Vibrations are never invited in the world of machines. Be it cars, motors, machine tools, buildings and constructions or oil and gas platforms, vibrations create huge troubles for these industries.

With competitive price and timely delivery, Sanshi sincerely hope to be your supplier and partner.

And this is where the vibration absorber sets its foot in. Utilizing the rubber components design & manufactured by Sujan Industries, one of the pioneers among the top rubber companies in India, the vibration absorbers help to reduce the unwanted vibrations and ensure smooth running of the entire process.

Now let&#;s start the basics before we dive deep into the reasons for rubber being used in vibration absorption.

What is Vibration Absorber?

Vibration, in dynamic machines, occurs when there&#;s an imbalance of moving mass. It causes an undesirable vibration and stress that minimizes the durability of the machine.

Now, to get rid of the vibration, a tuned spring and secondary mass as a system are attached to the revolving apparatus. This technique is called vibration absorption and the mass-spring system is called vibration absorber.

Why is Rubber Used as Vibration Absorbers?

Rubbers are compounded with such various additives that make it so versatile and useful for almost limitless numbers of industrial applications. Specifically, natural rubbers are valuable as spring materials for their longevity, flexibility, lower price and durability in high temperatures.

Besides, Rubber has enough high shear modulus compared to other materials. That means, when a rubber material is a stressed parallel to its cross-sectional area, it can be stressed more before it becomes completely deformed. Whenever rubber materials receive any vibrational stresses, rubber vibration absorbers absorb them before damage or transferring the vibrations. All these aspects make rubber a great component for vibration absorption, indeed. Hence, Rubber is the best material used as a vibration absorber.

Passive Vibration Absorbers

Among various types of vibration absorbers, one that is used daily and widely is passive vibration absorber. This consists of a spring and damper. Whereas the spring softens the vibrations and pushes, the damper ends the oscillation. Mainly the spring acts as the absorber here and the damper helps the spring to do the task.

There are a handful of instances of the passive vibration absorbers that are used daily. One such instance found is the suspension bracket of an automobile. One can easily understand the operations of passive vibration absorbers and isolators by the way it works in automobile suspensions. The rubber parts found in every suspension bracket soften the push and impact of the road on which the automobile travels. Another element of the suspension found in an automobile is the shock-absorber.

Advantage of Rubber over Steel in Passive Vibration Absorber

Most of the time when we think of spring, an image of a spiral metal comes to our mind. But the spring used in Passive Vibration Absorbers has to be of rubber for different reasons.

With steel springs, there&#;s a linear relationship between the force and the bounce. But rubber springs can be designed to give varied stiffness in non-linear directions. Rubber materials are much more stretchable than steels before they get completely damaged.

Rubber products are easier and more convenient to handle and install than steel springs. Also rubbers have more capacity to store energy and when deflected it has the potential to convert some energy to heat. This is the reason why heat doesn&#;t spread in rubber much unlike steel.

Natural rubber without fillers can provide damping in a system subjected to vibrational forces. Thus unlike steel, the inherent damping ability in rubber makes it more potential as a vibration absorber.

The Largest Rubber Company in India

Sujan Industries is one of the largest rubber products manufacturers in India. It is an exceptional wing of the Sujan Group with multiple plants producing Rubber Parts, Antivibration components and Casting Components etc. World-class rubber goods for industrial applications and other such purposes produced in Sujan Industries includes, but not limited to, the following:

• Side Bearer
• Fiat Bogie Parts
• Pu Roller
• Pu Seal
• Ballast Broom
• Draft Gear Pad
• NBC Pads
• Rubber boot
• Strut Mount
• Shackle Assembly
• Cab Mount
• Engine Mount
• Gasket & Seal
• Casting Parts etc.

Apart from providing a wide variety of critical application anti-vibration rubber products that ensure excellent quality, high durability, low service intervals & more stability during working conditions, they also supply aftermarket products for Car, truck & trailer parts replacement.

Since inception Sujan Industries has always focused on Innovation & Creativity. Being a strong believer of the saying &#;innovation stimulates the progress of any organization,&#; they innovate in every way, be it new and improved products, techniques, practices of development & production and so on. The company heavily invests in research and development and keeps themselves up to date with the new introductions, requirements, trends and demands of the market.

Sujan Industries also provide design solutions and products to the core public sectors of India like:

• Aerospace
• Railways
• Off-Highway
• Defence
• Automotive
• Power
• Electrical
• Engines
• Commercial Vehicles
• Casting etc.

Why Sujan Industries is the Best among All?

Quality is the pride of workmanship. And Team Sujan Industries, with their approach to state-of-the-art equipment and a dedicated R&D department, extends the concept of excellence to the maximum. Committed to produce and supply only high quality products, they believe in the saying &#;Quality is never an accident; it begins with the intent, which is fixed by management.&#; Apart from the latest machinery, the company&#;s quality control system ensures excellence at every stage of production to manufacture premium products that are truly unparalleled.

Wrap Up

To sum up, the natural properties of rubber like flexibility, firmness, stress resistance, endurance etc. makes the rubber an ideal material for absorbing vibrational forces in any machine.
Have more queries on rubber products? Get in Touch with us to explore new business possibilities.

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DIY Shock: Rubber vs Hydraulic Damping + Information Help

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DIY Shock: Rubber vs Hydraulic Damping + Information Help

DIY Shock: Rubber vs Hydraulic Damping + Information Help

ChrisDanger

(Mechanical)

(OP)

21 Jul 16 14:34

The way I see it, a rubber damper might suffer from wear and need friction elements replaced fairly frequently (also giving a declining performance), whereas the hydraulic damper might be (slightly?) more expensive to produce but last longer between maintenance schedules (and give more uniform performance over time).

Both designs have stumbling blocks. I can't find any guidelines on gland dimensions, seal material, or required surface finish for any friction dampers. And for the hydraulic shock how is oil inserted and topped up? I imagine some kind of valve but again, I couldn't find any information on this either.

Preliminary designs are below for reference.

Elastomeric:


Hydraulic:

I'm helping a friend design a coilover shock for a wheelchair for his nephew. He suggested using an o-ring or seal friction damper, but after not finding much information to aid in design I wondered if using hydraulics would be viable, but I couldn't find much information on that either. I'm wondering two things: Which would be cheaper in the long term, and where can I find information about design details? He works in a machine shop and will be fabricating everything himself.The way I see it, a rubber damper might suffer from wear and need friction elements replaced fairly frequently (also giving a declining performance), whereas the hydraulic damper might be (slightly?) more expensive to produce but last longer between maintenance schedules (and give more uniform performance over time).Both designs have stumbling blocks. I can't find any guidelines on gland dimensions, seal material, or required surface finish for any friction dampers. And for the hydraulic shock how is oil inserted and topped up? I imagine some kind of valve but again, I couldn't find any information on this either.Preliminary designs are below for reference.Elastomeric:Hydraulic:

Replies continue below

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RE: DIY Shock: Rubber vs Hydraulic Damping + Information Help

KENAT

(Mechanical)

21 Jul 16 14:56

If you're going to use rubber, why not use the rubber as both the spring & the damper? As I recall the DeHaviland Mosquito used a stack of O-rings as it's suspension. Googling 'rubber spring suspension' got me some hits that explained the idea.

In the top one, are you saying the damping will be from the friction of the rubber O-rings against teh internal walls of the cylinder? Does seem like you may have wear issues. It will also be acting as a pneumatic spring won't it - unless you have a relief valve I don't see.If you're going to use rubber, why not use the rubber as both the spring & the damper? As I recall the DeHaviland Mosquito used a stack of O-rings as it's suspension. Googling 'rubber spring suspension' got me some hits that explained the idea.

Posting guidelines FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm? (probably not aimed specifically at you)
What is Engineering anyway: FAQ-: In layman terms, what is "engineering"?

RE: DIY Shock: Rubber vs Hydraulic Damping + Information Help

GregLocock

(Automotive)

21 Jul 16 15:38

For hydraulics you just unscrew the top and pour oil in. If you want get fancy put a fill plug or Schrader valve in the bottom. Look at mountain bikes for ideas, personally I think you'd be nuts to go with rubber.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?

RE: DIY Shock: Rubber vs Hydraulic Damping + Information Help

drawoh

(Mechanical)

21 Jul 16 15:53

A lot of commercial and military anti-vibration mounts are stuffed with wire mesh to provide damping.

How badly do you need damping on this thing, or an automotive style suspension? Wheelchairs do not go very fast. If I were designing one, I would go for sturdy, light weight, stable and cheap. I don't see a suspension helping with this.

ChrisDanger,A lot of commercial and military anti-vibration mounts are stuffed with wire mesh to provide damping.How badly do you need damping on this thing, or an automotive style suspension? Wheelchairs do not go very fast. If I were designing one, I would go for sturdy, light weight, stable and cheap. I don't see a suspension helping with this.

--
JHG

RE: DIY Shock: Rubber vs Hydraulic Damping + Information Help

btrueblood

(Mechanical)

21 Jul 16 16:06

In the first drawing, you would probably get some leakage past the triple o-rings, thus a pneumatic damper. If you deliberately created a leak path for the air (via an orifice, or cut gaps in the o-rings) you could actually control/tune the amount of damping, just like you could by sizing the orifice(s) in the hydraulic fluid version's piston.

RE: DIY Shock: Rubber vs Hydraulic Damping + Information Help

ChrisDanger

(Mechanical)

(OP)

21 Jul 16 16:16

Greg, I was thinking of just filling with oil and screwing in the plug but wasn't sure if an excess pressure would damage the seal if it was overfilled. I'll look at putting a valve in, and at mountain bike shocks for ideas. Thanks. (PS Thought I recognised your name from f1t. Searched and first result was a thread on dampers/shocks )

drawoh, I've used a wheelchair without suspension and it's not fun. I wouldn't want to subject the little guy to any more discomfort than is possible.

Thanks for your help guys.

EDIT: btrueblood, yeah, unintentional design flaw there. Damping was supposed to be from friction between the triple rings and inner cylinder surface.

Hi KENAT. Thanks, yeah, I should've added some kind of pneumatic relief to the design.Greg, I was thinking of just filling with oil and screwing in the plug but wasn't sure if an excess pressure would damage the seal if it was overfilled. I'll look at putting a valve in, and at mountain bike shocks for ideas. Thanks. (PS Thought I recognised your name from f1t. Searched and first result was a thread on dampers/shocksdrawoh, I've used a wheelchair without suspension and it's not fun. I wouldn't want to subject the little guy to any more discomfort than is possible.Thanks for your help guys.EDIT: btrueblood, yeah, unintentional design flaw there. Damping was supposed to be from friction between the triple rings and inner cylinder surface.

For more information, please visit Rubber Damper.

RE: DIY Shock: Rubber vs Hydraulic Damping + Information Help

MintJulep

(Mechanical)

21 Jul 16 17:02
I think rubber o-rings would not last very long.

Proper Friction Snubbers use friction material that is basically the same as brake pad material.I think rubber o-rings would not last very long.

RE: DIY Shock: Rubber vs Hydraulic Damping + Information Help

ChrisDanger

(Mechanical)

(OP)

21 Jul 16 17:19

Hi MintJulep. Thanks for the info. I'll look into this option too.

RE: DIY Shock: Rubber vs Hydraulic Damping + Information Help

gruntguru

(Mechanical)

21 Jul 16 17:20

You should be able to find a coil over damper to suit your application at far lower cost and fewer tears than DIY. Mountain bike sounds like a great starting place.

je suis charlie

RE: DIY Shock: Rubber vs Hydraulic Damping + Information Help

ornerynorsk

(Industrial)

21 Jul 16 17:23

My dayjob is currently in medical equipment, so I deal with a lot of these parts and components. Presuming that your friend's wheelchair is electric, have you absolutely verified that there is no suspension currently in the chassis? Many (most) chairs do have some suspension. Get ahold of the manual, and barring that, talk to the technician at the dealer. There are also some really good "flotation" cushions available to reduce pressure concentration, ROHO being one of the better ones.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

RE: DIY Shock: Rubber vs Hydraulic Damping + Information Help

ChrisDanger

(Mechanical)

(OP)

21 Jul 16 17:51

Hi gruntguru. Yeah, we're looking at maybe producing a few of these for the other kids at the school, so it may not be a 1-off. My friend is keen to make everything himself for that custom look. He only has to pay for material, and tears we can handle. Hopefully we get it more or less right first time, although clearly at this stage we don't really know what we're doing. I have plenty of free time though, and am eager to apply some of my engineering knowledge.

Hi ornerynorsk. We're fabricating this chair (manual, not electric) totally from scratch. Thanks for the advice though. Will pass the ROHO recommendation on.

RE: DIY Shock: Rubber vs Hydraulic Damping + Information Help

ornerynorsk

(Industrial)

21 Jul 16 18:17

This

OK, got it. Mountain bike shocks as a previous poster mentioned are well worth consideration, as are non-locking gas springs.This http://softwheel.technology/theacrobat/ may also be of interest.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

RE: DIY Shock: Rubber vs Hydraulic Damping + Information Help

ChrisDanger

(Mechanical)

(OP)

21 Jul 16 18:51

Thanks. Yeah, I saw a video of those. Very interesting concept. A bit like the below, but using a more conventional method.

RE: DIY Shock: Rubber vs Hydraulic Damping + Information Help

SwinnyGG

(Mechanical)

21 Jul 16 19:30

You can buy an off-the-shelf MTB shock for less than $50. Considering what's required to make a shock that actually works (high-end materials, hardened shaft with very fine chroming, intricately machined parts with fine surface finishes, etc) I doubt your buddy will be able to beat that, even only paying for materials.

A shock designed for a mountain bike, if used on a wheelchair, is going to last probably until the end of time. They are low maintenance as it is, and a shock on a mountain bike takes a LOT of abuse.

If you want to take it on as a design exercise then that's fun, but for cost and performance you won't be able to beat something off the shelf.

RE: DIY Shock: Rubber vs Hydraulic Damping + Information Help

Tmoose

(Mechanical)

21 Jul 16 20:09 http://u.cubeupload.com/ChrisDanger/Hydraulic.png

Will this damper be mounted shaft ~ vertical?
When the damper compresses, the volume of the shaft reduces the space within the shock.
If the shock is full of oil the damper won't be able to compress at all.
Real shocks provide a volume of gas to compress so the displaced oil has some place to go when the shock is compressed/shortened.

https://upload.wikimedia.org/wikipedia/commons/thu...

http://1.bp.blogspot.com/-Y7cwzj1-4Rg/T3mKrzT1CiI/...

A few include a volume of gas that was intended to mix with the oil and form an emulsion, and the valving in the shock was designed to perform with the emulsion, not "pure" oil.
British manufacturer Girling offered an emulsion shock for off road motor cycles.

Will this damper be mounted shaft ~ vertical?When the damper compresses, the volume of the shaft reduces the space within the shock.If the shock is full of oil the damper won't be able to compress at all.Real shocks provide a volume of gas to compress so the displaced oil has some place to go when the shock is compressed/shortened.A few include a volume of gas that was intended to mix with the oil and form an emulsion, and the valving in the shock was designed to perform with the emulsion, not "pure" oil.British manufacturer Girling offered an emulsion shock for off road motor cycles.

RE: DIY Shock: Rubber vs Hydraulic Damping + Information Help

ChrisDanger

(Mechanical)

(OP)

22 Jul 16 10:20

Riiiiiight. I did see the gas-filled chamber but I thought this was to regulate oil pressure to prevent cavitation which I figured wouldn't be a problem in this application. So that shock will not work. That's quite a serious oversight, thanks!

I'm starting to lean towards buying one. They're not so cheap or available here in South Africa but I'll see what I can do.

RE: DIY Shock: Rubber vs Hydraulic Damping + Information Help

Tmoose

(Mechanical)

22 Jul 16 14:11
And some space is still needed for thermal expansion of the oil.

http://www.ducati.ms/forums/attachments/apparel-ac...

You could make a damper with a "counterbalancing " extended shaft extension for ~ constant internal volume, but that brings on twice as much sealing trouble and complicates manufacturing.And some space is still needed for thermal expansion of the oil.

RE: DIY Shock: Rubber vs Hydraulic Damping + Information Help

ornerynorsk

(Industrial)

22 Jul 16 15:38

Anything on Bid or Buy? Any local bike shops? Ebay (US) has scads of them, most shipping from China at fairly reasonable prices. Just a thought. Best wishes on the project!

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

RE: DIY Shock: Rubber vs Hydraulic Damping + Information Help

ChrisDanger

(Mechanical)

(OP)

23 Jul 16 11:36

Interesting, thanks Tmoose.

Hi ornerynorsk. Nothing on Bid or Buy. Found some places in China but trying to get prices and see if they'll do small volumes.

RE: DIY Shock: Rubber vs Hydraulic Damping + Information Help

GregLocock

(Automotive)

23 Jul 16 12:03

If the shock is upright then you just need to leave room for stroke * rod CSA for the oil that is displaced. That is common practice with monoshocks. I see no point in gas pressurisation for any likely usage profile.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?

RE: DIY Shock: Rubber vs Hydraulic Damping + Information Help

ChrisDanger

(Mechanical)

(OP)

24 Jul 16 07:13

Thanks Greg. Good to know.

RE: DIY Shock: Rubber vs Hydraulic Damping + Information Help

GregLocock

(Automotive)

24 Jul 16 09:34

Bear in mind that all the energy burnt in the shock absorbers has to be supplied by your power source. Human powered vehicles are very sensitive to this.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?

RE: DIY Shock: Rubber vs Hydraulic Damping + Information Help

LittleInch

(Petroleum)

24 Jul 16 12:50

Maybe take a peek at a truck drivers chair to see what they use.

Also these guys. They do custom units.

Depends on what your deflection and load requirements are.

Have you come across these guys http://www.suspa.com/uk/sectors/medical-laboratory... Maybe take a peek at a truck drivers chair to see what they use.Also these guys. They do custom units. http://timbren.com/aeon-springs/ Depends on what your deflection and load requirements are.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: DIY Shock: Rubber vs Hydraulic Damping + Information Help

BUGGAR

(Structural)

25 Jul 16 14:05

I agree with Greg. Bump energy is essentially absorbed by a reaction provided by the user. Springs reflect more force reaction to a given bumps than good hydraulic dampers. Has this been engineered yet?

I've got a write up on this from my Ariel Atom post that I will add.

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