Four Support Forms of Ball Screw Drive

The installation method is an important basis for selecting the appropriate ball screw specifications. Different support forms (i.e., installation methods) have their own characteristics, which will affect the accuracy, efficiency, rigidity and other performance of the entire equipment. According to different application requirements, ball screw drives can adopt the following four common support forms.

1. Fixed-Free

One end of the ball screw is supported by a fixed support seat, and the other end is a free end without any support seat. This support method is suitable for occasions with low rigidity requirements and vertical installation.
This method has a simple structure, low axial stiffness and critical speed, and poor screw stability. It is mostly used for short stroke and vertical transmission;
Advantages: No additional support seat is required, which reduces the difficulty of installation; Due to the reduction in the number of support seats, the manufacturing cost is reduced.
Disadvantages: The free end has no support, which makes the screw easy to bend and deform, affecting the transmission accuracy; The free end causes the screw to vibrate, reducing the stability of the system.

2. Fixed-Supported

The most typical and most commonly used installation method for ball screw mechanisms is the so-called one-end fixed and one-end supported installation method.
One end of the ball screw is supported by a fixed support seat, and the other end is supported by a support seat. This support method reduces the complexity of installation and adjustment while ensuring a certain rigidity.
Advantages: The rigidity of the screw is guaranteed, and installation and adjustment are also easier; The support method is more flexible and the operation difficulty is reduced.
Disadvantages: Since one end is a support seat, its stability is slightly inferior to that of a fixed support seat, and it may not perform well in some high-precision applications.
Suitable for occasions with medium speed, high rigidity and high precision.

3. Support-Support

Both ends of the ball screw are supported by support seats, and there is no fixed end. This support method is suitable for occasions with moderate rigidity and precision requirements, and requires a certain flexibility in installation and adjustment.
Suitable for applications with long strokes and low loads, such as light machinery and conveying systems.
Advantages: The support seats at both ends can adjust the gap between the screw and the support seat; Moderate cost: The cost is moderate compared to other methods.
Disadvantages: Because both ends are support seats, its rigidity and stability are worse than fixed support seats.

4. Fixed-Fixed

Both ends of the ball screw drive are supported by fixed support seats. This support method has high rigidity and stability and is suitable for applications requiring high precision and high rigidity.
High rigidity machine tools;
Advantages: Prevent bending and deformation, ensure transmission accuracy; Suppress vibration and improve the stability of the mechanical system.
Disadvantages: The installation requires precise adjustment of the gap between the screw and the support seat to ensure smooth rotation without excessive friction. Long-term high-load operation and thermal expansion may cause changes in the gap between the screw and the support seat, affecting the transmission accuracy.

Fixed-Fixed Support Forms of Ball Screw Drive

Summary

Choosing the right ball screw drive support form is crucial to improving the stability, accuracy and reliability of the equipment. When choosing, the most suitable support method should be determined based on the specific application requirements, load conditions and working environment. Each support form has its specific advantages and disadvantages, and a reasonable choice can significantly improve the performance and service life of the equipment.