Linear actuators get really clever
Linear actuators get really clever
KeywordsActivators, Automation, EMS Ltd, Intelligent systems
Current demand for greater control over linear actuators has prompted the development of the ILD intelligent linear drive from EMS Limited.
EMS anticipates applications for the intelligent linear drive will include: adjustment of medical therapy couches with speed regulation, positioning and telemonitoring;tracking of satellite and radio link system antennae; raising platforms for level adjustment; and points technology for rail cars.
At the core, the ILD has an electronically commutated motor, from which the drive is fed information on the position, direction, speed and rotation of the motor via Hall sensors. A micro controller then uses this information to regulate the rotating field generation for the motor phase windings.
An incoming mains adaptor transforms mains voltage to the required auxiliary voltage for the logic and controller elements, and also supplies the intermediate circuit voltage for the motor windings.
This rotative power is then transmitted by a spur gear to the spindle unit. The use of a choice of either acme threads or ball screws then determines how the power output translates into force and speed. The actuator is available in two configurations: either using ball screws at 20kN with 25mm/s, 10kN with 50mm/s and 5kN with 100mm/s; or using acme threads at 15kN with 7mm/s and 5kN with 15mm/s. The range includes adjustable user and safety limit switches, and an emergency hand control. An integrated safety nut guards against any danger from a load nut breaking.
Digital control and information processing provide functions that could not previously be offered,including: programming of speed profiles; high speed/slow movements; positioning with memory functions; and inputs and outputs for definition/feedback of signals. There is also a telediagnostic service function through which operation history can be downloaded.
Future developments expected soon include CAN-bus compatibility for fast machine control networks. Using the fieldbus, central control is possible over the locally driven equipment. These advanced drive systems are now offered in a single attractively packaged aluminium cased unit.
Contact Mr Jeff Mead,Electro Mechanical Systems Limited, Eros House, Calleva Industrial Park,Aldermaston, Reading RG7 4QW, UK. Tel: +44 (0) 1189 817391; Fax: +44 (0) 1189 817613.
