Published on March 12, 2014
Making heavy haul heavier Exploring technical advancements towards increased wheel bearing reliability Presented to: ARA Heavy Haul Rail 2013 Conference Presented by Milan Soukup August 1, 2013
© SKF Group 2 August 2013Slide 2 Agenda 1. SKF introduction 2. Drivers for higher reliability in heavy haul 3. Reliability approach in passenger versus freight 4. Technical advancements extending wheel bearing service life 5. Principles of Condition Monitoring in Heavy Haul Rail 6. Summary
SKF Group 1
© SKF Group 2 August 2013Slide 4 2 August, 2013Slide 4 SKF – a truly global company • Established 1907 • Sales 2012 AUD 10 345 million • Employees 46,775 • Production sites around 140 in 28 countries • SKF presence in over 130 countries • Distributors/dealers 15,000 locations • Global certificates ISO 14001 OHSAS 18001 certification
© SKF Group 2 August 2013Slide 5 SKF in Rail • Axleboxes • Axle bearings • Axletronic • AMPEP – High performance plain bearing • Axletronic systems • Sensors • IMxR monitoring system • Multilog • Gearbox bearings • Motor bearings • Bearing design & consultancy • Training • Bearing refurbishing • Bearing investigation • Bearing exchange • Bearing re-lubrication • Bearing Condition Monitoring OTHER RAILWAY SERVICES • Axlebox overhaul • Suspension Tubes overhaul • Drive system bearings overhaul BOGIE • Slewing bearings • Suspension tubes DRIVE SYSTEMS • Wheel flange lubrication systems CONDITION MONITORING OTHER APPLICATIONS • Articulation joints SERVICES PRODUCTS OTHER APPLICATIONS
2 Drivers for higher reliability in heavy haul
© SKF Group 2 August 2013Slide 7 Drivers for higher reliability in heavy haul Main issues: Unplanned stops – profit loss in operation Accidents, damaged asset or even human health and life – cost of repair and other related cost Maintenance cost COST OF OWNERSHIP
© SKF Group 2 August 2013Slide 8 Specific heavy haul conditions in Australia The most extreme conditions in the bearing world Iron ore cars in Western Australia currently run the highest axle loads of anywhere in the world, 40 tonnes. Each failure causes extreme profit losses due to single line arrangement Class K, Class G & Short Class G operated with axle loads certainly more than what they were designed for Industry has expressed desire to move to even higher axle loads, in line with plans of shipping higher tonnages. Industry has expressed desire for higher reliability and longer service intervals
© SKF Group 2 August 2013Slide 9 Operation conditions in Heavy Haul – application example CTBU BT2-8609 Iron ore wagons, with 3 piece AAR style bogies 170,000km/yr in ambient temperatures of 0-50deg C in Western Australia • Axle load 38 tonnes • Speed 75 km/hr • CTBU units in service 7,000 (60,000 total)
© SKF Group 2 August 2013Slide 10 Operation conditions in Heavy Haul – application example CTBU BT2-8606C Iron ore wagons, with 3 piece AAR style bogies 190,000km/yr in ambient temperatures of 0-50deg C in Western Australia • Axle load 36 tonnes • Speed 80 km/hr • CTBU units in service 40,000 (74,000 total)
© SKF Group 2 August 2013Slide 11 Operation conditions in Heavy Haul – application example CTBU BT2-8609 Iron ore wagons, with 3 piece AAR style bogies 170,000km/yr in ambient temperatures of 0-50deg C in Western Australia • Axle load 40 tonnes • Speed 80 km/hr • CTBU units in service 1,500 (26,000 total)
© SKF Group 2 August 2013Slide 12 Overloading E-class25tonnes F-class32.5tonnes G-class35.5tonnes G,ShortG-class40tonnes 45tonnes? K-class32.5tonnes AAR limits K-class36tonnes
© SKF Group 2 August 2013Slide 13 Western Australia – SKF bearing damage modes investigation Sample size > 5,000 pcs Since 94% of the failures are due to spalling, we can see that it is predominantly load related. Hence, this relates to the issue of reliability. Example - SKF bearing damage modes investigation - 2010 0 500 1000 1500 2000 2500 Spalling- OR Spalling- IR Brinelling Corrosion Fracture Other Damage Mode Quantity
© SKF Group 2 August 2013Slide 14 Result of overloading Spalling (Fatigue) ~90% cause of failure in some Western Australia operators
© SKF Group 2 August 2013Slide 15 Technical possibilities prolonging bearing service life Higher capacity bearing without increasing axle dimensions Lower friction and better functioning seals reducing friction and minimizing bearing contamination Optimised bearing design minimizing fretting (p-spacer) and increasing safety (polymer cage) Improved monitoring of bearing conditions allowing operating conditions to be altered, or maintenance to be scheduled
Reliability approach in passenger versus freight 3
© SKF Group 2 August 2013Slide 17 Reliability approach in passenger versus freight Traditional model: the railway vehicle producer sells the vehicle to the operator, who takes care of service. This concept is used by most freight operators New model: the railway vehicle producer sells the vehicle including service to the operator The railway vehicle producer focuses more on component reliability This concept is increasingly used in passenger operation RAMS was developed to meet these requirements
© SKF Group 2 August 2013Slide 18 RAMS (EN 50126) RAMS = Reliability, Availability, Maintainability, Safety Within RAMS there are for each component values called „Lambda*T“ calculated and compared with RAMS standards: The complete system (coach, train) has to fulfil the value of 10-9, because it is a safety relevant item. This value must be reached with or without barriers. Very effective barrier is for example Condition Monitoring. Severity of the event Consequences of the event „Lambda*T“ Catastrophic Death 10-9 Hazard/Critical Injuries 10-7 Major Stress to driver/workload 10-5 Minor N.C. 10-3
© SKF Group 2 August 2013Slide 19 Example of RAMS fault tree for axlebox bearing in passenger application
© SKF Group 2 August 2013Slide 20 Reliability approach in freight Calculation example: Load leading to calculated L10 life of 1.6Mkm. (L10 = 1.6Mkm) Maintenance interval is 0.8Mkm. Probability a single bearing will survive until the maintenance interval is 0.96 (using formula ). Probability a wagon pair (16 bearings) will survive until the maintenance interval 0.96^16= 0.52 . Implication: 48% of paired wagons will need to be brought in ahead of time. Unplanned maintenance impacting availability of wagons. Considering >10,000 wagons in service considerable maintenance and labour costs. Alternative with higher capacity bearing: Higher capacity, same load leading to calculated L10 = 3.2Mkm. R (0.8Mkm) = 0.99, and two-wagon reliability over the maintenance interval is now 0.99^16= 0.85. 15% unplanned maintenance instead of 48%
© SKF Group 2 August 2013Slide 21 Calculation example: freight car, lower capacity bearing Single bearing: reliability is 96% @ 0,8 Mkm Pair wagons: reliability = (96%)16 = 52% @ 0,8 Mkm
© SKF Group 2 August 2013Slide 22 Calculation example: freight car, higher capacity bearing Single bearing: reliability is 99% @ 0,8 Mkm Pair wagons: reliability = (99%)16 = 85% @ 0,8 Mkm
© SKF Group 2 August 2013Slide 23 1. Basic rating life – still the standard in railway industry 2. More advanced - SKF life modification factor aSKF 3. Very advanced calculation - SKF Bearing Beacon Bearing life calculation approach lubrication, contamination, clearance, bearing internal geometry, temperature, flexibility of components, …
Technical advancements extending wheel bearing service life 4
© SKF Group 2 August 2013Slide 26 Typical bearing designs for freight SRB (open bearing) CRB (open bearing) TBU CTBU •Robust design •Common outer ring •Polymer cage •Integrated contact seals •Factory greased and sealed •Polymer spacer •Ready to mount unit •Cold mounted •Phosphated •Robust design •Common outer ring •Polymer cage •Integrated contact seals •Factory greased and sealed •Ready to mount unit •Cold mounted •Phosphated •Robust design •Polymer cage •Robust design
© SKF Group 2 August 2013Slide 28 Compact TBU (CTBU) advantages Compact design->Shorter axle length, reducing axle bending Polyamide cage improves performance & safety Polymer spacer to avoid fretting corrosion Excellent contamination protection by contact seal High reliability and long service life under high axle loads In operation in Australia since 2000 (Class K, Class G variants)
© SKF Group 2 August 2013Slide 29 Fretting in wheel set bearings Due to axle bending, relative micro movements occur between bearing components and between bearing and adjacent parts Most affected interfaces are: Inner rings – spacer Inner ring inboard side – backing ring
© SKF Group 2 August 2013Slide 30 The polymer spacer design No contamination from fretting corrosion particles Longer grease life and extended maintenance intervals No inner ring rejection at reconditioning due to “side face wear” No increase in bearing internal clearance -> longer life Polymer spacerBacking ring Inner ring Without polymer spacer With polymer spacer
© SKF Group 2 August 2013Slide 31 Long lip seal design for lower friction Contact pressure = 1.4 bar von Mises Stress Mi (10 4 N/m 2 ) Contact pressure = 0.34 bar von Mises Stress Mi (10 4 N/m 2 ) Seal friction = µ x contact pressure New designPresent design
© SKF Group 2 August 2013Slide 32 Bearing Energy Savings ratio 13% EnergySaving 1 bearing [MJ] 27.556 24.000 3.556 0 5.000 10.000 15.000 20.000 25.000 30.000 Energyspent (standard) [MJ] Energyspent (E2) [MJ] Application example: Energy savings - standard seal versus low friction seal
© SKF Group 2 August 2013Slide 33 Application example: Energy savings - standard seal versus low friction seal Based on 200,000 freight cars in operation at an average speed of 80 km/h the total Power Saving is 160 MW. This leads to energy savings of 1.6 TWh for the fleet over the life of the seals. The total energy saving for the complete train is approximately 1%. Energy Saving 1 train [kWh/km] 10,00 9,92 0,08 0 2 4 6 8 10 Energy spent (standard) [kWh/km] Energy spent (E2) [kWh/km]
© SKF Group 2 August 2013Slide 34 Technical advancements in cage materials 02/08/2013 ©SKF SKF Railway Business Unit Resilient polymer material Channelled roller pocket design Lower friction coefficient, less roller slip and wear, lower temperature Self-lubricating material, improved safety Slide 13
© SKF Group 2 August 2013Slide 35 "Oil - off" : temperature development in dry running P- cage Distance 220 °C Steel cage 200 0 70 500 km Temperature °C Polymer cage "oil-off" test
© SKF Group 2 August 2013Slide 36 Through hardened rollers - proposal for heavy haul SKF has good experience with through hardened rollers Cleaner steel and lower risk of crack propagation Case carburisation calls for a low carbon content before carburisation (0.2%) This gives a higher oxygen content than through hardened rollers that uses a steel with higher carbon content (1%) Oxygen drives oxides and slag formation which gives inclusions and drives crack propagation Higher hardness and wear resistance Through hardened rollers gives 3-5% carbides Case carburisation does not produce carbides Carbides contribute to hardness and wear resistance
© SKF Group 2 August 2013Slide 38 Next generation of CTBU – 45t for heavy haul freight Design goal – 45t/axle Higher dynamic load rating in order to get 2x longer fatigue life that of TBU Class G for the same load Same journal diameter and length Same design features as existing CTBUs already proven in West Australia. (P-spacer, low friction seals, polyamide cage, long life grease) Greater outer ring OD
© SKF Group 2 August 2013Slide 40 Next generation of CTBU 45t – testing SKF RTC test just finished, 200 Tkm. Good temperature development through the test.
© SKF Group 2 August 2013Slide 41 Next generation of CTBU 45t – testing
© SKF Group 2 August 2013Slide 42 Adaptor design – outer ring creep The adaptor design must allow the bearing outer ring to creep, thus avoiding a fixed point load There are adaptor designs that do not enable the outer ring to creep. Either due to more than 180° contact or due to other design features Adaptors must be modified to accommodate the larger 45t bearing
Principles of Condition Monitoring in Heavy Haul Rail 5
© SKF Group 2 August 2013Slide 44 Increasing wheel bearing reliability Two basic approaches: 1. Technical advancements prolonging the service life of the wheel bearing 2. More accurate prediction of failures using modern condition monitoring technology
© SKF Group 2 August 2013Slide 46 Condition Monitoring in rail Different systems and technologies are available to detect bearing or other mechanical (electrical) component failure before it develops into heavy damage or accidents. Two basic approaches: Along the track (bearing surface temperature detection via infrared beams or Acoustic Waves Emission based devices) Integration of sensors in the bearing or in the bogie SKF approach is the integration of sensors in the bearing The immediate contact with the bearing enables reliable extraction of high quality bearing condition info, allowing early detection of bearing degradation Newly developed wireless communication further enables this approach in heavy haul
© SKF Group 2 August 2013Slide 48 Along the track hot box detection - infrared Trenitalia DB SBB SNCB Absolute alarm Relative alarm – Delta T Relative alarm – threshold for the hottest bearing Single alarm (T linear dependent, value at 20°C ambient T)
© SKF Group 2 August 2013Slide 49 Along the track hot box detection - acoustic Railway trackside acoustic detector (photo Saferail)
© SKF Group 2 August 2013Slide 50 Under track bogie testing Wheel bearing condition monitoring system integrated into bogie testing machines to evaluate the total bogie condition. The system allows workshop to investigate rotating bogie components without dismounting for: Certifying maintenance works Enabling condition based maintenance
Technical advancements in the application of condition monitoring in heavy haul rail
© SKF Group 2 August 2013Slide 52 Coming from a research & development program R&D focused on combining SKF’s bearing life and condition monitoring knowledge Factor aSKF for radial roller bearings hc Pu/P 0.005 0.02 0.05 0.2 0.5 2 50.01 0.1 1 aSKF 0.05 0.2 0.5 2 5 20 50 0.1 1 10 k=4 2 1 0.8 0.6 0.5 0.4 0.3 0.2 0.15 0.1 0.005 0.02 0.05 0.2 0.5 20.01 0.1 1 c Explorer
© SKF Group 2 August 2013Slide 53 SKF InsightTM – embedding self powered CoMo sensors within railway bearing units Power harvesting from application environment Embedded sensors for measurement of Load Lubrication Speed Vibration Temperature Intelligent wireless communication packaged inside the bearing SKF InsightTM embedded sensors allows operators to alter operating conditions to avoid bearing damage SKF InsightTM is currently tested in heavy haul rail
© SKF Group 2 August 2013Slide 54 Application of embedded wireless CoMo sensors Wireless communication from bearing to gateway Information relating to actual operating condition is sent to Cloud servers for remote diagnostics Smart Components are integrated into the bearing or housing. Monitor lubrication, speed, temperature and vibration Self powered Understand how the bearing’s service life is being consumed and the risks of failure
© SKF Group 2 August 2013Slide 55 2 August 2013Slide 55 Smart End Cap for Freight Cars with Insight™ Technology
© SKF Group 2 August 2013Slide 56 Advantages of this breakthrough innovation Eliminate damaging operating conditions Avoid expensive and disruptive failures Optimise major overhaul schedules based on equipment health Improve process control Reduced maintenance costs Extended bearing life through optimised operation Reduce cost of ownership
© SKF Group 2 August 2013Slide 59 Technical advancements increasing Heavy haul wheel bearing reliability New technologies increasing wheel bearing service life - Higher capacity bearings without increasing axle dimensions - Lower friction and better functioning seals reducing energy consumption and minimizing bearing contamination - Optimised bearing design minimizing fretting (p-spacer) and increasing safety (polymer cage) Embedding self-powered sensors for accurate online condition data, allowing operating conditions to be altered, or maintenance to be scheduled.
Thank you for your attention
© SKF Group 2 August 2013Slide 61
Canvas Prints at Affordable Prices make you smile.Visit http://www.shopcanvasprint...
30 Días en Bici en Gijón organiza un recorrido por los comercios históricos de la ...
Con el fin de conocer mejor el rol que juega internet en el proceso de compra en E...
With three established projects across the country and seven more in the pipeline,...
Retailing is not a rocket science, neither it's walk-in-the-park. In this presenta...
Milan Soukup, SKG Railway: Making heavy haul heavier: Exploring technical advancements towards increased wheel bearing reliability.
Stephen So delivered the presentation at 2014 Student Housing Forum. The 5th annual Student Housing Forum brought together university planners and managers ...