162 results about "Variable displacement pump" patented technology

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.

A turbo engine for an aircraft includes a gas turbine engine having a fuel system to provide fuel to a combustion section. The fuel system includes a variable displacement pump driven by an accessory gearbox that is powered by a shaft of the gas turbine engine. The variable displacement pump has an inlet side and an outlet side. The variable displacement pump includes an actuator configured to adjust a discharge flow rate of the variable displacement pump. The fuel system also includes a fuel metering valve configured to receive pressurized fuel from the variable displacement pump and control a flow rate of the pressurized fuel to the combustion section. The fuel system further includes a bypass valve fluidly coupling the outlet side and the inlet side of the variable displacement pump to direct an excess portion of the pressurized fuel at the outlet side back to the inlet side.

A turbine engine for an aircraft includes a gas turbine engine having a fuel system that provides fuel to a combustion section. The fuel system includes a variable displacement pump driven by an accessory gearbox powered by a shaft of a gas turbine engine. The variable displacement pump has an inlet side and an outlet side. The variable displacement pump includes an actuator configured to adjust a discharge flow rate of the variable displacement pump. The fuel system also includes a fuel metering valve configured to receive the pressurized fuel from the variable displacement pump and control a flow rate of the pressurized fuel to the combustion section. The fuel system further includes a bypass valve fluidly coupling the outlet side and the inlet side of the variable displacement pump to direct excess of the pressurized fuel at the outlet side back to the inlet side.

The drive system comprises a hydraulic pump and a hydraulic motor, both having an inlet port and an outlet port, the motor being a fixed displacement motor directly coupled to the cleaning fan for rotationally driving said fan, the pump being a variable displacement pump configured to produce a flow of hydraulic liquid to the motor. In a system according to the invention, the outlet port of the pump is coupled to the inlet port of the motor by a hydraulic line, wherein said line does not comprise a valve for regulating a flow of hydraulic liquid to the motor. In the system of the invention, the flow to the motor is not regulated through a flow regulating valve between pump and motor, but by changing the pump displacement electronically. To this aim, the pump includes an electronically actuated hydraulic control system for controlling the pump displacement regardless of the hydraulic pressure of the liquid in the hydraulic line between the pump and the motor. The pump and the motor are part of an open hydraulic circuit.

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.

An aerial work platform and a floating control system thereof, the system comprising a driving mechanism, a hydraulic oil tank, a hydraulic pump, a floating control valve, a floating mechanism, a boom function valve, an actuator, and an accumulator: the floating control valve comprises a first one-way valve, a second one-way valve, a pressure reducing valve, and a logic valve; and an oil inlet of the first one-way valve serves as the oil inlet of the floating control valve, an oil outlet of the first one-way valve is connected to a pipeline connecting the accumulator, the pressure reducing valve and the logic valve, the logic valve is connected to the second one-way valve, an oil outlet of the second one-way valve serves as the feedback oil port of the floating control valve, when the hydraulic pump is a variable displacement pump, a feedback oil port of the floating control valve and a feedback oil port of the boom function valve are connected to a feedback oil port of the variable displacement pump; when the hydraulic pump is a fixed displacement pump, a feedback oil port of the floating control valve is connected to a feedback oil port of the boom function valve. The invention can reduce the power loss and improve the reliability of the system.

The invention relates to the technical field of non-variable-capacity pump set parallel control, and discloses a multi-blower parallel air volume control method, which comprises the following steps of: acquiring the real-time rotating speed and the real-time input power of a driving frequency converter of each single blower in a parallel system, and superposing a periodic rotating speed perturbation signal at a common pressure given value to obtain a multi-blower parallel air volume control result; power response amplitudes of all single blowers are extracted synchronously, the change rate of real-time power relative to the rotating speed is calculated to generate a power response gradient representing the energy conversion characteristic of the unit, the unbalanced blowers are recognized according to deviation parameters of the power response gradient relative to the global average value, the rotating speed instruction gain of the blowers is reduced, and the unit energy conversion characteristic is obtained. According to the method, load distribution is converted into an active adjustment mechanism based on the physical characteristics of the impeller, accurate identification of the offset of the physical operation sites of the parallel unit is achieved, and the accuracy of the offset of the physical operation sites of the parallel unit is improved on the premise that branch flow sensing hardware is not needed. And the recessive surge risk caused by single-machine performance discretization is inhibited.

A dispensing pump having a calibration system including a base including an upper base portion having a first end for mounting a motor and a second end and a lower base portion for mounting a pump on a first end and a second end. A hinge pivotally connects the second end of the upper base portion and the second end of the lower base portion. A linear actuator is mounted on the base and includes a drive rod having a coupler secured to an end thereof. The coupler joins the drive rod to a first end of a connecting member. A second end of the connecting member is secured to the lower base portion. An attachment plate attaches the motor to the first end of the upper base portion. The attachment plate extends outwardly from the motor for mounting the linear actuator. A proximity sensor is secured to the base upper position. A flag is secured to the drive rod coupler, wherein the flag moves directly with the drive rod. The flag includes a body and a calibration element projecting therefrom. The calibration element is positionally adjustable relative to the flag body. The calibration element is adapted to activate the proximity sensor when the linear drive is in a home position. The home position is adjustable upon adjustment of the calibration member. An actuation of the linear actuator drives the connecting member causing the lower base portion and upper base portion to pivot with respect to each other about the hinge, thereby changing an angle between the lower base portion and the upper base portion.

An agricultural work machine comprising at least one blower (40) for pneumatically actuating one or more conveying lines and / or for conveying material to be distributed, and a hydraulic system (1) for hydraulically actuating and / or operating one or more consumers (21A-21D), wherein the hydraulic system (1) has at least one hydraulic displacement unit (30) provided for driving the blower (40). In order to design an agricultural work machine such that the hydraulic system (1) is further simplified on the one hand and even more efficient on the other, it is provided that the displacement unit (30) is designed in the manner of an adjustable drive, preferably an adjustable motor or a variable displacement pump, with an adjustable displacement volume, which is coupled to the blower (40) in a mechanical and force-transmitting manner.

The invention relates to the technical field of variable displacement pump equipment, in particular to an energy-saving type electric delivery pump for material proportioning, which comprises a delivery pump body and an empty load prevention mechanism mounted on the delivery pump body, in the material delivery process, on one hand, pressure detection is associated with countdown of a controller, and on the other hand, pressure detection is associated with countdown of the controller; by means of the structure, when the liquid inlet end of the conveying pump body is lack of materials, a shutdown program can be automatically started, shutdown can be delayed, then when material supply is delayed and the material supply speed is unstable, continuous operation of the conveying pump body can be maintained, the degree of frequent starting and stopping of equipment can be reduced, and on the basis that materials are completely conveyed, the starting frequency is reduced, and the efficiency is improved. On the other hand, when the liquid outlet end is insufficient in material supply, the materials stored in the flow storage box are used for providing material supply for the delivery pump body, so that the no-load degree of the delivery pump body in the delayed shutdown process is reduced, and the problem that the service life of the delivery pump body is shortened due to no-load is solved.

An aerial work platform and a floating control system therefor. The system comprises a driving mechanism (5), a hydraulic oil tank (1), a hydraulic pump, a floating control valve (3), a floating mechanism, a movable arm function valve (4), an actuating mechanism, and an energy accumulator (8); the floating control valve (3) comprises a first one-way valve (32), a second one-way valve (33), a pressure reducing valve (34), and a logic valve (31); an oil inlet of the first one-way valve (32) serves as an oil inlet of the floating control valve (3), an oil outlet of the first one-way valve (32) is connected to a pipeline connecting the energy accumulator (8), the pressure reducing valve (34) and the logic valve (31), the logic valve (31) is connected to the second one-way valve (33), and an oil outlet of the second one-way valve (33) serves as a feedback oil port of the floating control valve (3); when the hydraulic pump is a variable displacement pump, the feedback oil ports of the floating control valve (3) and the movable arm function valve (4) are connected to a feedback oil port of the variable displacement pump; and when the hydraulic pump is a constant displacement pump, the feedback oil port of the floating control valve (3) is connected to the feedback oil port of the movable arm function valve (4). Thus, power loss can be reduced, and the reliability of the system can be improved.

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.

The application relates to the technical field of centrifugal pumps, and particularly discloses a high-sealing non-variable-volume pump and components thereof, which comprises a pump shell and an impeller, a water inlet and a water outlet are respectively arranged on the pump shell, the pump shell is in a volute type, the volute type comprises a wide section and a narrow section, and the pump shell further comprises a flow assisting mechanism which comprises a flow distribution port and a flow distribution sleeve arranged on the narrow section of the pump shell, a plurality of liquid inlet holes are arranged in a circular array on the water inlet, and the flow distribution sleeve is covered on the flow distribution port and the liquid inlet hole at two ends respectively. In the application, the flow distribution sleeve guides the fluid into the flow distribution sleeve along the flow distribution port at the narrow section of the volute type with the largest pressure during the operation of the impeller, then the flow distribution sleeve supplements the fluid to the water inlet of the pump shell, and the negative pressure at the water inlet is supplemented to reduce the cavitation and prolong the service life of the centrifugal pump.

The utility model discloses a novel hydraulic control system of household garbage dry-wet classification equipment, and belongs to the field of hydraulic control. The hydraulic control system comprises a large variable pump connected and driven by a first motor, a small variable pump connected and driven by a second motor, a duplex vane pump connected and driven by a third motor, a cooling circulating pump connected and driven by a fourth motor, a pressure control valve group, an extrusion roller feeding control valve group, a cooperative control valve group, an extrusion oil cylinder and a low-speed large-torque hydraulic motor; the device comprises a feeding oil cylinder, a door blocking oil cylinder, a door lifting oil cylinder, a push-pull box oil cylinder, a box locking oil cylinder, an oil return filter, a circulating filter, an air cooler and an oil tank. According to the utility model, the multifunctional control variable pump with constant power and remote constant-pressure control is adopted, so that the device is suitable for the extrusion working condition of household garbage dry-wet classification equipment, the working efficiency is higher, and small-load high speed and large-load low speed are easier to realize; and the system is more energy-saving and smaller in heat generation.

The utility model discloses a hydraulic station hydraulic system capable of providing two oil sources, which relates to the technical field of hydraulic systems and comprises a main oil way and an oil return way which are connected with an oil tank. A constant-pressure variable pump is mounted on the main oil way, and a proportional overflow valve is arranged on the constant-pressure variable pump; a connecting oil way connected with the main oil way is further arranged on the oil return oil way, and an overflow valve is installed on the connecting oil way. According to the utility model, two hydraulic oil sources can be provided, one is a constant displacement pump and an overflow valve, and the other is a constant-pressure variable displacement pump, so that whether the influence of the hydraulic oil sources on the pressure control effect of the designed electro-hydraulic proportional (servo) control system is different can be tested.

The application discloses a kind of pneumatic-hydraulic hybrid wave energy device energy conversion systems, including nozzle, impulse turbine, torque output shaft, shaft coupling, rotational speed sensor, variable displacement pump, energy accumulator, manual reversing valve, first electromagnetic ball valve, second electromagnetic ball valve, hydraulic motor, permanent magnet generator, PID control module, hydraulic oil tank, oil pressure sensor, first hysteresis comparator, second hysteresis comparator, air pressure sensor and overflow valve.The application realizes an innovative pneumatic-hydraulic energy conversion mode by combining air turbine and hydraulic conversion system.

The invention discloses a hydraulic system for a servo valve test bed, and relates to the technical field of servo valve hydraulics, the hydraulic system comprises a bottom plate, the lower side of the bottom plate is fixedly connected with supporting legs, the upper side of the bottom plate is fixedly connected with an oil tank, a variable pump and a high-pressure oil filter, and the upper side of the bottom plate is provided with a stabilizing unit for stabilizing the high-pressure oil filter to operate. Oil pipes are arranged on the left side and the right side of the high-pressure oil filter, the stabilizing unit comprises a plurality of stand columns, the stand columns are fixedly connected to the upper side of the bottom plate, fixing rings are fixedly connected to the upper ends of the stand columns, and vibration reduction assemblies are arranged on the inner sides of the fixing rings. According to the hydraulic system for the servo valve test bed, through the arrangement of the fixing ring, the stand columns, the branch rods, the clamping blocks, the rubber blocks, the lifting rods, the chassis and the electric push rod, the electric push rod is conveniently controlled to stretch out and draw back, the rubber blocks on the multiple clamping blocks are controlled to make contact with a high-pressure oil filter, and vibration generated by the high-pressure oil filter is conveniently buffered; and the stability of the high-pressure oil filter during operation is improved.

A dispensing pump includes a linear actuator mounted on a base. The linear actuator includes a drive rod having a coupler. The coupler joins the drive rod to a first end of a connecting member. A second end of the connecting member is secured to a lower base portion of the base. An attachment plate attaches a motor to a first end of an upper base portion of the base. A flag is secured to the drive rod coupler, wherein the flag moves directly with the drive rod. The flag includes a body and a calibration element. The calibration element is positionally adjustable relative to the flag body. The calibration element is adapted to activate a proximity sensor when the linear drive is in a home position. The home position is adjustable upon adjustment of the calibration member.

A method of controlling a propulsion system of a work or agricultural vehicle, wherein the propulsion system includes a prime mover (E) and a hydraulic transmission (HY) including a variable displacement pump (HP) configured to be driven in rotation by the prime mover and a variable displacement hydraulic motor (HM), operationally connected to the pump via a high pressure (F) and a low pressure (R) hydraulic line. The method providing an ECO mode in which the prime mover is operated at a predetermined fixed limit speed, such that the accelerator controls only the gear ratio defined by the hydraulic transmission, and in which the value of the limit speed is selected from two or multiple values belonging to a finite and countable set of values, depending on the current speed (VS) of the vehicle and an activation state of the hydraulic functions (HF).

A hydraulic pump circuit for a hydraulic system on a work machine may include a variable displacement pump in fluid communication with a hydraulic system via a supply line on a work machine. The variable displacement pump may be configured to provide hydraulic fluid flow to the hydraulic system. The hydraulic pump circuit may also include a stroke actuator in fluid communication with the supply line via a restriction orifice and may be configured for controlling the displacement volume of the variable displacement pump. The hydraulic pump circuit may also include a control valve configured for controlling the stroke actuator to upstroke and de-stroke the pump. The hydraulic pump circuit may also include a cutoff valve arranged and configured to de-stroke the pump when a threshold pressure develops within the hydraulic system.

A hydraulic system (1) according to one embodiment comprises: a first bidirectional pump (2) connected to a head-side chamber (4h) of a differential cylinder (4) via a head-side line (21) and to a rod-side chamber (4r) of the differential cylinder (4) via a rod-side line (22), wherein the first bidirectional pump (2) is a variable displacement pump; and a second bidirectional pump (3) connected to the head-side line (21) via a supply / discharge line (31), wherein the second bidirectional pump (3) is a variable displacement pump. The hydraulic system (1) further comprises: a low-pressure selector valve (6) connected to the head-side line (21) via a first outlet line (61) and to the rod-side line (22) via a second outlet line (62); and a position detector (9) that detects a position of the low pressure selector valve (6).

This utility model relates to the field of hydraulic pumping unit technology, and in particular to a one-to-two hydraulic pumping unit, comprising a mounting base plate, with support frames mounted on both the left and right sides of the top front side of the mounting base plate. Servo hydraulic cylinders are installed inside the support frames, and displacement sensors are installed inside the servo hydraulic cylinders. A hydraulic oil tank is bolted to the rear side of the top of the mounting base plate, and a proportional valve and a variable displacement pump motor are bolted to the top of the hydraulic oil tank. An accumulator is connected to the front side of the solenoid valve assembly. The proportional valve controls the two variable displacement pump motors to alternately work to supply oil to the servo hydraulic cylinders at both ends. When one servo hydraulic cylinder rises, the other servo hydraulic cylinder descends, transferring hydraulic energy to the other lifting variable displacement pump motor, causing the servo hydraulic cylinders at both ends to reciprocate. This one-to-two configuration achieves energy recovery and improves production efficiency.

The utility model relates to the technical field of hydraulic pressure, in particular to an open type plunger variable pump which comprises a pump body, a control valve body is installed on the pump body, the control valve body comprises a flow control valve and a pressure valve, a flow valve cavity is formed in the flow control valve, and a pressure valve cavity is formed in the pressure valve. A middle oil channel connecting the flow valve cavity and the pressure valve cavity is arranged in the control valve body, a pressure oil channel connecting the pressure valve cavity and the variable cavity is arranged in the control valve body, a flow oil channel connecting the flow valve cavity and the pressure valve cavity is arranged in the control valve body, an oil return channel is arranged on the pump body, one end of the oil return channel is connected with the flow oil channel, and the other end of the oil return channel is connected with the variable cavity. The other end of the oil return channel is connected with the oil outlet, the control valve body is provided with a load oil port connected with a load pipeline, and the load oil port is communicated with the flow valve cavity. According to the open type plunger variable pump, the flow and the pressure of the variable pump can be accurately and visually controlled, and the response speed, the equipment stability and the operation convenience of a system are improved.

A hydraulic pump circuit for a hydraulic system on a work machine may include a variable displacement pump in fluid communication with a hydraulic system via a supply line on a work machine. The variable displacement pump may be configured to provide hydraulic fluid flow to the hydraulic system. The hydraulic pump circuit may also include a stroke actuator in fluid communication with the supply line via a restriction orifice and may be configured for controlling the displacement volume of the variable displacement pump. The hydraulic pump circuit may also include a control valve configured for controlling the stroke actuator to upstroke and de-stroke the pump. The hydraulic pump circuit may also include a cutoff valve arranged and configured to de-stroke the pump when a threshold pressure develops within the hydraulic system.

A hydraulic system includes: a first bi-directional pump connected to a head-side chamber of a single-rod cylinder by a head-side line and connected to a rod-side chamber of the single-rod cylinder by a rod-side line; and a second bi-directional pump connected to the head-side line by a supply / discharge line, the second bi-directional pump being a variable displacement pump. The hydraulic system further includes a low-pressure selection valve connected to the head-side line by a first discharge line and connected to the rod-side line by a second discharge line, wherein the low-pressure selection valve allows the second discharge line or the first discharge line to communicate with a relief line on which a relief valve is located.

In accordance with at least one aspect of this disclosure, a variable displacement pump system can include, a variable displacement pump disposed in a main line and configured to supply pressure to receive a low pressure fluid and to output a high pressure fluid. The main line can connect a hydraulic fluid source to a plurality of system actuators, where the variable displacement pump is disposed in the main line between the hydraulic fluid source and the plurality of system actuators to pressurize the hydraulic fluid.

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. An electromechanical actuator (EMA) is operatively connected to actuate the variable displacement mechanism. A flow sensing valve (FSV) connected in the outlet line. The FSV includes a sensor configured to generate sensor data indicative of flow out of the outlet line. A controller is operatively connected to the EMA to control the variable displacement mechanism based on the sensor data to support flow demands from one or more downstream systems.

This invention discloses a method for designing the additional angle of the swashplate in a constant pressure variable displacement piston pump, comprising the following steps: A. When the additional angle β is 0, based on the inlet pressure P of the variable displacement pump... 始 Constant pressure P 终 Given the maximum swashplate angle α, determine the compression angle B. Based on equations 1 and 2), calculate the corresponding additional angle β at the maximum swashplate angle α. Then, using equation 3), calculate the angle C between the z-axis and the low-pressure zone oil window of the distributor plate. Calculate the curves showing the volume ratio changing with the additional angle β at different swashplate angles α. The intersection of these curves represents the optimal design value for the additional angle β under different operating conditions. This invention enables the variable pump to minimize pressure pulsation under any operating condition, thereby improving the performance of the constant pressure variable piston pump and the reliability and lifespan of the onboard hydraulic system.

The utility model discloses a mining machine cutting cylinder hydraulic control system which comprises a variable oil pump, the variable oil pump is connected with a first pipeline and a second pipeline, a left side motor and a three-way selector valve are arranged between the first pipeline and the second pipeline, the tail end of the first pipeline is connected with a first control valve, and the tail end of the second pipeline is connected with a second control valve. A reversing valve is arranged at the other end of the three-way selection valve and connected with a sequence control valve, the direction of the reversing valve is selected through the sequence control valve, one port of the reversing valve is connected with the control ends of the first control valve and the second control valve, the other port of the reversing valve is connected with a third control valve, and closed pipelines are arranged at one ends of the first control valve and the second control valve. The third control valve is connected to a closed pipeline in parallel, and a right motor is arranged on the closed pipeline. By switching the independent work of the left motor and the simultaneous work of the left motor and the right motor, the stepless speed regulation of the cutting cylinder is realized, so that the speed regulation interval is expanded, and the requirements under different working conditions are met.

An engine assembly for an aircraft propulsion system includes an engine, a rotational assembly, a gearbox assembly (38), and a controller (46). The engine includes an engine shaft (24) and the rotational assembly includes a shaft (30), a bladed compressor rotor (32), and a bladed turbine rotor (34). The shaft (30) interconnects the bladed compressor rotor (32) and the bladed turbine rotor (34). The gearbox assembly (38) includes a transmission assembly (44) having a first pump (54), a second pump (56), and a conduit circuit (58) connecting the first pump (54) and the second pump (56) in fluid communication. The first pump (54) is coupled with the engine shaft (24) and is a variable displacement pump. The second pump (56) is coupled with the rotational assembly. The controller (46) is configured to identify a target rotation speed for the rotational assembly with an outer closed loop, identify a control signal with an inner closed loop using the target rotation speed, and controlling a displacement of the first pump (54) using the control signal.