Efficient and Effective bearing performance evaluation The right software platform for dedicated technical questions, based on the right knowledge and design criteria
A typical design process Changes
SKF software in a typical design process
SKF software portfolio SKF Bearing calculator SKF Bearing Select SKF SimPro Quick SKF SimPro Expert SKF BEAST Less Complexity and technical depth More Also external Only internal
Exploration : Bearing Type and Sizing Single Bearing Approach
Bearing Life Final Customer OEM Bearing manufacturer Service life Design life Fatigue life
Basic Rating Life versus SKF Rating Life Basic rating life: p C L10 P if speed is constant: L 10h 10 6 C. n.60 P C: Basic dynamic load rating (kn) P: Equivalent dynamic bearing load (kn) p: Exponent for life equation n: Speed (rpm) p Full film k 4 Lubrication Conditions Mixed lubrication k < 4 Contamination Boundary lubrication k < 1 SKF rating life: L nm C a. 1 askf. P if speed is constant: L 10h 10 6 C. askf. n.60 P a 1 : Life adjustment factor for reliability a SKF : SKF life modification factor p p
Other Design Criteria Maintenance Strategy Power Loss - Efficiency Minimum Load Requirements Load versus Speed Capability Available space Speed Misalignment Life L 10 = [ C / P] p Load/Direction Operating conditions
SKF Bearing Calculator (web & mobile app)
Life calculation with variable load Load P [kn] P 1 Load bin P 2 L 10m U L 1 10m1 1 U L 2 10m2... P 3 P 4 Life Fractions Example : Peak Load V 3 V 2 Speed V [r/min] V 4 V 1 U 1 U 2 U 3 U 4 Life Fractions 100%
SKF Bearing Select (web only) One or two bearings Assortment of bearings No shaft details Catalogue lives methods Load Cycle Evaluation
Development : Shaft-Bearing- Housing-Approach
Influence Bearing Operational Clearance Reduction due to mounting Reduction due to temperature
Influence Preload Enhanced Stiffness Reduced noise levels Improved shaft guidance Compensation of wear and settling Extended bearing service life
Bearing Stiffness Reaction loads, stiff <-> flexible bearing Left radial load + 40% Mid radial load + 20% Right radial load + 670%
Housing Stiffness Central bearing position B = stiff housing G = flexible housing All components affected
SKF SimPro Quick Calculations: FEM-based Bearing rating life Bearing catalogue friction Shaft deflection Re-lubrication intervals Defect frequencies The tools includes: Material database Lubricant database Integrated report Warning from SKF catalogue Link to SKF SimPro Expert
SKF Simpro Quick - User-friendly Interface
Development-Commercialisation : The full 3D-System- Approach
Advanced Life Method - Why Why more advanced methods? Catalogue method relies on simplifying assumptions! Parallel ring displacement Zero clearance Straight stress distribution
Advanced Life Method - Pro/Contra Advantages Catalogue method: Quick and easy Manual calculation possible Few inputs Reasonable accuracy if: Well supported bearings Zero clearance, no preload No moments loads Limited speeds Disadvantages Catalogue method: Cannot consider: Preload Moment loads Flexibility in application / components High speeds Does not include stress integration of overrolled volume
Advanced Life Method - Moment Load Equivalent load on the bearing is not sufficient to determine bearing life: It can not include preload, misalignment, moment load,... Example: pure moment load results in infinite basic rating life
Influence of Misalignment Edge stresses Truncation
Influence Contact Profile Output: Contact stress along roller
Influence Housing Support Fixed Fixed Fixed Sliding
Influence Housing Support Fully fixed supports Sliding supports 40000 40000 30000 30000 20000 10000 0 2 feet 3 feet 20000 10000 0 2 feet2 - sliding 3 feet - sliding
Influence Bearing Kinematics e A w R w A e I w I A w BA w I w I w BI Fr/Fc Fa D M C Contact angle variation Spin-to-roll 3Point Contact Fa
The challenges of simulating the whole system Gearbox modelling aspects: Detailed bearings geometry Lubricant properties & quantity Bearing friction Housings flexibility Heat exchange Influence of the environment Gears geometry & friction
SKF SimPro Expert ~1000 SKF users: Product developers Application engineers Product engineers Engineering consultancy services
Thermal Simulations in SKF Simpro Expert Sensitivity Analysis Target: minimum temperature OR
Seal Simulation in SKF SimPro Expert Full non-linear FEM calculations Easy connection with CAD Moulding simulations On-shaft simulations Pressurised seal simulations Contact with & without friction
SKF Beast : The full Dynamic 3D- System-Approach
SKF BEAST: The virtual test rig Multi-body simulation software Specialized in contact problems Detailed surface description Accurate tribology Any contacting machine element Application operating conditions Massive parallel computation
Conclusions
You learned what software are available at and by SKF You learned the importance to have the right tool for the right task You learned about web/mobile tools You learned about SKF SimPro Quick You learned about SKF SimPro Expert You learned about SKF BEAST Do you want to know more? Please contact you local sales team Please contact you local SKF Application Engineering team
Questions?
Thanks for your attention!