Method for correcting misalignment of at least one shafting

Abstract

The invention relates to a method (100) for correcting misalignments of at least one shaft set (5, 5a, 5b) of a drive train (3) on a test stand (1), wherein at least one piezoelectric force sensor (4a, 4b, 4c, 4d) is arranged in a force path through which a force flow can be transmitted by means of the shaft set (5; 5a, 5b) when power is transmitted between a loading machine (14; 14a, 14b) of the test stand (1) and a drive machine (2) of the drive train (3) or of the test stand (1), the method having the following working steps: performing (101) a force measurement in and / or perpendicular to at least one plane (A, B; F) which is intersected by and preferably at least substantially perpendicular to an axis of rotation (D) of the shaft set (5; 5a, 5b); analyzing (102) the measurement values or measurement value curve of the force measurement in order to detect a misalignment of the shaft set (5; 5a, 5b); determining (103) a target value for a position correction of the loading machine (14; 14a, 14b) or of the drive machine (2) in order to minimize the misalignment; and outputting (105) the target value.

Description

Technical Field

[0001] This invention relates to a method for correcting misalignment of at least one shaft system of a drive system on a test bench, wherein at least one piezoelectric sensor is arranged in a force path through which force current can be transmitted by means of the shaft system when power is transmitted between the loading machine of the test bench and the drive system or the drive mechanism of the test bench. Furthermore, this invention relates to a test bench on which the method can be performed. Background Technology

[0002] Misalignment arises from uncertainties in assembly and manufacturing, settlement phenomena, and thermal expansion, which lead to displacement of the rotating body. This displacement has a destructive impact on the function and service life of the rotating body. Misalignment results in tension forces, particularly bending moments and compressive forces, acting on the rotating body and its supports.

[0003] Patent application WO / 2021 / 011982 discloses various test stands and measuring devices for detecting misalignment on the test stand using piezoelectric sensors. The contents of that application are also incorporated herein by reference. Summary of the Invention

[0004] The purpose of this invention is to provide a method for detecting and / or correcting imbalances and / or misalignments in the shaft system of a drive system test bench, as well as a corresponding drive system test bench.

[0005] The objective is achieved through the independent claims. Advantageous designs are claimed in the dependent claims.

[0006] A first aspect of the invention relates to a method for correcting misalignment of at least one shaft system of a drive system on a test bench, wherein at least one piezoelectric sensor is arranged in a force path through which force current can be transmitted by means of the shaft system when power is transmitted between the loading machine of the test bench and the drive system or the drive machine of the test bench, the method comprising the following operational steps:

[0007] Force measurement is performed in and / or perpendicular to at least one plane, said plane being intersected by the axis of rotation of the shaft system, and preferably at least substantially perpendicular to the axis of rotation;

[0008] Analyze the measured values ​​or curves of force measurements to detect misalignment in the shaft system;

[0009] Determine the target value for position correction of the loading or driving machine to minimize misalignment; and

[0010] Output the target value.

[0011] A second aspect of the present invention relates to a drive system test bench, which has:

[0012] A loading machine, which can be connected to the shaft system to be tested;

[0013] At least one piezoelectric sensor is arranged in a force path to transmit a force flow via the force path when power is transmitted from a loading machine on the test bench via the shaft system, and the piezoelectric sensor is designed to: perform force measurement in and / or perpendicular to at least one plane, said plane being intersected by the rotation axis of the shaft system, and preferably at least substantially perpendicular to the rotation axis; and

[0014] Signal processing device, the signal processing device having

[0015] - Mechanism designed to perform force measurement;

[0016] - Mechanisms designed to analyze force measurements or measurement curves to detect misalignment of shaft systems;

[0017] - A mechanism used to determine the target value for the position correction of a loading or driving machine to minimize misalignment; and

[0018] - Mechanisms, especially interfaces, used to output target values.

[0019] Another aspect of the invention relates to computer programs and computer-readable media. Correspondingly, the method according to the first aspect of the invention can be implemented in a computer-based manner.

[0020] In the context of this invention, the target value preferably specifies the direction and value of the displacement and / or rotation of the component to be aligned. Furthermore, the target value may also specify the absolute value of the direction and position to which the component to be aligned should be displaced and / or rotated.

[0021] The shaft system in the context of this invention has one or more rotating shafts.

[0022] In the context of this invention, "transferable" preferably means "can be transmitted" or "will be transmitted".

[0023] In the context of this invention, the force flow is preferably the path of force and / or torque in a mechanical system from the point of application, particularly the starting point, to one or more locations, where the force and / or torque is absorbed by reaction forces and / or reaction torques. The force flow preferably consists of forces, particularly lateral forces relative to the direction of rotation of the shaft, and torques, particularly torques about the axis of rotation.

[0024] In the context of this invention, the power flow is preferably the power transmission path in a mechanical system from the starting point to one or more power receiving points.

[0025] The piezoelectric measuring element for the purposes of this invention preferably has a piezoelectric crystal and charge leads or circuitry.

[0026] The machine of this invention is designed to convert energy, preferably kinetic energy, particularly rotational energy, into electrical energy or vice versa, or to convert chemical energy into kinetic energy. The machine of this invention preferably has a housing.

[0027] The support device for the purposes of this invention is preferably a device for supporting an element against forces and / or torques acting on that element. Preferably, the support device is designed to provide a so-called reaction force or supporting reaction force. The support device for the purposes of this invention is preferably used to support a support device. The support device is preferably a gearbox, drivetrain housing, or base plate.

[0028] In the context of this invention, detection is preferably confirmation and / or quantification and / or localization and / or analysis.

[0029] The mechanism for the purposes of this invention can be constructed in hardware and / or software, particularly having a digital processing unit, especially a microprocessor unit (CPU), preferably connected to a storage and / or bus system in a data or signal manner, and / or having one or more programs or program modules. The CPU can be configured to: process instructions implemented as a program stored in the storage system to detect input signals from the data bus and / or provide output signals to the data bus. The storage system can have one or more, particularly different, storage media, especially optical, magnetic, solid-state, and / or other non-volatile media. The program can be created such that it embodies or is capable of executing the methods described herein, enabling the CPU to perform the steps of this method and, in particular, to detect imbalances and / or misalignments.

[0030] The incremental encoder of this invention can preferably identify each corner segment and / or full revolution. In particular, the incremental encoder provides at least one pulse per revolution.

[0031] This invention is specifically based on the following approach: aligning misalignments in the shaft system of the drive system on the test bench using a force sensor, particularly a force sensor configured to determine torque during test runs on the test bench. By using this invention, no additional measurement methods or instruments are required, especially optical methods commonly used in the prior art.

[0032] Specifically, the shaft system does not need to be aligned externally, i.e., not on a test bench. More precisely, misalignment is detected by establishing a force fit directly on the test bench between the loading machine (so-called dynamometer) and the drive machine. Therefore, with this invention, the shaft system can be aligned in the assembled state and has all assembly uncertainties, such as unequal screw weights, alignment errors, fit clearances, and manufacturing errors, such as eccentricity, asymmetry, density errors, etc.

[0033] According to the invention, the piezoelectric measuring element is preferably used for calibrating required force measurements. This piezoelectric measuring element allows for particularly reliable measurements and, due to its rigidity, adds only a slight elasticity to the oscillating system of the drive mechanism. The piezoelectric measuring element is preferably fixedly constructed in a test bench, thereby allowing the measurement signal to be detected in a physically unchanged manner. In particular, the measuring element can be supported by an intermediate plate or a base plate.

[0034] Because the physical variable "force" is directly measured, conclusions can be drawn regarding the damage effect on mechanical components. No empirical methods are needed to assess machine condition. Therefore, new standards for machine safety can be specified based on alignment errors determined in accordance with the present invention. Besides gravity, misalignment also results in other spatially fixed forces or torques that do not change with rotational speed. The present invention allows misalignment to be confirmed without additional vibration analysis.

[0035] If the alignment of the shaft system changes during operation, this can be detected on the test bench using the present invention, and countermeasures can be taken, such as emergency stop or load reduction, to avoid permanent damage to the drive system or even the test bench.

[0036] Furthermore, a target value according to the invention is determined to correct misalignment. Based on the target value, position correction, particularly automatic position correction, can be performed on the loading and / or driving machines. Thus, misalignment can be reduced or even eliminated directly on the test bench. Determining the target value greatly simplifies the setup or calibration of the measuring device, which has traditionally been performed manually using optical methods. In particular, this can reduce the time required for this by several orders of magnitude. Due to the possibility of automation, highly skilled personnel can also be eliminated from the task.

[0037] In a favorable design of this method, the following additional steps are performed to determine the target value:

[0038] The bending moment curve at the shaft system is derived from the measured values ​​or curves of force measurements; and

[0039] The bending moment curve is derived, especially considering boundary and connection conditions, to determine the bending line of the shaft system, where the target value is determined using the bending line.

[0040] In another advantageous design, the method also includes the following steps:

[0041] Check whether the bending moment or bending moment curve at the shaft system exceeds the threshold; and

[0042] If the threshold is exceeded, the method is repeated iteratively; otherwise, the method is terminated.

[0043] An iterative process that optimizes shaft alignment based on a specific bending moment or bending moment curve enables the precise determination of target values.

[0044] In another advantageous design, the method also includes the following steps:

[0045] Disengage the force between the loading and driving machines, especially by disconnecting the clutch of the shaft system.

[0046] By using the disengagement force, the position of the loading machine and / or the driving machine can be changed particularly easily.

[0047] In another advantageous design, the method also includes the following steps:

[0048] The position of the loading machine and / or driving machine on the test bench is changed based on the output target value.

[0049] Preferably, the position change is performed automatically. More preferably, the test stand has an adjustment device designed to translate and / or rotate the position of the loading or driving machine.

[0050] In another advantageous design, the method also includes the following steps:

[0051] Establish force coordination between the loading machine and the driving machine.

[0052] Preferably, force engagement is re-established after the position of the loading machine and / or driving machine has changed.

[0053] In another advantageous design of this method, constants of the shaft system with respect to the characteristics of the test bench are determined, in particular the product of the elastic modulus and the drag torque, so that the bending line can be calculated by means of two force measurements taken at different positions of the drive machine or the loading machine.

[0054] This allows for the calibration of measuring devices without knowing the material properties of the shaft system, especially its rigidity.

[0055] In another advantageous design of the method, the axis of rotation of the shaft system is the axis of rotation of the shaft in which the force measurement is performed.

[0056] Preferably, the plane for performing force measurement is defined by a support point of the shaft system at a machine where a force sensor is mounted. More preferably, the plane is defined by a point where a force sensor is arranged.

[0057] In another advantageous design of this method, force measurement is performed in a static or quasi-static state of the shaft system.

[0058] When the shaft system is not rotating, it is preferably in a static state, which is significant in this invention.

[0059] When the shaft system rotates at an angular velocity with a relatively small reaction time of the force sensor relative to the rate of change of the shaft system's rotational position, a quasi-stationary state of the shaft system, as is characteristic of this invention, is preferably present. Specifically, the force can be measured in such a way that it is unaffected by dynamics. Preferably, the angular velocity is small enough that its inertial mass has little or no effect, particularly requiring the shaft system to stop within a rotational angle range of less than approximately 90°, preferably approximately 70°, more preferably approximately 15°, more preferably approximately 10°, and most preferably approximately 5°. The shaft system preferably exhibits no vibration in the quasi-stationary state.

[0060] This allows for misalignment detection while the shaft system is stationary or quasi-stationary. This achieves the goal of identifying misalignment before actual test runs on the test bench. This method avoids damage to the drive mechanism or test bench being tested.

[0061] In another advantageous design of the method, force measurement is monitored by comparing one or more measurements with a threshold characterizing the critical load of the shaft system, wherein if the threshold is exceeded, the rotation of the shaft system stops or ceases.

[0062] This also avoids damaging the drive machine or test bench being tested.

[0063] In another advantageous design of this method, multiple piezoelectric sensors are present in the force path, and each force measurement of the piezoelectric sensors is monitored.

[0064] In another advantageous design of this method, during analysis, a distinction is made between parallel offset and / or angular offset of the shaft system in terms of misalignment.

[0065] The features and advantages further described with respect to the first aspect of the invention are applicable accordingly to the other aspects of the invention, and vice versa.

[0066] In an advantageous design, the drive system test bench additionally includes an adjustment device designed for translating and / or rotating to change the position of the loading machine.

[0067] The drive system test bench, especially the signal processing device, also features:

[0068] The mechanism is designed for controlling the regulating device based on the target value of the output. Attached Figure Description

[0069] Other advantages and features will become apparent from the following description of preferred embodiments with reference to the accompanying drawings. The drawings are at least partially schematic:

[0070] Figure 1a A top view of the end side of the loading machine is shown, with the axis of the loading machine appearing on the end side;

[0071] Figure 1b Showing according to Figure 1a A side view of the loading machine;

[0072] Figure 1c Showing according to Figure 1a and Figure 1b Two top views of the measuring device of the first embodiment of the drive system test bench and loading machine, by means of which a method for correcting misalignment can be performed;

[0073] Figure 2 An embodiment of a method for correcting misalignment is shown;

[0074] Figure 3 Four graphs are shown, which illustrate the forces, bending moments, angular offset bending lines, and parallel offset bending lines of the shaft system on the test bench;

[0075] Figure 4 A diagram showing the bending lines of parallel offset and angular offset in the axial direction of the shaft system.

[0076] Figure 5 A top view of a measuring device with a second embodiment of a drive system test bench is shown;

[0077] Figure 6 A top view of a measuring apparatus according to a third embodiment with a drive system test bench is shown;

[0078] Figure 7 A top view showing a fourth embodiment of the drive system test bench; and

[0079] Figure 8 As shown in Figure 1, Figure 5 , Figure 6 and Figure 7 Details of the drive system test bench. Detailed Implementation

[0080] Figure 1a , 1bFigures 1 and 1c show three different views of a first embodiment of the drive system test bench 1. Figure 1a and 1b The views show only one loading machine 14 of the drive system test bench 1. Figure 1c Showing according to Figure 1a and 1b Two views of the loading machine 14 and the measuring device of the drive machine 2 to be tested.

[0081] Figure 1a , 1b The alignment of the various views of 1c with each other is derived from the x, y, and c axes of the reference frame.

[0082] Figure 1a A top view of the end side of the loading machine 14 is shown in the opposite direction of the z-axis, on which the shaft 5b of the loading machine 14 appears. Figure 1b Showing according to Figure 1a A side view of the loading machine along the x-axis. The loading machine 14 is supported on a base plate or intermediate plate 10 via measuring elements 4a, 4b, 4c, and 4d of force sensors. Preferably, the base plate or intermediate plate 10 also supports the measuring elements 4a, 4b, 4c, and 4d in the horizontal direction. Adjustment devices 12a, 12, and 12c are preferably disposed on the base plate or intermediate plate 10. Preferably, the adjustment devices have a first actuator 12a, a second actuator 12b, and a third actuator 12c to displace the alignment of the base plate or intermediate plate 10 in the x-axis and / or y-axis directions, thereby also displacing the alignment of the loading machine 14, and pivoting about the x-axis and / or y-axis.

[0083] exist Figure 1c In this figure, the drive machine 2 and the loading machine 14 are respectively connected to or can be connected to the shaft system in a manner that transmits torque. For clarity, the shaft system is not shown in its entirety in this figure.

[0084] Figure 1c The left-hand view shows the measuring device, where the misalignment is a pure parallel offset in the x-direction between the rotation axis D of the shaft 5b of the loading machine 14 and the rotation axis D' of the shaft 5a of the driving machine 2. Figure 1c The view on the right shows the measuring device, where the misalignment is a pure angular offset about the y-axis between the rotation axis D of shaft 5b of loading machine 14 and the rotation axis D' of shaft 5a of drive machine 2. However, misalignment typically occurs as a superposition of angular and parallel offsets. Furthermore, drive machine 2 may additionally or alternatively be displaced in the y-direction and / or pivot about the x-axis. Additionally, the measuring element may be arranged at drive machine 2 or in the shaft system, as further referenced below. Figure 5 , 6 And 7 further describe.

[0085] also, Figure 1c Different planes A, B, F, G, and H are shown. Plane A is perpendicular to the rotation axis D of the loading machine 14 and contains two measuring elements 4a and 4d, which are arranged at the lower end of the loading machine 14 opposite to the axis 5b of the loading machine 14. Plane B is also perpendicular to the rotation axis D of the loading machine 14 and contains two measuring elements 4b and 4c, which are arranged at the lower end of the loading machine 14 facing the axis 5b of the loading machine 14.

[0086] Plane G is a plane perpendicular to the rotation axis D' of the drive machine 2, in which a first support member of the drive machine 2's shaft 5a is located, the support member being arranged at the end of the drive machine 2 facing the loading machine 14's shaft 5b. Plane H is also a plane perpendicular to the rotation axis D' of the drive machine 2, in which a second support member of the drive machine 2's shaft 5a is located, the second support member being arranged at the end of the drive machine 2 facing away from the loading machine 14's shaft 5b.

[0087] exist Figure 1c The forces are drawn in the right-hand portion, caused by misalignment as shown in planes A, B, and F, respectively. In planes A and B, the forces... The force acts on the measuring elements 4a, 4b, 4c, and 4d that support the loading machine 14. In plane F, the force... Acting on the shaft system (not shown).

[0088] This method allows for the simultaneous detection and correction of misalignments in both the XZ and YZ planes.

[0089] Furthermore, test bench 1 preferably includes a signal processing device 7 (not shown). Reference will be made below. Figure 8 Describe the signal processing device.

[0090] Figure 2 An embodiment of a method for correcting misalignment is shown, the method being implemented according to... Figures 1a to 1c It is used in measuring devices.

[0091] After the measuring device is installed, it is preferable to first calibrate the measuring device. For this purpose, the scaling factor or constant of the shaft systems 5; 5a, 5b is specifically determined, particularly the product of the elastic modulus and the drag torque, preferably the stiffness constant. The scaling factor or the material constant is preferably used to calculate the bending curve, as further referenced below. Figure 3 As explained. More preferably, the scaling factor or material constant is determined by two force measurements performed with the aid of the driving machine 2 and the loading machine 14 at their respective different relative positions.

[0092] In the first working step 101 of method 100, force measurement is performed in and / or perpendicular to planes A and B. Planes A and B intersect by the axis of rotation D of shaft 5b of shaft 5a and 5b, which is the axis of loading machine 14. Preferably, planes A and B are aligned at least substantially perpendicular to the axis of rotation D. Figure 1c As shown, the rotation axis D is preferably the rotation axis of shaft 5b of shaft system 5; force measurement is performed at the shaft, that is, force is measured relative to the shaft.

[0093] More preferably, the force measurement is performed in a static or quasi-static state of the shaft systems 5; 5a, 5b. As explained therein, damage to the measuring device can be avoided.

[0094] More preferably, continuous force measurement is performed. Specifically, for this purpose, the measured value of the last measurement is compared with a threshold value, which identifies the critical load of shaft systems 5; 5a, 5b. If the threshold value is exceeded, rotation of shaft systems 5; 5a, 5b is stopped, or rotation is not performed. Furthermore, method 100 is then preferably terminated. Preferably, as... Figure 7 As shown, there are multiple force sensors 4 and 11 in the force path. In this case, it is preferable to monitor the force measurement of each force sensor 4 and 11.

[0095] Any lateral force of constant rotation indicates an angular deviation in the shaft system, which can then be distinguished from misalignment by means of the method according to the invention.

[0096] In the second working step 102, the measured values ​​or curves of the force measurement are analyzed to detect misalignment of shaft systems 5; 5a, 5b. Preferably, regarding misalignment, a distinction is made between parallel offset and / or angular offset of shaft systems 5; 5a, 5b.

[0097] In the third working step 103, the target value for the position correction of the loading machine 14 or the driving machine 2 is determined to minimize misalignment. For this purpose, preferably in the first sub-step 103-1, the bending moment or bending moment curve at shafts 5; 5a, 5b is determined based on the measured value or curve of the force measurement. In the second sub-step 103-2, the bending line of shafts 5; 5a, 5b is then preferably determined based on the determined bending moment or bending moment curve, taking into account boundary conditions. The target value for position correction is then preferably determined using the bending line. Preferably, when the bending line w x When (z) is the same as the axis of rotation D, the misalignment is minimized.

[0098] In the fourth working step 104, it is checked whether the bending moment or bending moment curve at shafts 5; 5a, 5b exceeds a threshold. If it exceeds the threshold, method 100 continues and repeats. For this purpose, a target value is output in the fifth working step 105. The output is preferably made to the next working step via data interface 10. Alternatively or additionally, the target value can also be output to the user via user interface 10.

[0099] If the threshold is no longer exceeded, method 100 preferably ends in the ninth and final working step 109.

[0100] As method 100 continues, the force engagement between the loading machine 14 and the driving machine 2 is preferably interrupted in the sixth working step 106, particularly by disengaging the clutches (not shown) of shafts 5; 5a, 5b. This allows the relative positions of the two machines 2, 14 to be changed without reaction force.

[0101] In the seventh working step 107, the positions of the loading machine 14 and / or the drive machine 2 on the test bench are changed based on the target output value. This will result in a reduction of misalignment.

[0102] In the eighth working step 108, the force engagement between the loading machine 14 and the driving machine 2 is then preferably re-established. Preferably, method 100 then restarts in the first working step 101. Alternatively, method 100 may have already started from scratch after an earlier working step.

[0103] Below, according to Figures 3 to 4 The explanation is based on the calculation of the target value by way of example, using forces measured in planes A and B or plane F.

[0104] If the fixed-support drive machine 2 and the loading machine 14 are mechanically connected by a shaft system, a force fit is formed, which can be simplified as a bending carrier (assuming a fixed floating support shaft assembly, such as in...). Figure 1c and 3 (as shown in the image).

[0105] Depending on the location of the force flow measurement, in the case shown, either in planes A and B or in plane F, the bearing force can be calculated from the average of the resulting moments. and or misalignment force

[0106] Used to determine the misaligned force component F x and F y Force component F z and torque component M bx and M byThis can be achieved in a manner known per se by means of the targeted arrangement of the preferred orientations of the various measuring elements 4a, 4b, 4c or their piezoelectric elements.

[0107] Other methods may also be used to determine the parameters. For example, the measurement signals of the individual measuring elements 4a, 4b, 4c, or the measured forces F1, ..., F1 derived from the measurement signals. i Decomposition, especially orthogonal decomposition.

[0108] Here, for example, the parameter M to be determined z F X F Y This is the solution to the system of equations, where for each measured signal, the following equation applies:

[0109] S1=a 11 ·M z +a 12 ·F x +a 13 ·F y

[0110] S2=a 21 ·M z +a 22 ·F x +a 23 ·F y

[0111] S3=a 31 ·M z +a 32 ·F x +a 33 ·F y

[0112] SN = a N1 ·M z …

[0113] Here, S1, S2, ... Si, ... SN are the measurement signals of the respective measuring elements 4a, 4b, 4c, ... 2, N. Each coefficient a depends on several factors, such as the corresponding positions of the measuring elements 4a, 4b, 4c, ... 4i, 4N and the orientation of the corresponding preferred directions in the reference system, the sensitivity of the corresponding measuring elements 4a, 4b, 4c, ... 4i, ... 4N, and the possible signal loss due to force shunting caused by the fixing mechanism.

[0114] To solve for this torque M z First lateral force component F x Second transverse force component F yThe system of equations requires measurement signals from at least three measuring elements 4a, 4b, and 4c, preferably aligned such that they lie in a single plane. Furthermore, at least two of the preferred orientations must be neither parallel nor antiparallel aligned.

[0115] For the general case described above, where N=3, i.e., three measuring elements 4a, 4b, and 4c, the solution to the system of equations shown above is single-valued. If other measuring elements are added to the measuring system 1, then there are three parameters M to be determined. z F x F y The equations are overdetermined, but the measurement accuracy can be improved again.

[0116] When N=4, four different systems of equations can be established: F(S1, S2, S3), F(S1, S2, S4), F(S1, S3, S4), and F(S2, S3, S4). Then, the parameters M to be determined can be... z F x F y The determined values ​​are added together and averaged, i.e., divided by four in the case of four measuring elements 4a, 4b, 4c, ..., 4i, ..., 4N. Similarly, an overdetermined system of equations F(S1, S2, ..., SN) can be established, which is solved by means of a minimization problem.

[0117] If the general solution to the system of equations is found, then the parameter M needs to be determined. z F x F y The calculation can then be simplified to matrix multiplication. The matrix has three rows and as many columns as the available measurement signals S1, S2, S3, ... SN. The matrix elements, or coefficients, form the parameters M to be determined for each sensor. z F x F y Their corresponding contributions.

[0118]

[0119] This decomposition also allows us to determine the bending moment M. bx and M by .

[0120] In order to decompose the measurement signals S1, S2, ... Si, ... SN into corresponding parameters M to be determined z F x F y To determine the contributing component, it is necessary to understand the position and preferred orientation of the measuring elements 4a, 4b, 4c, ..., 4i, ..., 4N.

[0121] The geometric parameters can be determined from the design drawings of the drive system test bench 1 and from the knowledge of the preferred orientations of the measuring elements 4a, 4b, 4c, ..., 2i, ..., 2N.

[0122] However, the preferred orientation of the measuring elements 4a, 4b, 4c, ..., 4i, ..., 4N can also be determined by means of calibration measurement. For this purpose, force sensors 4, 11 are preferably clamped between plates of two planes. In the next step, an external lateral force with a known direction is applied. The preferred orientation of the measuring elements 4a, 4b, 4c, ..., 4i, ..., 4N in the plane can be determined from the magnitude of each measuring signal S1, S2, ..., Si, ..., SN relative to the amount and direction of the applied lateral force: said plane unfolds through the preferred orientation of the measuring elements 4a, 4b, 4c, ..., 4i, ..., 4N.

[0123] With this decomposition, when the preferred orientations of each measuring element 4a, 4b, 4c, ..., 4i, ..., 4N are known, a defined torque M is applied. z By measuring the various measurement signals S1, S2, ... Si, ... SN, the distance between the measuring elements 4a, 4b, 4c, ..., 4i, ..., 4N and the rotation axis can be determined.

[0124] like Figure 3 As shown, the calculated force can be used as a basis. The bending moment M is determined based on its position along the rotation axis D of the loading machine 14 and along the z-axis in the indicated reference frame. by (z).

[0125] Here, the curved line w x (z) and bending moment M by The relationship between (z) follows the differential equation

[0126]

[0127] Where E is the elastic modulus, and J y This refers to the resistance torque of the measuring device. Together, these factors form the so-called scaling factor, which is constant for a particular shaft system or measuring device. The scaling factor takes into account the stiffness and material constants of the corresponding shaft system or shaft segment or the corresponding measuring device.

[0128] Differential equations can be expressed by polynomial functions w. x (z) is used to solve for the polynomial function w. x (z) Explains the curved line. In the case of a shaft system with multiple shaft segments 5a and 5b, when solving the coupled differential equation system w... xWhen (z)″', the corresponding polynomial w can be determined by combining the relevant connection conditions. x (z).

[0129] The scaling factor can be preset by the curve w x The boundary conditions for (z) were determined experimentally. For example, in Figure 1c and Figure 3 In the case shown, the following boundary conditions exist, i.e., w x (0) = 0 and w x (a) = 0. Furthermore, at the location z = a + b, the derivative of the curved line with respect to the angular offset is zero in all cases, i.e., w′ x (a+b) = 0. The scaling factor can then be calculated by measuring the force twice in different relative alignments of the drive machine 2 and the loading machine 14. Alternatively, the scaling factor can be estimated by FEM simulation of the shaft system or measuring device.

[0130] Figure 4 against Figure 1c The pure angular offset of the rotation axes D and D' in the middle ( Figure 4 (above) and targeting Figure 1c The pure parallel offset of the rotation axes D and D' in the middle ( Figure 4 Below are two different curved lines w. x (z), the curved line is determined by the proposed calculation method. The dotted lines illustrate the curved lines in cases where the angular offset and parallel offset are stronger than those of the dashed lines.

[0131] Obviously, there will also be separate parallel and angular offsets in the y-direction due to rotation around the x-axis, which produce a curved line w. y (z). Then, the two-dimensional curved line w can be calculated by superposition. xy (z). The superposition is preferably the addition of curved lines, which are vectors due to their orientation, i.e., vector addition.

[0132] Figures 5 to 7 Another embodiment of the drivetrain test bench 1 is shown. Even though the arrangement of one or more force sensors in this embodiment differs significantly from the arrangement shown with respect to the first embodiment in FIG1, the calculation of the bending moment and bending line of the drivetrain can be attributed to the above reference. Figure 3 and Figure 4 Explanation of the calculation method.

[0133] Figure 5 A second embodiment of the drive system test bench 1 is shown, on which misalignment can be detected in addition to calibration or application testing. In particular, misalignment can be detected independently of test bench operation.

[0134] The drive system test bench 1 has, but is not limited to, a loading machine or dynamometer 14a, 14b, which can be connected to the slave of the drive system shown in FIG1 in a torsional manner.

[0135] Furthermore, the drive system test bench 1 preferably has an incremental encoder 6, which is designed to measure the rotation angles of shaft systems 5a and 5b. The function of the incremental encoder 6 is known from the prior art; in particular, the incremental encoder can determine the rotation angles or changes in rotation angles and / or directions of shaft systems 5a and 5b by photoelectric, magnetic and / or by means of sliding contacts.

[0136] Furthermore, the drive system 1 preferably has a force sensor 4, which in turn preferably has multiple piezoelectric measuring elements, specifically three piezoelectric measuring elements 4a, 4b, and 4c in Figure 1. In the embodiment according to Figure 1, the measuring elements 4a, 4b, and 4c are arranged at a measuring flange 12, which may be part of the actuator test bench 1 or the drive system 3. Strain gauges may also preferably be used as measuring elements 4a, 4b, and 4c.

[0137] The measuring flange connects the first shaft section 5a and the second shaft section 5b of shaft system 3. Shaft systems 5a and 5b rotate about the rotation axis D, which is located at... Figure 5 The text uses dots and dashes to illustrate the meaning.

[0138] Depending on which components of the drive system 3 should be tested on the drive system test bench 1, the drive machine 2 can be a component of the drive system test bench 1 or the drive system 3.

[0139] exist Figure 5 In the illustrated embodiment, the drive system 3 includes a drive unit 2, shafts 5a and 5b, a differential 13, and shaft sections (not shown in the figures). Power flow can be transmitted from the drive unit 2 via the first shaft section 5a, a measuring flange 12, a first piezoelectric sensor, the differential 13, and the shaft sections to the loading units 14a and 14b.

[0140] The test bench 1 also includes a support device 10, on which the entire drive test bench, the various components of the drive system test bench 1, and / or the drive system 3 are supported. Here, the support device 10 may have a mechanical structure to support the various components, for example, on the floor of the test bench hall. More preferably, the support device 10 may have a substrate or be configured as such a substrate.

[0141] In the embodiment shown in FIG1, at least the drive machine 2 and the power machines 14a, 14b are supported by the support device 10.

[0142] Preferably, the power flow generated by the drive machine 2 induces a force flow, which, in the embodiment shown in FIG1, extends from the support device 10 via the drive machine 2 and drive system 3, loading machines 14a, 14b, and back to the support device 10. Here, the support device 10 provides reaction forces for supporting the drive machine 2 and the loading machines 14a, 14b, respectively.

[0143] The measuring elements 4a, 4b, and 4c are preferably designed and configured to measure forces in the plane F, i.e., in a plane parallel to the XY plane of the illustrated reference system. The first force sensor 4 preferably has piezoelectric elements 4a, 4b, and 4c that utilize the piezoelectric shear effect. In the illustrated embodiment, the force or torque at the measuring flange 12 is introduced into the piezoelectric elements 4a, 4b, and 4c via the end faces of the measuring elements 4a, 4b, and 4c. The end faces of the piezoelectric elements 4a, 4b, and 4c are preferably connected to the surface of the measuring flange 12 in a friction fit.

[0144] If a force in the X direction of the reference frame and / or a force in the Y direction of the reference frame are applied to the measuring flange 12, the piezoelectric measuring elements 4a, 4b, and 4c generate corresponding measuring signals by means of the piezoelectric shear effect. The same applies when a torque acting in the Z direction is applied to the measuring flange 12.

[0145] Alternatively or additionally, the measuring elements 4a, 4b, 4c can perform force measurements perpendicular to the first plane F. For this purpose, the measuring elements 4a, 4b, 4c preferably utilize either a piezoelectric longitudinal effect or a piezoelectric transverse effect. If the force is measured both in and perpendicular to the first plane F, then preferably there is a measuring element that measures along the Z direction and a measuring element capable of measuring the force in the X or XY plane. More preferably, each measuring element 4a, 4b, 4c has at least two piezoelectric elements connected in series with respect to the force flow, wherein the first piezoelectric element utilizes a piezoelectric shear effect, and the second piezoelectric element utilizes either a piezoelectric transverse or longitudinal effect.

[0146] Figure 6 A third embodiment of the test bench 1 is shown, which allows for the detection of misalignment of the shaft system during test bench operation.

[0147] Figure 6 The test bench 1 of the second embodiment and Figure 5 The main difference in the second embodiment is that the force sensor 11 is not arranged in the power flow between the drive machine 2 and the loading machines 14a, 14b, but is arranged between the support device 10 and the drive machine 2.

[0148] With the aforementioned arrangement, when torque is applied between the shaft system 5 and the drive machine 2, the first force sensor 4 measures the reaction force applied to the drive machine 2 via the support device 10.

[0149] Here, the force sensor 11 can preferably be as follows: Figure 6 As shown, it is supported along the axial direction of the rotation axis D. However, similarly, the drive mechanism 2 is also supported according to... Figure 1a , Figure 1b or Figure 7 As shown in the top view, it is laterally supported downward or upward by the force sensor 11. Depending on how the piezoelectric measuring elements 11a, 11b, 11c act on the drive machine 2, then a piezoelectric shear effect, piezoelectric longitudinal or transverse effect, or as already referred to... Figure 5 The explanation is that the element has two different effects.

[0150] Also according to Figure 6 In the embodiments, the force is preferably measured in plane C;D and / or perpendicular to plane G;H.

[0151] Another feasible approach is to: based on Figure 5 The second embodiment and according to Figure 6 A third embodiment combination: Therefore, for example, the second embodiment may also have a measuring flange 12, at which another piezoelectric sensor is arranged. The second piezoelectric sensor can then define a second plane F for measuring force and / or torque.

[0152] In addition, there may be additional piezoelectric sensors for measuring the reaction forces at loading machines 14a, 14b, and these additional piezoelectric sensors may preferably support the respective loading machines 14a, 14b relative to the support equipment, particularly relative to the substrate or base plate 10, so that the reaction forces between the loading machines 14a, 14b and the support equipment 10 can also be measured.

[0153] according to Figure 6 Measuring the reaction force has the following advantages over directly measuring the force in shaft system 5: the corresponding force sensor 4 has no effect on the inertial torque and balance of shaft system 5.

[0154] Figure 7 The diagram shows a fourth embodiment of a drive system test bench, which can be used to detect misalignment of shaft systems.

[0155] The drive system 3 has only the shaft system 5 and possibly the drive machine 2. Unlike the first embodiment of the test bench according to FIG1, the reaction forces of the loading machine 14 and the drive machine 2 are measured relative to the support device 10, preferably relative to at least one measuring plane A, B at the loading machine 14 and relative to at least one measuring plane G, H at the drive machine 2.

[0156] However, as in accordance with Figure 5 and Figure 6As in the embodiments described above, the drive system 1 according to the first embodiment or the second embodiment may also have additional components, particularly a transmission or differential, a shaft section, etc.

[0157] However, in the described embodiment, it can also be proposed that the corresponding force sensors 4, 11 have two elements connected in series with respect to the force flow, making two different measurement directions, particularly two mutually orthogonal measurement directions, possible. Specifically, the measurement directions can be aligned in the Y and X directions. Force in the Z direction can also be measured by a third piezoelectric element in the measuring elements of the force sensors 4, 11.

[0158] Figure 8 Details of the drive system test bench 1 or a separate control unit designed to control the drive system test bench 1 are shown according to Figures 1, 5, 6 or 7.

[0159] The signal processing device 7 includes: a mechanism 8 designed to analyze measured values ​​or curves of force measurements to detect misalignment of shaft systems 5; 5a, 5b; a mechanism 9 for determining a target value for position correction of the loading or driving machine to minimize misalignment; and a mechanism 10, particularly an interface, for outputting the target value. More preferably, the signal processing device 7 includes a mechanism 15 that controls adjustment devices 12a, 12, 12c based on the output target value. The signal processing device 7 is signal-connected to both the measuring elements 4a, 4b, 4c of the force sensor and the adjustment devices 12a, 12, 12c.

[0160] The foregoing embodiments are merely examples and are by no means intended to limit the scope of protection, application, or structure. Rather, the foregoing description provides guidance to those skilled in the art for implementing at least one embodiment, thereby allowing for various changes, particularly in the function and arrangement of the described components, without departing from the scope of protection derived from the claims and equivalent combinations of features of the invention. In particular, the various embodiments can be combined with each other, especially with respect to drive system test benches or measuring devices. Therefore, in particular, Figure 5 , Figure 6 and Figure 7 Embodiments of the drive system test bench may also include adjustment devices 12a, 12b, and 12c. The sequence of the operating steps of the described method 100 may also differ from that shown. Similarly, force measurement, particularly force measurement at the shaft, can be performed using strain gauge-based sensors.

[0161] List of reference numerals

[0162] 1. Drive System Test Bench

[0163] 2. Drive machine

[0164] 3. Drive System

[0165] 4 First voltage power sensor

[0166] 4a, 4b, 4c Piezoelectric measuring elements

[0167] Shaft systems 5, 5a, and 5b

[0168] 6 Incremental encoder

[0169] 7. Signal Processing Device

[0170] 8, 9, 10, 15 Mechanism of signal processing devices

[0171] 11 Second voltage sensor

[0172] 12 Measuring flange

[0173] 13 Differential / Transmission

[0174] 14, 14a, 14b Loading Machine

Claims

1. A method (100) for correcting misalignment of at least one shaft (5, 5a, 5b) of a drive system (3) on a test bench (1). At least one piezoelectric force sensor (4a, 4b, 4c, 4d) is arranged in the force path, through which force current can be transmitted by means of the shaft system (5; 5a, 5b) when power is transmitted between the loading machine (14; 14a, 14b) of the test bench (1) and the drive system (3) or the drive machine (2) of the test bench (1), the method having the following working steps: Force measurement is performed by means of at least one piezoelectric force sensor (4a, 4b, 4c, 4d) in and / or perpendicular to at least one plane (A, B; F), said plane intersecting the axis of rotation (D) of said shaft system (5; 5a, 5b) and at least substantially perpendicular to said axis of rotation (D); Analyze the force measurements or measurement curves to detect misalignment of the shaft system (5; 5a, 5b); Determine the target value for position correction of the loading machine (14; 14a, 14b) or the driving machine (2) to minimize the misalignment; and Output the target value; The following additional steps are performed to determine the target value: The bending moment or bending moment curve at the shaft system (5; 5a, 5b) is determined based on the measured value or the measured value curve of the force measurement. and The bending line of the shaft system (5; 5a, 5b) is determined based on the obtained bending moment or the bending moment curve, wherein the target value is determined by means of the bending line.

2. The method (100) according to claim 1 further comprises the following working steps: Check whether the bending moment or bending moment curve at the shaft system (5; 5a, 5b) exceeds the threshold; and If the threshold is exceeded, the method (100) is repeated iteratively, or if the threshold is not exceeded, the method (100) is terminated.

3. The method (100) according to claim 1 or 2 further comprises the following working steps: The force engagement between the loading machine (14) and the driving machine (2) is disengaged by disconnecting the clutch of the shaft system (5; 5a, 5b).

4. The method (100) according to any one of claims 1 to 3 further comprises the following working steps: The position of the loading machine (14) and / or the driving machine (2) on the test bench is changed based on the output target value.

5. The method (100) according to any one of claims 1 to 4 further comprises the following working steps: Force coordination is established between the loading machine (14) and the driving machine (2).

6. The method (100) according to any one of claims 1 to 5, wherein the constants of the shaft system (5; 5a, 5b) are determined to calculate the bending line by means of two force measurements associated with different positions of the drive machine (2) or the loading machine (14).

7. The method (100) according to claim 6, wherein the product of the elastic modulus and the drag torque of the shaft system (5; 5a, 5b) is determined to calculate the bending line by means of two force measurements associated with different positions of the drive machine (2) or the loading machine (14).

8. The method (100) according to any one of claims 1 to 7, wherein the axis of rotation (D) of the shaft system (5; 5a, 5b) is the axis of rotation of the shaft in the shaft system (5; 5a, 5b) on which the force measurement is performed.

9. The method (100) according to any one of claims 1 to 8, wherein the force measurement is performed in a static or quasi-static state of the shaft system (5; 5a, 5b).

10. The method (100) according to any one of claims 1 to 9, wherein the force measurement is monitored by comparing one or more measurements with a threshold characterizing a critical load of the shaft system (5; 5a, 5b), wherein if the threshold is exceeded, the rotation of the shaft system (5; 5a, 5b) stops or ceases to rotate.

11. The method (100) according to any one of claims 1 to 10, wherein a plurality of force sensors (4, 11) are present in the force path, and wherein each force measurement of the force sensors (4, 11) is monitored.

12. The method (100) according to any one of claims 1 to 11, wherein, during analysis, a distinction is made between parallel offset and / or angular offset of the axis system (5; 5a, 5b) in terms of misalignment.

13. A computer-readable medium having a computer program stored thereon, the computer program comprising instructions that, when executed by a computer, cause the computer to perform the steps of the method according to any one of claims 1 to 12.

14. A drive system test bench (1), comprising: Loading machines (14a, 14b) are capable of being connected to the shaft system (5; 5a, 5b) to be tested; At least one piezoelectric sensor (4a, 4b, 4c, 4d) is arranged in a force path to transmit a force flow via the force path when power is transmitted from the loading machine (14a, 14b) of the test bench (1) via the shaft system (5; 5a, 5b), and the piezoelectric sensor is designed to be in at least one plane (A, B; F) and / or perpendicular to the plane (A, B; F). F) Perform force measurement, wherein the plane intersects the axis of rotation (D) of the axis system (5; 5a, 5b) and is at least substantially perpendicular to the axis of rotation (D); as well as Signal processing device (7), the signal processing device having - Mechanism (8), designed to analyze the measured values ​​or curves of the force measurement to detect misalignment of the shaft system (5; 5a, 5b); - Mechanism (9) for determining a target value for the position correction of the loading machine or driving machine to minimize the misalignment, wherein the following working steps are performed to determine the target value: The bending moment or bending moment curve at the shaft system (5; 5a, 5b) is determined based on the measured value or the measured value curve of the force measurement. and The bending line of the shaft system (5; 5a, 5b) is determined based on the obtained bending moment or the bending moment curve, wherein the target value is determined by means of the bending line; and - Mechanism (10) is used to output the target value.

15. The drive system test bench (1) according to claim 14, wherein, The signal processing device (7) has an interface for outputting the target value.

16. The drive system test bench (1) according to claim 14, wherein the drive system test bench (1) additionally has adjustment devices (12a, 12b, 12c) designed to change the position of the loading machine (14a, 14b) or the drive machine (2) by translation and / or rotation. The drive system test bench (1) further includes: - Mechanism (15), designed to control the regulating device (12) based on the target value of the output.

17. The drive system test bench (1) according to claim 16, wherein the signal processing device (7) further comprises: - Mechanism (15), designed to control the regulating device (12) based on the target value of the output.

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