While manual and automatic transmissions have been the dominant types for most of automotive history, continuously variable transmissions (CVTs) have carved out a growing niche for themselves. Although CVTs date back to the era of Leonardo DaVinci, they have gained widespread adoption in the automotive industry only in recent decades. This piece aims to provide a detailed understanding of CVTs, including how they operate, their advantages and disadvantages, and cost implications.
A Historical Perspective: The Journey of CVTs
The concept of a continuously variable transmission is not new; it was first conceptualized by Leonardo DaVinci in 1490. Despite being patented in 1886 and gaining some recognition by 1910, CVTs only started to feature prominently in automobile lineups around the 1980s. Still, many people today are unfamiliar with the mechanics and advantages of CVTs.
How Does a CVT Work?
Unlike automatic or manual transmissions that employ a fixed number of gears, CVTs function without gears—or rather, they function with an infinite number of gears. Traditional transmissions use three to six fixed gears to transfer power from the engine to the wheels, leading to a noticeable “surge” during gear shifts. CVTs, on the other hand, use a belt or chain connecting two variable-diameter pulleys. One pulley is attached to the engine and the other to the wheels. As these pulleys change size, the belt shifts position, resulting in a seamless and infinite range of gear ratios. This complex system is managed either hydraulically or electronically, using sensors to determine the optimal gear ratio for the current driving conditions.
Comparison with Automatic Transmission
While automatic transmissions also relieve the driver from manually selecting gears, they differ significantly in operation. Automatic transmissions use a predetermined set of gears and shift between them, whereas CVTs continuously vary the gear ratio without any fixed states. This offers a smoother and more efficient transition of power from the engine to the wheels, eliminating the jerky sensation often experienced with traditional automatic transmissions.
The Advantages of Using a CVT
Smooth Ride: Traditional transmissions shift gears at predetermined points, leading to a momentary pause or “jerk” as the vehicle moves from one gear to another. CVTs eliminate this jerkiness by continuously varying the gear ratio, ensuring a smooth, uninterrupted acceleration curve. This can make for a more comfortable and less stressful driving experience.
