General view of the wheel

General view.
A gear wheel or gear is a main part of a gear train in the form of a disk with teeth on a cylindrical or conical surface engaged with the teeth of another gear wheel. In mechanical engineering, a small gear wheel with a smaller number of teeth is called a gear, and a large one is called a wheel. However, often all gear wheels are called gears. Gear wheels have one feature - they fundamentally cannot have less than 6 teeth. Otherwise, the condition of smooth and reliable engagement will not be met. Hence the name - gear. Toothed wheels are usually used by pairs with a different number of teeth in order to convert the torque and the number of revolutions of shafts at the inlet and outlet. The wheel to which the torque is supplied from the outside is called the driving wheel, and the wheel from which the torque is removed is called the driven wheel. If the diameter of the driving wheel is less, then the torque of the driven wheel increases due to a proportional decrease in rotation speed, and vice versa. In accordance with the gear ratio, an increase in torque will cause a proportional decrease in the angular speed of rotation of the driven gear, and their product - mechanical power - will remain unchanged. This relationship is valid only for the ideal case, which does not take into account friction losses and other effects characteristic of real devices.