Power transmission specialist presents braking systems for high braking torques and large-scale applications in harsh environments
Applications involving extreme torques call for reliable and high-performance safety brakes. This is especially true when the environment presents additional challenges, such as in harbors or on the open sea. With new models in the ROBA-stop® S and ROBA-stop M® series mayr® power transmission now opens up the braking torque range above 1,000 Nm in the maritime sector as well.
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With two new sizes in the proven ROBA-stop® S and ROBA-stop M® series, mayr® power transmission now offers new solutions for these extreme-duty applications. The ROBA-stop M® safety brakes are used in harbor or construction cranes, as well as in hoists or overhead traveling cranes in factory halls at various positions: specifically in the slewing, travel, and hoist drives, usually at the free shaft end. In normal operation, they frequently function as holding brakes. Only at a speed of zero does the brake engage and hold the load securely. The brakes are also designed to absorb peak loads with extreme friction work. This is the case, for example, when downward-moving loads must be braked from full speed in the event of an EMERGENCY STOP or power failure. New to the lineup is the ROBA-stop M® 2000, which achieves a braking torque of 3,500 Nm in the holding brake version and up to 2,500 Nm as a dynamic brake. The brake is available in two protection ratings: Protection rating IP54 for all conventional applications in which exposure to dust and water is not a major factor. For outdoor applications such as large construction cranes, where such conditions are the norm, protection rating IP66 is the better choice. It is achieved through a fully enclosed and sealed design.
The electromagnetic ROBA-stop M® safety brake operates according to the fail-safe principle, meaning it is failure-proof. In the de-energized state – including during a power failure or EMERGENCY STOP – it is engaged. When power is applied, a magnetic field builds up in the brake. The armature disk is attracted to the coil carrier against the spring pressure. This releases the rotor, which means the brake is released. The motor can rotate freely. A further advantage for safety-critical applications: Even in the event of damage to the brake – caused, for example, by a line breakage or failure of the magnetic coil – the braking torque is maintained.
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If even more protection is required – for example, when maritime conditions and seawater come into play – protection rating IP67 in combination with high-performance corrosion protection is the better choice. This applies to harbor crane installations or deck winches and cranes on ships. mayr® has had the ROBA-stop® S in its product range for some time now for such applications. In addition to the high protection rating, the brake is provided with a special seawater primer depending on customer requirements, and also meets the highest corrosion protection classes per DIN EN ISO 12944 when the customer applies a corresponding topcoat. With the ROBA-stop® S in the new size 11, which delivers up to 1,200 Nm dynamic braking torque as standard, an additional model for high loads is now available in the series.
The ROBA-stop® S is specifically designed for the demanding conditions of maritime applications. With protection rating IP67 and high corrosion protection, it withstands the stresses caused by saltwater, heavy seas, and storms, and ensures reliable safety on deck or in harbor installations.
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In difficult installation positions, criteria such as easy installation and handling as well as long maintenance intervals are particularly important, in addition to protection against external influences. Thanks to their reliable and sturdy design, the safety brakes are easy to handle and can be installed quickly and easily. The high-quality friction material of the brake linings with high wear resistance also substantially reduces the number of inspections necessary, and therefore the failure times. If the friction linings wear down, the maintenance effort is minimal: For the ROBA-stop® S series, only the air gap needs to be re-adjusted, or the rotor with the friction linings replaced at the end of the service lifetime. This is even easier with the new size 11 than before: The rotor is accessible from the rear of the brake, even when the brake is installed. This facilitates service and maintenance under extreme conditions and minimizes risks for the crew and equipment.
“We have been present on the market with our robust motor brakes for a comparatively long time, including in extreme applications,” says Andreas Merz, Product Manager at mayr® power transmission. “Our ROBA-stop® went into series production in 1986, so we have already been able to gather extensive experience. However, we are seeing significant developments in the course of electrification. Electric drives are becoming more compact and power-dense, but they also need to handle significantly more torque than before. That is why we are moving into the range well above 1,000 Newton meters with our new brake models. With our new XL brakes, we too are now serving a market segment in which the options available to the user are rather limited.”
mayr® power transmission at SMM 2026 in Hamburg: Hall A4, Booth 326.