所谓直线导轨就是只用于运输的轨道。常见的直线导轨有铁路、电梯的运行槽、工厂生产车间用于运输的槽道等，直线导轨不像柴米油盐酱醋茶一样天天的出现在我们的生活当中，但是对于我们整个国民生产、生活活动都起着关重要的作用。在选购直线导轨的时候都希望能够挑到比较好的，那么怎么确定什么样的直线导轨恰到好处？

The so-called linear guide rail is a track that is only used for transportation. Common linear guides include running grooves for railways and elevators, and grooves used for transportation in factory production workshops. Unlike firewood, rice, oil, salt, soy sauce, vinegar, and tea, linear guides do not appear in our daily lives. However, they play a crucial role in the production and daily activities of our entire nation. When choosing a linear guide rail, we all hope to find a better one, so how do we determine which type of linear guide rail is just right?

1、承重力高

1. High load-bearing capacity

无论所选购的直线导轨是用于运输什么物品，承重力比较高的直线导轨无疑是比较好的。因为承重力比较高的直线导轨，在所传送的物品重量方面限制没有那么多，就不会因为一时的疏忽大意或者是一些必要的运输情况下导致直线导轨的损坏。承重力比较高的直线导轨使用寿命也会大大的高于承重力比较低的直线导轨。

No matter what item is being transported with the selected linear guide rail, a linear guide rail with high load-bearing capacity is undoubtedly better. Due to the relatively high load-bearing capacity of the linear guide rail, there are not as many restrictions on the weight of the transported items, so it will not be damaged due to momentary negligence or necessary transportation situations. The service life of linear guides with high load-bearing capacity will also be significantly higher than that of linear guides with low load-bearing capacity.

2、容易保养

2. Easy to maintain

就像花无百日红，直线导轨也不可能永远保持初的使用效果，想要延长直线导轨的使用寿命，平时是要定时的做保养的，通常是需要对直线导轨加一些润滑油，增加直线导轨的润滑度，减少摩擦，从而延长直线导轨的使用寿命，有一些材料的直线导轨是无法加润滑油的，在保养方面也比较麻烦。

Just like a hundred days without a hundred red flowers, linear guides cannot always maintain their initial use effect. To extend the service life of linear guides, regular maintenance is necessary. Usually, it is necessary to add some lubricating oil to the linear guide to increase its lubrication, reduce friction, and thus extend its service life. Some materials of linear guides cannot be lubricated, and maintenance is also quite troublesome.

3、做工精致

3. Exquisite workmanship

在挑选直线导轨的时候，做工精致的直线导轨也是比较好的，因为做工精致就在运输的过程中会大大的减少物品和直线导轨之间的摩擦，从而延长直线导轨的使用寿命，还能够避免不必要的意外，比如物品在运输过程中卡顿。

When selecting a linear guide rail, a finely crafted linear guide rail is also better, because exquisite workmanship greatly reduces the friction between the item and the linear guide rail during transportation, thereby extending the service life of the linear guide rail and avoiding unnecessary accidents, such as items getting stuck during transportation.

总之，直线导轨在我们的日常生产和生活中扮演着重要的角色，在挑选直线导轨的时候好是挑选承重力比较高的，比较好做保养的，而且做工比较精致的直线导轨。

In short, linear guides play an important role in our daily production and life. When selecting linear guides, it is better to choose ones with high load-bearing capacity, easy maintenance, and exquisite workmanship.

滚珠丝杆的选型步骤：

Selection steps for ball screw:

1、以负载确定直径。电机性能参数中有输出扭矩，如果还带减速器也要算进去（考虑效率），计算一下实际工况中需要多大推力，滚珠丝杆样本（跟厂家要）有负载参数（即推力参数，一般标示为动负荷和静负荷，看前者即可），选择滚珠丝杆的公称直径。

1. Determine the diameter based on the load. The output torque is included in the motor performance parameters, and if a reducer is also included (considering efficiency), calculate how much thrust is required in actual working conditions. The ball screw sample (to be consulted with the manufacturer) has load parameters (i.e. thrust parameters, usually marked as dynamic load and static load, the former is sufficient), and select the nominal diameter of the ball screw.

2、以马达的直线速度和旋转速度确定滚珠丝杆导程。电机确定了就知道输出转速，考虑一下你需要的大直线速度，把电机转速（如果带减速器再除以减速比）乘以丝杆导程的值就是直线速度，该值大于需要值即可。

2. Determine the lead of the ball screw based on the linear speed and rotational speed of the motor. Once the motor is determined, the output speed is known. Consider the maximum linear speed you need. Multiply the motor speed (if equipped with a reducer, then divide by the reduction ratio) by the lead of the screw to obtain the linear speed, which is greater than the required value.

3、以实际需要确定确定滚珠丝杆长度（总长=工作行程+螺母长度+余量+安装长度+连接长度+余量。如果增加了防护，比如护套，需要把护套的伸缩比值（一般是1：8，即护套的大伸长量除以8）考虑进去。

3. Determine the length of the ball screw according to actual needs (total length=working stroke+nut length+safety margin+installation length+connection length+margin). If protection is added, such as a protective sheath, the expansion ratio of the sheath (usually 1:8, that is, the large elongation of the sheath divided by 8) needs to be taken into account.

4、以实际需要确定滚珠丝杆精度。一般机械选C7即可，数控机床类选C5的比较多（对应国内标准一般是P5~P4和P4~P3级，具体参看样本）。

4. Determine the accuracy of the ball screw according to actual needs. Generally, C7 is sufficient for mechanical selection, while C5 is more commonly used for CNC machine tools (corresponding to domestic standards generally ranging from P5 to P4 and P4 to P3 levels, please refer to the sample for details).

5、以安装条件和尺寸结构等确定滚珠丝杆螺母形式（螺母有很多结构，不同的螺母结构尺寸略有不同，视情况选择，建议不要选太特殊的，万一出点毛病维修换件无门）。

5. Determine the form of the ball screw nut based on installation conditions and size structure (nuts have many structures, and different nut structures have slightly different sizes. Choose according to the situation, and it is recommended not to choose too special ones, in case of any problems, repair or replacement parts without doors).

6、询问所选产品厂家的、付款条件和交货时间。这一点设计人员不要以为就是采购的事，事实上很多厂家（进口国产一个样）的产品样本上有的型号它根本就不生产或者不接小额订单，印上去大概是为了显示我是大厂，无所不能造。别等你选完了出完图了其他件按这个型号开始做配件了去购买的时候人家告诉你这个型号交货期需要3、4个月就完蛋了。

6. Inquire about the price, payment terms, and delivery time of the selected product manufacturer. Designers should not assume that this is just a matter of procurement. In fact, many manufacturers (one sample imported from China) do not produce or accept small orders for certain models on their product samples. Printing them is probably to show that I am a large factory and can make anything. Don't wait until you finish selecting and drawing other parts, and start making accessories based on this model. When you make a purchase, they will tell you that the delivery time for this model will take 3-4 months and it will be over.

7、选择确定安装方式（端部）。这个安装件可以自己设计，也可以买现成的，有标准安装座可选。自己设计注意受力状态，轴承好选择7000系列的，因为丝杆工作时主要受轴向力，径向受力要尽力避免。

7. Choose to determine the installation method (end). This installation component can be designed by oneself or purchased ready-made, with a standard mounting base available for selection. Design yourself and pay attention to the stress state. It is recommended to choose bearings from the 7000 series, as the screw is mainly subjected to axial force during operation, and radial force should be avoided as much as possible.

8、考虑导向件和安装能力。和滚珠丝杆配套的导向件选择滚珠直线导轨，当然直线轴和直线轴承的搭配是相对经济的选择。

8. Consider guide components and installation capabilities. It is recommended to choose a ball linear guide rail as the guide component that matches the ball screw. Of course, the combination of linear shaft and linear bearing is a relatively economical choice.

9、根据以上已确定条件绘出滚珠丝杆图纸（主要是端部安装尺寸，这个要详细，要提供形位尺寸和公差）。

9. Draw a drawing of the ball screw based on the determined conditions above (mainly the end installation dimensions, which should be detailed and provide geometric dimensions and tolerances).