Effect of tooth waist order parameters of double involute gears on lubrication performance of gear drive

2016 ◽  
Vol 68 (6) ◽  
pp. 671-675 ◽  
Author(s):  
Zhimin Fan ◽  
Wanfeng Zhou ◽  
Ruixue Wang ◽  
Na Wang
Keyword(s):  
Elastohydrodynamic Lubrication ◽  
Reference Value ◽  
Tooth Profile ◽  
Order Parameters ◽  
Content Type ◽  
Oil Film ◽  
Gear Drive ◽  
Involute Gear ◽  
Lubrication Performance ◽  
Involute Gears

Purpose The purpose of this paper is to derive a new lubrication model of double involute gears drive and study the effect of the tooth waist order parameters of double involute gears on lubrication performance. Design/methodology/approach The new lubrication model of double involute gears drive was established according to the meshing characteristics of double involute gears drive and the finite length line contact elastohydrodynamic lubrication theory. Numerical calculation of the lubrication model of gear drive was conducted using the multigrid method. Findings The results show that the oil film necking phenomenon and the oil film pressure peak emerged at the tooth waist order area and the tooth profile ends, and when compared with involute gear, the lubrication performance at the tooth waist order area is better than that at the tooth profile ends. The effect of tooth waist order parameters on lubrication performance at the tooth waist order area was greater than that at other areas. Originality/value This research will promote the application of the double involute gear as soon as possible, and it has the reference value for other types of gears.

Effect of recess depth on lubrication performance of annular recess hydrostatic thrust bearing by constant rate flow

2018 ◽  
Vol 70 (1) ◽  
pp. 68-75 ◽  
Author(s):  
Jun-peng Shao ◽  
Guang-dong Liu ◽  
Xiao-dong Yu ◽  
Yan-qin Zhang ◽  
Xiu-li Meng ◽  
...  
Keyword(s):  
Thrust Bearing ◽  
Simulation Method ◽  
Content Type ◽  
Oil Film ◽  
Constant Rate ◽  
Lubrication Performance ◽  
Optimal Value ◽  
Improved Performance ◽  
Lubrication Characteristics ◽  
Volume Method

Purpose The purpose of this paper is to describe a simulation and experimental research concerning the effect of recess depth on the lubrication performance of a hydrostatic thrust bearing by constant rate flow. Design/methodology/approach The computational fluid dynamics and finite volume method have been used to compute the lubrication characteristics of an annular recess hydrostatic thrust bearing with different recess depths. The performances are oil recess pressure, oil recess temperature and oil film velocity. The recess depth has been optimized. A test rig is established for testing the pressure field of the structure of hydrostatic thrust bearing after recess depth optimization, and experimental results show that experimental data are basically identical with the simulation results, which demonstrates the validity of the proposed numerical simulation method. Findings The results demonstrate that the oil film temperature decreases and the oil film pressure first increases and then decreases with an increase in the recess depth, but oil film velocity is constant. To sum up comprehensive lubrication performance, the recess depth of 3.5 mm is its optimal value for the annular recess hydrostatic thrust bearing. Originality/value The computed results indicate that to get an improved performance from a constant flow hydrostatic thrust bearing, a proper selection of the recess depth is essential.

Size effect on thermal elastohydrodynamic lubrication of industrial chain bush-pin hinge pair

2019 ◽  
Vol 71 (9) ◽  
pp. 1080-1085 ◽  
Author(s):  
Mingyu Zhang ◽  
Jing Wang ◽  
Yi Liu ◽  
Longjie Dai ◽  
Zhaohua Shang
Keyword(s):  
Friction Coefficient ◽  
Film Thickness ◽  
Temperature Rise ◽  
Elastohydrodynamic Lubrication ◽  
Curvature Radius ◽  
Line Contact ◽  
Content Type ◽  
Oil Film ◽  
Industrial Chain ◽  
Infinite Line

Purpose The purpose of this paper is to use elastohydrodynamic lubrication (EHL) theory to study the variation of the equivalent curvature radius “R” on the change of oil film thickness, pressure, temperature rise and friction coefficient in the contact zone between bush-pin in industrial chain drive. Design/methodology/approach In this paper, the contact between bush and pin is simplified as infinitely long line contact. The lubrication state is studied by numerical simulation using steady-state line contact thermal EHL. The two constitutive equations, namely, Newton fluid and Ree–Eyring fluid are used in the calculations. Findings It is found that with the increase of equivalent curvature radius, the thickness of oil film decreases and the temperature rise increases. Under the same condition, the friction coefficient of Newton fluid is higher than that of Ree–Eyring fluid. When the load increases, the oil film thickness decreases, the temperature rise increases and the friction coefficient decreases; and the film thickness increases with the increase of the entraining speed under the condition “R < 1,000 mm”. Research limitations/implications The infinite line contact assumption is only an approximation. For example, the distances between the two inner plates are 5.72 mm, by considering the two parts assembled into the inner plates, the total length of the bush is less than 6 mm. The diameter of the pin and the bore diameter of the bush are 3.28 and 3.33 mm. However, the infinite line contact is also helpful in understanding the general variation of oil film characteristics and provides a reference for the future study of finite line contact of chain problems. Originality/value The change of the equivalent radius R on the variation of the oil film in the contact of the bush and the pin in industrial chain drive was investigated. The size effect influences the lubrication characteristic greatly in the bush-pin pair.

Sliding ratio for novel cycloidal gear drive

2017 ◽  
Vol 232 (21) ◽  
pp. 3954-3963
Author(s):  
Lizhong Xu ◽  
Shuang Li ◽  
Wenping Wang
Keyword(s):  
Tooth Profile ◽  
The Novel ◽  
Gear Drive ◽  
Involute Gear ◽  
Wear Life

In this paper, for a novel spur cycloidal gear drive with a modified tooth profile, the equations of the sliding ratio are deduced from those of its tooth profile. Using the sliding ratio equations, the sliding ratio of the novel cycloidal gear drive is investigated and effects of the drive parameters on the sliding ratio are analysed. The sliding ratio of the novel cycloidal gear drive is then compared with that of an involute gear drive. The results show that the sliding ratio of the novel cycloidal gear drive is small and distributed evenly along its rotating angles, which makes the drive operate smoothly and have a long wear life.

Effect of surface micro-groove texture on lubrication performance of tripod universal coupling

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Fuqin Yang ◽  
Q.H. Xiao ◽  
Chunhui Geng
Keyword(s):  
Friction Coefficient ◽  
Bearing Capacity ◽  
Geometric Parameters ◽  
Grease Lubrication ◽  
Navier Stokes Equation ◽  
Content Type ◽  
Oil Film ◽  
Lubrication Performance ◽  
Universal Coupling ◽  
Groove Texture

Purpose This study aims to study the effect of micro-groove texture geometric parameters on the lubrication characteristics of the tripod universal coupling. Design/methodology/approach The Navier–Stokes equation was used to analyse the influence of micro-groove geometric parameters on the coupling’s lubrication performance. Further, Kriging approximate model and neighborhood cultivation genetic algorithm (NCGA) were used to optimise the micro-groove geometric parameters and improve the coupling’s lubrication performance. Findings The results show that as the micro-groove depth and width increase, respectively, the oil film-bearing capacity first increases and then decreases; on the contrary, the friction coefficient first decreases and then increases. With the increase of the micro-groove inclination angle, the bearing capacity of the oil film first increases and then remains unchanged. At the same time, the friction coefficient first decreases and then increases slightly. The lubricating performance of the optimised coupling is significantly improved: the optimised oil film-bearing capacity increases by 12.5%, the friction coefficient reduces by 14% and the maximum oil film pressure increases by 4.3%. Originality/value At present, the grease lubrication performance of the micro-groove textured tripod universal coupling has not been studied. The micro-groove parameters are optimised, and the coupling’s lubrication performance is improved greatly by the Kriging model and NCGA algorithm. It is of great significance to extend the coupling’s fatigue life.

Effect of the Shape of Inlet Oil-Supply Layer on Starved Lubrication Performance of a Cycloid Drive

2015 ◽  
Author(s):  
Caichao Zhu ◽  
Zhangdong Sun ◽  
Huaiju Liu ◽  
Chaosheng Song ◽  
Zufeng Li ◽  
...  
Keyword(s):  
Film Thickness ◽  
Fatigue Behavior ◽  
Contact Fatigue ◽  
Elastohydrodynamic Lubrication ◽  
Mechanical Efficiency ◽  
Grease Lubrication ◽  
Oil Film ◽  
Oil Supply ◽  
Lubrication Performance ◽  
Starved Lubrication

The lubrication performances of cycloid drives affect the dynamic characteristics, the mechanical efficiency and the contact fatigue behavior of the system. To maintain tranmission precision it is required to minimum the times of disassebly, hence grease lubrication is often applied where starvation might occur in service. Starved lubrication performance of a cycloid gear drive is studied using a numerical finte line starved-elastohydrodynamic lubrication model. The parameter of the inlet oil film thickness is chosen to represent the starved status. Effects of the inlet film thickness on the centralfilm thickness, the friction coefficient and the frictional power loss are investigated. In addition, effects of different shape of inlet oil-supply layer in the same starved degree on lubrication performance are studied. Under the same inlet oil supply volume, the convex type profile would present a better oil film within the nominal contact zone compared with other four different shapes of the inlet film supply.

Novel Torus-Involute Gear Transmission

2012 ◽  
Vol 155-156 ◽  
pp. 1050-1055
Author(s):  
Lei Liu ◽  
Zhu Qing Huang
Keyword(s):  
Design Method ◽  
Gear Transmission ◽  
Transmission Ratio ◽  
Gear Drive ◽  
Involute Gear ◽  
Involute Gears ◽  
Shaft Angle

A novel torus-involute gear transmission is presented in this paper. There are two types of tooth profiles for torus-involute gears: convex tooth and concave tooth. Torus-involute gears are non-sensitive to axial misalignments and allow variable shaft angle without meshing interference. Based on revealing of essence for tooth profiles, introducing the parameter t and discretizing this type of gear into tiny linear continuous corrected gears, a design method is proposed. To testify whether the transmission ratio of torus-involute gear transmission is constant, simulation is implemented in commercial codes ADAMS. The computed results show that this novel gear drive can achieve a constant transmission ratio with variable shaft angle.

Gearing principle and geometric design of conical involute gear pairs with crossed axes

2004 ◽  
Vol 218 (12) ◽  
pp. 1517-1526 ◽  
Author(s):  
J He ◽  
X Wu ◽  
Y Cui
Keyword(s):  
Helix Angle ◽  
Design Methods ◽  
Reference Plane ◽  
Gear Drive ◽  
Involute Gear ◽  
Involute Gears ◽  
Crossed Axes ◽  
Gear Drives ◽  
Design And Manufacture ◽  
Reverse Methods

A group of formulae for the geometric parameters, such as the gear mounting distance, crossed-axes angle, centre distance and helix angle of the tooth projection on the reference plane of a reference rack, of a crossed-axes gear drive of different arrangements are derived based on the analysis of the spatial mesh relationship between conjugate gears and their reference rack. A set of geometrical design methods for conical involute gear pairs with crossed axes (non-intersecting and non-parallel axes) is presented. The formulae can be applied not only to all of the possible independent forms of crossed-axes gear drives but also to the case of gearing with parallel axes and intersecting axes. The design methods consist of two parts, the sequential and the reverse methods. The former is used to determine the mounting dimensions when the basic dimensions of a pair of conical involute gears are given, while the latter is used to determine basic dimensions of a pair of gears when the mounting dimensions are known. The formulae and the methods are verified through the design and manufacture of a set of testing gears.

Tribological and thermal properties of a crowned gear pair with high-speed and heavy-load in thermal micro-elastohydrodynamic lubrication

2019 ◽  
Vol 234 (4) ◽  
pp. 541-553 ◽  
Author(s):  
Zeliang Xiao ◽  
Xi Shi
Keyword(s):  
Temperature Rise ◽  
High Speed ◽  
Elastohydrodynamic Lubrication ◽  
Loss Ratio ◽  
Flash Temperature ◽  
Heavy Load ◽  
Frictional Loss ◽  
Oil Film ◽  
Gear Drive ◽  
Film Stiffness

The oil film stiffness, temperature rise of oil film, flash temperature and frictional loss ratio of a crowned gear pair with non-Newtonian transient thermal elastohydrodynamic lubrication of rough surfaces in high-speed and heavy-load operating conditions are investigated. The pressure, film thickness, coefficient of friction and temperature rise are calculated along the action line of spur gears to verify the validity of full numerical solution. Subsequently, the effects of high-speed, heavy-load and roughness on those tribological and thermal properties of a crowned gear drive are discussed. The results show that in high-speed, heavy-load and rough surface contact, the crown modification is in favor of stability improvement of gear drive due to smoother curve of oil film stiffness. The temperature rise of the oil film and flash temperature on tooth surface are quite high which are prone to result in gear scuffing. Moreover, small flash temperature and frictional loss ratio occur in the domains near the start of active profile and the tip due to the effect of crown modification.

scholarly journals Marine Four-Stroke Diesel Engine Crankshaft Main Bearing Oil Film Lubrication Characteristic Analysis

2018 ◽  
Vol 25 (s2) ◽  
pp. 30-34
Author(s):  
Teng Xian Bin ◽  
Zhang Jun Dong
Keyword(s):  
Diesel Engine ◽  
Film Thickness ◽  
Dynamic Pressure ◽  
Synthesis Method ◽  
Elastohydrodynamic Lubrication ◽  
Characteristic Analysis ◽  
Main Bearing ◽  
Oil Film ◽  
Modal Synthesis ◽  
Lubrication Performance

Abstract The Craig-Bampton modal synthesis method was used to establish the dynamic model of marine four-stroke diesel engine body and crankshaft. Based on the Greenwood/Tripp microlong contact theory considering the surface roughness and the generalized Reynolds equation considering the oil filling rate, the elastohydrodynamic lubrication model of the main bearing of the four - stroke diesel engine is found. At the rated speed, the lubrication performance of the main bearing is simulated and analyzed by the maximum dynamic pressure, the minimum oil film thickness and the friction power. The results show that the oil pressure of 4 # main bearing is the largest and the maximum oil film pressure is in the 4 # main bearing position. The friction load of 4 # main bearing is the largest. The average oil film thickness of 4 # main bearing is the smallest and the minimum oil film The thickness also occurred in the 4 # main bearing position; it can be seen 4 # bearing the most bad lubrication conditions.

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