3. Installation - Mechanical Installation
Variable Torque Linkage
A variable torque linkage is employed when it is desired to provide a non-linear torque profile throughout
the full range of final control element travel. In this general situation, the actuator and driven crank arms
will be set up to provide a higher torque for seating or unseating the final control element. Figure 7 shows a
general linkage setup to achieve a non-linear torque profile and Figure 8 shows the resultant profile. Note
that this linkage can be characterized in many different ways by varying start angles and rotation
requirements of both the Actuator Crank Arm and the Driven Arm.
Actuator
Crank Arm
5°
a/n 23200
18
10260S HercuLine® Actuator Installation, Operation and Maintenance Manual
Vertical
Centerline
Linkage
Horizontal Offset
Figure 7 Variable Torque Linkage
Figure 8 Variable Torque Profile
Vertical
Centerline
45°
45°
Close
Open
Damper
Crank Arm
Revision 5
7/07