Autonomous overhaul BB Goss web offset press experience

Newspaper rotary offset presses have high speed, high impact and other characteristics. In recent years, many units of printing equipment have gradually become ageing, and inevitably, the wear of drum wall plate and eccentric sleeve bearings has occurred. As the wear causes the roller to run out, white spots appear during the printing process. Imprinting is not allowed, which directly leads to a decline in printing quality and it is difficult to guarantee customer requirements.

Causes of wear:

BB type Gauss will produce a larger impact at the intersection of the two rubber rollers in the printing. Vibration, due to printing pressure, self-gravity, and centrifugal force of the drum, especially in the event of a sudden break (when the break protection fails), the drum continues to run and generates a large number of paper rolls. The drastic increase in pressure causes the drums to accumulate against each other and make the eccentric sleeve The wall plate rotates in the air and rubs against the wall plate, resulting in wear and tear. Over time, the result is an irregular expansion of the wall plate. . Eccentric sleeves and wall plate empty manufacturing materials, heat treatment processes, and poor lubrication all cause wall plate wear.

Basic method for repairing deformation

1: The basic principle of repairing the deformation The airframe requires two concentricity errors between each pair of blank space, and the parallelism error between the two pairs of voids must be controlled between 0.01-0.02mm.

2: Repair methods and operating procedures (Taking Dongfang Gaussian manual emptying as an example)
There may be motor drive cutouts and manual cutouts. Take the 2-3 version as a straight set. The good wear of the wall plate is superimposed by the impact of several directions. . The measurement is repeated on the circumference according to the direction of the impact force, the null center is initially calibrated, and the reference mandrel 1 is installed. The other mandrel 2 passes through the blank holder and is ready to be fixed on the wall plate to be supported on both sides of the blank plate (fixed after being corrected). Use a dial indicator to measure the relationship between the reference rod 1 and the mandrel 2, and debug it so that the main and side busbars are all between 0.01-0.02mm. After positioning, measure the null center again. If the error value of the above two parallelisms is not within the required range, it means that the pair of empty concentricity is not between 0.01-0.02mm, and the null center must be measured. To make it within the scope of the requirement, it can be hollowed out.

3 Hollowing:
After the parallelism of the main side busbars has reached the required level, the flange on the mandrel 2 is fixed on the wall plate, the mandrel bar 2 and the reference sleeve to be hollowed are removed, and the mandrel bar 2 with the hollow knife holder is removed. It is hollowed directly by the blue support fixed on both sides to be emptied. Hollowing is a small amount of each feed, and the speed of the knife is uniform. It cannot be eager to be formed. The maximum deformation of the blank is minimized, and as little as possible, the machining accuracy is ensured.

4: After the inspection is finished, a pair of sleeves with shoulders are machined in accordance with the dimensions of the hollow, so that they can meet the intermittent tolerances of the new hollow slides. In the wall plate, the sleeves and mandrels are measured and hollowed out. Between the main busbar parallelism, the error should be controlled at 0.01-0.02mm. If not, the above steps should be repeated.

Replace the eccentric sleeve that has been newly machined and reassemble the machine after it is empty. Replace the other components that need to be replaced. Finally, perform debugging and debugging.