Has anyone seen this type of rubber bushing arrangement?

rustygreen

Aluminum

Joined

Oct 20, 2010

Location

Waltham MA

• Aug 23, 2018

• #1

This knuckle is part of the suspension system for a shaking machine. The machine was rebuilt 5-10 years ago, not by the manufacturer, so I'm not sure if this is original. It gets constant usage and it hasn't held up well.

The threaded center goes all the way through, and it looks like it was pressed in with 4 pieces of round rubber stock. Is this a reasonable arrangement? Or should this be molded solid?

The square tubing is about 2 1/2 inches. If I try to rebuild these, any guess as to the tonnage that would be required to press this out, then back in with fresh elastomer?

 

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D

DDoug

Diamond

Joined

Oct 18, 2005

Location

NW Pa

• Aug 23, 2018

• #2

Torflex trailer axle

 

H

howieranger

Aluminum

Joined

Jan 24, 2007

Location

Mountain Home AR.

• Aug 23, 2018

• #3

That type of arrangement is used on pleasure boat trailers. Some have a cross shaped center axle with four rods or a square section axle with rubber bonded in the open space. I would think the tonnage to press out the current center section wouldn't be to bad < ten tons depending how long the part is. The secret to getting a lasting rebuild would the right rubber. Dexter Axle builds torsion tube axles and they may be of help. Have you contacted the OEM, they do not look expensive to build.

 

Peter from Holland

Diamond

Joined

Jan 15, 2005

Location

The Netherlands

• Aug 23, 2018

• #4

Look at Rosta elements
https://www.rosta.us/

Peter

 

Chip Chester

Diamond

Joined

Dec 13, 2007

Location

Central Ohio USA

• Aug 23, 2018

• #5

Yup on the trailer axle. They even make stub axles, with about a 1' segment for welding to frame, with no complete cross-axle. Which means you can buy one easily, if you want to 'wing it'.

 

J

john.k

Diamond

Joined

Dec 21, 2012

Location

Brisbane Qld Australia

• Aug 23, 2018

• #6

We rebuilt a shaker conveyor system......the OEM rubber mounts were something like 10x the price of a visually similar item.........so we went with the cheap item.........they lasted about six months.....and I had to replace eventually over a hundred of these blocks in a confined space under the shakers with filth and dust everywhere. The genuine blocks had lasted years.

 

D

DDoug

Diamond

Joined

Oct 18, 2005

Location

NW Pa

• Aug 23, 2018

• #7

john.k said:

We rebuilt a shaker conveyor system......the OEM rubber mounts were something like 10x the price of a visually similar item.........so we went with the cheap item.........they lasted about six months.....and I had to replace eventually over a hundred of these blocks in a confined space under the shakers with filth and dust everywhere. The genuine blocks had lasted years.

Click to expand...

Trailer people tell me that the torflex (and similar) suffer in cold weather
from being stiff.

Aftermarket car suspensions use polyurethanes, much better.
So I suspect the OEM from the conveyor company was a little more
engineered (like using polyurethanes) than the off the shelf trailer
components.

 

Mud

Diamond

Joined

May 20, 2002

Location

South Central PA

• Aug 23, 2018

• #8

Try Lord - Vibration Isolators | LORD Corp

 

S

surplusjohn

Diamond

Joined

Apr 11, 2002

Location

Syracuse, NY USA

• Aug 23, 2018

• #9

lovejoy idler arm meant for loading a sprocket against a chain, these use two square sections with a rubber element. many sizes, cheap

 

D

DDoug

Diamond

Joined

Oct 18, 2005

Location

NW Pa

• Aug 23, 2018

• #10

Mud said:

Try Lord - Vibration Isolators | LORD Corp

Click to expand...

I looked at the linked, and didn't see something for the Op.

I have seen allot of their products (they are local to me) but
have never seen the torflex type of device from Lord.

 

C

Clive603

Titanium

Joined

Aug 2, 2008

Location

Sussex, England

• Aug 23, 2018

• #11

Failure mode suggests that some sort of void bush arrangement would be better suited to the loads involved but that sort of arrangement needs to be rather larger. Worth looking into if there is room.

Solid "rubber" and "rubber-like" materials are very non-linear. Its easy to build up ridiculous localised stresses in something that looks perfectly innocuous. Voids locally tune compliance to control such stress build-up but, inevitably, reduce stiffness in certain directions.

Clive

 

P

PeteM

Diamond

Joined

Jan 15, 2002

Location

West Coast, USA

• Aug 23, 2018

• #12

Since what you're replacing seems to have been a kludge, here's another:

RUBBER PLATE COMPACTOR MOUNT replaces WACKER 2944 SET OF 4 | eBay

A set of these will handle a couple thousand pounds of oscillating force in a "Wacker." Might be adaptable to your application. The thread doesn't go all the way through, but is embedded in elastomer. Typically takes a 1000 hours or so before they start tearing apart (though not sure of the quality or longevity) of the linked item.

 

rustygreen

Aluminum

Joined

Oct 20, 2010

Location

Waltham MA

• Aug 24, 2018

• #13

Peter from Holland said:

Look at Rosta elements
https://www.rosta.us/

Peter

Click to expand...

Direct hit, Peter!

These are definitely Rosta bushings. Re-engineering the linkages is not an option cost-wise. I'll check to see if they'll sell me the rubber elements, I don't think they're supposed to be round stock.