Strength test tool for high-lift marine pump

Abstract

The invention relates to a strength test tool for a high-lift marine pump, which is characterized in that a sealing body is arranged in a pump body, has a cylindrical structure with external threads at two ends and a sealing groove in the middle, and is used for sealing pressure of different cavities; sealing glands are respectively connected between two ends of the sealing body and the pump body and are used for sealing the pump body and the sealing body; the two ends of the sealing body are in threaded connection with the sealing end covers respectively, and the sealing end covers are provided with cap structures with internal threads and sealing grooves and used for adjusting the axial distance of the sealing body in a pump cavity, preventing the sealing body from axially moving when the pressure of a high-pressure cavity and the pressure of a low-pressure cavity is unbalanced and providing fastening force pointing to the interior of the pump body during pressing. The pump body is prevented from expanding and deforming outwards under internal pressure; and the O-shaped ring is arranged among the sealing body, the sealing gland and the pump body and is used for sealing pressure. The marine high-pressure pump can effectively solve the problem that the low-pressure cavity is seriously deformed due to large strength test pressure in a predelivery test of the marine high-pressure pump, and the service life of the pump body is prolonged.

Description

Technical Field

[0001] The invention relates to a factory strength test device for a marine pump, in particular to a strength test tool suitable for a split-center multi-stage marine pump with high rotation speed and high head. Background Art

[0002] Marine pumps have strict requirements on weight, dimensions, reliability and maintainability due to their use environment and characteristics, so they are mostly split-center multi-stage high-speed centrifugal pumps. This means that the thickness of the centrifugal pump cannot be designed according to the maximum pressure (weight limit) during design, and the thickness of the pump body on the low-pressure side is relatively small; the speed is high (dimensional limit), the head of the single-stage impeller is high, and the pressure difference of the pump body is large; therefore, during the strength test at the factory test stage, the pump body is often greatly deformed on the low-pressure side due to the high strength test pressure, making the pump body scrapped.

[0003] like Figure 1 As shown, conventional high-pressure pumps mostly use segmented structures for staged pressurization, and there are no weight and size requirements, so a low-speed, multi-stage impeller design can be used. In addition, the outer wall can be thickened enough during design to ensure the use requirements; the head of the single-stage distribution is not very high, and the pressure difference on the pump body is small; and strong bolts are used for fastening in the axial direction, so that there will be no significant deformation due to pressure.

[0004] like Figure 2 As shown in the figure, a high-pressure pump for a ship. Because of the strict requirements on weight, dimensions, reliability and maintainability in the use environment, a split-center multi-stage high-speed centrifugal pump is often used. This means that the thickness of the centrifugal pump cannot be designed according to the maximum pressure (weight limit) during design, and the thickness of the pump body on the low-pressure side is relatively small; high speed (dimensional limit), high head of the single-stage impeller, and large pressure difference of the pump body; split-center type (maintainability); integrated (reliability, fewer parts). Therefore, when conducting strength tests at the factory test stage, the pump body often deforms significantly on the low-pressure side due to the high strength test pressure, making the pump body scrapped.

[0005] At present, during the factory test of marine multi-stage high-pressure water pumps, blind plates are often used to block both ends, and the pump inlet and outlet are pressurized as a whole. This pressure-pressurization method mainly has the following safety hazards:

[0006] 1. The whole machine is pressurized at the highest pressure, and the pump body on the low-pressure side is deformed. After the whole machine is assembled, the rotor and stator parts are scratched;

[0007] 2. The blind plate is connected to the pump body through the threaded hole of the pump body. The connection strength is insufficient and the thread is squeezed and damaged and cannot be used;

[0008] 3. During the pressure test, the bolts and nuts on the low-pressure side are prone to flying collision accidents, resulting in unpredictable consequences;

[0009] In order to fully verify the rationality of the design of the pump body and the eligibility of the production process, the present invention proposes a strength test fixture suitable for high-lift marine pumps, which can better solve the above-mentioned problems in the factory strength test of the pump. Summary of the invention

[0010] The present invention is to provide a strength test fixture suitable for high-lift marine pumps, the purpose of which is to fully verify the design rationality and production process qualification of the pump body during the factory test of the pump, and to prevent the pump body from being deformed and scrapped, ultimately ensuring the overall low noise performance and service life of the equipment.

[0011] To achieve the above-mentioned purpose, the technical scheme of the present invention is: a strength test tool for a high-lift marine pump, comprising a sealing body, a sealing gland, a sealing end cover, and an O-ring. The sealing body is placed in the pump body, and has a cylindrical structure with external threads at both ends and a sealing groove in the middle, which is used to seal the pressure of different cavities to prevent the pressure of the high-pressure cavity from leaking to the low-pressure cavity during the strength test; the sealing glands are respectively connected between the two ends of the sealing body and the pump body to seal the pump body and the sealing body; the two ends of the sealing body are respectively screwed to the sealing end covers, and the sealing end covers The cap-mounted structure with internal threads and sealing grooves is used to adjust the axial distance of the sealing body in the pump chamber to prevent axial movement of the sealing body when the pressures in the high and low pressure chambers are unbalanced, and to provide a fastening force directed into the pump body when pressurized to prevent the pump body from expanding and deforming outward under the internal pressure; the O-ring is arranged between the sealing body, the sealing gland and the pump body to seal the pressure. The sealing body, the sealing gland, the sealing end cover and the O-ring work together to protect the low-pressure side while offsetting the axial force to prevent deformation of the low-pressure side of the water pump body during the strength test.

[0012] Furthermore, the axial and radial dimensions of the sealing body and the position of the O-ring groove are adapted to the size of the working chamber of the marine high-pressure water pump.

[0013] Furthermore, the sealing gland is installed on the pump body, and the axial position of the sealing body is adjusted through two sealing end covers, and the length of the pump body is adapted.

[0014] Furthermore, the sealing body is combined with the O-ring to isolate the high and low pressure sealing chambers, the sealing glands at both ends are combined with the O-ring to prevent pressure leakage, and the sealing end caps are combined with the O-ring to form a second seal to prevent pressure leakage.

[0015] Furthermore, the sealing gland is fixedly connected to the pump body by bolts and nuts; the thread diameter and thread length at both ends of the sealing body are determined after strength design verification based on the axial force exerted on the sealing body.

[0016] Furthermore, the thickness of the sealing body and the sealing end cover is determined after strength design verification based on the axial force exerted on the sealing body, the sealing gland and the sealing end cover.

[0017] Beneficial effects of the present invention:

[0018] The strength test fixture of a high-lift marine pump of the present invention can produce the following beneficial effects through the joint action of the sealing body, the sealing gland, the sealing end cover and the O-ring:

[0019] 1. The pump body is pressurized at the highest pressure, and the tooling can offset the axial force caused by the pressure difference and protect the low-pressure side from deformation;

[0020] 2. The threaded hole of the pump body is connected to the sealing gland and fastened through the sealing end cover to protect the pump body thread from being damaged;

[0021] 3. It improves the adequacy of the factory test verification of the water pump, reduces the deformation caused by the test, and to a certain extent increases the service life of the pump body and the vibration and noise of the whole machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the structure of a conventional high-pressure water pump;

[0023] Figure 2 It is a schematic diagram of the structure of a marine high-pressure water pump;

[0024] Figure 3 Schematic diagram of a strength test tooling for a high-lift marine pump according to a first embodiment of the present invention;

[0025] Figure 4 Schematic diagram of a strength test tooling for a high-lift marine pump according to a second embodiment of the present invention;

[0026] Figure 5 It is a schematic diagram of the axial force acting on the relevant parts in the strength test fixture of the high-lift marine pump. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0028] like Figures 3 to 5As shown, a strength test tool for a high-lift marine pump of the present invention comprises a sealing body 3, a left sealing gland 2, a right sealing gland 5, a left sealing end cover 1, a right sealing end cover 6, and an O-ring 4. The sealing body 3 has a cylindrical structure with external threads at both ends and a sealing groove in the middle, which is used to seal the pressure of different cavities to prevent the pressure of the high-pressure cavity from leaking into the low-pressure cavity during the strength test; the left sealing gland 2 and the right sealing gland 5 are used to seal the pump body and the sealing body 3, and are connected to the pump body through bolts and nuts; the left sealing end cover 1 and the right sealing end cover 6 have a cap-mounted structure with internal threads and sealing grooves, which is used to adjust the axial distance of the sealing body 3 in the pump cavity, on the one hand to prevent the sealing body from axial movement when the pressure of the high and low pressure cavities is unbalanced, and on the other hand to provide a fastening force directed to the inside of the pump body during pressurization to prevent the pump body from expanding and deforming outward under the internal pressure; the O-ring 4 is used to seal the pressure. The sealing body 3, the left sealing gland 2, the right sealing gland 5, the left sealing end cover 1, the right sealing end cover 6 and the O-ring 4 work together to protect the low-pressure side while offsetting the axial force to prevent deformation of the low-pressure side of the water pump body during the strength test.

[0029] Preferably, the axial and radial dimensions of the sealing body 3 and the position of the O-ring groove are adapted to the size of the working chamber of the marine high-pressure water pump.

[0030] Preferably, the left sealing gland 2 and the right sealing gland 5 can be installed on the pump body, and the axial position of the sealing body 3 can be adjusted through the two sealing end covers, and the length of the pump body can be adapted.

[0031] Preferably, the sealing body 3 is combined with the O-ring 4 to isolate the high and low pressure sealing chambers, the sealing glands at both ends are combined with the O-ring 3 to prevent pressure leakage, and the two sealing end covers are combined with the O-ring 4 to form a second seal to prevent pressure leakage.

[0032] Preferably, the connecting bolts 7 and nuts 8 between the two sealing glands and the pump body should adopt national standards as much as possible; the thread diameter and thread length at both ends of the sealing body should be determined after strength design verification based on the axial force exerted on the sealing body.

[0033] Preferably, the thickness of the sealing body 3 and the two sealing end covers should be determined after strength design verification based on the axial force to which the sealing body, the sealing gland and the sealing end covers are subjected.

[0034] Implementation plan 1:

[0035] like Figure 3 As shown, a strength test fixture for a high-lift marine pump includes a sealing body 3, O-rings 4 (several), a left sealing end cover 1, a right sealing end cover 6, a left sealing gland 2, a right sealing gland 5, bolts 7, and nuts 8.

[0036] When pressurizing, it can be done from the inlet and outlet respectively. The seal body 3 and the O-ring 4 in the seal body 3 can prevent the high-pressure side from leaking to the low-pressure side, protecting the pump body on the low-pressure side; because the pressures on the high-pressure side and the low-pressure side are different, axial forces to both ends will be generated. During installation, by locking the left sealing end cover 1 and the right sealing end cover 6, the position of the seal body can be adjusted to convert the axial forces to both ends into the tension of the shaft; the left sealing gland 2 and the right sealing gland 5 are connected to the pump body by bolts 7 and nuts 8 respectively, and the strength generates an outward axial force, which is also converted into the tension of the shaft through the left sealing end cover 1 and the right sealing end cover 6 to protect the bolts on the pump body from damage.

[0037] Implementation Plan 2:

[0038] On the basis of implementation scheme 1, the sealing gland and the sealing end cap are integrated into a design, such as Figure 4 As shown in the middle left sealing end cover 1 and the right sealing end cover 6, Figure 4 The case is used when the bolt hole strength on the pump body is insufficient. The warning force can be increased by increasing the thread length and diameter at both ends of the sealing body 3.

[0039] The axial forces on the relevant parts are mainly related to Figure 5 It is related to the parameters D1~D7, P1~P3 shown in the figure; the thread length and diameter of the sealing body, the thickness of the sealing cover and the sealing end cover are all subject to strength design verification. When verifying the strength design, the material, heat treatment process and locking torque of the parts must be fully considered, and at least 1.5 to 4 times the safety margin must be left.

[0040] The above embodiments are only preferred embodiments of the present invention and are not intended to limit the present invention in any form. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, use the above disclosed technical content to make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A strength test tool for a high-lift marine pump, characterized in that: It includes a sealing body, a sealing gland, a sealing end cover, and an O-ring. The sealing body is placed in the pump body, and has an external thread at both ends and a sealing groove in the middle. The cylindrical structure is used to seal the pressure of different cavities to prevent the pressure of the high-pressure chamber from leaking into the low-pressure chamber during the strength test; the sealing glands are respectively connected between the two ends of the sealing body and the pump body to seal the pump body and the sealing body; the two ends of the sealing body are respectively screwed to the sealing end covers, and the sealing end covers have a cap-mounted structure with internal threads and sealing grooves, which are used to adjust the axial distance of the sealing body in the pump chamber to prevent the sealing body from axial movement when the pressures in the high and low pressure chambers are unbalanced, and to provide a tightening force pointing to the inside of the pump body when pressurizing to prevent the pump body from expanding and deforming outward under the internal pressure; the O-ring is arranged between the sealing body, the sealing gland, and the pump body to seal the pressure. The sealing body, the sealing gland, the sealing end cover, and the O-ring work together to protect the low-pressure side while offsetting the axial force to prevent deformation of the low-pressure side of the water pump body during the strength test.

2. The strength test tool for high-lift marine pump according to claim 1 is characterized in that: The axial and radial dimensions of the sealing body and the position of the O-ring groove are adapted to the size of the working chamber of the marine high-pressure water pump.

3. The strength test tool for high-lift marine pump according to claim 1 is characterized in that: The sealing gland is installed on the pump body, and the axial position of the sealing body is adjusted through two sealing end covers, and the length of the pump body is adapted.

4. The strength test tool for high-lift marine pump according to claim 1 is characterized in that: The sealing body is combined with the O-ring to isolate the high and low pressure sealing chambers, the sealing glands at both ends are combined with the O-ring to prevent pressure leakage, and the sealing end caps are combined with the O-ring to form a second seal to prevent pressure leakage.

5. The strength test tool for high-lift marine pump according to claim 1 is characterized in that: The sealing gland is fixedly connected to the pump body by bolts and nuts; the thread specifications and thread lengths at both ends of the sealing body are determined after strength design verification based on the axial force applied to the sealing body.

6. The strength test tool for high-lift marine pump according to claim 1, characterized in that: The thickness of the sealing body and the sealing end cover is determined after strength design verification based on the axial force applied to the sealing body, the sealing gland and the sealing end cover.

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