Developing Five Planets Wheel Reduction to Improve Rear Axle Life Time of AUMAN Mining Dump Truck

1、developing five planets wheel reduction to improve rear axle life time of auman mining dump trucksubmitted by tang yu fustudent id number 052101197007310617supervised by shi ze huaa paper submitted in partial fulfillment of the requirements of the degree of bachelor of artsthe institute of online ed

2、ucationbeijing foreign studies university北京外国语大学网络教育学院学士学位论文诚信声明本人郑重声明： 所呈交的学士学位论文，是本人在导师的指导下，独立进行研究工作所取得的成果。论文所涉及的项目为本人亲自负责或者参与实施的项目。除文中已经注明引用的内容外，本论文不含任何其他个人或集体已经发表或撰写过的作品成果。本人完全了解本声明的法律结果由本人承担。学士学位论文作者签名：唐玉福 日期：2011 年 5 月 28 日论文摘要 北京欧曼重型汽车厂（简称欧曼）是一家专门从事中重型卡车生产销售的汽车生产企业。2000年在北京怀柔建厂，隶属于北汽福田汽车股份有限公

3、司，具有独立的整车产品研发机构即欧曼技术中心，先进的生产制造和质量控制系统和完备的营销和售后服务体系，为运输行业提供12吨到41吨牵引车、自卸车和专用车整车产品。自建厂以来，欧曼中重型卡车已累计销售50多万辆，并出口20多个国家和地区，目前已成为世界知名品牌之一。近年来，在国内矿区市场出现一种非公路矿用自卸车，其特点是配18吨双后桥，工程轮胎和大马力发动机，与运输型自卸车比具有较大的爬坡和承载能力，运输效率高。经市场调查，该产品在矿区有替代通用自卸车的趋势，并以平均90%的速率连年递增，预计到2011年总量可突破一万辆。根据上述情况，2010年公司立项开发矿用自卸车，并计划在2011年投放市场

4、。然而经市场调研发现这一类车匹配的18吨级后桥故障率较高，平均故障里程仅为5000km，远达不到行业标准（即10000km），已引起用户极大抱怨。为欧曼矿用车开发并成功进入市场，首要问题是如何提高后桥可靠性。为此公司成立了包括整车和车桥设计工程师、徐州美驰车桥厂在内的专项小组。经过对市场调研数据的筛选和分析发现，后桥故障的主要模式为轮边齿轮打齿，约占75%，其原因是实际整车总质量为65吨左右，远大于标定的50吨，原18吨后桥超载严重。经过小组讨论、问卷调查和swot分析确定开发五行星轮轮边减速后桥，预计其承载能力可达到25吨，首次故障里程可达到10000km以上，满足用户实际使用需求。该项目于

5、2010年3月份启动，历经7个月时间，通过台架试验证明五行星轮后桥开发达到了预期目标，并随整车产品于2011年3月份正式投放市场。五行星轮后桥开发项目开创了进口车桥重大结构改进的先例，不仅为欧曼矿用车开发提供了可靠保障，使欧曼矿车更具有品牌竞争力，同时通过项目实施，积累了宝贵的设计经验，为今后汽车零部件的开发改进，提高用户满意度，提升欧曼品牌形象奠定了良好的基础。关键词：矿用自卸车；首次故障里程；五行星轮轮边减速；结构改进abstractthis paper presents a detailed report of a project implemented to develop a new

6、 type of five planets wheel reduction to improve mining dumper rear axle reliability. in 2010, auman determined to enter the promising mining dumper truck market, however, according to marketing research, the competitors mining dumper rear axle reliability was very low and the problem focus on the w

7、heel reduction which accounted at least 85% among all kinds of failure mode. the average initial malfunction mileage (that was a index used for evaluating reliability and life time) was no more than 5000km far from expected 10,000km that is also minimum value limited by vehicle industry standard. as

8、 the well-known manufacturer of commercial vehicle, we should solve the problem before introducing auman products into market, so an experimental group was set up to develop a new type rear axle to tackle this problem. after a series of preliminary analysis and calculation, it is hypothesized that i

9、f we can develop a five planets wheel reduction, the average initial malfunction mileages would be increased 50% to more than 10,000km. prior to carrying out this two years development project, several research techniques such as relevant engineers opinion survey, brainstorming and swot analysis wer

10、e applied to the identification and analysis of problems and project evaluation. to ensure that the whole project has been efficiently and effectively monitored and under control, the project framework, activity flow chart with time scale and project master file were designed and every team member r

11、eferred to them to check whether the every specific task was fulfilled and on schedule. at last, the goal was achieved with the team efforts. with five planets wheel reduction, all of three rear axle samples passed the reliability test of 10,000km. the successful development of five planets wheel re

12、duction not only prolong the mining dumper rear axle life- time, it also provided valuable experiences for development of new products or improvement of existing products to improve our products competitiveness.table of contentspages1. project introduction 72. project problem identification and anal

13、ysis8 2.1 project problem8 2.2 problem analysis93. project objective and hypothesis15 3.1 project objective15 3.2 project hypothesis154. project rationale155. project design 17 5.1 planning of activities17 5.1.1 activities planned to take place17 5.1.2 a critical path analysis of these activities19

14、5.1.3 people involved and their responsibilities20 5.1.4 time scale of activities21 5.2 cost analysis23 5.3 risk analysis24 5.3.1 the potential risks analysis24 5.3.2 protective measures to be taken25 5.4 plan for the monitoring and evaluation of the project 25 5.4.1 monitoring the plan25 5.4.2 eval

15、uating the plan26 5.4.3 project framework266. project implementation and monitoring28 6.1 project implementation 28 6.2 project monitoring297. project findings and discussion30 7.1 project findings30 7.2 results discussion328. conclusion32bibliographyappendix i. appendix ii. appendix iii. developing

16、 five planets wheel reduction to improve rear axle life time of auman mining dump truck1. project introduction beijing auman heavy truck plant (hereafter referred as auman) was founded in huai rou district in 2000 by its parent company foton, which is top rank commercial vehicle manufacture. it was

17、specialized in media size and heavy truck manufacture and distribution. with integrative function of r&d, manufacture, quality control, distribution, after sale service, and manufacture capacity of 100,000 unit per year, it has manufactured and sold more than 500,000 unit and built most famous brand

18、 both in domestic and overseas market in past decade. in recent years, a new type mining dumper truck equipped with 18t rear axle appeared in most coalmine areas widely spread in inner mongolia autonomous. auman was also eager to share this emerging market. however, according to marketing research,

19、the existing 18t rear axles reliability was very low and the problem focused on the wheel reduction, which accounted at least 85% among all kinds of failure mode. the average initial malfunction mileage (that was the most important index used for evaluating reliability and life time) was no more tha

20、n 5000km far from expected 10,000km that is also minimum value limited by vehicle industry standard. to tackle this problem, we proposed to develop five planets wheel reduction to improve reliability of this rear axle. according to preliminary calculation and analysis, it was hypothesized that if th

21、is new type wheel reduction was applied to existing 18t rear axle, its carrying capacity would be increased to 25t and therefore its initial malfunction mileage would be prolonged to more than 10,000km.prior to carrying out this project, several research techniques such as relevant engineers opinion

22、 survey, brainstorming and swot analysis were applied to the identification and analysis of problems and project evaluation. to ensure that the whole project has been efficiently and effectively monitored and under control, the project framework, activity flow chart with time scale and project maste

23、r file were designed and every team member referred to them to check whether the every specific task was fulfilled and on schedule. at last, all of three samples of this mode rear axle passed the reliability test of 10,000km. the successful development of five planets wheel reduction not only prolon

24、g the mining dumper rear axle life- time, it also provided valuable experiences for development of new products or improvement of existing products to improve our products competitiveness.2. project problem identification and analysis2.1 project problemin march 2010, beijing auman heavy truck plant

25、(hereafter refer as auman) determined to enter mining market by developing a new type mining dumper truck. after a preliminary marketing research, we found that all of competitors products equipped with 18t double drive rear axle, which was produced by xuzhou meichi axle plant. while in practice, th

26、e real burden imposed on rear axle was often around 25t. so it has resulted in frequent breakdown of rear axle and raised complaints from customers. after collection and consolidation of data, the original failure mileage that is used to evaluate reliability of rear axle was averagely no more than 5

27、000km. it is far from 10,000km, the value limited by vehicle industry standard. if we follow these competitors to develop the same one, we would lose competitiveness and our company image would be damaged. so the problem we faced was how to enhance the carrying capacity of the existing 18t rear axle

28、 to 25t, thereby to improve its reliability to meet both requirement of standard and expectation of customers before we introduce auman brand mining dumper truck into market.as the director of special purpose vehicle department, i was appointed as the manager of this project. i organized an experime

29、ntal group in which included chassis engineers, test engineers, cae engineers and members from development management department and xuzhou meichi axle plant to collect and consolidate data to determine what the failure mode was, proposed to develop five planets wheel reduction as the final solution

30、 and ensure the project would be carried out smoothly and achieve the set goal. this project was the key for auman to develop mining dumper truck successfully. also it was a challenging and meaningful project for development team.1. situation analysis of the existing 18t rear axle.l physical resourc

31、esto fulfill this project, we needed three samples and to examine them on test bed. after talking with representatives of xuzhou meichi axle plant, they agreed to make full use of all facilities and other relevant resources to manufacture and test the three rear axle samples for our company. xuzhou

32、meichi axle plant has been being specialized in manufacture of vehicle axle for more than decades and well equipped with all kinds of advanced facilities among which 60% were imported from america. high precision of these facilities makes sure to meet the design requirement. in particular, by settin

33、g and adjusting some parameters, the test bed can stimulate the real situation in which the rear axle works.l financial statusauman heavy truck plant has planed to enter mining dumper market so this project gained a lot of support from top leaders. we had successfully applied for rmb 2 million as th

34、e project funding from the financial department as soon as the project report got approval. this funding would cover the development expenses, cae analysis expenses, three samples manufacturing and testing expenses, cost of labor, stationery expenses and contingency allowance during the project impl

35、ementation.l human resourcesin this project group there were two chassis engineers for product design, one cae engineer for analysis of the design, one person from development and management department whose responsibility was to assist to me to deal with daily work, one plant manager from xuzhou me

36、ichi axle plant whose responsibility was to organize the samples manufacture according to design requirement, one laboratory director from xuzhou meichi axle plant who was in charge of the samples test and submit the test report. i was appointed as the project manager to co-ordinate all kinds of pro

37、blems encountered during the project implementation and report to top leaders. l technological analysiscurrent 18t rear axle equipped with four planet wheel reduction while the real load imposed on rear axle was about 25t, which overloaded almost 40% of carrying capacity and led to frequently damage

38、 of wheel reduction. after analysis and discussion, we found that if we add another planet pinion, the carrying capacity of the rear axle would be increased to 25t. so the target of this project was to develop five planets wheel reduction to enhance the carrying capacity of rear axle and thereby to

39、prolong the rear axles life- time. 2. needs and wants analysis. after preliminary research in understanding current situation of the existing 18t rear axles transmission principle and malfunction mode, a series of activities were conducted to find out what measures should be taken to improve reliabi

40、lity of the rear axle.on 12th march 2010 a brainstorm meeting was organized to collect advices on how to strengthen the rear axle. the participants were the representatives from chassis room and vehicle layout room in r&d and technicians from xuzhou meichi rear axle plant. the meeting discussed thre

41、e ways to enhance the carrying capacity of the rear axle from 18t to 25t thereby to improve reliability of the rear axle from current average 5000km to 10,000km. the first design is to enlarge the ratio and diameter of the final drive in order to transfer more torque from wheel reduction to final dr

42、ive thus the load on the wheel reduction can be reduced to a great extend. the second one is to enlarge the width of wheel reduction gears to increase the carrying capacity of the wheel reduction directly. the last one is to add another planet pinion to strengthen the wheel reduction-the weakness of

43、 current 18t rear axle.however, all of the three designs mentioned above had negative effect in terms of both the performance of vehicle and related parts process. for example, the first design would reduce the clearance between rear axle and ground, which is the most important indicator of vehicle

44、ability to pass through obstacle. the second one needed almost unachievable process precision. the last one was the most feasible solution towards current situation. so the further step should be taken to identify the feasibility of five planets wheel reduction development. in order to achieve the g

45、oal, a questionnaire form (please refer to appendix i) was designed to conduct a survey concerning main factors related to process of the five planets wheel reduction manufacture. 70 copies was printed out and distributed to technicians in xuzhou meichi axle plan on the second day of the meeting. af

46、ter a week, 63 forms was completed and fed back by e- mail. the results are listed as below:80% technicians reflected that developing five planets wheel reduction would have no effect on productivity.65% technicians agreed that it would be necessary to adjust or reset some facility for this new stru

47、cture product without any investment.75% technicians considered the new structure would be convenient for maintenance.70% technicians agreed that the cost of the five-planets wheel reduction would be between 300500 rmb.the result of the survey demonstrated that developing five planets wheel reductio

48、n was a feasible solution to solve current problem. then several items should be planed. first, we need to finish the design within two months. next, we need three samples of this new type rear axle for final test. the process of manufacture would last two months. at last, the fatigue life- time tes

49、t should be conducted to prove whether the new type rear axle would meet the set goal. it would take another three months.3. swot analysisstrengthsas the rear axle supplier, xuzhou meichi axle plant agrees to co-operate with us on this project.xuzhou meichi axle plant has advanced machining and heat

50、 treatment facilities and perfect test bed introduced from the usa to ensure the precision demand and test the reliability of the new product.xuzhou meichi axle plant has enough engineers and technicians with rich experience to ensure the implementation of this project.sales department agree to intr

51、oduce tree samples of auman mining dumper equipped with this 25t rear axle to customers to conduct in real operating conditions.test department can appoint a veteran trier to monitor the reliability test all through the process.all of expense can be disbursed from the budget of auman mining dumper d

52、evelopment, which was up to rmb 18,000,000.weaknessthe structure of five wheels deduction needs some more accurate technical equipment and special tools.as yet there have been no experience of development of five wheels deduction for reference at home.the samples need to be tested together with auma

53、n brand mining dumper in real situation so it would take at least about half year to prove whether the design is successful.opportunitiesif the design were successful, auman brand mining dumper would be more competitive against other brand with high carrying capacity and reliability.beijing auman he

54、avy truck plant would benefit from this new type rear axle both in sale volume and image improvement.the experience can be applied to other new product development and existing products improvement in the future.threatsit was possible for competitors to develop the same rear axle to compete with aum

55、an mining dumper.once the design had not passed the test, we have to make a big modification that would waste a long time and has significant effect on the development of auman mining dumper.the swot analysis helps us to have a lot of confidence and take some necessary measures to ensure the project

56、 to be successful.strengthsweaknessthe close cooperation with rear axle supplier. advanced equipments offered by rear axle supplier.experts offered by rear axle supplier.adequate environment for reliability testample budget for this project requirement of high level precisionabsence of experiencetim

57、e consuming opportunitiesthreatsto gain more competitiveness for auman productsgreat profits from the new productexperiences applied to other products possible simulation by competitorsinfluence on the development of auman mining dumper3. project objective and hypothesis3.1 project objectivethe prob

58、lem we confronted was that we found the current rear axle used by competitors did not meet the requirement of real situation with frequently breakdown when our company planed to enter mine truck market. if we use the same rear axle following those competitors, not only we would pay heavy compensations, but also our company image would be affected deeply. the management paid more attention to this issue at the very beginning of auman mining dumper development. in order