Positioning method for the shaft sleeve of modular mechanical seals
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What are the common positioning methods for modular mechanical seal shaft sleeves? Screw jacks and clamping rings are used – what are their advantages and disadvantages?
The set screw is also very important; it is the key component used to overcome the friction between the rotating and stationary rings. The head of the set screw in JE3l8 features spiral grooves, which prevent the screw from slipping or loosening on the shaft. The 318i is a wafer-shaped static ring gland. It has 2 gland bolts that can be replaced directly. It was originally sealed with sealing packers, and no modifications to the original equipment are required. When flushing is required for the mechanical seal, a gland made of 318A with flushing holes, along with 4 gland bolts, can be used, and these components meet API standard requirements.
The easy loosening of the set screw can lead to eccentricity of the shaft sleeve! The clamping ring is quite tight, ensuring good concentricity between the sleeve and the shaft!
The slotted positioning method is better for mechanical seals, but it reduces the strength of the shaft
We mostly use key drives!
The drive screw tends to loosen； The locking screw can cause the shaft sleeve and the shaft to be out of alignment, which in turn leads to tilting of the sealing dynamic and static rings ； When tightening screws with pointed tips, point-like damage is formed on the shaft, while tightening screws with flat tips results in circular damage on the shaft. The sleeve gets stuck when pulled out of the shaft. Holding the ring tightly can prevent the above problems.
Fixed with set screws, they tend to leave dents on the shaft, and such tapered set screws need to be replaced after just one or two uses. The press-fitting type has virtually no damage to the shaft alignment, but its axial length is large, so it is necessary to consider whether there is sufficient space.