Usually, a felt ring is used to seal the nut pair. The thickness of the felt ring is 2 to 3 times the pitch, and the inner hole is made into a threaded shape to tightly wrap the screw and fit into the groove at both ends of the nut or sleeve. 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 friction resistance torque of the ball screw nut pair is also increased. In order to avoid this frictional resistance moment, a non-contact labyrinth seal ring made of harder plastic can be used, and the inner hole is made into the opposite shape of the screw thread raceway, and a certain gap is left.
For the lead screw exposed to the outside, the protective cover in the form of spiral rigid belt, telescopic sleeve, tapered sleeve, and folding plastic or artificial leather is generally used to prevent dust and abrasive particles from adhering to the surface of the screw. Except that it is 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 supporting seat of the ball screw. This can be more solid.
