直線導軌的選型問題 通常，依據工程使用的慣例，直線導軌如果與滾珠絲杠配合使用則其規格應與滾珠絲杠的外徑相近似。譬如：滾珠絲杠的公稱直徑為 20mm，則選擇 20 規 格的直線導軌。而滑塊數量通常是依據載荷狀態或者設計師的經驗選擇。

The selection of linear guides is usually based on engineering practices. If a linear guide is used in conjunction with a ball screw, its specifications should be similar to the outer diameter of the ball screw. For example, if the nominal diameter of the ball screw is 20mm, choose a 20 gauge linear guide rail. The number of sliders is usually selected based on the load state or the designer's experience.

要注意的是：在選擇直線導軌的精度等級的時候，請根據自身 使用狀況選用能夠滿足工程實際要求的導軌即可，不要無謂地提高精度等級加大制造裝配難度和制造成本。下面，介紹一下其中相對重要的幾個基本的概念。

It should be noted that when selecting the accuracy level of linear guide rails, please choose a guide rail that can meet the actual engineering requirements based on your own usage situation. Do not unnecessarily increase the difficulty and cost of manufacturing and assembly by increasing the accuracy level. Below, we will introduce several relatively important basic concepts.

基本靜額定負荷：直線導軌在靜止或者運動過程中如果承受過大的負載或者承受很大的沖擊負載時，會導致導軌滾珠滑道的接觸面和滾珠產生局部的永久的塑性變形，當這種變形量超過一定限度后，將會影響到直線導軌運行精度和平穩性。基本靜額定負荷就是容許這種變形量的出眾負荷。

Basic static rated load: If a linear guide rail is subjected to excessive load or impact load during stationary or moving processes, it will cause local permanent plastic deformation of the contact surface and balls of the guide rail ball slide. When this deformation exceeds a certain limit, it will affect the accuracy and stability of the linear guide rail operation. The basic static rated load is the ultimate load that allows for this amount of deformation.

國際通用的定義是：在負載的方向和大小不變的情況下，受到非常大應力的接觸面處，鋼珠與滑道的永久變形量為鋼珠直徑萬分之一時的靜止載荷。所以，這個參數對于直線導軌來說是非常重要的，我們在使用過程中建議保證施加給直線導軌的非常大靜止載荷在允許范圍內。通常，為了考慮其使用壽命和安全性，在使用時需要有一個安全系數來保證其正常使用的安全性和使用壽命，非常是在有沖擊載荷時，這個安全數更要取得相對較大。普通的運行狀態下通常取安全系數1.5 ≤ S ≤ 3，在有沖擊載荷的時候通常3 ≤ S ≤ 5。

The internationally accepted definition is the static load at the contact surface where the maximum stress is applied, with the direction and magnitude of the load unchanged, when the permanent deformation between the steel ball and the slide is one thousandth of the diameter of the steel ball. So, this parameter is very important for the linear guide rail, and we must ensure that the maximum static load applied to the linear guide rail is within the allowable range during use. Usually, in order to consider its service life and safety, a safety factor is required during use to ensure its normal safety and service life, especially when there is an impact load, this safety factor needs to be relatively large. Under normal operating conditions, a safety factor of 1.5 ≤ S ≤ 3 is usually taken, and under impact loads, it is usually 3 ≤ S ≤ 5.

基本動額定負荷：在直線導軌的負荷大小和方向不變的情況下，直線導軌的 額定壽命為 50km 時的非常大負載。由定義可以知道，這個參數主要是為了計算和保證直線導軌的使用壽命的。這里我們給出滾珠直線導軌的額定壽命計算公式：

Basic dynamic rated load: The maximum load at which the rated life of a linear guide rail is 50km, while the load magnitude and direction remain unchanged. From the definition, it can be seen that this parameter is mainly used to calculate and ensure the service life of the linear guide rail. Here we provide the formula for calculating the rated life of the ball linear guide rail:

以上介紹滾珠絲杠傳動系統選型計算完畢。

The selection and calculation of the ball screw transmission system mentioned above have been completed.

除此之外，利用同步帶和齒輪齒條驅動負載直線運動的機構元器件選型計算與伺服電機基本類似，唯一的區別：是同步帶需要根據負載功率計算同步帶的容量，齒輪齒條機構需要根據負載功率計算模數。其計算方法與大學教材《機械設計》中講解的一致。關于具體元器件的負載能力、使用壽命等方面的參數，在使用過程中咨詢相應的供應商即可。在此，無須贅述。需要強調的是：如果在實際使用中由伺服或者步進電機驅動則需要根據我們前面給出的慣量公式和扭矩公式進行相應的計算選擇合適的啟動扭矩。

In addition, the selection and calculation of components for the mechanism that uses synchronous belts and gear racks to drive load linear motion are basically similar to servo motors, with the only difference being that the synchronous belt needs to calculate the capacity of the synchronous belt based on load power, while the gear rack mechanism needs to calculate the modulus based on load power. The calculation method is consistent with the explanation in the university textbook "Mechanical Design". For specific parameters such as load capacity and service life of components, consult the corresponding supplier during use. Here, there is no need to elaborate further. It should be emphasized that if it is driven by a servo or stepper motor in practical use, it is necessary to calculate and select the appropriate starting torque based on the inertia formula and torque formula we provided earlier.