188 results about "Dynamical friction" patented technology

A hinge assembly rotationally connecting two components includes at least a shaft coupled to one of the components and a tubular member connected to the other component and a defining an annular space around said shaft. A viscous damping fluid is disposed in said space and provides a damping force resisting relative rotation between the two components. A second tubular member is also provided that is connected to the shaft and is arranged axially around the first tubular member. In this latter configuration, static and dynamic frictional forces are generated between the tubular members that resist rotation between the components as well.

The invention discloses a servo system self-adaptive robust controller with dynamic frictional compensation, which is used for improving output tracking precision and fast response of a motor servo system and is particularly suitable for a precise motor servo system with requirements on high precision and fast response. The servo system self-adaptive robust controller comprises a parameter self-adaptive adjusting module, a dynamic frictional compensator and a robust control module. The online estimation of a frictional force value is realized by adopting a frictional model approximator constructed by a LuGre dynamic frictional model Lipschitz coefficient through self-adaptive adjustment of a parameter of the frictional approximator, and accordingly, the frictional compensation is carried out for overcoming the adverse effect of frictional force on the output tracking precision and the fast response of the servo system. The controller adopts a robust control law and ensures that the servo system has enough disturbance resistance. Because the controller can realize rapid and accurate frictional compensation and effectively inhibit the influence of external disturbance, the output tracking precision and the fast response of the servo system can be greatly improved.

The invention discloses a testing device and a testing method for monitoring steel wire rope-friction pad dynamic micro-friction state. The testing device comprises a base frame, a loading system, a micro-slip system and a state monitoring system, wherein the loading system comprises a weight loading system, a hydraulic loading system and a steel wire rope; the micro-slip system comprises a support system, a drive system and a friction transmission system; the state monitoring system comprises a dynamic tension monitoring system, a pad stress measuring system, a friction force measuring system and a micro-slip monitoring system. By utilizing the testing device and the testing method, dynamic alternating tension can be applied to the steel wire rope and dynamic micro-friction can be applied between the steel wire rope and a friction pad simultaneously, and dynamic tension evolution of the steel wire ropes at both sides of the friction pad, micro-slip amplitudes of different sections of a contact arc of the steel wire rope and the friction pad, stress change of the friction pad near the contact zone of the steel wire rope and the friction pad and dynamic friction force between the steep wire rope and the friction pad can be measured in real time.

The invention provides a dynamic frictional force testing system and a dynamic frictional force testing method of pavement materials, which aim at solving the problems that a skid resistant testing method in the prior art is large in deviation of testing results, cannot perform testing in all weather and is poor in stability of testing results and the like. The dynamic frictional force testing system of pavement materials comprises a turning system, a loading system, a temperature control system and a testing system. The dynamic frictional force testing system of pavement materials and the testing method adopt simulated dynamic friction and simulate temperature, rotation speed, pressure and other key factors to test dynamic frictional force of the pavement materials. The dynamic frictional force testing system and the dynamic frictional force testing method of pavement materials have the advantages of being capable of performing testing in all weather, accurate in testing results, stable in testing results, and further capable of directly observing appearance changing of the pavement materials under the dynamic friction condition.

The invention discloses a test system and method of dynamic friction parameter, the test system is characterized in that's: an absolute encoder 14 is arranged on a motor 13, a moment sensor 4 is arranged axially between a test part, a weight fixing device 6 and a locking mechanism 2, the test part is arranged at upper and lower layers of the weight fixing device, when testing, the operation of the motor is controlled by a controller, moreover the parameters including the sampling time, friction moment, rotating speed, rotating angle and motor winding current are recorded synchronously, the evaluated value of current friction parameters are set at Sigma 0, Sigma 1, Fc, Fs, Omegas, and Sigma, and then differential equation of systematic movement is solved so as to obtain the evaluated value Theta(t) of moment motor rotating angle of each sampling time, thereby respectively calculating the errors of the evaluated values of the moment motor rotating angle and the friction moment of each sampling time, the error parameters are contrasted with the set testing parameters so as to meet the required evaluated value of the output friction parameters, otherwise correction is re-made. The test system and method of dynamic friction parameter has the advantages of convenient testing and high precision. The test system is applicable for dynamic friction parameter test on various materials.

A heave motion compensator (30, 40, 70, 100, 140, 300) for compensating heave motions comprises a cylinder (41) and a piston (44) delimiting a variable volume fluid chamber (49) in said cylinder (41), wherein said piston (44) can oscillate within said cylinder (41), said piston (44) being provided with a seal (48) frictionally engaging said cylinder. The compensator further includes a motor (65) that causes said seal (48) to revolve relative to said cylinder (41) so as to obtain a dynamic friction regime between the seal (48) and the cylinder (41). In a possible embodiment the motor (65) is arranged to rotate said piston (44), and the seal (48) is mounted on said piston (44) so as to rotate along with said piston (44).

The invention discloses a device for testing dynamic friction torque of an air static-pressure axial thrust bearing. The device for testing dynamic friction torque of the air static-pressure axial thrust bearing comprises an engine base, an electrified coil, a permanent magnet, a force sensor, a thrust collar, a main shaft rotor, an electric main shaft, a supporting shaft, and a radial air thrust bearing to be tested. The radial air thrust bearing is arranged on the supporting shaft, a pressing rod is arranged on the end face of the radial air thrust bearing, and the section extending out the pressing rod is arranged on the force sensor; the radial air thrust bearing loads axially through a non-contact type electromagnetic loading device, the electrified coil is fixed at one end of the engine base, the permanent magnet is fixed on one end face of the radical air thrust bearing, the coil has the magnetism and has the same magnetic characteristics with the permanent magnet, and the radial air thrust bearing is subject to an axial thrust. To obtain the dynamic friction torques under different axial thrusts, the non-contact type electromagnetic loading device is used for axial loading. The non-contract loading way eliminates the influence of friction caused by contact on a testing result.

The invention relates to a mechanical shoulder joint position control method with dynamic friction compensation, which is realized through a global control unit and a local control unit. The global control unit is used for tracking the trajectory of a mechanical shoulder joint in a global large range, the trajectory tracking is realized through a PD (Proportional Differential) controller widely applied in the mechanical shoulder joint, and the input vector of the PD controller comprises the position error of the mechanical arm joint and the change rate of the position error; and the local control unit is used for completing dynamic friction compensation in a local small range, the dynamic friction compensation is realized through a five-layer autoregressive wavelet neutral network controller having an observation layer, and the input vector of the autoregressive wavelet neutral network controller comprises the expected position, the expected speed and the actual position of the mechanical shoulder joint. The actual speed of the mechanical shoulder joint required in the autoregressive wavelet neutral network controller can be calculated through the observation layer. The mechanical shoulder joint position control method provided by the invention can be realized by only installing one position sensor in the mechanical shoulder joint without installing a speed sensor.

The invention provides a hydraulic reciprocating seal dynamic property detection device and design. The device comprises a dynamic friction property detection module, an inner leakage detection module and an outer leakage detection module which share a part of a testing device. When a hydraulic cylinder (1) is connected with a first testing cylinder (2) through an S-shaped tension pressure sensor (4), the S-shaped tension pressure sensor only achieves a connection effect, and thus the structure of the outer leakage detection module and the structure of the dynamic friction property detection module are similar. As long as an oil level sensor (8) is additionally arranged on a left gland of the first testing cylinder, the oil level sensor is welded to the left gland of the first testing cylinder through a supporting steel tube. According to the detection device, under the premise that the function requirements of a hydraulic reciprocating structure and a hydraulic execution element are not changed, detection of the dynamic friction property and the leakage property of a hydraulic reciprocating seal in application is conducted according to the normal operation condition of the hydraulic execution element. According to the hydraulic reciprocating seal dynamic property detection device and design, analysis and evaluation of the dynamic property of the hydraulic reciprocating seal can be achieved.

Provided herein are exemplary embodiments of novel and nonobvious liners, methods of lining passageways or pipelines using said liners, and uses of said liners. In one embodiment of the present invention, the liner comprises a resin absorbent material and a substantially impermeable coating. The substantially impermeable coating includes a modified polymer including a polymer having at least one additive incorporated thereto; wherein the dynamic coefficient of friction of the modified polymer is lower than the coefficient of friction of the polymer

The invention discloses a device for comprehensively measuring linear guide rail friction force and manufacturing and mounting errors, and belongs the technical fields of measurement. The device for comprehensively measuring the linear guide rail friction force and the manufacturing and mounting errors mainly comprises a linear feeding system, a guide rail and sliding block friction force measuring device, a guide rail linearity error measuring device and a guide rail mounting parallelism error measuring device. The guide rail and sliding block friction force measuring device drives a sliding block to move through a servo motor to achieve measurement of the dynamic friction force of the sliding block at different running speed and under different loading effects, and the value of the friction force can be obtained by utilizing a pull pressure sensor. The guide rail mounting parallelism error measuring device converts parallelism errors among guide rails into internal stress of a connecting rod, and the values of the parallelism errors can be obtained through measurement of the pull pressure sensor. A standard straight gauge block is utilized by the guide rail linearity error measuring device as a reference of measurement, the linearity error of the guide rails is converted into changes of compression amount of a spring, a least square method is utilized for processing, measurement is convenient, and measurement accuracy is high.

The invention relates to a hydraulic winch, comprising a machine frame, a winding barrel, a hydraulic motor, and a hydraulic brake, a planet gear speed reducer and a hydraulic clutch which are arranged in the winding barrel. The hydraulic clutch comprises an outer barrel, a clutch friction plate and a clutch oil cylinder. A bearing shaft is fixed on the machine frame. The outer barrel and a piston of the clutch oil cylinder are fixed on the bearing shaft through bearings respectively. The piston is in transmission connection with an output end of a planet carrier of the planet gear speed reducer. The outer barrel and the piston are fixed on the bearing shaft, so that the outer barrel, the piston and the bearing shaft have a relatively high coaxiality, and a dynamical friction plate and a static friction plate which are arranged on the outer barrel and the piston respectively have relatively high parallelism. The dynamical friction plate and the static friction plate can be well contacted with each other and completely separated from each other as well so that the hydraulic winch has more stable and reliable clutch performance, and the abrasion and the heat generation of the clutch friction plate are reduced. In the hydraulic winch, transmission efficiency and operational reliability can be improved, and service life can be prolonged. The hydraulic winch has a simplified integral structure and higher machining and assembling manufacturability.

The present invention presents novel apparatus and methods to address the problem of measuring surface characteristics of a coated medical device. A preferred embodiment of the invention incorporates a processor-controlled transport module to move a test sample at a predetermined velocity profile past a variety of fixtures. The fixtures include a processor-based, feedback-controlled servo mechanism that applies an predetermined normal force on a test sample with selected test surfaces to measure dynamic friction, abrasion resistance and durability of a coating. More generally, the invention can be used to characterize surface and pull or push properties of a wide variety of objects that also include threads, filaments, rods, tubing, wires, extrusions, films and ribbons.

The invention provides a bionic sensor for testing dynamic friction of fabric. The sensor consists of a friction head embedded with a PVDF film and a cantilever structure of a thin girder elastomer; and the cantilever structure is symmetrical according to the axes which are vertical with each other. The sensor comprises the PVDF film, an acrylic resin solidified body connecting rod, an acetate fiber film, vulcanized rubber, a vertical type strain girder, a horizontal type strain girder, a pedestal, a connecting girder and another connecting girder. The bionic sensor of the invention has simple structure, convenient mounting, large integrated rigidity, high inherent frequency and sensitivity of each direction of two-dimensional force, can be used for the friction test of fabric tactility evaluation and has rotary and reciprocating sliding flexibility.

The invention relates to a device for testing the dynamic friction torque of a precise micro rolling bearing. The device comprises a machine base, an air static pressure suspension bearing block, two sets of tested bearings, a driving electric spindle, a pressure sensor and a speed sensor, wherein the two sets of tested bearings are arranged in a central hole of a suspension shaft in the air static pressure suspension bearing block; a rotary central spindle is sleeved in the central hole of the two sets of tested bearings and is connected with the driving electric spindle through a rubber hose flexible coupling; the pressure sensor is arranged on the part close to the left end of the suspension shaft; and the speed sensor is arranged on the part close to the right end of the suspension shaft. The dynamic friction torque of the tested bearings can be tested in real time in a start process, a stop process and an operation process with different rotation speeds.

A tissue paper product having at least one ply, wherein only one outer surface of said tissue paper product has a polyhydroxy compound applied thereto by slot extrusion, said polyhydroxy compound providing said tissue paper product with a Wet Burst greater than about 90 g, a Dynamic Coefficient of Friction less than about 0.9, and a Bending Flexibility less than about 0.1 gf cm²/cm.

The invention relates to a rubber dynamic friction wear detection device, belonging to the technical field of machinery. An electric machine is connected with a driving pulley and a belt type transmission structure is formed by a belt and a driven pulley. The driven pulley is fixed on a main shaft and forms a middle transmission structure together with a bearing. A support plate is mounted on the left side of the main shaft near to the driven pulley. An eccentric wheel fixed on the right side of the main shaft is connected with a sliding body by a connection rod. A slide detection platform is fixed on a guide rail, the upper end side of the slide detection platform is fixedly connected with a friction sample plate for detection, a temperature control device is mounted in the platform, a load adjustment device is arranged right above the platform, a sample clamping device is fixed on the load adjustment device, a force application handle is formed on the top of a screw rod, a displacement control handle formed besides the force application handle is fixed on the load adjustment device by a lead screw and the load adjustment device is vertically fixedly connected with the support plate. The rubber dynamic friction wear detection device has the characteristics of reasonable structure, safe and reliable principle and low cost, and is simple to manufacture, convenient to control and operate, the detection is accurate and has good effect, and the detection technology is convenient and easy.

The invention discloses a system for accurately testing friction damping. The system comprises a piston, a damping sealing member, a sleeve, a piston rod, force sensors, a cutting sleeve coupler, a displacement sensor, a driving motor, a measurement control platform, an experiment table body and a sleeve centering adjusting rod. The piston, the damping sealing member and the sleeve are matched together to simulate a moving part structure of a liquid rocket valve, and then are assembled together with the experiment tale body and the sleeve centering adjusting rod to form an experiment table of friction testing system; the piston is in rigid connection with the driving motor through the piston rod and the cutting sleeve coupler; the force sensors at two ends of the sleeve and the displacement sensor of the driving motor are connected with the measurement control platform; and the driving motor is connected with the measurement control platform to form a control test bed of the friction testing system. The system provides a valve piston friction structure for simulating reality, adopts a driving mode combining direct driving and macro-micro motions, and has the advantages of automatic control, high control accuracy, high reciprocating frequency, large motion stroke, high dynamic frictional force measurement accuracy and the like.

The invention discloses a construction method of a car steel plate spring multi-body model. The construction method comprises the following steps: firstly, testing static stiffness and dynamic force of a steel plate spring; secondly, establishing a dynamic friction model; thirdly, establishing the steel plate spring multi-body model in a multi-body dynamics program; fourthly, adding a dynamic dry friction model to the steel plate spring multi-body model; and fifthly, establishing a suspension system model for simulating a suspension and an entire car. In the construction method, dry friction among steel plate spring reeds is uniformly processed as characteristics of plate spring assembly, and assembly dry friction is described by the dynamic friction model, therefore, dynamic force characteristics of the car steep plate spring can be accurately reflected to reflect the dynamic stiffness formed by the friction, and ride comfort simulation is more accurate.