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Views: 1 Author: Site Editor Publish Time: 2025-08-11 Origin: Site
Ball screw and planetary roller screw are two common transmission components. The core difference lies in the form and structural design of rolling bodies, which determines their significant differences in bearing capacity, precision and application scenarios.
1. Core structure differences
The core difference between ball screw and planetary roller screw lies in the type and arrangement of rolling bodies.
Type | Rolling element | Contact form | Design feature |
steel ball | Point contact (steel ball and thread groove) | The steel ball rolls between the screw thread groove and nut thread groove, forming a circulating circuit through the returner. | |
pin roller | Wire contact (roller and thread groove) | The rollers are evenly distributed around the screw thread in a "planetary" manner and mesh with the screw thread and the internal thread of the nut, without the need for a circulating device. |
· Ball screw: The key to the structure is the steel ball circulation system. The design should ensure that the steel ball flows smoothly through the returner to avoid jamming or wear.
· Planetary roller screw: The structure is more complex, and the rollers need to accurately match the thread parameters of the screw and nut, which makes the processing more difficult.
2. Performance differences
The structural differences directly affect the performance of both, as follows:
· Bearing capacity: The rolling columns of planetary ball screw are in line contact, and the bearing capacity is much stronger than the point contact of ball screw. The static load of planetary ball screw is about 3 times that of ball screw.
· Lifespan: According to the Hertz pressure law, the life of planetary ball screw is 10-15 times that of ball screw.
· Speed and acceleration: The rollers of the planetary ball screw are non-cyclic, the rotation speed is about twice that of the ball screw, the acceleration can reach 3g, the highest linear speed can reach 2000mm/s, and the input rotation speed can reach 5000rpm or higher.
· Lead and pitch: The lead of a planetary ball screw can be designed to be smaller, less than 0.5mm, and can be an integer or decimal, while the lead of a ball screw is limited by the diameter of the ball and is usually standard.
· Stiffness and strength: the planetary ball screw has a large number of contact lines, which greatly improves its stiffness and impact resistance, more than three times higher than the same specification ball screw.
3. Different application scenarios
Different performance characteristics determine the application scenarios of the two are significantly different:
Type | Typical application scenarios | Core advantages are reflected |
Widely used in machine tools, semiconductor manufacturing equipment, medical machinery, robots, special machinery, battery manufacturing equipment, automobiles and other fields | Low load, high precision, high speed, low noise, suitable for light load scenarios with high requirements on accuracy and speed. | |
It is often used in high speed, heavy load and high precision occasions, such as aerospace, weapons equipment, CNC machine tools, aircraft landing gear, precision robots and other fields. | Heavy load with high bearing capacity, high rigidity and long life, suitable for heavy load scenarios with high requirements on bearing capacity and reliability. |