Implementing the right gearboxes for machining and automatic fiber placement of composite materials is no easy task. Torsional, radial and axial stiffness (i.e., stiffness on rack) are important factors that can affect the positioning accuracy of heavy-duty robotic axes. However, when laying up fiber, quick load reversals during linear or rotary motion can create vibrations, compromise the positioning accuracy and repeatability of the mechanism, and damage machine components or the composite part itself.
When choosing gearboxes for composite industry applications, it’s important to have a strategy to eliminate backlash. This two-part blog post series will explain how you can arrange our planetary gear reducers to solve backlash issues.
The Preload Principle
Backlash is lost motion that occurs when gears alternate during acceleration, steady state and deceleration. Fortunately, you can prevent backlash from occurring by setting the preload torque equal to the application preload torque to synchronize the axes.
For example, our SRP Series is part of a family of modular units that can be combined to build a preloaded reducer and motor drive system that prevents backlash in composite machinery with robotic axes. The SRP Series offers exceptional stiffness-on-rack, as well as design flexibility for the most demanding machines. Features include:
- Minimum backlash (one to three arc-minutes).
- A high-tech planetary gear train.
- Patented output bearing design.
- High input speeds.
- Superior acceleration and excellent torque density.
SRP gearboxes leverage two Redex-patented preloading technologies to deliver zero-backlash systems:
- REDEX Patented DualDRIVE. These systems reach preload by spring loading or torsionally winding one pinion against the other. This feature allows you to eliminate backlash using only one motor without a CNC controller, making the systems well-suited for use with carbon fiber robots.
- Twin Drive. For larger machines, Twin Drive technology electrically brakes one pinion against the other. These systems incorporate two motors and gearboxes and CNC control.
The SRP Series offers exceptional versatility thanks to a universal ISO 9409-1 output flange that you can integrate with any pinion, as well as ballscrews, couplings or direct machine attachment.
Our sales engineers can assist you in building a preloaded gear reducer system that will provide zero-backlash motion for your composite machinery. For rack and pinion or pinion ring gear drives, our next blog post will cover DRP, KRP and KRPX Series gearboxes, which are also well-suited for creating mechanical and electrical preload systems that eliminate backlash.
For more information about SRP Series gear reducers for composite machinery designs, visit our product page.