JP2000333410A - Rotating electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce noise and windage loss, as well of a machine in the cource of operation by causing one end side of a cylindrical ventilating guide duct to be in a trumpet-like shape from its end part over to the inside. SOLUTION: An suction part 8 of the ventilating guide duct 1 of this rotating electric machine has a trumpet-like shape, and its cross section against the shaft 3 gradually becomes small as it leaves an intake surface 10 toward the inside. Accordingly, securing of a wind quantity necessary for cooling becomes easy, since it tends to take in a large amount of wind against a fan effect generated in the intake part 8 through the rotation of ribs 2. Additionally, the quantity of noise becomes small while the rotating electric machine is operated also, since its windage loss, etc., become hard to be generated in this area. Moreover, the side cross section of the guide duct 1 may be gradually decreased at a constant rate from the intake surface 10 up to suction surface 11. Consequently, reduction in the windage loss of the intake part of the ventilating guide duct becomes feasible and along with superior cooling effect and reduction in operation-time noise also become feasible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ventilation guide duct for use in a rotating electric machine such as a generator, an induction motor, a synchronous motor, etc., for guiding wind passing through a rotating electric machine as a refrigerant. is there.

[0002]

2. Description of the Related Art Normally, in order to efficiently cool a rotating electric machine, a refrigerant is circulated inside the rotating electric machine, but air is generally used as the refrigerant.

A conventional rotary electric machine B using air as a refrigerant will be briefly described with reference to the drawings. FIG. 3 is a schematic side sectional view of the conventional rotary electric machine B, and FIG. 4 is a perspective view of the relationship between the ventilation guide duct 20, the rib 2 and the rotary shaft 3 of the conventional rotary electric machine B viewed from the intake side. And in the figure, 4 is a laminated rotor core, 5 is a secondary conductor, 6 is a secondary conductor short-circuit ring,
2 is a rib and 3 is a rotation axis. The rib 2 is welded to the rotating shaft 3, but the rotating shaft 3 may be a laminated core, and the rib 2 may be formed by extending the laminated core. Further, a ventilation guide duct 20 is provided to improve ventilation for cooling the inside of the rotating electric machine B. Further, a fan 7 for ventilating the inside of the rotating electric machine B is also provided, but since the center axis of the rotation of the fan 7 has the same center axis as the rotating axis 3 of the rotating electric machine B, the rotating shaft 3 When the fan rotates, the fan 7 also rotates in synchronization with the rotation of the fan.

Next, the operation of the rotating electric machine B will be described.
First, when the rotating shaft 3 rotates, the rib 2 rotates accordingly. When the rib 2 rotates, the ventilation guide duct 2
The air inside 0 is agitated. At the same time, the rotation of the rotating shaft 3 causes the fan 7 to start rotating, and the ventilation guide duct 2
A wind is generated toward the zero intake part. In this way, the wind generated by the fan 7 is applied to the intake surface 1 of the ventilation guide duct 20.
From 0, the air passes through the inside of the ventilation guide duct 20 to the exhaust surface 11 while being stirred by the ribs 2, so that this wind becomes a refrigerant and continues to cool the inside of the ventilation guide duct 20, and thus the entire rotating electric machine B. Let it cool.

[0005]

However, if the ventilation guide duct 20 has a shape as shown in FIG. 3, the volume of the ventilation section of the ventilation guide duct 20 is limited to the amount of wind required for cooling the rotating electric machine B. And the wind speed increases near the intake surface 10, so that the pressure loss in this portion increases, that is, it is difficult to flow a sufficient amount of air into the ventilation guide duct 20, It was a problem.

[0006] Further, the ventilation guide duct 2 is also caused by the fan effect inside the ventilation guide duct 20 accompanying the rotation of the rib 2.
This impedes the flow of the wind near the zero intake surface 10 and causes an increase in pressure loss. If the pressure loss in the vicinity of the suction surface 10 is large, a large amount of air flows through the ventilation guide duct 20 in order to counter the increased pressure loss and to secure the air volume required for cooling the rotating electrical machine B. However, if this is done, the noise during the operation of the rotating electrical machine B increases, and the amount of windage loss increases as a large amount of wind is sent in, which is a problem.

Accordingly, the present invention has been made in view of such circumstances, and has as its object to reduce the resistance to the flow of cooling air into the ventilation guide duct of a rotating electric machine, and to reduce windage near the suction portion. It is an object of the present invention to provide a rotating electric machine that has low noise and low windage loss even when operated, by reducing power consumption.

[0008]

According to a first aspect of the present invention, there is provided a rotating electric machine having a cylindrical ventilation guide duct for covering a rib of a rotating shaft. One end side of the cylindrical ventilation guide duct is formed in a trumpet shape from the end to the inside,
It is characterized by.

In the rotating electric machine according to a second aspect of the present invention, in the rotating electric machine according to the first aspect, an end surface of the rib on the intake side of the ventilation guide duct is formed into a tapered shape. Features.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. The embodiment described here is merely an example, and the present invention is not necessarily limited to this embodiment.

Embodiment 1 First, a rotary electric machine A according to the present invention will be described as a first embodiment with reference to the drawings.

Since the rotating electric machine A is made of the same components as the conventional rotating electric machine B, a detailed description of each member will be omitted, but the shape of the ventilation guide duct 1 used in the rotating electric machine A will be omitted. Is different from the ventilation guide duct 20 of the conventional rotary electric machine B.

That is, as shown in FIGS. 1 and 2, the intake section 8 of the ventilation guide duct 1 of the rotary electric machine A in the present embodiment has a so-called trumpet shape. In other words, the cross-sectional area with respect to the rotating shaft 3 is gradually reduced as it proceeds from the intake surface 10 to the inside.

By forming the ventilation guide duct 1 in this manner, a larger amount of wind can be taken in against the fan effect caused by the rotation of the rib 2 generated in the intake section 8, so that the rotation can be increased. It is easy to secure the air volume required for cooling the electric machine A, which is preferable. Further, since a phenomenon such as windage is unlikely to occur in this portion, the noise amount can be reduced while the rotating electric machine A is operating, which is preferable.

In this case, the side cross-sectional shape of the ventilation guide duct 1 has a trumpet shape up to a position within a predetermined distance from the intake surface 10 and then maintains the same inner diameter up to the discharge surface 11. However, the shape is not necessarily limited to this shape, and although not shown, for example, it may be formed so as to gradually decrease at a constant rate from the intake surface 10 to the discharge surface 11.

The shape of the end face 15 of the rib 2 in the intake section 8 of the ventilation guide duct 1 may be flat as in the case of the conventional rotary electric machine B shown in FIG. 4, for example. When it is formed into a tapered shape as shown in FIG. 2, the efficiency of air intake to the ventilation guide duct 1 is further improved, which is very preferable. This is because the intake air that hits the end face 15 of the rib 2 can flow smoothly into the ventilation guide duct 1 without being disturbed by processing the end face 15 into a tapered shape. In addition, since the resistance to the flow of the wind is reduced as described above, the amount of noise generated by the rotating electric machine A can be further reduced.

[0017]

As described above, according to the rotating electric machine according to the first aspect of the present invention, since one end of the cylindrical ventilation guide duct is formed in a trumpet shape from the end to the inside, the ventilation is improved. It is possible to reduce the windage loss at the suction portion of the guide duct, and therefore, it is possible to obtain a rotating electric machine having an excellent cooling effect and low noise during operation.

Further, according to the rotating electric machine according to the second aspect of the present invention, since one end of the rib on the intake side of the ventilation guide duct is formed into a tapered shape, the rib at the suction portion of the ventilation guide duct is further improved. It is possible to reduce the windage loss and to obtain a rotating electric machine having an excellent cooling effect and low noise during operation.

[Brief description of the drawings]

FIG. 1 is a schematic side sectional view of a rotating electric machine according to the present invention.

FIG. 2 is a perspective view of a ventilation guide duct, ribs, and a rotating shaft of the rotating electric machine according to the present invention as viewed from an intake side.

FIG. 3 is a schematic side sectional view of a conventional rotating electric machine.

FIG. 4 is a perspective view of a ventilation guide duct, ribs, and a rotating shaft of a conventional rotating electric machine viewed from an intake side.

[Explanation of symbols]

A rotating electric machine, 1 ventilation guide duct, 2 ribs, 3 rotors, 4 laminated rotor cores, 5 secondary conductors, 6 secondary conductor short-circuit ring, 7 fan, 8 intake section of ventilation guide duct,
10 intake surface of ventilation guide duct, 11 exhaust surface of ventilation guide duct, 15 rib end surface, B rotating electric machine, 20 ventilation guide duct.

Claims (2)

[Claims] 1. A rotating electric machine having a cylindrical ventilation guide duct that covers a rib of a rotating shaft, wherein one end of the cylindrical ventilation guide duct is formed in a trumpet shape from the end to the inside. Characterized by a rotating electric machine. 2. The rotating electric machine according to claim 1, wherein an end surface of the rib on the intake side of the ventilation guide duct is formed into a tapered shape.