A few years ago my wife wanted to buy the LG Roboking vacuum cleaner. The top of the line model wasn't available in Australia yet so we bought the VR6272LVM direct from South Korea via eBay.

All went well until one time after cleaning the sweeping brushes, we didn't tighten the brush screw enough which lead to sloppy engagement with the brush head, which lead to the head of the drive axle being stripped, meaning the brush doesn't turn anymore.

the brush screws into this and turns the brush with its rotation

Above, the brush screws into this head which turns the brush with its rotation. It looks hexagonal from top view down but it is rounded off at the top due to a screw that wasn't tightened enough

It looked like a professional repair was required to replace that worn axle. An email to the service center indicated that they weren't able to order parts for Korean models into Australia. This was a bit smelly since the VR6270LVMB is now available in Australia and looks identical except it probably has a nice English voice instead of trumpeting triumphant Korean phrases at the completion of a cleaning mission like ours. I noted this similarity to the service center but they declined to reply. It seems (conjecture here) LG Australia doesn't want to encourage grey imports and so prohibits their servicing.

So taking a different tact, I disassembled our model and ordered parts from the wholesaler quoting the Australian model number using this parts diagram

The brush assembly turned up and as expected was exactly the same as our Korean version. The robot reassembled with ease and now we have dust free floors again!