Nabtesco

Nabtesco is a Japanese group that made its name in robotics with precision RV cycloidal gears. Its European arm, Nabtesco Precision Europe of Düsseldorf, presents itself in its catalogue as the world's largest and most recognised maker of such gears, cites more than 8 million units in use and claims that they go into more than 60 percent of the world's industrial robots. These are the manufacturer's claims.

The working principle is two-stage. The motor drives a spur-gear stage through a pinion, and then eccentric crankshafts move cams around a ring of pins, which gives a large reduction with an even distribution of forces. The catalogue lists the advantages: high rigidity, hysteresis below one arcminute, low inertia, low wear and shock resistance, because the gear withstands five times its rated torque in an emergency stop without damage.

The range covers many series. The solid-shaft RV-N has torques from 245 to 28,000 Nm and ratios of 41–203.52. The hollow-shaft RV-C is 98–11,760 Nm. The RV series without an output bearing reaches 137–5,390 Nm. The RDR-E, RDS-E and RDP-E series cover 58–3,136 Nm. The GH is for high output speeds, up to 270 rpm, at 69–980 Nm, and the RS with an integrated rectangular stage is 480–8,820 Nm. A separate catalogue covers zero-backlash strain wave gears, made to automotive standards.

The latest item of interest concerns humanoid robots. A flyer from November 2025 describes "Short Gears", strain wave gears with new geometry that, according to the manufacturer, give 120 percent of the power density and 140 percent of the life (10,000 hours against the 7,000 assumed for the market) in the same installation space, intended for humanoids and cobots. They are made in Germany, at the Ovalo plant in Limburg. There is also a digital strain wave gear with torque, temperature and vibration sensors and an electronics unit, meant to predict failures, because a stopped robot costs money.

In which robots? The catalogue points generally to industrial robots, but we do not tie specific models in our catalog to Nabtesco, because makers of arms such as FANUC, Yaskawa Electric or Kawasaki Heavy Industries do not always disclose gearbox suppliers. In cobots and humanoid robots the gear decides the mass of the joint, as “Actuators in Humanoid Robots” explains at greater length. Competitors are Harmonic Drive and Spinea.

The gearbox is one of the most expensive elements of an arm, so its class affects the robot's price and durability, and backlash decides accuracy, as “Degrees of Freedom (DOF) in Humanoid Robots” and the guide to a datasheet in “How to Read a Robot Datasheet” explain.

In Poland the catalogue names a distributor: P.P.H. Wobit of Pniewy near Poznań, a firm also known as the maker of MOBOT mobile robots (WObit). It is one of the few well-documented Polish purchasing routes for RV gears, relevant to integrators in factories.