Delta robots are parallel-arm robots with tripod kinematics that combine great positioning precision with extremely quick movements. As a result, the servo motors of the primary drives and the matching gearboxes must meet certain requirements. The NDF gearbox serves as an example of how these gearboxes must satisfy the highest standards, particularly with regard to stiffness and torsional backlash, in order to guarantee the required precision even at maximum speed.
The special requirements for a Delta robot
The Neugart NDF gearbox meets these special requirements with numerous technical details: for example, the gearbox enables extremely fast changes of direction thanks to a low-inertia clamping system at the input stage, which improves the dynamics and thus the cycle time of the robot. At the same time, the torsional backlash is limited to < 1 arcmin as a standard feature.
The output of the NDF has also received special attention in order to optimally meet the specific requirements of a Delta robot: the gear ratio at the output is i=5.5, which allows transmission of very high torques. A special radial shaft sealing ring ensures optimum sealing of the shaft during rapid changes of direction. A food-grade oil lubrication system, a stainless steel output shaft and a nickel-plated output flange are available as options for the NDF.
NDF: The “must have” for Delta robots
The heavy-duty output increases accuracy and improves cycle times
Four specially designed planet gears in the output stage result in greater dynamics and shorter cycle times. At the same time, the control quality and precision increase when quickly approaching the target point.
The optimized radial shaft sealing ring improves durability
This is due to the fact that the radial shaft sealing ring exhibits optimum flexing behavior. This is particularly crucial for the frequent and rapid changes in the direction of rotation of Delta robots. This leads to greater longevity and reliable sealing.
The position repeatability and high cycle rate due to less torsional backlash
The backlash of the gear teeth is less than 1 arcmin. The target point is approached more precisely, readjustments are reduced, and position repeatability as well as cycle time are improved.
The torque interface for dynamics and precision
They have equipped the NDF with more holes on the output shaft and output flange. This makes higher torques and greater rigidity at the interfaces possible. At the same time, the dynamics and precision of the robot joints increase.
The Dynamic drive system
For the NDF, Neugart uses an aluminum clamping ring instead of steel. This reduces the inertia at the fast-rotating input shaft. A low-friction radial shaft sealing ring also reduces the breakaway torque. This allows extremely fast changes of the direction of rotation possible.
The features:
- Application-specific gearbox;
- Coaxial gearbox;
- Helical gear;
- Preloaded angular contact roller bearings;
- Rotary shaft seal;
- Torque interface;
- Equidirectional rotation;
- Planet carrier in cage design;
- Four planet gears at the output.
Even more possibilities with these options
Nickel plating and stainless steel to protect against corrosion
Upon request, Neugart can nickel-plate the output flange. In conjunction with the stainless steel output shaft, the gearbox is then fully protected against corrosion on the output side.
The food grade lubrication
If needed, they can also provide the NDF gearbox with food grade oil lubrication. The lubricant used is certified to NSF H1 and ISO 21469.
Wide range of output shaft options
The output shaft can, on request, also be equipped with an interface to ISO 9409-1. In addition, it can be made of steel or stainless steel and with or without a dowel hole. It is the choice.
Special gearboxes for the rotary axis
For the rotary axis, it is possible fall back on the large modular system of Neugart gearboxes. This gives all the freedom you need – and it is possible to use gearboxes in coaxial or angular versions, for example, or mount them on the top of the frame or on the bottom of the tool holder.
