Industrial Brakes: When Precision Means Safety
For us at Kern Antriebstechnik, brakes are much more than just components that stop motion. They generate defined counter-torques, stabilize processes, and ensure controlled motion sequences. In this article, we provide an overview of our brake portfolio—from magnetic powder and hysteresis brakes to friction surface brakes. We’ll show how their operating principles differ and why precise design and testing under realistic conditions are crucial for process reliability.
Powder-Magnetic Brakes: Electrically Controlling Braking Torque
In powder-magnetic brakes, a specially developed magnetic powder is located between the rotor and the housing. A coil through which current flows generates a magnetic field in which the particles align themselves. This creates a frictional connection whose braking torque can be continuously adjusted via the current.
This allows the braking torque to be adapted to changing process conditions. For example, web tensions in textile, paper, or packaging processes can be stabilized, and defined load torques can be generated on test benches. Our magnetic powder brakes are available in four sizes ranging from 10 to 100 Nm and with various hollow shaft diameters. We also offer a control unit.
Under continuous slip, mechanical power is converted into heat. The resulting slip power is therefore central to the thermal design. Optional heat sinks are available for applications requiring higher braking power.
Hysteresis Brakes: Fixed, Mechanically or Electrically Adjustable
In hysteresis brakes, a magnetic field acts on the hysteresis material in the rotor. Magnetic hysteresis generates a braking torque—without direct mechanical contact. Our permanent magnet series include PMK, Campanello, PMB-2, and BDH. In addition, we offer electrically adjustable variants with and without controllers, as well as versions with and without bearings.
Fixed-setting hysteresis brakes: Our permanent magnet variants deliver a defined torque without an additional power supply. The PMK series comprises five variants ranging from 0.15 to 0.6 Nm. The BDH series offers four fixed settings ranging from 1 to 8 Nm; its aluminum housing aids heat dissipation during higher slip performance.
Mechanically adjustable hysteresis brakes: These variants allow the braking torque to be adjusted directly to the application. The Campanello PMK 0.05 offers ten adjustment levels ranging from 0.008 to 0.05 Nm for compact thread and wire applications. On the PMB-2, a detent and adjustment ring enables an approximately linear torque increase from nearly 0 to over 2 Nm.
Electrically adjustable hysteresis brakes: They allow the countertorque to be adjusted to changing requirements during operation. Depending on the model, they are controlled with or without a controller. The range thus extends from non-powered brakes with a fixed torque to mechanically adjustable variants and electrically adjustable solutions.
Friction Brakes: Braking Torque Through Frictional Contact
Friction brakes are also part of our product portfolio. In these brakes, we utilize—either directly or indirectly—the interaction of magnetic poles. The braking torque is transmitted through contact between the friction surfaces. Friction behavior, wear, and heat generation are therefore important factors for application-specific design.
Properly Sizing Industrial Brakes
Each operating principle comes with different requirements: magnetic powder brakes allow for variable countertorques, hysteresis brakes operate without contact, and with friction-surface brakes, the effects of direct friction contact must be taken into account.
However, the key factor is the interaction with the motor, mechanical components, control system, load profile, and installation conditions. Speed and operating time also influence the appropriate sizing. Oversizing complicates integration, while undersizing fails to reliably provide the required countertorque.
Brake Testing: Evaluating Performance Under Realistic Conditions
Precision must be proven under real-world conditions. We use test benches developed in-house for clutches and brakes to evaluate load-bearing capacity and temperature resistance. For our magnetic powder brakes, we also offer functional and torque testing. The specific test required depends on the operating principle and the intended operating point.
Brake testing complements the theoretical design. The test bench reveals the actual behavior under load and temperature stress. The result: deviations become apparent early on, and compliance with the specified quality requirements can be specifically verified.
Depending on the requirements, either 100-percent or random sampling testing is performed. The results can be documented for traceability. Our test equipment is subject to test equipment management and is an integral part of our quality management system in accordance with DIN EN ISO 9001.
At our company, development, manufacturing, and testing technology are closely integrated. This allows us to create, in addition to our existing product series, braking solutions tailored to the specific motion task and intended operating conditions.
Do you need a brake tailored to your braking torque, installation space, and operating conditions? We’ll support you in selecting, developing, and designing the right solution.