DE4301368A1 - Device and method for exciting vibrations - Google Patents

Abstract

Device for the excitation of vibrations in a frame in a predeterminable direction with a motor drive and a degree of imbalance which is adjustable during operation, whereby the unbalanced masses are divided into partial unbalanced bodies. Special steps concerning the drive of the partial unbalanced bodies can reduce shock loads on the drive components caused by reactive torque and hence noise emissions arising therefrom. For use in ram vibrators and vibration benches, e.g. for moulding machines.

Description

The invention relates generally to a device and a method for vibrating a device frame in a predetermined direction, and in particular to such a device in which the resulting centrifugal force F _R determining the resulting centrifugal torque M _{R is} adjustable (F _R = M _R × w ² , with w as Angular velocity).

Such devices are used for. B. as vibrating vibrators in Forming machines or as ram vibrators.

To generate a directional vibration, two unbalanced masses, each with a centrifugal moment M, are required, which must be forced with suitable means to an angularly synchronous rotation with the opposite direction of rotation. If an adjustability of the centrifugal torques M _{R is} required, each of the unbalance bodies must be replaced by a pair of two partial unbalance bodies (first and second type unbalanced bodies).

Each partial unbalance body has a partial centrifugal moment with the absolute amount | M / 2 | = mu × | e |, where mu is the (point-concentrated) unbalanced mass and | e | the distance of the center of gravity of the unbalanced mass from the axis of rotation. Since e can be understood as a vector, the centrifugal moment M / 2 is also to be regarded as a vector, as is the centrifugal force F = mu × e × w ² that occurs when a part unbalance body rotates at the angular velocity w.

The adjustability of the centrifugal moment M _R is expressed in that the partial centrifugal moments of each pair can have different directions.

By the vectorial sum of the partial centrifugal moments of each pair between To change the value between zero and the maximum value M, he has to do so proper actuator of a corresponding vibration device between the partial centrifugal moments a relative setting angle β = zero and β = 180 ° adjust.  

The vectorial sum of the partial centrifugal moments of both pairs gives the resulting (total) centrifugal moment M _R with the maximum value M _{R, max} .

A device for generating directed vibrations with an adjustable centrifugal moment M _R therefore requires at least 4 rotatable partial unbalance bodies, which is why the present invention is also explained using examples with 4 partial unbalance bodies each. Of course, the invention also extends to vibration excitation devices in which the at least two pairs required or the at least two partial centrifugal moments required per pair are distributed over a larger number of pairs or rotatable partial unbalance bodies.

The known prior art closest to the present invention is disclosed in PCT / EP 90/02 239. Here, a device for vibration excitation is described in which the least necessary 4 partial unbalance bodies can also be adjusted by several actuators driven in parallel. A predetermined, maximally adjustable resulting centrifugal torque M _{R, max} results when a relative setting angle β = 180 °.

A simple, robust and inexpensive operating mode is obtained if, for the purpose of setting a predetermined resulting centrifugal torque M _R, the actuating motors are impressed with such an actuating torque by means of the actuating device which is in equilibrium with the reaction resulting when the centrifugal torque M _R is set. Torque MR stands.

With this control process it is therefore sufficient if, in the case of hydraulic servomotors, this one very specific, the actuating rotation moment determining pressure. With this type of control of the Relative actuation angle β can then also be actuated by several actuators same pressure can be applied.

A disadvantage of this control method has been found that in the range of values above β = 90 °, compliance with specified Values for the relative positioning angle β without the addition of additional ones control aids is not possible. You force them Fulfillment of functions with additional control engineering effort assuming that relative positioning angles β greater than 90 ° can be controlled,  this results in additional difficulties for the range β = 90 ° to β = 180 ° due to the torque fluctuations that then occur the control process and as a result of alternating torques which to be described later.

Through the patent DE 41 16 647 C1 is a device for Schwin excitation, in which each of the 4 partial unbalance body is assigned its own electric servomotor.

The servomotors equipped with angle measuring systems are torsionally rigid the unbalance shafts carrying the 4 partial unbalance bodies connected, and a position control system superior to all 4 servomotors controls the angular Position of all motors in such a way that the part-Un balancing body adjusted in a symmetrical way, or, in a symmetrical win be kept in the same position.

A relative setting angle β can easily be set to any value between β = 0 ° and β = 180 °. A predetermined, maximum adjustable resultant centrifugal moment M _{R, max} results when a relative actuation angle β = 180 ° is set.

With this adjustment strategy, the angular position of one of the 4 motors is considered independent variable (guide variable), while the angular positions of the 3 others Engines as dependent or changeable variables (subsequent variables) will be.

So that the 3 dependent angular positions always remain at the prescribed setpoint under the influence of disturbance variables, which also include the reaction torques MR , each servomotor must be permanently acted upon by its own controller.

Because of the resonating common dynamic mass mg an ener Proper coupling of all partial unbalance bodies to one another is given (Transformer effect), such that with an adjustment of the angular position on one partial unbalance body the three other partial unbalance bodies want to adjust as well, all controllers are constantly adjusting of angular deviations in both directions.  

The resulting demands on the dynamics of the controller exacerbated by the fact that the definition of angular Location of one of the unbalanced shafts as a guide, and the control technology Tracking of the subsequent sizes of the 3 other angular positions to asymmetrical lead to burdens. As a result of the necessary highly dynamic Regulation there are ongoing changes in rotational speeds and torques on the motors.

The negative effects of resulting torque Jumps to the drive elements are known to the person skilled in the art. The bean The drive elements are particularly stressed when the motors are should be arranged (i.e. not resonating) and still above suitable drive elements a torsionally rigid torque transmission between Actuator and unbalanced shaft must be done.

The type of vibration excitation devices characterized by DE-PS 41 16 647 C1 with adjustable resulting centrifugal moment M _R and with a separate servomotor assigned to each partial unbalance body has the two disadvantages mentioned below:

• - The control devices for regulating or controlling the relative Adjustment angle β very expensive, or, also very expensive.
• - Obviously, it affects the drive elements involved (e.g. Gears, toothed belts, cardan shafts) high dynamic loads, those for rapid wear and tear or rapid uselessness of the type drive organs and at the same time are responsible for high Ge noise emissions.

The invention has set itself the task by the previously schil Other examples of the genus of vibration excitation to improve directions. On the one hand, the improvement should help the costs and the device-related effort for control purposes to keep the flow of the relative setting angle β low and on the other hand also have the consequence that the aforementioned wear and noise Pro bleme, whose causes are to be found in the existence of alternating moments are to reduce.  

Before going into the solution to this problem according to the invention, should be tried first on the theoretical causes of be called difficulties.

In the PCT-OS PCT / EP 90/02 239 is explained with reference to FIG. 4 for a Vorrich device for vibration excitation with 4 part-unbalance bodies that between the part-unbalance bodies of the first and second types caused by inertia reaction torques M _RI and M _RII work. (However, note that the angle β identified there is identical to the angle α used in the description of the present invention).

These known theoretical considerations will be expanded below with reference to FIGS. 5 and 6.

The reaction torques MR occur as alternating torques with a sinoid course over the angle of rotation with a frequency twice as high as the rotational frequency, that is to say with two peak values per revolution (see FIG. 5). The absolute magnitude of the reaction torques MR depends on the dynamic mass mg, on the angular velocity w, on the centrifugal moment M _R and on the relative actuation angle β.

Fig. 5 shows the course of the reaction torque MR as a function of the angle β of the angular values of β = 30 °, 90 ° and 180 °. (The meaning of the angles α and β used in the following can be seen clearly from Fig. 1. While α and β are indicated as adjustment angles, the angle µ is the common angle of rotation of the unbalanced shafts.)

 The examples indicate that up to MR = f (β = 90 °) with increasing Angle β both the amplitude values of the alternating moments increase as the proportion of negative MR values increases.

From the function course for MR = f (β = 90 °) to MR = f (β = 180 °) there is a slight decrease in amplitude values. More remarkable, however, that the negative MR values increase continuously with increasing angle β, until finally at β = 180 ° the proportion of positive MR values equal to that Share of negative MR values.  

If you integrate the function of MR over the rotation angle 2 π, you get the so-called angular momentum D. If you divide the value for D by 2π, you get an average reaction torque MR .

The size of MR corresponds to the size of the actuating torque MD on the unbalanced shaft, which must be applied by an adjusting motor in order to maintain the associated relative actuating angle β.

If, according to FIG. 5, the average reaction torque MR is determined for all values of β and the values for MR are plotted over the angle β, a curve profile as shown in FIG. 6 is obtained. The curve for the function MR = f (β) is at the same time a measure of the actuating torque MD = f (β) to be maintained to maintain an angle β [with MR = -MD].

It is noteworthy in Fig. 6 that the decrease in the function value for MR after exceeding the maximum point MP from the maximum value to the value zero at β = 180 ° is not primarily due to a decrease in the amplitude values of the corresponding functions is shown in FIG. 5 due, but mainly to the fact that with increasing β value for angle of the positive and negative MR values more and more balanced. It can be demonstrated mathematically that the maximum point MP must be at β = 90 ° and the curve is a pure sine line.

From Fig. 6 it can be seen from the curve for MD = f (β) [= - MR ] for an operating point AP _{I to the} left of the maximum point MP that with an actuating torque MD _AI embossed on the servomotor there is an angle β _AI sets, whereby no regulation is required for compliance with this assignment.

The stability of the operating state that can be achieved without control at a given constant value for MD _AI can be explained by the behavior in the event of deviations in the value of β _AI upwards or downwards: If β _AI tends to larger values, the resetting reaction torque MR also increases and ensures for a reduction of β _AI . If β _AI tends to lower values, the internal restoring torque MR also decreases, so that the value β _AI must inevitably increase again under the influence of the actuating torque MD _AI .

However, the operating _behavior at a working point A _PII on the descending curve branch looks completely different:

If the angle β _AII tends to larger values, then the resetting reaction torque MR decreases, which leads to acceleration of the adjustment rotation of the corresponding partial imbalance bodies due to the resulting excess of MD _AII compared to the current value of MR the angle β automatically increases further. A similarly negative operating behavior arises when the value β _{AII deviates} from the target value to smaller values. Keeping the working point A _PII stable, especially in the right part of the descending curve branch, can only be achieved with counter-rules with a negative actuating torque.

The stable adjustment of a working point on the right part of the curve the function MD = f (β) requires on the one hand for the reasons shown a real controller (with feedback of the actual value of the controlled variable β) and on the other hand caused by the ongoing change of sign Actuating torque MD a current load reversal on the transmission parts what because of the mostly existing backlash to undesirable high dynamic loads.

In comparison, even higher dynamic loads result from this the course of the reaction torques MR = f (β, µ) over the angle of rotation µ seen:

From Fig. 5, it is the following relationships extracts: The peak values of the reaction torques MR = f (β, μ) project beyond the size of the average reaction torque MR = f (β), which for the example MR = f (β = 90 ° ) is represented by hatching.

Since the size of MR can be equated with the constant actuating torque MD, the effect of the torques can be seen using the example MR = f (β = 90 °) and MD = f (β = 90 °) in the event that No play occurs when the power is transmitted through all of the drive elements involved, as follows:

Both torques act on the rotatable masses in the opposite direction. During phase 1 to 2 (in FIG. 5) MR predominates and there is an additional acceleration of the rotating masses by MR, which manifests itself in an increase in the angular velocity by the amount delta-w (see also the curve for delta w in FIG . 5).

The (decelerating) actuating torque predominates during phases 2 to 3 MD, which increases the angular velocity w by the amount delta-w is undone.

However, if there is a backlash in the chain of power transmission through all the drive elements involved, which is usually always the case, not only is there a force or torque curve, as shown in FIG. 5, but striking stresses occur with a great deal higher peak values. Because in the presence of backlash, the "smoothing effect" of MR is often no longer guaranteed, and the energy of the swirl (corresponding to the area under the curve "A", from 0 to 2a in Fig. 5) settles through mass acceleration completely into kinetic energy.

This explains in large part the cause of the negative effects of dynamic loads in the drive elements of oscillation excitation devices which can be changed with regard to their centrifugal torque M _R.

The associated with the angular velocity deviations delta-w Rotation angle deviations delta-µ are typically in the range between rule 0.5 ° and 1 °, which, for. B. in Zahnrä used as drive elements who can make up an amount larger than the backlash. The reject the differences between a partial unbalance body the first type and the second type.

The ratios in the cited example β = 90 ° do not yet represent the sharpest alternating loads. These arise with increasing value for angle β, the amplitudes of the alternating torques hardly decreasing, but the size of the average reaction torque MR , which the latter even reaches zero at β = 180 °. With decreasing MR , the effect of the alternating moments increases.

The solution to the problem is in the independent patent claims Chen 1 and 6 defines and is based on that described below Concept:

• a) To set and maintain a predetermined relative Setting angle β with the help of the higher-level setting device is everyone Actuator is a one-way actuating torque MD impressed, the direction of the actuating torque acting in such a way that an increase in the actuating torque an increase in the relative Adjustment angle β results.
• b) The partial centrifugal torques are (up to 30%) larger than actually absolutely necessary, dimensioned such that, for the purpose of setting the intended maximum and permissible resulting centrifugal moment M _{R, max} an adjustment of the relative actuation angle β only up to around 90 °.
• c) The limitation of the relative setting angle β has the consequence that the Effects of the reaction torques MR, or that too dynamic effects of manufacturing-related or of use-related play (reverse game) on or between such Drive elements which synchronize the angle of rotation of two part Imbalance body of the first type or the second type of a pair each (e.g. on gears, timing belts, cardan shafts), at the latest after he following setting of the predetermined relative setting angle β reduced or To get picked up.
• d) The avoidance of adverse alternating moments is also achieved by using in the range of a relative setting angle β less than 90 ° automatically (due to the dynamic mass that resonates mg) acting internal forces. When the Servomotors with actuating torques are the symmetry of the adjusting angle of rotation of all partial unbalance bodies namely in such a way stable state that on other synchronization means in principle entirely can be dispensed with.

According to claim 1, the drive elements can be freed from the load on the reaction torques MR practically completely by assigning a separate servomotor to each partial unbalance body, with the servomotors assigned to the partial unbalance bodies of the same type to the partial unbalance bodies actuating torques MD the same amount, but une different direction of action, and the amounts of the actuating torques MD correspond to the average reaction torque MR of the assigned part-Unwuchtkör pers with a constant relative actuation angle β.

With the means according to claim 6, the effect of dynamic loads from backlash can be reduced or eliminated in that when the predetermined relative setting angle β _{max is reached} at least in one pair against a relative setting angle β limiting stop and the stop position with a setting - Torque is tight.

In principle, a device according to claim 1 surprisingly does not require any additional synchronizing means for synchronously guiding the angles of rotation of all partial unbalanced bodies. The synchronism of the relative actuation angle β is worried by the same torque MR for each pair or by the counteracting actuating torque MD, while the synchronous position of the angle of both pairs is caused by such mass forces resulting from the desire for inertia dynamic mass mg acting on both pairs can be explained. It should be borne in mind that the oscillating dynamic mass mg continuously and alternately impresses the partial unbalance bodies on rotational accelerations and rotational delays, and thus in a synchronizing manner.

Although synchronizing means are not required to synchronize the rotation angle, it may still be expedient to provide such as a safety measure. In Fig. 2, as in Fig. 4 between two partial unbalanced bodies of the same type two pairs of gears are provided as safety measures. These gears normally do not transmit synchronizing forces or other forces and can therefore be operated without the addition of lubricant. They only have the task of ensuring synchronous operation in emergencies in the event of external symmetry disturbances.

In complete contrast to the invention according to DE-PS 41 16 647 C1 the present invention does not provide feedback of the actual angle of rotation position  necessary, as is not a position control with regard to the angle of rotation takes place.

The possible parallel loading of several motors, like that at all Apply the principle of control (instead of regulation) Main contribution to simplification and cost reduction for users extension of a device according to the invention.

The advantages that result from the limitation of the adjustment range essentially to values between 0 ° and 90 ° for the relative adjustment angle β also include the fact that the range with the highest alternating moments MR is avoided. [See also MR = f (β = 180 °) in FIG. 5] The additional use of a stop limiting the relative positioning angle β can be useful for several reasons. For example, you can set angle β <90 ° or protect a desired relative setting angle β against changes caused by various conceivable disturbance variables at β <90 °.

The relative setting angle β is limited in the solution according to Pa claim 6 by a stop, two stop members with egg tightened torque generated by the servomotors.

In order to be able to vary the relative setting angle β in this solution, to move or change the stop yourself.

A simple solution arises if you have one of the anchor gane parallel or coaxially displaceable to an axis of rotation of the Vorrich device arranges, which is why the stop element is not also circulating can be brought.

Such a variable stop would also be suitable for a device Claim 1 can be used.

The subclaims define further preferred configurations of the inventive concept.

The following should be particularly emphasized - in the subclaims considered - further developments of the invention:

• - It can be very useful to use servomotors as well To operate drive motors. It should be borne in mind that the servomotors an actuating torque MD with the partial unbalance bodies of one type the opposite sign as on the partial unbalance bodies of the other type have to bring up. Since the actuating torques MD are such Torques that are only partially used for useful work , it makes sense to set the actuating torques MD over a To have series connection of the servomotors supported against each other. This is easiest possible when using hydraulic motors. How about it a pressure distribution with regard to the actuating torques and the working Drive torque can look like is based on a hydraulic solution of a concrete example in OS PCT / EP 90/02 239 (page 14) in detail described.
• - Since the rotation angle is synchronized (up to a possible Stop) only via the size of the actuating torques MD or takes place via the magnitude of torques derived from mass forces, the drive means with the help of which the torques motors are guided to the shafts of the partial unbalance bodies, which rotate moments do not necessarily have to be transmitted in the correct angle.

It is therefore possible to use V-belts without the disadvantages of their To accept the resulting slip.

• - As servomotors, which have their actuating torque MD on the one hand in the direction of rotation and on the other hand against the direction of rotation have to generate, are particularly suitable (commercially available) three-phase Mo gates, which when adjusting the angle β of the actuator with two different three-phase systems, whereby one of the three-phase systems must be identical to the normal local network can.

When used as pure servomotors, the one operated directly on the network could Three-phase motor - working as a generator - the one with a higher frequency energy supplied to the working servomotor returned to the network far (from always to be accepted change and friction losses apart from once).  

Because in this case the motor slip is the torque and consequently sen also determines the actuating torque MD, the frequency difference would be a measure of the relative setting angle β.

The advantage of this operating mode remains when using three-phase asyn chron motors still get when the asynchronous motors are servomotors and working drive motors at the same time. An application is particularly advantageous when electric motors because of Costs and / or the function are preferred and at the same time also electrical adjustability of the speeds is desired.

• - The size of the output of a device the present invention is generally dependent on the Vibration amplitude, therefore also dependent on the relative setting angle β.

With a predetermined limited power supply from the outside to the Vibration excitation device can be influenced by the Rela tiv-setting angle β ensure that the output power together with the inevitable power loss just the maximum from the outside supplyable drive power corresponds.

It is often desirable to be able to briefly increase the useful power beyond the limit of the continuously deliverable power, for which purpose one can use the stored kinetic energy (or the energy stored in a pressure accumulator) while accepting falling speeds and using the adjustability of the resulting centrifugal torque M _R .

In order to replenish the energy storage, the Power output levy can be reduced again or completely interrupted.

A method in which the adjustability of the relative Stellwin kels β is used is defined in claims 30 to 35.

Equipped with the appropriate features, you can e.g. B. one with an excavator motor driven ram vibrator for a short time with a height operate (e.g. twice as much) ram force as normal Would allow engine power of the excavator.  

Combining this property with others, through the present one Invention also enabled advantageous features of a Ramm Vi brators (such as quiet operation and the possibility of driving through of resonance frequencies predetermined by the ramming floor with zero Amplitude), you get an ideal so-called city vibrator.

• - A vibration excitation device with the features according to In principle, claim 1 does not require any synchronization means Synchronous control of the angle of rotation of the partial unbalance body of one Paa res relative to the other couple. This property enables set different relative positioning angles β for both pairs.

This results in the possibility of the direction of the directional swing change relative to the device frame. Applications for Such an oscillation direction controllability results, for. B. Rütt learn for soil compaction, which means that not only vertical acting vibrating intensity varies, but also a horizontally acting Acceleration component for the displacement feed generated who that can.

Forming machine vibrating tables can be controlled with the Direction of vibration z. B. also horizontal vibrations are excited.

Embodiments of the invention are described below with reference took explained in detail on the drawings.

Fig. 1 shows schematically a vibration excitation device with 4 partial unbalance bodies and 4 hydraulically operated motors.

FIG. 2 shows in a section in FIG. 3 marked EF or KL perpendicular to the axes of rotation a device for excitation of vibration with two pairs of partial unbalanced bodies with partial unbalanced bodies arranged coaxially for each pair.

Fig. 3 is a section through a device according to Fig. 2 according to the cut marked there with GH.

Fig. 4 shows schematically a device according to the invention with 4 electric motors and their control by means of a frequency converter.

Fig. 5 shows diagrams of the course of reaction torques, up wear over the angle of rotation µ of the unbalance body.

Fig. 6 shows diagrams for the course of the necessary actuating torque MD and the resulting centrifugal torque M _R over the relative actuating angle β.

In Fig. 1 4 shafts 116 to 119 are mounted in a frame 109 with masses, with unbalanced bodies 101 , 102 , 105 , 106 of the same size with respect to their partial centrifugal moment.

Each of the 4 shafts is assigned a hydraulic motor 103 , 104 , 107 , 108 of the same torque. The direction of rotation of the shafts is marked with w (w for angular velocity).

The partial unbalance bodies 101 + 105 and 102 + 106 each form a pair (also characterized in the example by the same circumferential directions) with partial unbalance bodies of the first type 101 or 102 and the second type 105 or 106 , between which a relative Setting angle β must be set (angle α is complementary angle α = 180 ° -β).

An assembly for generating two separate fluid volume flows is provided, with an electric drive motor 110 , a pump 115 with a constant delivery volume and a pump 214 with a variable delivery volume, which can be specified electrically by the setpoint generator 213 . The pressure at the outlet of the pump 115 can be adjusted with a pressure limiting valve 111 . Via an electrically controllable pressure control valve 112 , the pressure in the line part 117 can be set as desired within certain limits.

The motor groups assigned to the two pairs are acted upon in parallel by the pump 114 with the same inlet pressure at the motors. The motors of each pair are connected in series. In this way, all motors are given the same rotational speed, which in turn can be varied by changing the delivery volume of the pump 114 .

The operation of the device according to FIG. 1 is as follows:

The technical teaching according to claim 1 is used. The hydraulic motors are used both as working drive motors and as servomotors. The partial unbalance bodies 101 and 102 may be forcibly synchronized for safety reasons by means of two gearwheels, each associated with a shaft 117 and 118 (indicated by the contact of the circles symbolizing the partial unbalance bodies). Since no forces are normally to be transmitted via these gears, this type of forced synchronization could also be omitted.

It is assumed that the pressure at the outlet 117 of the pressure control valve 112 is initially lower than in the line part 118 and that all the motors rotate at the same speed, the relative actuating angle β also initially having the value zero.

In line parts L ₃ or L ₁ and L ₂ , pressures have built up, which are primarily determined by the rheological conditions and by the friction generated during the rotation of the rotating parts.

If you now set a pressure at the output 117 of the pressure control valve 112 that is greater than that prevailing in the line part 118 , the motors 103 and 104 must additionally work against this pressure, which means a simultaneous pump operation (generator operation) for the motors , for which you need the additional torque MD _P.

Due to the pressure increase at L ₁ and L ₂ , the motors deliver an additional torque MD _M.

By the action of the additional torques MD _P and MD _M , the relative setting angle β was generated on each pair, which in turn acted on the part-unbalance bodies of the first kind 101 , 102, a reaction torque MR _I and on the part-unbalance bodies of the second type 105 , 106 an opposite reaction torque MR _II occurred.

With the amount of pressure at the line part 118 , the angle β can be set as desired within the range of 0 ° and 90 °.

As can be seen from FIG. 1, the reaction torques are opposite to the additional torques, the respective amounts of the opposite torques being the same. The additional torques represent the actuating torques MD (MD = -MR).

After conversion by internal forces acting on the frame, the additional torques MD _{M to} be applied by the motors 107 and 108 are fed back to the motors 103 and 104 as additional torques MD _P.

It can be seen that, for each pair, it applies that an apparent power corresponding to the product Ps = MD _M × w = MD _P × w is continuously circulated on a closed transport route (shafts, frame, motors, lines L ₁ and L ₂ ) becomes. (For an explanation of the pressure conditions in front of and behind the motors, see also OS PCT / EP 90/02 239, page 14).

In FIGS. 2 and 3, an oscillation excitation apparatus is shown according to the invention, which is a special variant of the presented in FIG. 1 in schematic form tisierter device.

It is a variant in which the partial unbalance body ei nes of each pair are arranged coaxially.

In Fig. 2, the left part of the drawing corresponds to the cut EF and the right part of the drawing to the cut KL. In Fig. 3 one recognizes a composite of portions 209 and 219 frame with roller bearings 202 and 206, in which a divided shaft with the sub-shaft 216 and is mounted 217th

A coaxial guide of both part shafts with the possibility of a relative rotation against each other is achieved in that the right Wel lenende 220 of part shaft 216 is mounted in two needle bearings 211 , while the needle bearings in turn in a bore 210 of the hollow cylinder-En of 207 the Roll part shaft 217 .

On the hollow cylinder end 207 , two unbalanced bodies 201 a and 201 b with the same centrifugal moment are attached with the same center of gravity (see also FIG. 2). Between them is another unbalance body 205 with a centrifugal torque twice as large as that of unbalance body 201 a and with a 180 ° rotated th position of the center of gravity (based on unbalance body 201 a), in such a way that it is - supported with a needle bearing 218 - Is rotatable relative to the partial shaft 217 .

The unbalance body 205 is connected to the partial shaft 216 in a torque-transmitting manner, which is accomplished by a stop pin 213 . The water is pressed with two stepped cylinder parts each in a bore 224 in the unbalanced body 205 and in a bore 222 in the disk part 212 of the part shaft 216 .

The arrangement shown in Fig. 3 is housed together with storage with the roller bearings twice in the same design in the frame 209/219 , as can also be seen from Fig. 2, where the same parts of both groups are identified with the same reference numerals. Both groups are positively synchronized by two meshing gears 204 , 204 'with pitch circles 226 , 226 '. As can be seen in Fig. 3, the gears 204 , 204 'are firmly connected to the partial shafts 217 , 218 .

The rotatability of the unbalance body 205 relative to the Unwuchtkör pern 201 a and 201 b is limited by a stop which is formed by the fact that after a relative rotation of β = 90 ° from the ge drawn position of the stop bolt 213 (symbolized by the circle 228 ) ) comes to rest against a stop surface 230 on the unbalance body 201 a.

As indicated schematically in FIG. 3 with the motors 203 and 207 , 4 hydraulic motors are present and are connected to the 4 partial shafts 216 , 219 , 217 , 218 in a torque-transmitting manner.

In comparison with the arrangement in FIG. 1, the following correspondences result for the device shown in FIGS. 2 and 3:

Waves 117 and 118 or waves 116 and 119 are the partial waves 217 and 218 or 217 'and 218 '.

Motors 103 and 104 or motors 107 and 108 are motors 203 and 203 'or 207 and 207 '.

The partial unbalance bodies 101 and 102 correspond to the two-part partial unbalance bodies 201 a and 201 b or 201 a 'and 201 b'. The partial unbalance bodies 105 and 106 correspond to the partial unbalance bodies 205 and 205 '.

The mode of operation is the same as that described for FIG. 1. However, the motors could also be electric motors and then e.g. B. can also be operated as described for the arrangement according to FIG. 4.

The drawn position of the focal points in FIGS. 2 and 3 corresponds to a relative setting angle β = 0 °. The adjustment range for the angle β is a maximum of 90 ° and is limited by the mechanical impact already described. Contrary to the drawing, the adjustment range for the relative adjustment angle β, which is limited by the stop, could also be made larger or smaller than 90 °.

The particular advantage of a coaxial version as shown in FIGS. 2 and 3 shows, in addition to a space-saving design, is above all the fact that when the device is operated with a small amount or even with zero amount for the relative setting angle β itself a reduction or even a complete relief of the shaft bearings from the centrifugal forces. This aspect is particularly important for applications where - such as B. with vibrating tables for molding machines - a constant Durchlaufbe operation is provided with predominant operating mode β = 0 °.

With a device according to FIGS. 2 and 3, one could also implement the technical teaching according to claim 6:

For example, after reaching the stops, motors 203 and 207 or 203 'and 207 ' could be braced against each other (e.g. by pressurizing line parts L ₂ , L ₃ ). You could also the discs parts 212 and 212 'form as meshing gears and - by ensuring that only the stop pin 213 ' a relative setting angle β limiting stop - just brace the motors 203 and 207 against each other, so that the bracing over both gear pairs would be directed to the stop.

Fig. 4 shows a vibration excitation device, which is constructed similar to the device in Fig. 1 with respect to the arrangement and operation of the partial imbalance body and the Moto ren, with the only difference that the motors as a 3-phase asynchronous Motors are electrically operated. Organs comparable in function have the same two end digits in the reference numerals in both figures.

The motors 403 and 404 are struck directly by the network generator 430 , while the connection of the motors 407 and 408 to the network is carried out with the interposition of a frequency converter 432 .

The mode of operation is based on the assumption simplifying the circumstances, that friction and other power losses are set to zero can do as follows:

First, all motors run at the same speed in the specified direction of rotation w with a relative setting angle β = 0 °, the frequency f _{2 being} equal to the mains frequency f ₁ . The additional torques or actuating torques MD, like the motor and generator slip, have an absolute value of zero.

In order to set a specific relative setting angle β, the frequency f _{2 is} increased by 10% with respect to f ₁ . With the now occurring slip of 5%, a motor actuating torque MD _{M is} developed in the motors 407 and 408 , which in both pairs results in an adjustment of the relative actuation angle β to a corresponding value, with the result being the adjustment develop the partial unbalance bodies 405 and 406 reaction torques MR _II which have the same amount as the motor actuating torques MD _M.

The reaction torques MR _I , which are automatically set on the partial unbalance bodies 401 and 402 , drive the motors 403 and 404 beyond their synchronous speeds into generator operation with 5% regenerative slip, in which a regenerative actuating torque MD _{G is} the same Set the amount as for motors 407 and 408 .

The power fed into the network by motors 403 and 404 has the same size as the power drawn from the network by motors 407 and 408 (power losses assumed as zero). Both services can be viewed as apparent services.

In real, practical operation, the motors work as servomotors and working drive motors at the same time. A working torque MD _{A must be} applied to each of the 4 shafts, which also includes the friction losses. As long as MD _A <MR _I on shafts 417 and 418 , motors 403 and 404 work as generators. In the event that the motors 403 and 404 are also to be operated via a frequency converter ( 434 ), a different energy discharge would have to be carried out for the generator operation. Instead of this there are of course other solutions (such as DC braking) to generate a "braking torque" on these motors.

The content of the curve diagrams in FIGS. 5 and 6 was already discussed in the course of the introduction to the description.

In FIG. 5 the unbalanced bodies is on the rotational angle represented μ π over an angular range of 2:

• - The course of the reaction torques MR as a function of Relative positioning angle β for β = 30 °, 90 ° and 180 °.
• - The size of the average reaction torques MR as a function of the relative setting angle β for β = 30 ° and 90 ° [ MR (β = 180 °) = 0]. It should be noted that the magnitude of the average reaction torques MR are always equal to the magnitude of the actuating torques MD required for setting the corresponding relative actuation angle β.
• - The size of the optimal bracing torque MDVS for the Case β = 90 °. When dimensioning the torque MDVS in this Size ensures that the attachment elements after application the backlash torque no more backlash occurs.
• - The size of the angular velocity fluctuations delta w in follow the deviations of the variable MR f (β) from the actuating torque MD = f (β) for the case β = 90 ° and provided there is no reversal game les in the drive links.

In Fig. 6 is shown as a graph curve over the relative positioning angle β Darge:

• - The course of the average reaction torque MR = f (β). Since MR = f (β) can always be equated with the necessary actuating torque MD = f (β), and since the actuating torque in hydraulic motors is proportionally dependent on the hydraulic actuating pressure p _s , represents the same curve all 3 sizes.
• - The resulting centrifugal moment M _R. The curve shows that at β = 90 ° 70.7% of the maximum possible value has already been reached.

Claims (39)

1. Device for vibrating a device frame in a predeterminable direction with the features:

• - The device has in the frame and driven to rotate around an associated axis part-unbalance body for generating part-centrifugal force vectors, of which a first and a second part-unbalance body form a pair, the part-centrifugal moments rela tive to each other can be rotated by a relative setting angle β at least between a first position (β = 0 °) in which the resulting centrifugal moment is minimal and a second position in which the resulting centrifugal moment has reached a predetermined maximum value,
• the device comprises at least 2 pairs of partial unbalanced bodies,
• - An actuator with actuator consisting of rotor and stator is provided for the generation of a relative rotation between the pair-forming part-unbalance bodies also during their order, the actuating torques MD, which are the adjusting torques or the holding Torques for the adjustment or maintenance of a relative setting angle β, for the first and the second partial unbalance bodies are each derived from with rotating motor rotors,
• - An actuating device is provided to act upon the actuating motors with the actuating torques that determine the actuating torques or actuating powers, with which the relative actuating angles β are also determined for a specific constellation of operating conditions,
  characterized by the combination of the following features:
• a) each partial unbalance body ( 101 , 102 , 105 , 106 ) is assigned its own servomotor ( 103 , 104 , 107 , 108 ) with which it is connected in a torque-transmitting manner,
• b) the partial unbalance bodies of the same type ( 101 , 102 ); ( 105 , 106 ) assigned servomotors ( 103 , 104 ; 107 , 108 ) transmit impressed actuating torques MD to the partial unbalance bodies with the same amount, but with different directions of action, in one type in the direction of rotation and in the other Counteracting direction,
• c) for the maximum setpoint of the resulting centrifugal torque M _R , a maximum allowable size M _{R, max is} defined, which is converted by the actuating device after entering the maximum setpoint into a maximum relative setting angle β _max , the size of the maximum Re relative positioning angle β _{max are set} to values in the range of β = 90 ° or to values below 90 °,
• d) the partial unbalance bodies have partial centrifugal torques with a value which can be defined in mkg, such that the sum of the absolute values of the partial centrifugal torques of the at least 2 pairs is greater than the absolute value of the maximum permissible resulting centrifugal torque | M _{R, max} |.

2. Apparatus according to claim 1, characterized in that a mirror-image symmetrical synchronous guidance of the rotation angle as a sum of the rotation angle and the proportional relative positioning angle β for we at least two partial unbalance bodies of one type ( 101 , 102 ); ( 105 , 106 ) is essentially accomplished by the action of inertial forces, and that the angle of rotation component for the relative setting angle β is guided synchronously by the acting on the at least two partial unbalance bodies of one type, with the same setting torque MD. 3. Apparatus according to claim 1 or 2, in which the equalization of the amounts of the actuating torques, which are assigned to the partial unbalance bodies of each type, is effected by specifying the same physical quantity determining the actuating torque (e.g. Pressure) to the servomotors by connecting the servomotors in parallel to the same actuating variable generating device ( 112 ); ( 432 , 434 ) by means of hydraulic or electrical lines ( 118 ); ( 436 , 438 ). 4. Device according to one of claims 1 to 3, in which a loading limiting device ( 230 ) for the adjustment of the relative actuating angle β to the maximum relative actuating angle β _{max is} provided, upon reaching which limit an intervention in the actuating torque or in the angular adjustment movement. 5. The device according to claim 4, wherein the Winkel-Verstellbewe movement is limited by a mechanical stop ( 213 , 230 ), against which stop a clamping torque generated by the adjusting motors is effective. 6. Device for vibrating a device frame in a predeterminable direction with the features:

• - The device has in the frame and driven to rotate around an associated axis part-unbalance body for generating part-centrifugal force vectors, of which a first and a second part-unbalance body form a pair, the part-centrifugal moments rela tive to each other can be rotated by a relative setting angle β at least between a first position (β = 0 °) in which the resulting centrifugal moment is minimal and a second position in which the resulting centrifugal moment has reached a predetermined maximum value,
• - The device comprises at least 2 pairs of partial Unwuchtkör bodies,
• - An actuator with actuator consisting of rotor and stator is provided for the generation of a relative rotation between the pair-forming part-unbalance bodies also during their order, the actuating torques MD, which are the adjusting torques or the holding Torques for the adjustment or maintenance of a relative setting angle β, for the first and the second partial unbalance bodies are each derived from with rotating motor rotors,
• - An actuating device is provided to act upon the actuating motors with the actuating torques that determine the actuating torques or actuating powers, with which the relative actuating angles β are also determined for a specific constellation of operating conditions,
  characterized by the combination of the following features:
• a) the partial unbalance bodies of the first type ( 101 , 102 ) and second type ( 105 , 106 ) are each assigned at least one servomotor ( 103 , 107 ), the rotor of which is connected to the partial unbalance bodies in a torque-transmitting manner,
• b) for the maximum setpoint of the resulting centrifugal torque M _R at the end of the continuously adjustable adjustment range, a maximum permissible quantity M _{R, Kon, max is} defined, which is determined by the actuating device after the maximum setpoint has been entered into a maximum relative setting angle β _{Kon, max is} converted, the size of the maximum relative actuation angle β _{Kon, max being} fixed to values in the range from β = 90 ° or to values below 90 °,
• c) the partial unbalance bodies have partial centrifugal moments with a value which can be defined in mkg, such that the sum of the absolute values of the partial centrifugal moments of the at least 2 pairs is greater than the absolute value of the maximum permissible resulting centrifugal torque | M _{R, Kon , max} |.
• d) at the latest when the predetermined maximum relative actuation angle β _max is reached at least in a pair of the relative actuation angles β by a mechanical stop ( 213 ', 230 '), against which stop a clamping torque generated by the adjusting motors is effective is.

7. Device according to one of claims 5 or 6, in which the ge gene against the stop ( 213 , 230 ) directed angle adjustment movement is selected such that the average reaction torques MR counteract the fixed clamping torques. 8. The device according to claim 6 or 7, wherein the tightening torques are greater than the average reaction torques MR . 9. Device according to one of the preceding claims, in which at least between two partial unbalance bodies of a type of two pairs, a device for forced synchronization ( 204 , 204 ') of the rotation angle is provided. 10. Device according to one of the preceding claims 4 to 9, in which the rotational movement of the partial unbalance body of a pair is transmitted to components arranged on an axis of rotation ( 214 ) and in that a stop angle ( 213 , 230 ) limiting the relative setting angle β between these components is manufactured. 11. The device according to any one of the preceding claims, in which the partial unbalance body of a pair are arranged axially on a common axis ( 214 ). 12. Device according to one of the preceding claims, in which the servomotors work partly as motors ( 407 , 408 ) and partly as generators 403 , 404 ). 13. Device according to one of the preceding claims, in which the servomotors are at the same time drive motors ( 103 , 104 ; 107 , 108 ) for the rotational rotational movement of the partial unbalance bodies. 14. Device according to one of the preceding claims, in which the transmission of the engine torques to the shafts of the part-un balancing body is caused by belt drives. 15. The apparatus of claim 14, wherein the belt drives as a wedge belts are executed. 16. Device according to one of the preceding claims, in which the servomotors or drive motors are AC motors. 17. The apparatus of claim 16, wherein the AC motors from the actuator with alternating current of different frequencies are acted upon. 18. Device according to one of the preceding claims 1 to 15, in which the servomotors or drive motors of the first and second type are three-phase motors, characterized by the combination of the following features:

• a) Both types of three-phase motors are connected to two different three-phase systems with a parameter difference either with regard to the parameter frequency or with respect to the parameter angular position of the resulting rotating field vector,
• b) at least one of the three-phase systems is not identical to the network-type three-phase system and is artificially generated by a control part,
• c) the control part for generating the at least one artificial three-phase system has a semiconductor current path switch for each phase of the system, by means of whose pulse on-off switches a predetermined amount of energy is passed through the switch per cycle, the passage of the Currents for each phase are cyclically interchanged, based on the maximum time values of the energy quantities,
• d) the relative setting angle β is produced by generating a generator torque on one of the three-phase motors by inducing an oversynchronous mode of operation, the state of which is determined by the difference in parameters,
• e) the parameter difference is the sum of a first, between the first three-phase system and the rotor of the driving motor Tor measurable partial difference and a second, between the rotor of the braking motor and the second three-phase system measurable partial difference.

19. The apparatus according to claim 19, characterized in that the decoupled elec trical power, or that in the generation of the generator Torque compared to motor operation backwards through the Motor connection terminals flowing, torque-determining active currents i * are included in their effective size and that this effective size control tech is evaluated either to determine the actual size of the relay tiv-setting angle β or for setting and / or keeping a constant predetermined relative setting angle β. 20. The apparatus according to claim 18 or 19, characterized in that for the setting and / or keeping a predetermined Re relative positioning angle β when influencing the control of the motors the lawfulness of the relationship between active currents i * and relative Setting angle β, preferably according to the relationship "i * is proportional to sin β ", is processed with. 21. Device according to one of claims 18 to 20, characterized characterized that both different three-phase systems artificially are generated by using one control part each. 22. The apparatus according to claim 21, characterized in that the Semiconductor current path switches are designed as inverters. 23. The device according to any one of claims 18 to 22, characterized characterized in that the switching elements of the control part in their Circuitry are controlled by a computer, and that the rotation frequency of the motors and the relative positioning angle β are adjustable at the same time are.   24. The device according to one of claims 18 to 23, characterized characterized in that the setting and / or keeping the relative Setting angle β is effected by a control loop and that the control algo In addition to a proportional component, the rhythm also has an integral component disposes. 25. The device according to any one of claims 21 to 24, characterized characterized in that the control parts each have a, in the direction of the local network connection upstream of the semiconductor current path switches tied, energy-storing intermediate circuit, and that the intermediate Circles of both control parts are connected such that the generato Coupled energy is fed back to the driving motor can be. 26. Device according to one of the preceding claims 18 to 25, characterized in that at least one of the control parts part egg nes frequency converter, the power section of the frequency converter ters from the function groups inverter, DC link and DC judge exists, and the rectifier part to the local network is closable. 27. The device according to one of claims 1 to 26, characterized records that the vibration excitation device is part of a shaker is a molding machine. 28. Device according to one of claims 16 to 27, in which the same Motors acted upon by the control device connected in parallel are. 29. Device according to one of the preceding claims, in which an adjustment of the relative setting angle β only in the area of increasing Values for β to less than or equal to the value β = 90 ° is provided.   30. The method, using a device according to one of the preceding claims, characterized in that

• - If the rotational speed of the unbalance body drops as a result of inadequate external power supply
• - During an operating mode to deliver a useful power dependent on the relative setting angle β
• a reduction of the relative actuation angle β is carried out,
• - So that the speed and thus the speed-dependent ge stored kinetic energy and / or the stored energy of a pressure accumulator is increased again.

31. The method according to claim 30, characterized in that after after the speed has increased, the relative setting angle β is increased again, to temporarily deliver a useful power, its converted energy is partly obtained from the stored kinetic energy. 32. The method according to claim 30 or 31, characterized in that that a speed reduction and a speed increase in cyclical Sequence is done. 33. The method according to any one of claims 30 to 32, characterized records that lower speed limits and upper speed limits are given ben are, when the adjustment of the relative setting angle β is reached is made. 34. The method according to any one of claims 30 to 33, characterized records that the reduction of the relative positioning angle β up to the value β = 0 ° is made. 35. Device for performing a method according to one of the Claims 30 to 34, in which an automatic control device is seen, which the adjustment processes for adjusting the relative position angle β depending on the specified speed limits or / and of predetermined time intervals by acting on the Actuating device.   36. Device according to one of claims 4 to 29, wherein the Limit for the adjustment of the relative adjustment angle β is adjustable by the adjustment of a control body or a stop element in one Direction parallel to the axis of rotation of the unbalanced shafts. 37. Device according to one of claims 1 or 2, in which on the Actuator one for each partial unbalance body Pair of the same size, but different from pair to pair Torque MD is impressed, which makes a different for each pair cher relative setting angle is set. 38. Device according to one of claims 1 or 2, wherein for the Adjustment of the relative positioning angle β for each pair is an angle β limiting device is provided and by the action the device limiting the angle β for each pair under different relative setting angle β is set. 39. Device according to one of claims 1 to 36, wherein optionally additionally according to the characterizing parts of claims 37 or 38 for each pair a different relative positioning angle β can be set.