Contact Force Measurements in Cam and Follower Lubricated Contacts

Ciulli, Enrico; Fazzolari, Francesco; Pugliese, Giovanni

doi:10.3389/fmech.2020.601410

Cited by 5 publications

(4 citation statements)

References 26 publications

(35 reference statements)

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“…Under varied cam rotational speeds, Alzate et al 2 observed that the follower is detached from the cam and begins to show the emergence of periodic impacting behavior characterized by many impacts and chattering. Ciulli et al 3 measured the contact force experimentally during the rotation of a circular eccentric at different rotational speeds and preloads. Yousuf 4 calculated the contact force against time for a greasy and dry profile of the cam based on Hertzian contact pressure.…”

Section: Introductionmentioning

confidence: 99%

Nonlinear dynamics investigation of contact force in a cam–follower system using the Lyapunov exponent parameter, power spectrum analysis, and Poincaré maps

Yousuf

2022

Int Journal of Mech Sys Dyn

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The aim of this article is to detect the detachment between the cam and the follower using the largest Lyapunov exponent parameter, the power density function of fast Fourier transform, and Poinaré maps due to the nonlinear dynamics phenomenon of the follower. The detachment between the cam and the follower was investigated for different cam speeds and different internal distances of the follower guide from inside.This study focuses on the use of the cam-follower system with a bionic quadruped robot through a linkage mechanism. Multishock absorber (spring-damper-mass) systems at the very end of the follower were used to improve the dynamic performance and to reduce the detachment between the cam and the follower. The SolidWorks program was used in the numerical solution, while a high-speed camera at the foreground of the OPTOTRAK 30/20 equipment was used to identify the follower position. The friction and impact were considered between the cam and the follower and between the follower and its guide. In general, when the cam and the follower are in permanent contact, there is no loss in potential energy, and no impact or restitution.The detachment between the cam and the follower increases with increasing coefficient of restitution in the presence of the impact.

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Section: Introductionmentioning

confidence: 99%

Nonlinear dynamics investigation of contact force in a cam–follower system using the Lyapunov exponent parameter, power spectrum analysis, and Poincaré maps

Yousuf

2022

Int Journal of Mech Sys Dyn

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“…Due to the high proportion of friction within the valve train, there is a potential for savings, especially in the cam-tappet contact. In order to understand the contact conditions, experimental work has been concerned with determining the contact normal forces, lubrication gap heights or time-dependent friction values [8,9]. Experimental work by KANO [10] and DOBRENIZKI [11] investigated the potential for the friction reduction of DLC coatings in cam-tappet contacts under conditions close to the application on model test rigs.…”

Section: Introductionmentioning

confidence: 99%

Understanding Friction in Cam–Tappet Contacts—An Application-Oriented Time-Dependent Simulation Approach Considering Surface Asperities and Edge Effects

Orgeldinger

Tremmel

2021

Lubricants

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With the increasing challenges of climate change and scarce resources, the development of sustainable and energy-efficient technical systems is becoming increasingly important. In many applications, the friction losses occurring in contacts have a decisive influence on the overall efficiency. At this point, tribological contact optimization can make an important contribution to increasing the efficiency of technical systems. However, improvements are often associated with a considerable experimental effort. To reduce the development time, additional simulation models can be applied to predict the tribological behavior. This requires the closest possible approximation of the real contact within a numerical model. This paper presents a simulation approach for the time-dependent simulation of a cam–tappet contact. The simulation uses realistic operating conditions as they arise in the valve train of internal combustion engines. The influence of edge effects on the friction behavior is considered by a scaled calculation area and the influence of the surface roughness is investigated using stochastic asperity models. It is shown that the tribological behavior within the contact strongly depends on the surface properties and the load spectrum used. In addition, edge effects on the sides of the contact area have a clear influence on the pressure and film thickness distribution.

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“…They showed different conditions for the contact at low and high magnification to detect the angular positions of the cam, [4]. Ciulli et al measured the contact force experimentally during the rotation of a circular eccentric cam and an engine spline cam at different rotational speeds and preloads in the presence of lubricant film thickness between the cam and the follower, [5]. Alzate et al observed experimentally the detachment when the contact force exceeds the restoring force at critical velocity region.…”

Section: Introductionmentioning

confidence: 99%

“…Dimensions of the follower stem, mm. K 1 , K 2 , K 3 , K 4 , K5 Spring stiffness, N/mm. C 1 , C2 , C 3 , C 4 , C 5 Damping coefficient, Ns/mm.…”

mentioning

confidence: 99%

Detachment Detection in Cam Follower System Due to Nonlinear Dynamics Phenomenon

Yousuf

2021

Machines

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The detachment between the cam and the follower was investigated for different cam speeds (N) and different internal distance of the follower guide from inside (I.D.). The detachment between the cam and the follower were detected using largest Lyapunov exponent parameter, power density function of Fast Fourier Transform (FFT), and Poincare’ maps due to the nonlinear dynamics phenomenon of the follower. The follower displacement and the contact force between the cam and the follower were used in the detection of the detachment heights. Multi-degrees of freedom (spring-damper-mass) systems at the very end of the follower were used to improve the dynamic performance and to reduce the detachment between the cam and the follower. Nonlinear response of the follower displacement was calculated at different cam speeds, different coefficient of restitution, different contact conditions, and different internal distance of the follower guide from inside. SolidWorks program was used in the numerical solution while high speed camera at the foreground of the OPTOTRAK 30/20 equipment was used to catch the follower position. The friction and impact were considered between the cam and the follower and between the follower and its guide. The peak of nonlinear response of the follower displacement was reduced to (15%, 32%, 45%, and 62%) after using multiple degrees of freedom systems.

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Contact Force Measurements in Cam and Follower Lubricated Contacts

Cited by 5 publications

References 26 publications

Nonlinear dynamics investigation of contact force in a cam–follower system using the Lyapunov exponent parameter, power spectrum analysis, and Poincaré maps

Nonlinear dynamics investigation of contact force in a cam–follower system using the Lyapunov exponent parameter, power spectrum analysis, and Poincaré maps

Understanding Friction in Cam–Tappet Contacts—An Application-Oriented Time-Dependent Simulation Approach Considering Surface Asperities and Edge Effects

Detachment Detection in Cam Follower System Due to Nonlinear Dynamics Phenomenon

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