scholarly journals Modeling and analysis of transient lubrication characteristic of the helicopter main transmission spiral bevel gears in point contacts

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yanzhong Wang ◽  
Kai Yang ◽  
Xiaomeng Chu ◽  
Wen Tang ◽  
Changyong Huang
Keyword(s):  
Film Thickness ◽  
Contact Area ◽  
Bevel Gear ◽  
Spiral Bevel Gear ◽  
Spiral Bevel Gears ◽  
Oil Film ◽  
Bevel Gears ◽  
Lubrication Performance ◽  
Spiral Bevel ◽  
Meshing Process

AbstractAn engineering calculation model is introduced for point-contact elastohydrodynamic lubrication analysis of spiral bevel gears. This model can analyze transient lubrication characteristics of spiral bevel gears. The influence of the angle between the lubricant entrainment and the minor axis of the contact ellipse is included in this model. The contact parameters of the spiral bevel gear are calculated, which will change with time during the meshing process. The variation of lubricant film thickness during the meshing process of spiral bevel gears is unraveled. Due to the influence of entrainment velocity, the oil film thickness at the out mesh side is smaller than that at the enter mesh side under the same contact force. It is evident that the higher the pressure is, the larger the contact area will be. Meanwhile, the thickness of the oil film is reduced, and the oil film distribution in the contact area is relatively uniform. Taking helicopter main transmission spiral bevel gears as an example, this study finally calculates the distribution characteristics of the oil film thickness of the spiral bevel gear, and solves the lubrication performance of the spiral bevel gear under different working conditions.

scholarly journals Lubrication characteristics of gear after shot peening base on 25-pellet model

2018 ◽  
Vol 10 (7) ◽  
pp. 168781401879065 ◽  
Author(s):  
Shuai Mo ◽  
Shengping Zhu ◽  
Guoguang Jin ◽  
Jiabei Gong ◽  
Zhanyong Feng ◽  
...  
Keyword(s):  
Shot Peening ◽  
High Speed ◽  
Target Material ◽  
Bevel Gear ◽  
Tooth Surface ◽  
Spiral Bevel Gear ◽  
Spiral Bevel Gears ◽  
Bevel Gears ◽  
Spiral Bevel ◽  
Lubrication Characteristics

High-speed heavy-load spiral bevel gears put forward high requirement for flexural strength; shot peening is a technique that greatly improves the bending fatigue strength of gears. During shot peening, a large number of fine pellets bombard the surface of the metal target material at very high speeds and let the target material undergo plastic deformation, at the same time strengthening layer is produced. Spiral bevel gear as the object of being bombarded inevitably brought the tooth surface micro-morphology changes. In this article, we aim to reveal the effect of microtopography of tooth shot peening on gear lubrication in spiral bevel gear, try to establish a reasonable description of the microscopic morphology for tooth surface by shot peening, to reveal the lubrication characteristics of spiral bevel gears after shot peening treatment based on the lubrication theory, and do comparative research on the surface lubrication characteristics of a variety of microstructures.

Kinematical Optimization of Spiral Bevel Gears

1992 ◽  
Author(s):  
Zhang-Hua Fong ◽  
Chung-Biau Tsay
Keyword(s):  
Mathematical Model ◽  
Bevel Gear ◽  
Tooth Surface ◽  
Spiral Bevel Gear ◽  
Tooth Contact ◽  
Spiral Bevel Gears ◽  
Bevel Gears ◽  
Contact Patterns ◽  
Spiral Bevel ◽  
Kinematic Errors

Abstract Kinematical optimization and sensitivity analysis of circular-cut spiral bevel gears are investigated in this paper. Based on the Gleason spiral bevel gear generator and EPG test machine, a mathematical model is proposed to simulate the tooth contact conditions of the spiral bevel gear set. All the machine settings and assembly data are simulated by simplified parameters. The tooth contact patterns and kinematic errors are obtained by the proposed mathematical model and the tooth contact analysis techniques. Loaded tooth contact patterns are obtained by the differential geometry and the Hertz contact formulas. Tooth surface sensitivity due to the variation of machine settings is studied. The corrective machine settings can be calculated by the sensitive matrix and the linear regression method. An optimization algorithm is also developed to minimize the kinematic errors and the discontinuity of tooth meshing. According to the proposed studies, an improved procedure for development of spiral bevel gears is suggested. The results of this paper can be applied to determine the sensitivity and precision requirements in manufacturing, and improve the running quality of the spiral bevel gears. Two examples are presented to demonstrate the applications of the optimization model.

Parametric Modeling for Spiral Bevel Gear Based on PRO/E

2012 ◽  
Vol 215-216 ◽  
pp. 1062-1066
Author(s):  
Xiu Hai Wu
Keyword(s):  
Parametric Design ◽  
Three Dimensional ◽  
Parametric Modeling ◽  
Bevel Gear ◽  
Secondary Development ◽  
Spiral Bevel Gear ◽  
Spiral Bevel Gears ◽  
Bevel Gears ◽  
Three Dimensional Modeling ◽  
Spiral Bevel

The author describes tooth profile formatting mechanism of spherical involute spiral bevel gear based on Principles of Gear conjugate, establishes the mathematical model of spiral bevel gears. The precise spherical involute of spiral bevel gears is generated with parametric modeling idea and th secondary development method based on PROGRAM of PRO/E software. Finally, a complete spherical three-dimensional modeling of the involute spiral bevel gear is established, which provides a method of parametric design and manufacturing of spiral bevel gears.

scholarly journals Effect of roller bearing elasticity on spiral bevel gear dynamics

2020 ◽  
Vol 12 (7) ◽  
pp. 168781402093889
Author(s):  
Xia Hua ◽  
Zaigang Chen
Keyword(s):  
Roller Bearing ◽  
Bevel Gear ◽  
Spiral Bevel Gear ◽  
Element Formulation ◽  
Dynamic Force ◽  
Spiral Bevel Gears ◽  
Gear Dynamics ◽  
Bevel Gears ◽  
Bearing Stiffness ◽  
Spiral Bevel

The dynamics of spiral bevel gears have gained increasing importance due to concerns relating to noise and durability. This is because the mesh force acting on the gear teeth is amplified under dynamic conditions, potentially reducing the fatigue life of the gears. Furthermore, a sizable dynamic force can be transmitted to the housing, inducing structure-born gear whine. The elasticity of the bearings can influence the dynamics of spiral bevel gears. In this article, the finite element formulation of a spiral bevel geared rotor dynamic system is applied to investigate the influence of bearing elasticity on the dynamics of spiral bevel gears. The designs and configurations of rear axles are modeled and analyzed for real-world applications, to gain an enhanced practical understanding of the effect of bearing stiffness on spiral bevel gear dynamics.

Design and analysis of high contact ratio spiral bevel gears by modified curvature motion method

2017 ◽  
Vol 232 (19) ◽  
pp. 3396-3409 ◽  
Author(s):  
Yanming Mu ◽  
Zongde Fang
Keyword(s):  
Transmission Error ◽  
Bevel Gear ◽  
Spiral Bevel Gear ◽  
Contact Ratio ◽  
Spiral Bevel Gears ◽  
Bevel Gears ◽  
Curvature Motion ◽  
Seventh Order ◽  
Spiral Bevel ◽  
Motion Method

This paper presents a new method to design a seventh-order transmission error for high contact ratio spiral bevel gears by the modified curvature motion method to reach the purpose of reducing or eliminating gear vibration and noise. In this paper, firstly, based on the predesigned seventh-order transmission error, the polynomial coefficients of transmission error curve can be obtained. Secondly, a method named modified curvature motion method is used to generate the spiral bevel gear with the predesigned transmission error. Lastly, based on TCA and LTCA, we verify the feasibility of the modified curvature motion method to generate spiral bevel gear with seventh-order transmission error, and the meshing impact of gear set with the seventh-order and second-order function of transmission error is analyzed and compared. The results of a numerical example show that the seventh-order transmission error acquired by the modified curvature motion method can effectively reduce the meshing impact of spiral bevel gears. The tooth modification method and meshing impact analysis method can serve as a basis for developing a general technique of flank modification for spiral bevel gears.

The Undercutting of Circular-Cut Spiral Bevel Gears

1992 ◽  
Vol 114 (2) ◽  
pp. 317-325 ◽  
Author(s):  
Zhang-Hua Fong ◽  
Chung-Biau Tsay
Keyword(s):  
Gear Tooth ◽  
Sufficient Conditions ◽  
Bevel Gear ◽  
Tooth Surface ◽  
Spiral Bevel Gear ◽  
Spiral Bevel Gears ◽  
Bevel Gears ◽  
Tooth Surfaces ◽  
Sufficient And Necessary Conditions ◽  
Spiral Bevel

Undercutting is a serious problem in designing spiral bevel gears with small numbers of teeth. Conditions of undercutting for spiral bevel gears vary with the manufacturing methods. Based on the theory of gearing [1], the tooth geometry of the Gleason type circular-cut spiral bevel gear is mathematically modeled. The sufficient and necessary conditions for the existence and regularity of the generated gear tooth surfaces are investigated. The conditions of undercutting for a circular-cut spiral bevel gear are defined by the sufficient conditions of the regular gear tooth surface. The derived undercutting equations can be applicable for checking the undercutting conditions of spiral bevel gears manufactured by the Gleason Duplex Method, Helical Duplex Method, Fixed Setting Method, and Modified Roll Method. An example is included to illustrate the application of the proposed undercut checking equations.

scholarly journals Surface Geometry of Circular Cut Spiral Bevel Gears

1982 ◽  
Vol 104 (4) ◽  
pp. 743-748 ◽  
Author(s):  
R. L. Huston ◽  
J. J. Coy
Keyword(s):  
Logarithmic Spiral ◽  
Bevel Gear ◽  
Tooth Surface ◽  
Spiral Bevel Gear ◽  
Surface Geometry ◽  
Spiral Bevel Gears ◽  
Bevel Gears ◽  
Spiral Bevel

An analysis of the surface geometry of spiral bevel gears formed by a circular cutter is presented. The emphasis is upon determining the tooth surface principal radii of curvature of crown (flat) gears. Specific results are presented for involute, straight, and hyperbolic cutter profiles. It is shown that the geometry of circular cut spiral bevel gears is somewhat simpler than a theoretical logarithmic spiral bevel gear.

Designing and Manufacturing Spiral Bevel Gears Using 5-Axis CNC Milling Machines

2011 ◽  
Author(s):  
Joe¨l Teixeira Alves ◽  
Miche`le Guingand ◽  
Jean-Pierre de Vaujany
Keyword(s):  
Manufacturing Process ◽  
Gear Tooth ◽  
Bevel Gear ◽  
Spiral Bevel Gear ◽  
Milling Machine ◽  
Cnc Milling ◽  
Spiral Bevel Gears ◽  
Bevel Gears ◽  
Tooth Surfaces ◽  
Spiral Bevel

The design of spiral bevel gears still remains complex since tooth geometry and the resulting kinematics performance stem directly from the manufacturing process. Spiral bevel gear manufacture owes most to the works of Gleason and Klingelnberg. However, recent advances in milling machine technology and CAM (Computer Aided Manufacturing) make it possible to manufacture good quality spiral bevel gears on a standard 5-axis milling machine. This paper describes the CAD definition and manufacturing of spiral bevel gear tooth surfaces. Process performance is assessed by comparing the resulting surfaces after machining with the pre-defined CAD surfaces. Using this manufacturing process allows to propose new type of geometry. This one is more theoretical and, in some respects, easier to design than the standard spiral bevel gear as it enables simpler mesh optimization. The latter can be achieved by using the model of meshing under load recalled in this paper.

scholarly journals Dynamical wear prediction along meshing path in mixed lubrication of spiral bevel gears

2020 ◽  
Vol 12 (9) ◽  
pp. 168781402095823
Author(s):  
Xin Pei ◽  
Lu Huang ◽  
Wei Pu ◽  
Pengchong Wei
Keyword(s):  
Film Thickness ◽  
Mixed Lubrication ◽  
Tooth Surface ◽  
Time Varying ◽  
Flash Temperature ◽  
Wear Model ◽  
Spiral Bevel Gears ◽  
Bevel Gears ◽  
Spiral Bevel ◽  
Meshing Process

Surfaces of gears under combined rolling and sliding motions may suffer a complicated wear process due to the transient time-varying effect along the meshing path. In this paper, a methodology for predicting the wear of tooth surfaces is developed for the spiral bevel gears. In the wear model, the machined surface roughness, mixed lubrication, friction, flash temperature and the dynamic behavior of gears are all considered. Tooth-Contact-Analysis (TCA) method is used to get the time-varying parameters of meshing points along the meshing path. By simulating real movement process, the material is removed according to the Arrhenius equation. First, the distribution of pressure and film thickness is obtained by solving the mixed EHL model. After that, the flash temperature can be computed by the point heat source integration method with the obtained pressure, film thickness and velocity vector. The material removal is based on surface temperature and sliding distance. The numerical results are compared to the ball-on-disk experiments to demonstrate the reasonableness of the present wear model. And it shows that the angle difference between velocity vectors has strong influences on the wear profile. Furthermore, the mechanism of surface wear evolution is investigated systematically in spiral bevel gears. The difference of the wear track between the pinion and gear surfaces is observed. Besides, in the meshing process of tooth surface, the wear along the meshing path is uneven, which appears to be much greater at the engaging-in and engaging-out areas. There is a position with maximum wear rate in the meshing process, and the position is affected by the load and speed.

scholarly journals EHL Analysis of Spiral Bevel Gear Pairs considering the Contact Point Migration due to Deformation under Load

2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Xiaoyu Sun ◽  
Yanping Liu ◽  
Yongqiang Zhao ◽  
Ming Liu
Keyword(s):  
Contact Point ◽  
Bevel Gear ◽  
Tooth Surface ◽  
Spiral Bevel Gear ◽  
Gear Pair ◽  
Spiral Bevel Gears ◽  
Actual Contact ◽  
Bevel Gears ◽  
Contact Points ◽  
Spiral Bevel

The actual contact point of a spiral bevel gear pair deviates from the theoretical contact point due to the gear deformation caused by the load. However, changes in meshing characteristics due to the migration of contact points are often ignored in previous studies on the elastohydrodynamic lubrication (EHL) analysis of spiral bevel gears. The purpose of this article is to analyze the impact of contact point migration on the results of EHL analysis. Loaded tooth contact analysis (LTCA) based on the finite element method is applied to determine the loaded contact point of the meshing tooth pair. Then, the osculating paraboloids at this point are extracted from the gear tooth surface geometry. The geometric and kinematic parameters for EHL simulation are determined according to the differential geometry theory. Numerical solutions to the Newtonian isothermal EHL of a spiral bevel gear pair at the migrated and theoretical contact points are compared to quantify the error involved in neglecting the contact point adjustment. The results show that under heavy-loaded conditions, the actual contact point of the deformed gear pair at a given pinion (gear) roll angle is different from the theoretical contact point considerably, and so do the meshing parameters. EHL analysis of spiral bevel gears under significant load using theoretical meshing parameters will result in obvious errors, especially in the prediction of film thickness.

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