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.
I have seen a few dead green melted bodies laying around a few shaping bays. Usually a result of heavy use and bad bearings. I would keep friction and heat to a minimum on a Hitachi. Your to be commended for having sense enough to change bearings before you melt the housing.
Thanks for the replies, I’m going to go for the non contact type
I need to replace bearings as well. Do you mind letting me know the part numbers and where you purchased them?
I went to my local bearing shop and asked for non contact sealed bearings. Part numbers below:
x2 6200 VV
x1 6000 VV
x1 608 VV
The part numbers vary slightly between brands but any decent bearing supplier will have crossovers
SKF would be 6200-2Z, 6000-2Z and 608-2Z for instance
NTN’s would be ZZ etc