直線(xiàn)導(dǎo)軌的選型問(wèn)題 通常，依據(jù)工程使用的慣例，直線(xiàn)導(dǎo)軌如果與滾珠絲杠配合使用則其規(guī)格應(yīng)與滾珠絲杠的外徑相近似。譬如：滾珠絲杠的公稱(chēng)直徑為 20mm，則選擇 20 規(guī) 格的直線(xiàn)導(dǎo)軌。而滑塊數(shù)量通常是依據(jù)載荷狀態(tài)或者設(shè)計(jì)師的經(jīng)驗(yàn)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(xiàn)導(dǎo)軌的精度等級(jí)的時(shí)候，請(qǐng)根據(jù)自身 使用狀況選用能夠滿(mǎn)足工程實(shí)際要求的導(dǎo)軌即可，不要無(wú)謂地提高精度等級(jí)加大制造裝配難度和制造成本。下面，介紹一下其中相對(duì)重要的幾個(gè)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(fù)荷：直線(xiàn)導(dǎo)軌在靜止或者運(yùn)動(dòng)過(guò)程中如果承受過(guò)大的負(fù)載或者承受很大的沖擊負(fù)載時(shí)，會(huì)導(dǎo)致導(dǎo)軌滾珠滑道的接觸面和滾珠產(chǎn)生局部的的塑性變形，當(dāng)這種變形量超過(guò)一定限度后，將會(huì)影響到直線(xiàn)導(dǎo)軌運(yùn)行精度和平穩(wěn)性。基本靜額定負(fù)荷就是容許這種變形量的極限負(fù)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(guó)際通用的定義是：在負(fù)載的方向和大小不變的情況下，受到應(yīng)力的接觸面處，鋼珠與滑道的變形量為鋼珠直徑萬(wàn)分之一時(shí)的靜止載荷。所以，這個(gè)參數(shù)對(duì)于直線(xiàn)導(dǎo)軌來(lái)說(shuō)是非常重要的，我們?cè)谑褂眠^(guò)程中必須保證施加給直線(xiàn)導(dǎo)軌的靜止載荷在允許范圍內(nèi)。通常，為了考慮其使用壽命和性，在使用時(shí)需要有一個(gè)系數(shù)來(lái)保證其正常使用的性和使用壽命，特別是在有沖擊載荷時(shí)，這個(gè)數(shù)更要取得相對(duì)較大。普通的運(yùn)行狀態(tài)下通常取系數(shù)1.5 ≤ S ≤ 3，在有沖擊載荷的時(shí)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(dòng)額定負(fù)荷：在直線(xiàn)導(dǎo)軌的負(fù)荷大小和方向不變的情況下，直線(xiàn)導(dǎo)軌的 額定壽命為 50km 時(shí)的負(fù)載。由定義可以知道，這個(gè)參數(shù)主要是為了計(jì)算和保證直線(xiàn)導(dǎo)軌的使用壽命的。這里我們給出滾珠直線(xiàn)導(dǎo)軌的額定壽命計(jì)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(dòng)系統(tǒng)選型計(jì)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(qū)動(dòng)負(fù)載直線(xiàn)運(yùn)動(dòng)的機(jī)構(gòu)元器件選型計(jì)算與伺服電機(jī)基本類(lèi)似，的區(qū)別：是同步帶需要根據(jù)負(fù)載功率計(jì)算同步帶的容量，齒輪齒條機(jī)構(gòu)需要根據(jù)負(fù)載功率計(jì)算模數(shù)。其計(jì)算方法與大學(xué)教材《機(jī)械設(shè)計(jì)》中講解的一致。關(guān)于具體元器件的負(fù)載能力、使用壽命等方面的參數(shù)，在使用過(guò)程中咨詢(xún)相應(yīng)的供應(yīng)商即可。在此，無(wú)須贅述。需要強(qiáng)調(diào)的是：如果在實(shí)際使用中由伺服或者步進(jìn)電機(jī)驅(qū)動(dòng)則需要根據(jù)我們前面給出的慣量公式和扭矩公式進(jìn)行相應(yīng)的計(jì)算選擇合適的啟動(dòng)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.