外文翻译原文-汽车差速器小齿轮轴失效分析.pdf

1、Failure analysis of an automobile differential pinion shaftH.Bayrakceken*Afyon Kocatepe University,Technical Education Faculty,03200 Afyon,TurkeyReceived 8 July 2005;accepted 14 July 2005Available online 2 September 2005AbstractDifferential is used to decrease the speed and to provide moment increas

2、e for transmitting the movement comingfrom the engine to the wheels by turning it according to the suitable angle in vehicles and to provide that inner andouter wheels turn differently.Pinion gear and shaft at the entrance are manufactured as a single part whereas theyare in different forms accordin

3、g to automobile types.Mirror gear which will work with this gear should become familiarbefore the assembly.In case of any breakdown,they should be changed as a pair.Generally,in these systems there arewear damages in gears.The gear inspected in this study has damage as a form of shaft fracture.In th

4、is study,failure analysis of the differential pinion shaft is carried out.Mechanical characteristics of the materialare obtained first.Then,the microstructure and chemical compositions are determined.Some fractographic studies arecarried out to asses the fatigue and fracture conditions.?2005 Elsevie

5、r Ltd.All rights reserved.Keywords:Differential;Fracture;Power transfer;Pinion shaft1.IntroductionThe final-drive gears may be directly or indirectly driven from the output gearing of the gearbox.Di-rectly driven final drives are used when the engine and transmission units are combined together to f

6、orman integral construction.Indirectly driven final drives are used at the rear of the vehicle being either sprungand attached to the body structure or unsprung and incorporated in the rear-axle casing.The final-drivegears are used in the transmission system for the following reasons 1:(a)to redirec

7、t the drive from the gearbox or propeller shaft through 90?and,(b)to provide a permanent gear reduction between the engine and the driving road-wheels.1350-6307/$-see front matter?2005 Elsevier Ltd.All rights reserved.doi:10.1016/j.engfailanal.2005.07.019*Tel.:+90 272 228 1311;fax:+90 272 228 1319.E

8、-mail address:bcekenaku.edu.tr.Engineering Failure Analysis 13(2006) vehicles,differential is the main part which transmits the movement coming from the engine to thewheels.On a smooth road,the movement comes to both wheels evenly.The inner wheel should turn lessand the outer wheel should turn more

9、to do the turning without lateral slipping and being flung.Differen-tial,which is generally placed in the middle part of the rear bridge,consists of pinion gear,mirror gear,differential box,two axle gear and two pinion spider gears.A schematic illustration of a differential is given in Fig.1.The tec

10、hnical drawing of the fractured pinionshaft is also given in Fig.2.Fig.3 shows the photograph of the fractured pinion shaft and the fracture sec-tion is indicated.In differentials,mirror and pinion gear are made to get used to each other during manufacturing and thesame serial number is given.Both o

11、f them are changed on condition that there are any problems.In thesesystems,the common damage is the wear of gears 24.In this study,the pinion shaft of the differential of aminibus has been inspected.The minibus is a diesel vehicle driven at the rear axle and has a passengercapacity of 15 people.Max

12、imum engine power is 90/4000 HP/rpm,and maximum torque is 205/1600Nm/rpm.Its transmission box has manual system(5 forward,1 back).The damage was caused by stoppingand starting the minibus at a traffic lights.In this differential,entrance shaft which carries the pinion gearwas broken.Various studies

13、have been made to determine the type and possible reasons of the damage.These are:?studies carried out to determine the material of the shaft;?studies carried out to determine the micro-structure;?studies related to the fracture surface.There is a closer photograph of the fractured surfaces and frac

14、ture area in Fig.4.The fracture wascaused by taking out circular mark gear seen in the middle of surfaces.Fig.1.Schematic of the analysed differential.H.Bayrakceken/Engineering Failure Analysis 13(2006)142214281423Fig.2.Technical drawing of the analysed pinion shaft.Fig.3.The picture of the undamage

15、d differential pinion analysed in the study.Fig.4.Photographs of failed shaft and fracture surfaces.1424H.Bayrakceken/Engineering Failure Analysis 13(2006)142214282.Experimental procedureSpecimens extracted from the shaft were subjected to various tests including hardness tests and metal-lographic a

16、nd scanning electron microscopy as well as the determination of chemical composition.All testswere carried out at room temperature.2.1.Chemical and metallurgical analysisChemical analysis of the fractured differential material was carried out using a spectrometer.The chem-ical composition of the material is given in Table 1.Chemical composition shows that the material is a lowalloy carburising steel of the AISI 8620 type.Hardenability of this steel is very low because of low carbon proportion.Th