94 results about "Centripetal force" patented technology

A placing seat is fixed to the upper portion of a base through a plurality of supporting columns in a suspended mode, a plurality of linear sliding grooves distributed in an annular array mode are formed in the placing seat, and an inner supporting piece and an outer pressing piece are installed in each linear sliding groove; a clamping push plate is connected between the multiple supporting columns in an up-down sliding and sleeving mode, a plurality of pushing pieces are installed on the clamping push plate, the pushing pieces are in sliding connection with the inner supporting piece and the outer pressing piece, and a plurality of position adjusting mechanisms distributed in an annular array are installed below the containing base in a sliding mode; a plurality of inner supporting pieces and outer pressing pieces which are distributed in an annular array mode are arranged above the containing base, two positioning rollers on the inner supporting pieces and the outer pressing pieces can synchronously move in the opposite directions from the inner side and the outer side, the inner wall and the outer wall of a workpiece are clamped at the same time, clamping force appears in pairs, radial force is offset, the workpiece mainly bears uniform centripetal force, and the deformation risk is greatly reduced.

The invention discloses an energy storage frequency modulation instruction prediction method and system based on a centripetal force method, and relates to the technical field of artificial intelligence in a power system, and the method comprises the steps: decomposing an original frequency modulation sequence through VMD, decomposing the original frequency modulation sequence into a plurality of subsequences, setting the number of decomposition layers as K, recognizing convex points and concave points in the sequence, and carrying out the prediction of an energy storage frequency modulation instruction. Obtaining a resultant force of each sub-sequence to evaluate features; evaluating the centripetal force direction and magnitude of each subsequence decomposed by the VMD by adopting a centripetal force method, and determining the maximum centripetal force as a target function; and an improved frost ice optimization algorithm is applied to optimize the decomposition layer number K of the VMD so as to maximize the objective function and obtain the optimal decomposition effect. According to the invention, the processing efficiency and accuracy of the frequency modulation signal are effectively improved, and important support is provided for real-time prediction of a frequency modulation instruction in an energy management system.

The invention belongs to the technical field of sliding bearings and protection thereof, and discloses a metal radial elastic sheath for a ceramic sliding bearing under a high-temperature working condition, and the sheath comprises an inner sheath and an outer sheath; the inner sheath sleeves the periphery of the ceramic bushing, is a thin-wall metal sleeve, and is provided with a plurality of spiral openings in the circumferential direction, so that the inner sheath generates elastic bending when being stressed in the radial direction and disperses stress in the annular range; the outer sheath is sleeved on the periphery of the inner sheath, helical teeth are uniformly distributed on the inner circumferential surface of the outer sheath, and the helical teeth apply centripetal acting force to the inner sheath through radial elastic deformation under assembly and high-temperature working conditions. Through flexible deformation of the spiral opening of the inner sheath and radial elastic pre-tightening fit of the helical teeth of the outer sheath, fastening fit can be maintained when a thermal expansion difference exists between the metal bearing seat and the ceramic bushing, stress concentration of the ceramic bushing is reduced, and the risk of axis drift is reduced.

The invention discloses a centripetal force sensor and a using method thereof, and belongs to the field of sensors. According to the technical scheme, the centripetal force sensor comprises a fixed part and a rotating part, the rotating part comprises a sensor shell, the sensor shell is hollow, a center signal column is fixedly installed in an inner cavity of the sensor shell, a plurality of notches are formed in the outer circumferential face of the center signal column, and mass blocks are placed in the notches; piezoelectric ceramics are arranged on the outer side of the mass block, and the piezoelectric ceramics and the mass block are clamped between the inner wall of the sensor shell and the outer wall of the center signal column. The sensor is directly installed at the rotation center of a detected object, additional centrifugal force generated by the mass of the sensor approaches to zero, the authenticity of the detection result is greatly improved, meanwhile, the sensor is in direct conductive contact with the signal output structure through the center signal column, the mouthpiece does not rotate along with the detected object, and the detection accuracy is improved. The winding and pulling faults of the mouthpiece and an external pipeline are completely eradicated, and the durability of the sensor is improved.

The invention discloses a robot adaptive neural optimal tracking control method and device considering dynamic constraints, and the method comprises the steps: building a kinetic model of a robot in a joint space, and considering the input torque, inertia matrix, centripetal force and Coriolis force matrix and gravity torque of a robot system; the dynamics of the robot system is mapped to a Cartesian space, a position vector and a speed vector are defined, and a state space model of the robot system is established; and under the condition that dynamic constraints exist, a self-adaptive optimal nerve tracking controller is designed based on an optimal backstepping method and an actor-commentator Sheng network method so as to process the dynamic constraints and realize optimal tracking performance. Under the dynamic constraint environment, the robot can track the expected trajectory more accurately, and meanwhile movement safety is ensured.

The utility model relates to the technical field of sealing ring installation, and discloses a new energy precision servo actuator sealing ring adjusting device which comprises a guide supporting assembly, a guide ring and a guide sleeve coaxial with the guide ring, and guide grooves extending in the radial direction are distributed in the side edge of the guide ring in the circumferential direction. The movable assembly sleeve comprises an assembly sleeve body, a sliding block and an elastic annular piece, the assembly sleeve body is annularly formed by arranging a plurality of disconnected arc-shaped blocks on the periphery of the guide ring in a surrounding mode, one end of the sliding block is perpendicularly connected with the inner side face of the arc-shaped block, and the other end of the sliding block extends into the guide groove; one end of the connecting rod reamer is a conical head, the other end of the connecting rod reamer is a connecting rod with threads, and the end of the connecting rod is in threaded fit with the guide sleeve. The connecting rod reamer achieves horizontal movement through rotation, the conical head extrudes the sliding block, the elastic annular piece exerts coaxial centripetal force on the movable assembly sleeve, expansion and locking of the movable assembly sleeve are achieved, physical supporting expansion can be conducted on the installed sealing ring, and the sealing ring is restored to the original shape.

A torque output assembly, comprising a centering sleeve (11). A power input end (111) rotates around an axis of rotation (112). An operation hole (114) is formed inside a power output end (113), The axis of the operation hole (114) basically coincides with the axis of rotation (112). The depth of the operation hole (114) is greater than the thickness of a workpiece (4). A free end of the power output end (113) extends transversely outward to form an abutting portion (115). The end face of the abutting portion (115) facing away from the power input end (111) is recessed inwards to form a centering recess (116). The depth of the centering recess (116) is smaller than the thickness of the workpiece (4). The recess (116) is in communication with the operation hole (114). When the centering sleeve (11) rotates, the centering recess (116) applies a centripetal force to the workpiece (4) so as to guide the workpiece (4) into the operation hole (114). By means of the centering sleeve (11), centering before coupling and torque transmission after coupling can be smoothly completed, so that the centering sleeve (11) and the workpiece (4) can be quickly positioned relative to each other, thus improving the operation efficiency and reducing requirements for the attitude of the centering sleeve (11) relative to the workpiece (4) during centering.

A method for coating products is provided. The method includes the steps of applying a coating liquid to a product and removing excess coating liquid from the product. It is desirable to provide a method for efficiently and reliably coating delicate or easily deformable products, such as products molded from a pulp fiber slurry. The method includes fixing the product to a receiving portion of a product carrier that is configured in the same shape as the product, such that an exterior surface of the product abuts the interior concave surface of the receiving portion of the device. A coating liquid is applied to the product in the product carrier. The product carrier is affixed to a centrifuging device and the coating liquid is dispersed over the surface of the product using centripetal force.

The invention relates to the technical field of vacuum pumps, in particular to a double-end spiral screw and a vacuum screw pump, the double-end spiral screw comprises a pump body, screws, threads and a sealing ring, the two screws are installed in the pump body, the threads are symmetrically arranged on the screws, the two screws are meshed with each other through the threads, the screws are connected with a motor, spiral grooves are formed in the threads, the thread pitches of the spiral grooves are equal to the thread pitches of the threads, and the sealing ring is arranged in the pump body. A radial compensation assembly is arranged in the spiral groove, a plurality of sealing rings are installed on the outer end face of the thread, the radial compensation assembly is connected with the sealing rings, one ends of the sealing rings are connected with axial compensation assemblies, and the sealing rings are connected with the adjacent sealing rings through the axial compensation assemblies. The radial compensation assembly is used for enabling centripetal force generated when the screw rotates to extend the sealing ring in the radial direction, and the axial compensation assembly is used for enabling the sealing ring to stretch out and draw back in the axial direction when the sealing ring rotates. The outer diameter end face of the sealing ring is in sliding connection with the side wall of the vacuum cavity through the axial compensation assembly and the radial compensation assembly. The vacuum efficiency of the vacuum pump is improved.

1. The name of this design product: Centripetal force demonstrator. 2. Purpose of this design product: This design product is a physical experiment instrument used to demonstrate centripetal force. 3. The design key point of this appearance design product lies in the shape. 4. The picture or photo that best illustrates the design points: three-dimensional picture.

The application belongs to the field of flywheel energy storage, and particularly relates to a super-high energy density superconducting flywheel energy storage system containing an additional centripetal force device, aiming at solving the problem that the flywheel rotation speed is limited by the strength of the material itself. The application comprises a vacuum cavity, a driving device, a flywheel, an additional centripetal force providing device and a high-temperature superconducting magnetic suspension bearing. The driving device is in transmission connection with the flywheel, and the additional centripetal force providing device is arranged outside the flywheel. The additional centripetal force providing device can provide additional centripetal force to the flywheel, so that the rotation speed of the flywheel can be higher than the limit rotation speed determined by the limit strength of the flywheel material itself, thereby breaking the problem that the flywheel rotation speed is limited by the material strength, and enabling the superconducting flywheel energy storage system to realize super-high energy density energy storage.

The present application discloses an adaptive finite-time manipulator disturbance observation method, system, device and medium, which mainly relates to the technical field of manipulator disturbance observation, and is used to solve the problems that the existing observers involve restrictions on "derivative being 0" and "known upper bound" and the implementation process is cumbersome. It includes: obtaining a preset trend factor, a robot inertia matrix, a robot Coriolis force and centripetal force matrix, a robot gravity torque, and a robot speed; calculating a preset auxiliary state variable through the preset trend factor, the robot inertia matrix, the robot Coriolis force and centripetal force matrix, the robot gravity torque, and the robot speed; importing the preset auxiliary state variable, the preset trend factor, the robot inertia matrix, and the robot speed into the expression of a preset observer to obtain the disturbance output value of the observer.

A distributed high-fidelity simulation system for large-scale high-speed AUVs based on real disturbance data is proposed. Through a large-scale AUV virtual test vehicle subsystem, the system simulates the motion state of a real large-scale high-speed AUV physical prototype under the interaction of rigid body inertia, gravity, buoyancy, inertial hydrodynamic forces, centripetal force, Coriolis force, drag, thrust, rudder force, and external environmental disturbances. Collision attributes are added to the prototype through a physics engine. The system also utilizes an underwater 3D virtual environment subsystem to render a large-scale underwater environment, build dynamic and static obstacle visualization models, and simulate the generation of realistic ocean currents and wave disturbances with high fidelity. The simulation presents a realistic underwater environment for a large, high-speed AUV. A motion solution subsystem describes the transformation relationships between the fixed coordinate systems of all objects in the underwater virtual environment and solves the motion equations of the large AUV, synchronously updating its pose and velocity states. A data management subsystem manages various data generated during the simulation, supporting write and read data operations, and also manages and coordinates data communication between nodes, supporting receive and send data operations. A visualization subsystem loads and dynamically displays the underwater 3D environment and the large AUV virtual test vehicle model, synchronously updating real-time data curves and visualizing the AUV's motion trajectory.

The invention discloses a modularized middle school physical mechanics experiment measurement and control system and a centripetal force experiment method, and belongs to the technical field of middle school physical experiment teaching equipment. The measurement and control system comprises a rotation and speed measurement module and a tension measurement module which can work independently and can also be combined flexibly, the rotation and speed measurement module takes an STM32 single-chip microcomputer as a core, and accurate measurement and control of the rotation speed are realized through Hall encoder orthogonal pulse acquisition, quadruplicated frequency processing and M-method speed measurement; the tension measurement module realizes accurate acquisition of tension through a tension sensor and a 24-bit high-precision AD conversion chip. Modularization and modularization design is adopted in the core of the device, the two modules can independently adapt to various mechanical experiments and can also be integrated to build a centripetal force experiment platform, and verification of a centripetal force formula is completed through a matched experiment method. The problems that traditional experimental equipment is poor in universality and complex in operation are solved, the scheme is simplified and focused, and extremely high practicability and patent authorization are achieved.

The present disclosure relates to a work vehicle magnetorheological fluid joystick system that can operate in a modified centripetal mode. The work vehicle magnetorheological fluid (MRF) joystick system includes: a joystick device, an MRF joystick resistance mechanism, and a controller architecture. The joystick device further includes: a base housing, a joystick movably mounted to the base housing, and a joystick biasing mechanism, which is connected to the joystick and applies a centripetal force to urge the joystick to return to the neutral position when the joystick is moved away from the neutral position. The controller architecture is capable of operating in a modified centripetal mode, wherein the controller architecture: (i) determines when the joystick begins to return toward the neutral position due to the centripetal force applied to the joystick by the joystick biasing mechanism; and (ii) when so determined, issues a command to the MRF joystick resistance mechanism to modify the rate at which the joystick returns to the neutral position by changing the MRF resistance applied to the joystick.

The present invention discloses a method for dynamic control of an excavator arm, wherein the dynamic model of the excavator arm is linearized, the parameters of the dynamic parameter matrix of the excavator arm are identified, and the identified dynamic feedforward model of the excavator arm is obtained. The feedforward signal output by the dynamic feedforward model of the excavator arm is input into a pre-built three-loop PID control system, and the three-loop PID control system outputs the control results of each joint of the excavator arm. The method for dynamic control of an excavator arm provided by the present invention adopts a control mode of dynamic feedforward + three-loop PID feedback, calculates in real time the inertial force, Coriolis force, centripetal force, gravity and friction force generated when the excavator arm moves, and designs an excavator arm control system, which can improve the dynamic accuracy of the excavator arm during movement and improve the reliability and stability of the excavator during movement.

A spinning device, such as a top, that can selectively spin about a central axis of rotation. The spinning device has a body that contains a fluid chamber that is visible through at least part of the body. A plurality of liquids are held within the fluid chamber. Some solid objects can also be mixed within the liquids. At least some of the plurality of liquids have different densities. Accordingly, when the spinning device spins about a central axis of rotation, centripetal forces are generated that cause at least some of said plurality of liquids to migrate to different distances from the central axis of rotation. At least some of the liquids are different colors and are insoluble with one another. Accordingly, the liquids produce a pattern of separate bands that can be seen through the body of the device.

The application discloses a kind of frame structure building rotation displacement method, it is related to civil construction technical field, construction circular arc-shaped displacement track in the two sides of frame column along displacement direction, the displacement track of far side from rotation center is outside track, the displacement track of near side to rotation center is inside track, support plate is respectively laid on the top surface of inside track, outside track, and several rollers are placed on the top surface of support plate along the displacement direction of building;Connecting is implanted with insert reinforcement in the two sides of frame column perpendicular to displacement direction;First, the concrete of underpinning beam perpendicular to displacement track direction is poured, then the concrete of underpinning beam parallel to displacement track direction is poured;Frame column between the bottom of underpinning beam and the top of foundation is cut off;Pushing system is set in each displacement track, and building is moved to predetermined position by pushing system.The application utilizes outside inclined displacement track to provide centripetal force to realize building frame displacement rotation, meet the demand of changing building orientation, and displacement process is stable and controllable.

The invention discloses a novel dynamic vacuum hemisphere theoretical technology, belongs to the field of gaseous flow dynamics, and solves the problem of an experimental technology for controlling the flow of a gaseous substance, and two hemispheres with different depths are overlapped and vacuumized to break through the bottom and rotate to change the flow direction of the gaseous substance to generate centripetal force and centrifugal force. Therefore, the flow of the gaseous substance is controlled.

Methods of separating excess resin from an object include additively manufacturing an object on a build platform, the object (115, 415) carrying excess resin therein and / or thereon; removing the object from the build platform; placing the object in a cradle (100, 400) and / or cradle support (155, 455), optionally wherein a surface 110, 140) of the cradle aligns with a surface of the object (125,145) and contacts the surface of the object when the cradle and / or cradle support moves under centripetal force; placing the cradle and / or cradle support in a spinning apparatus; centrifugally separating excess resin from the object; and removing the cradle, cradle support, and / or object from the spinning apparatus, at least a portion of the excess resin being separated from the object.

The utility model discloses a teaching experiment teaching aid for centripetal force magnitude influence factors, and relates to the technical field of experiment teaching aids, the teaching experiment teaching aid comprises a bottom plate, four vertical rods, four cross rods and fixing columns, the vertical rods are fixedly installed at four corners of the top surface of the bottom plate, the cross rods are fixedly installed between the top ends of the vertical rods which are opposite in pairs, and the fixing columns are fixed on the bottom plate. A driving assembly is fixedly connected to the center of the top face of the bottom plate, and the fixing column is fixedly installed on the top face of a transverse rod. The speed regulation motor is used for stabilizing the rotating speed to improve unstable rotating speed caused by using hands, the rotating speed can be adjusted through the numerical control module, the movement radius is changed by adjusting the height of the force measurement module, operation is simple and visual, and the principle is easy to understand; experimental phenomena of the same mass and different rotating speeds, the same rotating speed and different radiuses, and the same mass and the same rotating speed radius are obvious, so that students can intuitively and quantitatively understand the influence factors of the magnitude of centripetal force.

A method for coating products is provided. The method includes the steps of applying a coating liquid to a product and removing excess coating liquid from the product. It is desirable to provide a method for efficiently and reliably coating delicate or easily deformable products, such as products molded from a pulp fiber slurry. The method includes fixing the product to a receiving portion of a product carrier that is configured in the same shape as the product, such that an exterior surface of the product abuts the interior concave surface of the receiving portion of the device. A coating liquid is applied to the product in the product carrier. The product carrier is affixed to a centrifuging device and the coating liquid is dispersed over the surface of the product using centripetal force.

The utility model discloses a wireless centripetal force experimenter, comprising a base, a rotating bracket installed on the top of the base, a motor fixing bracket fixed below the rotating bracket, and a stepping motor fixed in the motor fixing bracket; a pulley of a belt transmission structure is fixed on the output shaft of the stepping motor, another pulley is fixedly connected to the lower end of the transmission shaft, and the top end of the transmission shaft is connected to a main body lower cover; a force sensor is installed in a rotating arm; one end of a weight fixing rod is connected to one end of the main body upper cover, and the other end of the weight fixing rod is connected to one side of the force sensor, and the weight is fixed on the weight fixing rod; one end of a balancing rod is connected to the other end of the main body upper cover, and the other end is connected to the other side of the force sensor; a single-chip microcomputer is fixed in the rotating arm, and the force sensor is electrically connected to the single-chip microcomputer; the centripetal force generated during the rotation of the weight acts on the force sensor to accurately collect centripetal force experimental data.

The utility model relates to the technical field of tile production equipment, in particular to a whole-body marble tile production line turning conveyor which comprises a rack, a U-shaped conveying frame and a fine adjustment mechanism, and a plurality of material guide rollers are rotationally arranged on the U-shaped conveying frame in the conveying direction of the U-shaped conveying frame; the two ends of the U-shaped conveying frame are rotationally connected with the rack through a first rotating shaft and a second rotating shaft correspondingly. Through the rotary connection mode, the contact surface of the U-shaped conveying frame and the product can incline relative to the horizontal plane. Through the design of the mechanism, the resultant force of the gravity of the product and the supporting force of the material guide roller can provide additional centripetal force for the product so as to offset part of centrifugal force, and it is ensured that the product cannot generate large deviation when passing through the device. The inclination angle of the U-shaped conveying frame can be accurately adjusted through the fine adjustment mechanism so as to meet different production line speeds, and through the design of the mechanism, the influence of centrifugal force can be reduced, the production efficiency can be improved, and potential safety hazards can be reduced.

The kitchen waste crushing treatment device is characterized in that upper cutting blades are arranged on the two circumferential sides of a barrel connecting piece respectively, each upper cutting blade is sequentially provided with a point position a, a point position b, a point position c and a point position d from outside to inside, and the point position d to the point position c extend in the direction away from the center of a rotating shaft body to form a section cd; the point c to the point b extend towards the center of the rotating shaft body to form a bc section, the point b to the point a extend towards the center of the rotating shaft body to form an ab section, and the cd section is provided with at least one arc-shaped cutting surface. When the movable cutter assembly rotates, centripetal force is applied to clustered or caked kitchen garbage through the arc-shaped cutting face of the upper cutting blade, and when the kitchen garbage far away from the rotating shaft body cannot be crushed, the kitchen garbage moves towards the rotating shaft body under the action of the centripetal force, so that the force arm is reduced, the cutting force is improved, and the crushing effect is improved; and the phenomenon that the cutter is stuck is avoided.

The present invention relates to a method for calculating node motion parameters, a computer-readable medium, an electronic device, a method for calculating centripetal force, and a method for selecting spacer dampers. In the method for calculating centripetal force, when using motion finite element simulation to calculate the centripetal force of the spacer damper, the established node motion model of the sub-conductor takes into account the effects of the mass of the conductor system, the damping of the conductor system, the stiffness of the conductor system, and the external load factors of the sub-conductor on the motion of the sub-conductor. The external load of the sub-conductor includes the self-weight load of the conductor system and the electromagnetic attraction load of the sub-conductor. When calculating the node position in the sub-conductor motion model, the present invention takes into account the influence of the collision factor on the motion of the sub-conductor during the motion of the sub-conductor, making the calculated node motion parameters closer to the actual node motion parameters. In this way, when calculating the centripetal force, the obtained centripetal force data is more accurate.

The invention provides a balance-free fan blade and a fan device, and relates to the technical field of fans, the balance-free fan blade comprises an annular sealing structure and a fan blade body, the annular sealing structure is embedded in the fan blade body, and the annular sealing structure is filled with high-density liquid. The annular sealing structure is an annular hollow closed pipe with two closed ends. And the hollow closed pipe and the fan blade body are molded. After the fan runs, the mass ratio of the high-density liquid at different positions is automatically adjusted through the rotating centripetal force of the fan, and therefore the dynamic balance of the fan blades under high-speed movement is achieved. According to the fan blade, the high-density liquid is filled in the hollow closed pipe, so that when the fan runs, the mass ratio of different positions is automatically adjusted, and the fan blade automatically reaches the balance state.

This invention provides a highly efficient automated welding structure for robots, relating to the field of welding equipment technology. It includes: a main frame structure with a slide rail at its bottom; a support and pressure application component slidably mounted on the slide rail for supporting and clamping a cylindrical workpiece from both sides and applying a centripetal force to the workpiece to cause radial contraction; a positioning support component mounted on the main frame structure, including a liftable calibration plate for insertion into the weld gap of the cylindrical workpiece before welding to calibrate and position the weld; and a welding execution component located above the positioning support component and connected to the main frame structure for automated welding of the calibrated weld after the calibration plate is withdrawn. This invention, through the mechanical alignment of the calibration plate and the centripetal pressure of the support and pressure application component, can automatically eliminate weld gaps and ensure weld alignment accuracy, thereby improving welding quality and automated operation efficiency.

The utility model relates to the technical field of fan blades, and discloses a double-blade opposite axial flow fan blade and an air supply device using the same, the double-blade opposite axial flow fan blade comprises a hub and a plurality of blade groups annularly and uniformly distributed on the peripheral surface of the hub, each blade group comprises a front bent blade and a rear bent blade, and the front bent blades and the rear bent blades are respectively and obliquely arranged relative to the axis of the hub. By means of the front bent blades and the rear bent blades which are alternately arranged, the centripetal force of the front bent blades and the centrifugal force of the rear bent blades can be integrated by means of the opposite bending directions of the front bent blades and the rear bent blades; therefore, the problems of noise and energy loss caused by airflow path extension due to centripetal airflow gathering caused by unidirectional forward bending inertia force and centrifugal airflow dispersion caused by unidirectional backward bending are solved.

The utility model discloses a powerful turbofan and a propulsion mechanism, and relates to the technical field of power propulsion, the powerful turbofan comprises a rotor part and a stator part which can rotate relatively, the stator part is sleeved outside the rotor part, and the rotor part comprises an inner ring and a plurality of permanent magnet rotors arranged around the inner ring. The stator component comprises a plurality of coil stators arranged on the periphery of the permanent magnet rotor, fan blades are connected to the inner wall of the inner ring, and the stator component is connected with the rotor component through a bearing. The motor has the beneficial effects that a central motor is changed into the peripheral motor, centrifugal force of the motor for driving the fan blades is completely eliminated, centripetal force is generated, all the fan blades and the rotor part are integrally arranged, the technical problem that the fan blades shake due to the centrifugal force when the motor rotates at a high speed in the prior art is solved, the energy efficiency is remarkably improved, and noise is reduced; the flow speed of fluid is increased through the airflow gathering part, the fluid area is increased through the airflow diffusion part, and therefore the fluid propelling efficiency of the fan blades is improved.