Linkage pushrod mechanism design

[richardflong]

Hi,

I have what I think is a simple problem to solve but I just do not know the details of the correct way to do it. I need to connect a lever arm to a push-rod by rod end bearing similar to this

https://www.ondrives.com/bem-05lh-ss.

My question is what kind of pin or fastener should be used to connect the two items without any play/float in the linkage? If the hole bores are 5mm should I size a Transition Fit 5mm pin between them and fasten retaining nuts to threaded ends? Should i used busings in the bore?

Thanks for any help you can give

Richard

 

[SnTMan]

Why not ask the manufacturer?

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[Jboggs]

Any standard cylindrical part can be used. I have used shoulder bolts in the past. They are good, but only if applied correctly. If applied incorrectly they can easily break. I have also used a welded or press-fit dowel pin. You can also use a yoke arrangement where you capture the pin and rod end between two fixed features like a bolt head and nut, or retaining rings.

 

[MintJulep]

without any play/float in the linkage

Then by definition a transition fit will not do. You will need and interference fit.

 

[Compositepro]

Use this type instead so you do not have to worry about fits.

http://images2.mcmaster.com/mvA/contents/gfx/large/60645kc1l.png?ver=1316686931

http://www.mcmaster.com/#rod-ends/=11614y6

 

[rb1957]

you want to screw the rod-end into a linkage member ?

the normal approach (at least in my business) is to tap the hole and to secure the rod-end with a jam nut. If you want to lock it down tight, add an anti-rotation device for the jam nut

another day in paradise, or is paradise one day closer ?

 

[BUGGAR]

Even if you get zero play in the connecting bolt, your race (especially Teflon lined as specified) will wear. Do you need zero play in both push and pull, or just in one direction?

 

[Tmoose]

I assume the linkage needs to pivot with reasonably low effort once in a while.
Do you R-E-A-L-L-Y need zero clearance ?
0.002" radial clearance would not suffice?

How much force must these 5 mm pivot shafts endure?
Through how many degrees must the linkages pivot?
How may cycles?
What is the environment?

Possibilities I'd be considering, with the limited input you provided.
true, zero clearance
1 - those hinges made from thin metal plate. ( 90 degree motion or so )
2 - plastic "living" hinges.

http://www.spencerindustries.com/index.cfm?pfile=PlasticLivingHinge

( 90 degree motion or so )
3 - axially preloaded tapered bushings ( full rotation )
4 - axially preloaded tapered roller bearings ( full rotation )
5 - axially preloaded ball bearings ( full rotation )

Low radial force required - castellated metal or plastic bushings that snap onto the shaft with negative clearance, but low radial force.

Preloaded ball and socket joints, hydraulically preloaded as done many millions of times as shown here -

http://grumpysperformance.com/oilpassage.jpg

 

[tbuelna]

Clamp the spherical race of the rod end tightly between the inner faces of a lever arm clevis ears using a shear fit bolt. Torque the bolt so that there is sufficient clamped friction between the spherical inner race and clevis faces to ensure any rotational motion at this joint occurs at the spherical bearing race interface, rather than at the bolt.

 

[chicopee]

Richardflong, look at the rocker and push rod in Tmoose's "

http://grumpysperformance.com/oilpassage.jpg

"