外文翻譯--萬向節(jié)十字軸總成失效分析

1、<p><b>　　附 錄</b></p><p>　　Cross-axis gimbal assembly Failure Analysis </p><p>　　The main function of joints in different axis passing between the rotating shaft torque, it has

2、been widely used in various types of truck axle shaft connected between the cross section, usually in the course of cross-axis universal joint of the Needle Roller Bearings for rotary movement is not, but for the rotatio

3、n of the swing movement, the load cycle changes submitted. Based on the heavy-duty vehicle WX0082 Cross-axis gimbal assembly of less than life pieces of the failure mode of failure, fa</p><p>　　1. Oblique im

4、print</p><p>　　The author of a company from the provision of three packs of the three packs of Service returned failure cases observed that the cross-axis oblique journal imprint is relatively serious, beari

5、ng rings also produce the inner wall of the imprint, but the depth of cross-axis than the light. By the analysis of joints installed on the bearing assembly, when the total space bearing a larger circle, the needle easil

6、y skewed, with the result that journal have a cross-axis tilt angle with the axis of the</p><p>　　2. Fatigue spalling</p><p>　　Shaft angle in the use of a smaller state, universal joint assembly

7、 of the needle bearing journal diameter and cross-axis angle in the framework of repeated smaller swing, when the cross-axis with the bearing radial clearance with the wear and tear expansion will lead to concentration o

8、f load, the load will be large local indentation fatigue prematurely in order to develop into a large area off the fatigue. Especially in the cross-axis the first axis, the stress concentration due to the impact o</p&

9、gt;<p>　　Because users do not use lubricants or as a result of time added on the universal joints bearings sealed properly, resulting in early loss of oil-bearing materials as well as the dust temperature intolera

10、nce, lip oil seals in the winter cold weather aging cracks under so that the early loss of grease. In addition, the universal joint assembly less oil in operation due to high temperature generated, so that shaft bearings

11、 and killed, resulting in a broken needle and the damage to seals and dust j</p><p>　　4. Needle failure </p><p>　　I lapsed from the universal joint assembly observed in the sample found that the

12、 majority of needle point of the surface there are Ma, Ma Hang, and large-scale fatigue spalling, a small number of needle head was broken, a small number of needle from the needle about 1.5mm Department head Ma Hang, an

13、d the existence of a larger phenomenon of bite wounds, the majority of needle fracture fracture from here, this occurrence of the main bearing structure and the size parameters and the circular design</p><p>

14、;　　5. Gasket failure </p><p>　　Gasket is the first universal joint assembly of the components failure, the form of gasket failure nylon fracture and wear pads. I carefully analyzed samples gasket failure fou

15、nd that the outer gasket has obvious cracks, gasket has cracks and debris outside. Obviously, the gasket is the gasket by the external force resulting in rise of the local stress concentration, once the gasket external d

16、amage to the axial force will be borne by the rest of the pads to bear, the bear pads per unit area will</p><p>　　6. Cross-axis fracture </p><p>　　Cross shaft fracture is usually a serious overl

17、oading the user under the premise of the factors or unusual conditions occur, as joints in the design of the Department of full compliance with the standards of universal joints JB/T8925-2008 static torsional strength sa

18、fety factor of 2.5 times the provisions of However, OEMs fault occurred during the three packs of the proportion of the total failure still accounts for 2% ~ 5% of such cases is sudden, but inevitable, universal joints a

19、nd therefore </p><p>　　7. Metallographic test analysis</p><p>　　Cases of failure to carry out physical and chemical analysis, respectively, in the cross shaft, ferrule and needle selection of th

20、e typical characteristics of the location of the site, cutting under the specimen and along the vertical cross-section metallographic sample preparation, the microstructure-level qualified. To determine the cross shaft,

21、ferrule and the center needle hardness, respectively, by micro-hardness of various parts of a gradient distribution of Vickers hardness measured, and </p><p>　　萬向節(jié)十字軸總成失效分析</p><p>　　萬向節(jié)的主要作用是在不同

22、軸線上的軸之間傳遞旋轉轉矩，它被廣泛應用于各類卡車的傳動軸聯接軸節(jié)叉之間，通常在使用過程中萬向節(jié)十字軸上的滾針軸承不是作旋轉運動，而是作旋轉擺動的運動，其載荷呈交變的周期變化。本文是通過對重型載車用WX0082萬向節(jié)十字軸總成壽命不足失效件的失效形式、失效原因進行分析。 分析結果如下：</p><p><b>　　1.斜壓印 </b></p><p>　　從某公司三包

23、服務處提供的三包退回失效件中觀察到，十字軸軸頸斜壓印情況比較嚴重，軸承套圈內壁也產生相應的壓印，但深度要比十字軸輕。經分析，安裝在萬向節(jié)總成上的軸承，當軸承圓周總間隙較大時，滾針易產生歪斜，致使十字軸軸頸產生與軸線傾斜一定角度的壓印，當壓印深度擴展較深時，滾針就不能自轉，因此使摩擦阻力增大，加劇壓痕的延伸。其合適的圓周總間隙應控制在0.1～0.4mm范圍內，JB/T3232中給定的圓周總間隙為不超過0.5mm。 </p>

24、<p><b>　　2.疲勞剝落 </b></p><p>　　在傳動軸擺角較小的使用狀態(tài)下，萬向節(jié)總成上的滾針軸承內徑與十字軸軸頸在較小角度范圍內反復擺動，當十字軸與軸承徑向游隙隨著磨損而擴大時，會導致產品載荷集中，載荷大的地方就會過早地產生疲勞壓痕，從而發(fā)展成為大面積的疲勞剝落。特別是在十字軸軸頭處，由于應力集中影響，其受載部位的倒角幾乎全部被啃掉，嚴重時會在高溫狀態(tài)下出現燒結

25、現象。 </p><p><b>　　3.缺油燒蝕 </b></p><p>　　由于在使用過程中用戶不按期加注潤滑油或由于萬向節(jié)上的軸承密封不好，導致軸承早期失油以及防塵罩材料不耐低溫，油封唇口在冬季寒冷氣候下產生老化裂紋，使?jié)櫥缙诹魇АＡ硗?，萬向節(jié)總成在運行中因缺油而產生高溫，使軸承與軸徑咬死，致使?jié)L針折斷以及密封和防塵外罩損壞，套圈表面有燒蝕痕跡，這種失效形

26、式均屬于非正常失效形式。 </p><p><b>　　4.滾針失效 </b></p><p>　　從萬向節(jié)總成失效樣品中觀察發(fā)現，大多數滾針表面都存在麻點、麻坑和大面積疲勞剝落，少數滾針頭部被折斷，少數滾針在離滾針頭部1.5mm左右處存在較大麻坑和啃傷現象，滾針斷裂大部分也是從此處斷裂，這種情況的發(fā)生主要與軸承結構尺寸參數及圓周總間隙設計有關。 </p>

27、<p><b>　　5.墊片失效 </b></p><p>　　墊片是萬向節(jié)總成中首先失效的部件，墊片失效形式為尼龍墊片斷裂和磨損。仔細分析失效墊片樣品發(fā)現，墊片的外圍有明顯的裂紋，墊片外圍有裂紋及碎片。很明顯，墊片外圍是墊片受漲力致使應力集中的地方，一旦墊片外圍破壞，其軸向力將全部由余下的墊片承受，墊片單位面積上承受的力將增加，整個墊片將被破壞。因此需要設計合理的墊片形狀和軸

28、承結構。同時，由于墊片每次失效破壞都伴隨著磨損失效，所以墊片材料必須選取強度和耐磨性較高的材料。 </p><p><b>　　6.十字軸斷裂 </b></p><p>　　十字軸的斷裂一般是在用戶嚴重超載前提下或異常因素條件下發(fā)生，因為萬向節(jié)在設計時完全遵循部標準JB/T8925-2008中萬向節(jié)靜扭強度安全系數2.5倍的規(guī)定，但在主機廠三包期內發(fā)生的故障比例仍占總

29、故障的2％～5％，此種情況雖然是突發(fā)性的，但也不可避免，因此對萬向節(jié)的靜扭強度匹配，必須在發(fā)動機最大輸出扭矩的3倍以上才能避免特殊超載引起的突發(fā)性故障的出現。 </p><p><b>　　7.金相檢驗分析 </b></p><p>　　對失效件進行理化分析，分別在十字軸、套圈和滾針的典型部位選擇特征位置，切割下試件，并沿縱截面制取金相試樣，其金相組織級別合格。為確定