变速箱是汽车动力传输的核心部件，其作用是通过调整齿轮比，平衡发动机转速与车轮扭矩，从而适应不同驾驶场景。从传统机械到电子智能，变速箱技术经历了多次迭代。本文将系统介绍主流变速箱类型及其技术特点，帮助读者理解其工作原理与适用场景。

The gearbox is the core component of automobile power transmission, which adjusts the gear ratio to balance the engine speed and wheel torque, thus adapting to different driving scenarios. From traditional mechanical to electronic intelligence, gearbox technology has undergone multiple iterations. This article will systematically introduce the mainstream transmission types and their technical characteristics, helping readers understand their working principles and applicable scenarios.

一、手动变速箱（MT）：驾驶乐趣的“原始基因”

1、 Manual Transmission (MT): The "Primitive Gene" of Driving Pleasure

手动变速箱（Manual Transmission）是最基础的变速机构，由离合器、齿轮组和换挡杆组成。驾驶者需通过踩离合、拨换挡杆手动切换齿轮比。其优势在于结构简单、传动效率高（可达95%以上），且维修成本低。例如，五菱宏光MINI EV的手动版凭借低门槛操作，成为驾校教练车首选。但缺点是操作繁琐，城市拥堵路况下易疲劳。随着自动挡普及，MT逐渐退居入门级车型或性能车市场（如保时捷911 GT3保留MT以强化操控感）。

A manual transmission is the most basic transmission mechanism, consisting of clutches, gear sets, and shift levers. Drivers need to manually switch gear ratios by stepping on the clutch and shifting the gear lever. Its advantages lie in its simple structure, high transmission efficiency (up to 95% or more), and low maintenance costs. For example, the manual version of the Wuling Hongguang MINI EV has become the first choice for driving school coaches due to its low threshold operation. But the disadvantage is that the operation is cumbersome and prone to fatigue under congested urban road conditions. With the popularity of automatic transmission, the MT gradually retreated to the entry-level or performance car market (such as the Porsche 911 GT3 retaining the MT to enhance handling).

二、自动变速箱（AT）：舒适与可靠的“平衡大师”

2、 Automatic Transmission (AT): A Comfortable and Reliable 'Master of Balance'

自动变速箱（Automatic Transmission）通过液力变矩器与行星齿轮组实现自动换挡，无需驾驶者干预。其核心部件液力变矩器可缓冲发动机冲击，提供平顺的起步体验。例如，丰田爱信6AT因换挡逻辑聪明、可靠性高，被广泛应用于卡罗拉、汉兰达等车型。现代AT变速箱通过多挡位设计（如采埃孚8AT、奔驰9AT）提升燃油经济性，但结构复杂导致成本较高，维修难度大于MT。

Automatic transmission achieves automatic shifting through a hydraulic torque converter and planetary gear set, without the need for driver intervention. Its core component, the hydraulic torque converter, can cushion engine impact and provide a smooth starting experience. For example, the Toyota Aisin 6AT is widely used in models such as Corolla and Highlander due to its intelligent shifting logic and high reliability. Modern AT transmissions improve fuel economy through multi gear design (such as ZF 8AT, Mercedes Benz 9AT), but the complex structure leads to higher costs and greater maintenance difficulty than MT.

三、无级变速箱（CVT）：平顺经济的“节能专家”

3、 Continuously variable transmission (CVT): a smooth and economical "energy-saving expert"

无级变速箱（Continuously Variable Transmission）采用钢带或链条连接两组锥形轮，通过改变轮径比实现连续变速，理论上拥有无限挡位。其优势在于换挡无顿挫，且能始终让发动机保持在最佳效率区间。例如，日产轩逸搭载的CVT变速箱可使综合油耗低至5L/100km。但CVT的钢带承受扭矩有限，多用于小型车或混动车型（如丰田卡罗拉双擎），且急加速时易出现“打滑”现象，影响驾驶激情。

A continuously variable transmission uses steel strips or chains to connect two sets of conical wheels, and achieves continuous shifting by changing the wheel diameter ratio, theoretically having infinite gears. Its advantage lies in the absence of jerks during gear shifts and the ability to consistently maintain the engine in the optimal efficiency range. For example, the Nissan Sylphy is equipped with a CVT gearbox that can reduce the overall fuel consumption to 5L/100km. However, the steel strip of CVT has limited torque capacity and is mostly used for small cars or hybrid models (such as Toyota Corolla dual engine), and it is prone to "slip" during rapid acceleration, which affects driving passion.

四、双离合变速箱（DCT）：性能与效率的“双面手”

4、 Dual clutch transmission (DCT): a "dual hand" of performance and efficiency

双离合变速箱（Dual Clutch Transmission）结合了MT与AT的特点，通过两组离合器分别控制奇数挡与偶数挡，实现毫秒级换挡。其干式版本（如大众DQ200）成本低，但散热差；湿式版本（如大众DQ381）通过油液冷却，可承受更大扭矩，多用于高性能车（如奥迪S3）。DCT的传动效率接近MT（可达92%），但低速蠕行时易产生顿挫，需通过软件优化改善。

The Dual Clutch Transmission combines the characteristics of MT and AT, controlling odd and even gears through two sets of clutches to achieve millisecond level shifting. Its dry version (such as Volkswagen DQ200) has low cost, but poor heat dissipation; The wet version (such as Volkswagen DQ381) can withstand greater torque through oil cooling and is commonly used in high-performance cars (such as Audi S3). The transmission efficiency of DCT is close to MT (up to 92%), but it is prone to jerking during low-speed creeping and needs to be improved through software optimization.

五、序列式变速箱（SMG）：赛道专属的“暴力机器”

5、 Sequential Transmission (SMG): A Track Exclusive 'Violent Machine'

序列式变速箱（Sequential Manual Gearbox）常见于赛车，通过推拉换挡杆实现顺序升挡/降挡，无需离合器操作。其换挡速度极快（可低于50毫秒），但顿挫感强烈，且无法跳挡（如无法从3挡直接降至1挡）。法拉利SF90 Stradale的8速序列式变速箱专为赛道设计，兼顾高速竞技与日常驾驶，但民用车型极少采用。

Sequential Manual Gearbox is commonly used in racing cars, which achieves sequential upshifts/downshifts by pushing and pulling the shift lever, without the need for clutch operation. Its shifting speed is extremely fast (can be less than 50 milliseconds), but it has a strong jerking sensation and cannot jump gears (such as not being able to directly shift from 3rd gear to 1st gear). The 8-speed sequential transmission of the Ferrari SF90 Stradale is designed specifically for racing tracks, balancing high-speed competition and daily driving, but it is rarely used in civilian models.