Breathing device for gearbox

Abstract

The invention provides a breathing device for a gearbox. The breathing device is installed on the gear box, the interior of the gear box and the position below the elastic film in the breathing device form a sealed whole, and air expands to push the elastic film to move upwards along with temperature rise of the gear box. Along with temperature reduction of the gearbox, air contracts to pull the elastic film to move downwards. And separation between the lubricating oil and the surrounding environment is realized. In a petrochemical plant in which the operating environment is a humid environment and chemical gas reacting with the lubricating oil exists, the lubricating oil can be protected from being influenced by water vapor and the chemical gas, so that the cleanliness of the lubricating oil is protected, the lubricating effect of the gearbox is guaranteed, the reliability, economical efficiency and competitive power of the system are improved, and the service life of the system is prolonged. The method has a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of gearboxes, and particularly to a breathing device for a gearbox. Background Art

[0002] In a humid environment, due to the temperature change during the operation of the gearbox, the gas containing water vapor will enter the inside of the box body along the breather of the gearbox. The water vapor will enter the lubricating oil and increase the moisture content of the lubricating oil. Under the influence of a large amount of water vapor, the lubricating oil with an appropriate viscosity originally cannot form a thick enough oil film on the gear surface, resulting in poor lubrication effect and increased wear and friction of the gears. At the same time, the water and some components in the lubricating oil (such as the emulsifier in the additive) interact to form an emulsion. The lubricating performance of the emulsified lubricating oil will decline, and it will also promote the corrosion of components.

[0003] In a chemical environment, some chemical gases will react with the lubricating oil, and after a period of time, the lubricating oil will deteriorate. Due to the decline in the performance of the lubricating oil, it aggravates the wear of gears and bearings, affects the smoothness and reliability of gear transmission, and because the lubricating oil needs to be replaced in advance, the operating cost is increased.

[0004] Some users, in order to avoid the early failure of the lubricating oil, use a breather with a drying agent or a filter cartridge for adsorbing chemical gases. It can effectively prevent external water vapor from entering the inside of the box body within a certain period of time, but it requires the staff to regularly check and replace the drying agent and adsorbent, increasing the operation and maintenance cost of the product.

[0005] Therefore, it is of great significance to develop a breathing device for a gearbox. Summary of the Invention

[0006] The purpose of the present invention is to provide a breathing device for a gearbox to solve the problems existing in the prior art.

[0007] The technical solution adopted to achieve the purpose of the present invention is as follows: a breathing device for a gearbox includes a breathing tank and an elastic membrane.

[0008] The breathing tank adopts a detachable split structure. The breathing tank can be split into an upper tank body with an open lower end and a lower tank body with an open upper end. The docking open ends of the upper tank body and the lower tank body both extend out connection flanges outward. A ventilation pipe is connected to the top of the upper tank body. The ventilation pipe communicates the inner cavity of the upper tank body with the outside. An internal threaded hole is provided at the bottom of the lower tank body.

[0009] The periphery of the elastic membrane is clamped between the connection flanges of the upper tank body and the lower tank body and is locked by circumferentially evenly distributed positioning pins. In the non-working state, the elastic membrane is folded and accommodated in the lower tank body.

[0010] The breathing device for the gearbox is arranged on the top of the gearbox body. The elastic membrane, the lower tank body and the internal cavity of the gearbox body enclose a sealed adjustable air cavity. During operation, the volume of the adjustable air cavity changes dynamically with the operating temperature of the gearbox, and the shape of the elastic membrane changes accordingly. When the operating temperature of the gearbox rises, the air expands, and the elastic membrane is driven by the air pressure to unfold and fill the space of the upper tank body. When the operating temperature of the gearbox drops, the air contracts, and the elastic membrane falls back into the lower tank body.

[0011] Furthermore, it also includes an upper positioning ring and a lower positioning ring. The inner annular surface extending outward on the upper positioning ring contacts the corresponding annular surface of the upper tank body. The inner annular surface extending outward on the lower positioning ring contacts the corresponding annular surface of the lower tank body. Ten circumferentially arranged screws are passed through the corresponding holes of the upper positioning ring and the lower positioning ring, and flat washers, elastic washers and nuts are installed for locking.

[0012] Furthermore, the ventilation pipe is of a bent structure.

[0013] Furthermore, a filter screen is arranged at the end of the ventilation pipe.

[0014] Furthermore, the material of the elastic membrane is selected from polyurethane, styrene or polyethylene-based composite materials.

[0015] Furthermore, calculate the remaining cavity volume v3 = v1 - v2 according to the internal cavity size v1 of the gearbox and the volume v2 of the lubricating oil to be filled. Then record the current ambient temperature t1 and estimate the operating temperature t2 of the gearbox during normal operation, and calculate the temperature difference value t3 = t2 - t1. Calculate the thermal expansion volume v4 of the gas according to the temperature difference value t3 and the remaining cavity v3 by the thermal expansion coefficient method. Select the corresponding breathing tank specification according to the thermal expansion volume v4.

[0016] The technical effects of the present invention are beyond doubt: The breathing device is installed on the gearbox, and the interior of the gearbox and the elastic membrane inside the breathing device form a sealed whole. As the temperature of the gearbox rises, the air expands and pushes the elastic membrane upward; as the temperature of the gearbox drops, the air contracts and pulls the elastic membrane downward; realizing the separation of the lubricating oil from the surrounding environment. Inside a petrochemical plant with a humid operating environment and chemical gases that react with the lubricating oil, it can protect the lubricating oil from the influence of water vapor and chemical gases, thereby protecting the cleanliness of the lubricating oil, ensuring the lubrication effect of the gearbox, improving the reliability, economy and competitiveness of the system, and having a wide application prospect. Description of the Drawings

[0017] Figure 1 It is a three-dimensional structure diagram of the breathing device;

[0018] Figure 2 It is a structure diagram of the gearbox;

[0019] Figure 3 This is a three-dimensional structural diagram of the gearbox with a breathing device;

[0020] Figure 4 This is a structural diagram of the elastic membrane in the upper position of the breathing device;

[0021] Figure 5 This is a structural diagram of the elastic membrane in the breathing device in the lower end position.

[0022] In the figure: gear box body 1, breathing tank 2, upper tank body 11, lower tank body 12, internal threaded hole 121, elastic membrane 13, positioning pin 14, ventilation pipe 15, filter screen 152, upper positioning ring 16, lower positioning ring 17, screw 18, flat washer 19, elastic washer 20, nut 21. DETAILED DESCRIPTION

[0023] The present invention is further described below in conjunction with the embodiments, but it should not be understood that the above subject matter of the present invention is limited to the following embodiments. Without departing from the above technical ideas of the present invention, various substitutions and changes are made according to the common technical knowledge and customary means in the art, which should all be included in the protection scope of the present invention.

[0024] Embodiment 1:

[0025] See also Figures 1 to 5 This embodiment provides a breathing device for a gear box, including a breathing tank 2 and an elastic membrane 13.

[0026] The breathing tank 2 adopts a detachable split structure. The breathing tank 2 can be split into an upper tank body 11 with an open lower end and a lower tank body 12 with an open upper end. The butt-jointed open ends of the upper tank body 11 and the lower tank body 12 both extend outwardly with connecting flanges. A vent pipe 15 is connected to the top of the upper tank body 11. The vent pipe 15 connects the inner cavity of the upper tank body 11 with the outside. An internal threaded hole 121 is provided at the bottom of the lower tank body 12.

[0027] The periphery of the elastic membrane 13 is clamped between the connecting flanges of the upper tank body 11 and the lower tank body 12, and is locked by circumferentially uniformly distributed positioning pins 14. In a non-working state, the elastic membrane 13 is folded and accommodated in the lower tank body 12.

[0028] The breathing device for the gearbox is arranged on the top of the gearbox body 1. The elastic membrane 13, the lower tank body 12 and the internal cavity of the gearbox body 1 enclose a closed adjustable air cavity. During operation, the volume of the adjustable air cavity changes dynamically with the operating temperature of the gearbox 1, and the shape of the elastic membrane 13 changes accordingly. When the operating temperature of the gearbox 1 increases, the air expands, and the elastic membrane 13 is driven by the air pressure to expand and fill the space of the upper tank body 11. When the operating temperature of the gearbox 1 decreases, the air contracts, and the elastic membrane 13 falls back into the lower tank body 12.

[0029] It should be noted that during long-term use, the elastic membrane 13 is prone to damage. In this embodiment, the breathing tank 2 adopts a detachable split structure, which can realize timely replacement of the elastic membrane 13 before it reaches fatigue damage. Without replacing the remaining parts, a new breathing device is reassembled to meet long-term effective operation.

[0030] Embodiment 2:

[0031] The main content of this embodiment is the same as that of Embodiment 1. Among them, it also includes an upper positioning ring 16 and a lower positioning ring 17. The inner annular surface extending outward on the upper positioning ring 16 contacts the corresponding annular surface of the upper tank body 11. The inner annular surface extending outward on the lower positioning ring 17 contacts the corresponding annular surface of the lower tank body 12. Ten circumferentially arranged screws 18 are passed through the corresponding holes of the upper positioning ring 16 and the lower positioning ring 17, and flat washers 19, elastic washers 20 and nuts 21 are installed for locking. After the upper positioning ring 16 and the lower positioning ring 17 are locked by the screws 18, there is a gap between the upper positioning ring 16 and the lower positioning ring 17 to ensure the seal between the upper tank body 11, the lower tank body 12 and the elastic membrane 13.

[0032] Embodiment 3:

[0033] The main content of this embodiment is the same as that of Embodiment 1 or 2. Among them, the ventilation pipe 15 is a bent structure. An external thread 151 is provided on the outer wall of the lower end of the ventilation pipe 15. The ventilation pipe 15 is connected to the internal thread hole 111 of the upper tank body 11 through the external thread 151. A filter net 152 is provided at the upper end of the ventilation pipe 15 to prevent particulate matter from entering the interior of the breathing tank 2.

[0034] Embodiment 4:

[0035] The main content of this embodiment is the same as that of Embodiment 1 or 2. Among them, according to the space requirements around the gearbox, the breathing tank 2 can be selected from a vertical circular tank, a horizontal circular tank, a square tank, an oval tank, a special-shaped tank, a necked-down tank, a spherical tank or a domed tank.

[0036] Embodiment 5:

[0037] The main content of this embodiment is the same as any one of Embodiments 1 to 3. Among them, the material of the elastic membrane 13 is selected from polyurethane, styrene or polyethylene-based composite materials.

[0038] Embodiment 6:

[0039] The main content of this embodiment is the same as any one of Embodiments 1 to 4. Among them, the volume v3 of the remaining cavity is calculated according to the size v1 of the internal cavity of the gearbox 1 and the volume v2 of the lubricating oil to be filled, i.e., v3 = v1 - v2. Then, the current ambient temperature t1 is recorded and the operating temperature t2 of the gearbox 1 during normal operation is estimated, and the temperature difference value t3 = t2 - t1 is calculated. Under the temperature difference value t3 and the remaining cavity v3, the thermal expansion amount v4 of the gas is calculated according to the thermal expansion coefficient method. The corresponding specification of the breathing tank 2 is selected according to the thermal expansion amount v4.

Claims

1. A breathing device for a gearbox, characterized in that: It includes a breathing tank (2) and an elastic membrane (13); The breathing tank (2) adopts a detachable split structure; the breathing tank (2) can be split into an upper tank body (11) with an open lower end and a lower tank body (12) with an open upper end; the docking open ends of the upper tank body (11) and the lower tank body (12) both extend outwards to form connecting flanges; a ventilation pipe (15) is connected to the top of the upper tank body (11); the ventilation pipe (15) communicates the inner cavity of the upper tank body (11) with the outside; an internal thread hole (121) is provided at the bottom of the lower tank body (12); The periphery of the elastic membrane (13) is clamped between the connecting flanges of the upper tank body (11) and the lower tank body (12), and is locked by circumferentially evenly distributed positioning pins (14); in the non-working state, the elastic membrane (13) is folded and accommodated in the lower tank body (12); The breathing device for the gearbox is arranged on the top of the gearbox body (1); the internal cavities of the elastic membrane (13), the lower tank body (12) and the gearbox body (1) enclose a closed adjustable air cavity; during operation, the volume of the adjustable air cavity changes dynamically with the operating temperature of the gearbox (1), and the shape of the elastic membrane (13) changes accordingly; when the operating temperature of the gearbox (1) rises, the air expands, and the elastic membrane (13) is driven by the air pressure to expand and fill the space of the upper tank body (11); when the operating temperature of the gearbox (1) drops, the air contracts, and the elastic membrane (13) falls back into the lower tank body (12).

2. The breathing device for a gearbox according to claim 1, characterized in that: It also includes an upper positioning ring (16) and a lower positioning ring (17); the inner annular surface extending outwards on the upper positioning ring (16) contacts the corresponding annular surface of the upper tank body (11); the inner annular surface extending outwards on the lower positioning ring (17) contacts the corresponding annular surface of the lower tank body (12); ten circumferentially arranged screws (18) are passed through the corresponding holes of the upper positioning ring (16) and the lower positioning ring (17), and flat washers (19), elastic washers (20) and nuts (21) are installed for locking.

3. The breathing device for a gearbox according to claim 1, characterized in that: The ventilation pipe (15) is of a bent structure.

4. A breathing device for a gearbox according to claim 3, characterized in that: A filter screen (152) is provided at the end of the ventilation pipe (15).

5. The breathing device for a gearbox according to claim 1, wherein: The material of the elastic membrane (13) is selected from polyurethane, styrene or polyethylene-based composite materials.

6. The breathing device for a gearbox according to claim 1, wherein: The breathing tank (2) is selected from a vertical circular tank, a horizontal circular tank, a square tank, an oval tank, a special-shaped tank, a necked-down tank, a spherical tank or a domed tank.

7. A breathing device for a gearbox according to claim 1, characterized in that: Calculate the remaining cavity volume v3 = v1 - v2 according to the internal cavity size v1 of the gearbox (1) and the volume v2 of the lubricating oil to be filled; then record the current ambient temperature t1 and estimate the operating temperature t2 of the gearbox (1) during normal operation, and calculate the temperature difference value t3 = t2 - t1; Calculate the thermal expansion volume v4 of the gas according to the temperature difference value t3 and the remaining cavity v3 by the thermal expansion coefficient method; select the corresponding specification of the breathing tank (2) according to the thermal expansion volume v4.

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