McNamham wheels have so many advantages, why haven't they replaced traditional tires on a large scale?

The first is efficiency. The price of realizing the omni-directional movement of the wheat wheel is to sacrifice some speed for the lateral movement. Even if you want to move ordinary wheels, you need wheel A and wheel B to cancel each other's lateral speed. The specific explanation may be complicated. The subject can learn about the principle of wheat wheel by himself.

The second is the structural problem. Wheat wheels move in all directions by attaching unpowered rollers, which means that each wheel needs an independent power system, and the bearings at both ends of the rollers need sufficient strength to support the load. Bearings are precision parts, and rollers need to be considered separately. The complexity of the structure is not a little more than that of ordinary wheels.

The third is the defects of the wheat wheel itself. The omni-directional movement of the wheat wheel is realized when the roller of each wheat wheel touches the ground alone, that is to say, if it is on the rugged ground, the speed cannot be decomposed and it cannot move laterally, so the pavement requirements of the wheat wheel itself are relatively high.

The fourth is the cost. Complexity increases the cost. Four sets of wheat wheels need four sets of power systems. To achieve the efficiency of modern transportation, the power system itself should not be too weak, but to be efficient and self-respecting is another problem. Just like a rocket, in order to overcome the gravity of the earth, it needs a high-powered engine and a small self-weight, but a high-powered engine needs a lot of fuel, and a lot of fuel increases its self-weight. It is obviously uneconomical to carry out a large number of design and calculation experiments to popularize wheat wheels on a large scale.

My understanding is that it is handmade. After all, I am still learning the relevant knowledge. If there is anything wrong, I hope the boss will point it out.