Most of the electric vehicle transmission parts are extremely compact and can only be equipped with a single transmission. This makes the motor run at a critical point for a long time, reducing the efficiency of the power output, but the BMW i8 was first equipped with a 2AT to solve the critical speed problem. . In an article on gearboxes, we saw that most electric vehicles can only achieve the performance of ordinary power cars by matching a compact single-stage gearbox. The author therefore proposes that conventional gearboxes be built in the future. The scene will become history. This point of view points out that the "multi-position gearbox" is a "legacy product" of the internal combustion engine era. Is it really so? Tesla being dragged by the gearbox at the finish Taking the best performance electric vehicle Tesla Model S P85 (hereinafter referred to as Model S) as an example, it can easily win at the start, but in the middle and late stages, it accelerates and loses opponents. The reason is that the problem lies in the Tesla-matched single-speed gearbox, which allows Tesla to use one gear at a time to complete the journey from the start to the maximum speed. This is equivalent to opening a fuel vehicle and driving without shifting after one block, until the speed is pulled up to the red line area, the engine cannot return to the optimal torque output range, and then the acceleration power is greatly reduced. Similarly, Tesla's "reacceleration potential" was also dragged down by this single-stage gearbox that will take over the world and will be surpassed by opponents in the middle. Single-stage gearbox reduces Tesla's potential The single-stage gearbox results in the torque output generated by the motor at one go. Perhaps the uninterrupted power output is beneficial to the start-up acceleration, but it is not conducive to the economical efficiency and comfort of the vehicle. Especially for the pursuit of performance using high-speed motor Model S, it configures a high-rotation motor power consumption is larger, and single-stage gearbox a block gear ratio, resulting in the vehicle cruising state is also at a high speed critical point, economy not tall. As for how severe the efficiency of the discount, you can look at the use of 47.5 kwh battery capacity of the Teng potential, the best cruising range of about 250 km, while the Model S configuration with a capacity of 85 kwh lithium battery pack, the best mileage for About 400 kilometers, Tesla is nearly twice as powerful as Teng, but its cruising range has not doubled. What are the advantages of multi-speed gearboxes? The multi-gear transmission has a smaller loss of power output than a fixed gear and can increase the power output efficiency of the engine. This is why R&D personnel are always eagerly pursuing the ultimate gear position of the transmission, taking into account the light weight and volume. The problem is that the gearbox will not increase the gear limitlessly. So if you can match a multi-speed gearbox with a reasonable range of speed ratios to optimize the timing of the motor power outbreak, it will greatly increase the economic efficiency, followed by continuous acceleration performance. Having said that the disadvantages of a block, the advantage of multiple blocks, electric car manufacturers are still using a single transmission, which is why? The key point is that the single stage has the advantage of extremely compact structure. The volume is much smaller than that of the ordinary gearbox. It does not require the clutch (motor output shaft is directly connected to the transmission instead of the internal combustion engine flywheel). The electronically controlled shifting structure is also simpler and more reliable than the hydraulic pressure. . The single-stage gearbox is outweighing the disadvantages and the main performance has been met with the current use, so it is widely used. This is not to say that the manufacturers have given up on improving their economy, but they have not paid attention to it now. GKN has introduced a two-stage gearbox for mass production of electric motors. Although there are still misnames in terms of number of gears, the performance of the BMW i8 after it was assembled has been better than that of a single-stage gearbox. Stone Crusher,Jaw Crusher,Crusher Machine,Rock Crusher Shaoxing Dongjing Machinery Instrument Equipment Co.,Ltd. , https://www.sxdj-machine.com