290 results about "Axial load" patented technology

A surrounding rock deformation and failure test system with a rotatable stress main shaft in a three-dimensional crustal stress field is characterized in that a press machine upper pressure head and a press machine base are oppositely distributed up and down, and a loading hydraulic cylinder is connected with the press machine upper pressure head; the surrounding rock sample is vertically arranged in the axial loading space, and a simulation roadway is formed in the axis part of the surrounding rock sample; annular upper and lower end plates are fixedly connected in the upper and lower ends of the confining pressure cylinder respectively; the confining pressure cylinder sleeves the outer side of the axial loading space; a plurality of groups of mounting holes are uniformly formed in the circumferential directions of the annular upper and lower end plates; the radial pressurizing assembly comprises a supporting steel pipe and an elastic capsule. The main supporting section is sleeved with the elastic capsule, and a plurality of through holes are formed in the main supporting section. A plurality of strain bricks are pre-buried in the surrounding rock sample; the track is fixedly mounted in the simulated roadway; the micro camera is assembled on the track through the electric control trolley; and the strain gauge II and the acoustic emission probe are arranged in the simulated roadway. According to the system, the working condition that the direction of a stress field changes can be simulated in a three-dimensional true triaxial stress environment.

The invention discloses a variable-shaft-diameter rolling bearing testing device and testing method, and aims to solve the problems that an existing rolling bearing testing device is difficult to adapt to bearings with different shaft diameter specifications, and a main shaft needs to be replaced frequently. The device is composed of a testing platform, a lead screw driving mechanism, an axial loading mechanism, an inner diameter variable mechanism, an outer diameter variable mechanism, a main shaft, a bearing seat mechanism, a main shaft coupler, a main shaft motor and a supporting frame. The inner diameter variable mechanism adapts to the inner diameters of different rolling bearings through a plurality of ring petals and a chuck structure, the outer diameter variable mechanism can adjust the outer diameter and the radial applied force in real time according to the outer diameter of the rolling bearing, the axial loading mechanism can apply a preset axial load to the bearing, and besides conventional constant axial force, the axial loading mechanism can also apply axial torque in different directions. The device can adapt to the testing of rolling bearings with various shaft diameter specifications without replacing the whole set of main shaft, effectively shortens the testing preparation time, and improves the testing efficiency. And the universality and the applicability are high.

The invention provides an axial force active balancing method for a fluid machine. The axial force active balancing method for the fluid machine comprises the steps that S1, fluid axial force borne by an impeller of the fluid machine during working is obtained; s2, configuring a motor for driving the impeller, and enabling the motor to generate an electromagnetic axial force through design or control; and S3, the direction of the electromagnetic axial force is opposite to that of the fluid axial force, the magnitude of the electromagnetic axial force is controlled to at least partially counteract the fluid axial force, and therefore the net axial load transmitted to the supporting bearing is reduced. The driving motor is actively designed and controlled to generate electromagnetic axial force which is equal to the pneumatic / hydraulic axial force of the impeller in magnitude and opposite to the pneumatic / hydraulic axial force of the impeller in direction, so that zero returning or minimization of net axial force is realized at the bearing.

The invention discloses a mechanical metamaterial cell element with a zero Poisson's ratio property, and belongs to the technical field of mechanical metamaterials. The upper top plate and the lower bottom plate are symmetrically arranged, the upper cleat nail set and the lower cleat nail set are arranged at the four corners of the inner side faces of the upper top plate and the lower bottom plate, the elastic body set is connected through the upper cleat nail set and the lower cleat nail set, and the flexible hinge component set is arranged at the midpoint position of four side lines of the upper top plate and the lower bottom plate. The flexible hinge component set keeps inward pre-bending through the pre-tension of the elastomer set, and when the cell element bears an axial load, the flexible hinge component set generates coordinated inward bending deformation, so that the cell element shrinks in the axial direction, the transverse size is kept stable, the axial zero Poisson's ratio characteristic is achieved, and meanwhile the energy absorption capacity is achieved. The cell element is based on elastic deformation, has self-recovery capability and long cycle life, adopts modular design, is convenient to assemble, disassemble and maintain, and is suitable for application scenes of aerospace buffer devices, biomedical implants, precise instrument supporting structures and the like.

The invention discloses a wall type Z-shaped metal torsion tube damper anti-seismic system and method. The wall type Z-shaped metal torsion tube damper anti-seismic system comprises a frame beam, a frame column, a cantilever wall and a Z-shaped metal torsion tube damper. The frame beams and the frame columns are connected with a building, the cantilever walls are connected with the frame beams, and the Z-shaped metal torsion tube dampers are arranged between the paired cantilever walls and connected with the cantilever walls so as to dissipate energy transmitted by the cantilever walls. According to the damper anti-seismic system, the Z-shaped metal torsion tube damper is arranged to replace a traditional mild steel metal damper and a viscous damper to conduct damping design of a building structure, the problem that the low-cycle fatigue performance of the traditional metal damper is poor is solved, the oil leakage risk of the viscous damper is avoided, and the anti-seismic performance of the building structure is improved. Moreover, due to the structural design in the damper, the influence of the bending and shearing effect on the deformation of the torsion tube under the action of an axial load is eliminated, so that the section of the torsion tube is always kept a stable circular section in the hysteresis energy consumption period of the torsion tube, and the energy consumption efficiency is ensured.

The utility model discloses a bearing axial load monitoring device, and relates to the technical field of bearing monitoring devices. The bearing axial load monitoring device comprises a bearing bracket, a monitoring rod, a fixed frame, a movable rod, a pressure sensor main body and a controller, the bearing bracket is arranged at a target supporting position and is provided with a main shaft for supporting the bearing main body; the monitoring rod is connected to the bearing support in a sliding mode and is aligned with the side face of the bearing body. The bearing axial load monitoring device utilizes the design of the bearing bracket, the monitoring rod, the fixed frame, the movable rod, the pressure sensor main body and the controller, is simple and reliable in overall structure, stable in operation, convenient to install and cost-saving, adopts a mode of directly monitoring the side surface of the bearing main body, improves the monitoring precision, ensures the monitoring accuracy and stability, and is suitable for popularization and application. And important data support is provided for operation and maintenance of equipment.

The invention relates to the technical field of bolt connection fatigue life prediction, in particular to a high-strength bolt connection fatigue life prediction method and system, and the method comprises the steps: obtaining a bolt entity morphology discrete point cloud, and generating a continuous geometric topology function through non-uniform rational B-spline interpolation reconstruction; discretizing the standard thread parameters to construct a standard finite element model, calculating a normal spatial position difference value based on a continuous geometric topology function, and packaging to generate a geometric defect mapping tensor; according to the converted node coordinates, constructing a real morphology finite element model; solving the nonlinear equilibrium equation by utilizing a penalty function method, and generating a contact stiffness characteristic matrix; calculating an axial load distribution sequence and executing gradient convolution operation, and extracting a local field variable peak value; and calculating an accumulated damage index in combination with a damage evolution equation and outputting a predicted life. By mapping the entity discrete point cloud into a finite element geometric defect tensor and reconstructing a real morphology model, the accurate prediction of the fatigue life of the bolt considering the micromachining deviation influence is realized.

The invention provides a method for establishing a nonlinear constitutive model of low-temperature marine steel, and relates to the technical field of ships and materials. A heterogeneous time series data set is provided for model construction through multi-type sample multi-axial load tests and full-field strain acquisition; nonlinear mapping of deformation activation energy about temperature and microscopic state variables is established by taking a crystal plasticity theory as a framework, and the defect that a low-temperature dislocation evolution rule cannot be reflected due to the fact that a traditional model solidifies physical parameters into constants is overcome; a damage evolution operator jointly induced by stress triaxial degree and a principal stress threshold is embedded, Bayesian inference is adopted to carry out parameter joint calibration, model dynamic calibration and parameter continuous optimization are realized through a simulation and experiment closed-loop iteration mechanism, and finally a digital design evaluation model capable of being under untested extreme working conditions is produced. And an engineering tool taking physical interpretability and probabilistic safety margin into consideration is provided for the ice-resistant design of the polar region ship.

The utility model provides a coke pot trolley walking mechanism suitable for a curve. The coke pot trolley walking mechanism comprises a frame; a plurality of wheels are arranged at the bottom of the frame, and inclined areas and connecting areas are sequentially arranged at the ends, making contact with the rails, of hubs of the wheels; the center plate structure is arranged on the frame, the center plate structure comprises an upper center plate and a lower center plate, and an adjusting structure is arranged between the upper center plate and the lower center plate and used for generating rolling friction between the upper center plate and the lower center plate. The inclined areas are arranged on the wheels to effectively cope with lateral force brought by a curve, the adjusting structure in the center plate structure can bear very large axial load and radial load, and the adjusting structure and the center plate structure work cooperatively, so that the coke tank trolley can safely and stably pass through the curve, the risk of overturning of the trolley and a coke tank is greatly reduced, and the service life of the coke tank trolley is prolonged. And the transportation requirement under a complex reshipment route is met, the production efficiency is improved, and the production safety is guaranteed.

The present application relates to the technical field of wind turbine bearing, in particular to a method and device for adjusting axial force balance of double-row self-aligning roller bearing, the device comprises an axial force applying assembly arranged outside the bearing seat, the axial force applying assembly is composed of a ring-shaped positioning element and a plurality of groups of elastic elements arranged uniformly along the circumference in the cavity of the positioning element, the inner ring of the positioning element extends radially inward and projects to cover the outer ring of the bearing, one end of the elastic element faces the inner part of the cavity, and the other end contacts the outer ring of the bearing through a pressure equalizing ring. The present application generates a reverse additional support force under the action of axial load, actively transfers part of the load from the stressed side bearing row to the non-stressed side, solves the problem that the roller contact stress of the stressed side of the existing double-row self-aligning roller bearing is too high under the single-sided axial load working condition, and early fatigue spalling is easily caused, realizes the balanced distribution of axial force, effectively reduces the peak contact stress, and significantly prolongs the service life of the bearing.

A deflectable tube (312) has a deflectable tip section (301) and a bendable body section (309). The deflectable tube has one or more turning wires (16 (i)) that rotate helically in the body section (309) in order to compensate for path length differences occurring in the body section (309) when the body section (309) is bent. In order to isolate axial loads in the body section (309), the deflectable tube (312) is provided with one or more longitudinal force isolation elements (322 (k)) in the body section (309), the one or more longitudinal force isolation elements extending parallel to the one or more steering wires (16 (i)). Both ends of the force isolation element (322 (k)) are attached to the outer tube (340) or the inner tube (330) or both.

The invention relates to the technical field of bearing test devices, in particular to a bearing precision life test device and method, and the device comprises a housing, one side of the housing is rotatably provided with a driving shaft, the driving shaft penetrates through the housing and is in transmission connection with a mandrel, one side of the mandrel is fixedly connected with a sleeve, and the inner side of the sleeve is in sliding clamping connection with a bearing to be tested. A bearing clamping mechanism is movably installed between the fixed spring seat and the sleeve, a pressure frame is movably installed on the outer side of the stress bearing cover, a transition frame is fixedly installed on the outer side of the pressure frame, and an axial loading mechanism is fixedly installed between the transition frame and the stress bearing cover. Precision monitoring mechanisms are fixedly installed on the opposite outer sides of the pressure frames. According to the scheme, core data such as radial run-out, axial load and temperature are collected in real time through multi-dimensional monitoring assemblies such as a non-contact eddy current displacement sensor and a pressure sensor, and the precision decline amount can be accurately quantified by combining radial run-out index comparison before and after the test.

This invention relates to the technical field of boring machines and discloses a boring machine column device with a U-shaped guide rail layout. The device includes a machine bed with a worktable. A U-shaped column is fixedly installed on the right side of the machine bed. A U-shaped guide rail is fixedly installed on the inner wall of the U-shaped column. Two guide rail assemblies a are provided on the U-shaped guide rail. Two crossbars are fixedly installed on the two guide rail assemblies a. Connecting blocks are provided on the two crossbars. A spindle box is fixedly installed below the connecting blocks. Two vertical blocks are fixedly installed on each of the two guide rail assemblies a. Lead screws are threaded through each of the two vertical blocks. A housing is fixedly installed on the upper side of the U-shaped column. The housing is connected to the two lead screws. A rotary starter inside the housing can drive the lead screws to rotate back and forth. The U-shaped guide rail layout enhances the moment of inertia of the U-shaped column section, effectively resisting deformation caused by cutting forces and vibrations. The U-shaped layout can simultaneously withstand radial cutting forces, axial loads, and overturning moments. Multi-point support disperses stress and reduces the risk of local deformation.

The utility model relates to a motor capable of improving axial support and a wet mill, which comprise a casing, a stator fixed on the casing, a rotor which is rotatably accommodated at the inner side of the stator and is provided with a rotating shaft, and a first end cover and a second end cover which are arranged at the two axial sides of the casing, and are respectively provided with a first cavity and a second cavity, the device is characterized in that a first self-aligning roller bearing for supporting the rotating shaft is arranged in the first cavity, and a thrust bearing for supporting the rotating shaft, a spacer bush and a second self-aligning roller bearing are sequentially arranged in the second cavity from bottom to top along the axis. According to the motor capable of improving the axial bearing, the supporting structures on the two axial sides of the motor are improved, so that the motor can conveniently transmit the borne axial load to the second end cover, meanwhile, the rotating shaft of the motor can be self-adaptively aligned through the self-aligning roller bearings on the two axial sides, the radial run-out of the rotating shaft during rotation is reduced, and the service life of the motor is prolonged. And the axial load capacity of the motor is improved while the smooth rotation of the motor is ensured.

The present application relates to the technical field of bearing measurement, in particular to a kind of matching conical roller bearing axial play measuring method, comprising the following steps: step one, initial measurement preparation;Step two, preliminary play measurement;Step three, self-locking amount measurement, separately place upper bearing in measurement state, under the same axial load, respectively measure its positive assembly attitude under assembly height T1 With assembly height T0 Under reverse assembly attitude, calculate self-locking amount δT=T1-T0;Step four, actual play calculation, according to formula δA=δA'+δT Calculation, obtain bearing actual axial play δA.The present application eliminates the numerical distortion caused by inverted measurement through self-locking amount compensation, significantly improves the measurement accuracy, and is simple and easy to operate, without special equipment, suitable for on-site rapid batch detection, and gives consideration to accuracy and practicality.

Gas turbine engines and methods of securing rotating components therein with a threaded nut. The threaded nut is configured to releasably couple with a shaft to secure a rotating component thereon. The threaded nut may include a body having a bore extending therethrough defined by inner surfaces thereof, threads protruding from the inner surfaces configured to mate with threads of the shaft, and a nut face on an end of the body configured to contact a contact surface of the rotating component or another component in contact therewith and apply an axial load thereon that is sufficient to maintain a fixed axial position of the rotating component. The nut face includes a contoured surface configured to bias the axial load toward a radially outer portion of the nut face to reduce loading on a first of the threads of the shaft closest to the contact surface.

The invention belongs to the field of unmanned aerial vehicle rotor power systems, and particularly relates to a compact rotor power system tension measurement structure and a design method thereof, and the method comprises the following steps: selecting an annular tension sensor which is geometrically compatible with a motor shaft and has a redundant range according to the size parameter and the maximum theoretical tension of a rotor motor; a force transmission assembly used for bearing an axial load is arranged between the lower end of the motor shaft and the annular tension sensor, and an axial limiting component matched with the force transmission assembly is arranged; constructing an axial stacking size chain based on the height of the force transmission assembly, the size of the limiting component and the height of the sensor, and determining the axial extension amount of the motor shaft and the mounting position of the limiting component according to the axial stacking size chain; and a mounting base for enveloping the force transmission assembly and the annular sensor is designed, so that the motor stator and the base are fixed to form a compact integral structure. By simplifying a force transmission path and shortening a dimension chain, the number of parts and the axial height are remarkably reduced, and the structural rigidity and the measurement stability are improved.

A shelter apparatus for an interior of a vehicle. 2.1, a shielding device of the type is known, the shielding device has a flexible flat structure, the flat structure can be wound and unwound on a winding shaft and can move between a rest position wound on the winding shaft and a shielding position unwound from the winding shaft, the winding shaft is embodied as a hollow profile having a non-rotationally symmetrical inner cross-section and is rotatably mounted on the vehicle side in the opposite end-side end region thereof, and wherein a roll spring is arranged in the interior of the winding shaft, which roll spring exerts a continuous torque on the winding shaft in the winding direction, and the roll spring is statically held at one end on the roll shaft bearing and at the other end on a roll spring carrier, which is arranged in a rotationally locked manner with the roll shaft and is arranged in an axially movable manner in a hollow profile of the roll shaft. 2.2 according to the invention, a counter bearing of the winding shaft opposite the winding shaft bearing is provided with an axial pressure device which exerts an axial load on the end face of the winding shaft in the direction of the opposite winding shaft bearing. And 2.3, a use scheme for shielding the side window of the passenger car is provided.

According to the device and method for the efficient test of the compression joint inhaul cable load holding test, uniform balance of stress of the compression joint inhaul cables on the left side and the right side is achieved through the pulleys and the balance inhaul cables, measurement inaccuracy caused by the length difference of the compression joint inhaul cables is avoided, it is guaranteed that the stress states of the series connection inhaul cables are consistent through a series connection mode, and measurement accuracy is improved. Meanwhile, by matching with the concentric device provided by the invention, the axial load holding test state of a plurality of crimp cables to be tested can be well ensured, the stability and reliability of test data are ensured, the high-efficiency test problem of the load holding test of the crimp cables is well solved, the test efficiency is improved by more than 4 times, the test is accurate, the structure is stable and reliable, and the test cost is reduced. Operation is convenient, cost is low, and the applicable inhaul cable specification range is wide.

The utility model provides a movable tooth speed reducer which comprises a crossed roller bearing capable of bearing radial and axial loads and a movable tooth transmission mechanism capable of achieving the speed reduction function. The oscillating tooth transmission mechanism comprises an input end cam, an oscillating tooth isolation ring, oscillating teeth and an inner gear ring, the oscillating teeth are arranged in a plurality of evenly-arranged oscillating tooth grooves of the oscillating tooth isolation ring, the inner gear ring is used for being connected with the oscillating teeth in a meshed mode, and one side of each oscillating tooth is connected with the input end cam in a rolling mode. The other side of the oscillating tooth is in meshed connection with the inner gear ring and is used for performing tangent motion with an inner tooth profile to drive the oscillating tooth isolation ring to perform rotary motion; the crossed roller bearing comprises a crossed roller bearing outer ring, a roller and a crossed roller bearing inner ring, and the oscillating tooth isolation ring is fixedly connected with the crossed roller bearing inner ring through a bolt. The transmission mechanism with the small tooth difference is good in rigidity, stable in operation, large in transmission ratio, small in return difference, long in service life and low in maintenance cost.

The invention provides a kingpin assembly for a commercial vehicle and the vehicle. The rolling parts are arranged at the two ends of the main pin and matched with the thrust tapered roller bearings, the rolling parts are used for bearing loads in the radial direction of the main pin assembly, and the thrust tapered roller bearings are used for bearing loads in the axial direction of the main pin assembly. According to the kingpin assembly of the structure, loads from all system directions of the vehicle can be effectively decomposed to the rolling part and the thrust tapered roller bearing, and the problem that the kingpin assembly is pressed due to the fact that the same bearing component is subjected to excessive loads at the same time is effectively solved. According to the main pin assembly, the bearing capacity of the main pin assembly can be further improved, meanwhile, the main pin assembly adopting the structure is simple in structure and convenient to install, the safety performance of a vehicle with the main pin assembly is effectively improved, the main pin assembly can be particularly suitable for a heavy-load commercial vehicle, and the practicability of the main pin assembly is further improved.

The present disclosure relates to a mechanical metamaterial with a variable bistable state. The mechanical metamaterial comprises a plurality of metamaterial unit cells connected in sequence in a first direction. Each metamaterial unit cell comprises a connecting head, a variable part and a fixed part connected in sequence in the first direction. The variable part comprises a plurality of variable sheet groups, each variable sheet group comprising two variable sheets, each variable sheet having a top end connected to the connecting head and a bottom end connected to the fixed part, and the width of each variable sheet increasing from the top end to the bottom end. The two variable sheets of each variable sheet group are symmetric about the axis center of the connecting head. The fixed part has a cavity facing the connecting head, and when an axial load is applied to the top of the connecting head, the top end of the variable sheet is bent in the direction of the cavity under the action of the connecting head, and part of the variable sheet and part of the connecting head can be accommodated in the cavity at the top of the fixed part. The mechanical metamaterial of the present disclosure can maintain stable and large deformation and has good band gap regulation ability.

The application provides a magnetic suspension mixed three-degree-of-freedom bearing and an air compressor, wherein the bearing comprises a radial magnetic bearing assembly and an axial magnetic bearing assembly, a permanent magnet capable of providing a bias magnetic field is clamped between the radial magnetic bearing assembly and the axial magnetic bearing assembly, the axial magnetic bearing assembly comprises a first axial stator core and a second axial stator core, the first axial stator core has a first magnetic ring, the radial thickness of the first magnetic ring is la, the second axial stator core has a second magnetic ring, the radial thickness of the second magnetic ring is le, and la < le. The application increases the radial thickness of the side with smaller axial output, thereby improving the axial output of the second axial stator core, making the structures of the first axial stator core and the second axial stator core asymmetric, achieving axial force balance design without increasing the overall volume of the bearing, meeting the axial load demand, and thereby improving the rotor dynamics characteristics.

The invention relates to the technical field of oil pump assemblies, and discloses a wear-resistant structure for an electronic oil pump and the electronic oil pump, the wear-resistant structure comprises a pump head module and a motor module, the pump head module comprises a pump cover, the pump cover is provided with a first oil guide structure, the first oil guide structure is used for introducing high-pressure oil and acting the high-pressure oil on the upper end face of an inner rotor, and the motor module comprises a machine shell. The machine shell is provided with a second oil guide structure, the second oil guide structure is used for introducing high-pressure oil and acting on the lower end face of the inner rotor, and axial load balance is achieved by arranging the oil guide structures on the upper end face and the lower end face of the inner rotor correspondingly; meanwhile, the pump cover is further provided with a first sliding bearing, the machine shell is further provided with a sliding bearing set distributed in the axial direction of the motor shaft, the first sliding bearing and the sliding bearing set form a lever structure with the sliding bearing, farthest from a load point, in the sliding bearing set as a fulcrum, and lateral loads are scientifically dispersed to the multiple bearings by means of the lever principle. The bearing pressure of a single bearing is greatly reduced, and the problem of eccentric wear of the shaft and the bearing chamber is effectively solved.

The invention belongs to the technical field of hybrid magnetic suspension bearings, and discloses a staggered self-centering hybrid magnetic thrust bearing structure and a restoring force calculation method. According to the staggered self-centering hybrid magnetic thrust bearing structure, a radial repulsive force ring is used for generating a restoring force which counteracts the unbalanced force of an axial repulsive force ring in the radial direction and the gravity of a rotor, and the stability of two offset freedom degrees in a radial plane of the rotor is maintained; the axial repulsive force rings are used for counteracting unbalanced loads of the radial repulsive force rings in the axial direction and external axial loads and maintaining the stability of the rotor in the axial direction; the axial electromagnetic bearing is used for counteracting the overturning moment of the rotor around the radial plane and maintaining the stability of the rotor around the transverse rotation freedom degree and the vertical rotation freedom degree. The restoring force calculation method does not need to depend on finite element simulation, is suitable for occasions where calculation resources are limited and parameters in the initial stage of design need to be rapidly iterated, and has good rapidity, practicability and convenience in actual engineering application.

The invention discloses an axial loading inner and outer ring rotating bearing testing machine and a testing method, and belongs to the technical field of bearing testing. The axial loading inner and outer ring rotating bearing testing machine comprises an environment control device and a supporting device in the environment control device; a loading device, a bearing clamping device, a measuring device and a driving device are sequentially and coaxially arranged on the side part of the supporting device from bottom to top; the loading device comprises a lifting platform and a loading base, a first supporting frame and a second supporting frame which are arranged in a crossed and hinged mode are arranged between the lifting platform and the loading base, a rotary knob is arranged on one side of the lifting platform and connected with the first supporting frame through a lead screw structure, and a pressure sensor and a straight cylinder are sequentially arranged on the lifting platform. The problems that in the prior art, bearing operation parameters cannot be collected in real time, and actual working conditions cannot be truly simulated are solved.

This utility model discloses a high-precision horizontal rotary table, relating to the field of precision machining equipment technology, comprising: a housing, a spindle core, a front bearing assembly, a rear bearing assembly, a sleeve, a worktable, a brake, a motor rotor-stator assembly, and an angle encoder; the spindle core is fixed to the housing via the front and rear bearing assemblies, the front bearing assembly having a transition fit with the spindle core and being fixed by end face screws, the outer ring of the front bearing assembly having a transition fit with the housing and being fixed by end face screws; the rear bearing assembly having a transition fit with the spindle core, and the bearing sleeve having a clearance fit with the housing; the worktable is fixed to the front end face of the spindle core, the brake is fixedly mounted on the housing, the output end of the motor rotor-stator assembly is connected to the spindle core, and the angle encoder is mounted on the sleeve; in the technical solution provided by this utility model, by using cylindrical roller rotary table bearings or thrust angular contact ball rotary table bearings in the front bearing assembly and having a transition fit with the spindle core and housing, the axial load-bearing capacity is significantly improved.

The invention relates to a reverse friction buckling-restrained energy dissipation support and a control method, the reverse friction buckling-restrained energy dissipation support comprises a buckling-free energy dissipation unit, a forward constraint unit and a reverse constraint unit, and the forward constraint unit is arranged at one end of the buckling-free energy dissipation unit and is in sliding connection with the end of the buckling-free energy dissipation unit; the reverse constraint unit is arranged at the other end of the buckling-free energy dissipation unit and is fixedly connected with the end of the buckling-free energy dissipation unit; wherein the forward constraint unit and the reverse constraint unit are oppositely arranged, and when the support bears an axial load, the forward constraint unit and the reverse constraint unit respectively follow different end parts of the buckling-free energy dissipation unit to move in opposite directions, so that a reverse friction mechanism is realized. According to the reverse friction buckling-restrained energy dissipation support and the control method, the double-order yield of the buckling energy dissipation support is fused with the support limiting device, meanwhile, the friction force in the energy dissipation core of the buckling restrained support is self-balanced, the deformation uniformity of the support is improved, and therefore the fatigue performance is improved. The overall structure of the support is free of numerous external additional devices, low in manufacturing cost and convenient for engineering application.

A compact linear actuator having a long stroke is provided. An actuator housing houses a motor having a tubular shaft and a ball nut, both of which are rotatable about an axis. The motor shaft and ball nut are axially spaced and a torque transfer assembly transfers torque from the motor shaft to the ball nut. The assembly includes a torque transfer tube having a first axial end coupled to the motor shaft and a second axial end coupled to a coupling between the tube and ball nut. A ball screw extends through at least a portion of the motor shaft, the tube and the ball nut and outward from the housing and moves along the axis responsive to rotation of the ball nut. The coupling is axially spaced from, and configured for movement along the axis relative to, the tube to prevent transfer of axial loads to the tube.

The invention discloses a fiber reinforced composite material fretting fatigue test clamp suitable for a uniaxial testing machine. The clamp and a test device comprise an upper clamp assembly with a fretting pad limiting device, a lower clamp assembly, a fretting pad, an upper gasket, a lower gasket, a test piece and a stress ring assembly. Wherein the upper clamp assembly and the lower clamp assembly are clamped through a hydraulic chuck and are used for fixing a test piece and transmitting an axial load. The test pieces are arranged in the limiting grooves of the upper and lower clamps, and the upper and lower gaskets are arranged between the two test pieces. The clamp is tightened through the fastening bolt to fix the test piece and prevent slipping; the set screw penetrates through the clamp, the test piece and the gasket to further fix the test piece. The micro-motion pad is arranged in the micro-motion pad limiting groove of the upper clamp, centering is guaranteed, and normal loads are transmitted. The device solves the problem that a fiber reinforced composite material is not matched with a metal material clamp, and has the advantages that the parallelism of a test piece and the centering degree of a micro-motion pad can be ensured, the test piece is prevented from slipping, the test precision is ensured, and the experiment success rate is improved.