The newly disclosed patent seems to be an updated version of the patent that Mazda applied for earlier last year. Both patent applications describe in detail rear-wheel drive vehicles equipped with front engines. The car is equipped with two hub motors on the front axle and a third motor, a capacitor and a small lithium-ion battery at the rear of the engine. The first patent document shows an in-line four-cylinder engine, but the patent document published on April 9, local time describes a V-type engine with unknown cylinder number and Wankel rotary cylinder engine.
The traditional problem of hub motor is that it will increase the unsprung load, which may have a negative impact on driving and driver control. Mazda's solution is to equip the front wheel hub with a relatively small engine, which is driven by a double-layer capacitor in the engine compartment (the top of the rotating engine or between the cylinders of a V-shaped engine). Capacitors can release energy quickly and recover braking energy more effectively than batteries. In addition, Mazda also uses a speed sensor to indicate when the front wheel hub motor can be used.
But how does Mazda intend to drive the wheel hub with such a small motor? The working voltage of hub motor and capacitor is higher than that of other parts of the car (120V). Higher voltage means that the motor can generate the same power as the lower voltage motor under the condition of lower current, and lower current means that smaller wire groups and windings can be realized. According to this patent document, all these contribute to the realization of a compact and lightweight electric all-wheel drive (e-AWD) solution. In addition, due to the leverage, the hub motor will not have the same torque advantage as the shaft end motor.
In order to adapt to the voltage of different systems, Mazda also uses three inverters, one of which is connected with the main drive motor between the engine (without flywheel) and the transmission shaft. This 25kW permanent magnet synchronous device consists of a 48V? 3.5 kW lithium-ion battery pack (oddly, this battery pack is placed in the drive shaft channel, below the center of the vehicle) provides power, which can drive the rear wheels and can also replace the internal combustion engine. Crucially, this design occupies the space of the traditional gearbox (the rear of the engine), so Mazda's design also needs a rear drive axle.
According to the patent document, one of the advantages of the rear drive axle is that there is no gearbox protruding from the car floor, which can make the front space of the car larger, thus allowing Mazda to design more symmetrical seat positions in the center of the car. In addition, the rear drive axle can better distribute the weight of vehicles with front engines, and it is also a common device in high-performance vehicles such as Corvette.
Therefore, the design of hybrid electric vehicle with front engine, all-wheel drive and rotary cylinder engine is very complicated. Although the system is likely to be suitable for the upcoming rear-wheel drive mazda 6 and its inline six-cylinder engine, another Mazda patent application document shows that the power system will also be equipped with a traditional eight-speed gearbox. (The pictures in the text are all from motortrend.com)
This article comes from car home, the author of the car manufacturer, and does not represent car home's position.