More Trident details

I had read on the Trident website that the front wheels could be removed without messing with the brake caliper. This is a nice feature for changing tires and wasn't explained to me by my LBS when I bought the trike, but it was kind of hectic at the time. So today while waiting for the outside air temperature to hit my riding value I decided to take a front wheel off and see what the procedure entails. It took less than 30 seconds first time, that's damn easy.

Loosen the quick release a few turns.

Pushing in on quick release then remove quick release and pull axle out. It
does not need to come out completely just enough to clear the brake disk.

Arrangement of axle and outboard spacer

Spacer comes off when axle removed. Now wheel can slide out of brake.

Quick release is removed completely.

Axle and quick release. The spacer that is on the quick release side stays in the kingpin hub.
I used the 2gal plastic paint bucket to support the trike with the wheel off.

It takes longer to explain than to do. The wheel rides on two sealed bearings that rest on the shiny parts of the axle. The only question I have is why are there set screw threads in the outer collar/spacer? When reassembling the quick release should not be to tight as it will bind the bearings and slow wheel rotation, this tightness is my idea not from Trident.
Note about terms:
I hate using the wrong term but I can't figure out what these components all should be called. This is somewhat embarrassing considering how many years I've messed about cars. I call the assembly that connects to the frame minus the wheel the Kingpin assembly since this is what it most resembles to me. I call the removable black tube in the above picture an axle even though it might be thought of as a  removable spindle of a standard kingpin assembly.  

UPDATE: Tom from Trident Trikes responded within one hour to my email about the mysterious set screw threads! Not used in this application. Thanks Tom