Main bearing bush and mounting structure

Abstract

The invention belongs to the technical field of engines and discloses a main bearing bush and a mounting structure. The main bearing bush comprises an upper bearing bush and a lower bearing bush, the two ends of the upper bearing bush abut against the two ends of the lower bearing bush, the upper bearing bush comprises a first transition portion and two supporting portions, the two ends of the first transition portion are connected to the two supporting portions, and the axial width of the first transition portion is smaller than the axial width of the supporting portions. The upper bearing bush of the main bearing bush adopts a variable cross section manner, the partial cross section of the upper bearing bush is reduced, the contact area between the upper bearing bush and a main journal of a crankshaft is reduced through the upper bearing bush, friction force between the upper bearing bush and the main journal of the crankshaft is reduced, and the friction loss is reduced. Meanwhile, compared with the prior art, on the premise of ensuring the strength of the upper bearing bush, the weight of the upper bearing bush is equivalently reduced, the weight reducing effect is achieved, the whole vehicle dead load fuel consumption is reduced, and the aims of improving the net output power of the engine and reducing the fuel consumption are achieved.

Description

technical field [0001] The invention relates to the technical field of engines, in particular to a main bearing bush and an installation structure. Background technique [0002] During the working process of the engine, the force of the main bearing of the crankshaft is mainly affected by the engine explosion pressure and the inertial force of the crank connecting rod mechanism. The force suffered is mainly inertial force, and the bearing pressure of the oil film is very small. The existing main bearing upper bearing bush has the following defects: [0003] First of all, the design safety margin of the pad on the main bearing is too much, resulting in waste. More importantly, due to the large contact area between the pad on the main bearing and the main journal of the crankshaft, the friction generated is relatively large, so that the engine crank connecting rod The friction loss of the mechanism is more. [0004] Secondly, the upper pad of the main bearing generally has ...

AI Technical Summary

Problems solved by technology

At the same time, the bearing pressure of the oil film changes drastically, which will easily cause the alloy coating of the bearing bush to peel off, reducing the service life, and it is easy to have a large lubricating oil leakage at the joint end surface of the main bearing upper bush and the main bearing lower bush

Images