JPS5916855B2 - Manufacturing method of rotating shaft for completely hermetic electric compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a rotating shaft used in a small hermetic electric compressor used in an electric refrigerator or the like.

A conventional compressor will be explained with reference to FIGS. 1 and 2.

The compressor main body 2 is attached to a coil spring or the like inside the airtight container 1, 9
It is supported by an elastic support device 3 consisting of. In the compressor main body 2, an electric motor 5 is arranged at the lower part of the frame 4, and a compression mechanism section 6 is arranged at the upper part. The rotating shaft T consists of a main shaft part Ta and an eccentric shaft part 7b, and the rotor 5a of the electric motor 5
is directly connected to the lower part of the main shaft Ta. Moreover, an eccentric shaft portion Tb is formed on the opposite side of the main shaft through the main bearing portion 4a of the frame 4. This eccentric shaft portion Tb is connected to a part of the compression mechanism portion 6 and has a function of converting the rotational motion of the electric motor 5 into reciprocating motion of the compression mechanism portion 6. As shown in FIG. 2, the rotating shaft □ is a single piece; an eccentric shaft portion Tb is formed by plastic working from a steel pipe.

In this case, the balance weight 7c is formed of a steel plate and joined. However, according to the manufacturing method of the rotating shaft T, the eccentric portion Tb is plastically worked from an integral steel pipe.
However, the degree of plastic working of the stepped bent portion Td was extremely high, making it difficult to increase the amount of eccentricity.

In addition, although it is desirable to make the height of the stepped bending part Td as small as possible, this would further increase the degree of plastic working, making it easy for fractures or cracks to occur during plastic working, resulting in poor versatility. . Furthermore, due to the strength of the rotating shaft T, stress will be concentrated in the stepped bent portion 7d due to its shape, and it is desirable to have a sufficient section modulus in this portion.
Increasing the material diameter of the steel pipe that forms the compressor will lead to a decrease in the characteristics of the directly connected electric motor 5, which will lead to an increase in the size of the electric motor, and furthermore, a defect that will increase the size and weight of the hermetic electric compressor itself. It was hot. The present invention has been made in an attempt to eliminate such deficiencies.

5 The present invention is characterized in that the main shaft member 12 connected to the rotor 5a is formed from a steel pipe material, the eccentric shaft member 14 connected to the compression mechanism is formed by drawing from a steel plate material, and the eccentric shaft member 14 and the above-mentioned Since the main shaft member 12 is fixed so that its axis is eccentric, even if the amount of eccentricity between the main shaft member 12 and the eccentric shaft member 14 is increased, the eccentric shaft portion 14 of the eccentric shaft member 14
It is sufficient to simply shift the constriction position of a, and there is no possibility of breakage, cracks, etc. occurring in the rotating shaft as in the conventional case.

Further, the height required for eccentricity between the main shaft member 12 and the eccentric shaft member 14 is only the thickness of the flange portion 14b of the eccentric shaft member 14, and can be made very small. In this case, unlike the conventional case, stress does not concentrate on the stepped bending portion, so the fully hermetic electric compressor can be made smaller. Furthermore, since the rotating shaft 11 is formed from a steel pipe material and a steel plate material,
High processing efficiency. An embodiment of the present invention will be described below with reference to FIGS. 3 and 4. As shown in FIG. 4, the rotating shaft 11 includes a main shaft member 12, a balance weight member 13, and an eccentric shaft member 1.
Produced from 4. The main shaft member 12 has an oil hole 12a and an oil groove 12b formed in a straight pipe shape cut from a steel pipe material. The balance weight member 13 is extruded from a steel plate material to form a convex shape that serves as a thrust surface 13a, and a hole 13c to which the main shaft member 12 is joined is provided in the thrust surface 13a.
, and integrally includes a weight portion 13b that matches the performance of the compressor. The eccentric shaft member 14 is formed by drawing from a single steel plate, so that the eccentric shaft portion 14a and the seven flange portions 14 are formed by drawing.
It forms b. An oil hole 14c and an oil groove 14d are formed in this eccentric shaft portion 14a. Moreover, this flange part 1
4b is cut out in the same shape as the outer shape of the balance weight 13. Next, the main shaft member 13 is inserted into the hole 13c of the balance weight member 13 as shown in FIG. stick.
This brazing can be easily performed using a high-temperature brazing furnace in a reducing atmosphere.Also, there are problems caused by high-temperature heating during brazing, such as a decrease in the hardness and strength of the rotating shaft 11 due to the annealing effect and deformation due to the release of plastic residual stress. However, as shown in FIG. The opposite side of the mating surface 11a is fixed by welding, and a hole 13c is provided in the balance weight member 13 and the flange portion 14b of the eccentric shaft member 14.
This problem can be solved by passing the rivet 15 through the rivet 14c and fixing it by caulking.

Note that welding can be performed instantaneously and efficiently by plasma laser welding, and rivet caulking is a common technique. Furthermore, as shown in FIG. 6, the outer circumferences of the balance weight member 13 and the flange portion 14b of the eccentric shaft member 14 may be welded. The main shaft member 12, balance weight member 13, and eccentric shaft member 14 are temporarily assembled by press-fitting or crimping the balance weight member 13 into the main shaft member 12,
The balance weight member 13 and the eccentric shaft member 14 are welded together by resistance welding such as spot or projection welding.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view of a conventional fully hermetic electric compressor, Fig. 2 is a perspective view of a rotating shaft used in the compressor, and Fig. 3 is a perspective view showing an example of the rotating shaft according to the present invention. 4 is a perspective view showing an exploded state of the constituent members of the rotating shaft shown in FIG. 3,
FIG. 5 is a side sectional view showing another method of fixing the rotating shaft of the present invention, and FIG. 6 is a side sectional view showing still another method of fixing the rotating shaft of the present invention. Axis, 12...
...Main shaft member, 12a...Oil hole, 12b...
...Oil groove, 13...Rotating balance weight member, 13a...Thrust surface, 13b...
・Weight part, 13c... Hole, 14...
・Eccentric shaft member, 14a...Eccentric shaft portion, 14b・
...Flange part, 14c...Oil hole, 14
d...Oil groove, 15...Repetition.

Claims (1)

[Claims] 1. The main shaft member 12 connected to the rotor 5a is formed from a steel pipe material, the eccentric shaft member 14 connected to the compression mechanism is formed by drawing from a steel plate material, and the eccentric shaft member 14 and the main shaft member 12 are A method of manufacturing a rotating shaft for a completely hermetic electric compressor, in which the rotating shaft is fixed so that its shaft center is eccentric.