Choosing the right ball screw lubricant

Choosing the right ball screw lubricant - 2020 05 - 29 for design and selection of ball screw pair, many parameters must be considered. Operation load, speed, accuracy, environmental and power requirements in the design criteria are very important conditions. No matter the design engineer is to choose rolling ball screw or precision grinding ball screw, must be fully aware of the lubricant factors. Choose the appropriate lubricant can reduce friction, reduce the friction torque, improve the efficiency of the screw, and prolong service life. Ball screw can maintain a low friction advantage, is through the use of lubricant to reduce rolling resistance between the ball and the raceway surface and the adjacent sliding friction between the ball. With lubrication and supplemental lubrication before, must to thoroughly clean ball screw pair, to remove all of the pollutants. Pollutants ball screw is one of the major causes of premature failure. Correct lubrication can avoid most of pollutants into the screw nut, which greatly reduces the external contaminants may cause damage. Ball screw components are generally used in the process of transporting and storing the anti-rust oil, before using of lubricant is finally, should be completely erased anti-rust oil. A variety of methods can be used to the ball screw vice filling lubricant and keep lubricant inside the nut. For example, the use of grease lubrication, through the nut ontology or nut greasing holes on the flange to add grease inside the nut, nut ends for wiping or seal to prevent grease spill and external contaminants into the nut; When using oil lubrication, need a lubricating system with pump, filter system, and to consider filling method. The choice of lubricant is often ignored, On the market with hundreds of varieties to choose from, and the performance of many varieties are almost identical, can ask lubricant specialist or ball screw manufacturer to shrink range) , according to the specific application to select the correct lubricant, can ensure the ball screw reached its design life. Lubricating oil and grease can provide corrosion protection, but specific to choose what kind of lubricant should be based on each of the lubricant in the specific application of optimal evaluation, comprehensive consideration before make a decision. When the user to select oil lubrication, can to a certain velocity directly to the position of lubricant filling lubricating oil, lubricating oil, when through the ball nut, can remove nut internal residual moisture and other contaminants. Oil can also provide a cooling effect. Oil lubrication faults must be considered include: lubricating oil charging too much may cause to the machining process of the cooling fluid pollution, such as mixed with cutting fluid in machining applications. You need to use the pump and the metering system brought about by the rising costs. Lower than the cost of oil, grease and loaded with lower frequency, and will not pollute the cutting fluid. But on the other hand, grease was difficult to remain in the nut, and easier to accumulate in the end of the nut travel, and gathered machining debris and abrasive particles in the area. Used to supplement the lubrication grease may be incompatible with the old grease. Be sure to check compatibility. If you want to use of lubricating oil for lubrication, shall be determined according to the working temperature, load and speed lubricating oil viscosity and the amount of oil. If the lubricating oil viscosity is too high, or if there is excessive dosage, may cause overheating. If the viscosity is too low or the dosage is too little, it may not be able to adequately lubricated, which leads to the friction between metal and rapid wear. The choice of lubricating oil will directly affect the ball screw when use temperature and service life. Grease lubrication, must to correct lubrication of ball screw, in order to ensure that can meet the design life. Grease can be directly filling to trip the end of the race, or, if there is a grease filling holes, can pump directly into the ball nut. Choose the latter, it is recommended to use scraping brush or seal to keep grease inside the ball nut. High speed movement has no effect on grease of ball screw, so screw speed is not choose the factors of the grease. For example, the grease can be used in the dn value ( Ball bearings pitch circle diameter x speed) As high as 1000000 spindle and ball screw the dn value of little more than 100000. For the ball screw pair to choose the appropriate lubricating oil or grease can reduce maintenance downtime, ensure that products meet the design life.