279 results about "Spherical bearing" patented technology

An orthopaedic joint prosthesis assembly includes a head part of an orthopaedic joint prosthesis component and an alignment guide. The head part has a spherical bearing surface for articulation with a corresponding joint surface, and an assembly surface having a first bore formed in it for receiving a spigot on another part of the orthopaedic joint prosthesis. The bore has a first axis that extends perpendicular to the assembly surface. The alignment guide has an axial portion defining a second axis and an arm extending from the axial portion. The arm includes a distal portion which is configured to engage the assembly surface, with the axial portion being arranged to engage the bearing surface of the head part when the head part is mounted within the guide such that an impaction force applied along the second axis is directed along the first axis.

An aircraft pipework assembly is disclosed including an aircraft structure; pipework; a fixture arrangement between the pipework and the aircraft structure; a tie rod connecting the pipework to the aircraft structure; a first tie rod bearing which connects the tie rod to the pipework; and a second tie rod bearing which connects the tie rod to the aircraft structure. The fixture arrangement includes a spherical bearing, the spherical bearing comprising a ball mounted to the pipework, and a housing coupled to the aircraft structure. The ball includes a convex spherical bearing surface; and the housing comprises a concave spherical bearing surface which mates with the convex spherical bearing surface of the ball. The fixture arrangement is configured to enable the pipework to translate relative to the ball in an axial direction aligned with a longitudinal axis of the pipework.

Disclosed is a variable-A-value free bending forming device capable of processing pipe fittings of different outer diameters. The device comprises a bending forming module, clamping and fixing modules, and a spherical bearing. The bending forming module is used for clamping a bent section of a pipe blank. Multiple clamping and fixing modules on a rear side of the bending forming module are evenly distributed along the circumference of the pipe blank, and are used for clamping and limiting an unbent section of the pipe blank during a bending forming process. Clamping mechanisms of the bending forming module and the clamping and fixing module have overall radial movement freedom and circumferential movement freedom for clamping jaws, and can meet the requirements for clamping pipe fittings of different outer diameters. Each clamping and fixing module adjusts the A-value during forming by adjusting the positions of an arc-shaped limiting block and a clamping support base. The present invention enables efficient single-die, multi-pipe processing in a free bending forming device for pipe fittings, reducing the time and cost required for die changes. The variable A value expands the application range of the device and further improves the forming quality of three-dimensional bent pipes.

The utility model relates to a friction type quasi seismic isolation support, a bridge and a building body, comprising a spherical support used for forming a first plane friction pair with a building body cross beam, and further comprising an additional plane support used for being fixed on a building bottom pier and used for being supported between the spherical support and the building bottom pier; a second plane friction pair is formed between the additional plane support and the spherical support, and the friction coefficient of the second plane friction pair is larger than that of the first plane friction pair; the structure further comprises a plurality of fragile shear keys, the upper ends of the fragile shear keys are connected to the spherical support, and the fragile shear keys abut against the two opposite sides of the additional plane support in the midspan direction of the building cross beam in a limited mode. According to the utility model, the upper structure of the building body can be prevented from being easily lifted when the building body suffers from a rare earthquake, the building body is prevented from losing the shock resistance after the rare earthquake, and the controllability of the friction coefficient is stronger.

The invention relates to a trunnion device adapting to the running posture of a floating body gate, the trunnion device is used for connecting a lock wall and the floating body gate, the trunnion device comprises a fixed support, a connecting mechanism and a movable support, the fixed support is fixedly connected with the lock wall, the movable support is fixedly connected with the floating body gate, and the connecting mechanism is fixedly connected with the fixed support. The fixed support is hinged to the movable support through a connecting mechanism. The connecting mechanism comprises a vertical shaft, a horizontal shaft, a knuckle bearing and a sliding bearing, a bearing seat is fixedly arranged at one end of the horizontal shaft, the knuckle bearing is arranged in the bearing seat of the horizontal shaft, the knuckle bearing is arranged on the vertical shaft in a sleeving mode, an outer ring of the knuckle bearing is in interference fit with the bearing seat, and the sliding bearing is arranged on the bearing seat. An inner ring of the knuckle bearing is in clearance fit with the vertical shaft, the fixed support is detachably and fixedly connected with the vertical shaft, a mounting hole is formed in the movable support, the sliding bearing is arranged at the end, away from the bearing seat, of the horizontal shaft in a sleeving mode, and the sliding bearing is detachably mounted between the horizontal shaft and the mounting hole. An outer ring of the sliding bearing is in interference fit with the mounting hole, and an inner ring of the sliding bearing is in transition fit with the horizontal shaft.

A rotor assembly for a rotary wing aircraft includes a rotor hub, a rotor blade coupling coupled to the rotor hub, a hub extender coupled to the rotor hub, and a first bearing assembly. The first bearing assembly includes a clevis coupled to the hub extender and including two arms, each arm including a clevis opening, two cylindrical bearings, each cylindrical bearing extending through one of the clevis openings, a spherical bearing positioned between the two arms and coupled to the rotor blade coupling, and a first pin extending through the two cylindrical bearings and the spherical bearing.

A height adjustment device includes a lower part, an upper part, and a height adjustment unit including a first spherical plain bearing, a second spherical plain bearing, a third spherical plain bearing, a first lifter, a second lifter, and a third lifter. The height adjustment device is configured to adjust a height of the upper part with respect to the lower part by driving the first lifter, the second lifter, and the third lifter.

A quick-connect steam wand assembly for steaming beverages and more particularly to a wand that can be easily attached or detached quickly to a beverage / espresso making machine. Wherein the steam wand assembly is formed at least two parts. Wherein the second part attaches to the first part via a spherical bearing or by pair of magnets that allows quick connection or disconnection for effectively cleaning the wand without taking the machine out of commission.

The rod end knuckle bearing comprises a rod end body, an inner hole is formed in the rod end body, an inner ring is installed in the inner hole in a matched mode, an annular limiting groove is formed in the outer spherical surface of the inner ring, and a limiting pin used for being matched with the annular limiting groove in a limiting mode so as to limit the swing freedom degree of the inner ring in the designated direction is fixed to the rod end body. The limiting pin is arranged on the rod end body, meanwhile, the annular limiting groove is formed in the outer spherical surface of the inner ring, and therefore the swing freedom degree of the inner ring in the left-right direction can be limited through limiting cooperation of the inner side end of the limiting pin and the annular limiting groove; and the walking stability of the humanoid robot can be effectively improved.

The invention relates to the technical field of machining monitoring, in particular to an insert bearing machining monitoring method and system. The method comprises the following steps that torque signals and axial position information of a to-be-monitored grinding spindle at each moment are collected; performing time synchronization on the torque signal and the axial position information at each moment, and confirming the torque signal and the axial position information at each moment after synchronization; analyzing the fluctuation form of the torque signal at each moment after synchronization, and comparing the fluctuation form with a preset torque fluctuation characteristic to obtain an abnormal torque signal; and on the basis of the abnormal torque signal and the axial position information at each moment, the monitoring result of the local area of the surface of the grinding wheel is confirmed. The invention aims to solve the problem that the abnormal state and the abnormal position of the local area of the surface of the grinding wheel cannot be accurately identified by the existing monitoring method.

The bearing assembly is used for arranging a synchronizing shaft of the photovoltaic support and comprises a bearing seat and a spherical bearing. The bearing seat comprises a first seat body and a second seat body, the first seat body is provided with a first mounting hole, the second seat body is provided with a second mounting hole, and the first seat body and the second seat body are fixedly connected through a connecting structure. When the first seat body and the second seat body are in butt joint and matched, the first mounting hole and the second mounting hole are coaxial, and the hole wall of the first mounting hole and the hole wall of the second mounting hole are used for jointly supporting the spherical bearing and enabling the spherical bearing to rotate around the axis of the first mounting hole and the axis of the second mounting hole. By arranging the spherical bearing, upward supporting force can be provided for the synchronizing shaft, deflection deformation is reduced, and meanwhile the phenomenon that the synchronizing shaft is stuck is effectively improved. In addition, the split type bearing seat is adopted, a pre-tightening structure is arranged, pre-installation of the bearing assembly can be achieved, a user can achieve assembly of the bearing assembly through fewer fasteners, and installation is faster.

The utility model relates to the technical field of photovoltaic equipment, and discloses a bearing assembly and a photovoltaic tracking support, the bearing assembly comprises a first spherical bearing assembly and a second spherical bearing assembly, the first spherical bearing assembly comprises a first spherical bearing and a first bearing pedestal, the first spherical bearing is provided with a first mounting space penetrating through the axial direction of the first spherical bearing, and the second spherical bearing is provided with a second mounting space penetrating through the axial direction of the second spherical bearing; and the second spherical bearing assembly comprises a second spherical bearing and a second bearing seat, and the second spherical bearing is provided with a second mounting space used for mounting a synchronizing shaft. The first bearing seat and the second bearing seat are respectively provided with a first mounting part and a second mounting part which penetrate through the axial direction, the first mounting part is used for mounting the first spherical bearing, and the second mounting part is used for mounting the second spherical bearing. According to the structural design, the bearing assembly can adapt to complex terrain changes, the stability and tracking precision of the photovoltaic tracking support are improved, and therefore the sunlight receiving efficiency of the photovoltaic module is optimized.

The utility model discloses a graded energy consumption type seismic mitigation and isolation support, and relates to the technical field of seismic mitigation and isolation supports. The rubber support is connected to the bottom of the spherical support; the bottom basin assembly comprises a bottom plate and supporting stoppers, the supporting stoppers are fixed to the periphery of the bottom plate, the ends, away from the spherical support, of the rubber supports are connected with the bottom plate, the rubber supports are located in the supporting stoppers, and threaded holes are formed in the ends, away from the bottom plate, of the supporting stoppers; and the limiting stop block is fixed in the threaded hole in the supporting stop piece through the anti-shear pin, and the inner edge of the limiting stop block protrudes out of the inner side of the supporting stop piece and is used for limiting the spherical support. The graded energy dissipation function is achieved, when a bridge and a building structure normally operate, the spherical support horizontally moves and turns, and friction energy dissipation of the spherical support is mainly achieved; under the action of an earthquake, the rubber support is subjected to shear deformation, and the spherical support and the rubber support are combined to consume energy.

The utility model discloses a welding electrode assembly installation structure which comprises a telescopic driving piece, a guide rod, an anti-rotation rod, a guide seat assembly and an electrode assembly, the telescopic driving piece is arranged on the guide seat assembly, and the guide rod and the anti-rotation rod are arranged in the guide seat assembly in a penetrating mode; the telescopic driving part is connected with the guide rod through a knuckle bearing, and / or the mounting position of the telescopic driving part on the guide seat assembly is adjustable and is connected with the guide rod; and the mounting position of the guide rod and / or the anti-rotation rod on the electrode assembly is adjustable. The guide rod and the anti-rotation rod are arranged in the guide seat component in a penetrating manner, so that a guide effect can be achieved, and rotation can be prevented. Due to the fact that the installation position of the guide rod and / or the anti-rotation rod on the electrode assembly is adjustable, in the assembling process, the guide rod and the anti-rotation rod can penetrate through the guide seat assembly firstly, then the guide rod and the anti-rotation rod are fixed to the electrode assembly, the structure is simple, assembling performance is good, the requirement for hole site precision on the guide seat assembly can be lowered, and fit clearance does not need to be increased.

A supporting system for rotating shafts (3) which can be arranged inclined with respect to one another having a supporting pillar (2.1), a first rotating shaft (3.1) which is supported on the supporting pillar (2.1) by a first bearing assembly (5.1), and a second rotating shaft (3.2) which is supported on the supporting pillar (2.1) by a second bearing assembly (5.2), the first bearing assembly (5.1) and / or the second bearing assembly (5.2) having a spherical bearing (5.4) capable of rotating freely both about the corresponding rotating shaft (3, 3.1, 3.2) and out of the plane perpendicular to the rotating shaft (3), (3.1), (3.2).

The invention discloses a machining tool that produces little wear at the joint of a main drive shaft (14) and a transmission shaft (5). The machining tool comprises an upper shaft (6) attached to a main machine device, a transmission shaft (5) inserted into the upper shaft (6), a main drive shaft (14) attached to the head of the transmission shaft (5), a holder (15) inserted into the head of the main drive shaft (14) and having a cutting tool attached thereto, a spherical bearing (4) supporting the outer side of the main drive shaft (14) so that the main drive shaft (14) can be tilted, a center steel ball (7) clamped between the recess of the head of the transmission shaft (5) and the opposite recess of the rear end of the main drive shaft (14), and an axial steel ball (10) disposed in the long groove (11) of the outer surface of the head of the transmission shaft (5) and in the hole (18) of the main drive shaft (14).

The utility model relates to a self-adaptive liquid inlet and outlet device in a battery cold plate performance detection device. The self-adaptive liquid inlet and outlet device comprises a pipe nozzle seat and a pipe nozzle bracket, a liquid inlet pipe nozzle and a liquid return pipe nozzle are mounted on the left end surface of the pipe nozzle seat; a vertical connecting plate is mounted on the left side of the nozzle bracket, and a knuckle bearing is mounted in a central hole of the connecting plate; a universal shaft is installed on the right end face of the pipe nozzle base, and the right end of the universal shaft is inserted into an inner ring of the knuckle bearing in a sliding mode. A plurality of buffers are installed on the connecting plate, and buffer heads of the buffers are arranged leftwards and abut against the pipe nozzle base. A first pipe joint and a second pipe joint are arranged on the pipe nozzle seat, the first pipe joint is communicated with the liquid inlet pipe nozzle, and the second pipe joint is communicated with the liquid return pipe nozzle. According to the utility model, the impact force generated when the liquid inlet pipe nozzle and the liquid return pipe nozzle are butted with the joint seat on the battery cold plate can be reduced, and the liquid inlet pipe nozzle, the liquid return pipe nozzle and the joint seat on the battery cold plate are effectively protected.

The invention discloses a wrapping control device which comprises a working bottom plate and a hollow rotating wheel, the hollow rotating wheel is assembled on the upper end face of the working bottom plate, a hollow auxiliary wheel is assembled on the right side of the hollow rotating wheel, the hollow auxiliary wheel is sleeved with a spherical bearing, and the bottom of the spherical bearing is connected with a bearing plate. The bottom of the bearing plate is connected with a telescopic cylinder body, and the telescopic cylinder body is connected with the working bottom plate. According to the wrapping control device, the proportional valve is driven to adjust the height of the telescopic cylinder body, so that the height of the hollow rotating wheel is changed, then the tension of the cable is changed, finally, the tension of the cable is automatically changed, the problem that the cable is pulled in the wrapping process, and consequently the outside is broken is solved, and the service life of the cable is prolonged. The speed of cable wrapping operation is greatly improved, the tension of the winding roller is rapidly adjusted and controlled in cooperation with the control module and the bearing plate, and then the speed of cable wrapping operation is improved.

This invention relates to the field of clean energy power generation technology, and proposes a three-source coupled synergistic power generation device based on hydropower, gravity, and kinetic energy. The device includes a water storage tank, a wheel, an upper water tank, an upper water baffle, a closed-loop water tank pump system, a main shaft, counterweight grooves, counterweight blocks, high-pressure spherical bearings, buffer springs, and a dual-start transmission power generation assembly. The wheel diameter is unlimited and can be arbitrarily enlarged according to actual power demand. The wheel size is directly proportional to the output torque and power generation. The upper water tank is circularly arranged on the wheel. The closed-loop water tank pump system is installed on the upper side of the water storage tank. Multiple counterweight grooves are arranged in a circular array on both sides of the top water tank of the wheel. Multiple high-pressure spherical bearings are respectively installed at the bottom of each counterweight block. Multiple buffer springs are symmetrically installed on the upper and lower sides of each counterweight groove. This technical solution solves the problems of limited power output, single starting method, low energy conversion efficiency, and inability to operate with zero carbon emissions in traditional power generation equipment.

The utility model relates to a constant tension film laminating machine which comprises a rack, a workbench is arranged in the middle of the rack, an upper rubber roller and a lower rubber roller are arranged at the position of the workbench, a film releasing shaft and a waste collecting shaft are arranged above the workbench, an unwinding shaft and a winding shaft are arranged on the two sides of the lower portion of the workbench respectively, and a temperature measuring probe is installed on a lifting support at the end of the upper rubber roller. One end of the film shaft, one end of the waste collecting shaft, one end of the unwinding shaft and one end of the winding shaft are installed on one side of the rack through spherical bearings, and the other ends of the film shaft, the waste collecting shaft, the unwinding shaft and the winding shaft are installed on the other side of the rack through a limiting mechanism and driven by a servo motor through a gear set to rotate; the film laminating machine is provided with five servo motors which independently operate to drive the lower rubber roller, the film shaft, the waste collecting shaft, the unwinding shaft and the winding shaft to rotate, so that a film and drawing paper keep constant tension during operation, and stable film laminating quality is guaranteed.

The present application relates to a kind of mechanical dexterous hand fingers and dexterous hand, which includes: palm base;Finger knuckles, which includes sequentially connected finger root knuckles, middle knuckles and distal knuckles;Finger root component, which includes finger root pivot installed on the palm base, spherical bearing is set on the finger root pivot and matches the installation finger root knuckles;Bending transmission mechanism, which includes driving bevel gear, driven bevel gear, finger root transmission member and finger flexion shaft;Side swing transmission mechanism, which includes side swing drive installed on palm base, and side swing transmission shaft is connected with the side swing drive, and the side swing transmission shaft keeps contact with the finger root knuckles in side swing operation.Compared with prior art, the present application can satisfy the side swing of dexterous hand finger joint, bending, while ensuring that it occupies small volume while providing certain gripping force and durability.

The invention relates to the technical field of fuel conveying devices, and discloses a conveying device for thermal power plant fuel treatment and a method thereof.The conveying device comprises conveying equipment, partition plates and a storage bin, the storage bin is arranged outside the conveying equipment, the partition plates are evenly arranged in an inner cavity of the conveying equipment, and a servo motor is arranged at the top of the storage bin; the output end of the servo motor is connected with the stirring rod, the servo motor drives the stirring rod to rotate, the fuel in the storage bin can be stirred, the fuel is prevented from caking due to accumulation, the looseness of the fuel is guaranteed, and follow-up quantitative feeding is facilitated. According to the conveying device and method for fuel treatment of the thermal power plant, the collection box at the bottom of the hollow column facilitates collection and cleaning of filtered dust, stable rotation of the fan blade set can be guaranteed through the spherical bearing, the dust removal effect is further improved, and the whole device is more stable through the synergistic effect of all mechanisms; the stability, the high efficiency and the environmental protection property of fuel treatment and conveying are enhanced, and meanwhile, the use convenience is improved.

The present invention describes a detachable connection between a pitch control unit arm (5) and a pitch angle piece (8) of a blade holder (7) in a tail rotor head (3) of a tail rotor (1) of a rotary wing aircraft, said detachable connection comprising a pin connecting said pitch angle piece (8) attached to the blade holder (7) with said pitch control unit arm (5) of a pitch control unit (4), thereby reducing material wear and shortening the maintenance cycle. This is achieved because said pin is designed as a sliding pin (9) protruding between the pitch angle piece (8) and the pitch control unit arm (5), which in its length direction passes through a spherical bearing in the form of a ball (6) with a central ball through hole (61), wherein the ball (6) and the part of the sliding pin (9) are surrounded by an outer ring (60) of the spherical bearing, thus allowing a sliding and pivoting movement of the sliding pin (9) inside the spherical bearing.

An isolated spherical shock / strut mount assembly is provided. The assembly may include an isolator and a spherical bearing coupled within the isolator. The assembly may further include a bearing housing receiving the isolator and spherical bearing within the housing. A mounting plate may be coupled to the bearing housing, wherein the isolator and spherical bearing are retained within the bearing housing in response to coupling the mounting plate to the bearing housing. The isolator may include a spherical bearing mount coupled within an over-molding portion. The over-molding portion may be formed of rubber. The assembly may further include one or more stiffeners removably coupled to the over-molding portion of the isolator, wherein coupling the one or more stiffeners to the over-molding portion of the isolator increases an effective durometer of the over-molding portion.

This invention relates to a continuously variable transmission (CVT) structure that facilitates belt disassembly and assembly. It includes a bottom support plate, on the upper surface of which is a pulley mounting base plate. The pulley mounting base plate is secured to the bottom support plate using reamed bolts. A left-side bearing mounting seat and a right-side bearing mounting seat are spaced apart on the pulley mounting base plate. The right-side bearing mounting seat is fixedly connected to the pulley mounting base plate. The threaded end of the reamed bolt passes sequentially through the left-side bearing mounting seat and the pulley mounting base plate, and is threadedly connected to a nut. The left-side and right-side bearing mounting seats are rotatably connected to the two ends of a rotating shaft via spherical bearings. This invention, through a rational structural arrangement, effectively transmits power from the engine output to the end components. Taking advantage of the self-aligning characteristics of spherical bearings, the rational structural arrangement facilitates belt disassembly and assembly.

The utility model belongs to a bridge support, and particularly relates to a long-acting spherical support with height adjusting and sliding plate replacing functions. Comprising an upper base plate, a sliding lining plate assembly, a spherical crown plate and a lower base plate which are stacked from top to bottom. The sliding lining plate assembly is fixed to the upper surface of the spherical crown plate, the spherical crown plate is in rotating fit with the adjacent face of the lower base plate, the upper base plate is in plane sliding fit with the adjacent face of the sliding lining plate assembly, and the adjacent face of the upper base plate and the sliding lining plate assembly is provided with a grease storage pit capable of containing silicone grease and a sealing ring capable of preventing the silicone grease from overflowing. The upper surface of the sealing ring is attached to the upper base plate, an annular groove is formed in the adjacent part, and a clamping part capable of achieving radial limiting and height adjusting with the spherical crown plate is arranged at the bottom of the sliding lining plate assembly. The problems that in the prior art, due to large abrasion of the sliding plate, a support needs to be replaced as a whole, and silicone grease consumption is large are effectively solved. The sliding lining plate assembly can be replaced independently, and the consumption of silicone grease is low.

The present invention provides a protective assembly for use in an aircraft cargo hold, comprising: a plurality of connectors, each of which is fixedly attached to the aircraft fuselage structure; a barrier wall, the barrier wall being movably connected to at least a portion of the plurality of connectors via couplings on its top and bottom sides; wherein each coupling comprises: a first tab disposed on the top or bottom side of the barrier wall, the first tab having an oblong hole extending vertically therein; a second tab disposed at the connector; a spherical bearing disposed in the second tab; and a bolt member, the bolt member being inserted through the spherical bearing in the second tab and the oblong hole in the first tab and being capable of moving vertically within the oblong hole. The protective assembly of the present invention does not participate in the transmission of loads from the main fuselage structure, is easy to assemble and disassemble, and has good reliability and maintainability.

The utility model provides a single-layer convex-edge insert bearing sealing cover, belongs to the technical field of bearing sealing covers, and aims to solve the problems that the contact surface between the inner edge of the conventional sealing cover and a bearing is relatively small, and oil leakage is easy to occur after the conventional sealing cover is used for a period of time. A supporting ring is installed on the bottom face of the sealing cover body, and a dustproof layer is fixedly arranged on the top face of the sealing cover body. After the sealing cover body is installed on the insert bearing, the convex edge can be attached to the inner wall of the inner ring of the insert bearing, the convex edge is higher than a roller, meanwhile, the sealing area is increased, and compared with a traditional sealing cover, lubricating grease in the bearing can be better prevented from leaking out; and the dustproof layer is arranged, so that grease leakage at a gap where the convex edge is in contact with the bearing can be further prevented, and better water-draining, antifouling, dustproof and oil-leakage-proof effects are achieved.

The utility model belongs to the field of fatigue testing machines, and particularly relates to a dynamic anti-backlash ball seat. The device comprises a main body part, a bearing seat, two thrust knuckle bearings and a pull rod, an installation cavity is formed in the main body part, the two thrust knuckle bearings are installed at the two ends of the bearing seat, the thrust knuckle bearings and the bearing seat are both arranged in the installation cavity, and the pull rod is arranged in the installation cavity. The thrust knuckle bearing is connected with the inner wall of the mounting cavity, a through hole is formed in one side of the main body part, and the pull rod penetrates through the through hole to be connected with the thrust knuckle bearing and the bearing seat; the device overcomes the defects of complicated original structure, high processing difficulty, poor reliability and the like, and is simple and convenient to manufacture and process, simple to mount, low in cost and easy to process and mount.

The invention provides a double-side buckle type bearing assembly for a solar photovoltaic tracking support, which comprises two bearing sub-parts with the same structure, each bearing sub-part comprises a main body part, two ends of each main body part are respectively provided with a buckle part, and the two bearing sub-parts are mutually buckled through the respective buckle parts; the buckling part comprises a first buckling unit and a second buckling unit; the first buckle unit comprises a first connecting block, a first clamping block and a first L-shaped hook groove. The second buckle unit comprises a second connecting block, a second clamping block and a second L-shaped hook groove. The projection plane of the second clamping block on the first buckle unit is located in the area of the first L-shaped hook groove. No matter a spherical bearing or a cylindrical bearing, through the inclined boss and the groove designed at the left end and the right end of the plastic bearing, no additional limiting part is needed, and the two bearing parts are combined into an integral bearing assembly which does not move or fall off only through material deformation of the plastic bearing. The rotating and slipping phenomenon between the bearing and the main shaft is avoided; meanwhile, the mounting steps are simplified.