321 results about "Variable displacement" patented technology

The invention discloses an oil supply control system of a hydraulic pump station, and relates to the technical field of hydraulic systems. The oil supply control system of the hydraulic pump station comprises an oil tank; the oil inlet end of the oil supply pump communicates with the oil tank, and the oil outlet end of the oil supply pump is connected to the oil suction end of the variable plunger pump through an oil supply path; a heat exchanger and a filter are sequentially arranged in the oil supply path and used for conducting temperature adjustment and particle filtration on oil. The oil supply path is connected with a bypass pipeline in parallel, the bypass pipeline is communicated with the oil tank through a one-way valve, the opening pressure of the one-way valve is smaller than 2 bar, and the one-way valve is used for guaranteeing the positive pressure of the oil suction end of the variable pump. The oil outlet end of the variable displacement piston pump is connected to an external hydraulic system and is provided with a high-pressure filter; the detection device is arranged in the oil supply path and used for collecting oil temperature and / or pressure signals; and the control module is connected with the detection device and the execution components and is configured to control the start and stop states of the oil supply pump, the variable displacement piston pump and the heat exchanger according to the comparison result of the detection result and a preset threshold value.

A hydraulic system includes a prime mover, a variable displacement first hydraulic pump to be driven by the prime mover to deliver hydraulic fluid, a first hydraulic actuator to be driven by fluid delivered by the first hydraulic pump, a variable displacement second hydraulic pump to be driven by the prime mover to deliver hydraulic fluid, a second hydraulic actuator to be driven by fluid delivered by the second hydraulic pump, and first and second restrictors configured or programmed to restrict an output of the respective first and second hydraulic pumps based on a load on the prime mover. The first restrictor is configured or programmed to change an output restriction of the first hydraulic pump based on priority information about the first and second hydraulic actuators and / or the second restrictor is configured or programmed to change an output restriction of the second hydraulic pump based on the priority information.

The invention relates to the technical field of injection molding machine hydraulic control, in particular to an injection molding machine hydraulic pump control system and a control method thereof, and aims to solve the problems of high energy consumption, high cost or poor temperature control of a traditional hydraulic scheme. The system comprises a hydraulic oil tank, a driving unit and an oil way control module. The driving unit comprises a driving motor, and a fixed displacement pump and a plurality of swash plate type variable displacement piston pumps which are driven by the driving motor, and swash plates of the variable displacement pumps can be switched between negative and positive angles so as to adjust the displacement or actively suck oil; the oil way control module is provided with a flow collecting valve set capable of switching flow collecting / independent states of oil outlet ways of the constant displacement pump and the variable displacement pump, the integrated cooling unit forms an independent cooling filtering loop, the temperature and pressure adjusting assembly is combined with a temperature sensor to control temperature and adjust pressure, and the pressure limiting protection valve set is connected with the constant displacement pump and the variable displacement pump. And the pressure limiting protection valve is matched with a pressure sensor to realize overpressure protection. According to the invention, cost and energy saving are both considered, precise temperature control and pressure protection are realized, and system stability and plastic part forming precision are improved.

The invention provides a variable rotating speed-variable displacement differential pressure controllable valve front compensation load sensitive system. The variable rotating speed-variable displacement differential pressure controllable valve front compensation load sensitive system comprises a control unit, a driving motor assembly, a variable differential pressure load sensitive pump assembly, a variable differential pressure load sensitive valve assembly, a pilot hydraulic control unit, a pilot handle assembly, an actuator assembly, a sensor assembly and a motor rotating speed control module. The driving motor assembly drives the variable pressure difference load sensitive pump assembly to supply oil to the variable pressure difference load sensitive valve assembly, and then the actuator assembly is driven to operate. The pilot hydraulic control unit provides set pressure; the pilot handle assembly outputs a signal to the variable pressure difference load sensitive valve assembly; the sensor assembly detects the maximum load pressure of the system and the outlet pressure of the variable pressure difference load sensitive pump assembly; the control unit controls the target rotating speed of the driving motor assembly and the control pressure of the pilot hydraulic control unit. Compared with an existing upstream compensation load sensitive system, the problem of speed imbalance of an actuator under the flow saturation working condition is effectively avoided, and the control performance is remarkably improved.

The invention relates to the technical field of industrial automation, and discloses a multi-mode switching control method for a variable displacement piston pump driven by a servo motor, which comprises the following steps of: acquiring multi-dimensional operation state parameters and load power of a variable displacement piston pump system; performing dynamic mode decomposition on the load power signal, and executing preset state switching compensation mapping to complete mode switching on the basis of the extracted mode characteristics and the current state parameter under the condition of judging that the switching condition is satisfied; executing a corresponding control strategy in the new mode, and dynamically adjusting the pump displacement and the rotating speed of the servo motor through feedback control; and detecting the response and energy efficiency performance of the regulation and control system according to the performance index in the system operation process. By adopting a dynamic mode intelligent switching mechanism, the system can automatically match the optimal operation mode in different working environments, the energy utilization efficiency is greatly improved, and the effects of effectively reducing energy waste and reducing the total energy consumption of the system during stable load or low load operation are achieved.

The invention relates to the technical field of variable displacement pumps, and particularly discloses a hydraulic pump with a filtering function and a using method thereof.The hydraulic pump comprises a water inlet pipe fixedly arranged at the water inlet end of a pump body, a connecting pipe and a water guide pipe, and a first sealing plate used for controlling the water inlet pipe to be opened or closed is hinged to the inner wall of the end, close to the pump body, of the water inlet pipe; according to the invention, the driving mechanism is matched with the cleaning mechanism and the like, and the first filter plate is brushed from one side, far away from the water inlet pipe, of the first filter plate while the first filter plate is vibrated in the process of opening and closing the first sealing plate, so that the first filter plate is cleaned and brushed, and the impurities in the liquid are filtered out; the effect of cleaning the impurities filtered by the first filter plate is further improved, the first filter plate can be conveniently used for filtering for a long time, and the impurities dispersed in the liquid can be conveniently sucked out along with the liquid, so that the quantity of the impurities around the first filter plate is reduced, and the long-time continuous filtering effect of the first filter plate is further improved.

The utility model belongs to the technical field of hydraulic systems, and discloses a one-way valve and a hydraulic system. The one-way valve comprises a valve sleeve and a valve element, the valve sleeve is provided with a cavity and an oil inlet channel which are communicated, the valve element is arranged in the cavity in a sliding mode and can block the oil inlet channel, the valve element is provided with a first boss, the first boss and the inner wall of the cavity are arranged in a spaced mode to form a first filtering channel, and the first filtering channel is used for oil liquid to pass through; and at least part of impurities in the oil can be prevented from crossing the first boss. The one-way valve is simple in structure, impurities in oil can be filtered out, the situation that the impurities enter a controller after passing through the one-way valve, and consequently a valve element of the controller is blocked can be avoided, it is guaranteed that the variable displacement of the hydraulic motor can be normally adjusted, and the normal function of the hydraulic motor is guaranteed.

A turbocharger includes a bearing housing, a variable displacement mechanism, and a restricting member. The variable displacement mechanism includes a nozzle ring and a drive ring. The restricting member includes a flange part, a drive ring guide pin part, and a phase determining pin part. The flange part straddles a first surface of the nozzle ring facing the bearing housing and a second surface of the drive ring facing the bearing housing so that a position thereof with respect to the nozzle ring is fixed. The drive ring guide pin part is formed integrally with the flange part and disposed in a first hole formed on the first surface. The phase determining pin part is formed integrally with the flange part and disposed in a second hole formed on a third surface of the bearing housing facing the variable displacement mechanism.

The invention discloses a variable displacement mechanism in an asymmetric pump, relates to the technical field of fluid transmission and control, and aims at solving the problems that an existing variable displacement mechanism is large in auxiliary oil source pressure, high in energy consumption and poor in control stability due to the fact that a swash plate is affected by one-way torque due to the oil port pressure difference of an axial plunger pump with three flow distribution windows. The variable displacement mechanism in the asymmetric pump comprises a variable displacement cylinder, wherein the variable displacement cylinder comprises a first cylinder barrel and a second cylinder barrel which are oppositely arranged in the movement direction of a piston; the piston is arranged in the first cylinder barrel and the second cylinder barrel; the first piston rod and the second piston rod are respectively arranged at two ends of the piston; the first piston rod is sleeved with the first stiffness spring, the second piston rod is sleeved with the second stiffness spring, and the stiffness of the first stiffness spring is larger than that of the second stiffness spring; and the at least two stop blocks are fixed on the inner wall of the first cylinder barrel. The pressure of the auxiliary oil source in the asymmetric pump is reduced, and the control stability is improved.

The utility model provides a variable displacement structure of a compressor and the compressor, and belongs to the technical field of compressors, the variable displacement structure of the compressor comprises a crankshaft and a roller, the crankshaft is provided with an adjusting screw, the axis of the adjusting screw is perpendicular to the axis of the crankshaft, and the adjusting screw can move on the crankshaft. And the distance between the end part of the adjusting screw rod and the axis of the crankshaft is changed. The rollers are arranged on the periphery of the crankshaft and connected to the two ends of the adjusting screw in a sleeving mode. According to the variable displacement structure of the compressor, the eccentricity of the crankshaft can be adjusted by adjusting the movement of the screw, then the displacement of the compressor is adjusted, use is convenient, universality is high, and the machining difficulty and the machining cost of the compressor can be reduced.

The invention relates to the technical field of loader hydraulic control, in particular to a low-power-consumption hydraulic system of an electric loader, aiming at steering and normal work of the loader, a first power module and a second power module which are independently regulated and controlled are respectively arranged, and independent valve port control is adapted by utilizing the coordination effect of a flow scheduling module and a pressure matching module; a throttling link is completely eliminated, an inlet valve port and an outlet valve port are fully opened, the pressure loss of oil flowing through the valve ports is reduced to the minimum, and the energy consumption of a whole machine steering loop is greatly reduced; and meanwhile, independent and accurate control over oil inlet and oil return of the oil cylinder is achieved through speed regulation of variable rotating speed and variable displacement, real stepless speed regulation is achieved by avoiding limitation of the opening degree of a main valve port, and therefore the energy efficiency of the system is greatly improved.

Apparatus and associated methods relate to using a Pulse-Width Modulated (PWM) electro-hydraulic solenoid valve to provide regulation of fluid displacement pumped by a variable-displacement hydraulic pump. The PWM electro-hydraulic solenoid valve regulates fluid conductivity between a hydraulic output port and a hydraulic control port of the variable-displacement hydraulic pump. Such regulation of fluid conductivity therebetween controls fluid displacement through the variable-displacement hydraulic pump. An electronic control unit is configured to generate and transmit a PWM electrical control signal to the PWM electro-hydraulic solenoid valve in response to a metric of the variable-displacement hydraulic pump as measured by a transducer. The electronic control unit generates the PWM electrical control signal so as to control the metric measured to within a predetermined control band about a target value.

A system includes a variable displacement pump (VDP) in fluid communication with an inlet line and with an outlet line. The VDP includes a variable displacement mechanism configured to vary pressure to the outlet line. A bypass valve (BPV) includes a BPV inlet in fluid communication with the outlet line, and a BPV outlet in fluid communication with a bypass line that feeds into the inlet line upstream of the VDP. A minimum pressure shutoff valve (MPSOV) is connected in fluid communication with the outlet line, configured to block flow through the outlet line for shutoff. The MPSOV is connected in fluid communication with the BPV for triggering recirculation through the BPV.

Apparatus and associated methods relate to using an electro-hydraulic solenoid valve to provide regulation of fluid displacement of a variable-displacement hydraulic pump. A mechanical control mechanism is configured to control displacement of hydraulic fluid pumped from a hydraulic input port to a hydraulic output port. The electro-hydraulic solenoid valve regulates fluid conductivity between a hydraulic output port of the variable-displacement hydraulic pump and a hydraulic control cylinder, which operates a hydraulic control piston coupled to the mechanical control mechanism controlling fluid displacement. An electronic control unit is configured to generate and transmit an electrical control signal to the electro-hydraulic solenoid valve in response to a metric of the variable-displacement hydraulic pump as measured by a transducer. The electronic control unit generates the electrical control signal so as to control the metric measured to within a predetermined control band about a target value.

The present application relates to the field of heating and ventilation technology, and particularly relates to a control method of a heating system. The present application aims to solve the problems of high cost and high risk of refrigerant leakage existing in the current heat pump heating. For this purpose, the heating system of the present application comprises a heat pump cycle and a water cycle, the heat pump cycle comprises a variable displacement compressor, a tubular heat exchanger, a throttling device and an evaporator connected through a refrigerant pipeline, the water cycle comprises an indoor radiator and the tubular heat exchanger connected through a heat exchange pipeline, the refrigerant in the heat pump cycle and the circulating water in the water cycle exchange heat in the tubular heat exchanger, the variable displacement compressor has two compression cylinders, and the control method comprises: acquiring an outdoor environment temperature; determining a working mode of the variable displacement compressor according to a temperature interval in which the outdoor environment temperature is located; and controlling the variable displacement compressor to operate based on the working mode. The present application has good heating effect, low cost, low risk of leakage and good heat pump heating effect.

The invention discloses a variable-displacement water pump for an engine and a water pump displacement control method, and relates to the technical field of water pumps, the variable-displacement water pump comprises a pump body, an impeller disc, an elastic part and a driving part, a pump shaft is rotationally connected to the center of the pump body, an impeller cover is fixedly connected to one end of the pump shaft, and a plurality of blades are arranged on the face, facing the pump body, of the impeller cover in the circumferential direction; the impeller disc sleeves the pump shaft, the impeller disc and the impeller cover are coaxially and oppositely arranged, the impeller disc can slide in the axial direction of the pump shaft, the impeller disc is provided with holes allowing the blades to penetrate through, the hole walls of the holes and the peripheral surfaces of the blades define liquid drainage intervals, the pump shaft is sleeved with the elastic piece, one end of the elastic piece abuts against the impeller disc, and the other end of the elastic piece abuts against the impeller disc. The driving part is arranged on the face, away from the impeller cover, of the impeller disc, the driving end of the driving part abuts against the impeller disc, and the acting force of the elastic part is opposite to that of the driving part. The size of the liquid drainage interval is adjusted through cooperation of the driving piece and the elastic piece, and variable displacement and oil consumption reduction are achieved.

The application discloses a device of a circular ring type plunger variable hydraulic pump, which comprises a base, a curved rod, a piston, a swing rod two, a rear cover, a connecting rod five, a connecting rod six, a compression bolt, a connecting rod eight and a main shaft two. The base is fixedly connected with the rear cover through welding. The outer side of the rear cover is in butt joint with a sealing gasket and a front cover, and the sealing gasket, the front cover and the rear cover are fixed through bolts. The device of the circular ring type plunger variable hydraulic pump can reduce the volume of the whole device in the axial direction while pumping oil. Only a given signal is needed to operate the driving circuit of the stepping motor, so that the stepping motor rotates at a corresponding speed and rotates a corresponding number of turns. The gear installed on the stepping motor drives the rack to move a corresponding distance, so that three groups of hinges move, the distance of the linear motion of the other end of the connecting rod two is changed, the included angle of the connecting rod one and the connecting rod three is changed, the swing angle of the swing rod one and the swing rod two is changed, and then the movement distance of the piston is changed, so that the variable oil pumping is realized.

An oil pump capable of optimizing the noise problem of first starting after long-term standing relates to the technical field of variable displacement vane pumps, and comprises a pump body, a sliding block is arranged in an oil cavity of the pump body, a vane cavity is arranged in the sliding block, a vane is arranged in the vane cavity, an oil storage cavity capable of storing oil during shutdown is arranged in the pump body, and the vane is arranged in the oil storage cavity. A pressure discharging hole used for discharging excessive oil is formed in the upper portion of the oil storage cavity, the lowest point of the oil storage cavity is located at the lowest point of the pump body oil cavity, and the oil in the oil storage cavity can enter the sliding block from the end face gap of the sliding block so as to be used for rapidly providing oil for the blade cavity during starting. According to the utility model, the technical effects that the oil pressure is fast and stable, the blades are fast lubricated and the air mixing amount is relatively low after long-term standing during first-time starting can be realized, and the blade knocking abnormal sound is weakened to a great extent.

A valvetrain control system includes a rocker shaft that attaches to an engine assembly and includes an internal bore that receives hydraulic fluid. An oil control valve (OCV) is attached to the rocker shaft and fluidly coupled to the internal bore to receive therefrom hydraulic fluid. Pivotably mounted onto the rocker shaft is a rocker arm with opposing ends thereof that mate with a pushrod and a valve. The rocker arm includes a spring lock unit that attaches to the pushrod and fluidly couples to the OCV to receive hydraulic fluid and thereby drivingly disengage the rocker arm from the pushrod. An insert sleeve mounted in the internal bore receives hydraulic fluid from the rocker shaft. The insert sleeve includes a feed port that transmits hydraulic fluid from the insert sleeve to the OCV, and a feed pocket that transmits hydraulic fluid from the OCV to the spring lock unit.

The application relates to the technical field of air conditioners, and discloses a control method for a variable displacement compressor air conditioner, wherein an exhaust port of a variable displacement compressor is connected to a variable displacement chamber of the variable displacement compressor through an exhaust pipeline, and an electric heating device is arranged on the exhaust pipeline; the control method comprises the following steps: in the case that the variable displacement compressor air conditioner executes a heating mode, obtaining an exhaust temperature of the variable displacement compressor, an exhaust pressure and a saturated steam temperature corresponding to the exhaust pressure; and in the case that the difference between the exhaust temperature and the saturated steam temperature is less than a first temperature, controlling the electric heating device to start. The method can avoid liquid accumulation in the variable displacement chamber and eliminate noise caused by liquid accumulation. The application further discloses a control device for the variable displacement compressor air conditioner, a variable displacement compressor air conditioner and a storage medium.

The application discloses a hydraulic driving multi-cylinder double-acting variable piston diaphragm pump. The pump comprises a pump base body, a power end, a liquid cylinder body, a diaphragm tank and a buffer tank which are installed on the pump base body, the power end is connected with the liquid cylinder body, the diaphragm tank is connected with the liquid cylinder body through connecting pipes respectively, flanges at two ends of the diaphragm tank are connected with suction valves and discharge valves respectively, wherein, the lower end suction valves are connected with suction pipes respectively, the upper end discharge valves are connected with discharge pipes respectively, and the discharge pipes are connected with the buffer tank. The application adopts a swash plate mechanism to realize the reciprocating motion of the multi-cylinder piston, drives the fluid medium in the working cavities on both sides of the piston to make the diaphragm in the diaphragm tank periodically concave-convex deformation, and realizes the self-suction of the pump feeding pulp from the suction pipe and the output of the discharge buffer tank. The diaphragm pump has the advantages of compact structure, small size, reduced output flow pulsation and reduced pulsation load impact of the filter press feeding on the filter plate.

The present application relates to the air conditioning technical field, specifically to a kind of air conditioner's shunt control method.This application aims to solve the problems of existing shunt mode, such as complex shunt system, large structure space, not conducive to assembly and application.To this end, the air conditioner of the present application is provided with a variable displacement compressor, the indoor heat exchanger includes inner discharge heat pipe line, outer discharge heat pipe line and the communication pipe line connecting the two, the outdoor heat exchanger includes a plurality of heat pipe sections and the on-off valve group that can switch the communication form between heat pipe sections, and the control method includes: obtaining the operating mode of the air conditioner;Based on the operating mode, determine the communication form of the outdoor heat exchanger and the indoor heat exchanger, and the working mode of the variable displacement compressor;Based on the communication form and the working mode, control the air conditioner to work.This application can realize the adaptive coupling change of shunt, improve the heat exchange effect of air conditioner, and the variable displacement compressor can further improve the operating efficiency of air conditioner.

The invention discloses a power control valve, a variable displacement piston pump control system, a variable displacement piston pump control method and a swash plate type variable displacement piston pump in the technical field of hydraulic control. The power control valve comprises a push rod, a valve body, a valve element assembly and a spring assembly and further comprises a pump variable transmission device, an armature and an electromagnetic coil; a valve cavity is formed in the valve body, a push rod, a valve element assembly, a spring assembly and an armature are sequentially arranged in the valve cavity, and the outer side of the push rod extends out of the valve cavity to make contact with a pump variable transmission device. The electromagnetic coil surrounds the armature and is arranged on the outer side of the valve body; the pump variable transmission device is connected with a swash plate of the swash plate type variable plunger pump and used for pushing the push rod, oil liquid of the oil inlet X acts on the end face of the valve element to push the valve element assembly to jointly overcome the spring force of the spring assembly, and when the pressure of the oil liquid input by the oil inlet X continues to be increased to reach a set value, the oil drainage port T and the oil inlet X are communicated. The power limiting point of the electric control variable pump can be changed, and the limiting power of the hydraulic pump can be changed according to the environment and working conditions.

A hydrostatic servo assembly unit (1) for being arranged inside, outside or distant from a variable displacement hydrostatic unit (100) and for controlling the displacement of the variable displacement hydrostatic unit (100). The servo assembly unit (1) includes a servo housing (10) in which at least one servo piston (40) is arranged. The piston head (42) of the servo piston (40) can be pressurized such that the servo piston (40) can move linear relative to a servo cylinder (12) formed in the servo housing (10). The servo assembly unit (100) further includes a movable output element (49) protruding outside of the servo housing (10), which can be mechanically coupled to a displacement element (102) of a variable displacement hydrostatic unit (100).

A valve train control system comprises a rocker arm shaft mounted to an engine assembly and featuring an internal bore that receives hydraulic fluid. An oil control valve (OCV) is mounted on the rocker arm shaft and is fluid-connected to the internal bore to receive hydraulic fluid. A rocker arm is pivotally mounted on the rocker arm shaft, its opposite ends mating with a pushrod and a valve. The rocker arm includes a spring-loaded locking assembly attached to the pushrod and fluid-connected to the OCV to receive hydraulic fluid and thereby release the rocker arm from the pushrod. An insert sleeve mounted in the internal bore receives hydraulic fluid from the rocker arm shaft. The insert sleeve includes a feed port that transfers hydraulic fluid from the insert sleeve to the OCV and a feed pocket that transfers hydraulic fluid from the OCV to the spring-loaded locking assembly.

A method for driving a tilt rotor between vertical and horizontal using a variable displacement motor controlled in response to a swash angle of the motor measured in a feedback loop. The loop includes an algorithm configured to monitor change in swash angle as the motor speed reduces and the actual tilt position of the rotor pylon approaches the second position and, based on the change and actual tilt position, to limit change in swash angle to be within a predetermined range as a percentage of the operating load.

The utility model relates to the technical field of hydraulic compressors, in particular to a hydraulic system of a hydraulic compressor. Comprising an oil tank, an oil outlet of the oil tank is connected with an oil inlet of a variable displacement piston pump through a low-pressure oil pipeline, one branch of the oil outlet of the variable displacement piston pump is connected with an energy accumulator through a high-pressure oil pipeline and a one-way valve, and the other branch of the oil outlet of the variable displacement piston pump is connected with an oil inlet of an electromagnetic reversing valve. An oil outlet of the electromagnetic directional valve is connected with the hydraulic drive compressor through oil inlet and outlet pipelines, the electromagnetic directional valve is further connected with an oil return opening of the oil tank through an oil return pipeline, and a shuttle valve is arranged between the two oil inlet and outlet pipelines and connected with the variable displacement piston pump through a variable displacement oil pipeline. Pressure oil in the oil inlet and outlet pipeline can enter the shuttle valve and then enter the variable displacement piston pump through the variable displacement oil pipeline, a terminal pressure oil signal is provided for the variable displacement piston pump, the variable displacement piston pump can conduct power adjustment according to the pressure change of the terminal pressure oil, the pressure of the terminal pressure oil is kept stable, and therefore stable work of the hydraulic drive compressor is guaranteed.

The present disclosure relates to a positive displacement machine device (1) comprising a constant displacement machine (2) with a fixed displacement volume and a variable displacement machine (3) with an adjustable displacement volume, wherein in pump operation of the positive displacement machine device (1) a fluid (4) can be conveyed from an inlet (5) of the positive displacement machine device (1) to an outlet (6) of the positive displacement machine device (1) by means of the constant displacement machine (2) and / or the variable displacement machine (3), wherein in motor operation of the positive displacement machine device the constant displacement machine and / or the variable displacement machine can be driven by fluid flowing from the inlet to the outlet. Noise emissions of the displacement machine device (1) are reduced and / or the displacement machine device (1) can be operated at high speed by fluidically connecting the inlet (5) to a first port (21) of the constant displacement machine (2) and to a first port (31) of the variable displacement machine (3), and wherein the outlet (6) is fluidically connected to a second port (22) of the constant displacement machine (2) and to a second port (32) of the variable displacement machine (3).

The utility model discloses a variable displacement compressor top clearance measuring device which comprises a device frame, a pressing assembly, a positioning tool, a detection tool and a jacking assembly are arranged in the device frame, the pressing assembly is located over the positioning tool, the pressing assembly is provided with an automatic lifting pressing plate, the pressing assembly further comprises a lifting air cylinder, and the lifting air cylinder is connected with the detection tool. The telescopic end of the lifting air cylinder is fixedly connected with a rotating motor, the rotating motor is connected with a rotating head through a speed reducer, the rotating head movably penetrates through the pressing plate and then is fixedly connected with a compressor main shaft in an inserted mode in the radial direction, the jacking assembly comprises a jacking air cylinder, the telescopic end of the jacking air cylinder is connected with a detection tool, and a displacement sensor is installed on the side face of the detection tool. The lower end of a piston rod of the top piston cylinder is connected with a displacement sensor contact plate. The device is high in automation degree in the whole process, and improves the measurement efficiency and precision.

The present invention provides a variable speed, variable displacement, pressure differential, controllable pre-valve compensation load-sensing system, comprising a control unit, a drive motor assembly, a variable pressure differential load-sensing pump assembly, a variable pressure differential load-sensing valve assembly, a pilot hydraulic control unit, a pilot handle assembly, an actuator assembly, a sensor assembly, and a motor speed control module. The drive motor assembly drives the variable pressure differential load-sensing pump assembly to supply oil to the variable pressure differential load-sensing valve assembly, thereby driving the actuator assembly. The pilot hydraulic control unit provides a set pressure. The pilot handle assembly outputs a signal to the variable pressure differential load-sensing valve assembly. The sensor assembly detects the system's maximum load pressure and the outlet pressure of the variable pressure differential load-sensing pump assembly. The control unit controls the target speed of the drive motor assembly and the control pressure of the pilot hydraulic control unit. Compared with existing pre-valve compensation load-sensing systems, this system effectively avoids the problem of actuator speed imbalance under flow saturation conditions, significantly improving control performance.