Parameter design of double-circular-arc tooth profile and its influence on meshing characteristics of harmonic drive

2022 ◽  
Vol 167 ◽  
pp. 104567
Author(s):  
Chaosheng Song ◽  
Xinzi Li ◽  
Yong Yang ◽  
Jianquan Sun
Author(s):  
Ting Tang ◽  
Junyang Li ◽  
Jiaxu Wang ◽  
Ke Xiao ◽  
Yanfeng Han

A tooth profile is of significant importance to the performance of a harmonic drive. Available studies about designing a tooth profile only consider the influence of the tooth profile on the meshing characteristics from a macro perspective. However, the effects of the surface roughness and contact geometry of the tooth on the lubrication characteristics from the micro perspective are rarely reported. In the present study, a double-circular-arc tooth profile is used as the basic tooth profile of the flexspline. Based on the modified kinematic method, a conjugate profile is calculated and the tooth profile of the circular spline is obtained. On this basis, the mathematical model for the mixed lubrication of the harmonic drive with a double-circular-arc tooth profile is established by considering the factors of the normal load of meshing point, relative velocity, contact geometry, and surface roughness. The comprehensive performance under different double-circular-arc tooth profile parameters (tooth face radius, tooth flank radius, and common inclination) is analyzed. To verify the correctness of the research, four sets of harmonic drives are designed and machined for testing their basic performance. The results show that the parameters of the double-circular-arc tooth profile have multiple influences on the comprehensive performance. The meshing performance and lubrication performance are restricted. Parameter control can effectively improve comprehensive performance and different tooth profile parameters should be designed for different applications.


Author(s):  
Dong Liang ◽  
Bingkui Chen ◽  
Rulong Tan ◽  
Ruijin Liao

A novel gear transmission with double circular arc-involute tooth profile is studied in this paper. The generation principle and mathematical models of this proposed gear drive are provided based on gear geometry. The meshing characteristics of tooth surfaces are evaluated according to the analyses of motion simulation, mechanics property and sliding coefficient. The transmission efficiency experiment is based on the developed gear prototype, and a comparison with an involute gear drive is presented. The further study on dynamics analysis and key manufacturing technology will be conducted, and this new type of gear drive is expected to have excellent transmission performance.


Author(s):  
Faxiang Xie ◽  
Jing Zhang ◽  
Yinan Han ◽  
Canyuan Wu ◽  
Zhengyang Zhao ◽  
...  

Abstract In the current harmonic drive tooth profile design, the three-dimensional spatial spline tooth meshing is not fully considered, which results in problems such as inconsistence of harmonic gearing backlash, low loading capacity, low transmission accuracy and even meshing tooth profile interference in actual machining of the harmonic reducer. Based on this, this paper proposes a harmonic drive meshing quality test method at extremely low input speed based on tooth profile of double–circular-arc profile (DCTP). And combined with the theory of spatial multi-tooth meshing, the corresponding pre-control of different tooth profile modification is analyzed. The optimized non-interference three-dimensional spatial tooth profile modification method is proposed, which effectively reduces its transmission error.


Author(s):  
Ahmed M. M. El-Bahloul ◽  
Yasser Z. R. Ali

The main objective of this paper is to study the effect of gear geometry on the discharge of gear pumps. We have used gears of circular-arc tooth profile as gear pumps and have compared between these types of gearing and spur, helical gear pumps according to discharge. The chosen module change from 2 to 16 mm, number of teeth change from 8 to 20 teeth, pressure angle change from 10 to 30 deg, face width change from 20 to 120 mm, correction factor change from −1 to 1, helix angle change from 5 to 30 deg, and radii of curvature equal 1.4, 1.5, 2, 2.5, 2.75, and 3m are considered. The authors deduced that the tooth rack profile with radius of curvature equal 2.5, 2.75, 3m for all addendum circular arc tooth and convex-concave tooth profile, and derived equations representing the tooth profile, and calculated the points of intersections between curves of tooth profile. We drive the formulas for the volume of oil between adjacent teeth. Computer program has been prepared to calculate the discharge from the derived formulae with all variables for different types of gear pumps. Curves showing the change of discharge with module, number of teeth, pressure angle, face width, correction factor, helix angle, and radius of curvature are presented. The results show that: 1) The discharge increases with increasing module, number of teeth, positive correction factor, face width and radius of curvature of the tooth. 2) The discharge increases with increasing pressure angle to a certain value and then decreases with increasing pressure angle. 3) The discharge decreases with increasing helix angle. 4) The convex-concave circular-arc gears gives discharge higher than that of alla ddendum circular arc, spur, and helical gear pumps respectively. 5) A curve fitting of the results are done and the following formulae derived for the discharge of involute and circular arc gear pumps respectively: Q=A1bm2z0.895e0.065xe0.0033αe−0.0079βQ=A2bm2z0.91ρ10.669e−0.0047β


2020 ◽  
Vol 34 (22n24) ◽  
pp. 2040141
Author(s):  
Van-The Tran ◽  
Bui Trung Thanh ◽  
Banh Tien Long ◽  
Hoang Quoc Tuan ◽  
Duc Toan Nguyen

The vacuum pump usually used traditional curves such as the circular, cycloidal curves and their combinations to construct tooth profile. However, to increase efficiency and design flexibility for the vacuum pump, a novel rotor tooth profile for Roots rotor of vacuum pumps is proposed. Which is named “CEIEC” tooth profile and orderly composed of five significant segments, a circular arc for tooth tip, an epicycloid curve with variable extension, an involute, an enveloped epicycloid curve and a conjugated circular arc for tooth root. A numerical example is presented to evaluate the performance indices for proposed vacuum pump, including the hermeticity coefficients of the rotor mesh gap and tip gap.


2015 ◽  
Vol 741 ◽  
pp. 99-107
Author(s):  
Li Zu ◽  
Lan Lan Feng ◽  
Yan Yang Sun

We focused on the parametric design and simulation of new tooth profile “circular arc-involute-circular arc” for flexspline in this paper. Based on the MATLAB software, the basic tooth profile of hob was designed. According to gear generating cutting principle, the simulation of processing for flexspline tooth profile has been realized. By tooth profile normal method, we calculated flexspline tooth profile which is conjugated with the basic tooth profile of the cutting tool, and gave the contrastive studies on process simulation and theoretical calculation. Results show that they are feasible in solving the new tooth profile of flexspline. When changing the key structure parameters, the different changing regulations of flexspline tooth profile can be gained. The research results are meaningful to improve the capacity of harmonic gear drive.


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