust passage 94 are all in communication in the radial direction inside and outside of the housing 2. Since the second air exhaust passage 94 is formed in an annular shape, the second air exhaust passage 94 and the third air exhaust passage 95 communicate with each other in the radial direction of the housing 2.

  In the electric motor 1 having the above configuration, the heat generated by the driving is cooled by the cooling structure. That is, when each suction fan unit 5 is driven, cooling air K is sucked from each suction port 21, and the air K is cooled by being discharged from a third air exhaust path 95 formed in the housing 2. . Since the discharge port of the air K formed in the housing 2 is only the third air exhaust path 95, the air K sucked by the suction fan unit 5 moves along the path reaching the third air exhaust path 95, The air is discharged from the third air exhaust path 95. Hereinafter, a process until the air K sucked from the suction port 21 is discharged from the third exhaust path 95 will be described.

  First, an outline until the air K sucked into the suction space 22 of the housing 2 is discharged from the third air exhaust path 95 will be described. The air K sucked into the suction space 22 by the suction fan unit 5 is introduced into each introduction groove 432 from each end 432 a of the introduction groove 432. The air K introduced into each introduction groove 432 subsequently moves in the radial direction of the rotor 4 from the heat radiating portion 42 to reach the gap G, and the gap space 92 between the gap G and the stay 32, the first air exhaust path. 93, then reaches the second exhaust passage 94 and is then discharged from the third exhaust passage 95.

  Next, the flow of the air K will be described in detail. The air K sucked into the suction space 22 is introduced into the introduction grooves 432 from the end portions 432a of the introduction grooves 432. The spaces directly communicating with the suction spaces 22 are the end portions of the introduction grooves 432. This is because it is only 432a. The air K introduced into the introduction groove 432 from each end 432 a of the introduction groove 432 moves to the center side in the longitudinal direction of the introduction groove 432 and reaches the heat radiating portion 42. This is because the space communicating with the introduction groove 432 on the third air exhaust path 95 side is the heat radiating portion 42. Here, the background of the air K from the introduction groove 432 to the outside in the radial direction of the heat radiating portion 42 will be described in detail.

  The heat dissipating part 42 includes a guide wall member 422, which is located at a location corresponding to the radially outer side of each introduction groove 432, and the circumferential length of the guide wall member 422 is the circumferential length of the introduction groove 432. It is set longer than. That is, the guide wall member 422 covers the entire region where the circumferential length of the introduction groove 432 is projected outward in the radial direction. For this reason, when the air K moves from the introduction groove 432 outward in the radial direction of the shaft 43, the air K collides with the inner circular arc surface 422a of the guide wall member 422. That is, the guide wall member 422 has a function of a baffle plate member that prevents the air K from moving radially outward. The air K further extends outward in the radial direction from the escape portion 421c between the guide wall members 422.

  On the outer side in the radial direction of the guide wall member 422, there are a large number of discharge wall members 423 along the circumferential direction of the disk surface 421 b, and a discharge path 90 is formed by the discharge wall members 423. The discharge path 90 is narrower than the circumferential width of the escape portion 421c. Therefore, the velocity of the air K that has reached the diffusion region 7 radially outward from the escape portion 421c between the guide wall members 422 is once reduced. As the speed of the air K is reduced in this way, the air K is sufficiently diffused in the diffusion region 7 between the guide wall member 422 and the discharge wall member 423. Moreover, since there is a discharge path 90 radially outward of the diffusion region 7, the air K smoothly reaches the gap G outside the disk body 421 from the discharge path 90 without stopping.

  In addition, in the heat radiating portion 42, the guide wall member 422, the diffusion region 7, and the discharge path 90 (discharge wall member 423) are present on both disk surfaces 421 b of the disk main body 421. The flow of air K is generated on both disk surfaces 421b of the disk body 421. Further, two heat radiating portions 42 are provided, and the above-described flow of air K is generated for each heat radiating portion 42.

  The air K that has reached the gap G further passes through the gap space 92 between the stays 32 that are radially outward, to the first wind exhaust path 93 that communicates with the gap space 92, and then the first exhaust air. A second exhaust path 94 communicating with the path 93 is reached. And it discharges | emits from the 3rd exhaust path 95 connected to the 2nd exhaust path 94. FIG. As a result, the heat generated by driving the electric motor 1 is discharged from the inside of the housing 2 to the outside, and the electric motor 1 can be cooled.

  In particular, in the flow of the air K in the heat radiating portion 42 in the cooling process as described above, the air K collides with the inner circular arc surface 422a of the guide wall member 422, and the rotor 4 is rotated so that the guide wall member 422 is rotated. From the escape portion 421c between the circumferential end portions of the disk, it reaches radially outward, is sufficiently diffused in the diffusion region 7, and is discharged from each discharge path 90 radially outward of the disc body 421. That is, the air K in the heat radiation part 42 flows on the flat disk surface 421b. In other words, the air K does not change its direction in the direction along the axis 4a, and therefore the air K flows smoothly without stopping. For this reason, the fall of heat dissipation efficiency can be suppressed.

  In one guide wall member 422, the air K that collides with the inner arcuate surface 422a of the guide wall member 422 moves from the escape portion 421c, that is, radially outward from both circumferential ends of the guide wall member 422. The amount to be changed varies depending on the rotation direction of the heat radiation part 42 (disk main body 421). That is, there is a difference between the amount that moves radially outward from the circumferential end on the rotational direction side and the amount that moves radially outward from the circumferential end on the counter-rotating direction side. The amount of movement radially outward from the direction end is smaller than the amount of movement radially outward from the circumferential end on the counter-rotation direction side.

  The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. The same applies to the specific configuration of each part.

  For example, the configuration of the heat dissipation part 42 is not limited to the above embodiment. Here, FIG. 5 shows another embodiment of the heat radiation part 42. 5 is different from the above-described embodiment in that another guide wall member 4220 is disposed outward in the radial direction with respect to the escape portion 421c between the guide wall members 422.

  Another guide wall member 4220 is an arcuate wall member disposed concentrically with the center hole 42a, and has an inner arc surface 4220a and an outer arc surface 4220b, and is formed integrally with each disk surface 421b. Has been. Another guide wall member 4220 is intermittently arranged at equal intervals in the circumferential direction. Between another guide wall member 4220 adjacent in the circumferential direction, an escape portion 4220c is provided for allowing air K from the shaft 43 side (the escape portion 421c) to escape further outward in the radial direction.

  Since another guide wall member 4220 is provided so as to correspond to each escape portion 421c, four guide wall members 4220 are provided in this case. Another guide wall member 4220 has a circumferential length set shorter than a circumferential length of the relief portion 421c. Another guide wall member 4220 is provided in the diffusion region 7 because it is disposed radially outward with respect to the escape portion 421c.

  In the above configuration, the air K that has moved radially outward from the escape portion 421c reaches the diffusion region 7 and is prevented from moving radially outward by another guide wall member 4220. To the outside of the disk main body 421 in the radial direction and reach the gap G. Therefore, also in this configuration, the air K in the heat radiating portion 42 flows on the flat disk surface 421b. In other words, the direction of the air K does not change in the direction along the axis 4a, so the air K does not stop and the flow is smooth. For this reason, the fall of heat dissipation efficiency can be suppressed. Since the subsequent movement of the air K is the same as that in the above embodiment, the description thereof is omitted.

  In each of the above embodiments, the circumferential width of each discharge path 90 is set constant. However, the present invention is not limited to this. For example, the circumferential width of the discharge path 90 corresponding to the radially outward direction of the guide wall member 422 is compared with the circumferential width of the discharge path 90 corresponding to the radially outward direction of the escape portion 421c. It is conceivable that the configuration is narrow.

  According to this configuration, compared with the case where all the discharge passages 90 have the same circumferential width, the air K is more easily moved outward in the radial direction from the discharge passage 90 having a wider circumferential width. However, since there is the diffusion region 7 radially outward from the escape portion 421c, the diffusion region 7 is diffused to some extent by the diffusion region 7 and moves outward in the radial direction, so that it corresponds to the radially outward direction of the guide wall member 422. Even if the circumferential width of the discharge path 90 is narrower than the circumferential width of the discharge path 90 corresponding to the radially outer side of the escape portion 421c, it is possible to suppress a decrease in heat dissipation efficiency.

  It is also conceivable to form a heat radiating hole (not shown) in the disc body 421. For example, it is conceivable that the heat radiating hole is formed at a position near the center in the thickness direction of the disk main body 421 so as to extend from the outer peripheral surface of the disk main body 421 to the center hole 42a. It is also preferable to form a plurality of the heat radiating holes so as to be arranged in the radial direction around the center hole 42a.

  It is also conceivable to form a heat radiation hole (not shown) in the rotor core 41. For example, the heat radiating hole is radially inward of the electric conductor insertion hole 41b of the rotor core 41 and radially outward of the center hole 41a, along the axis 4a of the rotor core 41. It is conceivable to make a hole. It is also conceivable to form a heat radiation hole corresponding to the heat radiation hole on the plate surface of the disk main body 421 of the heat radiation portion 42. Heat generated in the rotor 4 from these heat radiation holes moves from the heat radiation part 42 to the gap G and is discharged as in the above embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Electric motor, 2 ... Housing, 3 ... Stator, 4 ... Rotor, 7 ... Diffusion area, 31 ... Stator iron core, 41 ... Rotor iron core, 42 ... Radiation part, 43 ... Shaft, 90 ... Discharge path, 421 ... disc main body, 421b ... disc surface, 422 ... guide wall member, 423 ... discharge wall member, 4220 ... guide wall member, 432 ... introduction groove, K ... air

Claims (5)

A plurality of rotor cores, a disk-shaped heat dissipation portion sandwiched between the rotor cores, and a shaft inserted through the rotor core and the center of the heat dissipation portion, and at least the rotor core of the shaft A groove in the axial direction is formed on the surface extending from the heat dissipation part,
The heat dissipating part has a flat disk main body having a flat disk surface, and air that moves radially outward from the groove in a region corresponding to the outer radial direction of the groove on the disk surface in the circumferential direction. A guide wall member that guides the guide wall member and a discharge passage that is spaced apart radially outward of the guide wall member and discharges air guided in the circumferential direction by the guide wall member to the radially outer side of the disk body. A squirrel-cage rotor comprising a discharge wall member for forming.   The groove is intermittently formed in the circumferential direction on the surface of the shaft, the guide wall member is intermittently arranged in the circumferential direction of the disk surface, and the discharge wall member is intermittent in the circumferential direction over the entire circumference of the disk surface. 2. The cage rotor according to claim 1, wherein the discharge path is provided intermittently in the circumferential direction of the disk surface.   3. A squirrel-cage rotor according to claim 1 or 2, wherein a space between the guide wall member and the discharge wall member is a diffusion region for diffusing the air before reaching the discharge path.   The disk main body is a flat disk surface on both sides, and the guide wall member and the discharge wall member are on the disk surfaces on both sides, and are formed integrally with the disk main body. The cage rotor according to any one of 3 above.   An electric motor comprising the cage rotor according to any one of claims 1 to 4.

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