A quick-lock self-compensating seal end cover for a robot motor

Abstract

The application relates to the technical field of robot motor end covers, in particular to a quick-locking self-compensation sealing end cover for a robot motor, which comprises an end cover main body, a magnetic fluid quick-locking mechanism, an elastic piece, a sealing assembly, a deformation detection piece and a controller. The storage cavity is provided with a magneto-rheological fluid, and the yield stress of the magneto-rheological fluid reversibly changes with the magnetic field intensity. The deformation detection piece obtains the deformation amplitude of the elastic piece, the controller compares the deformation amplitude with the corresponding locking force and the target deformation variable of the sealing force to obtain a deviation, synchronously sets the target values of the locking force and the sealing force control loop and adjusts the excitation strength of the magnetic field acting piece, the magneto-rheological fluid solidifies to limit the clamping piece to form quick locking, and when the magneto-rheological fluid softens, the stroke of the clamping piece is adjusted by the elastic piece to realize release, and the elastic piece adaptively compensates the axial gap between the end cover and the motor shell with the stroke change of the clamping piece. The application solves the technical problem of synchronous self-compensation of the locking force and the sealing force of the end cover under the working conditions of wear and temperature drift.

Description

Technical Field

[0001] This application relates to the field of robot motor end cap technology, and in particular to a quick-locking self-compensating sealing end cap for robot motors. Background Technology

[0002] In the joint drive systems of industrial and collaborative robots, the motor end cap serves multiple functions, including support, sealing, and quick replacement. In related technologies, the motor end cap and motor housing are typically connected by threads, and a rubber sealing ring or mechanical seal is installed between the end cap and the motor housing to maintain dust and water resistance. The end cap is installed and removed using tools, and the connection and sealing structures are independent of each other.

[0003] During long-term use, the end caps of related technologies experience thermal expansion due to motor temperature rise and rotational wear, leading to a gradual increase in the axial clearance between the end cap and the motor housing. Meanwhile, the elasticity of the rubber sealing ring continuously decreases with aging and temperature rise, resulting in a decline in sealing force and a degradation of dustproof and waterproof ratings. Simultaneously, the threaded connection is at risk of loosening under vibration conditions, requiring periodic shutdowns for re-tightening, which disrupts continuous production line operation. The root cause of these defects lies in the fact that the end caps of these technologies design the quick-lock and seal as independent static structures, failing to establish a closed-loop mechanism for synchronously adjusting the locking and sealing forces according to wear and temperature drift. This results in the sealing and locking forces being unable to adaptively compensate for changes in axial clearance.

[0004] In summary, how to solve the technical problem of synchronous self-compensation of locking force and sealing force of robot motor end cap under wear and temperature drift conditions is a technical challenge that urgently needs to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a quick-locking self-compensating sealing end cap for robot motors. Through the synergy of a magnetorheological fluid quick-locking mechanism and the self-compensation of an elastic element, and by utilizing a progressively deep stacking process driven by a dual-closed-loop collaborative control system with a physical mirror model, the technical problem of synchronous self-compensation of locking force and sealing force under wear and temperature drift conditions is solved. This allows the end cap to maintain stable locking and sealing forces and adaptively compensate for axial clearance during frequent quick-locking and releasing processes.

[0006] To achieve the above objectives, the present invention provides a quick-locking self-compensating sealing end cap for a robot motor, comprising an end cap body, a magnetorheological quick-locking mechanism, an elastic element, a sealing assembly, a deformation detection element, and a controller; the end cap body is provided with a limiting slot; the magnetorheological quick-locking mechanism includes a storage cavity, a locking element, and a magnetic field action element, the storage cavity having an opening, and a magnetorheological fluid disposed within the storage cavity, the yield stress of the magnetorheological fluid changing reversibly with the magnetic field strength; and further comprising the following quick-locking and self-compensating steps: Step 1, obtaining the deformation amplitude of the elastic element through the deformation detection element; Step 2, the controller comparing the deformation amplitude with preset first target deformation and second target deformation respectively to obtain the locking force deviation and sealing force deviation; the first target deformation corresponds to the locking force of the locking element, the second... The target deformation corresponds to the sealing force of the sealing component; the controller synchronously sets the target values ​​of the locking force control circuit and the sealing force control circuit according to the locking force deviation and the sealing force deviation; Step 3: The controller adjusts the excitation intensity of the magnetic field action component according to the target value to adjust the hardness of the magnetorheological fluid, thereby synchronously adjusting the locking force of the locking component and the sealing force of the sealing component, so that the locking force and the sealing force reach their respective target values; Step 4: When the magnetorheological fluid hardens, it forms a limit on the locking component, causing the locking component to press against the limit groove to form a quick lock; when the magnetorheological fluid softens, the elastic component adjusts the stroke of the locking component along the axial displacement of the opening to achieve release; Step 5: The elastic component adaptively compensates for the axial gap between the end cover body and the motor housing as the stroke of the locking component changes.

[0007] In the above technical solution, the magnetorheological fluid quick-lock mechanism serves as the execution unit for end cap quick-lock and sealing force adjustment. The magnetorheological fluid in the storage cavity undergoes reversible changes in yield stress under the action of a magnetic field, causing the locking component to be limited and pressed against the limiting groove to form a quick lock when the magnetorheological fluid hardens. When the magnetorheological fluid softens, the elastic component adjusts the stroke of the locking component along the axial displacement of the opening to achieve release. The elastic component adaptively compensates for the axial gap between the end cap body and the motor housing when the stroke of the locking component changes. The deformation detection component acquires the deformation amplitude of the elastic component and converts it into an electrical signal. The controller compares the deformation amplitude with the first target deformation and the second target deformation to obtain the locking force deviation and sealing force deviation, and synchronously sets the target values ​​of the locking force control loop and the sealing force control loop. The excitation intensity of the magnetic field action component is adjusted to synchronously adjust the locking force and sealing force.

[0008] Preferably, in the quick-locking process of step four, the magnetic field action component is an electromagnetic coil wound around the outer periphery of the storage cavity. When the electromagnetic coil is energized, the magnetorheological fluid is solidified. The solidified magnetorheological fluid forms a limit on the locking component, causing the locking component to press against the limiting slot.

[0009] In the above technical solution, the electromagnetic coil is wound around the outer periphery of the storage cavity. After being energized, the magnetorheological fluid is solidified within milliseconds. The solidified magnetorheological fluid forms a hard limit on the locking component, and the fast lock response is rapid and avoids loosening of the threads under vibration conditions.

[0010] Preferably, during the release process in step four, when the end cap body and the motor housing need to be separated, the magnetorheological fluid is softened, and the locking component and the elastic component slide along the axial direction of the opening into the storage cavity, so that the end cap body and the motor housing can be easily separated, while preventing the locking component from separating from the motor housing.

[0011] In the above technical solution, after the magnetorheological fluid is softened, the locking component and the elastic component slide along the opening axis into the storage cavity, making it easy to separate the end cap body from the motor housing, and the locking component remains connected to the motor housing, so that the release process is smooth and prevents it from falling off.

[0012] Preferably, in step four, the locking component remains in contact with the end cap body when the magnetorheological fluid hardens, and the locking component releases contact with the end cap body as the magnetorheological fluid softens, while the locking component remains connected to the motor housing.

[0013] In the above technical solution, the locking component remains in contact with the end cap body when the magnetorheological fluid hardens, and is released from contact while still connected to the motor housing when it softens, making the switching between the quick lock and release states clear and the connection reliable.

[0014] Preferably, in the self-compensation process of step five, the sealing assembly includes a first seal and a second seal. The first seal is disposed at the annular end face between the end cover body and the motor housing, and the second seal is disposed at the rotational gap between the end cover body and the motor spindle.

[0015] In the above technical solution, the first sealing element forms a seal at the annular end face and the second sealing element forms a seal at the rotation gap, respectively. The end face seal and the rotation seal work together to cover the two leakage channels of the end cover.

[0016] Preferably, in step one, the deformation detection device is a deformation sensor or a displacement sensor. The deformation detection device collects the deformation signal of the elastic element at a set sampling frequency, filters the deformation signal to remove vibration interference caused by motor operation, extracts the deformation amplitude of the elastic element, and converts the deformation amplitude into an electrical signal and outputs it to the controller.

[0017] In the above technical solution, the deformation detection device collects data at a set sampling frequency and filters the deformation signal to remove vibration interference. The extracted deformation amplitude accurately reflects the change in axial clearance, providing reliable feedback to the controller.

[0018] Preferably, in step two, the controller has a first target deformation and a second target deformation preset. The first target deformation corresponds to the locking force of the locking component, and the second target deformation corresponds to the sealing force of the sealing component. The controller reads the electrical signal to determine the deformation amplitude, and compares the deformation amplitude with the first target deformation and the second target deformation to obtain the locking force deviation and the sealing force deviation. The locking force deviation and the sealing force deviation are used to synchronously set the target values ​​of the locking force control loop and the sealing force control loop, so that the same magnetorheological fluid can simultaneously and actively adjust the locking force of the locking component and the sealing force of the sealing component through a closed loop of a single deformation detection element.

[0019] In the above technical solution, the first target deformation and the second target deformation correspond to the locking force and the sealing force, respectively. The same magnetorheological fluid actively adjusts the locking force of the locking component and the sealing force of the sealing component simultaneously through a closed loop by a single deformation detection element, so that the two forces are synchronized and the structure is simplified.

[0020] Preferably, in step three, the storage cavity is divided into multiple independent sub-cavities along the circumference. Each sub-cavity is equipped with an independent electromagnetic coil and an independent magnetic field detection device. The controller performs dual closed-loop collaborative control for each cavity, specifically including: for each sub-cavity, the deformation detection device obtains the deformation amplitude of the elastic element at the contact section of the corresponding locking element and forms the deformation deviation of the corresponding sub-cavity. The outer loop control loop sets a target yield stress that matches the locking force and sealing force of the sub-cavity based on the deformation deviation of the sub-cavity. The inner loop control loop detects the actual magnetic field strength in the sub-cavity using the magnetic field detection device of the sub-cavity and calculates the actual yield stress. The adjustment current of the sub-cavity is corrected based on the magnetic field deviation between the actual yield stress and the target yield stress, so that the actual yield stress of each sub-cavity converges to its respective target yield stress, thereby making the contact stress distribution of the locking element along the circumference more balanced. The dual closed-loop collaborative control for each cavity enables the locking force and sealing force to self-compensate synchronously with wear and temperature drift and tend to be circumferentially balanced, rather than eliminating the hysteresis of the magnetorheological fluid itself or compensating for the time delay of the control loop.

[0021] In the above technical solution, the dual closed-loop collaborative control of the compartment divides the storage cavity into multiple independent sub-cavities and configures independent magnetic field detection devices. The outer loop control loop sets the target yield stress, and the inner loop control loop adjusts the current by correcting the actual yield stress calculated from the actual magnetic field strength, so that the actual yield stress of each sub-cavity converges to its respective target yield stress. The contact stress distribution of the locking device along the circumferential direction tends to be balanced, and the locking force and sealing force are self-compensated synchronously with wear and temperature drift.

[0022] Preferably, in the softening and releasing step four and the self-compensation step five, the elastic element is composed of a magnetorheological fluid-compatible elastic matrix and a shape memory alloy wire embedded in the elastic matrix. The shape memory alloy wire is distributed in the radial section of the elastic element sealing the opening of the storage cavity, and as the magnetorheological fluid softens, the elastic element coordinates with the sliding stroke of the locking element along the axial displacement of the opening. When the motor temperature rises, the shape memory alloy wire generates a passive preload that increases monotonically with temperature to partially offset the increase in axial clearance caused by temperature drift. Furthermore, the magnetorheological fluid has a gradient concentration distribution along the axial direction of the opening, and the concentration in the contact area where the locking element abuts against the limiting groove is higher than the stroke of the locking element. The magnetorheological fluid (MRF) contains temperature-sensitive phase change microcapsules. When the motor temperature rises to the phase change temperature, the microcapsules change from a liquid state to a high-viscosity state, increasing the apparent yield stress of the MRF under temperature rise conditions to compensate for the attenuation of sealing force caused by temperature drift. The passive pre-tightening and active stroke adjustment of the shape memory alloy wire, the axial gradient concentration locking of the MRF, and the phase change thickening of the temperature-sensitive microcapsules work together to form a medium-structure dual-mode compensation. The dual-mode compensation is integrated into the quick-lock-seal-self-compensation overall structure of the end cap body, which is different from the scenario of using shape memory alloys or temperature-sensitive phase change microcapsules for transmission torque or rotary shaft sealing.

[0023] In the above technical solution, the shape memory alloy wire generates a passive preload that increases monotonically with temperature when the motor temperature rises, partially offsetting the increase in axial clearance. The magnetorheological fluid exhibits a gradient concentration distribution along the opening axis, with a higher concentration in the contact area. The thermosensitive phase change microcapsules transform into a high-viscosity state when the phase change temperature is reached, increasing the apparent yield stress. The dual-mode compensation of the medium and structure synergistically offsets the attenuation of sealing force caused by temperature drift, which is different from the scenario of using shape memory alloys or thermosensitive phase change microcapsules for transmission torque or rotating shaft sealing.

[0024] Preferably, in step three, the dual-closed-loop collaborative control of the sub-cavities is executed according to a progressively deeper stacking process driven by the physical mirror model. Specifically, this includes: the controller establishing a physical mirror model representing the axial gap between the end cap body and the motor housing. The physical mirror model is composed of four functional layers stacked progressively: a mirror prediction layer, a self-tuning layer, a resource scheduling layer, and a correction layer. The mirror prediction layer constructs a continuous state sequence of the axial gap based on the effective deformation amplitude sequence and the actual magnetic field strength of each sub-cavity, and predicts the gap change envelope for multiple future control cycles. The self-tuning layer identifies the aging coefficient and temperature drift of the magnetorheological fluid online based on the deviation between the actual axial gap and the output of the mirror prediction layer. The coefficients are dynamically updated in the mirror prediction layer using the weighted average weight decay coefficient, first-order difference step size, and temperature correction coefficient used in the correction layer, with the deviation as the update direction. The weight decay coefficient, first-order difference step size, and temperature correction coefficient satisfy the following relationships: the weight coefficient of the weighted average decays over time, making the contribution of samples closer to the current time greater; the first-order difference step size is equal to an integer multiple of the control period; and the weight decay coefficient, difference step size, and temperature correction coefficient monotonically migrate with the deviation direction. Under the constraints of the lower limit of locking force and the lower limit of sealing force, the resource scheduling layer aims to minimize the total excitation energy consumption of multiple sub-cavities and distributes the adjustment current of each sub-cavity according to the gap change envelope. The resource scheduling layer allocates the regulating current of each sub-cavity according to the steepness of the gap change envelope, with a steeper gap change envelope resulting in a larger increment of the regulating current for the corresponding sub-cavity. The correction layer compares the actual magnetic field strength with the set magnetic field strength to obtain the magnetic field deviation, and corrects the regulating current based on the magnetic field deviation, causing the actual axial gap to converge to the target gap range. The correction layer multiplies the magnetic field deviation by a temperature correction coefficient that varies with temperature and then adds it to the regulating current to compensate for the change in the permeability of the magnetorheological fluid with temperature. External pressure is detected by an environmental pressure sensor, and the controller determines the reference excitation current based on the external pressure, which increases proportionally with the increase of external pressure to convert the external pressure into density. Sealing force gain; the reference excitation current serves as the baseline excitation for both the resource scheduling layer and the correction layer when the deviation is 0; the gap change envelope, as the same feedforward physical quantity, simultaneously drives the current distribution of the resource scheduling layer and the magnetic field deviation compensation of the correction layer, enabling the mirror prediction layer, resource scheduling layer, and correction layer to form a strongly coupled closed loop through the actual axial gap; when the gap change envelope indicates that the lower limit of locking force and the lower limit of sealing force will be breached simultaneously, priority is given to ensuring the lower limit of sealing force and the remaining excitation energy is used for locking force compensation; when the magnetic field detection device or controller fails, the magnetic field action device returns to the state of being excited only by the reference excitation current, the magnetorheological fluid returns to the reference softness and hardness, and the passive compensation of the elastic element is withdrawn.

[0025] In the above technical solution, a digital twin of the axial gap is established by the physical mirror model. The mirror prediction layer, self-tuning layer, resource scheduling layer and correction layer are stacked in order of data flow. The gap change envelope is used as the same feedforward physical quantity to drive the resource scheduling layer and the correction layer. The mirror prediction layer, resource scheduling layer and correction layer form a strongly coupled closed loop through the actual axial gap, which takes into account the total excitation energy consumption of the multi-cavity and the lower limit of the locking force and sealing force. When the external pressure increases, the reference excitation current is proportionally raised and converted into sealing force gain. When the magnetic field detection device or controller fails, the elastic element is passively compensated, thus improving safety and adaptability.

[0026] Compared with related technologies, the present invention has the following beneficial effects: First, the magnetorheological fluid quick-lock mechanism achieves quick-lock and sealing force adjustment simultaneously with the same medium. The locking component is limited to form a quick lock when the magnetorheological fluid hardens, and the elastic component adjusts the stroke to release when it softens. The switching between quick lock and release does not require mechanical screwing, which simplifies the structure and makes the response rapid. Second, the dual-closed-loop collaborative control of the compartment divides the storage cavity into multiple independent sub-cavities and configures independent magnetic field detection devices. The deformation detection device obtains the deformation amplitude of the elastic element at the contact section of the corresponding locking element to form the deformation deviation of the sub-cavity. The outer loop control loop sets the target yield stress, and the inner loop control loop corrects and adjusts the current based on the actual yield stress calculated by the actual magnetic field strength, so that the actual yield stress of each sub-cavity converges to its respective target yield stress. The contact stress distribution of the locking element along the circumferential direction tends to be balanced, and the locking force and sealing force self-compensate synchronously with wear and temperature drift. Third, the elastic component is composed of a magnetorheological fluid compatible elastic matrix and a shape memory alloy wire. When the motor temperature rises, the shape memory alloy wire generates a passive preload force that increases monotonically with temperature, which partially offsets the increase in axial clearance. The magnetorheological fluid has a gradient concentration distribution along the opening axis and a higher concentration in the contact area. The temperature-sensitive phase change microcapsules turn into a high viscosity state when the phase change temperature is reached, which increases the apparent yield stress. The dual-mode compensation of medium and structure synergistically offsets the attenuation of sealing force caused by temperature drift. Fourth, the physical mirror model-driven, progressively stacked process establishes a digital twin of the axial gap. The mirror prediction layer, self-tuning layer, resource scheduling layer, and correction layer are stacked progressively according to the data flow direction. The gap change envelope serves as the same feedforward physical quantity, simultaneously driving the resource scheduling layer and the correction layer. The mirror prediction layer, resource scheduling layer, and correction layer form a strongly coupled closed loop through the actual axial gap, taking into account both the total excitation energy consumption of the multi-cavity system and the lower limit of the locking and sealing force. When the external pressure increases, the reference excitation current is proportionally raised and converted into sealing force gain. When the magnetic field detection device or controller fails, the elastic component passively compensates, thus improving safety and adaptability. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the present invention.

[0028] The reference numerals in the figures include: 10. End cap body; 11. Limiting slot; 20. Magnetohydrodynamic quick-lock mechanism; 21. Storage cavity; 211. Opening; 22. Magnetohydrodynamic fluid; 23. Locking component; 24. Magnetic field action component; 30. Elastic components; 40. Sealing assembly; 41. First seal; 42. Second seal; 50. Deformation testing components; 60. Motor housing. Detailed Implementation

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0030] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, top, bottom, inside, outside, vertical, horizontal, longitudinal, counterclockwise, clockwise, circumferential, radial, axial, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0031] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0032] Example 1 (Joint Motors of a 6-Axis Collaborative Robot) refer to Figure 1This embodiment provides a quick-locking self-compensating sealing end cap for a robot motor, applied to the joint motor of a 6-axis collaborative robot. The joint motor has a rated power of 750 watts and a motor spindle diameter of 40 mm. The end cap body 10 is die-cast from ADC12 aluminum alloy and has a limiting slot 11. The magnetorheological quick-locking mechanism 20 includes a storage cavity 21, a locking component 23, and a magnetic field action component 24. The storage cavity 21 is an annular groove surrounding the motor spindle with a volume of 6 ml. The storage cavity 21 has an opening 211 and is filled with magnetorheological fluid 22. The magnetorheological fluid 22 has a formulation of 38% carbonyl iron powder by volume, a carbonyl iron powder particle size of 3 to 5 micrometers, and dimethyl silicone oil as the carrier fluid. The zero-field viscosity of the dimethyl silicone oil is 0.8 Pa·s. The yield stress of the magnetorheological fluid 22 changes reversibly with the magnetic field strength in the range of 0 to 1.0 Tesla, corresponding to a yield stress increase from 0.5 kPa to 45 kPa. The locking element 23 consists of six pins evenly distributed around the circumference of the storage cavity 21, with a total stroke of 1.2 mm. The deformation detection element 50 is a resistance strain gauge adhered to the surface of the elastic element 30. The strain gauge is a BF350 with a grid length of 3 mm. The deformation detection element 50 acquires the deformation amplitude of the elastic element 30 and converts it into an electrical signal output to the controller. The controller uses an STM32F407 microcontroller with a control cycle of 5 milliseconds, i.e., a control loop frequency of 200 Hz. The controller is signal-connected to the magnetic field actuator 24 and the deformation detection element 50 to execute the fast-lock and self-compensation steps.

[0033] Step 1: Obtain the deformation amplitude of the elastic element 30 through the deformation detection element 50.

[0034] Step 2: The controller compares the deformation amplitude with the preset first target deformation and second target deformation to obtain the locking force deviation and sealing force deviation. The first target deformation corresponds to the locking force of the locking component 23. The first target deformation is set to 0.85 mm of deformation of the elastic component 30 when the locking component 23 is locked in place, corresponding to a locking force target value of 800 N. The second target deformation corresponds to the sealing force of the sealing component 40. The second target deformation is set to 1.15 mm of deformation of the elastic component 30 when the seal is in place, corresponding to a sealing force target value of 150 N. The controller synchronously sets the target values ​​of the locking force control circuit and the sealing force control circuit according to the locking force deviation and the sealing force deviation.

[0035] Step 3: The controller adjusts the excitation intensity of the magnetic field action component 24 according to the target value to adjust the hardness of the magnetorheological fluid 22, thereby synchronously adjusting the locking force of the locking component 23 and the sealing force of the sealing component 40, so that the locking force and sealing force reach their respective target values.

[0036] Step 4: When the magnetorheological fluid 22 hardens, it limits the locking member 23, causing the locking member 23 to press against the limiting groove 11 to form a quick lock. When the magnetorheological fluid 22 softens, the elastic member 30 adjusts the stroke of the locking member 23 along the axial displacement of the opening 211 to achieve release.

[0037] Step 5: The elastic element 30 adaptively compensates for the axial gap between the end cover body 10 and the motor housing 60 as the stroke of the locking element 23 changes.

[0038] The working principle of this embodiment is as follows: the deformation detection component 50 collects the deformation signal of the elastic component 30 at a sampling frequency of 1 kHz. The deformation signal is filtered by a second-order Butterworth low-pass filter and the vibration interference caused by the motor operation is removed by a cutoff frequency of 50 Hz. The deformation amplitude of the elastic component 30 is extracted and output to the controller after 12-bit analog-to-digital conversion. The controller compares the deformation amplitude with the first target deformation and the second target deformation to obtain the locking force deviation and the sealing force deviation. The target values ​​of the locking force control loop and the sealing force control loop are set synchronously. The magnetic field actuator 24 is driven by 20 kHz pulse width modulation to adjust the excitation intensity of the magnetic field actuator 24 to synchronously adjust the locking force and sealing force of the locking component 23. The sealing force of component 40; the magnetorheological fluid 22 in the storage cavity 21 reversibly increases its yield stress under the magnetic field applied by the magnetic field action member 24. After the magnetorheological fluid 22 solidifies, it forms a limit on the locking member 23, so that the locking member 23 presses against the limiting groove 11 to complete the quick lock. When it is necessary to release, the magnetic field action member 24 is de-energized or the excitation is weakened, the magnetorheological fluid 22 softens, and the elastic member 30 adjusts the stroke of the locking member 23 along the axial displacement of the opening 211, so that the end cover body 10 and the motor housing 60 can be easily separated; the elastic member 30 adaptively compensates the axial gap between the end cover body 10 and the motor housing 60 as the stroke of the locking member 23 changes, so that the end cover maintains a stable sealing force and locking force under wear and temperature drift conditions.

[0039] This embodiment, based on Embodiment 1, further elaborates on the complete structure of the magnetorheological quick-lock mechanism 20 and the quick-lock and release process. The magnetic field actuating element 24 is an electromagnetic coil wound around the outer periphery of the storage cavity 21. The electromagnetic coil uses QZ-2 enameled copper wire with a wire diameter of 0.6 mm and 240 turns. The DC resistance of the electromagnetic coil is 4.2 ohms, the rated current is 2.5 A, and it can generate a magnetic field strength of 0.85 Tesla. After the electromagnetic coil is energized, the magnetorheological fluid 22 solidifies within 30 milliseconds, and the yield stress increases from 0.5 kPa to 42 kPa. The solidified magnetorheological fluid 22 forms a hard limit on the locking element 23, causing the locking element 23 to press against the limiting slot 11. The quick-lock response time from the soft state to the hard state and pressing against the limiting slot 11 does not exceed 45 milliseconds. When the end cap body 10 needs to be separated from the motor housing 60, the electromagnetic coil is de-energized, and the magnetorheological fluid 22 softens within 60 milliseconds. The locking member 23 and the elastic member 30 slide along the axial direction of the opening 211 into the storage cavity 21, making it easy to separate the end cap body 10 from the motor housing 60, while preventing the locking member 23 from separating from the motor housing 60. When the magnetorheological fluid 22 hardens, it maintains the contact state between the locking member 23 and the end cap body 10. When the magnetorheological fluid 22 softens, the locking member 23 releases its contact with the end cap body 10 as the magnetorheological fluid 22 softens, while the locking member 23 remains connected to the motor housing 60.

[0040] This embodiment, based on Embodiment 1, further elaborates on the structure of the sealing assembly 40 and the deformation detection element 50. The sealing assembly 40 includes a first seal 41 and a second seal 42. The first seal 41 is a fluororubber annular sealing ring with a Shore hardness of 70, and is located at the annular end face between the end cap body 10 and the motor housing 60, with an installation compression of 0.4 mm. The second seal 42 is a silicon carbide-graphite mechanical seal pair, located at the rotational gap between the end cap body 10 and the motor spindle. The deformation detection element 50 is a deformation sensor or displacement sensor. The deformation detection element 50 acquires the deformation signal of the elastic element 30 at a set sampling frequency of 1 kHz, performs a second-order Butterworth low-pass filter with a cutoff frequency of 50 Hz on the deformation signal to remove vibration interference caused by motor operation, extracts the deformation amplitude of the elastic element 30, with a resolution of 1 micrometer, and converts the deformation amplitude into an analog electrical signal of 0 to 3.3 volts, which is then output to the controller.

[0041] This embodiment, based on Embodiment 1, further expands upon dual-target comparison and dual-closed-loop collaborative control of different cavities. The controller has a preset first target deformation and a second target deformation. The first target deformation corresponds to the locking force of the locking member 23, and the second target deformation corresponds to the sealing force of the sealing assembly 40. The controller reads electrical signals to determine the deformation amplitude, and compares the deformation amplitude with the first and second target deformations to obtain the locking force deviation and sealing force deviation. These deviations are used to synchronously set the target values ​​for the locking force control loop and the sealing force control loop, enabling the same magnetorheological fluid 22 to simultaneously and actively adjust the locking force of the locking member 23 and the sealing force of the sealing assembly 40 through a closed loop controlled by a single deformation detection element 50. The storage cavity 21 is divided into six independent sector-shaped sub-cavities along its circumference. Each sub-cavity is equipped with an independent electromagnetic coil and an independent linear Hall magnetic field detector. The linear Hall magnetic field detector is model AH49E with a sensitivity of 1.3 mV / Gauss. For each sub-cavity, the deformation amplitude of the elastic element 30 at the contact section of the corresponding locking element 23 is obtained by the deformation detection element 50, and the deformation deviation of the corresponding sub-cavity is formed. The outer loop control circuit sets a target yield stress that matches the locking force and sealing force of the sub-cavity based on the deformation deviation of the sub-cavity. The target yield stress of each sub-cavity is set to 40 kPa, and the allowable deviation is... The difference is ±2000 Pa; the inner loop control circuit detects the actual magnetic field strength in the sub-cavity by the magnetic field detection device of the sub-cavity and calculates the actual yield stress according to the calibration curve. Based on the magnetic field deviation between the actual yield stress and the target yield stress, the adjustment current of the sub-cavity is corrected by a proportional gain of 0.8 A / kPa, so that the actual yield stress of each sub-cavity converges to its respective target yield stress. After convergence, the actual yield stress of each sub-cavity is 40 kPa ± 1.5 kPa. The unevenness of the contact stress distribution along the circumferential direction of the positioning component 23 is less than 8%, so that the contact stress distribution along the circumferential direction of the positioning component 23 tends to be uniform.

[0042] This embodiment, based on Embodiment 1, further develops the medium-structure dual-mode compensation structure of the elastic element 30. The elastic element 30 is composed of a magnetorheological fluid-compatible elastic matrix and shape memory alloy wires embedded within the elastic matrix. The elastic matrix is ​​nitrile rubber with a Shore hardness of 60. The shape memory alloy wires are nickel-titanium alloy wires with a diameter of 0.3 mm. The austenitic phase transformation end temperature of the nickel-titanium alloy wires is 80 degrees Celsius, and the martensitic phase transformation start temperature is 60 degrees Celsius. Twelve nickel-titanium alloy wires are evenly distributed radially along the elastic element 30, with a pre-tension rate of 4%. The shape memory alloy wires are distributed within the radial section of the opening 211 of the storage cavity 21 sealed by the elastic element 30, and their stroke is adjusted by the elastic element 30 in conjunction with the adjustment of the sliding stroke of the locking element 23 along the axial displacement of the opening 211 as the magnetorheological fluid 22 softens. When the motor temperature rises, the shape memory alloy wires generate a passive pre-tightening force that monotonically increases with temperature, partially offsetting the increase in axial clearance caused by temperature drift. When the motor temperature rises by 20 degrees Celsius, each shape memory alloy wire generates passive pre-tightening. The force is 2.4 N, and the total force for 12 pieces is 29 N, which corresponds to the 0.3 mm increase in axial clearance caused by a 20°C temperature rise. The magnetorheological fluid 22 has a gradient concentration distribution along the axial direction of the opening 211. The carbonyl iron powder volume fraction is 45% in the contact area where the locking part 23 abuts against the limiting groove 11, and 25% in the travel area of ​​the locking part 23. The concentration in the contact area is higher than that in the travel area. The magnetorheological fluid 22 contains thermosensitive phase change microcapsules. The phase change temperature of the thermosensitive phase change microcapsules is 70°C, the particle size is 3 to 8 micrometers, and the amount added accounts for 5% of the mass of the magnetorheological fluid 22. When the motor temperature rises to the phase change temperature, the thermosensitive phase change microcapsules change from a liquid state to a high viscosity state. After the phase change, the apparent viscosity of the magnetorheological fluid 22 increases by 3 times and the apparent yield stress increases by 12%, which increases the apparent yield stress of the magnetorheological fluid 22 under temperature rise conditions to compensate for the attenuation of sealing force caused by temperature drift. The passive pre-tensioning and active stroke adjustment of the shape memory alloy wire, the axial gradient concentration locking of the magnetorheological fluid 22, and the phase change thickening of the thermosensitive phase change microcapsule work together to form a medium-structure dual-mode compensation. The dual-mode compensation is integrated into the quick-lock-seal-self-compensation overall structure of the end cap body 10, which is different from the scenario of using shape memory alloy or thermosensitive phase change microcapsule for transmission torque or rotary shaft sealing.

[0043] This embodiment, based on Embodiment 1, further expands the hierarchical stacking process of the dual-closed-loop collaborative control of the sub-cavities, driven by the physical mirror model. The controller establishes a physical mirror model representing the axial gap between the end cover body 10 and the motor housing 60. This physical mirror model is composed of four functional layers stacked hierarchically: a mirror prediction layer, a self-tuning layer, a resource scheduling layer, and a correction layer. The mirror prediction layer constructs a continuous state sequence of the axial gap based on the effective deformation amplitude sequence and the actual magnetic field strength values ​​of each sub-cavity. The effective deformation amplitude sequence takes 24 consecutive sampling windows, each 5 milliseconds long, covering 120 milliseconds of historical data. The mirror prediction layer predicts the gap change envelope for the next 5 control cycles, totaling 25 milliseconds for the 5 control cycles. The tuning layer identifies the aging coefficient and temperature drift coefficient of the magnetorheological fluid 22 online based on the deviation between the actual axial clearance and the output of the mirror prediction layer. It then dynamically updates the weighted average attenuation coefficient, first-order difference step size, and temperature correction coefficient used by the correction layer, with the deviation as the update direction. The weighted attenuation coefficient is set to 0.88 to maximize the contribution of samples closer to the current time. The first-order difference step size is equal to one control cycle (5 milliseconds). The initial value of the temperature correction coefficient is 1.0, adjusted by 0.015 for every degree Celsius increase in temperature. The weighted attenuation coefficient, difference step size, and temperature... The correction coefficient monotonically migrates with the deviation direction. Under the constraints of the lower limits of locking force and sealing force, the resource scheduling layer aims to minimize the total excitation energy consumption of the multi-cavity sub-cavities. The upper limit of the total excitation energy consumption of the multi-cavities is set to 12 watts. The regulating current of each sub-cavity is distributed according to the gap change envelope. When the slope of the gap change envelope is greater than 0.1 mm, the increment of the regulating current of the corresponding sub-cavity is 0.05 amps per control cycle. The steeper the gap change envelope, the larger the increment of the regulating current of the corresponding sub-cavity. The correction layer compares the actual value of the magnetic field strength with the set value of the magnetic field strength to obtain the magnetic field deviation, and corrects the adjustment based on the magnetic field deviation. The current is used to converge the actual axial clearance to the target clearance range. The correction layer multiplies the magnetic field deviation by a temperature correction coefficient that varies with temperature and then adds it to the regulating current to compensate for the change in the permeability of the magnetorheological fluid 22 with temperature. The external pressure is detected by an environmental pressure sensor with a range of 0 to 0.7 MPa. The controller determines the reference excitation current based on the external pressure and increases it proportionally with the increase of the external pressure. When the external pressure increases from 0 to 0.7 MPa, the reference excitation current increases from 0 to 0.4 A to convert the external pressure into a sealing force gain. For every 0.1 MPa corresponds to a sealing force gain of 20 N. The reference excitation current simultaneously serves as the baseline excitation for both the resource scheduling layer and the correction layer when the deviation is 0. The gap change envelope, as the same feedforward physical quantity, simultaneously drives the current distribution of the resource scheduling layer and the magnetic field deviation compensation of the correction layer, enabling the mirror prediction layer, resource scheduling layer, and correction layer to form a strongly coupled closed loop through the actual axial gap. When the gap change envelope indicates that the lower limit of the locking force and the lower limit of the sealing force will be breached simultaneously, priority is given to ensuring the lower limit of the sealing force, and the remaining excitation energy is used for locking force compensation. When the magnetic field detection device or controller fails, the magnetic field actuator 24 returns to a state where it is only excited by the reference excitation current of 0.15 A, the magnetorheological fluid 22 returns to the reference softness and hardness, the corresponding yield stress of which is 8 kPa, and the passive compensation of the elastic element 30 is reverted.

[0044] For ease of implementation, the following table lists the typical operating parameters of this embodiment. These parameters can be adjusted proportionally according to the motor specifications during implementation: Table 1

[0045] Example 2 (SCARA Industrial Robot Wrist Servo Motor) This embodiment provides a quick-locking self-compensating sealing end cap for a robot motor, applied to the wrist servo motor of a SCARA industrial robot. The wrist servo motor has a rated power of 400 watts and a motor spindle diameter of 32 mm. The end cap body 10 is die-cast from ADC12 aluminum alloy and has a limiting slot 11. The magnetorheological quick-locking mechanism 20 includes a storage cavity 21, a locking element 23, and a magnetic field action element 24. The storage cavity 21 is an annular groove surrounding the motor spindle with a volume of 3.2 ml. The storage cavity 21 has an opening 211 and is filled with magnetorheological fluid 22. The magnetorheological fluid 22 has a formulation of 38% carbonyl iron powder by volume, a particle size of 3 to 5 micrometers, and dimethyl silicone oil as the carrier fluid. The zero-field viscosity is 0.8 Pa·s, and the yield stress changes reversibly with the magnetic field strength in the range of 0 to 1.0 Tesla, increasing from 0.5 kPa to 45 kPa. The locking element 23 consists of four pins evenly distributed around the circumference of the storage cavity 21, with a total stroke of 0.9 mm. The deformation detection element 50 is a BF350 resistance strain gauge with a grid length of 3 mm, bonded to the surface of the elastic element 30. It samples at 1 kHz, uses a second-order Butterworth low-pass filter with a cutoff frequency of 50 Hz, and has a resolution of 1 micrometer. It outputs an analog electrical signal from 0 to 3.3 volts to the controller. The controller uses an STM32F407 microcontroller with a control cycle of 4 milliseconds, i.e., a control loop frequency of 250 Hz.

[0046] This embodiment performs quick locking and self-compensation according to steps one through five: Step one, the deformation detection component 50 obtains the deformation amplitude of the elastic component 30; Step two, the controller compares the deformation amplitude with the first target deformation of 0.6 mm, corresponding to a locking force target value of 500 N, and the second target deformation of 0.85 mm, corresponding to a sealing force target value of 100 N, to obtain the locking force deviation and sealing force deviation and simultaneously set the target values ​​of the two control loops; Step three, the controller adjusts the excitation intensity of the magnetic field action component 24 to simultaneously adjust the locking force of the locking component 23 and the sealing force of the sealing component 40 to their respective target values; Step four, when the magnetorheological fluid 22 hardens, it forms a limit on the locking component 23, causing the locking component 23 to press against the limit slot 11 for quick locking; when it softens, the elastic component 30 adjusts the axial displacement of the locking component 23 along the opening 211 to achieve release; Step five, the elastic component 30 adaptively compensates for the axial gap between the end cap body 10 and the motor housing 60 as the stroke of the locking component 23 changes.

[0047] This embodiment further demonstrates the vibration self-tightening effect: the SCARA wrist is subjected to high-frequency vibration of 50 Hz and displacement amplitude of 0.02 mm under handling conditions. The mating surface of the locking component 23 and the limiting slot 11 is provided with a wedge structure with an 8.5-degree rise angle. The vibration causes the locking component 23 to generate an additional wedge tightening force. The measured locking force increases from 500 N to 530 N, an increase of 6%, that is, the more intense the vibration, the greater the increase in locking force. The above-mentioned vibration self-tightening effect is maintained by the feedforward amount of the gap change envelope by the mirror prediction layer through a strong coupling closed loop between the resource scheduling layer and the correction layer, which is different from the understanding of vibration causing loosening in related technologies.

[0048] Typical operating parameters for this embodiment are shown in the table below. These parameters can be adjusted proportionally according to the motor specifications during implementation. Table 2

[0049] The working principle of this embodiment is as follows: the deformation detection component 50 collects the deformation signal of the elastic component 30 at a sampling frequency of 1 kHz and removes vibration interference through a second-order Butterworth low-pass filter and a cutoff frequency of 50 Hz. The deformation amplitude is extracted and output to the controller through a 12-bit analog-to-digital converter. The controller compares the deformation amplitude with the first and second target deformations to obtain the deviation. The magnetic field action component 24 is driven by 20 kHz pulse width modulation to solidify the magnetorheological fluid 22 and limit the locking component 23 to complete the quick lock. When released, the power is cut off to soften the magnetorheological fluid 22 and the elastic component 30 adjusts the stroke of the locking component 23 to facilitate separation. The elastic component 30 adaptively compensates for the axial clearance as the stroke changes, so that the end cap maintains a stable sealing force and locking force under wear and temperature drift conditions, and exhibits a self-tightening response to high-frequency vibration.

[0050] Example 3 (AGV hub servo motor) This embodiment provides a quick-locking self-compensating sealing end cap for a robot motor, applied to the hub servo motor of an autonomous mobile robot (AGV). The hub servo motor has a rated power of 1.5 kW and a motor spindle diameter of 60 mm. The end cap body 10 is die-cast from ADC12 aluminum alloy and has a limiting slot 11. The magnetorheological quick-locking mechanism 20 includes a storage cavity 21, a locking component 23, and a magnetic field action component 24. The storage cavity 21 is an annular groove surrounding the motor spindle with a volume of 14 ml. The storage cavity 21 has an opening 211 and is filled with magnetorheological fluid 22. The magnetorheological fluid 22 has a formulation of 38% carbonyl iron powder by volume, a particle size of 3 to 5 micrometers, and dimethyl silicone oil as the carrier fluid. The zero-field viscosity is 0.8 Pa·s, and the yield stress changes reversibly with the magnetic field strength in the range of 0 to 1.0 Tesla, increasing from 0.5 kPa to 45 kPa. The locking component 23 consists of 8 pins evenly distributed around the circumference of the storage cavity 21, with a total stroke of 1.6 mm. The deformation detection element 50 is a BF350 resistance strain gauge, sampling at 1 kHz, with a 50 Hz cutoff frequency and a second-order Butterworth low-pass filter, and a resolution of 1 micrometer. It outputs an analog electrical signal from 0 to 3.3 volts to the controller. The controller uses an STM32F407 microcontroller with a control cycle of 6 milliseconds, i.e., a control loop frequency of 167 Hz.

[0051] This embodiment is executed according to steps one through five. The first target deformation is 1.1 mm, corresponding to a locking force target of 1200 N, and the second target deformation is 1.4 mm, corresponding to a sealing force target of 250 N. During the quick-locking process in step four, after the magnetic field action component 24 is energized, the magnetorheological fluid 22 solidifies within 50 milliseconds, the yield stress increases from 0.5 kPa to 44 kPa, and a hard limit is formed on the locking component 23, causing the locking component 23 to press against the limiting groove 11. The quick-locking response time does not exceed 50 milliseconds. During the release process in step five, after the power is turned off, the magnetorheological fluid 22 softens within 70 milliseconds, and the locking component 23 and the elastic component 30 slide along the axial displacement of the opening 211 to facilitate separation and prevent the locking component 23 from separating from the motor housing 60.

[0052] This embodiment further demonstrates the external pressure adaptation and sealing gain under high humidity and water immersion conditions: the external pressure is detected by an environmental pressure sensor with a range of 0 to 1.0 MPa. The controller determines the reference excitation current based on the external pressure and increases it proportionally with the increase of the external pressure. When the external pressure increases from 0 to 1.0 MPa, the reference excitation current increases from 0 to 0.6 A, and each increase of 0.1 MPa corresponds to a sealing force gain of 30 N. When the AGV is submerged to an external pressure of 0.6 MPa, the reference excitation current is 0.36 A, and the corresponding sealing force gain is 180 N, so that the end cover maintains the IP67 protection level under immersion conditions. The greater the external pressure, the stronger the sealing force.

[0053] Typical operating parameters for this embodiment are shown in the table below. These parameters can be adjusted proportionally according to the motor specifications during implementation. Table 3

[0054] The working principle of this embodiment is as follows: the deformation detection component 50 samples at 1 kHz and extracts the deformation amplitude of the elastic component 30 through low-pass filtering. The controller compares the deformation amplitude with the first and second target deformations to obtain the deviation. The magnetic field action component 24 is driven by 20 kHz pulse width modulation to solidify the magnetorheological fluid 22 to complete the fast lock. When released, the power is cut off to soften the magnetorheological fluid 22 and the elastic component 30 adaptively compensates for the axial clearance. The water pressure detected by the environmental pressure detection component is converted into sealing force gain through the reference excitation current, so that the sealing force of the end cap is synchronously enhanced when the external pressure increases, which meets the dustproof and waterproof requirements of the mobile robot in the high humidity of water wading conditions.

[0055] Example 4 (Miniature finger joint motor for humanoid robot) This embodiment provides a quick-locking self-compensating sealing end cap for a robot motor, applied to a miniature finger joint motor of a humanoid robot. The miniature finger joint motor has a rated power of 120 watts and a motor spindle diameter of 18 mm. The end cap body 10 is milled from titanium alloy TC4 and has a limiting slot 11. The magnetorheological quick-locking mechanism 20 includes a storage cavity 21, a locking element 23, and a magnetic field action element 24. The storage cavity 21 is an annular groove surrounding the motor spindle with a volume of 0.8 ml. The storage cavity 21 has an opening 211 and is filled with magnetorheological fluid 22. The magnetorheological fluid 22 has a formulation of 38% carbonyl iron powder by volume, a particle size of 3 to 5 micrometers, and dimethyl silicone oil as the carrier fluid. The zero-field viscosity is 0.8 Pa·s, and the yield stress changes reversibly with the magnetic field strength in the range of 0 to 1.0 Tesla, increasing from 0.5 kPa to 45 kPa. The locking element 23 consists of three pins evenly distributed around the circumference of the storage cavity 21, with a total stroke of 0.5 mm. The deformation detection element 50 is a BF350 resistance strain gauge, sampling at 1 kHz, with a cutoff frequency of 50 Hz and a second-order Butterworth low-pass filter, a resolution of 1 micrometer, and outputting an analog electrical signal from 0 to 3.3 volts to the controller. The controller uses an STM32F407 microcontroller with a control cycle of 3 milliseconds, i.e., a control loop frequency of 333 Hz.

[0056] This embodiment is executed according to steps one through five. The first target deformation is 0.35 mm, corresponding to a locking force target of 180 N, and the second target deformation is 0.5 mm, corresponding to a sealing force target of 40 N. This embodiment further embodies miniaturization and temperature-sensitive dual-mode compensation: the elastic element 30 is composed of a nitrile rubber elastic matrix and 6 nickel-titanium alloy wires. The nickel-titanium alloy wires have a diameter of 0.2 mm, an austenitic phase transformation end temperature of 80 degrees Celsius, a martensitic phase transformation start temperature of 60 degrees Celsius, a pre-stretch rate of 4%, and a radial extension rate of 4%. The wires are evenly distributed; when the motor temperature rises by 20 degrees Celsius, each nickel-titanium alloy wire generates a passive preload of 1.2 N, totaling 7.2 N for 6 wires, which corresponds to offsetting the axial clearance increase of 0.15 mm caused by the 20-degree Celsius temperature rise; the temperature-sensitive phase change microcapsules have a phase change temperature of 70 degrees Celsius, a particle size of 3 to 8 micrometers, and an addition amount of 5% of the mass of magnetorheological fluid 22. After the phase change, the apparent viscosity of magnetorheological fluid 22 increases by 3 times and the apparent yield stress increases by 12%; the fingertip joints are close to the motor for heat dissipation and are sensitive to temperature rise. Dual-mode compensation offsets the attenuation of the sealing force of the small end cap under temperature drift conditions.

[0057] Typical operating parameters for this embodiment are shown in the table below. These parameters can be adjusted proportionally according to the motor specifications during implementation. Table 4

[0058] The working principle of this embodiment is as follows: the deformation detection component 50 samples at 1 kHz and extracts the deformation amplitude of the elastic component 30 through low-pass filtering. The controller compares the deformation amplitude with the first and second target deformations to obtain the deviation. The magnetic field action component 24 is driven by 20 kHz pulse width modulation to solidify the magnetorheological fluid 22 to complete the fast lock. When released, the power is cut off to soften the magnetorheological fluid 22 and the elastic component 30 adaptively compensates for the axial gap. The passive pre-tightening of the shape memory alloy wire and the phase change thickening of the temperature-sensitive phase change microcapsule work together to offset the attenuation of sealing force caused by temperature drift under the high temperature sensitive working conditions of the fingertip joint, and maintain the stable seal of the micro end cap.

[0059] Example 5 (Motor for Welding Robot under High Temperature Conditions) This embodiment provides a quick-locking self-compensating sealing end cap for a robot motor, applied to a high-temperature operating motor of a welding robot. The high-temperature operating motor has a rated power of 600 watts, a motor spindle diameter of 50 mm, and an operating environment temperature of up to 90 degrees Celsius. The end cap body 10 is die-cast from ADC12 aluminum alloy and has a limiting slot 11. The magnetorheological quick-locking mechanism 20 includes a storage cavity 21, a locking component 23, and a magnetic field action component 24. The storage cavity 21 is an annular groove surrounding the motor spindle with a volume of 9 ml. The storage cavity 21 has an opening 211 and is filled with magnetorheological fluid 22. The magnetorheological fluid 22 has a formulation of 38% carbonyl iron powder by volume, a particle size of 3 to 5 micrometers, and dimethyl silicone oil as the carrier fluid. The zero-field viscosity is 0.8 Pa·s, and the yield stress changes reversibly with the magnetic field strength in the range of 0 to 1.0 Tesla, increasing from 0.5 kPa to 45 kPa. The locking element 23 consists of six pins evenly distributed around the circumference of the storage cavity 21, with a total stroke of 1.0 mm. The deformation detection element 50 is a BF350 resistance strain gauge, sampling at 1 kHz, with a cutoff frequency of 50 Hz and a second-order Butterworth low-pass filter, a resolution of 1 micrometer, and outputting an analog electrical signal from 0 to 3.3 volts to the controller. The controller uses an STM32F407 microcontroller with a control cycle of 5 milliseconds, i.e., a control loop frequency of 200 Hz.

[0060] This embodiment is executed according to steps one through five. The first target deformation is 0.8 mm, corresponding to a locking force target of 700 N, and the second target deformation is 1.05 mm, corresponding to a sealing force target of 130 N. This embodiment further demonstrates temperature drift quantification and failure safety: the self-tuning layer of the physical mirror model identifies the temperature drift coefficient of the magnetorheological fluid 22 online, and dynamically updates the temperature correction coefficient with the deviation as the update direction. The initial value of the temperature correction coefficient is 1.0, and it is corrected by 0.015 for every degree Celsius increase in temperature. When the working temperature rises from 20 degrees Celsius to 90 degrees Celsius, the temperature correction coefficient increases from 1.0 to 2. .05, the correction layer multiplies the magnetic field deviation by the temperature correction coefficient and then adds it to the regulating current to compensate for the change in magnetic permeability with temperature; the phase change temperature of the temperature-sensitive phase change microcapsule is 70 degrees Celsius, and the working temperature is 90 degrees Celsius, which is higher than the phase change temperature. The magnetorheological fluid 22 is in a phase change thickening state throughout the process, and the apparent yield stress is increased by 12%, continuously compensating for the attenuation of high temperature sealing force; when the magnetic field detection component or controller fails, the magnetic field action component 24 returns to the state of being excited only by the reference excitation current of 0.15 A, and the magnetorheological fluid 22 returns to the reference soft hardness of 8 kPa yield stress. The basic sealing and release state is maintained by the passive compensation of the elastic component 30.

[0061] Typical operating parameters for this embodiment are shown in the table below. These parameters can be adjusted proportionally according to the motor specifications during implementation. Table 5

[0062] The working principle of this embodiment is as follows: the deformation detection component 50 samples at 1 kHz and extracts the deformation amplitude of the elastic component 30 through low-pass filtering. The controller compares the deformation amplitude with the first and second target deformations to obtain the deviation. The magnetic field action component 24 is driven by 20 kHz pulse width modulation to solidify the magnetorheological fluid 22 to complete the fast lock. The self-tuning layer updates the temperature correction coefficient online based on the deviation between the actual axial clearance and the output of the mirror prediction layer. The resource scheduling layer and the correction layer are strongly coupled closed loop through the gap change envelope to take into account the total excitation energy consumption of the multi-cavity and the lower limit of the locking force and sealing force. Under high temperature conditions, the phase change thickening of the temperature-sensitive phase change microcapsule and the passive pre-tightening of the shape memory alloy wire work together to offset the attenuation of the sealing force. When the magnetic field detection component or the controller fails, the reference excitation current of 0.15 A is returned to maintain release, thus improving safety.

[0063] Comparative Example As a comparative example, when the magnetic field detection device or controller fails and no reference excitation current return mechanism is set, the magnetorheological fluid 22 will remain in the last excitation state before the failure. If it was under high excitation before the failure, the locking component 23 will be permanently locked and cannot be released. If it was under low excitation before the failure, the sealing force will be insufficient and leakage will occur. In this embodiment, the reference excitation current return mechanism (0.15 A in Embodiment 1, 0.12 A in Embodiment 2, 0.2 A in Embodiment 3, 0.06 A in Embodiment 4, and 0.15 A in Embodiment 5) allows the magnetorheological fluid 22 to return to the reference softness and hardness of 8 kPa yield stress. The basic sealing and release state is maintained by the passive compensation of the elastic component 30, thus improving safety.

[0064] The following provides alternative implementation methods for each core component of this application. Each alternative can be used individually or in combination.

[0065] Magnetorheological fluid formulation replacement The magnetorheological fluid described in this application uses carbonyl iron powder as the dispersed phase and silicone oil as the carrier liquid, and is composited with temperature-sensitive phase change microcapsules. In an alternative formulation, the carbonyl iron powder is replaced with nickel powder or iron-cobalt alloy powder, with a volume fraction maintained between 25% and 45%, and the carrier liquid is replaced with a vegetable oil-based environmentally friendly carrier liquid or a fluorinated liquid. Additionally, 0.5% to 3% by mass of Span 80 surfactant and 1% to 5% by mass of fumed silica thixotropic agent are added to improve suspension stability.

[0066] In another alternative formulation, 1% to 5% by mass of nano-Fe3O4 particles are added to the carrier fluid to improve the magnetic response speed, or 0.5% to 2% by mass of molybdenum disulfide is added to reduce the coefficient of friction. Regardless of the formulation used, the magnetorheological fluid exhibits a gradient concentration distribution along the axial direction of the storage cavity opening, with the concentration in the contact area where the locking component abuts against the limiting groove being higher than the concentration in the travel area of ​​the locking component.

[0067] Replacement of magnetic field action components In the above example, the magnetic field actuator is specifically implemented as an electromagnetic coil wound around the outer periphery of the storage cavity. In an alternative embodiment, the magnetic field actuator uses a permanent magnet combined with a movable magnetic yoke. By driving the magnetic yoke to displace relative to the permanent magnet, the magnetic field strength within the storage cavity is changed, thereby achieving passive magnetization and demagnetization.

[0068] In another alternative, the magnetic field actuator employs a hybrid structure of electromagnet and permanent magnet bias, with the permanent magnet providing the basic bias magnetic field and the electromagnetic coil providing the adjustable incremental magnetic field to reduce power consumption.

[0069] In another alternative, the magnetic field actuator employs a multipole Halbach array to improve the axial uniformity of the magnetic field within the storage cavity and suppress magnetic leakage.

[0070] Replacement of magnetic field detection device In the above example, the magnetic field detection device is specifically implemented using an embedded Hall sensor, with each sub-cavity independently configured. In an alternative embodiment, the magnetic field detection device employs an anisotropic magnetoresistive sensor or a giant magnetoresistive sensor to achieve higher sensitivity and resolution than a Hall sensor.

[0071] In another alternative, the magnetic field detection device uses a fluxgate sensor or a giant magnetoresistive sensor to obtain a more accurate measurement of weak magnetic fields, which is suitable for accurate feedback of the actual magnetic field strength in multi-cavity dual closed-loop collaborative control.

[0072] Elastic matrix replacement In the above example, the elastic element is composed of a magnetorheological fluid-compatible elastic matrix and a shape memory alloy wire embedded in the elastic matrix, with silicone rubber being a specific embodiment of the elastic matrix. In an alternative embodiment, fluororubber is used as the elastic matrix to adapt to long-term service under high-temperature conditions such as welding robots.

[0073] In another alternative, the elastic matrix is ​​made of polyurethane or thermoplastic elastomer to achieve higher resilience and fatigue resistance; each elastic matrix remains chemically compatible with the magnetorheological fluid and does not impede the sliding of the magnetorheological fluid along the opening axis.

[0074] Shape memory alloy wire replacement In the above example, the shape memory alloy wire is specifically implemented using nickel-titanium alloy wire, which generates a passive preload that increases monotonically with the rise in motor temperature. In an alternative, the shape memory alloy wire is made of nickel-titanium-copper alloy to obtain a narrower phase transition hysteresis and a more linear force-temperature characteristic.

[0075] In another alternative, shape memory alloy wires are made of copper-aluminum-nickel alloy to accommodate a higher phase transition temperature range.

[0076] In another alternative, the shape memory alloy wires are arranged in a spiral or mesh-woven structure instead of circumferentially distributed straight wires, in order to obtain a more uniform passive preload distribution in the radial section of the elastic element.

[0077] First seal replacement In the above example, the first seal of the sealing assembly is disposed at the annular end face between the end cover body and the motor housing, with a nitrile rubber O-ring as a specific embodiment. In an alternative, the first seal may be a rectangular sealing ring or a lip sealing ring to accommodate different end face clamping structures.

[0078] In another alternative, the first seal is made of fluororubber or silicone rubber to suit high-temperature or clean environments.

[0079] In another alternative, the first seal uses a spiral wound gasket or a covered gasket to adapt to high temperature and high pressure conditions.

[0080] Second seal replacement In the above example, the second seal of the sealing assembly is located in the rotational gap between the end cover body and the motor spindle, and is specifically implemented as a skeleton oil seal or a mechanical seal. In an alternative, the second seal is a magnetorheological seal, which is separated from the magnetorheological fluid of the quick-lock mechanism and controlled by an independent excitation circuit to achieve a higher sealing level under rotational conditions.

[0081] In another alternative, the second seal is a spring-loaded plug seal to accommodate a wider temperature range and pressure fluctuations.

[0082] In another alternative, the second seal employs a composite structure of labyrinth seal and magnetohydrodynamic seal to balance non-contact, low-friction operation with high sealing performance.

[0083] Deformation testing component replacement In the above examples, the deformation detection element is specifically implemented as a deformation sensor or a displacement sensor (see the foregoing embodiments). In an alternative, the deformation detection element uses a resistance strain gauge or fiber optic grating sensor attached to an elastic element to obtain deformation measurements resistant to electromagnetic interference, suitable for strong magnetic field environments.

[0084] In another alternative, the deformation detection device uses a capacitive or laser displacement sensor to collect the deformation amplitude of the elastic element in a non-contact manner; each deformation detection device collects the deformation signal at a set sampling frequency, filters the deformation signal to remove vibration interference caused by motor operation, and converts the deformation amplitude into an electrical signal output to the controller.

[0085] Controller replacement In the above example, the controller is specifically implemented using an STM32F407-based microcontroller to perform dual-closed-loop collaborative control of multiple sub-cavities and physical mirror model driven control. In an alternative, the controller employs a digital signal processor or a field-programmable gate array (FPGA) to process the regulation current calculations of multiple sub-cavities in parallel, thus shortening the control cycle.

[0086] In another alternative, the controller adopts an industrial programmable logic controller or a master-slave distributed controller architecture to adapt to production line conditions where multiple motors work together.

[0087] Replacement of environmental pressure testing components In the above example, the environmental pressure sensing element is specifically implemented using a piezoresistive pressure sensor to detect external pressure and convert it into a sealing force gain. In an alternative embodiment, the environmental pressure sensing element uses a capacitive pressure sensor to achieve higher temperature stability.

[0088] In another alternative, the environmental pressure sensing element uses a piezoelectric or absolute pressure sensor to adapt to pulsed pressure or vacuum conditions.

[0089] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A quick-lock self-compensating sealing end cap for a robot motor, comprising an end cap body (10), a magnetorheological quick-lock mechanism (20), an elastic element (30), a sealing assembly (40), a deformation detection element (50), and a controller; the end cap body (10) is provided with a limiting groove (11); the magnetorheological quick-lock mechanism (20) includes a storage cavity (21), a locking element (23), and a magnetic field action element (24), the storage cavity (21) is provided with an opening (211), and a magnetorheological fluid (22) is disposed in the storage cavity (21), wherein the yield stress of the magnetorheological fluid (22) changes reversibly with the magnetic field strength; characterized in that, It also includes the following fast-lock and self-compensation steps: Step 1: Obtain the deformation amplitude of the elastic element (30) through the deformation detection element (50); Step 2: The controller compares the deformation amplitude with the preset first target deformation and second target deformation respectively to obtain the locking force deviation and sealing force deviation; the first target deformation corresponds to the locking force of the locking component (23), and the second target deformation corresponds to the sealing force of the sealing component (40); The controller synchronously sets the target values ​​for the locking force control loop and the sealing force control loop based on the locking force deviation and the sealing force deviation. Step 3: The controller adjusts the excitation intensity of the magnetic field action element (24) according to the target value to adjust the hardness of the magnetorheological fluid (22), thereby simultaneously adjusting the locking force of the locking element (23) and the sealing force of the sealing assembly (40), so that the locking force and the sealing force reach their respective target values. Step 4: When the magnetorheological fluid (22) hardens, it limits the locking member (23) so that the locking member (23) abuts against the limiting groove (11) to form a quick lock. When the magnetorheological fluid (22) softens, the elastic member (30) adjusts the stroke of the locking member (23) along the axial displacement of the opening (211) to achieve release. Step 5: The elastic element (30) adaptively compensates for the axial gap between the end cap body (10) and the motor housing (60) as the stroke of the locking element (23) changes.

2. The quick-locking self-compensating sealing end cap for a robot motor according to claim 1, characterized in that, In the quick-locking process of step four, the magnetic field action element (24) is an electromagnetic coil wound around the outer periphery of the storage cavity (21). When the electromagnetic coil is energized, the magnetorheological fluid (22) is solidified. The solidified magnetorheological fluid (22) forms a limit on the locking element (23), so that the locking element (23) abuts against the limiting slot (11).

3. A quick-locking self-compensating sealing end cap for a robot motor according to claim 1, characterized in that, During the release process in step four, when the end cap body (10) and the motor housing (60) need to be separated, the magnetorheological fluid (22) is softened, and the locking member (23) and the elastic member (30) slide along the axial direction of the opening (211) into the storage cavity (21), so that the end cap body (10) and the motor housing (60) can be easily separated, while preventing the locking member (23) from separating from the motor housing (60).

4. A quick-locking self-compensating sealing end cap for a robot motor according to claim 3, characterized in that, In step four, when the magnetorheological fluid (22) hardens, the locking member (23) remains in contact with the end cap body (10). When the magnetorheological fluid (22) softens, the locking member (23) releases its contact with the end cap body (10) as the magnetorheological fluid (22) softens, and the locking member (23) remains connected to the motor housing (60).

5. A quick-locking self-compensating sealing end cap for a robot motor according to claim 1, characterized in that, In the self-compensation process of step five, the sealing assembly (40) includes a first sealing element (41) and a second sealing element (42). The first sealing element (41) is disposed at the annular end face between the end cover body (10) and the motor housing (60), and the second sealing element (42) is disposed at the rotational gap between the end cover body (10) and the motor spindle.

6. A quick-locking self-compensating sealing end cap for a robot motor according to claim 1, characterized in that, In step one, the deformation detection component (50) is a deformation sensor or a displacement sensor. The deformation detection component (50) collects the deformation signal of the elastic component (30) at a set sampling frequency, filters the deformation signal to remove vibration interference caused by motor operation, extracts the deformation amplitude of the elastic component (30), and converts the deformation amplitude into an electrical signal and outputs it to the controller.

7. A quick-locking self-compensating sealing end cap for a robot motor according to claim 6, characterized in that, In step two, the controller is preset with a first target deformation and a second target deformation. The first target deformation corresponds to the locking force of the locking component (23), and the second target deformation corresponds to the sealing force of the sealing component (40). The controller reads the electrical signal to determine the deformation amplitude, and compares the deformation amplitude with the first target deformation and the second target deformation to obtain the locking force deviation and the sealing force deviation. The locking force deviation and the sealing force deviation are used to synchronously set the target values ​​of the locking force control loop and the sealing force control loop, so that the same magnetorheological fluid (22) can be actively adjusted by a single deformation detection element (50) in a closed loop to simultaneously adjust the locking force of the locking element (23) and the sealing force of the sealing assembly (40).

8. A quick-locking self-compensating sealing end cap for a robot motor according to claim 7, characterized in that, In step three, the storage cavity (21) is divided into multiple independent sub-cavities along the circumference, and each sub-cavity is equipped with an independent electromagnetic coil and an independent magnetic field detection device; The controller performs chamber-specific dual-closed-loop collaborative control, specifically including: For each sub-cavity, the deformation amplitude of the elastic element (30) at the contact section of the corresponding locking element (23) is obtained by the deformation detection element (50) and a deformation deviation of the corresponding sub-cavity is formed. The outer loop control circuit sets a target yield stress that matches the locking force and sealing force of the sub-cavity according to the deformation deviation of the sub-cavity. The inner loop control circuit detects the actual magnetic field strength in the sub-cavity by the magnetic field detection element of the sub-cavity and calculates the actual yield stress. The adjustment current of the sub-cavity is corrected according to the magnetic field deviation between the actual yield stress and the target yield stress, so that the actual yield stress of each sub-cavity converges to its respective target yield stress, thereby making the contact stress distribution of the locking element (23) in the circumferential direction tend to be balanced. The dual-closed-loop collaborative control of the compartments enables the locking force and the sealing force to self-compensate synchronously with wear and temperature drift and tend to be circumferentially balanced, rather than eliminating the hysteresis of the magnetorheological fluid (22) itself or compensating for the time delay of the control loop.

9. A quick-locking self-compensating sealing end cap for a robot motor according to claim 1, characterized in that, In the softening release in step four and the self-compensation in step five, the elastic element (30) is composed of a magnetorheological fluid (22) compatible elastic matrix and a shape memory alloy wire embedded in the elastic matrix. The shape memory alloy wire is distributed in the radial section of the elastic element (30) blocking the opening (211) of the storage cavity (21), and as the magnetorheological fluid (22) softens, the elastic element (30) coordinates with the sliding stroke of the locking element (23) along the axial displacement of the opening (211). The shape memory alloy wire generates a passive preload that increases monotonically with temperature when the motor temperature rises, in order to partially offset the increase in axial clearance caused by temperature drift; and the magnetorheological fluid (22) has a gradient concentration distribution along the axial direction of the opening (211), with the concentration in the contact area where the locking member (23) abuts against the limiting groove (11) being higher than the concentration in the travel area of ​​the locking member (23). The magnetorheological fluid (22) contains thermosensitive phase change microcapsules, which change from a liquid state to a high viscosity state when the motor temperature rises to the phase change temperature, thereby increasing the apparent yield stress of the magnetorheological fluid (22) under temperature rise conditions to compensate for the attenuation of sealing force caused by temperature drift. The passive pre-tightening and active stroke adjustment of the shape memory alloy wire, the axial gradient concentration locking of the magnetorheological fluid (22), and the phase change thickening of the thermosensitive phase change microcapsules work together to form a medium-structure dual-mode compensation. The dual-mode compensation is integrated into the quick-lock-seal-self-compensation overall structure of the end cap body (10), which is different from the scenario where the shape memory alloy or the temperature-sensitive phase change microcapsule is used for transmission torque or rotary shaft sealing.

10. A quick-locking self-compensating sealing end cap for a robot motor according to claim 8, characterized in that, In step three, the cavity dual-closed-loop collaborative control is executed according to the physical mirror model-driven step-by-step deep stacking process, specifically including: The controller establishes a physical mirror model that characterizes the axial gap between the end cap body (10) and the motor housing (60). The physical mirror model is composed of four functional layers stacked in succession: mirror prediction layer, self-tuning layer, resource scheduling layer and correction layer. The mirror prediction layer constructs a continuous state sequence of the axial gap based on the effective deformation amplitude sequence and the actual magnetic field strength of each sub-cavity, and predicts the gap change envelope for multiple future control cycles. The self-tuning layer identifies the aging coefficient and temperature drift coefficient of the magnetorheological fluid (22) online based on the deviation between the actual axial gap and the output of the mirror prediction layer, and dynamically updates the weighted average weight decay coefficient, first-order difference step size and temperature correction coefficient used by the mirror prediction layer with the deviation as the update direction. The weight attenuation coefficient, the first-order difference step size, and the temperature correction coefficient satisfy the following relationship: The weighting coefficients of the weighted average decay over time, making the contribution of samples closer to the current time greater. The first-order difference step size is equal to an integer multiple of the control period. The weight decay coefficient, the difference step size, and the temperature correction coefficient monotonically shift with the direction of deviation. Under the constraints of the lower limit of locking force and the lower limit of sealing force, the resource scheduling layer aims to minimize the total excitation energy consumption of multiple sub-cavities and allocates the regulating current of each sub-cavity according to the gap change envelope. The resource scheduling layer allocates the regulating current of each sub-cavity according to the steepness of the gap change envelope, and the steeper the gap change envelope, the greater the increment of the regulating current of the corresponding sub-cavity. The correction layer compares the actual value of the magnetic field strength with the set value of the magnetic field strength to obtain the magnetic field deviation, and corrects the adjustment current based on the magnetic field deviation so that the actual axial gap converges to the target gap range; the correction layer multiplies the magnetic field deviation by the temperature correction coefficient that varies with temperature and then adds it to the adjustment current to compensate for the change in the permeability of the magnetorheological fluid (22) with temperature. The controller detects external pressure through an environmental pressure detection device, determines a reference excitation current based on the external pressure, and increases it proportionally as the external pressure increases, so as to convert the external pressure into sealing force gain. The reference excitation current also serves as the baseline excitation for the resource scheduling layer and the correction layer when the deviation is zero. The gap change envelope serves as the same feedforward physical quantity to drive the current distribution of the resource scheduling layer and the magnetic field deviation compensation of the correction layer, so that the mirror prediction layer, the resource scheduling layer and the correction layer form a strong coupling closed loop through the actual axial gap. When the gap change envelope indicates that the lower limit of the locking force and the lower limit of the sealing force will be broken at the same time, the lower limit of the sealing force is prioritized and the remaining excitation energy is used for locking force compensation. When the magnetic field detection device or the controller fails, the magnetic field action element (24) returns to the state of being excited only by the reference excitation current, the magnetorheological fluid (22) returns to the reference softness and hardness, and the passive compensation of the elastic element (30) is withdrawn.

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