Research Center for Advanced Retarder for Vehicle of Tianjin Research Institute for Advanced Equipment of Tsinghua University was found on June 20th, 2016. The team led by Professor Desheng LI, includes one expert of ‘The Thousand Talents Plan’, one professor, two associate professors and a number of doctors and masters.

The goal of this research institute grasp the international forefront technology of retarder, expanding internal and international academic exchanges actively, doing theoretical and experimental research of retarder, cooperating with enterprises, completely solve the backward situation of our trucks retarder as own duty based on the intellectual resource of domestic well-known universities.

The content of research and industrialization of retarder as follows:
▶　The R&D and industrialization of electromagnetic liquid-cooled retarder series products applied on trucks;
▶　The R&D of retarder integrate with engine and flywheel;
▶　The R&D of energy recovery retarder;
▶　The R&D of electronic control unit of retarder;
▶　The research of military application of retarder;

The retarder is one kind of non-contact braking device, known as the third brake, it has three functions: first one is effectively guarantee the driving safety of oversize vehicle on mountainous road; second one is reducing the using cost of vehicle; third one is reducing the dust emission and noise of braking device, energy conservation and environmental protection.

At present, there are three main types of retarder products in the world. The first eddy current retarder was born in France in 1936. The hydraulic retarder was released by Voith in 1961. Besides, the engine exhaust brake installation was also released. These three types of retarder occupy the current main market. In the developed countries in Europe, the retarder has been widely adopted in accordance with the law in the 1980s. China has been promoted retarder on the certain level of transportation and city bus since 2002, and the vehicle which longer than 9 meters should be installed according to the law. However, the installation ratio of retarder on domestic heavy truck is very low, many vehicles install one bucket to spray water on wheel hub to solve the problem of braking when driving downhill. But, as the promotion of GB-7258-2012, the requirement of retarder on heavy track will occur blowout situation in the next years. The expected requirement of retarder will be around one million units, it is a huge market.

Comparing with other types, the eddy current retarder has 80 years’ application history, it has simple structure, low price, occupying large proportion of small and medium-sized retarder, and also be widely installed on Chinese vehicle. But, the defect is the big volume, heavy weight, energy consuming, high temperature, serious heat recession, so it was not recognized by large-sized vehicles’ market. The hydraulic retarder with small volume, light weight, low working temperature, larger brake torque and other advantages. But, it also has disadvantages of complex technology, high cost, after-sales maintenance inconvenience, and poor characteristic at low speed. It is pretty hard to promote widely due to these factors. The engine exhaust brake installation with low cost, while the brake torque is not enough at high speed. Generally, it is used to cooperate with hydraulic retarder in Europe.

For the shortcomings of foreign retarder and backward situation of R&D of domestic retarder, Professor Desheng LI has led team to research the new type retarder continually since 2006. The permanent magnet retarder (Figure.1) which early developed fills the international blank. It is not consume power when working, and the weight is light. However, the price of rare-earth magnet fluctuate sharply and the bad stability, it has not been able to get large-scale promotion. Based on R&D of permanent magnet retarder, the electro-magnetic liquid-cooled retarder with dual salient (Figure.2) was invented in 2011. It avoids the disadvantages of permanent magnet retarder, the working principle is same with the traditional eddy current retarder, while the basic parts from 36 drastically reduced to 4, the rotor with no fever, the stator with internal water cooling channel. The performance was enhanced significantly due to the way of liquid-cooled, the weight and cost is reduced greatly. It is one disruptive technology comparing with traditional eddy current retarder. Compared with the hydraulic retarder, it has no liquid dynamic seal, the technology difficulty greatly reduced, does not use the oil medium, free maintenance, and higher reliability. The invention has won the national invention patent and patent license in the United States.

The Yangzhou Anxing electromechanical technology co., LTD （http://www.axjdkj.com）was found in August 2013. The Anxing on the basis of patent of electromagnetic liquid-cooled retarder with dual salient, did the transformation of scientific and technological achievements. After more than two years of efforts, the developed coach series of retarder products (Figures.2) has been won exclusive sales from domestic major gearbox manufacturer (The Qijiang gear transmission co., LTD), it will obtain good social benefit and economic benefit.

Fig1  Liquid-cooled permanent magnet retarder with rear-mounted transmission

Fig2  Electromagnetic liquid-cooled retarder with dual salient
 

During the process of researching and developing tank's retarder, the team were invented one type retarder with embedded rotor, it is named electromagnetic liquid-cooled retarder. Compared with doubly salient structure，this retarder has three units. Moreover, it overcomes the shortcoming of traditional eddy current retarder, because the new retarder can reduce the rotor's weight and the rotational inertia. This retarder can be used to coach and truck. About the installation, it can be put in the back of gearbox, or the flywheel part of engine to reduce the weight of retarder exponentially.

As the social requirement of future, this team will research and develop energy recovery retarder to adapt the demand of energy conservation and emission reduction of the nation and international community.

Fig3 Electromagnetic liquid-cooled retarder with embedded rotor
 

This institute sincerely accept any proposal from you, also would like to carry out various forms of cooperation!



Contact us
Address: Building No.5, TI-Park , Hongshun Road, Huaming Hi-Tech Zone, Dongli Destrict, Tianjin, P.R.China
Postcode: 300300
Linkman: Prof. LI
Fixed-line Tel: 022-84958260
Mobile: 13693694962
Email: 13693694962@163.com
Category: Research instituteCategory
Keywords: Retarder, Electromagnetic field, Energy conversion, Automobile engineering, Automobile flywheel