See
this pic and
this diagram. The pump is at the opposite
end of the transaxle from the engine, and sends a gentle flow
of transmission fluid down the assembly of shafts where small
holes let some out into the bearings along the way as well as
the final-drive chain. It doesn't seem to go much of anywhere
else, just ensures that those parts stay lubricated. The pump
is paradoxically turned by the *ICE* shaft which passes [in
two pieces] all the way through the middle.
.
It is already pretty clear that the bearings [the majority of
which are ball or needle, so they're already very low-friction]
stay adequately lubricated over long periods of engine-off time.
The transmission fluid isn't involved in actual power transmission
like it is in a normal A/T; it's just a lubricant which is one
reason its service interval is so long. The jury is still out
on *very* longterm lubrication issues, such as when weeks on
end go by and someone's commuting to work under EV only and
avoiding even the brief warmup run by invoking EV mode early
enough and staying under 34 mph. Just one shot of ICE-run now
and again is enough to circulate some fresh fluid down the
shaft assembly.
.
There may be some other sources of fluid movement, such as being
carried up the drive chain and falling back over various gears
and parts, but how much of that happens [if at all] depends on
fluid level inside the case and possibly the slope of where the
car's sitting and/or lateral G-forces.
.
_H*
Linear Mode
