JP4532964B2 - Double rotor motor - Google Patents

Description

  The present invention relates to cooling of an electric motor, and more particularly to cooling of a double rotor electric motor in which a magnetic pole body, that is, a rotor is arranged opposite to the inside and outside of a stator.

  Electric motors are used in many devices and devices. However, the heat generated inside when the motor starts up increases the temperature of peripheral devices and devices in which the motor is incorporated, and affects the performance. For this reason, a cooling fan is attached to the rotating shaft of the electric motor, and the electric fan is rotated by rotating the electric motor to send air into the electric motor to cool the electric transmitter (for example, refer to Patent Documents 1 and 2). .

On the other hand, many types of electric motors have been developed. Basically, an electric motor is basically composed of a stator fixed to a casing and having a coil, and a rotor disposed inside and supported by a rotating shaft. It is structured. However, in order to improve the rotation efficiency by effectively using the magnetic flux leaking from the stator to the outside, in addition to the rotor arranged inside the stator, the double is arranged with the rotor outside the stator. A rotor-type electric motor has attracted attention (see, for example, Patent Documents 3 and 4).
As shown in FIG. 6, the electric motor includes a stator 51 formed by winding a coil 53 around a yoke 50 fixed to a non-magnetic base 55 supported by a shaft 58 via bearings 59 and 59. And cylindrical magnets 56 and 56 (rotors) fixed to a cup-shaped case 54 fixed to a shaft 58 so that the stator 51 is coaxially arranged with a space therebetween.
JP 2002-58205 A JP 2002-64957 A JP 61-35245 Japanese Patent Laid-Open No. 10-271782

However, if a cooling fan such as that disclosed in Patent Document 1 or 2 is used to cool the double rotor motor, it is necessary to secure a mounting space and the cost increases. The effect of improving the rotation efficiency as a child is offset.
In view of such circumstances, it is an object of the present invention to provide a technique for efficiently cooling a double rotor motor at low cost.

The present invention has been made to solve the above-described problems, and the gist thereof is as follows.
(1) An annular stator core, a stator composed of a plurality of coils wound around the stator core, and an inner side that is supported by the rotating shaft and arranged in an annular shape so as to face the inner side and the outer side of the stator In a double rotor motor in which a rotor having an iron core and an outer iron core is housed in a case,
A plurality of vent holes are provided in each of a position corresponding to a radially inner side of the stator on a surface orthogonal to the rotation axis of the case and a surface parallel to the rotation axis of the case, and a cooling fan is provided. A double rotor electric motor characterized in that the electric motor is cooled without any problems.
(2) A ventilation hole provided at a position corresponding to a radially inner side of the stator on a surface orthogonal to the rotation axis of the case and a ventilation hole provided on a surface parallel to the rotation axis of the case are rotated. The double rotor electric motor according to (1), wherein the double rotor electric motor is arranged with an angle in a rotation direction in a plan view orthogonal to the axis.

  According to the present invention, a vent is formed in each of the position corresponding to the radially inner side from the stator of the surface orthogonal to the rotation axis of the rotor of the double rotor motor case and the surface parallel to the rotation axis of the rotor. With the rotation of the rotor, a vent hole provided in a surface perpendicular to the rotation axis of the case rotor and a passage provided in a surface parallel to the rotation axis of the case rotor are provided. An air flow passing through the upper surface or the lower surface of the stator is generated between the air holes and the stator coil can be efficiently cooled.

  Further, a vent hole provided at a position corresponding to a radially inner side of the stator on a surface orthogonal to the rotation axis of the rotor of the case, and a vent hole provided on a surface parallel to the rotation axis of the case, When arranged in an angle with the rotation direction in a plan view from a direction orthogonal to the rotation axis, the air flow between the two air holes flows so as to cross the annular stator in the circumferential direction. Efficiency becomes even more efficient. Moreover, it is desirable to prevent the inflow of dust into the electric motor by installing a filter in the vent hole.

  The double rotor electric motor of the present invention can cool the double rotor electric motor only by providing a vent hole at an appropriate position of the case, and it is not necessary to provide a cooling fan. Or efficient cooling without cost.

  FIG. 1 is a perspective view including a partially cut section of the double rotor motor of the present invention. 2 and 3 are a partial longitudinal sectional view and a partial transverse sectional view showing the configuration of the double rotor motor of FIG. 1, and the positions of the cross sections are shown in FIG. 2 and FIG. 3 in relation to each other. ing.

2A is a partial vertical cross-sectional view as viewed in OP or OQ of FIG. 3, FIG. 2B is a partial vertical cross-sectional view as viewed in OR of FIG. 3, and FIG. (D) is the OT view partial longitudinal cross-sectional view of FIG. 3A is a partial cross-sectional view taken along the line AA ′ of FIG. 2, FIG. 3B is a partial cross-sectional view taken along the line BB ′ of FIG. 2, and FIG. C 'partial cross-sectional view, (d) is a DD' partial cross-sectional view of FIG.
In the following description, the direction orthogonal to the rotation axis of the rotor is defined as the top and bottom, and the direction parallel to this is defined as the side.

In FIG. 1, the double rotor motor 1 is configured such that a stator 2 and a rotor 6 are housed in a case 11 including an upper case 12 and a lower case 14 in which side portions 15 and a lower portion 16 are integrally formed. Has been.
First, the stator 2 is an annular iron core that is disposed outside the rotating shaft 5 and formed in an annular shape, and has a plurality of slots 22 for storing coils that are provided at equal intervals in the circumferential direction. 3 and a coil 4 wound so as to cross the iron core in the radial direction for each slot.
The stator 2 is fixed to the upper case 12 as will be described later.

On the other hand, the rotor is annularly opposed to the stator 2 on the rotor case 9 supported by the rotating shaft 5 in the radial direction inside and outside of the stator 2 with a radial distance therebetween. The plurality of inner cores 7 and the outer cores 8 are arranged and embedded with a plurality of permanent magnets 10. The inner iron core may be referred to as an inner rotor and the outer iron core may be referred to as an inner rotor.
The rotating shaft 5 of the rotor 6 is connected to the upper case 12 and the lower case 14 of the case via a bearing 19.

  Further, on the lower part of the upper case, protrusions 13 having a width narrower than that of the teeth 21 of the stator are protruded downward at several positions corresponding to the teeth 21 of the stator 2, and the protrusions 13 are fixed. At the position of the core around which the coil of the child is not wound, it is connected to the stator by, for example, a bolt (not shown), and the stator is fixed to the case.

  The upper case 12 of the case 11 is connected by a bolt (not shown) or the like at the upper end of the side portion of the lower case 14 to form a double rotor motor.

  The upper part of the upper case 12 of the case 11, that is, the surface orthogonal to the rotation axis of the case, has a plurality of holes penetrating in and out of the case at positions corresponding to the radially inner side of the stator 2, that is, the rotation axis side. (Ventilation holes) 17 are provided, and a plurality of holes (ventilation holes) 18 penetrating into the inside and outside of the case are also provided on the side portion 15 of the lower case, that is, the surface (side portion) parallel to the rotation axis of the case. Is provided. The airflow in these cases can be continued by the air flow from these holes, and the double rotor motor can be cooled.

As described above, the double rotor motor has iron cores (rotors) 7 and 8 on the inner and outer sides in the radial direction of the stator, and the inner iron core (rotor) and the outer iron core (rotor). Between the two cores (rotor) when the rotor rotates, there is a difference in the circumferential speed.
Due to this difference in peripheral speed, a difference in flow velocity also occurs in the flow of airflow generated along with the rotation of the rotor, that is, the accompanying flow, resulting in a difference in atmospheric pressure. In other words, by providing vent holes on the high-pressure side and the low-pressure side, it is possible to maintain a difference in atmospheric pressure and continuously generate an airflow from the high-pressure side to the low-pressure side. The inside of the child electric motor can be cooled.

  That is, as shown in FIGS. 2A to 2D, when the inner and outer iron cores (rotors) are connected to the same shaft, the inner and outer iron cores (rotors) have the same rotational speed. For this reason, as described above, a peripheral speed difference inevitably exists, and an air current flows. Accordingly, as described above, vent holes that communicate inward and outward are provided at the corresponding positions on the radially inner side and the outer side of the stator of the double rotor motor, for example, the upper surface of the upper case 12 and the side portion 15 of the lower case 14. Then, the flow of the air via the air passage 20 above the stator coil is continuously formed from the upper surface of the upper case to the side of the lower case, and the inside of the case can be cooled.

In addition, a vent hole 17 provided at a position corresponding to a radially inner side of the stator on a surface orthogonal to the rotation axis of the case, and a vent hole 18 provided on a surface (side portion) parallel to the rotation axis of the case. May be arranged so that the straight lines connecting the rotation axis and these air holes overlap in a plan view orthogonal to the rotation axis, that is, arranged on the same straight line. As can be seen from c) and FIGS. 3 (a) and 3 (d), it is preferable that the straight line connecting the rotation shaft and each of the vent holes is arranged to have an angle in the rotation direction.
When arranged in this way, the flow of air flows so as to cross the annular stator in the circumferential direction as compared with the case where both vent holes are arranged on the same straight line. Is more efficient.

In this example, the upper case 12 is provided as a vent hole at a position corresponding to the radially inner side from the stator. However, a vent hole penetrating the bottom 16 of the lower case 14 may be provided, or the upper case 12 may be provided. It may be provided on both the upper surface of the lower case 14 and the bottom 16 of the lower case 14.
Further, the shape and number of the vent holes provided in the case may be appropriately selected in consideration of the cooling state.

4 and 5 show a double structure in which the inner and outer magnetic pole bodies (rotors) of the stator are provided in two rotor cases 9 and 9 ′ that are coaxially supported by the rotation shaft 5. FIGS. 2 and 3 are partial cross-sectional views showing examples of the rotor motor in association with each other. However, even in this case, a difference in peripheral speed often occurs between the inner and outer rotors. The same cooling effect can be obtained by providing the vent holes as in the example.
4 and 5 are the same as those described in FIGS. 2 and 3, except that the rotor cases 9 and 9 ′ are coaxially supported by the rotating shaft 5 and provided with an iron core (rotor). Since it is the same as that of a heavy rotor motor, the overlapping description is omitted.

In the double rotor type electric motor configured as shown in FIGS. 1 to 3, the stator has 24 slots and is fixed to the case at a portion where no coil is wound.
The rotor has 8 poles both inside and outside. Four vents are provided on two surfaces (upper and lower) orthogonal to the rotation axis of the case, and 12 vent holes are provided at equal intervals around the side of the case.
When rotated at 3000 rpm for 5 minutes, the average temperature of the coil decreased by about 10 ° C. as compared to the case without air holes.

1 is a perspective view including a partially cutaway cross section of a double rotor motor according to an embodiment of the present invention. FIG. 4 is a partial longitudinal sectional view showing a configuration of the double rotor motor of FIG. 1, (a) is a partial longitudinal sectional view of OP or OQ in FIG. 3, (b) is a partial longitudinal sectional view of FIG. FIG. 3C shows a partial vertical cross section viewed from the OS in FIG. 3, and FIG. 3D shows a partial vertical cross section viewed from the OT in FIG. 3. 2 is a partial plan cross-sectional view showing the configuration of the double rotor motor of FIG. 1, (a) is a partial cross-sectional view taken along line AA ′ of FIG. 2, and (b) is a view taken along line BB ′ of FIG. (C) is a partial cross section taken along line CC ′ of FIG. 2, and (d) is a partial cross section taken along line DD ′ of FIG. FIG. 6 is a partial cross-sectional view illustrating a configuration of a double rotor motor according to another embodiment of the present invention, in which (a) is a vertical cross-sectional view taken along OP or OQ in FIG. 5, and (b) is a view taken from OS in FIG. A longitudinal section is shown respectively. It is a fragmentary sectional view which shows the structure of the double rotor electric motor of the other Example of this invention, (a) is AA 'view partial cross section of FIG. 4, (b) is D- of FIG. D 'each partial cross section is shown. It is a figure which shows the structure of the conventional double rotor motor coil, (a) is a cross-sectional view, (b) is a longitudinal cross-sectional view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Double rotor motor 2 ... Stator 3 ... Stator iron core 4 ... Coil 5 ... Rotating shaft 6 ... Rotor 7 ... Inner iron core (inner rotor)
8 ... Outer iron core (outer rotor)
9, 9 '... Rotor case 10 ... Permanent magnet 11 ... Case 12 ... Upper case 13 ... Projection 14 ... Lower case 15 ... Side 16 ... Bottom 17 ... Upper vent 18 ... Side vent 19 ... Bearing 20 ... Ventilation Path 21 ... Teeth 22 ... Slot 50 ... Yoke 51 ... Stator 52 ... Magnet structure 53 ... Coil 54 ... Cup-shaped case 55 ... Nonmagnetic base 56 ... Cylindrical magnet 58 ... Shaft 59 ... Bearing

Claims (2)

An annular stator core, a stator composed of a plurality of coils wound around the stator core, and an inner core and an outer side that are supported by a rotating shaft and arranged annularly so as to face the inner side and the outer side of the stator In a double rotor motor in which a rotor having an iron core is housed in a case,
A plurality of ventilation holes are provided in each of a position corresponding to a radially inner side of the stator on a surface orthogonal to the rotation axis of the case and a surface parallel to the rotation axis of the case, and a cooling fan is provided. A double rotor electric motor characterized in that the electric motor is cooled without any problems.   A vent hole provided at a position corresponding to a radially inner side of the stator on a surface orthogonal to the rotation axis of the case, and a vent hole provided on a surface parallel to the rotation axis of the case are orthogonal to the rotation axis. The double rotor electric motor according to claim 1, wherein the double rotor electric motor is arranged with an angle in a rotation direction in a plan view.

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