Soil compactor

Abstract

A soil compactor includes at least one compactor roller, which is free to rotate about an axis of rotation of the roller, with a plurality of roller segments, which follow one another along the direction of the axis of rotation of the roller. In each case, at least one electromotive drive for producing an oscillating torque is assigned to each roller segment.

Claims

1. A soil compactor comprising at least one compactor roller rotatable about an axis of rotation of the roller and a plurality of roller segments following one another along the direction of the axis of rotation of the roller, each roller segment having a casing surrounding an interior space of the respective roller segment, each roller segment having exclusively assigned therewith an electromotive drive arranged in the interior space surrounded by the casing of the respective roller segment for producing a propulsion drive torque, each electromotive drive for producing a propulsion drive torque being arranged for additionally producing an oscillating torque applied to the roller segment associated therewith, a roller axle extending along the axis of rotation of the roller being fixed at both axial ends thereof at a compactor frame such that the roller axle does not rotate about the axis of rotation of the roller, each roller segment being rotatably carried on the roller axle by at least one roller bearing so as to rotate about the roller axle, the interior space of each roller segment being closed off or limited in the axial direction by at least one side support, the at least one side support being rotatably carried by at least one roller bearing of the at least one roller bearing on the roller axle.

2. The soil compactor of claim 1, wherein each electromotive drive is configured as an external rotor motor including a stator and a rotor, which surrounds the stator and is coupled with the assigned roller segment, for a joint rotation about the axis of rotation of the roller.

3. The soil compactor of claim 2, wherein the stator of each external rotor motor is carried on the roller axle.

4. The soil compactor of claim 2, further comprising electric supply lines and/or supply lines for a cooling medium for each stator.

5. The soil compactor of claim 4, wherein the electric supply lines and/or cooling medium supply lines are provided in the interior of the roller axle.

6. The soil compactor of claim 1, wherein the electromotive drives of the roller segments can be activated individually.

7. The soil compactor of claim 1, wherein the interior space of each roller segment is closed off or limited in the axial direction by two side supports, each side support of the two side supports being rotatably carried on the roller axle by one roller bearing of the at least one roller bearing.

8. The soil compactor of claim 1, wherein the at least one side support is connected to the casing of the associated one of the roller segments at a radial outer region thereof and is rotatably carried by the at least one roller bearing of the at least one roller bearing at a radial inner region thereof.

9. The soil compactor of claim 1, wherein the at least one side support has a disc-shaped configuration.

Description

(1) In the following, the present invention will be described in detail with reference to the enclosed Figures. In the drawing,

(2) FIG. 1 shows a soil compactor with a compacting roller;

(3) FIG. 2 is a longitudinal section view of the compactor roller of the soil compactor of FIG. 1.

(4) In FIG. 1, a self-propelled soil compactor as a whole is designated by 10. The soil compactor 10 comprises a drive assembly at a rear section 12, which may be designed, for example, to drive the wheels 14 at the rear section 12. A front section 16, which is hinged to the rear section 12, comprises a compactor roller 18, which is free to rotate at a compactor frame 20 of the front section 16 or of the soil compactor 10 about an axis of rotation D, which is orthogonal to the drawing plane of FIG. 1. By moving the soil compactor 10 on the ground 22 to be compacted, compaction of the ground 22 is effected by the load exerted by the compactor roller 18 in conjunction with an oscillating movement thereof, produced at the compactor roller 18, that is a periodic back-and-forth movement about the axis of rotation D of the compactor roller, optionally also in conjunction with a vibrational movement of the compactor roller, that is, a periodic up and down movement of said roller.

(5) In FIG. 2, the compactor roller 18 is shown in the longitudinal section, that is, cut along the axis of rotation D of the compactor roller. In the exemplary embodiment shown, the compactor roller 18 comprises two roller segments 24, 26, which follow one another along the direction of the axis of rotation D of the compactor roller and are disposed close to one another. Each of the roller segments 24, 26 comprises a casing 28, 30, which provides the outer circumferential surface of the respective roller segment 24, 26, as well as two side pieces 32, 34 or 36, 38, which are connected, for example, on the outside with the casing 28, 30 and are designed, disk-like, for example. In their radially inner region, these side pieces 32, 34, 36, 38 are pivoted by roller bearings 40, 42, 44, 46 on a roller axle 48, which is elongated in the direction of the axis of rotation D of the compactor roller and extends concentrically thereto. In its two axial end regions 50, 52, the roller axle 48 is rigidly carried on the compactor frame 20, for example, at so-called bracket plates 54, 56, so that it cannot be rotated about the axis of rotation D of the compactor roller.

(6) The casing 28 of the roller segment 24 surrounds an interior space 57 of the roller segment 24. Correspondingly, the casing 30 of the roller segment 26 surrounds an interior space 59 of the roller segment 26. This interior space 57 or 59 of the roller segment can be closed off or limited in the axial direction by the respective side pieces 32, 34, 36, 38.

(7) In each case, an electromotive drive 58, 60 is assigned to each of the two roller segments 24, 26. Each of these electromotive drives 58, 60 is configured as an external rotor motor with a stator 62, 64 rigidly carried on the roller axle 48 and an external rotor motor 66, 68 carried on each roller segment 24, 26 or connected non-rotatably therewith. For this purpose, plate-like carriers 70 may be provided in the interior of the respective roller segments 57, 59, which grip radially inward from the roller casing 28, 30 and may be used for fixing the rotors 66, 68.

(8) Electrical supply lines 72 and 74, respectively, can be passed through the axial ends 50, 52 into the interior of the roller axis 48 for supplying the stators 62, 64 with electric energy and can be connected to the stators, more precisely to the stator coils thereof. The electric energy can be generated by the drive assembly provided at the rear section 12. Likewise, coolant supply lines can be passed through the interior of the roller axle 48 and take up coolant for dissipating heat from the interior of the roller segments 24, 26, which has been generated in the area of the electromotive drives, 58, 60, and for conducting heat to and from the stators 62, 64, respectively.

(9) Because of the configuration of the electromotive drives as external rotor motors and with the electromotive drives 58, 60 assigned to the two roller segments 24, 26, a compact, simple to realize construction is attained, which offers especially the advantage that compactor rollers with more than two roller segments can be constructed in the same way. With this construction, it is also possible to assign more than one such electromotive drive to each or at least some of the roller segments.

(10) Due to the electromotive drives 58, 60, an oscillating torque can be generated, that is, a torque changing in amplitude and direction, by means of which the roller segments 24, 26 for carrying out an oscillating movement, that is a periodic back-and-forth rotational movement about the axis D of the compactor roller, are moved with a comparatively small oscillation amplitude, for example, of 2 mm or about 0.2° at an oscillation frequency of up to 50 Hz. Due to such an oscillation movement, which is superimposed on the rolling motion of the of the roller segments 24, 26, an improved compaction result is achieved. Since the electromotive drives, assigned to the various roller segments 24, 26, can be activated independently of one another, it is still possible to ensure that the two roller segments 24, 26 roll with different speeds, that is, rotate with a different RPM about the axis of rotation D of the compactor D, while passing through a curve, nevertheless the oscillating movement of the two roller segments 24, 26, which is superimposed on the rolling motion, is carried out synchronously and in phase.

(11) If the soil compactor 10 is constructed in such a way that the wheels 14, also provided at the rear section 12, are driven by the drive assembly, such as a diesel internal combustion engine, the electromotive drives 58, 60 of the roller segments 24, 26 may be designed or activated in such a way, that they generate substantially only the oscillating torque, since the soil compactor 10 is driven via wheels 14. In particular, in an embodiment of a soil compactor with a compactor roller also at the rear section, it is also possible to use the electromotive drives not only for producing the oscillating torque, but also for generating the drive torque. Here, the electromotive drive is then activated in such a way that an oscillating torque portion for the oscillating torque is superimposed on the comparatively constant drive torque generally required for the propulsion. For example, when activating the electromotive drives, the voltage applied to the electromotive drives for generating the propulsion torque can be superimposed by the oscillating voltage, required for producing the oscillating torque, as a dither signal. For this purpose, an open loop control of the oscillation is feasible just as well as a closed loop control of the oscillation. The oscillating movement can be force-controlled or position-controlled, and the combination of different motion sequences is also possible.

(12) Since the electromotive drives 58, 60 of the roller segments 24, 26 can be activated individually, it is furthermore possible to react very rapidly to changing driving conditions and to adapt the rolling velocity or the propulsion torque as well as the oscillation torque very rapidly and in a large variation range according to changing circumstances by appropriately activating the electromotive drives 58, 60.