Have you ever tried to remove a driveshaft coupling from a Goss Community press (shown in fig 1)? The normal way is to loosen the setscrews in the spline coupling and then slide the collar by tapping it gently with a hammer. In some cases tapping the collar will not cause the collar to slide. If this is the case you will have to become more aggressive with a hammer. (Get a bigger hammer is the most common solution to the problem.) Using a bigger hammer or using more force to remove the coupling can cause the drive-side oil case to become damaged if too much force is applied.
When a four pound hammer doesn’t slide the coupling on the splined shaft, a two piece collar can be made that will clamp down on the drive shaft close enough to the drive shaft spline coupling to allow you to use a small hydraulic pump & cylinder. Hopefully at this point the splined drive coupling can be forced off. If the range of the hydraulic cylinder has been reached before the coupling clears the end of the shaft the hydraulics can be released and the collar can be repositioned and then the process of removing the drive shaft collar can be continued until the collar has been moved far enough to allow the drive shaft to be removed. The locking collar can be made from scrap material as shown in fig 2. I prefer to make the collar at least two inches thick, two inches in depth and the inside diameter of the collar should be two to three thousands of an inch smaller than the outside diameter of the drive shaft. Once the collar is complete the collar is then drilled (with a drill bit that is sized to tap for a three-eights bolt) on each side so that once the collar is cut in half the holes in each half of the collar will lineup up with one another. One half of the collar will be tapped for the three-eighth inch bolt on each side and the other half of the collar will be drilled out large enough for the three-eighth inch bolt to pass through the hole that was drilled. The collar can then be fasted to the drive shaft as shown in fig 3.
The coupling can also be heated to enlarge the coupling and to loosen the rust inside the collar before using any of the methods that I mentioned above. The reason that I am reluctant to mention this is because of the oil, ink, paper lint and paper in this area. However this significantly increases your chances of removing the coupling but extreme caution must be exercised if you choose to use an open flame.
When all else fails the spline couplings can be cut in half, which will ruin the coupling and the poly spacers that are located inside the splined coupling. This procedure will cost an extra $125 for two new spline couplings and two new spacers, but will definitely allow you to remove the drive shaft without causing damage to the press units or to the drive shafts.
Frank Bourlon has more than 30 years experience in the newspaper industry. He is the Associate Director for Newspaper Production & Research Center. He can be reached @ 405-524-7774.