A main bearing bush and its mounting structure

Abstract

The invention belongs to the technical field of engines, and discloses a main bearing bush and an installation structure. The main bearing bush includes an upper bearing bush and a lower bearing bush. The two ends of the upper bearing bush are respectively abutted against the two ends of the lower bearing bush. For the two supporting parts, the axial width of the first transition part is smaller than the axial width of the supporting part. The upper bearing bush of the main bearing bush adopts a variable cross-section method to reduce part of the cross section of the upper bearing bush, which is used to reduce the contact area between the upper bearing bush and the main journal of the crankshaft, so that the friction between the upper bearing bush and the main journal of the crankshaft is reduced. to reduce friction loss. At the same time, compared with the existing technology, under the premise of ensuring the strength of the upper bearing pad, it is equivalent to reducing the weight of the upper bearing pad, which plays a role in weight reduction, thereby reducing the fuel consumption of the whole vehicle, so as to increase the net output power of the engine and reduce fuel consumption. the goal of.

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 ...

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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

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