24 Jul 2024


Gearboxes for geared servomotors are ‘the smallest’

Stober says that its new generation of gearboxes for geared servomotors are the smallest of their type

The German drives specialist Stober has announced a third generation of gearboxes for servo geared motors that, it claims, are the smallest on the market that offer their level of versatility. The company has reduced the lengths of the gearboxes “considerably”, resulting in smaller installation spaces, lower weights, higher torque levels, and a power densities that are up to 65% better than before.

Any Stober motor – including its EZ series and sensorless Lean motors – can be attached directly to the gearboxes without needing an adapter. The absence of an adapter means that the mass moment of inertia is lower, allowing the full dynamics of the drive to be used. This will be particularly noticeable in terms of shorter cycle times for small-to-medium sized applications.

The gearboxes can also be attached to third-party motors of any size using variable adapters. These adapters are available with different couplings, and include a ServoStop variant with a built-in brake. They can also be combined with standard or reduced-play gearboxes.

The design of the adapters, with their “extra-large” motor plates, makes it possible to connect the smallest gearboxes to large motors – an ability which Stober describes as “truly unique”.

The new geared motors offer high backlash stability and ruggedness, as well as high running accuracy and precision. Acceleration torques are said to have been increased by 60%, speeds by 45%, and torsional stiffness by up to 50%.

Another claimed advantage over the competition is the ability to select the “right” bearing – which can be deep-groove ball, cylindrical roller or angular contact types. The low-friction bearings enable generally higher speeds.

Because of the wide range of options, Stober says that engineers will be able to put together exactly the right drive for any application. And if, for example, they choose a smaller motor to optimise efficiency, they will also be able to use smaller drives, helping to cut costs.

All of the geared motors incorporate electronic nameplates that transmit their electronic and mechanical data automatically to a drive during commissioning, using plug-and-play principles. This identifies the geared motors “uniquely” and eliminates error-prone parameterisation, cutting system configuration times “significantly”.

Stober will present its new generation of servo planetary gearboxes and geared motors publicly for the first time at the SPS exhibition in Germany in November. Sizes 2, 3 and 4 are already available, with sizes 5 and 7 following in March 2020, and sizes 8 and 9 in May.