In recent years, thanks to a grater awareness concerning the need for environmental improvements, there has been an increase in vehicles using electric motors such as EVs and HEVs. Crucially, there are now increased expectations of enhanced kinematic and safety performance in vehicles, as well as improved transmission efficiency. With regard to in-wheel motor loaded vehicles, improved running stability by left- and right-wheel independent driving can be expected and, thanks to the reduction of the transmission path, improved response can also be realized. Problems regarding the in-wheel motor unit include feasibility of the structure using the suspension and how to secure reliability in a severe under-spring environment. The motor also faces many other problems such as achieving a smaller size, lighter weight, and cooling. It therefore remains difficult at this stage to put an in-wheel motor for passenger vehicles to practical use. Toyota Motor Corporation has developed an in-wheel motor system to deliver the functions of steering and suspension, as well as in-wheel drive. A procedure for selecting the proper motor pole number and gear ratio was established by determining the outer diameter of the motor and reduction gear, based on the loading restrictions of peripheral parts (such as a brake) and by considering the balance of each parameter among them. According to the above procedure, by downsizing the motor through multipolarization, etc., and by performing design for peripheral parts, it was possible to design and prepare a unit capable of being loaded on and run an 18-inch wheel. In order to achieve practical applications of the in-wheel motor, the issues listed below must be resolved in the future. (1) Securing the reliability of the unit under the severe environment of the wheel. (2) Downsizing the power cable and connector, and enhancing durability. (3) Reducing the unsprung mass so as to ensure a comfortable ride. (4) Securing the cooling performance of the motor, which it is difficult to subject to a cooling wind. (5) Improving the feasibility of the structure using a suspension, and reliability. In the future, we intend to evaluate heat and vibration using the research vehicle and clarify the design requirements of the in-wheel motor. Moreover, we plan to develop element technology with an aim for smaller and lighter weight units.
Development of an in-wheel motor system
Entwicklung eines Radmotorsystems
Review of Automotive Engineering (JSAE) ; 28 , 3 ; 371-376
2007
6 Seiten, 12 Bilder, 4 Tabellen, 4 Quellen
Article (Journal)
English
Anwendung im Fahrzeugbau , Anwendung im Motorenbau , technische Entwicklung , Einzelradantrieb , Elektroantrieb , Pkw (Personenkraftwagen) , Fahrzeugfederung , Fahrzeuglenkung , Fahrverhalten , Fahrzeugsicherheit , Gerätezuverlässigkeit , technische Beschreibung , Downsizing (Rechnernetz) , Lebensdauer , Motorkühlung , Fahrzeugerprobung
Development of the In-Wheel Motor System
British Library Conference Proceedings | 2006
|Six-wheel motor-vehicle development history
Engineering Index Backfile | 1930
|Six-wheel motor-vehicle development history
Engineering Index Backfile | 1930
|