IMAC-U course 6th semester

Tribology 1. Introduction

Assoc. Prof. Takeshi YAMAGUCHI yamatake@gdl.mech.tohoku.ac.jp

Schedule

1. Introduction April 8, 2019 2. Surface of solid body April 11, 2019 3. Contact of solid bodies April 18, 2019 4. Friction 1 April 22, 2019 5. Friction 2 (Bobsleigh) April 25, 2019 6. Boundary lubrication May 9, 2019 7. Midterm exam May 13, 2019 8. Hydrodynamic lubrication May 16, 2019 9. Wear May 23, 2019 10.Tribo-materials May 27, 2019 11.Machine elements May 30, 2019 12.Applications of tribology 1 June 3, 2019 13.Applications of tribology 2 June 6, 2019 14.Final exam June 10, 2019

Evaluation

Attendance 30% Midterm Exam 35% Final Exam 35%

( )

Tribology Academic and engineering field related to friction, wear, and lubrication

Solid body

Solid body

Contact Friction

Lubrication

Wear

1966年 The Jost Report (England）

Tribology?

History of Tribology A wall painting of the transportation of a colossus in Egypt (～BC1900) The first record of LUBRICATION in human history!

How large force is needed for a single Egyptian worker?

Traction forces for a single Egyptian worker ranges 250-500N depending on friction coefficient between wood-wood contact.

Da Vince’s Ball Bearing

Drawing of ball bearing devised by

Leonard Da Vince (15th century)

Restoration model based on the Da Vince’s drawing

What Does Tribology Control?

1. Control of ( ) Reduce friction loss: pistons and cylinders Increase in friction: brakes and friction drive system

2. Control of ( ) Increase wear resistance: increase in reliability and machine life Enhance wear: increase in removal rate during processing

3. Control of ( ) Suppress emission: friction noise, vibration, wear debris, environmental burden Use emission: friction sound in musical instruments, frictional heat

As approximated for a speed of 60 km/h.

K. Holmberg, P. Anderson, A. Erdemir, Global energy consumption due to friction in passenger cars, Tribology International, 47, (2012) 221-234.

Fuel energy dissipation in passenger cars

Breakdown of passenger car energy consumption.

( )losses account for 33% of ( )power loss!

nm

mm

mm

m

km

Subject Fields of Tribology Si

ze o

f su

bje

cts

Nanotribology

Microtribology

Chemistry of lubricants

Biotribology

Railway tribology

Automobile tribology

Tibology for industrial instruments

Geotribology

Sports tribology