Papers by Keyword: Mechanical Seals

Abstract: Surface texturing is more and more frequently used in modern machines to attain such aims as lubrication enhancement, heat flow intensification and micro-flow stimulation. The development of technologies using concentrated energy flux, e.g. laser technology, has contributed to it. Pumps contain a lot of elements where textured surfaces can be used. The article concentrates on the selection of operating parameters of a picoseconds laser used to produce texturing in elements made of steel, bronze and silicon carbide.

Abstract: Mechanical face seals are usually described as contacting seals because their faces are in partial contact during static conditions. However, many experiments demonstrated that this contact is not maintained during operation. Indeed a full fluid film can separate the seal surfaces leading to lower friction and wear. In this paper, the mechanisms of lubrication taking place at the seal interface are reviewed and analyzed through simulations and experiments. It is shown that several lubrication regimes can be experienced, depending on the operating conditions and on the seal design. At low speed values the lubrication regime is mixed and turns to hydrodynamic lubrication regime when the speed is increased. At higher rotation velocity, the dissipated power generates thermal gradients and leads to thermally controlled lubrication regime. The transition between the lubrication regimes is also discussed and dimensionless parameters controlling the transition are proposed.

Abstract: A method for measuring the thickness of liquid-lubricated film of end face and detecting the friction of end face of mechanical seals has been presented in this article. Eddy current sensors installed on the inner ring embedded in the stationary ring of mechanical seals are used to measure the thickness of the liquid-lubricated film. Acoustic emission sensor placed on the stationary ring base is used to detect the friction of end face. The micro scope condition monitoring of end face is of importance to ensure mechanical seals run normally. With a set of tests, the results demonstrate that the method is effective.