Constant Torque Spring Design

Record spring output, lubricant behavior and bearing or seal resistance separately where possible. An assembly torque change can have several causes.

A counterweight can offset part of the load, leaving the spring to address a residual requirement. Compare the combined load curve rather than simply adding.

Provide a defined way to inspect tracking, retained material and contact without exposing an uncontrolled energized mechanism.

Only if the effective lever arm remains constant. External geometry can transform nearly constant torque into changing linear force.

Include the actual setting operation and tolerance correction in the required rotation window, using an approved margin rather than an arbitrary extra turn.

When bearing and seal drag occupy a significant share of the available torque, measure them explicitly instead of treating them as negligible.