Mechanical differential pressure signal feedback device and application

Abstract

The invention belongs to the technical field of hydraulic pressure, and particularly relates to a mechanical differential pressure signal feedback device and application. The feedback device is composed of a diaphragm assembly, a spring, a blanking cap and a valve seat. An oil through hole is formed in the valve seat; a spring is arranged in an inner cavity of the blanking cap; one end of the spring abuts against the end of the blanking cap, and the other end abuts against the diaphragm assembly. An oil through hole is formed in the blanking cap; external oil is communicated with the inner cavity of the blanking cap, and the oil pressure can act on the left side of the diaphragm assembly; the diaphragm assembly is in contact fit with the end part of the valve seat under the action of the spring; the feedback device designed by the invention is matched with a certain type of gas turbine for use, is a mechanical hydraulic signal feedback device capable of meeting oil filter pressure difference monitoring and maintenance of a lubricating oil circuit of an oil supply pump, and has the advantages of visual monitoring, no electromagnetic interference, simple structure, convenience in maintenance and the like.

Description

Technical Field

[0001] This invention belongs to the field of hydraulic technology, specifically relating to a mechanical differential pressure signal feedback device and its application. Background Technology

[0002] Traditionally, a pressure signaler or pressure sensor is installed in the lubrication circuit inside the fuel supply pump of a gas turbine's fuel control system. To protect the safe and reliable operation of the fuel supply pump and prevent contaminants from entering the lubrication circuit and causing abnormal wear and damage, an oil filter is installed in the lubrication circuit to filter contaminants in the lubrication system. This causes an increase in pressure before and after the oil filter. By setting a pressure limit, the signal is transmitted to the pressure signaler, which converts it into a usable output electrical signal according to a certain rule. This allows the system to determine the oil filter blockage and maintain or replace the oil filter as needed to protect the fuel supply pump and ensure the safe and reliable operation of the engine.

[0003] Since pressure signal sensors convert the strain of external objects or systems into easily measurable or detectable electrical signals, they are electrical components with high precision requirements for their parts, complex coil manufacturing processes, and the connecting coil wires needing to withstand high temperatures and being easily broken, resulting in high manufacturing costs. Therefore, a simple and highly reliable mechanical hydraulic signal sensor was invented. Summary of the Invention

[0004] Purpose of the invention: In order to solve the problem of system complexity caused by the use of electrical signal devices in the fuel supply pump of the fuel control system of gas turbines, this invention proposes a mechanical differential pressure signal feedback device.

[0005] Technical Solution: To achieve the above-mentioned objectives, this invention provides a mechanical differential pressure signal feedback device, comprising a diaphragm assembly, a spring, a plug, and a valve seat. The valve seat has an oil passage hole. A spring is installed inside the plug. One end of the spring abuts against the end of the plug, and the other end abuts against the diaphragm assembly. The plug has an oil passage hole. External oil is connected to the inner cavity of the plug, and the oil pressure can act on the left side of the diaphragm assembly. The diaphragm assembly contacts and engages with the end of the valve seat under the action of the spring. The diaphragm assembly senses the oil pressure and spring force of P2 on its left side and the oil pressure of P1 on its right side. When the pressure of P1 is equal to that of P2, the diaphragm assembly is subjected to the spring force, causing the diaphragm assembly to adhere tightly to the valve seat, and the nozzle of the valve seat cannot discharge the oil pressure of P1. When the pressure of P1 is greater than the sum of the pressure of P2 and the spring force, that is, when a certain pressure difference is formed between the hydraulic pressures of P1 and P2, and the force of the pressure difference is greater than that of the spring force, a certain gap is formed between the diaphragm assembly and the valve seat, and P1 communicates with P0. When oil flows out at P0, it is immediately determined that the hydraulic signal sensor sends out a signal oil.

[0006] Furthermore, the diaphragm assembly consists of a diaphragm plate, a valve, and a fixing seat. One end of the valve has a circular sealing surface, and the other end passes through the diaphragm plate and is fixed by the fixing seat. The circular sealing surface of the valve contacts and engages with the end of the valve seat.

[0007] Furthermore, the fixing base is provided with an annular protrusion on its periphery, serving as a mounting base for the spring. Furthermore, the valve has an outward-facing flange at one end that mates with the fixed seat, and the flange mates with the diaphragm plate to define the position of the fixed seat.

[0008] Furthermore, the membrane plate adopts a corrugated structure.

[0009] Furthermore, the membrane is made of a combination of cotton cloth and rubber, and is formed by injection molding. It is a rubber-coated component and is required to withstand a static pressure differential test of 1MPa without deformation, damage, oil leakage, or air leakage.

[0010] Furthermore, the circular sealing surface that contacts the valve seat has a high degree of flatness, and there should be no scratches or pores on the sealing mating surface with the valve seat to prevent oil leakage due to defects in the mating surface.

[0011] The mechanical-hydraulic signal feedback device designed above is applied to the fuel supply pump of a certain type of gas turbine fuel control system. High-pressure oil is drawn from the outlet of the fuel supply pump as internal lubricating oil. An oil filter is installed in the lubricating oil circuit to ensure the cleanliness of the lubricating oil. During use, in order to monitor the degree of contamination and clogging of the oil filter, the mechanical-hydraulic signal feedback device works in conjunction with the oil filter. The oil pressure connected before the oil filter is defined as P2, and the oil pressure connected after the oil filter is defined as P1. When a certain pressure difference is formed between P1 and P2, a certain gap will be formed between the diaphragm assembly and the valve seat under the action of the P1 oil pressure to counteract the spring force. This is manifested as signal oil flowing out at the valve seat of P1, which can directly monitor the clogging of the lubricating oil filter and maintain or replace the oil filter as needed. If no oil is discharged from the signal oil port, the oil filter is in good condition. There is no pressure difference before and after the oil filter, and the valve seat cannot discharge fuel due to the spring force. The oil filter can continue to be used without maintenance or replacement.

[0012] Technical benefits: This invention relates to a mechanical hydraulic signal feedback device that is used in conjunction with a certain type of gas turbine and can meet the monitoring and maintenance requirements of differential pressure of the oil filter in the lubrication circuit of the oil supply pump. It has the advantages of intuitive monitoring, immunity to electromagnetic interference, simple structure, and convenient maintenance. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of a mechanical hydraulic signal sensor. Figure 2 This is a schematic diagram of the working principle of a mechanical hydraulic signal sensor. Figure 3 This is a schematic diagram of the diaphragm assembly structure; Figure 4 This is a schematic diagram of a spring structure; Figure 5 This is a schematic diagram of the valve seat structure; The components include: diaphragm assembly 1, plug 2, adjusting shim 3, spring 4, valve seat 5, diaphragm plate 1a, valve 1b, disc 1c, and adjusting washer 1d. Detailed Implementation

[0014] To more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below with reference to the accompanying drawings or specific implementation examples. It should be noted that some (but not all) of the disclosed examples are shown in the drawings. In fact, many different examples can be described, and these examples should not be construed as limited to the examples set forth herein. Rather, these examples are described to better demonstrate the positive effects of the present invention, and all aspects not detailed herein are considered to be well-known or conventional techniques in the art.

[0015] See appendix Figures 1-5 The mechanical hydraulic signal feedback device structure specifically designed in this invention is as follows: Figure 1 It consists of a diaphragm assembly 1, a plug 2, an adjusting shim 3, a spring 4, and a valve seat 5. The diaphragm assembly 1 is installed on the left side of the valve seat 5 and is pressed by the spring 4. The spring 4 is set in the cavity of the plug 2. The plug 3 can also be fixed by a retainer. The plug 3 has an axial through hole to allow external oil to communicate with the inner cavity. During operation, the left side of the diaphragm assembly senses the hydraulic pressure of P2 and the spring force, while the right side senses the hydraulic pressure of P1. When the pressures of P1 and P2 are roughly equal, the diaphragm assembly, under the influence of the spring force, causes it to adhere tightly to the valve seat, preventing the valve seat nozzle from discharging P1 pressure oil. However, when the pressure of P1 exceeds the sum of the pressure of P2 and the spring force, a pressure difference is created between P1 and P2, and the force exerted on this pressure difference exceeds the spring force. This creates a gap between the diaphragm assembly and the valve seat, allowing communication between P1 and P0. Oil flow is observed at P0, indicating that the hydraulic signal sensor is sending a signal.

[0016] The mechanical hydraulic signal feedback device is used in the fuel supply pump of a certain type of gas turbine fuel control system. Its working principle is as follows: Figure 2As shown. To ensure the efficient, safe, and reliable operation of the fuel pump, high-pressure oil is drawn from the pump outlet as internal lubricant. An oil filter is installed in the lubrication line to ensure the cleanliness of the lubricant. During use, to monitor the degree of contamination and clogging of the oil filter, a mechanical hydraulic signal sensor is used in conjunction with the oil filter. The oil pressure is connected to P2 before the oil filter and to P1 after the oil filter. When a certain pressure difference is formed between P1 and P2, a certain gap will be formed between the diaphragm assembly and the valve seat under the action of P1 hydraulic pressure, which will counteract the spring force. This is manifested as signal oil flowing out at the valve seat of PO, which can directly monitor the clogging of the lubricating oil filter. The oil filter can be maintained or replaced as needed. If no fuel is discharged from the signal oil port, the oil filter is in good condition. There is no pressure difference before and after the oil filter, and the valve seat cannot discharge fuel due to the spring force. The oil filter can continue to be used and does not require maintenance or replacement for the time being.

[0017] In practical implementation, the diaphragm assembly, which serves as the sensing element of the mechanical hydraulic signal sensor, is a crucial component of the mechanical hydraulic signal sensor in the mechanical hydraulic signal sensor designed in this invention. Its structure is as follows: Figure 3 .

[0018] It consists of components including diaphragm plate 1a, valve 1b, disc 1c, and adjusting washer 1d. The diaphragm plate is made of cotton cloth 115 / FZ66102-1995 and rubber 5080 / GJB250A-1996, formed by injection molding using a mold. It is a rubber-coated component and is required to withstand a static pressure differential test of 1MPa without deformation, damage, or leakage of oil or air. The A-side of the valve (the left side in the diagram) where it contacts the valve seat has high precision requirements, such as... Figure 4 As shown, it is required that there be no scratches or pores on the sealing surface between surface A and the valve seat within a certain range to prevent oil leakage due to defects in the mating surface.

[0019] The specific design of the spring in the mechanical hydraulic signal feedback device designed in this invention is as follows: A common helical compression spring is used here. The spring force is designed to be related only to the pressure difference between P1 and P2 and the force-bearing area of ​​the diaphragm assembly. When the pressure difference between P1 and P2 does not meet the set requirements, the spring force acts on the diaphragm and does not leak oil at the valve seat outlet. In this case, the spring force is to return to its original position, and the diaphragm assembly is considered to be only subjected to the spring force.

[0020] When the pressure difference between P1 and P2 reaches the set requirement, such as P2-P1=0.45+0.05MPa, and the maximum force radius of the diaphragm is r=16.6, the designed spring parameters are shown in Table 1, and the model is shown in [reference needed]. Figure 5 .

[0021] Table 1 Spring Design Parameters

[0022] The material is 50CrVA, and its shear modulus is taken as 8000 kg / mm². 2 Under the action of a compression spring displacement of 6.7, a spring force of 389N can be generated, which prevents oil leakage when it comes into contact with the valve seat outlet. This is equivalent to the valve seat being opened to unload oil when subjected to a hydraulic pressure of 0.45MPa on a surface with a force radius of 16.6.

[0023] In the specific implementation process, the valve seat is designed as follows: The valve seat has a nozzle-baffle-like structure, with one end connected to the valve and the other end connected to the housing. The connection between the valve seat and the housing is sealed with a radial sealing ring. The design requirements for the end of the valve seat connected to the valve are as follows: Figure 5 As shown in the figure. Carburization is applied to surfaces A and B, with a depth of not less than 0.4 mm and a hardness of not more than 59 HRC. The hardness of the matrix is ​​39–46.5 HRC.

[0024] This invention discloses a mechanical hydraulic signal feedback device applied to an oil supply pump or regulator with a filter-equipped servo oil circuit. It collects pressures P1 and P2 from before and after the oil filter, which act on opposite sides of the diaphragm of the feedback device. When a pressure difference is established before and after the oil filter, the pressure before the filter is greater than the pressure after the filter, increasing resistance. Under a set opening pressure, the spring force is compressed, opening the valve seat to discharge oil, thus monitoring the oil filter contamination status. Simultaneously, the design of the diaphragm assembly, return spring, valve seat nozzle, and plug effectively improves the reliability of the feedback device. Furthermore, the device has a simple working principle and structure, low manufacturing cost, convenient replacement, and is easy to assemble and disassemble.

[0025] This mechanical hydraulic differential pressure signal feedback device is easy to implement, without the complex structure and cable connections of electrical signal devices. It provides intuitive monitoring, high reliability, wide applicability, and strong practicality. It has already been used to monitor the oil filter contamination in the self-circulating oil circuit of the fuel supply pump in a certain type of gas turbine fuel control system.

[0026] The above specific embodiments or examples are only used to explain the technical solutions of the present invention and are not intended to limit the present application. Parts not described in detail are considered to be conventional technical means or common knowledge in the field. It can be understood by those skilled in the art that, based on the design concept of the present application, the technical solutions described in the foregoing embodiments can be adapted or some or all of the technical features can be equivalently replaced. These modifications, equivalent replacements, and adaptive improvements do not depart from the technical essence of the present invention and should all be covered within the protection scope of the present application.

Claims

1. A mechanical differential pressure signal feedback device, characterized in that, It consists of a diaphragm assembly, a spring, a plug, and a valve seat; the valve seat has an oil passage hole; the plug has a spring inside; one end of the spring abuts against the end of the plug and the other end abuts against the diaphragm assembly; the plug has an oil passage hole; external oil is connected to the inner cavity of the plug, and the oil pressure can act on the left side of the diaphragm assembly; the diaphragm assembly contacts and engages with the end of the valve seat under the action of the spring; The diaphragm assembly senses the oil pressure and spring force of P2 on its left side and the oil pressure of P1 on its right side. When the pressure of P1 is equal to that of P2, the diaphragm assembly is subjected to the spring force, causing the diaphragm assembly to adhere tightly to the valve seat, and the nozzle of the valve seat cannot discharge the oil pressure of P1. When the pressure of P1 is greater than the sum of the pressure of P2 and the spring force, that is, when a certain pressure difference is formed between the hydraulic pressures of P1 and P2, and the force of the pressure difference is greater than that of the spring force, a certain gap is formed between the diaphragm assembly and the valve seat, and P1 communicates with P0. When oil flows out at P0, it is immediately determined that the hydraulic signal sensor sends out a signal oil.

2. The mechanical differential pressure signal feedback device as described in claim 1, characterized in that, The diaphragm assembly consists of a diaphragm plate, a valve, and a fixing seat. One end of the valve has a circular sealing surface, and the other end passes through the diaphragm plate and is fixed by the fixing seat. The circular sealing surface of the valve contacts and engages with the end of the valve seat.

3. The mechanical differential pressure signal feedback device as described in claim 2, characterized in that, The fixed base has an annular protrusion on its periphery, which serves as a mounting base for the spring.

4. The mechanical differential pressure signal feedback device as described in claim 2, characterized in that, The valve has an outward-facing flange at one end that mates with the fixed seat. The flange mates with the diaphragm plate to define the position of the fixed seat.

5. A mechanical differential pressure signal feedback device as described in claim 4, characterized in that, The membrane plate has a corrugated structure.

6. The mechanical differential pressure signal feedback device as described in claim 5, characterized in that, The diaphragm is made of cotton cloth and rubber, and is formed by injection molding. It is a rubber-coated component that can withstand a static pressure differential test of 1MPa without deformation, damage, oil leakage, or air leakage.

7. A mechanical differential pressure signal feedback device as described in claim 1, characterized in that, The circular sealing surface that contacts the valve seat has a high degree of flatness, and there should be no scratches or pores on the sealing mating surface with the valve seat.

8. The mechanical hydraulic signal feedback device as described in any one of claims 1 to 7 is applied to the fuel supply pump of a certain type of gas turbine fuel control system. High-pressure oil is drawn out from the outlet of the fuel supply pump as internal lubricating oil. An oil filter is installed in the lubricating oil circuit to ensure the cleanliness of the lubricating oil. During use, in order to monitor the degree of contamination and clogging of the oil filter, the mechanical hydraulic signal feedback device is used in conjunction with the oil filter. The oil pressure connected before the oil filter is defined as P2, and the oil pressure connected after the oil filter is defined as P1. When a certain pressure difference is formed between P1 and P2, a certain gap will be formed between the diaphragm assembly and the valve seat under the action of the P1 oil pressure to counteract the spring force. This is manifested as signal oil flowing out at the valve seat of P0, which can directly monitor the clogging of the lubricating oil filter and maintain or replace the oil filter as needed. If no oil is discharged from the signal oil port, the oil filter is in good condition. There is no pressure difference before and after the oil filter, and the valve seat cannot discharge fuel due to the spring force. The oil filter can continue to be used without maintenance or replacement.

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