HYDROSTATIC-MECHANICAL TRANSMISSIONS OF MOBILE MACHINES. CALCULATION OF KINEMATIC AND FORCE PARAMETERS

High efficiency, stepless regulation of speed and power increasingly attracts consumers and manufacturers of technological mobile machines, especially agricultural, to use multi-flow transmissions. To date, amongs 80% of the world market of tractor equipment, produced by leading manufacturers, 18% are tractors with hydrostatic-mechanical transmissions. The aim of this work is to develop a methodology for determining the ability to work of hydrostatic-mechanical transmissions possible schemes. From the literature it is known that 12 single-circuit (with one differential) and 288 double-circuit (with two differentials) there can be only the main structural schemes of hydrostatic-mechanical transmissions. To achieve the aim, a method for estimating an ability to work of possible schemes of hydrostatic-mechanical transmissions according to the criterion of continuity of the function of angular velocities of the links from the regulation parameters of hydraulic machines is proposed. To implement the proposed method, a methodology of calculation of kinematic and power parameters by means of appraising and solving equations that describe the interaction between the elements of single-circuit and double-circuit schemes of hydrostatic-mechanical transmissions, is developed. Analytical dependences for determination of points of discontinuity of the second kind of function of angular velocities of links from the regulation parameters and the working volume of hydraulic machines, the gear ratio of planetary gear set of differential, are determined.
The calculation algorithm and the software for selection of the inoperative scheme of hydrostatic-mechanical transmissions are developed. For example, by means of calculations and analysis of variants of schemes for wheeled tractor of tractive class 4, the conditions under which the transmission loses ability to work due to exceeding of angular velocities of links their allowable values, were defined. As a result, the method allows excluding from consideration 5 variants of single-circuit schemes and 257 variants from the 576 double-circuit schemes of hydrostatic-mechanical transmissions.

mobile machines, stepless regulation of speed, hydrostatic-mechanical transmission, hydrostatic transmission, differentials, single-circuit and double-circuit schemes, regulation parameters of hydraulic machines calculation, analysis, operability

1. Dоubovik, D. A., Elovoi, O. M. and Bakalova, L. Ju. (2014), Osnovnye napravleniya razvitiya avtotraktorokombainostroeniya [Main directions of development of the automobile, tractor and harvester engineering], Dep. in BelISA 17.07.2014 no. D201411, Ob″edinennyi institut mashinostroeniya Natsional’noi akademii nauk Belarusi, Minsk, BY.

2. Amel’chenko, P. A., Dubovik, D. A., Zhukovskii, I. N., Klyuchnikov, A. V. and Zhukovskii, A. I. (2013), ″Select the type and parameters of modern tractor transmissions″, Traktory i sel’khozmashiny [Tractors and Agricultural Machinery], no. 8, pp. 14–19.

3. Dubovik, D. A. (2012), ″Decreasing of expenditure of energy of multi-wheel drive vehicles by perfection of mechanical drives of driving wheels″, Abstract of D. Sc. Dissertation, Wheeled and tracked vehicles, State Institution of Higher Professional Education ″Belarusian-Russian University″, Mogilev, BY.

4. Taran, I. A. (2012), Transmissii shakhtnykh dizelevozov [Transmissions of mine diesel locomotives], Nacional’nyj gornyj universitet, Dnepropetrovsk, UA.

5. Samorodov, V. B., Burlyga, M. B., Koval’, A. A., Rogov, A. V. and Samorodov, B. V. (2008), ″Methodology of refinement of mathematical models volumetric efficiency axial-piston hydraulic pumps″, ″Atomobіle- ta traktorobuduvannya″: Vіsnik NTU ”KhPІ” [″Automobile and tractor.″ Vestnik NTU ″HPI″], no. 58, pp. 3–10.

6. Samorodov, V. B. and Bondarenko, A. I. (2012), ″Comparative analysis of the continuously variable double-split hydrostatic mechanical transmissions″, Sb. nauch. tr. ″Vestnik Har’kovskogo avtomobil’no-dorozhnogo universiteta″ [Collection of scientific works ″Bulletin of the Kharkov Automobile and Road University″], HNADU, Har’kov, UA, vol. 56, pp. 37–45.

7. Samorodov, V. B., Grigorov, O. V. and Bondarenko, A. I. (2012), ″Analysis of double-split continuously variable hydrostatic-mechanical tractor transmissions: selection and justification of promising schemes″, ″Transportnoe mashinostroenie″: Vestnik NTU KhPI [Transport engineering: Herald NTU KPI], no. 20, pp. 24–46.

8. Petrov, V. A. (1988), Gidroob″emnye transmissii samokhodnykh mashin [Hydrostatic transmissions for self-propelled machines], Mashinostroenie, Moscow, RU.

9. Babaev, O. M., Ignatov, L. N., Kistochkin, E. S., Sokolov, G. S. and Tsvetkov, V. A. (1987), Ob″emnye gidromekhanicheskie peredachi: raschet i konstruirovanie [Volume hydromechanical transmissions: calculation and design], Mashinostroenie, Leningrad, RU.

10. Sobol’, I. M. and Statnikov, R. B. (1981), Vybor optimal’nykh parametrov v zadachakh so mnogimi kriteriyami [Choosing the optimal parameters in problems with many criteria], Nauka, Moscow, RU.