Linear Motor Electromechanical Brake System Design and Actuation ENS 491492

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Linear Motor Electromechanical Brake System
Design and ActuationENS 491/492

• Ömer Taner Sarper , 9325
• Mustafa Hakan Çakmakci , 8283

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Outline

• Linear Motor Elevator Systems
• Aim of the Project
• Old Brake Design
• New Brake System Design
• Experimental Analysis Results
• Manufacturing Implimentation
• Conclusion

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What is Linear Motor Elevator?

• Linear Motor Elevator is mounted system in a
  manner permitting motion of the entire linear
  motor, including stator, through the hoistway.

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Linear Motor Elevator consists of...

• Mover
• Stator Assembly
• Magnet Assembly
• Motor Coils
• Brake Actuator

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History of Linear Motors

• 1840s, to the work of Charles Wheatstone at
  King's College in London , too inefficient
• US patent 1905 - inventor Alfred Zehden of
  Frankfurt am Main , for driving trains or lifts
• Late 1940s, professor Eric Laithwaite of
  Imperial College in London, development of
  thefirst full-size working model
• 1980s British engineer HughPeter Kelly designed
  the firsttubular linear motor
• Recent Developments

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Applications of Linear Motors

• Usage with conventional rails
• Usage with monorails
• Usage with magnetic levitation
• Usage with Elevators

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Aim of the project

• To research and build a linear motor
  multicar elevator
• Design and manufacturing of the brake mechanism
  and actuator including analysis of itself

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Old Brake Design
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Old Brake Design
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Old Brake System

• Because of the not directly grasping the
  stators head of shoes, it doesnt work.
• The force, which would be expected to be
  conveyed to shoes entire surface, would now be
  exerted on only one line on each of the this
  makes the pressure on the shoes skyrocket.

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Reshaping of Old Brake System

• Modificated model of old designis grasping the
  stators headdirectly hence the pressure
  will be dispersed on the surface of the brake
  shoes.

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New Brake System

• The bell crank consists of an Lpivoted
  wherethe two arms of the Lmeet and it is used
  toconvert the direction of reciprocating
  movement.
• Changing the length of the arms changes
  the mechanical advantage (MA).

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New Brake System
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New Brake System

• The magnet attached parts caused a little
  reverse and the magnet position should be
  thought as between movers.

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New Brake System
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New Brake System

• Before manufacturing the Brake
• Brake grabbing 2.30 Brake releasing 4.60
• Distance the magnet can travel on linear bearing
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• Gain 14/ (4.60-2.30) 6.087

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New Brake System
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Experimental Analysis of Brake

• FEA of the Brake Shoe (1) - Design
• FEA of the Brake Shoe (2) - Results
• FEA of the Brake Shoe (3) - Discussion
• Experimental Analysis of Shoe Link

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FEA of the Brake Shoe (1) Design

• Strength analysis of the brake shoe is done with
  Finite Element Method.
• Material 7075 Aluminum alloy
• Properties Yield Strength 145 MPa
  Youngs Modulus 71.7 GPa Poissons Ratio
  0.33
• Load on the surface is 10000 N.

Load on the part
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FEA of the Brake Shoe (2) - Results

• The results converged for 2mm-sized elements.
• The maximum stress is 12.588 MPa
• Yield strength was 145 MPa.
• Only elastic deformation.
• No fracture.

von Mises stress analysis
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FEA of the Brake Shoe (3) - Discussion

• Maximum elastic deformation 3.8 µm
• So small, can be ignored.

Displacement analysis
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Experimental Analysis of Shoe Link

• The critical part, Shoe Link,has come out of
  the analysis,chosen material as AISI
  304Steel and it result as minimumsafety factor
  4.244.

Shoe Link
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Analysis of New Stator

• Back EMF Measurements (1) - Circuits
• Back EMF Measurements (2) Programs
• Back EMF Measurements (3) Results
• Resistance and Inductance Measurement

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Back EMF Measurements (1) - Circuits

• The Back-EMF is measured for three different
  cases.
• Circuit 1 and 2 are when the motor is being
  driven.
• Circuit 3 is when all the coils are open.

Circuit 1
Circuit 3
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Back EMF Measurements (2) - Programs

• DSpace and MATLABs Simulink were used.

DSpace interface
Simulink Model
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Back EMF Measurements (3) - Results

• The results were normal and expected.
• The shifts betweenthe coils are clear.

Results
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Resistance and Inductance Measurement
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New Stator Measurements

• For the new stator, the coils are not
  totally linear and for the electromagnetic
  force analysis it is needed to be calculated
• Aim to know how much clearance the new
  statorscoils have and the minimaand maxima
  point of thesurface levels

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New Stator Measurements (1)
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New Stator Measurements(2)
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New Stator Measurements(3)
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New Stator Measurements(4)
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Manufacturing Implimentation
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Manufacturing Implimentation
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Manufacturing Implimentation

• Gain Report (Real)
• Distance Between Shoes
• Open 7.85 mm
• Closed 3.07 mm
• Moves 4.78 mm
• Magnet Set (66)
• Open 88.38 mm
• Closed 104.02 mm
• Moves 15.64 mm
• Gain 15.64/4.78 mm
• Gain 3.272

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Manufacturing Implimentation

• Weight Report
• Total 7 Movers 30 Assembly_Parts
  Brake_System
• Weight
• 1 Mover 5500 gr
• 1 Assembly_Part 65 gr
• Volume
• Brake_System 1037962 mm3 1037.962 cm3
• Density
• Al 7075 2.796 gr/cm3
• Steel 8.01 gr/cm3
• Weight
• Brake_System w/o Steel Parts 2902.14 gr
• Brake_System 2950 gr
• Total 43400 gr 43.4 kg

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Conclusion

• The system gives expected outcomes, as
  designed logically and with simulation. The
  brake shoes grab the steel plate and with the
  help of the magnetic force it releases.

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References

• Bell crank. (2009, March 11). In Wikipedia, The
  Free Encyclopedia. Retrieved 2028, April 10,
  2009, from http//en.wikipedia.org/w/index.php?tit
  leBell_crankoldid276485040
• Sandor Markon Yasuhiro Komatsu, Akitomo Yamanaka,
  Ahmet Onat, Ender Kazan, Linear Motor Coils as
  Brake Actuators for Multi-Car Elevators,
  ICEMS07, CDROM bildiri kitabi, 2007
• http//www.fujitec.co.jp/

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Questions?

• Thank you !