FIELD: mechanical engineering. SUBSTANCE: sealing unit had hollow cylinder which is received and sealed in the opening of the hollow shaft. The hollow cylinder has outer grooves, which interact with inner projections of the hollow shaft and is coupled with a locking device provided with a pin received in the opening of the hollow cylinder and sealed in it, control handle secured to one of the pin ends and partially overlapping the face of the hollow shaft, and valving member. The valving member is coupled with the other end of the pin for permitting sliding along the inner grooves of the hollow shaft. The valving member is locked due to abutting the valving member against the faces of the inner projections of the hollow shaft when it rotates under the action of a torsion spring interposed between the hollow cylinder and valving member. The rotation of the valving member is arrested in two end positions: locking position and unlocking position. EFFECT: enhanced reliability. 6 cl, 5 dwg
