Drive Characteristic Analysis and Design of an Elliptic Gear Mechanism

One notable transmission characteristic of an elliptic gear mechanism is that the driven gear will rotate at varying speed according to a given rule when the drive gear rotates at a uniform speed, which can just meet some special requirements that a common mechanism cannot meet. It is important for the design of special mechanisms. In this paper, the transmission characteristic of an elliptic gear mechanism was analyzed and the design method was researched. The application of the elliptic gear used in the grooved gearing mechanism was designed and the validity was proved.

Design and experimental research on the sweet potato seedling transplanting mechanism of the planetary gear train with deformed elliptical gear transmission

Aiming at the lack of suitable machines for sweet potato seedling transplanting in China,and according to the agronomic requirements for the horizontal insertion method of sweet potato seedling,a new sweet potato seedling transplanting mechanism of planetary gear train was proposed based on the non-uniform transmission of deformed elliptical gear.The working principle of the transplanting mechanism was analyzed,and the kinematics modeling and analysis of the mechanism were carried out.The study established the numerical objectives of the transplanting mechanism and applied the theory of membership function to establish a mathematical model for the parameter-guided optimization design of the transplanting mechanism.The parameter-guided optimization design software was developed to obtain a set of optimal mechanism parameters that satisfied the motion trajectory of sweet potato transplanting and the posture of the transplanting arm.Based on the optimized parameters,the structure of the transplanting mechanism was designed,and a virtual prototype of the mechanism was created,whereby a virtual motion simulation of the transplanting mechanism was conducted to verify the correctness of the kinematics model and design of the mechanism.The high-speed photographic kinematics test of the mechanism prototype and sweet potato seedling transplanting tests were conducted to test the mechanism’s kinematic characteristics and transplanting performance.The test results show that the test trajectory of the mechanism and test posture of the transplanting arm are almost consistent with the theoretical and simulation trajectory,meeting the agronomic requirements of the horizontal insertion method of sweet potato seedling;And when the rotary speed of the mechanism are 20 r/min and 30 r/min,the average success ratios of sweet potato seedlings transplanting are 90%and 82%,respectively,which prove the application feasibility of the mechanism in the practical machines.

Investigation and Application of Non-sinusoidal Oscillation Technique of Mold

To improve the slab quality, a kind of non-sinusoidal oscillation technique of mold driven by elliptic gears was developed. The waveform functions of non-sinusoidal oscillation were determined, and the calculation method and curves of technological parameters for non-sinusoidal oscillation were given. At the case of waveform deviation factor a equal to 0.31 and oscillation amplitude h equal to ±2.7 mm, the relationship between oscillation frequency and casting speed is determined, and the technological parameters for non-sinusoidal oscillation are calculated. The testing results of industrial application indicated that this technique could not only improve the Slab surface quality, but also reduce the steel breakout.

New type of transverse moving box mechanism for pot seedling transplanting machine

The existing moving box mechanism pot seedling transplanting machine on the market moves too fast when the picked seedling is collected,which negatively impacts the seedling picking performance.In order to improve the performance,two types of variable speed continuous moving box schemes were designed in this study.The first scheme was to apply a spiral-gear moving box spiral shaft with sine curve characteristics in the box moving mechanism,whereas the second one was to change the circular gear in the moving box into an elliptical gear with a speed shifting transmission mechanism.The working mechanism of the mechanical structure was analyzed,and the kinematic model was established.A dynamic analysis of the slider mechanism was performed.A virtual prototype was established according to agronomic parameters,and the virtual prototype experiments were conducted in ADAMS.The physical prototype and the high-speed photography experiment were performed on the test bench of a transplanting machine frame.The theoretical analysis,virtual prototype and physical prototype test results were consistent,which verified the validity of the theoretical model,virtual prototype and physical prototype and ensured the feasibility of the system.