High Guality Round Linear Guide SBR25 for CNC Machine From Shac Factory Made in China

Linear guides can maintain efficient linear motion, requiring clean and tidy working environment. Prevention of dust and other workshops iron chips

Sealing film is selected at the bottom, and the linear guideway fixing screw is equipped with anti biogenic screw hole cover to prevent dust accumulation.

Linear guides are mainly used in Pressing Machine, Woodworking Machine,  lathes, industrial automation machines, Container Switching Device,  etc.

Data unit is mm

The types of lubrication system can be categorized into three groups:^[10]

• Class I — bearings that require the application of a lubricant from an external source (e.g., oil, grease, etc.).

• Class II — Bearings that contain a lubricant within the walls of the bearing (e.g., bronze, graphite, etc.,). Typically these bearings require an outside lubricant to achieve maximum performance.

• Class III — bearings made of materials that are the lubricant. These bearings are typically considered "self-lubricating" and can run without an external lubricant.

Examples of the second type of bearing are Oilites and plastic bearings made from polyacetal; examples of the third type are metalized graphite bearings and PTFE bearings.^[10]

Most plain bearings have a plain inner surface; however, some are grooved, such as spiral groove bearing. The grooves help lubrication enter the bearing and cover the whole journal.^[28]

Self-lubricating plain bearings have a lubricant contained within the bearing walls. There are many forms of self-lubricating bearings. The first, and most common, are sintered metal bearings, which have porous walls. The porous walls draw oil in via capillary action^[29] and release the oil when pressure or heat is applied.^[30] An example of a sintered metal bearing in action can be seen in self-lubricating chains, which require no additional lubrication during operation. Another form is a solid one-piece metal bushing with a figure eight groove channel on the inner diameter that is filled with graphite. A similar bearing replaces the figure eight groove with holes plugged with graphite. This lubricates the bearing inside and out.^[31] The last form is a plastic bearing, which has the lubricant molded into the bearing. The lubricant is released as the bearing is run in.^[32]

There are three main types of lubrication: full-film condition, boundary condition, and dry condition. Full-film conditions are when the bearing's load is carried solely by a film of fluid lubricant and there is no contact between the two bearing surfaces. In mix or boundary conditions, load is carried partly by direct surface contact and partly by a film forming between the two. In a dry condition, the full load is carried by surface-to-surface contact.

Bearings that are made from bearing grade materials always run in the dry condition. The other two classes of plain bearings can run in all three conditions; the condition in which a bearing runs is dependent on the operating conditions, load, relative surface speed, clearance within the bearing, quality and quantity of lubricant, and temperature (affecting lubricant viscosity). If the plain bearing is not designed to run in the dry or boundary condition, it has a high coefficient of friction and wears out. Dry and boundary conditions may be experienced even in a fluid bearing when operating outside of its normal operating conditions; e.g., at startup and shutdown.