The journal bearing consists of a journal that is free to rotate in the support metal sleeve or housing. There are no rolling elements in these bearings. Their design and construction may be relatively simple, but the theory and operation of these bearings may be complicated. This article focuses on grease lubricated full fluid journal journal bearings, but first briefly discusses pins and bushings, dry and semi-lubricated journal bearings and tilting pad bearings.
Low-speed pins and bushings are a form of journal bearings, where the shaft or housing is usually not fully rotated. In the typical reverse direction, the low-speed part of the rotation does not allow the formation of a complete fluid film, so the metal and metal in the bearing contact. The pins and bushings are constantly running on the boundary lubrication. These types of bearings are usually lubricated with extreme pressure greases to help support the load. Solid molybdenum disulfide (molybdenum) is contained in the grease to enhance the carrying capacity of the lubricant. Many outdoor construction and mining equipment applications use pins and bushings. Therefore, the impact load and water pollution pollution is usually the main factor of its lubrication.
The shaft shaft bearing consists of a polymer consisting of a polymer, which can be mixed with a solid such as molybdenum, graphite, PTFE or nylon. These bearings are limited to low load and low surface speed applications. A semiconductor journal bearing includes a shaft that rotates in a sintered bronze or aluminum porous metal sleeve, wherein the lubricating oil is contained in the pores of the porous metal.
The tilting pad or the rotary shoe bearing consists of a shaft that rotates within the housing consisting of a curved pad. Each gasket can be independently pivoted and aligned with the curvature of the shaft. The design has the advantage of supporting more accurate alignment of the housing with the rotary shaft and improved shaft stability.