CN102759450A - Bearing load recognition method based on coupler opening and height difference - Google Patents

Abstract

A bearing load recognition method based on coupler opening and height difference is provided by the invention, and includes the following two steps: load recognition of bearings based on the given openings and height difference values at couplers, installation instruction for a machine set, and failure control; and acquisition of the openings and the height difference values at the couplers during the machine set installation based on the given load of bearings, and design instruction for the machine set. The method provided by the invention also takes the influence of bending deformation of a rotator on the openings and the height difference values of the couplers into consideration.

Description

A kind of based on the shaft coupling bearing load recognition methods with difference of height of dehiscing

Technical field

The present invention relates to a kind of multispan, supporting the static indeterminacy axle more is the bearing load recognition methods, helps the technician to analyze the load condition that each bearing bore in the multispan static indeterminacy axle system.Main application fields comprises: large rotating machineries such as electric power, metallurgy, petrochemical industry, aviation, and like bearing load recognition methods technical fields such as steam turbine, compressor, generator, gas turbine, pump, blower fans.

Background technology

Though all kinds of rotating machinery principle of work such as Turbo-generator Set, gas turbine generator group, large-scale compressor are different with the course of work, they all have a common characteristic, that is: axle system is made up of many transfer and a plurality of bearings.This is a statically indeterminate system.Bearing is the critical component of this type systematic, and is most important for the safe and stable operation that guarantees unit.Can know that by lubrication theory bearing load has determined the bearing working state, and bearing load depends on that axle fastens the centering situation between many rotors.High-speed rotating machine is had relatively high expectations for accuracy of alignment between the rotor.When the centre deviation between the rotor is big, the faults such as bearing unstability that are easy to produce fault such as the stone roller that causes because of bearing load is overweight watt, broken watt and kick the beam and cause because of bearing load.These all can cause unit to produce bigger vibration, and the fault that is caused thus is of common occurrence on engineering.Adjust through axial center that to optimize that bearing load distributes also be the main means that the unit vibration fault is administered.Therefore, bearing load identification and method of adjustment have the important use meaning for large rotating machineries such as steam turbine, compressor.Along with unit to the maximization direction develop and modern electric power industry to unit safety operation require increasingly highly, the identification bearing load is analyzed the bearing working condition, and on this basis axial center is optimized adjustment and just seems more and more important.

Early stage people discern bearing load through punching and install pressure transducer additional at bearing inner surface.This method has not only been destroyed bearing inner surface and oil film, and identification error is bigger.Add the method for dynamometer not only workload is big in bearing seat bottom, and has changed the bearing seat supporting form.When adopting the lifting jack method to measure bearing load,, then can't come axle jack-up if institute's reinforcing is too light; If institute's reinforcing is too heavy, because the bearing clearance is less, then be easy to touch watt, it is downward to produce an additional force.The both can produce than mistake.Said method all is difficult to accurately identify bearing load.

The axle system of large rotating machinery comprises the bearing more than 3 or 3 usually, and this is a statically indeterminate system, and bearing load can't directly be obtained by power and torque equilibrium equation.On the engineering, the bearing load adjustment is that technology is carried out in looking for through axle system, and shaft coupling is dehisced and the height difference is carried out and be based on mostly in looking for, and these two values can be measured through dial gauge or high-precision laser centering instrument more exactly.Though dehisce with the height difference can measure out more easily, people and do not know bearing the actual load condition that bears.

Summary of the invention

It is the bearing load recognition methods that the present invention proposes a kind of many support static indeterminacy axles.The method that this invention provided comprises two aspect contents: by dehiscing and each bearing load of height difference identification of given each shaft coupling place, instruct unit installation, fault to administer; The dehiscing and the height difference of each shaft coupling place when being obtained unit and installed by given bearing load instructed the unit design.Method proposed by the invention can also consider that the rotor bow distortion is dehisced to shaft coupling and the influence of height difference.

The present invention adopts following technical scheme:

A kind of based on the shaft coupling bearing load recognition methods with difference of height of dehiscing, the present invention is characterised in that:

This method is regarded as nonprismatic continuous beam with axle system; Each shaft part deadweight is as being uniformly distributed with quality; Shaft coupling, thrust disc, blade and wheel disc are regarded as rigid support as being carried in the centre-point load on the continuous beam with bearing, are that to be in concentric be initial baseline to each bearing with axle.Calculation procedure is:

At first, each rotor in the axle system is broken off at the shaft coupling place, make up the solving equation group, the sensitivity matrix that calculates the dehiscing of each shaft coupling place under the initial baseline, difference of height and bearing height is changed by theory of mechanics of materials and boundary condition.

Secondly, a plurality of shaft parts of formation are broken off in axle system,, utilize theory of mechanics of materials, set up state parameter relation between top and the clearing end for each shaft part at the bearing place.Wherein, state parameter comprises: deflection, corner, shearing and moment of flexure.Utilize known boundary condition, bearing place right ends state parameter relation, known bearing height, set up bearing load known variables solving equation group, the sensitivity matrix of obtaining initial baseline lower bearing load distribution and bearing height being changed.

Once more, a plurality of shaft parts of formation are broken off in axle system, adopt and set up rotating shaft deflection deformation known variables solving equation group with above-mentioned identical method at the shaft coupling place.Obtain that initial baseline lower rotary shaft distortion, shaft coupling are dehisced, height difference and sensitivity matrix that bearing height is changed thereof, realize thus that each bearing load in the axle system distributes and the shaft coupling state between two-way calculating.That is: by given each shaft coupling place dehisce obtain with the height difference that each bearing load distributes and obtain dehiscing and the height difference of each shaft coupling place by the load distribution at given each bearing place.

It is mechanics analysis model that the present invention sets up axle; Solve under the connection status each bearing load to bearing height changing sensitivity matrix and initial straight normal condition lower bearing load distribution, solve under the off-state that shaft coupling is dehisced and difference of height is dehisced and difference of height to shaft coupling under bearing height changing sensitivity matrix and the initial straight normal condition; By the actual measurement shaft coupling dehisce with difference of height, two sensitivity matrix and initial baseline under load distribution identification bearing load; Dehisce and difference of height by shaft coupling under given bearing load, two sensitivity matrix and the initial baseline, design and installation during with maintenance shaft coupling dehisce and the difference of height standard value.

The present invention compared with prior art, the present invention has following advantage:

(1) realized two-way calculating between bearing load and the shaft coupling state: measure shaft coupling dehisce with the height difference after; Can obtain bearing load apace; This is very important for large rotating machinery, can instruct unit installation, fault diagnosis and improvement; During the unit design, given bearing load distributes, and can design shaft coupling easily and dehisce and difference of height installation code value.

When (2) adjusting axial center traditionally, rotor is regarded as straight line, does not consider the deflection deformation of rotor itself.When the rotor deflection deformation was big, this method had certain error.The method that the present invention proposes has been considered the influence of rotor deflection deformation.

Description of drawings

Fig. 1 is that multispan static indeterminacy axle is the model sketch;

Fig. 2 breaks off each shaft part force analysis synoptic diagram of back at the bearing place with rotor;

Fig. 3 breaks off each rotor bow distortion synoptic diagram of back at the shaft coupling place with rotor;

Fig. 4 considers and does not consider that the rotor bow distortion influences synoptic diagram to shaft coupling opening and difference of height

Fig. 5 is a method flow diagram of the present invention.

Embodiment

A kind of based on the shaft coupling bearing load recognition methods with difference of height of dehiscing, the present invention is characterised in that:

This method is regarded as nonprismatic continuous beam with axle system; Each shaft part deadweight is as being uniformly distributed with quality; Shaft coupling, thrust disc, blade and wheel disc are regarded as rigid support as being carried in the centre-point load on the continuous beam with bearing, are that to be in concentric be initial baseline to each bearing with axle.Calculation procedure is:

At first, each rotor in the axle system is broken off at the shaft coupling place, make up the solving equation group, the sensitivity matrix that calculates the dehiscing of each shaft coupling place under the initial baseline, difference of height and bearing height is changed by theory of mechanics of materials and boundary condition.

Secondly, a plurality of shaft parts of formation are broken off in axle system,, utilize theory of mechanics of materials, set up state parameter relation between top and the clearing end for each shaft part at the bearing place.Wherein, state parameter comprises: deflection, corner, shearing and moment of flexure.Utilize known boundary condition, bearing place right ends state parameter relation, known bearing height, set up bearing load known variables solving equation group, the sensitivity matrix of obtaining initial baseline lower bearing load distribution and bearing height being changed.

Once more, a plurality of shaft parts of formation are broken off in axle system, adopt and set up rotating shaft deflection deformation known variables solving equation group with above-mentioned identical method at the shaft coupling place.Obtain that initial baseline lower rotary shaft distortion, shaft coupling are dehisced, height difference and sensitivity matrix that bearing height is changed thereof, realize thus that each bearing load in the axle system distributes and the shaft coupling state between two-way calculating.That is: by given each shaft coupling place dehisce obtain with the height difference that each bearing load distributes and obtain dehiscing and the height difference of each shaft coupling place by the load distribution at given each bearing place.

Present embodiment is to be that example is analyzed with multispan statically indeterminate system shown in Figure 1, with reference to Fig. 2～5.As shown in Figure 1, axle is fastened and is provided with rotor 1, bearing 2, shaft coupling 3.Proposed by the invention dehisces to may further comprise the steps with the bearing load recognition methods of difference of height data based on shaft coupling:

(1) set up the computational analysis model: system is regarded as nonprismatic continuous beam with axle, and each shaft part deadweight is as being uniformly distributed with quality, and shaft coupling, thrust disc, blade and impeller are regarded as rigid support as being carried in the centre-point load on the continuous beam with bearing, and be as shown in Figure 2.

(2) at n-1 bearing surface place axle system is broken into n elementary section; First segment unit is made up of initial cross section and the 1st bearing cross section; The rear unit is made up of last bearing cross section and termination cross section, and remaining element is by any two adjacent bearing section constitutions, and is as shown in Figure 2; The unknown number of each unit is left and right end state parameter (displacement, corner, shearing and moment of flexure) and bearing reaction.It is individual that n unit unknown state parameter adds up to (9n-1).Being in concentric with each bearing in the axle system is initial baseline, in each elementary section, sets up initial cross section and stops state parameter relationship analysis model between the cross section by theory of mechanics of materials.With a certain unit i shown in Figure 2 is that example describes:

${\left\{\begin{array}{c}y\\ \mathrm{\&theta;}\\ M\\ Q\\ 1\end{array}\right\}}_i^R=\left[\begin{array}{ccccc}1& \mathrm{<figure-callout\; id="2"\; label="L\; L"\; filenames="HDA00001915876700011.png"\; state="\{\{state\}\}">L</figure-callout>}& \frac{L^{}}{}\frac{{}^2}{2\mathrm{EI}}& \frac{{\mathrm{<figure-callout\; id="3"\; label="L"\; filenames="HDA00001915876700011.png"\; state="\{\{state\}\}">L</figure-callout>}}^3}{6\mathrm{EI}}& -\frac{{\mathrm{qL}}^4}{24\mathrm{EI}}\\ 0& 1& \frac{L}{\mathrm{EI}}& \frac{{\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="HDA00001915876700011.png"\; state="\{\{state\}\}">L</figure-callout>}}^2}{2\mathrm{EI}}& -\frac{{\mathrm{<figure-callout\; id="3"\; label="qL"\; filenames="HDA00001915876700011.png"\; state="\{\{state\}\}">qL</figure-callout>}}^3}{6\mathrm{EI}}\\ 0& 0& 1& L& -\frac{{\mathrm{<figure-callout\; id="2"\; label="qL"\; filenames="HDA00001915876700011.png"\; state="\{\{state\}\}">qL</figure-callout>}}^2}{2}\\ 0& 0& 0& 1& -\mathrm{<figure-callout\; id="0"\; label="qL"\; filenames="HDA00001915876700012.png"\; state="\{\{state\}\}">qL</figure-callout>}\\ 0& 0& 0& 0& 1\end{array}\right]{\left\{\begin{array}{c}y\\ \mathrm{\&theta;}\\ M\\ Q\\ 1\end{array}\right\}}_i^L$

L is a length in the formula, is known quantity; Q is a known quantity for the axle unit length is uniformly distributed with quality; Subscript L and R be representative unit left end and right-hand member respectively; E is the shaft part elasticity modulus of materials, is known quantity; I is the shaft part cross sectional moment of inertia, is known quantity.

If shaft section diameter does not wait in the unit, then can in each uniform cross section shaft part, set up the relation between the state parameter of two ends, a plurality of relational matrix are multiplied each other can obtain the relation between the state parameter of non-constant section shaft part two ends:

${\left\{\begin{array}{c}y\\ \mathrm{\&theta;}\\ M\\ Q\\ 1\end{array}\right\}}_i^R={\left[A\right]\left\{\begin{array}{c}y\\ \mathrm{\&theta;}\\ M\\ Q\\ 1\end{array}\right\}}_i^L$

Following formula can obtain 4 equations after launching, and n unit can obtain 4n solving equation.Following relation is arranged between i-1 unit right-hand member state parameter and the i unit left end state parameter:

${\left\{\begin{array}{c}y\\ \mathrm{\&theta;}\\ M\\ Q\\ 1\end{array}\right\}}_i^L=\left[\begin{array}{ccccc}1& 0& 0& 0& 0\\ 0& 1& 0& 0& 0\\ 0& 0& 1& 0& 0\\ 0& 0& 0& 1& {-F}_{i-1}\\ 0& 0& 0& 0& 1\end{array}\right]{\left\{\begin{array}{c}y\\ \mathrm{\&theta;}\\ M\\ Q\\ 1\end{array}\right\}}_{i-1}^R$

F wherein _I-1It is the support reaction at i-1 bearing place.Can list the individual equation of 4 (n-1) at n-1 bearing place.Axle is that initiating terminal and clearing end place shearing and moment of flexure are 0, can list 4 equations.If the height of a known n-1 bearing then can list n-1 system of equations.The solving equation group that is constituted thus adds up to 4n+4 (n-1)+4+ (n-1)=9n-1.The system of equations number equates with the unknown number number, can find the solution.Calculating the initial baseline lower shaft on this basis is each bearing load { F ₀And bearing load sensitivity matrix [A that bearing height is changed _F].The load that arbitrary height distribution lower bearing is born is:

{F}={F ₀}+[A _F]{Y}

(3) at the shaft coupling place each rotor is broken off, as shown in Figure 3, adopt with above-mentioned identical method and calculate each rotor bow deformation curve of disconnection back.Calculate under the initial baseline that dehisce in each shaft coupling place, difference of height { C ₀And the dehisce sensitivity matrix [A that the bearing absolute altitude changed with difference of height of shaft coupling _C]:

$\left\{C_0\right\}=\left\{\begin{array}{c}{\mathrm{\&Delta;}}_1\\ {\mathrm{\&Phi;}}_1\\ .\\ .\\ .\\ .\\ .\\ .\\ {\mathrm{\&Delta;}}_n\\ {\mathrm{\&Phi;}}_n\end{array}\right\}$

In the formula, Δ, Φ are respectively the shaft coupling difference of height and dehisce.This method has been considered the influence of rotor bow distortion.Fig. 4 has provided consideration (solid line) and has not considered that the deflection deformation of (dotted line) rotor is dehisced to shaft coupling and the influence of difference of height.When the rotor deflection deformation was big, its influence can not ignore.

(4) set up two-way calculating solving equation group between bearing load and the shaft coupling state:

By design bearing load Load} find the solution the axle be each shaft coupling dehisce and difference of height Coupling}:

{Coupling}={C ₀}+[A _C][A _F] ^-1(1{Load}-{F ₀})

By shaft coupling dehisce and difference of height Coupling} find the solution bearing load Load}:

{Load}={F ₀}+[A _F][A _c] ^-1(1{Coupling}-{C ₀})。

Claims (1)

1. one kind based on the shaft coupling bearing load recognition methods with difference of height of dehiscing, and it is characterized in that:

This method is regarded as nonprismatic continuous beam with axle system; Each shaft part deadweight is as being uniformly distributed with quality; Shaft coupling, thrust disc, blade and wheel disc are regarded as rigid support as being carried in the centre-point load on the continuous beam with bearing, are that to be in concentric be initial baseline to each bearing with axle; Calculation procedure is:

At first, each rotor in the axle system is broken off at the shaft coupling place, make up the solving equation group, the sensitivity matrix that calculates the dehiscing of each shaft coupling place under the initial baseline, difference of height and bearing height is changed by theory of mechanics of materials and boundary condition;

Secondly, a plurality of shaft parts of formation are broken off in axle system,, utilize theory of mechanics of materials, set up state parameter relation between top and the clearing end for each shaft part at the bearing place; Wherein, state parameter comprises: deflection, corner, shearing and moment of flexure; Utilize known boundary condition, bearing place right ends state parameter relation, known bearing height, set up bearing load known variables solving equation group, the sensitivity matrix of obtaining initial baseline lower bearing load distribution and bearing height being changed;

Once more, a plurality of shaft parts of formation are broken off in axle system, adopt and set up rotating shaft deflection deformation known variables solving equation group with above-mentioned identical method at the shaft coupling place; Obtain that initial baseline lower rotary shaft distortion, shaft coupling are dehisced, height difference and sensitivity matrix that bearing height is changed thereof, realize thus that each bearing load in the axle system distributes and the shaft coupling state between two-way calculating.

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