Device and method for measuring torque of rotating shaft

Abstract

To provide an improved device and method for measuring a torque of a rotating shaft.SOLUTION: The invention provides a device V for measuring a torque M of a rotating shaft W, W'. The device V includes a measurement body 1, 1' and an evaluation unit 2. The measurement body 1, 1' can be attached to the shaft W, W' to rotate with the shaft W, W' about a longitudinal axis A of the shaft W, W' in the attached state. The measurement body 1, 1' includes a measuring unit 12, a measuring amplifier unit 13, and a telemetry unit 14. The measuring unit 12 generates a measurement signal MS under the effect of the torque M in the attached state. The measuring amplifier unit 13 amplifies the measurement signal MS. The telemetry unit 14 digitizes the amplified measurement signal MS. The telemetry unit 14 transmits it to the evaluation unit 2 by wireless transmission. The measurement body 1, 1' has a principal axis of inertia X, and the principal axis of inertia X lies on the longitudinal axis A in the attached state.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a device and a method for measuring the torque of a rotating shaft according to the preambles of the independent claims. [Background technology]

[0002] A shaft is a machine component that rotates around an axis and whose function is to transmit rotary motion and torque during rotation. Such shafts have a wide range of applications in machines, for example as drive shafts in automotive technology and as turbine shafts in energy technology.

[0003] The torque transmitted by a shaft can be used to determine important parameters of a machine, such as performance, efficiency, friction values, etc. For this reason, torque is measured both during machine development and in industrial use.

[0004] A device for measuring the torque of a rotating shaft is known from document DE19719921A1, which comprises a measuring body which rotates with the shaft and is designed as a measuring flange, and an evaluation unit. The evaluation unit comprises a stator antenna. The evaluation unit is separate from the shaft and the measuring body. The measuring body itself comprises a telemetry unit with a strain gauge, a measurement amplifier and a rotor antenna. Under the action of the torque to be measured, the strain gauge generates a measurement signal, the measurement amplifier amplifies the measurement signal, the telemetry unit digitizes the amplified measurement signal to obtain measurement data and transmits the measurement data via the rotor antenna to the stator antenna, from where the measurement data is sent to the evaluation unit. Parameters of the measurement amplifier, such as zero or gain coefficient, can be adjusted using the signal transmitted from the stator antenna to the rotor antenna.

[0005] However, users want to use the above device with shafts having different diameters. For this purpose, several measuring bodies are provided, the dimensions of which are adapted to the respective shaft diameters, while the evaluation unit used remains the same. Different sizes of measuring bodies affect the measurement accuracy, especially in the case of high-speed rotating shafts rotating at speeds much higher than 1000 rpm, so that the comparison of the measurement signals obtained for different sizes of shaft diameters is limited. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] DE19719921A1 Summary of the Invention [Problem to be solved by the invention]

[0007] It is a first object of the present invention to improve the device for measuring the torque of a rotating shaft known from DE 19719921 A1. The measurement accuracy is thus increased. It is a further object of the present invention to provide a method which allows a simple, fast and cost-effective measurement of the torque of a rotating shaft. [Means for solving the problem]

[0008] These objects are achieved by means of the features of the independent claims.

[0009] The invention relates to a device for measuring the torque of a rotating shaft, the device comprising a measuring body and an evaluation unit, the measuring body being capable of being mounted on the shaft and rotating together with the shaft around its longitudinal axis in the mounted state, the measuring body comprising a measuring unit, a measurement amplifier unit and a telemetry unit, the measuring unit generating a measurement signal under the action of a torque in the mounted state, the measurement amplifier unit amplifying the measurement signal, the telemetry unit digitizing the amplified measurement signal which the telemetry unit transmits to the evaluation unit by wireless transmission, the measuring body having a principal axis of inertia which in the mounted state lies on the longitudinal axis.

[0010] The invention also relates to a method for measuring the torque of a rotating shaft with a device comprising a measuring body and an evaluation unit, the measuring body comprising a measurement unit, a measurement amplifier unit and a telemetry unit, the measuring body being mounted on the shaft, the shaft being rotated about its longitudinal axis and transmitting a torque, the measuring unit generating a measurement signal under the action of the torque, the measurement amplifier unit amplifying the measurement signal, the telemetry unit digitizing the amplified measurement signal which the telemetry unit transmits by wireless transmission to the evaluation unit, and a measuring body is provided, the measuring body having a principal axis of inertia which in the mounted state lies on the longitudinal axis.

[0011] The invention is based on the finding that the measuring body of the device for measuring the torque of a rotating shaft known from DE 19719921 A1 is of a different construction, since it is composed of a measuring flange, a strain gauge, a measurement amplifier and a remote measuring unit with a rotor antenna. Furthermore, due to this different construction, it has an asymmetric mass distribution with respect to the longitudinal axis of the rotating shaft, as a result of which either the center of gravity of the measuring body is not on the longitudinal axis, thereby resulting in a static unbalance, or the principal axis of inertia of the measuring body is tilted at an angle of ≠ 0° to the longitudinal axis, thereby resulting in a dynamic unbalance. The resulting imbalance of the static and dynamic unbalance causes interference torques which are added to the measured torque and thus falsify the torque measurement. The measuring body of the device according to the invention is balanced both statically and dynamically, so that interference torques are minimized and thus the measurement accuracy of the device is increased.

[0012] Advantageous embodiments of the invention are provided in the dependent claims.

[0013] In the following, the invention is explained in more detail and by way of example with reference to the figures. [Brief description of the drawings]

[0014] [Figure 1] 1 is a schematic representation of a device V for measuring the torque M of a shaft W, W' and comprising measuring bodies 1, 1' and an evaluation unit 2; [Diagram 2] FIG. 2 is a partial view of a first embodiment of the measuring body 1 and shaft W according to FIG. [Diagram 3] 2 is a partial view of a second embodiment of the measuring body 1' and shaft W' according to FIG. [Figure 4] FIG. 2 is a partial view of the measuring body 1, 1' according to FIG. 1 with a measuring unit 12 installed between a first measuring body housing part 11a and a second measuring body housing part 11b. [Diagram 5]1 with a measurement amplifier unit 13 and a remote measurement unit 14 in the first measurement body housing part 11a and an energy storage unit 15 in the second measurement body housing part 11b. [Figure 6] 6 is a first cross-sectional view BB along a first section line B through the first measuring body housing part 11a according to FIG. 5. [Figure 7] 5. A second cross-sectional view CC along a second section line C through the second measuring body housing part 11b according to FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Throughout the figures, like objects are designated by like numerals.

[0016] 1 shows a shaft W, W' that can rotate about its longitudinal axis A and transmits a torque M during the rotation. With respect to the longitudinal axis A, the shaft W, W' is rotationally symmetric and is made of a mechanically resistant material such as metal, plastic, etc.

[0017] 1 also shows an apparatus V for measuring the torque M of a shaft W, W'. The apparatus V consists of a measuring body 1, 1' and an evaluation unit 2. The measuring body 1, 1' is attached to the shaft W, W' and rotates together with the shaft W, W' about the longitudinal axis A. The evaluation unit 2 is remote from the shaft W, W' and from the measuring body 1, 1'.

[0018] In the representation according to Fig. 1 to Fig. 4 and in the exploded view according to Fig. 5, the measuring body 1, 1' is shaped like a hollow cylinder. The measuring body 1, 1' comprises an axial cavity 10, 10' in the vicinity of the longitudinal axis A. The axial cavity 10, 10' has a cavity diameter D10, D10'. The size of the cavity diameter D10, D10' is such that it is equal to the size of the shaft diameter DW, DW' in the radial direction perpendicular to the longitudinal axis A. In the direction of the longitudinal axis A, the measuring body 1, 1' is attached radially to the outside of the shaft W, W'. Preferably, the attachment is achieved by a form-locking and force-locking connection by clamps. The attachment is reversible.

[0019] However, the shafts W, W' may have different shaft diameters WD, WD'. The device is therefore equipped with various measuring bodies 1, 1' with cavity diameters D1, D1' corresponding to different shaft diameters DW, DW'. In this respect, Fig. 2 and Fig. 3 show two examples of the axial cavities 10, 10' of the shafts W, W' and of the measuring bodies 1, 1'. In the first example shown in Fig. 2, the shaft W has a shaft diameter DW of 25 mm, while the shaft W' in the second example shown in Fig. 3 has a shaft diameter DW' of 45 mm. In the first example according to Fig. 2, the measuring body 1 has a cavity diameter D10 of 25 mm, while the measuring body 1' in the second example according to Fig. 3 has a cavity diameter D10' of 45 mm. Naturally, the skilled person is free to implement the invention with shafts and axial cavities with diameters less than 25 mm, as well as with shafts and axial cavities with diameters greater than 45 mm.

[0020] The measuring body 1 , 1 ′ comprises a measuring body housing 11 , a measuring unit 12 , a measuring amplifier unit 13 , a remote measuring unit 14 and an energy storage unit 15 .

[0021] The measurement body housing 11 is configured to protect the measurement unit 12, the measurement amplifier unit 13, the remote measurement unit 14 and the energy storage unit 15 from adverse environmental conditions such as dust and moisture.

[0022] In the view according to Figure 4 and the exploded view according to Figure 5, it is shown that the measuring body housing part 11 consists of multiple parts, has a first measuring body housing part 11a and a second measuring body housing part 11b, and has a first measuring body closing part 11aa and a second measuring body closing part 11bb.

[0023] Preferably, the measuring body housing 11 is bisected by a plane containing the longitudinal axis A, the two measuring body housing parts 11a, 11b having the shape of congruent halves of a hollow cylinder and the two measuring body closing parts 11aa, 11bb having the shape of half of an end face of a hollow cylinder. Each of the two measuring body housing parts 11a, 11b is separated by an axial cavity 10, 10' in the vicinity of the longitudinal axis A. The two measuring body housing parts 11a, 11b and the two measuring body closing parts 11aa, 11bb are made of a mechanically resistant material such as metal, plastic, etc.

[0024] The first measuring body housing part 11a comprises at least one first housing cavity 110a, 110a'. The first measuring body closure 11aa is configured to provide a sealing of the first housing cavity 110a, 110a' against dust and moisture. The second measuring body housing part 11b comprises at least one second housing cavity 110b, 110b'. The second measuring body closure 11bb is configured to provide a sealing of the second housing cavity 110b, 110b' against dust and moisture. Preferably, the first and second housing cavities 110a, 110a', 110b, 110b' are closed by a combination of form-locking and force-locking connections, such as screw connections.

[0025] In the exploded view according to FIG. 5, the first housing cavity 110 a , 110 a ′ accommodates the measurement amplifier unit 13 and the telemetry unit 14 , and the second housing cavity 110 b , 110 b ′ accommodates the energy storage unit 15 .

[0026] In the following, the first measurement body housing part 11a equipped with the measurement amplifier unit 13 and the remote measurement unit 14 in the first housing cavity 110a, 110a' and sealed by the first measurement body closure 11a is also referred to as the first measurement body part 1a. The second measurement body housing part 11b equipped with the energy storage unit 15 in the second housing cavity 110b, 110b' and sealed by the second measurement body closure 11b is therefore referred to in the following as the second measurement body part 1b.

[0027] Preferably, the two measuring body housing parts 11 a, 11 b are provided with a hinge unit 111 and a connection unit 112 .

[0028] The hinge unit 111 is configured to hold the two measuring body housing parts 11a, 11b together such that they can be pivoted about a longitudinal axis A. In the exploded view according to FIG. 5, the hinge unit 111 is a hinge with at least one pin 111a and a number of sockets 111b. The hinge unit 111 holds the two measuring body housing parts 11a, 11b together on one side. By pivoting about the longitudinal axis A, it allows the two measuring body housing parts 11a, 11b to be reversibly moved from an open state to a closed state while they are held together by the hinge unit 111.

[0029] The connection unit 112 is configured to detachably connect the two measuring body housing parts 11a, 11b to one another. Preferably, the connection unit 112 is a combination of form-locking and force-locking connections, such as screw connections, plug connections, etc. In the depiction according to FIG. 4 and the exploded view according to FIG. 5, the connection unit 112 consists of at least one screw 112a and at least one through hole 112aa in the first measuring body housing part 11a and at least one threaded hole 112b in the second measuring body housing part 11b. The head of the screw 112a is supported in the through hole 112aa and the thread of the screw 112a protrudes through the through hole 112aa and can be screwed into the threaded hole 112b. Only after the connection unit 112 is released is it possible to pivot the two measuring body housing parts 11a, 11b about the longitudinal axis A. The release of the connection unit 112 is also reversible.

[0030] The views according to Figures 2 and 3 show the two measuring body housing parts 11a, 11b in the closed state, held together on one side by a hinge unit 111 and connected to one another on the other side by a connection unit 112. In the view according to Figure 4, the connection unit 112 has been released and the two measuring body housing parts 11a, 11b have been brought to the open state by pivoting about the longitudinal axis A and are held together on one side only by the hinge unit 111.

[0031] In the closed state, the two measuring body parts 1a, 1b are balanced, i.e. the centre of gravity S of the measuring bodies 1, 1' lies on the longitudinal axis A and furthermore the principal axis of inertia X of the measuring bodies 1, 1' lies on the longitudinal axis A and extends at an angle of 0° to the longitudinal axis A, i.e. without tilt.

[0032] Since the external dimensions and weight of the measurement amplifier unit 13 and the remote measurement unit 14 arranged in the first measurement body housing part 11a are given, as are the external dimensions and weight of the energy storage unit 15 arranged in the second measurement body housing part 11b, only a few degrees of freedom are available for balancing. Furthermore, the shaft diameters DW, DW' of the axial cavities 10, 10' and therefore also the cavity diameters D10, D10' are given.

[0033] The degree of freedom remaining for balancing is therefore the weight and weight distribution of each of the two measuring body housing parts 11a, 11b. The weight and weight distribution of the first and second measuring body housing parts 11a and 11b are balanced such that the two measuring body parts 1a, 1b are balanced in the closed state.

[0034] For illustration purposes, FIG. 6 shows a representation of a first cross section BB along a first cutting line B through the first measuring body housing part 11a according to FIG. 5, and FIG. 7 shows a view of a second cross section CC along a second cutting line C through the second measuring body housing part 11b according to FIG. 5.

[0035] The view according to FIG. 6 shows the first housing cavity 110a, 110a' as a first cavity 110a in the shape of an elongated hole for accommodating the measurement amplifier unit 13 and as a further first cavity 110a' in the shape of an elongated hole for accommodating the remote measurement unit 14. The first housing cavity 110a in the shape of an elongated hole is delimited by a first edge 110aa to the outside of the first measuring body housing part 11a. On its inside, the first housing cavity 110a in the shape of an elongated hole comprises at least one first undercut 110aaa shown as a dashed line. The further first housing cavity 110a' in the shape of an elongated hole is delimited by a further first edge 110aa' to the outside of the first measuring body housing part 11a. Inside thereof, the further first housing cavity 110a' having the shape of an oblong hole is provided with at least one further first undercut 110aaa' shown as a dashed line. In the following, the first undercut 110aaa and the further first undercut 110aaa' are also referred to as first undercuts 110aaa, 110aaa'. The weight and weight distribution of the first measuring body housing part 11a is adjusted via the size and shape of the first undercuts 110aaa, 110aaa' such that the principal axis of inertia X of the measuring body 1, 1' in the mounted state lies on the longitudinal axis A.

[0036] In the view according to FIG. 7, the second housing cavity 110b, 110b' consists of a first kidney-shaped cavity 110b for accommodating two first lithium-ion batteries of the energy storage unit 15 and a further first kidney-shaped cavity 110b' for accommodating two more lithium-ion batteries of the energy storage unit 15. The second kidney-shaped housing cavity 110b is delimited by a second edge 110bb to the outside of the second measuring body housing 11b. On its inside, the second kidney-shaped housing cavity 110b comprises at least one second undercut 110bbb shown as a dashed line. The further second kidney-shaped housing cavity 110b' is delimited by a further second edge 110bb' to the outside of the second measuring body housing 11b. Inside thereof, the further second kidney-shaped housing cavity 110b' comprises at least one further second undercut 110bbb' shown as a dashed line. In the following, the second undercut 110bbb and the further second undercut 110bbb' are also referred to as second undercuts 110bbb, 110bbb'. The weight and weight distribution of the second measuring body housing part 11b is adjusted via the size and shape of the second undercuts 110bbb, 110bbb' such that the principal axis of inertia X of the measuring bodies 1, 1' in the mounted state lies on the longitudinal axis A.

[0037] By balancing, the two measuring bodies 1a, 1b are matched to one another with regard to their weight and weight distribution. Two balanced measuring bodies 1a, 1b have the same weight and the same weight distribution.

[0038] The balancing precision is expressed as a balancing quality according to standard DIN ISO 1940-1. Preferably, the balancing quality of the measuring bodies 1, 1' is less than or equal to 10 / 10, preferentially less than or equal to 5 / 5.

[0039] By balancing, the interference torques caused by static and dynamic unbalance are minimized and the measurement accuracy is improved. Furthermore, the minimization of the interference torques due to balancing also corresponds to a standardization of the measurement signal. In this way, the measurement signals obtained with the measuring bodies 1, 1' of different cavity diameters D10, D10' are equal for all measuring bodies 1, 1', since the center of gravity S of the measuring bodies 1, 1' lies on the longitudinal axis A and, furthermore, the principal axis of inertia X of the measuring bodies 1, 1' lies on the longitudinal axis A.

[0040] Preferably, the first housing cavity 110a, 110a' in the first measuring body housing part 11a is additively manufactured, since this is the only way to create the first undercuts 110aaa, 110aaa' with favorable balancing qualities. Preferably, the second housing cavity 110b, 110b' in the second measuring body housing part 11b is also additively manufactured, since this is the only way to create the second undercuts 110bbb, 110bbb' with favorable balancing qualities.

[0041] The measurement unit 12 includes a support unit 121 , a strain gauge 122 and an electrical contact member 123 .

[0042] The support unit 121 is hollow cylindrical in shape. In the view according to Fig. 4 and in the exploded view according to Fig. 5, the support unit 121 is made of several parts. Preferably, the support unit 121 is bisected in a plane containing the longitudinal axis A into two support members 121a, 121b, the two support members 121a, 121b having the shape of congruent halves of a hollow cylinder. The two support members 121a, 121b are made of a material with high mechanical resistance, such as metal, plastic, etc.

[0043] The two support members 121a, 121c are provided with a plug member 121c, such as a snap hook. The plug member 123c is disposed at the ends of the two support members 121a, 121b. The plug members 121c are configured to form a detachable connection with each other by a form-locking connection.

[0044] The support unit 121 is configured to support the strain gauge 122 and the contact member 123. The support unit 121 supports the strain gauge 122 on its inner side radially facing the shafts W, W'.

[0045] The strain gauge 122 is configured to generate a measurement signal MS under the action of a torque M. The strain gauge 122 may be a full bridge, a half bridge, or a quarter bridge. The strain gauge 122 generates the measurement signal MS, preferably with a bandwidth of 5 kHz. The measurement signal MS is a voltage. The strain gauge 122 is electrically connected to the electrical contact member 123 by an electrical conductor. The electrical conductor conveys the measurement signal MS to the electrical contact member 123.

[0046] The electrical contact member 123 is configured to transmit the measurement signal MS through the support member 121 to an outer side surface facing radially outwardly from the shafts W, W'.

[0047] The diagram according to Fig. 4 shows the measuring bodies 1, 1' in the open state. The diagrams according to Fig. 2 and 3 show the measuring bodies 1, 1' in the closed state. When the measuring bodies 1, 1' are in the closed state, the electrical contact member 123 and the measurement amplifier unit 13 are arranged to be electrically connected to each other via the electrical contacts. The electrical contacts transmit the measurement signal MS to the measurement amplifier unit 13.

[0048] The measurement amplifier unit 13 comprises an amplifier circuit 131 having an operational amplifier. The amplifier circuit 131 is configured to amplify the measurement signal MS. The amplified measurement signal MS is also a voltage. The amplifier circuit 131 is 1 , 10 2 , 10 3 , 10 4 , etc. The measurement amplifier unit 13 is electrically connected to a remote measurement unit 14 via electrical conductors. The electrical conductors transmit the amplified measurement signal MS to the remote measurement unit 14. Furthermore, the electrical conductors transmit control data SD to the measurement amplifier unit 13.

[0049] The telemetry unit 14 comprises a telemetry electrical circuit 141 and a rotor antenna 142 .

[0050] The telemetry circuit 141 comprises an analog / digital converter and is arranged to digitise the amplified measurement signal MS to obtain measurement data MD, which are preferably binary sequences with a resolution of 16 bits.

[0051] The rotor antenna 142 is configured to transmit the measurement data MD to the evaluation unit 2 by wireless transmission. For this purpose, the evaluation unit 2 comprises a stator antenna 20. The stator antenna 20 is configured to receive the measurement data MD transmitted by the rotor antenna 142. The wireless data transmission between the rotor antenna 142 and the stator antenna 20 is bidirectional. The stator antenna 20 is capable of transmitting the control data SD to the rotor antenna 142 and the rotor antenna 142 is capable of receiving the control data SD transmitted from the stator antenna 20. The measurement data MD and the control data SD are transmitted and received in this wireless transmission in the form of electromagnetic waves. Preferably, the rotor antenna 142 and the stator antenna 20 transmit the measurement data MD and the control data SD by wireless transmission in the Industrial, Scientific and Medical (ISM) band from 2,402 GHz to 2,480 GHz. In FIG. 1, the wireless transmission of the measurement data MD and the control data SD is represented as a curved arc.

[0052] The stator antenna 20 is electrically connected to the evaluation unit 2 via an electrical data line 21. The electrical data line 21 transmits the measurement data MD to the evaluation unit 2 and the control data SD to the stator antenna 20.

[0053] The energy storage unit 15 comprises at least one electrical energy storage device, such as a rechargeable battery, a non-rechargeable battery, etc. Preferably, the energy storage unit 15 is a lithium-ion battery, a lithium-polymer battery, an air-zinc battery, etc. The energy storage unit 15 is configured to supply electrical energy to the measuring body 1, 1' for an operating period of at least 40 hours. The energy storage unit 15 is small and lightweight. In the exploded view according to FIG. 5, the energy storage unit 15 comprises four lithium-ion batteries serving as storage elements, each having a capacity of 715 mAh, a weight of 20 g, and external dimensions with a length of 49 mm and a diameter of 14 mm.

[0054] The energy storage unit 15 comprises an energy supply member 151. When the measuring body 1, 1′ is in the closed state, the energy supply member 151, the measurement amplifier unit 13 and the remote measurement unit 14 are arranged to be electrically connected to one another via electrical contacts. Electrical energy is supplied through these electrical contacts from the energy storage unit 15 in the second measuring body housing part 11b to the measurement amplifier unit 13 and the remote measurement unit 14 in the first measuring body housing part 11a.

[0055] Furthermore, the energy storage unit 15 comprises a power supply connection 152. The power supply connection 152 is a plug connector, such as USB-C. In the view according to FIG. 4 and in the exploded view according to FIG. 5, the power supply connection 152 is arranged in the first measuring body closure 11aa. The power supply connection 152 is electrically connected to the measurement amplifier unit 13 in the first measuring body housing part 11a. The power supply connection 152 is therefore electrically connected to the energy supply member 151 in the second measuring body housing part 11b and to the energy storage unit 15 via the measurement amplifier unit 13 when the measuring body 1, 1' is in the closed state. The energy storage unit 15 can be charged with electrical energy by connecting an external power source by means of a cable to the power supply connection 152. The measuring body 1, 1' attached to the shaft W, W' is charged quickly and simply. It is not necessary to remove the measuring body 1, 1' from the shaft W, W' for this purpose. In a charging time of less than 30 minutes, an empty energy storage unit 15 is charged to at least 80% with electrical energy.

[0056] In addition, the energy storage unit 15 of the measuring body 1, 1' attached to the shaft W, W' can be easily and quickly exchanged. There is no need to remove the measuring body 1, 1' from the shaft W, W' for this purpose. The second housing cavity 110b, 110b' is accessible from the outside of the measuring body 1, 1' by opening the second measuring body closure 11bb. It is then possible to remove the energy storage unit 15 from the second housing cavity 110b, 110b'. A new energy storage unit 15' can be inserted into the second housing cavity 110b, 110b' and replace the removed energy storage unit 15. Thus, when the four lithium-ion batteries depicted as storage elements in the exploded view according to FIG. 5 are empty, they can be replaced with charged lithium-ion batteries. The second housing cavity 110b, 110b' is then closed by the second measuring body closure 11bb. The exchange of the energy storage unit 15 takes place in less than five minutes.

[0057] The evaluation unit 2 comprises at least one data memory 22 , at least one data processor 23 , at least one input / receiving unit 24 and at least one output unit 25 .

[0058] The evaluation unit 2 is arranged to evaluate the measurement data MD and to generate control data SD for controlling the measuring bodies 1, 1'.

[0059] A data memory 22 in the evaluation unit 2 stores an evaluation program P, which can be loaded into the data processor 23. The evaluation program P loaded into the data processor 23 generates instructions, which are executed automatically by the evaluation unit 2. The adverb "automatically" in the sense of the present invention means that the instructions generated by the evaluation program P are executed by the evaluation unit 2 without any human intervention.

[0060] By using the input / receiving unit 24 it is possible to operate the evaluation unit 2. The verb "operate" in the context of the present invention means that a person can input commands via the input / receiving unit 24, which are executed by the evaluation unit 2. The input / receiving unit 24 can be a keyboard for inputting commands, an antenna for receiving commands etc. The commands are input by the keyboard in the form of character strings, in response to which the evaluation unit 2 generates control data SD. The commands are received by the antenna as electromagnetic waves, in response to which the evaluation unit 2 generates control data SD.

[0061] The evaluation unit 2 thus generates control data SD for controlling the measuring bodies 1, 1' according to the instructions of the evaluation program P or according to instructions entered at the input / receiver unit 24. The control data SD implement various instructions.

[0062] It is therefore possible to start or stop the measuring bodies 1, 1' by means of the control data SD. For this purpose, the evaluation unit 2 generates control data SD which contains information regarding the starting or stopping of the measuring bodies 1, 1' and transmits it to the measurement amplifier unit 13. The measurement amplifier unit 13 starts or stops the measuring bodies 1, 1' in accordance with the control data SD.

[0063] Furthermore, the control data SD can also be used to set the zero point of the amplifier circuit 131. The zero point may change over time and under external influences such as temperature. The zero point needs to be adjusted to achieve a high level of measurement accuracy. The zero point must not differ from the actual zero point by more than 10% (upper and lower limits). For zero points that are not within these limits, the evaluation program P determines a new zero point that is within the limits. Alternatively, the new zero point is set according to a command entered via the input / receiving unit 24. The evaluation unit 2 therefore generates control data SD indicating the zero point and transmits the control data SD to the measurement amplifier unit 13. The amplifier circuit 131 then uses the new zero point specified in the control data SD.

[0064] In addition, the control data SD can also be used to set the gain factor of the amplifier circuit 131. Each amplified measurement signal MS can be represented up to a maximum or final value (full scale). For the best possible representation, the amplified measurement signal MS must not exceed the final value (upper limit) and it must not be more than one order of magnitude smaller than the final value (lower limit). If the amplified measurement signal MS is not within these limits, the evaluation program P determines a different amplification factor so that the amplified measurement signal MS is within the limits. Alternatively, a command entered via the input / receiver unit 24 serves to set such a different gain factor. The evaluation unit 2 thus generates control data SD indicating the amplification factor and transmits the control data SD to the measurement amplifier unit 13. The amplifier circuit 131 amplifies the measurement signal MS according to the control data SD.

[0065] Optionally, the device V comprises a rotation angle sensor 30. The rotation angle sensor 30 may be an optical sensor, a magnetic sensor or the like which detects the rotation angle α of the shafts W, W′ in a contactless manner and generates a rotation angle signal WS for the detected rotation angle α. The rotation angle sensor 30 is electrically connected to the evaluation unit 2 by an electrical signal line 31. The electrical signal line 31 transmits the angle signal WS to the evaluation unit 2.

[0066] The evaluation unit 2 is configured to evaluate the angle signal WS. From the angle signal WS an evaluation program P loaded into a data processor 23 generates information regarding the direction of rotation of the shafts W, W' and the angular positions of the shafts W, W'.

[0067] The measuring bodies 1, 1' are attached to the shafts W, W' in a three-step process.

[0068] In a first step, the two support members 121 a , 121 b are installed on the shafts W, W′ and connected to each other via the plug members 121 .

[0069] In a second step, the two measuring body housing parts 11a, 11b are placed in the support unit 121 in an open state.

[0070] In a third step, the two measuring body housing parts 11a, 11b are connected to each other by the connection unit 112 by pivoting them about the longitudinal axis A. When the measuring bodies 1, 1' are in the closed state, the electrical contact member 123 and the measurement amplifier unit 13 are electrically connected to each other by the electrical contacts. In the closed state of the measuring bodies 1, 1', the energy supply member 151, the measurement amplifier unit 13 and the remote measurement unit 14 are electrically connected to each other via the electrical contacts, and the measurement amplifier unit 13 and the remote measurement unit 14 in the first measuring body housing part 11a are supplied with power by the energy storage unit 15 in the second measuring body housing part 11b. [Explanation of symbols]

[0071] α Rotation angle A Longitudinal axis B First cutting line BB 1st section C Second cutting line CC 2nd Section D10, D10' Cavity diameter M Torque MD measurement data MS measurement signal P Evaluation Program S center of gravity SD Control Data V device W, W' shaft WD, WD' shaft diameter WS angle signal X axis of inertia 1, 1' Measuring body 1a, 1b' Measuring body 10, 10' axial cavity 11 Measurement body housing 11a, 11b Measuring body housing part 11aa, 11bb Measuring body closure 110a, 110a' first housing cavity 110aa, 110aa' first edge 110aaa, 110aaa' First undercut 110b, 110b' second housing cavity 110bb, 110bb' second edge 110bbb, 110bbb' Second undercut 111 Hinge unit 111a Pin 111b socket 112 Connection Unit 112a Screw 112aa through hole 112b screw hole 12 Measurement Units 121 Support Unit 121a, 121b Support member 121c Plug parts 122 Strain Gauge 123 Electrical contact parts 13 Measuring Amplifier Unit 131 Amplifier Electrical Circuit 14 Telemetry Unit 141 Telemetry Electrical Circuits 142 Rotor Antenna 15, 15' Energy Storage Unit 151 Energy supply components 152 Power connection 20 Stator antenna 21 Electrical data lines 2 Evaluation Unit 22 Data Memory 23 Data processor 24 Input / Receive Units 25 Output Unit 30 Rotation angle sensor 31 Electrical signal circuits

Claims

1. A device (V) for measuring the torque (M) of a rotating shaft (W, W'), said device (V) comprising a measuring body (1, 1') and an evaluation unit (2), said measuring body (1, 1') being capable of being attached to said shaft (W, W') and in the attached state rotating together with said shaft (W, W') about the longitudinal axis (A) of said shaft (W, W'), said measuring body (1, 1') comprising a measuring unit (12), a measurement amplifier unit (13) and a remote measuring unit (14), said measuring unit (1, 1') being configured to measure the torque (M) of a rotating shaft (W, W'), 2) generates a measurement signal (MS) under the action of the torque (M) in the mounted state, the measurement amplifier unit (13) amplifies the measurement signal (MS), the telemetry unit (14) digitizes the amplified measurement signal (MS) and transmits it to the evaluation unit (2) by wireless transmission, and the measuring body (1, 1') has a principal axis of inertia (X), which in the mounted state lies on the longitudinal axis (A).

2. 2. The device (V) according to claim 1, characterized in that the measuring body (1, 1') comprises a measuring body housing (11), which is manufactured from a plurality of parts and comprises a first measuring body housing part (11a) having a first housing cavity (110a, 110a'), and the first housing cavity (110a, 110a') accommodates the measuring amplifier unit (13) and the remote measuring unit (14).

3. 3. The device (V) according to claim 2, characterized in that the measuring body housing (11) comprises a second measuring body housing part (11b) having a second housing cavity (110b, 110b'), the measuring body (1, 1') comprises an energy storage unit (15), and the second housing cavity (110b, 110b') accommodates the energy storage unit (15).

4. The measuring body housing (11) comprises a second measuring body closure (11bb), which closes the second housing cavity (110b) which accommodates the energy storage unit (15), the second measuring body closure (11bb) being capable of being opened and the second housing cavity (110b, 110b') which accommodates the energy storage unit (15) being accessible from the outside of the measuring body (1, 1') in the mounted state, the energy 4. The device (V) according to claim 3, characterized in that the storage unit (15) can be removed from the second housing cavity (110b, 110b') and a new energy storage unit (15') can be inserted into the second housing cavity (110b, 110b'), and that the second housing cavity (110b, 110b') containing the new energy storage unit (15') can be closed by the second measuring body closure (11bb).

5. The first housing cavity (110a, 110a') comprises at least a first undercut (110aaa, 110aa'), the weight and weight distribution of the first measuring body housing part (11a) is adjusted via the size and shape of the first undercut (110aaa, 110aaa') such that the principal axis of inertia (X) of the measuring body (1, 1') in the mounted state is on the longitudinal axis (A), the second housing cavity (1 5. The device (V) according to claim 3 or 4, characterized in that the second measuring body housing part (11b) comprises at least one second undercut (110bbb, 110bbb') and that the weight and weight distribution of the second measuring body housing part (11b) is adjusted via the size and shape of the second undercut (111bbb, 111bbb') in such a way that the principal axis of inertia (X) of the measuring body (1, 1') in the mounted state lies on the longitudinal axis (A).

6. 6. Device (V) according to claim 3, characterized in that the two measuring body housing parts (11a, 11b) have the shape of congruent halves of a hollow cylinder.

7. 7. The device (V) according to claim 3, wherein the two measuring body housing parts (11a, 11b) are manufactured additively.

8. 8. Apparatus (V) according to claim 1, characterized in that the measuring body (1, 1') is hollow cylindrical in shape and comprises an axial cavity (10, 10'), the axial cavity (10, 10') having a cavity diameter (D1, D1') equal to a shaft diameter (DW, DW') of the shaft (W, W') on which the measuring body (1, 1') can be attached, and that for shafts (W, W') with different shaft diameters (DW, DW'), the apparatus (V) comprises a plurality of measuring bodies (1, 1') with cavity diameters (D1, D1'), the cavity diameters (D1, D1') being equal to the different shaft diameters (DW, DW') of the shafts (W, W').

9. 9. The device (V) according to claim 1, characterized in that the measuring unit (12) comprises a support unit (121) and a strain gauge (122), the support unit (121) supports the strain gauge (122) on its inner side facing the shaft (W, W') in the radial direction, and the strain gauge (122) is configured to generate a measurement signal (MS) under the action of the torque (M).

10. 10. Apparatus (V) according to claim 9, characterized in that the support unit (121) is made from a plurality of parts and comprises a first support member (121a) and a second support member (121b), and that the two support members (121a, 121b) have the shape of congruent halves of a hollow cylinder.

11. 11. The device (V) according to claim 10, characterized in that the two support members (121a, 121b) comprise plug members (121c), and that the plug members (121c) are configured to form a detachable connection with each other by a form-locking connection.

12. A method for measuring a torque (M) of a rotating shaft (W, W') using a device (V) comprising a measuring body (1, 1') and an evaluation unit (2), said measuring body (1, 1') comprising a measurement unit (12), a measurement amplifier unit (13) and a remote measurement unit (14), said measuring body (1, 1') being attached to said shaft (W, W'), said shaft (W, W') being fixed in rotation about its longitudinal axis (A) and transmitting said torque (M), said measuring unit (12) being attached to said shaft (W, W'), said shaft (W, W') being fixed in rotation about its longitudinal axis (A) and transmitting said torque (M), ) generates a measurement signal (MS) under the action of the torque (M), the measurement amplifier unit (13) amplifies the measurement signal (MS), the telemetry unit (14) digitizes the amplified measurement signal (MS) which is transmitted to the evaluation unit (2) by wireless transmission, and a measuring body (1, 1') is provided, the measuring body (1, 1') having a principal axis of inertia (X), the principal axis of inertia (X) lying on the longitudinal axis (A) in the mounted state.

13. 13. The method according to claim 12, characterized in that a measuring unit (12) is provided, said measuring unit (12) comprising a support unit (121) and a strain gauge (122), said support unit (121) being manufactured from a plurality of parts and comprising a first support member (121a) and a second support member (121b), said two support members (121a, 121b) comprising a plug member (121c), and in that in a first step of mounting the measuring body (1, 1') to the shaft (W, W'), the two support members (121a, 121b) are placed on the shaft (W, W') and connected to each other by the plug member (121).

14. 14. The method according to claim 13, characterized in that a measuring body (1, 1') is provided, the measuring body (1, 1') comprising a measuring body housing (11), the measuring body housing (11) being made from a plurality of parts and comprising a first measuring body housing part (11a) and a second measuring body housing part (11b), the two measuring body housing parts (11a, 11b) comprising a hinge unit (111), the hinge unit (111) being configured to hold the two measuring body housing parts (11a, 11b) together such that they are able to pivot about the longitudinal axis (A), and in that in a second step of attaching the measuring body (1, 1') to the shaft (W, W'), the two measuring body housing parts (11a, 11b) are placed in an open state on the support unit (121).

15. 15. The method according to claim 14, characterized in that two measuring body housing parts (11a, 11b) are provided, the two measuring body housing parts (11a, 11b) comprise a connection unit (112), the connection unit (112) is configured to connect the two measuring body housing parts (11a, 11b) such that they can be releasably closed, and in a third step of attaching the measuring body (1, 1') to the shaft (W, W'), the two measuring body housing parts (11a, 11b) are connected to each other by the connection unit (112) by pivoting them about the longitudinal axis (A).

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