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

Indexing System Information

Physical Properties Info.

Rotary Indexer with Dial Table Driving Application

Rotary Indexer with Dial Table Driving Application

Dial Table Info.

• Diameter, [D_dial] = 1000 mm
• Thickness, [Y] = 20 mm
• Material = Aluminum (Density 0.00274 g/mm³)

Mass of dial table

• Then Table Mass, [M_dial] = 43.040 Kg.

Station Info.

• Number of Stations, [N_stations] = 8 stations
• Mass per Station, [M_station] = 20 Kg/staion
• Then Total Station Mass, [SM_stations] = 8 x 20 = 160 Kg
• Rotating Radius to Station Center, [R_st] = 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, [N_{add part}] = 4 parts
• Part Mass, [M_{add part}] = 2 Kg/part
• Total Additional Part Mass, [SM_addpart] = 4 x 2 = 8 Kg
• Rotating Radius to Part Center, [R_{add 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 Movement Term

• Number of Stops, [S] = 8 stops

Displacement per 1 index

• Dial Plate Displacement per Index, [h_m] = 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, [N_rpm] = 60/1 = 60 rpm
• Indexing Period, [B_m] = 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, [t_m] = 270/360 x 60/60 = 0.750 sec

Dwell Time

• Dwell Time, [t_dwell] = 1 - 0.750 = 0.250 sec
• Required Dwell Time, [t_{dwell required}] = 10 sec (This is actual required dwell time according to the working process.)
• In case of t_{dwell required} > t_dwell  we can use clutch and brake to extend the dwell period, but if t_{dwell required} < t_dwell that mean we can reduce t_dwell to be the same as t_{dwell required}
• Reducing t_{dwell required} can be consider in 2 cases. Reducing indexer input shaft cycle [T] or Increasing indexing period [B_m].
• This case,   t_{dwell required} > t_dwell

Motor stop time

• Input Shaft Stop Time, [t_stop] = 9.750 sec

Machine cycle time

• Machine Cycle Time, [Tmachine] = T + t_stop = 1 + 9.750 = 10.750 sec
• Machine Speed, [Speedmachine] = 3600/10.750 x 8/8 = 334.884 UPH

Machine Speed

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

• Example of Rotary Indexer Sizing Calculation for Table Plate Drive Application Part 2
• Example of Rotary Indexer Sizing Calculation for Table Plate Drive Application Part 3