JP3219947U - Rotating electric machine - Google Patents

Abstract

A rotating electrical machine capable of efficiently radiating heat from a rotor and a bearing is provided.
A shaft 19 of a rotating electrical machine 10 includes a hollow first shaft portion 31 joined to one end surface of a rotor core 18, a hollow second shaft portion 32 joined to the other end surface of the rotor core, and a first shaft portion. The first shaft portion 31 and the second shaft portion 32 have through holes 34 and 44 and a third shaft portion 33 formed over the shaft hole 18A provided in the rotor core 18, and the third shaft portion 33 is The first shaft portion 31 and the second shaft portion 32 are formed of a material having a higher thermal conductivity than the first shaft portion 31 and the second shaft portion 32. The first shaft portion 31 and the second shaft portion 32 have an outer peripheral surface and a through hole corresponding to the position where the bearing is mounted. The communication holes 43 and 53 are connected to each other, and the communication holes 43 and 53 are filled with the material of the third shaft portion 33.
[Selection] Figure 1

Description

  The present invention relates to a rotating electrical machine.

  As a conventional rotating electrical machine, for example, a rotating machine disclosed in Patent Document 1 is known. In the rotating machine disclosed in Patent Document 1, the shaft of the hollow shaft is made of two or more kinds of materials having different thermal conductivities, a material having a high thermal conductivity is arranged on the inner side of the shaft, and a fitting portion made of different materials At the same time, a ventilation path is provided in the shaft having the higher thermal conductivity. According to this rotating machine, the heat generated by the loss generated in the rotating machine is dissipated from the bracket surface contacting the bearing through the fan or the bearing through the outer shaft, but the outer shaft and the inner shaft are heated. The heat generated in the inner shaft having a high thermal conductivity is transmitted through the outer shaft, and the temperature of the inner shaft rises. However, the cooling air passes through the ventilation path to promote heat dissipation. On the other hand, the space shields heat and suppresses heat transfer to the bearing.

JP-A-6-141509

  However, in the rotating machine disclosed in Patent Document 1, since the heat of the rotor (rotor) whose temperature has been increased is transferred to the outer shaft and then transferred to the inner shaft having a high thermal conductivity, the heat transfer efficiency is low. is there. Moreover, although the heat of the shaft is suppressed from being transferred to the bearing by the space, it is difficult to radiate the heat generated in the bearing.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a rotating electrical machine capable of efficiently radiating heat from a rotor and a bearing.

  To achieve the above object, the present invention includes a rotor including a rotor core and a shaft, a stator including a stator core and a coil, a housing supporting the stator, and a pair of bearings supporting the shaft to the housing. In the rotating electrical machine, the shaft includes a hollow first shaft portion joined to one end face of the rotor core, a hollow second shaft portion joined to the other end face of the rotor core, and the first shaft. And a third shaft portion formed over a shaft hole provided in the rotor core, and the third shaft portion includes the first shaft portion and the second shaft portion. It is made of a material having a higher thermal conductivity than that of the shaft portion, and the first shaft portion and the second shaft portion are mounted with the bearings. It has that an outer peripheral surface corresponding to the position and the communicating hole communicating with the through hole, respectively, said communication hole, the material of the third shaft portion is characterized in that it is filled.

  In this invention, the 3rd shaft part formed with the material whose heat conductivity is higher than a 1st shaft part and a 2nd shaft part is a shaft provided in the through-hole of a 1st shaft part and a 2nd shaft part, and a rotor core. It is formed over the hole. For this reason, the heat generated in the rotor core is dissipated through the third shaft portion formed of a material having a higher thermal conductivity than the first shaft portion and the second shaft portion. The first shaft portion and the second shaft portion each have a communication hole that communicates the outer peripheral surface and the through hole corresponding to the position where the bearing is mounted, and the communication hole has a material for the third shaft portion. Is filled. For this reason, the heat generated in the bearing is radiated to the third shaft portion through the material having high thermal conductivity filled in the communication hole. Therefore, it is possible to efficiently dissipate heat from the rotor and the bearing.

In the above rotating electric machine, the inner circumferential wall of the rotor core that forms the shaft hole may be formed by an uneven surface.
In this case, the inner peripheral wall of the rotor core that forms the shaft hole is formed by an uneven surface, so that the contact area between the rotor core and the third shaft can be increased. As a result, the heat transfer efficiency between the rotor core and the third shaft can be increased.

In the above rotating electric machine, a shaft inner peripheral wall that forms the through hole of the first shaft portion and the second shaft portion may be formed by an uneven surface.
In this case, the contact area between the first shaft portion and the second shaft portion and the third shaft can be increased by forming the inner peripheral wall of the shaft with an uneven surface. As a result, the heat transfer efficiency of the first shaft portion, the second shaft portion, and the third shaft portion can be increased.

  ADVANTAGE OF THE INVENTION According to this invention, the rotary electric machine which can perform the thermal radiation of a rotor and a bearing efficiently can be provided.

1 is a longitudinal sectional view showing a rotary electric machine according to a first embodiment of the present invention. (A) is a longitudinal cross-sectional view which expands and shows the one edge part vicinity of a rotor core, (b) is a longitudinal cross-sectional view which expands and shows the other edge part vicinity of a rotor core. It is an AA line (BB line) arrow line view in FIG. (A) is a longitudinal cross-sectional view which shows the principal part of the 1st shaft part which concerns on 2nd Embodiment, (b) is a longitudinal cross-sectional view which shows the principal part of the 2nd shaft part, (c) is It is an arrow line view of a CC line and a DD line.

(First embodiment)
Hereinafter, the rotating electrical machine according to the first embodiment will be described with reference to the drawings. The rotating electrical machine of this embodiment is a three-phase induction motor. As shown in FIG. 1, the rotating electrical machine 10 includes a first housing 12 that supports one end surface of the stator 11 and a second housing 13 that supports the other end surface of the stator 11. The stator 11 includes a cylindrical stator core 14 and a coil 16 inserted into a slot 15 of the stator core 14. A part of the coil 16 protrudes from the slot 15 of the stator core 14 to form a coil end.

  The 1st housing 12 and the 2nd housing 13 are equivalent to a housing, and support the rotor 17 rotatably. The rotor 17 includes a rotor core 18 having a shaft hole 18A and a shaft 19. The rotor core 18 has a core body 20 and a secondary conductor 22 filled in a slot 21 formed in the core body 20. The core body 20 is made of iron, and the secondary conductor 22 is aluminum filled in the slot 21 by aluminum die casting. The secondary conductor 22 includes a main body portion 22A filled in the core main body 20, and end rings 22B formed at both ends of the main body portion 22A and at the end portions of the core main body. Further, fins 27 protruding in the axial direction are integrally formed on the end ring 22B.

  As shown in FIGS. 2A and 2B, the core body 20 includes three types of laminated steel plates 23, 24, and 25. In the core body 20, a plurality of laminated steel plates 23, 24, and 25 are laminated. The inner diameter of the through hole formed at the center of the laminated steel plate 23 is smaller than the inner diameter of the through hole formed at the center of the laminated steel plate 24. In the present embodiment, most of the core main body 20 is formed by repeatedly laminating a predetermined number of laminated steel plates 24 after laminating a predetermined number of laminated steel plates 23. Therefore, the inner circumferential wall of the rotor core that forms the shaft hole 18 </ b> A of the rotor core 18 is formed by the uneven surface 26. A plurality of laminated steel plates 25 are laminated at both ends of the aggregate of the laminated steel plates 23 and 24 in which the laminated steel plates 23 and 24 are laminated. The inner diameter of the through hole formed at the center of the laminated steel plate 25 is set so that the first shaft portion 31 described later is fitted. Therefore, the inner diameter of the through hole of the laminated steel plate 25 is larger than the inner diameter of the through hole formed at the center of the laminated steel plates 23 and 24.

  The end rings 22B are arranged so as to be positioned at both ends of the core body 20 in the stacking direction. FIG. 2A illustrates one end ring 22B and the fin 27, and FIG. 2B illustrates the other end ring 22B and the fin 27.

  Next, the shaft 19 will be described. As shown in FIG. 1, the shaft 19 includes a first shaft portion 31, a second shaft portion 32, and a third shaft portion 33. The first shaft portion 31 and the second shaft portion 32 are made of iron, and the third shaft portion 33 is made of aluminum.

  The first shaft portion 31 is a hollow shaft member having a through hole 34. The first shaft portion 31 is joined to one end face of the rotor core 18 and forms a shaft portion on the output side of the rotating electrical machine 10. One end portion 35 of the first shaft portion 31 protrudes from the first housing 12 to the outside. The outer peripheral diameter of the other end portion 36 of the first shaft portion 31 is larger than the outer peripheral diameter of the one end portion 35. The first shaft portion 31 is joined to one end surface of the rotor core 18 by fitting the other end portion 36 of the first shaft portion 31 with the through hole of the one laminated steel plate 25 in the core body 20.

  On the inner peripheral wall of the shaft that forms the through hole 34 of the first shaft portion 31, a thread groove is formed so that an uneven surface 37 is formed. The thread groove is formed by a tap, and the surface area of the inner peripheral wall of the shaft is increased by the uneven surface 37 formed by the thread groove. The first shaft portion 31 is rotatably supported by the first housing 12 by a first bearing 38. The first bearing 38 is a radial bearing and includes an inner ring 39, an outer ring 40, and rolling elements 41. A plurality of communication holes 43 penetrating in the radial direction from the through hole 34 to the outer peripheral surface are formed in the mounting portion 42 to which the inner ring 39 is mounted in the first shaft portion 31. As shown in FIG. 3, the plurality of communication holes 43 are arranged radially about the axis P. The communication hole 43 is filled with aluminum, which is the same material as the third shaft portion 33 described later, by aluminum die casting.

  The second shaft portion 32 is a hollow shaft member having a through hole 44. The second shaft portion 32 is joined to the other end surface of the rotor core 18 and forms a shaft portion on the opposite side to the shaft portion on the output side of the rotating electrical machine 10. The other end 45 of the second shaft portion 32 does not protrude from the second housing 13 to the outside. The outer diameter of one end 46 of the second shaft portion 32 is larger than the outer diameter of the other end 45. The second shaft portion 32 is joined to the other end surface of the rotor core 18 by fitting one end portion 46 of the second shaft portion 32 with the through hole of the other laminated steel plate 25 in the core body 20. The other end 45 of the second shaft portion 32 does not protrude from the second housing 13 to the outside, but may be protruded from the second housing 13 when a sensor gear or a fan is attached.

  On the inner peripheral wall of the shaft that forms the through hole 44 of the second shaft portion 32, a thread groove is formed so that an uneven surface 47 is formed. The thread groove is formed by a tap, and the surface area of the inner peripheral wall of the shaft is increased by the uneven surface 47 by the thread groove. The second shaft portion 32 is rotatably supported by the second housing 13 by a second bearing 48. The second bearing 48 is a radial bearing and includes an inner ring 49, an outer ring 50, and rolling elements 51. A plurality of communication holes 53 penetrating in the radial direction from the through hole 34 to the outer peripheral surface are formed in the mounting portion 52 to which the inner ring 49 is mounted in the second shaft portion 32. As shown in FIG. 3, the plurality of communication holes 53 are arranged radially about the axis P. The communication hole 53 is filled with aluminum, which is the same material as the third shaft portion 33 described later, by aluminum die casting.

  The third shaft portion 33 is formed across the through hole 34 of the first shaft portion 31, the through hole 44 of the second shaft portion 32, and the shaft hole 18 </ b> A of the rotor core 18. Accordingly, the third shaft portion 33 extends from one end portion 35 of the first shaft portion 31 to the other end portion 45 of the second shaft portion 32. The third shaft portion 33 is made of aluminum filled with aluminum die casting. For this reason, the third shaft portion 33 has a higher thermal conductivity than the first shaft portion 31 and the second shaft portion 32.

  The procedure for forming the third shaft portion 33 will be described. First, the first shaft portion 31 is joined to one end surface of the rotor core 18, and the second shaft portion 32 is joined to the other end surface of the rotor core 18. Next, while closing the opening on the outer peripheral surface side of the communication holes 43 and 53, while opening one of the end portion 35 of the first shaft portion 31 or the end portion 45 of the second shaft portion 32, the end portion 35 or the end portion Block the other of 45. Next, the molten metal is poured and filled into the through hole 34 of the first shaft portion 31, the through hole 44 of the second shaft portion 32, and the shaft hole 18 </ b> A of the rotor core 18. The third shaft portion 33 is formed by cooling the filled molten metal. When the rotor 17 is completed by forming the third shaft portion 33, the rotor 17 is inserted into the stator 11 and supported by the first housing 12 and the second housing 13 via the first bearing 38 and the second bearing 48. The rotating electrical machine 10 is completed.

  Next, the effect | action of the rotary electric machine 10 which concerns on this embodiment is demonstrated. In the rotating electrical machine 10, a rotating magnetic field is generated in the stator 11 by passing a current through the coil 16 of the stator 11. A magnetic field generated in the stator 11 links the rotor core 18, an induced current flows through the secondary conductor 22, and an induced current flows through the secondary conductor 22, whereby an electromagnetic force acts on each secondary conductor 22 in one direction. To do. As a result, the rotor 17 rotates about the axis P of the shaft 19. Further, the rotor core 18 generates heat when an induced current flows through the rotor core 18.

  The heat generated in the rotor core 18 moves to the third shaft portion 33 through the uneven surface 26. The contact area between the rotor core 18 and the third shaft portion 33 is increased as much as possible by the uneven surface 26, and heat transfer from the rotor core 18 to the third shaft portion 33 is performed efficiently. The heat transmitted to the third shaft portion 33 is radiated from both ends of the third shaft portion 33. Since the rotor core 18 which is a heat generation source and the third shaft portion 33 having a high thermal conductivity are in contact with each other, the heat dissipation of the rotor core 18 is efficiently performed.

  The heat transferred from the rotor core 18 to the first shaft portion 31 and the second shaft portion 32 is transferred to the third shaft portion 33 via the uneven surface 37 of the first shaft portion 31 and the uneven surface 47 of the second shaft portion 32. Moving. The contact surfaces of the first shaft portion 31 and the second shaft portion 32 and the third shaft portion 33 are increased as much as possible by the uneven surfaces 37 and 47, and the first shaft portion 31 and the second shaft portion 32 Heat transfer to the three shaft portions 33 is performed efficiently.

  Further, the first bearing 38 and the second bearing 48 generate heat due to mechanical loss due to the rotation of the rotor 17. The heat of the first bearing 38 is transmitted to the third shaft portion 33 through the material filled in the communication hole 43 formed in the mounting portion 42 of the first bearing 38. Further, the heat of the second bearing 48 is transmitted to the third shaft portion 33 through the material filled in the communication hole 53 formed in the mounting portion 52 of the second bearing 48. Therefore, since the material filled in the communication holes 43 and 53 is in contact with the inner rings 39 and 49, the heat radiation of the first bearing 38 and the second bearing 48 is efficiently performed.

The rotating electrical machine 10 of the present embodiment has the following effects.
(1) The third shaft portion 33 formed of a material having higher thermal conductivity than the first shaft portion 31 and the second shaft portion 32 is connected to the through hole 34 of the first shaft portion 31 and the second shaft portion 32. The hole 44 is formed over the shaft hole 18 </ b> A provided in the rotor core 18. For this reason, the heat generated in the rotor core 18 is dissipated through the third shaft portion 33 formed of a material having higher thermal conductivity than the first shaft portion 31 and the second shaft portion 32. In addition, the first shaft portion 31 and the second shaft portion 32 have communication holes 43 and 53 that communicate the outer peripheral surface with the through holes 34 and 44 corresponding to positions where the first bearing 38 and the second bearing 48 are mounted. The communication holes 43 and 53 are filled with the material of the third shaft portion 33. For this reason, the heat generated in the first bearing 38 and the second bearing 48 is radiated to the third shaft portion 33 through the material having high thermal conductivity filled in the communication holes 43 and 53. Therefore, it is possible to efficiently dissipate heat from the rotor 17, the first bearing 38, and the second bearing 48.

(2) The inner circumferential wall of the rotor core that forms the shaft hole 18 </ b> A of the rotor core 18 is formed by the uneven surface 26. For this reason, the contact area between the rotor core 18 and the third shaft portion 33 can be increased. As a result, the heat transfer efficiency between the rotor core 18 and the third shaft portion 33 can be increased.

(3) The shaft inner peripheral wall forming the first shaft portion 31 is formed by the uneven surface 37, and the shaft inner peripheral wall forming the second shaft portion 32 is formed by the uneven surface 47. For this reason, the contact area of the 1st shaft part 31, the 2nd shaft part 32, and the 3rd shaft part 33 can be increased. As a result, the heat transfer efficiency of the first shaft portion 31, the second shaft portion 32, and the third shaft portion 33 can be increased.

(4) Since the first shaft portion 31 and the second shaft portion 32 of the shaft 19 are fixed to both sides of the rotor core 18, even if the axial thickness of the rotor core 18 is changed, the first shaft portion 31 and the second shaft portion 32 The two shaft portions 32 can be used. Incidentally, when the shaft is fixed to the rotor by press fitting or shrink fitting, it is necessary to prepare a shaft corresponding to the axial thickness of the rotor core, but in this embodiment, depending on the axial thickness of the rotor core. There is no need to prepare a shaft.

(5) A plurality of communication holes 43 penetrating in the radial direction from the through hole 34 to the outer peripheral surface are formed in the mounting portion 42 to which the inner ring 39 of the first shaft portion 31 is mounted. The mounting portion 52 to which the inner ring 49 of the second shaft portion 32 is mounted is formed with a plurality of communication holes 53 penetrating in a radial direction from the through hole 44 to the outer peripheral surface. For this reason, the heat of the first bearing 38 is transmitted to the third shaft portion 33 through the material filled in the communication hole 43 formed in the mounting portion 42 of the first bearing 38. Further, the heat of the second bearing 48 is transmitted to the third shaft portion 33 through the material filled in the communication hole 53 formed in the mounting portion 52 of the second bearing 48. Therefore, the heat radiation of the first bearing 38 and the second bearing 48 can be efficiently performed.

(Second Embodiment)
Next, the rotating electrical machine according to the second embodiment will be described. The rotating electrical machine of the present embodiment is different from the first embodiment in the configuration of the first shaft portion and the second shaft portion. In the present embodiment, for the same configuration as that of the first embodiment, the description of the first embodiment is used, and common reference numerals are used.

  In the first shaft portion 61 of the rotating electrical machine 60 shown in FIG. 4A, the mounting portion 62 to which the inner ring 39 of the first bearing 38 is mounted has an annular groove 63 that is engraved in the circumferential direction of the mounting portion 62. Is formed. A plurality of communication holes 64 penetrating in the radial direction from the through hole 34 to the bottom of the annular groove 63 is formed. As shown in FIG. 4C, the plurality of communication holes 64 are arranged radially about the axis P. The annular groove 63 and the communication hole 64 are filled with aluminum, which is the same material as the third shaft portion 33 described later, by aluminum die casting. The material filled in the annular groove 63 contacts the inner ring 39.

  As shown in FIG. 4 (b), in the second shaft portion 71, an annular groove 73 carved over the circumferential direction of the mounting portion 72 is formed in the mounting portion 72 where the inner ring 49 of the second bearing 48 is mounted. Has been. A plurality of communication holes 74 penetrating in the radial direction from the through hole 44 to the bottom of the annular groove 73 are formed. As shown in FIG. 4C, the plurality of communication holes 74 are arranged radially about the axis P. The annular groove 73 and the communication hole 74 are filled with aluminum, which is the same material as the third shaft portion 33 described later, by aluminum die casting. The material filled in the annular groove 73 contacts the inner ring 49.

  This embodiment has the same operational effects as (1) to (4) of the first embodiment. Further, in the first shaft portion 61, an annular groove 63 that is engraved in the circumferential direction of the attachment portion 62 is formed in the attachment portion 62 to which the inner ring 39 of the first bearing 38 is attached, and the annular groove 63 extends from the through hole 34. A plurality of communication holes 64 penetrating in the radial direction up to the bottom of 63 is formed. In the second shaft portion 71, the mounting portion 72 to which the inner ring 49 of the second bearing 48 is mounted is formed with an annular groove 73 carved in the circumferential direction of the mounting portion 72, and the annular groove 73 is formed from the through hole 44. A plurality of communication holes 74 penetrating in the radial direction to the bottom are formed. Therefore, heat can be transferred from the inner ring 39 (49) to the third shaft portion 33 through the material filled in the annular groove 63 (73) and the communication hole 64 (74), and more heat can be radiated from the first bearing 38 and the second bearing 48. It can be performed more efficiently.

  The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the spirit of the invention. For example, the following modifications may be made.

In the above embodiment, aluminum is used as the material of the third shaft portion, but the material of the third shaft portion is not limited to aluminum. For example, copper or a copper alloy may be used as the material of the third shaft portion, and the material of the third shaft portion may be a metal material having a higher thermal conductivity than the first shaft portion and the second shaft portion.
In the above embodiment, the inner circumferential wall of the rotor core of the rotor core is formed by an uneven surface, but the present invention is not limited to this. The inner peripheral wall of the rotor core may be formed by a surface other than the uneven surface.
In the above embodiment, the shaft inner peripheral wall forming the shaft hole of the first shaft portion and the second shaft portion has been described as a screw groove as the uneven surface, but the uneven surface is not limited to the screw groove. The shaft inner peripheral wall forming the shaft hole of the first shaft portion and the second shaft portion may be formed by a surface other than the uneven surface. For example, the uneven surface may be a spline or a serration.
In the above embodiment, the inner circumferential wall of the rotor core of the rotor core is an uneven surface, but is not limited thereto. The inner circumferential wall of the rotor core may be a surface without unevenness.
In the above embodiment, the plurality of communication holes are arranged radially from the through holes of the first shaft portion and the second shaft portion in the radial direction, but the number of communication holes is not limited to the example of the embodiment. . For example, the number of communication holes may be two.
○ In the above embodiment, by preparing two types of laminated steel plates, the inner peripheral wall of the rotor core is made uneven, but the types of laminated steel plates are not limited to two types, for example, using three types of laminated steel plates An uneven surface may be formed.
In the above embodiment, an induction motor as a rotating electrical machine is illustrated, but the rotating electrical machine is not limited to an induction motor. The rotating electrical machine may be an electric motor other than an induction motor, such as a synchronous motor.

10, 60 Rotating electrical machine 11 Stator 12 First housing 13 Second housing 14 Stator core 16 Coil 17 Rotor 18 Rotor core 18A Shaft hole 19 Shaft 20 Core body 23 Laminated steel sheet 24 Laminated steel sheet 25 Laminated steel sheets 26, 37, 47 Uneven surface 31 First Shaft portion 32 Second shaft portion 33 Third shaft portion 34, 44 Through hole 38 First bearing 42, 52, 61, 71 Mounting portion 43, 53, 63, 73 Communication hole 48 Second bearing 52 Mounting portion 53 Communication hole 62 , 73 annular groove P axial center

Claims (3)

A rotor comprising a rotor core and a shaft;
A stator comprising a stator core and a coil;
A housing that supports the stator;
A rotating electrical machine comprising a pair of bearings for supporting the shaft on the housing,
The shaft is
A hollow first shaft portion joined to one end face of the rotor core;
A hollow second shaft portion joined to the other end face of the rotor core;
A third shaft portion formed across the through hole of the first shaft portion and the second shaft portion and a shaft hole provided in the rotor core;
The third shaft portion is made of a material having higher thermal conductivity than the first shaft portion and the second shaft portion,
The first shaft portion and the second shaft portion each have a communication hole that communicates the outer peripheral surface and the through hole corresponding to a position where the bearing is mounted,
The rotating electrical machine, wherein the communication hole is filled with a material of the third shaft portion.   The rotating electrical machine according to claim 1, wherein an inner peripheral wall of the rotor core that forms the shaft hole is formed by an uneven surface.   3. The rotating electrical machine according to claim 1, wherein an inner peripheral wall of the shaft forming the through hole of the first shaft portion and the second shaft portion is formed by an uneven surface.

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