Gear reducer with torque detection structure and its flexible assembly

Abstract

The present invention provides a gearbox having a torque detection structure and its flexible assembly. [Solution] The flexible assembly 5 is installed on the output disk of a rotating mechanical device such as a speed reducer along the axial direction and comprises a flexible body 51 and at least two flexible arms 52. The flexible body 51 is installed on the output disk along the axial direction. At least two flexible arms 52 extend outward from the flexible body 51 perpendicular to the axial direction. When the speed reducer 1 outputs torque via the output disk, at least two flexible arms 52 are subjected to force and deform, causing a displacement of the flexible body 51. By comparing this displacement with the rotational position of the output disk, the output torque value can be calculated, realizing its application as a torque sensor.

Description

Technical Field

[0001] The present invention relates to the structure of a speed reducer, and particularly to a speed reducer having a torque detection structure and its flexible assembly, which realizes torque detection by arranging a flexible assembly and an encoder, performs closed-loop feedback control, and improves the control accuracy of the system.

Background Art

[0002] Currently, in equipment that requires high precision and high torque, many transmission systems adopt a combination of a direct drive motor (DD motor) or a servo motor and a speed reducer. Among them, the direct drive motor exhibits excellent performance in terms of efficiency and accuracy, and there are no problems such as losses caused by the speed reducer and backlash rigidity of the speed reducer. However, when it is necessary to provide higher torque, the volume of the motor becomes very large, and the cost also increases correspondingly. On the other hand, a configuration in which a speed reducer is mounted on a motor can usually provide larger torque in the same design space. However, in conventional applications that combine a speed reducer and a servo motor, many adopt an open-loop design, and an encoder is only arranged on the input-side motor to control the position. Therefore, the output position after passing through the speed reducer depends on the accuracy of the speed reducer and is also easily affected by temperature. Therefore, in terms of precision control, it is slightly inferior to the direct drive motor system.

[0003] In order to improve precision control, it is also possible to add another encoder to the output side of the speed reducer to perform feedback control. However, in a conventional configuration that combines a servo motor and a speed reducer, since the output end of the speed reducer and the motor are installed in opposite directions at both ends of the speed reducer, when an encoder is added to the output end of the speed reducer to perform closed-loop feedback control, not only does the mechanism become complicated in design, but the cost also increases significantly. Furthermore, the electrical circuit and wiring also become another difficult problem.

[0004] In light of this, there is a real need to provide a gearbox and its flexible assembly that have a torque detection structure, which achieves torque detection by arranging a flexible assembly and encoder, performs closed-loop feedback control, improves the control accuracy of the system, and solves the shortcomings of conventional technology. [Overview of the project]

[0005] The object of the present invention is to provide a gearbox and its flexible assembly having a torque detection structure that achieves torque detection by arranging a flexible assembly and an encoder, performs closed-loop feedback control, and improves the control accuracy of the system.

[0006] Another object of the present invention is to provide a gearbox having a torque detection structure and its flexible assembly. In addition to achieving miniaturization of the gearbox by optimizing the assembly structure, closed-loop feedback control is performed by placing an encoder between the gearbox and the motor, and torque detection is achieved by further coupling the output end of the gearbox with the flexible assembly. In this configuration, the rotational position of the output end of the gearbox is measured using a first encoder module, and the position of the flexible assembly is measured using a second encoder module. There is a positional misalignment between the two, and this misalignment is the result of deformation of the flexible assembly due to torsional force. If the rigidity of the flexible assembly is known, the output torque value can be calculated, realizing its application as a torque sensor. The output end of the gearbox of the present invention employs a front and rear output disk design, with the rear output disk facing the motor, and the flexible assembly built on the front output disk. Furthermore, it can be connected to the second encoder module by passing through the rear output disk along the axial direction. The first encoder module, together with the third encoder module, is built between the rear output disk and the motor and can have a common encoder reading head, thereby reducing costs and improving ease of use and space utilization. On the other hand, the flexible assembly installed at the output end comprises a flexible body and at least two flexible arms. The at least two flexible arms extend or curve outward from the flexible body perpendicular to the axial direction of the output end, deform under force when the reducer outputs torque, creating displacement of the flexible body and enabling its application as a torque sensor. The inner ends of the flexible arms extend or curve outward from the flexible body and have a thin-walled structure perpendicular to the output disk, thus providing sufficient deformation. The outer ends of the flexible arms are fastened to the side wall of the protrusion at the output end via at least one screw along the circumferential or radial (perpendicular to the axial direction), or fixed in a fixed ring manner, providing better torque resistance capability. Of course, the flexible assembly should absorb torque as much as possible, and radial and axial stresses should be supported by other structures, such as cross roller bearings or bearing sets.In the gearbox of the present invention, torque is transmitted between the front and rear output discs by the eccentric motion of multiple straight shafts, with the extended portion of the straight shafts penetrating the front output disc and connecting the outer bearing and the front output disc in an interference manner. Furthermore, the flexible assembly of the present invention is provided with multiple grooves installed on the outer circumference of the flexible body, which contact the outer bearings constructed on the multiple straight shafts, and the outer rings of the outer bearings are positioned in the corresponding grooves. This allows the outer rings of the outer bearings to provide radial support stress to the flexible body, and the plane of the outer ring of the outer bearing abuts against the plane of the corresponding groove, providing axial support stress to the flexible body. Moreover, the grooves are designed to have a larger arc curvature corresponding to the diameter of the outer ring, forming an interference point between the flexible body and the outer bearing at one end of the groove, which functions as a limiting stopping point for the limit of allowable deformation. In other words, the arc curvature of the grooves can be optimized to design a contact position based on the limiting angle of displacement of the flexible body after deformation, and can serve as a limiting stopping point. Of course, the structure of the grooves is not limited to a single arc curvature. The present invention can also be applied to a configuration in which a flexible assembly interferes with the outer bearing and stops at the maximum deformation angle by using grooves designed with multiple line segments. In this way, the flexible body of the present invention is installed axially on the output disk of a rotating machine, enabling torque detection.

[0007] To achieve the above objective, the present invention provides a gearbox having a torque detection structure, comprising an input shaft, a gearbox body, an output end, a first encoder module, a flexible assembly, and a second encoder module. The input shaft is configured to be connected to a motor along the axial direction and is driven by the motor. The gearbox body is positioned along the axial direction and fits onto the outside of the input shaft. The output end is positioned along the axial direction and is connected to the gearbox body. Here, the input shaft is driven to act on the gearbox body and the output end, causing the output end to rotate. The first encoder module is installed between the output end and the motor and is configured to measure the rotational position of the output end. The flexible assembly comprises a flexible body and at least two flexible arms, the flexible body being installed at the output end along the axial direction, and the at least two flexible arms extending outward from the flexible body perpendicular to the axial direction, allowing the at least two flexible arms to deform under force, thereby forming a displacement of the flexible body. The second encoder module is positioned spatially relative to the flexible assembly, and the output torque value is calculated by comparing the displacement measured by the second encoder module with the rotational position of the output terminal measured by the first encoder module.

[0008] In one embodiment, the output terminal comprises a first output disc and a second output disc, which are mounted on the outside of both sides of the gearbox body along the axial direction and connected to the gearbox body via a plurality of straight shafts. Here, the first output disc faces the motor, and when the motor's power input source is input via the input shaft, the input shaft drives the eccentric motion of the gearbox body and the plurality of straight shafts, thereby causing the plurality of straight shafts to rotate the first output disc and the second output disc respectively, and the first output disc and the second output disc each output power.

[0009] In one embodiment, a first encoder module is installed between a first output disk and a motor and is configured to measure the rotation of the first output disk for feedback control.

[0010] In one embodiment, the first encoder module comprises an encoder and an encoder reading head, the encoder being connected to a first output disk, and the first output disk driving the encoder to output rotation synchronously. Here, the encoder reading head is spatially positioned relative to the encoder and is configured to measure the position of the first output disk for feedback control.

[0011] In one embodiment, the gearbox having a torque detection structure further includes a third encoder module, which is installed between the first output disk and the motor. Here, the input shaft is a hollow input shaft, and the third encoder module includes a motor encoder and an encoder reading head, which are assembled to measure the position of the input shaft or the position of the motor's drive shaft for feedback control. Here, the encoder reading head of the first encoder module and the encoder reading head of the third encoder module are installed on opposite sides of the circuit board, respectively.

[0012] In one embodiment, the input shaft is a hollow input shaft, and the flexible assembly includes an extendable end that extends axially from the flexible body through the input shaft to the rear end of the motor. Here, a second encoder module is installed at the rear end and is configured to measure the rotation of the extendable end to achieve torque detection.

[0013] In one embodiment, multiple straight shafts are provided with extensions that penetrate the second output disk and are connected to the second output disk in an interference manner, with the extensions interfering with the outer bearing.

[0014] In one embodiment, the flexible body comprises a plurality of grooves spatially arranged with respect to the outer bearings of a plurality of straight shafts, the outer bearings partially in contact with the corresponding grooves.

[0015] In one embodiment, the groove has an arc curvature corresponding to the outer bearing, and this arc curvature is greater than the outer diameter of the outer bearing, forming an interference point between the flexible body and the outer bearing at one end of the groove.

[0016] In one embodiment, at least two flexible arms extend radially from the inside to the outside, the inner ends of at least two flexible arms are connected to a flexible body, and the outer ends of at least two flexible arms are fixed circumferentially to the side wall of a projection at the output end via at least one screw.

[0017] In one embodiment, at least two flexible arms extend from the inside to the outside and are curved, the inner ends of at least two flexible arms are connected to a flexible body, and the outer ends of at least two flexible arms are fixed radially to the side wall of a protrusion at the output end via at least one screw.

[0018] In one embodiment, the flexible assembly further includes a retaining ring, which is provided annularly on the outside of the flexible body. At least two flexible arms extend from the inside to the outside and are curved, the inner ends of at least two flexible arms are connected to the flexible body, and the outer ends of at least two flexible arms are connected to the retaining ring, which is fixed to the output end axially via a plurality of screws.

[0019] To achieve the above objectives, the present invention also provides a flexible assembly configured to be mounted axially at the output end of a rotating mechanical device. The flexible assembly comprises a flexible body and at least two flexible arms. The flexible body is mounted axially at the output end. The at least two flexible arms extend outward from the flexible body perpendicular to the axial direction. Here, when the rotating mechanical device outputs torque through the output end, it is permissible for the at least two flexible arms to be subjected to force and deform, creating a displacement in the flexible body, and for the output torque value to be calculated by comparing the displacement with the rotational position of the output end. [Brief explanation of the drawing]

[0020] [Figure 1] This is a three-dimensional structural diagram of a gearbox assembly according to the first embodiment of the present invention, viewed from the front. [Figure 2] It is a three-dimensional structure diagram of the speed reducer assembly according to the first embodiment of the present invention, viewed from the rear. [Figure 3] It is a cross-sectional view of the speed reducer assembly according to the first embodiment of the present invention. [Figure 4] It is a front view of the speed reducer assembly according to the first embodiment of the present invention. [Figure 5] It is a three-dimensional structure diagram of the flexible assembly according to the first embodiment of the present invention. [Figure 6A] It is a diagram showing the transmission paths of the radial stress and the axial stress in the flexible assembly according to the first embodiment of the present invention. [Figure 6B] It is a diagram showing the transmission paths of the radial stress and the axial stress in the flexible assembly according to the first embodiment of the present invention. [Figure 7A] It is a diagram showing the correspondence relationship with the outer bearing before and after deformation of the flexible assembly according to the first embodiment of the present invention. [Figure 7B] It is a diagram showing the correspondence relationship with the outer bearing before and after deformation of the flexible assembly according to the first embodiment of the present invention. [Figure 8] It is a three-dimensional structure diagram of the speed reducer assembly according to the second embodiment of the present invention, viewed from the front. [Figure 9] It is a three-dimensional structure diagram of the speed reducer assembly according to the second embodiment of the present invention, viewed from the rear. [Figure 10] It is a cross-sectional view of the speed reducer assembly according to the second embodiment of the present invention. [Figure 11] It is a front view of the speed reducer assembly according to the second embodiment of the present invention. [Figure 12] It is a three-dimensional structure diagram of the flexible assembly according to the second embodiment of the present invention. [Figure 13] It is a three-dimensional structure diagram of the speed reducer assembly according to the third embodiment of the present invention, viewed from the front. [Figure 14] It is a three-dimensional structure diagram of the speed reducer assembly according to the third embodiment of the present invention, viewed from the rear. [Figure 15]This is a cross-sectional view of a gearbox assembly according to a third embodiment of the present invention. [Figure 16] This is a front view of a gearbox assembly according to a third embodiment of the present invention. [Figure 17] This is a three-dimensional structural diagram of a flexible assembly according to a third embodiment of the present invention. [Modes for carrying out the invention]

[0021] Several typical embodiments that embody the features and advantages of the present invention are described in detail below. The present invention can be modified in various ways in different embodiments without departing from its scope, and it should be understood that the descriptions and drawings herein are for illustrative purposes only and do not limit the invention. For example, where the following description of this disclosure states that a first feature is placed above or above a second feature, it includes embodiments in which the placed first feature and the placed second feature are in direct contact, as well as embodiments in which an additional feature may be placed between the first feature and the placed second feature, thereby preventing direct contact between the first and second features. Also, different embodiments of this disclosure may use redundant reference numerals and / or symbols. These redundancies are for the purpose of simplification and clarification and do not limit the relationships between each embodiment and / or described external structure. Furthermore, spatial terms such as “front,” “rear,” “inside,” “outside,” and similar terms may be used to describe the relationship between one component or feature part and other components or feature parts in the drawings. Beyond the orientations shown in the drawings, spatial terminology is intended to encompass different orientations of the device during use or operation. The device may also be positioned in a different location (e.g., rotated 90 degrees or in a different orientation), and the spatial terminology used will be interpreted accordingly. Furthermore, where one component is referred to as "connected" or "joined" to another, it may be directly connected or joined to the other component, or there may be an intervening component. Numerical ranges and parameters within the broad scope of this disclosure are approximations, but in specific examples, numerical values ​​are described as precisely as possible. Also, while terms such as "first," "second," etc., may be used in the claims to describe different components, these components should not be limited by these terms, and it should be understood that these components, described correspondingly in embodiments, are represented by different component symbols. These terms are intended to distinguish different components.For example, the first component may be referred to as the second component, and similarly, the second component may be referred to as the first component without departing from the scope of the embodiment. The term “and / or” as used in this way includes any combination and all combinations of one or more of the items listed in relation.

[0022] Figures 1 and 2 are three-dimensional structural diagrams of a gearbox assembly according to a first embodiment of the present invention. Figure 3 is a cross-sectional view of the gearbox assembly according to a first embodiment of the present invention. Figure 4 is a front view of the gearbox assembly according to a first embodiment of the present invention. Figure 5 is a three-dimensional structural diagram of a flexible assembly according to a first embodiment of the present invention. Refer to Figures 1 to 5. The present invention provides a gearbox 1 having a torque detection structure, the gearbox 1 adopts a front and rear end output design and is coupled with a motor 9 to constitute a gearbox assembly 2. In this embodiment, the gearbox 1 comprises an input shaft 10, a gearbox body 20, an output end 30, a first encoder module 41, a flexible assembly 5, and a second encoder module 44. The input shaft 10 is configured to be connected to the rotor 91 of the motor 9 along the axial direction C, and both the rotor 91 and stator 92 of the motor 9 are fitted to the outside of the input shaft 10, so that the power input provided by the motor 9 can drive and rotate the input shaft 10. The gearbox body 20 is arranged along the axial direction C and is fitted to the outside of the input shaft 10. The output end 30 is positioned along the axial direction C and connected to the gearbox body 20. A substantially central opening (not shown) is provided in the gearbox body 20 for some of the input shafts 10 to pass through. In this embodiment, the input shaft 10 is a hollow input shaft located substantially at the center of the gearbox assembly 2 and is driven by a motor 9 to act on the gearbox body 20 and the output end 30, causing the output end 30 to rotate. In this embodiment, the output end 30 comprises a first output disc 31 and a second output disc 32, positioned on the outside of both sides of the gearbox body 20 along the axial direction C and connected to the gearbox body 20 via a plurality of straight shafts 33. The first output disc 31 faces the motor 9, and when the power input source of the motor 9 is input via the input shaft 10, the input shaft 10 drives the gearbox body 20 and the plurality of straight shafts 33 to eccentrically rotate the plurality of straight shafts 33, thereby causing the plurality of straight shafts 33 to rotate the first output disc 31 and the second output disc 32, respectively, and the first output disc 31 and the second output disc 32 to output power, respectively. The first encoder module 41 is installed between the first output disk 31 of the output terminal 30 and the motor 9, and is configured to measure the rotational position of the output terminal 30.The flexible assembly 5 comprises a flexible body 51 and at least two flexible arms 52, the flexible body 51 being mounted on the output end 30 along the axial direction C, and the at least two flexible arms 52 extending outward from the flexible body 51 perpendicular to the axial direction C, allowing the at least two flexible arms 52 to be subjected to stress and deform, thereby forming a displacement of the flexible body 51. The second encoder module 44 is spatially positioned opposite the flexible assembly 5 and calculates an output torque value by comparing the displacement measured by the second encoder module 44 with the rotational position of the output end 30 measured by the first encoder module 41. In other words, the present invention measures the rotational position of the output terminal 30 of the reduction gear 1 using a first encoder module 41, and further measures the position of the flexible assembly 5 using a second encoder module 44. There is a positional misalignment between the two, and this misalignment is the result of the flexible assembly 5 being deformed by a torsional force. If the rigidity of the flexible assembly 5 is known, the output torque value can be calculated, realizing its application as a torque sensor. As a result, the reduction gear 1 can detect torque and perform closed-loop feedback control, improving the control accuracy of the system.

[0023] In this embodiment, the first output disk 31 and the second output disk 32 are located on opposite outer sides of the reduction gear body 20, the reduction gear body 20 is interposed between the first output disk 31 and the second output disk 32, and both the first output disk 31 and the second output disk 32 can function as power outputs. The first output disk 31 faces the motor 9, the flexible assembly 5 is provided on the second output disk 32, and is further connected to the second encoder module 44, passing through the first output disk 31 and the motor 9 along the axial direction C. In this embodiment, the first encoder module 41 is installed between the first output disk 31 and the motor 9 and is configured to measure the rotation of the first output disk 31 for feedback control, thereby improving the accuracy of the cycloidal reduction gear 1. In this embodiment, the first encoder module 41 includes, for example, an encoder 42 and an encoder reading head 43, the encoder 42 is connected to the first output disk 31 via a connecting plate member, and the first output disk 31 can drive the encoder 42 to output rotation synchronously. In this embodiment, the encoder reading head 43 is spatially positioned relative to the encoder 42 and configured to measure the position of the first output disk 31 for feedback control. In this embodiment, the input shaft 10 is a hollow input shaft, and the flexible assembly 5 further includes an extension end 53 that extends from the flexible body 51 through the input shaft 10 along the axial direction C to the rear end of the motor 9. In this embodiment, the second encoder module 44 includes, for example, an encoder 45 and an encoder reading head 46, the encoder 45 being connected to the extension end 53 of the flexible assembly 5 via a connecting member, and the extension end 53 of the flexible assembly 5 being able to drive the encoder 45 to output rotation synchronously. In this embodiment, the encoder reading head 46 is spatially positioned relative to the encoder 42 and configured to measure the displacement of the flexible assembly 5 to achieve torque detection. In this embodiment, the reduction gear 1 further includes a third encoder module 47 installed between the first output disk 31 and the motor 9.The third encoder module 47 includes a motor encoder 48 and an encoder reading head 49, and is configured to measure the position of the motor's drive shaft or input shaft 10 for feedback control. In this embodiment, the encoder reading head 43 of the first encoder module 41 and the encoder reading head 49 of the third encoder module 47 are located on opposite sides of the circuit board 40, contributing to cost reduction and improving ease of use and space utilization. The first output disk 31 and the second output disk 32 are both super-reduction ratios (i.e., output ends 30), with the first output disk 31 being located towards the rear end, near the mounted fixed housing 90 and the servo motor 9. The wiring of the first encoder module 41 and the third encoder module 47 can be routed from the encoder wiring lead-out end 400 through the fixed housing 90 and is not affected by the input shaft 10. The encoder wiring lead-out end 401 of the second encoder module 44 can be routed from the rear end of the motor 9. Of course, the present invention is not limited thereto.

[0024] In this embodiment, the gearbox 1 having a torque detection structure further includes a control module (not shown) connected to a first encoder module 41 and a second encoder module 44, which compares the output of the first encoder module 41 with the output of the second encoder module 44 corresponding to the flexible assembly 5 to calculate the output torque value. In another embodiment, the control module (not shown) of the gearbox 1 having a torque detection structure is installed, for example, outside the gearbox 1 and the motor 9, and is connected to a second encoder module 44 and a third encoder module 47, which compares the output of the third encoder module 47 located at the input shaft 10 with the output of the second encoder module 44 corresponding to the flexible assembly 5 to detect torque. Of course, the installation position of the control module can be adjusted according to the requirements of the actual application, and the present invention is not limited thereto, and a detailed explanation thereof is omitted.

[0025] On the other hand, in this embodiment, the flexible assembly 5 comprises four flexible arms 52 extending radially from the inside to the outside. Each flexible arm 52 has a thin-walled structure and is perpendicular to the second output disk 32 of the output end 30, so that it can provide sufficient deformation, and when the reduction gear 1 outputs torque it is subjected to stress and deforms, causing a displacement of the flexible body 51, thereby realizing its application as a torque sensor. The inner ends 521 of at least two of the flexible arms 52 are connected to the flexible body 51, and the outer ends 522 of at least two of the flexible arms 52 are fixed circumferentially to the side wall of the protrusion 301 of the output end 30 via at least one screw 6, thereby providing better torque resistance capability.

[0026] The flexible assembly 5 absorbs torque as much as possible, and other structures, such as cross roller bearings and bearing sets, support radial and axial stresses. Figures 6A and 6B show the transmission paths of radial and axial stresses in the flexible assembly according to the first embodiment of the present invention, respectively. Figures 7A and 7B show the correspondence with the outer bearing before and after deformation of the flexible assembly according to the first embodiment of the present invention, respectively. Refer to Figures 1 to 5, 6A, 6B, 7A, and 7B. In this embodiment, the first output disk 31 and the second output disk 32 transmit torque by the eccentric motion of a plurality of straight shafts 33. In this embodiment, the plurality of straight shafts 33 are provided with extensions 331 that penetrate the second output disk 32 and are connected to the second output disk 32 in an interference manner, and the extensions 331 of the straight shafts 33 interfere with (contact with) the outer bearing 34. In this embodiment, the flexible body 51 further comprises a plurality of grooves 512, which are spatially positioned relative to the outer bearings 34 outside a plurality of straight shafts 33, with the outer rings 341 of the outer bearings 34 partially contacting the corresponding grooves 512 and located at the bottom 513 of the corresponding grooves 512. In this embodiment, the reducer 1 can install a clamping tool or other operating assembly through a hollow hole 510 or mounting hole 511 on the flexible assembly 5. When the reducer 1 operates, the outer rings 341 of the outer bearings 34 can provide a radial support stress Fr to the flexible body, and the plane of the outer rings 341 of the outer bearings 34 abuts against the plane of the bottom 513 of the corresponding grooves 512, providing an axial support stress Fa to the flexible body 51, which can effectively prevent the flexible assembly 5 from undergoing unnecessary deformation and affecting measurement accuracy. Furthermore, in this embodiment, the groove 512 has an arc curvature corresponding to the outer bearing 34, and this arc curvature is greater than the outer diameter of the outer bearing 34, providing a margin for deformation and rotation of the flexible assembly 5 when it deforms.In addition, the arc curvature of the groove 512 can be designed (formed) to optimize the contact position based on the limit angle of displacement of the deformed flexible body 51, thereby forming an interference point 514 between the flexible body 51 and the outer bearing 34 at one end of the groove 512, which functions as the limit stopping point of the limit position of allowable deformation. Of course, the structure of the groove 512 is not limited to a single arc curvature. A configuration in which the flexible assembly 5 interferes with the outer bearing 34 and stops at the maximum deformation angle, using a groove 512 designed with multiple line segments, is also applicable to the present invention. In this way, the flexible body 51 of the present invention is installed along the axial direction C on the output disk of a rotating machine, enabling torque detection.

[0027] Figures 8 and 9 are three-dimensional structural diagrams of a gearbox assembly according to a second embodiment of the present invention. Figure 10 is a cross-sectional view of the gearbox assembly according to a second embodiment of the present invention. Figure 11 is a front view of the gearbox assembly according to a second embodiment of the present invention. Figure 12 is a three-dimensional structural diagram of a flexible assembly according to a second embodiment of the present invention. In this embodiment, the structures of the gearbox assembly 2a and the flexible assembly 5a are generally similar to those of the gearbox assembly 2 and the flexible assembly 5 shown in Figures 1 to 5, and the same reference numerals represent the same components, structures, and functions, so redundant explanations are omitted here.

[0028] In this embodiment, the flexible assembly 5a comprises four flexible arms 52 that extend from the inside out and are curved, and each flexible arm 52 has a thin-walled structure and is perpendicular to the output end 30, so that it can provide a sufficient amount of deformation, and when the reducer 1 of the reducer assembly 2a outputs torque it is subjected to force and deforms, causing a displacement of the flexible body 51, thereby realizing its application as a torque sensor. In this embodiment, the inner end 521 of each flexible arm 52 is connected to the flexible body 51, and the outer end 522 of each flexible arm 52 is fixed radially to the side wall of the protrusion 301 of the output end 30 via at least one screw 6, providing better torque resistance capability.

[0029] Figures 13 and 14 are three-dimensional structural diagrams of a gearbox assembly according to a third embodiment of the present invention. Figure 15 is a cross-sectional view of the gearbox assembly according to a third embodiment of the present invention. Figure 16 is a front view of the gearbox assembly according to a third embodiment of the present invention. Figure 17 is a three-dimensional structural diagram of a flexible assembly according to a third embodiment of the present invention. In this embodiment, the structures of the gearbox assembly 2b and the flexible assembly 5b are generally similar to those of the gearbox assembly 2 and flexible assembly 5 shown in Figures 1 to 5, and the same reference numerals represent the same components, structures, and functions, so redundant explanations are omitted here. In this embodiment, the flexible assembly 5b further includes a fixing ring 54, which is provided annularly on the outside of the flexible body 51. The two flexible arms 52 extend from the inside to the outside and are curved. Furthermore, the inner ends 521 of the two flexible arms 52 are connected to the flexible body 51, and the outer ends 522 of the two flexible arms 52 are connected to a fixing ring 54, which is fixed to the output end 30 along the axial direction C via multiple screws 6, providing better torque resistance capability.

[0030] As described above, the flexible assemblies 5, 5a, and 5b installed on the output end 30 of the reduction gear 1 can adjust the form and number of at least two flexible arms 52 included in their structure that extend outward or curve from the flexible body 51 according to the requirements of the actual application. By providing sufficient deformation with a thin-walled structure perpendicular to the output end 30 of the flexible arms 52, it is possible to improve the accuracy of torque detection. On the other hand, the fixing of the flexible assemblies 5, 5a, and 5b to the output end 30 of the reduction gear 1 is mainly achieved via the outer ends 522 of the flexible arms 52. By fixing the outer ends 522 of the flexible arms 52 in a manner that connects to the protrusion 301 or the fixing ring 54 using a screw 6, both flexible assemblies 5, 5a, and 5b can maintain sufficient torque resistance. Of course, the present invention is not limited thereto, and further explanation is omitted.

[0031] As described above, the present invention provides a gearbox having a torque detection structure and its flexible assembly, which achieves torque detection by arranging the flexible assembly and encoder, and improves the control accuracy of the system by performing closed-loop feedback control. In addition to achieving miniaturization of the gearbox by optimizing the assembly structure, the present invention enables closed-loop feedback control by arranging the encoder between the gearbox and the motor, and further enables torque detection by coupling the output end of the gearbox with the flexible assembly. Furthermore, the rotational position of the output end of the gearbox is measured using a first encoder module, and the position of the flexible assembly is measured using a second encoder module. There is a positional misalignment between the two, and this misalignment is the result of the flexible assembly deforming under torsional force. If the rigidity of the flexible assembly is known, the output torque value can be calculated, and it can be applied as a torque sensor. The output end of the gearbox of the present invention employs a front and rear output disk design, with the rear output disk facing the motor, and the flexible assembly built on the front output disk. Furthermore, it can be connected to the second encoder module by passing through the rear output disk along the axial direction. The first and second encoder modules are constructed together between the output disk and the motor, and can have a common encoder reading head, thereby reducing costs and improving ease of use and space utilization. Meanwhile, the flexible assembly installed at the output end has a structure that includes a flexible body and at least two flexible arms. The at least two flexible arms extend or curve outward from the flexible body perpendicular to the axial direction of the output end, and deform under force when the reduction gear outputs torque, creating a displacement in the flexible body and realizing its application as a torque sensor. The inner ends of the flexible arms extend or curve outward from the flexible body and have a thin-walled structure perpendicular to the output disk, so that sufficient deformation can be provided. The outer ends of the flexible arms are fastened to the side wall of the protrusion of the output end along the circumferential or radial (perpendicular to the axial direction) direction via at least one screw, or fixed in a fixed ring manner, providing better torque resistance capability.The flexible assembly should absorb torque as much as possible, and radial and axial stresses should be supported by other structures, such as cross roller bearings or bearing sets. In the reduction gear of the present invention, the front and rear output discs transmit torque through the eccentric motion of multiple straight shafts, the extended portion of the straight shafts penetrates the front output disc, and the outer bearing and the front output disc are coupled in an interference fit manner. Furthermore, the flexible assembly of the present invention is provided with multiple grooves installed on the outer circumference of the flexible body, which contact the outer bearings constructed on the multiple straight shafts, and the outer rings of the outer bearings are positioned in the corresponding grooves. As a result, the outer rings of the outer bearings can provide radial support stress to the flexible body, and the plane of the outer ring of the outer bearing abuts against the plane of the corresponding groove, providing axial support stress to the flexible body. Furthermore, the grooves are designed to have a larger arc curvature corresponding to the diameter of the outer ring, forming an interference point between the flexible body and the outer bearing at one end of the groove, which functions as a limiting stopping point for the limit of allowable deformation. In other words, the circular curvature of the groove can be optimized to design a contact position based on the limit angle of displacement of the deformed flexible body, and can serve as a limit stopping point. Of course, the structure of the groove is not limited to a single circular curvature. Configurations using grooves designed with multiple line segments, in which the flexible assembly interferes with the outer bearing and stops at the maximum deformation angle, are also applicable to the present invention. Thus, the flexible body of the present invention can be installed axially on the output disk of a rotating machine, enabling torque detection.

[0032] While this invention may be modified in various ways based on the considerations of those familiar with this art, none of these modifications will exceed the scope intended to be protected by the attached claims. [Explanation of symbols]

[0033] 1: Reducer 2, 2a, 2b: Gear reducer assembly 10: Input axis 20: Reducer body 30: Output terminal 301: Convex part 31: First output disk 32: Second output disk 33: Straight axis 331: Stretching part 34: Outer bearing 341: Outer ring 40: Circuit board 400, 401: Encoder wiring output terminals 41: First encoder module 42: Encoder 43: Encoder reading head 44: Second encoder module 45: Encoder 46: Encoder reading head 47: Third encoder module 48: Motor Encoder 49: Encoder reading head 5, 5a, 5b: Flexible assemblies 51:Flexible body 510: Hollow hole 511: Mounting hole 512: Groove 513: Bottom 514: Interference point 52: Flexible Arm 521: Inner edge 53:Stretched end 54: Fixing ring 6: Screw 9: Motor 90: Fixed Housing 91: Rotor 92: Status C: Axial direction Fa: Axial support stress Fr: Radial support stress

Claims

1. An input shaft connected to a motor along a single axis and configured to be driven by the motor, A reduction gear body is arranged along the axial direction and fitted to the outside of the input shaft, An output end, arranged along the axial direction and connected to the reduction gear body, which, when the input shaft is driven, acts on the reduction gear body and the output end to rotate the output end, A first encoder module is installed between the output terminal and the motor and configured to measure the rotational position of the output terminal, A flexible assembly comprising a flexible body and at least two flexible arms, wherein the flexible body is mounted on the output end along the axial direction, and the at least two flexible arms extend outward from the flexible body perpendicular to the axial direction, allowing the at least two flexible arms to deform under stress, thereby causing displacement of the flexible body; A second encoder module is spatially opposed to the flexible assembly, and calculates an output torque value by comparing the positional displacement measured by the second encoder module with the rotational position of the output terminal measured by the first encoder module. A gearbox having a torque detection structure characterized by comprising the following features.

2. The output terminal comprises a first output disk and a second output disk, which are installed on the outside of both sides of the reduction gear body along the axial direction and connected to the reduction gear body via a plurality of straight shafts, wherein the first output disk faces the motor, and when the power input source of the motor is input via the input shaft, the input shaft drives the eccentric motion between the reduction gear body and the plurality of straight shafts, causing the plurality of straight shafts to rotate the first output disk and the second output disk, and the first output disk and the second output disk each output power, characterized in that the reduction gear has a torque detection structure according to claim 1.

3. The gearbox having a torque detection structure according to claim 2, characterized in that the first encoder module is installed between the first output disk and the motor and is configured to measure the rotation of the first output disk for feedback control.

4. The torque detection structure reduction gear according to claim 3, wherein the first encoder module comprises an encoder and an encoder reading head, the encoder is connected to a first output disk, the first output disk drives the encoder to rotate synchronously, and the encoder reading head is positioned spatially opposite to the encoder and configured to measure the position of the first output disk for feedback control.

5. The system includes a third encoder module installed between the first output disk and the motor, The aforementioned input shaft is a hollow input shaft. The third encoder module comprises a motor encoder and an encoder reading head, and is configured to measure the position of the input shaft or the position of the motor's drive shaft for feedback control. The torque detection structure reduction gear according to claim 4, characterized in that the encoder reading head of the first encoder module and the encoder reading head of the third encoder module are each installed on opposite sides of the circuit board.

6. The aforementioned input shaft is a hollow input shaft. The flexible assembly further includes an extended end that extends from the flexible body along the axial direction through the input shaft to the rear end of the motor, The torque detection structure of the reduction gear according to claim 2, characterized in that the second encoder module is installed at the rear end and is configured to measure the rotation of the extended end in order to detect torque.

7. The torque detection structure of the reduction gear according to claim 2, characterized in that the plurality of straight shafts have extensions that penetrate the second output disk and are connected to the second output disk in an interference manner, and the extensions interfere with the outer bearing.

8. The torque detection structure of the reduction gear according to claim 7, further comprising a plurality of grooves arranged spatially opposite to the outer bearings located outside the plurality of straight shafts, wherein the outer bearings partially contact the corresponding grooves.

9. The torque detection structure of the reduction gear according to claim 8, characterized in that the groove has an arc curvature corresponding to the outer bearing, the arc curvature is greater than the outer diameter of the outer bearing, and an interference point between the flexible body and the outer bearing is formed at one end of the groove.

10. A reduction gear having a torque detection structure according to claim 1, characterized in that the at least two flexible arms extend radially from the inside to the outside, the inner ends of the at least two flexible arms are connected to the flexible body, and the outer ends of the at least two flexible arms are fixed circumferentially to the side wall of the protrusion of the output end via at least one screw.

11. A reduction gear having a torque detection structure according to claim 1, characterized in that the at least two flexible arms extend from the inside to the outside and are curved, the inner ends of the at least two flexible arms are connected to the flexible body, and the outer ends of the at least two flexible arms are fixed radially to the side wall of the protrusion of the output end via at least one screw.

12. The flexible assembly comprises a fixing ring provided in an annular shape on the outside of the flexible body, A reduction gear having a torque detection structure according to claim 1, characterized in that the at least two flexible arms extend from the inside to the outside and are curved, the inner ends of the at least two flexible arms are connected to the flexible body, the outer ends of the at least two flexible arms are connected to the fixing ring, and the fixing ring is fixed to the output end along the axial direction via a plurality of screws.

13. A flexible assembly configured to be installed on the output end of a rotating machine along a single axis, A flexible body installed on the output end along the axial direction, At least two flexible arms extending outward from the flexible body perpendicular to the axial direction, Equipped with, When the rotating machine outputs torque through the output terminal, the at least two flexible arms are subjected to stress and deform, causing a displacement of the flexible body. The output torque value is calculated by comparing this displacement with the rotational position of the output terminal. A flexible assembly characterized by the following.

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