4 ms·

Seems the flywheel in the device is what does the magic - dampening oscillations (which would demand the flywheel turn faster/slower, which its intertia will re

Seems the flywheel in the device is what does the magic - dampening oscillations (which would demand the flywheel turn faster/slower, which its intertia will resist). Then it gets put in series with normal dampers that reduce compression/expansion. The inerter cancels vibrations & high frequency movement while the usual shock absorption components handle the rest of the shock absorption, making a great team. Have I understood it right?

Daneel_ 1y ago
The key takeaway for me was that it actively resists the oscillations, making it a more effective damper than a shock absorber in a range of situations, but it doesn't replace the shock. Donut Media actually has a great video on the topic: https://www.youtube.com/watch?v=t58qjcNwEbo https://www.youtube.com/watch?v=t58qjcNwEbo As far as my understanding goes, it's basically a low-pass filter that also provides momentum in the direction of movement - this actively dampens spring oscillation (as opposed to a shock absorber, which passively dampens oscillation). It should be installed in parallel with the spring and shock.
brudgers 1y ago
If I understood the video correctly, the simple mechanical model is an inerter is the inverse of a spring. Analogous to a capacitor being the inverse of an inductor in an electrical model. Trying to find a better mechanical analog to the capacitor to optimize a passive suspension was the motivation because mass-damping suspensions had already been banned when active suspension got banned. But I probably misunderstood the video.
gorgoiler 1y ago
What the inerter does is it gives the feeling of greater inertial mass between the two ends of the device. If you push on the inerter it feels like you are pushing on a boat in a marina: slow go get moving when you push it, and slow to come to rest when you push (or pull) it back the other way. It does this because flywheels hold momentum but as angular momentum. The inerter converts linear motion to angular momentum. The gearing also it to give the same effect of an enormous inertial mass without itself being massive. My understanding as to why this is useful is as follows. Suspension works best when the vehicle is heavy and the wheels are light. Imagine a battle tank on ultra strong bicycle wheels: the tank would glide along as the wheels jump up and down over every dip and bump. Something similar happens when you drive home with a car load of paving slabs. Having a massive vehicle is a huge penalty though for other reasons. Battle tanks are not nimble! The only thing you really want the mass for is as an inertial mass in the suspension system. For accelerating and going around corners you’d rather it wasn’t there at all.

Daneel_ 1y ago

The key takeaway for me was that it actively resists the oscillations, making it a more effective damper than a shock absorber in a range of situations, but it doesn't replace the shock. Donut Media actually has a great video on the topic: https://www.youtube.com/watch?v=t58qjcNwEbo https://www.youtube.com/watch?v=t58qjcNwEbo As far as my understanding goes, it's basically a low-pass filter that also provides momentum in the direction of movement - this actively dampens spring oscillation (as opposed to a shock absorber, which passively dampens oscillation). It should be installed in parallel with the spring and shock.

brudgers 1y ago

If I understood the video correctly, the simple mechanical model is an inerter is the inverse of a spring. Analogous to a capacitor being the inverse of an inductor in an electrical model. Trying to find a better mechanical analog to the capacitor to optimize a passive suspension was the motivation because mass-damping suspensions had already been banned when active suspension got banned. But I probably misunderstood the video.

gorgoiler 1y ago

What the inerter does is it gives the feeling of greater inertial mass between the two ends of the device. If you push on the inerter it feels like you are pushing on a boat in a marina: slow go get moving when you push it, and slow to come to rest when you push (or pull) it back the other way. It does this because flywheels hold momentum but as angular momentum. The inerter converts linear motion to angular momentum. The gearing also it to give the same effect of an enormous inertial mass without itself being massive. My understanding as to why this is useful is as follows. Suspension works best when the vehicle is heavy and the wheels are light. Imagine a battle tank on ultra strong bicycle wheels: the tank would glide along as the wheels jump up and down over every dip and bump. Something similar happens when you drive home with a car load of paving slabs. Having a massive vehicle is a huge penalty though for other reasons. Battle tanks are not nimble! The only thing you really want the mass for is as an inertial mass in the suspension system. For accelerating and going around corners you’d rather it wasn’t there at all.