SHOCK LOADING EXPLAINED: WHY HYBRID LINEAR ACTUATORS OUTPERFORM EMAS

Learn how shock loading impacts actuator life and why hybrid linear actuators deliver superior reliability, durability, and control compared to EMAs.

WHAT IS SHOCK LOADING & WHY DOES IT MATTER?

In many industrial applications, sudden impacts, rapid force changes, or unpredictable part variation are unavoidable. These momentary spikes — known as shock loads — can cause significant mechanical stress on an actuator. While electro-mechanical actuators (EMAs) are widely used for motion control, they are especially vulnerable to shock loading because of their use of mechanical components including on screws, nuts, bearings, and gearboxes.

worn ball screw actuator

Hybrid Linear Actuators use servo-controlled motion and a hybrid design that can absorb shock loads. This means maintaining consistent operation even in applications where forces can spike suddenly, reducing the risk of mechanical damage or degradation over time.

WHY EMAS ARE VULNERABLE TO SHOCK LOADS

Because EMAs rely entirely on mechanical components to transmit force, all shock loads travel directly through the screw, nut, bearings, and motor. This can lead to:

  1. Accelerated Wear of the Screw Assembly
    Shock loads cause brinelling, deformation, and pitting — especially in ball screws or roller screws.
  2. Positioning Errors and Repeatability Issues
    The mechanical system deflects under shock, causing loss of accuracy.
  3. Lost Motion and Backlash Over Time
    Repeated impacts loosen critical mechanical interfaces, reducing their precision.
  4. Sudden or Catastrophic Failure
    Shock load impacts can strip threads or nuts, crack bearings, or damage the motor.

HOW HYBRID LINEAR ACTUATORS HANDLE SHOCK LOADS

  1. Built-In Shock Absorption
    Servo hydraulic fluid acts as a shock absorber, providing a natural energy buffer that prevents force spikes from damaging the system.
  2. No Screw Assemblies to Fatigue
    Without ball screws, roller screws, or mechanical nuts, there’s no direct mechanical path for shock to damage critical components.
  3. Stable Position & Force Control During Shock Loads
    Closed-loop servo control maintains smooth motion and consistent accuracy even when load force  changes abruptly.
  4. Integrated Relief Valve Protection
    Relief valves protect the hybrid linear actuator and the machine from extreme shock conditions.
  5. Significantly Reduced Wear
    Because shock loads are dissipated within the hydraulic system rather than transferred into hardware components, lifespan of the actuator increases substantially.
  6. High Reliability in Harsh, High-Force Environments
    Hybrid actuators are robust and reliable in applications where shock loading is expected.