What are the supporting forms of the driving bevel gear of the final drive? Each has its own characteristics? What is the difference between a two-speed final drive and a two-stage final drive?
What are the supporting forms of the driving bevel gear of the final drive? Each has its own characteristics? What is the difference between a two-speed final drive and a two-stage final drive?
There are two types: straddle support and cantilever support.
Features:
1) Cross-position support means that the front and rear ends of the gear swing have bearings as the support form. Generally speaking, the front end of the gear is supported on tapered roller bearings, a pair near the small end, and the rear end is supported on cylindrical roller bearings. This form of support has high support strength, but has a large space, and is generally used for single-stage final reducers.
2) Cantilever support is a form of support, the active bevel gear is supported on two tapered roller bearings that are far apart, and the active bevel gear is suspended outside the bearing. This type of support has a simple structure and requires little space. It is generally used for double main reducers, but the support rigidity is not as good as that of a span support.
The double-stage main reducer is composed of two gear pairs, which are reduced twice. The transmission ratio of the final drive is only one, and it is fixed. However, there are two transmission ratios output by the two-speed final drive, and the transmission ratio of the final drive changes according to the driver's operation.
The support form of the active bevel gear can be divided into cantilever support and straddle support. The characteristic of the straddle support structure is that both ends of the bevel gear are supported by bearings, which can greatly increase the support rigidity, reduce the bearing load, and improve the meshing conditions of the gears. Therefore, the load carrying capacity of the gear is higher than that of the cantilever. In addition, since the distance between two oppositely installed tapered roller bearings on the journal of the large end of the gear is very small, the length of the driving gear shaft can be shortened, the layout is more compact, and the included angle of the transmission shaft is reduced, which is beneficial to the vehicle layout . However, the housing of the main reducer must have a bearing seat required to support the guide bearing, which makes the structure of the main reducer housing complex and increases the processing cost. In addition, due to the small space between the driving and driven gears, the size of the guide bearing of the driving gear is limited, and sometimes it is even impossible to arrange or disassemble the gear. The guide bearings in the straddle support are cylindrical roller bearings with separable inner and outer rings or no inner ring at all. It only bears radial force, the size depends on the arrangement position, and it is an easily damaged bearing. In the case where a large torque needs to be transmitted, a straddle support is used.
