41 results about "Serpentine channel" patented technology

The utility model discloses a waveguide slot antenna comprising a feed port layer, a slow wave line layer and a radiation slot layer which are stacked in sequence. The feed port layer is provided with a feed port used for inputting electromagnetic waves or outputting electromagnetic waves. The end face of one end, facing the feed port layer, of the slow wave line layer is provided with a snakelike slow wave cavity, one end of the snakelike slow wave cavity is provided with a feed signal end, and the feed signal end is correspondingly connected with the feed port. A plurality of waveguide radiation slots are formed in the snake-shaped channel of the snake-shaped slow wave cavity at intervals; a plurality of radiation cavity units in one-to-one correspondence with the waveguide radiation slots are arranged on the end face of one end, facing the slow wave line layer, of the radiation slot layer at intervals, a plurality of radiation slots are arranged in the radiation cavity units at intervals, and signal connecting ends correspondingly coupled with the waveguide radiation slots are arranged at one ends of the radiation cavity units. According to the utility model, the scanning angle of the antenna can be increased to adapt to application occasions with high antenna scanning angle requirements, and the adaptability is high.

The invention discloses a snakelike slow wave plate which comprises a waveguide radiation body, a snakelike slow wave groove is formed in the front end face of the waveguide radiation body, and a feed signal end is arranged at one end of the snakelike slow wave groove. A snakelike channel is formed in the snakelike slow wave slot, the snakelike channel is connected with the feed signal end, the snakelike channel comprises a plurality of linear waveguide sections and connecting waveguide sections, a gap part is reserved between every two adjacent linear waveguide sections, and every two adjacent linear waveguide sections are connected through the corresponding connecting waveguide section; waveguide radiation slots are arranged at intervals in the plurality of linear waveguide sections or the waveguide radiation slots are respectively arranged in the plurality of linear waveguide sections, and the central lines of the linear waveguide sections and the central lines of the corresponding waveguide radiation slots are arranged in a staggered manner; and the center lines of the plurality of waveguide radiation slots have different offsets. The antenna has the advantages of simple structure, low cost, good radiation effect, wide application range and the like.

The invention discloses a waveguide slot antenna and a control method thereof. The antenna comprises a feed port layer, a slow wave line layer and a radiation slot layer which are stacked in sequence, the feed port layer is provided with a feed port used for inputting electromagnetic waves or outputting electromagnetic waves. The end face of one end, facing the feed port layer, of the slow wave line layer is provided with a snakelike slow wave cavity, one end of the snakelike slow wave cavity is provided with a feed signal end, and the feed signal end is correspondingly connected with the feed port. A plurality of waveguide radiation slots are formed in the snake-shaped channel of the snake-shaped slow wave cavity at intervals; a plurality of radiation cavity units in one-to-one correspondence with the waveguide radiation slots are arranged on the end face of one end, facing the slow wave line layer, of the radiation slot layer at intervals, a plurality of radiation slots are arranged in the radiation cavity units at intervals, and signal connecting ends correspondingly coupled with the waveguide radiation slots are arranged at one ends of the radiation cavity units. According to the invention, the scanning angle of the antenna can be improved to adapt to application occasions with high antenna scanning angle requirements.

The invention belongs to the technical field of microfluidics, and particularly relates to a microfluidic chip and a method for preparing liquid drops in a high-flux and large-scale manner. A step emulsification structure and a liquid drop splitting structure are used together, a liquid drop generation structure is arranged at the communication position of a branch splitting channel and a main channel unit correspondingly communicated with the branch splitting channel, a dispersion phase necks at the liquid drop generation structure under the action of interfacial tension to form liquid drops, and the liquid drops are generated under the leading of the interfacial tension, so that the dispersion phase is uniform in dispersion. Therefore, the size of the liquid drops is basically determined by the channel width of the liquid drop generation structure, the branch splitting channel is designed to be wide, the influence of manufacturing errors on the uniformity of the generated liquid drops can be reduced, the branch splitting channel is designed to be a plurality of serpentine channels, and the uniformity of the liquid drops is improved while high-flux liquid drop preparation is guaranteed; and then the liquid drops flow through the main channel unit and are converged into the main splitting channel, and the liquid drops are uniformly split into liquid drops with smaller sizes through the liquid drop splitting structure, so that the preparation of the liquid drops with high flux and uniform sizes is realized.

The invention discloses a method for preparing a thin-wall part with a snakelike hollow channel by adopting superplastic forming / diffusion bonding. The method comprises the following specific steps: step 1, plate preparation and surface cleaning treatment; and step 2, solder resist coating: using a mask plate to deposit on a specific area of the plate and coating the solder resist according to an S-shaped shape, and removing the protective adhesive tape after spraying is completed. And 3, assembling and sealing, wherein the plates are stacked according to the design sequence, the edges are sealed and welded, and an air inlet / outlet is reserved to be connected with an air pipe. And 4, heating is conducted, specifically, the assembly is put into a mold, then the mold is uniformly put into a superplastic forming machine tool, and heating is conducted till the plate superplastic forming temperature is reached. And fifthly, diffusion bonding is conducted, specifically, uniform pressure is applied to the mold through a pressing head in the superplastic machine tool, so that diffusion bonding combination is conducted on the contact face, not coated with the solder resist, of the plate at high temperature and high pressure, and a connecting rib is formed. And 6, superplastic forming / diffusion bonding is conducted, specifically, the temperature is kept, and high-pressure inert gas is introduced into the assembly through a reserved air inlet according to an air pressure loading curve. And the plate coated with the solder resist is subjected to superplastic deformation and is attached to a mold cavity, diffusion connection between the plates is completed in the area not coated with the solder resist, and finally the needed thin-wall part with the serpentine channel cavity is formed. And 7, cooling and demolding are conducted, specifically, the thin-wall part with the snake-shaped hollow channel is taken out after cooling to the room temperature, and the residual solder resist is cleaned.

A cooling circuit of an airfoil for a gas turbine engine includes a serpentine channel having a plurality of fluidly connected radially extending flow passages and a tip flag channel disposed adjacent to the serpentine channel. The tip flag channel includes a first tip flag passage extending radially and a second tip flag passage extending axially from a terminal end of the first tip flag passage, the second tip flag passage disposed radially outward of the serpentine channel. The second tip flag passage is in direct fluid communication with each of the first tip flag passage and a final passage of the serpentine channel.

The application discloses a kind of bionics proton exchange membrane fuel cell based on snowflake structure, including bipolar plate, bipolar plate includes the flow field on by 4 flow channel modules combination, each flow channel module includes serpentine channel with import and export, 4 flow channel modules on serpentine channel are sequentially connected to constitute bionic flow channel, flow channel is full in bipolar plate, and then the import of serpentine channel on the first flow channel module forms flow channel entrance, and the export of serpentine channel on the last flow channel module forms flow channel exit.The bionic flow channel of the device has good pressure drop, can make gas distribution uniform, improve the flow smoothness of flow channel, beneficial to discharge liquid water.

This invention discloses a nested serpentine channel liquid cooling plate and its battery thermal management system, belonging to the field of energy storage battery thermal management technology. The liquid cooling plate has a double-inlet, double-outlet serpentine flow channel inside, forming two parallel coolant flow paths to shorten the heat transfer path and improve temperature uniformity. A battery thermal management system includes a battery module composed of multiple square batteries and at least one liquid cooling plate, which is nested between the battery cells. Preferably, for a module composed of 20 square batteries, only three liquid cooling plates are used, respectively arranged on both sides and in the middle of the module, achieving a compact configuration of "one cooling plate cooling two battery cells". More preferably, the liquid cooling plate adopts an inlet / outlet direction of left-up-right-down and right-up-left-down, with a coolant mass flow rate of 1 g / s and an inlet temperature of 25°C. Experimental results show that at an ambient temperature of 45℃ and a discharge rate of 2C, the battery module's highest temperature is 28.75℃, the maximum temperature difference is 2.17℃, the voltage drop is 229.31Pa, and the comprehensive performance evaluation index PEC reaches 4.02. This invention significantly reduces system complexity, manufacturing costs, and flow resistance while ensuring efficient heat dissipation and excellent temperature uniformity, making it suitable for large-scale lithium iron phosphate energy storage modules.

The invention discloses an in-wall serpentine channel cooling structure and a using method. The in-wall serpentine channel cooling structure mainly comprises a cooling wall and a serpentine channel. Cooling air enters the cooling wall from the cold air inlet, passes through the S-shaped channel in the cooling wall and then flows out from the cold air outlet, and an air film is formed on the outer wall face to protect the outer layer wall. By arranging the snakelike micro-channels in the wall surfaces, the internal cooling area and the cold air cooling stroke are increased, cross flow interference and cold air retention between new cold air and old cold air are avoided, the cold air cooling potential is fully explored, the laminate cooling effect is remarkably improved, and good application prospects are achieved.

Described is a flow plate (10) for a fuel cell. The flow plate comprises a substrate (12) comprising a flow inlet (16) and a flow outlet (18), as well as a flow field (14) in fluid communication with both the flow inlet (16) and the flow outlet (18) comprising a plurality of flow channels. The plurality of flow channels comprises at least two serpentine channels, each of the at least two serpentine channels defining a channel inlet and a channel outlet and comprising at least one curved section inducing a change in the flow direction in the respective serpentine channel, and the plurality of flow channels also comprises an interdigitated channel extending between the at least two serpentine channels, and defining a channel inlet and a closed channel end.

The detachable antibacterial air filter element comprises a frame body and an air filter element body, lower snakelike strips are installed on the two sides of the interior of the frame body in the length direction, bottom rods connected with the lower snakelike strips are installed on the two sides of the interior of the frame body in the width direction, upper snakelike strips are arranged above the lower snakelike strips, and the lower snakelike strips are connected with the bottom rods. Top rods connected with the upper snakelike strips are arranged above the bottom rods, snakelike channels are formed between the upper snakelike strips and the lower snakelike strips, clamping channels are formed between the top rods and the bottom rods, the air filter element body is arranged in the frame body, and the two sides of the air filter element body in the length direction are inserted into the snakelike channels; and the upper snakelike strip and the lower snakelike strip are used for clamping and fixing. The air filter element is simple in structure, the sealing performance of the folding positions of the air filter element body can be guaranteed through clamping of the upper snakelike strip and the lower snakelike strip, the folding positions do not make contact with one another, all the folding positions are straightly arranged, it is avoided that air entering is affected due to the fact that the folding positions are attached or drawn close, and glue is not needed.

The silencing cover for the air compressor comprises a silencing cover body, a partition plate is fixedly arranged at the bottom of an inner cavity of the silencing cover body, a plurality of air holes are formed in the partition plate and distributed at equal intervals, a plurality of flow guide plates are fixedly arranged on the inner wall, located above the partition plate, of the silencing cover body, and the flow guide plates are arranged on the inner wall of the silencing cover body. A silencing cover is fixedly arranged on the guide plate, a serpentine channel is formed between the silencing cover and the guide plate, a plurality of buffer strips are fixedly arranged on the outer wall of the guide plate, every two corresponding buffer strips are correspondingly arranged, and a buffer area is formed between the guide plate and the buffer strips. The utility model relates to the technical field of air compressors, according to the design of the silencing cover, noise can be buffered through the S-shaped channel and can also be buffered in the buffering area of the buffering strip, finally, the noise is thoroughly eliminated through buffering of the buffering plate, the rigidity of the silencing cover is guaranteed through the integrally-designed silencing cover, and the noise reduction effect is good. And certain practicability is achieved.

The present application discloses a slow-wave plate structure, comprising a waveguide radiation body, wherein the front end face of the waveguide radiation body is provided with a serpentine slow-wave groove, and one end of the serpentine slow-wave groove is provided with a feed signal end; a serpentine channel is formed in the serpentine slow-wave groove, the serpentine channel is connected to the feed signal end, the serpentine channel comprises a plurality of straight waveguide sections and connecting waveguide sections, a gap portion is present between two adjacent straight waveguide sections, and the two adjacent straight waveguide sections are connected by means of one connecting waveguide section; and the plurality of straight waveguide sections are provided with waveguide radiation gaps at intervals, or the waveguide radiation gaps are respectively provided in the plurality of straight waveguide sections. The present application has the advantages of simple structure, low cost, good radiation effect, wide application range, etc.

The present invention relates to a preparation method of TEMTP, belonging to the technical field of organic cyclic peroxides. Based on an efficient preparation method using a three-stage microchannel reactor, the first-stage 2 ± 0.2 mm serpentine channel realizes high-shear mixing, the inner wall of the second-stage 1 ± 0.2 mm spiral channel is loaded with TiO2-Ag nano-photocatalyst, and supercritical CO2 is introduced into the third-stage 2 ± 0.2 mm straight channel to reduce the viscosity of the material and improve the mass transfer efficiency. The catalytic system uses the ionic liquid [BMIM][HSO4] and sulfuric acid in combination, with segmented temperature control. The post-treatment process includes electric field-assisted phase separation, which improves the product purity, selectivity and stability, and has important industrial application value.

An electric heater (1) for a vehicle, adapted to heat a liquid crossing said heater, comprising : - a body (2) made of die-cast metal material; - at least one electrical resistor (3); - an inlet connection (12), projecting from the body (2), for the liquid to enter into said body (2); - an outlet connection (13), projecting from the body (2), for the liquid to exit from said body (2); - a first flow path (4) for the liquid, from said inlet connection (12) to said outlet connection (13), made on a first face of said body (2); - a first cover (6) that closes, with a first side thereof, the first flow path (4); wherein the first flow path (4) comprises at least one serpentine channel (21) which starts from the inlet connection (12) and ends in the outlet connection (13); wherein said at least one serpentine channel (21) comprises a first straight stretch (35) proximal to the inlet connection (12), a second straight stretch (36) proximal to the outlet connection (13), at least one third straight stretch (37) interposed between said first straight stretch (35) and said second straight stretch (36), and a plurality of hairpin bends (30), each hairpin bend (30) being arranged between one straight stretch and the next one; wherein a heating part of said first electrical resistor (3) is serpentine-shaped and comprises respective straight stretches (50, 50') and curved stretches (51), each curved stretch (51) being arranged between a straight stretch (50, 50') of said heating part and the next one; and wherein the straight stretches (50, 50') of said heating part are arranged transversely to the straight stretches (35, 36, 37) of said at least one serpentine channel (21).

The invention provides a cascade viscoelastic micro-fluidic chip and a method for preparing, sorting and enriching circulating tumor cells. The cascade viscoelastic micro-fluidic chip comprises a cell sorting module, a transition section and a cell concentration module. The cell sorting module is composed of an inlet I, an inlet II, an annular bifurcated branch, a straight channel section I, an amplification section, a serpentine channel I and an outlet I; the cell concentration module is composed of a second straight channel section, a first bifurcation structure, a second serpentine channel, a second outlet, a third straight channel section, a second bifurcation structure, a third serpentine channel, a third outlet, a fourth straight channel section, a third bifurcation structure, a fourth outlet and a fifth outlet. The cell sorting module and the cell concentration module are cascaded through a transition section. The invention breaks through the bottleneck that the traditional sorting technology can be compatible with downstream biological analysis only by intervening manual centrifugation and other operations at the rear end, and can provide powerful technical support for developing a tumor liquid biopsy integrated system.

A flow plate for a fuel cell includes a substrate including a flow inlet and a flow outlet, and a flow field in fluid communication with both the flow inlet and the flow outlet including flow channels. The flow channels include at least two serpentine channels, each of the at least two serpentine channels defining a channel inlet and a channel outlet and including at least one curved section inducing a change in the flow direction in the respective serpentine channel, and the flow channels also including a straight interdigitated channel extending between the at least two serpentine channels, and defining a channel inlet and a closed channel end.

Disclosed in the present invention are a waveguide slot antenna and a control method therefor. The antenna comprises a feed port layer, a slow-wave line layer, and a radiation slot layer which are stacked in sequence; the feed port layer is provided with a feed port for inputting electromagnetic waves or outputting electromagnetic waves; one end face of the slow-wave line layer facing the feed port layer is provided with a serpentine slow-wave cavity, one end of the serpentine slow-wave cavity is provided with a feed signal end, and the feed signal end is correspondingly connected to the feed port; a plurality of waveguide radiation slots are arranged at intervals in a serpentine channel of the serpentine slow-wave cavity; and a plurality of radiation cavity units having one-to-one correspondence to the waveguide radiation slots are arranged at intervals on one end face of the radiation slot layer facing the slow-wave line layer, a plurality of radiation slots are arranged at intervals in each radiation cavity unit, and one end of each radiation cavity unit is provided with a signal connection end correspondingly coupled to the waveguide radiation slot. The present invention can increase the antenna scanning angle, thereby meeting application scenarios requiring a large antenna scanning range.

A feed trough for an electric arc furnace includes first and second arcuate plates, each having first and second opposing end edges and first and second opposing side edges, the first and second end edges including an arcuate contour, the first and second end edges of the first and second arcuate plates connected, and the first and second side edges of the first and second arcuate plates connected. A channel is disposed between the first and second end edges, the first and second side edges, and the inner surfaces of the first and second arcuate plates, the channel including at least one serpentine channel and at least one peripheral channel, the at least one serpentine channel being disposed toward a centerline of the feed trough, and the at least one peripheral channel being disposed outward of the at least one serpentine channel.

A redox flow battery includes at least one flow field including a plurality of serpentine channels to communicate electrolyte. Each of the serpentine channels define an inlet end, an outlet end, and a flow path fluidly connecting the inlet end with the outlet end. The serpentine channels are arranged in a parallel flow configuration.

The present disclosure relates to inductive acoustic filters for acoustic devices. Various aspects of the subject technology relate to inductive acoustic filters for acoustic devices. The inductive filter can include a substrate, an etched serpentine channel in and within a surface of the substrate extending from a first port in the substrate to a second port in the substrate. The inductive filter can also include a polymer cover layer adhesively attached to the surface of the substrate over the etched serpentine channel. The inductive filter can be positioned over an opening in a substrate of an acoustic module, such as a microphone module or a speaker module.

Techniques for semiconductor processing including one or both of a showerhead and a pedestal configured for use of a flexible and malleable temperature probe are disclosed. The temperature probe is configured for installation into and removal from a serpentine channel provided in the showerhead, in some examples. In other examples, the temperature probe is configured for installation into and removal from a serpentine channel provided in the pedestal.

The invention discloses a microcolumn chip as well as a preparation method and a use method thereof, and relates to the technical field of biological chips. The microcolumn chip comprises a glass substrate and a PDMS chip arranged on one side of the glass substrate, a cell migration and deformation channel is arranged in the PDMS chip, and a plurality of microcolumns are arranged in the cell migration and deformation channel; the device further comprises a cell injection channel, the downstream of the cell injection channel is communicated with a cell calibration channel, and the cell calibration channel is communicated with the cell migration and deformation channel; the downstream of the Christmas tree-shaped channel is communicated with the cell migration and deformation channel, and the upstream of the Christmas tree-shaped channel is communicated with multiple groups of serpentine channels; according to the microcolumn chip, through the coupling design of the microcolumn channel and the stable chemical gradient, mechanical extrusion and chemotactic signals can be synchronously applied on the basis of simulating the real microenvironment of cells, high bionic simulation of single cell migration and deformation behaviors is achieved, and the limitation that an existing chip can only independently simulate the chemical gradient or mechanical compression is broken through.

The invention discloses a dual-channel snakelike cold plate coupled phase change material battery thermal management system, which comprises a plurality of batteries, a dual-channel snakelike liquid cooling plate and a phase change material, two snakelike channels are arranged in the liquid cooling plate, and the flowing directions of fluids in the two snakelike channels are opposite; a secondary flow channel is arranged between every two adjacent straight flow channels of the same serpentine channel, the tops or the bottoms of the batteries are tightly attached to the liquid cooling plate, the batteries are arranged into a plurality of rows one by one in the direction of the straight flow channels in the liquid cooling plate, a gap between every two adjacent batteries in each row is filled with a phase change material, and the thickness of the phase change material between every two adjacent batteries is non-uniform. The dual-channel snakelike cold plate coupled phase change material battery thermal management system has relatively low battery pack temperature difference and relatively small cold plate inlet and outlet pressure drop at the same time.

The invention discloses a micro-fluidic panel, a mercury ion concentration detection device based on gallium nitride and a preparation method thereof, and relates to the technical field of ion concentration detection.The micro-fluidic panel comprises a serpentine channel, the head end of the serpentine channel is connected with a reaction tank, and the tail end of the serpentine channel is connected with a first channel and a second channel; the first channel flows through the gate region of the semiconductor structure; magnetic parts are arranged at the joints of the serpentine channel, the first channel and the second channel and are used for shunting positive ions and negative ions in a solution. An electrochemical method is adopted, thymine bases on the surface of the aptamer are combined with mercury ions, a stable T-Hg-T compound is formed on the surface of the sensor, charge distribution on the surface of a grid electrode of a GaN device is changed, two-dimensional electron gas concentration change and source-drain current change are caused, and the sensing device is not provided with a reference electrode, simple in structure and convenient to operate. The detected drain current is sensitive to the surface charge change of the device. The detection sensitivity is improved.

The application discloses a serpentine slow wave plate, which comprises a waveguide radiation body, a serpentine slow wave groove is arranged on the front end surface of the waveguide radiation body, and a feeding signal end is arranged at one end of the serpentine slow wave groove; a serpentine channel is formed in the serpentine slow wave groove, the serpentine channel is connected with the feeding signal end, the serpentine channel comprises a plurality of straight waveguide segments and connecting waveguide segments, a gap part is arranged between two adjacent straight waveguide segments, and the two adjacent straight waveguide segments are connected through the connecting waveguide segments; waveguide radiation slots are arranged at intervals in the plurality of straight waveguide segments or are respectively arranged; the center line of the straight waveguide segment is arranged in a staggered mode with the center line of the corresponding waveguide radiation slot; and the center lines of the plurality of waveguide radiation slots have different offset amounts. The application has the advantages of simple structure, low cost, good radiation effect, wide application range and the like.

The invention relates to the field of mechanical manufacturing, and discloses a bearing production automatic conveying tool which comprises a supporting frame, a fixing plate is arranged at the top end of the supporting frame, conveyors are arranged on the two sides of the fixing plate correspondingly, working platforms are arranged on the two sides of the top end of the fixing plate correspondingly, and side frames and two discharging assemblies are arranged on one sides of the two working platforms correspondingly. And the discharging assemblies are arranged on the surfaces of the two working platforms correspondingly and used for bearing input bearings and achieving switching conveying of the bearings to the conveyors on the two sides, the discharging assemblies comprise material conveying shells, the material conveying shells are fixedly installed on the surfaces of the working platforms, S-shaped channels are formed in the material conveying shells, and feeding ports are formed in the top ends of the S-shaped channels. Flexible shunting of a conveying line is achieved through overturning of the flow guide plate, the blocking problem is solved through air hole anti-skid and vibration knocking, meanwhile, the conveying stability and statistical convenience are guaranteed through shifting strip buffering and photoelectric sensor counting, and the production flexibility and efficiency are improved.

A device and method for preparing semi-solid gold slurry based on an acoustic-magnetic coupled serpentine channel. The dual stirring force of the electromagnetic field and the serpentine channel can more effectively break up dendrites. When the melt flows into a mold under ultrasonic action, the grain size is improved and the degree of spheroidization is increased. The dual stirring force of the gradient spiral magnetic field and the serpentine channel can effectively promote the shedding of grains to varying degrees on the inner wall of the serpentine channel, producing more and more uniform free crystals. The strong stirring effect of the electromagnetic field on the melt can quickly generate strong convection in the melt in the channel, promoting uniform composition and structure. When the melt flows into the mold, the ultrasonic cavitation effect is utilized to further improve the quality of the semi-solid slurry. The present invention can also produce better semi-solid slurry when cast at a higher temperature, achieving a greater degree of supercooling and producing more free crystals. High-temperature casting can effectively reduce the hanging material in the serpentine channel. Under the action of ultrasound, the grain size is further improved, thereby improving the quality of the semi-solid slurry.

A cooling circuit of an airfoil for a gas turbine engine includes a serpentine channel having a plurality of fluidly connected radially extending flow passages and a tip flag channel disposed adjacent to the serpentine channel. The tip flag channel includes a first tip flag passage extending radially and a second tip flag passage extending axially from a terminal end of the first tip flag passage, the second tip flag passage disposed radially outward of the serpentine channel. The second tip flag passage is in direct fluid communication with each of the first tip flag passage and a final passage of the serpentine channel.

The present invention relates to the technical field of rapping shaft sealing for electrostatic precipitators. Disclosed is a rapping shaft sealing device for an electrostatic precipitator. The rapping shaft sealing device comprises: an electrostatic precipitation assembly, which comprises an electrostatic precipitator housing and a rapping shaft body arranged on the electrostatic precipitator housing; an outer sealing assembly, which comprises a base mounted and arranged on the electrostatic precipitator housing, a sealing outer sleeve arranged on the base, and a sealing cavity formed in the sealing outer sleeve; and an inner sealing assembly, which comprises an inner sealing portion arranged in the sealing cavity and sealing rings arranged in a sleeved manner in the inner sealing portion, wherein the sealing rings are sleeved on the rapping shaft body, and a sealing medium is provided between the sealing outer sleeve and the inner sealing portion. The inner sealing portion is capable of rotating synchronously with the rapping shaft body by means of cooperation with the sealing rings and the rapping shaft body, the multiple stages of sealing rings are capable of blocking airflow between the sealing inner sleeve and the rapping shaft body, and the sealing medium and multiple stages of serpentine channels work together to form a seal, thereby isolating the passage of external air to the greatest extent.