If your application involves rotary motion, it’s important to consider how you mount your shock absorbers. In this blog post, we’ll explore some of the common issues that can arise and provide you with some helpful tips on how to maximize your shock absorber’s lifespan and damping capability.
Challenge #1: Side Load
Let’s consider a packaging machine that incorporates rotary motion. In cases like this, the machine’s rotary movement can cause side load on the piston rod—leading to wear and tear and lowering the shock’s lifespan.
ACE Tip: Whenever you encounter a lateral impact angle greater than 2 degrees, you can incorporate a side load adaptor, which removes the side loading from the piston rod to achieve considerably longer life.
Challenge #2: Moving Your Mounting Point
Sometimes your shock absorber—which is already sized for a specific mounting point—needs to move closer to the pivot point. Now, the shock absorber is too soft and can’t absorb the energy properly.
In rotary applications, moving the mounting point will impact the stiffness of the damper, as well as the effective weight—a calculation that considers the total energy affecting your shock absorber and the impact velocity on the damper:
$$ \large{\mathsf{W_E=\frac{2 \times W_3}{V_D {^2}}}} $$
- WE = effective weight
- W3 = complete energy that affects the damper
- VD = impact velocity on the damper
ACE Tip: In rotary applications, moving a shock absorber closer to the pivot point increases its effective weight. You can use this value to help you select the right shock absorber for the new mounting point.
In one case example, the original mounting point on a rotary machine called for an ACE MC600 miniature shock absorber, which has a maximum effective weight of 136 kg. Because the damper moved closer to the pivot point, however, the application required a stiffer damper with a higher effective weight capacity. In this case, the original unit was swapped out for an MC600MH3 shock absorber, which has a maximum effective weight of 4,536 kg.
Learn More
With our free ACE calculation program, you can size shock absorbers for almost every movement and application. Visit our calculations page to learn more.