Dynamic torque tester

Abstract

A dynamic torque tester relates to the technical field of torque testing structures and comprises a fixedly arranged stator coil, a main shaft rotatably arranged in the stator coil, a strain gauge fixedly connected to the main shaft, a rotor coil matched with the stator coil and electrically connected with the strain gauge, one end of the main shaft is a driven load end, and the other end of the main shaft is a driven load end. The other end of the spindle is a driving motor end. The torque sensor solves the problems that the torque sensor in the prior art adopts a slip ring to realize electric connection from a shell to a rotating shaft, the slip ring bears millivolt signals from a strain gauge, the slip ring is in contact with the shaft, abrasion exists, the service life is short, the torque sensor cannot be used for a long time, and the rotating speed is not easy to be too high.

Description

Technical Field

[0001] The utility model relates to the technical field of torque testing structures, in particular to a dynamic torque tester. Background Art

[0002] Torque is an important parameter of rotating machinery. If the torque value of the mechanical parts to be tested can be measured accurately and conveniently, it will be very beneficial for further improving and enhancing the performance of the mechanical parts.

[0003] Regarding torque measurement, the traditional method is to cut the shaft and then connect the two cut shafts together using a torque sensor through a coupling or flange. This method is reliable, but at the work site, there is often insufficient space to install the torque sensor, and it is not allowed to remove and cut the shaft of the entire machine.

[0004] The prior art discloses a patent with the publication number CN108955972A. This solution includes the following steps: (1) installing a dynamic torque test device on the shaft to be tested; (2) starting the dynamic torque test device on the shaft to be tested. When the shaft to be tested is operating normally, the resistance strain gauge attached to it deforms, causing the resistance of the strain gauge to change, thereby causing the voltage of the entire equal-arm full-bridge circuit to change. The circuit voltage change signal is transmitted to the torque acquisition module via a wire, and then converted to a corresponding torque signal. The method of the present invention does not require the shaft to be cut off when measuring the shaft torque, and no wire entanglement occurs during normal measurement. The method of attaching resistance strain gauges to measure torque has a simple measurement principle and low production cost.

[0005] As the existing devices are used, the shortcomings of the existing technology are gradually exposed, which are mainly manifested in the following aspects:

[0006] Traditional torque sensors all use slip rings to achieve electrical connection from the housing to the rotating shaft. The slip rings carry the millivolt signal from the strain gauge. Because the slip rings are in contact with the shaft, they wear out, resulting in a short lifespan and cannot be used for long periods of time. In addition, the rotational speed cannot be too high.

[0007] In summary, the existing technology has obvious inconveniences and defects in actual use, so it is necessary to improve it. Utility Model Content

[0008] In response to the defects in the existing technology, the utility model provides a dynamic torque tester to solve the problems that torque sensors in traditional technology all use slip rings to achieve electrical connection from the housing to the rotating shaft. The slip rings carry the millivolt signal from the strain gauge. Because the slip rings are in contact with the shaft, they wear out, resulting in a short lifespan and cannot be used for a long time. In addition, the rotation speed is not easy to be too high.

[0009] To achieve the above objectives, the present invention provides the following technical solutions:

[0010] The dynamic torque tester includes a fixed stator coil, a main shaft is rotatably provided inside the stator coil, a strain gauge is fixedly connected to the main shaft, and a rotor coil that cooperates with the stator coil is also connected to the main shaft. The strain gauge is electrically connected to the rotor coil. One end of the main shaft is the driven load end, and the other end of the main shaft is the active motor end.

[0011] As an optimized solution, mounting grooves are respectively provided on opposite side walls of the main shaft, and a plurality of strain gauges are arranged in parallel and fixed in the mounting grooves.

[0012] As an optimized solution, the main shaft is an elastic shaft.

[0013] As an optimized solution, a rotor bracket is fixed on the outer wall of the main shaft, and the rotor coil is fixed on the rotor bracket.

[0014] As an optimized solution, the stator coil is fixed on the stator bracket.

[0015] As an optimized solution, the strain gauge is connected to the rotor coil via a wire.

[0016] As an optimized solution, a support bearing is connected to the main shaft.

[0017] As an optimized solution, the support bearing is close to the driven load end.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] Provided is an improved torque sensor that uses contactless electrical signal transmission to avoid contact with the shaft, resulting in no friction, no sensor loss, long-term use, and support for signal output under high-speed rotation;

[0020] Strain gauges are usually attached to elastic shafts. When the elastic shaft is subjected to torque, the shaft will undergo a slight torsional deformation, causing the strain gauge to also produce strain, and its shape and size will change.

[0021] Multiple strain gauges form a Wheatstone bridge circuit. When there is no torque, the bridge is in a balanced state and the output voltage is zero. When torque is applied, causing the strain gauge resistance to change, the balance of the bridge is broken, generating a stable output voltage signal that is proportional to the torque. The weak voltage signal output by the bridge is amplified and output to the electromagnetic induction coil to generate a certain magnetic field. When the shaft rotates, the magnetic field is cut through the outer coil, and the outer coil generates a certain voltage, which in turn generates a certain inductance. The electrical signal corresponding to the change in inductance is amplified, shaped, digitized, and other processing to ultimately obtain an output signal corresponding to the torque.

[0022] Through a series of signal processing such as analog-to-digital conversion, it is converted into a digital signal to facilitate subsequent data collection, analysis and processing. The change in torque can cause the internal coil to generate different magnetic flux, and the change in magnetic flux will cause the outer ring induction coil to generate different electrical signals. Through decoding and algorithm processing, data transmission is achieved;

[0023] The contactless electrical signal transmission technology adopted effectively increases the service life of the sensor. The use of wireless transmission also effectively eliminates the phenomenon of unstable electrical signal output caused by mechanical wear.

[0024] The contactless electrical signal transmission technology adopted by this patent effectively improves the accuracy and stability of electrical signal output;

[0025] Electromagnetic induction output signal, no contact friction between the shaft and the housing, so that the torque output loss is reduced and closer to the actual value. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly describes the drawings required for the specific embodiments or the description of the prior art. Similar elements or parts are generally identified by similar reference numerals throughout the drawings. Elements or parts in the drawings are not necessarily drawn to scale.

[0027] Figure 1 It is a structural diagram of the present utility model.

[0028] In the figure: 1- stator coil; 2- main shaft; 3- rotor coil; 4- strain gauge; 5- stator bracket; 6- rotor bracket; 7- wire; 8- transmission wire; 9- mounting slot; 10- support bearing; 11- driven load end; 12- active motor end. DETAILED DESCRIPTION

[0029] The following embodiments of the technical solution of the present invention are described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention and are therefore only examples and are not intended to limit the scope of protection of the present invention.

[0030] like Figure 1 As shown, the dynamic torque tester includes a fixed stator coil 1, a main shaft 2 is provided for rotation inside the stator coil 1, a strain gauge 4 is fixedly connected to the main shaft 2, and a rotor coil 3 that matches the stator coil 1 is also connected to the main shaft 2. The strain gauge 4 is electrically connected to the rotor coil 3. One end of the main shaft 2 is a driven load end 11, and the other end of the main shaft 2 is an active motor end 12.

[0031] Mounting grooves 9 are respectively formed on opposite side walls of the main shaft 2 , and a plurality of strain gauges 4 are arranged in parallel and fixed in the mounting grooves 9 .

[0032] The main shaft 2 is an elastic shaft.

[0033] A rotor bracket 6 is fixed on the outer wall of the main shaft 2 , and the rotor coil 3 is fixed on the rotor bracket 6 .

[0034] The stator coil 1 is fixed on the stator bracket 5 , and the stator bracket 5 is fixed on the housing or other fixing frames.

[0035] The strain gauge 4 is connected to the rotor coil 3 via a wire 7 .

[0036] A support bearing 10 is connected to the main shaft 2 .

[0037] The support bearing 10 is located close to the driven load end 11 .

[0038] The stator coil 1 is connected to the processor via a transmission wire 8 .

[0039] Provided is an improved torque sensor that uses contactless electrical signal transmission to avoid contact with the shaft, resulting in no friction, no sensor loss, long-term use, and support for signal output under high-speed rotation;

[0040] The strain gauge 4 is usually attached to an elastic shaft. When the elastic shaft is subjected to torque, the shaft will undergo a slight torsional deformation, causing the strain gauge 4 to also produce strain, and its shape and size will change.

[0041] Multiple strain gauges 4 form a Wheatstone bridge circuit. When there is no torque, the bridge is in a balanced state and the output voltage is zero. When torque is applied, causing the resistance of the strain gauge 4 to change, the balance of the bridge is broken, generating a stable output voltage signal that is proportional to the torque. The weak voltage signal output by the bridge is amplified and output to the electromagnetic induction coil to generate a certain magnetic field. When the shaft rotates, the magnetic field is cut through the outer coil, and the outer coil generates a certain voltage, which in turn generates a certain inductance. The electrical signal corresponding to the change in inductance is amplified, shaped, digitized, and other processing to ultimately obtain an output signal corresponding to the torque magnitude.

[0042] Through a series of signal processing such as analog-to-digital conversion, it is converted into a digital signal to facilitate subsequent data collection, analysis and processing. The change in torque can cause the internal coil to generate different magnetic flux, and the change in magnetic flux will cause the outer ring induction coil to generate different electrical signals. Through decoding and algorithm processing, data transmission is achieved;

[0043] The contactless electrical signal transmission technology adopted effectively increases the service life of the sensor. The use of wireless transmission also effectively eliminates the phenomenon of unstable electrical signal output caused by mechanical wear.

[0044] The contactless electrical signal transmission technology adopted by this patent effectively improves the accuracy and stability of electrical signal output;

[0045] Electromagnetic induction output signal, no contact friction between the shaft and the housing, so that the torque output loss is reduced and closer to the actual value.

[0046] The working principle of this device is:

[0047] One end of the main shaft 2 is connected to the active motor and the other end is connected to the driven load. When the motor applies torque, the shaft will undergo a slight torsional deformation, causing the strain gauge 4 to also generate strain. A trace voltage is output through the bridge circuit, and the voltage is amplified to the required level through the algorithm and amplifier. The voltage is applied to the rotor coil 3 to generate an electromagnetic field. As the main shaft 2 rotates, the stator coil 1 will cut the magnetic field and then generate a corresponding voltage output. The voltage output by the stator coil 1 is analyzed and converted into a corresponding torque value output to achieve torque measurement.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.

Claims

1. Dynamic torque tester, characterized by: The invention comprises a fixedly arranged stator coil (1), a main shaft (2) rotatably provided inside the stator coil (1), a strain gauge (4) fixedly connected to the main shaft (2), a rotor coil (3) matched with the stator coil (1) further connected to the main shaft (2), the strain gauge (4) being electrically connected to the rotor coil (3), one end of the main shaft (2) being a driven load end (11), and the other end of the main shaft (2) being an active motor end (12).

2. The dynamic torque tester according to claim 1, characterized in that: Mounting grooves (9) are respectively provided on opposite side walls of the main shaft (2), and a plurality of strain gauges (4) are arranged in parallel and fixed in the mounting grooves (9).

3. The dynamic torque tester according to claim 1, characterized in that: The main shaft (2) is an elastic shaft.

4. The dynamic torque tester according to claim 1, characterized in that: A rotor bracket (6) is fixed on the outer wall of the main shaft (2), and the rotor coil (3) is fixed on the rotor bracket (6).

5. The dynamic torque tester according to claim 1, characterized in that: The stator coil (1) is fixed on the stator bracket (5).

6. The dynamic torque tester according to claim 1, characterized in that: The strain gauge (4) is connected to the rotor coil (3) via a wire (7).

7. The dynamic torque tester according to claim 1, characterized in that: A support bearing (10) is connected to the main shaft (2).

8. The dynamic torque tester according to claim 7, characterized in that: The support bearing (10) is close to the driven load end (11).

9. The dynamic torque tester according to claim 1, characterized in that: The stator coil (1) is connected to the processor via a transmission wire (8).

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