Example of rotary indexer sizing calculation for table plate drive application (2/3)

Calculations

Rotary Indexer with Dial Plate Driving Application Torque Diagram

Step 1 : Moment of Inertia Calculations

• How to calculate the Moment of Inertia?
• Dial Plate Inertia, [I_d] = 1/2 x 43.040 x ((1000/1000)/2)^2 = 5.380 Kg.m²

Dial Plate Inertia

• Stations Inertia, [I_st] = 160 x ((450/1000)/2)^2 = 32.400 Kg.m²

Stations Inertia

• Additional Part Inertia, [I_{add part}] = 8 x ((300/1000)/2)^2 = 0.720 Kg.m²

Additional Parts Inertia

• If there are others group of additional parts, do the same method.
• Total Moment of Inertia, [I_total or ∑MK²] = 5.380 + 32.400 + 0.720 = 38.500 Kg.m²

Total Inertia

• GD² = 38.500 x 4 x 9.81 = 1510.739 N.m²

GD Square

• Total Moving Mass, [∑M] = 43.040 + 120 + 8 = 211.040 Kg.

Total Moving Mass

• Radius of Gyration, [K] = (I_total/∑M)^1/2 = 427.118 mm

Radius of Gyration

Step 2 : Maximum Angular Acceleration Calculation

Cam Curve Characteristic Value

• From the table, find the Dimensionless Maximum Angular Acceleration for Modified Sine Cam Curve, [A_m] = 5.53
• Then, the Maximum Angular Acceleration, [a_m] = 0.785 / 0.75^2 x 5.53 = 7.721 rad/sec²

Maximum Angular Acceleration

^{Step 3 : Required Torque Calculations}

Torque on Rotary Indexer

• Inertia Torque at Index Shaft, [T_i] = 38.500 x 7.721 = 297.271 N.m

• External Friction Torque to Indexer, [T_f] = 10 N.m (Such as outboard support bearings, assume to 10 N.m)
• Work Torque, [T_w] = 0 N.m (Indexer is doing work such as lifting parts, assume to 0)
• Total Output Torque, [T_t] = 297.271 + 10 + 0 = 307.271 N.m

Total Torque at Output Shaft

• Example of Rotary Indexer Sizing Calculation for Table Plate Drive Application Part 1
• Example of Rotary Indexer Sizing Calculation for Table Plate Drive Application Part 3