Quantitative restrictions in basic parameters for modern podjemno – transport vehicles do not exist. They are created for any conditions of possible application. There are only economic restrictions. Difficult heavy cars cost much and expediently to use them only in case it is possible to load so that they paid off for the real term of operation to moral and physical wear.
For ensuring the movement of wheels external 13 and internal 12 running carts without sliding running external 14 and internal 11th wheels carry out with different diameters or the frequency of rotation proportional to radiuses of R min and R max.
Magnetic cranes are intended for rise and transportation of ferromagnetic materials (a skrapa, shavings, sheet and profile hire, molds for pouring became, etc.). These cranes are supplied cargo electromagnetic, suspended on a hook suspension bracket or a traverse (on flexible or rigid subweight, located in the longitudinal or cross direction concerning the bridge.
Metalwork with sheet odnostenchaty main beams and auxiliary farms, and also the two-block box-shaped designs possessing the high resistance of fatigue is the most widespread.
At big speeds of forward movement of magnetic cranes it is rational to apply flexible rope subscales a traverse thanks to which rocking of freight in one or two directions decreases.
Trolls usually produce from rolling steel of an angular profile. On the crane apply the tokosjema of the sliding type attached to a crane metal construction which boots slide on when moving the bridge crane to giving of current.
Mechanisms of movement of these cranes and their carts have no differences in comparison with mechanisms of bridge cranes of general purpose. Recently mechanisms of movement of cranes with the divided drive of each side of the bridge gain ground.
Designs of special bridge cranes are very various. These cranes can be progressively moving on crane rails or rotating round a vertical axis. Treat the rotating cranes chordate, radial and rotary.
Traverses represent box-shaped beams constant, and with a big length – variable section. Traverses suspend on hooks of suspension brackets of the crane, 2-4 magnets are attached to their lower part. At a direct suspension bracket of four magnets to a traverse lack of contact of two magnets with a nonplanar surface of freight is possible. For ensuring reliable contact of all magnets with freight magnets in pairs connect lever system. At such system both four magnets, and two averages at shutdown of the extreme can work.
The carts moving on the top and lower belts of beams of bridges can be supplied with the rotary arrows, basic and rotary devices and rotary parts rotating round vertical axes. On rotary axes the arrows supplied with load gripping devices are located.