Sensor base buffer capable of controlling adjustable torque through magnetic force

Abstract

The invention discloses a sensor base buffer capable of controlling adjustable torque through magnetic force. The sensor base buffer comprises an output rotating frame, an outer rotor frame and an inner stator shaft. The output rotating stand is of a cup-shaped structure, and the cup-shaped structure of the output rotating stand is coaxially arranged outside the sleeve of the outer rotor frame in a sleeving mode and connected with the sleeve through a bearing. The inner stator shaft is arranged in an inner cavity of the outer rotor frame, and the lower end of the inner stator shaft is matched with the output rotating frame through a square tenon structure, so that circumferential synchronous rotation and axial sliding are achieved. The inner wall of the outer rotor frame and the outer wall of the inner stator shaft are respectively provided with magnetic assemblies which are alternately arranged in the polar direction, air gaps are reserved, and non-contact torque transmission is formed through magnetic field coupling force. A torque adjusting mechanism composed of an adjusting screw and a reset spring is arranged at the bottom of the device, the inner stator shaft is driven to generate axial displacement, the effective overlapping area of the inner and outer magnetic assemblies is changed, and then the torque is adjusted. Instantaneous protection is achieved through a magnetic slipping mechanism, and the device has the advantages of being free of mechanical abrasion, high in response speed, compact in structure and the like.

Description

Technical Field

[0001] This invention belongs to the field of mechanical overload protection, specifically a sensor base buffer with adjustable torque controlled by magnetic force. Background Technology

[0002] Miniature torque sensors are core components in precision testing. To ensure measurement accuracy, the elastic elements of these sensors are typically thin and thin, resulting in poor overload resistance. During torque detection, especially in rigidly connected mechanical transmission devices, if the applied torque exceeds the preset torque, relying solely on electronic alarms from the instrument may not provide timely responses to sudden mechanical impacts due to millisecond-level delays between electronic sampling and the actuator. This can lead to sensor damage from instantaneous overload.

[0003] Traditional mechanical overload protection devices mostly use friction plates or steel ball springs. Friction-based structures generate wear and dust when slipping, causing the protection threshold to drift over time, making it difficult to guarantee accuracy; moreover, they are usually bulky and difficult to integrate into a compact sensor base. Summary of the Invention

[0004] In view of this, the present invention provides a sensor base buffer with adjustable torque controlled by magnetic force. Through the mechanical structure of magnetic coupling, the overload instantaneous slippage effect is achieved, which serves as overload protection for small torque sensors.

[0005] The technical solution adopted in this invention is: a sensor base buffer with adjustable torque controlled by magnetic force, characterized in that: it includes an output rotating frame, an outer rotor frame, and an inner stator shaft; the outer rotor frame includes a top cover and a sleeve vertically disposed at the center of the lower end face of the top cover, and the top of the outer rotor frame is used to install a sensor; the output rotating frame includes an upward-opening cup-shaped structure and a sliding groove extending downward along the axis, and the cup-shaped structure of the output rotating frame is fitted onto the sleeve of the outer rotor frame by a bearing; the inner cavity of the sleeve of the outer rotor frame and the sliding groove of the output rotating frame form a cavity, and the inner stator shaft is disposed in the cavity; The outer rotor frame sleeve has an outer ring magnetic component on its inner circumferential wall, and the upper section of the inner stator shaft has an inner ring magnetic component that mates with the outer ring magnetic component on its outer circumferential wall. The lower section of the inner stator shaft is slidably inserted into the slide groove of the output frame, and the lower section of the inner stator shaft and the slide groove of the output frame are connected by a non-circular cross section. A torque adjustment mechanism is provided between the output frame and the inner stator shaft to adjust the axial displacement of the inner stator shaft relative to the outer rotor frame, thereby changing the axial overlap area of ​​the inner ring magnetic component and the outer ring magnetic component.

[0006] Furthermore, the inner stator shaft is a stepped shaft, with the upper section having a larger diameter than the lower section. The upper section is a magnetic coupling section, and the lower section is a guide section. The magnetic coupling section is a cylindrical shaft, and its outer circumferential surface is provided with an annular groove for installing the inner ring magnetic component.

[0007] Furthermore, the torque adjustment mechanism includes an adjusting screw and a return spring; the return spring is disposed between the top of the inner stator shaft and the sleeve of the outer rotor frame, one end of the return spring abuts against the top end of the inner stator shaft, and the other end abuts against the lower surface of the top cover of the outer rotor frame; the lower section of the slide groove of the output frame is provided with a threaded hole, and the adjusting screw is threadedly connected to the threaded hole in the lower section of the slide groove of the output frame, with the top end of the adjusting screw abutting against the end face of the lower section of the inner stator shaft; by screwing in or out the adjusting screw, the inner stator shaft is pushed to overcome the elastic force of the return spring and generate axial displacement.

[0008] Furthermore, the lower end face of the inner stator shaft is provided with a hemispherical boss, which is used to contact the adjusting screw.

[0009] Furthermore, the outer ring magnetic assembly includes multiple identical high-strength outer ring magnets, which are equally spaced and embedded in the inner circumferential wall of the outer rotor frame sleeve to form an inner circumferential surface; the inner ring magnetic assembly includes multiple identical high-strength inner ring magnets, which are equally spaced and embedded in the outer circumferential wall of the upper section of the inner stator shaft to form an outer circumferential surface; an air gap is maintained radially between the inner circumferential surface of the outer ring magnetic assembly and the outer circumferential surface of the inner ring magnetic assembly to form a non-contact magnetic coupling interface; the magnets in both sets of magnetic assemblies are arranged with alternating N and S poles along the circumferential direction to form a closed magnetic circuit in the air gap to generate tangential anti-shear magnetic force.

[0010] Furthermore, the non-circular cross-section mating structure is specifically a square tenon mating structure; the slide groove of the output rotating frame is a square tenon slide groove, the lower section of the inner stator shaft is a corresponding square tenon shaft, and the square tenon shaft is inserted into the square tenon slide groove.

[0011] Furthermore, the bearing is a deep groove ball bearing, and the output rotor and the outer rotor frame are respectively provided with retaining rings at both ends of the bearing to limit the axial displacement of the bearing.

[0012] Furthermore, the bottom of the output rotating frame is provided with a drive interface for docking with external testing instruments.

[0013] The beneficial effects of this invention are as follows: This invention utilizes the coaxial insertion structure of the outer rotor frame and the inner stator shaft to form a non-contact torque transmission channel through magnetic field coupling. This avoids the wear, heat generation, or dust generated by the original mechanical contact during overload slippage, ensuring the long-term stability and maintenance-free operation of the device. Furthermore, when an overload occurs, the magnetic coupling force is overcome by shear force, and the device instantly enters a slippage idling state, physically cutting off the transmission path of the overload torque to the sensor, eliminating the hysteresis of electronic protection, and effectively preventing sensor damage.

[0014] Furthermore, by adjusting the screw and the return spring, the axial position of the inner stator shaft can be changed simply by rotating the adjusting screw at the bottom, thereby altering the overlap area of ​​the inner and outer magnetic components. Since the magnetic coupling force is approximately proportional to the overlap area, this structure allows for the adjustment of a preset torque. Attached Figure Description

[0015] Figure 1 This is a perspective view of the present invention; Figure 2 This is the front view of the present invention; Figure 3 yes Figure 2 A sectional view; Figure 4 These are perspective and sectional views of the output rotating frame in this invention; Figure 5 These are perspective views, top views, bottom views, and sectional views of the outer rotor frame in this invention; Figure 6 This is a multi-directional view of the inner stator shaft in this invention; Figure 7 This is a schematic diagram of the torque adjustment principle of the device of the present invention.

[0016] In the diagram: 1. Output bracket; 101. Square tenon groove; 102. Threaded hole; 2. Outer rotor frame; 201. Top cover; 202. Sleeve; 203. Outer ring magnetic assembly; 3. Inner stator shaft; 301. Inner ring magnetic assembly; 302. Square tenon shaft; 303. Hemispherical boss 4. Hole end retaining ring; 5. Shaft end retaining ring; 6. Bearing; 7. Return spring; 8. Adjusting screw; 9. Sensor; 10. Fixing screw. Detailed Implementation

[0017] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] Example 1

[0019] like Figures 1 to 6 The sensor 9 base buffer shown is a magnetically controlled adjustable torque sensor, comprising an output rotating frame 1, an outer rotor frame 2, and an inner stator shaft 3. The outer rotor frame 2 includes a top cover 201 and a sleeve 202 vertically positioned at the center of the lower end face of the top cover 201. The sensor 9 is coaxially fixed to the top plane of the outer rotor frame 2 by fixing screws 10, allowing for sensor 9 replacement. The output rotating frame 1 includes an upward-opening cup-shaped structure and a downward-extending groove along its axis. The sleeve 202 of the outer rotor frame 2 is coaxially fitted with the cup-shaped structure of the output rotating frame 1. The output rotating frame 1 and the outer rotor frame 2 are connected by bearings 6, enabling mutual rotation. The inner cavity of the sleeve 202 of the outer rotor frame 2 and the groove of the output rotating frame 1 together form a cavity. The inner stator shaft 3 is disposed within this cavity.

[0020] The inner stator shaft 3 is a stepped shaft, with the upper section having a larger diameter than the lower section. The upper section is the magnetic coupling section, and the lower section is the guide section.

[0021] To achieve non-contact torque transmission, this embodiment features an outer ring magnetic assembly 203 on the inner circumferential wall of the outer rotor frame 2, and an inner ring magnetic assembly 301 that mates with the outer ring magnetic assembly 203 on the outer circumferential wall of the upper section of the inner stator shaft 3. Specifically, the inner wall of the outer rotor frame 2 has an annular mounting position, within which the outer ring magnetic assembly 203 is composed of multiple high-strength magnets embedded, arranged in an alternating "N-pole-S-pole-N-Pole-S-pole" polarity pattern along the circumferential direction. Correspondingly, the inner ring magnetic assembly 301 is also composed of multiple high-strength magnets embedded on the outer circumference of the upper section of the inner stator shaft 3, with the magnetic poles also arranged in an alternating polarity pattern. A radial air gap is maintained between the outer circumferential surface of the inner ring magnetic assembly 301 and the inner circumferential surface of the outer ring magnetic assembly 203, forming a non-contact fit. The number of inner ring magnets and the number of pole pairs are matched with those of outer ring magnets to ensure that, under normal meshing conditions, the N pole of the inner ring is directly opposite the S pole of the outer ring, forming a high-gradient closed magnetic circuit across the air gap, thereby generating a strong tangential anti-shear magnetic force and forming a non-contact transmission connection through magnetic field coupling.

[0022] It should be noted that the fixing method of the outer ring magnetic component 203 and the inner ring magnetic component 301 is not limited to embedded fixing. In another embodiment of the present invention, adhesive fixing can also be used. Specifically, as Figure 6 As shown, the upper section of the inner stator shaft 3 is provided with an annular bearing platform, and the bottom surface of the inner ring magnetic assembly 301 is fixed to this platform with adhesive. Although the magnetic assembly is subjected to tangential shear force during operation, the bonding strength provided by the high-strength structural adhesive is sufficient to meet the torque transmission requirements. In this embodiment, the inner ring magnetic assembly 301 is composed of multiple magnet units circumferentially spliced ​​together, and its outer surface together forms a regular cylindrical outline to ensure that a uniform air gap is formed between it and the outer ring magnetic assembly 203.

[0023] It should be noted that the outer ring magnetic assembly 203 and the inner ring magnetic assembly 301 can also be fixed to the corresponding positions of the outer rotor frame 2 and the inner stator shaft 3 by adhesive bonding. Since the outer ring magnetic assembly 203 and the inner ring magnetic assembly 301 are subjected to shear force during operation, the adhesive force is sufficient. Figure 6 The image shows one embodiment of the inner ring magnetic component 301, which is attached to a circular platform by means of its bottom. As long as the outer circumference of the inner ring magnetic component 301 is a cylinder.

[0024] The lower section of the inner stator shaft 3 is connected to the slide groove of the output frame 1 through a non-circular cross-section fit. In this embodiment, a square tenon shaft 302 is preferably used to fit with a square tenon slide groove 101, so as to realize that the inner stator shaft 3 and the output frame 1 can rotate synchronously in the circumference and slide axially. It should be noted that the non-circular cross-section fit connection can also be a hexagonal tenon, spline or D-type shaft, etc.

[0025] In this embodiment, external power is transmitted through the output frame 1, driving the inner stator shaft 3 to rotate. Due to the strong magnetic attraction between the inner and outer ring magnetic components 203, the inner stator shaft 3 drives the outer rotor frame 2 and the sensor 9 on top to rotate synchronously. When the load torque is less than the magnetic coupling torque, the device performs rigid transmission; when an overload occurs, the mechanical shear force between the outer rotor frame 2 and the inner stator shaft 3 exceeds the horizontal component of the magnetic attraction force, causing the inner and outer magnetic poles to momentarily misalign (N pole to N pole), resulting in relative sliding and cutting off torque transmission, thus protecting the sensor 9 from damage.

[0026] Example 2

[0027] This embodiment is a further improvement based on Embodiment 1. For example... Figure 3 and Figure 7 As shown, this embodiment includes a torque adjustment mechanism, comprising an adjusting screw 8 and a return spring 7. The return spring 7 is positioned between the top of the inner stator shaft 3 and the sleeve 202 of the outer rotor frame 2, ensuring that the inner stator shaft 3 is always subjected to a downward preload. The adjusting screw 8 is threaded into the bottom of the slide groove of the output rotor frame 1, with its top end abutting against the bottom surface of the inner stator shaft 3.

[0028] This embodiment utilizes the rotating adjusting screw 8 to adjust the overlap area between the magnetic components, thereby achieving adjustment of the magnetic transmission. The specific adjustment principle is as follows: When the adjusting screw 8 is turned clockwise, it overcomes the spring force of the return spring 7, pushing the square tenon shaft 302 of the inner stator shaft 3 upward along the square tenon groove 101 of the output frame 1. At this time, the effective overlap area in the axial direction between the inner ring magnetic assembly 301 on the inner stator shaft 3 and the outer ring magnetic assembly 203 on the outer rotor frame 2 increases, such as... Figure 7As shown in state (1), with the increase of the overlapping area, the magnetic flux involved in the coupling increases significantly, which increases the mutual magnetic attraction between the outer rotor frame 2 and the inner stator shaft 3, thereby increasing the preset torque value of the device.

[0029] Conversely, when the adjusting screw 8 is unscrewed, the inner stator shaft 3 returns to its original position under the action of the return spring 7, and the effective overlap area becomes smaller, such as... Figure 7 As shown in state (2), as the overlapping area decreases, the magnetic flux involved in the coupling decreases significantly, which reduces the mutual magnetic attraction between the outer rotor frame 2 and the inner stator shaft 3, and consequently reduces the preset torque value of the device.

[0030] Through the above structure, this embodiment simplifies complex electromagnetic control into reliable mechanical displacement control. Users only need to adjust the screw at the bottom to accurately set the overload protection threshold according to the specific range of sensor 9, thereby realizing torque adjustment.

[0031] Example 3

[0032] like Figure 6 As shown, this embodiment is a supplement to embodiment 2. A hemispherical boss 303 is provided at the end of the square tenon shaft 302 of the inner stator shaft 3. This hemispherical boss 303 is used to contact the adjusting screw 8. The arc surface design ensures that the adjusting screw 8 forms a point-to-surface contact during rotation adjustment, resulting in smooth twisting and the force point is always concentrated on the central axis, avoiding jamming or uneven wear.

[0033] Example 4

[0034] like Figure 3 As shown, this embodiment is a structural supplement to the above embodiment. To ensure the axial stability of the rotating components during high-speed operation or magnetic slippage, and to prevent axial movement after the inner stator shaft 3 is adjusted to the correct position, this embodiment has a shaft end retaining ring 5 on the outer circumference of the sleeve 202 of the outer rotor frame 2 to limit the axial displacement of the outer ring of the bearing 6; and a hole end retaining ring 4 on the inner cylindrical surface of the output frame 1 to limit the axial displacement of the inner ring of the bearing 6. This double retaining ring design, together with the adjusting screw 8 at the bottom, constitutes a stable axial constraint system, ensuring that the device can maintain the set magnetic coupling gap and overlap area unchanged at the moment of overload slippage, thus ensuring the repeatability and reliability of the overload protection action.

Claims

1. A sensor base buffer with adjustable torque controlled by magnetic force, characterized in that: The system includes an output rotating frame (1), an outer rotor frame (2), and an inner stator shaft (3). The outer rotor frame (2) includes a top cover (201) and a sleeve (202) vertically positioned at the center of the lower end face of the top cover (201). The top of the outer rotor frame (2) is used to mount a sensor (9). The output rotating frame (1) includes an upward-opening cup-shaped structure and a downward-extending groove along the axis. The cup-shaped structure of the output rotating frame (1) is mounted on the sleeve (202) of the outer rotor frame (2) via a bearing (6). The inner cavity of the sleeve (202) of the outer rotor frame (2) and the groove of the output rotating frame (1) form a cavity, and the inner stator shaft (3) is disposed in this cavity. The outer rotor frame (2) sleeve (202) has an outer ring magnetic component (203) on its inner circumferential wall, and the upper section of the inner stator shaft (3) has an inner ring magnetic component (301) that cooperates with the outer ring magnetic component (203) on its outer circumferential wall. The lower section of the inner stator shaft (3) is slidably inserted into the groove of the output frame (1), and the lower section of the inner stator shaft (3) and the groove of the output frame (1) are connected by a non-circular cross section. A torque adjustment mechanism is provided between the output frame (1) and the inner stator shaft (3) to adjust the axial displacement of the inner stator shaft (3) relative to the outer rotor frame (2), thereby changing the axial overlap area of ​​the inner ring magnetic component (301) and the outer ring magnetic component (203).

2. The sensor base buffer with adjustable torque controlled by magnetic force according to claim 1, characterized in that: The inner stator shaft (3) is a stepped shaft with the upper section having a larger diameter than the lower section. The upper section is a magnetic coupling section, and the lower section is a guide section. The magnetic coupling section is a cylindrical shaft with an annular groove on its outer circumferential surface for installing the inner ring magnetic component (301).

3. A sensor base buffer with adjustable torque controlled by magnetic force according to claim 1, characterized in that: The torque adjustment mechanism includes an adjusting screw (8) and a return spring (7); the return spring (7) is located between the top of the inner stator shaft (3) and the sleeve (202) of the outer rotor frame (2), one end of the return spring (7) abuts against the top of the inner stator shaft (3), and the other end abuts against the lower surface of the top cover (201) of the outer rotor frame (2); the lower section of the slide groove of the output frame (1) is provided with a threaded hole (102), and the adjusting screw (8) is threadedly connected in the threaded hole (102) of the lower section of the slide groove of the output frame (1), and the top of the adjusting screw (8) abuts against the end face of the lower section of the inner stator shaft (3); by screwing in or out the adjusting screw (8), the inner stator shaft (3) is pushed to overcome the elastic force of the return spring (7) to generate axial displacement.

4. A sensor base buffer with adjustable torque controlled by magnetic force according to claim 3, characterized in that: The lower end face of the inner stator shaft (3) is provided with a hemispherical boss (303), which is used to contact the adjusting screw (8).

5. A sensor base buffer with adjustable torque controlled by magnetic force according to claim 1, characterized in that: The outer ring magnetic assembly (203) includes multiple identical high-strength outer ring magnets, which are equally spaced and embedded in the inner circumferential wall of the outer rotor frame (2) sleeve (202) to form an inner circumferential surface; the inner ring magnetic assembly (301) includes multiple identical high-strength inner ring magnets, which are equally spaced and embedded in the outer circumferential wall of the upper section of the inner stator shaft (3) to form an outer circumferential surface; an air gap is maintained radially between the inner circumferential surface of the outer ring magnetic assembly (203) and the outer circumferential surface of the inner ring magnetic assembly (301) to form a non-contact magnetic coupling interface; the magnets in both sets of magnetic assemblies are arranged in an alternating manner of N pole and S pole along the circumferential direction to form a closed magnetic circuit in the air gap to generate tangential anti-shear magnetic force.

6. A sensor base buffer with adjustable torque controlled by magnetic force according to claim 1, characterized in that: The non-circular cross-section fitting structure is specifically a square tenon fitting structure; the slide of the output rotating frame (1) is a square tenon slide (101), the lower section of the inner stator shaft (3) is a corresponding square tenon shaft (302), and the square tenon shaft (302) is inserted into the square tenon slide (101).

7. A sensor base buffer with adjustable torque controlled by magnetic force according to claim 1, characterized in that: The bearing (6) is a deep groove ball bearing (6). The output frame (1) and the outer rotor frame (2) are respectively provided with retaining rings at both ends of the bearing (6) to limit the axial displacement of the bearing (6).

8. A sensor base buffer with adjustable torque controlled by magnetic force according to claim 1, characterized in that: The bottom of the output turntable (1) is provided with a drive interface for docking with external testing instruments.

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