The optimization of spring and hydrolic element to obtain suitable vibration and damping characteristic for farm tractors seats

ABSTRACT MSc THESIS THE OPTIMIZATION OF SPRING AND HYDROLIC ELEMENTS TO OBTAIN SUITABLE VIBRATION AND DAMPING CHARACTERISTICS FOR FARM TRACTORS SEATS TAYFUN KORUCU DEPARTMENT OF AGRICALTURAL MACHINERY INSTITUTE OF NATURAL AND APPLIED SCIENCES UNIVERSITY OF ÇUKUROVA Supervisor: Prof. Dr. Alaettin SABANCI Year: 1997, Pages: 123 Jury: Prof. Dr. Alaettin SABANCI Prof. Dr. Faruk ÖZGÜVEN Prof. Dr. Alim IŞIK In this research, it is aimed to optimize the dimensions of springs used as partly vibration remover between tractor roof and seat and to select the most appropriate spring. For this purpose, 32 springs whose spring diameter and spring thickness are different from each other were used and trials were done on these springs. In the labaratoiy v. oik, springs were connected on a mechanism firstly one by one later as serial and parallel and by putting 10 kg of mass displacement amount of each spring were measured for three different positions. Spring coefficient and undamped natural frequencies which depend on displacement and mass were calculated. Later on springs were installed on seat and the most suitable screw adjustments were found for 40, 50 and 60 kg. Springs were tested for dropping by using screw adjustments and weights, and damped natural frequencies were calculated. As a result of these trials, effect of diameter of spring and spring thickness are very significant on displacement, spring coefficient and natural frequency change. For a spring having same weight and same spring diameter, the more spring thickness, the less displacement and the more natural frequency and spring coefficient For a spring having same weight and same spring diameter, the more spring diameter, the more displacement and the less natural frequency and spring coefficient. The more weight on spring, the more displacement and the less spring coefficient. By using all these results and data obtained, a mathematical equation was developed depending on mass, displacement amount, spring diameter and spring thickness which are effective on natural frequency. Natural frequencies has a negative correlation with mass increase and a positive correlation with spring rigidity. The less natural frequency, the more displacement amount and the less spring coefficient. According to normal connection, the displacement amount doubles in serial connection, but decreases half in parallel connection. According to normal connection, spring coefficient decreases its half in serial connection, but doubles in parallel connection. According to normal connection, natural frequency decreases in serial connection, but increases in parallel connection. Keywords: Agricultural tractors, vibration, spring. n