JPS58222756A - Venting device for rotary electric machine - Google Patents

Abstract

PURPOSE:To enhance the ventilating efficiency of a cooling blade in a simple structure by employing a vent guide plate which has a hole of diameter smaller than the bore size of the bore side end of the blade and forming the end of the hole in a funnel shape. CONSTITUTION:The relationship between the bore size phiA of the end 7 of a cooling blade 7 and the diameter phiB of the hole end 8' of a vent guide plate 8 is set to phiA<phiB. The hole end 8' of the plate 8 is formed in a funnel shape, projected toward a rotor 6, and the end 7' of the blade 7 is lextended to the position near the size projected from the rotor 6 or inside from the position. Air which is reversely flowed between the end 7' of the blade 7 and the plate 8 is suppressed by the minimum gap size L, thereby improving the ventilating efficiency by the blade 7.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device that makes it possible to improve cooling performance and reduce noise in an open self-ventilation cooling type rotating electrical machine such as a general-purpose induction motor.

In rotating electric machines such as general-purpose induction motors, from small capacity to those with medium lids, open type self-ventilation cooling systems are widely used.

Conventional examples of such induction motors are shown in FIGS. 1 and 2.

In these figures, 1 is a frame, 2 is a stator core,
3 is a stator coil, 4.4' is a bracket, 5.5' is an air hole, 6 is a rotor, 7 is a cooling blade, 8 is a ventilation guide plate, 9
is the shaft, and 10.10' is the bearing. Note that FIG. 1 is a partial side sectional view, and FIG. 2 is a view of the rotor 6 viewed from the direction of the shaft 9.

A stator core 2 is attached to a frame 1, and a coil 3 is wound around the stator core 2.

On the other hand, the rotor 6 has its shaft 9 held in the platen 4, 4' by bearings io, io'.

The cooling vane 7 is provided on the end face of the rotor 6 by casting or the like, and its end 1' faces the end 8' of the circular opening of the ventilation guide plate 8.

Therefore, when the rotor 6 rotates, a ventilation effect is generated by the cooling blades 7, and as shown by the arrow in FIG. By the way, in a rotating electrical machine using such a cooling method, unless a predetermined amount or more of air is circulated, the temperature rise cannot be suppressed to a predetermined value or less.

However, in the above-mentioned conventional rotating electric machine, there are variations in the iron core thickness of the rotor 6 during manufacturing, and variations in the shaft 9
The position of the end γ' of the cooling vane T tends to vary along the direction of the shaft 9 due to variations in the fixing position to the bracket 4 or gaps between the bearing preload springs provided in the bracket 4 (therefore, the position of the end γ' of the cooling blade T tends to vary along the direction of the As shown in Figure 3, cooling vane 1
When determining the size of the gap W between the end 7' of the ventilation guide plate 8 and the opening end 8' of the ventilation guide plate 8, a margin is provided in consideration of the above-mentioned variations (if necessary, this gap W cannot be set small enough.

As a result, as shown in Fig. 3, in the conventional rotating electric machine described above, air backflow due to this gap WK occurs in many places, making it impossible to provide sufficient air volume, making it difficult to suppress temperature rise. The drawback was that it was difficult.

An object of the present invention is to provide a ventilation device for a rotating electric machine that can eliminate the drawbacks of the prior art described above, increase the ventilation efficiency of cooling blades with a simple configuration, obtain a sufficient amount of cooling air, and minimize temperature rise. To achieve this purpose, we provide
The present invention is characterized in that a ventilation guide plate having an opening having a diameter smaller than the inner diameter dimension of the inner diameter end of the cooling blade is used, and the end of the opening is formed into a funnel shape. Four embodiments of a ventilation device for a rotating electric machine will be described.

FIG. 4 shows an embodiment of the present invention, showing the same parts as the conventional example shown in FIG. The embodiment shown in FIG. 4 differs from the conventional example shown in FIG. 3 in that the inner diameter of the end 7' of the cooling vane 7 is φA, When the diameter is φB, in the embodiment shown in Fig. 4, φA × φB
1, whereas in the conventional example shown in Figure 3, φ
A>φB, and in the embodiment shown in FIG. In this example, although φA and φB are used, the bearing 10 When the diameter of is φC, set K so that φA>φC
It is easy to assemble.

Therefore, regarding the embodiment shown in FIG. 4, since the relative shape of the ventilation guide plate 8 with respect to the cooling blade 7 is as described above, the axis between the end γ' of the cooling blade 7 and the ventilation guide plate 8 is When L is the minimum gap dimension between these ends 7' and 8' with respect to the gap dimension W in the direction parallel to the direction, it can be set as W)L.

That is, according to this embodiment, even if W is set to a dimension that provides a margin for variations in the axial dimension that tend to occur at the end portion 7' of the cooling blade 7, the minimum gear tooth dimension lS! :L can be made sufficiently smaller than that.

On the other hand, since the air flowing backward between the end 7' of the cooling blade 7 and the ventilation guide plate 8 is suppressed by the minimum gap size, in the end, according to this embodiment, for the same axial gap size W, Since it is possible to provide a sufficiently small minimum gap size, the ventilation efficiency by the cooling vanes 7 is improved, and a sufficient amount of air is obtained, so that the temperature rise can be kept to a minimum of 1.

Furthermore, according to this embodiment, the distance J between the stator coil 3 and the ventilation guide plate 8 is made larger than the conventional example shown in FIG. Moreover, the cross-sectional area of the flow passage is wide (because of this, the dynamic pressure loss of the circulating air is reduced by 100%, further increasing ventilation efficiency).

Furthermore, in this embodiment, air is sucked in only from the inner diameter side of the cooling blade 1 by the ventilation guide plate 8, so there is no ventilation separation at the end 7', and noise generation is reduced. It becomes easier to make noise.

Next, the fifth section is another embodiment of the present invention, in which the corner on the inner diameter side of the end 7' of the cooling blade 7 is obliquely removed to form a cutout 7'. The end portion 8' of the ventilation guide plate 8 also extends along this notch T.

According to this embodiment, as shown in the enlarged view of FIG.
It is possible to provide a section in which the holes extend parallel to each other, and even if the minimum gap size is the same, the backflow of air in this section is even smaller (from 1), the ventilation efficiency can be further increased. It goes without saying that the effects are expected to be the same as or better than those in the example shown in Figure 4 (Q).
The relationship between dimensions W and L at this time is θ, which is the angle that the notch 7″ makes with respect to the axis 9, and when the angle θ is 45°,
L is 1/V7 of W. In such a rotating electrical machine, the installation state of the air holes 5 relative to the bracket 4 is often symmetrical with respect to the axis 9, and is not uniform. In many cases, it is provided only on the upper side or only on the lower side of the ventilation guide plate 8. Therefore, in such cases, the ventilation guide plate 8 may be provided in a shape other than circular to match the position of the ventilation hole 5. Good too.

FIG. 7 illustrates an embodiment of the present invention in such a case, in which the dimension from the shaft 9 to the end 8' representing the opening of the ventilation guide plate 8 is γ1 above the shaft 9, and γ1 below the shaft 9. Here, γ2 is set, and these n and others are set such that γ1<γ2.

The end 8' of the ventilation guide plate 8 with respect to the notch γ of the cooling blade 7
The longer the length of the parallel part, the less backflow of air will occur in this part, which will help improve efficiency, but on the other hand,
If the end portion 8' is closer to the shaft 9, the resistance to the air trying to be sucked into the cooling blade 7 will also increase.

Therefore, as in the embodiment shown in FIG. 7, if the dimension γ2 of the end portion 8' is made large in the part close to the air hole 5 and made small in other parts to γ1, the resistance to the intake air will not increase much. reflux is sufficiently small (can be
It is possible to sufficiently improve ventilation efficiency and reduce noise.

As explained above, according to the present invention, sufficient ventilation efficiency can be maintained even if there are variations in the axial direction of the end positions of the cooling vanes attached to the end face of the rotor.
Even when applied to a rotating electrical machine such as a cast rotor in which positioning accuracy of cooling blades in the axial direction is difficult to achieve, it is possible to reduce temperature rise and provide a ventilation device for a rotating electrical machine that can easily reduce noise at a low cost.

[Brief explanation of the drawing]

The first factor is a partial side cross-sectional view showing a conventional example of a rotating electric machine using an open self-ventilation cooling system, Fig. 2 is a partial front view looking at the end face of the rotor, and Fig. 3 is a partially enlarged view of Fig. 1. FIG. 4 is a partially enlarged view showing one embodiment of a ventilation device for a rotating electric machine according to the present invention, FIG. 5 is a partially enlarged view showing another embodiment, and FIG.
The factor is a partially enlarged view of FIG. 5, and the seventh factor is the same (an explanatory diagram of another embodiment) 1... Frame, 2... Stator core,
3...Stator coil, 4.4'...Bracket, 5.5'...Air hole, 6...
Rotor, 1... Cooling blade, 1'... End of cooling blade γ, γ... Notch of cooling blade 7,
8... Ventilation guide plate, 8'... End portion representing the opening provided in the ventilation guide plate 8, 9...
・Shaft, io, io'...Bearing block 3 circles 74 figures 5 decoys

Claims (1)

[Scope of Claims] 1. In a rotating electrical machine of a self-ventilation cooling type using a rotor having cooling blades on the end face, a ventilation guide having an opening having a diameter smaller than the inner diameter of the inner diameter end of the cooling blade. By providing a plate and forming the open end of the ventilation guide plate into a funnel shape facing in the direction of the cooling blade, the gap size that exists between the end of the cooling blade and the open end of the ventilation guide plate is A ventilation device for a rotating electric machine, characterized in that it is configured to reduce the amount of air. 2. A ventilation device for a rotating electrical machine according to claim 1, characterized in that the cooling blade is formed with an oblique notch at the inner end thereof.