Wilkes UniversityWilkes UniversityByBy

Frank LoPresti (Mechanical Frank LoPresti (Mechanical Engineering)Engineering)

Ankur Sharma (Electrical Ankur Sharma (Electrical Engineering)Engineering)

WHAT IS TRIBOLOGY ?WHAT IS TRIBOLOGY ?

Tribology is the study of lubrication, Tribology is the study of lubrication, friction and wear of moving or friction and wear of moving or stationary parts.stationary parts.

Study of design, friction, wear and Study of design, friction, wear and lubrication of interacting surfaces in lubrication of interacting surfaces in relative motion .relative motion .

The science of interacting surfaces, The science of interacting surfaces, encompassing the fields of friction, encompassing the fields of friction, lubrication, and wear lubrication, and wear

Thermo Thermo TribometerTribometerIs one used to measure Is one used to measure

friction generated friction generated temperatures of polymers temperatures of polymers

and their compositesand their composites

IntroductionIntroduction

Polymer Composites are Useful in Polymer Composites are Useful in Tribological Applications.Tribological Applications.

Subject to Friction, Friction-Subject to Friction, Friction-Generated Temperature.Generated Temperature.

Prototype Tribometer Needed to Prototype Tribometer Needed to MeasureMeasure Both Simultaneously Both Simultaneously..

Prototype TribometerPrototype Tribometer

Drill Press ConceptDrill Press Concept Source of Rotary Motion and Source of Rotary Motion and

Vertical DisplacementVertical Displacement ASTM D 3702 Thrust Washer ASTM D 3702 Thrust Washer

Test: Based on area contact not Test: Based on area contact not on point or line contact.on point or line contact.

Drill PressDrill Press

Drill Press ConceptDrill Press Concept

Rotation

Thrust

RING

TORQUE CELL

ANVIL

POLYMER

Mechanical Advantages of Mechanical Advantages of drill pressdrill press

Rack and pinion applies thrust on specimen, Rack and pinion applies thrust on specimen, thrust has to be reduced to prevent torque thrust has to be reduced to prevent torque cell from overloadingcell from overloading

The load cell with the thermocouple can pick The load cell with the thermocouple can pick up more accurate readings – noise is up more accurate readings – noise is minimized minimized

Much of signal conditioning is not necessary Much of signal conditioning is not necessary but amplification of the signal is a mustbut amplification of the signal is a must

The anvil is drilled easily at required positions The anvil is drilled easily at required positions to insert as many sensors and at desired to insert as many sensors and at desired positionspositions

Modifications Of The Modifications Of The EquipmentEquipment

Removal of spring from vertical translational Removal of spring from vertical translational mechanism.mechanism.

Motor power: ¼ horse power using conversions, Motor power: ¼ horse power using conversions, equaled to 186.425 Watts.equaled to 186.425 Watts.

Torque cell with low inertia and high stiffness Torque cell with low inertia and high stiffness was designed and boughtwas designed and bought

Required engg drawing in PRO-E and machining Required engg drawing in PRO-E and machining of base plate was done in machine shop.of base plate was done in machine shop.

Power transmission to chuck varies due to Power transmission to chuck varies due to different sized pulleys and belt positions, different sized pulleys and belt positions, manufactures give only average speeds of each manufactures give only average speeds of each position of belt. The actual speeds were position of belt. The actual speeds were measured using own built Tachometer. measured using own built Tachometer.

PRO-E DrawingPRO-E DrawingRotating Shaft

Sample

Anvil

Torque Table

Test ConditionsTest Conditions

Thrust, KgThrust, Kg Normal Normal Force, KgForce, Kg

Surface Surface Speed, m/sSpeed, m/s

0.50.5 9.389.38 0.81,2.25,4.00.81,2.25,4.066

1.01.0 18.7518.75 0.81,2.25,4.00.81,2.25,4.066

1.51.5 28.4328.43 0.81,2.25,4.00.81,2.25,4.066

Pro-E SimulationPro-E Simulation

Acetal-Stainless

Pro-E SimulationPro-E Simulation

Data AcquisitionData Acquisition Standalone microcontroller based design.Standalone microcontroller based design.

Design considerationsDesign considerations Data collection in high noise environment.Data collection in high noise environment. Accuracy required ( initially 1 deg C for temperature Accuracy required ( initially 1 deg C for temperature

& 1 Kg for Force Cell).& 1 Kg for Force Cell). User friendly and safe operation.User friendly and safe operation.

Two Version are planned. Two Version are planned. 8-bit microcontroller based on 68HC118-bit microcontroller based on 68HC11

Basic Input/Output display more localized data Basic Input/Output display more localized data collection.collection.

Windows Based but embedded Form Factor.Windows Based but embedded Form Factor. Highly interactive user-interface, real-time data Highly interactive user-interface, real-time data

plotting, remote data collection. Less training time.plotting, remote data collection. Less training time.

User Interface ExamplesUser Interface Examples

8-bit microcontroller based on 8-bit microcontroller based on 68HC1168HC11

Tribometer Enter Anvil Material:

Windows BasedWindows Based

Tribometer

Achieved ResultsAchieved Results

Temperature vs Time

-20

0

20

40

60

80

100

120

0 50 100 150 200 250

Time Seconds

Temperature (Deg Celcius)

THC1

THC2THC3

Log. (THC3)Log. (THC2)

Log. (THC1)

Questions ? ? ?Questions ? ? ?