Search

Email

A     B     C     D     E     F     G     H     I     J     K     L     M     N     O     P     Q     R     S     T     U     V     W     X     Y     Z



  Mobiles  

  F7     F9
 Bookstore

 Tests

 Formulary




  Construction site vehicles 5




Sometimes one has the impression that with hydraulics, anything can be done. Not only stroke-movements (up and down), but also rotary-movements are possible. Have a look at here, to see how the hydraulics can be used to achieve all-wheel drive in a vehicle. We however, will be dealing with the stroke-movements. This is also the case with the limited rotary-movement e.g., in a crane. In this case the piston force is transferred to a gear-rack with a pinion.

Of course, a cylinder like this must be double-acting, during the lifting of a heavy loading arm, the piston must be pressed back by the weight of the arm itself. Almost all the movements of the hydraulics are carried out when the actual vehicle is stationary. The force is provided by the hydraulic pump on the auxiliary drive, and can only be switched on when the vehicle is idling. Afterwards, the RPM is regulated according to the work demands, in the past this was done by the RQV-regulator and nowadays it's done through the engine management.

Indeed, not only do the hydraulics pose a challenge. Don't ever believe, that a loading crane, like the one in picture 2 shown above, can simply be attached to an extension of the frame. Since truck-frames are generally strengthened between the axle mountings and are weaker towards the ends. Therefore, it could be necessary here, to have a subframe which reaches far to the front or at least has a crosswise strengthening at the rear.

Best of all, is when the manufacturers of the truck and those of the additional superstructures, work hand-in-hand with each other. Then guidelines can be compiled and it may even be possible to introduce precautionary measures during the manufacturing. Thus e.g., changes to the roof of a the drivers cabin may be possible when fitting a concrete pump. What an advantage, if this can be done before the vehicle goes to the spray painters. This is sometimes possible with a great deal of work done when manufacturing a truck. 11/14

You can read more about hydraulics here.


Imprint