How to distinguish between good quality and bad linear guide rail

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Linear sliders can be divided into three types: roller linear guides, cylindrical linear guides, and ball linear guides. They are used to support and guide moving parts and perform reciprocating linear motion in a given direction. Depending on the nature of friction, linear motion guides can be divided into sliding friction guides, rolling friction guides, elastic friction guides, fluid friction guides, etc.

The function of linear guide motion is to support and guide the moving parts to make reciprocating linear motion in a given direction. Depending on the nature of friction, linear motion guides can be divided into sliding friction guides, rolling friction guides, elastic friction guides, fluid friction guides and other types. Linear bearings are mainly used in automated machinery, such as machine tools imported from Germany, bending machines, laser welding machines, etc. Of course, linear bearings and linear shafts are matched. Like linear guides, they are mainly used in mechanical structures that require relatively high precision. There is no intermediate medium between the moving element and the fixed element of the linear guide, but rolling steel balls.

So how to distinguish this linear guide?

Mainly identify the following points:

1. High positioning accuracy: Because the friction force of the linear slide rail is very small when it moves, it belongs to rolling friction. It can drive the platform with very little power. Because the friction force is small, the heat generated by the friction is very small, compared with the transmission The sliding method can greatly reduce the wear of the contact surface of the running track, and can maintain high positioning accuracy, walking accuracy and low wear for a long time.

2. High rigidity: Because the slide rail and track adopt four-direction equal load design, it must have sufficient resistance to the load from all directions, and have the ability to automatically adjust the center, which can allow larger installation errors Make processing easier, and can be applied to a sufficient amount of preload to obtain high rigidity.

3. Easy maintenance: Compared with the traditional sliding system, there are shoveling or grinding actions for the running track. The wear caused by sliding often makes the machine need to be shoveled or ground again for a period of time, which is time-consuming and time-consuming. And the cost is very high, the linear slide rail is interchangeable, if it is replaced or repaired, the normal operation of the machine can be restored.

4. High speed: Because the sliding block and the track and the steel ball adopt rolling point contact, the friction coefficient is very small and not easy to generate heat, and only a very small power is required to drive the machine to run, because the required driving force is small and The power consumption is low, so it is more suitable for high-speed running occasions than the sliding device.

Accuracy class

The accuracy of the R series linear slides is divided into five levels: ordinary N, high H, precision P, ultra-precision SP, and top UP. Customers can choose according to the accuracy requirements of the equipment.

Radial clearance and preload

Radial clearance is generally divided into five types: ZF micro clearance, Z0 zero preload, Z1 light preload, Z2 medium preload, and Z3 heavy preload. Choose according to the purpose; the radial clearance of the slide rail has a significant influence on the running accuracy, load resistance and rigidity, so it is very important to select the clearance appropriately according to the purpose. Generally, it is considered that the vibration and impact caused by reciprocating motion, the selection of negative clearance, and the service life and accuracy will bring good effects.

The purpose of the so-called preload is to increase the rigidity of the slider and eliminate the internal load applied to the rotor in advance such as clearance. The clearance marks ZF, Z0, Z1, Z2, and Z3 of the slide rail indicate that the clearance value is negative after the preload is applied.


When the slide rail bears a load, the steel ball, slide rail, track, etc. will be elastically deformed within the allowable load range. At this time, the ratio of the displacement to the load is the rigidity value. The rigidity of the slide rail increases with the increase of the preload. The effect of preloading can keep the external load increased until the preloading load is about 2.8 times.

The above is a brief introduction, if you have any other questions, please consult us



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