EP2363212B1 - Continuously adjustable vibration generator - Google Patents

Description

The invention relates according to the preamble of claim 1 a vibration exciter with a shaft and at least two arranged on the shaft imbalance weights, in which the radial distance of the common center of gravity of the imbalance weights of the axis of rotation of the shaft is infinitely adjustable by means of a transmission.

At one of the DE 24 09 417 A1 known vibration exciter with two imbalances, a pin is used for the purpose of adjusting the phase position of the imbalances, which engages in a helically extending groove of a hub. A translational movement of the pin causes a rotational movement of the hub, so that a mutual rotation of the imbalances is made possible. It is disadvantageous that high adjusting forces must be applied. Furthermore, the disadvantage is that a complex coupling between the imbalances must be provided. This not only leads to higher costs, but also to greater space requirements. From the DD 265 113 A1 a reciprocating vibrator is known in which the excitation force can be adjusted continuously during operation. For this purpose, a running as a flat push rocker, planar coupling gear is used. A displacement of the push rod leads to a swinging movement of the coupling and the rocker, so that the center of gravity distance of the unbalance weights can be varied to the axis of rotation of the unbalanced shaft. Again, there is the disadvantage that the vibration exciter principle inherent, since a swinging of the imbalance weights in the radial direction is required to increase the excitation force, a relatively large installation space in both the axial and radial direction of the unbalanced shaft claimed.

From the US 2007/0272043 A1 For example, a vibratory mechanism for conveyors having first and second members with respective weights, the radial distance of which can be varied, is known. Similar devices also describe the EP 2 067 533 A1 , the US 2002/0100339 A1 , the US 3,919,575 A and the DE 102 35 980 A1 ,

The invention is therefore based on the object to provide a vibration generator of the type mentioned, which overcomes the disadvantages of the known vibration exciter of the prior art.

This object is solved by the subject matter of independent claim 1. The dependent claims are directed to advantageous embodiments of the invention.

The vibration exciter according to the invention has a transmission, which is a spatial coupling mechanism, for example, a spatial thrust transmission, is.

"Coupling gears", such as pushrods, rockers, rocker arms, etc., belong to the group of non-uniformly translating transmissions and are used when a conversion from rotary to oscillating (rectilinear or oscillatory) motion and vice versa is required. Coupling gearboxes have at least four gear members, which by sliding joints, d. H. Joints such as push and pivot joints whose elements slide on each other or touch each other in surfaces are connected. All coupling gears have at least one fixed coupling, which represents a not stored in the frame or guided transmission link. Depending on the application, the coupling or coupling members may be designed as connecting rods, drive rods, etc.

Compared to cam gears, which form a widespread type of transmission, coupling gears allow easier and cheaper manufacture of the gear members. In addition, coupling gears are considered to be more robust thanks to the higher load capacity of the sliding joints.

Widely used are "flat coupling gear". Level coupling gears are characterized in that the limbs of all members perform a planar movement, d. H. only tracks in a plane or parallel planes. To distinguish this are "spherical coupling mechanism", all of whose limbs can only pass through tracks on concentric spherical surfaces.

According to the invention it is provided that the transmission for adjusting the center of gravity of the imbalance weights is a spatial coupling mechanism. Unlike flat or spherical In spatial coupling transmissions, member points of at least one member can perform a spatial movement with respect to at least one other member. A spatial movement is understood to mean a movement in which at least one point of a body passes through a spatial path that is no longer in a plane. In the case of spatial coupling transmissions, completely different methods of analysis and synthesis apply compared with planar or spherical coupling transmissions.

With the aid of the vibration exciter according to the invention a stepless adjustment of the amplitude of the vibration or the excitation force during operation is possible in a simple and cost-effective manner. Thanks to the transmission kinematics according to the invention, the required adjustment forces are very low. In addition, the vibration exciter according to the invention can be built to save space.

In an advantageous embodiment of the invention, the transmission comprises a variable slide and coupling members, each coupling member is connected by means of pivot connections with the adjusting slide and one of the imbalance weights.

According to this embodiment, the transmission according to the invention is a spatial coupling mechanism with a frame, a drive member designed as an adjusting slide, two coupling members and two output members, which are preferably connected to the imbalance weights or the imbalance weights themselves. It is therefore a parallel transmission with two four-link coupling gears.

In a further preferred embodiment of the invention, the pivot joints each have a joint degree of freedom of f = 2.

Joint freedom degree is understood as the degree of freedom that a joint attaches to a member in relation to the other member connected to it by the joint. Since these are swivel joints, each swivel joint allows two rotational movements about two different axes of rotation. Instead of a hinge joint with a joint degree of freedom of f = 2, it is also possible to use a rotary joint with a higher joint degree of freedom of f = 3, which is the case, for example, in the case of a ball joint.

According to an advantageous embodiment of the invention, the pivot joints each comprise a rotatably mounted clevis.

With this embodiment, a hinge joint with a joint degree of freedom of f = 2 is created in a simple and robust manner. The first axis of rotation is located as in conventional fork joints in the pin axis, which runs through the cheeks of the clevis. Due to the rotatable mounting of the fork head, a second axis of rotation is formed, which runs as a vertical axis of the fork head perpendicular to the first axis of rotation and centrally between the cheeks of the fork head.

According to a further advantageous embodiment of the invention, the shaft has coaxial partial waves, which each have a rotationally and axially fixedly connected imbalance weight, wherein the partial waves are arranged adjacent to each other via rotational sliding surfaces.

According to this embodiment, the total weight of the vibrator can be reduced because the shaft need not be continuous. In addition, the production of the exciter can be simplified by the coupling of the imbalance weights to the respective partial waves in a simple manner, for example by means of a casting process. The two imbalance weights, which are arranged adjacent to one another via rotational sliding surfaces, are coupled to one another and mounted in a common frame such that a single adjusting drive is sufficient to rotate the two imbalance weights relative to one another. The two imbalance weights are arranged mirror-inverted with respect to the center of the wave. However, they are the same in shape and size, allowing easy manufacturing. Preferably, the imbalance weights extend axially substantially over the entire length of the shaft. This creates an extremely compact vibration exciter.

The invention further relates to a directional vibrator for generating a directional vibration with at least two vibration exciters according to the invention, wherein the phase between the waves of the vibration exciter is continuously displaceable.

By a coupling of at least two vibration exciters according to the invention, wherein the coupling allows mutually opposite and synchronous rotation of the unbalanced shafts, a directional oscillator is created from two individual rotating orbiting agents, which can produce a directional vibration on a particular axis due to the superposition of individual vibrations. In devices for soil compaction, for example, predominantly vertically directed vibrations are generated. Preferably, in the directional vibrator according to the invention in addition to the amplitude of the oscillations and the phase between the individual Vibration exciters infinitely variable. In this context, the phase is understood to mean firstly the position of the exciter or imbalance shaft with respect to a freely determinable reference position and, secondly, the size ratio of the imbalances to one another. If the two imbalance shafts run in phase, ie if the center of gravity axes of the imbalance shafts rotating about the respective axis of rotation are arranged parallel to one another in at least two positions and if the imbalances of the two imbalance shafts are equal, then only forces in the vertical direction are generated. However, if the two imbalance shafts have a different phase relative to one another, ie if the center of gravity vectors have no position in which they are arranged parallel to one another or if the imbalances of the imbalance shafts vary in size, the axis of the directed oscillation tilts at a certain angle with respect to the imbalance vertical. This may be advantageous, for example, to generate and adapt a propulsion of the directional vibrator in addition to the compaction of the soil.

Furthermore, the invention relates to a vibrating plate or roller with a directional vibrator with two vibrators according to the invention. The vibrating plate or roller can thus be easily and inexpensively manufactured and adjusted with only small adjustment forces during operation. Not only the amplitude of the directed vibration, but also the inclination of the oscillation axis relative to the vertical can be adjusted continuously, so that depending on the application, the size of the imbalance and the speed and direction of the vibrating plate or roller can be adjusted.

Figur 1

Ein kinematisches Schema des erfindungsgemäßen räumlichen Koppelgetriebes;

Figur 2a

eine Vorderansicht des Schwingungserregers bei minimaler Unwucht;

Figur 2b

eine Vorderansicht des Schwingungserregers bei maximaler Unwucht;

Figur 3

eine perspektivische Ansicht des Schwingungserregers bei minimaler Unwucht;

Figur 4

eine perspektivische Ansicht des Schwingungserregers bei maximaler Unwucht;

Figur 5a

eine Draufsicht des Schwingungserregers bei minimaler Unwucht;

Figur 5b

eine Draufsicht des Schwingungserregers bei maximaler Unwucht;

Figur 6

eine perspektivische Ansicht des Verstellschiebers mit den Koppelgliedern und Drehgelenkverbindungen aus Fig. 3;

Figur 7

eine perspektivische Ansicht des ersten Unwuchtgewichtes aus Fig. 3;

Figur 8

eine perspektivische Ansicht des zweiten Unwuchtgewichtes aus Fig. 3;

Figur 9

eine perspektivische Ansicht des Richtschwingers;

Figur 10

eine perspektivische Ansicht des Richtschwingers aus Fig. 9 ohne Erregergehäuse und Deckel bei maximaler Unwucht;

Figur 11

eine perspektivische Ansicht des Richtschwingers aus Fig. 10 mit Phasenverschiebung;

Figur 12

Amplitudenverlauf der gerichteten Schwingung bei Phasenverschiebung gemäß Fig. 11.

The invention will be further explained by means of exemplary embodiments. They show schematically:

FIG. 1

A kinematic scheme of the spatial coupling transmission according to the invention;

FIG. 2a

a front view of the vibrator with minimal imbalance;

FIG. 2b

a front view of the vibrator at maximum imbalance;

FIG. 3

a perspective view of the vibrator with minimal imbalance;

FIG. 4

a perspective view of the vibrator at maximum imbalance;

FIG. 5a

a plan view of the vibrator with minimal imbalance;

FIG. 5b

a plan view of the vibrator at maximum imbalance;

FIG. 6

a perspective view of the adjusting slide with the coupling links and swivel joints Fig. 3 ;

FIG. 7

a perspective view of the first imbalance weight Fig. 3 ;

FIG. 8

a perspective view of the second imbalance weight Fig. 3 ;

FIG. 9

a perspective view of the stabilizer;

FIG. 10

a perspective view of the stabilizer Fig. 9 without exciter housing and cover with maximum unbalance;

FIG. 11

a perspective view of the stabilizer Fig. 10 with phase shift;

FIG. 12

Amplitude curve of the directional vibration in phase shift according to Fig. 11 ,

FIG. 1 shows a kinematic scheme of the spatial coupling transmission according to the invention. The transmission can be broken down into two four-membered transmissions, namely a first four-member with a frame 1, a drive member 2, a first coupling 3a and a first output member 4a and a second four-member with a frame 1, a drive member 2, a second coupling 3b and a second output member 4b. The coupling 3a, 4a are connected via the joints g ₂ , _3a and g ₂ , _3b with the drive member 2 and the joints g _3a , _4a and g _3b , _4b with the output members 4a, 4b. A translational movement of the drive member 2 along the axis Ax according to arrow T is converted into a swinging movement of the output members 4a, 4b about the axis Ax according to arrow R, wherein the directions of rotation of the output members 4a, 4b are opposite to each other. The coupling 3a, 3b perform in the adjustment of each a spatial movement.

FIG. 2a shows a front view of an embodiment of the vibration exciter according to the invention in a position in which the partial imbalances generated by the imbalance weights 20, 30 cancel each other, so that the total imbalance is minimal, that is substantially zero. The center of gravity S, which is formed on the one hand from the partial center of gravity S1 of the first imbalance weight 20 and on the other from the partial center of gravity S2 of the second imbalance weight 30, lies in this position on the horizontal H, so that there is no radial distance to the axis of rotation Ax. Thus, no appreciable imbalance occurs.

FIG. 2b shows the front view of the vibration exciter Fig. 2a in a position in which the oscillation amplitude or the total imbalance is maximum. By the gearbox for adjustment, the imbalance weights 20, 30 and thus also their centers of gravity S1, S2 are rotated along the arrow directions shown to each other, so that the center of gravity S now has a significant distance from the horizontal H or the axis of rotation Ax. The greater the distance of the center of gravity S from the axis of rotation Ax, the greater the imbalance produced. The distance of the center of gravity S from the axis of rotation can be between the in Fig. 2a shown, minimum value 0 and the in Fig. 2b shown, maximum value can be adjusted continuously.

FIG. 3 shows a perspective view of the vibrator 10 according to the invention for a better overview, in this case the housing is not shown. The vibration exciter essentially comprises the gear 11, which in turn comprises an adjusting slide 12, the two coupling links 13, 14, the imbalance weights 20, 30 and the four pivot joints 15. The exciter housing, not shown here corresponds to the in Fig. 1 shown frame 1. The adjusting slide 12 corresponds to the drive member 2 from Fig. 1 , The coupling links 13, 14 represent the coupling 3a, 3b Fig. 1 , The imbalance weights 20, 30 correspond to the output members 4a, 4b Fig. 1 , The four hinge joints 15 expose the joints g ₂ , _3a , g ₂ , _3b , g _3a , _4a , _3b , _4b Fig. 1 The shaft 18 of the vibration generator 10 is firstly composed of a first hollow-bored partial shaft 21, which carries the first imbalance weight 20, and on the other hand from a second hollow-drilled partial shaft 31, which carries the second imbalance weight 30. In the position shown, no unbalance is generated ( Fig. 2a ).

FIG. 4 shows a perspective view of the vibration exciter 10 Fig. 3 , but in a position where the generated imbalance is maximum ( Fig. 2b ). For this purpose, the adjusting slide 12 is pushed in the direction of the imbalance weights 20, 30. The articulated with the adjusting slide, rigid coupling members 13, 14 each perform a spatial movement, whereby the articulated weights also associated with them unbalanced weights 20, 30 together with the partial shafts 21, 31 perform a rotational movement about the axis of rotation Ax. During operation of the vibration exciter caused by the gear 11 rotational movements of the imbalance weights 20, 30 of the excitation drive or vibration drive (not shown) caused rotational movement of the imbalance weights 20, 30 are superimposed.

In FIGS. 5a, 5b the plan views of the vibrator 10 are shown before and after the adjustment. In the initial position, if no imbalance is to be generated ( Fig. 2a ), is the one end of the adjusting slide 12 at the position X1. Here are the bearings L1, L2, where the fork heads 15 of the hinge joints 15 are rotatably mounted to a distance Y1 away from each other.

As in FIG. 5b shown is the addressed end of the adjusting slide 12 via a hydraulic cylinder or a linear motor (both not shown) for the purpose of adjusting the unbalance by the amount X placed in the position X2. This corresponds to the position for the maximum unbalance ( Fig. 2b ). The imbalance weights 20, 30 are rotated about the axis of rotation Ax to each other, so that in the plan view, a distance Y2, which is smaller than the distance Y1 from Fig. 5a , is recognizable. Any position of the adjusting slide 12 between X1 and X2 is infinitely adjustable.

FIG. 6 shows a part of the transmission 11 from Fig. 3 , The adjusting slide 12 essentially comprises a cylindrical part, which is guided in the bore of the partial shaft 31. At the left end of the adjusting slide 12, a shaft shoulder can be seen, which serves to receive a roller bearing (not shown). At the opposite end of the adjusting slide 12 two fork heads 16 are rotatably mounted about a vertical axis and each form a hinge joint 15 with a joint degree of freedom of f = 2. Connected thereto are the rigid coupling members 13, 14, which in each case again by means of hinge joints 15 with the imbalance weights 20, 30 (not shown here) are connected. Instead of the illustrated pivot connections 15 with rotatably mounted fork heads 16, the coupling links 13, 14 can also be coupled via ball joints (f = 3) rotatably on the adjusting slide 12 or on the imbalance weights 20, 30. Alternatively, it is also possible to provide spherical plain bearings for the rotatable connection of the coupling members 13, 14 on the adjusting slide 12 or on the imbalance weights 20, 30.

In FIGS. 7 and 8 are the imbalance weights 20, 30 off Fig. 3 shown in detail. The partial waves 21, 31 produced integrally with the imbalance weights 20, 30 are also clearly visible. It is also clearly visible that the imbalance weights 20, 30 are identical in construction. In the assembled state, the one end (with the larger bore) of the second imbalance weight 30 on the outer circumferential surface of the partial shaft 21 of the first imbalance weight 20 can rotate rotationally. Accordingly, the one end of the first imbalance weight together with the part shaft 31 of the second imbalance weight also forms a rotary sliding surface. When adjusting the center of gravity distance the mentioned sliding slide relative to each other. It can also be clearly seen that the axial extent of the imbalance weights 20, 30 substantially corresponds to the axial extent of the shaft 18 with the partial shafts 21, 31.

In FIG. 9 is a directional vibrator 50 with two vibrators according to the invention including excitation housing 19 and cover 17 is shown.

In FIG. 10 the directional vibrator 50 is off Fig. 9 shown, but without cover 17 and exciter housing 19. The directional vibrator 50 includes two juxtaposed vibration exciters 10, 40, which means (not shown) for synchronously opposing rotation of the unbalanced shafts have. Instead of adjustment by means of separate adjusting cylinder, it is expedient to provide a main adjusting cylinder 41 with an adjusting piston 42. The connecting element 44 connected to the adjusting piston 42 ensures a synchronous adjustment of the adjusting slide of the vibration exciters 10, 40. The auxiliary cylinder 43 is provided in order to be able to carry out a phase adjustment of the imbalance shaft of the vibration exciter 40 with respect to the imbalance shaft of the vibration exciter 10. In the in Fig. 10 shown position run the unbalance shafts of the vibration exciter 10, 40 in the same phase with maximum imbalance. Thus, the excitation force generated by the directional oscillator 50 is directed vertically upwards or downwards.

FIG. 11 shows the directional oscillator 50 Fig. 10 , but with a phase shift. In this case, the phase of the shaft of the first vibration exciter 10 relative to the shaft of the second vibration exciter 40 is displaced by the fact that the imbalance of the first vibration exciter 10 due to an adjusting movement has an eccentricity e1, which - as also schematically in Fig. 11 Since the imbalance U is calculated according to the formula U = m ^* e from the product of the mass m and the eccentricity e (center of gravity distance from the axis of rotation), the eccentricity e2 of the imbalance of the second vibration exciter 40 is Unbalance of the first vibration exciter 10 is smaller than the imbalance of the second vibration exciter 40. Due to the synchronous rotation in opposite directions of the waves of the vibration exciters 10, 40, a directional vibration is generated whose axis A is not vertical, ie perpendicular to the horizontal H, but by a certain angle, For example, 15 °, is inclined relative to the vertical axis V, as well as in FIG. 12 good to see. This may expediently be used for setting an independent forward or backward movement of a vibration plate, which comprises a directional vibrator 50 according to the invention.

Claims (7)

1. A vibration exciter (10), comprising a shaft (18) and at least two unbalanced weights (20, 30) arranged on the shaft, with the radial distance of the common center of gravity of the unbalanced weights (20, 30) from the rotational axis (Ax) of the shaft (18) being adjustable in an infinitely variable manner by means of a gear (11),
   characterized in
   that the gear (11) is a spatial coupling gear.
2. A vibration exciter (10) according to claim 1,
   characterized in
   that the gear (11) comprises an adjusting slide (12) and coupling links (13, 14), with each coupling link (13, 14) being connected by means of pivot joint connections (15) with the adjusting slide (12) and one of the unbalanced weights (20, 30).
3. A vibration exciter (10) according to claim 2,
   characterized in
   that the pivot joint connections (15) each comprise a degree of freedom of the joint of f=2.
4. A vibration exciter (10) according to claim 2 or 3,
   characterized in
   that the pivot joint connections (15) each comprise a rotatably mounted fork head (16).
5. A vibration exciter (10) according to one of the preceding claims,
   characterized in
   that the shaft (18) comprises coaxial partial shafts (21, 31) which each comprise one unbalanced weight (20, 30) which is connected with said shaft in a torsion-proof and axially rigid manner, with the partial shafts (21, 31) being arranged adjacent to one another via rotational sliding surfaces.
6. A vibration exciter (50) for generating a directed vibration with at least two vibration exciters (10, 40) according to one of the preceding claims, with the phase between the shafts of the vibration exciter (10, 40) being displaceable in an infinitely variable manner.
7. A vibration plate or roller, comprising a directional vibrator (50) according to claim 6.

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