TPi March 2019

Products & developments

Compact magnetic gripper handles heavy steel parts

well as welding and grinding processes. The on/off position is detectable by means of standard sensors that can be mounted in the slotted holes provided for this purpose. It is also possible to join two or three power grippers together with special connection strips for heavy-lift applications, such as in shipyards, to lift hull sections that weigh tonnes. The magnets can be switched on and off via simple pneumatic control using a 5/2 or 5/3 valve. The magnet system is powerful when switched on, yet has hardly any residual magnetism when switched off. The magnet is maintenance-free, has a long life, and is available in various sizes. Goudsmit Magnetics Group – Netherlands

with neodymium magnets that makes direct contact with the handled product via steel legs. This pole configuration was calculated with FEM analysis and optimised to the extent that the circuit is less susceptible to widening of the air gap between the poles and the gripped object. This ensures the optimum holding force and even makes it possible to handle rusty products safely. The magnetic gripper is made with a special bearing-supported suction cup assembly that tests have shown to have a service life of at least one million strokes. This Powergripper is less suitable for use on thin-walled products. At wall thicknesses below 10mm the lifting force is relatively lower, so the normal gripper is more suitable. Tests show the relative lifting forces of power versus normal grippers; which gripper is best suited for which product; and what the safe holding force is. In a robot application the Powergripper serves to pick up or hold solid, heavy steel parts, such as cast parts, hot rolled profiles, solid bar material and thick-walled welded constructions. The magnetic grippers are also used for picking up steel workpieces for processing in saws and machine tools as

At EuroBLECH in Hanover, Germany, Goudsmit Magnetics presented a recently developed compact, strong magnetic gripper, known as the Powergripper. The magnet handles and holds heavy ferromagnetic parts such as rolled profiles, bar material and solid steel products in the shape of grilles, plates and milled parts, brake discs and steel wheels. The magnetic gripper, mounted on a robot or XYZ manipulator, can pick up over 100 kg. It is fitted with neodymium magnets and is pneumatically switch- able, yet is permanently magnetic. This provides extra safety, because the magnet retains the heavy load even in the event of a loss of compressed air. This requires no backup system of any kind, which means low investment and maintenance costs and a simple controller. As an example of the ratio of compactness to magnetic force, a 115mm Powergripper weighing 9.5 kg can safely lift a load of around 175 kg and has a holding force of 527 kg. In comparison with a standard magnetic gripper, which has the same application but is intended for thin- walled sheet material, a power gripper with the same diameter is 3.5 times stronger. To achieve this, Goudsmit has developed a closed magnetic circuit

info@goudsmitmagnets.com www.goudsmitmagnets.com

The magnetic Powergripper lifts or holds heavy metal parts, and is suitable for robot applications and as a lifting magnet

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March 2019 TUBE PRODUCTS INTERNATIONAL