Torque sensor of harmonic reducer

Abstract

The utility model discloses a harmonic reducer torque sensor, which comprises an elastic body, a double shear strain gauge, a signal amplification circuit board and a cable assembly, and is characterized in that the elastic body comprises a substrate, a first elastic body part, a second elastic body part and a third elastic body part which are integrally arranged, and the second elastic body part is uniformly provided with a plurality of shear beam arms along the circumferential direction; the double-shear strain gauge is arranged on the upper surface and / or the lower surface of the shear beam arm, an annular flange groove is formed between the second elastic body part and the third elastic body part, and the signal amplification circuit board is installed in the annular flange groove. The design of uniformly distributed shear beam arms is adopted, a flat symmetrical structure is adopted, the stress is uniform, the bending moment influence under torsion can be reduced, and the torsional rigidity is superior to that of a common bent beam structure. The strain gauges are pasted on the upper surface and the lower surface of the annular arm, so that better precision and compensation can be obtained through the bridging mode compared with the mode of pasting the strain gauges on one side.

Description

A torque sensor for a harmonic reducer Technical Field

[0001] This utility model belongs to the field of torque sensor manufacturing technology, specifically relating to a torque sensor for a harmonic reducer. Background Technology

[0002] Currently, mainstream torque sensors employ strain gauge technology. Strain gauges are mounted on the elastic beam arm to form a Wheatstone bridge. When the elastic arm is subjected to torque and undergoes slight deformation, it causes a change in the bridge resistance. This change in resistance is converted into a change in electrical signal (such as voltage or current), thus achieving torque measurement. This measurement technology offers high sensitivity and accuracy, uses small strain gauges, and is unaffected by the state and stress distribution of the measured object. It is suitable for various complex environments and allows for multi-point measurements. However, the measurement range of torque sensors is constrained by the size of the elastic body. Small-sized elastic bodies may undergo permanent deformation and fail when measuring large torques, while large-sized elastic bodies have low sensitivity and lead to large measurement errors when measuring small torques. This necessitates a wide variety of sensor specifications and increasingly complex structures.

[0003] Therefore, a torque sensor for harmonic reducers with high torsional rigidity is urgently needed. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this utility model provides a torque sensor for harmonic reducers.

[0005] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0006] This utility model provides a torque sensor for a harmonic reducer, including an elastomer, a dual shear strain gauge, a signal amplification circuit board, and a cable assembly. The elastomer includes an integrally formed base, a first elastomer portion, a second elastomer portion, and a third elastomer portion. The base has an annular structure. The first, second, and third elastomer portions are sequentially arranged on the base from the outside to the inside along the diameter direction of the base. The second elastomer portion has a plurality of shear beam arms evenly arranged along its circumference. The dual shear strain gauge is disposed on the upper surface and / or lower surface of the shear beam arm. An annular flange groove is provided between the second and third elastomer portions. The signal amplification circuit board is installed in the annular flange groove. The output end of the dual shear strain gauge is electrically connected to the input end of the signal amplification circuit board, and the output end of the signal amplification circuit board is electrically connected to the input end of the cable assembly.

[0007] Preferably, the elastomer is made of stainless steel.

[0008] Preferably, a gap is provided between the first elastic body portion and the second elastic body portion, a plurality of first mounting holes are uniformly provided on the first elastic body portion along its circumferential direction, and a plurality of second mounting holes are uniformly provided on the second elastic body portion along its circumferential direction, with the first mounting holes and the second mounting holes being staggered.

[0009] Preferably, the shear beam arm is located between any two adjacent first mounting holes and second mounting holes.

[0010] Preferably, the signal amplification circuit board has a ring-shaped structure.

[0011] Preferably, the dual shear strain gauge and the signal amplification circuit board are covered with silicone.

[0012] Compared with the prior art, this utility model has the following advantages:

[0013] This invention employs a uniformly distributed shear beam arm design with a flat, symmetrical structure, resulting in uniform stress distribution and reduced bending moment impact under torsional loads. Its torsional rigidity is superior to ordinary bending beam structures. Strain gauges are attached to both the upper and lower surfaces of the ring arm; this bridging method provides better accuracy and compensation than attaching strain gauges to only one side. This invention eliminates the need for a junction box; the signal amplifier is located inside the elastic body, resulting in a more compact structure and smaller overall size, making it more suitable for high-torque measurement in thin mechanisms such as harmonic reducers. Attached Figure Description

[0014] Figure 1 is a three-dimensional structural schematic diagram of a torque sensor for a harmonic reducer according to this utility model;

[0015] Figure 2 is an exploded view of a torque sensor for a harmonic reducer according to this utility model;

[0016] Figure 3 is a schematic diagram of the structure of the elastic body in the torque sensor of a harmonic reducer according to this utility model;

[0017] Figure 4 is a cross-sectional view along line AA in Figure 3 of this utility model. Detailed Implementation

[0018] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0019] In the description of this utility model, it should be understood that the terms "left" and "right" and other terms indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0020] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0021] As shown in Figures 1 to 4, this embodiment provides a torque sensor for a harmonic reducer, including an elastomer 1, a dual shear strain gauge 2, a signal amplification circuit board 3, and a cable assembly 4.

[0022] In this embodiment, the substrate has a ring-shaped structure, and the elastomer 1 is made of stainless steel. The elastomer 1 includes an integrally formed substrate, a first elastomer portion 11, a second elastomer portion 12, and a third elastomer portion 13. The first elastomer portion 11, the second elastomer portion 12, and the third elastomer portion 13 are sequentially arranged on the substrate from the outside to the inside along the diameter direction of the substrate. The second elastomer portion 12 is uniformly provided with 12 shear beam arms 122 along its circumference. The dual shear strain gauge 2 is disposed on the upper and lower surfaces of the shear beam arms 122. There is a gap between the first elastomer portion 11 and the second elastomer portion 12. The first elastomer portion 11 is uniformly provided with 12 first mounting holes 111 along its circumference, and the second elastomer portion 12 is uniformly provided with 12 second mounting holes 121 along its circumference. The first mounting holes 111 and the second mounting holes 121 are staggered. The shear beam arm 122 is located between any two adjacent first mounting holes 111 and second mounting holes 121.

[0023] The elastomer is constructed as a thin flange structure, connected to the flexure wheel via a thin flange. This design results in a small overall thickness, light weight, and minimal impact on the flexure wheel's operation. Half-bridge strain gauges are attached to both the upper and lower surfaces of the shear beam arm. The symmetrical structure of the elastic beam arm ensures uniform torque variation, thereby guaranteeing linear output of torque measurement results. The strain gauges on the shear beam arm can achieve various bridge circuit combinations, enabling multi-channel output.

[0024] In this embodiment, an annular flange groove 14 is provided between the second elastomer part 12 and the third elastomer part 13. The signal amplification circuit board 3 has a ring structure and is installed in the annular flange groove 14. The output end of the dual shear strain gauge 2 is electrically connected to the input end of the signal amplification circuit board 3, and the output end of the signal amplification circuit board 3 is electrically connected to the input end of the cable assembly 4.

[0025] The ring-shaped signal amplification circuit board is placed in the inner flange ring groove, which can save space for the elastomer. The circuit board can identify the weak resistance changes of the bridge, amplify the signal, enhance the signal output, and realize the measurement of small torque.

[0026] In this embodiment, the dual shear strain gauge 2 and the signal amplification circuit board 3 are covered with silicone, which can achieve a high level of protection.

[0027] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A torque sensor for a harmonic reducer, characterized in that, The system includes an elastomer (1), a dual shear strain gauge (2), a signal amplification circuit board (3), and a cable assembly (4). The elastomer (1) includes an integrally formed substrate, a first elastomer part (11), a second elastomer part (12), and a third elastomer part (13). The substrate has a ring-shaped structure. The first elastomer part (11), the second elastomer part (12), and the third elastomer part (13) are arranged sequentially from the outside to the inside along the diameter direction of the substrate. The second elastomer part (12) is uniformly provided along its circumference. Multiple shear beam arms (122), the dual shear strain gauge (2) is disposed on the upper surface and / or lower surface of the shear beam arm (122), an annular flange groove (14) is provided between the second elastomer part (12) and the third elastomer part (13), the signal amplification circuit board (3) is installed in the annular flange groove (14), the output end of the dual shear strain gauge (2) is electrically connected to the input end of the signal amplification circuit board (3), and the output end of the signal amplification circuit board (3) is electrically connected to the input end of the cable assembly (4).

2. The torque sensor for a harmonic reducer according to claim 1, characterized in that, The elastomer (1) is made of stainless steel.

3. A harmonic drive torque sensor according to claim 1, wherein, A gap is provided between the first elastic body part (11) and the second elastic body part (12). The first elastic body part (11) is provided with a plurality of first mounting holes (111) evenly along its circumference, and the second elastic body part (12) is provided with a plurality of second mounting holes (121) evenly along its circumference. The first mounting holes (111) and the second mounting holes (121) are arranged alternately.

4. A harmonic reducer torque sensor according to claim 3, characterized in that, The shear beam arm (122) is located between any two adjacent first mounting holes (111) and second mounting holes (121).

5. A harmonic reducer torque sensor according to claim 1, characterized in that, The signal amplification circuit board (3) has a ring structure.

6. A harmonic drive torque sensor according to claim 1, wherein, The dual shear strain gauge (2) and the signal amplification circuit board (3) are covered with silicone.

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