A V-ring consists of a seal body, a flexible, conical-shaped sealing lip and an integral, resilient “hinge” (fig 1). It is stretched and installed directly on the shaft, where it is held in place by the inherent tension of the seal body. It rotates with the shaft and seals axially against a stationary counterface.
The counterface can be the end face of a bearing, a washer, stamping, bearing housing, or even the metal case of a radial shaft seal.
The flexible sealing lip applies contact pressure against the counterface that is relatively low but sufficient enough to maintain the sealing function. The light contact pressure even enables the seal to run dry in some low-speed applications resulting in insignificant torque drag or heat build-up. The contact pressure varies with the fitted width.
The flexible lip and hinge provide adequate sealing even in applications with considerable end play and shaft misalignment.
As a result of centrifugal force, the contact pressure of the lip decreases as speed increases. This means that friction losses and heat are kept to a minimum, resulting in improved wear resistance and extended service life. The power loss reaches its maximum at a shaft speed of approximately 12 m/s (2 360 ft/min) and is thereafter gradually reduced up to 20 m/s (3 900 ft/min), where it will decrease to zero. The V-ring then serves as a gap-type seal and deflector.