Present Level of Technology Some manufacturers of compaction equipment use the following solution to reach directed vibration: the housing of the vibratory exciter is provided with a pair of shafts with eccentric weights in its lower part, while there is another shaft located in the upper part. This third shaft drives-either in concurrent or opposite direction-the above-mentioned shafts with eccentric weights. Such arrangement of the vibratory exciter of a compaction machine makes possible to adjust higher or lower amplitude of vibration. The disadvantage is, that the level of amplitude adjustment is quite inaccurate, as this solution does not enable exact positioning of "the two shafts with the eccentric weights against the third driving shaft. This inaccurateness causes problems at compaction works.

Another known solution of the vibratory mechanism with directed vibration is brought for example by the German invention application No. DE 41 29 182. It is based on a vibratory drum with a vibratory housing, which may slew around its axis, which is parallel to axis of shafts with eccentric weights. The vibratory box can be adjusted in the required position and the vibratory shafts thus get from the one-above-the-other position to the side-by-side position (approximately horizontal). The advantage of this solution is the possibility to adjust the vector of vibration from the vertical position up to approximately horizontal position. The disadvantage of this described solution is, however, that the vibratory box must be slewing in the drum, which poses high requirements to the bearings between the said drum and the vibratory box. The bearings have to transfer high alternating forces from the centrifugal forces of the directed vibration.

A similar solution of the vibratory mechanism with directed vibration is brought by the invention, which has received the European patent No. EP 0 530 546. Similarly, this invention uses the system of two vibratory shafts in a vibratory box, which may slew around its axis towards the drum, where it is rotary mounted. This solutions makes possible to adjust the vibratory box to the required position, while the vibratory shafts change their position from vertical to approximately horizontal. The disadvantages are the same as those mentioned for the solution described in the above paragraph, as for the invention application No. DE 41 29 182.

Disclosure of the Invention The said disadvantages can be solved by such arrangement of a vibratory roller drum provided with a vibratory mechanism with directed vibration, which consists of a drum, on whose axis there is located a motor fixed to a gearbox and connected to a vibratory box of a vibratory mechanism with directed vibration, while the gearbox consists of a cage containing bearings which hold gears and pinions and a vibratory box containing bearings with eccentric shafts, while such shafts are mutually connected via gears, and whose principal consists in that the gearbox is movably connected to the vibratory box, which is fixed to the shell of the drum, through a bearing.

The vibratory box of the drum, which contains the vibratory mechanism with directed vibration, has the central shaft with eccentric weight and two counter-rotating shafts, both with eccentric weights as well. These shafts generate centrifugal forces that are transferred to the drum shell via bearings, which the said shafts are hold in.

The position of the cage, which is hold in the gearbox, can be changed by a movement of the driven shaft towards the segment, which is fixed to the cage. Such change of position of the cage is independent on the position of the vibratory box. The advantage of this design is, that it enables to turn the cage into various positions around its axis, as well as smooth stepless alternation of the direction of vibration force vector, within the 0° to 180° range. Another advantage of this arrangement is, that the cage is turned in the same direction, as the vibration force vector of the vibratory mechanism, which is generated by the eccentrics.

The cage arrangement within the gearbox enables a coaxial output of counter-rotating independent shafts, namely the shaft 17 and the hollow shaft 18. These shafts connect the gearbox with the vibratory box. As a result, the direction of the vibration force vector of the vibratory drum with the mechanism with directed vibration is turned by the same angle, as the angle of the gearbox. Therefore the direction of the vibration force vector can be adjusted in required direction from vertical direction up to horizontal one.

The direction of the vibration force vector is independent on the position of the vibratory box and it is controlled by the rotary-mounted cage, while the position of the cage is independent on the position of the vibratory box.

Layout of the Illustrations The invention shall be further more closely explained with reference to the enclosed drawings. Fig. 1 includes a schematic general view of the vibratory roller drum containing the vibratory mechanism with directed vibration. Fig. 2 brings the view of the general arrangement of the gearbox. Fig. 3 illustrates in more detail the arrangement of the gearbox cage.

Examples of Implementation of the Invention The vibratory roller drum, which contains the vibratory mechanism with directed vibration, consists of the drum 29, on whose axis 30 there is mounted the motor 16, the gearbox 32 and the vibratory box 31. The motor 16 is fixed to the gearbox 32, which is then rotary connected <BR> <BR> to the vibratory box 31 via the bearing 35. Torque from the motor 16 (a hydromotor being the<BR> most convenient choice) is transferred through the coupling 33 to inside of the gearbox<BR> 32. The gearbox 32 consists of the moving cage 34, which holds the gears 10, 13, the pinions<BR> 11, 12 and the shafts 17,18.

The cage 34 is supported on the bearings 41A and 41B, which enable its easy turning towards the gearbox 32.

The vibratory box 31 consists of the eccentrics 22,23, 24, the shafts 19,20, 21, the layshaft<BR> 40, the gears 25,26, 27,28 and the bearings 37A, 37B, 38A, 38B, 39A and 39B.

The arrangement of the gears 10, 13, the pinions 11, 12 and the shafts 17, 18 hold in the cage 34 of the gearbox 32 enables the torque from the coupling 33 to be divided on the gear 10 in two different ways: <BR> <BR> One part of the torque is transferred from the left gear 10 to the shaft 17, located inside the<BR> hollow shaft 20; this shaft 20 bears the central eccentric 23.<BR> <P>The other part of the torque is transferred from the left gear 10 through the inserted pinions 11<BR> and 12 onto the right gear 13 and then to the hollow shaft 18 to inside of the vibratory box 31.<BR> <P>The hollow shaft 18 is then coimected to the left shaft 19. The left shaft 19 holds the left eccentric 22 and the gear 25, which mesh with the gear 26. The gear 26 is fixed to the gear 27 <BR> <BR> via the layshaft 40 ; the gear 27 is in mesh with the gear 28. This gear 28 is fixed on the right<BR> shaft 21, which holds the right eccentric 24. As the layshaft 40 is located out of the drum 39<BR> axis 30, the torque can be transferred from the left shaft 19 onto the co-rotating right shaft 21,<BR> while bypassing the counter-rotating central shaft 20, which is located in the axis 30 of the drum 29. <BR> <BR> <P>The left gear 10 located in the gearbox 34, which is fixed to the shaft 17, is in mesh with<BR> gearing of the left pinion 11, while the left pinion 11 is in mesh with the right pinion 12. The<BR> right pinion 12 is in mesh with the right gear 13, fixed to the hollow shaft 18.<BR> <P>This arrangement of the cage 34 with gears 10, 13 and pinions 11, 12 inside the gearbox 31<BR> enables the co-axial output of counter-rotating independent shafts 17 and 18. The counter-<BR> rotating output of the two independent shafts 17 and 18 is based on the shaft 17 fixed to the<BR> left gear 10 and the hollow shaft fixed to the right gear 13, while the off number of meshing pairs of gears changes the sense of rotation.

The opposite sense of rotation of the central eccentric 23 against the eccentrics 22 and 24-all<BR> of them being mounted together in the vibratory box 31-causes directioning of the vibratory force vector into the selected direction, normal to the axis 30 of the drum 29. The direction of the vibratory force vector of the vibratory mechanism of the compaction roller with directed vibration, generated by eccentrics 22,23 and 24 can be turned by the same angle as the cage 34 of the gearbox 32.

Thus, adjustment of the direction of the vibratory force vector is possible from the vertical direction to approximately horizontal one.

The centrifugal force from the central shaft 20 with the eccentric 23 and those from the <BR> <BR> counter-rotating shafts 19 and 20 with eccentrics 22 and 24, are transferred through the<BR> bearings 37A, 37B, 38A, 38B, 39A and 39B onto the shell 36 of the drum 29.

Movement of the driven shaft 15 towards the segment 14, which is fixed to the cage 34 of the gearbox 32 enables turning of the cage 34 into various position around the axis 30. This design makes possible smooth stepless alternation of the direction of the vibratory force vector from 0° to 180°.

Using this arrangement of the cage 34 with the driven shaft 15 moving towards the segment 14, the cage 34 is turned in the same angle as the vector of the vibratory force, generated by the eccentrics 22, 23 and 24. Turning of the cage 34 within the gearbox 32 enables the phase shift of the counter-rotating shafts 17 and 18.

Capability of Exploitation in Industry This compaction roller drum, containing the vibratory mechanism with directed vibration, as according to this invention, can be used for all compaction machines with both one-part and split drum that are required to generate directed vibration (with regards to the compaction job, etc.).