3 ms·

My understanding is that CVTs are more like a chain, i.e. a segmented metal belt. It sure seems like they would be great for large trucks if they could be made

• vel0city 2y ago
  When people use the term "chain" in this context, they're usually thinking of it moving a sprocket with teeth that fit in between gaps on the chain. You're right that automotive CVTs are made with a lot of metal bits connected on a band for greater durability, but most would still just call it a belt as it relies on the friction between the edges of it and the cones to move the cones instead of pulling on teeth. Think the differences between a timing "belt" versus a timing "chain", but I do acknowledge a timing belt is usually non-metallic. Sure, one could spend quite a bit of money making it even beefier with more and more exotic materials, but in the end its kind of hard to match the friction efficiency of well-fitting gears directly connecting the torque. You're pretty much guaranteed to encounter more friction on the belt sliding on the cones compared to well lubricated and properly made gears, and more friction means more wear which means shorter life. But this is kind of the idea of eCVTs. Instead of belts sliding on cones (pulleys), they use motor/generators and novel gearset placements to change how the torque flows through the system. In this way friction is considerably reduced. There are no belts to stretch or wear out.
  • jazzyjackson 2y ago
    after hearing that the prius cvt didn't use a belt I had to watch a few youtube videos on planetary gearsets - mind bending stuff and dead simple to boot!