Belleville spring characteristics on clutch actuation

[k.udhay]

Hi,

I have been working on designing something for a clutch. The clutch plate is pressed against the pressure plate using a belleville spring. The belleville spring is connected to the clutch pedal using a linkage with leverage. I came across a graph that describes the displacement of the linkage (this value divided by leverage will give the clutch plate movement) and the force at the linkage at that point. The graph is attached.

As you can see, the mechanism needs totally a different pattern of forces to displace the clutch between new and old. Especially when the clutch is new, the curve is flat at some place and climbs up again. For an old clutch condition there is no flat portion as such and there is a drop of force after a displacement of 12 mm.

Can someone pl explain why this happens? Thanks.

 

[kazx9r]

Man this is confusing, are you saying your using a belleville spring against the belleville spring already on the pressure plate?

 

[Pkruse]

I've done a lot of work with Belleville spring washers, but never in a clutch. I'm at a loss to explain this behavior, but it does not surprise me. Belleville springs are prone to doing things that seem strange at first, but can eventually be understood after testing and analyzing the system as a whole. One spring can behave much differently from another. Some have maximum force at full deflection, whereas others switch to zero force at full deflection.

I would also like to know how many springs you have in the system and how they are orientated with respect to each other. It is common to use more than one, and it matters how you stack them.

 

[k.udhay]

Man this is confusing, are you saying your using a belleville spring against the belleville spring already on the pressure plate?

No... The pressure plate is operated by a belleville spring. A mechanism with some leverage actuates the pressure plate. The graph shows the force and displacement on the mechanism to operate the belleville spring...

Thanks.

 

[k.udhay]

I've done a lot of work with Belleville spring washers, but never in a clutch. I'm at a loss to explain this behavior, but it does not surprise me. Belleville springs are prone to doing things that seem strange at first, but can eventually be understood after testing and analyzing the system as a whole. One spring can behave much differently from another. Some have maximum force at full deflection, whereas others switch to zero force at full deflection.

I would also like to know how many springs you have in the system and how they are orientated with respect to each other. It is common to use more than one, and it matters how you stack them.

Hi. Thanks for the answer. It has only one spring I think. I actually haven't seen the arrangement yet. The graph was handed-over to me and nothing else...