JPS6321162Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention relates to a shaft fixing device for an outer rotor type electric motor.

[Prior art and its problems]

An outside rotor type motor has a stator supported by a fixed shaft on the inside, and a rotor on the outside.A load such as a fan is attached to the outer circumference of the rotor of the motor. The fixed shaft must be connected and fixed to the motor mounting leg. It is desirable that this type of shaft fixing device be able to be mass-produced with as few parts as possible, and be highly reliable and inexpensive.

FIG. 1 is a partially sectional front view of a conventional outer rotor type electric motor. In the figure, 1 is an outer rotor, 2 is a stator, a fan 3 is attached to the outer periphery of the outer rotor 1, the stator 2 is supported by a fixed shaft 4 fitted on the inside, and The rotor 1 is supported by a fixed shaft 4 via a bearing 5.
The fixed shaft 4 is fixed to a motor installation leg 7 via a motor installation mounting plate 6.

In this structure, the motor installation leg mounting plate 6 is made of cast iron or aluminum molded product, and it is attached to the fixed shaft 4 by machining and fitting the boss part 61 and the fixed shaft 4 with high precision, using a key, stop spring, or I tried to fix it with screws etc. This resulted in the disadvantage that the manufacturing process was diverse and expensive.

[Purpose of invention]

The object of the present invention is to eliminate the above-mentioned drawbacks, and to provide a shaft fixing device for an outer rotor type motor that is simple in structure, can be mass-produced, is inexpensive, and has high reliability.

[Key points of the idea]

In order to achieve the above-mentioned purpose, this invention has four fixed shafts.
The outer rotor 1 is rotatably supported by the fixed shaft 4 via bearings 5 surrounding the stator 2 and provided at both ends thereof. In an outer rotor type electric motor, two steel discs are formed by extruding the central part with a press, providing a shaft hole in the center of the protruding ends, and joining the protruding ends so that they face each other outward to form the boss 81. 8, and electric motor installation legs 7 attached to the outer periphery of the steel disc 8.
The shaft hole of the steel disc 8 is fitted into the shaft end of the fixed shaft 4, and the boss 81 is screwed into the set screw 10.
It is designed to be fixed to a fixed shaft 4.

[Example of idea]

Next, embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a longitudinal sectional view of a shaft fixing device for an outer rotor type electric motor according to an embodiment of the present invention, and FIG. 3 is a side view thereof. Components designated by the same reference numerals as in FIG. 1 are the same parts. In order to form the boss 81, two steel discs 8 whose central portions are pressed out and a shaft hole is provided at the center of their protruding ends are made so that the protruding ends of the central portions face outward from each other. At its outer periphery, the motor installation legs 7 are inserted, and the bolts 9 are inserted.
The boss 81 is connected to the motor installation leg 7 by a screw.

Then, this boss 81 is fitted into the shaft end of the fixed shaft 4, and the boss 81 is fixed to the fixed shaft by a set screw 10 and a stop ring 11.

FIG. 4 is a vertical elevation view of a shaft fixing device for an outer rotor type electric motor according to a modified example of the present invention. The center part is pressed out and protruded, and a small disc 12 smaller than this disc 8 and pressed in the same way is placed on a steel disc 8 with a shaft hole in the center of the protrusion, with the protrusion facing outward. A boss 81 is formed by joining by welding or the like, and this boss 81 is fitted onto the fixed shaft 4 and fixed to the fixed shaft 4 with a set screw 10 and a stop ring 11. A motor is installed on the outer periphery of the disk 8. The legs 7 are connected by bolts 9.

Originally, the load applied to the disks 8, 12, the installation legs 7, etc. by the moment load due to the weight of the electric motor or the axial runout of the fixed shaft 4 due to vibrations is greater at the center portion, but according to the embodiment described above, the load at the center portion is larger. It's not just a leg, it's a disk, and it's especially strong because it's made up of two pieces. Furthermore, since the center portions of the disks 8 and 12 are shaped like truncated cones facing outward, they are even stronger. On the other hand, since the fitting portion between the fixed shaft 4 and the shaft hole can secure a long distance in the axial direction, stress can be reduced even when the fixed shaft is used. Even if the plate thickness of the coupling disk is somewhat thin, the surface pressure of the fitting portion is reduced and the fitting precision can be made rougher than in the past. In other words, the fixed shaft 4 may be roughly machined and the shaft hole may be pressed out.

[Effect of idea]

As described above, according to the present invention, the fixed shaft of the electric motor is fitted into the shaft hole of the two disks whose central portions have been pushed out, and the disks are fixed to the fixed shafts with set screws, so that the installation members can be easily installed. Since it is a press process that does not involve cutting, it has the effect of improving productivity and reducing costs. In addition, although it is a steel plate press, the strength of both the fixed shaft and the disk is improved, and the fixing means is simplified.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional front view of a conventional outer rotor type electric motor, FIG. 2 is a longitudinal sectional view of a shaft fixing device for an outer rotor type electric motor according to an embodiment of the present invention, and FIG.
The figure is a side view thereof, and FIG. 4 is a longitudinal sectional view of a shaft fixing device for an outer rotor type electric motor according to a modified example of the present invention. 1... Outer rotor, 2... Stator, 4... Fixed shaft, 5... Bearing, 7... Legs for installing motor, 8...
Disc, 9... Bolt, 10... Set screw, 12...
...Small disc, 81...Boss.

Claims (1)

[Scope of utility model registration request] A stator 2 to which a fixed shaft 4 is fitted, and an outer rotor 1 rotatably supported by the fixed shaft 4 via bearings 5 surrounding the stator 2 and provided at both ends thereof. In the outer rotor type electric motor, two steel plates are formed by extruding the center part with a press, providing a shaft hole in the center of the protruding end, and joining the two steel plates so that the protruding ends face each other outward to form the boss 81. Disc 8
and a motor installation leg 7 attached to the outer periphery of the steel disc 8, and the shaft hole of the steel disc 8 is fitted into the shaft end of the fixed shaft 4, and the boss 81 is fixed with a set screw 10. A shaft fixing device for an outer rotor type electric motor, characterized in that it is fixed to a fixed shaft 4.