bearing lubricant calculation roller bearing lubricant quantity needed is to a large extent depend on bearing type, lubricant supply system design, lubricant type and other factors. It is hard to offer a simple and clear formula with wide applicability for all cases. Lubricant amount for bearings with automatic lubricant liquid conveyance (e.g. Angle contact ball bearing) is larger than that for bearings without this automatic function (e.g. two column round shaft roller bearings). In the case of speed parameters (n.dm) are high, their difference becomes more apparent. Through many experiments, rough formula for the amount of lubricant supply is as follows:
n the formula Q=WdB, Q！lubricant amount, mm3/h, W！parameter, 0.01mm /h d！bearing inner diameter, mm B！bearing width, mm, however actual lubricant amount will be multiplied by 4！20 times of this quantity. Experiments are needed to modify the lubricant supply amount in order to make best use of the lubricant. 4.2 lubricant supply manner design lubricant supply manner design (e.g. sprinkling spout manner, installation position) should be emphasized for high speed rotating bearings in order to safely put the lubricant into the inner part of bearing. Bearing lubrication manner wholly depends on bearing types and assembly manners (figure 4a ).For one column bearings, the best lubrication manner is enter the bearing inner part from one side. The mouth of the sprinkling spout should be at the same height with the inner rings of the bearings, and not point towards the bearing retainers. Lubricant must enter in the way just mentioned the bearing inner part,particularly when the absorbing and draining direction of bearing itself can not be easily decided upon ( e.g. angle contact ball bearing). If possible lubricant should first pass through a specially made sprinkling tube, and then enters bearing inner parts. The length of the sprinkling tube depends on the bearing size, and the tube diameter is 0.5！ 1.0mm . Lubricant can also be delivered into the outer shell of the bearing (figure 4b). In this case, attention should be paid to decide whether lubricant enters the pressure area created by the steel ball and the bearing outer shell. For two column bearings, lubricant must be sprinkled into the bearing inner parts from the position at the same level with the outer ring of the rolling channel so as to lubricate the bearing fully.In the case of bearing diameter being between 150！ 280 mm , another sprinkling spout should be added. In addition, a lubricant drainage tube with its length of 5mm should be installed in order to prevent lubricant dregs from settling at the bearing bottom. Each parameter in the lubricant！gas centralized lubrication system should be further put to detailed and accurate study in order to meet the requirements of the high speed leading rollers of modern machine tools for the lubrication system. This is for: lubricant type, lubricant method, lubricant amount, bearing type and bearing assembly all have a decisive influence on the enhancement of bearing rotation speed.