A system for calculating the output flow of an aviation plunger pump based on the rotating speed and the tilt angle of a swash plate

Abstract

The application belongs to the technical field of aircraft hydraulic system, and particularly relates to an output flow calculation system of an aircraft plunger pump based on rotating speed and swash plate inclination angle, aiming to solve the problems of pipeline characteristic damage caused by installation of a traditional flowmeter and insufficient measurement accuracy. The system comprises a plunger pump, a rotating speed sensor of a transmission shaft, an inclination angle sensor of a swash plate, a shell temperature sensor and an acquisition and calculation device. The rotating speed sensor and the inclination angle sensor are used to respectively collect the rotating speed of the transmission shaft and the inclination angle of the swash plate in real time, the oil temperature monitored by the shell temperature sensor is combined, the acquisition and calculation device calculates the basic flow according to the plunger pump theory, and the temperature compensation quantity based on test calibration is superimposed, so that the high-precision actual output flow is obtained. The scheme does not need to connect the flowmeter in series in the hydraulic pipeline, and eliminates the flow resistance increase and the risk of jam caused by the additional sensor.

Description

Technical Field

[0001] This application belongs to the technical field of aircraft hydraulic systems, and specifically relates to an aircraft piston pump output flow calculation system based on rotational speed and swashplate tilt angle. Background Technology

[0002] Aircraft hydraulic systems utilize piston pumps driven by engine transmission housings or electric motors to generate hydraulic energy. This provides sufficient pressure and flow to the flight control system, landing gear retraction and extension control, wheel brakes, nose wheel steering, and other systems. Piston pumps are typically constant-pressure variable-displacement pumps; their outlet pressure is constant, and their output power is directly proportional to their output flow rate.

[0003] Insufficient output flow in a hydraulic system can easily lead to malfunction or reduced performance for hydraulic users, while excessive output flow can result in unnecessary weight due to over-design. During ground testing, the output flow of piston pumps under various operating conditions is typically tested thoroughly on iron bird test benches. However, ground conditions cannot simulate the loads of actual flight conditions for each user, resulting in a significant difference between the piston pump output flow measured on the ground and the output flow under actual flight conditions. Measuring the piston pump output flow under aircraft flight conditions is challenging. Turbine or gear flow meters are large and heavy, and they themselves can affect the flow characteristics of the pipeline; jamming can prevent hydraulic energy output. While indirect measurement methods such as ultrasonic measurements do not damage the system pipeline, their measurement accuracy is poor and they are easily affected by the aircraft's electromagnetic environment.

[0004] Therefore, there is a need for a technical solution to measure the output flow of a plunger pump with sufficiently high accuracy without disrupting the system's operating state. Summary of the Invention

[0005] To address the aforementioned problems, this application provides a system for calculating the output flow rate of an aircraft plunger pump based on rotational speed and swashplate tilt angle, comprising:

[0006] A plunger pump (1) is connected to an engine transmission housing or an electric motor via a drive shaft (2) and draws oil from a hydraulic tank (6) to provide high-pressure hydraulic oil to a hydraulic user (7);

[0007] A drive shaft speed sensor (3) is installed on the drive shaft (2) and is used to collect the speed signal of the drive shaft in real time.

[0008] A swashplate angle sensor (4) is installed on the swashplate of the piston pump (1) to collect the swashplate tilt angle signal in real time.

[0009] A housing temperature sensor (5) is installed on the housing of the plunger pump (1) to collect the temperature signal of the oil inside the pump housing in real time.

[0010] The data acquisition and calculation device (8) is electrically connected to the drive shaft speed sensor (3), swashplate angle sensor (4) and housing temperature sensor (5) respectively, and is used to receive the speed signal, tilt angle signal and temperature signal, and calculate the output flow of the plunger pump;

[0011] The signal receiving device (9) is communicatively connected to the acquisition and computing device (8) and is used to receive, display or process the output flow.

[0012] Preferably, the data acquisition and computing device (8) includes a data acquisition module, a data processing module, and a data transmission module connected in sequence;

[0013] The data acquisition module is configured to perform analog-to-digital conversion on the speed signal, tilt angle signal, and temperature signal.

[0014] The data processing module is configured to calculate the theoretical flow rate based on a preset algorithm and add temperature compensation.

[0015] The data transmission module is configured to send the output traffic to the signal receiving device (9) via the airborne bus.

[0016] Preferably, the data processing module uses the following formula to calculate the theoretical flow rate q:

[0017] ;

[0018] Where d is the plunger diameter, D is the pitch circle diameter of the plunger on the cylinder block, n is the spindle speed, z is the number of plungers, δ is the swashplate angle, and η is the volumetric efficiency of the plunger pump.

[0019] Preferably, the data processing module is further configured to calculate the actual output flow rate Q, and the calculation formula is:

[0020] ;

[0021] Wherein, Δq is the temperature compensation amount determined based on the temperature value collected by the housing temperature sensor (5).

[0022] Preferably, the temperature compensation amount Δq is obtained through pre-test calibration; the data processing module has a pre-stored table of the correspondence between temperature and compensation amount, and the data processing module is configured to obtain the corresponding Δq value by looking up the table using linear interpolation based on the current temperature collected by the shell temperature sensor (5).

[0023] Preferably, the swashplate angle sensor (4) is a non-contact displacement sensor or angular displacement sensor, with its probe positioned directly opposite the surface of the swashplate or the hinge point of the swashplate drive mechanism, in order to accurately measure the swashplate's deflection angle δ relative to the zero position.

[0024] Preferably, the transmission shaft speed sensor (3) is a magnetoelectric speed sensor or a Hall effect speed sensor, and its sensing end is located close to the gear ring or keyway on the transmission shaft (2).

[0025] Preferably, the signal receiving device (9) includes at least one of the following: flight control computer, data management system, and cockpit display device; the acquisition and computing device (8) is connected to the signal receiving device (9) via a bus.

[0026] Preferably, the acquisition and computing device (8) is integrated into the existing processing unit of the avionics equipment, or installed as an independent replaceable module in the avionics equipment bay.

[0027] Preferably, the hydraulic user (7) includes at least one of the flight control control surface actuator, landing gear retraction actuator, wheel braking system and nose wheel steering system; the plunger pump (1) is a constant pressure variable displacement plunger pump.

[0028] Preferably, the volumetric efficiency η of the plunger pump is stored in the memory of the data processing module. The volumetric efficiency η is a two-dimensional mapping table data that varies with rotational speed n and temperature. When calculating q, the data processing module calls the corresponding η value in real time according to the current rotational speed and temperature.

[0029] Preferably, the probe end of the housing temperature sensor (5) is immersed in the oil in the oil return chamber or the oil drain port of the plunger pump (1) housing to ensure that the measured temperature is the actual oil temperature that directly affects the oil viscosity.

[0030] This invention can calculate the output flow of an aviation plunger pump in real time with high accuracy, without damaging the inherent characteristics of the system due to the addition of flow sensors or other operations. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the aviation plunger pump output flow calculation system based on rotational speed and swashplate tilt angle according to this application.

[0032] Figure 2 This diagram illustrates the key parameters involved in the calculations of this application. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are only some, not all, of the embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0034] like Figure 1 As shown, the aviation plunger pump output flow calculation system based on rotational speed and swashplate tilt angle provided in this application includes: a plunger pump 1, a drive shaft 2, a drive shaft speed sensor 3, a swashplate angle sensor 4, a housing temperature sensor 5, a hydraulic oil tank 6, a hydraulic user 7, a data acquisition and calculation device 8, and a signal receiving device 9.

[0035] The plunger pump 1 is driven to rotate via the transmission shaft 2 by the engine transmission housing, electric motor, etc. The plunger pump 1 draws oil from the hydraulic oil tank 6, generating high-pressure hydraulic oil to provide hydraulic energy with a certain pressure and flow rate to the hydraulic user 7. In some examples of this application, the hydraulic user 7 can be one or more hydraulic users that require a hydraulic power source, such as flight control surfaces, landing gear retraction and extension, wheel brakes, or nose wheel steering.

[0036] A drive shaft speed sensor 3 is installed on the drive shaft 2 of the plunger pump 1 to measure the speed of the drive shaft 2 in real time.

[0037] Among them, a swashplate angle sensor 4 is installed on the swashplate of the piston pump 1 to measure the tilt angle of the swashplate in real time when the piston pump 1 is working.

[0038] Among them, a housing temperature sensor 5 is installed on the housing of the plunger pump 1 to measure the temperature of the oil in the housing cavity of the plunger pump 1 in real time.

[0039] The data acquisition and calculation device 8 is connected to the drive shaft speed sensor 3, swashplate angle sensor 4, and housing temperature sensor 5 via cables. It acquires the speed, angle, and temperature signals measured by these sensors and then calculates the output flow rate of the plunger pump 1. In some embodiments of this application, the data acquisition and calculation device 8 can be a single device, multiple devices separating data acquisition and processing, or one or more functions integrated into other devices.

[0040] The data acquisition and computing device 8 transmits the output flow of the plunger pump 1 to the signal receiving device 9 via a bus. In some embodiments of this application, the signal receiving device 9 may be one or more devices in an aircraft that require the output flow of the plunger pump 1, such as a flight control computer, a data management system, a display device, etc.

[0041] When the piston pump 1 is working, the flow rate changes with the rotational speed and the swashplate angle. Therefore, after measuring the spindle speed and the swashplate angle, the output flow rate of the piston pump 1 can be indirectly measured.

[0042] The theoretical flow rate calculation formula for plunger pump 1 is as follows:

[0043] ;

[0044] Where z is the number of plungers. The main spindle speed is given by D, where D is the pitch circle diameter of the plunger on the cylinder block, and d is the plunger diameter. This refers to the volumetric efficiency of the plunger pump. The swashplate inclination angle.

[0045] like Figure 2 As shown, the diameter of the pitch circle 12 is D, the diameter of the plunger 10 is d, the number of plungers 10 is z, and the inclination angle of the swashplate 11 is... .

[0046] Considering that the actual output flow rate of plunger pump 1 will be affected by temperature, the final actual output flow rate needs to be superimposed on q. ;

[0047] in The compensation amount was measured experimentally at the temperature difference between different points. Fitting values ​​at different temperatures using interpolation and other methods .

[0048] The actual output flow rate of plunger pump 1 is:

[0049] .

[0050] The beneficial effects of this application are as follows: It provides an aviation plunger pump output flow calculation system based on rotational speed and swashplate tilt angle. By collecting signals of drive shaft rotational speed, swashplate tilt angle, and casing oil temperature, the output flow is indirectly calculated using the working principle of the plunger pump. This completely avoids the safety hazards such as increased flow resistance, flow field distortion, and jamming / supply interruption caused by the need for traditional turbine or ultrasonic flow meters to be connected in series with the pipeline, thus ensuring the inherent safety of the hydraulic system. At the same time, by establishing a correction model that includes temperature compensation Δq, it effectively overcomes the volumetric efficiency fluctuation caused by changes in hydraulic oil viscosity with temperature, significantly improving the calculation accuracy under sensorless conditions. In addition, this system adopts a modular design and can be directly integrated into existing avionics equipment without modifying the original structure of the hydraulic system. It has the advantages of lightweight, high reliability, and real-time monitoring of the entire envelope, providing an effective technical means for condition monitoring and predictive maintenance of aircraft hydraulic systems.

[0051] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A system for calculating the output flow rate of an aircraft plunger pump based on rotational speed and swashplate tilt angle, characterized in that, include: A plunger pump (1) is connected to an engine transmission housing or an electric motor via a drive shaft (2) and draws oil from a hydraulic tank (6) to provide high-pressure hydraulic oil to a hydraulic user (7); A drive shaft speed sensor (3) is installed on the drive shaft (2) and is used to collect the speed signal of the drive shaft in real time. A swashplate angle sensor (4) is installed on the swashplate of the piston pump (1) to collect the swashplate tilt angle signal in real time. A housing temperature sensor (5) is installed on the housing of the plunger pump (1) to collect the temperature signal of the oil inside the pump housing in real time. The data acquisition and calculation device (8) is electrically connected to the drive shaft speed sensor (3), swashplate angle sensor (4) and housing temperature sensor (5) respectively, and is used to receive the speed signal, tilt angle signal and temperature signal, and calculate the output flow of the plunger pump; The signal receiving device (9) is communicatively connected to the acquisition and computing device (8) and is used to receive, display or process the output flow.

2. The aviation plunger pump output flow calculation system based on rotational speed and swashplate tilt angle according to claim 1, characterized in that, The data acquisition and computing device (8) includes a data acquisition module, a data processing module and a data transmission module connected in sequence; The data acquisition module is configured to perform analog-to-digital conversion on the speed signal, tilt angle signal, and temperature signal. The data processing module is configured to calculate the theoretical flow rate based on a preset algorithm and add a temperature compensation amount; The data transmission module is configured to send the output traffic to the signal receiving device (9) via the airborne bus.

3. The aviation plunger pump output flow calculation system based on rotational speed and swashplate tilt angle according to claim 2, characterized in that, The data processing module uses the following formula to calculate the theoretical flow rate q: ； Where d is the plunger diameter, D is the pitch circle diameter of the plunger on the cylinder block, n is the spindle speed, z is the number of plungers, δ is the swashplate angle, and η is the volumetric efficiency of the plunger pump.

4. The aviation plunger pump output flow calculation system based on rotational speed and swashplate tilt angle according to claim 3, characterized in that, The data processing module is also configured to calculate the actual output flow rate Q, and the calculation formula is: ； Wherein, Δq is the temperature compensation amount determined based on the temperature value collected by the housing temperature sensor (5).

5. The aviation plunger pump output flow calculation system based on rotational speed and swashplate tilt angle according to claim 4, characterized in that, The temperature compensation amount Δq is obtained through pre-test calibration; the data processing module has a pre-stored table of the correspondence between temperature and compensation amount, and the data processing module is configured to obtain the corresponding Δq value by looking up the table using linear interpolation based on the current temperature collected by the shell temperature sensor (5).

6. The aviation plunger pump output flow calculation system based on rotational speed and swashplate tilt angle according to claim 1, characterized in that, The swashplate angle sensor (4) is a non-contact displacement sensor or angular displacement sensor. Its probe is set directly opposite the surface of the swashplate or the hinge point of the swashplate drive mechanism to accurately measure the swashplate deflection angle δ relative to the zero position.

7. The aviation plunger pump output flow calculation system based on rotational speed and swashplate tilt angle according to claim 1, characterized in that, The transmission shaft speed sensor (3) is a magnetoelectric speed sensor or a Hall effect speed sensor, and its sensing end is located close to the gear ring or keyway on the transmission shaft (2).

8. The aviation plunger pump output flow calculation system based on rotational speed and swashplate tilt angle according to claim 1, characterized in that, The signal receiving device (9) includes at least one of the following: flight control computer, data management system, and cockpit display device; the acquisition and computing device (8) is connected to the signal receiving device (9) via a bus.

9. The aviation plunger pump output flow calculation system based on rotational speed and swashplate tilt angle according to claim 1, characterized in that, The acquisition and computing device (8) is integrated into the existing processing unit of the avionics equipment, or installed as an independent replaceable module in the avionics equipment bay.

10. The aviation plunger pump output flow calculation system based on rotational speed and swashplate tilt angle according to claim 1, characterized in that, The hydraulic user (7) includes at least one of the flight control control surface actuator, landing gear retraction actuator, wheel braking system and nose wheel steering system; the plunger pump (1) is a constant pressure variable displacement plunger pump.

11. The aviation plunger pump output flow calculation system based on rotational speed and swashplate tilt angle according to claim 3, characterized in that, The volumetric efficiency η of the plunger pump is stored in the memory of the data processing module. The volumetric efficiency η is a two-dimensional mapping table data that varies with rotational speed n and temperature. When calculating q, the data processing module calls the corresponding η value in real time according to the current rotational speed and temperature.

12. The aviation plunger pump output flow calculation system based on rotational speed and swashplate tilt angle according to claim 1, characterized in that, The probe end of the housing temperature sensor (5) is immersed in the oil in the return oil chamber or the drain port of the piston pump (1) housing to ensure that the measured temperature is the actual oil temperature that directly affects the viscosity of the oil.

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