CN102636304A - Torque measurement structure of water guide flap shaft of standardized high-precision model - Google Patents

Abstract

The invention relates to a torque measurement structure of a water guide flap shaft of a standardized high-precision water turbine model. By dividing a traditional integral water guide flap into three parts, namely a water guide flap shaft, a standard measurement section and a water guide flap body, when water guide flap shaft torque tests are performed on different types of models, only the water guide flap shaft and the water guide flap body need to be re-processed, and the standard measurement section which has a standard size and is subjected to quenching and tempering treatment can be used repeatedly. According to the invention, the standardization of the torque measurement structure of the water guide flap shaft of the water turbine model is realized, and the measurement precision is improved.

Description

The high-precision model water guide of standardization lobe axle torque measurement structure

Technical field: the present invention relates to the high-precision model water guide of a kind of standardization lobe axle torque measurement structure.

Background technology: the measurement of water guide lobe axle moment of torsion is a regular pilot project of model turbine.Ultimate principle is extrapolated the size of water guide lobe axle moment of torsion this moment for the strain value that utilizes measurement water guide lobe axle appropriate section under the suffered Hydraulic Moment effect of water guide lobe, to produce.As shown in Figure 1, traditional model water guide lobe axle torque measurement structure is: whole water guide lobe is a monolithic construction, and the water guide lobe axle appropriate section of measurement water guide lobe axle moment of torsion and other parts of water guide lobe adopt identical materials and do not heat-treat.There is following weak point in said structure: do not heat-treat owing to measure the water guide lobe axle appropriate section of water guide lobe axle moment of torsion; Make that the measuring section recoverability is relatively poor; The corresponding relation of water guide lobe axial strain value of measuring and water guide lobe axle moment of torsion can produce very big deviation, can directly influence the measuring accuracy of water guide lobe axle moment of torsion; Simultaneously, for the different model hydraulic turbine, as long as there is small difference in water guide lobe shape, each whole water guide lobe just all need design and process the measurement structure part non-interchangeability of water guide lobe axle moment of torsion again.In view of this, be necessary to develop a kind of standardized model water guide lobe axle torque measurement structure.

Summary of the invention: the objective of the invention is to disclose the high-precision model water guide of a kind of standardization lobe axle torque measurement structure.Technical scheme of the present invention is: the high-precision model water guide of a kind of standardization lobe axle torque measurement structure; Canonical measure section (3) top is fixedly connected with water guide lobe axle (1) by bolt (2); Canonical measure section (3) bottom is fixedly connected with water guide lobe body (4) by bolt (2); Canonical measure section (3) has all adopted seam to cooperate with water guide lobe axle (1) and water guide lobe body (4)

The corresponding relation of water guide lobe axle measuring section circular shaft structural strain and moment of torsion as shown in the formula:

$\mathrm{\γ}=\frac{M}{\mathrm{WG}}---\left(1\right)$

In the formula:

M----moment of torsion (Nm);

W----Torsion Section modulus (m ³);

γ----strain, dimensionless;

G----shear elasticity (10 ⁹N/m ²).

When carrying out dissimilar model water guide lobe axle torsional moment test; Only need process water guide lobe axle and water guide lobe body again; Can reuse and have standard-sized measuring section, simultaneously, the present invention also requires the canonical measure section is carried out the standard modifier treatment; Promptly increase temperature the Technology for Heating Processing of tempering through quenching; With the austenitic transformation in the canonical measure section mother metal that does not carry out modifier treatment is tempered sorbite (potpourri of ferrite and granular carbide), thereby when the strength of materials that makes the canonical measure section, hardness and wearing quality are improved, can also significantly improve the plasticity index of canonical measure section material; Strengthen the recoverability of canonical measure section, thereby make the measuring accuracy of model water guide lobe axle moment of torsion be improved moment of torsion.Can know according to shearing Hooke's law, as far as water guide lobe axle measuring section circular shaft structure, the corresponding relation of its strain and moment of torsion as shown in the formula:

$\mathrm{\γ}=\frac{M}{\mathrm{WG}}---\left(1\right)$

In the formula:

M----moment of torsion (Nm);

W----Torsion Section modulus (m ³);

γ----strain, dimensionless;

G----shear elasticity (10 ⁹N/m ²).

The Torsion Section modulus is determined by material, so can be found out by following formula, is receiving under the condition of same torque; Material strain value γ and shear elasticity are inversely proportional to, the canonical measure section is carried out modifier treatment after, the material shear elasticity diminishes; It is big that strain value becomes, and can improve measuring accuracy.In addition, when measuring water guide lobe axle moment of torsion, in the time spent of doing that receives same torque, the random uncertainty of corresponding relation is more little between measuring-signal and standard moment, and measuring accuracy is high more.

Principle of work of the present invention: because the version of canonical measure section is confirmed and can be used repeatedly; When carrying out the water guide lobe axle torsional moment test of other types water guide lobe; Needn't as traditional whole water guide lobe, need brand-new water guide lobe of processing; Only need process water guide lobe axle and water guide lobe body gets final product, need not processing criterion measuring section again, thereby realized the standardization of hydraulic turbine water guide lobe axle torque measurement structure.Simultaneously; The canonical measure section is carried out the standard modifier treatment; Improve the plasticity index of canonical measure section material; Strengthen the recoverability of canonical measure section to moment of torsion, have good corresponding relation between water guide lobe axial strain value that has guaranteed to measure and the water guide lobe axle moment of torsion, this will improve the measuring accuracy of model water guide lobe axle moment of torsion effectively.

Description of drawings

Fig. 1 is the prior art structural drawing

Fig. 2 is a water guide valve structure cut-open view of the present invention

Fig. 3 is a canonical measure segment structure cut-open view of the present invention

Fig. 4 is the calibration result table to monoblock type water guide lobe moment of torsion

Fig. 5 is the calibration result table to novel water guide lobe moment of torsion

Embodiment

As shown in Figure 2; The high-precision model water guide of a kind of standardization lobe axle torque measurement structure; It is characterized in that: canonical measure section 3 tops are fixedly connected with water guide lobe axle 1 by bolt 2; Canonical measure section 3 bottoms are fixedly connected with water guide lobe body 4 by bolt 2, and canonical measure section 3 has all adopted seam to cooperate with water guide lobe axle 1 and water guide lobe body 4.

Can know according to shearing Hooke's law, as far as guide vane teunnion measuring section circular shaft structure, the corresponding relation of its strain and moment of torsion as shown in the formula:

$\mathrm{\γ}=\frac{M}{\mathrm{WG}}---\left(1\right)$

In the formula:

M----moment of torsion (Nm);

W----Torsion Section modulus (m ³);

γ----strain, dimensionless;

G----shear elasticity (10 ⁹N/m ²).

The Torsion Section modulus is determined by material, so can be found out by following formula, is receiving under the condition of same torque; Material strain value γ and shear elasticity are inversely proportional to, the canonical measure section is carried out modifier treatment after, the material shear elasticity diminishes; It is big that strain value becomes, and can improve measuring accuracy.In addition, when measuring water guide lobe axle moment of torsion, in the time spent of doing that receives same torque, the random uncertainty of corresponding relation is more little between measuring-signal and standard moment, and measuring accuracy is high more.

The random uncertainty of corresponding relation is

between measuring-signal and standard moment

Wherein:

$s_Y=\sqrt{\frac{\mathrm{\Σ}{(y_i-y_j)}^2}{n-m-1}}---\left(2\right)$

$t=1.96+\frac{2.36}{v}+\frac{3.2}{v^2}+\frac{5.2}{v^{3.84}}---\left(3\right)$

v＝n-1 (4)

In the formula:

y _i----observed reading;

y _j----measured value;

The n----observation frequency;

The polynomial exponent number of m----.

The v----degree of freedom

Respectively monoblock type water guide lobe and novel assembled water guide lobe are carried out moment of torsion demarcation and random uncertainty calculating.

Fig. 4, Fig. 5 are respectively on same test unit the calibration result to monoblock type water guide lobe and novel water guide lobe moment of torsion.V is for measuring electric signal among the figure, and Nm is the theoretical torque value.

Calculate the result via above-mentioned formula; The random uncertainty of corresponding relation is 0.044105 between monoblock type water guide lobe measuring-signal and standard torque; The random uncertainty of corresponding relation is 0.02078 between novel water guide lobe measuring-signal and standard torque; Can find out, adopt novel water guide lobe not only to realize the standardization of measure portion parts, measuring accuracy also is doubled simultaneously.

Water guide lobe axle 1, canonical measure section 3 and water guide lobe body 4 are combined and have just been constituted the water guide lobe that can measure water guide lobe axle moment of torsion identical with traditional whole water guide lobe.Water guide lobe axle 1 and water guide lobe body 4 be except for dividing the body structure, and physical dimension is identical with the appropriate section of traditional whole water guide lobe.

Canonical measure section 3 is carried out modifier treatment.As shown in Figure 3, the part-structure form that canonical measure section 3 is used to measure water guide lobe axle moment of torsion is identical with the appropriate section of traditional whole water guide lobe, adopts form of flanges with connecting of 4 of water guide lobe axle 1 and water guide lobe bodies.The connecting flange size of canonical measure section 3 is not more than the water guide lobe axle 1 of connection with it and the size of water guide lobe body 4 appropriate sections.

Claims (2)

1. the high-precision model water guide of standardization lobe axle torque measurement structure; It is characterized in that: canonical measure section (3) top is fixedly connected with water guide lobe axle (1) by bolt (2); Canonical measure section (3) bottom is fixedly connected with water guide lobe body (4) by bolt (2); Canonical measure section (3) has all adopted seam to cooperate with water guide lobe axle (1) and water guide lobe body (4)

The corresponding relation of water guide lobe axle measuring section circular shaft structural strain and moment of torsion as shown in the formula:

$\mathrm{\γ}=\frac{M}{\mathrm{WG}}---\left(1\right)$

In the formula:

M----moment of torsion (Nm);

W----Torsion Section modulus (m ³);

γ----strain, dimensionless;

G----shear elasticity (10 ⁹N/m ²).

2. the high-precision model water guide of a kind of standardization according to claim 1 lobe axle torque measurement structure is characterized in that: canonical measure section (3) is carried out modifier treatment.

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