Group16: Assembly Fixture Design and Fabrication for 6 Pole Motor Magnets and their Retaining Parts Group Members: Jeffrey Morton John Pilgrim Marcus Rothberg November 12, 2009

Overview  Introduction  The Problem  Product Specification  The Design Concepts  Design Choice and Walkthrough  Experimental Calculations  Cost Analysis  Conclusion  Future Work

Danfoss Turbocor  Specializing in commercial HVACR applications  Designer and manufacturer of world’s first oil-free refrigerant compressors  The largest compressor, that is still in development, is the TT500

The Compressor – TT500  It is currently in its Beta phase of development  Inside the TT500 is a shaft that powers it  The shaft has a hexagonal center where six rows of magnets will be installed

The Shaft  Will have six rows of magnets secured to it via wedges  Each row of magnets will hold 9 magnets for a total of 54 magnets

The Problem  Load and secure magnets and wedges onto the shaft. Magnets need to be aligned with the poles adjacent Pole orientation alternating from column to column  Causes loading and alignment to be difficult

Magnets  The difficulty in installing the magnets is that the poles of the magnets are aligned  The repelling force of the magnets causes the installation to be difficult

Scope and Customer Needs  A new method to install magnets and wedges onto the shaft  Process must be Safe Ergonomic Accurate Time efficient Non-damaging to parts

Product Specification  Budget of $1500  Load and align 9 magnets to each row  Installs or allows wedges to be installed in between each row of magnets  A total of 6 rows of magnets  Repeatable  Completion of assembly within 45 minutes

Design 1: Plunger Fixture  Magnets placed all at once  Holds magnets for wedges and the next column of magnets to go  Initial plunger releases and moves to next column

 Loads and installs magnets one at a time.  Cylindrical Sleeve retains magnets on the shaft.  Ferrous bit constrains each magnet as they are lowered onto the shaft.  Wedges may be installed as each row of magnets is installed. Design 2: Cylinder Sleeve Aligning Rings Retaining Cylinder Ferrous Bit

Design 3: Bracket and Rail  Magnets loaded one at a time.  Magnets installed in rows of nine.  Magnets are aligned in rail, then loaded into the bracket and steel fixture.  Steel with magnets is lowered onto shaft and bracket locks into fixture.  Brackets retain magnets on the shaft until wedges can be installed. Aligning Rail Magnet Clamp Removable Ferrous Bit

Design 4: Trap Door  Magnets are loaded  Bar clamps and places magnets onto shaft  Magnets then secured by rods  Bar is removed and process is repeated

Concept Matrix Specifications: Precision (40%) Ease of Use (30%) Safety (10%) Durability (10%) Time (10%)

From Start to Finish  Bottom collar halves and aligning cylinder are placed

From Start to Finish  Shaft is placed  Top of the cylinder aligns shaft radially  Edge of cylinder aligns shaft axially

From Start to Finish  Top collar halves are placed

From Start to Finish  Alignment cylinder is removed  Collar tops are placed to retain collars

From Start to Finish  Shaft is placed and located  Magnets are to be loaded and placed

From Start to Finish  Magnets are loaded one at a time  (Part of the fixture base/frame is removed for visual purposes)

From Start to Finish  Magnet row alignment issues  Cam device and wall provides solution

From Start to Finish  Cam device and wall

From Start to Finish  Magnets loaded and aligned with cam  Magnets picked up by clamp

From Start to Finish  Trap door in loader opens  Clamp moves down path to place magnets on shaft

From Start to Finish  Retaining rods placed on magnet row

From Start to Finish  Shaft is indexed and next row of magnets is to be loaded  After all 6 magnet rows are loaded, shaft is removed from fixture

From Start to Finish  Retaining wedges are installed  Retaining rods and collars are no longer needed

Completion  GREAT SUCCESS!!!

Fixture Exploded View

Analysis  Force between two or more magnets  Cam displacement polynomials  Cam sva graphs  Cam profile  Time Analysis  Material Selection  Cost analysis

Magnet Testing  The magnets need to be loaded together.  As the magnets get closer together, the repelling force increases  A force of 26lbs is needed to place magnets together Loader Scale Magnets

Cam Aligner Design ActionDisplacementVelocityAccelerationDisplacement Polynomial Rise(0- 90deg) 000 h00 Dwell( deg) h00 h00 Fall( deg) h00 000

Cam Aligner SVA Graphs  No over shoot in displacement curve.  Smooth velocity curve.  No jumps in acceleration curve.

Cam Profile  From displacement curve.  Profile equations:  Center of axle equations:

Time Analysis

Preliminary Material Selection  Aluminum 6061 for most structural parts Easy to machine Relatively cheap Noncorrosive Yield strength of 8000psi (55MPa)  Oil impregnated bronze or Teflon for loader lining Low friction Non abrasive  Brass for inner collar Low friction

Cost Analysis PartDimensionMaterialQuantityPurchased?Price Loader H=1”; w=1”; Aluminum Square Tube1no$2.37 Sliding Door H=1”; w=1”; Aluminum Square Tube1no$2.37 Magnet Clamp T=1/2”; L=12”; w=2”Stainless Steel1no$38.90 Lever D=1”; L=36”Aluminum 60611no$13.33 Frame T=1/2”; W=4; L=12”Aluminum 60614no$52.36 Collar D=6”; L=6”Brass1no$ Hardware NA no$50.00 Cam D=1”; L=6”Aluminum 20241no$13.34 Cam Plate T=1/4”; L&W=8”Aluminum 20241no$16.38 Cam Aligner Side Plates T=1"; W=3"; L=12"Stainless Steel1yes$89.06 Base Plate T=1" ;W=8”; L=8”Aluminum 60613yes$ OtherDimensionsPrice per hourQuantityPurchased?Price Machine Work NA$50/hr10 hrsDonated$500 Total $776.30

Future Work  Finalize design and do detailed drawings with tolerances.  Analyze the four bar lever.  Fem Analysis of the magnetic fields and their resulting forces.  Order parts.

Acknowledgements  Robert Parsons Turbocor Machine Shop Supervisor  Clint Bencsik Turbocor Manufacturing Engineer  Alain Pepin Turbocor Mechanical Engineer Design Manager  Jean S. Cote  Dr. Daudi R. Waryoba  Davey Jones

Reference  McMaster-Carr,  Norton, Robert L. Design of Machinery 4 th edition, McGraw Hill.  Softwares – ProEngineer Wildfire, SolidWorks, Mathcad, Microsoft Office

ANY QUESTIONS? Comments also welcome