The Production Process for a Labyrinth Seal
Labyrinth Seals (a.k.a. Leidenfrost Seals or Mini Maze) have maze-like peaks that form between the inner and outer rings. This unique design keeps contaminants out and ensures the inner and outer rings of the seal stay inseparable.
Production process for a Labyrinth Seal:
- The steel inner ring is surrounded by molded aluminum.
- Next, it’s milled to the design specs of a type “L” or “M” Labyrinth Seal.
- While the seal is turning, radial pressure is strategically applied.
- Radial expansion causes maze-like peaks to form between the inner and outer rings.
The number of peaks included in the seal depends on the size of the labyrinth seal. But all of our GMN labyrinth seals have at least three maze-like peaks.
The Way a Labyrinth Seal… Seals
The protection a Labyrinth Seal provides is based on:
- The geometric shape of the seal
- The maze-like labyrinth created between the inner and outer rings
The maze-like labyrinth is great because contaminants or liquids have trouble making it through the seal’s maze to the bearing.
Then the centrifugal force, from the rotation of the machine, throws contaminants out of the seal. At higher rotational speeds an air barrier is formed inside the seal which also pushes out contamination.
This three-way approach offers the precision bearing a great amount of protection.
However, this doesn’t protect against liquid submersion or a pressure gradient between both sides of the seal. Pressure gradients may be reduced but not be sealed.
Limiting Speed Based on Size
Labyrinth seals are installed on a shaft with a certain type of press fit. Due to centrifugal forces the inner ring could lift off of the shaft. The diagram below shows the speed limit you should adhere to based on the size of the labyrinth seal.
Common Problems & Solutions When Trying to Optimize Sealing Efficiency
Problem: Liquid splashes directly on to the sealing gap
Solution: Place a disc in front of the seal, making sure it rotates with the shaft. Check to make sure there is enough distance between the seal and the disc to allow the splashed liquid to flow freely back to where it came, without backing up in the front of the seal.
Problem: Large quantities of liquids facing the seal.
Solution: First start by preparing drain areas or drain holes in front of the seal to avoid liquid backup. Next you will want to use our GMN Type M Labyrinth Seal with sufficient drain groove dimensions and a drain hole.
Using an air porche system with a Type M Seal may improve the seal efficiency by blowing the penetrating liquid out of the system.
Problem: Very large amount of liquids – pressure gradient
Solution: Solution: Try to prepare enough space for the sealing assembly, allow two labyrinth seals side-by-side with a parallel spacer of at least 0.5mm width in between. Penetrating liquids may calm down and may be drained back by an annular groove and an a drain hole placed in between the two seals.
