What are Planetary Roller Screws?

100 years ago , a Swiss started it all.

He thought: What if we replaced the steel balls with small screws, similar to the concept of planetary reducer?
And so the “planetary roller screws / satellite roller screws” was born.
Because small screws had much stronger vertical shear stress, this increased stress tolerance to 3 to 5 times compared to ball screws.
The overall speed without the return channel can be up to 3 times faster, and because the overall load of the small screws disperses the load, the service life is also enhanced by as much as 10 times.
Finally, it can be said that this product is a Rolls-Royce-class product in linear transmission.

How do Planetary Roller Screws work?

The small screw in the middle revolves and rotates around the big screw, just like the motion of a planetary celestial body.
This is the best, energy-saving and highly responsive motion.
Therefore, it can faithfully reflect the energy from the motor and convert the movement of the wire, and the efficiency is also the best. Since the small screws are integrated, it can disperse the load from high loads.
Enhanced very high life, so named “Planetary Roller Screw”!

Traditional ball screw vs planetary screw comparison?

What are the benefits of using planetary roller screws?

High load and long life are the biggest advantages of planetary roller screws. Compared with ordinary ball screws, applicable load is about 3-5 times, and useful life is as high as 15 times, so the stability of the product or machine will increase a lot.
Significantly reducing maintenance costs and downtime.

The disadvantage is: the manufacturing cost is relatively high and a bit more expensive, but with the efforts of U-SCREWS, the cost has dropped a lot, making it acceptable to many users.

Planetary Roller Screw

  • High load Capacity (3-5 times that of Ball screws)
  • Long Useful life (15 times that of Ball screws)
  • High Efficiency (Fully converts motor power into linear motion)

Traditional Ball screw

  • Relatively low load Capacity
  • Relatively shorter useful life

What are the most common applications for planetary roller screws?

Planetary roller screws are most suitable for applications that require fast, accurate and heavy-duty response time. The initial application were mainly used in missile defense systems, Aviation and other advanced applications… Since then, a group of engineers from U-SCREWS have improved the entire production process and greatly reduced the cost, so that the entire price can be greatly reduced… Now it has begun to appear in industrial-grade applications.

Example: All-electric injection molding machine (using a hollow motor), pipe bender, electric punch, bending machine, etc…

Which industries will use planetary roller screws in industrial applications?

For any application that  require high load, high precision and high reaction speed.

Example: All-electric injection molding machine, pipe bending machine, high-speed punching machine, bending machine, riveting machine, etc…

How to choose the best planetary roller screw for your needs?

Steps in choosing the right Planetary Roller Screw for your application.

1: Firstly we need to calculate the average load weight for the target use. A speedometer, load meter and any other other data that you can provide.

2: Select the appropriate planetary roller screw according to the average load weight

3: Choose the right shoulder size.

Conclusions and Summary

If you have a special requirements for high load, long life or high stability etc…
Planetary roller screws will be your best solution. Especially when replacing hydraulic cylinders. Planetary roller screws are the best choice for Industry 4.0 The choice of linear drive mechanism … almost all physical performance, energy saving, and other work performance will be better !