Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
  • G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
  • G01B7/30—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring angles or tapers; for testing the alignment of axes
  • G01B7/31—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring angles or tapers; for testing the alignment of axes for testing the alignment of axes
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
  • G01M1/00—Testing static or dynamic balance of machines or structures
  • G01M1/02—Details of balancing machines or devices
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
  • G01M1/00—Testing static or dynamic balance of machines or structures
  • G01M1/14—Determining imbalance
  • G01M1/16—Determining imbalance by oscillating or rotating the body to be tested
  • G01M1/22—Determining imbalance by oscillating or rotating the body to be tested and converting vibrations due to imbalance into electric variables
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
  • G01M15/00—Testing of engines
  • G01M15/02—Details or accessories of testing apparatus
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
  • G01L1/00—Measuring force or stress, in general
  • G01L1/16—Measuring force or stress, in general using properties of piezoelectric devices
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
  • G01M1/00—Testing static or dynamic balance of machines or structures
  • G01M1/14—Determining imbalance
  • G01M1/16—Determining imbalance by oscillating or rotating the body to be tested
  • G01M1/24—Performing balancing on elastic shafts, e.g. for crankshafts

Definitions

• the invention relates to a method for correcting a misalignment of at least one shaft train of a drive train on a test bench, with at least one piezoelectric force sensor being arranged in a force path via which during power transmission between a load machine of the test bench and a drive machine of the drive train or of the test bench by means of the shaft train a power flow is transferrable. Furthermore, the invention relates to a test stand on which the method can be carried out.
• Misalignments are caused by assembly and manufacturing uncertainties, settlement phenomena and thermal expansion, which lead to displacements of a rotating body. Such displacements have a detrimental effect on the function and service life of the rotating body. Misalignments lead to distortion forces, in particular bending moments and compressive forces, on the rotating body and its storage.
• Patent application WO/2021/011982 discloses various test benches and measuring arrangements to detect misalignments on the test benches using piezoelectric force sensors. The content of this application is also made part of the content of the present application by reference.
• a first aspect of the invention relates to a method for correcting a misalignment of at least one shaft train of a drive train on a test bench, wherein at least one piezoelectric force sensor is arranged in a force path, via soft power transmission between a load machine of the test bench and a drive machine of the drive train or the test bench a power flow can be transmitted by means of the shaft assembly, having the following work steps:
• a second aspect of the invention relates to a drive train test stand comprising: a loading machine which can be connected to a shaft train to be tested; at least one piezoelectric force sensor, which is arranged in a force path via which a force flow is transmitted during power transmission from the load machine of the test bench via the shaft assembly, and is set up to carry out a force measurement in a plane and/or normal to the plane which is an axis of rotation of the shafting and preferably at least substantially normal to the axis of rotation; and a signal processing device with
• Means set up to analyze a measured value or a measured value profile of the force measurement to detect a misalignment of the shafting
• a target value within the meaning of the invention preferably specifies a direction and an amount by which a component to be aligned is to be displaced and/or rotated. Furthermore, a target value can also indicate an absolute value of a direction and a position to which the component to be aligned is to be shifted and/or rotated.
• a shafting within the meaning of the invention has one or more rotationally connected shafts.
• Transportable within the meaning of the invention preferably means “can be transferred” or “will be transferred”.
• a power flow within the meaning of the invention is preferably a path of a force and/or a torque in a mechanical system from a point of application, in particular a point of introduction, to a point or points at which the force and/or the torque be absorbed by a reaction force and/or a reaction moment.
• the power flow is preferably composed of a force, in particular a transverse force to the direction of rotation of the shaft, and a torque, in particular about the axis of rotation.
• a power flow within the meaning of the invention is preferably a way of transmitting power in a mechanical system from a point of introduction to a point or points at which the power is removed.
• a piezoelectric measuring element within the meaning of the invention preferably has a piezoelectric crystal and a charge dissipation or an electrical interconnection.
• a machine within the meaning of the invention is set up to convert energy, preferably kinetic energy, in particular rotation, into electrical energy or vice versa, or chemical energy into kinetic energy.
• a machine according to the invention preferably has a housing.
• a supporting device within the meaning of the invention is preferably a device for supporting an element against a force acting on this element and/or a torque acting on this element.
• a support device is preferably set up to provide a so-called reaction force or bearing reaction force.
• a support device within the meaning of the invention preferably serves to support the storage device.
• the support device is preferably a bell housing, a housing of the drive train or a base plate.
• Detection within the meaning of the invention is preferably a determination and/or a quantification and/or a localization and/or an analysis.
• a means within the meaning of the invention can be designed in terms of hardware and/or software, in particular a processing unit (CPU), in particular a microprocessor unit, which is preferably digital and data- or signal-connected to a memory and/or bus system. and/or one or more programs or program modules.
• the CPU can be designed to process commands that are implemented as a program stored in a memory system, to detect input signals from a data bus and/or to send output signals to a data bus.
• a storage system can have one or more, in particular different, storage media, in particular optical, magnetic, solid-state and/or other non-volatile media.
• the program may be such that it embodies or is capable of executing the methods described herein, such that the CPU can execute the steps of such methods and thereby in particular can detect imbalance and/or misalignment.
• An incremental encoder within the meaning of the invention can preferably determine individual angle segments and/or complete revolutions. In particular, the incremental encoder gives at least one pulse per revolution.
• the invention is based in particular on the approach of aligning a misalignment of a shaft train of a drive train on a test stand using force sensors, in particular force sensors which are provided for determining torques in test operation on the test stand.
• force sensors in particular force sensors which are provided for determining torques in test operation on the test stand.
• Other measuring methods or measuring instruments, in particular the optical methods commonly used in the prior art, are not required when using the invention.
• a shaft assembly does not have to be aligned externally, i.e. not on the test bench. Rather, the misalignment is detected by establishing a frictional connection between the loading machine, a so-called dyno, and the drive machine directly on the test stand.
• a shaft assembly can therefore be aligned in the assembled state with all assembly uncertainties such as unequal screw weights, alignment errors, fitting clearances and manufacturing errors such as eccentricity, asymmetry, density errors, etc.
• piezoelectric measuring elements are preferably used according to the invention, which allow a particularly reliable measurement and, due to their rigidity, only add slight elasticity to the oscillatable system of the drive train.
• the piezoelectric measuring elements are preferably permanently installed in the test stand, as a result of which the measuring signal can be recorded in a physically unaltered manner.
• the measuring elements can be supported by an intermediate plate or base plate.
• target values for correcting the misalignment are determined according to the invention.
• a position correction in particular an automated one, of the loading machine and/or the drive machine can be carried out.
• the misalignment can be reduced or even eliminated directly on the test bench.
• the determination of the target values greatly simplifies the setting up or calibration of a measurement arrangement, which up to now has generally been carried out manually using optical methods. In particular, the time required for this can be reduced by orders of magnitude. Thanks to the possibility of automation, the use of highly qualified personnel for these tasks can also be dispensed with.
• Determining a deflection line of the shaft assembly in particular taking into account boundary and connection conditions, on the basis of the determined bending moment curves, with the target values being determined using the deflection line.
• the method also has the following work steps: Checking whether a bending moment or bending moment curve on the shafting exceeds a threshold value; and
• An iterative process for optimizing the alignment of the shaft assembly on the basis of the determined bending moments or bending moment curves enables target values to be determined particularly precisely.
• the method also has the following work steps:
• the method also has the following work steps:
• test stand preferably has an adjusting device, set up to change a position of the loading machine or the drive machine in a translatory and/or rotary manner.
• the method also has the following work steps:
• the frictional connection is preferably restored after the position of the loading machine and/or the drive machine has been changed.
• a constant specific to the test stand, in particular the product of E module and moment of resistance, of the shafting is determined for calculating the deflection lines by two force measurements, each with different positions of the drive machine or the loading machine.
• a measuring arrangement can be calibrated without the material properties of the shafting, in particular its rigidity, being known.
• the axis of rotation of the shaft assembly is an axis of rotation of that shaft of the shaft assembly on which the force measurement is carried out.
• the plane in which the force measurements are carried out is preferably defined by the bearing points of the shaft assembly on the machine on which the force sensors are mounted. More preferably, the plane is defined by the points at which the force sensors are arranged.
• the force is measured in a stationary state or in a quasi-stationary state of the shaft assembly.
• a stationary state of the shafting within the meaning of the invention is preferably present when the shafting is not rotating.
• a quasi-stationary state of the shafting within the meaning of the invention is preferably present when the shafting rotates at an angular velocity at which a reaction time of the force sensor in relation to a rate of change of a rotational position of the shafting is comparatively small.
• forces can be measured in such a way that they are not influenced by dynamics.
• the angular velocity is preferably so low that its inertial mass has little or no influence, in particular that the shaft assembly has a rotational angle range of less than about 90°, preferably about 70°, more preferably about 15°, even more preferably about 10°, and most preferably about 5°.
• the shafting preferably has no vibrations in the quasi-stationary state.
• a misalignment can also be detected in a stationary or quasi-stationary state of the shaft assembly. This makes it possible to determine the misalignment before an actual test operation on the test stand. Damage to the drive machine to be tested or the test stand can be avoided in this way.
• the force measurement is monitored by comparing the measured value or measured values with a threshold value, which indicates a critical load on the shaft assembly, with rotation of the shaft assembly being stopped or none at all if the threshold value is exceeded rotation is made.
• the drive train test bench additionally has an adjustment device set up to change a position of the loading machine in a translatory and/or rotational manner, the drive train test bench, in particular the signal processing device, also having:
• 1a is a plan view of an end face of a dynamometer, on which a shaft of the dynamometer emerges;
• Fig. 1b is a side view of the loading machine of Fig. 1a;
• FIGS. 1a and 1b shows two top views of a measuring arrangement with a first exemplary embodiment of a drive train test bench and a loading machine according to FIGS. 1a and 1b, by means of which a method for correcting a misalignment can be carried out;
• FIG. 3 shows four diagrams which show forces, bending moments, a bending line for an angular misalignment and a bending line for a parallel misalignment of a shaft assembly on a test bench; 4 shows a diagram with bending lines for parallel misalignment and bending lines for angular misalignment in the axial direction of a shaft assembly;
• FIG. 5 shows a top view of a measurement arrangement with a second exemplary embodiment of a drive train test bench
• FIG. 6 shows a plan view of a measurement arrangement with a third exemplary embodiment of a drive train test bench
• FIG. 7 shows a plan view of a fourth exemplary embodiment of a drive train test stand.
• Figures 1 a, 1 b and 1 c show three different views of a first embodiment of a drive train test bench 1.
• the views of Figures 1 a and 1 b each show only a loading machine 14 of the drive train test bench 1
• Fig. 1 c shows two views of a measuring arrangement one of the loading machine 14 according to Figures 1a and 1b and a drive machine 2 to be tested.
• FIGS. 1a, 1b and 1c The alignment of the individual views of FIGS. 1a, 1b and 1c with one another results from the coordinate axes x, y, c of a reference system drawn in in each case.
• FIG. 1a shows a plan view in the opposite direction of the z-axis onto an end face of a loading machine 14, on which a shaft 5b of the loading machine 14 emerges.
• Fig. 1b shows a side view along the x-axis of the loading machine according to Fig. 1a.
• the loading machine 14 is supported on a base plate or intermediate plate 10 via measuring elements 4a, 4b, 4c, 4d of a force sensor.
• the base plate or intermediate plate 10 preferably also supports the measuring elements 4a, 4b, 4c, 4d in the horizontal direction.
• An adjusting device 12a, 12, 12c is preferably provided on the base plate or intermediate plate 10.
• This preferably has a first actuator 12a, a second actuator 12b and a third actuator 12c in order to shift an orientation of the base plate or intermediate plate 10 and thus also an orientation of the loading machine 14 in the direction of the x-axis and/or the y-axis and about the x -Axis and / or to pivot the y-axis.
• the drive machine 2 and the load machine 14 are each connected or can be connected to a shaft train in a torque-transmitting manner.
• this shafting is not shown in full in this figure.
• the left view of Fig. 1c shows a measurement arrangement in which the misalignment is a pure parallel offset of an axis of rotation D of a shaft 5b of the loading machine 14 and an axis of rotation D' of a shaft 5a of the drive machine 2 in the x-direction.
• the right-hand view of FIG. 1c shows a measurement arrangement in which the misalignment is a pure angular offset of an axis of rotation D of a shaft 5b of the loading machine 14 and an axis of rotation D' of a shaft 5a of the drive machine 2 about the y-axis.
• misalignment occurs as a superposition of angular misalignment and parallel misalignment.
• the drive machine 2 could additionally or alternatively also be shifted in the y direction and/or pivoted about the x axis.
• the measuring elements could also be arranged on the drive machine 2 or in the shaft train, as described further below with reference to FIGS. 5, 6 and 7.
• Plane A is a plane which is normal to the axis of rotation D of the dynamometer 14 and in which there are two measuring elements 4a, 4d which are arranged at the end of the underside of the dynamometer 14 which is remote from the shaft 5b of the dynamometer 14.
• the plane B is a plane which is also aligned normal to the axis of rotation D of the dynamometer 14 and in which two measuring elements 4b, 4c are located, which are arranged at the end of the underside of the dynamometer 14 facing from the shaft 5b of the dynamometer 14.
• the plane G is a plane which is normal to the axis of rotation D' of the prime mover 2 and in which lies a first bearing of the shaft 5a of the prime mover 2, which is arranged at the end of the prime mover 2 facing away from the shaft 5b of the loading machine 14 is.
• the plane H is a plane which is also aligned normal to the axis of rotation D' of the drive machine 2 and in which a second bearing of the shaft 5a of the drive machine 2 lies, which is located at the end of the drive machine 2 is arranged.
• FIG. 1c shows the forces which are caused by the misalignments shown in planes A, B and F.
• the forces A, B act on the measuring elements 4a, 4b, 4c, 4d, which mount the loading machine 14.
• plane F the force F acts on the (not shown) shafting.
• misalignments can be detected both in the XZ plane and in the YZ plane, in particular simultaneously, and then corrected.
• test bench 1 preferably has a signal processing device 7 (not shown). This is described further below in relation to FIG.
• FIG. 2 shows an exemplary embodiment of a method for correcting a misalignment, which can be used in a measuring arrangement according to FIGS. 1a to 1c.
• the measuring arrangement After the measuring arrangement has been installed, it is preferably first calibrated.
• a scaling factor or a constant in particular the product of the modulus of elasticity and the moment of resistance, preferably a rigidity constant, of the shaft assembly 5; 5a, 5b determined.
• This scaling factor or this material constant is preferably used to calculate the bending line, as further below will be explained with reference to FIG. More preferably, the scaling factor or the material constant is determined by two force measurements, each with a different relative position of the drive machine 2 and the loading machine 14 to one another.
• a force measurement is carried out in the planes A, B and/or normal to the planes A, B.
• the planes A, B are from the axis of rotation D of the shaft 5b of the shaft assembly 5; 5a, 5b, which is the shaft of the loading machine 14, is cut.
• the planes A, B are oriented at least substantially normal to the axis of rotation D.
• the axis of rotation D is preferably, as shown in FIG. 1c, the axis of rotation of that shaft 5b of the shaft assembly 5; 5a, 5b on which the force measurement is carried out, i.e. in relation to which the forces are measured.
• the force is measured in stationary states or in quasi-stationary states of the shaft assembly 5; 5a, 5b. In this way, as already explained, damage to the measuring arrangement can be avoided.
• the force measurement is continuously monitored.
• the most recently measured value is compared or compared with a threshold value which indicates a critical load on the shaft assembly 5; 5a, 5b marks. If this threshold is exceeded, a rotation of the shaft assembly 5; 5a, 5b is stopped or no rotation is made.
• the method 100 is then preferably ended.
• Any constantly circulating transverse force indicates an angular offset in the shaft assembly and can therefore be distinguished from misalignments using the method according to the invention.
• a measured value or measured value curve of the force measurement for detecting a misalignment of the shaft assembly 5; 5a, 5b analyzed.
• a parallel offset and/or angular offset of the shafting 5; 5a, 5b with respect to misalignment Preferably, a parallel offset and/or angular offset of the shafting 5; 5a, 5b with respect to misalignment.
• target values for a position correction of the loading machine 14 or the prime mover 2 are determined in order to minimize the misalignment.
• a first sub-step 103-1 bending moments or a bending moment curve on the shaft assembly 5; 5a, 5b determined on the basis of the measured value or the measured value curves of the force measurement.
• a second sub-step 103-2 a bending line of the shafting 5; 5a, 5b, taking into account boundary conditions, based on the determined bending moments or the bending moment curve.
• the target values of the position correction are then preferably determined using this bending line.
• the bend line w x (z) is identical to the axis of rotation D, the misalignment is minimal.
• a fourth step 104 it is checked whether a bending moment or bending moment curve on the shaft assembly 5; 5a, 5b exceeds a threshold value. If the threshold is exceeded, the method 100 continues and repeats.
• the target values are output in a fifth work step 105 . This output preferably takes place via a data interface 10 to the next work step. Alternatively or additionally, the target values can also be output to a user via a user interface 10 .
• the method 100 is preferably ended in a ninth and last work step 109 .
• the frictional connection between the loading machine 14 and the drive machine 2 is preferably interrupted in a sixth work step 106, in particular by opening a clutch (not shown) of the shaft assembly 5; 5a, 5b.
• a position of the loading machine 14 and/or the drive machine 2 on the test stand is changed on the basis of the output target values. This should result in a reduction in misalignment.
• the frictional connection between the loading machine 14 and the drive machine 2 is then preferably restored.
• the method 100 then begins again at the first work step 101.
• the method 100 can also start again from the beginning after an earlier work step.
• bearing forces ⁇ and B or a misalignment force F can be calculated from a moment equilibrium that has arisen.
• the force components F x and F y and the force component F z and torque components M bx and M by for determining a misalignment can be achieved in a manner known per se by means of the targeted arrangement of preferred directions of the individual measuring elements 4a, 4b, 4c or their piezo elements.
• a decomposition in particular orthogonal decomposition, of Measuring signals of the individual measuring elements 4a, 4b, 4c or derived from the measuring signals, ie measured forces Fi, Fi.
• the parameters M z , Fx, FY to be determined are the solution to a system of equations, with an equation as follows for each measurement signal:
• S1, S2, . . . Si, . . . SN are the measurement signals of the individual measurement elements 4a, 4b, 4c, 4a, 4b, 4c, ... 4i, 4N and the orientation of the respective preferred direction in the reference system, a sensitivity of the respective measuring element 4a, 4b, 4c, ..., 4i, ..., N and a possible signal loss due to a force shunt via a fastener.
• measurement signals are required from at least three measuring elements 4a, 4b, 4c, whose preferred directions are aligned in such a way that they lie in a single plane .
• at least two of the preferred directions must be aligned neither parallel nor antiparallel.
• the calculation of the parameters M z , Fx, F y to be determined can be reduced to a matrix multiplication. This has three rows and as many columns as there are measurement signals S1, S2, S3, ... SN available.
• the matrix elements or coefficients map the respective contributions of the individual sensors to the parameters Mz, Fx, Fy to be determined.
• the bending moments M bx and M by can be determined by means of such a decomposition.
• the geometric parameters can be determined either from a design drawing of the drive train test bench 1 and from knowledge of the preferred directions of the measuring elements 4a, 4b, 4c, ..., 2i, ..., 2N.
• the orientation of the preferred directions of the measuring elements 4a, 4b, 4c, . . . 4i, . . . 4N can also be determined by measuring the preferred directions using a calibration measurement.
• the force sensor 4, 11 is preferably clamped between two flat plates.
• external transverse forces with a known direction are applied.
• a distance between the measuring elements 4a, 4b, 4c,..., 4i, . ..,4N can be determined from the axis of rotation D if the preferred directions of the individual measuring elements 4a, 4b, 4c,..., 4i,...,4N are known.
• the bending moment M by (z) can be determined as a function of the location in the direction of the axis of rotation D of the loading machine 14, in the direction of the z-axis in the reference system shown will.
• the differential equation can be solved in each case by a polynomial function w x (z).
• This polynomial function w x (z) specifies the bending line. If there are several shaft sections 5a, 5b of the shaft assembly, a corresponding number of polynomials w x (z) can be determined by including the respective connection conditions when solving the coupled differential equation system w x (z)".
• the scaling factor can then be calculated by two measurements of the forces at different relative alignments of the drive machine 2 and the loading machine 14 to one another. Alternatively, the scaling factor can also be estimated by means of an FEM simulation of the shafting or the measuring arrangement.
• Figure 4 shows two different bending lines w x (z) for a pure angular offset of the axes of rotation D, D' from Fig. 1 c (Fig. 4 above) and a pure parallel offset of the axes of rotation D, D' from Fig. 1 c (Fig 4 below), which are determined using the calculation method presented.
• the dash-dot line indicates the bending line at a greater angular offset and parallel offset than the dashed line.
• FIGS. 5 to 7 show further exemplary embodiments of drive train test benches 1. Even if the arrangement of the force sensor or the force sensors in these exemplary embodiments differs significantly from the arrangement shown in relation to the first exemplary embodiment in FIG was explained with reference to Figures 3 and 4.
• FIG. 5 shows a second exemplary embodiment of a drive train test stand 1, on which misalignments can be detected in addition to calibration or application tests.
• a misalignment can be detected independently of the test bench operation.
• the drive train test stand 1 has, among other things, loading machines or dynos 14a, 14b, which can be connected in a torque-proof manner to an output of a drive train, as shown in FIG.
• the drive train test bench 1 preferably has an incremental encoder 6, which is set up to measure a rotation angle of the shaft train 5a, 5b.
• the function of an incremental encoder 6 is known from the prior art, in particular it can determine the angle of rotation of the shaft assembly 5a, 5b or a change in the angle of rotation and/or direction photoelectrically, magnetically and/or with sliding contacts.
• the drive train 1 preferably has a force sensor 4, which in turn preferably has a plurality of piezoelectric measuring elements, in FIG. 1 three piezoelectric measuring elements 4a, 4b, 4c.
• the measuring elements 4a, 4b, 4c are arranged on a measuring flange 12 in the exemplary embodiment according to FIG. More preferably, strain gauges can also be used as measuring elements 4a, 4b, 4c.
• the measuring flange connects a first shaft section 5a to a second shaft section 5b of the shaft assembly 3.
• the shaft assembly 5a, 5b rotates about an axis of rotation D, which is indicated in FIG. 5 with a dot-dash line.
• the drive machine 2 can either be a part of the drive train test bench 1 or of the drive train 3 , depending on which components of a drive train 3 are to be tested on the drive train test bench 1 .
• the drive train 3 has the drive machine 2, the shaft train 5a, 5b, a differential 13 and axle sections (no reference number).
• a power flow can be transmitted from the drive machine 2 to the load machines 14a, 14b via the first shaft section 5a, the measuring flange 12, the first piezoelectric force sensor, the differential 13 and the axle sections.
• the test stand 1 also has a support device 10 on which the drive test stand as a whole, individual elements of the drive train test stand 1 and/or the drive train 3 are mounted.
• the supporting device 10 can hereby have mechanical structures in order to store the individual elements, for example on the floor of a test stand hall. More preferably, the supporting device 10 can have a base plate or be designed as such.
• At least the prime mover 2 and the power machines 14 a , 14 b are supported by the supporting device 10 .
• the flow of power which is preferably generated by the drive machine 2, causes a flow of force which, in the exemplary embodiment shown in FIG Support device 10 extends.
• the supporting device 10 provides the reaction forces for supporting the drive machine 2 and the loading machine 14a, 14b.
• the measuring elements 4a, 4b, 4c are preferably set up and designed to measure forces in the plane F, ie a plane parallel to the XY plane of the reference system shown.
• the first force sensor 4 preferably has piezo elements 4a, 4b, 4c, which utilize the piezoelectric shearing effect.
• forces or torques on the measuring flange 12 are introduced into the piezoelectric elements 4a, 4b, 4c via the end faces of the measuring elements 4a, 4b, 4c.
• the end faces of the piezoelectric elements 4a, 4b, 4c are preferably connected to a surface of the measuring flange 12 in a frictionally engaged manner.
• the piezoelectric measuring elements 4a, 4b, 4c generate corresponding measuring signals by means of the piezoelectric shearing effect. The same applies when a torque acting in the Z-direction is applied to the measuring flange 12 .
• the measuring elements 4a, 4b, 4c can carry out a force measurement perpendicular to the first plane F.
• the measuring elements 4a, 4b, 4c preferably use the piezoelectric longitudinal effect or the piezoelectric transverse effect. If both forces are measured in the first plane F and also perpendicular thereto, there are preferably both measuring elements which measure in the Z direction and measuring elements which can measure forces in the X or XY plane.
• each of the measuring elements 4a, 4b, 4c has at least two piezo elements which are connected in series with respect to the flow of force, with a first piezo element utilizing the piezoelectric shearing effect and a second piezo element utilizing the piezoelectric transverse or longitudinal effect.
• FIG. 6 shows a third exemplary embodiment of a test stand 1, by means of which a misalignment of a shafting can be detected during test stand operation.
• the test stand 1 of the second exemplary embodiment from FIG. 6 differs from the second exemplary embodiment from FIG. 5 essentially in that a Force sensor 11 is not arranged in the power flow between the drive machine 2 and the loading machines 14a, 14b, but between the supporting device 10 and the drive machine 2.
• the first force sensor 4 measures the reaction force which the supporting device 10 exerts on the drive machine 2 when a torque is present between the shaft assembly 5 and the drive machine 2 .
• the force sensor 11 can preferably be mounted in the axial direction of the axis of rotation D, as shown in FIG.
• the drive machine 2 could also, as shown in the plan view according to FIG. 1a, FIG. 1b or FIG. 7, be supported laterally by the force sensor 11, downwards or upwards.
• the piezoelectric measuring elements 11a, 11b, 11c act on the drive machine 2, there are then elements with a piezoelectric shear effect, a piezoelectric longitudinal or transverse effect or, as already explained with reference to FIG. 5, with two various effects used.
• forces are preferably in a plane C; D and/or perpendicular to the plane G; H measured.
• the second exemplary embodiment could also have a measuring flange 12 on which a further piezoelectric force sensor is arranged.
• This second piezoelectric force sensor could then define a second plane F for measuring forces and/or moments.
• piezoelectric force sensors for measuring the reaction forces on the loading machines 14a, 14b could be present and these further piezoelectric force sensors could also preferably mount the respective loading machine 14a, 14b relative to the supporting device, in particular relative to a base or bottom plate 10, so that here too the reaction forces between the loading machines 14a, 14b and the strut 10 could be measured.
• the measurement of reaction forces according to FIG. 6 has the advantage over the direct measurement of forces in the shaft assembly 5 that the respective force sensor 4 has no influence on the moment of inertia and the balance of the shaft assembly 5.
• FIG. 1 A fourth exemplary embodiment of a drive train test stand, by means of which a misalignment of a shaft train can be detected, is shown in FIG.
• the drive train 3 has only one shaft train 5 and optionally a drive machine 2 .
• the reaction forces of both the loading machine 14 and the drive machine 2 are measured in relation to the support device 10, preferably in relation to at least one measurement plane A, B on the loading machine 14 and in relation to at least one measurement plane G, H on the prime mover 2.
• the drive trains 1 according to the first exemplary embodiment or according to the second exemplary embodiment can also have further elements, in particular a transmission or differential, axle sections, etc.
• FIG. 8 shows a detail of a drive train test bench 1 according to FIGS. 1, 5, 6 or 7 or a separate control unit which is set up to control the drive train test bench 1.
• a signal processing device 7 has means 8, set up for analyzing a measured value or a measured value profile of the force measurement in order to detect a misalignment of the shaft assembly 5; 5a, 5b, means 9 for determining target values for a position correction of the loading machine or the prime mover in order to minimize the misalignment and means 10, in particular an interface, for outputting the target values. Further preferably, the signal processing device 7 has means 15 which control the adjusting device 12a, 12, 12c on the basis of the output target values. The signal processing device 7 is connected in terms of signals both to the measuring elements 4a, 4b, 4c of the force sensor and to the adjustment device 12a, 12, 12c.

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• 2021
  • 2021-01-15 AT ATA50011/2021A patent/AT524535B1/de active
• 2022
  • 2022-01-14 CN CN202280020969.8A patent/CN116981906A/zh active Pending
  • 2022-01-14 JP JP2023541985A patent/JP2024503411A/ja active Pending
  • 2022-01-14 US US18/261,525 patent/US20240077299A1/en active Pending
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