The Ring-cone mechanical variable speed drive was one of the first technologies developed during Nidec Drive Technology Corporation’s storied past. Although the demand for mechanical variable speed drives has decreased over time, Nidec DTC has been able to leverage the internal “traction drive” power train into more modern high-precision motion control applications for OEMs. Nidec DTC has a few different series of traction drive utilizing different differential design (traditional cone-cam mechanism, planetary roller system, etc.).
The Traction Drive mechanism produces smooth rotation and eliminates speed irregularity due to the high frequency vibration inherent in gear transmission. This is how the traction drive provides high rotational accuracy with low noise. Transmission through either cones or planet rollers being contacted under pressure allows the system to eliminate backlash when paired with full closed loop control. This allows the differential to approach zero backlash and achieve extremely high positional accuracy. The traction drive technology, in summary, provides many benefits over your tradition planetary gearbox;
- Capable of handling higher input (>6,000 rpm, no problem) and output speeds
- Exceptionally smooth rotation for better speed control
- Higher reduction ratios in the 1st stage
- Variable speed output
- Much lower backlash (to the arc-sec)
Leveraging the full capabilities of the NIDEC Group motor portfolio, Nidec DTC can supply a complete integrated drive package – traction drive, motor, sensors, encoders, etc. – depending on what is required for the application. For example our VGMR Series (planetary roller style) is an integrated drive assembly is a very popular solution for high speed color printer applications. The VGMR can provide the following performance benefits within this type of application;
- Speed variation: Negligible single color pitch irregularity (at single frequency) less than 0.1％ rms
- Precise position control by dual sensor control – Achieves less than 10μm on different drum sizes
- High reduction ratio: Reductions as low as 30:1 in 1 stage
- Requires no routine maintenance during the service life of the assembly
- Minimal footprint: Space savings – < 65mm Square at 0.3Nm of output torque
- Low power & heat generation : Highly efficient BLDC Motor integrated with Traction drive
- Low noise & vibration : Noise from Gear & Motor is less than 50dB (A scale･30cm)
There are many applications in an OEM environment where Nidec DTC can customize the Traction Drive technology for our customers. Please contact us if you have any questions about a specific application, and we can evaluate what technology is the best fit from both a technical and commercial standpoint.
Traction Technology: Operating Principles | Technology Benefits | Comparison with Planetary | Example Applications