112results about How to "Prevent expansion and deformation" patented technology

The invention discloses a pneumatic soft hand grab. The pneumatic soft hand grab comprises a central air guiding block provided with a plurality of air guiding holes and a plurality of flexible pneumatic finger units evenly arranged on the central air guiding block in a communicating mode. The inner concave face of each pneumatic finger unit in the inflating and deformation process is provided with a hard rubber layer. According to the pneumatic soft hand grab, compared with a metal pneumatic hand grab, the pneumatic soft hand grab is convenient and reliable to control, the structure is simple, and the cost is lower; the flexible characteristic of the pneumatic soft hand grab can well grab fragile and easy-to-break objects without being damaged and can further adapt to configuration structure characteristics of various grabbed objects, and the hand grab does not need to be replaced repeatedly because of changing of the configuration structures of the grabbed objects; and in addition, alayer of hard rubber is arranged on the lower portion of each pneumatic finger unit of the pneumatic soft hand grab, unnecessary swelling deformation can be prevented from being generated on the lower portion of the hand grab, and therefore a better finger bending effect is achieved.

A safety mechanism for a laminate battery. An exterior case (5) consists of two molded sheets (5a) made of laminate sheets, superposed upon one another, and bonded together around the outer edges. The exterior case has a protrusion (10) that communicates with the interior of the exterior case and protrudes outwardly from one side. A safety vent (13) is made up of an exhaust hole (11) formed in at lease one of the two molded sheets (5a) in the protrusion (10), and a valve element (12) making elastic pressure contact with the edge of the exhaust hole (11) to seal it. The safety mechanism does not operate within the range of internal pressure variation during normal use, but operates reliably at a time point when a predetermined valve operating pressure is reached to release a necessary amount of gas to the outside, this valve operating pressure being within the safe range relative to the pressure resistance of the exterior case (5) made of laminate sheets. Also, the safety vent configuration enables a reduction in production cost.

The invention discloses a protective coating for inhibiting a platinum bushing from being oxidized and volatilized and reducing the loss of noble metals, a preparation process and application. The protective coating mainly comprises the following components in percentage by weight: 20 to 50 percent of silicon oxide, 20 to 45 percent of aluminum oxide, 5 to 15 percent of sodium silicate and 10 to 25 percent of sodium tetraborate. The protective coating can prevent platinum and rhodium alloys from being oxidized and volatilized at high temperature effectively, and compared with the bushings which are not processed, the bushing which is processed by a coating process can reduce the loss amount by over 30 percent.

The invention relates to a novel soil radial expansion rate tester and a using method thereof. A displacement tester is arranged in a test piece inner ring by setting a circular test piece, so that the radial expansion rate is determined inside the test piece, and a traditional mode for determining the expansion deformation of a soil body from the outer side of the test piece is changed; a hoop is arranged outside the circular test piece, and the tester is arranged in the inner ring, so that the conflict between the arrangement of the tester and the lateral confinement of a rigid ring cutter in conventional radial expansion rate determination can be overcome, the dependence on a flexible consolidation meter and consolidation rings with different rigidities can be eliminated, the rigidity testing precision and complicated operation problems can be avoided, and the operation is simple, convenient and fast; a water injection device is improved, so that water can permeate gradually to the middle from the upper end and the lower end only, and a tested soil body of the inner ring is prevented from collapsing, disintegrating, chipping, softening and the like. A framework device consisting of a base, an upper cover, a screw rod and a bolt can be fixedly and vertically displaced during the testing, so that the test piece is prevented from generating vertical expansion deformation and the testing precision can be guaranteed.

The invention discloses an expansion protecting device, which belongs to the technical field of expansion protecting devices of electric oil storage equipment. The expansion protecting device comprises an elastic body communicated with an inner cavity of an electric equipment sealed oil tank, and a pressure block is arranged on the upper surface of the elastic body. When in use of the expansion protecting device, oil is filled into the oil tank and the elastic body, the pressure block presses the elastic body, so that oil in the elastic body and the oil tank is applied with positive pressure, and leakage of external rainwater, air and the like to the oil tank is avoided. When the electric equipment is heated during running, the temperature of oil in the oil tank rises and the oil expands. Since the elastic body is communicated with the inner cavity of the sealed oil tank, the elastic body can expand along with expansion of the oil, and deformation of the oil tank is avoided effectively. Meanwhile, positive pressure in the oil tank can be controlled by utilizing different elastic bodies and pressure blocks, and the service life of the electric equipment can be prolonged. The expansion protecting device can be used on electric equipment with oil, such as transformers, reactors, mutual inductors and the like.

The invention particularly relates to a visualized experimental device for CHF research in a bidirectionally visible rectangular narrow channel, belonging to the field of flow boiling visualization research. The experimental device comprises fastening bolts, a graphite gasket, flanges, a heating plate, a wide-side quartz glass, a wide-sided bearing plate, a fluoro rubber gasket, a narrow-sided quartz glass, a narrow-sided bearing plate, a housing, a substrate, and a support column. The experimental device used in the invention is all quartz glass on three sides, therefore, the behaviors of generation, aggregation, growth and detachment of bubbles on the heating surface can be observed from the side, and parameters such as a bubble layer and liquid film thickness can be measured; the heating plate is slightly narrower than the base, therefore, the rectangular flow channel corner effect is avoided; the heating plate is shorter in axial direction than the substrate, therefore, the inlet and outlet effect is eliminated; the substrate is made of insulating ceramic material, so that the heating plate is completely insulated from other parts of the experimental section; three support columns are welded on the heating plate and fixed to the substrate, so as to avoid expansion deformation of the heating plate at high temperature; and the flow path gap can be changed by changing the thickness of the gasket between the wide-side quartz glass and the housing.

The invention discloses a safety lithium battery shell which includes a battery shell body and an electrode inducing sealing structure. The safety lithium battery shell has characteristics in that: the shell body is a narrow strip structure, and has height more than 100mm, the shell body height is 10 times greater than width or thickness, the shell body narrow side has a row of safety explosion proof structure. The shell has narrow strip structure, and has the explosion proof structure in narrow side which can play a role of explosion proof effectively and solve problem of battery gassing.

The invention discloses a waterproof paint for a bamboo floor. The waterproof paint is prepared form the following raw materials in parts by weight: 68-73 parts of epoxy resin, 50-55 parts of alkyd resin, 15-25 parts of water glass, 5-7 parts of sodium fluosilicate, 6 parts of barium sulfate, 9 parts of hydroquinone, 14 parts of crylic acid and 145-155 parts of water through stirring. The formulacan also contain 10 parts of magnesium silicate. Proved by industrial tests, the waterproof paint product disclosed by the invention is used for carrying out coating treatment on the surface of the bamboo floor and is capable of effectively isolating bamboos from outside water, thereby avoiding the bamboos from expanding and deforming or rotting.

The invention discloses a styrene butadiene rubber waterproof paint for a wood material, wherein the paint is mainly prepared from the following raw materials in a stirring manner according to the weight ratio: 67-84 parts of styrene butadiene rubber, 3-5 parts of barium stearate, 11-15 parts of pine tar, 5 parts of aluminite powder, 20 parts of light calcium carbonate, 10 parts of phenol, 16 parts of polyvinyl alcohol, 5 parts of paraffin wax and 1-2 parts of sulphur. Industrial experiment shows that the styrene butadiene rubber waterproof coating formed by painting the surface of the wood material with the product of the invention can effectively isolate the wood material from outside water, so as to avoid swelling deformation or decomposition of the wood material, meanwhile, the styrene butadiene rubber waterproof paint has better application property and is environmentally-friendly and pollution-free, and the raw materials are cheap.

The invention relates to a log spliced board structure. The log spliced board structure is characterized by being mainly composed of a batten piece on the left outermost side, a batten piece on the right outermost side, a batten piece on the left second outer side, a batten piece on the right second outer side, a plurality of middle batten pieces, a plurality of screws connected in series, a plurality of nuts and the like. The design of expansion slits, the screws, the nuts, screw holes and nut holes is mainly adopted, the spliced wood board is not prone to expansion arching or shrinkage crack when weather changes, and the quality and the attractive appearance of the spliced wood board are greatly ensured. The splicing reliability and firmness of the batten pieces are greatly guaranteed, expansion deformation or cracking can be completely eradicated, and the quality of the spliced wood board is effectively guaranteed.

The invention relates to a mooncake coated with mixed sugar, belonging to the technical field of food production. The invention aims at the technical problems of the traditional production process of the mooncake that the mooncake is easy to expand and deform, the patterns on the mooncake are not clear and are easy to rewet, and the mooncake skin is fogged and has bad mouth feeling. The mooncake skin of the mooncake coated with mixed sugar is prepared from the following raw materials in parts by weight: 40-50 parts of flour, 15-30 parts of sugar, 14-18 parts of oil, 2-5 parts of honey and 16-18 parts of water. The specific preparation method comprises the following steps: wraping filling with the skin according to a skin-filling ratio of 2:3, filling the mooncake in a mould of which bottom is carved with patterns to compact, taking out the formed mooncake, coating a layer of flour paste accounting for 3-5wt% of the skin on the surface, drilling at least one hole in the mooncake, baking the mooncake in an oven, taking out the baked mooncake from the oven, and cooling to obtain the finished product. The mooncake coated with mixed sugar has the following advantages: the mooncake can not expand and deform, the patterns on the mooncake are clear and can not rewet, and the mooncake skin is not fogged and has good mouth feeling.

The invention discloses a testing ring for measuring the inner and outer radial contact stress of a rubber sleeve, and solves a problem that there is no effective means to measure the radial contact stress between the rubber sleeve and a casing pipe. The testing ring specifically comprises an outer contact stress testing ring and an inner contact stress testing ring, and a plurality of radial step holes are circumferentially arranged on a testing ring pedestal, wherein outer pressure-transmitting pistons are inserted in the inner sides of the step holes of the outer contact stress testing ring, plugs are fixed to the outer sides of the step holes, the pressure-transmitting contact surfaces of the heads of the outer pressure-transmitting pistons and the inner ring surface of the ring-shaped pedestal are on the same curved surface, and the mounting direction of inner pressure-transmitting pistons and plugs of the inner contact stress testing ring is the opposite direction of the outer contact stress testing ring; a sealing cavity between the pressure-transmitting piston and the plug of each above radial step hole is full of liquid, and holes communicated with the sealing cavities are arranged in the plug bodies. The testing ring adopts liquid to transmit the pressure, the radial contact stress test is converted to a test by using the hydraulic pressure, and the contact stress test data is real and reliable.

The invention discloses an internal supporting and reinforcing method for a large-scale underground comprehensive pipe gallery wall plate without an external mold, and belongs to the field of buildingengineering. According to the supporting and reinforcing method provided by the invention, a bottom plate after the pipe gallery is formed is used as a foundation of an integral formwork supporting system, and when concrete of the bottom plate of the pipe gallery reaches 50% of the design strength, a socket plate buckle type steel pipe supporting system is used for erecting an inner supporting system of a formwork. A middle wall after the pipe gallery is formed is used as a foundation of a single-side formwork supporting system of an outer wall, when the concrete of an inner wall reaches 50%of design strength, a single-side formwork of the wall is reinforced by adopting a fastener type steel pipe system, and the fastener type steel pipe system consists of a fastening part and a supporting part. According to the supporting and reinforcing method disclosed by the invention, steel pipe materials are easy to obtain, the use is economic and reasonable, the construction cost can be reduced, the construction quality can be improved, the problem of reinforcing the underground comprehensive pipe gallery project wall plate without the external mold is solved, and the supporting and reinforcing method is safe, reliable and simple to apply.

The invention discloses a composite shaving board. The composite shaving board comprises a board body, wherein the board body comprises a shaving sandwich layer which is mainly formed by distributing a rough shaving layer and a fine shaving layer in a staggered mode, a metal net layer is arranged between the rough shaving layer and the fine shaving layer, meshes of the metal net layer are filled with metal powder, vermiculite anti-flaming layers which are connected through a polymer glue layer are arranged on the upper surface and the lower surface of the shaving sandwich layer respectively, and the periphery of the board body is wrapped in a paraffin layer. The composite shaving board is simple in structure, easy to manufacture, resistant to water and fire, capable of insulating heat and preserving heat, high in strength, high in torsional property, capable of preventing radiation, environmentally friendly, firm in structure, resistant to abrasion, attractive, durable and the like and can be widely applied to various fields and occasions.

The invention discloses an ethylene perchloride waterproof paint for a wood material, wherein the paint is mainly prepared from the following raw materials in a stirring manner according to the weight ratio: 50-60 parts of ethylene perchloride, 3-5 parts of barium stearate, 15 parts of potassium peroxodisulfate, 5 parts of aluminum powder, 20 parts of benzoyl peroxide, 10 parts of phenol, 16 parts of acetone, 10 parts of petroleum ether, 15 parts of coal tar and 12 parts of calcium carbonate. Industrial experiment shows that the ethylene perchloride waterproof coating formed by painting the surface of the wood material with the product of the invention can effectively isolate itself from outside water, so as to avoid swelling deformation or decomposition of the wood material, meanwhile, the ethylene perchloride waterproof paint has better application property and is environmentally-friendly, and the raw materials are cheap.

The invention provides a die-casting double-bottom cooking utensil and a manufacturing method of the die-casting double-bottom cooking utensil, which belong to the technical field of machinery and solve the problem that a double-bottom sheet in an existing double-bottom pan body is easily deformed or easily falls off through heating. The manufacturing method comprises the following steps of A. manufacturing a metal sheet; B. punching; C. turning over edges; D. closing molds; E. casting molten aluminum; F. demolding. The die-casting cooking utensil comprises an open body which is made of an aluminum material, wherein the body is provided with a chassis for heating, the chassis is provided with the metal sheet which is made of a magnetic-conducting material, the metal sheet is provided with a plurality of through connecting holes, the chassis is provided with a plurality of connecting parts which are embedded into the connecting holes, the connecting parts and the connecting holes are in one-to-one correspondence, and a clamping structure which can be used for fixedly connecting each connecting part and the corresponding connecting hole is arranged between the connecting part and the connecting hole. The die-casting double-bottom cooking utensil has the advantages that the metal sheet is more firmly connected and does not easily fall off, and the like.

The invention discloses a steel-lined poly tetra fluoroethylene (PTFE) pipe. The steel-lined PTFE pipe comprises a steel pipe body, a PTFE lining and a steel wire circle, wherein flanges are arrangedat the two ends of the steel pipe body separately, each flange is uniformly provided with a plurality of mounting holes in the circumferential direction, the PTFE lining is arranged in a hollow hole in the steel pipe body and is cylindrical, T-type bulges are arranged at the two ends of the PTFE lining separately, the T-type bulges are tightly attached to the flanges, the steel wire circle is tightly attached to the outer sidewall of a straight pipe of the PTFE lining, a steel wire is wound around the PTFE lining, a resin bonding layer is arranged between the steel wire circle and the inner wall of the steel pipe body, and the resin bonding layer is a modified epoxy resin adhesive. The steel-lined PTFE pipe is of multi-layer composite, the negative pressure resistance of the steel-lined PTFE pipe is improved, falling off, bulging shrinkage and expansion deformation of the PTFE lining are avoided, and meanwhile leakage at a port of the steel-lined PTFE pipe is prevented.

The invention relates to a surface anti-oxidation protective coating of a platinum wire-drawing crucible as well as a preparation method and an application of the surface anti-oxidation protective coating. The protective coating comprises the following raw material components in percentage by weight: 20-35% of a-calcined aluminum oxide powder, 15-30% of quartz powder, 5-10% of boron nitride powder and 30-55% of kaolin. The protective coating disclosed by the invention has strong adhesion to the platinum wire-drawing crucible, and particularly has very high binding force after sintering treatment, so that the oxidizing volatilization loss of platinum under the condition at a high temperature can be effectively prevented, and the swelling deformation under the condition of conventional high-temperature sintering and the shrinkage deformation under the condition of rapid cooling after high-temperature power failure of the platinum crucible are effectively overcome.

The invention provides a self-heating pop-top can and belongs to food packages. The self-heating pop-top can comprises a can body, a can opening at the upper end of the can body and a can bottom at the bottom of the can body. A pull ring is arranged on the can opening, an inner container is arranged at the can bottom, and heating liquid fills the inner container; a metal sheet is further arranged on the wall of the inner container, and the metal sheet is connected with the pull ring through a metal wire. The self-heating pop-top can has the advantages that when the pull ring is pulled open, the liquid in the inner container is started to heat up drink, further heating is omitted, and the self-heating pop-top can is convenient and safe to use.

The invention relates to the technical field of semiconductor integrated circuit manufacturing, in particular to a thermal annealing processing method and device for preventing a wafer from warping. The method comprises the steps that a target wafer is sequentially divided into n closed heating areas from the circle center to the outer edge position, and n is a positive integer; the n heating areas are heated according to the corresponding heating conditions, so that the corresponding temperatures of the n heating areas are gradually decreased from the circle center of the target wafer to theouter edge of the target wafer, and the thermal stress of the target wafer in the rapid thermal annealing process extends from the center of the target wafer to the edge of the target wafer. The device comprises a working cavity, a plurality of target wafers sequentially enter the working cavity of the thermal annealing treatment device, and the thermal annealing treatment method for preventing the wafers from warping can solve the problems that in the related technology, in the rapid thermal annealing process, the edges of the wafers are thermally expanded due to overheating, stress on the wafers is compressed from the edges to the center, therefore, the whole wafer is concave and deformed.

The invention belongs to the field of garbage incineration boilers and particularly relates to a fluidization feeding device for a fluidized bed boiler. The fluidization feeding device comprises an expansion joint, a feed connecting chute, a feed cavity and a fluidizing device. One end of the expansion joint is connected with a material falling pipe. The fluidizing device comprises a plurality offeed air bellows. The feed air bellows are sequentially fixed to the lower end of the feed cavity in a stepped mode. A membrane water-cooling wall is arranged outside each feed cavity. The feed cavityis provided with a feed port and a discharge port. The feed port is connected with the lower end of the feed connecting chute. The discharge port is connected with the boiler. A plurality of directional wind caps are arranged in the feed cavity and are sequentially fixed to the inner wall of the lower end of the feed cavity in a stepped mode. The lower ends of the directional wind caps are connected with the feed air bellows. The fluidization feeding device is scientific in structure and can make charged garbage fuel keep in a fluidized state and sufficiently receive high-temperature radiantheat in a boiler hearth so as to reduce the water content of the garbage fuel. Meanwhile, the fluidization feeding device is provided with a plurality of cooling facilities which can protect the fluidization feeding device against expansive deformation and cracks due to being superheated.

The invention discloses a high temperature resistant valve-controlled lead-acid storage battery. The battery comprises a shell, a positive plate, a negative plate and an electrolyte, wherein the bottom inner surface of the shell is provided with a plurality of mutually parallel bumps, the shell is further externally provided with a metal groove, the positive plate includes a positive plate grid and a positive active substance, and the positive active substance includes the following components in parts by weight: 900-950 parts of lead powder, 50-100 parts of red lead, 0.5-2.0 parts of colloidal graphite, 0.5-1.5 parts of short fibers, 10-20 parts of 4BS crystal seeds, 85-105 parts of 50% dilute sulfuric acid, 0.5-1.2 parts of stannous sulfate, 0.05-0.5 part of three-layer graphene and 100-115 parts of pure water. The invention further discloses a manufacturing method of the positive plate, which comprises the steps of preparation of lead paste, paste coating, solidification and drying,assembly and formation. According to the high temperature resistant valve-controlled lead-acid storage battery and the manufacturing method of the positive plate provided by the invention, the prepared battery has the functions of heat dissipation and strong battery internal pressure resistance, can prevent the expansion and deformation of the battery shell and has long service life.

The invention relates to a first bonding component and a bonding device. The first bonding component is configured to be thermally bonded to a second bonding component through an annular rubber ring to form a closed space between the first bonding component and the second bonding component, and the first bonding component comprises the following parts: a bonding body, which is provided with a through hole, wherein the through hole runs through the bonding body in a direction from the first bonding component to the second bonding component, so that both ends of the through hole are respectivelycommunicated with the closed space and the outside; and a pressure releasing mechanism capable of movably closing the through hole, wherein when the air pressure in the closed space is greater than the external air pressure, the closed space communicates with the outside through the through hole to achieve pressure releasing, and when the air pressure in the closed space is less than or equal tothe external air pressure, the pressure releasing mechanism closes the through hole. In the above-mentioned first bonding component and bonding device, when the first bonding component and the secondbonding component are thermally bonded through the annular rubber ring, the air pressure in the closed space can be adjusted by the pressure releasing mechanism to prevent the air in the closed spacefrom being thermally expanded, resulting in deformation of the uncured annular rubber ring.

The invention discloses a battery module and a battery pack, and relates to the technical field of batteries. The battery module comprises an end plate assembly and a side plate assembly made of a material different from that of the end plate assembly. The end plate assembly comprises a fixed end plate and a transition connecting frame which are connected with each other; the transition connectingframe is connected to the end of the side plate assembly; and a connecting strap is arranged on the outer surface of the side plate assembly and connected with the transition connecting frame so as to prevent the side plate assembly from expanding. According to the battery module, the end plate assemblies and the side plate assemblies which are made of different materials are adopted; the connecting bridles are arranged to improve the structural strength of the battery module; the structural reliability is improved; machining and manufacturing are easy; and the cost is low.

An energy storage device is provided. In one embodiment, the energy storage device includes an energy storage chamber containing an electrolyte, a flexible package packaging the energy storage chamber, a set of electrodes contacting with the electrolyte and extending from the interior of the energy storage chamber to the exterior of the flexible package for electrical connection, a first pipe extending from the interior of the energy storage chamber to the exterior of the flexible package, and a second pipe extending from the interior of the energy storage chamber to the exterior of the flexible package, and the electrolyte is conducted to the interior of the energy storage chamber through the first pipe, and the electrolyte and gas produced inside the energy storage chamber are exhausted through the second pipe. A system and a fabricating method are also provided.

The invention discloses a battery pole piece group fixing frame, which is characterized in that the battery pole piece group fixing frame includes a bottom plate and an upper cover, the lower surface of the bottom plate and the upper surface of the upper cover are provided with elastic sheets and reinforcing ribs, and the upper cover also There are grasping jacks and through holes, and the bottom surface of the bottom plate is also provided with bottom plate concave holes. The connection mode of the bottom plate and the upper cover is a buckle connection or an external clamping device connection. The material of the bottom plate and the upper cover is aluminum, nickel, poly Propylene, polyethylene and other materials. The invention also discloses a battery provided with the fixing frame of the cell pole piece group. The invention can prevent the dislocation and spacing increase of the battery pole pieces during the production and assembly process of the battery pole piece group, prevent the expansion and deformation of the battery case, and ensure that the battery has excellent electrochemical performance. In addition, the present invention can also ensure that different types of batteries have efficient assembly process and production consistency, improve the assembly accuracy and production efficiency of batteries, and reduce the manufacturing cost.

The invention relates to a woodenware waterproof rubber paint comprising the components of: 100 parts of styrene butadiene rubber, 7 parts of toluene diisocyanate, 18 parts of polyvinyl alcohol, 4 parts of aluminum powder, 12 parts of ethylenediamine, 6 parts of sulfur, 8 parts of barium stearate, and 4 parts of the epoxy plant oil. The paint has the advantages that: as a result of industrial tests, when the paint is used for coating the surface of a wood material, a formed styrene butadiene rubber waterproof coating can effectively isolate the contact of the material with external water, such that wood material swelling, deformation, or rot are avoided. The paint also has good construction performance. The paint is environment-friendly, and has the advantages of no pollution and cheap raw materials.

The invention provides a manufacturing method of a composite board, comprising the following steps: hot-pressing straws into straw boards for use; uniformly coating hot-melt adhesive on both sides of the straw boards; covering the hot-melt adhesive with metal mesh; entering into a roller press, Heating to 180-220°C and rolling repeatedly, the number of times of rolling is not less than 3 times; the outer layer of metal mesh and hot melt adhesive is coated with adhesive, and the outer layer of adhesive is covered with fiberboard; the outer layer of fiberboard is coated with adhesive , and then cover the wooden board, rolling without heating, and the number of rolling is not less than 3 times; the outer layer of the wooden board is painted and dried. The invention can effectively improve the load-bearing capacity of the board, avoid the expansion and deformation of the composite board, enhance the toughness of the board, can replace the pure solid wood board, reduce the deformation probability of the board while maintaining the load-bearing performance of the board, gradually reduce the usage of the solid wood board, and protect the environment .

The invention provides a novel sealing ring for a roller bit. The novel sealing ring comprises a sealing ring body, a first projection and a second projection, the first projection and the second projection are positioned on the sealing ring body and close to one end of the sealing ring body and obliquely face the inner side and the outer side of the sealing ring respectively, a first concave structure is formed between the first projection and the second projection, and a second concave structure is arranged on the side surface of the sealing ring body. The sealing ring is provided with the first concave structure, so that the sealing ring has elastic margins, expansion deformation of the sealing ring is avoided, sealing performance of the sealing ring is improved, the sealing ring is provided with the second concave structure, more lubricating oil can be stored, good lubricating function is achieved, sludge cannot enter a sealing surface by the aid of the first projection and the second projection, so that the sealing ring is durably protected, and the service life of the sealing ring is prolonged.