Rockwell Automation Motion Analyzer Software - Manual (Page 84)

84 Rockwell Automation Publication MOTION-UM004B-EN-P - October 2012
Chapter 2 Sizing Your System
2.1.1.1. Advanced Considerations - Counterbalances
In a counterbalanced system, unbalanced mass should be entered as Table Mass
and balanced mass as Belt/Chain Mass. Values for Table Mass, Belt/Chain Mass,
and/or Slide Mass may be entered on the Mechanism tab (a future step in the
workflow) if a Belt Drive, Lead Screw, Chain and Sprocket, or Rack and Pinion
are selected.
There are two main types of counterbalance.
Table 50 - Counterbalance Types
Figure 67 - Counterbalance Types
Type Description
Mass
Counterbalance
A 100% counterbalance doubles the load mass entered on the Load tab. Friction is usually
negligible and the net force is zero. Accelerations are normally limited to less than gravity
(9.81 m/s
2 ) to maintain the suspension tension.
Force
Counterbalance
A 100% counterbalance means there is zero net force, but usually adds significant friction,
especially hydraulic types. For example, pneumatic, hydraulic, or spring. The increase in load
mass is usually negligible.
Counterbalance Mass
Mass Counterbalance Force Counterbalance
Counterbalance
Cylinder
Air Pressure
Force
Weight
Weight
Weight
Drive Belt
Drive Belt
Load Mass
Load Mass
Motor
Motor