the lateral bearing element 4 b the lateral bearing element 4 b is in a mechanical connection by way of a spindle rod 29 with a slide 28 a of a valve 28 thus as a result of the action of the lateral bearing element 4 a the roll shell 2 shifts to the right according to fig1 for a contact with the lateral bearing element 4 b which uses the spindle rod 29 to drive the slide 28 a of the valve 28 out of its position in front of a port 28 b thus the feed line p s is provided with a clear flow path through the valve 28 into the cavity 41 of the lateral bearing element 4 b the element 4 b and thus the slide 28 a travels a short distance until the port 28 b opens sufficiently for pressures in both cavities 40 and 41 of the lateral bearing elements 4 a and 4 b to become equal for holding the roll shell 2 in lateral direction substantially stationary and for preventing a lateral flattening of the roll shell 2 0026 fig3 illustrates a second embodiment of the invention a shaft 3 is provided with two main.