Hi Everyone,
I’m replacing the bearings on my Hitachi P20SB and wanted to ask if a contact or non-contact seal is the most suitable option. Both have NBR seals on both sides, however, the non-contact seal doesn’t contact the bearings inner race unlike the contact option. I understand that the contact option provides better sealing at the expense of friction, speed and heat. I’m concerned that the extra heat generated by the contact seal might damage my planer as it’s only plastic. Plus the planers no load RPM is very close to the bearings limit speed reference.
Hi John,
I would say the non contact bearings are the recommended type as the speed will most likely be very close to the limit of a rubber seal. The non contact seal is designed to keep out dust but not moisture. As a planer is unlikely to see moisture the non contact type are fine.