V-shaped sealing ring structure

The purpose of the clamping ring is to provide an initial compression to the V-seal, ensuring full contact with the sealed surface and allowing for adjustable compression of the V-seal. The V-seal assembly consists of three components: the support ring, the seal, and the clamping ring. The standard included angle for the V-seal is 90°, with 60° also used in special applications. The support ring is a crucial component for supporting the V-seal, featuring a thick and sturdy cross-section, precise dimensions, and a concave angle that matches or slightly exceeds the V-seal's (90°) angle, ensuring stable placement of the seal.

Sealing Principle:

In its free state, the outer diameter of the V-seal's lip is greater than the inner diameter of the filling cavity, and the inner diameter of the lip is smaller than the outer diameter of the piston rod. This results in some deformation upon assembly. Due to the support ring's action, this deformation occurs only at the tip of the lip, creating pressure at the contact points even without clamping force. Thanks to the "self-sealing" feature of the lip, as the working pressure of the medium increases, the tip of the lip changes its contact shape and increases the contact stress, making the lip fit more tightly against the sealed surface, achieving the sealing function. The contact stress increases correspondingly with the rise in medium pressure.

Sealing characteristics:

V-ring materials commonly use nitrile rubber and chloroprene rubber; natural rubber is used for sealing against water and air, butyl rubber for non-flammable hydraulic oils and phosphate-based hydraulic oils. Chlorine rubber is used for various chemicals and high temperatures. Polyurethane rubber is used when wear resistance is required. Fabric-reinforced rubber is also a common material for V-rings, characterized by enhancing the stiffness and strength of the seal, preventing extrusion and gasket bite, making them suitable for high pressure applications. During wear, the rubber wears before the fabric, ensuring that the wear on the entire sealing surface is uniform while friction remains relatively unchanged. However, the lips of the fabric-reinforced rubber seals are prone to scraping off the oil film on the sliding surface, thus having poor lubricity. The pressure ring and support ring are generally made from harder rubber sheet, and the support ring is sometimes made from hard plastic.