Study of Hybrid Lubrication at the Tooth Contact of a Wormgear Transmission: Part 1—Formulation and Analysis

1998 ◽  
Vol 120 (1) ◽  
pp. 103-111 ◽  
Author(s):  
Qin Yuan ◽  
D. C. Sun ◽  
D. E. Brewe
Keyword(s):  
Film Flow ◽  
Flow Problem ◽  
Normal Force ◽  
Capillary Tube ◽  
Gear Tooth ◽  
Analytical Form ◽  
Tooth Contact ◽  
Oil Film ◽  
Transmission Part ◽  
Film Lubrication

The paper presents a lubrication analysis for the tooth contact of a proposed wormgear transmission. The information needed for the lubrication analysis has been mostly obtained from a previously published wormgear analysis. The information includes the geometry of the clearance between the meshing surfaces, the velocity of the worm surface relative to the gear surface, and the normal force acting on a gear tooth as it moves through the meshing zone. The lubrication analysis is carried out after a design of the oil supply configuration is made, that consists of a single transverse oil recess and a capillary tube flow restrictor. Under the predetermined normal force, the lubrication analysis is aimed at obtaining the needed supply pressure to separate the meshing surfaces by a minimum oil film thickness, which is prescribed to insure the establishment of fluid film lubrication at the contact. The lubrication analysis considers (1) the hybrid lubrication effect (combined hydrostatic action and hydrodynamic wedge and squeeze actions), (2) the temperature rise in the oil film flow and the restrictor flow, and (3) the pressure and temperature dependence of oil properties. Part I describes the formulation of the oil film flow problem (in discrete form) and the restrictor flow problem (in analytical form). The two problems are coupled through the conditions of flow continuity and energy balance in the oil recess.

scholarly journals Research on the Lubrication Characteristics of Harmonic Gear Transmission Meshing Areas

2020 ◽  
Vol 66 (9) ◽  
pp. 513-522
Author(s):  
Xiangyang Xu ◽  
Xupeng Fan ◽  
Peitang Wei ◽  
Baojun Yang
Keyword(s):  
Film Thickness ◽  
Gear Tooth ◽  
Elastohydrodynamic Lubrication ◽  
Load Ratio ◽  
Thickness Ratio ◽  
Gear Transmission ◽  
Curvature Radius ◽  
Tooth Contact ◽  
Oil Film ◽  
Lubrication Characteristics

To analyse the lubrication characteristics of harmonic gears and lay the foundation for the study of its gear tooth failure performance and dynamic characteristics, based on the tooth contact geometry of harmonic gear, the integrated curvature radius, tooth load, and entrainment velocity at the meshing point of the gear teeth in the harmonic gear transmission are analysed. A finite-length line contact elastohydrodynamic lubrication (EHL) model for harmonic gears is established. The numerical calculation method is used to solve the oil film thickness and pressure distribution in the lubricating area, and the effects of rotational speed and temperature on the contacting load ratio and film thickness ratio of the meshing area are studied, as well as the change of oil film stiffness under different working conditions. The results show that along the meshing direction, the pressure is small at the end and reaches a peak at the centre, and the film thickness is the largest in the entrance area and is evenly distributed in the centre contact area. As the speed increases, the gear tooth contact load ratio decreases, the oil film thickness ratio increases, the stiffness of the oil film decreases significantly, and the lubrication effect is improved; but the temperature has the opposite effect. Proper increase of rotation speed and decrease of oil temperature can effectively improve the lubrication characteristics of the system.

Estimation of Gear Friction Coefficient using Directional Parameter of Tooth Surface

2021 ◽  
pp. 1-27
Author(s):  
Junichi Hongu ◽  
Ryohei Horita ◽  
Takao Koide
Keyword(s):  
Friction Coefficient ◽  
Contact Surface ◽  
Gear Tooth ◽  
Correction Term ◽  
Tooth Surface ◽  
Oil Film ◽  
Tooth Surfaces ◽  
Frictional Coefficients ◽  
Finishing Processes ◽  
The Relationship

Abstract This study proposes a modification of the Matsumoto equation using a directional parameter of tooth surfaces to adapt various gear finishing processes. The directional parameters of a contact surface, which affect oil film formations, have been discussed in the field of tribology; but this effect has been undetermined on the meshing gear tooth surfaces having directional machining marks. Thus, this paper investigates the relationship between the gear frictional coefficients and the directional parameters (based on ISO25178) of their tooth surfaces with the various finishing processes; and modifies the Matsumoto equation by introducing a new directional parameter to augment the various gear finishing processes. Our findings indicate that through optimizing the coefficient of the correction term the include the new directional parameter, the calculated friction values using the modified Matsumoto equation correlate more highly to the experimental friction values than that using the unmodified Matsumoto equation.

scholarly journals Coupling Analysis of Dynamics and Oil Film Lubrication on Rotor - Floating Bush Bearing System

2011 ◽  
Vol 5 (3) ◽  
pp. 461-473 ◽  
Author(s):  
Mizuho INAGAKI ◽  
Atsushi KAWAMOTO ◽  
Takanori ABEKURA ◽  
Atsushi SUZUKI ◽  
Jan RÜBEL ◽  
...  
Keyword(s):  
Coupling Analysis ◽  
Oil Film ◽  
Analysis Of Dynamics ◽  
Bearing System ◽  
Film Lubrication

Luminescent Oil Film Flow Tagging Skin Friction Meter Applied to FAITH Hill

AIAA Journal ◽  
2018 ◽  
Vol 56 (10) ◽  
pp. 3875-3886 ◽  
Author(s):  
Nicholas M. Husen ◽  
Tianshu Liu ◽  
John P. Sullivan
Keyword(s):  
Skin Friction ◽  
Film Flow ◽  
Oil Film

Gear Tribology and Lubrication

2005 ◽  
pp. 19-38
Keyword(s):  
Film Thickness ◽  
Case History ◽  
Failure Modes ◽  
Gear Tooth ◽  
Lubricant Film ◽  
Flash Temperature ◽  
Lubricant Film Thickness ◽  
Film Lubrication

Abstract This chapter reviews the knowledge of the field of gear tribology and is intended for both gear designers and gear operators. Gear tooth failure modes are discussed with emphasis on lubrication-related failures. The chapter is concerned with gear tooth failures that are influenced by friction, lubrication, and wear. Equations for calculating lubricant film thickness, which determines whether the gears operate in the boundary, elastohydrodynamic, or full-film lubrication range, are given. Also, given is an equation for Blok's flash temperature, which is used for predicting the risk of scuffing. In addition, recommendations for lubricant selection, viscosity, and method of application are discussed. The chapter discusses in greater detail the applications of oil lubricant. Finally, a case history demonstrates how the tribological principles discussed in the chapter can be applied practically to avoid gear failure.

Numerical Simulation and Evaluation of the Oil Film Flow Field in Hydro-Viscous Drive

2013 ◽  
Vol 7 (1) ◽  
pp. 764-771
Author(s):  
Gang Zheng ◽  
Fangwei Xie ◽  
Xialong Li ◽  
Jian Liu ◽  
Jianzhong Cui ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Film Flow ◽  
Oil Film ◽  
Simulation And Evaluation

Dynamic Analysis of Gear Mesh for Gear Pump Based on ANSYS Workbench

2013 ◽  
Vol 706-708 ◽  
pp. 1290-1293 ◽  
Author(s):  
Lei Zhao ◽  
Qing Qing Lv ◽  
Li Quan Yang
Keyword(s):  
Contact Stress ◽  
Gear Tooth ◽  
Corrosion Damage ◽  
Structure Design ◽  
Gear Pump ◽  
Three Dimension ◽  
Tooth Contact ◽  
Gear Teeth ◽  
Gear Mesh ◽  
Ansys Workbench

Based on the FEA software ANSYS Workbench, the soft body dynamics performance of the gear pump gear mesh of a hydraulic pump company was analyzed. In the practical engineering applications, gear pump gear teeth are effected by alternating pressure in the two working cavity. It can cause pitting corrosion damage for gear tooth, and even cause tooth crack and fracture. At first, a three dimension finite element models of the gear pump gear teeth was established. In the start-up process, the gear pump tooth mesh deputy of tooth contact stress strain and dynamic characteristics of gear teeth was analyzed. Obtain the velocity curves, acceleration curve and tooth contact stress and strain dynamic curves of the tooth of gear pump. Providing a new analysis method for gear pump of gear Structure design and having a practical application value.

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