1. 研究目的与意义（文献综述）

1.1 the purpose and significance of the electric design

1.1.1 electric wheel design

the early development of electric vehicles is very rapid. the world's first electric car was born in 1834 years, than the first car engine vehicle early more than half a century. then, the world's first rechargeable battery powered electric cars appeared in france in 1881. the early stage of development of electric vehicles is from 1895 to 1911, during this period, due to internal combustion engine technology is not mature enough, the electric car price has more than internal combustion engine; and the steam car in a water, its mileage is not first rechargeable electric vehicles after the long driving range. therefore, at the time, popularization and development of electric vehicles is much faster than the internal combustion engines and steam cars, so it occupies 1/3 share of the car market, car in 1900 cases of america's total holdings of electric vehicles accounted for 38%, steam car accounted for 40%, accounted for only 22% automotive internal combustion engine. the three basically formed a situation of tripartite confrontation pattern. the most gratifying is that in 1899 years, electric vehicle with 106km/h speed was the maximum speed of the car broke the world record. however, the development of the electric car is not long. 1911 years, appeared in production line greatly reduces the automobile production cost; in addition, found a large number of oil engine fuel is ensured, which promoted the rapid development of internal combustion engine, the internal combustion engine vehicles over electric vehicles in terms of performance and price. at the same time, the electric car battery technology is not developed, and because of its long charging time, inconvenient to use, small capacity and other shortcomings, making its driving distance is far less than that of the internal combustion engine car. so, from the beginning of twentieth century 30 at the end of the 1970s, a situation of tripartite confrontation situation being gradually broken, good dynamic performance of internal combustion engine will completely replace electric cars and steam car in the car market, car engine under the condition of the electric car lord it over a district, temporarily withdrew from the stage of history. however, with the continuous awakening of human awareness of environmental protection, electric vehicles in twentieth century 70 in the 1980s and developed. the second half of the twentieth century, people through investigation and study for years to know, 1943 years autumn in losangeles city caused byphotochemical smoke events and arch-criminal local residents, the yellow plant is in the internal combustion engine exhaust. subsequently, the united states to develop regulations to limit emissions of harmful substances in the exhaust gas of internal combustion engine, at the same time, electric vehicles have begun to be of concern. of course, the electric car back to the stage of history is mainly due to energy issues. the two oil crisis in 1973 years and 1979 years, it is clear that oil is not renewable energy, can only use 60 to 100 years, if long-term use of internal combustion engine, not only will cause serious pollution to the atmosphere, will lead to oil resources exhaustion. since then, in the case of electric vehicles to replace the internal combustion engine car is getting higher and higher, the electric vehicle has entered a stage of rapid development. the so-called "new generation of electric vehicles" refers to the twentieth century after the electric car in the year of 70s, the latter mentioned in this article refers to a new generation of electric vehicles. but the development of electric cars in developed countries is not as smooth as people think. from twentieth century 80s, along with the rapid development and exhaust gas treatment device of internal combustion engine is used, the exhaust emissions of internal combustion engine has reached the requirements, internal combustion engine develops rapidly, which contain the development scale of electric vehicles grow to a great extent. at the same time, the automobile industry in developed countries, automotive industry has formed a large scale production, fuel supply network extending in all directions, very perfect, if the overthrow, and to establish the electric vehicle charging network, the price is quite high. therefore, the developed countries have always been difficult to resolve the following efforts to develop electric vehicles. furthermore, the electric car itself factors, although countries have invested a lot of high specific power, high specific energy, a long time charge of electric vehicle battery drive, but the range of electric vehicles is always better than internal combustion engine vehicle. although the united states of california, the government has stipulated that, from 1998 onwards the annual sales of electric vehicles must be at least 2%, to 2001 have reached 5% to 2003 years, rose to 10%, but in view of the above a series of reasons, the plan was eventually aborted. this shows that the development of electric vehicles is facing strong resistance from the internal combustion engine car. but in our country, the situation is different. china's automobile industry started late, the reform and opening up for a variety of reasons, it is basically no development. after china's accession to the world trade organization, in order to quickly occupy the chinese market, foreign large automobile companies have introduced their mature internal combustion engine cars, rather than the introduction of electric vehicles, which is why? first of all, they have internal combustion engine core technology leader in china for decades, in order to obtain the maximum profit in the shortest time, only the most competitive vehicle; secondly, in the research and development of electric vehicles, they encountered a lot of difficulties and resistance. this is also reflected from the side, you can catch up with china in the aspect of internal combustion engine vehicle is not backward in a short time; but in some aspects of electric vehicles, we master the technology and some have reached the advanced level in the world, is expected to catch up with and surpass the developed countries. although the commercialization of electric vehicles is still time, but the early research work is essential. is based on

2. 研究的基本内容与方案

basic content of research

1. analysis of the development status and market demand of 1000kg electric wheel, collect the relevant data of electric wheel.

3. 研究计划与安排

1. the 7 semester of the 19-20 week to determine the topic selection of graduate design, graduate design task (parameters), the data collection.

2. the 8 semester of first week conception, literature retrieval, complete bernal.

3. the 8 semester of the 2-3 weeks internship, external data collection, complete the internship report.

4. 参考文献（12篇以上）

[1] chen xiaocen, yang guang, . mechanical design. beijing: higher education press, 2014.7 (in chinese)

[2] song youchuan. research on the design method of the electric wheel in the new generation electric vehicle [d]. master thesis of huazhong university of science and technology.2004