CN205315333U - Multistage centrifugal pump's pump shaft - Google Patents

Abstract

The utility model discloses a multistage centrifugal pump's pump shaft is equipped with at least one keyway at the position of every installation impeller on the pump shaft to fixed with the wheel hub of corresponding impeller through the fitting key, the pump shaft surface that is located every keyway notch outer lane is equipped with the guard circle of not chromium plating of round, the equal chromium plating in all the other surfaces of pump shaft. The utility model discloses before to multistage centrifugal pump's pump shaft chromium plating, the keyway at the pump shaft is equipped with the guard circle all around uniformly earlier, and not chromium plating in the guard circle has just so reduced keyway hydrogen embrittlement degree all around for the stress that pump shaft itself produced can not be concentrated all around the keyway and crack, thereby causes the pump shaft to become invalid or even the fracture, has improved multistage centrifugal pump's pump shaft life and reliability.

Description

A kind of pump shaft of centrifugal multistage pump multiple centrifugal pump

Technical field

This utility model relates to centrifugal multistage pump multiple centrifugal pump, more particularly, it relates to the pump shaft of a kind of centrifugal multistage pump multiple centrifugal pump.

Background technology

Centrifugal pump is flow media (gas and liquid, can also be the mixture of particle and gas or liquid) enter from impeller shaft root (import), medium relies on high-speed rotation impeller to obtain centrifugal force, produce a high pressure, from the medium conveying apparatus that pressure relief opening (outlet) flows out. The pump shaft of centrifugal multistage pump multiple centrifugal pump is to be gathered together by the plural pump with said function, on fluid channel structure, show that the medium pressure relief opening of the first order communicates with the import of the second level, the medium pressure relief opening of the second level communicates with the import of the third level, so the mechanism of series connection defines the pump shaft of centrifugal multistage pump multiple centrifugal pump, and the meaning of the pump shaft of centrifugal multistage pump multiple centrifugal pump is in that to improve setting pressure.

Incorporated by reference to shown in Fig. 1 to Fig. 3, the pump shaft 1 of centrifugal multistage pump multiple centrifugal pump, need to process at least one keyway 3 at each installation impeller 2 position, pump shaft 1 is by the wheel hub 201 of key 4 impeller 2 in keyway 3, impeller 2 is made to make high speed rotational operation, because considering pump shaft 1 hardness and its surface abrasion resistance antiseptical performance, and multi-stage impeller 2 installing/dismounting needs, when processing multiple stage pump shaft 1, little 0.1～0.3mm is first ground on pump shaft 1 surface at dress impeller 2 position, process keyway 3, chromium plating cylindrical grinding surface, because chromium coating 5 hardness ratio is higher, so 3 mouthfuls of very difficult chamfer machining of keyway after chromium plating, 3 mouthfuls of chromium coatings 5 of keyway usually come off, concavo-convex uneven, wedge angle mouth, and drive in key 4 process at pump shaft 1, stress is caused to concentrate in 3 mouthfuls of keyway, because chromium coating 5 fragility is big, in long-time high speed rotating runs, because being subject to alternating force effect, formation of crack often it is easily generated at 3 mouthfuls of chromium coating 5 positions of keyway, increase along with pump group runs the time, chromium coating 5 micro-crack expands, cause pump shaft 1 itself to produce stress concentration again to crack, cause pump shaft 1 to lose efficacy even to rupture, because of the Hydrogen Brittleness Phenomena caused by chromium plating, can only prevent, cannot repair, and the process conditions of its prevention are also more complicated, cost is also big.

Utility model content

For the disadvantages mentioned above existed in prior art, the purpose of this utility model is to provide the pump shaft of a kind of centrifugal multistage pump multiple centrifugal pump, can solve the problem that keyway mouth on the pump shaft of centrifugal multistage pump multiple centrifugal pump causes hydrogen embrittlement because of chromium coating by this utility model, in work runs, stress is concentrated and is caused Problem of Failure, improves pump shaft service life and the reliability of centrifugal multistage pump multiple centrifugal pump.

For achieving the above object, this utility model adopts the following technical scheme that

A kind of pump shaft of centrifugal multistage pump multiple centrifugal pump; pump shaft is provided with at least one keyway at the position of each installation impeller; and fix by installing the wheel hub of key and respective impeller, the pump shaft surface being positioned at each keyway notch outer ring is provided with a guard circle enclosing not chromium plating, the equal chromium plating of pump shaft remaining surface.

Described each keyway notch is all set to the chamfering of 45～60 °.

The chamfer surface also not chromium plating of described notch.

The base angle of described each keyway is rounded corner.

In technique scheme; before the pump shaft chromium plating of the pump shaft to centrifugal multistage pump multiple centrifugal pump; first it is evenly provided with guard circle in the keyway surrounding of pump shaft; not chromium plating in guard circle; this reduces the hydrogen embrittlement degree of keyway surrounding; keyway surrounding can not being concentrated by the stress that pump shaft itself produces crack, thus causing Cause of Losing Efficacy of Pump's Axle even to rupture, improve pump shaft service life and the reliability of centrifugal multistage pump multiple centrifugal pump.

Accompanying drawing explanation

Fig. 1 is the assembling figure of the pump shaft of the pump shaft of centrifugal multistage pump multiple centrifugal pump and impeller;

Fig. 2 is the left view sectional view of Fig. 1;

Fig. 3 is the enlarged drawing in a portion in Fig. 2;

Fig. 4 is the schematic diagram after Fig. 3 uses this utility model;

Fig. 5 is the schematic diagram of this utility model guard circle;

Fig. 6 is the schematic diagram of this utility model sunk key.

Detailed description of the invention

The technical solution of the utility model is further illustrated below in conjunction with drawings and Examples.

Incorporated by reference to shown in Fig. 4 to Fig. 6, the pump shaft of a kind of centrifugal multistage pump multiple centrifugal pump of the present utility model, same as the prior art is, equally also include pump shaft 1 is provided with at least one keyway 3 at the position of each installation impeller 2, and fixing with the wheel hub 201 of respective impeller 2 by installing key 4, just repeat no more at this. Unlike the prior art; of the present utility model before chromium plating; it is positioned on pump shaft 1 surface of each keyway 3 notch outer ring and is provided with a circle guard circle 6 uniformly; not needing chromium plating in guard circle 6, the size of guard circle 6 can be determined according to the size of the thickness of chromium coating 5 and keyway 3, and all needs chromium plating in pump shaft 1 remaining surface; after completing Deng chromium plating; get rid of guard circle 6 again, now, pump shaft 1 surface in guard circle 6 does not just have chromium coating 5.

It is also preferred that the left described each keyway 3 notch is adding man-hour, being arranged to the chamfering 8 of about 45～60 ° uniformly with rose reamer, the size of chamfering 8 can be determined according to the width of keyway 3, the also not chromium plating of chamfering 8 surface.

It is also preferred that the left the base angle of described each keyway 3 is on the basis of mach chamfering, more manually revise this chamfering, make chamfering become rounded corner 7.

In sum, solve the keyway mouth of multistage pump pump shaft after chromium plating by this utility model, because chromium coating stress concentrates the actual effect problem caused, improve service life and the reliability of multistage pump pump shaft.

Those of ordinary skill in the art will be appreciated that, above embodiments is intended merely to explanation this utility model, and it is not used as to restriction of the present utility model, as long as in spirit of the present utility model, the change of embodiment described above, modification all will be dropped in Claims scope of the present utility model.

Claims (4)

1. the pump shaft of a centrifugal multistage pump multiple centrifugal pump; pump shaft is provided with at least one keyway at the position of each installation impeller; and fix by installing the wheel hub of key and respective impeller; it is characterized in that: the pump shaft surface being positioned at each keyway notch outer ring is provided with a guard circle enclosing not chromium plating, the equal chromium plating of pump shaft remaining surface.

2. the pump shaft of a kind of centrifugal multistage pump multiple centrifugal pump as claimed in claim 1, it is characterised in that: described each keyway notch is all set to the chamfering of 45～60 °.

3. the pump shaft of a kind of centrifugal multistage pump multiple centrifugal pump as claimed in claim 2, it is characterised in that: the chamfer surface also not chromium plating of described notch.

4. the pump shaft of a kind of centrifugal multistage pump multiple centrifugal pump as claimed in claim 1, it is characterised in that: the base angle of described each keyway is rounded corner.