The labyrinth seals are produced in a special developed manufacturing process based on the patent of Mr. Leidenfrost.
The production process guarantees the absolute identity of the profiles of inner and outer ring. Both rings are inseparable and not to be disassembled. We use different profiles for different seal sizes with at least three peaks. The concrete geometry is depending on the size.
Inner ring: steel
Outer ring: aluminium - GD AlSi 12
For applications, which get in contact with aggressive or corrosive media there are certain possibilities to manufacture the seals from resistant materials, i.e. the inner ring made of stainless steel.
Seal effect bases on:
The basic principle of a labyrinth seal is based on the geometric shape of the labyrinth seals which causes some turns of the contaminant on its way to penetrate the seal. The major factor for the efficiency of a non-contact seal is the centrifugal force caused by rotation and applied to the contaminant to throw it radial away before penetrating the seal. At higher peripheral speed an air barrier is built inside the seal keeping different types of contamination (e.g. dust or liquids) out.
There is no chance for a labyrinth seal to protect against higher liquid levels and against any pressure gradient between both sides of the seals. Pressure gradients may be reduced but not be sealed.
The "M"-type seal incorporates drain grooves at the outer ring surface to centrifuge eventually penetrating liquids out into an annular groove of the customers' part to be led to a drain hole on the bottom and led back to the outside or to the reservoir depending on application.
Care should be taken for the sufficient cross section of the groove and the drain hole to avoid any backup of the liquid.
The grooves may also be used to apply an air cushion in the gap activated from external air pressure.
The catalogue information on axial end play means the total axial movement of the seals inner and outer ring in relation to each other; from one end position to the other.
Normally the seals should be installed in flush position - thus the axial allowance would be half the value in either direction.
Axial (Sa) and radial (Sr) clearance are almost in the same size. They interfere to each other.
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GMN labyrinth seals are pressed onto the shaft with a certain press fit.
Due to centrifugal forces the inner ring could lift off of the shaft.
The diagram below shows the speed limit depending on the size.
Without any additional device our Non-Contact Seals are providing Ingress Protection (IP) category IP44 according to DIN EN 60 529 (IEC 60 529).
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