Sliding bearing

Sliding bearings are very similar in design to rolling bearings except that they do not use ball bearings when sliding. If they are cylindrical, they are usually called bushings. The bushing can be metal or plastic material, or even air.
Sliding bearings can run on hardened steel or stainless steel shafting (raceways), and can also run on hard anodized aluminum or mild steel or aluminum. For plastic bushings, the specific type of polymer/fluoropolymer will determine the allowable hardness.
Sliding bearings are less rigid than rolling bearings.
Sliding bearings can deal with pollution well, and usually do not need sealing rings and dust caps.
Plain bearings usually handle a wider temperature range than rolling bearings.
Sliding bearings (plastic type) do not require oil or lubrication (usually can be used to improve performance characteristics).

1. Dovetail slide
Dovetail sliders or dovetail sliders are usually made of cast iron, but can also be made of hard-coated aluminum, acetal, or stainless steel. Like any bearing, the dovetail slider consists of a fixed linear base and a movable carriage. The dovetail bracket has a v-shaped or dovetail-shaped convex groove, which is locked into the groove of the corresponding linear base. Once the dovetail carriage is installed in the channel of its base, the carriage is locked in the linear axis of the channel and allows free linear movement. When the platform is connected to the carriage of the dovetail slide, the dovetail platform will be created, which can provide extended carrying capacity.
Because the dovetail slider has such a large surface contact area, the force required to move the saddle is greater than other linear sliders, resulting in slower acceleration. In addition, the dovetail slider has the disadvantage of high friction, but it has advantages in load-bearing capacity, bearability and durability. Dovetail sliders can run for a long time and are more resistant to impact than other bearings, and most of them are not contaminated by chemicals, dust and dirt. The dovetail slider can be electric, mechanical or electromechanical. Electric dovetail sliders are driven by many different devices, such as ball screws, belts, and cables. These devices are driven by functional motors such as stepper motors, linear motors, and hand wheels. The dovetail slider is a direct contact system that makes it suitable for heavy-duty applications, including CNC machine tools, shuttles, special machines, and workholding devices. Dovetail sliders are mainly used in manufacturing and laboratory science industries, and are ideal for high-precision applications.

2. Composite slider

2-section and 3-section compound slide rail
The slider may be composed of two parts or multiple parts. A two-part slider can only extend approximately 3/4 of the total compressed slider length. The composite slider usually has three parts: a fixed, floating intermediate member and a part connected to the equipment. The composite slider can extend at least to the length of the compressed slider, and usually can extend a little bit. In the case of rack sliding, this allows the device to extend completely out of the rack so that you can use or connect cables to the back of the device.

3. Frame Slider

Friction bearing frame slide
The rack slider is specially used to install the equipment in a 19-inch rack or a 23-inch rack. They can be friction bearings, ball bearings or roller bearings. Their size is suitable for installation in the rack, and the end mounting flanges match the mounting holes on the rack. In some cases, one mounting flange is connected to the adapter bracket at the other end to form a rack slider to accommodate different depths of the rack. The outer fixed member is connected to the rack, and the inner movable member is usually fixed to the side of the installation device with screws. Rack sliders are usually composite sliders or three-part sliders, which allow the complete extension of the installed equipment, and usually include the function of providing sliding internal components, so that the equipment is completely free to be removed from the rack. They can also include stops to prevent accidental pulling of the equipment out of the rack without releasing the stop mechanism.
The rack slider can have a proprietary configuration, for example, it can be clamped to the equipment without using screws, or it can be clamped to a properly designed rack. But the basic geometry is the same, no matter how they are installed.