- Joined
- Dec 20, 2012
- Messages
- 9,422
Sorry, I was leaving the house when I wrote what I wrote and I should have specified an oil bath. Let me explain.
A friend had an old lathe, I think it was a Clausing but I'm not sure. It had shielded bearings in the gearbox and he wanted to change them to sealed bearings. I didn't see why he couldn't and encouraged him to switch them but he queried SKF about it first. These bearings apparently live in an oil bath that gets hot and the concern he had was that this would thin the grease in a sealed bearing and reduce bearing life. SKF agreed with him for this application - low speed, oil bath, heat. I learned something that day and was glad he didn't listen to me. SKF also mentioned that oil baths in lathes can get hot and when they cool, water can condense - never thought of that one before. Water = rust, so they recommended he change oil on a regular basis (annually).
Ran home and opened up the gear box on my Emco lathe and found open FAG bearings - no shields, no seals - but no rust because I'm anal about gear oil changes annually.
Apparently, there is a great deal of controversy about which bearings to use in a gear box. Some guys use sealed, some shielded and some use open bearings. I don't know who is right but I do know I was wrong on this occasion.
A friend had an old lathe, I think it was a Clausing but I'm not sure. It had shielded bearings in the gearbox and he wanted to change them to sealed bearings. I didn't see why he couldn't and encouraged him to switch them but he queried SKF about it first. These bearings apparently live in an oil bath that gets hot and the concern he had was that this would thin the grease in a sealed bearing and reduce bearing life. SKF agreed with him for this application - low speed, oil bath, heat. I learned something that day and was glad he didn't listen to me. SKF also mentioned that oil baths in lathes can get hot and when they cool, water can condense - never thought of that one before. Water = rust, so they recommended he change oil on a regular basis (annually).
Ran home and opened up the gear box on my Emco lathe and found open FAG bearings - no shields, no seals - but no rust because I'm anal about gear oil changes annually.
Apparently, there is a great deal of controversy about which bearings to use in a gear box. Some guys use sealed, some shielded and some use open bearings. I don't know who is right but I do know I was wrong on this occasion.