JP2571289Y2 - Cooling structure of outer rotor type high speed rotating electric machine - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a cooling structure in an outer rotor type high speed rotating electric machine such as an outer rotor type spindle motor.

[0002]

2. Description of the Related Art FIG. 2 is a sectional side view of a conventional example of an outer rotor type spindle motor in which a rotor is arranged outside a spindle motor and rotates, and its outline will be described with reference to FIG. There is an iron core 2 fixed to the outer periphery of the free end of the fixed shaft 1 and a stator 4 having a plurality of coils 3 inserted into grooves of the iron core 2. A plurality of coils 4 surround the outer periphery of the stator 4. A free end of a rotor 6 having a plurality of magnets 5 extends outward beyond the coil 3 in the axial direction, and has the same axis as the fixed shaft 1, and is rotated on an axially outward extension of the fixed shaft 1. A free end spindle 6 '. The rotor 6 is housed in a casing 9 which is arranged outside and has an end flange 7 on the free end spindle 6 'side and a bearing flange 8 on the opposite proximal end spindle 6'a side, A support flange 10 for fixing the fixed shaft 1 is provided adjacent to the bearing flange 8 outside in the axial direction. Since the rotor 6 rotates at a high speed of, for example, tens of thousands of RPMs, in this conventional example, a plurality of air bearings 11 are arranged in a gap between the rotor 6 and the casing 9 as shown in FIG. , High-pressure air is jetted out to smoothly support the rotor 6.

On the other hand, the cooling structure of this outer rotor type spindle motor is such that two long holes 1a and 1b are formed in the fixed shaft 1 near the free end of the fixed shaft 1 in the axial direction as shown in FIG. The cooling water which is installed so as to be communicated with the provided communication chamber 1c and flows in from the cooling water inlet 10a provided in the support flange 10 on the bearing side has a long hole 1a,
The fluid circulates from an outlet 10b provided in the support flange 10 to a heat exchanger, a pump and the like via an external pipe (not shown) through the communication chamber 1c and the elongated hole 1b at the end of the elongated hole 1a.

[0004]

However, since the outer rotor spindle motor is rotated at a high speed,
Although the air flow as the air bearing is sufficient for the function as the bearing, it is not sufficient for the cooling effect, and the above-mentioned flow path through which the cooling water circulates is limited to the inside of the fixed shaft 1. Therefore, the stator 4 has heat,
In many cases, the temperature of the coil rises sharply and burns out. Therefore, improvement of the cooling efficiency of the cooling structure has been strongly desired.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a fixed shaft, an iron core fixed to the outer periphery of a free end of the fixed shaft, and a plurality of cores inserted into grooves of the iron core. And a secondary electric member surrounding the outer periphery of the stator, one end of which is extended beyond the end of the secondary electric member in the axial direction. A rotor serving as a rotating shaft coaxial with the rotor, a free end of the rotor having an end flange at an end on the spindle side, and a bearing flange at a base end spindle side opposite thereto having the stator and the rotor. , A supporting flange for supporting and fixing the fixed shaft adjacent to the bearing flange in the axial direction, and disposed between the rotor and the casing to support the rotor. Outer rotor type high speed rotating electric machine with air bearing The cooling structure for cooling the spindle motor is opened inside the fixed shaft through a cooling air inlet provided in the support flange, and introduces cooling air from a base end to a free end of the fixed shaft. An axial inflow path, and an outflow path for introducing the cooling air to an air outlet provided in the support flange through the space between the fixed shaft and the proximal end spindle of the rotor, and compressed by a compressor. The cooled cooling air is introduced from the cooling air inlet, passes through the inflow passage, passes through the surface of the stator core and the end of the coil, and flows out of the air outlet through the outflow passage. An object of the present invention is to provide a cooling structure in an outer rotor type high-speed rotating electric machine. Preferably, the outflow path between the fixed shaft and the spindle at the base end of the rotor has a tapered hole so that air can easily flow into the air outlet.

[0006]

According to the present invention, a cooling air passage is provided for returning the compressed cooling air introduced into the hollow fixed shaft along the gap between the stator and the rotor. Cooling is performed from the inside to the outer periphery, and the inner periphery of the rotor is also cooled, so that the overall cooling efficiency can be improved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a cooling structure of an outer rotor type spindle motor will be described below with reference to FIG. An outer rotor type spindle motor using an air bearing is shown in FIG. 1. Except for the cooling structure, the outer rotor type spindle motor is the same as the conventional outer rotor type spindle motor shown in FIG. 2, and the same components as those shown in FIG. In the following description, only different points will be described to avoid duplication.

The cooling structure newly provided according to the present invention will be described. The cooling structure for cooling the outer rotor type spindle motor in the present invention is opened inside the fixed shaft 1 through the cooling air inlet 10c provided in the support flange 10, and the cooling air is free from the base end of the fixed shaft 1. An axial inflow passage 12 for introducing the cooling air to the end;
a between the fixed shaft 1 and the fixed shaft 1, and an outflow passage 13 introduced into an air outlet 10 d provided in the support flange 10, and the cooling air compressed by the compressor is supplied to the cooling air inlet 10.
c, passes through the inflow path 12, passes through the outer peripheral surface of the iron core 2 of the stator 4 and the end of the coil 3, and flows out of the air outlet 10 d through the outflow path 13. During this time, the inner circumference of the rotor 6 is also cooled. The outflow passage 13 between the fixed shaft 1 and the spindle 6′a of the base end of the rotor 6 is provided.
Is desirably a tapered hole 13 '(shown by a dotted line in FIG. 1) so that air can easily flow into the air outlet 10d.
In the above-described embodiment, an example of a synchronous machine having a permanent magnet in the rotor has been described. However, instead of the permanent magnet, a secondary-side electric component of an induction machine including an iron core, a bar, and an end ring is used. You can also.

[0009]

The cooling structure in the outer rotor type high-speed rotating electric machine according to the present invention has the following effects because it is configured as described above. Since the cooling air is supplied to the inside of the fixed shaft and the outer periphery of the stator, the stator can sufficiently cool the inside of the fixed shaft, each part of the core and the coil, and Since the inner circumference is also cooled, the cooling efficiency of the rotating electric machine of the present invention is greatly improved. Since the compressed air used for the air bearing is used as the cooling medium, the cooling structure can be simplified. When the outflow path is a tapered hole, the cooling air is smoothly circulated.

[Brief description of the drawings]

FIG. 1 is a partially cut-away side view showing an embodiment of a cooling structure of an outer rotor type spindle motor according to the present invention.

FIG. 2 is a partial cutaway side view of a conventional outer rotor type spindle motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixed shaft 2 Iron core 3 Coil 4 Stator 5 Magnet 6 Rotor 6 'Free end spindle 6'a Base end spindle 7 End flange 8 Bearing flange 9 Casing 10 Support flange 10c Cooling air inlet 10d Air outlet 11 Air bearing 12 Inflow path 13 Outflow path 13 'Taper hole

Claims (2)

(57) [Scope of request for utility model registration] 1. A stator having a fixed shaft, an iron core fixed to an outer periphery of a free end of the fixed shaft, and a plurality of coils inserted into grooves of the iron core, and a stator surrounding the outer periphery of the stator. A rotor having a secondary-side electric member, one end of which extends axially beyond the end of the secondary-side electric member and serves as a rotating shaft coaxial with the fixed shaft; and a free end of the rotor. An end flange at the end on the side of the spindle, a casing having a bearing flange on the opposite end of the spindle, and accommodating the stator and the rotor inside, and an axially outer side of the bearing flange. In an outer rotor type high-speed rotating electric machine having a support flange for supporting and fixing the fixed shaft adjacent to the rotor and an air bearing disposed between the rotor and the casing to support the rotor, the spindle motor is Cooling structure for cooling An axial inflow path which is opened inside the fixed shaft through a cooling air inlet provided in the support flange and introduces cooling air from a base end to a free end of the fixed shaft; and An outlet which passes between a shaft and a base end spindle of the rotor and is introduced into an air outlet provided in the support flange, wherein cooling air compressed by a compressor is introduced from the cooling air inlet, and Cooling in the outer rotor type high speed rotating electric machine, wherein the cooling air flows out of the air outlet through the inflow passage, through the surface of the iron core of the stator and the end of the coil, through the outflow passage. Construction. 2. The outer rotor according to claim 1, wherein the outflow path between the fixed shaft and a base end spindle of the rotor has a tapered hole so that air can easily flow into the air outlet. Cooling structure in a high-speed rotary electric machine.