CVT Transmission / how does it work?
Here's a look inside a continuously variable transmission and how it works!
A continuously variable transmission uses a steel push belt to transfer power from an input variator to an output variator. The diameter of the belt's input and output shaft varies, which determines the drive ratio. The variators are hydraulic cylinders that have a cone shape to the pulley section that interface with the belt. When fluid is added, the belt is adjusted to ride on a larger diameter. Meanwhile, fluid is released from the opposing variator, allowing the belt to ride on a smaller diameter. Both variators must be adjusted together for belt tension to be retained.
A planetary gear set on the output variator allows a change in direction for reverse gear, as well as a two speed step to increase the range of the CVT. Similar to an automatic transmission, a valve body controls how much fluid is applied to the variators, planetary clutches and torque converter.
Typical failures with CVT's include overheating - which is likely due to too much load on the unit from driving uphills, overloading the vehicle, worn fluid or towing conditions.
Moreover, if belt tension cannot be retained, the belt will slip and shudder. Finally, since the belt itself is fragile and made up of hundreds of pieces, any minor alignment or over application of torque can cause it to catastrophically disintegrate.
he CVT in this video is a Jatco CVT-7 unit from a 2020 Chevrolet Spark with only 2000km on it. The vehicle was in a collision and the engine and transmission units were working when removed!
CVT Transmission / how does it work?
Here's a look inside a continuously variable transmission and how it works!
A continuously variable transmission uses a steel push belt to transfer power from an input variator to an output variator. The diameter of the belt's input and output shaft varies, which determines the drive ratio. The variators are hydraulic cylinders that have a cone shape to the pulley section that interface with the belt. When fluid is added, the belt is adjusted to ride on a larger diameter. Meanwhile, fluid is released from the opposing variator, allowing the belt to ride on a smaller diameter. Both variators must be adjusted together for belt tension to be retained.
A planetary gear set on the output variator allows a change in direction for reverse gear, as well as a two speed step to increase the range of the CVT. Similar to an automatic transmission, a valve body controls how much fluid is applied to the variators, planetary clutches and torque converter.
Typical failures with CVT's include overheating - which is likely due to too much load on the unit from driving uphills, overloading the vehicle, worn fluid or towing conditions.
Moreover, if belt tension cannot be retained, the belt will slip and shudder. Finally, since the belt itself is fragile and made up of hundreds of pieces, any minor alignment or over application of torque can cause it to catastrophically disintegrate.
he CVT in this video is a Jatco CVT-7 unit from a 2020 Chevrolet Spark with only 2000km on it. The vehicle was in a collision and the engine and transmission units were working when removed!
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