EP2789403B1 - Oscillation exciter for construction machines - Google Patents

Description

The invention relates to a vibration generator for construction machines, in particular for vibratory ramming, according to the preamble of patent claim 1.

In the construction industry, vibratory rams are used to bring in piles such as profiles in the ground or to pull them out of the ground. The soil is excited by vibrations with a frequency above the natural frequency of the soil and thus reaches a "pseudo-liquid state". By static load the pile can then be pressed into the ground. The vibration is generated by pairwise counter-rotating imbalances.

The vibration exciters of such vibration rams are linear-acting vibration exciters whose centrifugal force is generated by rotating imbalances. An essential feature of these vibration exciters is the static moment. This is a size that describes the installed imbalance. When trained as Verstellvibratoren vibration exciters, the effective size of the imbalance is adjustable. To limit the rolling bearing load, the static torque is adjusted by adjusting the effective unbalance of each shaft. As a rule, an average imbalance is rotated against two outer imbalances in order to adjust the resulting imbalance in this way. Since the internal imbalances of all shafts are interconnected via gears and the external imbalances of all shafts via gears or the shafts themselves, the relative angles between external and internal imbalances are the same on all shafts. Such a trained vibration exciter is for example in the DE 20 2007 005 283 U1 disclosed. Here, the adjustment of the imbalance groups via an additional shaft, which is designed as a phase shifter, in the present case in the form of a swing motor. A special design are upright vibrators, which are usually equipped with three or four unbalanced shafts. Such Hochkantvibrator is for example in the EP 2 392 413 A2 shown.

For example, further vibration exciters are known from EP 2 270 341 A2 . JP S59 77145 or AU 528 984 B2 ,

The aforementioned vibration exciter meet the task asked of them. However, it is desirable to be able to reduce the required adjustment pressure, to be able to dispense with sliding seals and to improve the reaction time of the pivoting motor arranged for the change of the static torque.

The invention aims to remedy this situation. The invention is based on the object to provide a vibration generator for construction equipment, in particular for vibratory ramming, in which the static torque is adjustable and its energy consumption is reduced. According to the invention, this object is achieved by features of the characterizing part of patent claim 1.

The invention provides a vibration exciter for construction machines, in particular for vibratory ramming, whose static moment is adjustable and whose energy requirement is reduced. Because the maximum angle of rotation of the at least one rotary vane, which is limited by at least one stop arranged on the swivel motor housing, is less than 160 degrees, preferably 150 degrees or less, the reaction time of the swivel motor is increased - the swivel motor adjusts faster. Furthermore, a reduction of the power supply required for the rotation of the swing motor is caused by the reduction of each limited space between the rotary wing and stop. It has been found that the 180 ° pivot angle provided in the prior art, which allows an opposing arrangement of the imbalance masses, whereby the static moment is reduced to zero, is dispensable in practice. Due to the reduced swivel angle, it is also possible to produce the swivel motor housing in a reduced design, whereby a reduction in the mass is possible.

In an embodiment of the invention, at least one imbalance mass is formed by the swivel motor housing of a single-rotor rotary piston pivoting motor designed as a circular sector and formed on the pivot motor shaft rotatable to this, which is part of at least one axis. As a result, an unbalance shaft is formed with adjustable resulting unbalance. Between the two stop surfaces of the stopper defined by the angle of rotation pivot space of the rotary wing of the Swivel motor opposite is formed at least one acted upon by oil oil bag. The at least one oil pocket achieves at least partial compensation of the resultant force acting on the bearings. The resulting from centrifugal force of the formed as imbalance pivot bearing housing and from the oil pressure in the chambers bearing load is reduced by the at least one oil pocket. Due to a reduced rotation angle, the oil pocket and the sealing distance can be increased.

In a further embodiment of the invention, at least one separate oil supply line is arranged for supplying oil to the at least one oil pocket (58) in addition to the oil supply lines for the chambers (57) arranged on both sides of the rotary vane (52).

In a further development of the invention, two oppositely arranged rotary vanes are arranged on the swivel motor shaft of the at least one swivel motor, so that two opposite pressure chambers are formed between the two rotary vanes and the associated stop of the swivel motor housing in each case in one direction of rotation. As a result, a uniform bearing load is effected. By the two oppositely arranged pressure chambers there is no additional bearing load by each introduced into the pressure chamber hydraulic oil. Likewise, the required oil pressure is lower for two wings, since doubles in two rotary blades, the specific torque of the swing motor.

In an embodiment of the invention, no seals are arranged for sealing the swivel motor housing relative to the swivel motor shaft of the at least one swivel motor, the sealing effect being effected exclusively via the gap dimension. As a result, the maintenance is reduced because a change of aged, worn or embrittled at high temperatures seals is not required. The sealing effect is achieved rather over narrow gaps. The risk of higher leakage is counteracted by a lower pressure operation, which is made possible by the lower swing angle and preferably by the arrangement of two oppositely disposed rotary vanes, which cause a higher torque.

In a further embodiment of the invention, the swivel motor shaft is provided at least one swivel motor with an axial bore into which projects a fixed lance having at least two channels for oil supply of the swivel motor, which open into a respective outside of the lance arranged annular groove, wherein in the swivel motor shaft Radial holes for connecting the at least two annular grooves of the lance are introduced with the chambers to be supplied. The fit between the lance and the shaft bore in the region of the annular grooves is preferably designed as a narrow slide bearing. The lance is preferably coated in this area with plastic. The provision of such a fixed lance encounters such a problem of the commonly used in the prior art rotary unions, which consist of a fixed housing which is flanged to the housing of the vibrator and a rotor which is rotatably mounted in this housing and the rotating pivot motor with is driven. Bearings always have a bearing clearance, whereby all components mounted in a swinging housing rotate with a certain eccentricity. While these are relatively large in self-mounted slew motors, very tight games are required in rotary joints for sealing reasons. A directly rigid connection between the rotor of the rotary feedthrough of the swing motor shaft is not possible because the heavy swing motor would damage the sensitive bearings of the rotary feedthrough. The fixedly arranged lance, however, compensates for the dancing movement of the pivot bearing shaft in the functionally bearing a game bearing bearings. This is done on the one hand by the long shaft of the lance, which is preferably designed to be elastic and is advantageously designed by attachment to the flange so that it can accommodate slight inclinations. In this case, the lance is preferably rotatably mounted end with play in a fixed to the housing of the vibration exciter flange.

In a further development of the invention, the lance has at its end an enlarged diameter head piece, with which it is mounted in the flange. As a result, a resilient attachment of the lance is made possible in the flange. For this purpose, preferably, the gap formed by the game between the lance and the flange by at least bridged an O-ring. Against rotation, the lance can be secured by means of an engaging in the head piece dowel pin.

Advantageously, at least one axis three unbalanced masses are arranged, wherein the average imbalance mass is formed by the swivel motor housing of a designed in the form of a single-pivot rotary engine pivot motor. As a result, an unbalance shaft is formed with adjustable resulting unbalance. Rotary piston pivot motors, also referred to as rotary vane pivot motors, generate torque directly through one or more vanes disposed on the swing motor shaft, which are pressurized with hydraulic oil under pressure. Depending on whether one or two wings are arranged on the swivel motor shaft, rotary swivel motors are referred to as single-leaf or double-leaf.

In an embodiment of the invention, at least three axes provided with unbalanced masses are arranged, which are interconnected via gears, wherein in each case at least one unbalanced mass is formed by at least two axes formed by an unbalanced mass swing motor housing of a swing motor. As a result, a very compact design is achieved. The total static moment of the upper and lower shaft corresponds to the static moment of the middle shaft. Therefore, the imbalances on the upper and lower shaft do not take up the available space.

Preferably, the swivel motor housing of the at least one swivel motor is designed as a sector of a circle. As a result, a space-optimized imbalance is formed by the swivel motor housing.

In the invention, at least one oil pocket which can be acted upon with oil is formed between the two abutment surfaces, opposite the pivoting space of the rotary vane defined by the angle of rotation. This achieves an at least partial compensation of the resulting force acting on the bearings. In an embodiment of the swivel motor housing as imbalance, the bearings with which the swivel motor housing is mounted on the swivel motor shaft, increasingly loaded with increasing speed by the centrifugal force. In addition, a bearing force results from the oil pressure in the chambers of the slewing motor. This resulting from centrifugal force and oil pressure in the chambers bearing load leads to an increased adjusting torque that can be reduced by the provision of at least one oil pocket.

For supplying oil to the at least one oil pocket, at least one separate oil supply line can advantageously be arranged in addition to the oil supply lines for the chambers arranged on both sides of the rotary vane. As a result, a hydraulic short circuit between the two chambers of the slewing motor is excluded. Alternatively, two check valves or a shuttle valve may be arranged. Valves, however, are sensitive to dynamic loads, which are essential in a vibrator gearbox.

Figur 1

die schematische Darstellung eines Vibratorgetriebes mit drei Unwuchtwellen;

Figur 2

die Darstellung des Vibratorgetriebes aus Figur 1 in der Vorderansicht;

Figur 3

die Darstellung des Vibratorgetriebes aus Figur 1 in der Seitenansicht;

Figur 4

die Darstellung einer oberen Unwuchtwelle des Vibratorgetriebes aus Figur 1;

Figur 5

die Darstellung der Unwuchtwelle aus Figur 4 mit einem durch den Schwenkmotor verlaufenden Querschnitt;

Figur 6

die schematische Darstellung der Unwuchtwelle aus Figur 5 a) bei maximalem statischen Moment; b) bei reduzierten statischen Moment;

Figur 7

die schematische Darstellung der Unwuchtwelle aus Figur 4 im Längsschnitt mit eingebrachter feststehender Lanze zur Ölversorgung;

Figur 8

die Darstellung der Anordnung aus Figur 7 mit entferntem Flanschteil;

Figur 9

die schematische Darstellung der Lanze der Anordnung aus Figur 7 mit angeordnetem Flanschteil;

Figur 10

die schematische Darstellung des Schwenkmotors der Unwuchtwelle aus Figur 7 im Querschnitt und

Figur 11

die schematische Darstellung eines entsprechend der Anordnung gemäß Figur 10 ausgebildeten Schwenkmotors in der erfindungsgemäßen Ausführungsform mit Öltasche.

Other developments and refinements of the invention are specified in the remaining subclaims. An embodiment of the invention is illustrated in the drawings and will be described in detail below. Show it:

FIG. 1

the schematic representation of a Vibratorgetriebes with three unbalanced shafts;

FIG. 2

the representation of the vibrator gearbox FIG. 1 in front view;

FIG. 3

the representation of the vibrator gearbox FIG. 1 in the side view;

FIG. 4

the representation of an upper imbalance shaft of the vibrator gear FIG. 1 ;

FIG. 5

the representation of the imbalance wave FIG. 4 with a running through the pivot motor cross-section;

FIG. 6

the schematic representation of the imbalance shaft FIG. 5 a) at maximum static moment; b) at reduced static moment;

FIG. 7

the schematic representation of the imbalance shaft FIG. 4 in longitudinal section with introduced fixed lance for oil supply;

FIG. 8

the representation of the arrangement FIG. 7 with the flange part removed;

FIG. 9

the schematic representation of the lance of the arrangement FIG. 7 with arranged flange part;

FIG. 10

the schematic representation of the swing motor of the imbalance shaft FIG. 7 in cross-section and

FIG. 11

the schematic representation of a according to the arrangement according to FIG. 10 trained swing motor in the embodiment according to the invention with oil pocket.

The selected as an exemplary vibration exciter is designed as a three-shaft vibrator gear. There are three unbalanced shafts 1, 1 'arranged, comprising an axis 2, on the spaced apart two outer imbalance masses 3 are arranged. On the respective opposite outer imbalance mass 3 arranged inside adjacent to the outer imbalance masses 3 each have a gear 4 is arranged on the axis 2. In the case of the outer imbalance shafts 1, a swivel motor 5 designed as a rotary swivel motor is arranged between the toothed wheels 4, the swivel motor shaft 51 of which is part of the axle 2. The central imbalance shaft 1 'has on its axis 2 between the gears 4 an inner imbalance mass 3'. The imbalance mass 3 'is dimensioned twice as wide as the outer imbalance masses. 3

The imbalance masses 3, 3 'are formed in a circular sector. The radius of the outer unbalance 3 of the outer unbalanced shafts 1 substantially corresponds to the radius of the gears 4. The radius of the outer imbalances 3 and the inner imbalance 3 'of the central imbalance shaft 3' is significantly greater than the radius of the gears 4 of the central imbalance shaft 1 ', which are dimensioned larger than the gears 4 of the outer unbalanced shafts 1, between which a rotary piston pivot motor 5 is arranged.

The rotary piston pivoting motor 5 is formed by a pivot motor shaft 51, which is part of the axis 2, and arranged on the pivot motor shaft 51 pivot motor housing 55. The pivot motor shaft is provided in the exemplary embodiment with an axial bore 511, spaced from each other two radial bores 512 are led to the outside. Externally, a rotary vane 52 is formed on the pivot motor shaft 51, which is arranged within the pivot space 55 formed by the inner contour 54 of the pivot motor housing 53.

The pivot motor housing 53 is formed according to the imbalance masses 3, 3 'as a sector-shaped unbalance. The pivot space 55 formed between the inner contour 54 of the pivot motor housing 53 and the pivot motor shaft 51 is limited by two stop surfaces 56, which allow a maximum rotation angle of 150 degrees. Between the abutment surfaces 56 of the pivot motor housing 53 and the rotary wing 52 of the pivot motor shaft 51, two chambers 57 are formed for the operation of the rotary piston pivot motor 5.

In the axial bore 511 of the pivot motor shaft 51, a lance 6 for supplying the chambers 57 of the rotary piston pivot motor 5 is introduced with hydraulic oil. The lance 6 is substantially cylindrical. At the end, the lance 6 has a head piece 61, which is adjoined by a shaft 62, which merges into a diameter-enlarged slide bearing portion 63. In the lance 6, two channels 64 are provided coaxially to the central axis 11 for supplying the chambers 57 of the rotary piston pivot motor 5. The channels 64 each open into an annular groove 65 arranged within the sliding bearing section 63, which is arranged such that one of the radial bores 512 is arranged as a pivoting motor 51 orthogonal thereto, which axial bore 511 connects to the respective chamber 57 of the rotary piston pivoting motor 5 represents. The sealing of the annular grooves 65 to the pivot motor shaft 51 via a very narrow gap between the sliding bearing portion 63 and the inner wall of the axial bore 511 of the pivot motor shaft 51, wherein the sliding bearing portion is provided in the embodiment with a sliding bearing coating made of plastic.

The lance 6 is mounted with its head piece 61 on a flange 7, which is fixed to the - not shown - housing of the vibrator gear. The flange part 7 consists essentially of a base plate 71, which is connected centrally with a cup-shaped recess 72 which is aligned with a bore 73 guided through the base plate 71. The cup-shaped recess 72 receives the lid part 75, which with a centrally arranged cylindrical formed recess 76 whose outer diameter is slightly larger than the outer diameter of the head piece 61 of the lance 6. The cover part 75 is provided with supply ports 77 for supplying the channels 64 of the cover part 75 lance 6 received. Furthermore, in the recess 76 of the cover part 75, a dowel pin 78 is arranged for engagement in an eccentrically arranged in the head piece of the lance 6 fitting hole 66. Surrounding the recess 72 of the cover part 75 are parallel to each other two annular grooves for receiving an O-ring 8 is introduced. The O-ring 8 bridges the gap between the head piece 61 of the lance 6 and the recess 76 of the cover part 75, whereby the head piece 61 is mounted slightly pivotable in the cover part 75. The cover part 75 is fixed in the recess 72 of the base plate 71 and receives the head piece 61 of the lance 6, whose shaft 62 projects through the bore 73 of the base plate into the axial bore 511 of the pivot motor shaft 51 of the rotary piston pivot motor 5. In this case, the cover part 75 is sealed relative to the cup-shaped recess 76 by means of an O-ring 81.

In the exemplary embodiment, the vibrator is operated by two - not shown - drives that drive the top and bottom unbalance shaft 1, which are identical to the pivot motor shafts 51 of the rotary piston pivot motor 5 here.

The entire static moment of the upper and lower imbalance shaft 1 corresponds to the static moment of the central imbalance shaft 1 'in this three-shaft vibrator. Therefore, the unbalance 3 on the lower and upper imbalance shaft 1 does not claim the available space. In the upper and in the lower imbalance shaft 1 each have a rotary piston pivot motor 5 is integrated, which is located in each case in the middle imbalance. The pivot motor housing 53 of the rotary piston pivot motor 5 is designed as a circular segment unbalanced mass and rotatably mounted on the respective unbalanced shaft 1. The angle of rotation is limited by the integrally formed on the pivot motor shaft 51 rotary vane 52 in interaction with the abutment surfaces 56 of the pivot space 55 to a maximum of 150 degrees. The rotary vane 52 also serves as a seal between the two chambers 57 which are delimited between the rotary vane 52 and the pivot motor housing 53 and the pivot motor shaft 51. The two chambers 57 are supplied with hydraulic oil, which is supplied via the radial bores 512 of the swing motor shaft 51. In order to supply the hydraulic oil to the rotating swing motor shaft 51, the fixed lance 6 is mounted in the central, axially extending bore 511. The sealing effect is achieved through narrow gaps. To prevent excessive leakage, the hydraulic transmission is equipped with two rotary actuators, which ensures low pressure operation while ensuring the required maximum torque of the swing motors.

The hydraulic oil is supplied through the supply ports 77 to the channels 64 of the lance 6. From these channels 64, the oil enters the annular grooves 65 on the outside of the lance. The chambers 57 of the rotary piston pivot motor 5 are connected by radial bores 512, which connect the respective annular groove space with the corresponding chamber 57. The sealing of the annular grooves 65 against each other via a narrow gap. In the embodiment, a Leckageringnut 67 is disposed between the two annular grooves 65, which serves to dissipate occurring leak oil. The fit between the lance 6 and the axial bore 511 of the pivot motor shaft 51 is designed in the region of the annular grooves 65, 67 as a narrow slide bearing. In this area, the lance is provided with a sliding bearing coating made of plastic. Due to the sliding bearing formed between the axial bore 511 of the pivot motor shaft 51 and the sliding bearing portion 63 of the lance 6, some leakage occurs, but at the same time lubricates the bearing, separates the surfaces and thereby counteracts wear.

Characterized in that the pivot motor housing 53 of the rotary vane pivot motor 5 is formed in each case as imbalance, the bearings with which the pivot motor housing 53 is mounted on the pivot motor shaft 51, increasingly loaded with centrifugal force with increasing speed. In addition, a bearing force results from the oil pressure in the chambers 57. This, resulting from centrifugal force and oil pressure in the chambers 57 bearing load leads to an increased adjusting torque. In order to at least partially compensate for the resultant force acting on the bearings, an oil pocket 58, which can be acted upon by oil pressure, can additionally be introduced into the swivel motor housing 53 (cf. FIG. 11 ). This oil pressure can be diverted, for example, in the control of the chambers 57. In this case, two Check valves or a shuttle valve required to preclude a hydraulic short circuit between the two chambers 57. Valves, however, are sensitive to dynamic loads, which are essential in a vibrator gearbox. In order to avoid valves on the swivel motor and to be able to select the oil pressure in the oil pocket 58 independently of the adjustment pressure of the rotary vane rotary motor 5, it makes sense to realize the oil supply in the oil pocket 58 via a separate connection. For example, for this purpose, the middle connection formed by the Leckageringnut 67 can be used.

Claims (14)

1. Oscillation exciter for construction machines, particularly for vibrating pile drivers, comprising at least one axle (2) with at least two imbalance masses (3, 3'), wherein at least one rotary piston oscillating motor is arranged, via which the rotary position of at least one imbalance mass is alterable vis-à-vis the at least one other imbalance mass, wherein the rotary piston oscillating motor has an oscillating motor housing, which is mounted rotatably to and on an oscillating motor shaft, wherein on the oscillating motor shaft at least one rotor is arranged whose rotation angle is delimited by at least one stop arranged at the oscillating motor housing, characterised in that the maximum rotation angle of the at least one rotor is less than 160 degrees, preferably 150 degrees or less, wherein at least one imbalance mass is formed by the oscillating motor housing (53) of an oscillating motor (5) designed as a single-leaf rotary piston oscillating motor, which is designed in the shape of a circle segment and is arranged on and rotatably to the oscillating motor shaft (51), which forms part of the at least one axle, wherein between the two stop surfaces (56) of the stop opposite the pivot area (55) defined by the rotation angle of the rotor (52) of the oscillating motor (5), at least one oil pocket (58) which can be supplied with oil is designed.
2. Oscillation exciter according to claim 1, characterised in that in order to supply the at least one oil pocket (58) with oil, at least one separate oil supply duct is arranged in addition to the oil supply ducts for the chambers (57) arranged on both sides of the rotor (52).
3. Oscillation exciter according to claim 1, characterised in that on the oscillating motor shaft of the at least one oscillating motor two oppositely arranged rotors are arranged, so that between the two rotors and the allocated stop of the oscillating motor housing two opposite pressure chambers are formed in one rotation direction, respectively.
4. Oscillation exciter according to one of claims 1 to 3, characterised in that in order to seal the oscillating motor housing (53) vis-à-vis the oscillating motor shaft (51) of the at least one oscillating motor (5), no seals are arranged, wherein the sealing effect is solely effected via the clearance.
5. Oscillation exciter according to one of the previous claims, characterised in that the oscillating motor shaft (51) of the at least one oscillating motor (5) is provided with an axial hole (511), into which a stationary lance (6) protrudes, which has at least two ducts (64) for supplying the oscillating motor (5) with oil, which respectively end in a ring groove (65) arranged outside at the lance (6), wherein in the oscillating motor shaft (51) radial holes (512) for connecting the at least two ring grooves (65) of the lance (6) with the chambers (57) of the oscillating motor (5) to be supplied are arranged.
6. Oscillation exciter according to claim 5, characterised in that the fit between the lance (6) and the axial hole (511) of the oscillating motor shaft (51) in the area of the ring grooves (65) of the lance (6) is designed as a narrow slide bearing.
7. Oscillation exciter according to claim 5 or 6, characterised in that the lance (6) in the area of the ring grooves (65) is provided with a plastic coating, which is preferably made of Teflon.
8. Oscillation exciter according to one of claims 5 to 7, characterised in that the lance (6) has an elastic shaft (62).
9. Oscillation exciter according to claim 8, characterised in that the lance (6) has a reduced diameter in the area of the shaft (62), whereby higher elasticity is effected.
10. Oscillation exciter according to one of claims 5 to 9, characterised in that no contact seals are provided over the length of the fit between the lance (6) and the axial hole (511) in the area of the ring grooves (65) of the lance (6).
11. Oscillation exciter according to claim 10, characterised in that the lance (6) at its end is mounted in a torsion-proof way with play in a flange part (7) affixed to the housing of the oscillation exciter.
12. Oscillation exciter according to claim 11, characterised in that the lance (6) at its end has a headpiece (61) with an increased diameter, with which it is mounted in the flange part (7).
13. Oscillation exciter according to claim 11 or 12, characterised in that the gap between the lance (6) and the flange part (7) formed by the play is bypassed by at least one O-ring (8).
14. Oscillation exciter according to one of claims 11 to 13, characterised in that the torsion protection of the lance (6) in the flange part (7) is effected by at least one locating pin (78) eccentrically axially protruding into the lance (6).

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