Prediction of Lubrication oil film thickness and oil entrainment velocity in sliding contact and rolling contact valve train

Paper #:
  • 2018-01-0931

Published:
  • 2018-04-03
Abstract:
Abstract Today Global Automotive Manufacturers are starving for increased demand of fuel economy, high performance and silent engine. One of the fundamental for improving fuel economy is by designing low friction mechanisms resulting less power requirements. Valve train is major contributor to overall engine friction losses. Main objective is to use the low viscosity oil (to reduce overall engine friction) while maintaining minimum required oil film thickness and high entrainment velocity at contact surface to achieve cam/ follower wear in acceptable limit. Lubrication oil film thickness need to be kept above minimum safe value and for maximum possible duration. Oil entrainment velocity at contact surface is controlled by type of contact at interface and is an important parameter controlling the wear in valve train parts. Higher entrainment velocity is better for wear resistance. At micro level major factor influencing the friction and wear in valve train are : ● Type of contact between cam and rocker ● Viscosity of oil used for lubrication ● Load acting at contact point This study is done using 1-D simulation tools. In this study, influence of type of contact (sliding type and rolling type) is predicted on Lubrication oil film thickness and oil entrainment velocity by using two different type of rocker arm- Sliding type and rolling type. Cam profile was changed keeping same valve lift & same spring load for both type of rocker arm. In roller type follower, impact of roller diameter, cam base circle and valve train layout also studied on lubrication oil film thickness and oil entrainment velocity. Influence of different lubricating oil grade / viscosity used for lubrication is also predicted on Lubrication oil film thickness and oil entrainment velocity. Valve train load is kept same for all the trails to quantify the impact of type of contact and different grade of lubrication oil on friction and wear of component.
Access
Now
SAE MOBILUS Subscriber? You may already have access.
Buy
Attention: This item is not yet published. Pre-Order to be notified, via email, when it becomes available.
Select
Price
List
Download
$22.00
Mail
$22.00
Members save up to 36% off list price.
Share
HTML for Linking to Page
Page URL

Related Items

Technical Paper / Journal Article
1990-02-01
Article
2017-07-26
Technical Paper / Journal Article
1990-02-01
Technical Paper / Journal Article
2012-06-13
Technical Paper / Journal Article
1990-02-01