EP1305121A1

EP1305121A1 - Controllable vibration generator

Info

Publication number: EP1305121A1
Application number: EP01969568A
Authority: EP
Inventors: Wolfgang Fervers; Martin Schreck; Franz Riedl
Original assignee: Wacker Construction Equipment AG
Current assignee: Wacker Construction Equipment AG
Priority date: 2000-08-04
Filing date: 2001-08-03
Publication date: 2003-05-02
Anticipated expiration: 2021-08-03
Also published as: EP1305121B1; DE10038206A1; US20040025608A1; WO2002011906A1; DE10038206C2; DE50104133D1; JP2004505756A; US7171866B2

Abstract

A vibration generator comprises two unbalance shafts (2, 3), which are positively coupled in a contra-rotative manner and whose relative phase position can be shifted by a phase shifting device (7). Each of the unbalance shafts (2, 3) supports a main unbalance mass (15) and a partial unbalance mass (16) that can move in relation thereto. The position of the partial unbalance masses (16) on the respective unbalance shafts (2, 3) can be actively altered within a large range by adjusting devices (17, 18). The resulting vibration vector generated by the vibration generator can be set in a diverse manner with regard to direction and magnitude.

Description

Adjustable vibration exciter

The invention relates to a vibration exciter according to the preamble of patent claim 1.

Such vibrators are such. B. in soil compaction machines, such as. B. vibration plates, advantageously used and are known from EP 0 358 744 B1.

In the known vibration exciters, two unbalanced shafts are rotatably coupled in opposite directions to one another, their relative phase position being adjustable by a phase change device. Each of the unbalance shafts carries an unbalance part rigidly attached to it and an unbalance part which can be freely rotated thereon over a predetermined angular range between end positions limited by stops. The stops with respect to the rigid unbalance part are arranged such that the resulting total unbalance from the rigid unbalance part and the movable unbalance part assumes a maximum value in one end position of the movable unbalance part and a minimum value in the other end position. The change of the rotatable unbalance parts between the two end positions is effected by reversing the direction of rotation of the unbalanced shafts, i. H. that the rotatable unbalance parts always assume the same end position depending on the direction of rotation of the unbalance shaft carrying them.

The relative adjustment between fixed unbalance parts and moving unbalance parts changes the effective resulting centrifugal force and thus the so-called mr value (product of the resulting unbalanced mass m and the radius r of the center of gravity of the resulting unbalanced mass). If the rigid and the movable unbalance part are arranged on the same side of the unbalance shaft, their centrifugal forces add up to a high mr value. If, on the other hand, the movable unbalance part is in its other end position with respect to the unbalance shaft opposite the rigid unbalance part, the mr value is reduced to a minimum.

Such a vibration exciter has proven to be excellent in practice. However, it has proven to be disadvantageous that for adjusting the moving unbalance parts in the opposite end position a reversal of the direction of rotation of the unbalanced shafts is required, which means a not inconsiderable technical effort for driving the unbalanced shafts. Furthermore, especially when using the vibration exciter in soil compaction machines, it is desirable to be able to optimally adapt the vibration generated by the vibration exciter to different soils and soil compaction conditions even during compaction. Such a fine adjustment of the vibration behavior is not possible with the known vibration exciters, especially not during operation.

From DE-A-12 14 616 a generic vibration exciter is known, in which a first adjusting device for adjusting the phase position between a main and a partial unbalanced mass on a first unbalanced shaft and a second adjusting device for adjusting the phase position between a main and a partial unbalanced mass are provided on a second unbalanced shaft, the phase position between the first and the second unbalanced shaft being adjustable by a phase change device. The first and the second adjusting device are coupled to one another via planetary gears, so that the adjustment of the phase position between the main and partial unbalanced mass on one unbalanced shaft results in a corresponding, opposite adjustment of the phase position of the unbalanced mass on the other unbalanced shaft.

The invention is based on the object of specifying a vibration exciter whose vibration parameters, in particular the vibration amplitude and direction, can be freely and variedly adjusted in large areas.

The object is achieved by a vibration exciter according to the invention. Advantageous further developments of the invention can be found in the dependent claims.

In the case of the vibration exciter according to the invention, a main unbalanced mass and a partial unbalanced mass movable relative to the main unbalanced mass are arranged on each of the two unbalanced shafts, with a first adjusting device for actively adjusting the phase position between the main and the partial unbalanced mass of the first unbalanced shaft and a second adjusting device for actively adjusting the phase position between the main and the partial unbalanced mass of the second unbalanced shaft are provided, the adjusting devices and the phase changing device determining the phase position of the two unbalanced waves being supplied with external energy and each having a separate one Have control. The adjustment devices enable almost any phase position between main and partial unbalanced masses to be set. Since the adjusting devices are active, a reversal of the direction of rotation of the unbalanced shafts - such. B. in the prior art - not required. In addition, the change in the phase position is not only limited to two end positions determined by stops. If the adjusting devices are controlled independently of one another, it is also possible to set a different phase position between the main and partial unbalanced mass on the first unbalanced shaft than on the second unbalanced shaft. This also allows certain vibration patterns to be set in a variety of ways, which are advantageous, for. B. can be used for soil compaction. Since the adjusting devices and the phase change device can thus be actuated individually, an almost infinite variety of oscillation patterns, ie in particular amplitudes and resulting oscillation directions, can be set.

In another advantageous embodiment of the invention, the first adjusting device and the phase change device are supplied with external energy and can each be controlled individually. However, the second adjustment device does not have its own external energy supply and is controlled via the effect of the phase change device alone or the first adjustment device and the phase change device. The control is advantageously carried out by means of a positive coupling, so that an adjustment effect by the first adjustment device or by the phase change device also directly effects an adjustment effect of the second adjustment device. Compared to the advantageous embodiment described above, this means that the setting spectrum is no longer quite as wide, since the second adjusting device cannot be controlled individually. Conversely, however, coupling them with the first adjusting device and / or the phase change device has the advantage that the movements are synchronized, in particular the adjustment of the partial unbalance masses is synchronized with the associated unbalanced shafts is very simple and does not require any special control effort for the operator to synchronize the adjustments. A synchronous control for the adjusting devices for the in-phase adjustment of the partial unbalanced masses on the associated unbalanced shaft, which may be necessary in the embodiment described above, is therefore unnecessary.

In a particularly advantageous embodiment of the invention, the partial unbalanced masses can be rotated relative to the main unbalanced mass under the control of the corresponding adjusting device and overlap the main unbalanced mass in the form of half-shells.

It is particularly advantageous if the adjusting devices and the phase change device each allow any continuous change and then fix the respective phase positions. The fixation of the phase position ensures that a vibration behavior of the vibration exciter set by the operator and a resulting relative position of the unbalanced shafts and the unbalanced masses carried by them are kept constant over a longer period of time.

If the phase positions can be changed in a range of up to 360 °, any direction and amplitude of vibration can be set within the limits determined by the mechanical structure.

These and other advantages and features of the invention are explained in more detail below with the aid of the accompanying figures. Show it:

Figure 1 is a schematic sectional plan view of a vibration exciter according to the invention according to a first embodiment.

2 shows a diagram to illustrate different relative positions of unbalanced shafts and unbalanced masses in the first embodiment of the invention;

Fig. 3 is a schematic sectional view in plan view of a

Vibrator according to a second embodiment the invention; and

4 shows a diagram for explaining relative positions of unbalanced shafts and unbalanced masses in the second embodiment of the invention.

Fig. 1 shows a first embodiment of the invention in a plan view.

A first unbalanced shaft 2 and a second unbalanced shaft 3 are rotatably mounted in an exciter housing 1. The first unbalanced shaft 2 is driven by a motor 4, e.g. B. an electric or hydraulic motor, driven in rotation. The rotational movement of the first unbalanced shaft 2 is positively transmitted via meshing gears 5, 6 to the second unbalanced shaft 3, which thus rotates in the opposite direction to the first unbalanced shaft 2.

On the second unbalanced shaft 3, a phase change device 7 is provided in the force flow of the positive connection between the first unbalanced shaft 2 and the second unbalanced shaft 3, which makes it possible to change the relative phase position between the first and second unbalanced shaft 2, 3.

Part of the phase change device 7 is a hub 8 formed on the gearwheel 6, on the inside of which one, preferably two, essentially obliquely running, helical groove (s) 9 are formed.

The phase change device 7 also includes a hydraulically axially actuable piston 10, with which a guide element 12 can also be moved axially via a piston rod 11. The guide element 12 carries a pin 13 extending perpendicular to the axis of rotation of the second unbalanced shaft 3. In the area of the pin 13, the second unbalanced shaft 3 is designed as a hollow shaft and is provided with opposing, mutually parallel slots 14 which extend parallel to the axial direction and which Push through the shaft wall. The length of the slots 14 essentially corresponds to the axial extent of the helical groove 9 in the gearwheel 6. The pin 13 extends through the slots 14 and extends into the groove 9, or possibly into two opposite grooves 9. The piston 10 is controlled hydraulically by the operator or by an appropriate control device. As an alternative to this, pneumatic, electromotive or electromagnetic controls of the piston 10 are also possible.

While the piston 10 is connected to the exciter housing 1 in a rotationally fixed manner with the piston rod 11, the guide element 12 and the pin 13 rotate with the second unbalanced shaft 3. Accordingly, a roller or slide bearing is provided for decoupling the movements.

When the piston 10 is displaced axially with the piston rod 11 and the guide element 12, the pin 13 also moves axially. A rotation of the pin 13 relative to the second unbalanced shaft 3 is excluded because it is guided in the slots 14. Due to the helical course of the grooves 9 in the gear 6, the axially non-displaceable gear 6 is rotated relative to the second unbalanced shaft 3. However, since the gear 6 is directly positively coupled to the first unbalanced shaft 2 via the gear 5, a change in the phase position between the two unbalanced shafts 2, 3 is thereby brought about. This principle is known from EP 0 358 744 B1 and therefore requires no further explanation.

Each of the unbalanced shafts 2, 3 carries a main unbalanced mass 15 shown only schematically in FIG. 1 and a partial unbalanced mass 16 rotatable on the respective unbalanced shaft 2, 3 relative to the main unbalanced mass 15, which overlaps the main unbalanced mass 15 in a half-shell shape.

The rotation of the partial unbalanced masses 16 on the associated unbalanced shafts 2, 3 and thus, a change in the phase positions between the main unbalanced masses 15 and the associated partial unbalanced masses 16 is carried out on the first unbalanced shaft 2 by a first adjusting device 17 and on the second unbalanced shaft 3 by a second adjusting device 18 causes. The partial unbalanced masses 16 are held on the unbalanced shafts 2, 3 by plain bearings.

The adjusting devices 17, 18 operate on the same principle as the phase change device 7, so that reference is made to the description already made for this purpose and, for simplification, the same reference numbers Chen can be used. Each time the piston 10 of the first adjusting device 17 or the second adjusting device 18 is actuated, the associated partial unbalanced mass 16 can be rotated relative to the associated main unbalanced mass 15 in a range of up to 180 °.

In Fig. 1, a case is shown in which the partial unbalanced masses 16 are held by the adjusting devices 17, 18 in a position in which they are on the same side as the main unbalanced masses 15 with respect to the axes of rotation of the unbalanced shafts 2, 3. Accordingly, the centrifugal forces add up to a large overall resultant force, which can lead to strong vibration and thus compaction performance of a soil compacting machine using the vibration exciter.

When the two adjusting devices 17, 18 are actuated simultaneously, the partial unbalanced masses 16 can be pivoted onto a side of the unbalanced masses 2, 3 opposite the main unbalanced mass 15, so that their centrifugal forces are directed in the opposite direction to the centrifugal forces of the main unbalanced masses 15. The resulting total force is accordingly low, which can be useful, for example, towards the end of a compaction process or to protect an already compacted soil.

FIG. 2 shows a diagram with various relative positions of the unbalanced shafts 2, 3, and the associated main unbalanced masses 15 and partial unbalanced masses 16, which are particularly relevant in practice. In FIG. 2, only end and maximum positions of the phase change device 7 and the adjusting devices 17, 18 are shown. Of course, almost an infinite number of intermediate positions are possible. The imbalance shafts 2, 3 shown schematically are shown in the form of a vertical section of FIG. 1.

It should be noted that the unbalanced shafts 2, 3 rotate in opposite directions and accordingly only snapshots can be shown. A large arrow means a large resulting total force with unbalanced masses 15, 16 lying on the same side, while a small arrow means a small resulting force with opposite unbalanced masses 15, 16 tet.

Depending on the setting of the phase change device 7, the direction of the overall resultant force generated by the vibration exciter can be changed, so that either a vibration direction in the backward or forward direction, but also a vertical vibration direction, can be set. When vibrating in the vertical direction, no horizontal force component is generated that could possibly move a vibrating plate in the corresponding direction.

When using the vibration exciter in a vibration plate, the phase change device 7 is actuated for the forward and backward movement of the vibration plate. The resulting force vector from both unbalanced shafts is adjusted accordingly in its direction.

With synchronized, i.e. H. When the adjusting devices 17, 18 are actuated in the same way, the mr value is adjusted with suitable inclination directions of the grooves 9 by the relative pivoting of the partial unbalanced masses 16 without the phase position of the resulting force vector changing. If the adjustment devices 17, 18 are actuated on one side or not at the same time, the mr value of the individual unbalanced shafts 2, 3 is changed. The phase position of the resulting total centrifugal force vector is also changed in size and direction, which offers a wide range of setting options.

Fig. 3 shows a second embodiment of the invention in a schematic section in plan view.

For the sake of simplicity, only the differences between the second embodiment and the previously described first embodiment are explained below, so that unchanged components are identified with the same reference numerals compared to the first embodiment.

The main difference from the first embodiment lies in the design of the second adjusting device (now reference number 19). While the second adjusting device 18 of the first embodiment is also supplied with external energy and can be individually controlled by means of externally supplied hydraulics. bar, like the first adjusting device 17, the second adjusting device 19 of the second embodiment has no separate energy supply from the outside and also no individual controllability. Furthermore, the adjusting device 19 is no longer used to adjust the phase between partial and main unbalance 15, 24, but rather to adjust the phase position between the partial unbalance 16 of the first shaft and the partial unbalance 24 of the second shaft.

This is realized in that the second adjusting device 19 has a gear wheel 20 which meshes with a gear wheel 21 fastened to the partial unbalanced mass 16 of the first unbalanced shaft 2.

In contrast to the first embodiment, a second unbalanced shaft 22 is not completely supported in the exciter housing 1. Rather, one end face is adjoined by a freely rotatable partial shaft 23, the second unbalanced shaft 22 and the partial shaft 23 being connected by a roller bearing 23a and forming a unit which in turn is mounted in the exciter housing 1.

A partial unbalanced mass 24 rotatable about the second unbalanced shaft 22 is fixedly connected to the partial shaft 23. Incidentally, the partial unbalanced mass 24 surrounds the main unbalanced mass 15 in the same manner as in the first embodiment.

The partial shaft 23 is designed as a hollow shaft and has two mutually opposite slots 25 which extend parallel to the axial direction. The slots 25 are penetrated perpendicular to the axial direction by a pin 26 which engages in helical grooves 27 formed in the hub of the gear wheel 20. The grooves 27 run on the inside of the hub of the gearwheel 20 with an axial extent which corresponds to the axial length of the slots 25.

The pin 26 is held by a guide element 28, which decouples from rotation, but is otherwise positively connected to the guide element 12 of the phase change device 7 via a piston rod 29.

The gears 20, 21 and the gears 5, 6 have the same diameter. The operation of the second embodiment is explained below.

When the first adjusting device 17 is actuated to change the phase position of the partial unbalanced mass 16 on the first unbalanced shaft 2, the corresponding pivoting movement via the gear 21, the gear 20, the grooves 27 and the slot 25 onto the partial shaft 23 and thus ultimately onto the partial unbalanced mass 24 the second unbalanced shaft 22 transmitted. The partial unbalanced mass 24 is thus pivoted in an analogous manner to the partial unbalanced mass 16 of the first unbalanced shaft 2. A synchronization of the movements is therefore not necessary. However, it is therefore also not possible to adjust the phase position of the partial unbalanced mass 24 on the second unbalanced shaft 22 individually.

When changing the phase position between the first unbalanced shaft 2 and the second unbalanced shaft 22 by actuating the phase change device 7, the piston 10 is axially displaced, which causes a corresponding axial displacement of the pins 13 and 26. Accordingly, as already explained in connection with the first embodiment, the associated gear wheels 6 and 20 are pivoted relative to the second unbalanced shaft 22 or the associated partial shaft 23, so that the overall phase position relative to the first unbalanced shaft 2 changes.

Various setting options in the second embodiment are shown schematically in FIG. 4. Here, too, a large arrow means that the main and partial unbalance masses are on the same side and thus generate a large resulting vibration amplitude, while a small arrow corresponds to an opposite arrangement of the unbalance masses and thus a low resulting vibration amplitude.

In the second embodiment, actuation of the first adjusting device 17 brings about the same change in the mr value for both unbalanced shafts 2, 22 without the phase position of the resulting force vector being changed.

The control of the adjusting devices 17, 18, 19 and the phase change approximately 7 can be done mechanically, hydraulically or electrically. It is easily possible to connect appropriate control algorithms that facilitate the operability of the vibration exciter. In this case, it will be expedient to provide additional rotation angle sensors, position sensors, position or displacement sensors, acceleration sensors, etc. for determining the respective parameters.

In further embodiments not shown in the figures, it is possible to change the arrangement and the interaction of the components without deviating from the basic principle of the invention. So z. B. in the first embodiment according to FIG. 1, the phase change device 7 and the motor 4 are interchanged in the arrangement, so that the motor 4 drives the second unbalanced shaft 3.

Claims

Patent claims

1. vibration exciter, with a first unbalanced shaft (2) and one with the first unbalanced shaft (2) axially parallel, positively rotatably coupled second unbalanced shaft (3; 22, 23), one of which is driven in rotation; and with a phase change device (7), which is integrated in the positive coupling between the first (2) and the second unbalanced shaft (3; 22, 23), for adjusting the relative phase position of the two unbalanced shafts; a main unbalanced mass (15) and a partial unbalanced mass (16; 24) movable relative to the main unbalanced mass are arranged on each of the two unbalanced shafts (2, 3; 2, 22, 23); a first adjusting device (17) is provided for actively adjusting the phase position between the main and the partial unbalanced mass (15, 16) of the first unbalanced shaft (2); and wherein a second adjusting device (18; 19) is provided for actively adjusting the phase position between the main and the partial unbalanced mass (15, 16; 15, 24) of the second unbalanced shaft (3; 22, 23); characterized in that the adjusting devices (17, 18) and the phase change device (7) are supplied with external energy and each have a separate control.

2. Vibration exciter according to claim 1, characterized in that the first and the second adjusting device (17, 18) can be actuated independently of one another.

3. vibration exciter, with a first unbalanced shaft (2) and with the first unbalanced shaft (2) axially parallel, positively rotatably coupled second unbalanced shaft (3; 22, 23), one of which is driven in rotation; and with a phase change device (7), which is integrated in the positive coupling between the first (2) and the second unbalanced shaft (3; 22, 23), for adjusting the relative phase position of the two unbalanced shafts; a main unbalanced mass (15) and a partial unbalanced mass movable relative to the main unbalanced mass on each of the two unbalanced shafts (2, 3; 2, 22, 23) mass (16; 24) are arranged; a first adjusting device (17) is provided for actively adjusting the phase position between the main and the partial unbalanced mass (15, 16) of the first unbalanced shaft (2); and wherein - a second adjusting device (18; 19) for actively adjusting the

Phase position between the main and the partial unbalanced mass (15, 16; 15, 24) of the second unbalanced shaft (3; 22, 23) is provided; characterized in that the first adjusting device (17) and the phase change device (7) are supplied with external energy and each have a separate control, and that the second adjusting device

(19) is not supplied with external energy and does not have its own control, but is controlled via the effect of the phase change device (7) or the first adjusting device (17) and the phase change device (7).

4. Vibration exciter according to claim 3, characterized in that the first and the second adjusting device (17, 19) are positively coupled such that an adjustment of the phase position of the main and partial unbalanced mass (15,. 16.) Effected by the first adjusting device (17) ) on the first unbalanced shaft (2) causes an opposite, analogous adjustment of the phase position of the main and partial unbalanced mass (15, 24) on the second unbalanced shaft (22, 23).

5. vibration exciter according to claim 3 or 4, characterized in that the second unbalanced shaft (22) and the main unbalanced mass (15) carried by it are firmly connected to one another; and that the second adjusting device (19) is positively coupled to the phase change device (7) in such a way that an adjustment of the phase position of the first and second unbalanced shaft (2, 22) brought about by the phase change device (7) results in an analog adjustment of the phase position of the partial unbalance (24) on the second unbalanced shaft (22).

6. Vibrator according to one of claims 1 to 5, characterized in that each of the main unbalanced masses (15) is attached to the associated unbalanced shaft (2, 3; 2, 22) and that the associated partial unbalanced mass (16; 24) is relative to the main unbalanced mass (15) under Control of the corresponding adjusting device (17, 18; 19) can be rotated.

7. Vibration exciter according to one of claims 1 to 6, characterized in that the partial unbalanced masses (16; 24) are designed as half-shells spanning the main unbalanced masses (15).

8. Vibration exciter according to one of claims 1 to 7, characterized in that the adjusting devices (17, 18; 19) and the phase change device (7) each allow any continuous change and fixation of the respective phase positions.

9. Vibration exciter according to one of claims 1 to 8, characterized in that the phase positions can be changed in a range up to 360 °.

10. Vibration exciter according to one of claims 1 to 9, characterized in that the respective externally powered adjustment devices (17, 18; 19) or the phase change device (7) each have an electromotive, electromagnetic, hydraulic or pneumatic, axially acting actuator.