VIBRATION ROLLER
A vibration roller includes a roller with a vibration generator that has at least one unbalance shaft. The vibration generator is located above the vibration roller.
The invention described and claimed hereinbelow is also described in German Patent Applications DE 10 2007 049 889.8 filed on Oct. 18, 2007. This German Patent Application, whose subject matter is incorporated here by reference, provides the basis for a claim of priority of invention under 35 U.S.C. 119(a)-(d).
BACKGROUND OF THE INVENTIONThe invention relates to a vibration roller, having a vibration generator that has at least one unbalance shaft.
Such vibration rollers are used for instance in self-propelled or manually movable trench compactors or in roller trains but are also used as compactor attachments for arms of excavators. To that end, they are moved over the area of soil to be compacted, while the vibration generator generates the vibration necessary for the compaction.
In most known vibration rollers, the vibration generator is located in the interior of the rollers. This has the disadvantage that in servicing work on the vibration generator, as a rule the removal of the vibration generator from the roller is necessary, which is time-consuming. Moreover, the unbalance shafts become quite hot, which especially with vibration rollers that in their interior contain not only the vibration generator but also a drive unit for their own rotational drive, can lead to problems with temperature-sensitive components, such as electronic components. The hydraulic medium typically used for the drive also heats up severely from a generator unit located on the inside and must be cooled, which is complicated and expensive.
SUMMARY OF THE INVENTIONThe object of the present invention is to furnish a vibration roller in which maintenance work can be done on a vibration generator without problems. It should furthermore be low in height, in order to reduce the lateral tilting moment and to assure good hill climbing capability.
This object is attained with a vibration roller, having a vibration generator that has at least one unbalance shaft, which is characterized in that the vibration generator is located above the vibration roller.
It has been demonstrated that when the vibration generator is located above the vibration roller, no disadvantages whatever in terms of the compacting performance arise, yet excellent accessibility to the vibration generator for maintenance work is assured. Since as a rule there is more space available above the vibration roller than in the interior of the roller, larger unbalance shafts can be provided than in the known vibration rollers, so that the generation of the complete vibrating mass and hence the compaction power can even be increased, compared to the known rollers with vibration generators located in the interior.
Heat dissipation is also markedly simpler with vibration generators located above the roller than with vibration generators integrated with the rollers.
Further advantages can be attained if the axis of the at least one unbalance shaft is oriented transversely to the axial direction of the vibration roller. The unit comprising the vibration roller and the vibration generator can then be manufactured with a lower height than when the axes of the vibration generator and roller are parallel to one another. Besides the lower height, a downward shift in the center of gravity of the unit is also attained, and as a result the risk of lateral tilting of the vibration roller can be reduced.
Preferably, the vibration generator can have two axially parallel, contrarily rotatable unbalance shafts, so that directional vibration can be generated with the vibration generator. For that purpose, the drive of the two unbalance shafts can expediently be coupled, and as a result, only one of the unbalance shafts has to be actively driven. The coupling of the unbalance shafts can be effected via a gear or in some other way. It is understood that a separate drive, adapted to one another, of the two unbalance shafts is also conceivable.
In a preferred embodiment, the at least one unbalance shaft can be provided with one eccentric weight mounted in a manner fixed against relative rotation and with one eccentric weight that is pivotable between two radially oriented stops. Depending on the quality of the soil to be compacted, a greater or lesser amplitude of the vibration generated can thus be selected. In one of the pivoted positions, the movable eccentric weight can reinforce the effect of the fixed eccentric weight, while in the other position it can reduce it. It is understood that naturally, the vibration frequency can be adapted to soil or ground conditions in a manner known per se.
The direction of rotation of the at least one unbalance shaft can also be reversible. Thus the amplitude of the vibration generated by the vibration generator can also be varied by simply reversing the direction of rotation of the unbalance shafts.
In principle, the invention also pertains to vibration rollers that are moved by hand. Preferably, however, a drive unit, preferably a hydraulic drive unit, for the rotational drive of the roller may be provided in the vibration roller. Such vibration rollers can be used for instance in remote-controlled, self-propelled equipment.
The drive direction of the drive unit can be reversible, to enable compacting in both directions of travel even in tight spaces, where there is often no room for turning the roller around.
Particularly with driven vibration rollers, it is advantageous if the vibration generator is located with its center of gravity in the cross-sectional plane of the vibration roller extending through the center of gravity of the vibration roller. In that case, the straight-ahead travel of the roller can be best assured. If the centers of gravity of the vibration generator and the vibration roller are too far apart, then lateral motions of the roller can occur, especially with vibration generators that generate directional vibration.
The manifold possibilities for using the vibration roller can be enhanced even more markedly if the vibration generator is supported limitedly movably above the vibration roller in such a way that its center of gravity can be shifted to in front of and/or behind the vertical plane that extends through the axis of the vibration roller.
If the vibration generator is supported limitedly displaceably horizontally, then by shifting the center of gravity of the vibration generator to in front of or behind the axis, the vibration amplitude can be reduced.
If the vibration generator is supported limitedly pivotably about the axis of the vibration roller, then by the pivoting motion, the center of gravity of the vibration generator can for instance be shifted somewhat behind the axis and at the same time the vibration generator can be inclined, thus enormously improving the forward motion of the vibration roller and hence its hill climbing capability. The vibration roller can then be used even for compacting sloping terrain or very poorly accessible ground.
A further way to increase the flexibility of use of the vibration roller is to equip it with replaceable bandages. Either smooth bandages, of the kind required more for compacting sandy soil, or profiled bandages for compacting heavy soils, can then be installed.
The invention moreover relates to a compacting device or compacting vehicle having at least one vibration roller of the invention.
The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
The amplitude and frequency of the vibration generated by the vibration generator 11 may be variable. For that purpose, the unbalance shafts 12, 13 may, in a manner known per se and not shown in further detail here, each have one eccentric weight located in a manner fixed against relative rotation and one adjustable eccentric weight. The adjustable eccentric weight can be pivoted between two stops, and in one position, it amplifies the effect of the fixed eccentric weight, and in the other direction, it lessens the effect of the fixed eccentric weight.
The vibration roller 10, in its interior, has a drive unit 18, which can preferably be a hydraulic motor. For supplying oil to the hydraulic motor, in a middle region of the vibration roller 10 connections 19 are provided, to which hydraulic lines from a vehicle or device to which the vibration roller 10 can be attached can be connected. Because of the closed construction of the drive unit 18, impairment of the drive from being contaminated with dirt is precluded.
The bandages 20, 21 are removable. Thus the profiled bandages 20, 21 shown here can also be replaced with smooth bandages, of the kind needed for instance for sandy soils.
The vibration generator 11 can also be limitedly pivotable about the axis 17 of the vibration roller 10 or limitedly displaceable on the vibration roller 10 in the axial direction 16 of the unbalance shafts 12, 13. By means of a horizontal displacement of the vibration generator 11 out of the middle position, the amplitude of the vibration exerted on the soil by the vibration roller 10 can be reduced. When the vibration generator 11 is pivoted out of the middle position, the vibration generated by the vibration generator acquires a component that reinforces the forward drive of the vibration roller 10.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.
While the invention has been illustrated and described as embodied in a vibration roller, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.
Claims
1. A vibration roller, comprising a roller; and a vibration generator having at least one unbalance shaft, said vibration generator being located above said roller.
2. The vibration roller as defined in claim 1, wherein said at least one unbalance shaft has an axis oriented transversely to said axial direction of said vibration roller.
3. The vibration roller as defined in claim 1, wherein said vibration generator has two such unbalance shafts which extend axially parallel to one another, said unbalanced shafts being rotatable in opposite directions.
4. The vibration roller as defined in claim 3, further comprising a drive of said two unbalance shafts, said drive of said two unbalanced shafts being coupled.
5. The vibration roller as defined in claim 1, wherein said at least one unbalance shaft is provided with one eccentric weight mounted in a manner fixed against relative rotation and one eccentric weight pivotable between two radially oriented stops.
6. The vibration roller as defined in claim 1, wherein said at least one unbalance shaft has a reversible direction of rotation.
7. The vibration roller as defined in claim 1, further comprising a drive unit provided in said roller for a rotational drive of said roller.
8. The vibration roller as defined in claim 1, wherein said drive unit is a hydraulic drive unit.
9. The vibration roller as defined in claim 7, wherein said drive unit has a reversible drive direction.
10. The vibration roller as defined in claim 1, wherein said vibration generator is located with its center of gravity in a cross-section of a plane of said roller, which extends through a central gravity of said roller.
11. The vibration roller as defined in claim 1, wherein said vibration generator is supported limitedly movable above said vibration roller in such a manner that its center of gravity is shiftable to in front of and/or behind a vertical plane extending through an axis of said roller.
12. The vibration roller as defined in claim 11, wherein said vibration generator is supported limitedly displaceably horizontally.
13. The vibration roller as defined in claim 11, wherein said vibration generator is supported limitedly pivotable above an axis of said roller.
14. The vibration roller as defined in claim 1, further comprising replaceable bandages.
15. A compacting device, comprising at least one vibration roller including a roller; and a vibration generator having at least one unbalance shaft, said vibration generator being located above said roller.
16. A compacting vehicle, comprising at least one vibration roller having a roller; and a vibration generator having at least one unbalance shaft, said vibration generator being located above said roller.
Type: Application
Filed: Sep 29, 2008
Publication Date: Apr 23, 2009
Inventor: Hermann Greschner (Metzingen)
Application Number: 12/240,400
International Classification: E01C 19/38 (20060101);
