JPS5882098A - Fixation of steel impeller to shaft - Google Patents

Abstract

PURPOSE:To improve the accuracy of assembly and to improve the productivity of the titled impeller by a method wherein a support plate subjected to a burring process is weided to the inner surface of a main plate and the welded whole is fitted about a same diametered section of the outer peripheral surface of the shaft through a flange of the suopport plate formed as a result of the burring process. CONSTITUTION:The support plate 2A having a center hole is welded to the main plate 1A having a center hole by a projection welding method capable of assuring a high rate of productivity and the welded whole is fitted about the shaft 3. In this case, the support plate 2A is subjected to the burring process prior to welding so that the plate 2A is provided with the flange 10 having a large fitting surface forming the peripheray of the center hole of the plate 2A and through which the plate is fitted about the same diametered section of the outer peripheral surface of the shaft 3, while, on the other hand, the main plate 1A is fitted about a tapered section 9 of the shaft, to thereby increase the precision of assembly. Next, the main plate 1A or the support plate 2A is fastened from outside by means of a male screw bolt 12 and a nut 8 through a washer 7 to thereby fix the impeller to the shaft 3. With the above sturcture, the fastening force applied on the main plate 1A by the bolt and the nut is equally balanced against the tapered section 9 of the shaft 3 so that the plates 1A and 2A are not deformed and since they do not bite in the shaft 3, they can be assembled with a high degree of precision. Further, the above fixing structure has such advantages that the assembly and disassembly of the main plate 1A and the support plate 2A are facilitated and the productivity of the impeller is improved because no key way forming process is required.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a structure for fixing a steel plate impeller to a shaft.

Recently, there has been a trend to manufacture centrifugal pump impellers from steel plates in order to improve performance and productivity. Conventionally, as a structure for fixing an impeller to a shaft, a structure is generally used in which a cut-out boss is welded to the main plate of the impeller, and the boss and the shaft are fastened with a key or with a taper. Enter. However, in these structures, the cut-out boss is expensive, and in the key fastening structure, machining of the keyway requires a lot of man-hours.

However, a structure has been proposed in which one impeller is tightened and fixed to the tapered portion of the shaft without using a cut-out boss as shown in FIG. In Figure 1, 1 is the main plate, 2 is the support plate,
3 is the mounting shaft, 4 is the welding (projection welding) part,
5 is a blade, 6 is a tapered portion of the shaft, 7 is a washer, and 8 is a nut. However, there is a problem with this structure because the hole edges of both the main plate 1 and the support plate 20 are tapered and fitted with the tapered part of the shaft 3! When the load is balanced, the deformation of both plates 1 decrease in assembly accuracy, and the elastic deformation of both plates causes them to bite into the shaft, making it impossible for the heel to escape. There is an i.

The purpose of the present invention is to eliminate the need for expensive cut-out bosses and keyway machining that requires a large number of man-hours and is difficult to process depending on the material. The purpose of this invention is to provide a structure for fixing a steel plate impeller to a shaft with excellent productivity.

The structure for fixing the steel plate impeller to the shaft according to the present invention □ is as follows.

The diameter of the end of the mounting shaft of the steel plate impeller is reduced by taper processing, and a male threaded rod portion with a diameter smaller than the minimum diameter part that is tapered at the tip is formed to have a diameter larger than the central hole diameter of the main plate of the steel plate impeller. A support plate having a hole in the center with an outer diameter of Draw the area near the edge, weld the support plate to the inside or outside of the main plate with the center aligned, insert both into the mounting shaft, and attach the hole edge of the inner support plate or main plate. Fit it into the constant diameter part of the shaft, fit the hole edge of the outer main plate or support plate into the tapered part of the mounting shaft, screw the nut into the male threaded rod at the tip of the shaft,
This is a fixed structure attached to the shaft of a steel plate impeller, characterized in that the outer main plate or support plate is tightened from the outside.

In a preferred embodiment of the fixing structure of the steel plate impeller to the shaft according to the present invention, the supporting plate is subjected to purling processing and welded to the inside of the main plate, and the seven points formed by the purling processing are provided. The flange forms a fitting surface with a constant diameter portion of the shaft. 1. 1. In another preferred embodiment of the structure for fixing the steel plate impeller to the shaft according to the present invention, the support plate is welded to the inside of the main plate, and the shaft is integrally attached to the outside of the main plate. A small-diameter auxiliary plate that fits into the tapered portion of the M main plate is in close contact with the M main plate.

It is thought that the meaning of inside and outside in the structure of the present invention can be fully understood from its structure, but just to be sure, if one impeller, and therefore the main plate, is inserted into the mounting shaft, The fruit side is considered the inside, and the tip side of the shaft is considered the outside.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The fixing structure of the present invention will be explained in detail below based on the drawings of embodiments. FIGS. 2-J show different embodiments of the fixing structure of the present invention. The same reference numerals as in Fig. 1 indicate the same members, and %1A and 2A are the main plate and support plate of the impeller in the structure of the present invention corresponding to 1 and 2 in Fig. 1.

The end of the mounting shaft 3 is tapered to reduce its diameter in the same way as the conventional mounting shaft shown in FIG. As in the case of FIG. 1, a male threaded rod portion 12 having a smaller diameter than the minimum diameter portion of the tapered portion 9 is formed.

The support plate 2A has a hole in the center with an outer diameter larger than the central hole diameter of one main plate. When the inner side 2 of the main plate 1A contacts the outer side with the support plate 2A aligned with the center, there is a hole between the two hole edges. The vicinity of one or both hole edges is drawn so that a slight gap is formed between the holes. In the embodiment shown in Fig. 2゜3.4.5, both are
In the embodiment shown in FIG. 6, only the support plate 2A is drawn. Two support plates are inside one main plate (Figures 2.5 and 5.6)
Or welded so that the center coincides with the outside (Fig. 4). In the embodiment shown in Figure 2.5.5.6, projection welding is sufficient for the welding of the two supporting plates to the main plate 1A (the welded part is indicated by 4) in terms of productivity. Therefore, I am doing projection welding. In the embodiment of FIG. 4, fillet welding is performed. In the embodiment shown in FIG. 4, the support plate 2A is tapered to reduce surface pressure stress on the tapered surface.

The thickness of the main plate 1A is not increased, but only the support plate 2A is made thicker to save material.

In the embodiment shown in FIG. 3, the supporting plate 2A is subjected to a purling process, and the formed flange 10 forms a wide A fitting gap to improve assembly accuracy.

Figures 5 and 116! i! In the example, main plate 1A
On the outside of the main plate, a small diameter auxiliary plate 11 which fits into the tapered part 9 of the shaft as one body with the main plate is welded in close contact with the main plate. Projection welding* is possible for this welding.

Thereby, the surface pressure stress of the tapered portion can be reduced.

Two support plates or one main plate to which the support plate 2A and the auxiliary plate 11 are welded are inserted into the shaft 3. Here, the inner support plate 2A
Or, the hole edge of the main plate IA (Fig. 814) fits into the constant diameter part of the shaft, and the outer main plate IA (Fig. 5-6 shows the auxiliary plate 11).
(attached) or the hole edge of the support plate 2A (FIG. 4) fits into the tapered portion 9 of the shaft 3. Of course, one main board (including the supplementary board 11) or the supporting board 2A on the outside of the kalpa
A taper that fits into the taper portion 9 is formed at the edge of the hole.

Next, the impeller is fixed to the shaft by inserting the washer 7 into the male threaded rod 12, screwing in the nut 8, and tightening the outer green plate 1A or support plate 2B from the outside.

Since the tightening force is balanced between the hole edge of the outer main plate 1A or the support plate 2B and the tapered part 9, it does not reach the other main plates or support plate parts, so no hairstyle occurs, and it is easy to assemble. Since it helps maintain accuracy, high assembly accuracy is maintained.

The fixing structure of the present invention is constructed as described above and can produce effects. The effects of the fixing structure of the present invention are summarized as follows: (1) Since the bolt tightening force is balanced at the tapered portion and does not affect other parts, there is no deformation and the assembly accuracy is high.

(2) There is no deformation, there is little biting into the shaft, and it is easy to disassemble and assemble.

(3) Due to no deformation and little biting into the hole,
Since the Taber angle can be reduced to about 1/2.5 of the conventional one, the fastening force (transmitted torque) is large.

(4) Cutting boss and keyway machining (stainless steel is machined, female Ln)ffl is not required, resulting in good productivity and economical.

[Brief explanation of the drawing]

Claims (3)

[Claims] (1) The diameter of the end of the mounting shaft of the steel plate impeller is reduced by taper processing, and a male threaded rod portion with a smaller diameter than the tapered minimum diameter portion is formed at the tip, and the center of the main plate of the steel plate impeller is When a support plate having a hole in the center with an outer diameter larger than the hole diameter is brought into contact with the inside or outside of the main plate with the center coincident, one or both of them are arranged so that a slight gap is formed between the hole edges of the two. The vicinity of the hole edge of the support plate is drawn, and the center of the support plate is aligned with the inside or outside of the main plate, and the center is welded.Insert both of them into the mounting shaft, and the hole edge of the inner support plate or the main plate is Fit the fixed diameter part of the mounting shaft, fit the hole edge of the outer main plate or support plate to the tapered part of the mounting shaft, screw the nut into the male threaded rod at the tip of the shaft, and then A structure for fixing a steel plate impeller to the shaft, which is characterized by the plate being tightened from the outside. (2) A patent claim in which the support plate Fi is pearled and welded to the inside of the main plate, and a flange not formed by the pearling process forms a fitting surface with a constant diameter portion of the shaft. The structure of the first term of the range. (3) The support plate is welded to the inside of the main plate, and integrated with the main plate to the outside of the main plate and attached to the tapered part of the shaft.