SERVO-HYDRAULIC DRIVES

Servo-hydraulic drives represent an advanced combination of hydraulic power and high-precision electronic motion control. By integrating a servo motor with a pump or controlling a servo valve, they achieve exceptional positioning accuracy, responsiveness, and efficiency under heavy loads.

This solution is especially suitable for applications requiring high pressures, large forces, and simultaneously controlled motion with dynamic feedback.

Structure and Operation

A typical servo-hydraulic system includes:

  • A servo motor with a vector drive that directly controls the pump (servo pump system)
  • A position-controlled hydraulic cylinder with feedback (LVDT, incremental or absolute encoder)
  • A control valve with electronic flow and pressure regulation
  • A motion controller for synchronizing and controlling position, speed, and force

The regulation occurs in a closed-loop system, enabling full control over the motion profile without continuous oil flow—resulting in greater energy efficiency compared to traditional hydraulic systems.

Technical Advantages of Servo-Hydraulics

  • High positioning accuracy (typically up to ±0.01 mm)
  • Full real-time control of speed and force
  • Energy efficiency, as oil flows only when needed
  • Compact design without the need for a separate hydraulic power unit
  • Quieter operation and reduced thermal losses
  • Easy integration into CNC, PLC, or mechatronic systems

Key Industrial Applications

  • Presses and injection molding machines requiring controlled force and precise travel
  • Automated tools and clamping systems with repeatable closing under adjustable pressure
  • High-dynamic machining units where standard electric actuators are too weak
  • Testing devices requiring accurate force, pressure, and position measurements under load
  • Forming and bending units with motion dependent on programmable parameters

Technology of the Future

Due to their efficiency and compactness, servo-hydraulic systems are increasingly replacing traditional hydraulic units in many applications. The growing demand for flexibility, diagnostics, and energy efficiency in industry further drives their adoption.

Modern servo-hydraulic drives offer full connectivity with industrial networks (EtherCAT, CANopen, Profinet), include predictive diagnostics, and enable fast optimization of motion profiles within existing automated systems.