Transient non-Newtonian elastohydrodynamic lubrication analysis of an involute spur gear

Larsson, Roland

doi:10.1016/s0043-1648(96)07484-4

Cited by 109 publications

(68 citation statements)

References 6 publications

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“…Contact of pinion and gear along the LoA was replaced by contact of cylinders that are under a varying load and their radii change to mimic the performance of a gear-pinion pair during the engagement. The scaling factors and film thickness based on isothermal analysis were determined and these two parameters were modified using the thermal correction factor developed by Hsu and Lee [5]. The corrected values of film thickness and scaling factors were employed to find the gear and pinion surface as well as fluid film temperature.…”

Section: Resultsmentioning

confidence: 99%

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Thermoelastohydrodynamic Analysis of Spur Gears with Consideration of Surface Roughness

Akbarzadeh

Khonsari

2008

Tribol Lett

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Thermoelastohydrodynamic lubrication (TEHL) analysis for spur gears with consideration of surface roughness is presented. The model is based on Johnson's load sharing concept where a portion of load is carried by fluid film and the rest by asperities. The solution algorithm consists of two parts. In the first part, the scaling factors and film thickness with consideration of thermal effect are determined. Then, simplified energy equation is solved to predict the surfaces and film temperature. Once the film temperature is known, the viscosity of the lubricant and therefore friction coefficient are calculated. The predicted results for the friction coefficient based on this algorithm are in agreement with published experimental data as well as those of EHL simulations for rough line contact. First point of contact is the point where the asperities carry a large portion of load and the lubricant has the highest temperature and the lowest thickness. Also, according to experimental investigations, the largest amount of wear in spur gears happens in the first point of contact. Effect of speed on film temperature and friction coefficient has been studied. As speed increases, more heat is generated and therefore film temperature will rise. Film temperature rise will result in reduction of lubricant viscosity and consequently decrease in friction coefficient. Surface roughness effect on friction coefficient is also studied. An increase in surface roughness will increase the asperities interaction and therefore friction coefficient will rise. Nomenclature bHalf-width of contact (m) BRoller's width (m) C pi Specific heat of roller i (J/kg/K) d wp Pitch radius of pinion (m) d wg Pitch radius of gear (m) E i Modulus of elasticity of roller i (N/m 2 ) E 0 2 1Àm 2 1 E 1

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Section: Resultsmentioning

confidence: 99%

“…Later [4] they solved the transient EHL problem in spur gears. Larsson [5] solved the transient EHL problem for non-Newtonian lubricant. He showed that the transient effect is most pronounced in the points where the shift in number of tooth in engagement occurs.…”

Section: Introductionmentioning

confidence: 99%

Thermoelastohydrodynamic Analysis of Spur Gears with Consideration of Surface Roughness

Akbarzadeh

Khonsari

2008

Tribol Lett

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“…Depending on the pinion operating speed (and the severity of any perturbation effects), the minimum oil film thickness decreases as the oil temperature increases. This behaviour has been described by Larsson (1997) (squeeze effect mechanism). To better illustrate this relation, Fig.…”

Section: Lubricant Stiffness and Damping Characteristicsmentioning

confidence: 88%

Analytical characterization of damping in gear teeth dynamics under hydrodynamic conditions

Liu

Theodossiades

Bergman

et al. 2015

Mechanism and Machine Theory

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“…Hua and Khonsari [6] gave an isothermal full transient solution of involute spur gear but did not consider the dynamic load in the model. More recently, a full isothermal transient non-Newtonian EHL solution to the Reynolds equation was given by Larsson [7]. Lubrecht, Ten Napel, and Bosma [8] showed that the multigrid algorithm is more efficient than the Newton-Raphson method in solving EHL with roughness effect.…”

Section: Introductionmentioning

confidence: 99%

TEHL Analysis of Rough Surface Spur Gears with Non-Newtonian Lubricants under Sudden Overloads

Mongkolwongrojn

Jesda

2012

JAMDSM

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The time-dependent modified Reynolds equation, elasticity equation, and energy equation with initial conditions were formulated and solved numerically using a multi-grid multilevel with full approximation technique for an involute spur gear. In this analysis, the normal load and sudden overload are applied on either two pairs or one pair of gear teeth. The transition from two pairs to one pair and vice versa are modeled as a step variation of load. The effects of overload, surface roughness, non-Newtonian lubricant properties of the meshing gear in the region along the line of action are examined. The results show that lubricant properties and surface roughness have significant effects on film thickness, film temperature and friction coefficient for spur gears with rough surfaces. The minimum film thickness is decreased rapidly with the decrease of lubricant power law index. For gears operated at a sudden overload condition, the film temperature and friction coefficient are severely increased.

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Transient non-Newtonian elastohydrodynamic lubrication analysis of an involute spur gear

Cited by 109 publications

References 6 publications

Thermoelastohydrodynamic Analysis of Spur Gears with Consideration of Surface Roughness

Thermoelastohydrodynamic Analysis of Spur Gears with Consideration of Surface Roughness

Analytical characterization of damping in gear teeth dynamics under hydrodynamic conditions

TEHL Analysis of Rough Surface Spur Gears with Non-Newtonian Lubricants under Sudden Overloads

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