pump shaft axial channeling large

　　The sealing surface of the mechanical seal to have a certain specific pressure, so as to play a role in sealing, which requires the mechanical seal the spring to have a certain amount of compression to the sealing end face of a thrust, spins up the sealing surface sealing the required ratio pressure. In order to guarantee a specific pressure, mechanical seal requirements of the pump shaft can not have too much channeling, and generally to ensure that less than 0.5 mm. But in the actual design which, due to improper design, often shaft produces a great amount of channeling is very detrimental to the use of the mechanical seal. This phenomenon often appears in the multi-stage centrifugal pumps, especially in the the pump startup process, channeling than larger.

　　Balance disc automatically change work balance disc and balance ring between the axial gap b, thereby changing the pressure on both sides around the balancing disc to produce an axial force in the opposite direction the biasing force to balance the axial force.Due to the fluctuations in the rotor ran the inertia and transient pump conditions, the operation of the rotor is not stationary at a certain axial equilibrium position. The balance disc always in the shifting of the state of the left and right. The balance disc normal work the axial channeling amount only 0105 ~ 011 mm, to meet the mechanical seal requirements allow the the axial channeling amount of 015 mm, but the balance disc the pump is started, stop, drastic changes in the working conditions axial channeling amount of possible greatly exceeds the mechanical seal allowed axial channeling amount of.

　　Pump after a long-running, balance disc and balance ring friction and wear, gap b increases, mechanical seal axial channeling amount of increasing. The suction side of the sealing surface of the pressing force due to the axial force increases, the sealing surface wear is intensified, until the sealing surface is damaged, the loss of sealing effect. The discharge side of the mechanical seal, with the balance the wear of the disc, the axial direction of the rotor member channeling greater than the sealing requirements of the amount of axial channeling, the pressing force of the sealing surface is reduced to reach the sealing requirements, and ultimately to the pump on both sides All of the mechanical seal to lose sealing effect.