Yes, that's right. The motor, gearbox and hydraulic pump sit bathed in the reservoir of non-conductive hydraulic oil.
This circulating hydraulic oil also serves to cool the motor.
This assembly is cylindrical, some 6" in diameter and several feet long, to fit down a wellbore.
The top end of the reservoir has a floating equalizing piston, the other side is open to the hydrostatic pressure of the wellbore.
None of the components 'see' any pressure this way; it's all just ambient at the current hydrostatic, but at a very high absolute value.
The bearings are nothing special, pressure-wise.
It means that for example when we attempt to extend probes out from the instrument using hydraulic pressure, we are not pushing against a huge differential between an atmospheric internal pressure and a huge external hydrostatic. It's all very clever. Until the equalizing piston jams as you pull the instrument out of the hole, and you end up with a severely over-pressured hydraulic reservoir back on the surface...