Posted to News on 11th Mar 2008, 20:45
Pneumatic rotary tables cost less than electrical servo models
Festo is launching a new generation of pneumatic rotary indexing tables that it describes as a flexible, cost-effective alternative to electrical models. The new DHTG series rotary tables are easy to install and commission, with all connections and adjusters accessible from only one side of the unit. They feature an open-bored stationary centre section for mounting electrical slip rings, rotary air distributors or additional on-table automation. Flexibility has been achieved through a simple effective design that enables the direction of rotation or the number of index stations to be modified, should the application requirements change.
Electrical tables undoubtedly have their place for ultimate control over position, acceleration and speed - but they require the drives and controls of a full servo motor system. Festo has identified numerous applications where the functionality can be completely met by pneumatic systems at a lower initial cost, with far simpler controls and reduced maintenance needs.
Festo's DHTG series pneumatic rotary indexing tables are suitable for fully or semi-automated applications such as assembly and light machining operations. They are initially available in three sizes, with 90, 140 and 220mm diameter top plates, capable of generating 4.4, 18.1 and 58.9Nm of torque, respectively. Each table can have 2, 4, 6, 8, 12 or 24 indexing points (stations), which can be driven clockwise, anticlockwise or toggled between the two. All three models are exceptionally compact - the 90mm table, for example, measures just 130 x 149mm and has a height of only 70mm. All three tables are equipped with adjustable hydraulic shock absorbers, and the 140 and 220mm models also incorporate automatic overload protection to guard against damage being caused by excessive mass moments of inertia.
The rotary movement is extremely quiet and smooth, with a near-sinusoidal acceleration characteristic. Inductive proximity detectors provide position feedback to the control system, once the table is locked in position at the end of an index movement.
Festo offers a comprehensive range of complementary accessories for its new DHTG series rotary tables, including single- and multiple-port rotary distributors, adapter kits, indexing conversion kits, toggle motion kits, proximity sensors and connecting cables.
