hightech ceram Dr. Steinmann + Partner GmbH

Pumps are machines used to convey various liquids, liquid-solid mixtures, pastes and gas-containing liquids. Depending on the medium, all components that come into contact with the medium are exposed to corrosion and wear, especially if components such as mechanical seal rings in mechanical seals, sliding bearings and shaft sleeves rub against each other. The mechanical and chemical resistance of some ceramics allows the bearing to be positioned, for example, in the medium to be pumped, which is thus also responsible for lubrication. Mechanical seals in pumps (there are both radial and axial seals) seal the rotating shaft against the pump housing. The main components are two seal rings that slide on each other, one ring being fixed in the housing and the other on the shaft and being pressed against the fixed ring by a spring. The partners sliding against each other usually have flat ground surfaces. Seal rings are mainly made of carbon-graphite materials, metal or ceramics. However, there are also seal rings made of resin-bonded carbon or plastic. The surrounding medium creates a lubricating film in the sealing gap between the seal faces, which prevents the seal from running dry. Mechanical seals are used in a hard-hard pairing or hard-soft pairing, depending on the medium. Solid-laden fluids are abrasive and hard/hard pairings are advantageous. Pumps are constantly supplied with the medium to be pumped (lubricant), which can be supplied via lubrication pockets (hydrostatic bearings) and therefore run almost frictionless. Hydrodynamic bearings, on the other hand, operate without lubrication pockets. Here there is increased wear during start-up and shut-down due to sliding resistance caused by mixed friction. Plain bearings are used in hermetically sealed pumps, the magnetic pumps, which are operated by a permanent magnetic drive system. The permanent magnets are separated by a non-magnetic can, which hermetically separates the product space filled with the medium from the environment.