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EMA Technology Overview. ElectroMagnetic Actuator – EMA4K. Peak Force = 19kN Peak Vel = 4m/sec Typical Damper Pk Performance: 10kN @ 4m/sec Freq response up to 300Hz 200mm stroke All Electric Motion Also avail in 1K, 2K, 6K configurations. Electromagnetic Actuator Fundamentals.
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ElectroMagnetic Actuator – EMA4K • Peak Force = 19kN • Peak Vel = 4m/sec • Typical Damper Pk Performance: 10kN @ 4m/sec • Freq response up to 300Hz • 200mm stroke • All Electric Motion • Also avail in 1K, 2K, 6K configurations
Electromagnetic Actuator Fundamentals • U-Channel Brushless Linear Servo Motor • Consists of a non-contacting forcer coil and a U-channel rare earth (Neodymium) magnet track • Ironless forcer means there are no attractive forces and no disturbance forces generated between forcer and magnet track • Ironless forcer has low mass resulting in high acceleration forces • Three phase coil winding with sinusoidal brushless commutation • U-Channel design reduces magnetic flux leakage • Non-contact design supported by standard bearings to handle off-axis loading
Assembly Automotive Data Storage Electronic Manufacturing Machine Tool Medical Military/Aerospace Fiber Optics Photovoltaics Packaging Engineered Systems Test & Inspection Electromagnetic Technology – Where Used
Electromagnetic Actuator (EMA)Major Components Actuator motion generated here Drylin actuator shaft bearing with replaceable inserts Forcer block attached to 3-phase forcer coils on each side (inside U-channel magnets) U-Channel Magnet Assembly bolted to column supports both sides End of Travel Limit Switches U-Channel Rare Earth Magnets Optical Encoder Read head with 1um resolution Lower T-rail bearing support – 1 each side
EMA Comparisons – Damper Testing Typical shock absorber performance as obtained from published literature
EMA Comparisons – General Performance • Estimates based on the following assumptions: • 2500kg GVW, 40kg unsprung, 650kg sprung mass, 6N/mm/sec viscous loading, 50N/mm spring load. • Hyd HS = Typical hydraulic actuator with hydrostatic bearings, dual 50l/min servovalves, 200l/min 210 bar hydraulic supply
EMA Comparisons – General Performance • Estimates based on the following assumptions: • 2500GVW, 40kg unsprung, 650kg sprung mass, 6N/mm/sec viscous loading, 50N/mm spring load. • Hyd HS = Typical hydraulic actuator with hydrostatic bearings, dual 60l/min servovalves, 200l/min 210 bar hydraulic supply
EMA2K Performance – Road Data Plot of Track Data Command and Feedback Profiles – Direct file Playback (No transfer function compensation required)
EMA2K Performance – Road Data Zoom In on portion of Command AND Feedback Track Data (there are 2 plots)
EMA2K Performance – Road Data Plot of Error throughout Entire Track File (Command – Feedback) RMS Error less than 0.001” (0.025mm)
EMA2K Performance – Road Data Plot of Actual Forces Achieved during dynamic Track Data Playback on EMA2K
EMA2K Performance – Road Data Zoom Plot of Dynamic Force - Track Data
EMA Benefits Summary • Higher performance / frequency response due to: • No oil column resonance • Lower actuator mass • Lower friction (no seals) • Tighter closed loop control Direct file playback often 10X better than hydraulic system with transfer function compensation! • Independent of operating temperature No oil viscosity variables to affect control loop • Independent of waveform content Can accurately run low velocity/low force and high velocity/high force without changeover from 2stage to 3stage, etc • Independent of accumulator charging/discharging cycles
EMA Benefits Summary • Less Maintenance and Downtime • No seals, accumulators, servovalves, filtration, oil contamination • DryLin bearings only contact points – easily replaceable • No system degradation due to component wear (pumps, valves, etc) • Modular design and less components makes troubleshooting easier • Lower Operating Costs • Increased efficiency over servohydraulics means annual electrical operating costs are 30% of comparable hydraulic systems • No filters, accumulators, servovalves, seals, hoses, pumps to repair/replace • Service and Support fees a fraction of major hydraulic competitors!