1. Abnormal noise of diesel generator bearing

（1）主軸承異響。其主要原因是，軸頸與軸承協作空位過大，在作功的瞬間彼此撞擊所發生的響聲。判別時要細心傾聽，當遽然改動發動機速度，宣告接連一陣沉重而有力的敲擊聲，即為主軸承響。其他，使發動機達到正常溫度，帶上負荷，中速工作，然后逐缸連續作業，當連續某缸作業時，響聲略有減小，一起連續相鄰兩缸的作業，響聲顯著減小或消失，即為相鄰兩缸之間的主軸承有響聲。

(1) Abnormal noise of main bearing. The main reason is that the coordinative vacancy of journal and bearing is too large, and the noise occurs when they collide with each other at the moment of work. When the engine speed is suddenly changed, a series of heavy and powerful knocking sounds are announced, that is, the main bearing rings. The other is to make the engine reach the normal temperature, load the engine, work at medium speed, and then operate continuously from cylinder to cylinder. When a certain cylinder is operated continuously, the noise decreases slightly. When two adjacent cylinders are operated together, the noise significantly decreases or disappears, which means that the main bearing between the two adjacent cylinders has a sound.

（2）連桿軸承異響。其主要原因是：連桿軸承與軸頸磨損，協作空位過大；連桿軸承合金焚毀或墜落；修補質量低，安裝空位過大或軸承表面刮削不平。判別時，可在不同轉速下細聽，由怠速遽然轉入中速時，有顯著的接連敲擊聲。連續可疑氣缸的作業，響聲減小或消失。當靈敏康復該缸作業的瞬間，宣告“當”的一聲敲擊聲，即為該缸連桿軸承響0如有兩道連桿軸承響，當連續某缸作業后，響聲只能減小不能消失，只要連續發生響聲的兩只氣缸的作業，響聲才能進一步減小或消失。

(2) Abnormal noise of connecting rod bearing. The main reasons are as follows: the connecting rod bearing and journal wear, the cooperative vacancy is too large; the connecting rod bearing alloy is burned or dropped; the repair quality is low, the installation vacancy is too large or the bearing surface is scratched unevenly. When judging, you can listen carefully at different speeds. When you suddenly change from idle speed to medium speed, there is a significant continuous knocking sound. The noise decreases or disappears when the suspicious cylinder is operated continuously. At the moment of sensitive rehabilitation of the cylinder operation, a knock sound of "Dang" is announced, that is, the cylinder connecting rod bearing rings 0. If there are two connecting rod bearings ringing, the noise can only be reduced and can not disappear after the continuous operation of a certain cylinder. As long as the two cylinders with continuous noise are operated, the noise can be further reduced or disappeared.

2.柴油發電機缸塞組異響

2. Abnormal noise of diesel generator cylinder plug group

（1）異響原因分析

(1) Cause analysis of abnormal noise

①活塞敲缸。柴油機冷態敲缸，一般由活塞與缸壁空位過大、機油壓力短少或油道阻塞導致的缸壁光滑不良構成；熱態敲缸，一般由連桿彎曲、扭曲構成活塞在氣缸內運動“走形”，連桿襯套軸向偏斜，連桿軸頸與主軸頸不平行，活塞與缸壁空位過小，活塞變形，活塞環端空位過小構成；柴油機冷、熱兩種情況都存在敲擊，一般由活塞銷與連桿小頭過盈量太大，連桿軸承安裝過緊，活塞裙部圓度超差等原因引起。

① The piston knocks. Cold knocking of diesel engine is generally composed of excessive piston and cylinder wall vacancy, short oil pressure or poor cylinder wall smoothness caused by blockage of oil duct; hot knocking generally consists of bending and twisting of connecting rod, and piston moves "out of shape" in the cylinder; connecting rod bushing is axially skewed; connecting rod Journal and main journal are not parallel; piston and cylinder wall vacancy are too small; piston deformation; piston ring end vacancy It is generally caused by excessive interference between piston pin and small end of connecting rod, too tight installation of connecting rod bearing and out of tolerance of roundness of piston skirt.

②活塞銷敲擊。活塞銷與連桿襯套由于光滑不良構成的磨損過甚，或加工不當發生了空位，活塞銷折斷，連桿小頭襯套外圓在小頭孔內松曠等；由于溫度升高，構成的活塞銷與孔協作空位進一步增大等。

② The piston pin strikes. The piston pin and connecting rod bushing are worn too much due to poor smoothness or improper processing, resulting in vacancy, broken piston pin, loose outer circle of connecting rod small end bushing in small end hole, etc.; due to the increase of temperature, the cooperative vacancy of piston pin and hole is further increased.

（2）活塞環漏氣噪聲。活塞環彈力短少，構成環與缸壁密封不良；活塞環折斷、活塞環卡死在環槽內及活塞環對口等發生的漏氣。

(2) Piston ring leakage noise. The elastic force of piston ring is short, which leads to poor sealing between ring and cylinder wall; air leakage occurs when the piston ring is broken, the piston ring is stuck in the ring groove and the piston ring is opposite.