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Friday, July 3, 2015

Example of rotary indexer sizing calculation for table plate drive application (1/3)

with 1 comment
Indexing System Information
Physical Properties Info.
Rotary Indexer with Dial Table Driving Application
Rotary Indexer with Dial Table Driving Application

Dial Table Info.
  • Diameter, [Ddial] = 1000 mm
  • Thickness, [Y] = 20 mm
  • Material = Aluminum (Density 0.00274 g/mm3)
Mass of dial table
  • Then Table Mass, [Mdial] = 43.040 Kg.
Station Info.
  • Number of Stations, [Nstations] = 8 stations
  • Mass per Station, [Mstation] = 20 Kg/staion
  • Then Total Station Mass, [SMstations] = 8 x 20 = 160 Kg
  • Rotating Radius to Station Center, [Rst] = 450 mm (If the station is large or complex shape, a radius of gyration of each station should be calculated.)
Additional Part Info. (The same part at the same rotation radius)
  • Number of parts, [Nadd part] = 4 parts
  • Part Mass, [Madd part] = 2 Kg/part
  • Total Additional Part Mass, [SMaddpart] = 4 x 2 = 8 Kg
  • Rotating Radius to Part Center, [Radd part] = 300 mm (If the part is large or complex shape, a radius of gyration of each part should be calculated.)
  • If there are others group of additional parts, do the same method.
Movement Info.
Rotary Indexer
Rotary Indexer Movement Term
  • Number of Stops, [S] = 8 stops
Displacement per 1 index
  • Dial Plate Displacement per Index, [hm] = 2 x 3.1416 / 8 = 0.785 rad
  • Indexer Input Shaft Cycle, [T] = 1 sec (Assume to 1 second, this can be adjusted later)
Indexing Rate
  • Indexing Rate, [Nrpm] = 60/1 = 60 rpm
  • Indexing Period, [Bm] = 270 deg (Assume to 270 degree, should be taken as long as possible for smoother movement. Please check to the manufacturer information)
Indexing Time
  • Indexing Time, [tm] = 270/360 x 60/60 = 0.750 sec
Dwell Time
  • Dwell Time, [tdwell] = 1 - 0.750 = 0.250 sec
  • Required Dwell Time, [tdwell required] = 10 sec (This is actual required dwell time according to the working process.)
  • In case of tdwell required > tdwell  we can use clutch and brake to extend the dwell period, but if tdwell required < tdwell that mean we can reduce tdwell to be the same as tdwell required
  • Reducing tdwell required can be consider in 2 cases. Reducing indexer input shaft cycle [T] or Increasing indexing period [Bm].
  • This case,   tdwell required > tdwell
Motor stop time
  • Input Shaft Stop Time, [tstop] = 9.750 sec
Machine cycle time
  • Machine Cycle Time, [Tmachine] = T + tstop = 1 + 9.750 = 10.750 sec
  • Machine Speed, [Speedmachine] = 3600/10.750 x 8/8 = 334.884 UPH
Machine Speed
Displacement VS Indexing Angle Timing
Displacement VS Indexing Angle

  • Cam Curve : Modified Sine (assumed, please check from rotary indexer manufacturer data)
  • Safety Factor, [SF] = 1.2
  • Operating Condition : 24 Hrs running, Steady load, Starts/stops 2 times per hour, Ambient temperature 30 C, Without cooling fan


1 comment:

  1. could you please send me excel program of Rotary Indexer Sizing Calculation for Table Plate Drive Application

    ReplyDelete

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