Fly hammer related explanation:

The flying hammer is also called "meteor hammer". A kind of ancient weapon fastening. Made of iron and ribbed with ropes to fight the enemy.

The fly hammer is a part of the governor of internal combustion engine. It is connected with the camshaft of the oil pump and rotates through the camshaft, driving the fly hammer to rotate, thus pushing the sliding rod to move to adjust the oil supply and further achieving the purpose of controlling the speed. It therefore ACTS to prevent flying cars.