A detachable low-resistance double-end centrifugal pump

Abstract

The utility model belongs to centrifugal pump structure technical field relates to a kind of low flow resistance double-end centrifugal pumps of multi-detachable state. Including pump core assembly and pump shell assembly, the design of parallel double-end centrifugal pump, different performance can be designed according to the actual use of working condition point respectively, and the direct action is given to impeller after the import fuel rectification pressurization of inducer, also improve the ability of product anti cavitation. The above-mentioned utility model structure is reasonable, and dismounting efficiency is high, and quality is stable and reliable, and can satisfy the parallel double-end centrifugal pump use demand of outer field replaceable unit.

Description

Technical Field

[0001] This utility model belongs to the field of centrifugal pump structure technology, and relates to a low flow resistance double-end centrifugal pump with multiple detachable states. Background Technology

[0002] Common double-ended centrifugal pumps have a series structure. Fuel is pre-pressurized by the inducer impellers at both ends before being introduced into the main impeller. After being pressurized by the main impeller, it is forced into the spiral oil collecting chamber, forming a certain flow rate and pressure of fuel output. In this structure, the two inducer impellers are connected in parallel. Before the pre-pressurized fuel at both ends enters the main impeller, a large impact loss is inevitably generated, which has a significant impact on the high-altitude performance of the centrifugal pump. This effect is more pronounced in series-connected centrifugal pumps with low specific speeds.

[0003] In common detachable double-ended centrifugal pumps, even when the fuel in the tank is completely depleted, the inlet window seal needs to move to maintain a proper seal after disassembly. Each disassembly and reassembly inevitably causes relative movement between the inlet window and the seal. Especially when size is limited and the inlet window cannot have a large radius, the seal is prone to shearing, significantly reducing product reliability. Designing a selectable inlet window seal movement mechanism based on the remaining fuel in the tank would greatly improve product reliability.

[0004] When the fuel pump malfunctions, the engine's own suction capacity can overcome some pump resistance and draw in a certain flow of fuel for emergency fuel supply, buying time for the aircraft to handle the emergency. However, due to the structure of a dual-end centrifugal pump, fuel must flow through the entire pump body during emergency fuel intake. Furthermore, aviation centrifugal pumps are often designed with precision, resulting in significant flow resistance. This restricts the flow of fuel into the engine, thus affecting flight safety. Utility Model Content

[0005] Utility Model Purpose A novel double-ended pump structure is proposed, which features good design compatibility, strong cavitation resistance, independent design of the pump ends, stable and reliable quality, significantly reduced flow resistance during engine oil intake, and the ability to select the pump core assembly disassembly method based on the remaining oil status in the tank.

[0006] Technical solution A multi-detachable, low-flow-resistance, double-ended centrifugal pump includes a pump core assembly and a pump housing assembly. The pump core assembly comprises: a handle 1, a wire clamp cover 2, a sintered terminal 3, a wire clamp assembly 4, a lower inlet 5, a lower inducer 6, a lower impeller 7, a lower housing 8, a motor 9, an upper impeller 10, an upper inducer 11, and an upper inlet 12. The upper impeller 10 and the upper inducer 11 are sequentially mounted on the output shaft of the motor 9 near the upper pump suction port and are fixed by a self-locking nut. The upper inlet 12 is fitted with the motor 9 with a locking clearance. A bolt is provided at the end of the motor 9 away from the upper pump suction port. The flange end of the lower housing 8 with a snap-fit ​​groove is fixed to the nut by the bolt. The lower impeller 7 and the lower inducer 6 are sequentially mounted on the output shaft of the motor 9 at the end away from the upper pump inlet, and are fixed by a self-locking nut; the flange face of the lower housing 8 with a sealing ring groove at one end is connected to the mounting flange of the lower liquid inlet 5 by fastening screws, and the flange face of the other end of the lower housing 8 is connected to the pump housing assembly by fastening screws, and is provided with a groove, which provides an installation position for the sintering terminal 3. After the outer side of the sintering terminal 3 is welded, it is bundled and fixed by the wire clamp assembly 4, and limited by the wire pressure cover 2.

[0007] The pump housing assembly includes: base 13, sleeve 14, pump housing 15, upper self-sealing valve assembly 16, upper filter screen 17, oil outlet 18, upper pump check valve 19, lower pump check valve 20, bypass valve 21, pressure inlet 22, and lower filter screen 23.

[0008] The pump housing 15 has a liquid inlet window on its cylindrical surface, and a mounting flange is located at one end near the liquid inlet window. A sealing gasket is mounted on the mounting flange, which is connected to the oil tank body by a ring of fastening screws. A sleeve 14 and a base 13 are sequentially installed in the cylindrical inner cavity of the pump housing 15 near the liquid inlet window. The base 13 is fixed to the pump housing 15 by fastening screws, providing partial axial restraint on the sleeve 14. This allows for overlap and misalignment between the liquid inlet window on the sleeve 14 and the liquid inlet window on the pump housing 15. Sealing grooves are provided on the upper and lower sides of the pump housing 15 at the mating surfaces with the sleeve 14, thus achieving a sealing function when the sleeve 14 moves partially. An upper self-sealing valve assembly 16 and an upper filter screen 17 are connected to the flange face of the upper pump housing 15 away from the liquid inlet window by fastening screws. After the pump core assembly and pump housing assembly are assembled separately, align the snap-fit ​​groove on the lower housing 8 of the pump core assembly with the snap-fit ​​on the sleeve 14 of the pump housing assembly, and then insert it. Furthermore, the pump housing 15 has an integrated volute oil collection chamber at the end away from the inlet window, providing a place for hydraulic collection and conversion during pump operation.

[0009] Furthermore, the pump housing 15 is equipped with an upper pump check valve 19 and a lower pump check valve 20 at the upper and lower pump outlets, respectively, which improves product efficiency while preventing liquid backflow when the bypass valve is opened.

[0010] Furthermore, a bypass valve 21 is provided on the outermost side of the support frame of the lower pump check valve 20. When the product is malfunctioning, it can be opened by the engine suction to ensure a small flow of fuel to the engine, thereby avoiding the occurrence of aircraft power failure due to fuel pump failure.

[0011] Furthermore, the pump housing 15 is provided with a pressure inlet 22 at the junction of the upper and lower pumps, which can be connected to an external pressure sensor to monitor the working status of the product in real time and ensure safety during flight.

[0012] Furthermore, the pump housing 15 has an installation space for the oil outlet 18, which is fixed by fastening screws.

[0013] Furthermore, the pump core assembly is also provided with a handle 1, which is located on the lower inlet 5 and fixed by screws, providing a force point for disassembling the new pump.

[0014] Furthermore, the sintered terminal 3 in the pump core assembly is provided with a sealing ring groove, which is axially limited by the pressure cover 2, and can prevent the oil from the immersion motor from leaking out after installation.

[0015] The beneficial effects of this application are as follows: The low-flow-resistance bypass structure provided by this utility model allows the engine to continue supplying fuel through engine suction even when the fuel pump malfunctions, greatly ensuring flight safety during flight. The design adjusts whether the seals move during pump core assembly disassembly based on the remaining fuel level in the fuel tank, reducing the risk of seal damage and improving product reliability and ease of maintenance. The parallel double-ended centrifugal pump design allows for different performance settings for each pump based on actual operating conditions. Furthermore, the inducer rectifies and pressurizes the inlet fuel, directly acting on the impeller, which also improves the product's resistance to cavitation. This utility model features a reasonable structure, high assembly and disassembly efficiency, and stable and reliable quality, meeting the requirements for field-use replaceable parallel double-ended centrifugal pumps. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the pump core assembly; Figure 2 This is a schematic diagram of the pump casing assembly; Figure 3 This is a diagram showing the installation of the pump core and housing. Figure 4 This is a schematic diagram of the bypass low flow resistance structure. Figure 5 This is a schematic diagram of the self-sealing structure of the upper pump (open); Figure 6 This is a schematic diagram of the self-sealing structure of the upper pump (closed); Figure 7 This is a diagram showing the pump opening and closing (open). Figure 8 This is a diagram showing the pump opening and closing (closed). Figure 9 This is a schematic diagram of a sleeve buckle; Figure 10 This is a schematic diagram of the pump core housing snap-fit ​​groove.

[0017] The components include: handle 1, wire clamp cover 2, sintered terminal 3, wire clamp assembly 4, lower liquid inlet 5, lower inducer wheel 6, lower impeller 7, lower housing 8, motor 9, upper impeller 10, upper inducer wheel 11, upper liquid inlet 12; base 13, sleeve 14, pump housing 15, upper self-sealing valve assembly 16, upper filter screen 17, oil outlet 18, upper pump check valve 19, lower pump check valve 20, bypass valve 21, pressure inlet 22, and lower filter screen 23. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions in the embodiments of this utility model will be described in more detail below with reference to the embodiments of this utility model. In the examples, the same or similar reference numerals denote the same or similar components or elements having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of this utility model. The embodiments described below with reference to the embodiments are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model. The embodiments of this utility model will be described in detail below with reference to their specific implementation.

[0019] The utility model features of this utility model are: Product / device type utility model creation: Key features of this utility model: A one-way bypass structure is provided. When the engine malfunctions and urgently needs to draw fuel, an additional bypass directly to the fuel tank is added in addition to the internal flow channel of the pump body. This significantly reduces the flow resistance during engine fuel intake and improves the reliability of aircraft flight. When the product is operating normally, the bypass directly to the fuel tank is sealed to prevent fuel leakage and ensure efficient operation.

[0020] Secondary utility model point 1: Preferably, the utility model is a parallel double-ended pump with replaceable units in the field. The pump core assembly can be selectively disassembled according to the remaining oil in the oil tank, which can greatly improve the reliability of the product. Moreover, the performance of the two ends of the pump can be designed independently without affecting each other.

[0021] Secondary utility model point 2: Preferably, the sealing ring is made of FM-2D high-temperature resistant static sealing material, which has a working temperature of -55℃ to 200℃, and for some parts of use, the temperature can be higher than 200℃. In this utility model, the sealing ring is located in a part of use where the temperature is higher than 200℃.

[0022] Secondary utility model point 3: Preferably, a self-sealing valve is designed at the upper end of the fuel pump housing. When the fuel pump core is pulled out, the self-sealing valve automatically seals itself through the action of spring force, preventing fuel in the fuel tank from leaking from the upper pump.

[0023] Secondary utility model point 4: Preferably, the fuel pump housing is designed with a sleeve, and the sleeve is provided with buckles on both the inside and outside. When the fuel pump core is pulled out or inserted, the sleeve will move axially according to the action of the buckles, so as to realize the self-sealing and opening of the lower pump inlet and prevent fuel in the fuel tank from leaking from the lower pump.

[0024] Secondary utility model point 5: Preferably, the parallel double-end centrifugal pump design shortens the distance between the inducer and the working impeller, avoids fluid collision at the working front end of the working impeller, and thus improves the resistance to cavitation.

[0025] After the pump core assembly and pump housing assembly are assembled separately, align the snap-fit ​​groove on the lower housing 8 of the pump core assembly with the snap-fit ​​on the sleeve 14 of the pump housing assembly and insert it. If you do not want the sleeve 14 to move with the pump core assembly, simply insert it directly. If you want the sleeve 14 to move with the pump core assembly, first rotate the pump core assembly 10° clockwise, install it in place, and then rotate it 10° counterclockwise to tighten it. Conversely, reverse the operation. This achieves oil supply and sealing of the lower oil inlet window, allowing you to select the disassembly / reassembly method based on the remaining oil condition. After the pump core assembly is installed, the upper self-sealing valve assembly 16 opens, enabling oil supply. After the pump core assembly is pulled out, the upper self-sealing valve assembly 16 closes, thus achieving oil supply and sealing of the upper pump.

[0026] refer to Figure 1 This utility model mainly consists of a sleeve 14, a pump housing 15, an upper self-sealing valve assembly 16, a lower housing 8, a bypass valve 21, an upper pump check valve 19, a lower pump check valve 20, a bypass valve 21, and a pressure inlet 22.

[0027] In some embodiments, the self-sealing valve assembly 16 can be modified by changing the sealing method, such as changing the size of the sealing ring or changing the structure of the compression component, to achieve the effect of self-sealing and connection of the pump after the pump core is pulled out or inserted.

[0028] In some embodiments, the axial movement of the sleeve can be achieved by changing the number, size, position, structure, etc. of the buckles and buckle slots in the sleeve 14, lower housing 8, and pump housing 15, so as to achieve the sealing and connection effect of the lower pump after the pump core is pulled out or inserted.

[0029] In some embodiments, the reverse sealing function of the double-ended pump can be achieved by changing the size, position, structure, etc. of the upper pump check valve 19 and the lower pump check valve 20, so that the performance of the single pump is not affected by the other pump when the single pump is working.

[0030] In some embodiments, the bypass function of the pump can be achieved by changing the size, position, structure, and spring force of the bypass valve 21. When the fuel pump is not working, the fuel in the fuel tank can flow directly to the outlet through the bypass, greatly reducing the flow resistance of the product and improving the reliability of aircraft flight.

[0031] Working principle explanation: Working principle of bypass low flow resistance structure: When a product malfunctions or encounters an abnormal situation, the engine's suction capacity can create a negative pressure of 20 kPa at the pump outlet. If the pump itself can overcome this negative pressure, the engine can operate at a low flow rate, thus ensuring flight safety. However, the pump's complex structure and high precision requirements make it impossible to achieve a flow resistance of less than 20 kPa. If a bypass valve is designed at the connection between the pump outlet and the fuel tank, the pump outlet pipeline will remain under low pressure when the pump is not operating. The bypass valve opens due to the pressure difference created by the engine's suction, allowing fuel from the tank to directly reach the outlet pipeline and supply the engine, significantly reducing flow resistance. (See schematic diagram below.) Figure 4 .

[0032] Explanation of the working principle of the detachable structure: The self-sealing structures of the upper and lower pumps are key to achieving the detachable design.

[0033] The upper pump self-sealing structure adds a self-sealing valve assembly to the upper part of the pump housing. Structurally, it consists of components such as the self-sealing valve housing, self-sealing valve base, spring, and valve core assembly. When the pump core is assembled, the upper oil inlet on the pump core pushes the valve core assembly to open the self-sealing valve, allowing fuel from the fuel tank to enter the product. When the pump core is disassembled, the self-sealing valve closes under the action of the spring force, cutting off the fuel inlet to the pump, thus achieving the upper pump self-sealing function. See Figures 5-6 .

[0034] The lower pump's self-sealing structure utilizes a sealing sleeve that mates with the housing to achieve its self-sealing function. The sleeve is designed with an oil passage window and an oil outlet. During operation, the oil passage window and outlet on the sleeve are perfectly aligned with the oil inlet and outlet on the lower pump housing, ensuring normal operation of the lower pump. When the pump core is disassembled, the sleeve moves downwards with the pump core, ultimately completely isolating the oil passage window on the sleeve from the oil inlet window on the lower pump housing, thus preventing fuel from entering the housing. See the diagram for the opening and closing principle of the lower pump sleeve. Figures 7-8 .

[0035] During pump core disassembly, the L-shaped locking groove on the pump core housing rotates to switch positions with the locking clip on the sleeve, thereby limiting and disengaging the sleeve. As the pump core assembly moves up and down, the oil inlet window is ultimately opened and sealed.

[0036] Furthermore, unless otherwise defined, the technical or scientific terms used in this application description shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "upper," "lower," "left," "right," "center," "vertical," "horizontal," "inner," and "outer," etc., used in this application description to indicate relative direction or positional relationship are used only to indicate relative orientation or positional relationship, and do not imply that the device or component must have a specific orientation, or be constructed and operated in a specific orientation. When the absolute position of the described object changes, its relative positional relationship may also change accordingly, and therefore should not be construed as a limitation on this application. The terms "first," "second," "third," and similar terms used in this application description are used only for descriptive purposes to distinguish different components, and should not be construed as indicating or implying relative importance. The terms "a," "one," or "the," etc., used in this application description should not be construed as an absolute limitation on quantity, but should be construed as indicating the existence of at least one. The terms "including," "comprising," etc., used in this application description mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, without excluding other elements or objects.

[0037] Furthermore, it should be noted that, unless otherwise explicitly specified and limited, terms such as “installation,” “connection,” and “linkage” used in the description of this application should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; or it can be a connection within two components. Those skilled in the art can understand its specific meaning in this application according to the specific circumstances.

[0038] The above description is merely a specific embodiment of this utility model and is not intended to limit this utility model. Within the spirit and principles of this utility model, any person skilled in the art may use the above-disclosed technical content to make changes or modifications to equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of this utility model without departing from the technical solution of this utility model, as well as any modifications, equivalent substitutions, improvements, etc., should be included within the protection scope of this utility model.

Claims

1. A low-flow-resistance, double-ended centrifugal pump with multiple detachable states, characterized in that, The system includes a pump core assembly and a pump housing assembly. The pump core assembly includes: a handle, a wire clamp cover, sintered terminals, a wire clamp assembly, a lower inlet, a lower inducer, a lower impeller, a lower housing, a motor, an upper impeller, an upper inducer, and an upper inlet. The upper impeller and upper inducer are sequentially mounted on the output shaft of the motor near the upper pump inlet and secured with self-locking nuts. The upper inlet is fitted with a locking clearance of the motor. A bolt is located on the motor end away from the upper pump inlet. A flange with a snap-fit ​​groove on the lower housing is secured to a nut via a bolt. The lower impeller and lower inducer are sequentially mounted on the output shaft of the motor end away from the upper pump inlet and secured with self-locking nuts. The flange face on the lower housing end with a sealing ring groove is connected to the mounting flange of the lower inlet via fastening screws. The flange face on the other end of the lower housing is connected to the pump housing assembly via fastening screws and has a groove providing an installation position for the sintered terminals. After the outer side of the sintered terminals is wire-welded, they are bundled and secured by the wire clamp assembly and limited by the wire clamp cover. The pump housing assembly includes: a base, a sleeve, a pump housing, an upper self-sealing valve assembly, an upper filter screen, an oil outlet, an upper pump check valve, a lower pump check valve, a bypass valve, a pressure inlet, and a lower filter screen. The pump housing has an inlet window on its cylindrical surface, and a mounting flange is located near the inlet window. A sealing gasket is placed on the mounting flange, which is connected to the oil tank body by a ring of fastening screws. A sleeve and a base are sequentially installed in the cylindrical cavity of the pump housing near the inlet window. The base is fixed to the pump housing by fastening screws, providing partial axial restraint on the sleeve, thus allowing for overlap and misalignment between the inlet window on the sleeve and the inlet window on the pump housing. Sealing grooves are provided on the upper and lower sides of the pump housing inlet at the mating surfaces with the sleeve, ensuring a sealing function when the sleeve moves partially. The upper pump housing flange, located away from the inlet window, is connected to the upper self-sealing valve assembly and the upper filter screen by fastening screws. After the pump core assembly and pump housing assembly are assembled separately, align the snap-fit ​​groove on the lower housing of the pump core assembly with the snap-fit ​​on the sleeve of the pump housing assembly and then insert them.

2. The centrifugal pump as described in claim 1, characterized in that, The pump housing has an integrated volute oil collection chamber at the end away from the inlet window, providing a place for hydraulic collection and conversion during pump operation.

3. The centrifugal pump as described in claim 1, characterized in that, The pump housing is equipped with an upper pump check valve and a lower pump check valve at the upper and lower pump outlets to prevent liquid backflow when the bypass valve is opened.

4. The centrifugal pump as described in claim 1, characterized in that, A bypass valve is installed on the outermost side of the lower pump check valve support frame. In case of product malfunction, it can be opened by engine suction to ensure a small flow of fuel to the engine, thereby avoiding the occurrence of aircraft power failure due to fuel pump failure.

5. The centrifugal pump as described in claim 1, characterized in that, The pump housing has a pressure inlet at the junction of the upper and lower pumps, which can be connected to an external pressure sensor to monitor the product's working status in real time and ensure safe operation during flight.

6. The centrifugal pump as claimed in claim 1, characterized in that, The pump housing has an installation space for the oil outlet and is fixed by fastening screws.

7. The centrifugal pump as claimed in claim 1, characterized in that, The pump core assembly also has a handle, which is located on the lower inlet and secured with screws.

8. The centrifugal pump as claimed in claim 1, characterized in that, The sintered terminal in the pump core assembly is provided with a sealing ring groove, which is axially limited by the pressure cap.

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