The most compact hollow-shaft gearbox with the highest torsional rigidity: The new miniaturized Galaxie® gearbox

The miniaturized Galaxie® gearbox takes the proven principle of our classic Galaxie® a step further. The result: innovative kinematics enabling almost full surface contact during power transmission – in an extremely compact footprint. Thanks to this unique concept, the miniaturized Galaxie® performs significantly better than established gearbox types with the same diameter in almost all dimensions. It combines the highest levels of torsional rigidity, torque density and overload capacity with a very large hollow shaft and maintains zero backlash throughout its entire lifetime.

With these outstanding characteristics, the miniaturized Galaxie® is the ideal choice for applications where maximum precision and safety are decisive even though only limited space is available and a lightweight design is paramount – for example, in medical robots.

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Galaxie® in miniature


The functional principle of Galaxie® new interpreted

Galaxie® in miniature – Your benefits

More precision

The miniaturized Galaxie® extremely high torsional rigidity and higher dampening mean medical robots can perform surgical procedures much more precisely. Thanks to the higher machining precision, the quality of industrial products can likewise be increased. Absolute zero backlash likewise enables more precision in the application, e. g. when moving robot axes. 


Space and weight savings

The miniaturized Galaxie® extremely high torsional rigidity and high torque density mean you can downsize the drive train or upgrade the application without any increase in footprint. The large hollow shaft can be used very efficiently, e. g. for wiring or for integrating media and / or components. The high torque density simultaneously permits the weight of the drive train to be reduced.


Maximum safety

The miniaturized Galaxie® extremely high torsional rigidity provides crucial safety reserves in case of overload. For example, there are no consequences if the surgeon accidentally touches the surgical robot’s arm. Media can be supplied through the large hollow shaft without any problem – and downtime due to broken or pinched cables is reduced to a minimum. The high torque density can serve as a safety buffer.


Faster and easier integration

The miniaturized Galaxie® can be installed quickly and easily in a variety of applications, and with the large hollow shaft the wiring is child’s play. Other features such as camera systems requiring extra wiring are thus very simple to integrate. The footprint is compatible with standard strain wave form (Harmonic Drive) gearboxes – an immense advantage.


Higher productivity

The miniaturized Galaxie® extremely high torsional rigidity allows higher acceleration rates and reduces vibration in the system. You also profit from faster and, above all, more accurate positioning because there is less oscillation time. The large hollow shaft minimizes cable breakage – the cause of more than 90% of all robot downtime.


Technical data

  Gear box



  Data Sheet


  Gearbox diameter

90 mm

110 mm


55.5 mm

59.6 mm

Hollow shaft diameter

31 mm42 mm
  Weight1.5 kg2.5 kg

Technical data


Overall ratio


Nominal output torque

70 Nm120 Nm
  Max. acceleration torque150 Nm250 Nm
  Emergency stop torque375 Nm625 Nm
  Max. input speed4200 1/min3600 1/min

Torsional rigidity & bearing

  Ct21 [Nm/arcmin | 104 Nm/rad]35 | 12.070 | 24.0
  K31) [Nm/arcmin | 104 Nm/rad]24 | 8.342 | 14.4
  K2 1) [Nm/arcmin | 104 Nm/rad]23 | 7.940 | 13.8
  K11) [Nm/arcmin | 104 Nm/rad]17 | 5.830 | 10.3
  Max. tilting moment150 Nm250 Nm


1) Torsional rigidity:
Ct21: Average gradient of the hysteresis in the range of 50 to 100% of Tmax
K1: Average gradient of the hysteresis in the range below 10 Nm for SAG090 and below 15 Nm for SAG110
K2: Average gradient of the hysteresis in the range between 10 and 25 Nm for SAG090 and between 15 and 50 Nm for SAG110
K3: Average gradient of the hysteresis in the range over 25 Nm for SAG090 and over 50 Nm for SAG110

Due to uninfluenced factors these values can vary ± 10%
Minimum length. The length can vary due to pre-stages and motor specific adapter plates.

Galaxie® in miniature compared to usual strain wave gearboxes


  • 40 % higher maximum torque Tmax
  • 30 % higher torque density
  • 3-times higher rigidity over complete torque range
  • Up to 50 % larger hollow-shaft
  • Zero backlash over service life




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Is there anything you'd like to know about Galaxie® in miniature? Do you require personal advice?

If so, please contact us directly. We look forward to hearing from you!


Your contact

Philipp Kordwig

Business Developer

+49 7931 493-10841


Dr. Karoline Scheuermann

Business Developer

+49 7931 493-18978