What is this thing?

[deema]

It’s a bit ambiguous title, but I can’t seem to find the right words to describe it to google a replacement. It’s a two way spring strut I think? It comes off a GreenMachine 400 series road sweeper and it’s no longer springy. I suspect it’s the same thing that motor bikes use for their suspension?

Anyway, if anyone can point me in the right direction yoi would have my thanks.

I bent the eye trying to free it up and get it moving again……grrrr it is solid.

 

[Jacob]

Gas strut?

 

[flying haggis]

what is usualy called a shock absorber but is most usually used as a damper to stop springs bouncing

e-mail them and ask

Email: [email protected], [email protected]

 

[deema]

Thanks, it’s not a shock absorber, there is a gas strut ahead of it that carry’s out this function. This is the main rear suspension and the manual description is that it’s a two way spring strut. Now tried googling that and all I’m getting is gas struts.

 

[Sideways]

Motorcycles typically use a coil spring wrapped around a shock absorber cylinder. One unit each side when they have proportions like yours.

The reference to twin spring could mean two springs in series. A soft one and a hard one to give a compliant ride plus resistance to bottoming out on big hits. That's not unheard of. The springs on bike shocks are often on display but in a sweeper, enclosed might last longer.

Alternatively:
Imagining a "piston" inside that cylinder and a coil spring on each side of that, that would give a spring unit that naturally centres and works in both tension and compression. I've no idea if such a thing exists and what it would be called. Does that configuration make any sense in your machine ?

Is the weight of the machine riding on this and the one on the other side, or is it involved in the ride height of just the sweeper mechanism ?

 

[ChaiLatte]

Is the weight of the machine riding on this and the one on the other side, or is it involved in the ride height of just the sweeper mechanism ?

That is a good point. We could maybe find out what a good name for it would be by determining its function.

It is also plausible that it is just like an inside-out motorbike twin shock.

In very simple terms, what happens when it is removed? Does the suspension collapse so the machine rests on the bump stops? Does the machine remain suspended but bounce all over the place when it hits a bump?

If it is truly beyond repair, cut it open and see how it works.

 

[Amplidyne]

Stupid question I will guess, but don't the company supply spares?
If it's "just" acting as a spring, and doesn't any longer, then I'd suspect it's some kind of gas strut. Never seen anything quite like it though. Custom made part?

 

[ChaiLatte]

I think there is a parts manual here:

http://d2z4qs2e3spnc1.cloudfront.net/product_file/file/526/400_green_machine_parts_manual.pdf

Item 24 on page 15 and oddly enough item 25 on page 16 (and not on page 54 at all). It is also item 5 on pages 55 & 56. The MA571 number appears here (https://shop.usaclean.com/2-way-spring-strut-assembly-tennant-industrial-475-7136/) and is a bargain at $944.39 plus shipping.

 

[Tris]

If you have no luck with greenmachines it might be worth emailing SGS engineering with a pic and description. They have been very helpful in the past when I've been looking for an odd spring or strut

 

[Amplidyne]

Wonder if it's not a standard gas strut with a fabricated cover over it for some reason?