An oil leakage-proof speed reducer venting device and a method of use

Abstract

The application discloses an oil-leakage-proof ventilation device of a speed reducer, which comprises a mounting flange, a hole-plate type short circuit and an expansion type shell, wherein the hole-plate type short circuit, a zigzag type labyrinth short circuit, an oil-blocking short circuit and a center oil-returning short circuit are arranged in the shell, a C type air filter is further arranged at the upper portion of the shell, and oil carried in the exhaust process is blocked by the multiple short circuits and filtered by the C type air filter and finally flows back to the speed reducer through an oil return pipe. The ventilation device of the speed reducer utilizes the advantages of the general and easy-to-obtain C type air filter and makes up for the oil-leakage deficiency of the conventional C type air filter. The application is especially suitable for the working condition that the speed reducer of a dynamic separator of a coal mill is operated in a dust environment and sealed air is introduced. The application enables the speed reducer under the working condition to smoothly exhaust and effectively blocks the lubricating oil from splashing out or being discharged with the gas to pollute the environment.

Description

Technical Field

[0001] This invention relates to the technical field of gearbox ventilation devices, specifically to a gearbox ventilation device for preventing oil leakage and its usage method. Background Technology

[0002] During operation, the gear pairs in a speed reducer rotate at high speed, agitating the lubricating oil and causing fluctuations in the oil level and oil splashing. The mixing of lubricating oil and air, further agitated by the gear pairs, generates air bubbles, increasing the oil volume. The high-speed rotation of the gear pairs generates heat, raising the lubricating oil temperature. This agitation also causes the gas within the reducer to expand, increasing pressure. When the pressure difference between the reducer and the external atmospheric pressure reaches a certain value, lubricating oil will leak from the mating surfaces of the reducer housing under the influence of this pressure difference. To prevent this, a venting device is typically installed on the speed reducer to balance the internal and external pressures.

[0003] In the pulverizing system of a thermal power plant, the gear reducer driving the rotor of the rotary separator in the coal mill requires a certain pressure and flow rate of sealing air to isolate the coal dust inside the mill, preventing it from entering the reducer and contaminating the lubricating oil. Inevitably, some of the sealing air will breach the reducer's seal and enter, further increasing the internal pressure. In this situation, conventional venting devices cannot effectively prevent the lubricating oil carried by the exhaust gas, leading to oil spillage or discharge with the gas, contaminating the environment around the reducer. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a leak-proof gearbox ventilation device and its usage method.

[0005] The present invention adopts the following technical solution:

[0006] A leak-proof gearbox ventilation device includes: a mounting flange, an orifice plate short connector, and an expanded housing. The mounting flange is a circular flange structure with a circular hole at its center. The lower end of the orifice plate short connector is inserted into the circular hole of the mounting flange and welded thereto. The upper end of the orifice plate short connector is butt-welded to the lower end of a zigzag labyrinth tube, and the upper end of the zigzag labyrinth tube is welded to the lower end of the oil-blocking short connector. The expanded housing is fitted over the zigzag labyrinth tube and the oil-blocking short connector, and its diameter is larger than the maximum diameter of the zigzag labyrinth tube and the oil-blocking short connector. Its lower end is welded to the middle of the zigzag labyrinth tube, and a C-type air filter is installed on its upper oil accumulation surface. The air filter interface is used to connect a type C air filter, and the interface position is lower than the top of the expansion housing. The upper oil return plane of the expansion housing is welded to the upper end of the upper oil return pipe. The other end of the upper oil return pipe passes through the lower oil return plane of the expansion housing and the housing of the orifice plate short connector, and its end is welded to the central oil return short connector. The lower oil return plane of the expansion housing is welded to the upper end of the lower oil return pipe. The other end of the lower oil return pipe passes through the housing of the orifice plate short connector, and its end is welded to the central oil return short connector. The upper end of the central oil return short connector is welded to the center of the top plate of the orifice plate short connector, and the lower end is connected to the upper end of the detachable main oil return pipe. The end of the detachable main oil return pipe is immersed in the reducer lubricating oil.

[0007] In a preferred embodiment of the present invention, the tortuous labyrinth tube is formed by welding together several labyrinth short circuits connected end to end.

[0008] In a preferred embodiment of the present invention, the C-type air filter interface of the expanded housing is further provided with multiple layers of filter screens.

[0009] In a preferred embodiment of the present invention, the C-type air filter and the expanded housing are connected by threads.

[0010] In a preferred embodiment of the present invention, the top of the C-type air filter is fitted with a double-layer dust cover using a wing nut.

[0011] In a preferred embodiment of the present invention, the outer diameter of the inner sleeve of the double-layer dust cover is smaller than the inner diameter of the expanded outer shell, the inner diameter of the outer sleeve is larger than the outer diameter of the expanded outer shell, and the inner sleeve is longer than the outer sleeve. The inner sleeve and the outer sleeve cooperate with the expanded outer shell to form a tortuous passage.

[0012] In a preferred embodiment of the present invention, the C-type air filter is a JB / ZQ4522 standard part or its alternative.

[0013] In a preferred embodiment of the present invention, the central return oil short connector is connected to the detachable main return oil pipe through a straight pipe joint during welding.

[0014] In a preferred embodiment of the present invention, the lower end of the central return oil short circuit is closed and equipped with a welded straight pipe joint.

[0015] In a preferred embodiment of the present invention, the welded straight pipe joint is welded to the upper end of the detachable main return oil pipe.

[0016] In a preferred embodiment of the present invention, the ventilation device is mounted on the top of the reducer via a mounting flange.

[0017] A method of using a leak-proof gearbox venting device as described above, the method comprising the following steps:

[0018] Step 1): When the gear pair in the reducer rotates at high speed, it agitates the lubricating oil, causing the lubricating oil level to fluctuate and oil to splash. The fluctuation of the lubricating oil level causes some lubricating oil to rush into the venting device and be discharged outward with the gas. During this process, after being blocked by the orifice plate short joint and the tortuous labyrinth tube, some oil flows back to the oil tank. Some oil enters the expansion shell through the vent hole of the orifice plate short joint, the tortuous labyrinth tube, and the vent hole of the oil blocking short joint with the gas. Under the influence of gravity, it flows along the pipe wall to the lower oil accumulation plane of the expansion shell and then returns to the oil tank through the lower oil return pipe, the central oil return short joint, the welded straight pipe joint, and the detachable main oil return pipe.

[0019] Step 2): When the gear pair in the reducer rotates at high speed, it generates heat, causing the lubricating oil temperature to rise. The gear pair also agitates the lubricating oil, leading to an increase in lubricating oil temperature. This causes the gas in the reducer to expand, increasing the pressure. The expanding gas carries small oil droplets through the obstruction of the orifice plate short-circuit and the tortuous labyrinth tube of the exhaust device, entering the expansion housing. Due to the increased flow area, the flow velocity of the expanding gas slows down, reducing the gas's ability to carry oil droplets. Some oil droplets settle, while others are carried by the airflow through the filter screen to the C-type air filter. The C-type air filter contains a filter element, which prevents oil droplets from passing through the filter element from settling on the upper oil accumulation platform of the expansion housing. The oil droplets that pass through the filter element enter the double-layer dust cover. In the double-layer dust cover, due to the rapid expansion of the gas flow area and the high resistance, the flow velocity decreases. The small oil droplets settle on the upper oil accumulation platform of the expansion housing in the double-layer dust cover, and then return to the oil tank through the upper return oil pipe center return short-circuit, welded straight pipe joint, and detachable main return oil pipe.

[0020] In a preferred embodiment of the present invention, the filter element of the C-type air filter can block oil droplets larger than 40 micrometers, while oil droplets smaller than 40 micrometers can pass through the filter element.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] This invention discloses a leak-proof venting device for a speed reducer. When the gear pair in the speed reducer rotates at high speed, it agitates the lubricating oil, causing fluctuations in the oil level and oil splashing. These fluctuations in oil level cause some lubricating oil to flow into the venting device and be discharged outwards with the gas. During this process, the orifice plate and the tortuous labyrinth tube block the flow, allowing some oil to flow back to the oil tank. The orifice plate and labyrinth structure of this device effectively block the splashed lubricating oil, allowing most of the splashed lubricating oil to return to the oil tank.

[0023] In addition to effectively blocking splashed lubricating oil, this device can also effectively block small oil droplets carried by the gas. The gas carrying these small oil droplets enters the expanded housing through the orifice plate-type short circuit and the tortuous labyrinth tube of the exhaust device. Due to the increased flow area, the gas flow rate slows down, reducing the gas's ability to carry oil droplets and causing them to settle. The filter screen and the filter element at the C-type air filter further prevent small oil droplets from being discharged with the gas. The double-layer protective cover design not only isolates dust but also forms a tortuous path with the expanded housing, further increasing airflow resistance and causing oil droplets to settle.

[0024] This innovative device combines a perforated plate short-circuit, a tortuous labyrinthine short tube, and an expanded housing with a conventional air filter. It leverages the versatility and readily available availability of conventional air filters while overcoming their tendency to leak oil. It is particularly suitable for applications such as coal mill dynamic separator reducers operating in high-temperature, high-pressure, dusty environments with sealed airflow. This allows the reducer to smoothly exhaust air, balancing internal and external pressures, and effectively blocking lubricating oil. The lubricating oil entering the ventilation device is then returned to the reducer housing, preventing oil droplets from being discharged with the gas and polluting the environment. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of a leak-proof gearbox ventilation device according to the present invention;

[0026] Figure 2 This is a practical application example of the present invention in the reducer of a dynamic separator in a coal mill;

[0027] In the picture:

[0028] 1-Mounting flange, 2-Orifice plate short connector, 3-Bent-down labyrinth tube, 4-Lower return oil pipe, 5-Expanded housing, 6-Oil blocking short connector, 7-Double dust cover, 8-Type C air filter, 9-Filter screen, 10-Upper return oil pipe, 11-Central return oil short connector, 12-Welded straight pipe joint, 13-Removable main return oil pipe. Detailed Implementation

[0029] The present application will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, and should not be construed as limiting the scope of protection of the present application.

[0030] Figure 1 This is a schematic diagram of a leak-proof gearbox ventilation device according to the present invention. Figure 2 This is a practical application example of the present invention in the reducer of a dynamic separator in a coal mill, such as... Figure 1 As shown, a leak-proof gearbox ventilation device of the present invention includes a mounting flange 1, a perforated plate short connector 2, and an expanded housing 5.

[0031] The mounting flange 1 is a circular flange structure with a circular hole in its center. The lower end of the orifice plate short connector 2 is inserted into the circular hole of the mounting flange 1 and welded to it. The upper end of the orifice plate short connector 2 is butt-welded to the lower end of the zigzag labyrinth tube 3. The upper end of the zigzag labyrinth tube 3 is welded to the lower end of the oil-blocking short connector 6.

[0032] The expanded housing 5 is sleeved on the outside of the tortuous labyrinth tube 3 and the oil blocking short circuit 6. Its housing diameter is larger than the maximum diameter of the tortuous labyrinth tube 3 and the oil blocking short circuit 6. Its lower end is welded to the middle of the tortuous labyrinth tube 3. Its upper oil accumulation plane is provided with a C-type air filter interface for connecting the C-type air filter 8. The interface position is lower than the top of the expanded housing.

[0033] The upper oil return plane of the expanded housing 5 is welded to the upper end of the upper oil return pipe 10. The other end of the upper oil return pipe 10 passes through the lower oil return plane of the expanded housing 5 and the housing of the orifice plate type short connector 2, and its end is welded to the central oil return short connector 11. The lower oil return plane of the expanded housing 5 is welded to the upper end of the lower oil return pipe 4. The other end of the lower oil return pipe 4 passes through the housing of the orifice plate type short connector 2, and its end is welded to the central oil return short connector 11.

[0034] The upper end of the center return oil short circuit 11 is welded to the center of the top plate of the orifice plate short circuit 2, and the lower end is connected to the upper end of the detachable main return oil pipe 13. The end of the detachable main return oil pipe 13 is immersed in the reducer lubricating oil.

[0035] The tortuous labyrinth tube 3 is composed of several labyrinth short circuits connected end to end and welded together.

[0036] The C-type air filter interface of the expanded housing 5 is also equipped with multiple layers of filters 9.

[0037] The C-type air filter 8 is connected to the expanded housing 5 by a threaded connection, and the top of the C-type air filter 8 is fitted with a double-layer dust cover 7 using a wing nut.

[0038] The outer diameter of the inner sleeve of the double-layer dust cover 7 is smaller than the inner diameter of the expanded outer shell 5, and the inner diameter of the outer sleeve is larger than the outer diameter of the expanded outer shell 5. The inner sleeve is longer than the outer sleeve, and the inner sleeve and the outer sleeve cooperate with the expanded outer shell 5 to form a tortuous passage.

[0039] Type C air filter 8 is a standard part of JB / ZQ4522 or its alternative.

[0040] The central return oil short connector 11 is connected to the detachable main return oil pipe 13 via a welded straight pipe connector 12. The lower end of the central return oil short connector 11 is closed and equipped with a welded straight pipe connector 12. The welded straight pipe connector 12 is welded to the upper end of the detachable main return oil pipe 13.

[0041] The ventilation device is mounted on the top of the reducer via mounting flange 1.

[0042] A method of using a leak-proof gearbox venting device as described above, the method comprising the following steps:

[0043] Step 1): When the gear pair in the reducer rotates at high speed, it agitates the lubricating oil, causing the lubricating oil level to fluctuate and the oil to splash. The fluctuation of the lubricating oil level causes some of the lubricating oil to rush into the venting device and be discharged outward with the gas. During this process, the oil flows back to the oil tank through the vent holes of the orifice plate short connector 2 and the tortuous labyrinth tube 3. The oil flows back into the expansion shell 5 with the gas through the vent holes of the orifice plate short connector 2, the tortuous labyrinth tube 3, and the vent holes of the oil blocking short connector 6. Under the influence of gravity, the oil flows along the pipe wall to the lower oil accumulation plane of the expansion shell 5 and then returns to the oil tank through the lower oil return pipe 4, the central oil return short connector 11, the welded straight pipe joint 12, and the detachable main oil return pipe 13.

[0044] Step 2): When the gear pair in the reducer rotates at high speed, it generates heat, causing the lubricating oil temperature to rise. The gear pair also agitates the lubricating oil, further increasing its temperature. This causes the gas in the reducer to expand, increasing its pressure. The expanding gas, carrying small oil droplets, passes through the obstruction of the orifice plate-type short-circuit 2 and the tortuous labyrinth tube 3 of the exhaust device and enters the expansion-type outer casing 5. Due to the increased flow area, the flow velocity of the expanding gas slows down, reducing its ability to carry oil droplets. Some oil droplets settle, while others are carried by the airflow through the filter screen 9. At the C-type air filter 8, a filter element is installed in the C-type air filter 8. Oil droplets that cannot pass through the filter element are blocked and settled on the upper oil accumulation platform of the expanded housing 5. Oil droplets that pass through the filter element enter the double-layer dust cover 7. In the double-layer dust cover 7, due to the rapid expansion of the gas flow area, the resistance is large and the flow rate is reduced. Small oil droplets settle on the upper oil accumulation platform of the expanded housing 5 in the double-layer dust cover 7, and then return to the oil tank through the upper return oil pipe center return oil short connector 11, welded straight pipe joint 12, and detachable main return oil pipe 13.

[0045] The C-type air filter 8's filter element can block oil droplets larger than 40 microns, while oil droplets smaller than 40 microns can pass through the filter element.

[0046] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0047] This invention discloses a leak-proof venting device for a speed reducer. When the gear pair in the speed reducer rotates at high speed, it agitates the lubricating oil, causing fluctuations in the oil level and oil splashing. These fluctuations in oil level cause some lubricating oil to flow into the venting device and be discharged outwards with the gas. During this process, the orifice plate and the tortuous labyrinth tube block the flow, allowing some oil to flow back to the oil tank. The orifice plate and labyrinth structure of this device effectively block the splashed lubricating oil, allowing most of the splashed lubricating oil to return to the oil tank.

[0048] In addition to effectively blocking splashed lubricating oil, this device can also effectively block small oil droplets carried by the gas. The gas carrying these small oil droplets enters the expanded housing through the orifice plate-type short circuit and the tortuous labyrinth tube of the exhaust device. Due to the increased flow area, the gas flow rate slows down, reducing the gas's ability to carry oil droplets and causing them to settle. The filter screen and the filter element at the C-type air filter further prevent small oil droplets from being discharged with the gas. The double-layer protective cover design not only isolates dust but also forms a tortuous path with the expanded housing, further increasing airflow resistance and causing oil droplets to settle.

[0049] This innovative device combines a perforated plate short-circuit, a tortuous labyrinthine short tube, and an expanded housing with a conventional air filter. It leverages the versatility and readily available availability of conventional air filters while overcoming their tendency to leak oil. It is particularly suitable for applications such as coal mill dynamic separator reducers operating in high-temperature, high-pressure, dusty environments with sealed airflow. This allows the reducer to smoothly exhaust air, balancing internal and external pressures, and effectively blocking lubricating oil. The lubricating oil entering the ventilation device is then returned to the reducer housing, preventing oil droplets from being discharged with the gas and polluting the environment.

[0050] The applicant of this invention has provided a detailed description of the embodiments of the invention in conjunction with the accompanying drawings. However, those skilled in the art should understand that the above embodiments are merely preferred embodiments of the invention. The detailed description is only intended to help readers better understand the spirit of the invention and is not intended to limit the scope of protection of the invention. On the contrary, any improvements or modifications made based on the inventive spirit of the invention should fall within the scope of protection of the invention.

Claims

1. A leak-proof venting device for a speed reducer, comprising: The mounting flange (1), orifice plate short connector (2), and expansion housing (5) are characterized by: The mounting flange (1) is a circular flange structure with a circular hole in its center. The lower end of the orifice plate short connector (2) is inserted into the circular hole of the mounting flange (1) and welded to it. The upper end of the orifice plate short connector (2) is welded to the lower end of the tortuous labyrinth tube (3), and the upper end of the tortuous labyrinth tube (3) is welded to the lower end of the oil-blocking short connector (6). The expansion housing (5) is sleeved on the outside of the tortuous labyrinth tube (3) and the oil blocking short circuit (6). Its housing diameter is larger than the maximum diameter of the tortuous labyrinth tube (3) and the oil blocking short circuit (6). Its lower end is welded to the middle of the tortuous labyrinth tube (3). Its upper oil accumulation plane is provided with a C-type air filter interface for connecting a C-type air filter (8). The interface position is lower than the uppermost end of the expansion housing. The upper oil return plane of the expanded housing (5) is welded to the upper end of the upper oil return pipe (10), and the other end of the upper oil return pipe (10) passes through the lower oil return plane of the expanded housing (5) and the housing of the orifice plate short connector (2), and its end is welded to the central oil return short connector (11). The lower oil return plane of the expanded housing (5) is welded to the upper end of the lower oil return pipe (4), and the other end of the lower oil return pipe (4) passes through the housing of the orifice plate short connector (2), and its end is welded to the central oil return short connector (11). The upper end of the central return oil short connector (11) is welded to the center of the top plate of the orifice plate short connector (2), and the lower end is connected to the upper end of the detachable main return oil pipe (13). The end of the detachable main return oil pipe (13) is immersed in the lubricating oil of the reducer.

2. The oil-leakage-proof gearbox ventilation device according to claim 1, characterized in that: The tortuous labyrinth tube (3) is composed of several labyrinth short circuits connected end to end and welded together.

3. The oil-leakage-proof reducer ventilation device according to claim 1, characterized in that: The C-type air filter interface of the expanded housing (5) is also provided with multiple layers of filter screens (9).

4. The oil-leakage-proof gearbox ventilation device according to claim 3, characterized in that: The C-type air filter (8) and the expanded housing (5) are connected by threads; The top of the C-type air filter (8) is fitted with a double-layer dust cover (7) using a wing nut.

5. The oil-leakage-proof gearbox ventilation device according to claim 4, characterized in that: The outer diameter of the inner sleeve of the double-layer dust cover (7) is smaller than the inner diameter of the expanded outer shell (5), and the inner diameter of the outer sleeve is larger than the outer diameter of the expanded outer shell (5). The inner sleeve is longer than the outer sleeve, and the inner sleeve and the outer sleeve cooperate with the expanded outer shell (5) to form a tortuous passage.

6. The oil-leakage-proof gearbox ventilation device according to claim 1, characterized in that: The C-type air filter (8) is a JB / ZQ4522 standard part or its alternative.

7. The oil-leakage-proof gearbox ventilation device according to claim 1, characterized in that: The central return oil short connector (11) is connected to the detachable main return oil pipe (13) through a straight pipe joint (12) during welding; The lower end of the central return oil short circuit (11) is closed and equipped with a welded straight pipe joint (12); The welded straight pipe joint (12) is welded to the upper end of the detachable main return oil pipe (13).

8. The oil-leakage-proof gearbox ventilation device according to claim 1, characterized in that: The ventilation device is mounted on the top of the reducer via a mounting flange (1).

9. A method of using a leak-proof venting device for a speed reducer as described in any one of claims 1 to 8, characterized in that: The method includes the following steps: Step 1), when the gear pair in the reducer rotates at high speed, it agitates the lubricating oil, causing the lubricating oil level to fluctuate and the oil to splash. The fluctuation of the lubricating oil level causes some of the lubricating oil to rush into the venting device and be discharged outward with the gas. During this process, the oil is blocked by the orifice plate short connector (2) and the tortuous labyrinth tube (3), and some of the oil flows back to the oil tank. Some of the oil enters the expansion shell (5) with the gas through the vent hole of the orifice plate short connector (2), the tortuous labyrinth tube (3), and the vent hole of the oil blocking short connector (6). Under the influence of gravity, it flows along the pipe wall to the lower oil accumulation plane of the expansion shell (5) and then flows back to the oil tank through the lower oil return pipe (4), the central oil return short connector (11), the welded straight pipe joint (12), and the detachable main oil return pipe (13). Step 2): When the gear pair in the reducer rotates at high speed, it generates heat, causing the lubricating oil temperature to rise. The gear pair also agitates the lubricating oil, causing the lubricating oil temperature to rise. This causes the gas in the reducer to expand and the pressure to rise. The expanded gas carries small oil droplets through the obstruction of the orifice plate short circuit (2) and the tortuous labyrinth tube (3) of the exhaust device and enters the expansion shell (5). Due to the increased flow area, the flow rate of the expanded gas slows down, and the gas's ability to carry oil droplets decreases. Some oil droplets settle, and some small oil droplets are carried by the airflow through the filter screen (9) to the C-type air filter. At the air purifier (8), a filter element is installed in the C-type air filter (8). Oil droplets that cannot pass through the filter element are blocked and settled on the upper oil accumulation platform of the expanded housing (5). Oil droplets that pass through the filter element enter the double-layer dust cover (7). In the double-layer dust cover (7), due to the rapid expansion of the gas flow area, the resistance is large and the flow rate is reduced. Small oil droplets settle on the upper oil accumulation platform of the expanded housing (5) in the double-layer dust cover (7), and then return to the oil tank through the upper return oil pipe center return oil short connector (11), welded straight pipe joint (12), and detachable main return oil pipe (13).

10. The method of using the oil-leakage-proof reducer ventilation device according to claim 9, characterized in that: The filter element of the C-type air filter (8) can block oil droplets larger than 40 micrometers, while oil droplets smaller than 40 micrometers can pass through the filter element.

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