Downloaded 109 times
More Related Content
Similar to Linear motor by_suman singha,b-tech,eee
Linear motor by_suman singha,b-tech,eee
- 1.
- 2. In 1947Linear motor was commercially invented by professor Eric Laithwait , the British Electrical Engineer...................... EEE 1317
- 3. Analogous to UnrolledDC Motor • F = LI x B • Force (F) is generated when the current (I) (along vector L) and the flux density (B) interact EEE 1317
- 4.
- 5. EEE 1317 Analysisis similar to that of rotary machines › Linear dimension and displacements replace angular ones › Forces replace torques
- 6.
- 7.
- 8.
- 9.
- 10. Copper windings aroundforcer laminations over a single magnet rail Iron PlateRare earth magnets Laminated forcer assembly and mounting plate Coil wound Around Forcer lamination Hall effect and thermal sensors EEE 1317
- 11. Forcer constructed ofwound coils held together with epoxy and running between two rails (North and South) Also known as “Aircore” or “U- channel” motors Forcer Mounting Plate Rare Earth Magnets Horseshoe Shaped backiron Winding, held by epoxy Hall Effect and Thermal Sensors in coil Front View EEE 1317
- 12. Mix of ironlessand iron core: coils with back iron contained within aluminum housing over a single magnet rail Back iron Mounting plate Coil assembly Thermal sensor Rare Earth Magnets Iron plate EEE 1317
- 13. Linear Brushless DCMotor Type Feature Iron Core Ironless Slotless Attraction Force Most None Moderate Cost Medium High Lowest Force Cogging Highest None Medium Power Density Highest Medium Medium Forcer Weight Heaviest Lightest Moderate EEE 1317
- 14. Stepper Speed: 1 to100 ips (25 to 2,500 mm/sec.) Force: 2 to 50 lbf (9 to 220 N) Accuracy: 2 to 250 um. Cost: Low EEE 1317
- 15. Hybrid linear Motor Speed:60 in/sec (1.5 meters/sec) Force: 180 lbf (800 N) Accuracy: Encoder dependent Cost: High. DC Brush Speed: 75 in/sec (3.8 meters/sec) Force: 171 lbf (1070 N) Accuracy: Encoder dependent. Cost: Moderate. EEE 1317
- 16. AC Induction Speed: 270in/sec (6.85 meters/sec) Force: 500 lbf (2,225 N) Accuracy: Encoder dependent. Cost: Moderate. Iron Core AC Synchronous Speed: 400 ips (10 meters/sec) Force: 2,500 lbf (11,000N) Accuracy: Encoder dependent. Cost: High. EEE 1317
- 17. Rs. 300000.00 Trilogy T1S Ironless linear motor 110V, 1 pole motor Single bearing rail ~12’’ travel magnetic encoder Peak Velocity = 7 m/s Resolution = 5μm EEE 1317
- 18. High MaximumSpeed › Limited primarily by bus voltage, control electronics High Precision › Accuracy, resolution, repeatability limited by feedback device, budget › Zero backlash: No mechanical transmission components. Fast Response › Response rate can be over 100 times that of a mechanical transmission faster accelerations, settling time (more throughput) Stiffness › No mechanical linkage, stiffness depends mostly on gain & current Durable › Modern linear motors have few/no contacting parts no wear EEE 1317
- 19. Cost › Highprice of magnets › Low production volume (relative to demand) Linear encoders (feedback) are much more expensive than rotary encoders, cost increases with length Higher Bandwidth Drives and Controls Lower force per package size Heating issues › Forcer is usually attached to load I2R losses are directly coupled to load No (minimal) Friction › No automatic brake EEE 1317
- 20. Small LinearMotors › Packaging and Material Handling › Automated Assembly › Reciprocating compressors and alternators Large Linear Induction Machines (3 phase) › Transportation › Materials handling › Extrusion presses a EEE 1317
- 21. http://www.physclips.unsw.edu.a u/jw/electricmotors.html http://www.speedace.info/solar_c ar_motor_and_drivetrain.htm http://www.allaboutcircuits.com/ vol_2/chpt_13/1.html http://www.tpub.com/neets/book 5/18d.htm single phase induction motor http://www.stefanv.com/rcstuff/q f200212.html Brushless DC motors https://www.geckodrive.com/uplo ad/Step_motor_basics.pdf http://www.solarbotics.net/librar y/pdflib/pdf/motorbas.pdf EEE 1317
- 22.
- 23.
Editor's Notes
- #19 Typical max speeds: 3-5 m/s with 1 micron resolution, 5+ m/s (>200 ips) with less resolution Budget is main restraint on controller bandwidth Higher stiffness (spring rate), though limited by motor peak force, available current, and feedbakc resolution
- #20 Linear encoders are usually around $500 for 100 mm travel encoder, cost increases with length. Rotary encoders are relatively inexpensive – tend to be under 100 dollars No mechanical reduction between motor and load, thus servo response (bandwidth) must be faster. Includes higher encoder bandwidth and servo update rates Linear motors are not compact force generators when compared to rotary motor with transmission offering mechanical advantage. Example 3/8” diam. Ball screw produces 100 lb of thrust, while 15 lb of linear thrust typically requires 2” x 1.5” cross section. Heat management techniques such as air and water cooling options (both common, popular) have to be applied Suppose it’s traveling at 3 m/s and loses power. Without resistance, it will quickly reach end of end of system, mechanical stops. Linear encoders are usually around $500 for 100 mm travel encoder, cost increases with length. Rotary encoders are relatively inexpensive – tend to be under 100 dollars No mechanical reduction between motor and load, thus servo response (bandwidth) must be faster. Includes higher encoder bandwidth and servo update rates Linear motors are not compact force generators when compared to rotary motor with transmission offering mechanical advantage. Example 3/8” diam. Ball screw produces 100 lb of thrust, while 15 lb of linear thrust typically requires 2” x 1.5” cross section. Heat management techniques such as air and water cooling options (both common, popular) have to be applied Suppose it’s traveling at 3 m/s and loses power. Without resistance, it will quickly reach end of end of system, mechanical stops.