Aviation fuel pump with self-adaptive liquid supplementing function
By setting a reflux hole and adjustment structure on the rear cover plate of the liquid ring pump, the self-priming performance of the liquid ring pump can be adaptively replenished, which solves the problem of decreased self-priming performance caused by liquid loss and improves the self-priming capability of the aviation fuel pump.
Patent Information
- Application Number
- CN202511952915.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-23
- Publication Date
- 2026-02-10
AI Technical Summary
Existing aviation fuel pumps suffer from reduced self-priming performance due to liquid loss in the liquid ring pump chamber at high altitudes, making it impossible to replenish the working fluid in a timely manner. This affects the self-priming capability of the fuel pump and may lead to flight accidents.
A reflux hole is provided on the rear cover plate of the liquid ring pump, and the opening and closing of the reflux hole is adjusted by a spring and a valve plate. The liquid volume is adaptively replenished according to the vacuum level inside the pump to ensure the stability of the liquid in the liquid ring pump cavity.
It improves the self-priming performance of the fuel pump, prevents prolonged self-priming time or cavitation, and ensures stable operation of the fuel pump in high-altitude environments.
Smart Images
Figure CN121497634A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to an aviation fuel pump, and more particularly to an adaptive fuel replenishment aviation fuel pump. Background Technology
[0002] Aviation fuel pumps are a special type of fuel pump composed of a centrifugal pump and a liquid ring pump. They are responsible for the critical task of continuously and stably delivering fuel in different high-altitude environments. The liquid ring pump is located after the centrifugal pump. As the self-priming structure of the fuel pump, it discharges the gas in the fuel pump system's suction line and the centrifugal pump chamber during the pump start-up process, thus achieving self-priming of the pump. Due to the weight reduction requirements of aviation pumps, fuel pumps lack a separate liquid replenishment system during self-priming. They rely solely on a small amount of liquid stored in the liquid ring pump chamber and front chamber after engine shutdown to establish a vacuum. Furthermore, some of the liquid in the liquid ring pump is discharged with the gas during exhaust, resulting in liquid loss within the chamber. Additionally, during high-altitude flight, the fuel pump is susceptible to cavitation due to the high-altitude environment. When cavitation occurs within the pump, some liquid vaporizes, causing further loss. This liquid loss leads to the liquid ring detaching from the blades more prematurely, causing seal failure and inducing gas backflow between the blades, thus reducing the pump's pumping capacity. These phenomena further prolong the self-priming time or cause cavitation, failing to meet the strong self-priming requirements of aviation fuel pumps. If the fuel pump cannot deliver fuel to the engine in a timely manner, it could lead to serious flight accidents. Summary of the Invention
[0003] The purpose of this invention is to provide an adaptive replenishment aviation fuel pump to solve the technical problem in the prior art where the working fluid cannot be replenished in time after the liquid volume in the liquid ring pump chamber is lost, resulting in a decrease in the self-priming performance of the fuel pump.
[0004] The technical solution adopted by this invention to solve its technical problem is: an adaptive replenishment aviation fuel pump, including a centrifugal pump, a liquid ring pump and a motor. A suction section is provided in front of the centrifugal pump, and a housing is provided behind the centrifugal pump. The motor is located behind the housing, and the liquid ring pump is located inside the housing. The centrifugal pump and the liquid ring pump are connected to the motor through a main shaft. A front liquid storage chamber is provided in front of the liquid ring pump inside the housing, and a rear liquid storage chamber is provided behind the liquid ring pump. An installation area is provided on the rear cover plate of the liquid ring pump. A reflux hole is provided in the installation area, and a spring is provided in the reflux hole. The front end of the spring is connected to a bracket and fixed to the rear cover plate by fastening screws. A valve plate is provided at the end of the spring.
[0005] Further improvements: The impeller outer diameter on the liquid ring pump is R, the mounting area is fan-shaped, the inner radius of the fan ring is 0.7R, the outer radius of the fan ring is 0.95R, and the included angle between the two sides of the fan ring is 60°.
[0006] Further improvement: Looking along the direction of the suction section, the mounting area is located on the right side of the rear cover, and the angle between the side and the horizontal plane is 30°.
[0007] Advantages of this invention: Compared with the prior art, this invention has a simple structure. By arranging a return hole on the rear cover plate corresponding to the vacuum area in the liquid ring pump, the opening and closing of the return hole can be adjusted according to the vacuum level in the pump, so as to realize the adaptive replenishment of the working fluid in the liquid ring pump cavity during the self-priming process of the fuel pump. This solves the problem of vacuum deterioration caused by the lack of liquid in the pump in the prior art and improves the self-priming performance of aviation fuel pumps. Attached Figure Description
[0008] Figure 1 This is a schematic diagram of the structure of the present invention.
[0009] Figure 2 This is a schematic diagram of the structure at the reflux hole of the present invention.
[0010] Figure 3 This is a schematic diagram showing the location of the installation area of the present invention.
[0011] Figure 4 This is a schematic diagram showing the dimensions of the installation area of the present invention.
[0012] Figure 5 This is a schematic diagram of the gas phase leakage principle of the present invention.
[0013] Figure 6 This is a schematic diagram of the liquid ring pump of the present invention.
[0014] In the diagram: 1. Suction section; 2. Centrifugal pump; 3. Housing; 4. Main shaft; 5. Motor; 6. Front liquid storage chamber; 7. Cover plate; 71. Suction port; 8. Liquid ring pump; 81. Hub; 82. Blade; 9. Cover plate; 91. Exhaust port; 10. Return hole; 101. Bracket; 102. Spring; 103. Valve plate; 11. Rear liquid storage chamber; 12. Installation area; 13. Inner surface of liquid ring; 14. Gas phase leakage vortex; 15. Rotation center of impeller O1; 6. Center of liquid ring pump housing O2. Detailed Implementation
[0015] The present invention will now be described in detail with reference to the accompanying drawings.
[0016] As shown in the figure, an adaptive replenishment aviation fuel pump includes a centrifugal pump 2, a liquid ring pump 8, and a motor 5. A suction section 1 is located in front of the centrifugal pump 2, and a housing 3 is located behind the centrifugal pump 2. The motor 5 is located behind the housing 3, and the liquid ring pump 8 is located inside the housing 3. The centrifugal pump 2 and the liquid ring pump 8 are connected to the motor 5 via a main shaft 4. A front liquid reservoir 6 is located in front of the liquid ring pump 8 inside the housing 3, and a rear liquid reservoir 11 is located behind the liquid ring pump 8. The liquid ring pump 8 is formed by a front cover... The pump consists of a front cover plate 7, a housing 80, an impeller, and a rear cover plate 9. An air intake 71 is provided on the front cover plate 7. The impeller is composed of a hub 81 and blades 82. An exhaust port 91 is provided on the rear cover plate 9. An installation area 12 is provided on the rear cover plate 9 of the liquid ring pump 8. A return hole 10 is provided in the installation area 12. A spring 102 is provided in the return hole 10. The front end of the spring 102 is connected to a bracket 101 and fixed to the rear cover plate 9 by fastening screws. A valve plate 103 is provided at the end of the spring 102.
[0017] The outer radius of the blade 82 on the liquid ring pump 8 is R. The mounting area 12 is fan-shaped. The radius of the inner edge 121 of the fan ring is 0.7R, the radius of the outer edge 122 of the fan ring is 0.95R, and the included angle between the two sides 123 of the fan ring is 60°. Looking along the direction of the suction section, the mounting area 12 is located on the right side of the rear cover plate 9, and the included angle between the side 123 and the horizontal plane is 30°.
[0018] Its working principle is as follows: After the aviation fuel pump stops, a portion of fuel will remain in the front reservoir 6, the liquid ring pump 8, and the rear reservoir 11. During pump startup, the liquid ring pump 8, relying on the remaining fuel, forms a liquid ring and establishes a vacuum under the high-speed rotation of the impeller, expelling the gas from the pipeline system and the centrifugal pump 2 chamber. In the initial stage of self-priming, due to the large amount of fuel in the liquid ring pump 8 and the high vacuum, when the pressure difference dominated by the negative pressure in the liquid ring pump 8 exceeds the preload of the spring 102, the valve plate 103 moves towards the front reservoir 6 and engages with the rear cover plate 9. The seal is tight, keeping the return hole 10 disconnected from the rear liquid storage chamber 11. As self-priming progresses, the oil in the liquid ring pump 8 is continuously discharged from the exhaust port 91 along with the gas. During the discharge process, a portion of the liquid undergoes gas-liquid separation in the rear liquid storage chamber 11 and is stored there, gradually reducing the amount of liquid in the liquid ring pump 8. Furthermore, when the liquid ring pump 8 operates at high altitudes, cavitation is highly likely to occur. Under cavitation, some of the oil vaporizes, further leading to oil loss within the liquid ring pump 8. In the above two... In certain situations, when the oil loss in the liquid ring pump 8 reaches a certain level, the inner surface 13 of the liquid ring will detach from the blade 82, causing the liquid ring seal to fail. The pumped gas leaks in the opposite direction of the rotation of the blade 81, forming a gas phase leakage vortex 14. This leads to a decrease in the vacuum level in the impeller flow channel. When the pressure difference force dominated by the negative pressure in the liquid ring pump 8 is less than the preload force of the spring 102, the valve plate 103 moves axially towards the rear liquid storage chamber 11, detaching from the rear cover plate 9. The return hole 10 communicates with the rear liquid storage chamber 11, and the oil remaining in the rear liquid storage chamber 11... The oil is automatically replenished into the liquid ring pump 8 through the return hole 10, increasing the amount of oil inside. The inner surface 13 of the liquid ring once again submerges the blades 82, increasing the vacuum. When the pressure difference force dominated by the negative pressure inside the liquid ring pump 8 exceeds the preload force of the spring 102 again, the valve plate 103 moves axially towards the forward liquid storage chamber 6 and fits tightly against the rear cover plate 9, so that the return hole 10 is disconnected from the rear liquid storage chamber 11. In this way, the adaptive replenishment function of the liquid volume in the liquid ring pump 8 is realized according to the vacuum level inside the liquid ring pump 8, which can improve the self-priming performance of the aviation fuel pump.
[0019] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.
Claims
1. An adaptive replenishment aviation fuel pump, comprising a centrifugal pump, a liquid ring pump, and a motor, characterized in that: A suction section is provided in front of the centrifugal pump, and a housing is provided behind the centrifugal pump. The motor is located behind the housing, and the liquid ring pump is located inside the housing. The centrifugal pump and the liquid ring pump are connected to the motor through a main shaft. A front liquid storage chamber is provided in front of the liquid ring pump and a rear liquid storage chamber is provided behind the liquid ring pump. An installation area is provided on the rear cover plate of the liquid ring pump. A reflux hole is provided in the installation area. A spring is provided in the reflux hole. The front end of the spring is connected to the inner wall of the rear cover plate through a bracket, and a valve plate is provided at the end of the spring.
2. The adaptive replenishment aviation fuel pump according to claim 1, characterized in that: The impeller on the liquid ring pump has an outer diameter of R, the mounting area is fan-shaped, the inner radius of the fan ring is 0.7R, the outer radius of the fan ring is 0.95R, and the included angle between the two sides of the fan ring is 60°.
3. The adaptive replenishment aviation fuel pump according to claim 2, characterized in that: Looking along the direction of the suction section, the mounting area is located on the right side of the rear cover, and the side is at an angle of 30° to the horizontal plane.