Steering Shaft Wobble

[ETUVBOB]

Hi All

I am having trouble with the steering shaft wobbling as it turns which is causing interference problems in near by components. This is a manual rack and pinion system. The steering shaft has 3 ujoints in it. I am aware of keeping the ujoints in phase to help the problem, but this doesn,t seem to help. Is there somthing that I am missing or some trade secret to getting the shaft not to wobble?

Any input will be greatly appreciated, or if you would like more information let me know.

Thanks and good luck!

 

[GregLocock]

(Classical) UJ phasing isn't your problem. How many bearings are there on the two intermediate shafts? One of them needs two, preferably. You also may need a sliding revolute joint, I think.

Is this a properly designed system or something you've put together as a prototype?

Cheers

Greg Locock

 

[ETUVBOB]

Greg-

Thanks for the reply!

There is one bearing on the first intermediate shaft coming down from the steering column.

The current system should be considered as a prototype. We have put about 15 of these vehiles together to use for protyping and marketing purposes. It seems that every system that we put together was a little bit different. Is this possibly due to out of tolerance parts or is it typical for these systems to each have a little different personality?

 

[GregLocock]

One bearing on the first I/S should be enough to make the system determinate, but that depends on the details. If the middle UJ is heavily cantilevered then the enormous forces it can generate will pushh the first I/S around, resulting in a lot of variation of position for the middle UJ, and hence the second I/S

Perhaps you could give us some coordinates?

eg brackets on the steering column, position of each UJ, position of I/S bearing

Do you have any slip (plunge) joints in the system? If you don't the forces can be enormous.

Cheers

Greg Locock

 

[ETUVBOB]

Greg-

the first and second uj are at about 28 degrees and the third is at about 20. I dont have any plunge joints in the system. After thinking about what you said and the way that the system acts this may be very benficial. I will have some more time to work on it towards the end of the week or early next.

Thanks for the help and i will let you know how it goes.