A range of intelligent dampers have been introduced by German manufacturer Bansbach which it claims are set to revolutionise damping technologies. Available in the UK from Albert Jagger, the EasyERF Intelligent Damping technology offers electronically adjustable dampers with reaction times measured in milliseconds. The technology was developed for active suspension systems in the top marque automotive sector, however it was realised that the technology had a much broader scope, particularly in industrial sectors involving machine suspensions, precision motion control actuators or self adaptive end-of-stroke damping elements.
The system combines smart PID (Proportional Integral Derivative) systems and the latest in electrorheological fluid (ERF) technology and continuously monitors and modifies resistant forces within the damper. Achievable by digitally managing an electronic input signal to change the ERF viscosity, this is said to offer instantaneous control of dynamic damping requirements with infinite adjustment possibilities.
Highly energy efficient with power consumption of just 24V DC, damping can be adjusted using a variety of digital controls including 0-4V analogue, a standard PWM, or 24V DC SPS. Further benefits include a wide adjustable range of forces between 100 and 2500 Newtons, and through strokes ranging from 25 to 125mm, enabling positioning to within 0.1mm.
The system consists of a piston with a defined gap – the Annular Gap – between housing and piston, and the two chambers are filled with silicon based ERF. With no electrical charge applied, the fluid flows through an annular valve as in a standard damper. The inherent resistance is caused by the hydraulic drag coefficient of the laminar fluid flow. On application of an electrical charge, the viscosity of the fluid increases, choking the annular valve and resulting in an increase in the resistance force of the damper. With PID systems, by increasing the electrical field to its maximum, the ERF solidifies, resulting in a total blocking of mass movements, achieving ‘zero velocity’ or ‘clamping’. The ERF remains unaffected by the number of times its viscosity changes, and the easyERF dampers have been tested to over half a million cycles with no signs of deterioration.
Key advantages of the easyERF with smart PID include: Continuous force control; Dynamics of control – Smart PID systems need only a few milliseconds to increase the damping force, so it is possible to control processes with high frequencies; Holding force; Remote control – Changing the damping characteristics can be done by an electrical signal; Improved efficiency; Silent acoustics; and Durability.
One application example could incorporate a slow reading sensor typically found on conveyors to monitor weights. The weight of the load is transmitted to a computer, which calculates the electrical signal to send to the easyERF damper which is acting as an end stop to arrest the loads movement. This would see a significant increase in productivity as conveyor speeds are considerably increased, as no human intervention is required to mechanically increase or decrease the end damper force.
A fast reading example could involve a high speed industrial centrifuge where multiple vibration sensors monitor erratic vibrations within the machinery. This data is interpreted and passed to an array of easyERF dampers to damp out the machines structural movements. The centrifuge’s efficiency and speeds can be significantly increased as the easyERF dampers prevent structural vibrations throughout the centrifuge acceleration and speed characteristics.
Furthermore, the electrorheological technology offers new possibilities for the development of mechatronic systems.
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