Shaft misalignment compensation couplings are essential components in test stands. Based on the proven ROBA^® DS steel disk pack coupling, mayr^® power transmission offers a weight-optimized aluminum variant with the ROBA^® DS Type 9120. Compared to the steel version, the outside diameter is reduced by up to 10 mm; mass and mass moment of inertia are 40% to 60% of the steel version, depending on the design and size – with unchanged performance density.

The development has incorporated extensive knowledge gained over many years in test stand technology, where high speed ranges have previously been the norm. The ROBA^® DS 9120 is therefore also suitable for speeds of up to 32,000 rpm. Thanks to its lightweight construction, low mass inertia and high performance density, the aluminum coupling offers measurable advantages. The balance between rigidity and elasticity ensures the lowest possible restoring forces on the system. A balance quality of G 2.5 at 5,000 rpm ensures the necessary smooth running and low-vibration operation – a decisive basis for high measurement accuracy across all speed ranges.

As standard, the coupling features manufacturing tolerance IT6. A nickel-plated surface, disk packs made of stainless steel and galvanized connecting screws provide comprehensive corrosion protection. Backlash-free shaft connections via shrink disk hubs or external shrink disk hubs ensure reproducible measurement results. The coupling is compatible with all common torque transducers as standard.

Thanks to the modular construction system, the ROBA^® DS 9120 can be flexibly configured from a variety of connection variants and modules, from high-performance test stands in research and development to end-of-line testing.

Safety brakes for test stands: Reliable protection for people and equipment

In addition to coupling technology, mayr^® power transmission is also presenting its extensive portfolio of safety brakes for test stand applications at Automotive Testing Expo. Test stands for automotive drives frequently include vertical axes and linear movements that must be reliably secured, whether during ongoing test operation, during maintenance work or in the event of a fault.

The ROBA^® guidestop^® profiled rail brake, for example, acts directly on the moving masses of the vertical axes and clamps them into position in a backlash-free manner and with high rigidity. It is available in hydraulic, pneumatic and electromagnetic designs and is compatible with all common linear guides. The ROBA^® linearstop piston rod brake secures linear movements on round rods. It is a safety brake based on the fail-safe principle, meaning it is closed in the de-energized state, and is designed for dynamic emergency braking. The series comprises six sizes with forces ranging from 70 to 17,000 N.

The ROBA-stop M^® series also provides a robust motor brake for compact protection directly at the drive motor. As a holding brake, it clamps reliably and holds the system in position; as a dynamic brake, it brings the load to a standstill in the shortest possible time.

The brake speaks: Smart modules for intelligent monitoring

Constant, meaningful data streams are now indispensable in modern test environments. The ROBA^® brake-checker^® module monitors safety brakes sensorless and simultaneously supplies them with power. By means of an advanced analysis of current and voltage, it detects the switching condition of the brake and issues a warning before the brake can no longer release under the current operating conditions. This facilitates planned maintenance and enables the user to specifically investigate critical boundary conditions such as supply voltage that is too low, incorrectly dimensioned supply lines, elevated coil temperature and an enlarged air gap.

In combination with the ROBA^® gateway module, the solution becomes network-compatible: The brake data can be continuously read out via an Ethernet connection and displayed visually on a dashboard. Anomalies in the test process can be detected at an early stage, maintenance becomes plannable, and downtime can be specifically minimized. Integration into remote maintenance systems is also possible.

mayr^® power transmission at Automotive Testing Expo 2026 in Stuttgart: