Greasing a cycloidal drive - GIF

**Altair** · Jun 22, 2023, 10:27 AM

Greasing a cycloidal drive.

Previously:

Grease applicator - GIF
Filling buckets with grease - GIFs
Drill-powered grease gun - GIF
Two stroke engine powered grease gun - GIF
Greasing angle grinders - GIF

**Toolmaker51** · Jun 22, 2023, 04:24 PM

Not having worked on a cycloidal [sp?], compared to average gear assembly, this would be excessive lube, especially that it'll run into periphery on it's own.

**nova_robotics** · Jun 22, 2023, 04:50 PM

Originally Posted by Toolmaker51

Not having worked on a cycloidal [sp?], compared to average gear assembly, this would be excessive lube, especially that it'll run into periphery on it's own.

That was my first reaction as well, but I think it might be acceptable to over-grease cycloidal/harmonic drives for a couple reasons. First they're sloooow. A normal bearing spinning quickly will create a ton of drag and heat if over greased. Cycloidals are much slower so that might not be a consideration, and everybody already expects their efficiency to be bad. Second they're generally made from two symmetrical stacks, 180 degrees out of phase. So as one side is engaging with the ring gear and grease is being squeezed out, the other side is disengaging and sucking grease in. I don't actually know what I'm talking about, but those would be my guesses. Or maybe they did just did it wrong and it'll blow up in a month.

**hemmjo** · Jun 22, 2023, 05:28 PM

There is a good video at this link showing how they work.

**Toolmaker51** · Jun 22, 2023, 08:04 PM

Originally Posted by nova_robotics

That was my first reaction as well, but I think it might be acceptable to over-grease cycloidal/harmonic drives for a couple reasons. First they're sloooow. A normal bearing spinning quickly will create a ton of drag and heat if over greased. Cycloidals are much slower so that might not be a consideration, and everybody already expects their efficiency to be bad. Second they're generally made from two symmetrical stacks, 180 degrees out of phase. So as one side is engaging with the ring gear and grease is being squeezed out, the other side is disengaging and sucking grease in. I don't actually know what I'm talking about, but those would be my guesses. Or maybe they did just did it wrong and it'll blow up in a month.

For 'not actually knowing' that description formed a really good visual image.