The parametric design of double-circular-arc tooth profile and its influence on the functional backlash of harmonic drive

2014 ◽  
Vol 73 ◽  
pp. 1-24 ◽  
Author(s):  
Xiaoxia Chen ◽  
Yusheng Liu ◽  
Jingzhong Xing ◽  
Shuzhong Lin ◽  
Wei Xu
Keyword(s):  
Parametric Design ◽  
Tooth Profile ◽  
Harmonic Drive ◽  
Circular Arc

Design and Simulation of New Tooth Profile of Flexspline for Harmonic Gear Drive

2015 ◽  
Vol 741 ◽  
pp. 99-107
Author(s):  
Li Zu ◽  
Lan Lan Feng ◽  
Yan Yang Sun
Keyword(s):  
Theoretical Calculation ◽  
Process Simulation ◽  
Cutting Tool ◽  
Parametric Design ◽  
Tooth Profile ◽  
Structure Parameters ◽  
Circular Arc ◽  
Gear Drive ◽  
Calculation Results ◽  
Normal Method

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.

Double-circular-arc tooth profile design and parametric analysis on the comprehensive performance of the harmonic drive

2021 ◽  
pp. 135065012110196
Author(s):  
Ting Tang ◽  
Junyang Li ◽  
Jiaxu Wang ◽  
Ke Xiao ◽  
Yanfeng Han
Keyword(s):  
Surface Roughness ◽  
Normal Load ◽  
Contact Geometry ◽  
Tooth Profile ◽  
Harmonic Drive ◽  
Circular Arc ◽  
Lubrication Performance ◽  
Comprehensive Performance ◽  
Meshing Characteristics ◽  
Tooth Flank

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.

Three-Dimensional Spatial Meshing Quality Pre-Control of Harmonic Drive Based on Double-Circular-Arc Tooth Profile

2019 ◽  
Author(s):  
Faxiang Xie ◽  
Jing Zhang ◽  
Yinan Han ◽  
Canyuan Wu ◽  
Zhengyang Zhao ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Transmission Error ◽  
Tooth Profile ◽  
Test Method ◽  
Harmonic Drive ◽  
Circular Arc ◽  
Current Harmonic ◽  
Profile Modification ◽  
Tooth Profile Modification ◽  
Modification Method

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.

Improving the Characteristics of Gear Pumps: Part A — Discharge

2003 ◽  
Author(s):  
Ahmed M. M. El-Bahloul ◽  
Yasser Z. R. Ali
Keyword(s):  
Correction Factor ◽  
Helix Angle ◽  
Tooth Profile ◽  
Radius Of Curvature ◽  
Circular Arc ◽  
Pressure Angle ◽  
Face Width ◽  
Angle Change ◽  
Number Of Teeth ◽  
Gear Pumps

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

Study on the effects of tooth profile design parameters of rotor to performance of vacuum pump

2020 ◽  
Vol 34 (22n24) ◽  
pp. 2040141
Author(s):  
Van-The Tran ◽  
Bui Trung Thanh ◽  
Banh Tien Long ◽  
Hoang Quoc Tuan ◽  
Duc Toan Nguyen
Keyword(s):  
Vacuum Pump ◽  
Tooth Profile ◽  
Design Parameters ◽  
Tooth Root ◽  
Performance Indices ◽  
Circular Arc ◽  
Numerical Example ◽  
Design Flexibility ◽  
Profile Design ◽  
Rotor Tooth

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.

Research on NC Technologies of Loxodromic Normal-Arc Bevel Gear

2014 ◽  
Vol 621 ◽  
pp. 570-575
Author(s):  
Su Zhen Wu ◽  
Jing Wang ◽  
Xue Liang Sui
Keyword(s):  
Planning Process ◽  
Tooth Profile ◽  
Bevel Gear ◽  
Spiral Bevel Gear ◽  
Circular Arc ◽  
Primary Condition ◽  
Bevel Gears ◽  
New Type ◽  
Machining Planning ◽  
Relationship Of

Normal circular-arc spiral bevel gear is a new type gear based on Bertrand conjugation principle. Normal circular-arc bevel gear selects directrix on the basis of paying attention to machining planning process. When the directrix serves as loxodrome, the formed tooth profile surface not only has fine transmissibility like general arc bevel gear, but also is convenient to machining. Starting with differential geometry, the geometry nature and inner relationship of Bertrand conjugation surface are studied. Then the normal circular-arc surface id put forward which is a typical Bertrand surface; the conjugation theory of loxodrome normal circular-arc bevel gears is studied. The characters of loxodrome line are analyzed. The tooth profile of loxodrome normal circular-arc bevel gears, the primary condition the directrix line must be satisfied, the relative curvature of the conjugating surfaces, the relations between non-interventional condition and curvature axle of the directrix line is provided; the NC machining theory of normal circular-arc bevel gears is studied, including the designing and manufacture of the tool, the movement of the machine, the adjustment of the tool under the condition of tangency and non-interventional condition and so on.

Design constraints of five-arc Roots vacuum pumps

2002 ◽  
Vol 216 (2) ◽  
pp. 225-234 ◽  
Author(s):  
P-Y Wang ◽  
Z-H Fong ◽  
H S Fang
Keyword(s):  
Design Procedure ◽  
Vacuum Pump ◽  
Tooth Profile ◽  
Design Constraints ◽  
Circular Arc ◽  
Ultimate Pressure ◽  
Rotor Profile ◽  
Circular Arcs ◽  
Centre Of Rotation ◽  
Inlet Opening

The design constraints for the tooth profile of the five-arc Roots vacuum pump are derived and discussed in this paper. The addendum portion of the five-arc tooth profile comprises five smoothly connected circular arcs, while the dedendum portion consists of conjugate curves of the addendum portion of the mating rotor. The top land of the proposed rotor profile is a circular arc with its centre coinciding with the centre of rotation. Therefore, the gap between the top land of the rotor and the wall of the chamber turns into a long and narrow path, which provides better gas sealing and wider inlet opening. The design constraints of the rotor profile are quite complex owing to the limitations of zero carryover and the condition of non-undercutting. A design procedure is proposed for determining the feasible design region by considering the geometry constraints, zero carryover and non-undercutting. By using the proposed procedure, wider inlet opening and better gas sealing are expected, while the characteristic of zero carryover is maintained. The results of experiment show that the ultimate pressure of the prototype of the five-arc Roots vacuum pump is 2,5 × 10-3 torr, and the maximum pumping speed is 1600L/min. The performance of the prototype is excellent compared with commercially available mechanical dry vacuum pumps.

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