Reasons for the deformation of the sealing surface of the high viscosity melt gear pump and the rupt

A professional melt gear pump manufacturer with decades of R&D and production experience and a professional after-sales service team. For problems that occur during the use of the melt gear pump, the Batte melt pump manufacturer can solve the problem for the user in time and reduce the user’s downtime . Below, the Batte manufacturer analyzes and interprets the specific reasons for the deformation of the sealing surface of the melt gear pump and the fracture of the bellows.

1. Reasons for the deformation of the sealing surface of the melt gear pump

The deformation of the sealing surface is manifested by uneven wear on the end surface of the moving ring seal, large wear near the inner diameter, narrow wear scars, and serious linear contact. The main reason for the deformation of the sealing surface is improper selection of the ring seat material, and the linear expansion coefficient is too large.

For the seal ring and seal seat of high viscosity gear metering melt pump, the inlaid structure should be adopted, and the interference fit should be adopted. If the interference is too large, the seal ring will deform or even break under the action of larger extrusion stress; If the amount is too small, the seal will easily loosen under high temperature. The linear expansion coefficient of the ring seat material 316 L stainless steel is 2-3 times that of impregnated PTFE resin. The interference between the ring seat and the sealing ring is 0.25 mm. Under the working temperature, the matching part of the sealing ring and the ring seat cannot Synchronous expansion and contraction, the amount of interference changes, and the contact stress also changes, which causes the seal to deform.

2. Reasons for the rupture of the bellows of the melt gear pump

The rupture of the bellows is the fatigue failure caused by excessive elongation or distortion during tension. The reasons for the excessive elongation or distortion of the melt gear pump include:

(1) the misalignment of the slurry pump and the motor coupling, the bending of the pump shaft, the damage of the bearing, the excessive axial movement, etc., which cause severe vibration;

(2) the movement, The static ring is eccentric;

(3) Resonance;

(4) Dry friction due to poor lubrication, will cause excessive frictional torque on the seal end face, which will cause the corrugated tube to twist and deform, and the cause of dry friction or semi-dry friction is due to severe evacuation and compression Too large, end-to-surface pressure is too high, etc.