At present, with the high speed of the machine tool industry, the load on the ball screw is increasing, and the high-precision and large-lead screw is very necessary. Therefore, the ball screw has become an indispensable part of the machine tool. The maintenance method of the ball screw is generally the same as other devices to prevent dust and dryness, which affects work efficiency and prevents accident risks. Doing the following points can more effectively improve the service life:
(1) Eliminate the axial clearance. After the ball screw pair is disassembled and assembled, in order to ensure the accuracy of the reverse transmission and the axial rigidity, the axial clearance must be eliminated. The method of double nut ball screw pair to eliminate the gap is to use the relative axial displacement of the two nuts to make the balls in the two ball nuts stick to the two opposite sides of the threaded raceway respectively. When using this method to pre-tighten to eliminate the axial gap, it should be noted that the pre-tightening force should not be too large, otherwise it will increase the no-load moment and reduce the transmission efficiency.
(2) Regularly check the lubrication of the ball screw pair. Can be lubricated with grease and lubricating oil. Grease is generally added to the threaded raceway and the housing space where the nut is installed, and the lubricating oil is injected into the space of the nut through the oil hole on the housing. The grease on the ball screw should be replaced every six months, the old grease on the screw should be cleaned, and new grease should be applied. The ball screw pair lubricated with lubricating oil can be oiled once before each machine tool work.
(3) Protect the ball screw pair. The ball screw pair should be protected from dust or chips and closed, such as spiral spring steel belt casing, telescopic casing or folding casing. When installing, connect one end of the protective cover to the end surface of the ball nut, and fix the other end to the support seat of the ball screw.
If the ball screw is in a hidden position, a sealing ring can be used for protection, and the sealing ring can be installed on both ends of the nut. The contact seal ring has a good dust-proof effect, but due to the contact pressure, the friction torque is slightly increased. Non-contact sealing can avoid friction torque, but the dustproof effect is slightly worse. Avoid hitting the protective device when working, and replace the protective device in time if it is damaged.
(4) Regularly check the supporting bearings. Regularly check whether the connection between the screw support and the bed is loose, and whether the support bearing is damaged. If there is any problem, fasten the loose part and replace the supporting bearing in time.