Effective protection of linear guides plays an important role in prolonging the life of the guides. To this end, we summarize the following eight characteristics of lubricating oil for linear guides:

一、直线导轨的粘度：直线导轨润滑脂通常用表观粘度或相似粘度来表示，在说明润滑脂的粘度时，必须指明温度和剪切速度。可采用相似粘度指标来控制其低温流动性和泵送性。

1. Viscosity of linear guideway: Linear guideway grease is usually expressed by apparent viscosity or similar viscosity. Temperature and shear speed must be specified when describing the viscosity of grease. Similar viscosity index can be used to control its low temperature fluidity and pumpability.

二、直线导轨的强度极限：直线导轨润滑脂的强度极限是指引起试样开始流动的所需较小切应力，又称极限切应力。润滑脂强度极限是温度的函数，温度越高脂的强度极限越小，温度降低，脂的强度极限变大，它的大小取决于稠化剂的种类与含量，和制脂工艺条件也有一定的关系。

Strength Limit of Linear Guide: Strength Limit of Linear Guide Grease refers to the minimum shear stress, also known as the ultimate shear stress, which causes the sample to start flowing. The strength limit of grease is a function of temperature. The higher the temperature, the smaller the strength limit of grease, the lower the temperature, and the greater the strength limit of grease. The size of grease depends on the type and content of thickener, and also has a certain relationship with the technological conditions of grease making.

三、直线导轨的滴点：直线导轨润滑脂在规定条件下达到一定流动性时的较低温度称为滴点。润滑脂的滴点有助于鉴别润滑脂类型和粗略估计润滑脂的较高使用温度，一般说来，对于皂基脂，其使用温度应低于滴点20~30°C滴点越高，其耐热性越好。

3. Dropping point of linear guideway: The lowest temperature of linear guideway grease when it reaches a certain fluidity under specified conditions is called dropping point. The dropping point of grease is helpful to distinguish the type of grease and roughly estimate the maximum operating temperature of grease. Generally speaking, for soap grease, the higher the dropping point is, the better the heat resistance is.

四、直线导轨的胶体安定性：直线导轨润滑脂的胶体安定性是指润滑脂在一定温度和压力下保持胶体结构稳定，防止润滑油从润滑脂中析出的性能，也就是润滑脂抵抗分油的能力。通常把润滑脂析出油的数量换算为质量分数来表示。润滑脂的胶体安定性反应出润滑脂在长期储存中与实际应用时分油趋势，如果润滑脂的胶体安定性差，则在受热、压力、离心力等作用下易下发生严重分油，导致寿命迅速降低，并使润滑脂变稠变干，失去润滑作用。

4. Colloidal Stability of Linear Guideway: Colloidal Stability of Linear Guideway Grease refers to the ability of lubricating grease to keep colloidal structure stable at a certain temperature and pressure and to prevent lubricating oil from precipitating from grease, that is, the ability of lubricating grease to resist oil separation. Usually the amount of oil released from grease is converted to the mass fraction. Colloidal stability of grease reflects the trend of oil in long-term storage and practical application. If the colloidal stability of grease is poor, serious oil distribution will occur under the action of heat, pressure and centrifugal force, which will lead to a rapid decrease in life and make grease thicker and drier, thus losing lubrication.

五、直线导轨的氧化安定性：氧化安定性是指润滑脂在长期储存或长期高温下使用时抵抗热和氧的作用，保持其性质不发生变化的能力。由于氧化，往往发生游离碱含量降低或游离有机酸含量增大，滴点下降，外观颜色变深，出现异臭味，稠度、强度极限，相似粘度下降，生成腐蚀性产物和破坏润滑脂结构的物质，造成皂油分离。因此，在润滑脂长期储存中，应存放在干燥通风的环境中，防止阳光曝晒，并应定期检查游离碱或游离有机酸、腐蚀性等项目的变化，以保证其质量和使用性能。

Fifth, oxidation stability of linear guideway: oxidation stability refers to the ability of grease to resist heat and oxygen during long-term storage or long-term high temperature use, and to maintain its properties without permanent change. Owing to oxidation, the content of free alkali decreases or the content of free organic acid increases, dropping point decreases, appearance color becomes darker, odor, consistency, strength limit, similar viscosity decreases, corrosive products and substances destroying the structure of grease are formed, resulting in the separation of soap oil. Therefore, in the long-term storage of grease, it should be stored in a dry and ventilated environment to prevent sunlight exposure, and periodically check the changes of free alkali or free organic acid, corrosion and other items to ensure its quality and performance.

六、直线导轨的触变性：直线导轨润滑脂所具有的较基本的特性，就是触变性。当施加一个外力时，润滑脂的流动在逐渐变软，表现粘度降低，但是一旦处于静止，经过一段时间(很短)后，稠度再次增加(恢复)，这种特性称为触变性。润滑脂的这种特性，决定了其可以在不适于润滑油润滑的部位润滑，而显示它优良的性能。

6. Thixotropy of linear guideway: Thixotropy is the most basic characteristic of linear guideway grease. When an external force is applied, the flow of grease gradually softens and the apparent viscosity decreases, but once at rest, after a period of time (very short), the consistency increases again (recovery), which is called thixotropy. This characteristic of grease determines that it can be lubricated in parts that are not suitable for lubricating oil and show its excellent performance.

七：直线导轨系统的固定元件(导轨)的基本功能如同轴承环，安装钢球的支架，形状为“v”字形。支架包裹着导轨的顶部和两侧面。为了支撑机床的工作部件，一套直线导轨少有四个支架。用于支撑大型的工作部件，支架的数量可以多于四个。

Seventh: The basic function of the fixed elements (guideways) of the linear guideway system is like bearing rings, and the support with steel balls is in the shape of "v". The bracket covers the top and sides of the guide rail. In order to support the working parts of the machine tool, a set of linear guides has at least four supports. For supporting large working parts, the number of supports can be more than four.

八：直线导轨导轨系统的设计，力求固定元件和移动元件之间有较大的接触面积，这不但能提高系统的承载能力，而且系统能承受间歇切削或重力切削产生的冲击力，把作用力广泛扩散，扩大承受力的面积。为了实现这一点，导轨系统的沟槽形状有多种多样，具有代表性的有两种，一种称为哥特式(尖拱式)，形状是半圆的延伸，接触点为顶点；另一种为圆弧形，同样能起相同的作用。无论哪一种结构形式，目的只有一个，力求更多的滚动钢球半径与导轨接触(固定元件)。决定系统性能特点的因素是：滚动元件怎样与导轨接触，这是问题的关键。

Eighth: The design of linear guideway system strives to maximize the contact area between fixed and mobile components, which can not only improve the bearing capacity of the system, but also withstand the impact force produced by intermittent cutting or gravity cutting, so that the force can be widely spread and the bearing area can be enlarged. In order to achieve this, the groove shape of the guideway system has many kinds, there are two representative types, one is called Gothic (pointed arch), the shape is the extension of the semi-circle, the contact point is the vertex; the other is circular arc, which can also play the same role. No matter which type of structure, there is only one purpose to make more contact between rolling ball radius and guide rail (fixed element). The key factor to determine the system performance characteristics is how the rolling element contacts the guide rail, which is the key to the problem.

直线导轨之所以有这么大的使用区域：1、直线导轨主要用在自动化机械上比较多,像德国进口的机床,纸碗机,激光焊接机等等,当然直线导轨和直线轴是配套用的。

Linear guides have such a large area of use: 1. Linear guides are mainly used in automation machinery, such as German imported machines, paper bowl machines, laser welding machines and so on. Of course, linear guides and straight axis are matched.
                            

2、直线导轨主要是用在精度要求比较高的机械结构上,直线导轨的移动元件和固定元件之间不用中间介质，而用滚动钢球。因为滚动钢球适应于高速运动、摩擦系数小、灵敏度高，满足运动部件的工作要求，如机床的刀架，拖板等。如果作用在钢球上的作用力太大，钢球经受预加负荷时间过长，导致支架运动阻力增大。

2. Linear guideways are mainly used in mechanical structures with high precision requirements. Rolling steel balls are used instead of intermediate medium between moving and fixed components of linear guides. Because rolling steel ball is suitable for high-speed movement, small friction coefficient and high sensitivity, it meets the working requirements of moving parts, such as tool holder, trailer, etc. If the force acting on the steel ball is too large, the steel ball will endure the preload for too long, which will lead to the increase of the bracket resistance.