Transmission case pressure control device, slot milling machine, and method

Abstract

This invention discloses a transmission box pressure control device, a milling machine, and a method, relating to the field of engineering machinery, to reduce the leakage risk of transmission boxes. The control device includes a transmission box, a pressurizing device, and a pressure regulating device. The transmission box includes a drive shaft, a motor, and a cylinder; the outer wall of the drive shaft and the inner wall of the cylinder form a first cavity. The pressurizing device includes a sleeve, a cover, a piston rod, a deformable body, and an elastic element; the sleeve and the cover are fixedly connected, forming a cavity between them; the deformable body is located in the cavity and forms a second cavity with the cover; the second cavity communicates with the first cavity. One end of the piston rod is installed in the sleeve, and the piston rod is at least partially installed in the sleeve; the elastic element is disposed between the piston rod and the sleeve, and the elastic element is compressed. The pressure regulating device includes a housing and a bladder installed inside the housing; the space between the inner wall of the housing and the outer wall of the bladder is a third cavity; the third cavity is in fluid communication with the first cavity.

Description

Technical Field

[0001] This invention relates to the field of engineering machinery, specifically to a transmission box pressure control device, a milling machine, and a method. Background Technology

[0002] The twin-wheel trenching machine is a type of equipment used for trenching underground continuous walls. During operation, the working device vertically excavates downwards within a slurry-filled trench, ultimately forming a deep trench. Currently, the working depth of twin-wheel trenching machines has exceeded 100 meters.

[0003] The working device of the twin-wheel trenching machine includes a milling wheel for cutting and breaking rock and a submersible mud pump for slag removal. Because these working components operate underwater, their transmission boxes require sealing. Since the trench is filled with mud, there is a high mud pressure outside the transmission box. To ensure an effective seal, pressure control of the transmission box is necessary to balance the internal pressure and the external mud pressure.

[0004] In related technologies, there is a device that maintains pressure balance inside and outside the gearbox. It uses a bladder filled with lubricating oil to sense the external mud pressure and transmits the external pressure to the inside of the gearbox through an oil pipe to ensure pressure balance inside and outside the gearbox.

[0005] The inventors have discovered that the prior art has at least the following problems: the device with this structure allows the pressure inside and outside the gearbox to be balanced when the twin-wheel grooving machine is working on land or in shallow water to prevent lubricating oil leakage, but when working in deep water, there is still a high risk of lubricating oil leakage inside the gearbox. Summary of the Invention

[0006] This invention proposes a transmission box pressure control device, a milling machine, and a method to achieve precise adjustment of the internal pressure of the transmission box and reduce the risk of leakage of lubricating oil inside the transmission box.

[0007] This invention provides a transmission box pressure control device, comprising:

[0008] A transmission box includes a transmission shaft, a motor, and a cylinder; one end of the transmission shaft is driven and connected to the motor, and the other end of the transmission shaft is rotatably mounted in the cylinder; the outer wall of the transmission shaft and the inner wall of the cylinder form a first cavity;

[0009] A pressurizing device includes a sleeve, a cover, a piston rod, a deformable body, and an elastic element; the sleeve and the cover are fixedly connected, forming a cavity between them; the deformable body is located in the cavity and is sealed to the cover to form a second cavity; the deformable body abuts against an end of the piston rod; the second cavity is in fluid communication with the first cavity; the piston rod is at least partially mounted in the sleeve; the elastic element is disposed between the piston rod and the sleeve, and the elastic element is configured to apply a force to the piston rod toward the cover; and,

[0010] A pressure regulating device includes a housing and a bladder installed inside the housing; the bladder is configured to store gas; the space between the inner wall of the housing and the outer wall of the bladder is a third cavity; the third cavity is in fluid communication with the first cavity.

[0011] In some embodiments, the pressure regulating device further includes:

[0012] A valve is installed at the inlet of the bladder; and,

[0013] The sealing element is also installed at the inlet of the bladder and is located outside the valve.

[0014] In some embodiments, the cover is configured to have a first recess, and the sleeve has a through hole; the cover and the sleeve are fixedly connected by a connector, and the first recess communicates with the through hole of the sleeve to form the cavity.

[0015] In some embodiments, the deformable body is configured to have a second recess, the deformable body is sealed and fixedly connected to the cover, and the first recess and the second recess communicate to form the second cavity.

[0016] In some embodiments, the piston rod head abuts against the deformable body, and the sleeve has a boss located on the side of the piston rod head away from the deformable body; the elastic element is configured as a compression spring and is clamped between the piston rod head and the boss.

[0017] In some embodiments, the outer wall of the sleeve is provided with a first protrusion, and the end of the piston rod away from the cover is provided with a second protrusion; the elastic element is constructed as a tension spring, one end of the elastic element is detachably or fixedly connected to the first protrusion, and the other end of the elastic element is detachably or fixedly connected to the second protrusion.

[0018] In some embodiments, the bladder is configured to be pre-filled with gas.

[0019] In some embodiments, the first cavity, the second cavity, and the third cavity are all configured to be filled with lubricating oil.

[0020] In some embodiments, the material of the cover is selected from metal; and / or, the material of the deformable body is selected from rubber.

[0021] In some embodiments, the housing is fixedly connected to the sleeve.

[0022] This invention also provides a milling machine, including the transmission box pressure control device provided by any of the technical solutions of this invention.

[0023] In some embodiments, the present invention provides a transmission box pressure control method, implemented using the transmission box pressure control device provided by any technical solution of the present invention, the method comprising the following steps:

[0024] Lubricating oil is filled into the first cavity, the second cavity, and the third cavity, and gas is filled into the bladder; and the first initial pressure of the lubricating oil in the first cavity, the second cavity, and the third cavity is greater than the second initial pressure of the gas filled into the bladder;

[0025] The pressurizing device is placed into the working fluid along with the tool holder of the milling machine. The piston rod of the pressurizing device reaches a balanced state under the action of the lubricating oil in the second chamber, the elastic element, and the combined pressure of the working fluid.

[0026] If the piston rod is stuck, the pressure in the second chamber decreases, causing the volume of the third chamber to decrease under the action of the gas in the bladder, thereby increasing the pressure of the lubricating oil in the first chamber, the second chamber and the third chamber;

[0027] The piston rod is pushed by the enlarged second cavity to release the jammed state.

[0028] In some embodiments, the transmission box pressure control method further includes the following steps:

[0029] If a leak occurs in the first cavity, the pressure in the first cavity, the second cavity, and the third cavity will decrease, causing the volume of the third cavity to decrease under the action of the gas inside the bladder. This increases the pressure of the lubricating oil in the first cavity, the second cavity, and the third cavity, so that the pressure in the first cavity is greater than the pressure of the working fluid.

[0030] The transmission box pressure control device provided by the above technical solution includes a transmission box, a pressurizing device, and a pressure regulating device. The transmission box has a drive shaft, a motor, and a cylinder, with a first chamber filled with lubricating oil. The first chamber is fluidly connected to the second chamber of the pressurizing device and the third chamber of the pressure regulating device. The pressures of the first, second, and third chambers are all interconnected. When the pressure in any of the first, second, and third chambers changes, it will affect the internal pressure of the remaining chambers. Therefore, by pressurizing the second chamber, the first and third chambers can be pressurized as well. When a leak occurs in the first chamber, the third chamber will be compressed by the bladder, thus being pressurized, which in turn pressurizes the first and second chambers, reducing the risk of leakage from the first chamber.

[0031] The causes of leakage in the first chamber can be mainly divided into two categories: the first is that the pressure in the first chamber itself decreases first, that is, the seals in the first chamber fail; the second is that the pressure in the second chamber decreases first, which is because the piston rod of the pressurizing device is stuck. Regardless of the cause, the technical solution provided by this invention can solve the problem, because both situations will lead to a decrease in the pressure in the third chamber of the pressure regulating device, which in turn causes the bladder to use the pressure of the gas inside to squeeze the third chamber, thus increasing the pressure in the third chamber. Finally, this leads to an increase in the pressure in both the first and second chambers. Therefore, it can solve both the problem of the piston rod being stuck and the problem of leakage in the first chamber.

[0032] As can be seen, the above technical solution achieves precise adjustment of the pressure in the first chamber inside the transmission box, making the pressure inside the first chamber slightly higher than the pressure of the external working fluid (including mud, water, etc.) to prevent the external working fluid from seeping into the transmission box; it can also provide pressure compensation for the pressurization device, so that when the piston rod or elastic element is stuck due to mud, sand, processing errors, etc., it can still provide pressure compensation for the pressurization device. These methods all reduce the risk of leakage in the transmission box. Attached Figure Description

[0033] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention.

[0034] Figure 1 This is a cross-sectional schematic diagram of a transmission box pressure control device provided in some embodiments of the present invention.

[0035] Figure 2 This is a cross-sectional schematic diagram of the transmission box of a transmission box pressure control device provided in some embodiments of the present invention.

[0036] Figure 3This is a cross-sectional schematic diagram of the pressurization device of the transmission box pressure control device provided in some embodiments of the present invention.

[0037] Figure 4 for Figure 3 A magnified view of part A.

[0038] Figure 5 This is a cross-sectional schematic diagram of the pressure regulating device of the transmission box pressure control device provided in some embodiments of the present invention.

[0039] Figure 6 This is a cross-sectional schematic diagram of the pressurization device of the transmission box pressure control device provided in some other embodiments of the present invention.

[0040] Figure 7 This is a schematic flowchart of a transmission box pressure control method provided in some embodiments of the present invention. Detailed Implementation

[0041] The following is combined with Figures 1 to 7 The technical solution provided by this invention will be described in more detail below.

[0042] This invention provides a transmission box pressure control device, particularly suitable for milling machines and similar engineering machinery. See also... Figures 1 to 5 The transmission box pressure control device includes a transmission box 1, a pressure regulating device 3, and a pressurizing device 2. The transmission box 1 includes a transmission shaft 11, a motor 12, a cylinder 13, and a bearing 14. One end of the transmission shaft 11 is driven by the motor 12, and the other end of the transmission shaft 11 is rotatably mounted in the cylinder 13, specifically, for example, using a bearing 14 to mount the transmission shaft 11. The bearing 14 is mounted in a first cavity 15. The outer wall of the transmission shaft 11 and the inner wall of the cylinder 13 form the first cavity 15. The pressurizing device 2 includes a sleeve 21, a cover 22, a piston rod 23, a deformable body 24, and an elastic element 25. The sleeve 21 and the cover 22 are fixedly connected, forming a cavity 26 between them. The deformable body 24 is located in the cavity 26 and is sealed to the cover 22 to form a second cavity 27. The deformable body 24 abuts against the end of the piston rod 23; the second cavity 27 communicates with the first cavity 15, specifically through a first pipe 4. The piston rod 23 is at least partially installed in the sleeve 21. That is, the piston rod 23 may be entirely or partially located in the sleeve 21. An elastic element 25 is disposed between the piston rod 23 and the sleeve 21, and the elastic element 25 is compressed. The pressure regulating device 3 includes a housing 31 and a bladder 32 installed inside the housing 31. The space between the inner wall of the housing 31 and the outer wall of the bladder 32 is a third cavity 33. The third cavity 33 is in fluid communication with the first cavity 15, specifically through the second conduit 5.

[0043] In some embodiments, the first cavity 15, the second cavity 27, and the third cavity 33 are all configured to be filled with lubricating oil. The sizes of the second cavity 27 and the third cavity 33 are variable. The size of the first cavity 15 is fixed.

[0044] Transmission box 1 is the working part of the milling machine. Figure 2 The direction shown is for reference. Motor 12 is located at the top and is driven by one end (specifically the top) of drive shaft 11. Pump body 6 is also driven by the bottom of drive shaft 11. Drive shaft 11 is installed inside cylinder 13, with a gap between them, which is the first cavity 15. Specifically, cylinder 13, drive shaft 11, and seal 16 form the first cavity 15, which is filled with lubricating oil. Cylinder 13 does not rotate with the rotation of motor 12; cylinder 13 is stationary. Drive shaft 11 is installed inside cylinder 13 via bearing 14. The outer ring of bearing 14 is installed inside cylinder 13; the inner ring of bearing 14 is connected to drive shaft 11 and supports the rotation of drive shaft 11. The outside of the first cavity 15 is a working fluid with a certain pressure, such as water or mud. Seal 16 isolates the working fluid from the lubricating oil inside the first cavity 15.

[0045] The entire driving process is as follows: the rotation of motor 12 drives the synchronous rotation of transmission shaft 11, which in turn drives pump body 6. Pump body 6 pumps out the working fluid. During the transmission of rotational kinetic energy, the entire transmission box 1 is located underwater, in mud, or in other working fluids. To ensure smooth rotation of transmission shaft 11, the first chamber 15 is filled with lubricating oil during use. Because the transmission box 1 is located at a relatively low position, the pressure of the working fluid outside the transmission box 1 is high. Therefore, to prevent lubricating oil leakage and to prevent external working fluid from entering the first chamber 15 and contaminating the lubricating oil inside, a seal 16, such as a sealing ring, is installed between transmission shaft 11 and cylinder 13. In a high-pressure mud environment, the sealing ring alone is insufficient to effectively prevent leakage or mud ingress into the first chamber 15. Therefore, the internal pressure of the first chamber 15 must be slightly greater than the external pressure of the transmission box 1.

[0046] The booster device 2 increases the pressure of the lubricating oil inside the first chamber 15. Specifically, the booster device 2 includes a piston rod 23, the rod head 231 of which is subjected to three forces: a force P1 exerted by the lubricating oil in the second chamber 27, a force F2 exerted by the external working fluid of the transmission box 1 on the rod head 231, and a force F3 exerted by the elastic element 25 located outside the second chamber 27 on the rod head 231. The forces on the rod head 231 are balanced, i.e., P1 = F2 + F3. The elastic element 25 is always in a compressed state, and the force F3 exerted by the elastic element 25 on the rod head 231 is preset. By presetting the value of F3, the magnitude of F3 can be controlled, thereby controlling the pressure P1 of the lubricating oil in the second chamber 27 to be greater than the force F2 exerted by the external working fluid of the transmission box 1 on the rod head 231.

[0047] The deformable body 24 and the cover 22 are fluid-sealed together to form a second cavity 27. The second cavity 27 and the first cavity 15 are always in communication, and the lubricating oil pressure inside both cavities is equal. Therefore, by adjusting the oil pressure inside the second cavity 27, the oil pressure inside the first cavity 15 can be adjusted. The second cavity 27 is not in communication with the cavity 26 containing the piston rod 23. The second cavity 27 contains lubricating oil, while the cavity 26 containing the piston rod 23 contains working fluids, including water and slurry.

[0048] Furthermore, the pressure in the second chamber 27 is automatically adjusted in real time. The booster device 2 and the transmission box 1 are located at the same working height. As the working position of the transmission box 1 decreases, the booster device 2 decreases synchronously. Therefore, the force F2 exerted by the external working fluid on the piston rod 23's rod head 231 changes in real time. This change causes the piston rod 23 to move linearly to change its position, thereby transmitting this pressure change to the second chamber 27. This ensures that the pressure of the lubricating oil inside the second chamber 27 is always greater than the pressure of the external working fluid by F3. Consequently, the pressure of the lubricating oil in the first chamber 15 is also always greater than the pressure of the external working fluid by F3. This ensures that regardless of the working position of the transmission box, the oil pressure in the first chamber 15 is always slightly greater than the pressure of the external working fluid, effectively preventing leakage or slurry ingress into the transmission box 1 during operation.

[0049] The transmission box pressure control device provided by the above technical solution also includes a pressure regulating device 3, which plays a pressure regulating role when the piston rod 23 is stuck or the seal 16 in the transmission box 1 leaks, so as to further reduce the risk of leakage and slurry ingress in the transmission box 1.

[0050] Specifically, the pressurization device 2 achieves pressurization through the piston rod 23, the cooperating elastic element 25, and the lubricating oil in the second chamber 27. Due to the harsh working environment of engineering machinery such as milling machines, the working fluid outside the transmission box 1 contains considerable amounts of sand, gravel, and mud. These substances may cause the piston rod 23 to become stuck, preventing it from automatically sliding as the working position of the transmission box 1 changes. This will result in the pressure inside the second chamber 27 not being greater than the pressure of the working fluid outside the transmission box 1. Consequently, the pressure in the first chamber 15, which is always equal to the pressure inside the second chamber 27, will no longer be greater than the pressure of the working fluid outside the transmission box 1, greatly increasing the risk of leakage and slurry ingress into the transmission box 1. Alternatively, in other cases, even if the piston rod 23 is not stuck, the seal 16 inside the transmission box 1 may fail or be damaged, leading to a decrease in pressure inside the first chamber 15, similarly increasing the risk of leakage. The pressure regulating device 3 effectively mitigates these adverse phenomena.

[0051] The pressure regulating device 3 comprises two main parts: a housing 31 and a bladder 32. Before use, the bladder 32 is pre-filled with gas. Gas is compressible. Since the third chamber 33 and the first chamber 15 are always in communication, during normal use, the lubricating oil in the third chamber 33 will compress the bladder 32. If the transmission box 1 leaks (reducing the lubricating oil pressure in the first chamber 15), or if the piston rod 23 of the booster device 2 becomes stuck (reducing the lubricating oil pressure in the second chamber 27), this will ultimately lead to a decrease in the lubricating oil pressure in the third chamber 33. Because the gas in the bladder 32 is compressible, the decrease in lubricating oil pressure in the third chamber 33 reduces the external pressure on the bladder 32, causing the bladder 32 to increase in volume. This reduces the volume of the third chamber 33, thus increasing the lubricating oil pressure within it. This increased lubricating oil pressure in the third chamber 33 will also increase the lubricating oil pressure in both the first chamber 15 and the second chamber 27. Even if there is a leak in the first chamber 15, the increased pressure in the first chamber 15 will still make the internal pressure greater than the external pressure of the working device. If the piston rod 23 of the booster device 2 becomes stuck, the increased lubricating oil pressure in the second chamber 27 will overcome the pressure of the external working fluid and the pressure of the elastic element 25, pushing the piston rod 23 to move slightly. This movement can push away the mud stuck in the piston rod 23, allowing the piston rod 23 to return to a free-moving state and no longer be stuck.

[0052] See Figure 3 and Figure 4 The following section introduces other aspects of the booster device 2.

[0053] As mentioned above, see Figure 3The pressurizing device 2 includes a sleeve 21, a piston rod 23, an elastic element 25, a deformable body 24, and a cover 22. The deformable body 24 is installed between the sleeve 21 and the cover 22, forming a second cavity 27 filled with lubricating oil. The piston rod 23 passes through the sleeve 21 and can slide back and forth along the axis of the sleeve 21. One end of the elastic element 25 is connected to the sleeve 21, and the other end of the elastic element 25 is connected to the piston rod 23.

[0054] See Figure 3 and Figure 4 In some embodiments, the cover 22 is configured to have a first recess 221, and the sleeve 21 has a through hole 211. The cover 22 and the sleeve 21 are fixedly connected by a connector 28. The connector 28 is specifically a detachable component such as a bolt. The cover 22 is similar to a cap, covering one end of the sleeve 21, thereby sealing one end of the pressurizing device 2. The first recess 221 communicates with the through hole 211 of the sleeve 21 to form a cavity 26. The piston rod 23 is mounted in the cavity 26 and can slide linearly along the axial direction of the cavity 26.

[0055] See also Figure 3 and Figure 4 In some embodiments, the deformable body 24 is configured to have a second recess 241. The deformable body 24 is fixedly connected to the cover 22, and the first recess 221 and the second recess 241 communicate to form a second cavity 27. The deformable body 24 is located on the side of the piston rod 23 with its rod head 231 facing the cover 22. In some embodiments, the cover 22 is made of a metal. And / or, the deformable body 24 is made of rubber.

[0056] The deformable body 24 and the cover 22 cooperate to form a region, namely the second cavity 27, within the cavity 26 described above. The second cavity 27 is always in fluid communication with the first cavity 15. The regions containing the second cavity 27 and the piston rod 23 are not connected; they are separate and there is no fluid exchange between them. The deformable body 24 is deformable and maintains contact with the rod head 231 of the piston rod 23. Figure 4 Taking the direction shown as an example, if the piston rod 23 moves downward, the deformable body 24, under the action of the lubricating oil in the second cavity 27, changes the pressure in the second cavity 27 as the piston rod 23 moves downward, ultimately making the piston rod 23 force-balanced. If the piston rod 23 moves upward, the deformable body 24, under the combined action of the elastic element 25 and the external working fluid, also changes the lubricating oil pressure in the second cavity 27 as the piston rod 23 moves upward, ultimately making the piston rod 23 force-balanced.

[0057] See Figure 3The elastic element 25 is installed in the following manner. In some embodiments, the rod head 231 of the piston rod 23 abuts against the deformable body 24, and a boss 212 is provided inside the sleeve 21, located on the side of the rod head 231 of the piston rod 23 away from the deformable body 24; the elastic element 25 is sandwiched between the rod head 231 of the piston rod 23 and the boss 212. In some embodiments, the elastic element 25 includes a spring.

[0058] Back Figure 1 In some embodiments, the housing 31 is fixedly connected to the sleeve 21. This simplifies the installation and positioning of the transmission box pressure control device during use, and also ensures that the pressurizing device 2 and the pressure regulating device 3 are at essentially the same working height, so as to achieve precise control of the internal pressure of the first chamber 15, the second chamber 27 and the third chamber 33.

[0059] The following details the other aspects of pressure regulating device 3.

[0060] See Figure 5 In some embodiments, the pressure regulating device 3 further includes a valve 34 and a plug 35. The valve 34 is installed at the inlet of the bladder 32; the plug 35 is also installed at the inlet of the bladder 32 and is located outside the valve 34. In some embodiments, the bladder 32 is configured to be pre-filled with gas. The valve 34 controls the opening and closing of the bladder 32 and the inflation component. When the valve 34 is open, gas can be injected into the bladder 32 and gas can be released from the bladder 32. When the valve 34 is closed, the bladder 32 is sealed, and there is no airflow exchange between the inside and outside of the bladder 32. The plug 35 is located outside the valve 34. When the valve 34 is closed, the plug 35 protects the valve 34 from blockage by sludge or other contaminants in the working fluid outside the transmission housing 1. The plug 35 is removed when it is necessary to release or output gas into the bladder 32.

[0061] See Figure 5The pressure regulating device 3 includes a housing 31, a bladder 32, a valve 34, and a sealing element 35. The housing 31 includes a rotating body 311, a first cover plate 312, and a second cover plate 313. Both the first cover plate 312 and the second cover plate 313 are hollow and have a hemispherical internal structure. Both ends of the rotating body 311 are open, and the first cover plate 312 and the second cover plate 313 are each located at one end of the rotating body 311, and the three are fixedly connected to form a hollow cavity. The bladder 32 is placed inside the hollow cavity and is also fixedly connected to the second cover plate 313, for example, through a threaded connection. The space between the inner wall of the hollow cavity and the outer wall of the bladder 32 is a third cavity 33. The first cover plate 312 has a mounting hole 312a, which is connected to the first cavity 15 of the transmission box 1 through a second pipe 5. The exterior of the bladder 32 and the interior of the third cavity 33 are filled with lubricating oil.

[0062] Gas is introduced into the bladder 32 through valve 34. The volume of the gas-filled bladder 32 will compress or expand depending on the pressure of the lubricating oil. When the volume of the bladder 32 expands, it will squeeze the lubricating oil inside the third chamber 33 into the first chamber 15 of the transmission box 1. The sealing member 35 is used to seal the port of the bladder 32 to prevent water from entering through the port during operation.

[0063] When the lubricating oil pressure inside the first chamber 15 of the transmission box 1 increases, the lubricating oil flows through the pressure transmission device to the third chamber 33 of the pressure regulating device 3. At this time, the lubricating oil pressure inside the third chamber 33 increases, compressing the volume of the bladder 32. After the volume of the bladder 32 decreases, since the bladder 32 is pre-filled with a certain amount of gas, the pressure increases after the gas is compressed. Ultimately, the internal pressure of the bladder 32 becomes equal to the pressure inside the third chamber 33.

[0064] The following describes how to set up the transmission box pressure control device before and during operation.

[0065] Before operation, perform the following steps: First, open the sealing component 35 and fill the bladder 32 with gas at pressure P0 through valve 34. Second, fill the first chamber 15 of the transmission box 1, the third chamber 33 of the pressure regulating device 3, and the second chamber 27 of the booster device 2 with lubricating oil. The lubricating oil pushes the piston rod 23 of the booster device 2 and squeezes the elastic element 25, so that the pressure of the lubricating oil reaches P1.

[0066] The operation during operation is as follows: First, the transmission box 1, pressure regulating device 3, and pressurizing device 2 reach a certain depth underwater with the working device. At this time, the external working fluid pressure of pressurizing device 2 is F2. Second, the lubricating oil in the second chamber 27 of pressurizing device 2 reaches a pressure of F2+F3 under the action of elastic element 25 and external fluid pressure. Third, the lubricating oil in the second chamber 27 flows to the first chamber 15 of transmission box 1 and continues to flow to the third chamber 33 of pressure regulating device 3. The lubricating oil pressure inside the first chamber 15 and the third chamber 33 is both F2+F3, which is higher than the external working fluid pressure. The seal 16 of transmission box 1 normally performs its sealing function. Fourth, the bladder 32 in pressure regulating device 3 is compressed under the pressure of F2+F3, which compresses the gas inside the bladder 32 until the gas pressure is balanced with the lubricating oil pressure.

[0067] If the piston rod 23 of the booster device 2 becomes stuck, the pressure of the elastic element 25 cannot act on the lubricating oil inside the booster device 2 through the piston rod 23, causing the lubricating oil pressure inside the booster device 2 to drop. At this time, the gas volume inside the bladder 32 will expand, squeezing the lubricating oil inside the third chamber 33 into the first chamber 15 of the transmission box 1, so that the lubricating oil pressure inside the transmission box 1 continues to be higher than the pressure of the external working fluid. The seal 16 normally performs its sealing function.

[0068] The working principle of the transmission box pressure control device is described below.

[0069] First, the process of dynamically adjusting the internal pressure of the first cavity 15 of the transmission housing 1 is described. The first cavity 15 of the transmission housing 1 is connected to the second cavity 27 of the pressurizing device 2, specifically through the first pipeline 4. During operation, under the combined action of the external working fluid pressure and the elastic force of the elastic element 25, the piston rod 23 pushes the deformable body 24 towards the cover 22 along the axial direction of the sleeve 21, thereby compressing the volume of the second cavity 27 and increasing the pressure of the lubricating oil inside the second cavity 27 due to compression. The lubricating oil flows to the first cavity 15 of the transmission housing 1 through the pipeline, increasing the lubricating oil pressure inside the first cavity 15. In this way, the lubricating oil pressure inside the transmission housing 1 is increased by the elastic element 25, ensuring that the sealing element 16 of the transmission housing 1 functions properly.

[0070] The following describes the adjustment process when the piston rod 23 is stuck or when leakage occurs in the first chamber 15. When the elastic element 25 or the piston rod 23 is stuck, energy is released through the expansion of the gas inside the bladder 32, maintaining pressure and ensuring that the internal lubricating oil pressure of the transmission box 1 is higher than the external working fluid pressure, allowing the seal 16 to continue to perform its sealing function normally. On the other hand, energy is absorbed through the compression of the gas inside the bladder 32. When there is a momentary high pressure inside the transmission box 1, the impact is absorbed to prevent damage to the seal.

[0071] The above technical solution ensures that the internal pressure of the transmission box 1 is higher than the external working fluid pressure, while also avoiding the problem of reduced lubricating oil pressure and subsequent seal failure caused by jamming of the piston rod 23 or elastic element 25. Furthermore, it absorbs the impact when the internal pressure of the transmission box 1 experiences a momentary high pressure, preventing seal failure. The compensation method using the elastic element 25 for pressure boosting has advantages such as high internal pressure and fast response speed. This technical solution prevents jamming during operation due to the presence of mud and sand in the external working fluid, machining errors of components such as the piston rod 23 and elastic element 25, or the torsional characteristics of the elastic element 25 itself. Therefore, it also prevents the internal pressure of the transmission box 1 from decreasing, ultimately leading to seal failure and leakage of external working fluid into the transmission box 1. This technical solution enables the transmission box 1 to operate stably and safely in deep water, thereby improving the reliability of the equipment. Additionally, it absorbs pressure shocks when the internal pressure of the transmission box 1 experiences a momentary high pressure, preventing seal damage.

[0072] See Figure 6 The following describes other implementations of the pressurizing device 2. Unlike the implementation of the elastic element 25 using a compression spring described above, the various embodiments described here use a tension spring for the elastic element 25. Specifically, the outer wall of the sleeve 21 is provided with a first protrusion 213, which may be an annular plate structure or only provided in a portion of the circumferential area of ​​the outer wall of the sleeve 21. The end of the piston rod 23 away from the cover 22 is located outside the sleeve 21, and this end is provided with a second protrusion 222. The elastic element 25 is constructed as a tension spring, with one end of the elastic element 25 detachably or fixedly connected to the first protrusion 213, and the other end of the elastic element 25 detachably or fixedly connected to the second protrusion 222. The elastic element 25 applies a force toward the cover 22 to the piston rod 23 in the form of tension. Regardless of whether the elastic element 25 is a tension spring or a compression spring as described in the above embodiment, the ultimate goal is to balance the pressure P1 of the lubricating oil in the second chamber 27 of the booster device 2 with the sum of the tension F3 applied by the elastic element 25 and the force F2 applied by the external fluid pressure, i.e., P1 = F2 + F3.

[0073] In some embodiments, there are multiple elastic elements 25, which are evenly arranged in the circumferential direction of the sleeve 21. Specifically, for example, there may be two or four. This structure ensures that the piston rod 23 experiences balanced and stable force in the circumferential direction. Using the technical solution provided by this embodiment, the elastic elements 25 are located on the outside of the sleeve 21, making installation very convenient. Furthermore, even if multiple elastic elements 25 need to be installed, there will be no interference or difficulty in installation. If any one or more elastic elements 25 are damaged, rusted, or blocked by the working fluid, the failed elastic element 25 can be easily replaced without affecting the normal operation of the other elastic elements 25.

[0074] This invention also provides a milling machine, including the transmission box pressure control device provided by any of the technical solutions of this invention.

[0075] See Figure 7 This invention also provides a transmission box pressure control method, implemented using the transmission box pressure control device provided by any of the technical solutions of this invention. The method includes the following steps.

[0076] Step S100: Lubricating oil is injected into the first cavity 15, the second cavity 27, and the third cavity 33, and gas is injected into the bladder 32 of the transmission box pressure control device; and the first initial pressure of the lubricating oil in the first cavity 15, the second cavity 27, and the third cavity 33 is greater than the second initial pressure of the gas injected into the bladder 32. Here, the first initial pressure refers to the final pressure of the lubricating oil injected when the first cavity 15, the second cavity 27, and the third cavity 33 are empty. The second initial pressure refers to the final pressure of the gas injected into the empty bladder 32. After the lubricating oil is injected into the first cavity 15, the second cavity 27, and the third cavity 33, and the gas is injected into the bladder 32, the volume of the bladder 32 decreases under the compression of the third cavity 33, and the internal pressure increases. The volume of the third cavity 33 increases slightly, and the pressure in the first cavity 15, the second cavity 27, and the third cavity 33 decreases. Ultimately, the pressure in the first chamber 15, the second chamber 27, and the third chamber 33 all reach the same level as the pressure inside the bladder 32, thus achieving balance in the entire transmission box pressure control device.

[0077] Since the volumes of the second chamber 27 and the third chamber 33, except for the first chamber 15, are variable, their initial volumes must be set according to the actual operating conditions. This can be determined by setting an initial pressure. For example, when the pressures inside the first chamber 15, the second chamber 27, and the third chamber 33 reach their initial set values, the entire transmission box pressure control device remains in a balanced state. At this time, the bladder 32 and the third chamber 33 are balanced, meaning the pressure inside the bladder 32 is the same as the pressure inside the third chamber 33. The position of the piston rod 23 is also stable, no longer oscillating back and forth, but remaining essentially stationary.

[0078] The order in which lubricating oil and gas are introduced in step S100 is not limited. Step S100 brings the transmission box pressure control device to an initial equilibrium state.

[0079] Step S200: The booster device 2 is placed into the working fluid along with the tool holder of the milling machine. The piston rod 23 of the booster device 2 reaches a balanced state under the action of the lubricating oil in the second chamber 27, the elastic element 25 and the working fluid.

[0080] Step S300: If the piston rod 23 is stuck, the pressure in the second chamber 27 decreases, causing the volume of the third chamber 33 to decrease under the action of the gas in the bladder 32, thereby increasing the pressure of the lubricating oil in the first chamber 15, the second chamber 27 and the third chamber 33.

[0081] In step S400, the piston rod 23 is pushed by the enlarged second cavity 27 to release the jammed state.

[0082] In some embodiments, the transmission box pressure control method further includes the following steps: Step S500: If leakage occurs in the first cavity 15, the pressure of the first cavity 15, the second cavity 27 and the third cavity 33 all decrease, causing the volume of the third cavity 33 to decrease under the action of the gas in the bladder 32, so as to increase the pressure of the lubricating oil in the first cavity 15, the second cavity 27 and the third cavity 33, so that the pressure in the first cavity 15 is greater than the pressure of the working fluid.

[0083] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to facilitate the description of this invention and to simplify the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. However, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A transmission box pressure control device, characterized in that, include: The transmission box (1) includes a transmission shaft (11), a motor (12), and a cylinder (13); one end of the transmission shaft (11) is drivenly connected to the motor (12), and the other end of the transmission shaft (11) is rotatably installed in the cylinder (13); the outer wall of the transmission shaft (11) and the inner wall of the cylinder (13) form a first cavity (15). The pressurizing device (2) includes a sleeve (21), a cover (22), a piston rod (23), a deformable body (24), and an elastic element (25); the sleeve (21) and the cover (22) are fixedly connected, and a cavity (26) is formed between them; the deformable body (24) is located in the cavity (26) and is sealed to the cover (22) to form a second cavity (27); the deformable body (24) abuts against the end of the piston rod (23); the second cavity (27) is in fluid communication with the first cavity (15); the piston rod (23) is at least partially installed in the sleeve (21); the elastic element (25) is configured to apply a force to the piston rod (23) toward the cover (22); as well as The pressure regulating device (3) includes a housing (31) and a bladder (32) installed inside the housing (31); the space between the inner wall of the housing (31) and the outer wall of the bladder (32) is a third cavity (33); the third cavity (33) is in fluid communication with the first cavity (15).

2. The transmission box pressure control device according to claim 1, characterized in that, The pressure regulating device (3) further includes: A valve (34) is installed at the inlet of the bladder (32); and The sealing element (35) is also installed at the inlet of the bladder (32) and is located outside the valve (34).

3. The transmission box pressure control device according to claim 1, characterized in that, The cover (22) is configured to have a first recess (221), and the sleeve (21) has a through hole (211); the cover (22) and the sleeve (21) are fixedly connected by a connector (28), and the first recess (221) communicates with the through hole (211) of the sleeve (21) to form the cavity (26).

4. The transmission box pressure control device according to claim 3, characterized in that, The deformable body (24) is configured to have a second recess (241), the deformable body (24) is sealed and fixedly connected to the cover (22), and the first recess (221) and the second recess (241) communicate to form the second cavity (27).

5. The transmission box pressure control device according to claim 4, characterized in that, The piston rod (23) has its head (231) abutting against the deformable body (24). The sleeve (21) has a boss (212) inside, which is located on the side of the piston rod (23) away from the deformable body (24). The elastic element (25) is constructed as a compression spring and is sandwiched between the piston rod (23) and the boss (212).

6. The transmission box pressure control device according to claim 1, characterized in that, The outer wall of the sleeve (21) is provided with a first protrusion (213), and the end of the piston rod (23) away from the cover (22) is provided with a second protrusion (222); the elastic element (25) is constructed as a tension spring, one end of the elastic element (25) is detachably or fixedly connected to the first protrusion (213), and the other end of the elastic element (25) is detachably or fixedly connected to the second protrusion (222).

7. The transmission box pressure control device according to claim 1, characterized in that, The bladder (32) is configured to be pre-filled with gas.

8. The transmission box pressure control device according to claim 1, characterized in that, The first cavity (15), the second cavity (27) and the third cavity (33) are all configured to be filled with lubricating oil.

9. The transmission box pressure control device according to claim 1, characterized in that, The material of the cover (22) is selected from metal; and / or the material of the deformable body (24) is selected from rubber.

10. The transmission box pressure control device according to claim 1, characterized in that, The housing (31) is fixedly connected to the sleeve (21).

11. A milling machine, characterized in that, Includes the transmission box pressure control device as described in any one of claims 1 to 10.

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