What are the characteristics of the universal shaft

The balance of the universal shaft of modern mills are hydraulically balanced, the advantage is that the universal joint is very easy to adjust when changing rolls. The principle and the balance of the rolls on the principle described later is basically the same. In recent years, in order to overcome the poor lubrication of the universal joint, the shortcomings of serious wear, widely used cross shaft type universal joint, and gradually replace the trend of open slide universal joint. In addition to the universal shaft, other types of coupling shaft balancing method, the principle and adjustment is similar to the above.

Universal shaft balance are used to balance the hydraulic, the initial rolling mill rolling pressure is very large, so generally use the closed frame. It is different from the general rack is the lower part of the front and rear columns have a hole and dovetail slot for the installation of rack rolls, dovetail slot is also used for the installation of rack rolls. That is to say, each column of the rack is left with a position for placing two rack rolls. The reason for setting rack rolls on the primary mill is that, in the first few rolling, the rolls are very short, in order to facilitate the feeding of steel, must be configured with a driving device rack rolls. In order to accommodate the heavy hammer balance, on the rack column. Each side of the inner window has a slot to accommodate the balance of the top bar, this two slots are reflected in the lower crossbeam of the rack for the corresponding two through holes.

As mentioned earlier, the universal shaft is generally longer and heavier, in order not to make the weight of the universal joint shaft all pressed on both ends of the fork head, are generally set up to balance the coupling shaft device. The balancing force is generally 10%-30% greater than the weight of the coupling shaft. The common balancing devices used in hematite ore dressing process are spring balancing, weight balancing and hydraulic balancing. Spring balance is generally used only for balancing the lower coupling shaft. Because the lower coupling shaft connected to the rolls in the rolling process is not required to adjust its position. The upper coupling axis because of the roll lift in the process of rolling, the old mill with a heavy hammer balance, the newer mills are using hydraulic balancing.