Static seal for pump shaft

摘要

The sleeve is displaced axially along the pump shaft by an electromagnet, in one direction, and by a spring in the opposite direction. An O-ring provides a seal between the sleeve and the pump body. The end face of the sleeve has a seal which abuts a sealing face on the static component. During rotation of the pump the electromagnet is energised and maintains the seal separate from the face. The magnet is de-energised just before the pump stops or starts. The radial sealing rings act as a sliding coupling between the shaft and the seal.