Protection Of Ball Screws

The ball screw pair can be lubricated to improve wear resistance and transmission efficiency. Lubricants are divided into two categories: lubricating oils and greases. Lubricating oil, No. 90-180 turbine oil or No. 140 spindle oil. The grease can be lithium-based grease. Grease is added to the threaded raceway and the housing space where the nut is installed, and the lubricating oil is injected into the nut space through the oil hole on the housing.

Ball screw pairs and other rolling friction transmission elements can be considered to work with almost no wear as long as the entry of abrasive particles and chemically active substances is avoided. However, if dirt falls on the raceway, or dirty lubricating oil is used, it will not only prevent the normal operation of the balls, but also increase the wear rapidly.

Usually, a felt ring is used to seal the nut pair. The thickness of the felt ring is 2 to 3 times of the pitch, and the inner hole is made into the shape of a thread, so that it tightly wraps the lead screw and fits into the grooves at both ends of the nut or sleeve. inside the hole. In addition to soft felt, the sealing ring can also be made of oil-resistant rubber or nylon. Since the sealing ring and the screw are in direct contact, the dustproof effect is better, but the frictional resistance torque of the ball screw nut pair is also increased. In order to avoid this frictional resistance torque, a non-contact labyrinth seal made of hard plastic can be used, and the inner hole is made in the opposite shape to the screw thread raceway, and there is a certain gap.

For exposed lead screws, protective covers in the form of spiral steel belts, telescopic sleeves, conical sleeves, and folded plastic or artificial leather are generally used to prevent dust and abrasive particles from adhering to the surface of the lead screw. In addition to being similar to the protective cover of the guide rail, one end of these protective covers is connected to the end face of the ball nut, and the other end is fixed on the bearing seat of the ball screw. This will make it more solid.