The chassis of the underground loader makes abnormal noise during the whole machine strengthening test. The specific situation is as follows: when the steering wheel is turned when the engine is running at idle speed, a part of the chassis will make a crisp metal impact sound, and it is uncertain where the steering wheel makes abnormal noise; When the accelerator is pressed to accelerate, the sound becomes weak or basically disappears.

根據(jù)該機(jī)故障現(xiàn)象和對(duì)其轉(zhuǎn)向系統(tǒng)結(jié)構(gòu)的分析，我們認(rèn)為其機(jī)架、轉(zhuǎn)向液壓系統(tǒng)、變速器出現(xiàn)故障的可能性很小，該異響可能來(lái)源于以下3方面：一是傳動(dòng)軸伸縮時(shí)產(chǎn)生異響，二是主減速器和差速器異響，三是后橋擺動(dòng)架異響。

According to the fault phenomenon of the machine and the analysis of its steering system structure, we believe that the possibility of failure of its frame, steering hydraulic system and transmission is very small, and the abnormal noise may come from the following three aspects: first, the abnormal noise generated during the expansion and contraction of the transmission shaft, second, the abnormal noise of the main reducer and differential, and third, the abnormal noise of the swing frame of the rear axle.

（1）排查傳動(dòng)軸

(1) Check the drive shaft

后橋在擺架上擺動(dòng)時(shí)，后橋中心的輸入法蘭也會(huì)隨后橋擺動(dòng)，使后傳動(dòng)軸的長(zhǎng)度及空間位置發(fā)生變化。檢查發(fā)現(xiàn)裝載機(jī)在轉(zhuǎn)向過(guò)程中，后傳動(dòng)軸并不會(huì)發(fā)生明顯伸縮，該處無(wú)存在異響的可能性。

When the rear axle swings on the swing frame, the input flange in the center of the rear axle will also swing with the rear axle, changing the length and spatial position of the rear transmission shaft. It is found that during the steering process of the loader, the rear drive shaft will not expand significantly, and there is no possibility of abnormal sound.

（2）排查主減速器和差速器

(2) Check the final drive and differential

在后驅(qū)動(dòng)橋的輪邊減速器位置用手觸摸能感覺(jué)到有撞擊動(dòng)作。我們更換了主減速器和差速器總成，經(jīng)試機(jī)異響問(wèn)題依然沒(méi)有。

At the wheel reducer position of the rear drive axle, the impact action can be felt by hand. We replaced the main reducer and differential assembly, but the problem of abnormal noise still hasn't been solved after commissioning.

（3）掃卜查后橋擺架

(3) Sweep the rear axle swing frame

為了模擬異響時(shí)的工狀，并能實(shí)時(shí)觀察前、后擺動(dòng)架的實(shí)際運(yùn)行情況，我們將該裝載機(jī)開(kāi)到檢修平臺(tái)上。通過(guò)多次原地轉(zhuǎn)向、進(jìn)退行駛試驗(yàn)，仔細(xì)觀察擺架狀態(tài)，發(fā)現(xiàn)后擺動(dòng)架與橋殼之間有3mm相對(duì)竄動(dòng)。正是由于后連接法蘭在后擺動(dòng)架的竄動(dòng)，引發(fā)了后擺動(dòng)架與后橋殼上的連接法蘭相互撞擊，從而產(chǎn)生了異響。

In order to simulate the working state in case of abnormal noise and observe the actual operation of the front and rear swing frames in real time, we drive the loader to the maintenance platform. Through many in-situ steering, forward and backward driving tests, carefully observe the swing frame state, and it is found that there is 3mm relative movement between the rear swing frame and the axle housing. It is the movement of the rear connecting flange on the rear swing frame that causes the rear swing frame and the connecting flange on the rear axle housing to collide with each other, resulting in abnormal noise.

找到異響發(fā)生位置后，我們分析產(chǎn)生該間隙的原因。查閱后橋圖紙，并從后橋的供應(yīng)商那里的到了相關(guān)情況。該型裝載機(jī)后橋橋殼與后擺動(dòng)架的理論設(shè)計(jì)間隙為1.1～2.15mm，安裝時(shí)的調(diào)整墊片只有厚度為6mm的1種規(guī)格。

After finding the location where the abnormal sound occurs, we analyze the cause of the gap. Refer to the rear axle drawing and get the relevant information from the rear axle supplier. The theoretical design clearance between the rear axle housing and the rear swing frame of this loader is 1.1 ~ 2.15mm. During installation, there is only one specification with a thickness of 6mm.

實(shí)際拆檢出現(xiàn)異響的這臺(tái)裝載機(jī)，測(cè)量其調(diào)整墊片厚度只有5.1mm。再加上設(shè)計(jì)間隙，總共累積成3mm間隙。

The loader with abnormal noise was actually disassembled and inspected, and the thickness of its adjusting gasket was only 5.1mm. In addition to the design clearance, the total accumulated clearance is 3mm.