The key to the quality and performance of electronic control translation table lies in the selection of driving screw and guide rail, as well as the body material, processing and installation quality.
1. The transmission screw is mostly used ball screw or grinding lead screw. Ball screw and nut through the formation of rolling friction, smooth movement, high transmission efficiency, easy to achieve high speed operation, and can change the diameter of the ball or the use of double nuts to effectively solve the axial clearance, but small lead production is difficult, is not conducive to improve the resolution; Grinding lead screw and nut for sliding friction, low efficiency, slow speed, but small lead can bring high resolution. The quality of drive screw has the greatest influence on positioning accuracy, axial clearance, velocity and resolution.
2. The choice of guide rail has the greatest influence on the stability and bearing capacity of the electric control translation platform. At present, the commonly used guide forms mainly include dovetail guide, cross roller guide, linear bearing, linear slide rail.
The performance of various guideways is shown in the following table:
| Type | Dovetail guide rail | cross roller guide rail | linear bearing | linear slide rail |
friction | large（0.25-0.35） | medium（0.003） | Small（0.002） | medium（0.003-0.005） |
rigidity | high | high | medium | high |
Load capacity | large | large | medium | large |
Travel | long | medium | medium | long |
positioning accuracy | low | high | medium | high |
3. The material and processing quality of the machine body play a decisive role in the overall accuracy and environmental resistance of the translation platform.
Comparison between stainless steel and aluminum:
(1) Temperature effect
The influence of temperature change on the material will cause dimensional change, which is expressed by the formula: Δ L= α L Δ T. Including α Is the coefficient of temperature expansion. The expansion coefficient of stainless steel is half that of aluminum, so the stainless steel body can ensure high stability in the case of slight temperature changes. However, when we use the electric moving table, the ambient temperature is generally not constant and changes greatly, especially when there are heat sources such as semiconductor lasers placed beside the electric moving table. At this time, the stability consideration is another case: material deformation Δ Temperature expansion coefficient of L and material α Divided by the quotient of temperature conductivity c（ α/ c) Is proportional. The temperature conductivity coefficient c of aluminum is nearly ten times that of stainless steel, so the deformation of aluminum body is much smaller than that of stainless steel.
(2) Vibration resistance
The material will deform when subjected to external force, which is expressed by the formula: F=kx, where F is the external force, x is the deformation, and k is the elastic modulus. The elastic modulus k of stainless steel is three times that of aluminum, so its stability is superior to aluminum. However, when considering the vibration resistance, the material density should also be considered ρ， When k/ ρ The higher the value, the better the vibration resistance. The density of stainless steel is three times that of aluminum, so its vibration resistance is slightly lower than that of aluminum.
All the electric translation tables produced by our company are selected with high-quality parts, which are novel and unique in design. They have a variety of structural forms, various accuracies, different strokes, various loads and various dimensions for customers to choose. Based on the principle of user first, we constantly develop more and better products to provide users with more choices.
