[雙語(yǔ)翻譯]齒輪設(shè)計(jì)外文翻譯--小齒輪的故障分析

1、2950 英文單詞， 英文單詞，14500 英文字符，中文 英文字符，中文 3700 字文獻(xiàn)出處： 文獻(xiàn)出處：Das C R, Albert S K, Bhaduri A K, et al. Failure analysis of a pinion[J]. Engineering Failure Analysis, 2005, 12(2): 287-298.Failure analysis of a pinionC.R. Das, S

2、.K. Albert, A.K. Bhaduri, S.K. RayAbstractA pinion, which was a part of an air-motor driving a diesel generator (DG) of a power plant’s emergency power- supply system, was found to have failed into three parts during a

3、routine check-up of the DG. This pinion, attached to the air-motor shaft is active only for a short duration during the start up, when the motion of the air-motor shaft is transferred to the ring gear attached to the DG

4、which in turn starts the DG. Once the DG has started, the pinion disengages from the ring gear and the air-motor stops. The pinion that failed had been in operation for a long time and experienced several start-up opera

5、tions before failure. A systematic failure analysis was carried out to find out the reasons for this unexpected fracture of the pinion during operation. The results indicate that the fracture was caused by fatigue with a

6、 fatigue crack initiating from the fillet of one of the pinion teeth. Due to misalignment that was present, the pinion did not mesh properly with the ring gear during the start- up operation and this led to a high stres

7、s concentration at the root of the pinion. The misalignment also led to severe wear and excessive heat generation at the mating surface. Misalignment, improper heat treatment, non-uniform distribution of sulphide inclus

8、ions and sharp corners would have all contributed to the failure of the pinion.Keywords: Gear failures; Misalignment; Inclusions; Fatigue crack; Heat treatment1. IntroductionContinuous operation of power plants necessita

9、tes the use of diesel generators (DGs) for providing emergency power supply during unexpected power failures. One of the common methods used for the start-up of these DGs is to use an air-motor that is driven by air rele

10、ased from an air compressor in the event of a power failure. A pinion attached to the shaft of an air-motor drives a large ring gear connected to the DG. Under idling conditions, the pinion remains unengaged and the gap

11、 between the pinion and the ring gear is about 2.5–3.0 mm. During the start-up of the air-motor, the pinion receives a short burst of air that moves the pinion forward to mesh with the ring gear, after which the main a

12、ir-valve opens for running the air-motor and driving the pinion, which in turn drives the large ring gear of the DG. Thus, before the air-motor applies full torque, the pinion rotates slowly as it meshes with the ring g

13、ear. To enable smooth meshing with the gears, the pinion has chamfered teeth to avoid abutment of the gear. Even if abutment occurs, the gear can ‘‘fall into’’ mesh as the air-motor begins to rotate. Once the DG has st

14、arted-up, the air supply to the air-motor stops and the pinion is withdrawn to its idling position. Thus, the air-motor runs only for a short duration and the loading of the pinion is only for a few seconds during each

15、 start- up operation.The failure, investigated in this paper, occurred while an air motor was being started up for a routine DG testing operation, and resulted in the DG failing to start. Fig. 3. Fracture piece of pinio

16、n.2. Investigations 2.1. Visual examinationVisual examination of the fracture surfaces of the failed pinion, after ultrasonic cleaning with acetone, showed the presence of burn marks on the edge of a spur tooth (Fig. 4)

17、and on the upper land of a helical tooth (Fig. 5). It was further observed that the front of the spur tooth had a smooth worn-out surface, while the rear side had a rough surface indicating improper contact with the rin

18、g gear during operation (Fig. 6). Gouging marks were also observed on the land of the spline helical tooth (Fig. 7). Small-size specimens were cut from location D in the spur teeth (Fig. 4) and prepared for metallograph