Difference between screw transmission and rack transmission

    Both ball screws and racks belong to transmission tools and are widely used in industrial fields, but they are used in different ranges because of their different characteristics. Which transmission tool should we choose in actual work? Firstly, we have to have a deep understanding of the two, the difference between ball screws transmission and rack transmission.

Rack Transmission

1. Definition:

    What are a rack and pinion? It is also divided into a spur rack and a helical rack, which are used in pairs with spur gears and helical spur gears. The tooth profile of the rack is straight rather than involute, which is equivalent to an infinite cylindrical gear with the radius of the index circle.

2. Working principle:

    Racks and pinions are mechanical parts with teeth that can mesh with each other. Racks are divided into straight teeth and helical teeth. Racks and pinions are widely used in machinery to realize the movement of transmission, change the speed of movement, and change the direction of movement.

Screw Transmission

1. Definition:

    What is a ball screw   Ball screw is an ideal product for converting rotary motion into linear motion, or converting linear motion into rotary motion. The ball screw is composed of a screw, a nut, and a ball. Its function is to convert helical motion into linear motion, which is a further extension and development of the trapezoidal screw. The important significance of this development is to change the sliding of the screw into rolling and reduce friction.

2. Working principle:

    Ball screw type of ball screw: The ball screw is divided into inner circulation and outer circulation according to the circulation mode. Ball screw is an ideal product for converting rotary motion into linear motion, or converting linear motion into rotary motion. The development of ball screw technology has turned the rolling action of the bearing into a sliding action. Due to their small frictional resistance, ball screws are widely used in various industrial equipment and precision instruments.

Difference

1. The working stroke

    The working stroke can be extended indefinitely to adapt to the long-distance movement, and the ball screw does not have this advantage. Generally, it is best to use a rack with a stroke of more than 6 meters.

2. Bearing capacity

    The bearing capacity of the rack is stronger than that of the ball screw, and it can work under high loads and heavy loads. The rack can carry a maximum load of 15-20 tons.

3. Positioning accuracy

    The positioning accuracy of the rack relative to the ball screw is not so high.

4. Moving speed

    The moving speed of the rack is not as fast as that of the ball screw.

5. Installation requirements

    There are requirements for rack installation, reserve clearance, and installation requires reverse gear gauges.

6. Wear condition

    The wear of the rack needs to be compensated, and the wear of the ball screw needs to be adjusted.

7. Purchase price

    The rack is cheaper than the ball screw. Generally, the rack is selected due to its economical, and the screw is selected due to its high precision.

8. Comparison of advantages

    (1) The rack is infinitely long, with a large load (15-20 tons), high speed (120-150m/min), long service life, and a large range of power transmitted by the applicable speed.

  (2) Ball screw has high transmission efficiency, sensitive and stable transmission, high positioning accuracy, good precision retention, high transmission rigidity, and good synchronization performance.