Friction wheel transmission of no-tillage corn planters

To overcome the unfavorable factors of ground wheel-driven chain transmission when a no-tillage planter operates on straw mulching fields,a friction wheel transmission based on ground wheel transmission was designed in this research.The stability,i.e.,the effects of friction wheel tyre pressure on stability of machine transmission was investigated via validation of main factors.The relationships among tyre pressure,deformation and load were determined via theoretical analysis.The tyre pressure extreme for transmission is 25.90 psi,the maximum pressure imposed on the friction wheel tyre is 14 kN,the maximum deformation of friction wheel is 8.7 mm.The stabilities of friction wheel slip rate and seeding distance were investigated via field tests and alteration of friction wheel tyre pressure.After processing the test data,it can be found that the minimum tyre pressure for acquisition of friction wheel slip rate was 24.35 psi.After processing the data of seeding distance,it can be validated that the tyre pressure was kept unchanged following the optimal transmission effect of the transmission through the abrupt change of working speed,which further proved the feasibility of the new friction wheel transmission.The transmission of friction wheel can reduce 14.67%in variation coefficient of seed spacing at the speed of 5 km/h,and 16.22%at the speed of 8 km/h.

Vibration transmissibility characteristics of smart spring vibration isolation system

The objective of this work was to study the vibration transmissibility characteristics of the undamped and damped smart spring systems. The frequency response characteristics of them were analyzed by using the equivalent linearization technique, and the possible types of the system motion were distinguished by using the starting and ending frequencies. The influences of system parameters on the vibration transmissibility characteristics were discussed. The following conclusions may be drawn from the analysis results. The undamped smart spring system may simultaneously have one starting frequency and one ending frequency or only have one starting frequency, and the damped system may simultaneously have two starting frequencies and one ending frequency. There is an optimal control parameter to make the peak value of the vibration transmissibility curve of the system be minimum. When the mass ratio is far away from the stiffness ratio, the vibration transmissibility is small. The effect of the damping ratio on the system vibration transmissibility is significant while the control parameter is less than its optimal value. But the influence of the relative damping ratio on the vibration transmissibility is small.