Non-contact seal for rolling bearings

     Commonly used non-contact seals are available in a variety of forms including gap seals, oil ring seals and labyrinth seals. Due to the presence of gaps, non-contact seals are often used for grease lubrication applications in addition to the slinger seal. In order to improve the reliability of the seal, various types of seals can be used in combination.

    Since the sealing gap of the non-contact sealing device does not cause any other friction except for the internal friction of the lubricant, the non-contact sealing does not cause wear and tear, and the use time is long and does not cause obvious Temperature rise, can be applied to places with higher speed. However, the gap of the seal should not be too large, otherwise the effect of the seal is extremely poor.

    Non-contact sealing of bearing bearing parts:

    1. Gap seal: The structure is simple and can meet the sealing requirements under general conditions. The choice of the gap e is d ≤ 50 mm, e = 0.25 ~ 0.40 mm; d > 50 mm, e = 0.25 ~ 0.6 mm.

    2. Groove sealing: After the grease is filled in the groove, the dust is difficult to invade, and there are two forms of ring groove and spiral groove. There are generally 3 ring grooves. The groove width b = 3 to 5 mm; the groove depth t = 4 to 5 mm.

    3. Labyrinth seal: When the labyrinth curve is filled with grease, the sealing effect is better than the groove seal. Labyrinth seals can be divided into radial and axial forms. Radial and axial clearance selection: d ≤ 50 mm, a = 0.20 to 0.30 mm, b = 1.0 to 1.5 mm; d = 50 to 200 mm, a = 0.30 to 0.50 mm, b = 1.5 to 2.0 mm.

    4. Oblique labyrinth seal: When the shaft deflection is large, the curved slope can swing with the center. A good sealing effect can be achieved by filling the curved road with the labyrinth seal obliquely.

    5. Stamped steel sheet labyrinth seal: Synthetic labyrinth seal composed of stamped steel sheet, the stamped steel sheet can be fitted on the shaft or the shell by the fit, without axial fastening, and the structure is simple. If the grease is filled in the curved road of the stamped steel labyrinth, it has a good sealing effect.

    6. 甩 oil ring seal: When oil lubrication, open the groove on the shaft, or install a ring, you can pull out the oil that wants to escape outward, through the oil collection chamber and oil hole on the bearing cover Flow back to the oil pool. It is also possible to install an oil ring close to the bearing, which is often used in conjunction with a gap seal.