If a spring is anchored at one end and the other is subject to a moment, the load case is labelled as lateral bending. While it is possible to subject a wire spring to lateral bending, machined springs are more commonly used in this load case because of the availability of attachments. Buckling is rarely a concern for Lateral Bending Springs.

Machined springs can easily be used in lateral translation. Lateral translation occurs when one end of a spring is anchored and the other end is laterally displaced by a force plus a moment to insure the end faces of the spring remain parallel. Such deflections are again ideally suited to machined springs because of attachment availability. Rate consistency for deflections between orthogonal axis found in the plane on the parallel ends increases with the number of starts (1, 2, 3 with 3 being best) and with the number of coils being 2 or more. Similar to lateral bending, buckling is rarely a concern for lateral translation springs.

When considering the dynamics of the machined spring the we look at the 6 possible Cartesian co-ordinates, those being X,Y,Z and then the ROTX, ROTY & ROTZ (please refer to illustration below).

Machined Springs: Lateral Bending and Translation Diagram

A wound spring tries to deliver all 6 axis potentials when it is asked to move. A machined spring can be a single degree of freedom system, delivering motion in only one of the possible six axis and the double start machined spring is the closest single Cartesian co-ordinate deflection part available with todays technology.

However it must not be forgotten that it is also possible to predict and deliver multi cartesian axis springs. For example, some applications have demanded an accurate mixture of compression, lateral and torsional spring rates. !


Search   ABSSAC

x