Actuators

The range of actuators includes electromechanical actuators, different series of servohydraulic test actuators as well as customized actuators for reliable and flexible single to multi-channel test systems.

Actuators are one key component in every high performance test system.
With an experience of more than 45 years in servohydraulic test systems and involvement in many demanding applications including civil, architectural, aerospace or automotive structural testing our actuators are designed for this challenging applications providing low maintenance, high performance level and reliablility.

The complete range of the w + b test cylinder ranges from electromechanical testing cylinders to differential, servohydraulic cylinders for the static or low-frequency testing up to test cylinders with hydrostatic piston bearing for highly dynamic test applications. Also Torsion drives are available.
All w + b test cylinders are designed for static, quasistatic, LCF and dynamic testing on standard samples or components in the threshold and variable load range designed for quality inspection, material development and materials research.
The w + b hydraulic cylinders usually work with standard European operating pressure of 250 to 280 bar, whereby the rated load usually is achieved at a pressure of about 250 bar (depending on the cylinder). In connection with hydraulic supplies with 280 bar operating pressure a »P of 30 bar for dynamic testing is available.
By designing the hydraulic cylinder to 250 bar = rated load, the piston area (piston diameter) can be compared to test systems with 207 bar (3000 psi) smaller. This reduces the moving mass of the piston accordingly. Next is through the smaller piston area the dynamic performance of a corresponding hydraulic with identical flow compared to 207 systems bar about 20% higher.

Electromechanical Test Actuators
The electro-thrust electrical actuators offer an alternative to hydraulic actuators for static and cyclic materials and components testing. According to the test requirements they are available with pre-loaded ball screw or roller screw with inline or parallel gearbox/motor mounting.

This actuators are available as standard designs up to 100 kN or as custom designs up to 1000 kN. The ball screw design is recommended for applications with considerable larger stroke during testing. It is recommended, that the test-stroke shall be more than the ball-diameter of the screw for fatigue testing.

The Roller Screw Actuators deliver heavy load capacity, high speed capabilities and exceptionally long life when compare to other linear actuator technologies. This Series of force tube actuators use a planetary roller screw mounted inside a telescoping tube mechanism. The Roller-Screw design delivery up to 15 times the work life of other comparably-sized screw actuator products on the market - specifically ball screw and acme screw actuators - have relatively low load capacities, short working lives and limited speed capabilities.
The bearing and roller screw components are mounted within the sealed housing. This prevents abrasive particles and other contaminants from entering the actuator's critical mechanism, and assures trouble-free operation even in the most severe environments.

Version with "Inline" drive
For the inline version, the entire drive train (rollerscrew or ballscrew, gearbox and motor) is in one axis. The torque does not have to be transmitted via toothed belts and toothed belt pulleys.

The connections of the individual drive components can be made backlash-free.
If the actuator integration in a test systems allows it, the inline version is technically preferable.

Parallel drive mounting
Test cylinders for component testing many times have a parallel mounting of the gearbox and motor in order a joint can be added also on the

actuator base (foot flange). The joints are used to avoid misalignment and elimination side load and moment which could invalid your test or
damage the actuator or its components.