What are the main reasons for mechanical seal leakage of gea

49. What are the main reasons for the mechanical seal leakage of the gear oil pump?

What are the main factors affecting the sealing?

Answer: 1) the quality of the seal itself, 2) the process operating conditions, 3) the accuracy of the assembly and installation, 4) the accuracy of the host itself, 5) the sealing auxiliary system answer: 1) the sealing end face between the moving ring and the static ring and there is too much wear, the design of the load coefficient is not reasonable, so that the sealing end face crack, deformation, damage and other phenomena.

2) Several auxiliary sealing rings have defects or defects caused by improper assembly, and the selection of auxiliary sealing rings is not suitable for working medium.

3) spring preloading force

 

Not enough or after a long time of operation, fracture, corrosion, relaxation, coking, and the working medium of suspended particles or crystals accumulated for a long time blocked in the spring gap, resulting in spring failure, compensation seal ring can not float, leakage;

4) Due to the large deviation of the verticality between the sealing end face of the dynamic and static rings and the center line of the shaft, the sealing end face is not tightly glued, resulting in leakage;

5) by

 

The axial channeling momentum of the shaft is large, and the related fittings at the sealing place are matched or the quality is not good, and the leakage phenomenon is easy to occur.

 

50. On what basis are the materials of mechanical seal friction pairs selected?

Answer: should be selected according to the nature of the medium, working pressure, temperature, sliding speed and other factors, sometimes even consider the ability to withstand a short time of dry friction when starting or liquid film damage.

 

51. What are the effective ways of labyrinth seal to increase the resistance of the medium?

Answer: 1) reduce the clearance, 2) strengthen the vortex, 3) increase the number of seal teeth, 4) try to convert the kinetic energy of the airflow into heat energy

 

52. How does the floating ring seal work?

A: Floating ring seal is based on the throttling effect generated in the narrow gap between the shaft and the floating ring, and the sealing oil higher than the gas pressure is injected into the gap to achieve the purpose of sealing the gas.

 

53. What is the reason for the increased leakage of floating ring seal?

A: 1) The floating ring will be worn normally after long-term use, which will increase the gap;

2) The bushing surface of the floating ring hole is rough, the accuracy is low, and the short time wear increases the clearance;

3) improper assembly causes deflection, the central attachment falls off, so that the oil flows out from other gaps, and the leak increases;

 

54. What is the function of the oil trap?

How to measure and adjust the gap of oil gauge?

Answer: 1) the function of the oil guard is to prevent the bearing lubricating oil from flowing to the outside of the bearing along the journal. There are two installation positions of the oil guard: one is on the bearing seat, the other is on the bearing bush;

2) The gap of the oil gauge can be measured with a gauge when the oil gauge is disassembled or assembled.

For the bearing bush in the oil gap can be appropriately relaxed,

 

In the face of the oil gap on the bearing seat, the general requirements are 0.05-0.10mm for the lower part, 0.10-0.20mm for both sides, and 0.20-0.25mm for the upper part.

 

55. What are the factors that affect the maze seal?

Answer: 1) the radial clearance is too large, or the clearance of the newly replaced air seal ring is too small;

2) The sealing piece or air seal ring, between the teeth because of wear and tear become blunt, or because of long-term wear and heat after deformation, causing damage and can not be used;

3) after long-term use, the spring relaxes and deforms, so that the air seal ring can not be in place. After operation, the precipitation and accumulation of dust and dirt is

 

Sealed medium pressure is lower than the working medium pressure or pressure instability.

 

56. What are the common types of dynamic seals?

Answer: bowl seal, swelling ring seal, spiral seal, pneumatic seal, hydraulic seal, centrifugal seal, packing seal, labyrinth seal, mechanical seal, etc.