3-point swivel joint

Articulated joints


 The H Series

The innovative and self levelling centre pivot assembly is based on 3 instead of 4 joints. From this result outstanding driving and direction characteristics. This unique Hamm pivoted steering with the 3 ball joints guarantees an unsurpassed directional stability and driving comfort. Even with full steering angle the chassis construction provides for an even weight distribution on drum and wheels and ensures in such a way for careful absorption also with uneven terrains. Tilting with driving along curves is also more strongly avoided.





1. Function


The intro of the animation shows the moving elements of the articulation module especially the control arm on top of the module.


2. While Driving


The highlighted display of the articulation module helps to see the moving action while the roller is running in rough terrain or the driver is steering.

3. Rough Terrain


Here you can see the low transaction of the orange Hamm-Roller while driving over the uneven terrain. The cabin of the blue roller with traditional articulation is moving a lot more not having the Hamm control arm.

4. Weight Distribution


While both rollers are turning, you can see the different weight distribution shown by the bars and the weight-models behind the tires. Additionally the marks created by the tires show the blue roller´s interior wheel lifting. This is also important for tandem rollers in hot asphalt like HD 8 – HD 14.

5. Turn over risk


The turn over risk is shown by the yellow-black lines. When the roller is steering and the blue tractor module is pushing the drum frame straight on, you can see the move into the red colored unstable bar area, outside the Drum. The control arm of the Hamm-System decreases the pushing angle by half, the line always remains inside the stable drum area.

6. Reactionforce


Again the distribution of the pushing force shon in detail. Clearly you can see the function of the control arm (left part of picture). You can also show this in a brilliant way by pushing the little steel model.

7. Restoring force


When the roller is steering, the front and back frame moves around the mainbearing on the bottom of the roller. At that moment the distance between the two control-arm-bearings on top decreases. The length of the control arm length do not change, so the middle of the roller and the centre of gravity moves upward, shown by black-yellow bar.

8. Directional stability


If you want to have a directional stability while driving an ariculated vehicle, the centre of gravity has to be at its lowest point. For example if you steer a traditional car, the front of the car moves up a little. If you open the hands, the restoring forces rotate the steeringweel automatically back and the car is running straight ahead.