Weird bolt setup on 18 speed Huffy back wheel

[jeffpas]

Oh here I am again, I'm all over this forum right now lol.
What's confusing me is this stock rear axle nut on an 18 speed Huffy mountain bike, opposite the original chain side.
Typically what I'm familiar with is a square metal piece that acts as a washer, that goes under this nut and has a small lobe sticking out, that tucks into the frame. This keeps the wheel from ever shifting out of place. At least I've seen these on other bikes.

Well look at this. The factory wheel has just a plain nut, no lock washer or anything under it.... and what's worse a long open axle slot that allows the axle to shift all over the place in position. Why would they do this, or such a design even be needed? It makes no sense at all to me.
I'm thinking well, the torque of the motorized bike chain is going to be pulling on this spot big time, so won't that keep knocking it out of alignment? But I hesitate to change things because its what the manufacturer designed/put in.
The nut itself appears to be a bit of a lock nut of sorts. Is this good enough?

 

[jeffpas]

Is this my very thought realized?

Rear wheel where bolt stays has opened up

Is there any way to fix this to make it the original size again? It has opened up significantly I put aome washers on there to make it fit. Any other options?

motorbicycling.com

 

[Sidewinder Jerry]

That's why we use a torque wrench. Then we know exactly how tight the nut is. For a regular bicycle 300 in/lb (25 ft/lb) is recommended for the rear wheel. For a motorized bicycle do 360 in/lb (30 ft/lb). For either normal or motorized the front wheel is 240 in/lb (20 ft/lb).

 

[jeffpas]

Yes but shouldn't that back bolt have some kind of washer or seat with it? I mean its just open on the frame.
Won't that come loose or get pulled out of place eventually with the chain lugging on it all the time.
Why is the location of the axle adjustible at all? It should only ever be in one spot, with the wheel exactly parallel with the frame. The design has me utterly confused.

 

[jeffpas]

Here's a pic of that guy's bike who posted the thread I linked.
He appears to have the same setup where the bolt is on a long unseated frame "loop"
And by bolt, it looks like over time its been moving around like crazy, with the chain pulling on it.
I don't want that! What a dumb design I guess

 

[Venice Motor Bikes]

You're over thinking it!!! These engines aren't powerful enough to move the axle... Torque the axle nut as Jerry said & you'll be fine.

 

[Mossy]

The rear drop out on the Electra cruiser 1... Steel frame Im 240# and the above posted style rear drop out wouldn't last a few rides and be twisted... The AliExpress rear drop out on the steel tank frame is similar to the old bikes but thicker... A chromolly dirt jump frame is something else I like... The dumb design wouldn't last long without a motor about one ride over the railroad tracks with one... Is my experience... I've welded 2 together and had an extra set of stays and it worked better but the metal is soft and still wanted to cam out on the drive side...