Replacing helical spring with other elastic elements

[THERMIK]

Hello,

I have some kind of positioning device that the back and for movement. The current block is positioned in the "0" position with helical spring. Helical spring produce noise and have insufficient range of stiffness.
I would like to replace helical springs with other elastic element (no gas spring).
Can you recommend me any isnt solution e.g. elestomer that is a durable compression and tension or material with quasi Newtonian fluid properties.

Thank you in advance.
//Termik

 

[drawoh]

THERMIK,

There are an awful lot of helical springs out there. A long leaf spring would centre your component. Do you have space for a leaf spring sticking out one side a considerable distance?

I suggest you set up a spreadsheet with your design parameters. Find a couple of spring catalogues. Punch in the spring specifications and see what works.

--
JHG

 

[Tmoose]

Is the noise caused by the springs rubbing on the inside wall of the cylinder? If you find a suitable helical springs then there are several fairly standard details that can provide quieter centering guidance.

here is one.

http://www.profender4x4.com.au/wp-content/uploads/2014/10/coilover-shock-absorber-25-coil-spring.jpg

 

[Lou Scannon]

Wave springs and Belleville springs are often considered as substitutes for helical springs when lower installed height is a priority.

"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz

 

[EdStainless]

What is causing the noise?

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P.E. Metallurgy, Plymouth Tube

 

[MikeHalloran]

THERMIK, your sketch seems to depict an enclosed tuned mass damper, as used to be found tucked in the corners of convertibles to compensate for lack of torsional stiffness in the frame. There seems to be no guide rod for the mass, which would of course make noise by bouncing off the chamber walls.
Filling the chamber with oil should reduce or at least change the noise.

Changing the spring rate would change the natural frequency of the damper, which may not be what you want.


Beyond that, I'm not clear what you're talking about. Do you have a native English speaker available to help you clarify what you want?




Mike Halloran
Pembroke Pines, FL, USA

 

[THERMIK]

I updated drawing with side view. My device is responsible for positioning "red block" on the drawing (skip what it is) so I cannot use leaf spring. I cannot merge spring with any oil as well. I would like to not apply any cylinder or guide for the helical spring.
Do you know any existing material for industry purpose or industry application with expanding rubber that you can see in chest expander (see below link).

http://www.nativefitness.se/våra-produkter/lifeline-usa/chest-expander-4603123

 

[moon161]

What if you locate the springs elsewhere, and use a cable and maybe pulley(s) to load and move the slider.

 

[MadMango]

What is the to distance travel for the centered component? What is the length change of your springs from extended to compressed? What loads are involved?

"Art without engineering is dreaming; Engineering without art is calculating."

Have you read faq731-376 to make the best use of these Forums?

 

[drawoh]

THERMIK,

This looks to me like an application for leaf springs. Search Google for information on die[ ]springs. I like the medium force, blue painted ones. These probably will not work for you, but the design guides are interesting reading. If the spring is over a certain length, you need to support it from buckling, either with a rod, or an external cylinder. If rod only has to stop buckling, it can be plastic, possibly fibre reinforced. The same goes for the cylinder. This will cut down your noise. If the spring is short enough, the ends can sit in pockets.

Extension springs do not buckle. Can you make them work?

There are people out there who machine coil springs. Maybe they can machine something out of Delrin. Your machine design textbook should tell you how to design coil springs.

Again, I suggest you set your design requirements up on a spreadsheet, and go through the catalogues. There is an incredible variety of coil springs out there.

--
JHG

 

[THERMIK]

Thank you all for the help.