Gear is one kind of mechanical parts. It can be widely used in industries. A gear is a rotating machine part having cut teeth, or cogs, which mesh with another toothed part in order to transmit torque.
Spur gear is the simplest type of gear which consists of a cylinder or disk. Its form is not straight-sided, thus, the edge of each tooth is straight and aligned parallel to the axis of rotation. Only gears fit to parallel axles can they rotate together correctly.
As the most common type, spur gears are often used because they are the simplest to design and manufacture. Besides, they are the most efficient. When compared to helical gears, they are more efficient. The efficiency of a gear is the power output of its shaft divided by the input power of its shaft multiplied by 100. Because helical gears have sliding contact between their teeth, they produce axial thrust, which in turn produces more heat. This causes a loss of power, which means efficiency is lost.
In addition to these, they also have many other advantages. Spur gears have a much simpler construction than helical gears because their teeth are straight rather than angular. Therefore, it is much easier to design and produce them. And they will not fail or break easily. And this makes them cheaper to purchase and to maintain which then leads to less cost.
Although they are common and efficient, spur gears have disadvantages as well. Firstly, they are very noisy when used at some speeds because the entire face engages at once. Therefore, they’re also known as slow-speed gears. Secondly, they can only be used to transfer power between parallel shafts. They cannot transfer power between non-parallel shafts. Thirdly, when compared with other types of gears, they are not as strong as them. They cannot handle as much of a load because the teeth are small and situated parallel to the gear axis, rather than being large and situated diagonally as the teeth on a helical gear are.
According to the above, we can conclude that spur gears have many advantages as well as some disadvantages. Although sometimes, its disadvantages may affect them a lot, their advantages still outweigh their disadvantages. That is to say, spur gears are still popular among many industries. And they can have good performances to meet people’s requirements.