JPS635196A - Pump structure - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field to which the Invention Pertains] The present invention relates to the structure of an impeller of a main oil pump that constitutes an integral part of a hydraulic speed governor for a % withering turbine.

The impeller of the main oil pump included in the hydraulic speed governor of the steam turbine has an impeller rotating shaft that is supported by bearings installed at both ends of the main oil pump casing, and its predetermined position! It consists of an impeller boss that is fixed at i (distributed at the center in the axial direction) and a plurality of blades that are arranged and fixed radially on the outer circumferential surface of this fixed impeller boss, The operating oil supplied within the pump casing is pumped out according to the rotation speed of the impeller rotating shaft (hereinafter referred to as "rotating shaft c") which rotates in synchronization with the rotation of the steam turbine, and primarily to the speed governor. The bellows, which forms an integral part of the steam turbine, acts as a primary hydraulic pressure, and further generates a secondary hydraulic pressure via a driven piston, which is transmitted to the servo motor to adjust the opening of the steam turbine's control valve to achieve a predetermined rotational speed (output). It is used to obtain

A conventional example will be explained below based on the drawings. FIG. 3 is a sectional view showing the structure of a conventional main oil pump.

In the figure, the main oil pump 1 has one end connected to the shaft end of a 4-bin I shaft 4 via a toothed shaft joint 3, and journal bearings 5 and 6 arranged at both left and right ends of a pump casing 13. The rotating shaft 2 is pivotally supported by the rotating shaft 1, and the rotating shaft 1 is
Impeller boss 1] connected to impeller boss 1] and impeller boss 1]
The pump casing 13 is assembled so that an impeller consisting of a plurality of blades 12 arranged radially on the outer peripheral surface of the pump and connected by welding is housed inside the pump casing 13 so as to be surrounded by a two-part pump casing 13.

At this time, the impeller boss 11 and the rotating shaft 2 are made separately. That is, the set or hole of the impeller boss 11 (not shown).

The inner diameter of the through hole (equipped with a keyway and a through hole drilled concentrically with the rotating shaft 2) and the diameter of the rotating shaft 2 are made to be approximately the same dimension, and the rotating shaft 2 is first provided with a stage on which the bearing 5 is arranged. In the meantime, fit the sleeve 7 to determine the right rotation position of the impeller boss 1, then fit the impeller boss 11, and press the key 8.
At the same time as setting the impeller boss 1 at a predetermined position on the rotating shaft 2, a rotation stopper is applied at the same time, and the sleeve 9 is fitted from the left side, and the nut 10 is screwed from the left side of the rotation @2. By tightening, the impeller boss 1 is clamped between the sleeve 7 and the spline 9 to stop its movement in the axial direction, and the rotating shaft 2 and the impeller boss 11 are integrated.

A plurality of blades 12 are arranged radially on the outer circumferential surface of the impeller boss 1 and are welded and joined to complete the impeller. After adjusting the balance of the completed impeller, it is pivotally supported by journal bearings 5 and 6 disposed at both ends of the split pump casing 13 and assembled, thereby completing the main pump 1.

In this type of impeller, in which the rotation shaft 2 and the impeller boss l are assembled by fitting together, the sleeves 7 and 9 and the nut 10 stop the axial movement, and the key 8 prevents rotation. It is necessary to provide a slight gap at the joint surface between the inner periphery of the impeller boss 1 and the inner periphery of the sleeves 7 and 9 and the outer periphery of the rotating shaft 2. The problem of unavoidable problems is that commonly called flaring or ting corrosion occurs at the end of the impeller and damages the inner circumferential surface of the impeller post and the outer circumferential surface of the rotating shaft.

[Purpose of the invention]

This invention has been made in view of the above, and proposes a main pump that has a simple structure in which the impeller boss and rotating shaft are integrated, is durable and free from fretting corrosion, and can be pumped in a short time. The purpose is to sing.

[Summary of the invention]

According to the present invention, the above object is achieved by making an impeller boss disposed on an impeller rotation shaft of a main oil pump integrally with the impeller rotation shaft at a predetermined position of the rotation shaft, orthogonal to the center line of the rotation shafts. This is achieved by forming a symmetrical tapered cross-sectional shape protruding from the circumference of the rotating shaft with the surface as the axis.

[Embodiments of the invention]

Hereinafter, an explanation will be given based on the I\1 page of the embodiment of the present invention.

Figures 1 and 2 are cross-sectional views 1 showing the structure of a main pump according to an embodiment of the present invention. In the first and second rectangles, parts that are the same as the third part described above are given the 1dl- symbol.

3 in FIG. 1, the impeller installed in the main oil pump 1 has its negative end connected to the shaft end of the turbine l shaft 4 via a toothed shaft joint 3, and is connected to a pump casing 13 divided into two parts. The impeller rotating shaft 2, which is supported by journal bearings 5 and 6 provided at both left and right ends, is placed at a predetermined position in the axial direction.
A protrusion (@
The impeller boss part 11 is machine-finished and becomes the impeller boss part 1. It is made by arraying and joining on a surface.

In addition, as shown in Fig. 2, the impeller boss section]1
is divided into two parts, the base part 14 and the flat plate part 15,
The flat plate portion 15 is manufactured as an annular flat plate separate from the impeller rotating shaft 2, and the base portion 14 is integrally formed with the impeller rotating shaft 2 at the above-mentioned head to protrude to a predetermined position of the rotating shaft 2. The outer circumferential surface of the base portion 14 and the inner circumferential surface of the flat plate portion 15 may be joined by welding to be integrated with the impeller boss portion 1 and the line propeller rotating shaft 2.

The impeller boss part 11 is rotated by the method described above.
By providing this on the circumferential surface of the impeller, the number of component parts of the impeller can be reduced, the occurrence of fretting corrosion can be completely eliminated, and the number of man-hours for manufacturing the impeller can be greatly reduced.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the impeller boss on the impeller rotating shaft of the main pump is integrated with the impeller rotating shaft, which not only makes the impeller sturdy but also prevents flaring and ring corrosion. Eliminate damage to the rotating shaft and impeller boss caused by
silk! Since the number of man-hours can be greatly reduced, it is possible to obtain the effect that the king pump can be provided at a low cost.

[Brief explanation of the drawing]

Figures 1 and 2 show l of a main oil pump to which the present invention is applied.
Fig. 3 is a cross section M of a conventional main oil pump. ■: Main oil pump, 2: Impeller rotating shaft, 5.6: Journal bearing, 1]: Impeller boss (or impeller post section)
l, 12 two blades, 13: pump casing, 14: base, 15: flat plate part.

Claims (1)

[Scope of Claims] 1) An impeller boss disposed on the impeller rotation shaft of the pump is integrally formed with the impeller rotation shaft so as to protrude in a symmetrical tapered cross-sectional shape on the circumference of the rotation shaft. The structure of the pump is characterized by: 2) In the pump according to claim 1, the impeller boss portion for rotating the impeller is divided into a base portion and a flat plate portion, the base portion is formed integrally with the impeller rotation shaft, and the flat plate portion is separate from the impeller rotation shaft. 1. A pump structure, characterized in that the body is formed into an annular flat plate, and the inner circumferential surface of the annular flat plate is joined to the outer circumferential surface of the base.