The forward gear is the gear used by the car. The use of helical gear can not only ensure sufficient strength but also make it more quiet and comfortable, so the car gears are basically helical gears. Let's talk about why the tooth lines of automobile gears are oblique?
This kind of gear is called helical gear. Compared with straight gear, helical gear has higher bearing capacity and less noise and vibration.
Moreover, the number and area of teeth engaged at the same time in the process of spur gear transmission is limited, which is not as large as that of helical gear. In addition, if you want to transmit more torque, you need larger teeth, and when the teeth become larger, the gear volume will become larger.
But the advantage of spur gear is that it can mesh and disengage freely in the horizontal direction. The reverse gear of many cars is directly meshed by spur gear, which can save a set of combination sleeves and reduce cost and weight. As a result, the gearbox will buzz when reversing. There is also a buzzing noise in the motorcycle's transmission line because it is small and can only be made simpler. It also uses spur gears to eliminate the complicated synchronization mechanism. The obvious thing is the rally we saw. The car in the rally is a sequential gearbox. The straight gear is directly meshed. In principle, it is basically the same as the motorcycle gearbox. The straight gear of the same color shifts quickly. The sound of the gearbox is very loud when driving.
In the process of meshing, each tooth of helical gear gradually completes all meshing from one point, with smooth meshing transition, low noise and vibration. Moreover, the meshing area is larger and the bearing capacity is larger in the transmission process.