Our Bearings / Technical Parameters / Shields & Seals

Shields and Seals

Closures, more commonly known as shields and seals are used to protect the internal parts of the bearing against dust, liquid, and gaseous particle contamination. The shields help contain the lubricant in the bearing but are not designed to keep out liquid and gaseous contamination. We manufacture our own shields at WIB to the precise tolerance to minimize the opening gap, thereby offering great grease retention and longer life. On the other hand, seals are designed to keep various types of contamination out, keeping the grease clear of foreign particles and extending the bearing life.

Shields

Pressed steel shields (described as Z shield in the nomenclature) are pressed into the bearing and offer some level of protection it against dust and solid particles ingress. Non-contact seals (RSF), constructed of mild steel and rubber material, provide similar advantages as shields, as they have no influence on the friction torque and on the admissible limiting speeds, but do offer enhanced protection.

Contact Seals

Contact seals (RSI, RSR, RSV, RSL, RST) offer better protection against dust, liquid, and gaseous particle contamination. These seals, which are manufactured using synthetic rubber and a zinc-steel core are pressed into the bearings outer ring. The friction at the seal lip on the inner ring increases the drag torque and slightly reduces the admissible limiting speeds. Our application engineers can work with you to determine the right seal architecture and material for your application. If your application goes being common industry designs, we can work to tailor a custom seal design to meet the most demanding needs of your application.

Nitrile seals are limited to a minimum-maximum temperature range of (-30 to +125°C).

For high temperature applications, Viton® seals are commonly used. They can withstand temperatures of up to +230°C.

Seal Design and Nomenclature

SHIELD TYPE	SPECIAL FEATURES		APPLICATIONS
Z	Z	- Mild Steel	Low torque High speed High temperature
	ZB	- Mild Steel, blackened
	ZM	- Brass Shield
	ZS	- Copper-Nick - Stainless Steel
	ZP	- Plastics
	Seal without contact Color blue	Low torque High speed Higher tightness than with a Z shield
	Non-rubbing RSR seal	Low torque High speed Higher tightness than with a Z shield
	Seal Standard color black	Designed to varying degrees of contact pressure	Low torque High speed
RSF	Contactless seal Standard color blue		Low torque High speed
RSI	Contactless or low-contact seal		Low torque High speed Prevents water ingress to a higher degree than Z shields
CONTACT SEALS
RSR	Contact seal providing robust protection from outside contaminants Standard color black		Standard WIB seal design
RSV	VITON® seals providing high temperature stability Standard color orange		Max operating temperature is 230°C.
RST	Special seal with tangential contact on a chamfer of the inner ring		Robust protection, especially for extreme environments.
RSL	Special seal with dual point contact on the inner ring groove.		Superior protection, in all environments.

SHIELD COMBINATIONS	DESIGNATION
Open	No seals applied on bearing
One Side	Z, RSR Same for RSF, RSI, RSV, RST, RSL and others
Both Sides (Identical)	Z, RSR Same for RSF, RSI, RSV, RST, RSL and others
Shield Combinations	Z RSR, RSF RSR All other possible combinations to the extent they are feasible

Shields and Seals

Shields

Contact Seals

Seal Design and Nomenclature

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