Roller Screws vs Ball Screws
"Compared to our ball screw based actuators, the CMC roller screw increased directly measured mechanical efficiency by nearly 15%!" VP of Engineering, Proprietary US based Actuator Manufacturer
There are significant operational differences between a CMC Performance Roller Screw and a ball screw. Most importantly, the roughly 400% increase in contact points in a CMC roller screw result in higher load capacity, longer life and greater shock resistance. This dispersion of force enables CMC roller screws to outperform precision ground ball screws in load/life performance by roughly 15 times. With a CMC Performance Roller Screw your entire assembly can be much smaller, lighter and more cost effective to produce, thereby directly improving your bottom line with increased revenue opportunities and increased profitability.
The loud noise associated with ball screws is generated by the bearings colliding in the returns. The noise grows exponentially with speed. The noise from CMC’s roller screws is produced by the rollers simply traveling through the threads and does not grow exponentially with speed. As a result, CMC’s roller screws are generally much quieter than ball screws.
Another critical difference is the speed capability of CMC roller screws. Due to the efficient design and inherent lack of collisions and opposing forces, CMC roller screws are capable of speeds 3 to 5 times that of high performance ball screws. All while delivering the same critical high precision you’re accustomed to in ground ball screws.
Roller Screw vs Hydraulics
Hydraulic cylinders rely on pressurized oils and require significant maintenance to achieve consistent levels of load and positioning accuracy. Hazardous fluid leaks are common, causing both end-product and environmental contamination. CMC Performance Roller Screws, alternatively, require little to no maintenance and do not pose environmental concerns.
Just as importantly, a shop running electromechanical machines is dramatically more efficient than a shop running hydraulic machines, and therefore will enable significant savings due to dramatically lower power consumption.
Roller Screw vs Pneumatics
As you can see in the table below, pneumatics also have advantages to offer, but do not provide a viable solution where positioning, stiffness or accuracy are required. And, as with hydraulics above, pneumatics are significantly less efficient. So over time, CMC Performance Roller Screws pay for themselves over and over again.
Technology Comparison Chart
| |
CMC Performance Roller Screw |
Planetary Roller Screw |
Inverted Planetary Roller Screw |
Recirculating Roller Screw |
Precision Ground Ball Screws |
Hydraulic Cylinders |
Pneumatic Cylinders |
| Load Rating |
Highest among roller screws: typically >10% greater than the next closest competitor |
Very High |
Very High |
Very High |
Moderate |
Very High |
High |
| Avg Efficiency |
>92% |
>90% |
>90% |
>90% |
>90% |
<50% |
<50% |
| Force Density |
High |
High |
High |
High |
Moderate |
High |
Moderate/Low |
| Synchronization |
Active Continuous Positioning |
Ring Gear Required |
Ring Gear Required |
Uncontrolled |
Return Tube |
n/a |
n/a |
| Rotational Speed |
Highest |
High |
High |
Low |
Moderate |
n/a |
n/a |
| Acceleration |
Very High |
High |
High |
Low |
Moderate |
Very High |
Highest |
| Positioning Control |
Easy |
Easy |
Easy |
Easy |
Easy |
Difficult |
Very Difficult |
| Stiffness |
Very High |
Very High |
Very High |
Very High |
Moderate |
High |
Low |
| Shock Loads |
Very High |
Very High |
Very High |
Very High |
Moderate |
Very High |
High |
| Operating Noise |
Low |
Low |
Low |
Low |
Moderate |
Very High |
Moderate/High |
| Friction |
Low |
Low |
Low |
Low |
Low |
High |
Moderate |
| Precision |
High |
High |
High |
High |
High |
Low |
Low |
| Accuracy |
High |
High |
High |
High |
High |
Low |
Low |
| Hysteresis |
Minimal |
Minimal |
Minimal |
Minimal |
Low |
High |
High |
| Configurability |
Readily Customizable |
High Expense |
None |
High Expense |
Limited |
Limited |
Limited |
| Installation |
Standard Servo Motor Controls |
Standard Servo Motor Controls |
Standard Servo Motor Controls |
Standard Servo Motor Controls |
Standard Servo Motor Controls |
Complex |
Very Complex |
| Maintenance |
Very Low |
Very Low |
Very Low |
Very Low |
Moderate |
Very High |
High |
| Environmental Impact |
Minimal |
Minimal |
Minimal |
Minimal |
Minimal |
Hydraulic Fluid Leaks & Disposal |
High Noise Levels |
| Lifetime |
Longest Among Roller Screws |
Very Long |
Very Long |
Very Long |
Moderate |
Can Be Long With Proper Maintenance |
Can Be Long With Proper Maintenance |
| Cost |
Moderate |
High |
High |
High |
Moderate |
Moderate |
Moderate |