228 results about "Damping torque" patented technology

The invention belongs to the technical field of matching control of a network construction type system, and particularly discloses a power feedback control method suitable for matching control low-frequency oscillation suppression, which comprises the following steps: establishing a power-frequency transfer relation of a multi-matching control parallel system, analyzing the torque of the multi-matching control parallel system based on a damping torque method, and calculating the power-frequency transfer relation of the multi-matching control parallel system; determining an introduction factor of a negative damping torque component in the multi-matching control parallel system and a stability condition in the multi-matching control parallel system; and then additional damping control based on power feedback is designed through a lead-lag compensator, a negative damping torque part in the multi-matching control parallel system is compensated, and power feedback control is completed. According to the method, the problems that the dynamic response of the whole system becomes extremely complex due to the dynamic interaction among the converters when a plurality of matched control network-forming converters exist in the network-forming system, and the oscillation suppression effect under the multi-machine system is difficult to guarantee by the existing suppression strategy are solved.

The invention relates to the technical field of hoisting equipment intelligent control based on multi-sensor cooperation, and discloses a hoisting equipment intelligent control method based on multi-sensor cooperation. A control unit reads and stores parameters such as air density, windward projection area, wind load arm length, arm section rotational inertia, rated output force of a hydraulic cylinder, sampling period and the like, and static self-inspection and dynamic calibration are performed on a wind speed sensor, a rotary encoder and a pressure sensor respectively; multiple paths of wind speeds are collected in parallel during operation, fused wind speeds are obtained through weighted fusion after abnormities are removed, and the wind load torque is calculated and limited by combining the windward area and the force arm length; reading two continuous encoder angle differences, performing amplitude limiting, calculating an angular velocity and kinetic energy, performing adaptive adjustment according to kinetic energy deviation, and performing amplitude limiting on a damping coefficient to generate a damping torque; and the amplitude-limited wind load torque and damping torque are synthesized into total control torque, and after amplitude limiting, the total control torque is converted into amplitude-limiting hydraulic cylinder operation output force which is issued and executed by a control unit.

The invention discloses a direct-driven wind turbine generator grid-connected low-frequency oscillation damping characteristic analysis and early warning method, and belongs to the field of wind power grid-connected system stability operation control. According to the method, a direct-driven wind turbine generator full-order grid-connected mathematical model is constructed, and dominant factors of low-frequency oscillation are identified according to the direct-driven wind turbine generator full-order grid-connected mathematical model; a wind turbine generator grid-connected order reduction model capable of accurately retaining oscillation characteristics is constructed, a direct-driven wind turbine generator damping torque model is constructed according to the order reduction model, and a damping coupling relation between damping paths and a system negative damping forming mechanism under different power grid strengths, operation conditions and control parameters are quantitatively analyzed from the damping angle. A low-frequency oscillation coupling factor induction mechanism is researched, a controller parameter stable operation domain is described, the wind power integration stability is discriminated according to the stable operation domain, and a theoretical basis is provided for early warning of grid-connected low-frequency oscillation instability of a wind turbine generator. The effectiveness and applicability of the analysis method are verified through simulation examples.

A damping adjustable rotary hydraulic damper belongs to the technical field of dampers. The utility model comprises a cylinder body, a rotating shaft, and an adjusting valve stem. A partition is provided on the inner wall of the cylinder body, the rotating shaft is rotatably connected to the cylinder body, a blade is provided on the side of the rotating shaft, a valve hole is provided in the rotating shaft along its axial direction, the adjusting valve stem is provided in the valve hole, and oil holes are provided on both sides of the blade on the rotating shaft, and the oil holes are connected to the valve hole. The utility model has a large damping torque, and the damping torque is easy to adjust, which can meet more usage requirements.

The invention relates to the technical field of robot control, and discloses a robot multi-mechanical-arm cooperative anti-collision control method and system.The method comprises the steps that a three-dimensional Cartesian global reference coordinate system with a kinematics pivot point as an original point is established, inner and outer side operation domains are divided, and outer side virtual nodes are defined; a virtual safety monitoring section is constructed in an outer side driving domain, a dynamic rejection light spot is generated, and collision early warning is generated through position and trend composite judgment; mapping the virtual repulsive force into equivalent joint damping torque, and superposing the equivalent joint damping torque to a current control ring of the servo driver; by means of kinematics reverse deduction and virtual force field construction, mathematical reconstruction of the outside non-sensing blind area state is achieved on the premise that an external sensor is not needed, and external connecting rod hidden physical collision caused by'cohesion and divergence 'motion coupling of multiple mechanical arms is effectively prevented through force sense feedback of a current control ring level.

This invention provides a virtual-real fusion-based force feedback simulation control method for ship rudder control sticks, comprising: constructing a set of fluid control equations for the flow field on the rudder surface; discretizing the set of fluid control equations using a standard structured mesh to obtain a discretized set of fluid control equations; solving the discretized set of fluid control equations based on the finite difference method and boundary conditions to obtain the drag torque value of the fluid acting on the rudder plate; converting the drag torque value into a damping torque value; the control unit outputting a motor drive command based on the magnitude of the damping torque value; and the motor driver, based on the motor drive command output by the control unit, driving the force feedback simulation motor to generate a corresponding simulated damping torque value, which acts on the control stick to produce force feedback. This invention provides real-time control stick force feedback for the helmsman, allowing for direct perception of the ship's navigation status and enhancing steering stability.

The invention provides a network construction type electromagnetic scale stabilization control method and system based on a phase compensator, and relates to the technical field of phase compensators, and the method comprises the steps: obtaining the virtual damping torque of each link of a network construction converter grid-connected system; identifying a system electromagnetic oscillation leading link based on the virtual damping torque of each link; constructing a second-order lead phase compensator, and designing a controller structure of the second-order lead phase compensator; calculating a phase lag angle and a margin of the electromagnetic oscillation dominant link, and calculating a phase compensation angle of a second-order lead phase compensator according to the phase lag angle and the margin; parameters of a second-order lead phase compensator are set according to the phase compensation angle, and net-building type electromagnetic scale stabilization control is carried out based on the second-order lead phase compensator after parameter setting and an electromagnetic oscillation leading link; the electromagnetic oscillation problem in traditional control is solved, and the electromagnetic oscillation stability of the system is improved.

The invention discloses a method for analyzing low-frequency oscillation interaction between parallel direct-driven wind turbine generators. The method comprises the following steps: establishing a parallel grid-connected simulation model of two direct-driven wind turbine generators; accessing to a simulation model of an alternating current system, linearizing at a balance point to obtain a system state space equation, calculating a characteristic value and participating in factor analysis, and analyzing low-frequency oscillation characteristics of the system; according to an analysis result, aiming at a low-frequency oscillation mode related to the direct-current voltage, establishing a damping torque model of a direct-current voltage loop mode of the direct-driven wind turbine generator; forming a two-machine parallel system damping torque model by using the damping torque model, and constructing an expression of interaction between units by using a damping transfer function; quantitatively evaluating the interaction between the direct-driven wind turbine generators; after evaluation, the system is expanded to a multi-machine parallel system and the interaction is analyzed. The mutual change trend is quantitatively analyzed in the form of the mutual damping coefficient, the dynamic coupling mechanism between the parallel direct-driven wind turbine generators is clearly and quantitatively elaborated, and the problem that the interaction mechanism between the generators cannot be quantitatively analyzed in the past is solved.

The embodiment of the invention discloses a connecting device and electronic equipment. The connecting device comprises a seat body; the first rotating shaft assembly is rotatably connected with the seat body, and a first damping structure is arranged between the first rotating shaft assembly and the seat body; the driving assembly is arranged on the seat body, and a second damping structure is arranged between the driving assembly and the first rotating shaft assembly; the driving assembly is used for driving the first rotating shaft assembly to rotate through the second damping structure; the damping force of the second damping structure is smaller than the static torsion of the driving assembly; the driving torque provided by the driving assembly for the first rotating shaft assembly through the second damping structure is larger than the damping torque provided by the first damping structure for the first rotating shaft assembly.

In one aspect, there is provided an isolation device, which includes a hub, a pulley and at least one isolation spring arrangement including first and second springs in series. The first spring rate is higher than the second spring rate. Initially during torque transfer from the first one to a second one of the hub and the pulley, the entire first isolation spring is slid along a friction surface towards the second one of the hub and the pulley during compression of the second isolation spring thereby generating a first frictional damping torque. During torque transfer the other way, at least a portion of the first isolation spring remains stationary relative to the friction surface, such that the first frictional damping torque is greater than the second frictional damping torque.

The invention provides a stability interaction analysis method for parallel connection of a grid-following converter and a grid-constructing converter. The method comprises the following steps: establishing a first grid-connected simulation model when the grid-following converter and the grid-constructing converter are connected in parallel; establishing a second grid-connected simulation model when the first grid-connected simulation model is connected to the alternating current system; based on the second grid-connected simulation model, establishing a damping torque model during grid connection of the grid-constructing converter and the grid-following converter; based on the damping torque model, constructing an interaction analytic expression between a network-constructing type converter and a network-following type converter, wherein the interaction analytic expression is related to control parameters; the control parameters are used for compensating the disturbance quantity in the power grid. The invention provides a mechanism for quantitatively analyzing interaction between network construction equipment and network following equipment.

The invention discloses a coating system and method for a double-sided tape, and belongs to the technical field of surface coating. The coating system of the double-sided tape comprises an unwinding device, a first adjusting device, a first gluing device, a second gluing device, a first detecting device, a drying device, a second adjusting device, an isolating device, a forming device, a second detecting device, a winding device and a control device. The first tensioning amount and the second tensioning amount are calculated according to the unwinding speed, the glue unwinding rotating speed and the reference speed, so that base material coating is more uniform. In the tension adjusting process of the non-adhesive base material, the first tension provided by the first adjusting device and the second tension provided by the second adjusting device are calculated according to the first adjusting angle and the second adjusting angle, and then the damping torque of the isolation device is adjusted. And the damping torque changes the deformation of the release paper, so that the deformation of the release paper is consistent with that of the adhesive-free base material, and the coating of the double-sided adhesive tape is more uniform.

The invention discloses a magnetic pole rotating type electromagnetic damping shimmy damper for a nose landing gear of an aircraft, and belongs to the technical field of vibration control of landing gears of aircrafts. The shimmy damper comprises a first stator disc and a second stator disc which are symmetrically arranged, a rotor disc, a plurality of pairs of permanent magnetic poles, a rotating shaft, a top cover, a base and a bearing. The rotor disc is in interference fit with the rotating shaft through the central square hole, the magnetic poles are circumferentially, uniformly and fixedly arranged on two sides of the rotor disc, and the magnetizing directions of the adjacent magnetic poles are opposite. An adjustable air gap is reserved between the stator disc and the magnetic pole. During working, shimmy motion of the nose landing gear is converted into rotation of the rotating shaft through the transmission mechanism, the rotor disc and the magnetic poles are driven to rotate, the stator disc cuts magnetic induction lines to generate eddy currents, damping torque is formed, kinetic energy is converted into heat energy, and efficient shimmy reduction is achieved. External power supply is not needed, the structure is compact, the weight is light, the problems of abrasion and maintenance of a traditional friction or oil damper are solved, and the damper is particularly suitable for a modern aircraft landing gear system.

The invention relates to the technical field of ship mounting equipment, and discloses a modular mechanical mounting structure for a ship deck, which comprises a wharf, and a slot is formed in one side, close to a ship body, of the top of the wharf; the ship body fixing base is connected with the lower portion of a ship side boarding opening, a springboard for personnel and micro-cargo to move up and down is arranged on the ship body fixing base, and the end, away from the ship body fixing base, of the springboard extends to the position above a wharf. The positions, close to the wharf, of the two sides of the ship body fixing base are fixedly connected with hinge connecting bases used for being connected with the hinged traction device. By adding and arranging the board body swinging stabilizing mechanism, when the ship docking personnel springboard is used, the mechanism can rapidly absorb and dissipate swinging energy through reverse damping torque generated by high-viscosity damping liquid on a universal inertia swinging ball according to the phenomena of high-frequency small-amplitude swinging, flutter and structural resonance of the springboard caused by sea waves, and the swinging energy is dissipated through the reverse damping torque generated by the high-viscosity damping liquid on the universal inertia swinging ball; swaggling superposition amplification is effectively restrained, and violent shaking of the springboard is avoided.

A motor control device is used in a battery electric vehicle provided with a motor that outputs power to a drive shaft connected to an axle via a gear mechanism, and controls the motor so as to output, to the drive shaft, a torque that is the sum of a required torque and an execution damping torque obtained by multiplying a required damping torque required for damping vibration by a gain, when the absolute value of the required torque is a first value greater than or equal to 0 and less than 0, the gain is set to a predetermined value greater than 0 and less than 1.

The invention provides a fan impeller turning system which is suitable for a wind generating set, the fan impeller turning system comprises a turning gear, the turning gear comprises a main body frame, a driving part, a main gear and a damping structure, the main body frame is used for being connected to the top of a tower, the main gear is rotatably connected to the main body frame, and the driving part is used for driving the main gear to rotate; the main gear is used for being connected with a rotor of a generator, and the driving piece is connected to the main body frame and can drive the main gear to rotate; the damping structure is used for providing damping torque for the main gear, the direction of the damping torque is opposite to the direction of torque provided by the driving part for the main gear, and the driving part is matched with the damping structure, so that the main gear can rotate stably, and the main gear can drive the rotor to rotate easily; and the main gear can be easily locked after rotating in place, so that the difficulty of rotating the hub is reduced, and the difficulty of mounting the blade of the wind driven generator is also reduced.

The utility model relates to an adjustable damping structure which comprises an output shaft, a driving motor, a damping piece and an adjusting assembly. The driving motor is connected with the output shaft and is used for driving the output shaft to rotate; the damping piece is installed on the output shaft and used for generating friction with the output shaft when the output shaft rotates. The adjusting assembly comprises a spring, a rotation stopping gasket and a locking nut which are sequentially installed on the output shaft, the damping piece is arranged on the side, away from the rotation stopping gasket, of the spring, and rotation stopping tooth-shaped parts which can be meshed with each other are arranged on the surface of the rotation stopping gasket and the surface of the locking nut. Wherein the output shaft is provided with a thread matched with the locking nut. The damping torque can be adjusted in real time, operation is easy and convenient, the anti-loosening function is achieved, it can be ensured that the damping torque is output stably, and use reliability is effectively improved.

The application discloses a single-shaft active and passive mixed driving intelligent artificial knee joint structure with energy recovery function, which comprises a joint rotating module, a gear transmission module, a hydraulic damping module, a rack and a motor. The gear transmission module comprises a primary bevel gear transmission system, a secondary gear transmission system, a synchronous belt wheel transmission assembly and a transmission rack. The motor is fixed on the transmission rack. In the active stage, the motor provides an active driving torque for the knee joint through the gear transmission module and the joint rotating module. In the passive stage, the joint rotating module transmits a passive torque of the knee joint to the motor through the gear transmission module, drives the motor to rotate, so that the motor generates electricity to recover energy, and the hydraulic damping module provides a damping torque to ensure the stability of the knee joint. In various use occasions, the required damping or driving torque can be obtained, the power consumption of the motor can be reduced by recovering the passive torque of the knee joint in the passive stage, and the working endurance of the intelligent artificial limb is improved.

This invention relates to the field of wind turbine technology, specifically to a wind turbine main shaft structure. The wind turbine main shaft structure includes a hub, a transmission frame, a main shaft, a nacelle base, a main bearing, and a rear bearing. The hub and transmission frame are respectively connected to both ends of the main shaft. The nacelle base has a main bearing seat and a rear bearing seat at both ends along the axial direction of the main shaft, with the main bearing connected to the main bearing seat and the rear bearing connected to the rear bearing seat. The main shaft is rotatably connected to the nacelle base via the main bearing, and the transmission frame is rotatably connected to the nacelle base via the rear bearing. The transmission frame is used for transmission connection with the generator. This wind turbine main shaft structure reduces the weight and load of the unit components, and the segmented design of the main shaft reduces the difficulty of main shaft machining. The structural installation design of the front and rear bearings improves the rigidity of the entire transmission chain and eliminates the requirement for vibration-damping torque arms in independent shaft transmission chains.

The present invention discloses a high-torque magnetorheological brake based on an internal circulation mode of magnetorheological fluid, which relates to the field of brakes and includes a shell, a left end cover, a right end cover, a main shaft and a rotating cylinder; a brake disc assembly is provided on the rotating cylinder, and the brake disc assembly includes an end brake disc arranged on the rotating cylinder near the left end cover and a plurality of conventional brake discs arranged on the rotating cylinder with uniform gaps; a winding rack assembly is provided on the circumferential side of the brake disc assembly in the shell, and an excitation coil for generating an excitation magnetic field is provided on the winding rack assembly; an impeller is provided on the main shaft, and the impeller can move between the left end cover and the end brake disc, and the impeller and the end brake disc are elastically connected, and the impeller can be attracted by electromagnetic force to move toward the end brake disc and rotate in coordination with the end brake disc; the rotating impeller drives the magnetorheological fluid to achieve a certain circulation flow inside the brake, and at the same time, the damping torque generated during the rotation of the impeller can enhance the braking torque of the system.

The application provides a torque output control method and device, an electric vehicle and a medium. The torque output control method comprises the following steps: in response to energy recovery starting, identifying a current working condition; if the current working condition is identified as a target energy recovery working condition, determining a target damping torque calibration value corresponding to the target energy recovery working condition according to a preset corresponding relationship between the energy recovery working condition and the damping torque calibration value; and adjusting an energy recovery torque value output by the motor through the target damping torque calibration value. Through the torque output control method provided by the application, the energy recovery torque value output by the motor can be quickly adjusted, the vehicle body can be timely ensured to be stable, and the occurrence of the vehicle body out of control can be reduced, so as to help improve the user's riding experience.

The invention discloses a stability analysis method and system for a virtual impedance control converter. The method comprises the steps that model parameters of a to-be-analyzed converter are acquired; establishing a chimeric torque analysis model of the converter; based on the embedded torque analysis model, deriving an analytical expression of damping torque provided by each feedback loop path in the multilayer feedback loop, and performing superposition calculation to obtain the total damping torque of the grid-connected system; positioning a key path which plays a leading role on the total damping torque of the grid-connected system; and analyzing a damping torque change trend of the key path, and determining an interaction relationship between the feedback loop paths, so as to determine an action mechanism between the virtual impedance and the stability of the converter. By using the scheme of the invention, the internal action mechanism of the virtual impedance control on the stability of the converter can be deeply disclosed. Compared with a traditional method which depends on empirical parameter design, the method has the advantages that the key control loops influencing the stability can be accurately traced, and the mutual excitation or competition relationship among the loops can be quantitatively analyzed.

The application relates to the technical field of robot control, and discloses a robot multi-mechanical arm cooperative anti-collision control method and system, which comprises the following steps: a three-dimensional global reference coordinate system with a kinematic pivot point as the origin is established, an inside and outside work area is divided, and an outside virtual node is defined; a virtual safety monitoring section is constructed in the outside driving area, a dynamic repulsion spot is generated, collision early warning is generated through position and trend compound judgment; the virtual repulsion force is mapped into equivalent joint damping torque, and is superimposed into a servo driver current control loop; the application realizes mathematical reconstruction of the outside non-perception blind area state without an external sensor through kinematic reverse deduction and virtual force field construction, and effectively prevents implicit physical collision of external connecting rods caused by the 'cohesion and external dispersion' motion coupling of the multi-mechanical arms through force feedback of the current control loop level.

The utility model relates to a folding electronic whiteboard which comprises an electronic whiteboard main board of a display and touch two-in-one all-in-one machine. The device further comprises an auxiliary plate and a damping torque hinge. The auxiliary board is installed on the side face of the electronic whiteboard main board through the damping torque hinge. The damping torque hinge comprises a damping torque device, a first torsion arm and a second torsion arm, wherein the first torsion arm and the second torsion arm are clamped on a torsion shaft of the damping torque device. In the utility model, the auxiliary board is hinged on the side surface of the electronic whiteboard main board by adopting the damping torque hinge, so that the auxiliary board can stay at any angle on the side surface of the electronic whiteboard main board, the use is flexible, and the requirements of teaching practice can be met.

The invention relates to the field of motor control, and discloses a motor control method and system and an electric power-assisted vehicle, and the motor control method comprises the steps: obtaining a sensor signal in the vehicle; initial power-assisted torque acting on the motor is obtained based on the input voltage of a built-in torque sensor of the motor; filtering the initial power-assisted torque through a first filter to obtain an optimized power-assisted torque; calculating a corresponding electrical angular velocity according to the electrical angle, inputting the electrical angular velocity into the active damper for processing, and outputting a corresponding damping torque; adjusting the optimized power-assisted torque by using the damping torque to obtain an adjusted power-assisted torque; and a closed-loop control strategy is utilized to distribute the adjustment assistance torque, and a three-phase voltage control signal input to the motor is obtained so as to drive the motor to rotate. The motor control method can solve the resonance problem caused by acceleration and deceleration of the vehicle, reduce the rotation speed fluctuation of the motor, inhibit the starting acceleration of the motor, effectively improve the riding smoothness and reduce the starting abrupt feeling.

The invention discloses a quick clamping type clamp for aluminum alloy precision forgings, and relates to the technical field of clamps, the quick clamping type clamp comprises a positioning plate, a bottom plate and a plurality of cushion columns, the positioning plate is mounted above the bottom plate through the cushion columns, a clamping groove is formed in the positioning plate, and a plurality of clamping pins and auxiliary supporting pins are arranged in the clamping groove. A pair of hinge blocks and a pulling mechanism are arranged on the same side of the positioning plate and the bottom plate, a transmission mechanism is arranged below the positioning plate and connected between the pulling mechanism and the clamping pin, when the pressing rod is pulled, the magnetic disc rotates, induction current and damping torque are generated in the copper anvil disc, the springback speed of the pressing rod is effectively reduced, mechanical damage is avoided, and the service life of the pressing rod is prolonged. The transmission mechanism can be of a spring inhaul cable structure or a hydraulic structure, synchronous deflection of the clamping pins is achieved, the clamping force can be changed in a stepless mode by adjusting the position of a nut, and the aluminum alloy precision forge piece clamping device is rapid in clamping, safe to operate, controllable in clamping force and suitable for efficient machining of aluminum alloy precision forge pieces.

A drive system and method of control. The method includes reducing damping of a damped torque command signal when an error between a torque command signal and the damped torque command signal exceeds a threshold amount. Torque is provided with a torque source of the drive system based on the damped torque command signal.

According to the four-degree-of-freedom force feedback master manipulator, a yaw operation assembly is used for controlling the overall yaw angle of a slave actuator and corresponds to the yaw angle of a wrist during operation, and a pitching operation assembly is used for controlling the overall pitching angle of the slave actuator and corresponds to the pitching angle of the wrist during operation. The rotating operation assembly is used for controlling the overall rotating angle of the slave actuator and corresponds to the rotating angle of the wrist during operation, and the shearing operation assembly is used for controlling shearing opening and closing of the slave actuator and corresponds to the shearing action of the finger during operation. The yaw operation assembly, the pitching operation assembly, the rotation operation assembly and the shearing operation assembly are each provided with a force feedback damper used for applying damping torque. Reasonability and convenience of hand operation of a human body are guaranteed, the corresponding force feedback damper can accurately record angles and apply damping torque, force feedback of a doctor during operation of a main manipulator is achieved, and reliability and precision of force feedback of the main manipulator are guaranteed.

The invention provides a method and a system for analyzing electromagnetic scale dynamic damping characteristics of network construction type equipment, and relates to the technical field of network construction type converters, and the method comprises the steps: carrying out the equivalent transformation of a system energy amplitude dynamic simplified model, and building a system class damping torque model; calculating a system energy amplitude dynamic dominant oscillation mode; based on the system type damping torque model and the dynamic dominant oscillation mode, virtual damping torque contributed by each feedback loop to the system is calculated; according to the virtual damping torque, the relation between the energy amplitude dynamic state and the virtual damping characteristic is established, and therefore the energy amplitude dynamic damping characteristic of the system is judged. According to the method, the oscillation mechanism of the network construction converter under the electromagnetic scale is disclosed, a complete analysis process is provided, and theoretical support is provided for engineering application and control link optimization, so that the oscillation suppression capability and stability of the system are effectively improved.

The invention provides a stepless hovering rotating shaft based on a rubber pad friction pair, and relates to the field of machinery. The stepless hovering rotating shaft based on the rubber pad friction pair comprises a front support, a rear support, a rubber pad, a bolt, a gasket, a disc spring and a nut, the front support, the rear support, the rubber pad, the bolt, the gasket, the disc spring and the nut are fastened through the nut, the bolt sequentially penetrates through the front support, the rubber pad and the rear support, the front support is installed in a first shell, and the rear support is installed in a second shell. According to the stepless hovering rotating shaft based on the rubber pad friction pair, through the design of the rubber pad friction pair, direct contact of metal is avoided, abrasion and stick-slip phenomena are reduced, and stable and smooth damping torque is provided; stepless hovering in the true sense is achieved, and the position can be stably kept at any angle. The structure is simple, cost is low, and production and maintenance are easy; the environment adaptability is good, and the vibration resistance and the impact resistance are excellent; the service life of the product can be prolonged by replacing the rubber pad, and maintenance cost is reduced.