Mechanical Installation; Figure 4 Constant Torque Linkage - Honeywell HercuLine 2000 Series Installation, Operation And Maintenance Manual

Mechanical Installation

Linkage Set-up
Many applications require the use of a linkage assembly and often the final control element does not have a
linear torque curve. The actuator linkage can be set up to achieve an optimal delivered torque distribution for
specific applications. To assist with linkage design, Honeywell offers a linkage analysis software application
(HAL). The software can be ordered as P/N 51197910-001.
Constant Torque Linkage (typical)
A constant torque linkage is employed when it is desired to provide a linear torque profile throughout the full
range of final control element travel. In this situation, the actuator and driven crank arms will be set-up
proportionally with respect to each other. Figure 4 shows a general linkage setup to achieve a linear torque
profile.
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 5 shows a general
linkage setup to achieve a non-linear torque 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.
Revision 7 HercuLine™ 2000 Series Actuator - Installation, Operation and Maintenance Manual
7/08
Vertical
Centerline
45° 45°
Start
Drive Unit
Crank Arm

Figure 4 Constant Torque Linkage

Linkage
Stop Close
Horizontal Offset
Mechanical Installation
Vertical
Centerline
45° 45°
Open
Damper
Crank Arm
a/n 23199
Installation
15