scholarly journals Generation and Meshing Analysis of a New Type of Double Helical Gear Transmission

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Dong Liang ◽  
Tianhong Luo ◽  
Rulong Tan
Keyword(s):  
Experimental Studies ◽  
Point Contact ◽  
Helical Gear ◽  
Gear Transmission ◽  
Cnc Machining ◽  
Gear Pair ◽  
Tooth Contact Analysis ◽  
Solid Models ◽  
Geometric Relationship ◽  
Curve Element

A study on the double helical gear transmission with curve element constructed tooth pairs is carried out in this paper. Generation and mathematical model of tooth profiles are proposed based on the geometric relationship. Tooth profiles equations are derived considering the developed equidistance-enveloping approach. Design of tooth profiles with point contact is conducted and numerical example is illustrated. And the solid models of double helical gear pair with curve element constructed tooth pairs are established. Computerized design and meshing simulation are also put forward. Furthermore, stress analysis of the gear pair is conducted and gear prototypes are manufactured using CNC machining technology. Further tooth contact analysis, dynamic and experimental studies on transmission properties of gear prototypes will be carried out.

Theoretical Method for Calculating the Unit Curve of Gear Integrated Error

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Zhaoyao Shi ◽  
Xiaoyi Wang ◽  
Zanhui Shu
Keyword(s):  
Differential Equations ◽  
Optimization Algorithm ◽  
Theoretical Method ◽  
Transmission Error ◽  
Helical Gear ◽  
Contact Analysis ◽  
Gear Transmission ◽  
Tooth Contact Analysis ◽  
Static Transmission Error ◽  
Integrated Error

A theoretical method is proposed in this paper to calculate the unit curve of gear integrated error (GIE). The calculated GIE unit curve includes the quasi-static transmission error (TE) curves of the approach stage, the involute stage, and the recession stage of the ZI worm and helical gear transmission. The misalignments between the two axes of the worm and gear, as well as the modifications or errors of the tooth flanks of the gear, are considered in the procedure of calculation. Optimization algorithm is introduced to replace the solving of implicit differential equations of the conventional tooth contact analysis (TCA) method. It is proved that the proposed method is clearer and more convenient than the conventional TCA methods in calculating the GIE unit curve. The correctness and merits of the proposed method are verified by two experiments.

Nonlinear Dynamic Analysis of Helical Gear Considering Meshing Impact

2012 ◽  
Vol 201-202 ◽  
pp. 135-138 ◽  
Author(s):  
Feng Wang ◽  
Zong De Fang ◽  
Sheng Jin Li
Keyword(s):  
Dynamic System ◽  
Nonlinear Dynamic ◽  
Helical Gear ◽  
Transmission System ◽  
Contact Analysis ◽  
Gear Transmission ◽  
Impact Excitation ◽  
Tooth Contact Analysis ◽  
Meshing Stiffness ◽  
Gear Transmission System

Comprehensive meshing stiffness and single tooth meshing stiffness are calculated by tooth contact analysis and load tooth contact analysis program. The corner meshing impact model is proposed. Nonlinear dynamic model of helical gear transmission system is established in this paper considering time-varying meshing stiffness excitation, transmission error excitation, corner meshing impact excitation, and the backlash excitation. Take the ship’s helical gear transmission system as an example, the mesh impact force is derived and the primary factors that produce noises are discussed. The effects which the mesh impact brings to vibration characteristics of the gear dynamic system are concluded. Meshing impact has an inevitable effect on the vibration of the dynamic system. Impact excitation costs 8.5% in maximum of vibration acceleration response, 31% in maximum of instantaneous acceleration, and 4.9% in maximum of spectral component amplitude.

Using variable modulus to modify a rack cutter and generate a gear pair

2022 ◽  
pp. 095440622110617
Author(s):  
Yang Hsueh-Cheng ◽  
Zhong-Wei Huang
Keyword(s):  
Helical Gear ◽  
Tooth Surface ◽  
Gear Pair ◽  
Tooth Contact Analysis ◽  
Parabolic Profile ◽  
Face Width ◽  
Variable Modulus ◽  
The Face ◽  
Helical Gear Pair ◽  
Assembly Error

In this paper, two normal imaginary helical rack cutters were first established. One of these cutters is a skewed-rack cutter with an asymmetrical straight edge. The other is a rack cutter with an asymmetric parabolic profile. Second, the gear’s tooth surface of the asymmetric parabolic rack cutter is modified to be barrel-shaped based on a variable modulus. The tooth thickness of the gear is gradually reduced along the face width of the tooth from the middle of the tooth surface. Then the coordinate relationship between the gears’ blanks and the imaginary helical rack cutters was established. Through the differential geometry, crowned and uncrowned helical gear pairs were generated. Because of human factors, when the gear pair is installed, it is easy to cause the gear pair edge contact. It is necessary to add artificial assembly error settings through the tooth contact analysis to investigate the kinematic errors and contact conditions of the crowned and uncrowned helical gear pair. The mathematical models and analysis methods proposed for the crowned imaginary rack cutter using variable modulus should be useful for the design and production of double crowned helical gears with asymmetric parabolic teeth.

Dynamic model of a helical gear pair considering tooth surface friction

2020 ◽  
Vol 26 (15-16) ◽  
pp. 1356-1366 ◽  
Author(s):  
Cheng Wang
Keyword(s):  
Friction Coefficient ◽  
Dynamic Model ◽  
Sliding Friction ◽  
Surface Friction ◽  
Helical Gear ◽  
Tooth Surface ◽  
Gear Pair ◽  
Tooth Contact Analysis ◽  
Sliding Friction Coefficient ◽  
Helical Gear Pair

The tooth surface friction is one of the main sources of gear vibration and noise. The current challenging problems in research of a helical gear pair dynamics considering tooth surface friction include the following: (1) Calculation accuracy of the tooth surface friction factor needs to be improved. (2) The meshing process of a helical gear pair has not been fully taken into account in a dynamic model. To solve these problems, a dynamic model of a helical gear pair considering tooth surface friction is proposed in this article. First, based on the tooth contact analysis and loaded tooth contact analysis of a helical gear pair, excitation of time-varying meshing stiffness, the sliding friction coefficient on tooth surface, and the arm of friction force are preliminarily calculated. Second, the dynamic model of a helical gear pair considering tooth surface friction is built and solved, in which the dynamic meshing force/speed/displacement is calculated. The sliding friction coefficient on tooth surface, arm of friction force, and dynamic equations form a coupled system. By decoupling calculation, the model system equations are solved. Finally, an example is presented to verify the proposed model.

A helical gear with discrete ring-involute teeth

2019 ◽  
Vol 234 (8) ◽  
pp. 1554-1568
Author(s):  
Hsueh-Cheng Yang ◽  
Wen-Jun Liang
Keyword(s):  
Contact Stress ◽  
Computer Aided Design ◽  
Transmission Error ◽  
Helical Gear ◽  
Gear Pair ◽  
Tooth Contact Analysis ◽  
Element Analysis ◽  
The Family ◽  
Aided Design ◽  
Assembly Error

This study produces a skewed-imaginary planar rack cutter with discrete conical teeth that is used to create a helical gear with discrete ring-involute teeth. A mathematical equation for the skewed-imaginary rack cutter with discrete conical teeth is firstly solved. The coordinate system for the rack cutter and gear pair is then established and a family of the rack-cutter surfaces is obtained using homogeneous coordinate transformation. The relative velocity method is used to produce the equation for meshing between the rack cutter and the gear pair. Substituting the equation of meshing into the family of the rack-cutter surfaces gives the mathematical models for the gear pair with discrete ring-involute teeth. The transmission error for the gear pair is calculated using the assembly error and a tooth contact analysis. A computer-aided design software package is used to establish solid model for the gear pair. A software interference function is used to simulate the contact condition for the gear pair for various assembly errors. Finite element analysis software is then used to determine the contact stress for the gear pair. The transmission error and the contact stress for the gear pair are insensitive to any horizontal misalignment in the assembly errors.

scholarly journals Dynamic Analysis of High-Speed Helical Gear Transmission in Pure Electric Vehicle Gearbox

2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Yanchao Zhang ◽  
Jinfu Du ◽  
Jin Mao ◽  
Min Xu
Keyword(s):  
Surface Modification ◽  
Electric Vehicle ◽  
High Speed ◽  
Helical Gear ◽  
Gear Transmission ◽  
Tooth Surface ◽  
Gear Pair ◽  
Two Stage ◽  
Rotating Speed ◽  
Tooth Surface Modification

This study is to systematically analyze the influences of time-varying meshing stiffness (TVMS) and meshing impact on the dynamic characteristics of high-speed gear transmission in the two-stage pure electric vehicle (PEV) gearbox, as well as the effect of tooth surface modification on the vibration control. First, the dynamic model was established, and the TVMS and meshing impact were calculated. Then, the vibration characteristics of single-stage and two-stage helical gear transmission were analyzed under three different excitation conditions, excitation of TVMS, excitation of meshing impact, and excitation of both. The results show that the effect of rotating speed on the system vibration is not significant outside the resonant region under the excitation of TVMS, while the effect of meshing impact becomes the main exciting component with the increasing rotating speed. The vibrations of the two gear pairs interact with each other; the vibration frequency of one gear pair contains both its meshing frequency and the coupling frequency of the other gear pair. Tooth surface modification in the input-stage gear pair can reduce the vibration of both the input- and the output-stage obviously; that is, more attention should be paid to the input-stage gear pair in the modification design of PEV gearbox.

A calculation method of sliding friction coefficient on tooth surface for helical gear pair based on loaded tooth contact analysis and elastohydrodynamic lubrication theory

2020 ◽  
pp. 135065012096689
Author(s):  
Cheng Wang ◽  
Mao Ken
Keyword(s):  
Friction Coefficient ◽  
Sliding Friction ◽  
Elastohydrodynamic Lubrication ◽  
Helical Gear ◽  
Tooth Surface ◽  
Gear Pair ◽  
Tooth Contact Analysis ◽  
Sliding Friction Coefficient ◽  
Loaded Tooth Contact Analysis ◽  
Helical Gear Pair

The sliding friction coefficient on tooth surface is related to power loss, carry capacity and transmission performance of gear. Reasonable transmission analysis of gear pair is the premise of accurate calculation of sliding friction coefficient on tooth surface. However, for helical gear pair, the line contact without considering machining error/installation error/modification of gear is usually adopted to replace the major axis of ellipse caused by contact load. Therefore, in this paper, contact path on tooth surface, length of contact line, load distribution on tooth surface and loaded transmission errors are accurately calculated by loaded tooth contact analysis (LTCA). Combing with elastohydrodynamic lubrication (EHL) theory, a calculation method of sliding friction coefficient on tooth surface for helical gear pair is proposed.

scholarly journals Optimal Vibration Suppression Modification Method for High-Speed Helical Gear Transmission of Battery Electric Vehicles under Full Working Conditions

Machines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 226
Author(s):  
Jinfu Du ◽  
Liang Hu ◽  
Jin Mao ◽  
Yanchao Zhang
Keyword(s):  
Working Conditions ◽  
High Speed ◽  
Vibration Suppression ◽  
Helical Gear ◽  
Contact Analysis ◽  
Gear Transmission ◽  
Tooth Surface ◽  
Time Varying ◽  
Tooth Contact Analysis ◽  
Tooth Contact

To improve the working performance of battery electric vehicle (BEV) high-speed helical gear transmission under full working conditions, combined with Tooth Contact Analysis (TCA) and Loaded Tooth Contact Analysis (LTCA), the vibration model of single-stage helical gear bending-torsion-axis-swing coupling system considering time-varying mesh stiffness was established. The genetic algorithm was used to optimize the tooth surface with the objective of minimizing the mean value of the vibration acceleration at full working conditions. Finally, a high-speed helical gear transmission system in a BEV gearbox was taken as a simulation example and the best-modified tooth surface at full working conditions was obtained. Experiment and simulation results show that the proposed calculation method of time-varying meshing stiffness is accurate, and tooth surface modification can effectively suppress the vibration of high-speed helical gear transmission in BEV; compared to the optimally modified tooth surface under a single load, the optimal modified tooth surface under full working conditions has a better vibration reduction effect over the entire working range.

The Engineering Design of Helical Spur Gear Transmission with Single Gear Pair for Electric Scooter

2015 ◽  
Vol 764-765 ◽  
pp. 374-378 ◽  
Author(s):  
Long Chang Hsieh ◽  
Tzu Hsia Chen ◽  
Hsiu Chen Tang
Keyword(s):  
Engineering Design ◽  
Spur Gear ◽  
Gear Transmission ◽  
Reduction Ratio ◽  
Gear Pair ◽  
Engineering Drawing ◽  
Electric Scooter ◽  
High Reduction ◽  
Cost Of Production ◽  
The Cost

Traditionally, the reduction ratio of a spur gear pair is limited to 4 ~ 7. For a spur gear transmission with reduction ratio more than 7, it is necessary to have more than two gear pairs. Consider the cost of production, this paper proposes a helical spur gear reducer with one gear pair having reduction ratio 19.25 to substitute the gear reducer with two gear pairs. Based on the involute theorem, the gear data of helical spur gear pair is obtained. According to the gear data, its corresponding engineering drawing is accomplished. This manuscript verify that one spur gear pair also can have high reduction ratio (20 ~ 30).

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