CN105698695A - Novel tooth root bending stress online monitoring device and novel tooth root bending stress online monitoring method based on fiber grating - Google Patents

Abstract

The invention discloses a novel tooth root bending stress online monitoring device and a novel tooth root bending stress online monitoring method based on a fiber grating. The novel tooth root bending stress online monitoring device comprises a signal detecting unit and a signal processing unit. The signal detecting unit comprises a measurement grating and a transmission optical fiber which are arranged on the side surface of a gear. The transmission optical fiber is closely adhered on a position which is next to a tooth tip on the side surface of the gear. The measurement grating is arranged on the transmission optical fiber between two adjacent gear teeth. The signal processing unit comprises an optical fiber slip ring, a fiber grating demodulator and a computer. The transmission optical fiber penetrates through the optical fiber slip ring and is connected with the fiber grating demodulator. The fiber grating demodulator is connected with the computer through a transmission netting twine. The measurement grating acquires the signal of the gear in real time. After processing by the fiber grating demodulator, the signal of the gear is converted to a tooth root bending stress, and furthermore a processing result is transmitted to the computer for realizing real-time display. The novel tooth root bending stress online monitoring device and the novel tooth root bending stress online monitoring method can realize gear transmission bending stress monitoring in various working conditions, and furthermore have advantages of simple structure, convenient operation, accurate measurement and easy realization.

Description

Novel Dedenda's bending stress on-Line Monitor Device and method based on fiber grating

Technical field

The present invention relates to optical fiber grating sensing and machinery performance monitoring crossing domain, particularly relate to a kind of novel Dedenda's bending stress on-Line Monitor Device based on fiber grating and method。

Background technology

The design of gear is typically all and carries out according to previously given rated load, but the alignment error etc. produced in the mismachining tolerance produced due to work in-process and use procedure, can cause that vibrations and deformation occur gear in actual transmission process, this not only can bring noise and vibrations, also can reduce gear-driven accuracy and work efficiency。Also allow the gear teeth bear certain extra dynamic stress simultaneously, cause that Dedenda's bending stress increases, if the bending stress at tooth root place has exceeded its fatigue limit, it is easy for broken teeth, broken teeth is one of failure mode common in gear drive, it is possible to the consequence caused is to damage plant equipment even to threaten personal safety。

In the last few years, in order to the intensity of gear is analyzed, domestic and international many scholars propose multiple method, are summed up and mainly have: theoretical derivation type, three-dimensional artificial type, three kinds of methods of foil gauge measurement type。Theoretical derivation and three-dimensional artificial are mainly based upon some and assume and on the basis of simplification, it is impossible to actual condition is substituted in calculating, although the effect of Guiding Practice can be played, but also must bring very big error；Although the method that foil gauge is measured can substitute into operating mode and carry out actual measurement, but owing to the group bridge mode of foil gauge is complex, and the stickup space at tooth root place is comparatively narrow and small, deliver the breakage also resulting in foil gauge for a long time even to come off, therefore foil gauge measures the general check being only used for carrying out additive method, and it is only static check, foil gauge can not be used under the operating mode of high-speed and continuous to measure。So how in gear drive process, it can be carried out real-time dynamic monitoring, and don't affect the nominal situation of gear, just become pendulum a difficult problem in face of numerous scholars。

Summary of the invention

The technical problem to be solved in the present invention is in that for the method error of prototype gear strain dynamics in prior art big, and easily affect the defect of working gear, it is provided that a kind of simple in construction, the novel Dedenda's bending stress on-Line Monitor Device based on fiber grating being easily achieved and method。

The technical solution adopted for the present invention to solve the technical problems is:

The present invention provides a kind of novel Dedenda's bending stress on-Line Monitor Device based on fiber grating, including acquisition of signal unit and signal processing unit；

Described acquisition of signal unit includes the measurement grating and the Transmission Fibers that are arranged on gear side, and Transmission Fibers is closely pasted onto the position near tooth top, the side of gear, measures grating and is arranged in the Transmission Fibers of two adjacent wheel between cog；

Described signal processing unit includes optical fiber slip ring, fiber Bragg grating (FBG) demodulator and computer, and Transmission Fibers is connected with fiber Bragg grating (FBG) demodulator by after optical fiber slip ring, and fiber Bragg grating (FBG) demodulator is connected with computer by transmitting netting twine；

Measure the signal of grating Real-time Collection gear, after being processed by fiber Bragg grating (FBG) demodulator, be converted to Dedenda's bending stress, and result is transferred to computer shows in real time。

Further, the described gear of the present invention also includes the output shaft being provided with optical fiber duct, and Transmission Fibers exports axle head by optical fiber duct。

Further, the described fiber Bragg grating (FBG) demodulator of the present invention is high speed optic fiber grating (FBG) demodulator。

Further, the length of the described measurement grating of the present invention, less than space width, is horizontally set on the centre position of two adjacent teeth。

Further, the described Transmission Fibers of the present invention is pasted onto on gear by glue, and the coat of the Transmission Fibers at paste position place is stripped。

The present invention provides a kind of novel Dedenda's bending stress on-line monitoring method based on fiber grating, comprises the following steps:

S1, pasting Transmission Fibers at the tooth top place of gear side, arrange measurement grating in the centre position of two adjacent teeth, Transmission Fibers is by being connected with fiber Bragg grating (FBG) demodulator after optical fiber slip ring；

The gear data that S2, acquisition Transmission Fibers transmission come, and it is demodulated and processes, obtain Dedenda's bending stress；

Further, the step S2 of the present invention carries out the method for data process particularly as follows:

The periodic relationship that the raw drift of grating transmitted wave long hair is stretched with grating and compresses is obtained by demodulating, process the amount of deflection obtaining detection gear, the gear teeth are considered as cantilever beam, according to the linear relationship determining on the gear teeth that tangential force suffered by the amount of deflection of position and the gear teeth presents, obtain the linear relationship of amount of deflection and Dedenda's bending stress。

Further, in the step S2 of the present invention, Dedenda's bending stress computing formula is:

${\mathrm{\σ}}_F=\frac{{\mathrm{KF}}_t{Y}_{Fa}{Y}_{Sa}}{bm}$

Wherein, K is assumed (specified) load coefficient, Y_SaFor stress correction coefficient, Y_FaForm factor, F_tFor the force of periphery, b is the facewidth, and m is module。

The beneficial effect comprise that: the novel Dedenda's bending stress on-Line Monitor Device based on fiber grating of the present invention, by the measurement of Dedenda's bending stress being converted into the measurement of Tooth Deflection, not only make measurement convenient, adopt fiber grating measurement to also overcome foil gauge simultaneously and can not measure the technical barrier of amount of deflection；Fiber grating is respectively positioned on wheel flank, do not affect the normal transmission of gear, effectively actual condition can be substituted in measuring, ensure accuracy and the reliability of result, optical fiber slip ring and high speed optic fiber grating (FBG) demodulator is have employed, so this invention is applicable to the gear drive under high-speed working condition due to the output of signal；The method removes the interference that temperature factor is brought, because without carrying out temperature compensation means, enormously simplify the structure of acquisition of signal part；By regulating the height of grating paste position distance tooth root, it is possible to obtain the monitoring of different sensitivity, the measurement to gear week upper each tooth can be realized by multiple grating of connecting。

Accompanying drawing explanation

Below in conjunction with drawings and Examples, the invention will be further described, in accompanying drawing:

Fig. 1 is the structural representation of the novel Dedenda's bending stress on-Line Monitor Device based on fiber grating of the embodiment of the present invention；

Fig. 2 is the partial enlarged drawing measuring grating probe portion of the novel Dedenda's bending stress on-Line Monitor Device based on fiber grating of the embodiment of the present invention；

Fig. 3 is the flow chart of the novel Dedenda's bending stress on-line monitoring method based on fiber grating of the embodiment of the present invention；

Fig. 4 is the cantilever beam force analysis figure of the novel Dedenda's bending stress on-line monitoring method based on fiber grating of the embodiment of the present invention；

Fig. 5 is the gear tooth deformation schematic diagram of the novel Dedenda's bending stress on-line monitoring method based on fiber grating of the embodiment of the present invention；

In figure, 1-gear, 2-measures grating, 3-Transmission Fibers, 4-optical fiber duct, 5-output shaft, 6-optical fiber slip ring, 7-high speed optic fiber grating (FBG) demodulator, and 8-transmits netting twine, 9-computer, and 10-pastes glue, 11-first gear teeth, 12-second gear teeth。

Detailed description of the invention

In order to make the purpose of the present invention, technical scheme and advantage clearly understand, below in conjunction with drawings and Examples, the present invention is further elaborated。Should be appreciated that specific embodiment described herein is only in order to explain the present invention, is not intended to limit the present invention。

As it is shown in figure 1, the novel Dedenda's bending stress on-Line Monitor Device based on fiber grating of the embodiment of the present invention, including acquisition of signal unit and signal processing unit；

Acquisition of signal unit includes the measurement grating 2 and the Transmission Fibers 3 that are arranged on gear 1 side, and Transmission Fibers 3 is closely pasted onto the position near tooth top, the side of gear 1, measures grating 2 and is arranged in the Transmission Fibers 3 of two adjacent wheel between cog；

Signal processing unit includes optical fiber slip ring 6, fiber Bragg grating (FBG) demodulator 7 and computer 9, and Transmission Fibers 3 is connected with fiber Bragg grating (FBG) demodulator 7 by after optical fiber slip ring 6, and fiber Bragg grating (FBG) demodulator 7 is connected with computer 9 by transmitting netting twine 8；

Measure the signal of grating 2 Real-time Collection gear 1, after being processed by fiber Bragg grating (FBG) demodulator 7, be converted to Dedenda's bending stress, and result is transferred to computer 9 shows in real time。

Gear 1 also includes the output shaft 5 being provided with optical fiber duct 4, and Transmission Fibers 3 is by optical fiber duct 4 output to axle head。Fiber Bragg grating (FBG) demodulator 7 is high speed optic fiber grating (FBG) demodulator。Measure the length of grating 2 less than space width, be horizontally set on the centre position of two adjacent teeth。Transmission Fibers 3 is pasted onto on gear 1 by glue, and the coat of the Transmission Fibers 3 at paste position place is stripped。Transmission Fibers 3 is exported to axle head by the optical fiber duct on transmission axle, is realized by the transformation of dynamic rotary to static transmission by optical fiber slip ring 6 at axle head。Glue is 353ND glue, and coat peeled off by uniform and paste position place the optical fiber of gluing, it is prevented that optical fiber stress produces displacement。

Paste grating in the side of gear, gear will not be caused any damage, the transmission of gear is not produced impact, it is ensured that the accuracy of conclusion。According to Machine Design, mechanical theory and mechanics of materials relevant knowledge, the gear teeth are considered as a cantilever beam in loading process, after stop position is fixing, the amount of deflection of the gear teeth is relevant with tangential force suffered by the gear teeth, and is linear relationship, therefore amount of deflection can react the stressing conditions of the gear teeth。

Signal transmission and acquisition process process in the present invention are as follows: be pasted onto the Transmission Fibers on the gear teeth 1 sidewall by gear 1 to output shaft, output shaft welds together with the input of optical fiber slip ring 6, and by the optical fiber duct 4 opened on output shaft, Transmission Fibers 3 is caused axle head, axle head center and optical fiber slip ring 6 center are maintained at sustained height, therebetween it is connected by moccasin pipe simultaneously, to ensure that optical fiber slip ring 6 can not be subject to external force when high-speed rotation, thus optical fiber slip ring 6 is played a protective role, so, after optical fiber slip ring 6, signal just can transmit to (FBG) demodulator 7 and carry out subsequent demodulation and process。

Gear gear teeth in the process of transmission moment of torsion are inevitably subject to tangential force, the main source that the bending stress of the gear teeth and amount of deflection produce is exactly this tangential force, under the effect of Tooth Deflection, it is pasted onto the grating between the gear teeth then can be subject to periodically stretching and compression, and then causes that corresponding drift occurs the wavelength that grating launches light。When calculating the bending strength of gear, whether adopt iso standard or AGMA standard, be all the single gear teeth are considered as cantilever beam solve。

As shown in Figure 4, the cantilever beam of to be a length be l is at free end by the deformation sketch under single load F effect, and with along the length direction of beam for coordinate axes, then according to mechanics of materials relevant knowledge, its deflection curve equation is:

$\{\begin{array}{c}\mathrm{\ω}=-\frac{{\mathrm{Fx}}^2}{6EI}(3a-x)(0\≤x\≤a)\\ \mathrm{\ω}=-\frac{{\mathrm{Fx}}^2}{6EI}(3a-x)(a\≤x\≤l)\end{array}---\left(1\right)$

In formula, E is the elastic modelling quantity of respective material, and I is the moment of inertia of centering axle, and EI is collectively referred to as the bending rigidity of beam, and a is the position of the fixing end of application point distance, and x is the position of the fixing end of optional position distance。

By in formula (1) it can be seen that after the position of the single load F effect applied is fixing, then in a certain fixed position, produced by this load effect, amount of deflection ω the size with load F has relation, and the two is linear。Thus consider, in elastic range, if gear tooth is regarded as cantilever beam, when gear is subject to the effect of load, it will along the circumferential direction produce only small amount of deflection, as shown in Figure 5。

According to the Dedenda's bending stress computing formula that analytic calculation obtains it is:

${\mathrm{\σ}}_F=\frac{{\mathrm{KF}}_t{Y}_{Fa}{Y}_{Sa}}{bm}---\left(2\right)$

In formula: K is assumed (specified) load coefficient, Y_SaFor stress correction coefficient, Y_FaForm factor, F_tFor the force of periphery, b is the facewidth, and m is module。

Except peripheral force F in formula_tOutside changing along with the moment of torsion of transmission, all the other all can be calculated by gear parameter or consult reference books obtaining, and when gear model is selected and do not change cooperate when, then the bending stress of tooth root is along with F_tMonotone variation and linear, and then the side-play amount with amount of deflection produced by gear and the reflection kernel wavelength of grating is linear equally, this just ensure that fiber grating has good linear convergent rate for surveying Dedenda's bending stress theoretically。In sum, Dedenda's bending stress is same linear with the drift of the reflection wavelength of grating, is undertaken by foil gauge experiment demarcating the linear formula that can obtain wave length shift with Dedenda's bending stress, reaches the purpose of monitoring Dedenda's bending stress。

In another embodiment of the present invention, torque and rotating speed is applied by Frequency Converter Control frequency conversion motor, different loads is applied by tension controller, purpose is to produce the signal of different operating mode lower gear transmission, and this signal is reflected as stretching or the compression of grating when the gear teeth pasting optical fiber are engaged。

The probe portion of signal is as in figure 2 it is shown, include measuring grating 2, Transmission Fibers 3, pasting glue 10, first gear teeth 11 and second gear teeth 12。The method of fixed grating is, by the Transmission Fibers 3 of grating 2 both sides is affixed to 353ND glue on first gear teeth 11 and second gear teeth 12 respectively, notice that optical fiber location for paste peels its overlay off, it is to avoid relative sliding occurs during stress, and ensures that grating is horizontal。When first gear teeth 11 or second gear teeth 12 are when being engaged, suffered bending stress will be reacted in the amount of deflection of the gear teeth, will stretch or Compressed grating when the gear teeth produce amount of deflection, produces the shifted signal of wavelength。

Signal sampling and processing part includes optical fiber slip ring 6, high speed optic fiber grating (FBG) demodulator 7, transmission netting twine 8 and computer 9, and gathering and process part can, away from monitoring field, accomplish on-the-spot passive。Wherein the signal of grating 2 detection is transferred to optical fiber slip ring 6 by Transmission Fibers 3, it is achieved by moving quiet transformation, and signal is delivered to (FBG) demodulator 7 and is demodulated processing by optical fiber slip ring, and the signal after process is delivered to computer 9 by netting twine 8 and displayed and preserve。Wherein, Transmission Fibers 3 is exported to optical fiber slip ring by the optical fiber duct 4 held successfully in advance on output shaft 5。

Present invention achieves the monitoring to Dedenda's bending stress, it is possible to realize the gear drive bending stress monitoring under various operating mode, there is simple in construction, easy to operate, measure accurately, it is easy to accomplish advantage。

As it is shown on figure 3, the novel Dedenda's bending stress on-line monitoring method based on fiber grating of the embodiment of the present invention, for realizing the novel Dedenda's bending stress on-Line Monitor Device based on fiber grating of the embodiment of the present invention, comprise the following steps:

S1, pasting Transmission Fibers at the tooth top place of gear side, arrange measurement grating in the centre position of two adjacent teeth, Transmission Fibers is by being connected with fiber Bragg grating (FBG) demodulator after optical fiber slip ring；

The gear data that S2, acquisition Transmission Fibers transmission come, and it is demodulated and processes, obtain Dedenda's bending stress；

Step S2 carries out the method for data process particularly as follows:

The periodic relationship that the raw drift of grating transmitted wave long hair is stretched with grating and compresses is obtained by demodulating, process the amount of deflection obtaining detection gear, the gear teeth are considered as cantilever beam, according to the linear relationship determining on the gear teeth that tangential force suffered by the amount of deflection of position and the gear teeth presents, obtain the linear relationship of amount of deflection and Dedenda's bending stress。

It should be appreciated that for those of ordinary skills, it is possible to improved according to the above description or converted, and all these are improved and convert the protection domain that all should belong to claims of the present invention。

Claims (8)

1. the novel Dedenda's bending stress on-Line Monitor Device based on fiber grating, it is characterised in that include acquisition of signal unit and signal processing unit；

Described acquisition of signal unit includes the measurement grating (2) and the Transmission Fibers (3) that are arranged on gear (1) side, Transmission Fibers (3) is closely pasted onto the side of gear (1) near the position of tooth top, measures grating (2) and is arranged in the Transmission Fibers (3) of two adjacent wheel between cog；

Described signal processing unit includes optical fiber slip ring (6), fiber Bragg grating (FBG) demodulator (7) and computer (9), Transmission Fibers (3) is connected with fiber Bragg grating (FBG) demodulator (7) afterwards by optical fiber slip ring (6), and fiber Bragg grating (FBG) demodulator (7) is connected with computer (9) by transmitting netting twine (8)；

Measure the signal of grating (2) Real-time Collection gear (1), after being processed by fiber Bragg grating (FBG) demodulator (7), be converted to Dedenda's bending stress, and result is transferred to computer (9) shows in real time。

2. the novel Dedenda's bending stress on-Line Monitor Device based on fiber grating according to claim 1, it is characterized in that, described gear (1) also includes the output shaft (5) being provided with optical fiber duct (4), and Transmission Fibers (3) is by optical fiber duct (4) output to axle head。

3. the novel Dedenda's bending stress on-Line Monitor Device based on fiber grating according to claim 1, it is characterised in that described fiber Bragg grating (FBG) demodulator (7) is high speed optic fiber grating (FBG) demodulator。

4. the novel Dedenda's bending stress on-Line Monitor Device based on fiber grating according to claim 1, it is characterised in that the length of described measurement grating (2), less than space width, is horizontally set on the centre position of two adjacent teeth。

5. the novel Dedenda's bending stress on-Line Monitor Device based on fiber grating according to claim 1, it is characterized in that, described Transmission Fibers (3) is pasted onto on gear (1) by glue, and the coat of the Transmission Fibers at paste position place (3) is stripped。

6. the novel Dedenda's bending stress on-line monitoring method based on fiber grating, it is characterised in that comprise the following steps:

S1, pasting Transmission Fibers at the tooth top place of gear side, arrange measurement grating in the centre position of two adjacent teeth, Transmission Fibers is by being connected with fiber Bragg grating (FBG) demodulator after optical fiber slip ring；

The gear data that S2, acquisition Transmission Fibers transmission come, and it is demodulated and processes, obtain Dedenda's bending stress。

7. the novel Dedenda's bending stress on-line monitoring method based on fiber grating according to claim 6, it is characterised in that step S2 carries out the method for data process particularly as follows:

The periodic relationship that the raw drift of grating transmitted wave long hair is stretched with grating and compresses is obtained by demodulating, process the amount of deflection obtaining detection gear, the gear teeth are considered as cantilever beam, according to the linear relationship determining on the gear teeth that tangential force suffered by the amount of deflection of position and the gear teeth presents, obtain the linear relationship of amount of deflection and Dedenda's bending stress。

8. the novel Dedenda's bending stress on-line monitoring method based on fiber grating according to claim 7, it is characterised in that in step S2, Dedenda's bending stress computing formula is:

Wherein, K is assumed (specified) load coefficient, Y_SaFor stress correction coefficient, Y_FaForm factor, F_tFor the force of periphery, b is the facewidth, and m is module。