Soil Compacting Device with Compensating Coupling

Abstract

A soil compacting device has an upper mass having a drive and a lower mass having an imbalance exciter. On the lower mass, there is provided a bearer device connected fixedly thereto, which bearer device bears a transmission device having an input shaft and an output shaft. The drive has a drive shaft that is coupled to the input shaft. The imbalance exciter has an exciter shaft that is coupled to the output shaft. A compensating coupling is provided between the drive shaft of the drive and the input shaft of the transmission device. The compensating coupling is designed to compensate for an axial offset, a radial offset, and an angular offset between the drive shaft and the input shaft.

Claims

1. A soil compacting device comprising: an upper mass having a drive; a lower mass connected to the upper mass so as to be movable relative thereto, and having a soil contact plate for soil compaction; an imbalance exciter provided on the lower mass and capable of being driven by the drive; a bearer device situated on one of the upper mass and the lower mass and connected fixedly thereto; the bearer device bearing a transmission device having an input shaft and an output shaft that are coupled together by a torque-transmitting device for transmitting a torque from the input shaft to the output shaft; the bearer device bearing the input shaft and the output shaft so that they are capable of rotation, the drive having a drive shaft that is coupled to the input shaft; the imbalance exciter having an exciter shaft that is coupled to the output shaft; a compensating coupling being provided between the drive shaft of the drive and the input shaft of the transmission device or between the output shaft of the transmission device and the exciter shaft of the imbalance exciter; and the compensating coupling being configured to compensate an axial offset, a radial offset, and an angular offset between one of 1) the drive shaft and the input shaft and 2) between the output shaft and the exciter shaft.

2. The soil compacting device as recited in claim 1, wherein: the bearer device is fixedly connected to the upper mass; the compensating coupling is provided between the output shaft of the transmission device and the exciter shaft of the imbalance exciter; and the compensating coupling is configured to compensate an axial offset, a radial offset, and an angular offset between the output shaft and the exciter shaft.

3. The soil compacting device as recited in claim 1, wherein: the bearer device is fixedly connected to the lower mass; the compensating coupling is provided between the drive shaft of the drive and the input shaft of the transmission device; and the compensating coupling is configured to compensate an axial offset, a radial offset, and an angular offset between the drive shaft and the input shaft.

4. The soil compacting device as recited in claim 3, wherein the bearer device is rigidly connected to at least one of the soil contact plate and an exciter housing appertaining to the imbalance exciter.

5. The soil compacting device as recited in claim 1, wherein the bearer device and the transmission device are at least partly enclosed by a transmission housing.

6. The soil compacting device as recited in claim 1, wherein the input shaft is aligned with the drive shaft of the drive in an idle state of the soil compacting device.

7. The soil compacting device as recited in claim 1, wherein: the transmission device is a belt drive having a first pulley and a second pulley capable of being driven by the first pulley via a belt; the first pulley is borne by the input shaft; the second pulley is borne by the output shaft; and the exciter shaft of the imbalance exciter is coupled to the output shaft and thus to the second pulley in such a way that is capable of being rotationally driven via the second pulley.

8. The soil compacting device as recited in claim 1, wherein: the compensating coupling is a link coupling that has: a first crank that is coupled to the drive shaft; a second crank that is coupled to the input shaft; and a connecting rod that couples the first crank and the second crank; or the compensating coupling is a link coupling that has: a first crank that is coupled to the output shaft; a second crank that is coupled to the exciter shaft; and a connecting rod that couples the first crank and the second crank.

9. The soil compacting device as recited in claim 8, wherein the first crank and the second crank are rotated by an angle relative to one another that is bridged by the connecting rod.

10. The soil compacting device as recited in claim 8, wherein the connecting rod is pivotable relative to at least one of the first crank and the second crank by at least a small angle.

11. The soil compacting device as recited in claim 8, wherein the connecting rod is coupled to at least one of the first crank and to the second crank via an elastic bearing.

12. The soil compacting device as recited in claim 11, wherein the elastic bearing is an elastomer spherical bearing.

13. The soil compacting device as recited in claim 1, wherein at least one of the first crank and the second crank has a compensating mass situated opposite, relative to their axis of rotation, a coupling point at which the connecting rod is coupled.

14. The soil compacting device as recited in one claim 1, wherein: a centrifugal clutch is provided as part of the drive; and the drive shaft is part of the centrifugal clutch.

15. A soil compacting device comprising: an upper mass having a drive; a lower mass that is connected to the upper mass so as to be movable relative thereto and that has a soil contact plate for soil compaction; an imbalance exciter that is provided on the lower mass and that is capable of being driven by the drive; a bearer device that is situated on one of the upper mass and the lower mass and that is connected fixedly thereto; wherein the bearer device bears a transmission device having an input shaft and an output shaft that are coupled together by a torque-transmitting device for transmitting a torque from the input shaft to the output shaft; the bearer device bears the input shaft and the output shaft so that they are capable of rotation, the drive has a drive shaft that is coupled to the input shaft; the imbalance exciter has an exciter shaft that is coupled to the output shaft; and further comprising a compensating coupling that is provided between one of 1) the drive shaft of the drive and the input shaft of the transmission device and 2) between the output shaft of the transmission device and the exciter shaft of the imbalance exciter, the compensating coupling being configured to compensate an axial offset, a radial offset, and an angular offset between one of 1) the drive shaft and the input shaft and 2) between the output shaft and the exciter shaft

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] FIG. 1A shows a highly schematized side view of a soil compacting device according to the present invention;

[0044] FIG. 1B shows a rear view of the soil compacting device of FIG. 1A;

[0045] FIG. 1C shows an enlarged detail of FIG. 1B;

[0046] FIG. 2A shows a schematic side view of another specific embodiment of the soil compacting device;

[0047] FIG. 2B shows a rear view of the soil compacting device of FIG. 2A;

[0048] FIGS. 3A-3D show various views of a compensating coupling according to the present invention, as a link coupling;

[0049] FIG. 4A shows a side view of an elastomer spherical bearing;

[0050] FIG. 4B shows a sectional view of the elastomer spherical bearing;

[0051] FIG. 5A shows a schematic side view of a soil compacting device according to the prior art; and

[0052] FIG. 5B shows a rear view of the soil compacting device of FIG. 5A.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0053] FIG. 1A (side view) and FIG. 1B (rear view) show a soil compacting device according to the present invention having an upper mass 1 that bears a drive 2, for example an internal combustion engine or an electric motor. Below upper mass 1, a lower mass 3 is provided that is coupled to upper mass 1 via a vibration decoupling device (not shown) and is movable relative to this upper mass. Lower mass 3 has a soil contact plate 4 and an imbalance exciter 5 that during operation imparts a vibration to soil contact plate 4.

[0054] Imbalance exciter 5 can be constructed in a known manner. In particular, imbalance exciter 5 can have for example one or two imbalance shafts, not shown in the Figures, that can be set into rotational movement by the drive in order to bring about the desired vibrations for the soil compaction.

[0055] A guide handle 6 having a control lever 7 is situated on upper mass 1.

[0056] Such a design of a vibrating plate is known from the prior art.

[0057] For the transmission of the drive power from drive 2 to imbalance exciter 5, a belt drive 8, acting as a transmission device, is provided. Belt drive 8 has various known components that are shown in the enlarged representation of FIG. 1C. These are, in particular, a first pulley 9, situated in the upper region, a second pulley 10, mounted in the lower region, and a V-belt 11 that circulates between first pulley 9 and second pulley 10.

[0058] Belt drive 8 is held by a bearer device 12 that is fastened rigidly to imbalance exciter 5, or to an exciter housing of imbalance exciter 5. Alternatively, bearer device 12 can also be attached directly on soil contact plate 4.

[0059] Bearer device 12 is in particular a construction that is realized to be as stiff or rigid as possible, e.g. as a cast or welded part, in order to enable the bearing functions required by bearer device 12.

[0060] At the output of drive 2 there is provided a drive shaft 13 that is aligned with an input shaft 14 of belt drive 8. First pulley 9 of belt drive 8 is mounted on input shaft 14. In the lower region, imbalance exciter 5 has an exciter shaft 15 that is aligned with an output shaft 16 of belt drive 8 and is coupled thereto. Exciter shaft 15 and output shaft 16 can also be realized in one piece as a shaft.

[0061] Second pulley 10 of belt drive 8 is mounted on output shaft 16.

[0062] Because both input shaft 14 and output shaft 16 are mounted in bearer device 12 together with first pulley 9 and second pulley 10, their axial spacing is held constant by bearer device 12. In addition, the parallel alignment of input shaft 14 and output shaft 16 is also maintained, including during operation.

[0063] Belt drive 8 can form, together with bearer device 12, a belt drive housing, and can thus seal the belt drive running in the interior from the external environment. In this case, only two bores are then to be provided through which on the one hand input shaft 14 and on the other hand output shaft 16 can extend. Because in this way a complete sealing of the belt drive housing in bearer device 12 can be achieved, no dust can penetrate. A penetration of dust can also be reduced through a corresponding fastening of bearer device 12 to the exciter housing of imbalance exciter 5.

[0064] Between drive shaft 13 and input shaft 14 there is provided a compensating coupling 17 that is used to compensate an axial offset, a radial offset, and an angular offset between drive shaft 13 and input shaft 14, and which is further explained below.

[0065] For the sealing of the housing of belt drive 8, a lateral cover 18 can be fastened on bearer device 12. Cover 18 can be mounted with a seal.

[0066] The relative movements that occur during operation of upper mass 1 and lower mass 3 are expressed in that the upper end of bearer device 12, with the housing of belt drive 8, and thus input shaft 14, comes closer to or moves away from the motor crankshaft or drive shaft 13 (axial offset), is displaced radially in all directions (radial offset), and that angular offsets occur between the two shafts (angular offset). Compensating coupling 17 compensates these offsets and transmits the drive power.

[0067] FIGS. 2A and 2B show another specific embodiment of the vibrating plate. The essential design of upper mass 1 and lower mass 3 is here identical to the specific embodiment of FIGS. 1A-1C.

[0068] However, differing from the variant of FIGS. 1A-1C, in the specific embodiment of FIGS. 2A and 2B, bearer device 12 is fastened fixedly or rigidly to upper mass 1. For example, bearer device 12 can be attached to the motor housing of drive 2. It is also possible to attach bearer device 12 to a bearing structure that is present on upper mass 1 but is not shown in FIGS. 2A and 2B. In any case, in this way bearer device 12 moves together with upper mass 1, so that the corresponding relative movement between upper mass 1 and lower mass 3 is present at the lower end of bearer device 12 on output shaft 16. Correspondingly, compensating coupling 17 is situated between output shaft 16 and exciter shaft 15.

[0069] If needed, compensating coupling 17 can be protected against the penetration of rocks by a bellows.

[0070] In the variant of FIGS. 2A and 2B, fewer movable components are situated on lower mass 3, which is strongly loaded with vibration, and this can improve the lifespan of these components. In addition, lower mass 3 is lighter, which can promote compacting power and can be favorable for the steering dynamics.

[0071] The design of compensating coupling 17 can be seen in FIGS. 3A-3D, where FIG. 3A shows the compensating coupling in a perspective view. FIG. 3B illustrates radial offset R, FIG. 3C shows an axial offset A, and FIG. 3D illustrates an angular offset W.

[0072] Compensating coupling 17 has a first crank 31 and a second crank 32. First crank 31 is connected to second crank 32 via a connecting rod 33. Connecting rod 33 is pivotable relative to each of the two cranks 31, 32 about an axis parallel to the shaft axes (cf. in particular FIG. 3B. In addition, connecting rod 33 is also pivotable about an axis that stands at an angle, e.g. perpendicular, to the shaft axes, in order to be able to execute the desired compensating movements (cf. FIGS. 3C and 3D).

[0073] For this purpose, connecting rod 33 is attached to a respective boom of crank 31, 32 by a respective spherical bearing 34, in particular an elastomer spherical bearing.

[0074] Compensating coupling 17, fashioned as a link coupling, can operate both in pulling fashion and in pushing fashion. That is, first crank 31 can push connecting rod 33 in front of it in the direction of rotation, so that second crank 32 is pushed. Alternatively, first crank 31 can also rotate and draw connecting rod 33 in the direction of rotation, so that second crank 32 is drawn along by connecting rod 33 and follows the movement.

[0075] Spherical bearing 34, fashioned as an elastomer spherical bearing, is shown in detail in FIGS. 4A and 4B, where FIG. 4A shows a front view and FIG. 4B shows a vertical section.

[0076] Correspondingly, elastomer spherical bearing 34 is made up of an inner metal sleeve 35 and an outer metal sleeve 36. Inner metal sleeve 35 has a spherical surface 37, while outer metal sleeve 36 has a spherical bore 38. Between spherical surface 37 and spherical bore 38 there is situated an elastomer 39, for example rubber.

[0077] The two metal sleeves 35, 36 are fastened to the respective crank 31, 32 and to connecting rod 33 in such a way that no relative movement occurs between the crank, or connecting rod, on the one hand, and the associated metal sleeve 35, 36 (cf. for example FIG. 3C). In contrast, the relative movement takes place exclusively between the two metal sleeves 35, 36, and is absorbed by elastomer 39. Spherical bearing 34 can thus both twist (FIG. 4A) and also deflect cardanically (FIG. 4B).

[0078] So that the link coupling (compensating coupling 17) does not itself produce a strong imbalance, which in turn could have negative effects on the respectively affected roller bearings (not shown), on the respective cranks 31, 32 a compensating mass 40 is provided at the booms situated opposite the coupling points of connecting rod 33. Each of the compensating masses 40 extends into the coupling center, so that each coupling half, made up of one of the cranks 31, 32, spherical bearing 34, compensating mass 40, respective fastening elements, and half of connecting rod 33, is always in itself balanced both statically and dynamically as long as the link coupling is not deflected. When there is a deflection of the link coupling, as a function of the deflection path there result smaller, subjectively imperceptible imbalance forces and corresponding resetting forces.

[0079] In the example shown in FIGS. 1A-1C, first crank 31 is fastened on drive shaft 13, or coupled thereto. Because it is entirely standard for a centrifugal clutch to be provided downstream from drive 2, so that during idling of drive 2 no torque is transmitted to imbalance exciter 5, and the centrifugal clutch closes, and the transmission of torque takes place, only when a particular rotational speed (switching rotational speed) is exceeded, drive shaft 13 can also be formed by a bell of the centrifugal clutch. In this case, first crank 31 can be attached directly on the bell (not shown in the Figures) of the centrifugal clutch (also not shown).

[0080] Second crank 32 is coupled to input shaft 14 or is attached thereon.

[0081] When first crank 31 is set into rotational movement by drive 2, this rotational movement is transmitted to second crank 32 via connecting rod 33.

[0082] When, due to the vibrating operation, the desired relative movement occurs between upper mass 1 and lower mass 3, this movement can be compensated in compensating coupling 17. If, for example, the two shafts, namely drive shaft 13 and input shaft 14, have an offset, then the two axes of cranks 31, 32 also have an offset. If for example the axes of cranks 31, 32 have a radial offset, spherical bearing 34 is alternately twisted in a respective direction within a rotation. When there is an axial offset of the two cranks 31, 32, spherical bearing 34 is deflected cardanically. When there is an angular offset, spherical bearing 34 is alternately cardanically deflected within a rotation.

[0083] The maximum movements that occur during operation between upper mass 1 and lower mass 3 are known to the manufacturer when designing a corresponding vibrating plate. From this, the maximum deflections of (elastomer) spherical bearing 34, and the frequency thereof, are ascertained, and in this way the spherical bearing can be designed so as to have long-term durability. In order to protect the spherical bearing against overloading in case of misuse, the offset between upper mass 1 and lower mass 3 can also be limited by stops.

[0084] In the specific embodiment of FIGS. 2A and 2B, compensating coupling 17 is situated in the lower region between output shaft 16 and exciter shaft 15. In this case, first crank 31 can be attached to output shaft 16 and second crank 32 can be attached to exciter shaft 15.

[0085] The link coupling is not sensitive to contamination, in particular to abrasive dust, because neither sliding or rolling friction between two bodies takes place. The friction takes place only internally, within elastomer 39. Only larger foreign bodies need be kept away from the link coupling, because at higher rotational speeds these are slung away and could thus present a danger.

[0086] In contrast to other known compensating couplings having a short constructive length, the link coupling offers a high transmissible torque in combination with comparatively high permissible offsets, in particular a high radial offset. All offsets can be increased continuously in all directions; aligned axes are also permissible. In addition, there is an insensitivity to dust, which is advantageous for the intended use of vibrating plates.