CN108155756B

CN108155756B - External rotation type rotating electric machine

Info

Publication number: CN108155756B
Application number: CN201711180246.1A
Authority: CN
Inventors: 堀雅宽; 床井博洋; 三好努; 矢岛健司
Original assignee: Hitachi Industrial Equipment Systems Co Ltd
Current assignee: Hitachi Industrial Equipment Systems Co Ltd
Priority date: 2016-12-02
Filing date: 2017-11-23
Publication date: 2020-05-01
Anticipated expiration: 2037-11-23
Also published as: CN108155756A; JP6694804B2; JP2018090381A

Abstract

The invention provides an outward turning type rotating motor, which can improve the cooling performance of the outward turning type rotating motor through a simple structure, and can reduce the weight and save the space. The outward turning type rotating electric machine includes: a rotating shaft that rotates around a rotation center axis; a rotor frame connected with the rotating shaft; a rotor connected to the rotor frame and rotating around a rotation center axis; a stator disposed on the inner diameter side of the rotor with a predetermined gap from the rotor; a stator frame connected with the stator; a heat radiation fin connected with the stator frame and arranged on the inner diameter side of the stator frame; and a cooling fan connected with the rotating shaft and arranged on the inner diameter side of the radiating fin.

Description

External rotation type rotating electric machine

Technical Field

The present invention relates to an external-rotor rotating electric machine, and more particularly to a rotating electric machine suitable for constituting an elevator hoisting machine that requires a small size and light weight.

Background

In recent years, due to the demand for downsizing of elevator hoisting machines, a mechanism (sheave, casing), a brake, and a rotating electrical machine are mainly constructed integrally.

Therefore, the rotating electric machine is also required to be downsized (to have high torque density). As a mechanism for increasing torque density of a rotating electric machine, there is an outward turning type rotating electric machine. In the external rotation type rotating electric machine, the rotor is disposed on the outer peripheral side of the stator, the radius of the gap (gap) between the rotor and the stator can be increased, and the rotor is disposed on the outside and has a feature that a large magnet having a long circumferential length of one pole can be disposed.

However, since the coil, which is a main heat generating source of the rotating electric machine, is located on the inner diameter side, the coil arrangement space is reduced, the heat radiation area is also reduced, and the internal temperature of the rotating electric machine is increased. Therefore, in order to realize a small and lightweight rotating electric machine, it is necessary to improve the cooling performance of the external rotation type rotating electric machine.

As a method for improving the cooling performance of an external rotor type rotating electric machine, for example, there is a technique described in patent document 1. In patent document 1, an outer rotor type hoist includes: a sheave rotatably mounted to the fixed shaft via a bearing; a rotor rotating integrally with the sheave; and a stator having a stator winding and a stator core provided inside the rotor so as to face the rotor, wherein a plurality of heat radiating fins for conducting heat generated by the stator and radiating heat are provided on an inner peripheral side of the stator. According to this configuration, the heat radiation area on the inner diameter side of the rotor can be increased, and the cooling performance can be improved.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2005-104620

Disclosure of Invention

Problems to be solved by the invention

In patent document 1, the heat radiating fins are provided on the inner diameter of the stator, but the space on the inner diameter side of the stator is surrounded by the structure except in one direction, and air circulation becomes difficult. Therefore, the temperature of the air around the heat dissipating fins becomes high, and the desired fin performance may not be obtained. Patent document 1 describes a structure in which a frame is provided with a vent hole, and a separately excited fan is used to cause wind to contact fins. However, if the frame is perforated, there is a possibility that strength is reduced or dust, dirt, etc. are introduced into the motor. Further, since a separate fan is used, a power supply must be prepared, and the structure is complicated.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an outward turning type rotating electric machine or a hoisting machine for an elevator, which can improve cooling performance of the outward turning type rotating electric machine with a simple configuration, and can achieve weight reduction and space saving.

Means for solving the problems

One aspect of the present invention is an outward turning type rotating electrical machine, comprising: a rotating shaft that rotates around a rotation center axis; a rotor frame connected with the rotating shaft; a rotor connected to the rotor frame and rotating around the central rotation axis; a stator disposed on the inner diameter side of the rotor with a predetermined gap from the rotor; a stator frame connected with the stator; a heat radiation fin connected with the stator frame and arranged on the inner diameter side of the stator frame; and a cooling fan connected with the rotating shaft and arranged on the inner diameter side of the radiating fin.

In order to solve the above problem, another aspect of the present invention is an outer rotor type rotating electric machine including: a rotating shaft; a rotor connected to the rotating shaft via a rotor frame and formed of a rotor core and a permanent magnet disposed on the inner diameter side of the rotor core; a stator in which coils are wound in a plurality of slots provided in a stator core disposed on an inner diameter side of a rotor with a predetermined gap therebetween; and a stator frame connected with the stator, the rotating shaft and the stator frame being connected via a bearing, the outward turning type rotating electrical machine being characterized in that: the inner diameter portion of the stator frame is provided with a fin, and a fan directly connected to the rotating shaft is provided on the inner diameter side of the fin and on the inner side of the stator frame in the axial direction.

Effects of the invention

By improving the cooling performance, a small and lightweight external rotation type rotating electric machine or a hoisting machine for an elevator can be provided.

Drawings

Fig. 1 is an axial sectional view showing an outline of an external rotating electric machine according to embodiment 1 of the present invention.

Fig. 2 is a perspective sectional view showing an example of a cooling fan and a heat dissipating fin.

Fig. 3 is an axial sectional view of an outer rotor type rotating electric machine according to embodiment 2 of the present invention.

Fig. 4 is a radial schematic view of a stator frame and vanes according to embodiment 3 of the present invention.

Fig. 5 relates to embodiment 4 of the present invention, which is a radial schematic view of a stator frame and a vane.

Fig. 6 is a radial schematic view of a stator frame and vanes according to embodiment 4 of the present invention.

Fig. 7 is a radial schematic view of a stator frame and vanes according to embodiment 4 of the present invention.

Fig. 8 is an axial sectional view of an elevator hoisting machine using an outer-rotor type rotating electrical machine according to an embodiment of the present invention.

Detailed Description

The outer rotating electric machine and the elevator hoisting machine according to the present invention will be described below based on the illustrated embodiments. The following describes the structure of each embodiment for improving the cooling performance of the outer rotor type rotating electric machine. In each embodiment, the same constituent elements will be described with the same reference numerals, and redundant description thereof will be omitted. In addition, components having the same basic configuration but partially changed may be described only with reference to the same reference numerals. In addition, when the description is given with a focus on the basic structure, the added characters may be omitted. The following are only examples, and the embodiments of the present invention are not limited to the specific examples described below.

For convenience of understanding of the present invention, the positions, sizes, shapes, ranges, and the like of the respective structures shown in the drawings and the like do not necessarily indicate actual positions, sizes, shapes, ranges, and the like. Therefore, the present invention is not limited to the positions, sizes, shapes, ranges, and the like disclosed in the drawings and the like.

[ example 1]

Fig. 1 is an axial sectional view of an outer rotor type rotating electric machine according to embodiment 1 of the present invention. Although fig. 1 is a sectional view, in order to facilitate understanding of the structure, black dots are applied to the rotating components, and the non-rotating (fixed) components are indicated by outlines other than the black dots.

The external-rotor rotating electric machine 1 of the present embodiment includes: a rotor 4 composed of a rotor core 2 and permanent magnets 3; a stator 8 disposed at a predetermined gap on the inner diameter side of the rotor 4 and including a stator core 6 and a coil 7; a rotation shaft 24 that rotates about a rotation center axis 100; a rotor frame 9 connecting the rotor 4 and the rotary shaft 24; and a stator frame 11 connected to the stator 8 and the rotary shaft 24 via a bearing and configured to cover the rotor 4 and the stator 8.

As can be seen from fig. 1, in the present embodiment, the rotor 4 rotates centering on the rotation center shaft 100. For convenience, the direction of the rotation center axis 100 is referred to as "axial direction" and the direction perpendicular to the axial direction is referred to as "radial direction" or "radial direction". In the radial direction, a direction approaching the rotation center axis 100 is referred to as "inner diameter side" or "inner side", and a direction separating from the rotation center axis is referred to as "outer diameter side" or "outer side".

Here, the coil 7 is preferably mounted to the stator core 6 so as to be wound in a concentrated manner. This shortens the axial length of the short portion of the coil 7, shortens the axial length of the external rotation type rotating electric machine 1, and enables downsizing. The bearing 10 is disposed at a position shifted from the axial center of the stator 8 and is provided on the inner diameter side of the stator frame 11. In fig. 1, the auxiliary bearing 12 for supporting the rotary shaft 24 is used in addition to the bearing 10, but the auxiliary bearing 12 may be omitted. Alternatively, the auxiliary bearing 12 may be disposed closer to the axial center side of the stator 8 than the bearing 10. Examples of the size and material of these components can follow the conventional technique described in patent document 1, for example. For example, the rotor frame 9 and the stator frame 11 are made of cast iron.

In the present embodiment, the stator frame 11 is provided with the heat dissipating fins 13 on the inner diameter side thereof, and further provided with the cooling fan 14 directly connected to the rotary shaft 24 via the fan center shaft 25 on the inner diameter side thereof. The heat dissipating fins 13 have, for example, a plate-like structure, and the surfaces of the plates are arranged perpendicular to the inner wall of the stator frame 11, and have long sides of the plates in the long axis direction (i.e., axial direction) of the rotary shaft 24. Since the surface area of the inner diameter of the stator frame 11 can be increased by the heat radiation fins 13, the heat generated by the coil 7, the stator core 6, and the like can be effectively dissipated to the outside of the rotating electric machine 1, and the cooling performance can be improved.

Further, by disposing the cooling fan 14 on the inner diameter side of the fin 13, the cooling fan 14 agitates the air as the rotation shaft 24 rotates, and an air flow such as the cooling air 15 can be formed, and the air can be circulated. Therefore, the temperature of the air around the heat dissipating fins 13 can be reduced, and the heat dissipating efficiency of the heat dissipating fins 13 can be improved. The cooling fan 14 has, for example, a plate-like structure, and the surface of the plate is arranged radially with respect to the rotation center axis 100 and has the long side of the plate in the long axis direction (i.e., axial direction) of the rotation shaft 24. As shown in fig. 1, the cooling fan 14 is fixed to the rotary shaft 24 together with the rotor 4, and rotates about the central axis of rotation 100, so that rotational power for the cooling fan 14 is not necessary.

Here, the cooling fan 14 is preferably a radial fan capable of discharging wind in a radial direction. In the case of an axial fan that discharges wind in the axial direction, it is necessary to provide ventilation holes in the stator frame 11, the rotor frame 9, or both of them in order to form a flow path, and there may be caused problems such as a reduction in strength, entry of dust, dirt, and the like into the inside of the external rotation type rotating electric machine, and the like. By discharging the air from the direction perpendicular to the rotation shaft 24, the discharged air collides with the inner wall of the stator frame 11 and the heat dissipating fins 13 and moves in the direction along the inner wall of the stator frame 11, thereby enabling efficient ventilation. The cooling fan 14 and the fan center shaft 25 are preferably configured to be detachable from the rotary shaft 24. For example, the rotary shaft 24 and the fan center shaft 25 can be combined by a screw structure or the like. This makes it possible to mount the cooling fan 14 after assembling the external rotation type rotating electric machine 1, and therefore, the manufacturing becomes easy and the cost is reduced.

Fig. 2 is a perspective view of the heat dissipating fins 13 and the cooling fan 14 of fig. 1, viewed obliquely from the direction of arrow 200 of fig. 1. The internal structure is shown in a state of being 2 minutes from the axial center of the fan center shaft 25. The cooling fan 14 is a radial fan, and blows air from the fan center axis 25 in the direction of the heat dissipating fins 13.

[ example 2]

Fig. 3 is a sectional view showing a second embodiment. In embodiment 1, the heat dissipating fins 13 are installed substantially parallel to the rotation center axis 100. However, as shown in fig. 3, the heat dissipating fins 13A may be arranged obliquely so that the radius increases as they are spaced apart from the rotation shaft 24 in the axial direction. That is, the closer to the opening 300, the greater the distance between the heat dissipating fins 13A and the rotation center axis 100. Thus, the heat dissipating fins 13A serve as flow path guide members for the air discharged from the cooling fan 14, so that the air can flow easily and the heat dissipating efficiency of the heat dissipating fins 13A can be improved.

In the structure of fig. 3, the stator frame 11A to which the heat dissipating fins 13A are attached has a tapered shape with a large diameter on the opening 300 side. Therefore, the cooling fan 14, which is a radial fan, guides the air flow blown to the inner wall of the stator frame 11A to the opening 500 side of the stator frame 11A, and the structure is capable of effective ventilation.

[ example 3]

Fig. 4 shows a frame structure according to a third embodiment. Fig. 4 is a view corresponding to the state in which the rotation center shaft 100 of fig. 1 is viewed from the arrow 200 side, and shows a part of the stator frame 11 and the heat dissipating fins 13.

As shown in fig. 4, the heat dissipating fins may be heat dissipating fins 13B formed integrally with the stator frame 11B. For example, the heat dissipating fins 13B are integrally cast as a part of the stator frame 11B, and the stator frame 11B and the heat dissipating fins 13B are formed of cast iron together. Thereby, the thermal resistance between the stator frame 11B and the heat dissipating fins 13B becomes small, and the cooling performance can be improved.

In fig. 4, the heat dissipating fins 13B are arranged vertically upward and in parallel, but may be formed so as to be radially formed toward the rotation center and so as to have narrower fin intervals toward the inner diameter, or may be formed so as to have larger fin intervals toward the inner diameter. The number of fins is 9 fins provided at equal intervals, but the number of fins is not limited and may be provided at unequal intervals. In fig. 4, 9 fins are provided at 1 position, but any number may be provided on the entire inner periphery of the stator frame 11.

[ example 4]

Fig. 5 shows a frame structure of a fourth embodiment. In embodiment 3, the stator frame 11B in which the fins are integrally formed is used, but as shown in fig. 5, a structure may be adopted in which the heat dissipation fins 13C in which a plurality of fins are concentrated are attached to the stator frame 11C. This facilitates the production of the stator frame 11C, and reduces the cost. That is, when the stator frame 11C is cast, the structure of the mold is simplified, and the manufacturing is facilitated.

Fig. 6 shows another example of the frame structure. As shown in fig. 6, a stator frame 11D having a flat surface at an inner diameter portion may be used. This enables the mounting of a commonly commercially available heat sink 13D, which further reduces the cost.

Fig. 7 shows another method of providing a flat surface on the inner diameter portion of the frame. As shown in fig. 7, a stator frame 13E having a flat-bottomed groove provided in an inner diameter portion may be used.

In fig. 4 to 7, the number of fins (fins) is 1, but may be 2 or more as shown in fig. 2, and the intervals between the fins may or may not be equal. Further, a plurality of fins may be arranged in the axial direction.

As shown in fig. 5 to 7, in the embodiment in which the heat sink and the heat radiating fins 13 are formed separately from (not integrally formed with) the stator frame 11 and joined thereto, the heat sink and the heat radiating fins 13 may be formed of a material different from that of the stator frame 11. For example, the heat dissipating fins 13 can be made of aluminum or copper. The heat dissipating fins 13 may be formed in a shape that is difficult to mold by integral casting. In order to achieve excellent heat conduction, the heat sink and the heat dissipating fins 13 are preferably in close contact with the stator frame 11. Therefore, the joining surface is preferably formed smoothly. The joining method can be performed by, for example, screwing.

[ example 5]

Fig. 8 shows an application of the external-rotation-type rotating electric machine of the present invention to an elevator hoisting machine

Example 5.

As shown in fig. 8, the external-rotor-type rotating electric machine 1 shown in fig. 1 is provided with: a sheave 802 around which a rope 801 (a cross section of the rope is shown) for an elevator hoisting machine is wound; and a brake 803 that mechanically brakes the rotation. The brake shoe of the brake 803 can be braked by frictional force by sandwiching a part of the rotor frame 9.

According to the present embodiment, since the outer turning-type rotating electrical machine 1 that is reduced in size by improving the cooling performance as described above is used, the elevator hoisting machine can be reduced in weight, and the cost for installation can be reduced.

Description of the reference numerals

1 … … rotating electrical machine; 2 … … rotor core; 3 … … permanent magnet; 4 … … rotor; 6 … … stator core; 7 … … coil; 8 … … stator; 9 … … rotor frame; 10 … … bearing; 11 … … stator frame; 12 … … auxiliary bearing; 24 … … rotating the shaft; 25 … … fan center shaft; 13 … … heat dissipating fins; 14 … … cooling fan; 15 … … cooling air; 100 … … center axis of rotation; a 801 … … cord; 802 … … sheave; 803 … … brake.

Claims

1. An external rotation type rotating electric machine, comprising:

a rotating shaft that rotates around a rotation center axis;

a rotor frame connected with the rotating shaft;

a rotor connected to the rotor frame and rotating around the rotation center axis;

a stator disposed on an inner diameter side of the rotor with a predetermined gap from the rotor;

a stator frame connected with the stator;

the heat dissipation fin is connected with the stator frame and arranged on the inner diameter side of the stator frame; and

a cooling fan connected with the rotating shaft and arranged on the inner diameter side of the radiating fin,

the cooling fan is a radial flow fan which releases air in a radial direction,

the air discharged by the cooling fan from the direction perpendicular to the rotation axis does not contact the rotor and the stator but collides with the inner wall of the stator frame and the heat radiating fins, moves in the direction along the inner wall of the stator frame,

the stator frame and the heat radiating fins are integrally formed.

2. The external rotation type rotating electric machine according to claim 1, wherein:

the heat dissipation fins are disposed so that the distance from the rotation center axis increases as the heat dissipation fins are axially spaced from the rotation axis.

3. The external rotation type rotating electric machine according to claim 1, wherein:

there are also additional heat dissipating fins mounted to the inner diameter portion of the stator frame.

4. The external rotation type rotating electric machine according to claim 1, wherein:

a plurality of radiating fins are integrated to form a radiating fin to be mounted on an inner diameter portion of the stator frame.

5. The external rotation type rotating electric machine according to claim 4, wherein:

and a plane for mounting the radiating fins is arranged on the inner diameter part of the stator frame.

6. The external rotation type rotating electric machine according to claim 5, wherein:

the stator frame is provided with a groove having the flat surface as a bottom surface in an inner diameter portion thereof.

7. The external rotation type rotating electric machine according to claim 1, wherein:

the rope winding device includes a sheave connected to the rotor frame and configured to wind a rope while rotating around the rotation center axis.

8. The external rotation type rotating electric machine according to claim 7, wherein:

a brake is included to brake the rotor frame.

9. The external rotation type rotating electric machine according to claim 1, wherein:

the rotor is formed of a rotor core and permanent magnets arranged on the inner diameter side of the rotor core,

the stator is formed of a stator core disposed on the inner diameter side of the rotor with a predetermined gap therebetween and a coil disposed on the stator core,

the rotating shaft and the stator frame are connected via a bearing.

10. The external rotation type rotating electric machine according to claim 1, wherein:

the stator frame has a substantially cylindrical member surrounding the rotation center axis, and is connected to the rotation shaft via a bearing,

and the cylindrical member is arranged to be offset in the axial direction from the rotary shaft,

the heat dissipating fins are provided on the inner side of the cylindrical member.

11. The external rotation type rotating electric machine according to claim 10, wherein:

a fan center shaft that serves as a rotation center of the cooling fan is attached to the rotation shaft, and the fan center shaft is disposed on an inner diameter side of the cylindrical member.

12. The external rotation type rotating electric machine according to claim 11, wherein:

the cylindrical member has an opening formed by opening one end thereof that is farther from the bearing, and has a tapered structure having a larger diameter at least in part of the opening side.

13. The external rotation type rotating electric machine according to claim 12, wherein:

the heat dissipation fins are arranged on the portion of the cone-shaped structure.

14. The external rotation type rotating electric machine according to claim 13, wherein:

the heat dissipating fins are disposed farther from the cooling fan on a side close to the opening.