The hub motor system is used in all kinds of vehicles. Different applications on the wheel motor structure and technical performance and so put forward a different request, the corresponding generation of a variety of wheel motor system and its characteristics of technology. This paper mainly analyzes the system characteristics of the hub motor.
Often, electric vehicles use a centralized motor-driven powertrain structure type.
This type of structure has the following advantages:
(1) can be used in the internal combustion engine power car part of the transmission device, arranged in the original engine compartment, good success;
(2) can be used motor and deceleration mechanism, and even the controller of the integrated structure type, compact structure, easy to handle motor cooling, vibration isolation and electromagnetic interference and other issues;
(3) The overall layout of the vehicle is close to the internal combustion engine, the front cabin heat management, sound insulation and collision safety are close to or easy to handle with the original car.
The downside is:
(1) drive chain length, transmission efficiency is low;
(2) usually require the use of high-speed high-power motor, the motor performance requirements.
The distributed motor drive has the following advantages relative to the centralized motor drive:
(1) to electronic differential control technology to achieve the internal and external wheels when turning different speed movement, and more accurate;
(2) to cancel the mechanical differential device is conducive to reduce the quality of power systems to improve transmission efficiency and reduce transmission noise;
(3) is conducive to the overall layout of the vehicle optimization and vehicle dynamics performance matching optimization;
(4) to reduce the performance requirements of the motor, and has the characteristics of high reliability and redundancy.
However, the decentralized motor drive method has the following disadvantages:
(1) to meet the round of movement coordination, the synchronization of multiple motor control requirements are high;
(2) The dispersion arrangement of the motor presents the technical problems such as structural arrangement, thermal management, electromagnetic compatibility and vibration control.
Dispersed motor drive usually has two kinds of wheel motor and wheel motor. The so-called wheel-side motor means that each drive wheel is driven by a separate motor, but the motor is not integrated in the wheel, but is connected to the wheel by means of a drive, such as a drive shaft. Wheel motor drive motor is a range of spring, the suspension system vibration isolation performance. However, the motor mounted on the vehicle body has a great influence on the overall layout of the vehicle, especially in the case of the rear axle drive. Moreover, due to the body and the wheel between the existence of a large deformation movement, the transmission shaft of the universal transmission also has some restrictions. Compared with the wheel motor mode, the wheel motor mode has obvious advantages, including:
(1) can completely omit the transmission of the transmission device, the overall power efficiency greatly improved;
(2) wheel motor makes the overall layout of the vehicle can be flat with the chassis structure type, interior space and layout degrees of freedom have been greatly improved;
(3) the body almost no high-power moving parts, the vehicle's vibration and noise comfort has been greatly improved;
(4) wheel motor way to facilitate the realization of four-wheel drive drive type, is conducive to greatly improve the vehicle's dynamic performance;
(5) wheel motor as an actuator, the use of fast response speed and accurate advantages to facilitate the realization, including wire-driven, linear control and dynamic control of vehicle-driven vehicle dynamics, including integrated control to improve the vehicle's initiative safety.