Tightness detection method for tail shaft sealing device

Abstract

The invention belongs to the technical field of sealing performance testing, and particularly relates to a sealing performance detection method for a tail shaft sealing device. The tightness detection method of the tail shaft sealing device comprises the following steps: detecting the static sealing performance of the tail shaft sealing device; the dynamic sealing performance of the stern shaft sealing device is detected; in the oil pressing state, the dynamic sealing performance of the tail shaft sealing device is detected, and the method comprises the following steps that a tail shaft is manually rotated, and the tail shaft drives a lining to rotate through a propeller hub; the oil outlet is closed, the oil inlet, the air inlet channel, the air outlet channel and the oil inlet channel are opened, oil is supplied to the lubricating oil channel through the oil inlet, and oil is supplied to the oil lubricating cavity through the oil inlet channel; and a second channel located below the air cavity is opened, whether oil drips in the second channel or not is checked after set time, and if no oil drips in the second channel, the sealing of the stern shaft sealing device is effective.

Description

Technical Field

[0001] The present application belongs to the technical field of sealing performance testing, and specifically relates to a method for detecting the tightness of a stern shaft sealing device. Background Art

[0002] The oil leakage detection type oil-lubricated stern shaft sealing device is a new type of oil-lubricated ship stern shaft sealing device. Due to its complex design and structural type, and the significant differences with the national standard "GB / T25017-2010 Ship Stern Shaft Oil Lubricated Sealing Device", it cannot be subjected to relevant tightness tests in accordance with the national standard "GB / T14273-1993 Rotating Shaft Lip Seal Performance Test Method".

[0003] During ship construction, the tightness test of the stern shaft seal is usually carried out after all the propulsion shaft systems are installed. The sealing of the stern shaft seal is tested statically by injecting oil into the stern tube, and the sealing of the stern shaft seal is tested dynamically by observing whether there are oil bubbles on the water surface during the movement of the tail shaft during the ship's mooring test.

[0004] In the related art, when performing a tightness test on a stern shaft sealing device, it is impossible to determine where the sealing of the stern shaft sealing device fails, which affects the use of the stern shaft sealing device. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a method for detecting the tightness of a stern shaft sealing device, which aims to at least to a certain extent solve the technical problem that when performing a tightness test of the stern shaft sealing device, it is impossible to determine where the seal of the stern shaft sealing device fails, thereby affecting the use of the stern shaft sealing device.

[0006] The technical solution of the present invention is:

[0007] A method for detecting the tightness of a stern shaft sealing device, the stern shaft sealing device comprising a bushing, a first seal, a second seal, a third seal, a fourth seal and a pressure piece, the bushing being detachably connected to a propeller hub, the propeller hub being connected to a stern shaft, a stern tube being provided on the outer shell of the stern shaft, the stern tube being spaced apart from the stern shaft to form a lubricating oil passage, the pressure piece being connected to a first end portion of the stern tube, the stern tube being provided with an air inlet passage, an air outlet passage, an oil inlet passage, an oil inlet communicating with the lubricating oil passage and an oil outlet communicating with the lubricating oil passage, the pressure piece being sleeved on the bushing, and the first seal, the second seal, the third seal and the fourth seal being spaced apart between the bushing and the pressure piece along the axial direction of the bushing. , a water-proof cavity is formed between the first seal and the second seal, an air cavity is formed between the second seal and the third seal, and an oil lubrication cavity is formed between the third seal and the fourth seal, and the pressing member is provided with a first channel connected to the water-proof cavity, a second channel connected to the air cavity and a third channel connected to the oil lubrication cavity, the air cavity is connected to the air inlet channel and the air outlet channel, and the oil lubrication cavity is connected to the oil inlet channel; the tightness detection method of the stern shaft sealing device includes the following steps: detecting the static sealing performance of the stern shaft sealing device, including the following steps: opening the second channel, closing the air inlet channel and the air outlet channel, and connecting the air pump assembly to the second channel The air pump assembly is connected to the third channel, and the air in the oil lubrication chamber is extracted to detect the sealing performance of the fourth seal; the first channel is opened, the second channel, the air inlet channel and the air outlet channel are closed, the air pump assembly is connected to the first channel, and the air in the air chamber is extracted to detect the sealing performance of the first seal; the dynamic sealing performance of the stern shaft sealing device is detected, including the following steps: manually rotating the stern shaft, and the stern shaft drives the bushing to rotate through the propeller hub; closing the first channel, and the second channel, the air inlet channel and the air outlet channel are closed, the air pump assembly is connected to the first channel, and the air in the air chamber is extracted to detect the sealing performance of the first seal; detecting the dynamic sealing performance of the stern shaft sealing device, including the following steps: manually rotating the stern shaft, and the stern shaft drives the bushing to rotate through the propeller hub; closing the propeller hub; The first channel, the second channel, the third channel, the oil outlet, the oil inlet pipe and the air inlet channel, the air pump assembly is connected to the oil inlet, supplies air to the lubricating oil channel, applies soapy water to the outside of the pressing piece, and detects the sealing performance of the first seal, the second seal, the third seal and the fourth seal; in the oil pressure state, detects the dynamic sealing performance of the stern shaft sealing device, including the following steps: manually rotating the stern shaft, the stern shaft drives the bushing to rotate through the propeller hub; closing the oil outlet, opening the oil inlet, the air inlet channel, the air outlet channel and the oil inlet channel, supplying oil to the lubricating oil channel through the oil inlet, and supplying oil to the oil lubrication cavity of the oil inlet channel box;Open the second passage below the air cavity, and after a set time, check whether oil is dripping from the second passage. If oil is not dripping from the second passage, the seal between the pressing member and the first end of the stern tube is effective.

[0008] In some embodiments, the air pump assembly includes a connecting pipe and an air pump connected to the connecting pipe, and the connecting pipe is provided with a vacuum gauge; when the connecting pipe is connected to the second channel, the air in the air cavity is extracted by the air pump, and the vacuum degree of the air cavity is obtained by the vacuum gauge; when the vacuum degree of the air cavity reaches a set vacuum degree, the air pump is turned off, and when the set time is reached, the vacuum degree of the air cavity obtained by the vacuum gauge is observed to see whether it changes; if the vacuum degree of the air cavity obtained by the vacuum gauge changes, the sealing of the second seal and the third seal fails; when the connecting pipe is connected to the third channel, the air in the oil lubrication cavity is extracted by the air pump, and the oil lubrication cavity is obtained by the vacuum gauge. The vacuum degree of the cavity, when the vacuum degree of the oil lubrication cavity reaches the set vacuum degree, the air pump is turned off. When the set time is reached, the vacuum degree of the oil lubrication cavity obtained by the vacuum gauge is observed to see whether there is a change. If the vacuum degree of the oil lubrication cavity obtained by the vacuum gauge has changed, the sealing of the fourth sealing component fails. When the connecting pipe is connected to the first channel, the air in the watertight cavity is extracted by the air pump, and the vacuum degree of the watertight cavity is obtained by the vacuum gauge. When the vacuum degree of the watertight cavity reaches the set vacuum degree, the air pump is turned off. When the set time is reached, the vacuum degree of the watertight cavity obtained by the vacuum gauge is observed to see whether there is a change. If the vacuum degree of the watertight cavity obtained by the vacuum gauge has changed, the sealing of the first sealing component fails.

[0009] In some embodiments, after soapy water is applied to the outside of the pressing member, if bubbles are generated outside the pressing member, the first seal, the second seal, the third seal, and the fourth seal fail to seal.

[0010] In some embodiments, a first gasket is provided between the pressure piece and the first end portion of the stern tube. When testing the dynamic sealing performance of the stern shaft sealing device, soapy water is applied to the first gasket to test the sealing performance between the pressure piece and the first end portion of the stern tube; if bubbles are generated at the first gasket, the sealing of the first gasket fails.

[0011] In some embodiments, the air outlet channel is opened and soapy water is applied to the air outlet channel; if bubbles are generated in the air outlet channel, the sealing of the first gasket fails.

[0012] In some embodiments, a second gasket is provided between the bushing and the hub. When testing the dynamic sealing performance of the stern shaft sealing device, soapy water is applied to the second gasket to test the sealing performance between the bushing and the hub. If bubbles are generated at the second gasket, the sealing of the second gasket fails.

[0013] In some embodiments, the stern shaft sealing device further includes a sealing assembly, which is sleeved on the stern shaft, the stern tube is located between the sealing assembly and the bushing, and the sealing assembly is connected to the second end of the stern tube. The tightness detection method of the stern shaft sealing device further includes the following steps: when detecting the dynamic sealing performance of the stern shaft sealing device, applying soapy water to the first sealing assembly to detect the sealing performance of the first sealing assembly; if bubbles are generated outside the first sealing assembly, the sealing of the first sealing assembly fails.

[0014] In some embodiments, a third gasket is provided between the first sealing assembly and the second end of the stern tube. When testing the dynamic sealing performance of the stern shaft sealing device, soapy water is applied to the third gasket to test the sealing performance between the first sealing assembly and the second end of the stern tube; if bubbles are generated at the third gasket, the sealing of the third gasket fails.

[0015] In some embodiments, after testing the dynamic sealing performance of the stern shaft sealing device, the oil outlet, the air inlet channel and the air outlet channel are closed, and the oil inlet channel is opened; the air pump assembly is connected to the oil inlet to supply air to the lubricating oil channel, and soapy water is applied to the oil inlet channel. If bubbles are generated in the oil inlet channel, the sealing of the fourth seal fails.

[0016] In some embodiments, when the dynamic sealing performance of the stern shaft sealing device is tested under the oil pressure state, if the second channel drips oil, the oil droplets in the second channel are blown out, and the second channel is perfused and cleaned with anhydrous alcohol. After the second channel is blown dry, the second channel is observed to see if there is oil leakage. If there is no oil dripping from the second channel, the sealing of the stern shaft sealing device is effective.

[0017] The beneficial effects of the present invention include at least:

[0018] Testing the static sealing performance of the stern shaft seal device includes the following steps:

[0019] Open the second channel, close the air inlet channel and the air outlet channel, connect the air pump assembly to the second channel, extract the air in the air cavity, and test the sealing performance of the second seal and the third seal. If the vacuum degree in the air cavity remains unchanged, it indicates that the sealing performance of the second seal and the third seal is good. If the vacuum degree in the air cavity remains unchanged, it indicates that the sealing performance of the second seal and the third seal has failed, and the second seal and the third seal need to be adjusted or replaced.

[0020] Open the third channel, close the second channel, the air inlet channel and the air outlet channel, connect the air pump assembly to the third channel, extract the air in the oil lubrication chamber, and test the sealing performance of the fourth seal. If the vacuum degree in the oil lubrication chamber remains unchanged, it indicates that the sealing performance of the fourth seal is good. If the vacuum degree in the oil lubrication chamber remains unchanged, it indicates that the sealing performance of the second seal and the third seal has failed, and the fourth seal needs to be adjusted or replaced.

[0021] Open the first channel, close the second channel, the air inlet channel and the air outlet channel, connect the air pump assembly to the first channel, extract the air in the air cavity, and test the sealing performance of the first seal. If the vacuum degree in the watertight cavity remains unchanged, it indicates that the sealing performance of the first seal is good. If the vacuum degree in the watertight cavity remains unchanged, it indicates that the sealing performance of the first seal has failed, and the first seal needs to be adjusted or replaced.

[0022] By detecting the static sealing performance of the stern shaft sealing device, the sealing performance of any one of the first seal, the second seal, the third seal and the fourth seal can be known, so as to facilitate the normal use of the stern shaft sealing device.

[0023] Testing the dynamic sealing performance of the stern shaft seal device includes the following steps:

[0024] Manually rotate the stern shaft, and the stern shaft drives the bushing to rotate through the propeller hub. Close the first channel, the second channel, the third channel, the oil outlet, the oil inlet pipe and the air inlet channel. Connect the air pump assembly to the oil inlet to supply air to the lubricating oil channel. Apply soapy water to the outside of the pressing piece and test the sealing performance of the first seal, the second seal, the third seal and the fourth seal. If bubbles appear outside the pressing piece, it indicates that the sealing of the first seal, the second seal, the third seal and the fourth seal has failed, and the stern shaft sealing device needs to be disassembled to clean and / or replace the first seal, the second seal, the third seal and the fourth seal.

[0025] After cleaning and / or replacing the first seal, the second seal, the third seal and the fourth seal, it is necessary to retest the static sealing performance of the stern shaft sealing device, and then retest the dynamic sealing performance of the stern shaft sealing device.

[0026] In the oil pressure state, the dynamic sealing performance of the stern shaft seal device is tested, including the following steps:

[0027] Manually rotate the stern shaft, and the stern shaft drives the bushing to rotate through the propeller hub, close the oil outlet, open the oil inlet, the air inlet channel, the air outlet channel and the oil inlet channel, supply oil to the lubricating oil channel through the oil inlet, and supply oil through the oil inlet channel oil lubrication chamber, open the second channel located below the air cavity, and after the set time, check whether the second channel is dripping oil. If the second channel is not dripping oil, the seal between the pressure piece and the first end of the stern tube is effective. If the second channel is dripping oil, it indicates that the seal between the pressure piece and the first end of the stern tube has failed, and the seal between the pressure piece and the first end of the stern tube needs to be readjusted.

[0028] After the seal between the pressure piece and the first end portion of the stern tube is readjusted, it is necessary to retest the static sealing performance of the stern shaft sealing device, then retest the dynamic sealing performance of the stern shaft sealing device, and then retest the dynamic sealing performance of the stern shaft sealing device under the oil pressure state.

[0029] Through the above steps, the cause of the oil leakage can be accurately identified, the sealing performance of any one of the first seal, the second seal, the third seal and the fourth seal can be accurately distinguished, and it can also be determined whether the seal between the pressure piece and the first end of the stern tube has failed. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application, a brief introduction will be given below to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0031] Figure 1 Schematic diagram of a stern shaft sealing device installed on a propeller hub according to some embodiments;

[0032] Figure 2 Schematic diagram of detecting whether the second seal and the third seal of the stern shaft sealing device have failed in some embodiments;

[0033] Figure 3 Schematic diagram of detecting whether the fourth sealing member of the stern shaft sealing device has failed in some embodiments;

[0034] Figure 4 This is a schematic diagram of detecting whether a first seal of a stern shaft sealing device has failed according to some embodiments.

[0035] In the attached figure:

[0036] Bushing 10, first seal 20, second seal 30, third seal 40, fourth seal 50, pressure piece 60, air inlet 61, air outlet 62, oil inlet 63, hub 70, stern shaft 80, stern tube 90, air inlet channel 91, air outlet channel 92, oil inlet channel 93, oil inlet 94, oil outlet 95, lubricating oil channel 100, water-isolating chamber 110, air chamber 120, oil lubrication chamber 130, first channel 140, second channel 150, third channel 160, air pump assembly 170, connecting pipe 171, air pump 172, vacuum gauge 173, stop valve 174, pressure plate 180, monkey clamp 190, third gasket 200, first gasket 210, second gasket 220, sealing assembly 230. DETAILED DESCRIPTION

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0038] It should be noted that all directional indications in the embodiments of the present invention are only used to explain the relative position relationship and movement status of various components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0039] In the present invention, unless otherwise specified or limited, the terms "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can mean fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will be able to understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0040] In addition, in the present invention, descriptions such as "first" and "second" are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0041] The present application is described below with reference to specific embodiments and with reference to the accompanying drawings:

[0042] The present embodiment provides a method for detecting the tightness of a stern shaft sealing device, which aims to at least to some extent solve the technical problem that, during a tightness test of the stern shaft sealing device, it is impossible to determine where the seal of the stern shaft sealing device has failed, thereby affecting the use of the stern shaft sealing device.

[0043] Combine Figure 1 、 Figure 2 、 Figure 3 and Figure 4 The stern shaft sealing device of the embodiment of the present application includes: a bushing 10, a first seal 20, a second seal 30, a third seal 40, a fourth seal 50 and a pressing piece 60. The bushing 10 is detachably connected to the hub 70, the hub 70 is connected to the stern shaft 80, the stern shaft 80 is provided with a stern tube 90, the stern tube 90 and the stern shaft 80 are spaced apart to form a lubricating oil passage 100, the pressing piece 60 is connected to the first end of the stern tube 90, the stern tube 90 is provided with an air inlet passage 91, an air outlet passage 92, an oil inlet passage 93, an oil inlet port 94 communicating with the lubricating oil passage 100 and an oil outlet port 95 communicating with the lubricating oil passage 100, the pressing piece 60 is sleeved on the bushing 10, along the axial direction of the bushing 10, the first seal 20, the second seal 30, the third seal 40 and the fourth seal 50 are connected. 0 is spaced between the bushing 10 and the pressure piece 60, a water-isolating chamber 110 is formed between the first seal 20 and the second seal 30, an air chamber 120 is formed between the second seal 30 and the third seal 40, and an oil lubrication chamber 130 is formed between the third seal 40 and the fourth seal 50. The pressure piece 60 is provided with a first channel 140 communicating with the water-isolating chamber 110, a second channel 150 communicating with the air chamber 120, and a third channel 160 communicating with the oil lubrication chamber 130. The air chamber 120 is communicated with the air inlet channel 91 and the air outlet channel 92, and the oil lubrication chamber 130 is communicated with the oil inlet channel 93.

[0044] The method for detecting the tightness of the stern shaft sealing device of the embodiment of the present application includes the following steps:

[0045] Testing the static sealing performance of the stern shaft sealing device includes the following steps:

[0046] The second channel 150 is opened, the air inlet channel 91 and the air outlet channel 92 are closed, the air pump assembly 170 is connected to the second channel 150, the air in the air cavity 120 is extracted, and the sealing performance of the second sealing member 30 and the third sealing member 40 is tested.

[0047] The third channel 160 is opened, the second channel 150 , the air inlet channel 91 and the air outlet channel 92 are closed, the air pump assembly 170 is connected to the third channel 160 , the air in the oil lubrication chamber 130 is extracted, and the sealing performance of the fourth sealing member 50 is tested.

[0048] The first channel 140 is opened, the second channel 150 , the air inlet channel 91 and the air outlet channel 92 are closed, the air pump assembly 170 is connected to the first channel 140 , the air in the air cavity 120 is extracted, and the sealing performance of the first sealing member 20 is tested.

[0049] Testing the dynamic sealing performance of the stern shaft sealing device includes the following steps:

[0050] The stern shaft 80 is manually rotated, and the stern shaft 80 drives the bushing 10 to rotate through the propeller hub 70 .

[0051] Close the first channel 140, the second channel 150, the third channel 160, the oil outlet 95, the oil inlet pipe and the air intake channel 91, connect the air pump assembly 170 to the oil inlet 94, supply air to the lubricating oil channel 100, apply soapy water to the outside of the pressing piece 60, and test the sealing performance of the first seal 20, the second seal 30, the third seal 40 and the fourth seal 50.

[0052] Under the oil pressure state, the dynamic sealing performance of the stern shaft sealing device is tested, including the following steps:

[0053] The stern shaft 80 is manually rotated, and the stern shaft 80 drives the bushing 10 to rotate through the propeller hub 70 .

[0054] Close the oil outlet 95, open the oil inlet 94, the air inlet channel 91, the air outlet channel 92 and the oil inlet channel 93, supply oil to the lubricating oil channel 100 through the oil inlet 94, and supply oil to the oil lubrication chamber 130 through the oil inlet channel 93.

[0055] The second passage 150 below the air cavity 120 is opened, and after a set time, the second passage 150 is checked for oil dripping. If no oil drips from the second passage 150 , the seal between the pressing piece 60 and the first end of the stern tube 90 is effective.

[0056] Testing the static sealing performance of the stern shaft seal device includes the following steps:

[0057] Open the second channel 150, close the air inlet channel 91 and the air outlet channel 92, connect the air pump assembly 170 to the second channel 150, extract the air in the air cavity 120, and test the sealing performance of the second seal 30 and the third seal 40. If the vacuum degree in the air cavity 120 remains unchanged, it indicates that the sealing performance of the second seal 30 and the third seal 40 is good. If the vacuum degree in the air cavity 120 remains unchanged, it indicates that the sealing performance of the second seal 30 and the third seal 40 has failed, and it is necessary to adjust the second seal 30 and the third seal 40 or replace the second seal 30 and the third seal 40.

[0058] Open the third channel 160, close the second channel 150, the air inlet channel 91 and the air outlet channel 92, connect the air pump assembly 170 to the third channel 160, extract the air in the oil lubrication chamber 130, and test the sealing performance of the fourth seal 50. If the vacuum degree in the oil lubrication chamber 130 remains unchanged, it indicates that the sealing performance of the fourth seal 50 is good. If the vacuum degree in the oil lubrication chamber 130 remains unchanged, it indicates that the sealing performance of the second seal 30 and the third seal 40 has failed, and the fourth seal 50 needs to be adjusted or replaced.

[0059] Open the first channel 140, close the second channel 150, the air inlet channel 91 and the air outlet channel 92, connect the air pump assembly 170 to the first channel 140, extract the air in the air cavity 120, and test the sealing performance of the first seal 20. If the vacuum degree in the watertight cavity 110 remains unchanged, it indicates that the sealing performance of the first seal 20 is good. If the vacuum degree in the watertight cavity 110 remains unchanged, it indicates that the sealing performance of the first seal 20 has failed, and the first seal 20 needs to be adjusted or replaced.

[0060] By testing the static sealing performance of the stern shaft sealing device, the sealing performance of any one of the first seal 20, the second seal 30, the third seal 40 and the fourth seal 50 can be known, so as to facilitate the normal use of the stern shaft sealing device.

[0061] Testing the dynamic sealing performance of the stern shaft seal device includes the following steps:

[0062] Manually rotate the stern shaft 80, and the stern shaft 80 drives the bushing 10 to rotate through the hub 70. Close the first channel 140, the second channel 150, the third channel 160, the oil outlet 95, the oil inlet pipe and the air inlet channel 91. The air pump assembly 170 is connected to the oil inlet 94 to supply air to the lubricating oil channel 100. Apply soapy water to the outside of the pressure piece 60 and test the sealing performance of the first seal 20, the second seal 30, the third seal 40 and the fourth seal 50. If bubbles appear outside the pressure piece 60, it indicates that the sealing of the first seal 20, the second seal 30, the third seal 40 and the fourth seal 50 has failed. The stern shaft sealing device needs to be disassembled to clean and / or replace the first seal 20, the second seal 30, the third seal 40 and the fourth seal 50.

[0063] After cleaning and / or replacing the first seal 20, the second seal 30, the third seal 40 and the fourth seal 50, it is necessary to retest the static sealing performance of the stern shaft sealing device, and then retest the dynamic sealing performance of the stern shaft sealing device.

[0064] In the oil pressure state, the dynamic sealing performance of the stern shaft seal device is tested, including the following steps:

[0065] Manually rotate the stern shaft 80, and the stern shaft 80 drives the bushing 10 to rotate through the hub 70, close the oil outlet 95, open the oil inlet 94, the air inlet channel 91, the air outlet channel 92 and the oil inlet channel 93, supply oil to the lubricating oil channel 100 through the oil inlet 94, supply oil to the oil lubrication chamber 130 through the oil inlet channel 93, open the second channel 150 located below the air chamber 120, and after the set time, check whether the second channel 150 is dripping oil. If the second channel 150 is not dripping oil, the seal between the pressure piece 60 and the first end of the stern tube 90 is effective. If the second channel 150 is dripping oil, it indicates that the seal between the pressure piece 60 and the first end of the stern tube 90 has failed, and the seal between the pressure piece 60 and the first end of the stern tube 90 needs to be readjusted.

[0066] After the seal between the pressure piece 60 and the first end portion of the stern tube 90 is readjusted, it is necessary to retest the static sealing performance of the stern shaft sealing device, then retest the dynamic sealing performance of the stern shaft sealing device, and then retest the dynamic sealing performance of the stern shaft sealing device under the oil pressure state.

[0067] Through the above steps, the cause of the oil leakage can be accurately distinguished, the sealing performance of any one of the first seal 20, the second seal 30, the third seal 40 and the fourth seal 50 can be accurately distinguished, and whether the seal between the pressure piece 60 and the first end of the stern tube 90 has failed can also be determined, thereby reducing adjustment time and improving efficiency.

[0068] In some embodiments, the rotational speed of the stern shaft 80 is 2-5 rpm, so that the bushing 10 and the first seal 20, the second seal 30, the third seal 40, and the fourth seal 50 rotate relative to each other. In other words, the bushing 10 rotates while the first seal 20, the second seal 30, the third seal 40, and the fourth seal 50 remain stationary. The first seal 20, the second seal 30, the third seal 40, and the fourth seal 50 may be lip seals.

[0069] In some embodiments, the air pump assembly 170 includes a connecting pipe 171 and an air pump 172 connected to the connecting pipe 171 , and the connecting pipe 171 is provided with a vacuum gauge 173 .

[0070] When the connecting tube 171 is connected to the second channel 150, the air in the air cavity 120 is extracted by the air pump 172, and the vacuum degree of the air cavity 120 is obtained by the vacuum gauge 173. When the vacuum degree of the air cavity 120 reaches the set vacuum degree, the air pump 172 is turned off. When the set time is reached, the vacuum degree of the air cavity 120 obtained by the vacuum gauge 173 is observed to see whether it changes. If the vacuum degree of the air cavity 120 obtained by the vacuum gauge 173 changes, the sealing of the second seal 30 and the third seal 40 fails, and the second seal 30 and the third seal 40 need to be adjusted or replaced.

[0071] The connecting pipe 171 is connected to the third channel 160, and the air in the oil lubrication chamber 130 is extracted by the air pump 172. The vacuum degree of the oil lubrication chamber 130 is obtained by the vacuum gauge 173. When the vacuum degree of the oil lubrication chamber 130 reaches the set vacuum degree, the air pump 172 is turned off. When the set time is reached, the vacuum degree of the oil lubrication chamber 130 obtained by the vacuum gauge 173 is observed to see whether there is a change. If the vacuum degree of the oil lubrication chamber 130 obtained by the vacuum gauge 173 changes, the sealing of the fourth seal 50 has failed, and the fourth seal 50 needs to be adjusted or replaced.

[0072] The connecting pipe 171 is connected to the first channel 140, and the air in the watertight chamber 110 is extracted by the air pump 172. The vacuum degree of the watertight chamber 110 is obtained by the vacuum gauge 173. When the vacuum degree of the watertight chamber 110 reaches the set vacuum degree, the air pump 172 is turned off. When the set time is reached, the vacuum degree of the watertight chamber 110 obtained by the vacuum gauge 173 is observed to see whether it changes. If the vacuum degree of the watertight chamber 110 obtained by the vacuum gauge 173 changes, the sealing of the first seal 20 fails, and the first seal 20 needs to be adjusted or replaced.

[0073] Through the above steps, the sealing performance of any one of the first seal 20, the second seal 30, the third seal 40 and the fourth seal 50 can be clearly known, so as to facilitate the normal use of the stern shaft sealing device.

[0074] In some embodiments, the time for observing the vacuum gauge 173 to obtain whether the vacuum level of the air cavity 120 changes may be 15 minutes.

[0075] In some embodiments, a stop valve 174 is provided on the vacuum tube 171. When the air pump 172 is started, the stop valve 174 is opened. When the vacuum degree reaches a set vacuum degree, the stop valve 174 is closed first, and then the air pump 172 is turned off. The air pump 172 can be a vacuum pump, and the set vacuum degree can be -0.05 MPa.

[0076] In some embodiments, when the air pump assembly 170 is connected to the oil inlet 94 and supplies air to the lubricating oil channel 100, so that the air pressure in the lubricating oil channel 100 reaches 1.25 times the design pressure of the lubricating oil system, the shut-off valve 174 of the air pump assembly 170 is closed first, and then the air pump 172 of the air pump assembly 170 is closed.

[0077] In some embodiments, the purchased stern shaft sealing device can be tested for static sealing performance in a workshop to determine whether the sealing performance of the first seal 20, the second seal 30, the third seal 40 and the fourth seal 50 has failed. If the sealing performance of at least one of the first seal 20, the second seal 30, the third seal 40 and the fourth seal 50 has failed, the product can be returned to reduce procurement costs and improve product quality.

[0078] In some embodiments, when the static sealing performance of the stern shaft sealing device is to be tested in a workshop, and the sealing performance of the second seal 30, the third seal 40, and the fourth seal 50 is to be tested, the pressing member 60 is provided with an air inlet 61 communicating with the air cavity 120, an air outlet 62 communicating with the air cavity 120, and an oil inlet 63 communicating with the oil lubrication cavity 130. The air inlet 61, the air outlet 62, and the oil inlet 63 are blocked by a pressing plate 180. The pressing plate 180 can be mounted on the pressing member 60 via a monkey clip 190.

[0079] In some embodiments, when the bushing 10 is installed on the hub 70, the air inlet channel 91 is connected to the air cavity 120 through the air inlet hole 61, the air outlet channel 92 is connected to the air cavity 120 through the air outlet hole 62, and the oil inlet channel 93 is connected to the oil lubrication cavity 130 through the oil inlet hole 63.

[0080] In some embodiments, after applying soapy water to the outside of the pressing piece 60, if bubbles are generated outside the pressing piece 60, the sealing of the first seal 20, the second seal 30, the third seal 40 and the fourth seal 50 fails; if no bubbles are generated outside the pressing piece 60, the sealing of the first seal 20, the second seal 30, the third seal 40 and the fourth seal 50 is effective. That is to say, whether bubbles are generated outside the pressing piece 60 can be used to determine whether the sealing of the first seal 20, the second seal 30, the third seal 40 and the fourth seal 50 fails.

[0081] In some embodiments, a first gasket 210 is provided between the pressure piece 60 and the first end of the stern tube 90 to achieve sealing between the pressure piece 60 and the first end of the stern tube 90. When testing the dynamic sealing performance of the stern shaft sealing device, soapy water is applied to the first gasket 210 to test the sealing performance between the pressure piece 60 and the first end of the stern tube 90 to determine whether the sealing between the pressure piece 60 and the first end of the stern tube 90 has failed.

[0082] If bubbles appear at the first gasket 210, it indicates that the sealing of the first gasket 210 has failed and needs to be replaced. After the first gasket 210 is replaced, the static sealing performance of the stern shaft sealing device and the dynamic sealing performance of the stern shaft sealing device are retested.

[0083] In some embodiments, the air outlet passage 92 is opened and soapy water is applied to the air outlet passage 92 to test the sealing performance between the pressing member 60 and the first end of the stern tube 90. If bubbles are generated in the air outlet passage 92, the sealing of the first gasket 210 has failed and the first gasket 210 needs to be replaced.

[0084] After the first gasket 210 is replaced, the static sealing performance of the stern shaft sealing device is retested and the dynamic sealing performance of the stern shaft sealing device is tested.

[0085] In some embodiments, to determine the sealing performance between the bushing 10 and the hub 70, a second gasket 220 is provided between the bushing 10 and the hub 70. When testing the dynamic sealing performance of the stern shaft seal, soapy water is applied to the second gasket 220 to test the sealing performance between the bushing 10 and the hub 70. If bubbles form at the second gasket 220, the seal of the second gasket 220 has failed, and the stern shaft seal needs to be disassembled to clean and / or replace the first seal 20, the second seal 30, the third seal 40, the fourth seal 50, and the second gasket 220. The second gasket 220 may be a metal frame O-ring.

[0086] In some embodiments, the stern shaft sealing device further includes a sealing assembly 230, which is sleeved on the stern shaft 80. The stern tube 90 is located between the sealing assembly and the bushing 10. The sealing assembly 230 is connected to the second end of the stern tube 90. The method for testing the tightness of the stern shaft sealing device further includes the following steps: when testing the dynamic sealing performance of the stern shaft sealing device, soapy water is applied to the first sealing assembly 230 to test the sealing performance of the first sealing assembly 230. If bubbles are generated outside the first sealing assembly 230, the sealing of the first sealing assembly 230 has failed and the first sealing assembly 230 needs to be replaced or repaired. The second end of the stern tube 90 and the first end of the stern tube 90 are respectively located at the two ends of the stern tube 90.

[0087] In some embodiments, to implement the primary seal assembly 230, a third gasket 200 is provided between the primary seal assembly 230 and the second end of the stern tube 90. When testing the dynamic sealing performance of the stern shaft sealing device, soapy water is applied to the third gasket 200 to test the sealing performance between the primary seal assembly 230 and the second end of the stern tube 90. If bubbles are generated in the third gasket 200, the seal of the third gasket 200 has failed and the third gasket 200 needs to be replaced. After the third gasket 200 is replaced, the dynamic sealing performance of the stern shaft sealing device needs to be retested.

[0088] In some embodiments, after testing the dynamic sealing performance of the stern shaft seal, the oil outlet 95, air inlet passage 91, and air outlet passage 92 are closed, and the oil inlet passage 93 is opened. The air pump assembly 170 is connected to the oil inlet 94 to supply air to the lubricating oil passage 100. Soapy water is applied to the oil inlet passage 93. If bubbles form there, the fourth seal 50 has failed, requiring cleaning and / or replacement. After cleaning and / or replacing the fourth seal 50, the static sealing performance of the stern shaft seal is retested, followed by testing its dynamic sealing performance.

[0089] In some embodiments, in order to accurately determine whether the seal between the pressure piece 60 and the first end of the stern tube 90 is effective, when testing the dynamic sealing performance of the stern shaft sealing device in the oil pressure state, if the second channel 150 drips oil, the oil droplets in the second channel 150 are blown out, and the second channel 150 is perfused and cleaned with anhydrous alcohol. After the second channel 150 is blown dry, observe whether there is oil leakage in the second channel 150. If there is no oil dripping in the second channel 150, the seal between the pressure piece 60 and the first end of the stern tube 90 is effective.

[0090] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0091] In the description of the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0092] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification.

[0093] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0094] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A method for detecting the tightness of a stern shaft sealing device, characterized in that: The stern shaft sealing device includes a bushing, a first seal, a second seal, a third seal, a fourth seal and a pressure piece. The bushing is detachably connected to the propeller hub, the propeller hub is connected to the stern shaft, a stern tube is provided on the outer shell of the stern shaft, the stern tube and the stern shaft are spaced apart to form a lubricating oil passage, the pressure piece is connected to the first end of the stern tube, the stern tube is provided with an air inlet passage, an air outlet passage, an oil inlet passage, an oil inlet communicating with the lubricating oil passage and an oil outlet communicating with the lubricating oil passage, the pressure piece is sleeved on the bushing, and along the axial direction of the bushing, the first seal, the second seal, the third seal and the fourth seal are The seal and the fourth seal are spaced between the bushing and the pressure piece, a water-proof cavity is formed between the first seal and the second seal, an air cavity is formed between the second seal and the third seal, and an oil lubrication cavity is formed between the third seal and the fourth seal. The pressure piece is provided with a first channel connected to the water-proof cavity, a second channel connected to the air cavity, and a third channel connected to the oil lubrication cavity. The air cavity is connected to the air inlet channel and the air outlet channel, and the oil lubrication cavity is connected to the oil inlet channel. The tightness detection method of the stern shaft sealing device includes the following steps: Testing the static sealing performance of the stern shaft sealing device comprises the following steps: Opening the second channel, closing the air inlet channel and the air outlet channel, connecting the air pump assembly to the second channel, extracting air from the air cavity, and testing the sealing performance of the second sealing member and the third sealing member; Open the third channel, close the second channel, the air inlet channel and the air outlet channel, connect the air pump assembly to the third channel, extract the air in the oil lubrication chamber, and test the sealing performance of the fourth sealing member; Opening the first channel, closing the second channel, the air inlet channel, and the air outlet channel, connecting the air pump assembly to the first channel, extracting air from the air cavity, and testing the sealing performance of the first sealing member; Testing the dynamic sealing performance of the stern shaft sealing device comprises the following steps: Manually rotating the stern shaft, so that the stern shaft drives the bushing to rotate through the propeller hub; The first channel, the second channel, the third channel, the oil outlet, the oil inlet pipe, and the air inlet channel are closed, the air pump assembly is connected to the oil inlet, air is supplied to the lubricating oil channel, soapy water is applied to the outside of the pressing piece, and the sealing performance of the first seal, the second seal, the third seal, and the fourth seal is tested; In the oil pressure state, detecting the dynamic sealing performance of the stern shaft sealing device includes the following steps: Manually rotating the stern shaft, so that the stern shaft drives the bushing to rotate through the propeller hub; Close the oil outlet, open the oil inlet, the air inlet channel, the air outlet channel and the oil inlet channel, supply oil to the lubricating oil channel through the oil inlet, and supply oil to the oil lubrication cavity through the oil inlet channel box; The second channel below the air cavity is opened, and after a set time, the second channel is checked for oil dripping. If the second channel does not drip oil, the seal between the pressing piece and the first end of the stern tube is effective.

2. The method for detecting the tightness of a stern shaft sealing device according to claim 1, characterized in that: The air pump assembly includes a connecting pipe and an air pump connected to the connecting pipe, wherein the connecting pipe is provided with a vacuum gauge; When the connecting pipe is connected to the second channel, the air in the air cavity is extracted by the air pump, and the vacuum degree of the air cavity is obtained by the vacuum gauge. When the vacuum degree of the air cavity reaches a set vacuum degree, the air pump is turned off. When a set time is reached, the vacuum degree of the air cavity obtained by the vacuum gauge is observed to see whether there is a change. If the vacuum degree of the air cavity obtained by the vacuum gauge changes, the sealing of the second sealing member and the third sealing member fails. The connecting pipe is connected to the third channel, and air in the oil lubrication chamber is extracted by the air pump. The vacuum degree of the oil lubrication chamber is obtained by the vacuum gauge. When the vacuum degree of the oil lubrication chamber reaches a set vacuum degree, the air pump is turned off. When a set time is reached, the vacuum degree of the oil lubrication chamber obtained by the vacuum gauge is observed to see whether there is a change. If the vacuum degree of the oil lubrication chamber obtained by the vacuum gauge changes, the sealing of the fourth sealing member fails. The connecting pipe is connected to the first channel, the air in the watertight chamber is extracted by the air pump, and the vacuum degree of the watertight chamber is obtained by the vacuum gauge. When the vacuum degree of the watertight chamber reaches a set vacuum degree, the air pump is turned off. When the set time is reached, the vacuum degree of the watertight chamber obtained by the vacuum gauge is observed to see whether it changes. If the vacuum degree of the watertight chamber obtained by the vacuum gauge changes, the sealing of the first sealing component fails.

3. The method for detecting the tightness of a stern shaft sealing device according to claim 1, characterized in that: After soapy water is applied to the outside of the pressing member, if bubbles are generated outside the pressing member, the first sealing member, the second sealing member, the third sealing member and the fourth sealing member will fail to seal.

4. The method for detecting the tightness of a stern shaft sealing device according to any one of claims 1 to 3, characterized in that: A first gasket is provided between the pressing piece and the first end portion of the stern tube. When testing the dynamic sealing performance of the stern shaft sealing device, soapy water is applied to the first gasket to test the sealing performance between the pressing piece and the first end portion of the stern tube. If bubbles are generated at the first gasket, the sealing of the first gasket will fail.

5. The method for detecting the tightness of a stern shaft sealing device according to claim 4, characterized in that: Open the air outlet channel and apply soapy water to the air outlet channel; If bubbles are generated in the air outlet channel, the sealing of the first gasket fails.

6. The method for detecting the tightness of a stern shaft sealing device according to any one of claims 1 to 3, characterized in that: A second gasket is provided between the bushing and the propeller hub. When testing the dynamic sealing performance of the stern shaft sealing device, soapy water is applied to the second gasket to test the sealing performance between the bushing and the propeller hub. If bubbles are generated at the second gasket, the sealing of the second gasket will fail.

7. The method for detecting the tightness of a stern shaft sealing device according to any one of claims 1 to 3, characterized in that: The stern shaft sealing device further includes a sealing assembly, the sealing assembly is sleeved on the stern shaft, the stern tube is located between the sealing assembly and the bushing, the sealing assembly is connected to the second end of the stern tube, and the tightness detection method of the stern shaft sealing device further includes the following steps: When testing the dynamic sealing performance of the stern shaft sealing device, applying soapy water to the first sealing component to test the sealing performance of the first sealing component; If bubbles are generated outside the first sealing component, the sealing of the first sealing component will fail.

8. The method for detecting the tightness of a stern shaft sealing device according to claim 7, characterized in that: A third gasket is provided between the first sealing assembly and the second end portion of the stern tube. When testing the dynamic sealing performance of the stern shaft sealing device, soapy water is applied to the third gasket to test the sealing performance between the first sealing assembly and the second end portion of the stern tube. If bubbles are generated at the third gasket, the sealing of the third gasket will fail.

9. The method for detecting the tightness of a stern shaft sealing device according to any one of claims 1 to 3, characterized in that: After detecting the dynamic sealing performance of the stern shaft sealing device, closing the oil outlet, the air inlet channel and the air outlet channel, and opening the oil inlet channel; The air pump assembly is connected to the oil inlet to supply air to the lubricating oil passage. Soap water is applied to the oil inlet passage. If bubbles are generated in the oil inlet passage, the fourth sealing component will fail to seal.

10. The method for detecting the tightness of a stern shaft sealing device according to any one of claims 1 to 3, characterized in that: When testing the dynamic sealing performance of the stern shaft sealing device in the oil pressure state, if oil drips from the second channel, the oil droplets in the second channel are blown out, and the second channel is perfused and cleaned with anhydrous alcohol. After the second channel is blown dry, the second channel is observed for oil droplet leakage. If there is no oil dripping from the second channel, the seal between the pressing piece and the first end portion of the stern tube is effective.

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