Hydraulic power unit and manufacturing tool and method thereof

Abstract

The application discloses a hydraulic power device for underwater vehicles, and a manufacturing tool and method thereof, and belongs to the technical field of underwater vehicles.The hydraulic power device comprises a motor, a screw pump, a front cover and a stator.The motor has an output shaft.The screw pump comprises a rotor, the rotor comprises a main rod and two slave rods, the main rod is connected with the output shaft of the motor, and the axis of the main rod is in a vertical direction.The front cover is fixedly connected with the stator, the front cover is internally provided with a main rod shaft hole, the main rod shaft hole comprises a shaft hole sealing section, the main rod comprises a main rod screw section, a main rod connecting section, a main rod sealing section and a main rod bearing section which are sequentially arranged from a liquid inlet cavity to a sealing cavity, the main rod sealing section is assembled and connected with the shaft hole sealing section, and the main rod bearing section is supported and connected with the front cover through a bearing.The application can better improve the volumetric efficiency of the high-pressure hydraulic power device as a whole, improve the working efficiency of the equipment as a whole, and ensure the reliability under long-time operation.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of hydraulic system and marine equipment design and manufacturing, and particularly relates to a hydraulic power device and a manufacturing tool and method thereof. BACKGROUND

[0002] In marine engineering, such as offshore platforms, underwater equipment, deepwater drilling and the like, hydraulic power devices are involved. Screw pumps are widely used due to their advantages of low pulsation, strong self-priming, and good adaptability to shaking working conditions. However, the highest working pressure of the three-screw hydraulic pump in the prior art is generally 10 MPa. In the marine environment, 20 MPa ultra-high pressure pumps on the hydraulic station and other systems are generally gear pumps or plunger pumps, which have poorer noise and reliability compared with three-screw pumps. However, the existing three-screw pumps cannot be applied to 20 MPa high pressure and above ultra-high pressure situations, and cannot meet the special use requirements of existing marine equipment. SUMMARY

[0003] In view of the above defects or improvement needs of the prior art, the present application provides a hydraulic power device and a manufacturing tool and method thereof, which can be used in underwater vehicles, better improve the volumetric efficiency of the overall high-pressure hydraulic power device, improve the overall working efficiency of the equipment, and ensure the reliability under long-time operation.

[0004] To achieve the above-mentioned purpose, the present application adopts the following technical solutions. In some embodiments, a hydraulic power device is provided, which is used in an underwater vehicle and includes: an electric motor having an output shaft; a screw pump including: a stator; a rotor including one main rod and two slave rods, the main rod being connected with the output shaft of the electric motor, and the axis of the main rod being along the vertical direction; a front cover fixedly connected with the stator, the front cover having a main rod shaft hole in it, the main rod shaft hole including a shaft hole sealing section, the main rod including a main rod screw section, a main rod connecting section, a main rod sealing section, and a main rod bearing section arranged in sequence from a liquid inlet cavity to a sealing cavity, the main rod sealing section being assembled and connected with the shaft hole sealing section, and the main rod bearing section being supported and connected with the front cover through a bearing; the diameter Dm of the main rod sealing section, the outer diameter Dn of the main rod screw section, and the outer diameter Dc of the main rod connecting section satisfy: , and the length Lm of the main rod sealing section and the length Ln of the main rod screw section satisfy: .

[0005] In some embodiments, the main rod sealing section has a plurality of main rod sealing grooves arranged along the axial direction, and the number of the main rod sealing grooves is 2-4; the groove width of each main rod sealing groove is 2-5 mm, and the groove depth of each main rod sealing groove is 3-5 mm.

[0006] In some embodiments, the mating gap between the main rod sealing section and the shaft hole sealing section is 0.06-0.08mm.

[0007] In some embodiments, the engaging gap between the main rod and the slave rod is 0.025-0.035mm.

[0008] In some embodiments, the main rod hole in the stator comprises a main rod threaded mating hole section and a main rod connecting mating hole section, the inner diameter of the main rod connecting mating hole section is larger than that of the main rod threaded mating hole section.

[0009] In some embodiments, the end of the non-working surface of the main rod is in the shape of a circular arc.

[0010] In some embodiments, the screw pump comprises a slave rod shaft sleeve, the slave rod shaft sleeve has a shaft sleeve support section and a shaft sleeve end section, the slave rod comprises a slave rod screw section and a slave rod shaft end section, the outer diameter of the shaft sleeve support section is equal to that of the slave rod screw section, the outer periphery of the shaft sleeve end section has a circular arc section and a straight line section, the outer diameter of the circular arc section is larger than that of the shaft sleeve support section, the distance between the straight line section and the axis of the slave rod shaft sleeve is smaller than the outer diameter of the shaft sleeve support section; the slave rod shaft sleeve has a slave rod shaft hole and a positioning hole, the central axis of the slave rod shaft hole does not coincide with that of the positioning hole; the front cover has a slave rod oil return hole, the central axis of the slave rod oil return hole coincides with that of the positioning hole, the oil return positioning pin is positioned and matched with the slave rod oil return hole and the positioning hole.

[0011] In some embodiments, a manufacturing tool for the hydraulic power device is also provided, the manufacturing tool comprises a bearing positioning and installation special tool, the bearing positioning and installation special tool comprises a base bench, a support frame, a hydraulic sleeve, and a holding bracket; the support frame is detachably arranged on the base bench; the hydraulic sleeve is used to be placed between the bearing and the holding bracket, and the holding bracket is movably connected with the base bench.

[0012] In some embodiments, the holding bracket comprises a first bracket column, a second bracket column, a support plate, one end of the first bracket column and the second bracket column are fixedly connected with the base stand, one end of the support plate is rotatably connected with the other end of the first bracket column, and the other end of the support plate is detachably connected with the other end of the second bracket column; the base stand comprises four columns, which are a first column, a second column, a third column and a fourth column, support holes are arranged on the first column, the second column, the third column and the fourth column respectively, the support frame comprises a first support rod, a second support rod and a support truss, the first support rod is detachably arranged through the support holes of the first column and the second column, the second support rod is detachably arranged through the support holes of the third column and the fourth column, and the support truss is detachably arranged on the first support rod and the second support rod.

[0013] In some embodiments, a manufacturing method of the hydraulic power device is also provided, which adopts the manufacturing tooling described above, and comprises: bearing positioning and installation, which comprises: placing the main rod on the base stand and lifting the main rod through the support frame; placing the bearing on the main rod, gently pressing the bearing by using the hydraulic sleeve; then fixing the hydraulic sleeve by using the holding bracket; slowly rotating the tap of the hydraulic sleeve, and slowly and smoothly pushing the bearing into the main rod by using the hydraulic force until the bearing is installed in place.

[0014] Compared with the prior art, the hydraulic power device and the manufacturing tooling and method thereof in some embodiments of the present application have at least the following beneficial effects: by reasonably setting the diameter Dm of the sealing section of the main rod, the outer diameter Dl of the screw section of the main rod and the outer diameter Dc of the connecting section of the main rod, the axial positioning requirement can be met without additional displacement compensation structures such as wave springs. It should be noted that the technical effects of the embodiments of the present application are not limited to this, and the specific advantages and effects are described and embodied in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a partial sectional view of a part of the screw pump in some embodiments of the present application in one direction.

[0016] Figure 2 is a partial sectional view of the screw pump in some embodiments of the present application in another direction.

[0017] Figure 3 is a schematic view of the front cover in some embodiments of the present application.

[0018] Figure 4 is a schematic view of the main rod in some embodiments of the present application.

[0019] Figure 5Schematic diagram of the slave rod in some embodiments of the present application.

[0020] Figure 6 Schematic diagram of the slave rod sleeve in some embodiments of the present application.

[0021] Figure 7 Schematic diagram of the pump body sleeve in some embodiments of the present application.

[0022] Figure 8 Schematic diagram of the partial structure of the screw pump in some embodiments of the present application.

[0023] Figure 9 Schematic diagram of the slave rod sleeve in another direction in some embodiments of the present application.

[0024] Figure 10 Schematic diagram of the oil return positioning pin in some embodiments of the present application.

[0025] Figure 11 Schematic diagram of the cross section of the master rod in some embodiments of the present application.

[0026] Figure 12 Schematic diagram of the oil return valve in some embodiments of the present application.

[0027] Figure 13 Schematic diagram of the assembly structure of the positioning assembly in some embodiments of the present application.

[0028] Figure 14 Schematic diagram of the screw profile correction in some embodiments of the present application.

[0029] Figure 15 Schematic diagram of the bearing positioning installation special tool in some embodiments of the present application.

[0030] Figure 16 Schematic diagram of the high-pressure hydraulic system of the underwater vehicle in some embodiments of the present application.

[0031] Figure 17 Schematic diagram of the cross section of the fairing device in some embodiments of the present application.

[0032] Figure 18 Schematic diagram of the flow hole in some embodiments of the present application.

[0033] Figure 19 Schematic diagram of the flow hole in another direction in some embodiments of the present application.

[0034] Figure 20 Schematic diagram of the coupling frame assembly in some embodiments of the present application.

[0035] Figure 21 Schematic diagram of the cross section of the coupling frame in some embodiments of the present application.

[0036] Figure 22 A schematic view of a coupling frame in some embodiments of the present application.

[0037] Figure 23 A schematic view of an isolator in some embodiments of the present application.

[0038] Figure 24 A schematic view of a part of a high-pressure hydraulic system in some embodiments of the present application. DETAILED DESCRIPTION

[0039] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application.

[0040] In some embodiments of the present application, a screw pump is provided, which is a positive displacement pump that moves a fluid forward by creating a change in volume in a stator within a pump body by two or more rotating screws. When the screws rotate, the volume in the pump cavity changes, thereby drawing in fluid and pushing it towards the outlet. Screw pumps have good sealing performance and can transport fluids of various viscosities, and thus are widely used in the fields of chemical industry, petroleum, pharmaceuticals, food, etc. In embodiments of the present application, the screw pump is used as a hydraulic power device and can be used in an underwater vehicle as a part of a high-pressure hydraulic system of the underwater vehicle to provide a high-pressure hydraulic source for the underwater vehicle.

[0041] Figure 1 A partial cross-sectional view of a screw pump in some embodiments of the present application in one direction. Figure 2 A partial cross-sectional view of a screw pump in some embodiments of the present application in another direction. Reference Figure 1 and Figure 2 In some embodiments, the screw pump includes a stator 100 and a rotor 200. In some embodiments, the rotor includes a main rod 201 and two slave rods 202. In embodiments of the present application, the screw pump is a three-screw pump. The two slave rods 202 are arranged on both sides of the main rod 201. In embodiments of the present application, the screw pump is a high-pressure screw pump. In some embodiments, a high-pressure screw pump refers to a screw pump with a maximum working pressure of more than 20 MPa. In some embodiments, the maximum working pressure of the screw pump is more than 20 MPa. In some embodiments, the maximum working pressure of the screw pump is up to 25 MPa.

[0042] In some embodiments, the stator is a pump body liner 101. In embodiments of the present application, the stator is a combination of the pump body and the liner, and the rotor is a triple screw consisting of a main screw and two slave screws. The main screw is the driving screw connected to the driving device, and the two slave screws are driven screws meshing with the main screw. The main and slave screws and the pump body liner are assembled into the stator-rotor structure of the screw pump.

[0043] In some embodiments, the pump body liner is made of bimetallic material, including alloy steel for the outer layer and copper alloy for the inner layer. On the basis of the whole high-strength alloy steel, the internal sintered copper alloy material is used. In embodiments of the present application, the sintering process is used for the two parts of the pump body and the liner to combine the two different materials of alloy steel and copper alloy into one, which is called the pump body liner, thereby improving the pressure resistance and reliability of the equipment, saving space, and facilitating maintenance. In embodiments of the present application, the internal alloy copper has low hardness, which reduces the friction power generated when the screw runs at high speed in the pump body liner. The external alloy steel has high strength, which improves the overall pressure resistance of the equipment. Through the use of bimetallic material, the stability of the equipment under ultra-high pressure is ensured, and the overall reliability of the equipment is improved.

[0044] In some embodiments, the screw pump includes an oil cavity, which includes a liquid inlet cavity 601 and a high-pressure cavity 602. In some embodiments, the screw pump includes a front cover 6021 and a rear cover 6011. The front cover and the rear cover are respectively located at the two ends of the stator.

[0045] In some embodiments, the rear cover is fixedly connected with the stator, and the rear cover has an oil inlet 6012. The space between the rear cover, the stator, and the rotor forms the liquid inlet cavity.

[0046] In some embodiments, the front cover is fixedly connected with the stator, and the space between the front cover, the stator, and the rotor forms the high-pressure cavity. The part of the stator corresponding to the high-pressure cavity has an oil outlet 102.

[0047] In embodiments of the present application, the liquid inlet cavity 601 communicates with the oil inlet, and the high-pressure cavity 602 communicates with the oil outlet. The medium oil enters the liquid inlet cavity 601 through the oil inlet, and the volume change caused by the screw in the stator makes the transported medium oil continuously advance to the high-pressure cavity 602, and then the high-pressure hydraulic oil flows out from the oil outlet.

[0048] In some embodiments, the rear cover has an inlet flange, and the stator has an outlet flange. The inlet flange and the outlet flange are respectively connected with the oil inlet 6012 and the oil outlet 102. The inlet flange and the outlet flange are both SAE standard flanges, which are convenient for installation and standardization. The length directions of the inlet flange and the outlet flange are perpendicular to each other, which reduces the installation size while ensuring the stability of the installation.

[0049] In some embodiments, the oil cavity 600 further comprises a sealing cavity 603. The sealing cavity 603 is located at the end of the main rod away from the liquid inlet cavity 601. The screw pump comprises a sealing cover 6031 which is fixedly connected with the front cover 6021. The space between the sealing cover, the front cover and the main rod forms the sealing cavity.

[0050] In some embodiments, the screw pump comprises a positioning assembly which is mainly used for positioning the main rod and the slave rod. In some embodiments, the positioning assembly comprises a main rod positioning assembly and a slave rod positioning assembly. In some embodiments, the positioning assembly comprises a spacer sleeve 501, a balance ring 502, a bearing 503, a support ring 504 and a nut 505. The spacer sleeve 501, the balance ring 502, the bearing 503, the support ring 504 and the nut 505 are mainly used for positioning the main rod, and form the main rod positioning assembly.

[0051] In some embodiments, the slave rod positioning assembly comprises a slave rod shaft sleeve 506 and an oil return positioning pin 507. The slave rod shaft sleeve 506 is arranged at the end of the slave rod located in the high-pressure cavity. The oil return positioning pin 507 is connected with the front cover at one end and inserted into the slave rod shaft sleeve 506 at the other end. In some embodiments, the slave rod shaft sleeve 506 plays a role in balancing the radial force of the slave rod.

[0052] Figure 3 The figure is a schematic view of the front cover in some embodiments of the present application. Referring to Figure 3 In some embodiments, the front cover 6021 has a main rod shaft hole therein, and the main rod shaft hole comprises a shaft hole sealing section 6024. In some embodiments, the front cover comprises a tapered section 6022 and a flange connecting section 6025, and the tapered section 6022 is connected with the flange connecting section 6025. The flange connecting section 6025 is used for fixedly mounting with the bench. In the embodiments of the present application, the arrangement of the tapered section 6022 not only enhances the overall strength of the front cover, but also makes it easier to center during the installation of the screw pump.

[0053] Figure 4 The figure is a schematic view of the main rod in some embodiments of the present application. Referring to Figure 4 The main rod 201 comprises, in sequence from the liquid inlet cavity to the sealing cavity, a main rod screw section 2011, a main rod connecting section 2012, a main rod sealing section 2013 and a main rod bearing section 2014, the main rod sealing section 2013 is assembled with the shaft hole sealing section, and the main rod bearing section 2014 is supported and connected with the front cover 6021 through the bearing 503.

[0054] In some embodiments, the diameter Dm of the main rod sealing section, the outer diameter Dn of the main rod screw section and the outer diameter Dc of the main rod connecting section satisfy: .

[0055] In the embodiments of the present application, the main rod sealing section 2013 on the main rod mainly bears the balance axial force, the bearing 503 balances the remaining axial force and radial force, and simultaneously plays the role of axial positioning.

[0056] In some embodiments, the diameter Dm of the main rod sealing section, the outer diameter Dn of the main rod screw section, and the outer diameter Dc of the main rod connecting section satisfy: In some embodiments, the bearing 503 is a deep groove ball bearing. In the embodiments of the present application, the main rod sealing section substantially balances all the axial forces, the bearing is substantially not affected by the axial force, and the adjustment of the axial size gap of the main rod relies on the cooperation of the front cover, the spacer sleeve, the bearing, the balance ring, the support ring, and the nut. In the embodiments of the present application, additional displacement compensation structures such as wave springs are not required, and the axial positioning requirement can be met.

[0057] Figure 5 A schematic diagram of a slave rod in some embodiments of the present application. Figure 6 A schematic diagram of a slave rod sleeve in some embodiments of the present application. Reference is made to Figure 5 and Figure 6 In some embodiments, the slave rod 202 includes a slave rod screw section 2021 and a slave rod shaft end section 2022. The slave rod sleeve 506 has a slave rod shaft hole 5061, a sleeve support section 5062, and a sleeve end section 5063. The slave rod shaft end section 2022 of the slave rod is located in the slave rod shaft hole 5061, the sleeve support section 5062 of the slave rod sleeve has a positioning hole 5064 that is positioned in cooperation with the oil return positioning pin 507, and the positioning hole is in communication with the slave rod shaft hole.

[0058] In some embodiments, the outer diameter of the slave rod screw section is Df, the outer diameter of the slave rod shaft end section is Dt, and the outer diameter Dt of the slave rod shaft end section and the outer diameter Df of the slave rod screw section satisfy In the embodiments of the present application, the slave rod screw section and the slave rod shaft end section have a slave rod neck section 2023, the slave rod neck section 2023 is tapered, and the outer diameter of the slave rod neck section 2023 gradually decreases from the slave rod screw section 2021 to the slave rod shaft end section 2022. The outer diameter Dj at the connection between the slave rod neck section 2023 and the slave rod shaft end section 2022 is smaller than the outer diameter Dt of the slave rod shaft end section. In some embodiments, the outer diameter Dj and the outer diameter Dt of the slave rod shaft end section satisfy the relationship: In some embodiments, the outer diameter Dz of the sleeve support section is equal to the outer diameter Df of the slave rod screw section. In some embodiments, the outer diameter Dj at the connection between the slave rod neck section 2023 and the slave rod shaft end section 2022 and the outer diameter Df of the slave rod screw section satisfy The slave rod neck section 2023 adopts a tapered structure and satisfies to ensure the connection strength.

[0059] In the embodiments of the present application, the method of increasing the outer diameter size of the shaft end of the follower is adopted, and the area of the shaft end is increased by more than 15%, so that the axial force generated by the high-pressure medium oil pushing the follower is basically offset, and the reliability of the follower during operation is improved.

[0060] Figure 7 Fig. 1 is a schematic view of a pump body liner in some embodiments of the present application. Fig. 1(a) is a perspective view, and Fig. 1(b) is a sectional view. Figure 8 Fig. 2 is an enlarged schematic view of part of the structure. Figure 9 Fig. 3 is a schematic view of the follower sleeve from another direction in some embodiments of the present application. Referring to Fig. 3, Figure 1 Figures 6-9 In some embodiments, the pump body liner 101 has a counterbore 1011, and the shaft end section 5063 of the follower sleeve 506 is located in the counterbore. Specifically, in some embodiments, the follower sleeve 506 includes a contact boss 5065 that protrudes from a first end face 5066 of the follower sleeve. The first end face is a radial face connecting the sleeve support section 5062 and the shaft end section 5063. In the embodiments of the present application, the contact boss 5065 abuts against the counterbore face of the counterbore 1011. In some embodiments, the contact face 5067 of the contact boss 5065 abutting against the counterbore 1011 is a flat surface, and the flatness of the surface has a higher requirement.

[0061] In some embodiments, the follower sleeve 506 has a second end face 5068. The contact face 5067 of the contact boss is parallel to the second end face 5068 and is completely perpendicular to the central axis of the follower sleeve 506. In the embodiments of the present application, the first end face does not abut against the counterbore 1011, and there is no special requirement for the surface roughness and flatness of the first end face.

[0062] In the embodiments of the present application, the abutting face of the follower sleeve 506 and the counterbore 1011 is the protruding face of the contact boss 5065, so that the contact area of the follower sleeve and the counterbore is greatly reduced, the problem of poor parallelism caused by the limitation of the machining process can be avoided, the cooperation between the end face of the follower sleeve and the front cover after the follower sleeve is installed in the pump body liner is more smooth, the sealing performance is enhanced, and the situation that the follower sleeve is stressed or even rotated due to too much high-pressure medium oil is prevented.

[0063] In some embodiments, the area S1 of the contact face of the contact boss and the area S2 of the first end face satisfy S1 / S2>1. In some embodiments, the area S1 of the contact face of the contact boss and the area S2 of the first end face satisfy S1 / S2>1. ​In the embodiments of the present application, the area S1 of the contact surface of the contact boss and the area S2 of the first end surface satisfy the above relationship, that is, the contact strength is ensured, and the parallelism and flatness are avoided due to the excessively large contact area. In some embodiments, the radial width of the contact boss is 2-5 mm, and the protruding height of the contact boss, that is, the axial length, is 5-8 mm. In this way, the width and height of the contact boss are set, which is convenient for processing and can ensure the contact strength and the parallelism as much as possible.

[0064] In some embodiments of the present application, the screw pump comprises a slave shaft sleeve having a sleeve support section and a sleeve end section, and a slave shaft comprising a slave shaft screw section and a slave shaft end section, and the outer diameter of the sleeve support section is equal to the outer diameter of the slave shaft screw section.

[0065] In some embodiments, the outer periphery of the sleeve end section 5063 has a circular arc section 50631 and a straight line section 50632, the outer diameter of the circular arc section is greater than the outer diameter of the sleeve support section, and the distance between the straight line section and the axis of the slave shaft sleeve is less than the outer diameter of the sleeve support section. In the embodiments of the present application, the straight line section 50632 is provided, which is simple to manufacture, and by setting the distance between the straight line section and the axis of the slave shaft sleeve to be less than the outer diameter of the sleeve support section, interference can be avoided as much as possible.

[0066] Figure 10 A schematic view of the oil return positioning pin in some embodiments of the present application is shown in FIG. 6. Figure 10 Specifically, in some embodiments, the oil return positioning pin 507 has a through hole 5071 at the center. The front cover has a slave shaft oil return hole 6023 matched with the oil return positioning pin 507.

[0067] In the embodiments of the present application, the oil return positioning pin is inserted into the slave shaft sleeve 506 of the slave shaft, and the oil return positioning pin is made of alloy steel. A hole is punched at the center of the oil return positioning pin, so that the inside is hollow, forming a through hole 5071 through which the medium oil flows, increasing the amount of medium oil passing through, and ensuring the lubrication of the bearing and the mechanical seal assembly.

[0068] In some embodiments, the center axis of the slave shaft hole 5061 does not coincide with the center axis of the positioning hole 5064, that is, the positioning hole 5064 is eccentrically arranged. Correspondingly, the center axis of the slave shaft oil return hole 6023 coincides with the center axis of the positioning hole 5064, and the slave shaft oil return hole 6023, the positioning hole 5064 and the oil return positioning pin 507 are positioned and matched. In the embodiments of the present application, the positioning hole 5064 is arranged eccentrically, and the outer periphery of the sleeve end section 5063 has a circular arc section 50631 and a straight line section 50632, which can well form circumferential positioning and prevent the slave shaft sleeve from rotating.

[0069] Figure 11Figure 1 is a schematic view of the cross section of the main rod in some embodiments of the present application. Reference is made to Figure 11 and Figure 1 In some embodiments, the screw pump comprises an oil return device, which comprises an oil return hole 301 and an oil return control assembly 300. The oil return hole is arranged in the main rod, with a first end connected to the sealed cavity 603 and a second end connected to the liquid inlet cavity 601. The oil return control assembly is used to open when the oil return pressure reaches a preset pressure, so that the oil is guided back to the liquid inlet cavity from the sealed cavity through the oil return hole.

[0070] In some embodiments of the present application, a through hole is processed in the main rod to form an oil return hole, an oil return control assembly is installed at the end of the main rod, and the oil return control assembly opens when the oil return pressure of the sealed cavity reaches the designed pressure, so that the medium oil is guided back to the liquid inlet cavity from the sealed cavity through the oil return hole in the main rod.

[0071] Figure 12 Figure 2 is a schematic view of the oil return valve in some embodiments of the present application. Reference is made to Figure 12 In some embodiments, the oil return control assembly comprises an oil return valve arranged in the liquid inlet cavity. The oil return valve comprises an oil return seat 302, a compression spring 303 and a ball core 304. The oil return seat is arranged at one end of the main rod in the liquid inlet cavity, the compression spring is arranged between the oil return seat and the ball core, and the ball core abuts against the second end of the oil return hole in the liquid inlet cavity under the initial elastic force of the compression spring. In some embodiments of the present application, the oil return control assembly is arranged in the liquid inlet cavity, directly using the space of the liquid inlet cavity, without the need to additionally arrange a corresponding space for the oil return control assembly, and the simplest oil return valve structure is adopted, which is a pure mechanical oil return valve structure and is stable and reliable.

[0072] In some embodiments of the present application, the main rod has an oil return valve hole 305 at one end of the liquid inlet cavity, and the oil return valve is arranged in the oil return valve hole 305. The high-pressure oil return of the triple-screw pump usually adopts an external copper pipe oil return or an oil return through a bushing. Of course, there is also a structure of a screw built-in oil return hole, but in some embodiments of the present application, the external copper pipe scheme is abandoned to ensure the integrity of the high-pressure screw pump. At the same time, the position of the mechanical seal assembly installed in the main rod is innovatively opened, the entire oil return hole penetrates from the sealed cavity to the tail end of the main rod, and an oil return valve structure is added at the tail end. The medium oil always fills the oil return hole, so even if the oil return valve is opened, it will not cause impact to the oil return hole, avoiding the vibration caused by the oil return impact. In some embodiments of the present application, the oil return amount can be automatically adjusted by the oil return pressure, which can better control the oil amount and oil pressure in the sealed cavity, and under the working conditions of the bearing and the mechanical seal, the medium oil can play the maximum lubrication and heat dissipation effect, improving the overall reliability of the equipment.

[0073] In some embodiments of the present application, the oil return hole comprises a first hole 3011, a second hole 3012, and a third hole 3013. The first hole is a through hole arranged along the radial direction of the main rod, and directly communicates with the sealing cavity. The second hole is arranged along the axial direction of the main rod, and one end of the second hole is connected with the first hole, and the other end of the second hole is connected with the oil return valve hole 305. The third hole is a through hole arranged along the radial direction of the main rod, and the axis of the third hole is in the same plane as the axis of the oil return valve hole and is perpendicular to the axis of the oil return valve hole. The third hole is divided into two sections by the oil return valve hole, and one end of each section of the third hole is connected with the oil return valve hole, and the other end is connected with the liquid inlet cavity. The axis of the third hole is in the same plane as the axis of the rotor. When the oil return valve is closed, the ball core 304 abuts against the second hole 3012.

[0074] In some embodiments, the screw pump comprises a sealing assembly. In some embodiments, the sealing assembly is used to ensure that the medium oil in the entire screw pump does not leak out. In some embodiments, the sealing assembly at least comprises a first sealing ring 701 and a second sealing ring 702. Specifically, in some embodiments, the front cover has the first sealing ring 701 between the stator and the slave rod shaft sleeve.

[0075] In some embodiments, the first sealing ring 701 is non-circular in shape. In some embodiments, the first sealing ring 701 is elliptical in shape. In embodiments of the present application, the first sealing ring between the stator and the front cover for sealing bears a high pressure, and the use of an elliptical shape instead of a circular shape can reduce the pressure area of the first sealing ring and reduce the high pressure shear force received thereby, thereby enhancing the reliability of the structure of the first sealing ring. In embodiments of the present application, the elliptical first sealing ring surrounds the main rod and the two slave rod shaft sleeves, thereby minimizing the size of the first sealing ring. In some embodiments, the stator has a sealing groove 1014 that matches the shape of the first sealing ring 701. In some embodiments, the sealing groove is also elliptical in shape.

[0076] Specifically, in some embodiments, the front cover has the second sealing ring 702 between the oil return positioning pin and the slave rod shaft sleeve. In embodiments of the present application, the screw pump operates at a very high pressure, and the high-pressure medium oil will flow into the space between the slave rod shaft sleeve and the front cover. By adding a second sealing ring at the oil return positioning pin, the high-pressure medium oil is prevented from flowing out, and the oil return positioning pin also serves to position the slave rod shaft sleeve. Through the combined action of the two, the rotation of the slave rod shaft sleeve during operation is completely eliminated. In some embodiments, the oil return positioning pin has a positioning shoulder 5072, and the second sealing ring is located between the positioning shoulder, the front cover, and the slave rod shaft sleeve.

[0077] In some embodiments, the sealing assembly further comprises a third sealing ring 703. The third sealing ring 703 is arranged between the front cover 6021 and the sealing cover 6031. In some embodiments, the sealing assembly further comprises a mechanical sealing assembly 704. The mechanical sealing assembly 704 is arranged between the main shaft 201 and the sealing cover 6031. In some embodiments, the mechanical sealing assembly is a rotating sealing ring. The rotating sealing ring can ensure reliable sealing between the main shaft 201 and the sealing cover 6031. In some embodiments of the present application, the sealing assembly comprises a first sealing ring, a second sealing ring, a third sealing ring, and a mechanical sealing assembly, the first sealing ring is arranged between the pump body bushing and the front cover, the second sealing ring is arranged between the slave shaft shaft sleeve and the front cover, the third sealing ring is arranged between the front cover and the sealing cover, and the mechanical sealing assembly is arranged between the sealing cover and the main shaft. Through the first sealing ring, the second sealing ring, the third sealing ring, and the mechanical sealing assembly, the high-pressure cavity and the sealing cavity of the screw pump are reliably sealed as a whole.

[0078] In some embodiments of the present application, a sealing and vibration reduction structure of a screw pump is also provided, and the sealing and vibration reduction structure comprises an oil return device. The oil return device comprises an oil return hole and an oil return control assembly. The oil return hole is arranged in the main shaft of the screw pump, a first end of the oil return hole is connected to the sealing cavity of the screw pump, and a second end of the oil return hole is connected to the liquid inlet cavity of the screw pump. The oil return control assembly is used to open when the oil return pressure reaches a preset pressure, so that the oil is guided back to the liquid inlet cavity from the sealing cavity through the oil return hole. In some embodiments of the present application, the oil return device is the oil return device in any of the above embodiments.

[0079] In some embodiments, the sealing and vibration reduction structure further comprises a sealing assembly. The sealing assembly at least comprises a first sealing ring. The first sealing ring is arranged between the front cover and the stator of the screw pump, and the shape of the first sealing ring is non-circular. In some embodiments of the present application, the sealing assembly is the sealing assembly in any of the above embodiments.

[0080] In some embodiments, the fitting gap between the main shaft sealing section 2013 and the shaft hole sealing section of the front cover is 0.06-0.08 mm. The length Lm of the main shaft sealing section and the length Ln of the main shaft screw section satisfy: In the embodiments of the present application, the medium oil pressure delivered is very high, and the structure of the main rod sealing section and the front cover is designed accordingly. No other components are arranged on the shaft hole sealing section of the front cover, and the front cover directly cooperates with the main rod sealing section. In the embodiments of the present application, a cooperation gap of 0.06-0.08 mm is adopted. Compared with a general screw pump, the cooperation gap is reduced, the leakage amount of high-pressure medium oil from this position is reduced, the volumetric efficiency of the high-pressure screw pump as a whole is improved, the working efficiency of the equipment as a whole is improved, the working pressure of 20 MPa is met, the internal oil circulation amount is kept in an allowable range during long-time operation, and the internal heating problem caused by excessive leakage is prevented. In the embodiments of the present application, the axial length of the main rod sealing section is increased to increase the sealing performance at this position.

[0081] It can be understood that the delivery pressure of the screw pump in the embodiments of the present application is up to 25 MPa, and the leakage amount in the screw pump is precisely controlled. The gap between the main rod sealing section and the front cover is one of the main leakage points. The size of the gap at this position determines the leakage amount. The larger the gap, the larger the leakage amount. If the leakage amount is too large, the volumetric efficiency is reduced, and the output pressure cannot reach more than 20 MPa. If the leakage amount is too small, the pressure and flow rate entering the sealing cavity are low, which is not conducive to the heat dissipation of the bearing and the lubrication of the mechanical seal. In addition, if the gap is too small, the risk of wear between the main rod sealing section and the front cover is increased, thereby affecting the reliability of the screw pump. In the embodiments of the present application, a cooperation gap of 0.06-0.08 mm is adopted, the upper limit of the pressure is finally achieved, and the wear is minimized. In this way, the high output pressure is achieved, and the high reliability requirement is met.

[0082] In some embodiments, the main rod sealing section 2013 has a plurality of main rod sealing grooves arranged in the axial direction. The number of the main rod sealing grooves is 2-4. In some embodiments, the number of the main rod sealing grooves is 2. The groove width of each main rod sealing groove is 2-3 mm, and the groove depth of each main rod sealing groove is 2-4 mm. In the embodiments of the present application, two main rod sealing grooves are arranged on the main rod sealing section. The labyrinth seal can be formed at the main rod sealing section, and oil can be stored in the main rod sealing grooves to ensure the lubricity of the cooperation position of the main rod sealing section and the front cover, thereby preventing the risk of “bearing seizure” caused by the reduction of the cooperation gap at this position.

[0083] In some embodiments, the gap between the shaft sleeve support section 5062 of the slave rod shaft sleeve 506 and the pump body bushing is 0.02-0.04 mm. The leakage amount of high-pressure medium oil from this position is reduced, and the installation is facilitated.

[0084] In some embodiments, the length Lt of the slave rod shaft end section and the length Lf of the slave rod screw section satisfy: In the embodiments of the present application, the length of the shaft end section of the slave rod is increased, the torsional resistance of the slave rod is improved, and the slave rod can withstand more than 30% of the radial force of the conventional medium and low pressure pump. When working at 20 MPa, the slave rod can meet the requirements of normal work.

[0085] In some embodiments, the shaft end section of the slave rod has a plurality of slave rod sealing grooves arranged in the axial direction, and the number of the slave rod sealing grooves is 2-4. In some embodiments, the number of the slave rod sealing grooves is 2. The groove width of each slave rod sealing groove is 1.5-2.5 mm, and the groove depth of each slave rod sealing groove is 2-3 mm. In the embodiments of the present application, the same scheme as the main rod sealing section is used at the shaft end section of the slave rod, two sealing grooves are arranged, a labyrinth seal is formed, the sealing performance at this position is improved, and excessive leakage of high-pressure medium oil to the sealing cavity is avoided.

[0086] Figure 13 The assembly structure diagram of the positioning assembly in some embodiments of the present application is shown in FIG. 6. Referring to FIG. 6, Figure 13 In some embodiments, the spacer sleeve 501 and the balance ring 502 are installed in the sealing cavity, the inner diameter of the spacer sleeve 501 is larger than the outer diameter of the balance ring 502. The first end of the spacer sleeve 501 is in contact with the front cover 6021, and the second end of the spacer sleeve 501 is in contact with the outer ring of the bearing. The first end of the balance ring 502 is in contact with the main rod sealing section 2013, and the second end of the balance ring 502 is in contact with the inner ring of the bearing. There is a gap between the spacer sleeve and the balance ring in the axial and radial directions, which is used for the flow of medium oil to the bearing and mechanical seal assembly, and provides heat dissipation and lubrication effects for the bearing and mechanical seal assembly.

[0087] In some embodiments, the inner diameter of the spacer sleeve is 55-60 mm, the outer diameter is 80-85 mm, the axial length is 9-11 mm, the outer diameter of the balance ring is 50-55 mm, the inner diameter is 35-50 mm, and the axial length is 8-10 mm. In the embodiments of the present application, the size difference between the inner diameter of the spacer sleeve and the outer diameter of the balance ring is DW1, the inner diameter of the slave rod oil return hole 6023 is DW2, and the size difference between the outer diameter of the inner ring 5031 of the bearing and the inner diameter of the outer ring 5032 of the bearing is WD3=6 mm, wherein DW1<DW2, and DW1<DW3. In some embodiments, the axial length of the spacer sleeve is greater than the axial length of the balance ring. In some embodiments, the difference between the axial length of the spacer sleeve and the axial length of the balance ring is 1 mm. In the embodiments of the present application, by strictly controlling the axial dimensions of the spacer sleeve and the balance ring, there is an assembly gap 5012 between the axial direction of the spacer sleeve and the axial direction of the balance ring, which ensures the smooth rotation of the main rod and the smooth flow path of the medium oil.

[0088] In the embodiments of the present application, by strictly controlling the size of the spacer sleeve 501 and the balance ring 502, the flow of medium oil to the bearing and mechanical seal assembly is controlled, avoiding excessive flow that increases leakage, reduces volumetric efficiency, and causes insufficient output pressure. At the same time, it also avoids the phenomenon of "jamming" between the driving screw and the driven screw caused by a sharp rise in pump body temperature.

[0089] In some embodiments, the engagement gap between the main rod and the slave rod is 0.025-0.035 mm. In the embodiments of the present application, the engagement gap between the driving screw and the driven screw determines the thickness of the oil film. If the oil film is too thin, it will not have enough stiffness to effectively support the high-speed rotating screw. If the oil film is too thick, it will cause unstable engagement. In the embodiments of the present application, the engagement gap between the main rod and the slave rod is 0.025-0.035 mm, which minimizes vibration and noise, provides the best engagement state, and ensures stable operation. In some embodiments, the engagement gap between the main rod and the slave rod can be 0.025 mm, 0.03 mm, or 0.035 mm.

[0090] In the embodiments of the present application, due to the very high working pressure of the high-pressure screw pump set, the vibration excitation source of the high-pressure screw pump is mainly in the engagement cavity formed by the driving screw and the driven screw and the pump body bushing, and is transmitted in the pump body flow passage. The most effective method is to minimize the excitation force. In the embodiments of the present application, the screw profile can be appropriately modified to address this issue.

[0091] In some embodiments, modifying the screw profile includes screw profile modification for pressure pulsation and screw profile modification for screw engagement interference. Specifically, in some embodiments, a special profile milling cutter is designed and manufactured through profile data calculation to ensure screw machining precision and efficiency, making the screw engagement smoother. In some embodiments, a special profile milling cutter is used for rough machining, and after nitriding, a special high-precision screw grinder is used for finishing to a live profile, further improving the machining precision and surface finish of the screw profile and reducing the error of lead.

[0092] In some embodiments, the screw profile modification for pressure pulsation includes reducing the screw pitch P. Specifically, the screw pitch of the main rod and the slave rod is 10-20 mm, and in some embodiments, the screw pitch of the main rod and the slave rod is 10 mm, and the length of the main rod screw segment 2011 of the main rod is 20 cm. In the embodiments of the present application, the screw pitch of the main rod and the slave rod is set to 10 mm under the condition that the length of the main rod screw segment 2011 is constant, the number of the entire thread is increased by setting the screw pitch to be small, and the purpose of reducing the inter-stage pressure difference of the screw seal cavity is achieved by increasing the number of the screw pitch, thereby reducing the pressure pulsation. In the embodiments of the present application, although the three-screw pump theoretically does not generate pressure pulsation, it is found in actual engineering that the existence of machining profile error and running gap will cause internal leakage between the screw, the pump body bushing, and the seal cavity, thereby generating pressure pulsation. Pressure pulsation causes system vibration of the three-screw. Under the same conditions, the higher the pressure, the greater the pulsation value. In the embodiments of the present application, the vibration caused by pressure pulsation is reduced by reasonable setting of the screw pitch. In some embodiments, after the screw is machined, a special screw detection instrument is used to check the profile, and according to the detection result, a grinding sand grinding process is added to further eliminate the residual sharp points in the screw machining to further reduce the possibility of meshing interference of the screw, and to reduce or even avoid pressure pulsation.

[0093] Figure 14 A schematic diagram of the screw profile modification in some embodiments of the present application. Referring to Figure 14In some embodiments, the screw profile modification for screw meshing interference includes setting the end shape of the non-working surface 2015 of the main rod to be arc-shaped. In the embodiments of the present application, the non-working surface of the main rod is the thread surface away from the high-pressure cavity. The end of the non-working surface 2015 is the radially outwardmost edge. In the embodiments of the present application, the end shape of the non-working surface of the main rod is arc-shaped. In the embodiments of the present application, the high-pressure screw pump set is a three-screw pump structure, and the theoretical helix forms a gear tooth curve that is point meshing when meshing. In theory, the helix of the driving screw and the driven screw does not interact when meshing, and thus does not produce vibration after physical contact. However, it is found that vibration noise is still generated during actual operation. After excluding various factors and optimizing the design, vibration noise is still generated during start-up and shutdown in the embodiments of the present application. After various tests and theoretical verification, it is finally found that the torque of the medium oil driving the driven screw is reduced due to the change of the pressure in the liquid inlet cavity and the high-pressure cavity during start-up and shutdown of the screw pump, which is insufficient to overcome the frictional resistance of rotation. Although the driving screw still drives the driven screw to rotate, the driving force of the driven screw has changed from relying on the medium to relying on the driving screw profile. At this time, the driving screw and the driven screw interact with each other, and the physical contact between the driving screw and the driven screw produces vibration noise. In the embodiments of the present application, the end of the non-working surface of the main rod is arc-modified to have a "circular arc" shape, so as to minimize the contact area between the driving screw and the driven screw and reduce the vibration noise generated by physical contact.

[0094] In the embodiments of the present application, the pump body bushing serves as a stator and forms a sealed volume chamber with the high-speed rotating rotor. The high-precision low-noise pump body bushing is a bottleneck link that restricts the low-noise high-pressure screw pump, and the machining quality thereof is directly related to the vibration noise level of the entire machine, especially the machining precision of the three holes of the pump body bushing corresponding to the three screws.

[0095] In some embodiments, the pump body bushing meshes with the main and driven rods, and the pump body bushing includes three holes 1012 corresponding to the three screws, including a main rod hole 10121 and two driven rod holes 10122, and the three holes together form the three holes 1012 of the pump body bushing. In some embodiments of the present application, the stator has a main rod hole, and the main rod hole includes a main rod threaded fitting hole section 10123 and a main rod connection fitting hole section 10124, and the inner diameter of the main rod connection fitting hole section is greater than the inner diameter of the main rod threaded fitting hole section.

[0096] The dimensional tolerance and shape tolerance, surface roughness, etc. of the three holes of the pump body bushing directly affect the smoothness of the engagement between the pump body bushing and the master and slave rods. In some embodiments of the present application, the straightness and coaxiality of the three holes of the pump body bushing are less than or equal to 0.01 mm. At the same time, the machining error of the three holes is accurately controlled to 0.01 mm to 0.02 mm, which ensures the gap size between the "rotor" master and slave screws and the "stator" pump body bushing, forms a stable oil film thickness, and reduces vibration noise.

[0097] In embodiments of the present application, the gap between the stator and rotor of the high-pressure screw pump is much smaller than that of a general screw pump, and the straightness and coaxiality of the three holes are less than or equal to 0.01 mm, which avoids vibration caused by the deviation of the three holes and the friction with the rotor screw. In embodiments of the present application, a special combined broach is designed and manufactured to machine the three holes of the pump body bushing, and the feed amount is kept at a minimum value each time. Through five broaching processes, the machining precision can be maximized. Then, a special grinding rod is used to cooperate with grinding sand for 12 hours of honing operation, and finally the three holes of the pump body bushing are honed to form a shape, which meets the design requirement of straightness and coaxiality ≤0.01 mm, and avoids vibration caused by the deviation of the location tolerance and the friction with the rotor screw.

[0098] In some embodiments, as the master and slave screws of the rotor, due to the characteristics of the high-pressure screw pump, the number of screw sealing stages is twice that of a general screw pump, which results in an elongated screw profile, which is a large-length-diameter screw. In embodiments of the present application, a special screw grinder and a special heat treatment process are used for two times of quenching treatment, which ensures that the straightness of the screw is less than or equal to 0.01 mm, and prevents vibration caused by the friction between the screw and the pump body bushing during operation.

[0099] In some embodiments, the machining error of the screw lead is controlled within ±0.015 mm. In embodiments of the present application, the machining program and process of the screw lead are specially designed to meet the machining error control of the screw lead within ±0.015 mm, while avoiding the interference of the error of the lead when the master and slave screws are engaged, avoiding mutual collision during operation, affecting the operation state, and reducing vibration noise.

[0100] In some embodiments, the installation of the bearing 503 and the master rod 201 is carried out by using a bearing positioning and installation special tool 2000, which ensures that the bearing is stably assembled to the driving screw. Figure 15 The figure is a schematic view of the bearing positioning and installation special tool in some embodiments of the present application. For reference Figure 15In some embodiments, the bearing positioning and installing special tool is used for stably assembling the bearing on the driving screw, and the bearing positioning and installing special tool 2000 comprises a base rack 2001, a support frame 2002, a hydraulic sleeve 2003 and a holding bracket 2004. The support frame is detachably arranged on the base rack. The hydraulic sleeve is arranged between the bearing and the holding bracket. The holding bracket is movably connected to the base rack. In the embodiment of the application, a manufacturing tool of the hydraulic power device is provided, and the manufacturing tool comprises the bearing positioning and installing special tool.

[0101] In some embodiments, the holding bracket comprises a first bracket column 20041, a second bracket column 20042 and a support plate 20043. One end of the first bracket column and one end of the second bracket column are fixedly connected to the base rack. One end of the support plate is rotatably connected to the other end of the first bracket column. The other end of the support plate is detachably connected to the other end of the second bracket column. The base rack comprises four columns, i.e., a first column 20011, a second column 20012, a third column 20013 and a fourth column 20014. Support holes 20015 are arranged on the first column, the second column, the third column and the fourth column, respectively. The support frame comprises a first support rod 20021, a second support rod 20022 and a support truss 20023. The first support rod is detachably arranged through the support holes of the first column and the second column. The second support rod is detachably arranged through the support holes of the third column and the fourth column. The support truss is detachably arranged on the first support rod and the second support rod.

[0102] The bearing positioning and installing method is as follows. The driving screw is placed on the base rack 2001 and is supported by the support frame 2002. Then, the bearing is placed on the driving screw. The bearing is gently pressed by the hydraulic sleeve 2003. Finally, the holding bracket 2004 is used to fix the hydraulic sleeve. The tap of the hydraulic sleeve is slowly rotated. The bearing is slowly and stably pushed into the driving screw by the hydraulic pressure until the bearing is installed in place.

[0103] In the embodiment of the application, the bearing positioning and installing special tool is used, which can greatly reduce the wear in the bearing installation process and prevent the reliability and vibration noise problems caused by the deviation of the bearing precision.

[0104] In the embodiments of the present application, a manufacturing method of the hydraulic power device is also provided, which uses the manufacturing tool described above, and the manufacturing method comprises: bearing positioning and installation, which comprises: placing the main rod on the base bench, and lifting the main rod through the support frame; placing the bearing on the main rod, and gently pressing the bearing using the hydraulic sleeve; then fixing the hydraulic sleeve using the holding bracket; slowly rotating the plug of the hydraulic sleeve, and slowly and smoothly pushing the bearing into the main rod using the hydraulic force until the bearing is installed in place.

[0105] In some embodiments, the present application provides a hydraulic power device for an underwater vehicle, which comprises: an electric motor and a screw pump, the electric motor having an output shaft; the screw pump comprising: a stator and a rotor; the rotor comprising one main rod and two slave rods, the main rod being connected with the output shaft of the electric motor, and the axis of the main rod being along the vertical direction. In the embodiments of the present application, the screw pump can be the screw pump in any of the above embodiments.

[0106] Figure 16 FIG. 1 is a schematic diagram of a high-pressure hydraulic system of an underwater vehicle in some embodiments of the present application. In the embodiments of the present application, the high-pressure hydraulic system of the underwater vehicle comprises a hydraulic power device. The hydraulic power device can be the hydraulic power device in any of the above embodiments.

[0107] Specifically, referring to FIG. 1, Figure 16 In some embodiments, the high-pressure hydraulic system of the underwater vehicle comprises: a bench 1100, an electric motor 1200, a booster pump 1300, a flexible connecting pipe 1400, and a rigid straight pipe 1500.

[0108] The bench 1100 comprises a horizontal fixed plate 1101; the electric motor 1200 is fixedly installed above the horizontal fixed plate; the booster pump 1300 is connected with the electric motor and located below the horizontal fixed plate, and the booster pump is a positive displacement pump comprising an oil inlet and an oil outlet; the flexible connecting pipe 1400 is connected at the oil inlet; and the rigid straight pipe 1500 is connected at the oil outlet.

[0109] In the embodiments of the present application, the booster pump can be the screw pump in any of the above embodiments. In the embodiments of the present application, a small section of flexible connecting pipe is added at the front end of the oil inlet, which can buffer the vibration caused by the suction of medium oil into the pipeline. A rigid straight pipe is used at the front end of the oil outlet, which is used to reinforce and relieve the pressure pulsation of the medium oil at the outlet. The inlet and outlet pipelines are both installed on the support horse shoe using special vibration isolators.

[0110] In some embodiments, the high-pressure hydraulic system of the underwater vehicle has three high-pressure relief valves, namely the first high-pressure relief valve 1601, the second high-pressure relief valve 1602, and the third high-pressure relief valve 1603 connected to the rigid straight pipe in turn from near to far. In the embodiments of the present application, multiple high-pressure relief valves are added at the outlet, and the multiple high-pressure relief valves can share the pressure of the entire system. Even if the pressure is increased to 20 MPa, the pressure is evenly established on each valve, and the opening of each valve is much larger than that of a single high-pressure valve, thereby avoiding the formation of flow noise due to too small valve opening. When three high-pressure relief valves are used to establish a pressure of 20 MPa with the same opening, the vibration noise is the smallest, and the working state of each valve is in the best interval, thereby reducing the vibration noise caused by too fast medium flow rate from the system.

[0111] In some embodiments, the high-pressure hydraulic system of the underwater vehicle includes multiple flow straightening devices 1700 connected to the rigid straight pipe, and each flow straightening device includes a flow straightening grid. In the embodiments of the present application, the working pressure of the high-pressure screw pump reaches 20 MPa, and the flow rate is fast, and the impact of the internal medium flow on the pipeline is very large. The impact of the fluid causes pipeline vibration, thereby increasing the vibration acceleration of the inlet and outlet flanges. In the embodiments of the present application, the flow straightening grid is added in the middle of the pipeline, so that the medium oil flow is more stable, the impact on the pipeline is reduced, and the vibration acceleration on the pipeline is reduced, thereby reducing the vibration on the inlet and outlet flanges.

[0112] Figure 17 The cross-sectional view of the flow straightening device in some embodiments of the present application is shown. Figure 18 The schematic view of the flow hole in some embodiments of the present application is shown. Figure 19 The schematic view of the flow hole in some embodiments of the present application is shown. Figures 17-19 In some embodiments, the flow straightening grid includes two flow straightening layers 1703, each of which has a baffle with multiple flow holes 1704. In some embodiments, the hole diameters of the multiple flow holes are distributed from large to small from the center to the outside.

[0113] In the embodiments of the present application, two flow straightening layers are designed inside the flow straightening grid, so that the fluid can be fully stabilized in the flow straightening device, and the fluid impact on the pipeline is reduced. The flow holes of each flow straightening layer are uniformly distributed from large to small from the center to the outside, so that the fluid is more evenly distributed in the entire channel, and fluid disturbance is prevented.

[0114] Reference is made to Figure 18 and Figure 19In some embodiments, the plurality of flow holes includes a central hole 17041 and circumferential holes, which are evenly distributed around the central hole, and the angle of each circumferential hole with the axis is 3°. In some embodiments, the diameter of the central hole is 6 mm. The circumferential holes include first circumferential holes 17402, second circumferential holes 17403, third circumferential holes 17404, and fourth circumferential holes 17405, which are radially outward from the center, and the number of the first circumferential holes 17402, the second circumferential holes 17403, the third circumferential holes 17404, and the fourth circumferential holes 17405 is 6, 12, 18, and 24, respectively, and the diameter of the circumferential holes radially outward from the center is 4 mm, 3 mm, 2 mm, and 1 mm, respectively. In the embodiments of the present application, except for the central 4 mm flow hole, the angles of the remaining flow holes are all deviated outward by 3° (the angle is smaller, and not directly marked in the figure), and are inclined to the central hole in the flow direction, so that the entire flow surface presents a "aggregation" shape. This design makes the medium oil slightly form a focused shape when flowing through this place, reducing the vibration caused by the fluid impacting the pipeline outward.

[0115] In some embodiments, the flow regulating device has two, namely a first flow regulating device 1701 and a second flow regulating device 1702, the first flow regulating device is arranged between the first high-pressure overflow valve and the rigid straight pipe, and the second flow regulating device is arranged between the first high-pressure overflow valve and the second high-pressure overflow valve.

[0116] Figure 20 The figure is a schematic view of the coupling bracket assembly in some embodiments of the present application. Referring to Figure 16 and Figure 20 In some embodiments, the high-pressure hydraulic system of the underwater vehicle includes a coupling bracket assembly 1800, which includes a coupling bracket 1801 and a mounting plate 1802, the motor and the booster pump are connected through the coupling bracket, the coupling bracket is fixed with the mounting plate, and the mounting plate is connected with the horizontal fixing plate.

[0117] In the embodiments of the present application, the coupling bracket assembly of the booster pump is composed of a coupling bracket and a mounting plate, the motor and the booster pump are connected through the coupling bracket, the coupling bracket is fixed with the mounting plate, and finally the entire pump set is connected with the horizontal fixing plate through the mounting plate. In the embodiments of the present application, the mounting plate of the coupling bracket is the mounting interface of the low-noise high-pressure screw pump to the outside, which is a main path for the external transmission of the vibration source, and the coupling bracket can be specially designed to achieve vibration reduction optimization of the entire pump set through vibration reduction design.

[0118] Figure 21 The figure is a cross-sectional view of the coupling bracket in some embodiments of the present application. Figure 22 The figure is a schematic view of the coupling bracket in some embodiments of the present application. Referring to Figure 21 and Figure 22In some embodiments, the coupling frame has a glue injection hole 1805 with damping rubber inside, and the coupling frame is different from the working frequency or excitation direction of the high-pressure hydraulic system of the underwater vehicle.

[0119] In the embodiments of the present application, the coupling frame is one of the main paths for transmitting vibration to the outside, and part of the vibration energy is isolated by designing the coupling frame to be damped and vibration-absorbed. In the embodiments of the present application, a special high-damping coupling frame is designed. Specifically, a flow channel is processed inside the high-damping coupling frame for injecting special damping rubber, and special upper and lower cover plates are designed to prevent the rubber liquid from flowing out. After the glue injection is completed, the damping glue is left to stand for 48 hours to complete air drying, and finally the high-damping coupling frame is manufactured.

[0120] In the embodiments of the present application, modal simulation calculation is also performed on the coupling frame to ensure that the coupling frame is different from the working frequency or excitation direction of the high-pressure hydraulic system of the underwater vehicle, thereby avoiding resonance. Since the high-damping coupling frame is a combination of metal materials and non-metal materials, the modal may change unpredictably after the materials are fused. In the embodiments of the present application, simulation modal calculation is performed. The calculation shows that the first-order modal of the system is about 6 Hz, the first five-order modals are relatively low, and the sixth-order modal frequency of the system exceeds 40 Hz, which is close to the excitation frequency of the device, but the vibration mode direction is different from the excitation direction. Therefore, the modal of the entire system is different from the working frequency or excitation direction of the device, and the system will not resonate, thereby meeting the design requirements.

[0121] In some embodiments, the motor has a damping ring between the motor and the coupling frame, the damping ring has a plurality of damping columns inside, and the damping columns are made of high-strength alloy materials for absorbing electromagnetic vibration generated by the motor.

[0122] In the embodiments of the present application, a damping ring is added between the motor and the high-damping coupling frame to achieve further damping effect. The damping ring has a plurality of damping columns inside, which are made of high-strength alloy materials and can absorb electromagnetic vibration generated by the motor. The high-damping coupling frame and the damping ring together form a damping system, and through actual measurement, the damping effect can be effectively reduced by more than 20 dB.

[0123] In the embodiments of the present application, an integrated mounting plate is designed, and vibration-absorbing materials are added to the internal structure of the mounting plate. At the same time, the strength of the mounting plate is strengthened, and the strength is weakened at some positions, thereby effectively changing the transmission path of vibration and reducing the vibration transmitted by the high-pressure screw pump to the outside.

[0124] In some embodiments, a plurality of vibration isolators 1900 are arranged between the horizontal fixing plate 1101 and the mounting plate 1802. In the embodiments of the present application, the vibration isolators serve as the main connecting components of the low-noise high-pressure screw pump set, and have the effect of blocking part of the vibration. In some embodiments, eight vibration isolators 1900 are arranged between the horizontal fixing plate 1101 and the mounting plate 1802. Specifically, the angles of the eight vibration isolators 1900 are matched with the vibration energy transmission path. During installation, the installation angles of the eight vibration isolators are adjusted so that each vibration isolator can better absorb the transmitted energy.

[0125] Figure 23 FIG. 1 is a schematic diagram of a high-pressure liquid system according to some embodiments of the present application. FIG. 2 is a schematic diagram of a high-pressure liquid system according to some embodiments of the present application. Figure 23 In some embodiments, the vibration isolators 1900 are BE type vibration isolators. In some embodiments, the horizontal degree and compression amount of the vibration isolators are also adjusted to optimize the vibration reduction effect.

[0126] In the embodiments of the present application, the upper and lower planes of the vibration isolators are guaranteed to be horizontal, and the parallelism error of the lower surface is not more than 0.02 mm based on the upper surface. This avoids vibration out-of-tolerance caused by non-horizontal installation of the equipment. In some embodiments, the compression amounts of all the vibration isolators are consistent, and the error is not more than 0.2 mm. In the embodiments of the present application, the manufacturing deviation of the vibration isolators themselves and the compression amount caused by the self-weight of the pump set are removed. The pre-tightening force of the fastening bolts connecting the vibration isolators to the equipment also affects the compression amount. In order to ensure that the compression amounts of the vibration isolators remain consistent, the pre-tightening force error of the fastening bolts cannot exceed ±5 N / m. In some embodiments, the compression amount of the vibration isolators is between 5 mm and 5.5 mm.

[0127] In the embodiments of the present application, the limit compression amount of the vibration isolators is 8 mm, and the working compression amount of the vibration isolators is between 5 mm and 5.5 mm, which is 62.5% to 68.8% of the limit compression amount. The compression amounts of all the vibration isolators are within this range, and the deviation is not more than 3%. In some embodiments, the working compression amount of the vibration isolators is 65% of the limit compression amount.

[0128] In the embodiments of the present application, the upper and lower planes of the vibration isolators are guaranteed to be horizontal, and the parallelism error of the lower surface is not more than 0.02 mm based on the upper surface. The compression amounts of the plurality of vibration isolators are consistent, and the error is not more than 0.2 mm. The working compression amount of the plurality of vibration isolators is 65% of the limit compression amount, and the deviation of the working compression amounts of all the vibration isolators is not more than 3%. The angles, horizontal degree, and compression amount of the vibration isolators are adjusted to optimize the vibration reduction effect.

[0129] Figure 24 FIG. 1 is a schematic diagram of a high-pressure liquid system according to some embodiments of the present application. FIG. 2 is a schematic diagram of a high-pressure liquid system according to some embodiments of the present application. Figure 24In some embodiments, the sleeve structure 1102 is arranged between the bottom of the screw pump and the front cover. By constraining the screw pump as a whole, the sleeve structure arranged between the bottom of the screw pump and the front cover constrains the "swing" of the bottom during operation, and makes the overall structure more stable.

[0130] In some embodiments, the inlet flange 6013, the outlet flange 1013 and the sleeve structure 1102 are all fixedly constrained to form an over-positioned mounting mode. In the embodiments of the present application, the over-positioned mounting mode strengthens the rigidity of the flanges and fixes the sleeve structure. The inlet flange 6013 is fixed to the rear cover and the sleeve structure, and the outlet flange 1013 is fixed to the pump body liner and the sleeve structure, thereby forming an over-positioned mounting mode to avoid the influence of the "swing" phenomenon to the greatest extent. It can be understood that the working pressure of the screw pump in the embodiments of the present application is very high, reaching 20 MPa, which results in a very large shaft power, and the matching motor power is 55 kW. The size and mass of the motor and the screw pump are greatly different, which greatly breaks the balance of the mass ratio, and the center of gravity of the pump set is far above the horizontal fixing plate 1101. The synchronous speed of the motor is 3000 r / min, and the high working pressure of the screw pump causes the pump to be relatively long, which results in a large "swing" phenomenon of the screw pump during high-speed and high-pressure operation. The inlet and outlet flanges of the high-pressure screw pump are a path for transmitting vibration to the outside. Due to the very high working pressure, the "slim" shape of the screw pump to meet the high-pressure working condition causes the inlet and outlet flanges to vibrate greatly, especially at the lower part, the vibration of the inlet flange is much greater than that of the upper part. The over-positioned mounting mode of the present application avoids the influence of the "swing" phenomenon to the greatest extent.

[0131] In some embodiments, high-damping energy-absorbing plates 1103 can be added to the inlet and outlet flanges to absorb part of the vibration energy and reduce the energy transmitted through the inlet and outlet flanges.

[0132] In some embodiments of the present application, a vibration reduction method for the high-pressure hydraulic system of the underwater vehicle is also provided. The vibration reduction method at least includes: correcting the screw profile, which includes screw profile correction for pressure pulsation and screw profile correction for screw meshing interference; adjusting the angle of the vibration isolator so that the angle of each vibration isolator matches the vibration energy transmission path; and adjusting the fastener pre-tightening force of the vibration isolator, with an error of each fastener pre-tightening force not exceeding ±5 N / m.

[0133] It can be understood that the vibration reduction method in the embodiments of the present application includes the vibration reduction design method and structure, features, components, etc. in the screw pump, the hydraulic power device or the high-pressure hydraulic system in any embodiment.

[0134] In some embodiments of the present application, a sealing and damping method of the screw pump is also provided, and the sealing and damping method comprises: setting the end shape of the non-working surface of the main rod as a circular arc shape; stably assembling the bearing to the main rod by using a bearing positioning installation special tool; connecting a flexible connecting pipe at the oil liquid inlet of the screw pump; and connecting a rigid straight pipe at the oil liquid outlet of the screw pump.

[0135] In embodiments of the present application, a high-pressure hydraulic system of an underwater vehicle is also provided, and the high-pressure hydraulic system comprises the high-pressure hydraulic system of the underwater vehicle according to any one of the above embodiments.

[0136] Those skilled in the art will easily understand that the above description is only the preferred embodiments of the present application, and is not intended to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A hydraulic power device characterized by comprising: The hydraulic power device is used for an underwater vehicle, and the hydraulic power device comprises: a motor having an output shaft; a screw pump comprising: a stator; a rotor comprising a main rod and two slave rods, the main rod being connected with the output shaft of the motor, and the main rod having an axis along a vertical direction; a front cover fixedly connected with the stator, the front cover having a main rod shaft hole in the front cover, the main rod shaft hole comprising a shaft hole sealing section, the main rod comprising a main rod screw section, a main rod connecting section, a main rod sealing section and a main rod bearing section arranged in sequence from a liquid inlet cavity to a sealing cavity, the main rod sealing section being assembled and connected with the shaft hole sealing section, and the main rod bearing section being supported and connected with the front cover through a bearing; The diameter Dm of the main rod sealing section, the outer diameter Dn of the main rod screw section, and the outer diameter Dc of the main rod connecting section satisfy: The length Lm of the main rod sealing section and the length Ln of the main rod screw section satisfy: .

2. The hydraulic power apparatus of claim 1, wherein the main rod sealing section having a plurality of main rod sealing grooves arranged along an axial direction, and the number of the main rod sealing grooves being 2-4; each main rod sealing groove having a groove width of 2-5 mm and a groove depth of 3-5 mm.

3. The hydraulic power apparatus of claim 1, wherein the fitting gap between the main rod sealing section and the shaft hole sealing section being 0.06-0.08 mm.

4. The hydraulic power apparatus of claim 1, wherein the meshing gap between the main rod and the slave rods being 0.025-0.035 mm.

5. The hydraulic power apparatus of claim 1, wherein the stator having a main rod hole in the stator, the main rod hole comprising a main rod screw thread fitting hole section and a main rod connecting fitting hole section, and the inner diameter of the main rod connecting fitting hole section being greater than the inner diameter of the main rod screw thread fitting hole section.

6. The hydraulic power apparatus of claim 1, wherein the end shape of the non-working surface of the main rod being in a circular arc shape.

7. The hydraulic power apparatus of claim 1, wherein the screw pump comprising a slave rod shaft sleeve and an oil return positioning pin, the slave rod shaft sleeve having a shaft sleeve support section and a shaft sleeve end section, the slave rod comprising a slave rod screw section and a slave rod shaft end section, the outer diameter of the shaft sleeve support section being equal to the outer diameter of the slave rod screw section, the outer periphery of the shaft sleeve end section having a circular arc section and a straight line section, the outer diameter of the circular arc section being greater than the outer diameter of the shaft sleeve support section, and the distance between the straight line section and the axis of the slave rod shaft sleeve being less than the outer diameter of the shaft sleeve support section; the slave rod shaft sleeve having a slave rod shaft hole and a positioning hole, and the central axis of the slave rod shaft hole not coinciding with the central axis of the positioning hole; the front cover having a slave rod oil return hole, the central axis of the slave rod oil return hole coinciding with the central axis of the positioning hole, and the oil return positioning pin being positioned and fitted with the slave rod oil return hole and the positioning hole.

8. The manufacturing tool for hydraulic power units according to any of claims 1 to 7, characterized in that the manufacturing tooling comprises bearing positioning and installation special tooling, and the bearing positioning and installation special tooling comprises a base bench, a support frame, a hydraulic sleeve and a holding bracket; the support frame is detachably arranged with the base bench; the hydraulic sleeve is arranged between the bearing and the holding bracket, and the holding bracket is movably connected with the base bench.

9. The manufacturing tool for hydraulic power units according to claim 8, characterized in that the holding bracket comprises a first bracket column, a second bracket column and a support plate, one end of the first bracket column and one end of the second bracket column are fixedly connected with the base bench, one end of the support plate is rotatably connected with the other end of the first bracket column, and the other end of the support plate is detachably connected with the other end of the second bracket column. The base rack comprises four columns, namely a first column, a second column, a third column and a fourth column, and support holes are arranged on the first column, the second column, the third column and the fourth column respectively, the support frame comprises a first support rod, a second support rod and a support truss, the first support rod is detachably arranged through the support holes of the first column and the second column, the second support rod is detachably arranged through the support holes of the third column and the fourth column, and the support truss is detachably arranged on the first support rod and the second support rod.

10. The method of manufacturing a hydraulic power unit according to any one of claims 1 to 7, characterized in that, The manufacturing method adopts the manufacturing tooling of claim 8 or 9, and the manufacturing method comprises the following steps: The bearing positioning installation comprises: The main rod is placed on the base rack, and the main rod is lifted by the support frame; The bearing is placed on the main rod, and the bearing is gently pressed by using the hydraulic sleeve; Then, the hydraulic sleeve is fixed by using the holding bracket; the tap of the hydraulic sleeve is slowly rotated, the bearing is slowly and smoothly pushed into the main rod by using the hydraulic pressure, and the bearing is installed in place.

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