nhbb :: hitech engineering :: shield & seal types

shield & seal types

Shields and seals are used in ball bearings to retain lubricants and prevent contamination from reaching critical surfaces. NHBB manufactures a variety of closures to optimize the useful life of the bearing. Seals are generally used in high contamination environments where a positive closure is required. The use of seals will increase torque and heat generation and may affect operation speed limits. Shields provide a labyrinth barrier to contamination without affecting speed and torque.

Consideration should be given to the compatibility of retainer and shield type designs to allow for appropriate clearance.

The following chart illustrates the most common types of shields and seals:

Shield & Seal Types

Description	Type	Design	Material	Operating Temp max.
Seal—Removable	D		Buna-N Bonded to Steel Insert	Limit of 250°F
Seal—With snap wire	Q		Glass-reinforced Teflon®	600°F
Seal—Removable, noncontact	S1		Viton Bonded to Steel Insert	400°F
Shield—Removable with snap wire	Z		Stainless Steel 300 Series	600°F
Shield—Non-Removable	H		Stainless Steel 300 Series	600°F