CALCULATING END-SEAL CHARACTERISTICS AND CONTACT SURFACE SHAPES

摘要

While one can avoid affecting the flat shape of the sealing surfaces in an end seal during installation, that form is often disrupted by the pressure of the ring and the heat produced in the relative displacement of the sealing surfaces. It is familiar that the contact surfaces of these sealing rings in end seals lose their original flat form during operation. The actual form of the contact surface under loading conditions has so far been debatable, since there are no experimental data, and the shape of the surfaces in the end junction is closely related to the calculation models used to derive the carrying capacity and sealing capacity of such a seal. While existing methods of calculating end seal ring deformation in relation to pressure in the medium are fairly accurate, there is uncertainty over the effects of temperature there on the deformation, so we do not have highly reliable knowledge on the actual contact surface, and some experts consider that the thermal deformations of these end seals for liquids exceed those due to the forces. Here I consider the following aspects: 1. determination of the thermal and other deformations in highly loaded end seals; 2. the solution for particular conditions of work are to be used to determine the form of the sealing slot in the mobile joint; 3. developments of a method of calculation for end seals. I consider a seal of hydrodynamic type undergoing viability tests and working life assessment. The limiting loading parameters were as follows: pressure difference across the seal up to 10 MPa, and sliding speed in the pair 19 m/sec (rotor speed 50 sec~(-1)). Untreated tap water was used as the medium.