87results about How to "Reduce overflow loss" patented technology

The invention discloses a rotary energy saving system of an excavator. When the excavator rotates to be started, corresponding flow is supplied according to a demand of a rotary motor, so that overflow loss of the system is reduced. A flow control valve is arranged between an overload buffering valve and an oil tank. In a process of accelerating rotary starting, the flow control valve works in a throttling mode; flow, namely overflow of the system, of the flow control valve is calculated according to pressure at an oil inlet of the flow control valve, and the discharge capacity of a hydraulic pump is adjusted according to the overflow of the system; when the overflow is increased, the discharge capacity of the hydraulic pump is reduced, so that most of the pump output flow is absorbed by the rotary motor, and energy loss is reduced; when the overflow is reduced, the discharge cavity of the hydraulic pump is improved, so that the requirement of the rotary motor can be met; moreover, the inlet pressure of the rotary motor is always kept at an overflow pressure value, and the rotary torque is increased, so that the rotary acceleration performance is guaranteed; and in a process of rotary deceleration brake, the flow control valve works in a direct through mode, so that oil can be normally filled into the rotary motor.

A hydraulic circuit controlling preferred movement of a moveable arm to lift or rotate is disclosed, and comprises a rotary motor (12), and a moveable arm lifting oil cylinder (8); a first hydraulic pump (P1), a second hydraulic pump (P2) and a guide oil pump (P3); a moveable arm control valve (7) located in the downstream of the second hydraulic pump (P2) to control hydraulic liquid which is supplied to the moveable arm lifting oil cylinder (8); a rotary control valve (4) located in the downstream of the first hydraulic pump (P1) to control the hydraulic liquid which is supplied to the rotary motor (12) and / or a confluence valve (11); a preferred valve (13) in the downstream of the first hydraulic pump (P1) for dividing the hydraulic liquid of the first hydraulic pump (P1); an electromagnetic valve (15) in the downstream of the guide oil pump (P3) for switching between the states that a guide control oil path (14) of the preferred valve (13) is communicated with the oil tank or communicated with the guide oil pump (P3); and the confluence valve (11) in the downstream of the rotary control valve (4) for controlling the oil path (1) to be communicated with the oil path (3) or an oil return pipeline.

A control device for a working machine according to the present invention comprises a capacity variable pump for supplying working oil, a controller for controlling the discharge amount of the pump, a control valve for controlling the working oil discharged from the pump, a hydraulic actuator operated by the working oil from the control valve, an operating lever for operating the hydraulic actuator, and a relief valve to be operated when the pressure of the working oil is a relief pressure or more. The controller has a dynamic emulation model of a hydraulic driving device, and is constituted to estimate the pressure oil flow rate passing through the relief valve from the emulation model according to the operation amount of the operating lever, and to control the pump flow rate of the pump so that the relief flow rate estimation value gets close to zero. According to this, relief loss can be precisely reduced without generating a response delay or pressure loss, and the power can be saved.

An electro-hydraulic control system based on frequency conversion type speed regulation is composed of frequency converter used to change rotation speed of pump, motor hydraulic pump, feedback unit for detection, hydraulic control system, energy regualting unit, and controller. The motor and hydraulic control valve are controlled by frequency converter. The electro-hydraulic control valve, energy regualting unit and frequency converter are controlled by controller. Its advantages are high efficiency, saving energy and high response speed.

The invention discloses an aerodynamic layout of a transatmospheric reusable aircraft, which comprises a head, a fuselage, a horizontal wing, a vertical tail, a body flap and a liquid hydrogen / liquid oxygen linear plug-type nozzle rocket engine. The invention has no booster, and adopts a single stage to vertically launch into orbit from the ground; after completing the mission, it can return to the atmosphere and glide horizontally to land, and can be completely reused after recovery. Through reasonable aerodynamic configuration and optimized design, the aircraft has a high lift-to-drag ratio and good stability and maneuverability in a wide range of altitudes and speeds. At the same time, the fuselage has a large effective volume and needs to carry propulsion Dose less. The invention has low launching cost, short launching preparation period and high reliability. It can overcome the shortcomings of current space vehicles that cannot be completely reused, expensive to launch, and cumbersome to use and maintain. It can be used not only for military space missions, but also for commercial and civil space services.

The present invention relates to a new type fork lifter walking speed-regulating equipment, which comprises variable displacement pump and double-speed hydraulic motor communicated with the variable displacement pump by means of reversing valve. It is characterized by that oil outlet of hydraulic pump is connected with oil inlet of high-lower pressure servo pressure-regulating valve, the working oil hole of the high-lower pressure servo pressure-regulating valve is connected with oil intake cavity of variable displacement oil cylinder for regulating displacement of variable displacement pump, and between reversing valve and hydraulic pump a precedence valve is set.

The invention relates to the technical field of drawbenches, in particular to a drawbench hydraulic system. The drawbench hydraulic system comprises a rodless chamber and a rod chamber, wherein the rodless chamber comprises a second installation valve cover, a second directional valve cover, a first cartridge valve, a second cartridge valve, a second overflow valve cover, a second one-way valve cover, a fifth cartridge valve and a sixth cartridge valve, wherein the second installation valve cover is connected with the second directional valve cover, the first cartridge valve is connected with the second cartridge valve, and the fifth cartridge valve is connected with the sixth cartridge valve; and the rod chamber comprises a first directional valve cover, a first safety valve cover, a third cartridge valve, a fourth cartridge valve, a first one-way valve cover, a first overflow valve cover, a seventh cartridge valve and an eighth connection cartridge valve, wherein the first directional valve cover is connected with the first safety valve cover, the third cartridge valve is connected with the fourth cartridge valve, and the seventh cartridge valve is connected with the eighth connection cartridge valve. A pressure regulation system comprising the cartridge valves is applicable to a high flow rate hydraulic system, and the drawbench hydraulic system has the advantages of simple structure of cartridge valves, high flow capacity, fast action response, excellent sealability, no leakage and strong pollution resistance.

The invention discloses a hydraulic energy-saving fuzzy control system for excavators, which comprises a fuzzy controller, a variable displacement pump regulator, a throttle controller, an engine, a pump and a pressure sensor; the fuzzy controller is connected with the variable displacement pump regulator, the variable displacement pump regulator is connected with the pump, the pump is connected with the pressure sensor, the pressure sensor is connected with the fuzzy controller, the fuzzy controller is also connected with the throttle controller, the throttle controller is then connected with the engine, and the engine is then connected with the pump. The hydraulic energy-saving fuzzy control system for excavators increases the energy transfer efficiency of the system, and reduces idle energy consumption inside a hydraulic transmission system.

The invention relates to an energy-saving design method for a variable-load servo control system. According to a hydraulic system designed through the design method, fitting of matched load force is achieved through arbitrary combination of different pressure grades, and throttling losses of a valve port are reduced. Overall management of energy is achieved by means of an energy transmission unit and an energy storage unit. Control is conducted according to the working condition, so that regeneration and recycling of energy are achieved. The transmission efficiency of the system is improved on the premise that the control characteristic is guaranteed.

The invention discloses an electro-hydraulic synchronous uniform loading cutter driving system of a tunneling machine. The electro-hydraulic synchronous uniform loading cutter driving system is characterized in that an ordinary motor is connected with a two-way proportional variable pump; an oil supplementation check valve group, a closed circuit safety valve group, oil openings in the two ends of a flush valve, a reversing valve, a large-drift diameter switching valve and a two-way proportional variable motor are connected in parallel between two oil openings of the two-way proportional variable pump through an isolating switching valve; an oil inlet between two check valves in the oil supplementation check valve group is connected with an oil supplementation system and an oil supplementation pressure limiting valve; an intermediate oil opening of the flush valve is connected with an oil tank through a flush pressure limiting valve; an intermediate oil opening of the reversing valve is connected with an energy accumulator and an electromagnetic proportional overflow valve; the electromagnetic proportional overflow valve and the oil supplementation pressure limiting valve are connected with the oil tank; and the two-way proportional variable motor is connected with a main variable frequency motor and a slave variable frequency motor through a drive system. According to the electro-hydraulic synchronous uniform loading cutter driving system, a motor system and a hydraulic motor system achieve real-time, synchronous and uniform loading drive, the trap escaping ability and adaptability for complex geology of a tunnel tunneling machine are improved, the installing power is decreased, and the energy utilization rate is improved.

The invention discloses an intelligent pump and an active-disturbance-rejection control method thereof. The active-disturbance-rejection control method comprises the steps that the motor rotating speed read from a motor driver is combined with the pressure of a high-pressure outlet measured by a pressure sensor to estimate the load flow, the desired rotating speed is obtained according to the speed corresponding to the load flow and the speed corresponding to the pressure deviation and transmitted to a rotating speed controller, according to the desired torque and the current rotating speed ofan alternating-current permanent magnet synchronous motor, the load torque is estimated by the rotating speed controller, the sum of the current value corresponding to the load torque and the currentvalue corresponding to the speed deviation is taken as a command current, and the command current is sent to the motor driver through a CANopen bus. According to the intelligent pump and the active-disturbance-rejection control method thereof, the outlet pressure of the pump and the output flow of the pump can be controlled according to the actual needs of the load, the overflow loss can be lowered, and oil liquid heating is reduced; the contradiction between the rapidity of pressure control and overshoot is solved; it can also be guaranteed that the performance is controlled under the condition of fast load change; and the contradiction between the excellent control effect and an accurate mathematical model is solved.

The invention relates to an energy storage type hydraulic wind generating set grid-connected rotating speed control system and method and belongs to the technical field of wind power generation technologies. The system comprises a wind turbine part, a hydraulic transmission part, a hydraulic energy storage part and a power generation part, when a wind turbine generator carries out grid-connected rotating speed control, variable pump motor swing angle control is preferred, energy conversion of an energy storage system is controlled, and the rotating speed of a variable motor is rapidly adjustedand stabilized, then a swing angle of the variable motor is controlled through indirect flow feedback and direct rotating speed closed-loop control, accurate control over the rotating speed of the variable motor is achieved, meanwhile, the opening degree of a valve port of a proportional throttle valve is controlled, the rotating speed of the variable motor is finely adjusted, accurate control over the rotating speed of the variable motor is achieved, redundant energy can be dissipated when system energy is excessive, and system safety is guaranteed. The system is advantaged in that through three-variable coordination control, a problem of accurate control over the grid-connected rotating speed of the system can be solved, the energy utilization rate is increased, and safe operation of the system is guaranteed.

A multi associated location electro hydraulic proportional servo system positioning controlling method uses flow proportional valve, so that the rate flowing into the fuel tank is adjusted according to the angle deviation of a camshaft, which overcomes the camshaft displacement frequently moving near the set value and the system vibration resulted by the moving in a former switch valve servo system. Oil source uses double-vane pump and control the working state of two sub-pumps according to specific condition, which reduces the overflow losses of system overflow valve to the largest extent. The present invention improves the system working efficiency, fundamentally resolves the problem of high oil temperature seriously affecting system working reliability in former system and improves the precision of large-scale forging hydraulic distributing machine position controlling system.

The invention provides a closed-type pump-controlled hydraulic system. The closed-type pump-controlled hydraulic system comprises an alternating-current servo motor, a two-way metering pump, two overflow valves and a hydraulic cylinder; an output shaft of the alternating-current servo motor is connected to an input shaft of the two-way metering pump through a coupler; the two-way metering pump is provided with two oil pumping ports including the first oil pumping port and the second oil pumping port, and the two overflow valves are connected to the two oil pumping ports of the two-way metering pump in a crossing mode respectively and connected with the two-way metering pump in parallel; an oil inlet of one overflow valve is connected with the first oil pumping port, and an oil outlet of one overflow valve is connected with the second oil pumping port; an oil inlet of the other overflow valve is connected with the second oil pumping port, and an oil outlet of the other overflow valve is connected with the first oil pumping port; the first oil pumping port of the two-way metering pump is connected to a first cylinder oil port of the hydraulic cylinder through a first oil way, and the second oil pumping port of the two-way metering pump is connected to a second cylinder oil port of the hydraulic cylinder through a second oil way. Therefore, the purpose of saving energy can be achieved by adjusting the rotation speed of the alternating-current servo motor, such as lowering the rotation speed of the alternating-current servo motor.

The invention provides a constant-power control method for equipment mounted on a pure electric compression type garbage truck. The method comprises performing working mode selection through a state signal of a multi-way valve, if a garbage can rises, a scraper plate performs scraping joining or a slide plate performs rising motion, entering a constant-power working mode; and if other motions are performed, entering a constant-rotating-speed operation mode. In the constant-power working mode, an outlet pressure of a hydraulic pump is detected. If the outlet pressure exceeds a preset pressure of an overflow valve, a motor rotating speed is set to a least allowed rotating speed, and otherwise, a motor target rotating speed is calculated according to a pressure-rotating-speed constant-power relationship. If the calculated rotating speed exceeds a maximal allowed rotating speed, the motor rotating speed is restricted to the maximal allowed rotating speed. If the calculated rotating speed does not exceed the maximal allowed rotating speed, the motor is operated according to the calculated rotating speed. According to the constant-power control method, not only can operation efficiency of the equipment mounted on the pure electric compression type garbage truck be improved, but also overflow loss of the hydraulic pump can be reduced, thereby prolonging duration mileage of an electric vehicle.

The invention relates to an energy-saving hydraulic hybrid power system of a loader and belongs to a power system of the loader. An engine of the hybrid power system is in mechanical connection with a hydraulic variable pump and a hydraulic torque converter; an oil outlet of the hydraulic variable pump is communicated with an oil inlet of a one-way valve; an oil inlet of a second overflow valve and a distribution valve are communicated with oil inlets or oil return ports of the one-way valve, an oil tank, a movable arm oil cylinder, a bucket oil cylinder and a steering oil cylinder respectively; an oil inlet of a hydraulic pump / motor control component is communicated with an oil outlet of a reducing valve; each oil return port is communicated with the oil tank; an oil outlet of a two-position two-way reversing valve is communicated with an oil inlet of the hydraulic pump / motor; the hydraulic pump / motor component and the hydraulic pump / motor are in mechanical connection; and an output shaft of the hydraulic pump / motor is in mechanical connection with the input ends of a front axle and a rear axle through an electromagnetic clutch and a torque coupler. The energy-saving hydraulic hybrid power system has the advantages that: the hydraulic hybrid power system can reclaim the braking kinetic energy of the whole machine, improves the working efficiency and working performance of thewhole machine and has long service life.

A return oil diversion system for a telescopic boom oil cylinder of a high altitude work vehicle comprises a multiple directional control valve, a balanced control valve and the oil cylinder. A port A of the multiple directional control valve is connected with a rodless cavity oil port C1 of the oil cylinder through the balanced control valve. A port B of the multiple directional control valve is connected with a control end K1 of the balanced control valve and a rod cavity oil port C2 of the oil cylinder simultaneously. The rod cavity oil port C2 of the oil cylinder is also connected with the control end K1 of the balanced control valve. A throttling valve and a balanced oil return valve are further connected between the port A and the port B of the multiple directional control valve in series. A control end K2 of the balanced oil return valve is connected with the port B of the multiple directional control valve. The throttling valve and the balanced oil return valve are both connected with an oil tank through a switching valve. According to the return oil diversion system for the telescopic boom oil cylinder of the high altitude work vehicle, the balanced oil return valve is added between the port A and the port B of the multiple directional control valve, and the throttling valve is added at the port B of the multiple directional control valve for oil return at the same time, so that the purpose of return oil diversion is achieved, and the problems of impact and shaking generated when the oil cylinder starts to retract are solved.

The invention relates to a multi-way valve. The multi-way valve comprises a connecting block, and the connecting block comprises a main pressure limiting valve, a filter, a three-way pressure reduction valve, a constant difference overflow valve, an electromagnetic unloading valve and a pump; and the connecting block is connected with reversing blocks, and the reversing blocks comprise whole handle seat mechanisms, secondary pressure limiting valves, constant difference pressure reduction valves, shuttle valves and ratio electromagnets. Different three-position four-way reversing valves are controlled to achieve single movement and composite movement of a plurality of working devices; according to real-time pressure and the flow magnitude of system loads, the output pressure and the flow magnitude of the hydraulic pump are adjusted, so that the aim that the output power of the pump is completely matched with the loads is achieved; and overflow losses and heating of a hydraulic system are reduced, and therefore energy saving and emission reduction are achieved.

The invention relates to the technical field of bulldozers, in particular to a hydraulic system of a bulldozer. The hydraulic system comprises a first oil way and a second oil way. Oil of the first oil way sequentially passes a pump I, an unloading valve, an energy accumulator and a decompression valve by means of an oil tank to be divided into two paths, one path is communicated with a speed change valve, and the other path is communicated with a steering brake valve. Oil of the second oil way sequentially passes a pump II, a torque converter, a back pressure valve and an oil cooler by means of the oil tank and returns to the oil tank, and a torque converter overflow valve is disposed between an inlet of the torque converter and an outlet of the oil cooler. The unloading valve is connected with an outlet of the pump II. The pump I and the pump II serve as power sources of the hydraulic system of the bulldozer, system power is reasonably allocated, and overflow loss is effectively reduced. Besides, the energy accumulator and the unloading valve are arranged, and the characteristic that flow required by a clutch is large at the moment of shifting is preferentially ensured. Meanwhile, power loss of the hydraulic pumps is reduced when shifting operation is not conducted.

The invention discloses a rotary energy saving system of an excavator. When the excavator rotates to be started, corresponding flow is supplied according to a demand of a rotary motor, so that overflow loss of the system is reduced. A flow control valve is arranged between an overload buffering valve and an oil tank. In a process of accelerating rotary starting, the flow control valve works in a throttling mode; flow, namely overflow of the system, of the flow control valve is calculated according to pressure at an oil inlet of the flow control valve, and the discharge capacity of a hydraulic pump is adjusted according to the overflow of the system; when the overflow is increased, the discharge capacity of the hydraulic pump is reduced, so that most of the pump output flow is absorbed by the rotary motor, and energy loss is reduced; when the overflow is reduced, the discharge cavity of the hydraulic pump is improved, so that the requirement of the rotary motor can be met; moreover, the inlet pressure of the rotary motor is always kept at an overflow pressure value, and the rotary torque is increased, so that the rotary acceleration performance is guaranteed; and in a process of rotary deceleration brake, the flow control valve works in a direct through mode, so that oil can be normally filled into the rotary motor.

A hydraulic circuit controlling preferred movement of a moveable arm to lift or rotate is disclosed, and comprises a rotary motor (12), and a moveable arm lifting oil cylinder (8); a first hydraulic pump (P1), a second hydraulic pump (P2) and a guide oil pump (P3); a moveable arm control valve (7) located in the downstream of the second hydraulic pump (P2) to control hydraulic liquid which is supplied to the moveable arm lifting oil cylinder (8); a rotary control valve (4) located in the downstream of the first hydraulic pump (P1) to control the hydraulic liquid which is supplied to the rotary motor (12) and / or a confluence valve (11); a preferred valve (13) in the downstream of the first hydraulic pump (P1) for dividing the hydraulic liquid of the first hydraulic pump (P1); an electromagnetic valve (15) in the downstream of the guide oil pump (P3) for switching between the states that a guide control oil path (14) of the preferred valve (13) is communicated with the oil tank or communicated with the guide oil pump (P3); and the confluence valve (11) in the downstream of the rotary control valve (4) for controlling the oil path (1) to be communicated with the oil path (3) or an oil return pipeline.

The invention discloses a boat pushing reducing furnace device and a gas supply method and belongs to the technical field of powder metallurgy. The boat pushing reducing furnace device comprises furnace pipe hydrogen inlet pipelines and hydrogen return pipelines. The hydrogen inlet pipelines are provided with program control valves and bypass valves, and the bypass valves are normally-open valves.The hydrogen inlet pipelines comprise a first hydrogen inlet pipeline and a second hydrogen inlet pipeline. The first hydrogen inlet pipeline is provided with the first program control valve and thefirst bypass valve, and the second hydrogen inlet pipeline is provided with the second program control valve and the second bypass valve. A third program control valve is arranged on a main hydrogen return pipe, and a fourth program control valve is arranged between the hydrogen return pipelines and the hydrogen inlet pipelines. The gas supply method of the boat pushing reducing furnace device mainly comprises the step that the program control valves are controlled to be opened and closed. The problem that due to the fact that the barometric pressure of the interior of a furnace pipe and atmosphere is zero or unstable, and consequently a recovery system stops operating, and the recovery process cannot be smoothly carried out is solved, and hydrogen losses caused during blow-in feeding arereduced.

The invention discloses an internal mixer upper jacking bolt oil cylinder hydraulic control system. Signals of the movement speed of an oil cylinder piston rod, the pressure of two cavities of an oilcylinder, and the rotation speed of a servo motor are monitored in real time and are fed back to a programmable logic controller (PLC), logical operation is conducted through a built-in PID, an inputsignal of a servo drive is given, the rotation speed of the servo motor is controlled, meanwhile the set pressure of a proportional pressure valve arranged on a constant pressure variable pump is controlled, finally closed-loop control of the speed of the internal mixer upper jacking bolt and the pressure of a pressing weight is achieved, namely rising, falling and pressurization of the upper jacking bolt and the working process of a floating weight are monitored and adjusted in real time, energy consumption is reduced to a great extent, and system work efficiency is improved. The rotation speed of the servo motor is controlled by the servo drive, then the output flow of the constant pressure variable pump is adjusted to adapt to system requirements, overflow loss is reduced maximally, system throttling loss is reduced, and the oil calorific value is lowered.

The invention discloses a direct-acting overflow motor and a hydraulic source loop thereof. The direct-acting overflow motor comprises an air filter, a first stop valve, a pressure adjustment screw, apressure measurement oil path, a motor member, an oil bottle, a pressure adjustment device shell body, a pressure measurement piston rod, a pressure measurement spring, a variable piston rod, and a swash plate push rod. According to the direct-acting overflow motor and the hydraulic source loop thereof, system pressure oil is led into a pressure measurement cavity through the pressure measurementoil path, and control pressure oil is enabled to directly act on a pressure measurement piston, and when a control pressure is greater than a spring force, the pressure measurement piston rod moves,and achieves a balanced state at a new position with the spring force; the pressure measurement piston rod moves to push oil sealed in a displacement amplification cavity to move, a force is transferred to a variable piston to drive the variable piston to move, and the purpose of increasing a displacement is achieved through the section area difference between the pressure measurement piston rod and the variable piston rod; and the variable piston rod drives the swash plate push rod to rotate to change the inclination angle of a motor swash plate, so that the displacement of a motor is changedto adapt to the overflow flow rate change of a system, and the pressure of an oil inlet port of the motor is enabled to keep constant.

The invention discloses a stacker-reclaimer pitching hydraulic system, a close loop control system and a control method. The system comprises a main loop for controlling the stacker-reclaimer suspension arm pitching mechanism to move, a hydraulic control check valve control loop for providing inverse opening pressure to a hydraulic control check valve, and a manual control loop for supplying power to the system when the system is power-off or has fault. According to the stacker-reclaimer pitching hydraulic system, the close loop control system and the control method, the design requirement is achieved through controlling the speed of the pitching hydraulic cylinder and the vertical displacement of the suspension arm to make sure that the stacker-reclaimer can operate highly efficiently, stably and reliably.

The invention provides a pump and valve coordinated control method used for a prestress intelligent tensioning device, and belongs to the technical field of engineering construction such as bridge engineering, highways and tall buildings. According to the pump and valve coordinated control method used for the prestress intelligent tensioning device, the problem that control accuracy of an existingtechnology is not high is solved. The prestress intelligent tensioning device, and belongs to the technical field of engineering construction comprises the following steps that a mould of a pump andvalve coordinated control system is established; a loaded flow prediction control algorithm is adopted to a pump control part of the pump and valve coordinated control system, and pump control singleum output is obtained; a feed forward compensation PID control algorithm is adopted by a valve control part of the pump and valve coordinated control system, and valve control single uv output is obtained; the pump control single um and the valve control single uv are input into the pump and valve coordinated control system, and the rotating speed is controlled by a servo motor according to the pump control signal um, so that output flow of oil source is matched with the loaded flow, a stepping motor drives a direction switching valve to work according to the valve control signal uv, and thusadjustment of the loaded flow is realized. According to the pump and valve coordinated control method used for the prestress intelligent tensioning device, the dynamic response and control accuracy ofthe pump and valve coordinated control system can be improved.

The invention discloses a novel constant delivery pump variable differential pressure load sensitive system which comprises a load sensitive valve, a safety protection valve, a pressure compensator, afirst reversing valve and a differential pressure control valve, the oil inlet ends of the load sensitive valve, the safety protection valve and the pressure compensator are connected to an oil inlet, and the load sensitive valve is connected with a differential pressure control mechanism and the safety protection valve. The pressure compensator is connected with the first reversing valve, the differential pressure control valve comprises a damping hole, the differential pressure control mechanism and a second reversing valve, the differential pressure control mechanism is connected with thesecond reversing valve, and the damping hole is formed between the differential pressure control mechanism and the second reversing valve. The pressure difference of the load sensitive valve in the constant delivery pump load system is changed through the pressure difference control valve, flow output is related to actual requirements of the system, overflow loss of the system in a standby state is reduced through variable pressure difference, and therefore energy saving performance of the system is improved.

The invention discloses a metal belt type continuously variable transmission with symmetrical-moving conical discs. The metal belt type continuously variable transmission comprises an input shaft, an output shaft, the drive and driven conical discs, a V metal belt, cam pressure device and a pump control closed type hydraulic transmission system. The drive and driven conical discs are respectively composed of two movable conical disc bodies, the V metal belt is sleeved with the two movable conical disc bodies on the input shaft and the two movable conical disc bodies on the output shaft, and the four movable conical disc bodies are respectively provided with an oil cylinder. The pump control hydraulic transmission system comprises a two-way hydraulic pump, a direct-current motor, one-way valves and an oil tank. One side of the two-way hydraulic pump is communicated with the two oil cylinders of the drive conical discs, and the other side of the two-way hydraulic pump is communicated with two oil cylinders of the driven conical discs. The cam pressure device is adopted for providing clamping force without consuming energy, a hydraulic control system is only used for changing the speed ratio and auxiliary clamping, the open type servo valve and proportional valve hydraulic control system is replaced with the pump control closed type hydraulic transmission system, in this way, overflow loss is reduced, energy consumption is greatly reduced, and the purposes that metal belt type continuously variable transmission saves more oil and is environmentally friendlier are achieved.

The invention discloses a horn antenna which is applied to a wave collector. The horn antenna comprises a cone and a connector. The cone is used for collecting a satellite signal. The cone comprises a number of ring bodies. A number of first notches and a number of second notches are formed on one ring body in a number of ring bodies. Each second notch is formed between two adjacent first notches in a number of first notches. The connector is coupled to the cone, and is used for coupling the horn antenna to a waveguide tube of the wave collector, so as to transmit the satellite signal to the waveguide tube. A number of first notches and a number of second notches are used as slots on the ring bodies to produce an interference effect, so that the beam field pattern of the horn antenna is adjusted.