JPS5834318Y2 - Main shaft protection pipe connection structure of vertical shaft/mixed flow pump - Google Patents

Description

[Detailed description of the invention] This invention is a main shaft protection pipe for a vertical shaft/mixed flow pump in which the main shaft protection pipes of a vertical shaft/mixed flow pump are connected to each other in the axial direction via a bearing holder. Regarding connection structure.

Conventionally, in this type of structure, for example, as shown in FIG. 1, a bearing holder 3 is fixed with bolts 2 or the like between the joints of the lifting pipe 1, and the main shaft 5 is surrounded by the underwater bearing 4 portion of the bearing holder 3. There is one in which the protective tubes 6 are connected to each other in the axial direction.

However, in the conventional one, as shown in FIG. 2, a fitting cylinder 7 is welded to the end of the main shaft protection tube 6, and this cylinder 7 is inserted into an annular groove 8 formed on the end surface of the bearing holder 3. 0 ring 9
The inner and outer circumferential surfaces are directly joined and fitted together, thereby establishing a sealed connection at the tube ends.

For this reason, it is necessary to perfectly align the annular groove 8 and the fitting cylinder 7 with each other, and to finish these groove widths and plate thicknesses to precise dimensions. Therefore, high precision is required in mechanical strength and assembly. However, there is a problem in that simply providing a sealing function requires many manufacturing steps and costs are extremely high.

In addition, the process of welding the cylindrical body 7 to the tube end is also required, which also increases the number of machining processes, and since this product cannot be used for products with different length dimensions, the amount of stock is also limited depending on the quality. There are some problems that require a lot of effort.

The present invention was developed to solve such problems, and it is possible to easily connect the spindle protection tube and the bearing holder in a sealed manner without the need for exceptionally high-precision mechanical power or assembly. We have developed a main shaft protection pipe connection structure for vertical shaft/mixed flow pumps that facilitates manufacturing and reduces costs, makes it relatively easy to repurpose main shaft protection pipes with different length dimensions, and allows for adjustment of stock amount. This is what we provide.

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 3 and 4.

10 is the main part of the pump, 11 is a pumping pipe, and 12 is a main shaft.

The main shaft 12 is supported via the sleeve 12af by the underwater bearing 15a, which is fixed to the intermediate bearing holder 15 with bolts 14 between the joint flanges 13 of the lifting pipe 11 and inserted into the shaft hole 16 of the intermediate bearing holder 15. Both ends of the boss portion 16 of the intermediate bearing holder 15 are connected to a pair of main shaft protection tubes 17 and 18.

1. The intermediate bearing holder 15 has a main shaft protection tube 17°1.
Fitting recesses 20 with a slightly larger diameter than the outer diameter of the spindle protection tube 17 and 18 are formed at both ends of the bearing holder boss portion to which the bearing holder boss 8 is to be connected. I am doing it.

On the other hand, an annular seal packing 21 is previously attached to the tube end of each main shaft protection tube 17, 18, for example, from the outer periphery to the end surface by vulcanization adhesive or the like.

Then, the tube end of each main shaft protection tube 17, 18 is fitted under pressure into the fitting recess 20 of the intermediate bearing holder 15 by utilizing the elastic contraction of the seal packing 21 attached thereto.
It is still fixed in contact with the stepped portion 19.

Among them, the lower end of one (lower) main shaft protection tube 17 is fixedly held by a base bearing holder 22 provided in the pump main part 10.

Similar to the intermediate bearing holder 15, this base bearing holder 22 is also provided with a large diameter fitting recess 25 via a step 24 at the end of the shaft hole 23 where the tube end is to be held. A seal packing 26 is attached to the outer periphery of the end of the main shaft protection tube 17 and fitted therein.

With such a configuration, even if there is some dimensional error or misalignment between the fitting recess 20 of the intermediate bearing holder 15 and the joining tube ends of the main shaft protection tubes 17, 1B, this will cause the seal packing to be removed during fitting. 21, it is not necessary to particularly increase the machining accuracy of the intermediate bearing holder 15 and the main shaft protection tube 17, 18 or the positioning accuracy during assembly.

Therefore, manufacturing is easy and costs can be reduced.

Moreover, according to the above configuration, since the seal packing 21 is simply attached to the tube end of the main shaft protection tube 17, 18, there is no need for troublesome processing such as welding a fitting cylinder as in the conventional case. By adjusting the length by cutting the main shaft protection tubes 17 and 11, and then applying the seal packing 21, a new one can be easily manufactured, so it is easy to convert the tubes to ones with different lengths. It is also possible to reduce the amount of stock.

In the above embodiment, the seal packing 21 is applied from the outer periphery of the end of the main shaft protection tubes 17 and 18 to the end surface thereof, but the seal packing 21 is not limited to such a structure, for example, as shown in FIGS.
As shown in the figure, those that cover the inner and outer peripheries of the tube ends, or those that have some unevenness to enhance the sealing effect when mating, etc.
It can be modified in various ways.

[Brief explanation of the drawing]

Fig. 1 is a partial sectional view showing a conventional example, Fig. 2 is an enlarged view of the main part of Fig. 1, Fig. 3 is a partial sectional view showing an embodiment of the present invention, and Fig. 4 is a main part of Fig. 3. The enlarged partial views and FIGS. 5 to 10 are sectional views of main parts showing other embodiments of the present invention. 15...(middle) bearing holder 16...shaft hole, 1
7.18... Main shaft protection tube, 20... Fitting recess, 21
゜21a-21f... Seal packing.

Claims (1)

[Scope of utility model registration request] A fitting recess with a diameter slightly larger than the outer diameter of the spindle protection tube is formed at the boss end of the bearing holder to which the tube end of the spindle protection tube is to be connected, and the tube end of the spindle protection tube is inserted into the fitting recess. A main shaft protection tube connection structure for a vertical shaft/mixed flow pump, characterized in that a sealing pad is fitted around the outer periphery of the main shaft protection tube.