Hello sganesh,

Do you have a photo of the whole assembly in operation? Has this assembly always been this maintenance intensive or when did this change? What is the angle of the shaft?

From what this looks like the joint is operating at quite an angle. It also looks like that there is a bit of corrosion on the part where the needle roller bearing rides on. How are contaminants getting into that part of the bearing? Were the seal shields found to be defective? ■

Using Hookes joints (with a (Cardan) shaft between!) in a screen drive is an unnecessary evil. I have seen many installation drawings for this arrangement. A manufacturer recommends a motor base level which he presumably bases on the working bed download, the support spring weight & the angular deflection of the driveshaft. They are never, to date, forthcoming to these questions, but the punter needs a screen, or 12.

Input & output shafts of a Hookes joint assembly must be parallel to cancel out the superimposed sinusoidal vellocity fluctuation which Hookes Joints produce. The output velocity is not the same as the input velocity for an individual joint because the drive planes, torque transmitting planes if you like, are not concurrent.

In a screen installation the shaft inclination angle is only known at 2 conditions: when the shaft rests in a vertical plane in the static unladen & static laden conditions. Anywhere else the shaft alignment is subject to the screen pitch & yaw motions as allowed by the support springs. Uniform rotation speed of the counterweight shaft is quite impossible & the spider trunnions will take a hammering as shown in the photos.

Hookes Joints are a Victorian method of joining shafts & rarely used to transmit torque nowadays. In a screen application like your you are fortunate to reach 4 months life.

"Because the grease path is "+" in shape. Grease inlet is at the junction of "+".

If one path is clear for easy flow of the grease, the remaining bearings will not get the grease." The lubrication drilling is quite normal & correct. If you rotate the shaft incrementally, as you grease, the individual drilling segments will be sequentially freed for grease passage as the needle bearings are sequentially relaxed. Are your fitters reading the mauals??? Do they ever...fitters in general?

If you want to increase the joint life you should invest in Rzeppa Joints where the torque is transmitted through a plane which lies midway between the shaft axes. Most cars use Rzeppas although trucks still use Hookes joints because the angular deflection can be limited by their longer Hotchkiss drive arrangements. Personally, I'd be grateful for the 4 - 6 months & keep my head down. ■

HI Ganesh

What is that you have done to increase the life of the bearing, if u can attach the drawing it would be better to understand the exact problem.

It will be hard to replace bearing once in 4 to 6 months

rk ■

Originally Posted by sganesh

......

Because the grease path is "+" in shape. Grease inlet is at the junction of "+".

If one path is clear for easy flow of the grease, the remaining bearings will not get the grease.

Please find the attached photos. Out of four spider's end , normally one end is good. Others are found worn out. Have you ever faced this problem?

......

Regards,

One end is good..... Others are worn out...because when 3 needle sets have gone down the coupling has plenty of slack & the 4th set is able to rock about & maintain the alignment which it would't have if all sets were transmitting the same torque.

On the old propshaft drives on 1970's cars I could reduce transmission noise by dropping the propshaft , clouting the fork with a 5lb hammer & reconnecting. Funny things, shafts. ■