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Labyrinth seal (bearing seal)
- Thread starter smaty
- Start date
Mendit
Mechanical
- Sep 12, 2003
- 95
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Labyrinth seals, types are many and varied.
Fixed, by means of spigot locating to the bearing housing.
This is the most ineffective, often has a larger gap at the top of the shaft. Adjsutable, these are loose spigot fitted and loose bolted, they are minimal clearance to the shaft as small as 0.008 per side.
Floating, as used in the DIN standard bearings, (Renk) the seal is light weight plastic type materials (Ryton or Peek)
These typically only have 0.002 to 0.004 total clearance. They are not bolted to the housing but retained in a locating groove with a garter spring and anti rotation pin. Most seals are made of a soft forgiving materials to prevent shaft wear in the event of bearing failures.
Fixed, by means of spigot locating to the bearing housing.
This is the most ineffective, often has a larger gap at the top of the shaft. Adjsutable, these are loose spigot fitted and loose bolted, they are minimal clearance to the shaft as small as 0.008 per side.
Floating, as used in the DIN standard bearings, (Renk) the seal is light weight plastic type materials (Ryton or Peek)
These typically only have 0.002 to 0.004 total clearance. They are not bolted to the housing but retained in a locating groove with a garter spring and anti rotation pin. Most seals are made of a soft forgiving materials to prevent shaft wear in the event of bearing failures.
- Thread starter
- #3
A labyrinth seal is a non-contacting circumferential seal utilizing a tortured path for flow between the stationary and rotating parts. The design utilizes a series of pressure drops to reduce the leakage.
The problem with these types of seals is that they do not seal in a "flooded" application. Oil levels must be lower than the seal or it will eventually weep through the seal.
Clearances between the housing and the seal vary with the manufacturer. Some utilize a press fit, while others rely on o-rings to retain it in the housing.
Clearances between the internal parts of the seal vary from manufacturer as well. Generally, the closer the clearances, the better the seal tends to exclude contamination. However, the close clearance limits the amount of relative movement that the seal can handle.
The problem with these types of seals is that they do not seal in a "flooded" application. Oil levels must be lower than the seal or it will eventually weep through the seal.
Clearances between the housing and the seal vary with the manufacturer. Some utilize a press fit, while others rely on o-rings to retain it in the housing.
Clearances between the internal parts of the seal vary from manufacturer as well. Generally, the closer the clearances, the better the seal tends to exclude contamination. However, the close clearance limits the amount of relative movement that the seal can handle.
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