Construction of CVT Metal push belt

[Yaksha]

I am trying to understand the construction of CVT Metal belts that are made up of steel elements and some rings. I do not understand the full construction details of the belt.
The most detailed information I have got ever is in this PDF on page 5
http://www.ijera.com/papers/Vol5_issue3/Part - 1/S5030199105.pdf

Specifically, I want to know about

• How do the elements not move backwards on the rings?
• How does this belt transmit power by compression than tension?
• How does the ring flex?

A complete explanation on the construction would be very helpful.

 

[Nidum]

 

[Nidum]

Is this a homework problem ?

 

[Yaksha]

Is this a homework problem ?

No we are solving a design problem and we wanted to incorporate the pushbelt in our design. So I want to understand the construction details properly and its working. Could you please go into the construction details?

 

[JBA]

By looking at the figure in the below you will see that the tapered inner faces of the pulleys are radially grooved so as to engage with the edges of the lateral segments on the belt in order for one pulley to "push" the other.

https://en.wikipedia.org/wiki/Variomatic

 

[Yaksha]

By looking at the figure in the below you will see that the tapered inner faces of the pulleys are radially grooved so as to engage with the edges of the lateral segments on the belt in order for one pulley to "push" the other.

https://en.wikipedia.org/wiki/Variomatic

This is a CVT chain and not the metal push belt i am talking about. Of course, i do understand that the application is same.

To all those answering this thread, I sincerely request you for a very detailed technical explanation OR answers to the the questions in the first message on the thread, rather than speaking in general terms.

Thank you

 

[CWatters]

Specifically, I want to know about

[*]How do the elements not move backwards on the rings?

The elements are driven by the drive pulley. Friction between the elements and the ring drives the rings. The rings are in tension. Imagine jamming your fingers in a rubber belt drive, you can bet they would be dragged around the pulley rather than slide backwards along the belt.

[*]How does this belt transmit power by compression than tension?

With a rubber belt one side is under greater tension than the other. On a metal belt the elements aren't fixed together so they cannot be in tension. Instead the driving pulley pushes the elements on the other side. Normally it would be hard to push something flexible (like trying to push a string) but the rings are in tension and act as a guide for the elements. It's more like pushing washers along a rigid rod.

[*]How does the ring flex?

The rings are laminated from 9-12 thin layers of very thin flexible metal. I believe these must stretch very slightly so the load is shared between all the layers.

 

[Yaksha]

The elements are driven by the drive pulley. Friction between the elements and the ring drives the rings. The rings are in tension. Imagine jamming your fingers in a rubber belt drive, you can bet they would be dragged around the pulley rather than slide backwards along the belt.

With a rubber belt one side is under greater tension than the other. On a metal belt the elements aren't fixed together so they cannot be in tension. Instead the driving pulley pushes the elements on the other side. Normally it would be hard to push something flexible (like trying to push a string) but the rings are in tension and act as a guide for the elements. It's more like pushing washers along a rigid rod.

The rings are laminated from 9-12 thin layers of very thin flexible metal. I believe these must stretch very slightly so the load is shared between all the layers.

Thanks a lot for the answer! I have got a very clear idea now!

If I have got it right, there are two friction interfaces here right?

• One between the element and the pulley.
• The other between the element and the rings.

 

[CWatters]

Yes.