The drive or servomotor is connected to the spur gear stage of the gearbox via a pinion. The rotating speed reduces at this point relative to the reduction ratio between the pinion and planetary gear. The planetary gears are connected to crankshafts which drive the cams using needle bearings. These cams rotate inside the case which is lined with pins.
The cam has exactly one eccentric section less than the pin ring has pins. A 360° revolution of the crankshafts therefore causes the cams to rotate one pin farther, whereby practically all the gear teeth are in continuous contact with the pins. The rotating movement is then transmitted from the input shaft to the crankshafts via the spur gear stage, and these then shift the cams in the pin ring and, consequently, generate a reduced speed with high precision. This technology enables the RV gears to absorb 5 times the rated torque in emergency-stop situations without suffering any damage. The resulting overall reduction is the same as the product of the two reduction ratios (spur gear stage and eccentric stage).
Nabtesco gearheads are completely sealed gear units. They are filled with grease, encapsulated and ready for installation. To reduce the design and assembly costs, we integrate the motor adapter plate and the motor shaft coupling for servo motors in the gearheads. The gearheads are based on our different component sets – with a hollow shaft or solid shaft – and their design features bring numerous advantages.
All gearheads form a completely sealed component. The basic features include an adapter plate for the motor and a motor shaft coupling for servo motors. This ensures fast and inexpensive installation of the gears. The large, integrated angular ball bearings in the gears absorb high forces and moments. This eliminates the need for additional bearings and minimizes design and assembly times. The result: lower overall costs!
These gearheads feature a large hollow shaft for the feed-through of cables and supply lines. The hollow shaft rotates at the output speed. This series is available for right-angle (RDR-C) or straight (RDS-C) installation, as well as for installation with a pulley input (RDP-C).
While the RDR-C series is designed for right-angle mounting, the RDS-C series is suitable for straight mounting and the RDP-C is the pulley input option. This enables fast, cost-effective installation and diverse application options: The efficient and extremely precise cycloidal gears are ideal for numerous applications, from machine tools to robotics systems and woodworking machinery.
We deliver the hollow shaft gearheads of the RD_-C series pre-filled with lubricants and completely encapsulated. This means they are immediately ready for use in your system!
Hollow shaft gearhead
The solid shaft gearheads of our new RH-N series are based on the RV-N component sets. They feature an integrated input gear and a motor flange for all standard motor types. This makes them ideal for use in machine tools, in modern rotary tables and in different handling applications. The gears are manufactured locally and adapted for individual applications as required.
The RH-N series was specially developed for the European market and is manufactured locally. The gearheads achieve outstanding torque performance as well as a high degree of precision in a compact design! Since a drive pinion and motor flange for all current motor types are already integrated in the gearhead, integration in the drive train is fast and easy. An uncomplicated plug & play solution for every machine design engineer!
We deliver the gearheads of the RH-N series pre-filled with lubricant (optionally with H1 grease) and completely enclosed. This makes them ideal for palletising applications in medical technology and foodstuff production! These eccentric gears are also used in milling heads. On request we can adapt them to your individual application!
Solid shaft gearhead
We designed these gearheads to be especially lightweight and compact. They can be operated with a right-angle (RDR-E) or straight (RDS-E) pre-stage or alternatively by means of a pulley input type (RDP-E).
The RDR_-E version is designed for right-angle mounting, the RDS-E version for straight mounting. The RDP-E series on the other hand is designed for pulley input. This diversity of versions allows fast and cost-effective installation in a wide range of applications. For example, the precision gears of this series can be used in machine tools, for positioning and palletising, and in solar technology. The gearheads are delivered fully sealed and pre-filled with lubricant. A motor coupling and motor flange for standard servo motors are included.
An alternative to the RD_-E series with a hollow shaft for the feed-through of data cables and supply lines is the RD_C-series.
Solid shaft gearhead
The solid shaft gears of the RA-EA/EC series are based on the RV-E component sets and are optimized for the precise positioning of chain or disk magazines
The precision gears of the RH-EA/EC series offer impressive rigidity and shock-load capability (up to 5 times the rated torque). Their precision, with a hysteresis loss of less than 1 arcmin, is likewise unusually high.
Users also benefit from low mass inertia and cost-effective installation in the machine tool or pallet changer system.
Solid shaft gearhead
The reduction gears of the GH series are the "easy-to-use" version of the RV series. They impress with drive rates of up to 270 rpm and a shock-load capacity of up to seven times the rated torque. These gears are typically used to automate robots in travel axes and conveyor systems.
Our precision gears of the GH series are designed for easy installation, which makes them ideal for diverse applications. They are commonly used in machine tools, pallet magazines, gantry robots and robot periphery.
Users also benefit from the fact that we deliver these cycloidal gears completely sealed and filled with the proper lubricant.
Hollow shaft gearhead
Nabtesco component sets stand for maximum precision, extremely low vibrations and low inertia. Our ingenious two-stage cycloidal design makes the gears insensitive to shock loads and allows high torques. The force transmission via rollers guaranteed high efficiency ratio of up to 85 percent and a long service life. The component sets of the RV-C and RV-N series also feature integrated angular ball bearings. Hence, there is no need for the customer to provide bearings, as well as the manufacturing costs for the bearing mounts.
RV-C gears are your ideal choice for very demanding applications. They have a hollow shaft through which power supply cables, drive shafts, etc. can be fed. The RV-C component sets are compact, lightweight and offer high torsional and moment rigidity. Thus, the RV-C gear series reaches exceptional repeat and path accuracy.
The gear sets of the RV-C series have an identical design and the same quality characteristics of the RV-E eccentric gears. The difference is the hollow shaft with a diameter of up to 138 mm.
The design of the RV-C component sets achieves very high repeat and path accuracy with a hysteresis loss of less than 1 arcmin. In combination with the low vibrations, the RV-C series is therefore ideal for applications in robotics, medical technology, 5-axis machining centres (CNC) and also for antenna systems, which require maximum precision.
Hollow shaft component set
The RV series forms the basic version of our component sets and therefore the basis for our entire product spectrum. It stands for high reduction ratios and low backlash. The output bearings can be defined individually.
Since the force is transferred by rollers in the eccentric gears of the RV series, they feature high precision and a low hysteresis loss (< 1 arcmin). An angular contact ball bearing is not integrated in the RV component sets. The external bearing provides for a very compact design and ensures high torsional rigidity. In combination with the individually configurable output bearing, this makes the RV series the ideal solution for integrated applications that exactly match your specifications!
The force is transferred by means of rollers in the cycloidal gears. This means that our RV gears feature high efficiency, a long service life and extremely low backlash. The virtually symmetrical gear design and the roller bearing support of all shafts guarantee constant operating behaviour throughout their entire life cycle. In addition, they allow temporary load peaks of up to 5 times the specified rated torque, such as those that can occur in emergency stop situations.
Our RV series has become established for use in a wide range of applications over the past years, for example in robotics, machine tool construction, solar technology and also in palletising applications.
Solid shaft component set
We developed the gear sets of the RV-N series as very compact, lightweight and high-performance solid shaft gears. These gears are used in applications with limited space that require high torque performance. Perfect for robotics!
RV-N cycloidal gears are very compact due to the main bearing with an integrated inner race. The reinforcement of the crankshaft bearing achieves very high power density. In addition, all gear components are FEM-optimized and are manufactured using state-of-the-art production processes.
An efficiency ratio of up to 85 %, shock resistance of 5 times the rated torque and extreme precision make the eccentric gears of the RV-N series an outstanding choice for diverse robotic applications. Robots benefit from excellent load conditions due to the reduced weight and lower mass inertia. The RV-N series is also used in medical technology, in machine tools and in positioning applications.
Solid shaft component set
The RF-P series is a completely new development! We designed these solid shaft gears for applications with extremely limited space. That makes them ideal for use in arm axes of Delta and SCARA robots or in wheel drives of Automated Guide Vehicle (AGV).
The compact cycloidal gears of the RF-P series set new standards for high-speed applications in a compact space. They enable output speeds of up to 200 rpm and operate with extremely high precision (hysteresis loss < 2 arcmin). The cycloidal design with a two-stage gear reduction principle minimizes wear – a decisive advantage over conventional planetary gears! The result is low backlash throughout the entire life of up to 20,000 hours of operation. The RF-P series is therefore the first choice for dynamic pick & place, handling and positioning applications!
In machine tool construction the RF-P gears are ideal for use in automatic tool changers (ATCs). The reduction gears offer advantages especially in the version with a chain, in which the output speed can be increased substantially. Tools can be changed much more quickly. In addition, the optional version with housing rotation allows rotation of the chain wheel directly with the gear housing. That saves time and money during installation!
Solid shaft component set
The RS series was developed especially for the positioning of heavy loads. These gear heads with hollow shaft have an integrated bevel gear and a stable, durable construction.
The high-precision Trochoid gear units of the RS series with integrated angular gearbox are designed for axial loads of up to 9 t. A cast-iron base ensures a stable, durable floor mounting. The motor is mounted at right angles and is thus easily accessible. With its compact design and exceptional power, the RS series hollow shaft gearboxes are far superior to conventional camshaft and worm gearboxes.
The hollow shaft makes it easy to perform supply lines and cables. In addition, these gear heads work almost free of play. This makes the RS series suitable for a wide range of demanding applications such as machine tools, welding table positioning and turntables as well as large robots.
Our gearheads are filled at the factory with the optimal lubricant and sealed, so they are ready for installation when they are delivered to our customers. The gears can therefore be installed directly in the machine or system as a plug-and-play solution.
Perfect for high RPMs: We have responded to the request of numerous customers for an oil as a high-performance alternative to lubricating grease and we now offer RV Oil SB150, a synthetic gear oil that perfectly fulfils the requirements of the market. In collaboration with users and one of Germany’s renowned research institutes we developed the lubricating oil with consideration for high-speed applications, long-term stability and use at high temperatures. These requirements were verified through extensive testing and analysis, as well as numerous field tests. The gear oil features a significantly better thermal capacity than lubricating grease and enables the homogeneous distribution of heat in the gear – which produces an efficient cooling effect.
From the beginning we have developed and produced custom products for the individual requirements of our clients. Today, we are going even one step further with customising.
Whether it is a drive train or a cover, a motor flange or an input gear:
there are many details which one can adapt in order to match our gears exactly to your application. With a team of experienced development engineers and our service team in Düsseldorf we can implement all these requirements quickly and professionally.
A look at the diverse applications in which Nabtesco gears are used shows that they cut a good figure – and not only on paper. Whether in robotics or packaging technology, wind power installations or machine tools, antenna construction or medical technology: Our precision gears are used in applications that require exact positioning and absolute reliability.
The alignment of large parabolic antennas, such as those used for communication with near-Earth satellites, requires high positioning accuracy. This applies both to the azimuth (the angle between the meridian and vertical plane of a celestial body) and the angle of elevation. The control of these antennas, which have dish diameters of up to 17 metres, requires high torsional and moment rigidity in addition to high reduction ratios. Nabtesco’s compact RV-C hollow shaft gear sets are ideal for this application.
Robotic welding systems have to operate with high speed and absolute precision. Positioners and rotary tables provide for exact alignment of the workpieces. In welding positioners, a precision gear drives the horizontal rotary axis. This makes it possible to weld all spots along this axis – even complex geometrical structures – within a tolerance of tenths of millimetres, without having to reclamp the workpiece. The weld puddle must be kept exactly in the tray. Nabtesco cycloidal gears are designed for such applications.
An important focus at Nabtesco is on the development of special gears for high-speed handling and robot-assisted positioning. Robots for pick & place applications and for workpiece positioning operate in industrial environments at ever increasing speeds, which also puts a strain on the gears installed in such systems. In addition to the high acceleration and braking forces of these machines, the engineers also have to be aware of heat generation from the high speeds. Our precision gears fulfil these requirements!
Motorized drives provide for extreme precision in the handling of patients and in imaging processes such as X-ray, MRI or ultrasonic examinations. These applications require positioning accuracy within a tolerance of millimetres or even less. Since the machines are used for examining human patients, safety margins are extremely important in the case of a malfunction. Nabtesco cycloidal gears are the ideal choice!
Many photovoltaic and solar thermal installations – especially central receiver power plants – adjust their panels to the position of the sun. In addition to high efficiency of the panels, constantly precise and reliable alignment is essential for a fast return on investment and long-term maintenance-free operation of the installation. Nabtesco cycloidal gears feature impressive precision, reliability and vibration-free operation.
Precision is the top priority in the construction of machine tools. Because the blanks and tools must be positioned quickly and with micron precision. Complete machining in one clamping set-up prevents inaccuracies that can occur as a result of frequent reclamping of the workpiece. Compact precision gears with an integer gear ratio ensure the exact positioning of the chain or disk magazines equipped with the different tools required for this application.
Hygiene and safety are the top priorities in food production and packaging applications. Compliance with extremely stringent hygiene standards is required in the handling, positioning and packaging of foodstuffs. In addition, these applications are becoming more dynamic, faster and more precise. Our cycloidal gears of the RF-P and RH-N series easily fulfil these requirements.