An application of the optics of oil films to the study of engineering surfaces

1982 ◽  
Vol 3 (2) ◽  
pp. 101-110 ◽  
Author(s):  
L.H. Tanner
Keyword(s):  
2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Peter Fietkau ◽  
Bernd Bertsche

This paper describes an efficient transient elastohydrodynamic simulation method for gear contacts. The model uses oil films and elastic deformations directly in the multibody simulation, and is based on the Reynolds equation including squeeze and wedge terms as well as an elastic half-space. Two transient solutions to this problem, an analytical and a numerical one, were developed. The analytical solution is accomplished using assumptions for the gap shape and the pressure in the middle of the gap. The numerical problem is solved using multilevel multi-integration algorithms. With this approach, tooth impacts during gear rattling as well as highly loaded power-transmitting gear contacts can be investigated and lubrication conditions like gap heights or type of friction may be determined. The method was implemented in the multibody simulation environment SIMPACK. Therefore it is easy to transfer the developed element to other models and use it for a multitude of different engineering problems. A detailed three-dimensional elastic multibody model of an experimental transmission is used to validate the developed method. Important values of the gear contact like normal and tangential forces, proportion of dry friction, and minimum gap heights are calculated and studied for different conditions. In addition, pressure distributions on tooth flanks as well as gap forms are determined based on the numerical solution method. Finally, the simulation approach is validated with measurements and shows good consistency. The simulation model is therefore capable of predicting transient gear contact under different operating conditions such as load vibrations or gear rattling. Simulations of complete transmissions are possible and therefore a direct determination of transmission vibration behavior and structure-borne noise as well as of forces and lubrication conditions can be done.


Author(s):  
Flávio Gomes Fernandes ◽  
Cristiani Viegas Brandão Grisi ◽  
Raunira Costa Araújo ◽  
Diego Alvarenga Botrel ◽  
Solange Sousa

2014 ◽  
Vol 7 (8) ◽  
pp. 2443-2450 ◽  
Author(s):  
Jeannine Bonilla ◽  
Maria Vargas ◽  
Lorena Atarés ◽  
Amparo Chiralt

1999 ◽  
Vol 353 (1-2) ◽  
pp. 249-253 ◽  
Author(s):  
D. Sakthi Kumar ◽  
M.G. Krishna Pillai

Wear ◽  
1975 ◽  
Vol 34 (3) ◽  
pp. 467-486 ◽  
Author(s):  
A. Capone ◽  
E. Capone
Keyword(s):  

1990 ◽  
Vol 112 (3) ◽  
pp. 447-452 ◽  
Author(s):  
M. Kaneta ◽  
H. Nishikawa ◽  
K. Kameishi

A new experimental technique using optical interferometry has been developed to obtain a direct indication of non-Newtonian response of an oil film under conditions of elastohydrodynamic (EHD) lubrication. A glass disk or a steel ball has been driven by a stepping motor so that crescent-shaped thick oil films with undulation in thickness along the direction of motion have been generated. The experiments have been carried out under pure rolling and pure sliding conditions. It has been found that the oil in an EHD contact behaves like a solid and slips at or near the contact surfaces.


1990 ◽  
Vol 112 (3) ◽  
pp. 268-275 ◽  
Author(s):  
A. R. Heath ◽  
P. M. McNamara

The conflicting legislative and customer pressures on engine design, for example, combining low friction and a high level of refinement, require sophisticated tools if competitive designs are to be realized. This is particularly true of crankshafts, probably the most analyzed of all engine components. This paper describes the hierarchy of methods used for crankshaft stress analysis with case studies. A computer-based analysis system is described that combines FE and classical methods to allow optimized designs to be produced efficiently. At the lowest level simplified classical techniques are integrated into the CAD-based design process. These methods give the rapid feedback necessary to perform concept design iterations. Various levels of FE analysis are available to carry out more detailed analyses of the crankshaft. The FE studies may feed information to or take information from the classical methods. At the highest level a method for including the load sharing effects of the flexible crankshaft within a flexible block interconnected by nonlinear oil films is described. This method includes the FE modeling of the complete crankshaft and the consideration of its stress field throughout an engine cycle. Fatigue assessment is performed to calculate the distribution of fatigue safety factor on the surface of the crankshaft. This level of analysis can be used for failure investigation, or detailed design optimization and verification. The method is compatible with those used for vibration and oil film analysis.


2021 ◽  
Vol 73 (6) ◽  
pp. 993-999
Author(s):  
Daguo Yu ◽  
Ming Zhao

Purpose This study and its centering device with Archimedes spirals designed on hydrodynamic lubrication aims to reduce the deviation of deep holes because the drill tube is long and easy to deviate in deep hole machining. Design/methodology/approach The centering device with Archimedes spirals was designed and fixed between the drilling tool and the drill tube. The wall of the deep hole and the novel centering device formed three wedge-shaped oil films. When the workpiece rotated relative to the centering device, pressure was generated in the oil films; therefore, three oil films supported drilling system as oil films support rotating journal in the full-film hydrodynamic bearing. Findings When the Boring and Trepanning Association (BTA) drilling system was equipped with the centering device, the cutting oil flowed smoothly and carried all the iron chips; the motors run normally; no additional vibration or sound was detected during processing; the surface of the centering device was smooth; and the deviation of the drilled deep hole decreased with a high probability. Originality/value To the best of the authors’ knowledge, no one has designed and made the centering device with Archimedes spirals to reduce the deviation of deep holes in deep hole machining. Three oil films formed by the centering device with Archimedes spirals support drilling system and prevent it from deviating, which has never appeared before and is creative.


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