The Study on Factors Affecting Performance of a Single Shank Vibrating Subsoiler

Abstract

A Single Shank Vibrating Subsoiler using the hydrostatic system was built for the reduction of vibration which caused rider’s discomfort and premature failures of tractor’s components. It consists of one blades attached to an unbalanced mass shaft which was
driven by hydraulic motor. The system was powered by a PTO shaft of a 50 hp tractor.
The experiments were conducted in sandy clay loam soil of 20.60% (db) moisture content, 1.66 g/cm3 dry bulk density and 2.58 MPa cone penetration resistance at two forward speeds (1.39 and 2.09 km/h), four oscillatory frequencies (0, 7, 9 and 11 Hz), two
tillage depths (30 and 40 cm) and a constant oscillatory amplitude of 36.5 mm. Comparing between the oscillatory and non-oscillatory modes, it was found that the
oscillatory mode gave a maximum reduction of draft force by 32.69% at 11 Hz oscillatory
frequency 2.09 km/h forward speed and 30 cm tillage depth. However, the oscillatory
mode resulted to 120.55% increase in total power, 19.77% reduction in soil disturbance
and 21.99% reduction in dry bulk density. Draft force, total power and soil disturbance
increased with increase of forward speed and tillage depth. As a conclusion, the forward
speed, oscillatory frequency and tillage depth significantly affected the draft force, total
power and soil disturbance. The tractor seat vibration was reduced by 32.14% - 34.22% at
the same of forward speed, oscillatory frequency and tillage depth in the hydrostatic
power transmission system as compared to the mechanical transmission one. The
optimum operating parameters were evaluated by means of questionnaire. The relative
importance of parameters was first determined and later used to calculate the weighted
arithmetic mean of user satisfactory index. The maximum value was found to be 3.372
which corresponded to 2.09 km/h forward speed, 30 cm tillage depth and 9 Hz oscillatory frequency.