I'm with Gresp on this. This patent isn't about that gearbox. The gearbox is mentioned, but there's also a lot of detail about a roller chain, and they've included information about an IGH, as shown on a traditional omafiets.
The guts of that gearbox aren't even important--from page 34, (emphasis mine):
"[ 0078 ] As seen in FIG . 1 , the bicycle internal transmission
device 12 is mounted to the bicycle frame B3 . The bicycle
internal transmission device 12 is configured to transmit the
pedaling force to the rear wheel B62 at a variable speed
stage . The variable speed stage includes speed stages dif
ferent from each other . The bicycle internal transmission
device 12 can have at least two speed stages . Furthermore ,
the bicycle internal transmission device 12 can have a
continuously variable speed stage if needed and / or desired ."
It's about some kind of "sliding components", maybe specially textured (at a micro scale, I'd think). The important stuff is all way down at the end:
"What is claimed is :
1 . A sliding component comprising :
a base member ;
a plated layer including a metallic material , the plated
layer being disposed on the base member ; and
a lubricant agent including a fatty acid containing a
carboxyl group , the lubricant agent contacting the
plated layer .
2 . The sliding component according to claim 1 , wherein
the fatty acid includes an olein acid .
3 . The sliding component according to claim 1 , wherein
the fatty acid includes a stearic acid .
4 . The sliding component according to claim 1 , wherein
the fatty acid includes a linoleic acid .
5 . The sliding component according to claim 1 , wherein
the plated layer has Vickers hardness ranging from 10 HV
to 200 HV .
6 . The sliding component according to claim 1 , wherein
the plated layer includes tin .
..."
So, apparently, they've done some kind of work developing combinations of surface coatings, lubricants, and possibly surface textures, to the end of reducing friction.