Design of a non circular gear Mechanism with Twice Unequal Amplitude Transmission Ratio

2022 ◽  
pp. 1-13
Author(s):  
Jiangang Liu ◽  
Zhipeng Tong ◽  
Yu Gao-hong ◽  
Xiong Zhao ◽  
Haili Zhou
Keyword(s):  
High Speed ◽  
Planetary Gear ◽  
Tooth Profile ◽  
Gear Transmission ◽  
Gear Train ◽  
Transmission Ratio ◽  
High Speed Camera ◽  
Contact Ratio ◽  
Ratio Curve ◽  
Amplitude Transmission

Abstract This study proposes a new non–circular gear transmission mechanism with an involute–cycloid composite tooth profile to realize the twice unequal amplitude transmission (In a complete rotation cycle of gear transmission, instantaneous transmission ratio has twice fluctuations obvious with unequal amplitude) of non–circular gears. The twice unequal amplitude transmission ratio curve was designed based on Fourier and polynomial functions, the change law of the Fourier coefficient on the instantaneous transmission ratio(In non-circular gear transmission, the transmission ratio changes with time, and the transmission ratio of non-circular gear should be instantaneous transmission ratio) was analyzed, and the pressure angle and contact ratio of the involute–cycloid composite tooth profile was calculated. The involute–cycloid composite tooth profile non–circular gear was machined by WEDM technology, while its meshing experiment was performed using high-speed camera technology. The results demonstrate that the instantaneous transmission ratio curve value obtained via the high-speed camera experiment was consistent with the simulation value of virtual software. Furthermore, the involute–cycloid composite tooth profile was applied in the seedling pickup mechanism of non–circular gear planetary gear train. The possibility of the application of the involute–cycloid composite tooth profile in the seedling pickup mechanism was verified by comparing the consistency of the theoretical and simulated seedling picking trajectory.

Novel Gear Transmission Mechanism With Twice Unequal Amplitude Transmission Ratio

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Gaohong Yu ◽  
Zhipeng Tong ◽  
Liang Sun ◽  
Junhua Tong ◽  
Xiong Zhao
Keyword(s):  
Structural Characteristics ◽  
Angular Displacement ◽  
Planetary Gear ◽  
Gear Transmission ◽  
Transmission Mechanism ◽  
Gear Train ◽  
Transmission Ratio ◽  
Gear Pair ◽  
Pitch Curve ◽  
Gear Rack

The operation effectiveness of multi-bar transplanting mechanisms is low, and the specific changing law of the transmission ratio (the curve of the transmission ratio has twice unequal amplitude [TUA] fluctuation.), which is needed in vegetable pot seedling transplanting, is difficult to fulfill using a planetary gear train with noncircular gears and a single-planet carrier. To address this problem, we propose a noncircular gear pair that comprises an incomplete noncircular gear, rack, partial noncircular gear, and elliptical gear. The structural characteristics and the working principle of the TUA gear pair were analyzed. The pitch curve equation of the noncircular TUA gears was derived from the relationship of the angular displacement of the corresponding pitch curves. The influence of central angle α and eccentricity k on the shape of the pitch curve, angular displacement, and transmission ratio of the TUA gear pair was analyzed. The TUA gear pair was applied to a proposed vegetable seedling pickup mechanism (SPM) considering the design requirements. Finally, the feasibility of the new noncircular TUA gear transmission mechanism was verified by an SPM test.

Design principle and modeling method of asymmetric involute internal helical gears

2018 ◽  
Vol 233 (1) ◽  
pp. 244-255 ◽  
Author(s):  
Mo Shuai ◽  
Ma Shuai ◽  
Jin Guoguang ◽  
Gong Jiabei ◽  
Zhang Ting ◽  
...  
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Planetary Gear ◽  
High Strength ◽  
Spur Gear ◽  
Low Noise ◽  
Gear Transmission ◽  
Contact Ratio ◽  
Transmission Systems ◽  
Helical Gears

In the field of mechanical engineering, involute helical gears are widely used. Compared with the involute spur gear, helical gears have a high bearing strength, more smooth transmission, less impact and less noise. The internal gear pairs have the features of large transmission ratio, low vibration, low noise and low wear and hence are widely used in planetary gear transmission systems. In order to meet the requirements of high strength, high speed of the modern gear transmission systems, a new type of asymmetric involute internal helical gears is designed based on conventional involute gears. This paper discusses the gear shaper cutter modeling for machining this new gear, analyzes the formation principle of asymmetric tooth profile and establishes a three-dimensional modeling by SolidWorks. Through MATLAB simulation, pressure angle, tooth number, coefficient of displacement and contact ratio of conventional and asymmetric gear are compared and analyzed. Using ANSYS, two types of gears are compared on strength in order to demonstrate superiority of asymmetric tooth and further study about the asymmetric internal helical gears.

Influence of the backlash generated by tooth accumulated wear on dynamic behavior of compound planetary gear set

2016 ◽  
Vol 231 (11) ◽  
pp. 2025-2041 ◽  
Author(s):  
Shijing Wu ◽  
Haibo Zhang ◽  
Xiaosun Wang ◽  
Zeming Peng ◽  
Kangkang Yang ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Dynamic Model ◽  
Dynamic Behavior ◽  
Planetary Gear ◽  
Tooth Wear ◽  
Transmission Error ◽  
Gear Transmission ◽  
Tooth Surface ◽  
Contact Ratio ◽  
The Impact

Backlash is a key internal excitation on the dynamic response of planetary gear transmission. After the gear transmission running for a long time under load torque, due to tooth wear accumulation, the backlash between the tooth surface of two mating gears increases, which results in a larger and irregular backlash. However, the increasing backlash generated by tooth accumulated wear is generally neglected in lots of dynamics analysis for epicyclic gear trains. In order to investigate the impact of backlash generated by tooth accumulated wear on dynamic behavior of compound planetary gear set, in this work, first a static tooth surface wear prediction model is incorporated with a dynamic iteration methodology to get the increasing backlash generated by tooth accumulated wear for one pair of mating teeth under the condition that contact ratio equals to one. Then in order to introduce the tooth accumulated wear into dynamic model of compound planetary gear set, the backlash excitation generated by tooth accumulated wear for each meshing pair in compound planetary gear set is given under the condition that contact ratio equals to one and does not equal to one. Last, in order to investigate the impact of the increasing backlash generated by tooth accumulated wear on dynamic response of compound planetary gear set, a nonlinear lumped-parameter dynamic model of compound planetary gear set is employed to describe the dynamic relationships of gear transmission under the internal excitations generated by worn profile, meshing stiffness, transmission error, and backlash. The results indicate that the introduction of the increasing backlash generated by tooth accumulated wear makes a significant influence on the bifurcation and chaotic characteristics, dynamic response in time domain, and load sharing behavior of compound planetary gear set.

scholarly journals The method for synthesis of the contact ratio of noncircular bevel gears

2021 ◽  
Vol 12 (1) ◽  
pp. 165-172
Author(s):  
Kan Shi ◽  
Shuai Lin ◽  
Yan'an Yao
Keyword(s):  
Transmission Ratio ◽  
Polar Coordinate System ◽  
Contact Ratio ◽  
Bevel Gears ◽  
Innovative Methods ◽  
Ratio Curve ◽  
Pure Rolling ◽  
Variable Transmission ◽  
Polar Coordinate ◽  
Pitch Curve

Abstract. As a type of spatial transmission mechanism, noncircular bevel gears can be used to transfer the power and motion with a variable transmission ratio between intersecting axes. In this paper, utilizing the spherical triangle theorem and meshing principle, the parametric equations of the contact ratio are established in the space polar coordinate system. Two innovative methods are proposed to analyze the contact ratio by using the rotation angle of the driving (driven) gears and the arc length of pitch curve as pure rolling. In the case of modified gear and X-zero gear, whether the noncircular bevel gear is continuously driven is deduced. The simulation transmission ratio curve and theoretical transmission ratio curve are compared to verify the rationality of the design.

Investigation of Planet Gear Motion in a Planetary Gear Train With Direct High Speed Monitoring

2018 ◽  
Author(s):  
Tomoki Fukuda ◽  
Masao Nakagawa ◽  
Syota Matsui ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama
Keyword(s):  
High Speed ◽  
Planetary Gear ◽  
Gear Train ◽  
Improved Method ◽  
Lighting Conditions ◽  
Planetary Gear Trains ◽  
Low Weight ◽  
Torque Capacity ◽  
Planet Gear ◽  
Gear Trains

Planetary gear trains (PGTs) are widely applied in various machines owing to their advantages, such as compactness, low weight, and high torque capacity. However, they experience the problems of vibration due to the structural and motional complexities caused by planet gears. In a previous study, it was shown that high speed monitoring is effective for evaluating the motion of planet gears under steady conditions and transient conditions including the influence of backrush. However graphical investigation was conducted manually, and improvement in accuracy is required. In this report, an improved method is proposed, which includes lighting conditions and measurement conditions. Throughout these improvement processes, instant center of rotation is calculated automatically with detected coordinates using software. This makes it possible to estimate the transient response of PGTs with planet gear motion.

scholarly journals Dynamic analysis of planetary gear train system with double moduli and pressure angles

2018 ◽  
Vol 211 ◽  
pp. 17003
Author(s):  
Heyun Bao ◽  
Guanghu Jin ◽  
Fengxia Lu ◽  
Rupeng Zhu ◽  
Xiaozhu Zou
Keyword(s):  
Differential Equation ◽  
Integration Method ◽  
High Reliability ◽  
Planetary Gear ◽  
Gear Transmission ◽  
Gear Train ◽  
Numerical Integration Method ◽  
Planetary Gear Train ◽  
Low Weight ◽  
Train System

The planetary gear transmission with double moduli and pressure angles gearing is proposed for meeting the low weight high reliability requires. A dynamic differential equation of the NGW planetary gear train system with double and pressure angles is established. The 4-Order Runge-Kutta numerical integration method is used to solve the equations from which the result of the dynamic response is got. The dynamic load coefficients are formulated and are compared with those of the normal gear train．The double modulus planetary gear transmission is designed and manufactured. The experiment of operating and vibration are carried out and provides.

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