Introduction And Application Of Ball Screw

A ball screw is a mechanical device that converts rotational motion into precise linear positioning motion. The following is a detailed introduction to the ball screw:

I. Structure and working principle

1. Structure: The ball screw is mainly composed of three parts: the screw, the nut and the ball. There are helical lines on the surface of the screw and the nut, and the ball rolls between the screw and the nut.

2. Working principle: When the screw rotates, the nut moves along the helical line to achieve linear motion. The ball rolls between the screw and the nut, reducing friction and wear, and improving rolling efficiency and precision. At the same time, the ball also bears the transmitted force and torque, and transmits it to the nut, thereby achieving control and positioning of linear motion.

II. Types and characteristics

1. Type:

According to the different ball circulation methods, ball screws can be divided into internal circulation, external circulation, end cover circulation, cover plate circulation and other types.

According to the different manufacturing processes and precision, ball screws can also be divided into single arc truncation and double arc truncation. Double arc truncation is widely used in machine tools because of its good precision retention and load performance, and its axial stiffness is greater than that of single arc truncation.

2. Features:

High transmission efficiency: Since the ball screw adopts rolling friction, the friction resistance is small, so the transmission efficiency is high.

High transmission accuracy: The ball screw has high processing accuracy and can achieve high-precision linear motion.

Smooth movement: The ball screw moves smoothly without creeping.

No empty travel when reversing: The pre-tightened ball screw can eliminate the axial clearance and there is no dead zone of empty travel when reversing.

Long service life: Since the friction loss of rolling friction is small, the service life of the ball screw is long.

III. Application field

The application range of ball screw is wide, including but not limited to the following fields:

1. Precision instruments: such as microscopes, measuring instruments, etc., which require high-precision linear motion control.

2. CNC machine tools: Ball screws are used in CNC machine tools to accurately control the position and speed of moving parts.

3. Automation equipment: such as industrial robots, automated assembly lines, etc., ball screws are used to accurately control the motion trajectory of moving parts.

4. Medical equipment: such as X-ray equipment, CT scanners, etc., require high-precision motion control to ensure image quality and patient safety.

IV. Advantages and Disadvantages

1. Advantages:

a. High transmission efficiency, high precision, and smooth movement.

b. No empty travel when reversing, reversible.

Long service life.

2. Disadvantages:

a. High manufacturing cost, because the processing precision of components such as ball screws and nuts is high, and the process requirements are complex.

b. It cannot be self-locking, especially the vertical screw, and a brake device is required to prevent the moving parts from sliding down after the transmission stops.

V. Selection and Use Precautions

1. Selection: When selecting a ball screw, factors such as the system's load capacity, precision requirements, and movement speed must be considered. At the same time, it is also necessary to select a suitable ball circulation method and manufacturing process according to the specific application scenario.

2. Use Precautions:

Regularly inspect and maintain the ball screw to ensure that it is in good working condition.

Avoid excessive impact and vibration of the ball screw to avoid affecting its accuracy and life.

During use, attention should be paid to the lubrication and cooling of the ball screw to reduce friction and wear.

In summary, the ball screw is a high-precision and high-efficiency transmission mechanism, which is widely used in precision instruments, CNC machine tools, automation equipment and medical equipment. During the selection and use process, reasonable selection and maintenance should be carried out according to the specific application scenarios and requirements.