Roller bearing dynamics under transient thermal-mixed non-Newtonian elastohydrodynamic regime of lubrication

Mohammadpour, Mahdi; Johns-Rahnejat, P.M.; Rahnejat, Homer

doi:10.1177/1464419315569621

Cited by 51 publications

(79 citation statements)

References 31 publications

(119 reference statements)

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“…[25][26][27] The effects of generated contact friction and heat generation are also taken into account in some studies. 8,9,28 Therefore, there are many interacting multi-physics issues which affect bearing dynamics, hence the plethora of research work in this area.…”

Section: Introductionmentioning

confidence: 99%

The effect of outer ring elastodynamics on vibration and power loss of radial ball bearings

Turnbull

Rahmani

Rahnejat

2020

Proceedings of the Institution of Mechanical Engineers, Part K:

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Ball bearings are an integral part of many machines and mechanisms and often determine their performance limits. Vibration, friction and power loss are some of the key measures of bearing performance. Therefore, there have been many predictive analyses of bearing performance with emphasis on various aspects. The current study presents a mathematical model, incorporating bearing dynamics, mechanics of rolling element-to-races contacts as well as the elastodynamics of the bearing outer ring as a focus of the study. It is shown that the bearing power loss in cage cycles increases by as much as 4% when the flexibility of the outer ring is taken into account as a thick elastic ring, based on Timoshenko beam theory as opposed to the usual assumption of a rigid ring in other studies. Geometric optimisation has shown that the lifetime power consumption can be reduced by 1.25%, which is a significant source of energy saving when considering the abundance of machines using rolling element bearings. The elastodynamics of bearing rings significantly affects the radial bearing clearance through increased roller loads and generated contact pressures. The flexible ring dynamics is shown to generate surface waviness through global elastic wave propagation, not hitherto taken into account in contact dynamics of rollers-to-raceways which are generally considered to be subjected to only localised Hertzian deflection. The elastodynamic behaviour reduces the elastohydrodynamic film thickness, affecting contact friction, wear, fatigue, vibration, noise and inefficiency.

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Section: Introductionmentioning

confidence: 99%

The effect of outer ring elastodynamics on vibration and power loss of radial ball bearings

Turnbull

Rahmani

Rahnejat

2020

Proceedings of the Institution of Mechanical Engineers, Part K:

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“…Under dry conditions, h min U and h min L are eliminated from equation (3). Therefore, the stiffness relationship is written as follows…”

Section: Quasi-static Stiffness For Linear Guideway Considering Dry Cmentioning

confidence: 99%

“…Incorporation of a full numerical solution of the lubricated contact in each step of the dynamic analysis is computationally time consuming, although possible. Therefore, the method used by Mohammadpour et al 3 for roller bearings is followed in this work for linear guideways. This model used an analytical tribological model based on extrapolated oil film formula, incorporated implicitly in the dynamic solution.…”

Section: Introductionmentioning

confidence: 99%

Coupled tribo-dynamic modelling of linear guideways for high precision machining application

Soleimanian

Mohammadpour

Ahmadian

2020

Proceedings of the Institution of Mechanical Engineers, Part J:

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Linear guideways play a crucial role in determining precision of machine tools. Understanding their dynamic response is essential for objectively controlling their behavior and performance in operation. Due to highly loaded lubricated contacts, mixed-elastohydrodynamic regime is dominant. The mixed-elastohydrodynamic film maintains the coupling between horizontal degree of freedom (feed velocity) and vertical degree of freedom (loading direction). This paper presents a novel tribo-dynamic solution for linear guideways, taking in to account the lubricant effects and coupling between horizontal and vertical degrees of freedom. An analytical tribology model is used implicitly within the dynamic model. For in-depth tribological quantities including pressure and film thickness distribution, an explicit full numerical solution for mixed-elastohydrodynamic is utilized. Results show that the coupled solution of vertical and horizontal degrees of freedom taking in to account lubricated contacts is essential. It is shown that at moderate and light loads, the effect of this coupling and presence of lubricant is more pronounced.

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“…The above set of equations (6) to (8) are nonlinear (N R þ 2), second-order differential equations. Rotor mass and its unbalanced effect have been added and no other external load interaction with the system has been considered.…”

Section: Damping Force Calculationmentioning

confidence: 99%

“…Wardle 5 established the analytical model to calculate the force generated due to the surface waviness in a ball bearing and also validate the result with the experiment. Mohammadpour et al 6 analyzed the tribo-dynamic condition of the roller bearing under the effect of non-Newtonian elasto-hydrodynamic lubrication and found that the effect of friction is low reasonably low compared to the dry contact condition. Ehrich 7 developed the relationship between higherorder sub-harmonic vibration responses and rotor speed.…”

Section: Introductionmentioning

confidence: 99%

Vibration response analysis of high-speed cylindrical roller bearings using response surface method

Patra

Saran

Harsha

2020

Proceedings of the Institution of Mechanical Engineers, Part K:

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The operating clearance in a bearing influences friction, load zone size and fatigue life of a bearing. Hence, an effort is made to investigate the effect of radial internal clearance on the dynamical behavior of a cylindrical roller bearing system with an unbalance present in the system. The differential equations representing the dynamics of the cylindrical roller bearings have been derived using Lagrange’s equations and solved numerically using the fourth-order Runge-Kutta iterative method. The nonlinear vibration signature has been analyzed due to the clearance and the same is represented by various tools like Acceleration-time plots, Poincaré plots and FFT plots. The approximation method is used to calculate the load distribution and deformation of the individual rollers located at a different position in the load zone, for a preloading/interference fit and positive internal clearance. A response surface method is used to analyze the severity involved in the system due to the combined effect of independent variables like rotor speed, radial load, and radial internal clearance. The observations presented here are not only useful to diagnose the bearing health condition with respect to parametric effects but also exhibit their interactive effects on bearing performance.

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Roller bearing dynamics under transient thermal-mixed non-Newtonian elastohydrodynamic regime of lubrication

Cited by 51 publications

References 31 publications

The effect of outer ring elastodynamics on vibration and power loss of radial ball bearings

The effect of outer ring elastodynamics on vibration and power loss of radial ball bearings

Coupled tribo-dynamic modelling of linear guideways for high precision machining application

Vibration response analysis of high-speed cylindrical roller bearings using response surface method

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