1660 results about "Back pressure" patented technology

Embodiments include a choke system that passes enlarged debris despite having a relatively small diameter for an input port of the choke system. Embodiments also include systems to prevent dislodging of a choke seat when backpressure is supplied to the choke system. Embodiments also include sealing systems to prevent fluid leaks around the choke seat of the choke system.

The intelligent control method comprises the steps that a plurality of sensors and frequency converters are installed and used for monitoring the air temperature and humidity, the moisture content and the front-back pressure difference of a fresh air filter in real time; regulating and controlling the rotating speed of an air feeder, the rotating speed of a regeneration fan and the rotating speed of a rotating wheel through a frequency converter, obtaining sensor data under corresponding rotating speeds, and establishing an air supply quantity model, a fresh air quantity model and a rotating wheel dehumidification quantity model; the power of an air feeder, the front-back pressure difference of a fresh air filter and air parameter data are collected in real time, and the current dehumidification load is calculated according to a fan air supply amount model, a fresh air amount model and a preset formula; and selecting a preset control strategy to dynamically adjust the rotating speed of the rotating wheel, the rotating speed of the regeneration fan and the regeneration temperature according to the current dehumidification load and / or the rotating wheel dehumidification amount model so as to realize indoor humidity control. Start and stop can be automatically controlled and the dehumidification amount can be matched according to the actual wet load, excessive dehumidification or idle work is avoided, and the dehumidification efficiency is improved through multi-parameter cooperative control.

The invention provides a backpressure adjusting method and device for a natural ventilation direct air cooling system, and the method comprises the steps: obtaining the current backpressure of a steam turbine, and executing an up-cut step sequence when the current backpressure is greater than a set backpressure first preset difference value, and the up-cut step sequence comprises the steps: setting a first target sector as a new commissioning sector, and setting a second target sector as a second commissioning sector; the control mode of the shutter opening degree of the new commissioning sector is set to be automatic adjustment within the first preset opening degree range; when the current back pressure is smaller than a second preset difference value of the set back pressure, a down-cut step sequence is executed, and the down-cut step sequence comprises the step that the control mode of the shutter of the second target sector is automatically adjusted in the first preset opening degree range from the second preset opening degree range to the second preset opening degree range till the second target sector quits operation. By controlling the automatic switching of the sectors and the automatic adjustment of the opening degree of the shutter, the automatic adjustment of the back pressure is realized, the automation degree of the back pressure adjustment is improved, the precision and efficiency of the back pressure adjustment are further improved, and the efficiency of the generator set is improved.

The invention discloses a polishing device and a polishing method for an inner curved surface of a steel casting, and relates to the technical field of cast steel production. The device comprises a main body frame and a polishing device, wherein the main body frame comprises a mounting table arranged on the main body frame; the stirring mechanism comprises a plurality of profiling plates which are mounted on the mounting table and used for stirring abrasive particle flow in the casting blank, and a plurality of rotating wheels are rotationally mounted on the inner wall of each profiling plate; the back pressure mechanism is used for driving the profiling plate to enter the casting blank; the rotating wheel is driven to rotate through resistance of abrasive particle flow, so that the abrasive particle flow completes switching between the distance from the abrasive particle flow to the central axis of the casting blank, and meanwhile, in the revolution process of the profiling plate, the abrasive particle flow in the casting blank is extruded up and down in a reciprocating mode through the action of a reciprocating mechanism; and the abrasive particle flow circularly polishes the inner wall of the casting blank up and down, so that the purposes of fully switching and contacting the abrasive particle flow and the inner wall of the casting blank, ensuring the polishing quality and improving the polishing efficiency are achieved.

The invention discloses a high-temperature supercritical carbon dioxide steady-state jet flow experiment device and method, and the device comprises a liquid storage tank, a liquid booster pump, a plunger pump, a first mass flow meter, a second mass flow meter, a heating section, a first electric control valve, a first-stage cooler, a second-stage condenser, a back pressure valve, and a main loop system composed of related pipe fittings and equipment. The gas supply system consists of a carbon dioxide gas cylinder group, a gas storage tank, a gas booster pump and related pipe fittings and equipment; and the jet experiment section consists of a spray pipe, a second electric control valve, an electric stop valve and related pipe fittings and equipment. The invention further provides an experimental method of the device. According to the invention, the steady-state jet flow experiment research of supercritical carbon dioxide under the high-temperature condition can be realized.

The invention provides an abrasive flow polishing device and method for gear tooth surface homogenization. According to the method, tooth-shaped drainage pieces with the same shape as the gear are installed at the two ends of the upper portion and the lower portion of the gear, drainage section design is introduced, an abrasive flow medium path runner model is constructed, main parameters influencing an experiment are sampled and grouped through a Latin hypercube sampling method, abrasive flow polishing simulation is conducted in a grouped mode, and a Gaussian regression process is utilized to obtain an abrasive flow polishing simulation result. Selecting the minimum root-mean-square error of each group of PiVi data, determining the group of experimental parameters, obtaining a group of abrasive flow machining process parameters of optimal inlet pressure, back pressure and drainage section length, and finally guiding the experiment; according to the method, the influence of the inlet effect is relieved, the abrasive flow medium path runner model is constructed, a set of optimal abrasive flow machining process parameter combination is obtained, and the method is suitable for spur gears and bevel gears and high in universality.

The invention discloses a system and method for testing flow, displacement and hydraulic power of a main valve element. The system comprises two displacement sensors, a tested balance valve and a hydraulic testing assembly. A main valve core and a pilot valve core of the tested balance valve are coaxially and oppositely arranged; the two displacement sensors are coaxially fixed with the main valve core and the control piston respectively; the hydraulic test assembly detects the pressure of an oil return port A, a load oil port B, a feedback spring cavity pressure measuring port Pc and a pilot oil inlet X through pressure sensors; the load pressure, the pilot pressure and the oil return back pressure are controlled through a main load oil way, a pilot control oil way and an oil return back pressure oil way respectively, and meanwhile the flow of the oil return is measured through a flow meter. According to the invention, the flow, displacement and hydraulic force of the main valve core under different working conditions can be synchronously and dynamically measured.

The invention discloses a method for evaluating forced vibration stress of a blisk, which relates to the technical field of aero-engines and comprises the following steps: constructing a single-sector finite element model of the blisk and a multi-stage single-channel model of a gas compressor, and carrying out modal analysis containing prestress to obtain a Campbell graph of the blisk, a dangerous mode and a dangerous rotating speed; the method comprises the following steps: calculating steady flow fields of different back pressures at dangerous rotating speeds to obtain working points, respectively carrying out nonlinear harmonic method oscillation flow field calculation and nonlinear harmonic method static interference unsteady flow field calculation at the working points to respectively obtain aerodynamic damping and wake excitation, carrying out dot product on the wake excitation and a dangerous mode to obtain modal force, and carrying out nonlinear harmonic method oscillation flow field calculation and nonlinear harmonic method static interference unsteady flow field calculation on the modal force. And calculating forced vibration complex stress response by adopting a modal force method based on the aerodynamic damping and the modal force so as to obtain real stress response and maximum vibration stress thereof. The blisk forced vibration stress assessment method provided by the invention has important engineering significance for improving the design level and test guidance capability of the blisk.

The invention provides a compressor pressure relief structure, a compressor and an air conditioner. The compressor pressure relief structure comprises a first-stage compression assembly and a second-stage compression assembly. A first pressure relief channel is formed in the partition plate assembly, an assembly avoiding groove and a second pressure relief channel are formed in the second-stage air cylinder, at least part of structure of an opening and closing element is arranged in the assembly avoiding groove, and the opening and closing element can move in the assembly avoiding groove and the second pressure relief channel so that the second pressure relief channel can be communicated with or disconnected from the first pressure relief channel; the opening and closing element comprises a first end and a second end which are opposite to each other, the first end is opposite to the first pressure relief channel so as to bear the gas pressure of the first pressure relief channel, the second-stage air cylinder is further provided with a first back pressure channel, and the first back pressure channel can introduce exhaust gas of the compressor into the assembly avoiding groove; and the pressure acts on the second end so as to apply pressure to the second end. According to the compressor, the technical problem that in the prior art, a rivet pressure relief valve plate structure is adopted for a compressor, and flutter occurs can be solved.

The invention discloses a self-adaptive test system and method for a hydraulic power unit, and the system comprises a test bench which is provided with a fixing tool for fixing the tested hydraulic power unit; the oil tank unit is arranged in the test bed and is used for supplying oil to and pumping oil from the tested hydraulic power unit; and the counterweight test unit is arranged in the test bench, the counterweight test unit comprises a counterweight module, and the counterweight module is connected with a working oil port of a tested hydraulic power unit through a first oil path. The device is simple in structure, directly simulates the real gravity load borne by the hydraulic execution mechanism through the counterweight module, and can accurately test the lifting and descending dynamic performance and the pressure maintaining internal leakage characteristic of the power unit under the load condition. The problems that a traditional back pressure method cannot truly simulate the gravity load, and descending speed control and energy recovery performance are difficult to evaluate are effectively solved.

A rock housing for horizontal directional drilling machine includes a cylindrical housing body with walls defining a longitudinal cavity. A bearing assembly is provided as a part of the housing and is located above a bit box region of the housing. The bearing assembly is lubricated by drilling mud which flows through the drill string of the drilling machine, which mud flow is normally used for cooling the drill bit and removing cuttings. A portion of the drilling mud is diverted and passes through a gap formed between the bearing races of the bearing assembly, the gap being sized so as to create the necessary back pressure to divert the needed flow of drilling mud to the assembly.

The utility model relates to the technical field of steam turbines, and discloses a thermodynamic system of a coupling back pressure turbine for wide-load peak regulation, which is provided with a boiler, a back pressure turbine, a high-pressure cylinder, an intermediate-pressure cylinder, a low-pressure cylinder, a generator and a recovery mechanism, the boiler is respectively connected with the back pressure machine, the high-pressure cylinder and the intermediate-pressure cylinder; the back pressure machine is connected with the high-pressure cylinder; the medium-pressure cylinder is connected with the low-pressure cylinder; the low-pressure cylinder is connected with the generator; the recycling mechanism is connected with the low-pressure cylinder and the boiler and used for condensing steam discharged by the low-pressure cylinder and recycling and conveying the steam to the boiler. In a high-load operation state, the thermodynamic system, the back pressure turbine and the high-pressure cylinder operate in parallel, and the boiler conveys steam to the back pressure turbine and the high-pressure cylinder. In the thermodynamic system in a low-load operation state, the back pressure machine and the high-pressure cylinder are connected in series for operation, the boiler conveys steam to the back pressure machine, and the back pressure machine conveys steam to the high-pressure cylinder. According to the utility model, the pressure of steam entering the steam turbine during low-load operation can be improved, and the feed water temperature and the operation economy can be improved.

The invention relates to an intelligent detection method and system for the compactness of a railroad bed, and belongs to the technical field of railroad bed construction.The intelligent detection method for the compactness of the railroad bed comprises the steps that meshing processing is conducted on a target compaction area; when the road roller carries out compaction, the compaction performance index of the current compaction grid is obtained; judging whether the compaction performance index is smaller than a target compaction performance index or not; if yes, triggering back pressure processing; if not, obtaining a uniformity index of the current compaction grid; judging whether the uniformity index is smaller than a target uniformity index or not; if yes, triggering an abnormal mark; in the compaction process, whether the abnormal mark continuously appears L times or not is judged; and if yes, triggering local replacement filling early warning. The method has the beneficial effects that the compaction detection efficiency is improved, and the safety of railway operation is improved.

The present invention provides a scroll compressor floating back pressure structure, a scroll compressor, and an air conditioner, wherein the scroll compressor floating back pressure structure comprises a crankshaft, a movable scroll plate, and an upper bracket, wherein the movable scroll plate has a movable plate bearing seat, the crankshaft has a crankshaft eccentric portion which can be rotatably inserted into the movable plate bearing seat, the upper bracket is configured with a sleeve matching hole, and further comprises a balancing sleeve, the balancing sleeve has an inner hole and an outer circle, wherein the movable plate bearing seat can be rotatably inserted into the inner hole, the balancing sleeve can be rotatably inserted into the sleeve matching hole, the center of the outer circle coincides with the rotation center of the crankshaft, and the center of the inner hole does not coincide with the center of the outer circle, and a sealing ring is provided on the axial end face of the balancing sleeve, the radial inner region of the sealing ring has a refrigerant of a first pressure, and the radial outer region has a refrigerant of a second pressure, and the first pressure is greater than the second pressure. According to the present invention, the stability of the movable plate movement is improved, end face leakage is avoided, and the performance of the compressor is improved.

According to the method and system for calculating the efficiency of the low-pressure cylinder of the steam turbine on line, under the reference working condition and multiple working conditions, parameters such as steam pressure, temperature and back pressure of an inlet and an outlet of a first stage, a second stage and a third stage of the low-pressure cylinder are collected, the efficiency of each stage and the efficiency of the low-pressure cylinder are calculated, dimensionless processing is carried out, and the efficiency of the low-pressure cylinder is calculated; and establishing a multiple regression model which takes the superheated steam stage efficiency as an independent variable and takes the low-pressure cylinder efficiency as a dependent variable. And considering the influence of the back pressure on the efficiency of the low-pressure cylinder, establishing a compensation model, and correcting the predicted efficiency of the low-pressure cylinder. In actual operation, the parameters are collected in real time, the efficiency of the current stage is calculated and substituted into the regression model and the compensation model, and the real-time efficiency of the low-pressure cylinder is obtained. According to the method, direct measurement of wet steam parameters is avoided by utilizing superheated steam stage data which are easy to obtain, real-time and accurate calculation of the efficiency of the low-pressure cylinder under different working conditions is realized, and the method can be widely applied to performance monitoring, operation optimization and fault diagnosis of a turboset.

The utility model relates to a dynamic and static pressure mixed thrust bearing structure which comprises a back plate, the back plate is of a hollow cylinder structure, a plurality of fan-shaped bosses are evenly distributed on the front face of the back plate at intervals in the circumferential direction, a gasket and a bottom foil are arranged between every two adjacent fan-shaped bosses, fan-shaped flat foils are arranged on the gaskets and the bottom foils, and pressure equalizing grooves are formed in the fan-shaped bosses. The pressure equalizing groove is an arc-shaped groove, air outlet holes are formed in the pressure equalizing groove, the air outlet holes are connected with air inlet holes through air supply flow channels, the air supply flow channels are located in the back plate, and the air inlet holes are located in the outer wall of the back plate. The dynamic and static pressure hybrid bearing provided by the utility model is of a multi-tile structure, and the flexible foils and the steps with the air inlet holes are distributed in a staggered manner. The working back pressure of the bearing can be improved through external high-pressure air supply of the air inlet holes, the dynamic pressure effect is improved, abrasion of the bearing during starting and stopping is avoided, and therefore the bearing capacity and rigidity of the bearing are improved.

The invention discloses a hole slag back pressure backfilling and roadbed structure integrated construction technology, and belongs to the technical field of road construction. Comprising the following steps: grading and screening the tunnel hole slag into large / medium / fine three-level aggregate, and then crushing and recombining to form graded improved aggregate; constructing a multi-layer backfill structure of a base layer, a transition layer and a reinforcing layer; interface shear strength is achieved through the gravel-geogrid composite transition layer; adopting a vibratory roller to implement a static pressure and vibratory rolling combined process with adaptive levels; a coarse / fine-particle-size two-stage cement stabilized macadam layer is laid on the top to form a permeation drainage channel, and a transverse drainage blind pipe system is arranged to achieve three-dimensional drainage. According to the technology, the problems that in traditional hole slag backfilling, aggregate grading discreteness is large, shear failure is likely to be caused by sudden change of interlayer modulus, interlayer combination weakening is caused by uneven layered rolling energy transfer, and structure instability is caused by pore water pressure accumulation are solved, and hole slag resource utilization and roadbed structure performance collaborative improvement are achieved.

The invention provides a jet nozzle aerodynamic characteristic modeling and optimizing method, and belongs to the technical field of aero-engines, and the method comprises the steps: determining a function relationship between an area ratio and a Mach number according to an isentropic flow theory, and taking the function relationship as a nozzle aerodynamic characteristic basic model; on the basis of different pressure ratios, the flowing state in the spray pipe is divided, and multiple working conditions and state parameters under all the working conditions are obtained; a nozzle model is constructed based on the nozzle aerodynamic characteristic basic model and the state parameters under all the working conditions, input parameters include total pressure, external back pressure, throat area and outlet area, and output parameters include Mach number, airflow velocity, temperature and flow under all the flowing states; performing multi-working-condition simulation verification on the spray pipe model; and checking the precision of the spray pipe model, and applying to an actual spray pipe control system for working condition judgment. By means of the processing scheme, the performance prediction and control precision of the spray pipe system in a high-altitude simulation test and practical application is improved.

The embodiment of the invention relates to the technical field of steam turbine cold end optimization, in particular to an air cooling unit spray cooling cooperative control method and device, equipment and a medium. And the spraying cooling amount needed for achieving the target back pressure is calculated based on a thermodynamic characteristic model, so that a feedforward spraying water amount control scheme is formulated, the predicted working condition and the spraying scheme are comprehensively considered, the rotating speed of the air cooling fan is optimized and set through a decision optimization model, and cooperative control over the fan and a spraying system is achieved. By means of the method, advanced and accurate control over the spraying water amount and the rotating speed of the draught fan is achieved. The collaborative optimization strategy ensures that the system can operate in an economic mode under different working conditions, that is to say, on the premise of meeting the backpressure constraint, the overall economic operation level of the system is remarkably improved while safe and efficient operation of a unit is ensured by weighing the fan power consumption cost and the spraying water consumption cost.

The invention belongs to the technical field of thermal generator set automatic control, and particularly discloses a BEST double-machine regenerative thermal power plant converter load shedding automatic control method which comprises the steps that the shaft power of a steam feed pump and the shaft power of a small generator are determined; according to the sum, the pre-action opening degree of a BEST feed pump turbine steam inlet adjusting valve after the converter is subjected to load shedding is determined; predicting the rising rotating speed of the BEST steam feed pump set according to the rotating speed of the BEST steam feed pump set; and a steam feed pump minimum flow recirculation valve control method and a BEST feed pump turbine backpressure control method are started, and a rotating speed control method of the BEST feed pump turbine is determined according to the control method. According to the method, the rotating speed fluctuation process of the BEST steam feed pump set is shortened, the fluctuation amplitude of the boiler inlet feed water flow is reduced, and the stability and safety of the whole set after load shedding of the converter are guaranteed.

The invention discloses a hydrogen compressor test device and a test method.The test device comprises a gas storage bottle set, two inlet buffer tanks, two testers, two outlet buffer tanks and a back pressure valve which are sequentially communicated through pipelines, and the inlet buffer tanks and the testers are connected in parallel; outlets of the back pressure valves are communicated to the two groups of inlet buffer tanks, and the two groups of back pressure valves are arranged in parallel; the pipe diameters of the inlet pipelines and the outlet pipelines corresponding to the inlets and the outlets of the two groups of testing machines are different, so that the displacement is controlled according to the pressure. The system has the characteristics of wide working condition, high pressure, large discharge capacity, automatic control and gas recovery, can monitor performance parameters such as temperature, pressure, discharge capacity and the like in a platform operation process in real time, meets the requirements of various hydrogen energy compressor type tests, predelivery tests and scientific research tests, and provides support for design, simulation and performance evaluation of a unit.

The invention relates to the technical field of petroleum engineering, in particular to a device and method for testing migration of a proppant in a shale reservoir, and the device comprises a model system, an injection system, a vacuumizing system, a pressure field measurement system, a differential pressure measurement system, a back pressure system and a data acquisition and processing system. The model system comprises a model box, a test bin is arranged in the model box, and the test bin penetrates through the side wall of one side in the width extension direction of the model box; the pressing plate can completely cover the test bin and is detachably connected with the model box; the two fluid conveying assemblies are arranged at the two ends of the model box in the length extension direction respectively, the structures are in mirror symmetry, each fluid conveying assembly comprises a first connecting pipe, and the first connecting pipes are communicated with the testing bin. According to the device and the method, different-width fracture and netlike fracture forms of the shale reservoir can be simulated, and the migration rule of shale reservoir fracturing fluid carrying sand in the fractures can be analyzed.

The invention relates to the technical field of thermal power generation, in particular to a closed circulation cold end optimization method, device and system, and the method comprises the following steps: obtaining the historical operation data of a unit from a power plant monitoring information system, the data comprises circulating water flow, circulating water inlet temperature, circulating water outlet temperature, condenser backpressure water pump motor current, generator power, medium and low pressure heat supply steam flow, condenser steam-water temperature and condenser water inlet and outlet pressure; s2, performing abnormal value processing on the data obtained in the step S1, namely screening out an abnormal value, and repairing and filling the abnormal value by using an interpolation method; based on the actual condition of the power plant, the unit load and the steam admission amount of the condenser are fitted through a large amount of historical data in the step S2; the total power for starting different numbers of circulating water pumps and fans and the water flow corresponding to the circulating water pumps are determined according to the historical data in the step S2; respectively establishing a condenser model and a cooling tower model; constructing a circulating cooling system model, coupling the condenser model and the cooling tower model, carrying out iterative calculation until convergence or reaching the maximum number of iterations, and obtaining the condenser outlet water temperature, the cooling tower outlet water temperature, the condenser back pressure, the vacuum degree and the power generation power; fitting a correction coefficient curve by referring to the technical specification of a power plant and combining the historical data in the step S2 with the condenser backpressure-generated power correction coefficient graph; and calculating the generated power and the net output power according to the unit load and the auxiliary machine consumption, and outputting an auxiliary machine configuration scheme corresponding to the maximum net power.

To provide a technique capable of reducing an axial size of a rod.SOLUTION: A buffer includes: an adjustment valve 41 that is disposed on a first communication passage for communicating a first chamber Y1 and a second chamber Y2 and opens the first communication passage when second pressure that is pressure of the second chamber Y2 is higher than first pressure that is pressure of the first chamber Y1; a float valve 52 that is provided on the second communication passage formed around a rod 20 and communicating the first chamber Y1 and the second chamber Y2, that closes the second communication passage and is elastically deformed so as to increase volume of a pressure adjustment chamber 500 for generating back pressure relative to the adjustment valve 41 when the second pressure is higher than the first pressure and that opens the second communication passage when the first pressure is higher than the second pressure; a formation member 48 that forms the pressure adjustment chamber 500 together with the float valve 52; and a nut 49 that regulates the elastic deformation of the float valve 52. An inner peripheral part of the float valve 52 is sandwiched between the formation member 48 and the nut 49.SELECTED DRAWING: Figure 2

The invention discloses a control method and device for a variable-frequency fan of an extractor hood, the extractor hood and a storage medium. The control method comprises the steps that first back pressure borne by the extractor hood during operation is obtained, and the air volume of the variable-frequency fan of the extractor hood under the first back pressure is obtained; a target backpressure interval where the first backpressure is located is determined from a plurality of preset backpressure intervals, a plurality of operation frequency adjusting curves correspondingly associated with the target backpressure interval are obtained, and the operation frequency adjusting curves are used for adjusting the operation frequency of the frequency conversion draught fan; according to the air volume and the first back pressure, a target operation frequency adjusting curve of the frequency conversion fan is determined from the multiple operation frequency adjusting curves; and the operation frequency of the frequency conversion fan is adjusted according to the target operation frequency adjusting curve. According to the embodiment of the invention, the variable-frequency fan of the range hood is controlled more accurately, and the oil smoke suction effect of the range hood is improved.

The invention discloses an air lift system and an air lift method for seabed ore, the air lift system comprises a lift pipe and an air compressor, a compressed air outlet of the air compressor is connected with the lift pipe through an air transmission header pipe, and an outlet of the lift pipe is connected with a backpressure cylinder; when the lifting pipe discharges solid-gas-liquid three-phase fluid into the back pressure cylinder, first pressure is kept in the back pressure cylinder, the first pressure is positive pressure, a gas outlet is formed in the back pressure cylinder, and a gas outlet is formed in the back pressure cylinder; and a first valve used for adjusting the first pressure in the backpressure cylinder so as to control the flow velocity of the solid-gas-liquid three-phase fluid in the lifting pipe is arranged at the gas outlet. According to the pneumatic lifting system and method, the back pressure cylinder is additionally arranged at the outlet of the lifting pipe of the pneumatic lifting system, expansion of compressed air is reduced, and the flow speed of solid-gas-liquid three-phase fluid at the outlet of the lifting pipe can be greatly reduced.

The invention relates to the technical field of non-electrical variable control or regulation systems, and discloses an exhaust gas aftertreatment flow channel back pressure dynamic regulation method, which comprises the following steps: acquiring a supply source phase reference signal and establishing cyclic mapping; a fluid channel pressure signal pulse range change rate is extracted to determine a feed-forward factor; determining a pressure signal trough interval as an action window; determining a reference amplitude based on the feedback deviation and using a feed-forward factor for compensation to determine a target adjustment instruction; the adjusting mechanism is driven to move in the action window, so that the response peak value is locked in the trough interval, the adjusting action is locked in the low-energy phase, kinetic energy intervention of fluid pulses on the adjusting mechanism is avoided, and mechanical abrasion is reduced; pulse characteristic feed-forward compensation is utilized to enable an adjusting instruction to sense the trend of a flow field, the response speed is increased while a signal is smoothed, and pressure balance under the transient working condition is maintained.

The invention relates to the technical field of automatic control, and discloses an automatic control method and system for bearing grease injection. The method comprises the steps that weight data in the grease injection process are collected, a weight change curve is obtained after filtering, and the flow pulsation amplitude is calculated; when flow pulsation is abnormal, pump cavity volume and pipeline impedance parameters are obtained, pump speed correction is calculated based on pressure feedback, the pump rotating speed is adjusted, and preliminary stable flow is obtained; the state of the servo system is monitored based on the initial stable flow, if the resonance peak value exceeds the limit, servo parameters are optimized, the pumping pressure is adjusted in combination with a temperature compensation mechanism, and a compensation pressure signal is obtained; the overshoot of the pressure signal is evaluated, if the overshoot exceeds the limit, the control parameters are adjusted, the pressure deviation is corrected, a final grease injection instruction is generated in combination with backpressure suppression, precise grease injection is executed, and the weight accumulation change is monitored to judge the completion state; and the deviation between the actual total grease injection amount and the target amount is calculated, the current parameter is recorded as the initial set value of next grease injection if the precision reaches the standard, and the control precision of the grease injection process is improved.

The independent control hydraulic system of the ultra-large mining excavator comprises a plurality of pump sets, each pump set is connected with a main valve, a plurality of working units are arranged in each main valve, and each main valve is provided with a working unit connected with a movable arm oil cylinder, a bucket rod oil cylinder and a bucket oil cylinder. The working unit is connected with the left walking motor, the opening and closing bucket oil cylinder, the rotary motor and the right walking motor, and two control ends of the working unit are proportional control ends. According to the independent control hydraulic system of the ultra-large mining excavator and the using method, one pump set controls one set of main valves, independent control over a plurality of working sets of the same executing mechanism is achieved, the oil inlet and return through-flow area requirements can be met at the same time, the speed is guaranteed, meanwhile, back pressure is convenient to adjust, and action smoothness is improved; meanwhile, through independent control of different pump sets and different working sets of the same valve set, independent oil supply of an executing mechanism can be achieved, load difference losses between composite actions are reduced, energy consumption is reduced, and operation efficiency is improved.

The utility model discloses a brake steel back blank pressing device, and particularly relates to the technical field of steel back stamping, in an initial state, a telescopic cylinder is contracted, a push-pull plate is in close contact with an elliptical surface of a connecting seat, an elastic seat is limited to pop up, a torsional spring accumulates force, after a stamping process is completed, a computer controls the telescopic cylinder to extend, the push-pull plate is far away from the connecting seat, and limitation is relieved; the rotating roller rotates under the elastic force effect of the torsional spring to drive the connecting base and the elastic base to move upwards, the elastic base pops up from the stretching-out window and the steel backing is popped up to the bearing frame, the automatic control aspect and the action from the telescopic air cylinder to the ejection of the elastic base are all controlled by a computer, manual intervention is reduced, the production accuracy and efficiency are improved, and an operator only needs to set and debug in the early stage; the push-pull plate and the telescopic air cylinder are combined to guarantee that ejection of the elastic base is limited during stamping, the elastic base can be smoothly ejected after stamping, a plurality of steel backs are stamped at a time and collected in a centralized mode, the carrying and equipment starting and stopping frequency is reduced, the working intensity of operators is reduced, and the production benefit and quality are comprehensively improved.