汽車傳動(dòng)軸的技術(shù)狀況變壞時(shí)，彎曲振動(dòng)的振幅增大，振動(dòng)劇烈，甚至引起車身振抖，并發(fā)出明顯的周期性響聲，即稱為振抖和異響汽車傳動(dòng)軸隨著車速的增高而加劇，傳動(dòng)軸產(chǎn)生振抖和異響的主要原因有以下幾個(gè)方面。

When the technical condition of the automobile transmission shaft deteriorates, the amplitude of bending vibration increases, the vibration is severe, and even causes the body to vibrate and produce obvious periodic sounds, which are called vibration and abnormal noise. The automobile transmission shaft intensifies with the increase of vehicle speed, and the main reasons for the vibration and abnormal noise of the transmission shaft are as follows.

傳動(dòng)軸總成失去平衡

Transmission shaft assembly out of balance

傳動(dòng)軸總成的裝配誤差超限、零件尺寸不精確及在使用中的磨損變形等都會(huì)使傳動(dòng)軸沿長(zhǎng)度方向的質(zhì)量分布不均勻而造成傳動(dòng)不平衡。不平衡的傳動(dòng)軸在運(yùn)轉(zhuǎn)中便會(huì)產(chǎn)生附加彎矩，附加彎矩的作用不僅會(huì)使配合件沖擊發(fā)響，還會(huì)增強(qiáng)傳動(dòng)軸的彎曲振動(dòng)，使傳動(dòng)軸的振抖和異響更為明顯。

The assembly error of the transmission shaft assembly exceeds the limit, the size of the parts is not accurate, and the wear and deformation during use can cause uneven distribution of mass along the length direction of the transmission shaft, resulting in transmission imbalance. An unbalanced transmission shaft will generate additional bending moments during operation. The effect of the additional bending moment not only causes the mating parts to impact and make noise, but also enhances the bending vibration of the transmission shaft, making the vibration and abnormal noise of the transmission shaft more obvious.

萬(wàn)向節(jié)損傷

Universal joint damage

萬(wàn)向節(jié)在使用中的主要損傷是十字軸軸頸和端面磨損及滾針和軸承座孔磨損等。萬(wàn)向節(jié)零件的損傷使十字軸配合松曠而產(chǎn)生擺動(dòng)和軸向竄動(dòng)，不僅在工作中發(fā)出撞擊聲，而且削弱傳動(dòng)軸的抗彎剛度。傳動(dòng)軸的質(zhì)量中心更加偏離旋轉(zhuǎn)軸線，從而增強(qiáng)振抖和異響。

The main damage to the universal joint during use is the wear of the cross shaft journal and end face, as well as the wear of the roller needle and bearing seat hole. The damage to the universal joint components causes the cross shaft to fit loosely, resulting in swinging and axial displacement. This not only makes a collision sound during operation, but also weakens the bending stiffness of the transmission shaft. The center of mass of the transmission shaft deviates further from the rotational axis, thereby enhancing vibration and abnormal noise.

傳動(dòng)軸和滑動(dòng)叉損傷

Damage to transmission shaft and sliding fork

傳動(dòng)軸軸管彎曲，即增大傳動(dòng)軸彎曲振動(dòng)的振幅，可使離心力增大，從而造成強(qiáng)烈的振抖和異響。傳動(dòng)軸鍵齒和滑動(dòng)叉鍵槽磨損，由于配合松曠，在工作中會(huì)發(fā)出撞擊聲，還會(huì)削弱傳動(dòng)軸的抗彎剛度，增強(qiáng)振抖和異響。

Bending of the transmission shaft tube, which increases the amplitude of the bending vibration of the transmission shaft, can increase the centrifugal force, causing strong vibration and abnormal noise. The key teeth of the transmission shaft and the sliding fork keyway are worn, and due to loose fit, there will be a collision sound during operation, which will weaken the bending stiffness of the transmission shaft, enhance vibration and abnormal noise.

傳動(dòng)軸兩端的安裝位置改變

Change in installation position at both ends of the drive shaft

對(duì)于不等角速萬(wàn)向節(jié)傳動(dòng)軸而言，為減小傳動(dòng)軸的振動(dòng)和保證驅(qū)動(dòng)橋齒輪的勻速轉(zhuǎn)動(dòng)，必須符合以下2個(gè)條件：

For unequal angular velocity universal joint drive shafts, in order to reduce vibration of the drive shaft and ensure uniform rotation of the drive axle gears, the following two conditions must be met:

傳動(dòng)軸兩端的萬(wàn)向節(jié)叉應(yīng)位于同一平面內(nèi)；

The universal joint forks at both ends of the transmission shaft should be located in the same plane;

輸入軸、輸出軸與傳動(dòng)軸的兩夾角應(yīng)相等。 傳動(dòng)軸在使用中，由于傳動(dòng)軸鍵齒和滑動(dòng)叉鍵槽磨損，萬(wàn)向節(jié)十字軸軸頸與滾針配合松曠等，會(huì)使1條件破壞；而傳動(dòng)軸安裝不良、彈性</a懸架技術(shù)狀況變化及傳動(dòng)軸的輸入軸和輸出軸磨損使安裝位置改變等，均會(huì)使第2條件破壞。 隨著等速傳動(dòng)條件的破壞，將使驅(qū)動(dòng)橋主減速齒輪產(chǎn)生沖擊，并引起傳動(dòng)軸運(yùn)轉(zhuǎn)不穩(wěn)定，增強(qiáng)抖動(dòng)和異響。

The angle between the input shaft, output shaft, and transmission shaft should be equal. During use, the transmission shaft may be damaged due to wear on the key teeth and sliding fork keyway, as well as loose fit between the universal joint cross shaft neck and the rolling needle; Poor installation of the transmission shaft, changes in suspension technology due to elasticity, and changes in the installation position caused by wear of the input and output shafts of the transmission shaft can all cause the second condition to be damaged. With the destruction of constant speed transmission conditions, it will cause impact on the main reduction gear of the drive axle, and cause unstable operation of the drive shaft, enhancing vibration and abnormal noise.

傳動(dòng)軸臨界轉(zhuǎn)速降低

The critical speed of the transmission shaft decreases

傳動(dòng)軸設(shè)計(jì)時(shí)的高轉(zhuǎn)速一般為臨界轉(zhuǎn)速的 0．7倍。但由于傳動(dòng)軸動(dòng)平衡的破壞、萬(wàn)向節(jié)的損傷及中間支承軸承松曠等，都會(huì)使傳動(dòng)軸臨界轉(zhuǎn)速降低。當(dāng)臨界轉(zhuǎn)速降低到傳動(dòng)軸的轉(zhuǎn)速時(shí)，傳動(dòng)軸在運(yùn)轉(zhuǎn)中便易于產(chǎn)生共振。傳動(dòng)軸共振時(shí)的振幅大，振動(dòng)劇烈，往往會(huì)造成傳動(dòng)軸折斷。

The high speed during the design of the transmission shaft is generally 0.7 times the critical speed. However, due to damage to the dynamic balance of the transmission shaft, damage to the universal joint, and looseness of the intermediate support bearing, the critical speed of the transmission shaft will decrease. When the critical speed drops to the speed of the drive shaft, the drive shaft is prone to resonance during operation. When the transmission shaft resonates, the amplitude is large and the vibration is severe, often causing the transmission shaft to break.