INVESTIGATION OF PARAMETERS OF ACCUMULATOR TRANSMISSION OF SELF- MOVING MACHINE

Transcription

1 ENGINEEING FO UL DEVELOENT Jelgv, INVESTIGTION OF ETES OF CCUULTO TNSISSION OF SELF- OVING CHINE leksdrs Kirk Lithui Uiversity of griculture, Kus bstrct. Uder the ifluece of vrious fctors the momet of resistce of the self movig mchie chges. The resece of hydrosttic trsmissio i the mchie llows to get the desired trsmissio rtio betwee the egie d the ledig wheels d rovide omil lod of the egie with the chgeble momet of resistce. Sice the oertig liquid rcticlly does ot comress the trsmissio rtio chges by regultig the workig volume of the hydrulic mchies. I view of ierti of the comoets to chge the workig volume is ossible oly with defiite frequecy which rcticlly is lwys less th the frequecy of chgig the momet of resistce. The fluctutios of the resistce momet withi the zoe of the isesitiveess of the regultor cuse fluctutios of the gulr seed of the mchie egie s the cosequece of which the usge of it might decrese. For reductio of fluctutios of lodig of the egie i zoe of tolerce of regultor the hydrulic ccumultor coected i delivery cvity of hydrosttic trsmissio is used. Theoreticl reserches re led d deedeces of key rmeters of the hydrulic ccumultor o the chge of the momet of resistce of the self-movig mchie re estblished. Key words: ccumultor, hydrulic system, self movig mchie, hydrosttic trsmissio, resistce momet, hydrulic motor, um, oertig liquid. Itroductio The ccumultor is secil cotier of certi ccity cble of ccumultig the retur to the hydrulic system of the oertig liquid. It c erform differet fuctios: to ccumulte eergy, to reduce the ulstio of ressure, to comeste the lekges of the oertig liquid i the hydrulic system d so o. The costructio of the ccumultor is simle, it cosists of the body divided ito two cvities: liquid d eril. The ier cvity is divided by the isto or the membre. The eril cvity is usully filled by itroge. The eergy is ccumulted whe ressig itroge d returs to the system with its wideig. Uder the ifluece of vrious fctors the momet of resistce of the self movig mchie chges. The resece of hydrosttic trsmissio i the mchie llows gettig the desired trsmissio rtio betwee the egie d the ledig wheels d rovidig omil lod of the egie with the chgeble momet of resistce. Sice the oertig liquid rcticlly does ot comress the trsmissio rtio chges by regultig the workig volume of the hydrulic mchies. I view of ierti of the comoets to chge the workig volume is ossible oly with defiite frequecy which rcticlly is lwys less th the frequecy of chgig the momet of resistce. The fluctutios of the resistce momet withi the zoe of the isesitiveess of the regultor cuse fluctutios of the gulr seed of the mchie egie s the cosequece of which the usge of it might decrese. The ims d tsks of the ivestigtio For reductio of the fluctutios of the egie lod withi the zoe of the isesitiveess of the regultor there c be used the ccumultor coected to the force cvity of the hydrosttic trsmissio (Fig. ). Fig.. Hydrosttic trsmissio scheme of self-movig mchies 00

2 ENGINEEING FO UL DEVELOENT Jelgv, The im of the ivestigtio is determitio of the mi rmeters of the ccumultor i deedecy o the desired dmig momet of the resistce momet of the self movig mchie. ethods d results of the ivestigtio For the lyticl ivestigtio d determitio of the deedecies of the mi rmeters of the ccumultor o the momet of the chge of resistce of the self movig mchie the followig ssumtios were tke.. The efficiecy fctor of the hydrulic mchie d ccumultor is equl to. 2. The chge of the momet of resistce goes o ccordig to the siusoidl lw. 3. The oertig liquid does ot comress. 4. The lekges of the oertig liquid d hydrosttic trsmissio re bset. Cosiderig the bove idicted ssumtios we c thik tht the torque of the hydrulic motor is directly roortiol to the ressure: V () The icrese of the momet of resistce of the self movig mchie with the costt workig volume of the hydrulic motor cuses icrese of ressure i hydrosttic trsmissio d by this icrese of the torque o the shft of the um: V (2) Irregulrity of the momet of resistce is determied by the coefficiet of irregulrity d the eriod of its chge: where mx mximl meig of the momet of resistce; mi miiml meig of the momet of resistce; verge meig of the momet of resistce. mx mi (3) ccordig to () the equtio the ressure of the oertig liquid i the hydrosttic trsmissio will chge from mx (with mx ) to mi (with mi ). Tht is why the coefficiet of ressure irregulrity will be equl: where mx mximl ressure; mi miiml ressure; verge ressure. mx mi (4) With siusoidl lw chges of the momet of resistce, the curret meig of the momet of resistce will be: where k frequecy of the chge of the momet of resistce; t time. 0 + si kt (5) 2 The mlitude of the fluctutios of the shft torque of the hydrulic motor ccordig to () d (4) equtios will be equl: V (6)

3 ENGINEEING FO UL DEVELOENT Jelgv, Irregulrity of the resistce momet is determied by the coefficiet irregulrity d the eriod of its chge will be equl: 2 (7) Tkig ito ccout () the equtios of the verge meig of the shft torque of the hydrulic motor will be equl: V (8) Tkig ito ccout (7) d (8) equtio: V (9) Sice р м, (5) the equtio c be rewritte: + si kt (0) 2 The gulr ccelertio of the hydrulic motor shft will be: () I where I ttched to the hydrulic motor shft the momet of ierti of the self movig mchie. Tkig ito ccout tht, we get: ( ) si kt (2) 2I Hvig itegrted them i the obtied exressio we determie the lw of the chge of the gulr seed of the hydrulic motor shft: ω ω ( ) coskt (3) 2Ik where ω the verge gulr seed of the shft rottio of the hydrulic motor withi the eriod T. With the costt workig volume of the hydrulic motor for gettig the seed of rottio ω it is ecessry to hve the followig cosumtio of the oertig liquid: Vω (4) Uder the coditio whe, the feedig of the um will be equl to the cosumtio of the hydrulic motor. With the chge of the momet of resistce the gulr seed of the shft rottio of the hydrulic motor will chge ccordig to the equtio (3). The differece of the um feedig d the cosumtio of the hydrulic motor will iflow to the ccumultor or from it: (5) Tkig ito ccout tht the feedig of the um d the cosumtio of the hydrulic motor re roortiol to the workig volume d the frequecy of rottio we c write: ( Vω Vω ) (6) 2 π 02

4 ENGINEEING FO UL DEVELOENT Jelgv, I cse whe i the hydrosttic trsmissio there re hydrulic mchies of the sme workig volume used, the equtio (6) tkes she: V ( ω ω ) (7) 2 π Tkig ito ccout tht ω ω ω, with the ccout of the equtios (7) d (3) we will get: V ( ) coskt (8) Ik Hvig itegrted the curret exressio i time we get the lw of chge of the volume of the oertig liquid i the ccumultor withi the eriod T: V V ( ) si kt V 2 + mi (9) Ik where V mi the miiml volume of the oertig liquid i the ccumultor. Chge of volume of the ccumultor occurs i rge from V mx (t sikt ) u to V mi ( t sikt -). Therefore we my write: V ( ) (20) 2 Ik ccordig to () d (20) equtios, we receive: V Ik ( ) Comressio d exsio of gs iside the ccumultor tkes lce ccordig to the Boyle- riotte lw regrdig the sttus chge i erfect gses: 0 V0 mivmx mi (2) V (22) I the remiig lictios, such s eergy ccumultor, ulstio dmer, emergecy ower source, dymic ressure comestor, hydrulic srig, etc., it is ossible to stte, with resoble ccurcy, tht the coditio is dibtic: where olytrohic exoet. V mx mx mi mx From the equtio (23) we receive deedece o which it is ossible to defie the useful volume of the ccumultor: V Vmx (24) mi mx Coclusios. The give equtios llow defiig i the lyticl wy the workig volume of the ccumultor for desirble size dmer the momet of resistce of the self-movig mchie. 2. Deedece of the chge of the twistig momet of the egie of the mchie o the chge of the momet of resistce of the self-movig mchie is show t the coected ccumultor. 3. Deedeces of the chge of seed d ccelertio of the hydrulic motor d the chge of volume of the oertig liquid i the ccumultor lso re show. (23) 03

5 ENGINEEING FO UL DEVELOENT Jelgv, efereces. Kirk. Hidruliės ir eumtiės vros. Vilius: B OVO, tthies H. J. Eifürug i die Ölhydrulik. Stuttgrt: Teuber, S. 3. Данилов Ю. А., Кирилловский Ю. Л., Колпаков Ю. Г. Аппаратура объемных гидроприводов.-м.: Машиностроение, с. 4. Bogdevičius., retkovskis O. Hidruliių ir eumtiių sistemų dimik. Vilius: Techik, Ölhydrulik ud eumtik. Kostruktios-Jhrbuch 2007/ S. 04