Oil lubricated bearing is a liquid bearing that uses a liquid lubricant such as oil and water in order to reduce friction and wear between two surfaces in relative motion. Liquid bearings can be divided into hydrostatic bearings and hydrodynamic bearings. These oil-lubricated bearings operate at higher speeds and they last longer. The oil in this bearing contains fewer contaminants and usually run cooler than grease-lubricated counterparts. These systems require more complex designs and more routine maintenance. The most common oil lubrication methods are bath oil lubrication, ring oil, force circulation, oil mist and grease lubrication. Industrial cryogenic turbo machines utilize oil-lubricated bearings, both rolling element and plain journal types, but require strict thermal control within the machine to prevent freezing the oil. These bearings require additional tubing lines to the spindle and these spindles establish the lubrication several minutes before the spindle is started. Oil-lubricated bearings continuously flush themselves of wear particles and other contaminants that can damage the bearings.