Simmerring and Rotary Seals GlobalCatalog_FNST

Technical Principles | Informations Techniques Informaciones Técnicas | Princípios técnicos 31 TechnicalPrinciples|InformationsTechniques InformacionesTécnicas|Princípiostécnicos Excessively high pressure must not be permitted to build up in the unit. A pressure that is too high shortens the service life. The housing is to be ventilated if there is not sufficient room available for expansion. Pressing into the housing We recommend pressing into the bore with the aid of mechanical, pneumatic or hydraulic insertion equipment and an assembly press (→ Fig. 8). The axis for the assembly press is the axis of the bore. An inclined position is not permitted (→ Fig. 10). A metal face (assembly press housing) must be present (→ Fig. 8, → Fig. 9). If this is not possible, a metal face must be provided on the underside of the fitting equipment. The press-in force, particularly when installing from the back side, must be applied as near as possible to the outside diameter of the seal. The diameter of the assembly press must be chosen to suit (→ Fig. 8, → Fig. 9). If necessary, please inquire. If the diameter of the assembly press is too small, there is a risk that the seal will bend (→ Fig. 11). A mounting plate must be used for hammer assembly (common with large seals) (→ Fig. 12). In case of an excessively high load on a specific point during installation, there is a risk that the seal will be bent (→ Fig. 10). When bonding the seal in the housing, the adhesive may not under any circumstances come into contact with the shaft or the sealing lip. Installing the shaft AA When fitting over a keyway on the shaft, the groove on the shaft must be covered with a protective cap (→ Fig. 14), to avoid damage to the sealing lip AA Wall thickness of protective cap < 0,5 mm (0.02 in) to avoid over-stretching the sealing lip AA When fitting part of a unit with a pre-assembled seal, a centering pin should be used to avoid tilting, which would damage the sealing lip AA When fitting a long shaft, the use of a guide plate to guide the shaft parallel is recommended to avoid deformation of the sealing lip. AA If parts of the unit with a press fitting and the same nominal diameter are pushed over the contact area, the diameter of the contact area is to be reduced by 0,2 mm (0.008 in) to avoid damage to the contact area. The sealing function is not impaired by the reduction of the diameter. Installation of Simmerring with sealing lip made from PTFE The same recommendations for Simmerring with ­elastomer sealing lip according to DIN 3760 apply to installing Simmer- ring with PTFE sealing lip. It is important that the PTFE sealing lip is not damaged, espe- cially when assembling the front side in the direction of the installation. The use of a pilot shaft with a chamfer angle of 10° … 15° (→ Fig. 14) is recommended. Replacement of Simmerring New seals must always be installed during the repair or overhaul of a unit. The sealing lip of the new seal must not be positioned over the old contact surface. Suitable measures for achieving this situation are: AA Installation of spacer rings (→ Fig. 15) AA replacement of shaft sleeves or selection of different press-in depth in the bore. Wall thickness max. 0,5 mm (0.02 in) Fig. 11  Diameter of assembly press too small WRONG! Fig. 12  Permissible hammer assembly USE MOUNTING PLATE! Fig. 13  Installation over a shaft with a keyway (also for a sharp-edged shoulder on shaft)

Pages Overview