Device and method for measuring torque of rotating shaft

Abstract

The invention relates to a device (V) for measuring a torque (M) of a rotating shaft (W, W '); the device (V) has a measuring body (1, 1 ') and an evaluation unit (2); the measuring body (1, 1 ') can be fastened to the shaft (W, W') and rotates together with the shaft (W, W ') about the longitudinal axis (A) of the shaft (W, W') in the fastened state; the measuring body (1, 1 ') has 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 action of a torque (M) in the fastened state; a measurement amplifier unit (13) amplifies the measurement signal (MS); the telemetry unit (14) digitizes and wirelessly transmits the amplified measurement signal (MS) to the evaluation unit (2); wherein the measuring body (1, 1 ') has a main axis of inertia (X) which lies on the longitudinal axis (A) in the fastened state.

Description

Technical Field

[0001] The 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 Art

[0002] A shaft is a machine element that rotates about an axis and has the function of transmitting rotational motion and torque during rotation. Such shafts have a wide range of applications in machines, for example as drive shafts in automotive technology, as turbine shafts in energy technology, etc.

[0003] The torque transmitted by a shaft determines key parameters of a machine, such as performance, efficiency, friction values, etc. For this reason, torque is measured both during machine development and during the industrial use of the machine.

[0004] A device for measuring the torque of a rotating shaft is known from document DE19719921A1, which comprises a measuring body in the form of a measuring flange that rotates with the shaft and an evaluation unit. The evaluation unit has a stator antenna. The evaluation unit is spatially separated from the shaft and the measuring body. The measuring body also has a strain gauge, a measuring amplifier and a telemetry device with a rotor antenna. Under the action of the torque to be measured, the strain gauge generates a measuring signal, the measuring amplifier amplifies the measuring signal, the telemetry unit digitizes the amplified measuring signal into measurement data, and sends the measuring data to the stator antenna via the rotor antenna, from which the measuring data arrives at the evaluation unit. The parameters of the measuring amplifier, such as the zero point or the gain factor, are adjusted by the signal sent from the stator antenna to the rotor antenna.

[0005] Now the user wants to use the above device for shafts with different diameters. For this purpose, a number of measuring bodies are provided, the geometric dimensions of which are adapted to the respective shaft diameter, while the evaluation unit used remains the same. The different geometric dimensions of the measuring bodies can affect the measuring accuracy, especially for shafts with a speed significantly exceeding 1000 min. -1 The measuring signals generated for shafts of different diameters are therefore only of limited comparability due to the fast rotating shaft.

[0006] A first object of the invention is to improve the device known from DE 197 19 921 A1 for measuring the torque of a rotating shaft. The measuring accuracy should thereby be improved. Another object of the invention is to provide a method which can measure the torque of a rotating shaft simply, quickly and at low cost. Summary of the invention

[0007] The objects of the invention are achieved by the features of the independent claims.

[0008] The invention relates to a device for measuring the torque of a rotating shaft; the device comprises a measuring body and an evaluation unit; the measuring body can be fastened to the shaft and rotate together with the shaft around the longitudinal axis of the shaft in the fastened state; the measuring body comprises a measuring unit, a measuring amplifier unit and a telemetry unit; the measuring unit generates a measuring signal under the action of the torque in the fastened state; the measuring amplifier unit amplifies the measuring signal; the telemetry unit digitizes the amplified measuring signal and transmits it wirelessly to the evaluation unit; wherein the measuring body comprises a main inertia axis, which is located on the longitudinal axis in the fastened state.

[0009] The invention also relates to a method for measuring the torque of a rotating shaft; using a device having a measuring body and an evaluation unit; the measuring body having a measuring unit, a measuring amplifier unit and a telemetry unit; wherein the measuring body is fastened to the shaft; wherein the shaft rotates about the longitudinal axis of the shaft and transmits torque; wherein the measuring unit generates a measurement signal under the action of the torque; wherein the measuring amplifier unit amplifies the measurement signal; wherein the telemetry unit digitizes the amplified measurement signal and transmits it wirelessly to the evaluation unit; and wherein a measuring body is provided, which has a main inertia axis, which in the fastened state is located on the longitudinal axis.

[0010] The invention is based on the recognition that the measuring body of the device for measuring the torque of a rotating shaft known from DE 197 19 921 A1 has an uneven assembly, since it consists of a measuring flange, a strain gauge, a measuring amplifier and a telemeter unit with a rotor antenna. Due to this uneven assembly, it has an asymmetrical mass distribution with respect to the longitudinal axis of the rotating shaft, as a result of which the center of gravity of the measuring body is not on the longitudinal axis, which leads to a static imbalance, or to a displacement of the main inertia axis of the measuring body relative to the longitudinal axis. The unbalance caused by static and dynamic imbalance induces interference torque, which is superimposed on the torque to be measured and causes distortion of the torque measurement. The measuring body of the device according to the present invention is statically and dynamically balanced, and the interference torque is minimized, which improves the measurement accuracy of the device.

[0011] Preferred embodiments of the invention are disclosed in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present invention will be described in detail hereinafter with reference to the accompanying drawings, wherein:

[0013] Figure 1 is a schematic diagram of a device V for measuring a torque M of a shaft W, W', the device having a measuring body 1, 1' and an evaluation unit 2;

[0014] Figure 2 is based on Figure 1A partial view of a first embodiment of the measuring body 1 and the shaft W;

[0015] Figure 3 is based on Figure 1 A partial view of a second embodiment of the measuring body 1 'and the shaft W';

[0016] Figure 4 is based on Figure 1 A partial view of a measuring body 1, 1' with a measuring unit 12 located between a first measuring body partial housing 11a and a second measuring body partial housing 11b;

[0017] Figure 5 is based on Figure 1 An exploded view of a measuring body 1, 1', which has a measuring amplifier unit 13 and a telemetry unit 14 located in a first measuring body partial housing 11a and an energy storage unit 15 located in a second measuring body partial housing 11b;

[0018] Figure 6 is along the basis Figure 5 a view of a first cross-sectional view BB of a first section axis B of the first measuring body partial housing 11 a; and

[0019] Figure 7 is along the basis Figure 5 FIG. 1 is a view of a second cross-section CC of a second section axis C of the second measuring body partial housing 11 b.

[0020] The reference numerals are listed as follows:

[0021] α rotation angle

[0022] A longitudinal axis

[0023] B First section axis

[0024] BB first cross section

[0025] C Second section axis

[0026] CC Second Cross Section

[0027] D10, D10' cavity diameter

[0028] M torque

[0029] MD measurement data

[0030] MS measurement signal

[0031] P Assessment Procedure

[0032] S Center of gravity

[0033] SD control data

[0034] V Device

[0035] W, W' axis

[0036] WD, WD' shaft diameter

[0037] WS rotation angle signal

[0038] X axis of inertia

[0039] 1, 1' measuring body

[0040] 1a, 1b' measuring body parts

[0041] 10, 10' axial cavity

[0042] 11 Measuring body shell

[0043] 11a, 11b Measuring body part shell

[0044] 11aa, 11bb measuring body partially enclosed part

[0045] 110a, 110a' first housing cavity

[0046] 110aa, 110aa' first edge

[0047] 110aaa, 110aaa' first undercut

[0048] 110b, 110b' second housing cavity

[0049] 110bb, 110bb' second edge

[0050] 110bbb, 110bbb' second undercut

[0051] 111 Joint Unit

[0052] 111a Pin

[0053] 111b socket

[0054] 112 Connection unit

[0055] 112a Bolt

[0056] 112aa through hole

[0057] 112b threaded hole

[0058] 12 measuring units

[0059] 121 load-bearing units

[0060] 121a, 121b load-bearing element

[0061] 121c Plug components

[0062] 122 Strain gauge

[0063] 123 Electrical contact elements

[0064] 13 Measuring amplifier unit

[0065] 131 Amplifier Circuit

[0066] 14 Telemetry Unit

[0067] 141 Telemetry Circuit

[0068] 142 rotor antenna

[0069] 15,15' Energy Storage Unit

[0070] 151 Energy Supply Components

[0071] 152 Power supply interface

[0072] 20 Stator antenna

[0073] 21 Electrical data cable

[0074] 2 Evaluation Units

[0075] 22 Data storage

[0076] 23 Data Processor

[0077] 24 Input / receive unit

[0078] 25 Output Units

[0079] 30 Rotation angle sensor

[0080] 31 Electrical signal line

[0081] In the figures, identical objects are denoted by identical reference numerals. DETAILED DESCRIPTION

[0082] Figure 1 A shaft W, W' is shown which can rotate about its longitudinal axis A and during rotation transmits a torque M. The shaft W, W' is a rotationally symmetrical body about the longitudinal axis A and is made of a mechanically resistant material such as metal, plastic or the like.

[0083] Figure 1 Also shown is a device V for measuring a torque M of a shaft W, W'. The device V consists of a measuring body 1, 1' and an evaluation unit 2. The measuring body 1, 1' is fastened to the shaft W, W' and rotates together with the shaft W, W' about a longitudinal axis A. The evaluation unit 2 is spatially spaced apart from the shaft W, W' and the measuring body 1, 1'.

[0084] In accordance with Figures 1 to 4 View and basis Figure 5 In the exploded view of , the measuring bodies 1, 1' are hollow cylinders. In the region of the longitudinal axis A, the measuring bodies 1, 1' have axial cavities 10, 10'. The axial cavities 10, 10' have cavity diameters D10, D10'. The size of the cavity diameters D10, D10' is determined so that they are equal to the shaft diameters DW, DW' in the radial direction perpendicular to the longitudinal axis A. The measuring bodies 1, 1' are fastened radially to the outside of the shafts W, W' with respect to the longitudinal axis A. Preferably, the fastening is achieved by clamping in a form-fitting and force-fitting manner. The fastening can be reversibly disassembled.

[0085] Now, the shafts W, W' can have different shaft diameters WD, WD'. Therefore, the device has a plurality of measuring bodies 1, 1', whose cavity diameters D1, D1' are equal to the different shaft diameters DW, DW'. For this purpose, Figure 2 and Figure 3 Two embodiments of the shaft W, W' and the axial cavity 10, 10' of the measuring body 1, 1' are shown. Figure 2 In the first embodiment, the shaft diameter DW of the shaft W is 25 mm; Figure 3 In the second embodiment, the shaft diameter DW' of the shaft W' is 45 mm. Figure 2 In the first embodiment, the diameter D10 of the cavity of the measuring body 1 is 25 mm; Figure 3 In the second embodiment, the cavity diameter D10' of the measuring body 1' is 45 mm. Of course, those skilled in the art can also freely use shafts and axial cavities with diameters less than 25 mm and shafts and axial cavities with diameters greater than 45 mm to implement the present invention.

[0086] The measuring body 1 , 1 ′ has a measuring body housing 11 , a measuring unit 12 , a measuring amplifier unit 13 , a telemetry unit 14 and an energy storage unit 15 .

[0087] The measuring body housing 11 is designed to protect the measuring unit 12 , the measuring amplifier unit 13 , the telemetry unit 14 and the energy storage unit 15 from harmful environmental conditions such as dust, moisture and the like.

[0088] In accordance with Figure 4 View and basis Figure 5 In the exploded view of FIG. 1 , the measuring body housing 11 is multi-part and has a first measuring body partial housing 11 a and a second measuring body partial housing 11 b and a first measuring body partial closure 11 aa and a second measuring body partial closure 11 bb.

[0089] Preferably, the measuring body housing 11 is divided into two along a plane lying on the longitudinal axis A, and the two measuring body part housings 11a, 11b have congruent halves of a hollow cylinder. ), and the two measuring body part enclosures 11aa, 11bb have the shape of end face halves of a hollow cylinder. In the region of the longitudinal axis A, each of the two measuring body part housings 11a, 11b is limited by an axial cavity 10, 10'. The two measuring body part housings 11a, 11b and the two measuring body part enclosures 11aa, 11bb are made of a mechanically resistant material, such as metal, plastic, etc.

[0090] The first measuring body partial housing 11a has at least one first housing cavity 110a, 110a'. The first measuring body partial closure portion 11aa is configured to seal the first housing cavity 110a, 110a' in a sealed manner to prevent dust and moisture. The second measuring body partial housing 11b has at least one second housing cavity 110b, 110b'. The second measuring body partial closure portion 11bb is configured to seal the second housing cavity 110b, 110b' in a sealed manner to prevent dust and moisture. Preferably, the closure of the first and second housing cavities 110a, 110a', 110b, 110b' is a combination of form fit and force fit, such as a bolted connection.

[0091] In accordance with Figure 5 In the exploded view of FIG. 1 , the first shell cavities 110 a and 110 a ′ accommodate the measuring amplifier unit 13 and the telemetry unit 14 , and the second shell cavities 110 b and 110 b ′ accommodate the energy storage unit 15 .

[0092] The first measuring body part housing 11a, which is equipped with a measuring amplifier unit 13 and a telemetry unit 14 in the first housing cavity 110a, 110a' and is closed by a first measuring body part closing portion 11aa, is also referred to as the first measuring body part 1a in the following. Correspondingly, the second measuring body part housing 11b, which is equipped with an energy storage unit 15 in the second housing cavity 110b, 110b' and is closed by a second measuring body part closing portion 11bb, is also referred to as the second measuring body part 1b in the following.

[0093] Preferably, the two measuring body part housings 11 a , 11 b have a joint unit 111 and a connection unit 112 .

[0094] The joint unit 111 is designed to hold the two measuring body part housings 11a, 11b together so that they can pivot about the longitudinal axis A. Figure 5 In the exploded view of FIG. 1 , the joint unit 111 is a hinge with at least one pin 111a and a plurality of sockets 111b. The joint unit 111 holds the two measuring body part housings 11a, 11b together on one side. By pivoting about the longitudinal axis A, the two measuring body part housings 11a, 11b can be reversibly changed from an open state to a closed state and are held together by the joint unit 111.

[0095] The connecting unit 112 is configured to releasably connect the two measuring body part housings 11a, 11b to each other. Preferably, the connecting unit 112 is a combination of form fit and force fit, such as a screw connection, a plug connection, etc. Figure 4 View and basis Figure 5 In the exploded view of , the connection unit 112 consists of at least one bolt 112a and at least one through hole 112aa in the first measuring body part housing 11a and at least one threaded hole 112b in the second measuring body part housing 11b. The head of the bolt 112a remains in the through hole 112aa and the thread of the bolt 112a protrudes through the through hole 112aa and can be connected to the threaded hole 112b. Only after the connection unit 112 is loosened, the two measuring body part housings 11a, 11b can be pivoted about the longitudinal axis A. Loosening the connection unit 112 is also reversible.

[0096] In accordance with Figure 2 and Figure 3 The view of FIG. 1 shows two measuring body part housings 11a, 11b in a closed state, and the two measuring body part housings are held together on one side by a joint unit 111 and are connected to each other on the other side by a connecting unit 112. Figure 4 In the view of FIG. 1 , the connecting unit 112 is released and the two measuring body part housings 11 a , 11 b are in an open state by pivoting about the longitudinal axis A and are held together only on one side by the joint unit 111 .

[0097] In the closed state, the two measuring body parts 1a, 1b are balanced, ie the center of gravity S of the measuring body 1, 1' lies on the longitudinal axis A, and the main inertia axis X of the measuring body 1, 1' also lies on the longitudinal axis A and extends at an angle of 0° to the longitudinal axis A without being tilted.

[0098] Since the outer dimensions and weight of the measuring amplifier unit 13 and the telemetry unit 14 in the first measuring body part housing 11a are predetermined, there are few degrees of freedom for balancing, as are the outer dimensions and weight of the energy storage unit 15 in the second measuring body part housing 11b. In addition, the shaft diameters DW, DW' are predetermined, and thus the cavity diameters D10, D10' of the axial cavities 10, 10' are also predetermined.

[0099] The weight and weight distribution of each of the two measuring body housing parts 11a, 11b therefore leaves degrees of freedom for balance. The weight and weight distribution of the first measuring body part housing 11a and the second measuring body part housing 11b are adjusted in a balanced manner so that the two measuring body parts 1a, 1b are balanced in the closed state.

[0100] To illustrate this point, Figure 6 Shown along the basis Figure 5 a view of a first cross-section BB of a first measuring body partial housing 11 a along a first section axis B, Figure 7 Shown along the basis Figure 5 FIG. 1 is a view of a second cross-section CC of a second sectional axis C of the second measuring body partial housing 11 b.

[0101] In accordance with Figure 6 In the view of , the first housing cavities 110a, 110a' are composed of a first long hole-shaped cavity 110a for accommodating the measuring amplifier unit 13 and another first long hole-shaped cavity 110a' for accommodating the telemetry unit 14. The first long hole-shaped housing cavity 110a is bounded by a first edge 110aa toward the outside of the first measuring body partial housing 11a. The first long hole-shaped housing cavity 110a has at least one first undercut 110aaa shown in dashed lines on the inside. The other first long hole-shaped housing cavity 110a' is bounded by another first edge 110aa' toward the outside of the first measuring body partial housing 11a. The other first long hole-shaped housing cavity 110a' has at least one other first undercut 110aaa' shown in dashed lines on the inside. In the following, the first undercut 110aaa and the other first undercut 110aaa' are also referred to as first undercuts 110aaa, 110aaa'. The weight and weight distribution of the first measuring body part housing 11a are adjusted by the size and shape of the first undercuts 110aaa, 110aaa' so that the main inertia axis X of the measuring body 1, 1' in the fastened state lies on the longitudinal axis A.

[0102] In accordance with Figure 7 In the view of, the second housing cavity 110b, 110b' includes a first kidney-shaped cavity 110b for accommodating two first lithium-ion batteries of the energy storage unit 15 and another first kidney-shaped cavity 110b' for accommodating the other two lithium-ion batteries of the energy storage unit 15. The second kidney-shaped housing cavity 110b is bounded by a second edge 110bb toward the outside of the second measuring body housing 11b. The second kidney-shaped housing cavity 110b has at least one second undercut 110bbb shown in dot-dash lines inside. Another second kidney-shaped housing cavity 110b' is bounded by another second edge 110bb' toward the outside of the second measuring body housing 11b. Another second kidney-shaped housing cavity 110b' has at least one other second undercut 110bbb' shown in dot-dash lines inside. In the following, the second undercut 110bbb and another second undercut 110bbb' are also referred to as second undercuts 110bbb, 110bbb'. The weight and weight distribution of the second measuring body partial housing 11 b are adjusted by the size and shape of the second undercuts 110 bbb , 110 bbb ′ in such a way that the main axis of inertia X of the measuring body 1 , 1 ′ lies on the longitudinal axis A in the fastened state.

[0103] By balancing, the two measuring body parts 1a, 1b are matched to one another in terms of weight and weight distribution. The two balanced measuring body parts 1a, 1b have the same weight and the same weight distribution.

[0104] According to standard DIN ISO 1940-1, the balancing accuracy is indicated by the balancing quality. Preferably, the balancing quality of the measuring body 1 , 1 ′ is less than / equal to 10, preferably less than / equal to 5.

[0105] By means of this balancing, the disturbance torques caused by static and dynamic imbalances are minimized, thereby increasing the measurement accuracy. Furthermore, the minimization of the disturbance torques achieved by balancing also represents a standardization of the measurement signal. In this way, the measurement signals obtained by measuring bodies 1, 1' with different cavity diameters D10, D10' can be compared, since for all these measuring bodies 1, 1' the center of gravity S of the measuring body 1, 1' lies on the longitudinal axis A and the main inertia axis X of the measuring body 1, 1' also lies on the longitudinal axis A.

[0106] Preferably, the first housing cavities 110a, 110a' in the first measuring body partial housing 11a are manufactured by an additive process, because only in this way can the first undercuts 110aaa, 110aaa' with the best balancing quality be manufactured. Preferably, the second housing cavities 110b, 110b' in the second measuring body partial housing 11b are also manufactured by an additive process, because only in this way can the second undercuts 110bbb, 110bbb' with the best balancing quality be manufactured.

[0107] The measuring unit 12 has a carrier unit 121 , a strain gauge 122 and an electrical contact element 123 .

[0108] The carrying unit 121 is a hollow cylindrical shape. Figure 4 View and basis Figure 5 In the exploded view of FIG. 1 , the carrying unit 121 is multi-piece. Preferably, the carrying unit 121 is divided into two carrying elements 121a, 121b along a plane located on the longitudinal axis A, and the two carrying elements 121a, 121b have the form of congruent halves of a hollow cylinder. The two carrying elements 121a, 121b are made of a mechanically resistant material, such as metal, plastic, etc.

[0109] The two support elements 121a, 121c have plug-in elements 121c, such as snap hooks, etc. The plug-in elements 121c are attached to the two support elements 121a, 121b at the end. For this purpose, the plug-in elements 121c are configured to be releasably connected to each other by form fit.

[0110] The bearing unit 121 is configured to bear the strain gauge 122 and the contact element 123. The bearing unit 121 bears the strain gauge 122 on an inner shroud surface radially facing the shafts W, W'.

[0111] The strain gauge 122 is designed to generate a measurement signal MS under the action of the torque M. The strain gauge 122 can be a full bridge, a half bridge or a quarter bridge. Preferably, the strain gauge 122 generates a measurement signal MS with a bandwidth of 5 kHz. The measurement signal MS is a voltage. The strain gauge 122 is electrically connected to the electrical contact element 123 via an electrical conductor. The electrical conductor conducts the measurement signal MS to the electrical contact element 123.

[0112] The electrical contact element 123 is designed to transmit the measurement signal MS via the carrier element 121 to an outer jacket surface facing radially away from the axis W, W′.

[0113] In accordance with Figure 4 The view of FIG. 1 shows the measuring body 1, 1' in the unfolded state. Figure 2 and Figure 3 The diagram of FIG. 1 shows the measuring bodies 1 and 1' in the closed state. When the measuring bodies 1 and 1' are in the closed state, the electrical contact element 123 and the measuring amplifier unit 13 are configured to be electrically connected to each other via electrical contacts. The electrical contacts transmit the measuring signal MS to the measuring amplifier unit 13.

[0114] The measuring amplifier unit 13 has an amplifier circuit 131 including an operational amplifier. The amplifier circuit 131 is designed to amplify the measuring signal MS. The amplified measuring signal MS is also a voltage. The amplifier circuit 131 is connected to the measuring signal MS via 10 1 , 10 2 , 10 3 , 10 4 The measuring amplifier unit 13 is electrically connected to the telemetry unit 14 via an electrical conductor. The electrical conductor transmits the amplified measuring signal MS to the telemetry unit 14. The electrical conductor also transmits control data SD to the measuring amplifier unit 13.

[0115] The telemetry unit 14 has a telemetry circuit 141 and a rotor antenna 142 .

[0116] The telemetry circuit 141 has an analog / digital converter and is designed to digitize the amplified measurement signal MS into measurement data MD. The measurement data MD is a binary digital sequence with a resolution of preferably 16 bits.

[0117] The rotor antenna 142 is designed to wirelessly transmit the measurement data MD to the evaluation unit 2. For this purpose, the evaluation unit 2 has a stator antenna 20. The stator antenna 20 is designed 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 can send control data SD to the rotor antenna 142, and the rotor antenna 142 can receive the control data SD sent from the stator antenna 20. In this wireless transmission, the measurement data MD and the control data SD are sent and received in the form of electromagnetic waves. Preferably, the rotor antenna 142 and the stator antenna 20 wirelessly transmit the measurement data MD and the control data SD in the Industrial Scientific and Medical (ISM) frequency band of 2.402 GHz to 2.480 GHz. The wireless transmission of the measurement data MD and the control data SD is carried out at Figure 1 It is drawn as a curved circular line segment.

[0118] The stator antenna 20 is electrically connected to the evaluation unit 2 via an electrical data line 21. The electrical data line 21 transmits measurement data MD to the evaluation unit 2 and control data SD to the stator antenna 20.

[0119] The energy storage unit 15 has 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, a zinc-air battery, etc. The energy storage unit 15 is designed to provide electrical energy to the measuring body 1, 1' for a continuous working time of at least 40 hours. The energy storage unit 15 is small in size and light in weight. Figure 5 In the exploded view of , the energy storage unit 15 has four lithium-ion batteries as reservoirs, each battery having a capacity of 715 mAh, a weight of 20 g, and external dimensions of 49 mm in length and 14 mm in diameter.

[0120] The energy storage unit 15 has an energy supply element 151. When the measuring bodies 1, 1' are in the closed state, the energy supply element 151, the measuring amplifier unit 13 and the telemetry unit 14 are designed to be electrically connected to each other via electrical contacts. Electrical energy is supplied from the energy storage unit 15 in the second measuring body partial housing 11b to the measuring amplifier unit 13 and the telemetry unit 14 in the first measuring body partial housing 11a via these electrical contacts.

[0121] The energy storage unit 15 also has a power supply interface 152. The power supply interface 152 is a plug connector, such as USB-C. Figure 4 View and basis Figure 5In the exploded view, the power supply interface 152 is arranged in the first measuring body partial enclosed portion 11aa. The power supply interface 152 is electrically connected to the measuring amplifier unit 13 in the first measuring body partial housing 11a. Therefore, when the measuring bodies 1, 1' are in the closed state, the power supply interface 152 is electrically connected to the energy supply element 151 and the energy storage unit 15 in the second measuring body partial housing 11b via the measuring amplifier unit 13. The energy storage unit 15 can be charged by connecting an external power source to the power supply interface 152 via a cable. Charging the measuring bodies 1, 1' fastened to the shafts W, W' is simple and quick. It is not necessary to remove the measuring bodies 1, 1' from the shafts W, W' for this purpose. The empty energy storage unit 15 can be charged to at least 80% in a charging time of less than 30 minutes.

[0122] In addition, the energy storage unit 15 of the measuring body 1, 1' fastened to the shaft W, W' can be easily and quickly replaced. There is no need to remove the measuring body 1, 1' from the shaft W, W' for this purpose. By opening the partial closure 11bb of the second measuring body, the second shell cavity 110b, 110b' can be entered from the outside of the measuring body 1, 1'. Now, the energy storage unit 15 can be removed from the second shell cavity 110b, 110b'. For the removed energy storage unit 15, a new energy storage unit 15' can be inserted into the second shell cavity 110b, 110b'. Therefore, when according to Figure 5 When the four lithium-ion batteries shown as storage devices in the exploded view of the embodiment are empty, they can be replaced with charged lithium-ion batteries. Then, the second housing cavities 110b, 110b' are sealed with the second measuring body partial sealing portion 11bb. Replacing the energy storage unit 15 can be completed in less than 5 minutes.

[0123] The evaluation unit 2 has at least one data memory 22 , at least one data processor 23 , at least one input / receive unit 24 and at least one output unit 25 .

[0124] The evaluation unit 2 is designed to evaluate the measurement data MD and to generate control data SD for actuating the measuring body 1 , 1 ′.

[0125] In the evaluation unit 2, an evaluation program P is stored in a data memory 22 and can be loaded into a data processor 23. The evaluation program P loaded into the data processor 23 generates instructions, which are automatically executed by the evaluation unit 2. The adjective "automatically" in the sense of the present invention has the meaning that the instructions generated by the evaluation program P are executed by the evaluation unit 2 without human intervention.

[0126] The evaluation unit 2 can be operated via the input / receiving unit 24. The verb "operate" in the sense of the present invention means that a person can issue instructions via the input / receiving unit 24, and these instructions are executed by the evaluation unit 2. The input / receiving unit 24 can be a keyboard for inputting instructions, an antenna for receiving instructions, etc. Instructions are input via the keyboard in the form of a character string, and the evaluation unit 2 generates control data SD based on them. Instructions are received via the antenna as electromagnetic waves, and the evaluation unit 2 generates control data SD based on them.

[0127] The evaluation unit 2 thus generates control data SD for controlling the measuring body 1 , 1 ′ according to the instructions of the evaluation program P or according to the instructions of the input / receiving unit 24 . The control data SD execute various instructions.

[0128] The measuring body 1, 1' can thus be started or stopped by the control data SD. For this purpose, the evaluation unit 2 generates control data SD with information for starting or stopping the measuring body 1, 1' and transmits it to the measuring amplifier unit 13. The measuring amplifier unit 13 starts or stops the measuring body 1, 1' as a function of the control data SD.

[0129] The control data SD can also be used to set the zero point of the amplifier circuit 131. The zero point may drift over time and under the influence of external factors such as temperature. Therefore, in order to achieve high measurement accuracy, the zero point must be adjusted. The zero point should not differ from the actual zero point by more than 10% (upper and lower limits). If the zero point is not within these limits, the evaluation program P will determine a new zero point within the limits. Alternatively, the input / receiving unit 24 gives an instruction to set a new zero point. Therefore, the evaluation unit 2 generates control data SD indicating the new zero point and transmits the control data SD to the measuring amplifier unit 13. The amplifier circuit 131 then uses the new zero point according to the control data SD.

[0130] The control data SD can also be used to adjust the amplification factor of the amplifier circuit 131. Each amplified measurement signal MS can be displayed to a maximum value or a final value (full scale). In order to represent it as well as possible, the amplified measurement signal MS should not exceed the final value (upper limit value) and should not be more than one order of magnitude smaller than the final value (lower limit value). If the amplified measurement signal MS is not within these limits, the evaluation program P determines another amplification factor for the amplified measurement signal MS so that it is within the limits. Alternatively, the input / receiving unit 24 gives an instruction to set the other amplification factor. Therefore, the evaluation unit 2 generates control data SD indicating the amplification factor and transmits the control data SD to the measuring amplifier unit 13. The amplifier circuit 131 amplifies the measurement signal MS according to the control data SD.

[0131] Optionally, the device V has a rotation angle sensor 30. The rotation angle sensor 30 may be an optical sensor, a magnetic sensor, etc., which detects the rotation angle α of the shaft W, W' in a non-contact 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 via an electrical signal line 31. The electrical signal line 31 transmits the rotation angle signal WS to the evaluation unit 2.

[0132] The evaluation unit 2 is designed to evaluate the rotation angle signal WS. From the rotation angle signal WS, an evaluation program P loaded into the data processor 23 forms information about the rotation direction of the shafts W, W′ and the angular position of the shafts W, W′.

[0133] The measuring bodies 1 , 1 ′ are fastened to the shafts W, W′ in three steps.

[0134] In a first step, the two support elements 121 a , 121 b are placed on the shafts W, W′ and connected to one another via the plug-in element 121 .

[0135] In a second step, the two measuring body part housings 11 a , 11 b are placed in the folded-open state on the carrying unit 121 .

[0136] In a third step, the two measuring body part housings 11a, 11b are connected to one another via the connecting unit 112 by pivoting about the longitudinal axis A. In the closed state of the measuring bodies 1, 1', the electrical contact element 123 and the measuring amplifier unit 13 are electrically connected to one another via the electrical contacts. In the closed state of the measuring bodies 1, 1', the energy supply element 151, the measuring amplifier unit 13 and the telemetry unit 14 are electrically connected to one another via the electrical contacts, and the measuring amplifier unit 13 and the telemetry unit 14 in the first measuring body part housing 11a are powered by the energy storage unit 15 in the second measuring body part housing 11b.

Claims

1. A device (V) for measuring a torque (M) of a rotating shaft (W, W'); wherein the device (V) comprises a measuring body (1, 1') and an evaluation unit (2); the measuring body (1, 1') can be fastened to the shaft (W, W') and rotate together with the shaft (W, W') around the longitudinal axis (A) of the shaft (W, W') in a fastened state; the measuring body (1, 1') comprises a measuring unit (12), a measuring amplifier unit (13) and a telemetry unit (14); the measuring unit (12) generates a measuring signal (MS) under the action of the torque (M) in a fastened state; the measuring amplifier unit (13) amplifies the measuring signal (MS); the telemetry unit (14) digitizes the amplified measuring signal (MS) and transmits it wirelessly to the evaluation unit (2); characterised in that The measuring body (1, 1') has a main axis of inertia (X) which, in the fixed state, lies on the longitudinal axis (A).

2. The device (V) according to claim 1, characterized in that The measuring body (1, 1') has a measuring body housing (11), which is multi-part and has a first measuring body partial housing (11a), which contains a first housing cavity (110a, 110a'); and the first housing cavity (110a, 110a') accommodates the measuring amplifier unit (13) and the telemetry unit (14).

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

4. The device (V) according to claim 3, characterized in that The measuring body housing (11) has a second measuring body partial closing portion (11bb), which closes a second housing cavity (110b) with the energy storage unit (15); the second measuring body partial closing portion (11bb) can be opened in a tightened state, and the second housing cavity (110b, 110b') with the energy storage unit (15) can be entered from the outside of the measuring body (1, 1'); the energy storage unit (15) can be taken out of the second housing cavity (110b, 110b'), and a new energy storage unit (15') can be inserted into the second housing cavity (110b, 110b'); and the second housing cavity (110b, 110b') with the new energy storage unit (15') can be closed by the second measuring body partial closing portion (11bb).

5. The device (V) according to claim 3 or 4, characterized in that The first shell cavity (110a, 110a') has at least one first undercut (110aaa, 110aaa'); the weight and weight distribution of the first measuring body partial shell (11a) are adjusted by the size and shape of the first undercut (110aaa, 110aaa'), so that the main inertia axis (X) of the measuring body (1, 1') is located on the longitudinal axis (A) in a tightened state; the second shell cavity (110b, 110b') has at least one second undercut (110bbb, 110bbbb'); the weight and weight distribution of the second measuring body partial shell (11b) are adjusted by the size and shape of the second undercut (110bbb, 111bbb'), so that the main inertia axis (X) of the measuring body (1, 1') is located on the longitudinal axis (A) in a tightened state.

6. The device (V) according to any one of claims 3 to 5, characterized in that The two measuring body part housings (11a, 11b) have the form of congruent halves of a hollow cylinder.

7. The device (V) according to any one of claims 3 to 6, characterized in that The two measuring body part housings (11a, 11b) are manufactured using an additive process.

8. The device (V) according to any one of claims 1 to 7, characterized in that The measuring body (1, 1') is hollow cylindrical and has an axial cavity (10, 10'); the axial cavity (10, 10') has a cavity diameter (D1, D1'), the cavity diameter (D1, D1') is equal to the shaft diameter (DW, DW') of the shaft (W, W'), and the measuring body (1, 1') can be fastened on the shaft; and for shafts (W, W') with different shaft diameters (DW, DW'), the device (V) has a plurality of measuring bodies (1, 1') with cavity diameters (D1, D1'), the cavity diameters (D1, D1') are equal to the different shaft diameters (DW, DW') of the shaft (W, W').

9. The device (V) according to any one of claims 1 to 8, characterized in that The measuring unit (12) has a bearing unit (121) and a strain gauge (122); the bearing unit (121) bears the strain gauge (122) on an inner shield surface radially facing the shaft (W, W'); and the strain gauge (122) is designed to generate a measurement signal (MS) under the action of the torque (M).

10. The device (V) according to claim 9, characterized in that The bearing unit (121) is multi-piece and has a first bearing element (121a) and a second bearing element (121b); and the two bearing elements (121a, 121b) have the form of congruent halves of a hollow cylinder.

11. The device (V) according to claim 10, characterized in that The two supporting elements (121a, 121b) have plug-in elements (121c); and the plug-in elements (121c) are configured to form a releasable connection with each other through a form fit.

12. A method for measuring a torque (M) of a rotating shaft (W, W'), using a device (V) having a measuring body (1, 1') and an evaluation unit (2); the measuring body (1, 1') having a measuring unit (12), a measuring amplifier unit (13) and a telemetry unit (14); wherein the measuring body (1, 1') is fastened to the shaft (W, W'); wherein the shaft (W, W') is arranged to rotate about a longitudinal axis (A) of the shaft (W, W') and to transmit the torque (M); wherein the measuring unit (12) generates a measurement signal (MS) under the effect of the torque (M); wherein the measuring amplifier unit (13) amplifies the measurement signal (MS); and wherein the telemetry unit (14) digitizes the amplified measurement signal (MS) and transmits it wirelessly to the evaluation unit (2); characterised in that A measuring body (1, 1') is provided, which has a main axis of inertia (X) which lies on the longitudinal axis (A) in the fastened state.

13. The method according to claim 12, characterized in that A measuring unit (12) is provided, the measuring unit (12) having a bearing unit (121) and a strain gauge (122), the bearing unit (121) being multi-piece and having a first bearing element (121a) and a second bearing element (121b), the two bearing elements (121a, 121b) having a plug-in element (121c); and in a first step of fastening the measuring body (1, 1') to the shaft (W, W'), the two bearing elements (121a, 121b) are placed on the shaft (W, W') and connected to each other via the plug-in element (121).

14. The method according to claim 13, characterized in that A measuring body (1, 1') is provided, wherein the measuring body (1, 1') has a measuring body shell (11), the measuring body shell (11) is multi-piece and has a first measuring body partial shell (11a) and a second measuring body partial shell (11b), the two measuring body partial shells (11a, 11b) have a joint unit (111), and the joint unit (111) is constructed so that the two measuring body partial shells (11a, 11b) can be pivotally held together around the longitudinal axis (A); and in a second step of fastening the measuring body (1, 1') to the shaft (W, W'), the two measuring body partial shells (11a, 11b) are placed on the carrying unit (121) in an unfolded state.

15. The method according to claim 14, characterized in that Two measuring body part housings (11a, 11b) are provided, wherein the two measuring body part housings (11a, 11b) have a connecting unit (112), and the connecting unit (112) is configured to enable the two measuring body part housings (11a, 11b) to be releasably closed to each other; And in a third step of fastening the measuring body (1, 1') to the shaft (W, W'), the two measuring body part shells (11a, 11b) are connected to each other by pivoting around the longitudinal axis (A) via the connecting unit (112).

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