- Volume 12 Issue 4
Because heavy-duty construction vehicles such as excavators are required for good engine-room cooling capacity, a hydraulic gear motor is adopted in the cooling fan drive mechanism to actively control the output speed, instead of adopting the conventional ON/OFF type belt drive. While gear motors are normally limited to 140bars of operating pressure, those for the cooling fan are capable of operating at continuous pressures of up to 220bars. After assembly, all gear motors for high pressure must pass an aging test which is a kind of the wearing process between the gear teeth and motor housing. During the aging process with gradual pressure increments, gear sticking sometimes occurs due to abnormal wear, resulting in defects. This paper focuses on a gear-sticking free aging test controller that is designed together with the knowledge of an experienced operator and the analysis results of experimental data of the gear jamming phenomenon. From the aging experiment, it is demonstrated that the developed controller that can alter the setting pressure of the load pump is effective for stabilizing the abrupt increase in the motor input pressure, thus preventing the hydraulic motor from stopping. This is expected to be helpful for the reduction of defects and increase in productivity.
유압모터;EPPR 밸브;모터 길들이기;유압모터 고착
- K. J. Won, J. H. Choi, K. W. Nam, W. N. Kim and K. H. Lim, "To Improve Evaluation Process of Engine-Room Thermal Performance Using CFD Analysis", 2015 spring conference on Drive and Control, pp.73-74, 2015.
- J. Y. Kim, K. N. Chung and J. G. Sim, "Cooling Analysis with Non-Uniform Flow Field for Construction Equipment", KSME autumn conference, pp.283-286, 2009.
- Anthony Esposito, Fluid Power with Appli- cation, 4th edition, Prentice Hall, New Jersey, pp.278-279, 1991.
- S. H. Kim, H. M. Son and J. C. Lee, "The effect of eccentricity between gear and housing in involute gear pump", Journal of the Korean Society of Marine Engineering, Vol. 37, No. 6. pp.631-637, 2013.
- D. Y. Shin, D. J. Seo, J. S. Yun, J. S. Jang, J. Y. Oh and B. Y. Choi, "Effect on the Wear Properties Inside Housing of Hydraulic Motors", KSFC 2014 autumn conference, pp.71-75, 2014.
- ATMEL, ATmega128 datasheet, 2005.
- G. H. Jung and G. H. Lee, "A Development of Proportional Control Solenoid Valve Performance Tester for Automatic Trans- mission", Journal of KFPS, Vol. 3, No. 4, pp.21-28, 2006.