Presentazione al World Tribology Congress 2013

DESIGN OF A TWIN DISC TEST MACHINE

1/31WTC 2013 – 5th world TRIBOLOGY congress – September 8-13, 2013, TORINO Italy

Speaker

Michele Amorena

P. Repola1, S. Manconi1, M. Amorena1, E. Ciulli2, M. Facchini3

1AM Testing – Via Di Torretta, 56121, San Piero a Grado (Pisa) – Italy

2DICI – Università di Pisa – Largo Lucio Lazzarino – 56126, Pisa – Italy

3Avio Aero – Via I Maggio 108, 10040, Rivalta (Torino) – Italy

PRESENTATION SUMMARY

�Introduction

� From gear teeth contact to discs contact

� Other possible use of a TDTM

� TDTM vs. Gear test rig

�Benchmark


�Design

� General requirements

� Performances

� Concept and concept study

�3D Modeling

PRESENTATION SUMMARY

�Manufacturing

�Test System description

� Performances

� Sub-systems

� Instrumentation


� Instrumentation

� DAQ & C. system

�Commissioning and preliminary results

�Conclusions

ρ1

v1,2

ve

RvP1 vP2

FROM GEAR TEETH CONTACT TO DISC CONTACT

The idea: To run simplified surface damage tests on simplified test

samples at test condition in similitude with mating teeth working

condition (at a given point along the action line)


ρ2

DRIVER

S1 > 0

FOLLOWER

S2 < 0

ω2 ω1

RT2

RT1

P1 P2

vP1 vP2

2

1

Mating gear teethGEAR TEST RIG

Mating discTWIN DISC TES MACHINE (TDTM)

� Gear damaging (Scuffing, Pitting, Micro-pitting)

� Material loading carrying capacity

� Contact parameters (e.g. pressure, temperature, oil film thickness)

� Surface fatigue on rolling components

OTHER POSSIBLE USES OF A TDTM


� Surface roughness, topology (texture) and coatings

� Lubricant performances evaluation and comparison

� Lubrication parameters evaluation

� Lubricant contamination effect on lubrication and surface damage

� To easily replicate several contact conditions

� To run continuously on a semi-steady-state contact condition

that otherwise would have been cyclical (e.g. gear teeth, cam-

plate)

TDTM vs. GEAR TEST RIG


plate)

� To manufacture less expensive test samples (e.g. discs

instead of gears)

� Driving system:

� Double shaft drives

� Single shaft drive + slave gear-box

� Test discs mounting arrangement:

� Suspended (end of the shaft)

� Straddle mounted

� Loading system:

BENCHMARK (CONFIGURATIONS)

M


� Loading system:

� Hydraulic

� Weights

� Calibrated spring

� Center distance:

� Fixed

� Variable

T2

T1S1

S2

M

DESIGN (GENERAL REQUIREMENTS)

Safety Performances


Lavorazioni

50%

Particolari

50%

Maintainability

Manufacturing

Reliability

DESIGN (PERFORMANCES)

Main test rig performance

parameters:

� Contact load


� Contact load

� Rotational speed

� Slide to roll ratio

Industrial application driven!(aeronautical gearing)

T2

T1S1

S2

M

DESIGN (CONCEP)


� Mechanical circulating power configuration

� Fixed center distance

� Hydraulic loaded

� Single shaft drive + slave gear-box driven

� Straddle mounted discs

Test-box

END OF SHAFT

MOUNTED

� Reaction load intensity

�Contact area (symmetry)

�Lubricant circuits separation

T1S1M

Slave-box

DESIGN (CONCEP EVALUATION 1/4)


STRADDLE

MOUNTED

�Lubricant circuits separation

� Mounting complexity

�Bearings/discs separation

T2S2

Friction force


Loading force

External torque


FF

F

External cylinder loadFrame load

reaction

RT1 max

ω1< ω2

i/2

RT1

Disc 2

follower

RT1 max = RS1 max

r.s.s.

S1 = S2 = 0


ω1> ω2

ω1 = ω2


RS1 min RS1 max

RT1 min

i/2RS1

Disc 1

follower



Housing deformation

Shaft deformation

3D MODEL 1/2


3D MODEL 2/2


MANUFACTURING DRAWINGS


TEST SYSTEM ASSEMBLING


TEST SYSTEM

Parameter Range

Radial force 0-35 kN

Contact pressure 0-3,5 GPa


Entraining velocity 0-60 m/s

Slide to roll ratio 0-1

Sliding velocity 0-20 m/s

Rotational speed 0-12.000 rpm

Inlet oil flow 0-20 l/min

Inlet oil temperature 25-150 °C

TEST-BOX AND TEST ARTICLES

� Surface crowning

� Grinding line direction

� Lubrication and cooling


LUBRICATION SYSTEM

� Independent bearing and discs lubrication


� Single nozzle lubrication control

� Temperature, pressure and flow control

� Debris control

SLAVE GEAR-BOX AND TRANSMISSION SHAFTS


DRIVING SYSTEM

� Continuous current electric motor + drive

� Poly-V belt and pulley transmission


� Slave gear-box + set of gears

�…

LOADING SYSTEM


� Hydraulic actuator

� Closed loop control (load cell)

� Gear pump (oil pressure up to 350 bar)

�…

INSTRUMENTATION

In order to measure and control the main test parameters thetest rig is equipped with several sensors and actuators.

�Torque meter: To measure transmitted torque (power lossesevaluation)

�Thermocouple: To measure bulk and sub-surface disctemperature (rotating shafts)


�Eddy current probes: To detect surface and sub-surfacedamage (e.g. micro-pitting, pitting) (on rotating discs)

INSTRUMENTATION

In order to measure and control the main test parameters thetest rig is equipped with several sensors and actuators.

�Telemetry system: To allows the electric power to be fed to theon-board conditioning and amplifying electronics and the on-board signals (e.g. temperature) to be transmitted.

�Easy positioning: Other instrumentation for a more accuratesurface analysis (e.g. portable roughness tester, image


surface analysis (e.g. portable roughness tester, imageacquisition unit)

3D roughness measurement

µm

0

12

3

45

67

8

910

11

1213

1415

16

17

18 µm

0.488 mm

0.494 mm

Alpha = 156° Beta = 30°

Optical microscopy

DAQ & C. SYSTEM 1/3

�Based on NI Compact RIO (PAC)

�Sampling frequency: 10 Hz


Electric cabinetNI Compact RIO

DAQ & C. SYSTEM 2/3


DAQ & C. SYSTEM 3/3


Graphical User Interface (GUI)

COMMISSIONING AND PRELIMINARY TESTS


Friction coefficient vs. contact pressure

�The design of a TDTM has lead to a very flexible and useful testmachine.

�The test rig can be used to study the performances ofmaterials, lubricants, coatings, heat treatments, macro and microgeometry features with respect to the main gear damagingphenomenon.

CONCLUSION


�Several types of tests can be carried out using this test rig: e.g.fatigue tests (pitting, micro-pitting), scuffing tests, lubricantsload carrying capacity tests.

�The TDTM can be a useful tool to promptly test engineeringinnovations that can lead to more efficient power transmissionsystems and to manufacturing process with a lowerenvironmental impact.

ARRIVEDERCI

Thank you very much for your attention! … any question?


Presentazione al World Tribology Congress 2013

Technology

Transcript of Presentazione al World Tribology Congress 2013