Fail-safe and fast

Electric motors are becoming increasingly popular in industry. In more and more factory buildings, hydraulic or pneumatic systems have to make way and are being replaced by electric drives. For this, reliable safety brakes are also increasingly required. With the new Roba-linearstop electromagnetic linear brake, Mayr Antriebstechnik now offers a fail-safe system with high holding forces that can also brake dynamically and impresses with its short switching times.

Linear movements are often safeguarded with safety brakes that act on separate round rods or piston rods or on guide rails. Depending on the application, pneumatic or hydraulic brakes are often used for this purpose, which achieve high holding forces. But today, drive axles are increasingly equipped with electric motors. Purely electric systems - also for safeguarding - are the trend. "We are the only manufacturer to offer electrically opening linear brakes that are also safety brakes," explains Bernd Kees, Product Manager at Mayr Antriebstechnik in Mauerstetten. This means that the brakes work according to the fail-safe principle. They generate the braking force by means of compression springs and are closed in the de-energised state. The new series of Roba-linearstop electromagnetic brakes comprises six sizes with forces from 70 to 17,000 N.  

More than just clamping units

"Most linear brakes available on the market function as static clamping units and are designed to hold the axes at standstill," explains Bernd Kees. "However, people can also be under suspended loads during commissioning, maintenance or even during the production process without first transferring the load to the mechanical linear brake." If a complete failure of the drive occurs in these operating states, the linear brake alone is responsible for safely decelerating the load. For this reason, the safety brakes from Mayr Antriebstechnik are also designed for such dynamic braking. The company has voluntarily subjected the brakes to a type examination as a safety component in accordance with the Machinery Directive (2006/42/EC).

Short switching times and reliable switching status control

Short stopping distances are important for the safety of man and machine, especially with safety-critical and vertical axes. The switching times of the brake are decisive for the braking distance. This is because during the time of free fall until the brake closes and deceleration sets in, the mass accelerates additionally. The new electromagnetic linear brakes therefore impress with their short switching times. "Compared to previously common products, our brakes switch faster by a factor of 10," adds Bernd Kees. However, the greatest possible safety is only achieved if the projected switching times are guaranteed over the entire service life. That is why a reliable switching status control is important. With the new electromagnetic Roba-linearstop brakes, this is done via the control module. For larger brakes (from size 40), a monitoring option with proximity initiator is also possible.

New solutions for the rail

In addition to linear brakes for piston rods, Mayr Antriebstechnik is also currently working on electric safety brakes for profile rails. The new Roba-guidestop brakes for rails in sizes 25 to 45 are almost ready for the market.