JP3834775B2 - Cooling fan for rotating electrical machine and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cooling fan for a rotating electrical machine for cooling the inside of the rotating electrical machine and a method for manufacturing the same.
[0002]
[Prior art]
A conventional rotating electrical machine having a cooling fan will be described with reference to FIGS.
FIG. 3 is a cross-sectional view of a conventional rotating electrical machine equipped with a cooling fan. 1 is a rotating machine frame, 2 is a stator fitted to the rotating machine frame 1, and 3 is provided on both sides of the rotating machine frame 1. A bearing 4 is a shaft supported by the bearing 3, 5 is a rotor fitted to the shaft 4 through a gap with the stator 2, and 6 is a cooling fan fitted to the shaft 4.
[0003]
In the rotating electrical machine having such a configuration, the cooling fan 6 sucks the cooling air W from one side of the rotary shaft, in the drawing, from the right side, cools the rotor 5 and the stator 2, and exhausts from the other side of the rotary shaft, in the drawing, from the left side. It has a cooling structure. For example, Patent Document 1 discloses an annular hollow blade.
[0004]
4A and 4B are detailed views of a conventional cooling fan. FIG. 4A is a side view and FIG. 4B is a plan view. The cooling fan is composed of a main plate 7, a blade 8 and a sub plate 9. The blade 8 is inserted into a round steel pipe having a predetermined diameter cut into a predetermined width, one of the shaping molds is inserted, and then the round steel pipe is pressed by a press machine provided on the other side of the shaping mold to obtain a desired hollow shape. Make feathers.
[0005]
[Patent Document 1]
JP-A-59-212137 [0006]
[Problems to be solved by the invention]
The rotary electric machine as described above is often combined with a diesel engine or a gas engine. It is known that these internal combustion motors generally generate torsional vibration when converting the reciprocating motion of the piston into the rotational motion. If the blades of the conventional cooling fan resonate with the torsional vibration of the engine, there is a possibility that the blades may break due to insufficient strength.
[0007]
The present invention has been made in view of the above circumstances, and its problem is to secure the strength in the torsional direction by making the blade cross section of the cooling fan annular and arc shape or blade shape, and at high efficiency and low noise. It is providing the cooling fan for rotary electric machines, and its manufacturing method.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in claim 1 is a cooling fan for a rotating electrical machine for cooling an in-machine of a rotating electrical machine, wherein the cooling fan has an annular blade cross-sectional shape and a hollow inside. The blade shape is characterized in that the outer peripheral surface and the inner peripheral surface are concentric circular arcs.
[0009]
According to the first aspect of the present invention, the blade attachment angle θ is larger than that of the conventional blade, so that the sectional modulus in the torsional direction is large, and sufficient strength against the torsional vibration of the prime mover can be obtained. Further, it is possible to arbitrarily determine the inlet angle and the outlet angle of the blade by the arcuate shape, it is possible to reduce the noise with improvement in fan efficiency.
[0010]
The invention of a method for manufacturing a cooling fan for a rotating electrical machine according to claim 2 is the cooling fan for a rotating electrical machine for cooling the interior of the rotating electrical machine, wherein the cooling fan is made of steel, and the fan blade is a hollow pipe. placed between the male die and the female die for molding, after inserting the core into the hollow pipe, molded into the blade shape by applying pressure to the mold, the blade shape cross section with an annular It is characterized in that a hollow is formed inside and the curved surfaces of the outer peripheral surface and the inner peripheral surface are formed in a concentric circular arc shape.
According to the second aspect of the present invention, there is no need for a welding operation, and the blade can be easily manufactured only by a pressing operation, and an inexpensive cooling fan can be provided with a short manufacturing time.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
Figure 1 is a block diagram of a rotary electric machine cooling fan of the first embodiment forms state of the present invention, FIG. (A) is a side view, and FIG. (B) is a front view. Note that the same components of the cooling fan of the rotating electrical machine of this embodiment as those of the conventional rotating electrical machine of FIG.
[0012]
As shown in FIG. 1, the cooling fan of this embodiment is a centrifugal cooling fan, and a main plate 7, a blade 8, and a sub-plate 9 are integrally formed, and the blade 8 has an annular and arcuate cross-sectional shape. Is formed. The number of blades 8 can be arbitrarily set.
[0013]
As described above, the blade 8 having an annular cross-sectional shape and an arc shape has a larger blade attachment angle θ than the conventional blade, and therefore has a larger section coefficient in the torsional direction, and the cooling fan in the torsional direction. The natural frequency can be increased. As a result, it is possible to sufficiently separate the torsional vibration frequency of the prime mover and the natural frequency of the cooling fan, such as a diesel engine or a gas engine, and the possibility of damage due to resonance becomes very small. Further, by making the shape arc, it is possible to arbitrarily determine the inlet angle and the outlet angle of the blade, and it is possible to improve fan efficiency and reduce noise.
[0014]
Figure 2 is a view for explaining the manufacturing method of the blade of the second embodiment forms state of the present invention, FIG. (A) is a side view of arranging the pipes on the female mold, FIG. (B) is male It is the side view which applied the predetermined pressure to the metal mold | die and press-molded the pipe in the predetermined shape.
[0015]
In the figure, the blade of the present embodiment has a standard pipe 10 that is commercially available, for example, a general structural steel pipe disposed on a female mold 12 as shown in FIG. The pipe 10 is press-molded by applying a predetermined pressure to form a blade having a predetermined shape.
[0016]
In the present embodiment, as described above, the pipe is press-molded to form a blade having a predetermined shape, so that there is no need for welding work as in the prior art, and the blade can be easily manufactured by only the press work. It can provide an inexpensive cooling fan with short production time.
[0017]
【The invention's effect】
As described above, according to the present invention, the blade cross-sectional shape is annular, a hollow is formed inside the annular shape to form a thickness in the cooling fan, and the curved surfaces of the outer peripheral surface and the inner peripheral surface are concentric circular arcs. By adopting the shape, it is possible to secure a sufficient strength against torsional vibration of the engine and to obtain a cooling fan with high efficiency and low noise.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a cooling fan for a rotating electrical machine according to a first embodiment of the present invention, where FIG. 1 (a) is a side view and FIG. 1 (b) is a front view.
FIGS. 2A and 2B are diagrams for explaining a blade manufacturing method according to a second embodiment of the present invention, in which FIG. 2A is a side view in which a pipe is arranged on a female mold, and FIG. The side view which applied the predetermined pressure to the metal mold | die and press-molded the pipe in the predetermined shape.
FIG. 3 is a cross-sectional view of a rotating electric machine equipped with a conventional cooling fan.
4A and 4B are configuration diagrams of a conventional cooling fan, where FIG. 4A is a side view and FIG. 4B is a plan view.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Frame of rotary electric machine, 2 ... Stator, 3 ... Bearing, 4 ... Shaft, 5 ... Rotor, 6 ... Cooling fan, 7 ... Main plate, 8 ... Blade, 9 ... Sub-plate, 10 ... Pipe , 11 ... Male Mold, 12 ... female mold , 14 ... core.

Claims (2)

  In a cooling fan for a rotating electrical machine for cooling the inside of a rotating electrical machine, the cooling fan has an annular cross-sectional shape with a hollow inside, and the blade shape is an arc shape in which the curved surfaces of the outer peripheral surface and the inner peripheral surface are concentric A cooling fan for rotating electrical machines.   In a rotating electric machine cooling fan for cooling an in-machine of a rotating electric machine, the cooling fan is made of steel, and the fan blade has a hollow pipe installed between a male mold and a female mold for molding, and the hollow After inserting the core into the pipe, pressurize the mold and mold it into a blade shape. The blade shape is annular in cross section and hollow inside, and the curved surfaces of the outer and inner peripheral surfaces are concentric. A method of manufacturing a cooling fan for a rotating electrical machine, wherein the cooling fan is molded into an arc shape.

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