Introduction to ball screw installation methods
Because the ball screw is a rolling motion and has higher efficiency than the sliding screw, the efficiency of converting rotary motion into linear motion and linear motion into rotary motion can reach η=88%~96%.
In addition, the ground precision ball screw can achieve micron-level feed accuracy because it is precision machined. When used as a lifting transmission mechanism, braking and other measures need to be taken, such as using a servo motor with brakes, etc.
Ball screw installation method:
1. Fixed-Freestyle
This installation method has small load-bearing capacity and low axial stiffness, and is only suitable for short screw rods.
Features: This method has a simple structure, low axial stiffness and critical speed, and poor stability of the screw rod. It is mostly used for short strokes and vertical transmission end combined angular contact bearings with one end free.
2. Fixed-support type
A thrust bearing is installed at one end, and a deep groove ball bearing is installed at the other end. When the ball screw is longer, a thrust bearing is installed at the end to fix it, and the other end is supported by a deep groove ball bearing. In order to reduce the influence of thermal deformation of the screw rod, the thrust bearing should be installed away from the heat source.
The most typical and commonly used installation method of the ball screw mechanism is suitable for medium speed, high stiffness and precision situations, and the support end is less rigid.
Remember, a modular angular contact bearing on one end and a deep groove ball bearing on the other.
3.Fixed-Fixed
It can withstand high axial loads. The axial stiffness of the screw is about 4 times higher than the one-end fixed and one-end support installation method. It is suitable for high-speed rotation, high precision and large screw length situations.
Highly rigid machine tools.
The biggest feature of this support method: the ball screw is pre-stretched to compensate for the thermal deformation caused by the frictional temperature rise of the ball screw during high-speed rotation.
Both ends are equipped with combined angular contact bearings (DT-DB is installed in group configuration).
This installation method also has disadvantages, such as complex structure and sensitivity to thermal deformation of the screw for axial requirements.
4. Support at both ends
It is suitable for general occasions where medium speed, stiffness and accuracy are not required. This form has a simple structure, small bearing rigidity, poor stress condition, and few applications.
Both ends are equipped with deep groove ball bearings.
Source: Mechanical Engineer Growth Camp Li Gong
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