Performance of the ferrofluid-spiral labyrinth combined seal for sealing liquid

When the ferrofluid is used to seal liquid, the relative movement between the ferrofluid and the sealed liquid causes the stability problem of their interface, and the sealing performance is poor. However, the spiral and the spiral sleeve of the spiral labyrinth seal interact with the sealed liquid to make it reverse flow to prevent leakage when the shaft rotates. In order to improve the performance of rotary ferrofluid seal, the ferrofluid-spiral combined seal structure and the ferrofluid-spiral labyrinth combined seal structure are designed. A combined seal test-bench is built. The pressure resistance experiments and seal life experiments of ferrofluid seal and two type of combined seals are carried out. The theoretical and experimental results show that the sealing performance of the ferrofluid-spiral labyrinth combined seal is better than that of the ferrofluid-spiral combined seal ferrofluid seal. Ferrofluid-spiral labyrinth combined seal can not only solve the failure problem of ferrofluid seal at high speed, but also solve the leakage problem of spiral seal at shutdown and low speed, so as to achieve a more stable sealing effect at different speeds. The higher the speed is, the better its sealing performance is.