161results about How to "No maintenance required" patented technology

The invention relates to an air intake manifold with an integrated air track, which comprises an air throttle (1) of an air inlet of an engine, a resonant cavity (2) of the air intake manifold, a plurality of branch pipes (3) of the air intake manifold, and a connecting flange (4), wherein the air throttle (1) at the upper end of each branch pipe (3) of the air intake manifold is communicated with the resonant cavity (2) of the air intake manifold; and air outlets at the lower parts of the branch pipes (3) of the air intake manifold are respectively connected with cylinder covers through the connecting flange (4). The air intake manifold is characterized in that the air intake manifold further comprises the air track (5) and a plurality of air track connecting branch pipes (6), wherein the air track connecting branch pipes (6) are corresponding to the branch pipes (3) of the air intake manifold one to one; and the air track (5) is communicated with the lower end of each branch pipe (3) of the air intake manifold through the corresponding air track connecting branch pipe (6). When the air intake manifold is fully loaded, resonance effects achieved at low rotating speeds and trough rotating speeds can be optimized, so that the air intake quantity is increased; when the air intake manifold is partially loaded, pumping loss of the engine is decreased, the fuel consumption rate is reduced, and the requirements for buses in different working conditions can be satisfied.

The present invention relates to a decomposition treatment method of organics refuse and organics refuse thermal decomposer, belonging to a method capable of utilizing corona hot plasma reaction to make decomposition treatment and its equipment. Said equipment includes an iron tank, its interior bottom portion is equipped with electricity-releasing material and permanent magnet, on the side wall of said iron tank several air magnetizers capable of generating negative ions and air flow regulating valves are set. Besides, said invention also provides its working principle and concrete operation method.

A wear member includes a pair of legs defining a slot straddles the digging edge of a piece of excavating equipment. In one construction, the slot is formed at its front end with a pair of inclined surfaces and a laterally extending ridge that is fit within a complementary channel on the digging edge. A lock is received within an opening in the wear member to releasably secure the wear member to the digging edge.

The invention provides a production process of an enamel steel plate, comprising the steps of forming, pretreating, ground coat spraying, drying, furnace burning, over glaze spraying, drying, furnace burning and back surface underboarding. The enamel steel plate has the advantages of bright color, even glaze distribution, seismic resistance, noise reduction and long service life, and is safe and environmental-friendly, and can be applied in the industries such as art murals, household enamel products, industries, buildings and the like. The enamel steel plate in the invention is a compound material which is formed by the steps that a high quality steel plate as a substrate is processed by a static dry method and then is burnt with inorganic nonmetallic material at high temperature so that tight chemical bonds are between the high quality steel plate and the inorganic nonmetallic material generate, and the enamel steel plate is a perfect combination of metals and inorganic materials. The enamel steel plate has flexibility of a steel plate substrate and also has the characteristics of acid-base resistance, endurance, non-combustion, safety, environmental protection and the like of an inorganic enamel layer. The enamel steel plate in the invention is static-free and is easy to clean, the enamel surface is fine and smooth, shakeproof, compression resistant and noise resistant and has small possibility of dust accumulation, the service life is long, and the enamel steel plate does not need to be maintained for 50 years under regular atmospheric environment.

The invention discloses a geocell reinforced rubber particles-sand mixture compound shock insulation layer and strip, which belongs to the technical field of structure shock absorbing and shock insulation, and is mainly used for solving the problem of serious destructions of a general multi-story building in an earthquake. According to the invention, the compound shock insulation layer and strip are manufactured by the filling and layered punning of rubber particles-sand mixture mixed by an optimal mix proportion in geocell inner layers; the shock insulation layer is arranged at the bottom of a base; shock insulation strips are arranged on two sides of the base; the geocell is a geotechnique material which can be bought easily and is low in cost; the rubber particles are rubber fragments with certain particle diameters, and are obtained by the mechanical fragmentation of junked tires; the sands are ordinary river sands used for construction. The shock insulation layer and strip have good shock insulation effect, low cost, environmental protection, simple structure, and convenience in construction, and is generally suitable for the compound shock insulation technology of the multi-story building; the technical scheme can effectively solve the problems of bad shock resistance and serious destructions of a low story dwelling in a town, and has a wide application prospect.

The invention relates to a novel air purifying and drying device. The air purifying and drying device comprises an air filtering module, an ultraviolet sterilization module, a freeze drying and dehumidifying module and a negative oxygen ion generating module. The four modules comprise an air filtering sleeve (1), an ultraviolet lamp tube (2), an air pumping fan (3), a freeze dryer heat exchanger (4), a negative oxygen ionizer (5), a chilled water tank (6), a chilled water circulation water pump (7), an installation box (8) on the outer layer of the device and a corresponding control system. The air purifying and drying device integrates a plurality of functions such as filtering, sterilizing, drying and generating negative active ions. The air purifying and drying device has the advantages that the air purifying and drying efficiency is high, machining, installing and debugging are convenient, the air purifying and drying device is convenient to carry, easy to arrange and chemical agent-free, and the air purifying and drying can be widely used in various climatic environments.

The invention discloses an embedded water permeable plate water collection siphon drainage method for side slope ground water interception. A groove is excavated on the upper middle part of a side slope, a water permeable plate is embedded into the groove, ground water on a shallow surface layer of the side slope is introduced into a water collecting pipe at the bottom of the water permeable plate, and the collected ground water is discharged from the surface of the side slope by a siphon. By the method, infiltrated ground water on the upper part of the side slope can be effectively intercepted, the ground water level of a slope body on the downstream side of an interception area is reduced, the construction cost of engineering for keeping the side slope stable is low, the workload of earth-rock excavation related in the treatment process is low, the implementation process of treatment engineering is simple and practicable, the drainage measure is high in reliability and adaptability and is flexibly used, power is not needed in the drainage process, and the drainage process is not required to be frequently managed or maintained.

The invention relates to a cold accumulation type energy-saving air conditioning system and an operation method thereof. The cold accumulation type energy-saving air conditioning system comprises a refrigerating circuit formed by serially connecting a compressor, a condenser, a refrigeration throttling element, and an evaporator through pipes, a cold accumulation box is arranged on a pipe between the condenser and the refrigeration throttling element, a cold accumulation medium and an overcooling heat exchanger are arranged in the cold accumulation box, the overcooling heat exchanger is serially connected with the refrigerating circuit, and the air conditioning system further comprises a cold accumulation circuit for providing the cold accumulation medium with cooling capacity. According to the cold accumulation type energy-saving air conditioning system and the operation method thereof, a control manner is simple and reliable, the cold accumulation box is arranged between the condenser and the refrigeration throttling element, the cold capacity is circularly stored through cold accumulation, and an overcooling degree is provided for circulation of the whole system, so that an energy efficiency ratio is increased; meanwhile, the overcooling degree is not required to be obtained by bypassing partial refrigerants, so that an air suction volume of the compressor is saved, an effective air delivery capacity of the compressor is increased, and the higher energy efficiency ratio is guaranteed.

The invention discloses an automatic drainage anchor rope system for slope protection and a construction method thereof. The automatic drainage anchor rope system has anchor rope reinforcement and drilled hole drainage functions at the same time, the effect that one hole has multiple purposes is achieved, and the slope safety coefficient is greatly increased under the same construction cost. The automatic drainage anchor rope system comprises a drilled hole, a steel strand, an isolating pipe, a water-pervious pipe, a water swelling rubber water stopping ring, a drainage pipe, a protective pipe, cement mortar and an outer anchor head; underground water infiltrates into the gap between the water-pervious pipe and the isolating pipe through a drainage section, so that the water pressure in the gap is increased, when the water head of a water inlet of the drainage pipe is higher than the elevation of an opening of the drilled hole due to the fact that the water level of the underground water rises, the underground water in the gap naturally flows out from the drainage pipe, syphonage is naturally started, and the underground water in a slope is discharged. The drainage work process is conducted circularly along with falling of rain, the pump drainage effect of the drainage pipe changes periodically and circularly, long-time efficient real-time continuous drainage of the system is achieved, and the drainage governance problem of large-scale landslide is solved.

The invention relates to an ultra low temperature cold storage warehouse, which belongs to the technical field of the structure of the cold storage warehouse. The invention is characterized in that the ammonia is used as the refrigerants and a low-temperature evaporator, and a middle-low temperature evaporator are arranged in the preparatory room and the reservoir pool; the low-temperature evaporator is communicated with an air-liquid separating heat exchange air return regulating station, a freezer with a single engine and a low-pressure circulation barrel through an air return regulating station for ammonia, and the liquid of the low-pressure circulation barrel is communicated with the middle-low temperature evaporator and communicated back to the low-pressure circulation barrel through a liquid pump; the low-temperature evaporator enters the low-pressure circulation barrel 6 through a regulating station for ammonia liquid and the air-liquid separating heat exchange air return regulating station is connected with the low-temperature evaporator through the regulating station for ammonia liquid; the gas of the low-pressure circulation barrel is communicated with a freezer with double engines, to an intermediate cooler and communicated back to the freezer with double engines, and the gas of the freezer with double engines is communicated with an oil separator; the output end of the oil separator is communicated with an evaporative cooler and the air-liquid separating heat exchange air return regulating station, and the evaporative cooler is communicated to a liquid receiver for ammonia; the liquid receiver for ammonia is communicated with the air-liquid separating heat exchange air return regulating station, the low-temperature circulation barrel and the intermediate cooler.

The digital label system urban road traffic comprises a RF card label to store address information code composed of absolute location code, relative location logic label code to show distance to coordinate center, natural number code for origin and end of road, and branch road code; a memory to store position, round building, road, and branch road information opposite label code information; and a label set system. Wherein, putting the label continual on road spaced some distance. This system is ordered and convenient to provide traffic information service.

The invention belongs to powder product field, and relates to a medical functional complex material with high curative effect. Said complex material comprises following raw materials: 66-96% of tourmaline ultra-micro powder and / or crystal infrared material ultra-micro powder, 0. 01-30% of dielectric strengthened material and 1-5% of embedding material, soft solid and hard solid material. It is used in the field of health-care, treatment and recovery, and can be used to produce medical apparatus.

The invention discloses a press machine intelligent overload protection device and a control method. The press machine intelligent overload protection device is mainly composed of a detecting part, amechanical executing part, a control part and a feedback part. When a press machine is overloaded, a force sensor transmits a signal to a system controller of the whole machine, the controller enablesthe press machine to stop working and enables a coil winding to be powered off, constraint of magnetorheological fluid from a magnetic field is removed, and the fluidity of the magnetorheological fluid is improved; under the pressure of a spherical support, the magnetorheological fluid passes through a throttling hole and a designed gap to enter an upper cavity, the spherical support and a connecting rod linkage ball fall, and the damage to the press machine due to overloaded blocking run is avoided; and after a crank sliding block mechanism breaks away from a dead area and exits out of the overloaded state, when a stroke switch detects that the spherical support recovers to an original height under the effects of a spring and the self-weight, the coil winding is powered on, a press machine sliding block is adjusted to an upper dead point, the press machine recovers to a normal state, and thus overloaded protection to the press machine is achieved.

The invention discloses an apparatus and method of monitoring unidirectional force by means of liquid mixing color changing. The apparatus of monitoring unidirectional force by means of liquid mixing color changing includes a bearing mechanism, a hydraulic control valve bank and a display mechanism, wherein the bearing mechanism is arranged at the outside of an anchor pole to be measured or a bolt to be measured; the bearing mechanism includes a cylindrical bearing body and a pressure cavity; the display mechanism is a color displaying cavity; the color displaying cavity is arranged in an annular groove at the outside of the bearing body; the hydraulic control valve bank includes a pressure-reducing valve and a non return valve; and the pressure cavity, the hydraulic control valve bank and the color displaying cavity are correspondingly connected one-to-one. The method of monitoring unidirectional force by means of liquid mixing color changing includes the steps: the bearing mechanism converts the axial force of the anchor pole as hydraulic pressure; and the colored liquid reaches the hydraulic control valve through an oil way in the apparatus after being pressurized; and opening or closing of the valve can be controlled in the corresponding pressure, so that injection and discharge of the liquid in the color displaying cavity can be controlled correspondingly and the color of the liquid in the color displaying cavity can be observed to determine the stress condition of the anchor pole. The apparatus and method of monitoring unidirectional force by means of liquid mixing color changing utilize the sensor to perform mass distribution monitoring for the whole anchoring engineering, and do not need maintenance and management, and do not need special people to perform point inspection, thus having great significance.

The invention discloses a household garbage flash mineralization processor, and relates to a household garbage processor. The household garbage flash mineralization processor comprises a furnace body,a feeding system, a slag discharging system, a flue gas purification system and an electric appliance control box, the furnace body comprises a furnace wall positioned at the side part of the furnacebody and a fire grate positioned at the lower part of the furnace body, the fire grate is a movable fire grate capable of rotating by 360 degrees, the fire grate comprises a grate shell, a rotating shaft, a chain wheel, a speed reducing transmission mechanism and a pyroelectric honeycomb ceramic body and a permanent magnet, vent holes are uniformly formed in the grate shell, the rotating shaft penetrates through the grate shell, and the two ends of the rotating shaft can be rotationally arranged on the furnace body, one end of the rotating shaft is connected with the speed reducing transmission mechanism through the chain wheel; the permanent magnet and the pyroelectric honeycomb honeycomb ceramic body are arranged in the grate shell in a spaced mode, the N pole of the permanent magnet isopposite to the S pole, and are grouped interval to establish an original magnetic field. The household garbage flash mineralization processor can realize harmless and daily-production daily cleaningtreatment of garbage, and has the advantages of being safe, clean, high in efficiency, economical, energy-saving, and is very suitable for rural large-scale application.

The invention relates to quick, sensitive and convenient six-in-one test paper for quickly detecting heavy metal residues. The test paper comprises six heavy metal indicators of mercury, cadmium, plumbum, copper, chromium and nickel, and belongs to the field of monitoring of food, the environment and water quality. The test paper comprises two parts namely a paper base and color rendering paper, and is simple in structure and easy to operate; chromatographic filter paper with the thickness of 3 mm is adopted as a carrier, so that the test paper can quickly detect the contents of the six heavy metals, namely, mercury, cadmium, plumbum, copper, chromium and nickel, in food, the environment and water quality within 1-3 min; an accurate quantitive detection conclusion can be obtained depending on visual observation, so that no expensive device is used for displaying the conclusion, and a user can master the operation without specialized training; moreover, the test paper is cheap, low in production cost and single-use, needs no inspection and maintenance, is high in accuracy, good in repeatability, and very suitable for on-site real-time and quick detection and monitoring.

The invention relates to an RGB quantitative quick detecting test paper for formaldehyde residue in food, and belongs to the field of food security detection. The RGB quantitative quick detecting test paper just comprises two parts of a paper base and a developing paper scrap; structure and operation are simple; 3 mm chromatography filter paper is adopted as a carrier; the test paper can conduct quick semiquantitative and RGB quantitative detection on formaldehyde residue in 8-10 min; accurate quantitative detection conclusion can be acquired by observing by eyesight or reading RGB of the test paper color; a precious instrument is not needed to display; a user can grasp the test paper without special training; meanwhile, the test paper is cheap in price and low in manufacturing cost, is disposable without inspection, repair and maintenance, and is relatively high in degree of accuracy, good in repeatability, and very suitable for on-site real-time quick detection and monitor.

The invention belongs to a preparation method of an explosion-suppressing material. The explosion-suppressing material comprises the following chemical compositions by weight percent: 0.3-0.5 percent of Si, 0.1-0.3 percent of Fe, 0.15-0.25 percent of Cu, 1.0-1.5 percent of Mn, 1.0-1.5 percent of Mg, 0.1-0.3 percent of Zn, 0.15-0.25 percent of Ti, 0.03-0.06 percent of La, 0.05-0.09 percent of Ce and the balance Al. A grain structure of the explosion-suppressing material is refined by adopting a repeated heating forging and pressing method. The explosion-suppressing material provided by the invention has excellent extrusion resistance, collapse prevention, zero dreg-falling and high-strength explosion-suppressing property. The performance indexes of the explosion-suppressing material, such as strength, plasticity, fracture toughness and fatigue resistance, are greatly increased according to the preparation method; the technology is simple and is easily performed; and the service life of the explosion-suppressing material is prolonged.

The invention belongs to the technical field of smoke denitration (namely NOx removal), and relates to a modular selective catalytic reduction (SCR) denitration rectification grating device, which is characterized in that longitudinal gratings and transverse gratings of rectification modules are in crossed connection mutually to be fixed and have a grid-shaped structure in which a plurality of hollow thin-wall pipes are arranged and connected regularly and mutually, and the axial directions of the hollow thin-wall pipes are consistent with the height directions of the rectification modules; asealing element is divided into an internal sealing element and an external sealing element; the internal sealing element is positioned in gaps among the rectification modules; and the external sealing element is positioned between the rectification modules and the inner wall of an SCR reactor. The invention has the advantages that after smoke passes through the modular SCR denitration rectification grating device, the flow direction and flow speed distribution of the smoke mingled with dust achieve an ideal effect; meanwhile, the dust in the smoke cannot be accumulated on the rectification grating device; and the rectification grating device is easy to manufacture and low in comprehensive investment cost, and is not needed to be overhauled or maintained, the cost of materials is low, andthe flow field performance of the smoke is improved, so the NOx removal performance of the system is improved.

The invention relates to the technical field of electric tools, in particular to a rechargeable electric screw driver. The rechargeable electric screw driver comprises a handle, a screw driver head and a shell, wherein the bottom of the handle is provided with a battery pack and a charger; the battery pack is positioned below the charger; the upper part of the handle is provided with a motor; the motor is connected with the screw driver head through a union joint; and the middle part of the handle is provided with a start switch. The rechargeable electric screw driver has the mandrel locking function; if the start switch is not pressed down, the mandrel is automatically locked; and at this time, even if the battery runs down, the screw driver head can be rotated to rotate the screw. Due to the adoption of high-performance motor without a carbon brush, the invention has excellent durability and does not need maintenance; due to the adoption of motor without a carbon brush, the invention does not discharge substances which affect electronic components; and even if the rechargeable electric screw driver is used continuously, the motor hardly emits heat.

The invention discloses a joint drainage type cement concrete road structure. The cement concrete road structure is formed by splicing a plurality of cement concrete slabs; vertically and horizontally staggered joints are retained among all the cement concrete slabs; and a water collecting aluminum plate which is similar to a groove shape and leads to an edge drainage system is arranged at the bottom of the cement concrete road structure and below all the joints. A construction method of the road structure comprises the following steps of: designing concrete positions of the joints at the construction planning road section; then placing and fixing the water collecting aluminum plate on a road base layer in the corresponding position; constructing on the road base layer paved with the water collecting aluminum plate according to the conventional process to obtain a road structure body; then sawing at the joint positions; and finally, constructing the edge drainage system. The cement concrete road structure of the invention has the advantages of simple structure, convenience of construction, high durability, and the like.

The embodiment of the invention discloses a capacitive touch screen, which comprises a display screen positioned on a lowermost layer and used for displaying images, and a Cover Lens positioned on an uppermost layer and used for protecting a nano-indium tin metal oxide (ITO) sensor, wherein the ITO sensor is positioned between the display screen and the Cover Lens, and is used for sensing a touch point; the Cover Lens is bonded with the ITO sensor through optical clear adhesive (OCA); a hole for accommodating a button icon is formed on the OCA. According to the capacitive touch screen, the technical problem of influence of bubbles produced easily by the attachment of the conventional button icon to the surface of a substrate on the appearance and service life of the touch screen is solved.

The invention relates to electric vehicle charging systems and discloses an electric vehicle charging system based on Internet of things. The electric vehicle charging system based on the Internet of things comprises a power supply device, a charging pile and a charging control terminal. The power supply device comprises a storage battery storing electric energy, a cable connected with the storage battery, and an RFID (radio frequency identification device) chip, and the free end of the cable is provided with a power supply interface; the charging pile comprises a casing, a power supply circuit is arranged inside the housing, the surface of the housing is provided with a power supply socket, and the power supply socket is connected with the power supply circuit and matched with the power supply interface; a charging control module, an RFID identification circuit and a communication module are mounted inside the housing, wherein the charging control module is connected with the power supply circuit to control the operation of the power supply circuit, and the RFID identification circuit is connected with the charging control module; the charging control terminal is communicated with the charging control module through the communication module. The electric vehicle charging system based on the Internet of things can identify the information of the RFID chip of the power supply device to achieve charging and payment settlement of electric vehicles, thereby being safe and convenient to use.

The invention discloses a contaminated soil thermal desorption remediation system and method. The contaminated soil thermal desorption remediation system comprises a contaminated soil thermal desorption device and a tail gas treatment system, wherein the tail gas treatment system is connected with a tail gas exhaust port of the contaminated soil thermal desorption device. The tail gas treatment system comprises a steam filter, a primary condensing device, a vacuum generator, a secondary condensing device, an activated carbon filter and a gas exhaust device which are connected in sequence. Thesystem and the method can significantly reduce the operation energy consumption and repair cost of the system, significantly reduce the maintenance frequency of the system, maintain the safe and stable continuous operation of the system, and improve the thermal desorption effect of the contaminated soil.

The invention relates to two stage rotary mixing equipment for ammonia gas and flue gas in an SCR denitrification system and belongs to the technical field of flue gas denitrification. The equipment is characterized in that: a smoke box is provided at the straight part of an inlet flue, two opposite sides of the smoke box are open to allow the passage of flue gas flow and communication between the smoke box and the inlet flue, and the rest four sides of the smoke box are engaged with the flue, wherein one side perpendicular to flue gas flow direction is provided with ammonia gas jet pipes; planes of mixing plates arranged in the smoke box are inclined relative to the flue gas flow direction at an angle of 45 degrees and are uniformly arranged at one side of the smoke box; ammonia gas jet orifices are arranged to direct to middle and lower parts of the planes. The beneficial effects of the invention are as follows: flue gas is in a state of two rotary flows after passing through two-stage mixing plates and the two rotary flows orthogonally join with ammonia gas from two-stage ammonia gas jet pipes in the same time, forming a strong fluidic crushing effect; therefore, flue gas and ammonia gas are ideally mixed before flue gas enters into an SCR reactor. The mixing equipment provided in the invention has the advantages of simple construction, fast installation, cheap materials, no need for examination, repair and maintenance, and low comprehensive investment cost.

The invention discloses a method and device for turning tiles, belonging to the field of packaging machinery. The device comprises a rack and a tile conveying conveyor belt, and is characterized in that the side of the tile conveying conveyor belt is provided with a tile turning support and a vertical pulling frame; a small shaft is fixed on the vertical pulling frame; the tile turning support can rotate around the small shaft; and the vertical pulling frame is connected with a vertical moving control device. By utilizing the method and device provided by the invention, the tiles can be directly turned on the tile conveying conveyor belt; the tiles move forwards along the conveyor belt in the whole process of turning the tiles, and does not need to wait for being turned, thus saving the tile turning time, and improving the working efficiency of the production line; at the moment that the tiles are pulled out and laid off by the vertical pulling frame, the tile stress is lighter, thus avoiding the damage on the tiles. The parts needed by the invention are not fine products, are low in purchasing cost and use cost, and need not to be maintained; and the method and device provided by the invention can be applied to turn the tiles and other thin-sheet objects.

The invention discloses a highway soil slope flood damage prevention method which includes steps of A1, piling; A2, planting shrub seeds at position which is 2-3cm lower than the ground of a slope; A3, laying local crop straws on the slope uniformly at the thickness ranging from 10cm to 15cm; and A4, covering with a net. After one or two years, the shrub seeds grow, the crop straws are decomposed completely to be a good organic fertilizer, and the organic fertilizer is absorbed and utilized by soil of the slope gradually and is an environment-friendly material. Willow or locust piles driven into the soil can grow and sprout at the probability of 80% at least during construction in spring or autumn, roots of the piles can grow and flourish gradually, then biological 'piles' and landscape 'piles' which grow strongly gradually are formed, and subsequent maintenance is almost omitted.

The invention relates to a roller backstop. The roller backstop comprises a pawl disc and a ratchet disc. The pawl disc comprises a flange, pawls and elastic steel wires. The ratchet disc comprises a backstopping wheel and a backstopping wheel fixing disc. The roller backstop is characterized in that a key groove is opened at a central hole of the flange; the pawls surround the flange circumferentially, one end of each pawl is connected to a position of the front of the flange, which is close to the circumferential edge, a 90-degree tooth opening is formed in the other end of each pawl, and a small hole is formed in one side of each 90-degree tooth opening; the elastic steel wires are arranged at the positions in the front of the flange between the pawls, which are close to the circumferential edge, one end of each elastic steel wire is connected with each small hole in each pawl tooth opening end, and the other end is fixed at the edge of the flange; 90-degree backstopping openings are formed in the edge of the backstopping wheel, and the backstopping wheel and the backstopping wheel fixing disc are welded and fixed in a face-to-face center symmetrical mode. The roller backstop is simple and light in structure and in no need of lubrication or sealing.

The invention provides a construction method of a long and narrow deep foundation pit surrounding system. High-rigidity steel plate piles are adopted as surrounding piles, and are combined with four steel supports including a top ring beam to guarantee safety of a foundation pit; through adoption of such construction resources as recoverable steel plate piles and steel supports, the construction resources are saved, no curing requirement is generated, and the construction period is saved; and the construction time length of the foundation pit surrounding system is an important factor for guaranteeing safety of the foundation pit.

The invention relates to the field of hoisting machinery, in particular to a low-speed outer rotor permanent magnet drive device with a rotating speed of an outer cylinder of 0.001-30r / min. The device comprises brakes, a winding, a permanent magnet, a central shaft, the outer cylinder, an iron core, a bearing, fixed seats and a frequency converter, wherein the brakes are arranged at both ends in the outer cylinder and fixed to the central shaft; the permanent magnet is installed on the inner wall of the outer cylinder; the outer cylinder is fixed to the central shaft by the bearing; the winding is embedded into the iron core; the iron core is installed on the central shaft to be connected into a whole; the central shaft is fixed in the fixed seats at both ends; and the frequency converteris connected with the winding by an output line. The invention has the two characteristics of simple structure and realization of large-torque output under the low speed condition, and also has the advantages of light weight, high reliability, stable running, microseism, low noise, safety, energy saving and long service life.