Types Of Gearbox
1. Sliding Mesh Gearbox
It is the simplest type of gearbox. In this gearbox, spur gears are used. The Figure shows the construction of a sliding mesh type transmission having three forward and one reverse speeds. There are three gears attached on the main shaft and four gears on the layshaft. The two gears on the main shaft can be slided by a shafting yoke and mesh with the gears on a layshaft. Therefore, it is called a sliding mesh gearbox. A separate idler gear is mounted on the idler shaft.
2. Constant Mesh Gearbox
Figure shows the construction of a constant mesh type gearbox having three forward and one reverse speeds. In this type of gearbox, all gears are constantly in mesh and dog clutches are used for engaging and disengaging the gears. The dog clutches (D) and D2) are mounted on the main shaft. One (D2) is connected between clutch gear and reverse gear whereas the other (D)) is placed between low speed gear and reverse gear. The splines are provided on the main shaft for the linear movement of dogs. Dog clutch can slide on the shaft and rotate along with it. All gears are rigidly fixed on the counter shaft. All main shaft and layshaft gears, and idler gears are engaged by dog clutch to obtain opposite and slow speed. Only reverse gears are spur gear type and all others are helical gears.
As compared with the sliding mesh type, the constant mesh type gearbox meshes more readily with the gears having less danger of damaging during meshing because the gear diameters are smaller with few numbers of teeth. So, this type has more defects when compared to a synchromesh type. The necessity of double clutching is needed so that it is not used to any large extent.
For sure, there are many kinds of gearboxed for different application, such as Small Car Gearbox, Light Truck Gearbox, Heavy-duty Gearbox, ATV Gear Box, Agricultural Gearbox, Electric Vehicle Gearbox, Motorcycle Gearbox, Electric Vehicle Gearbox, Heavy-duty Gearbox, etc.