Explosion-proof draw-out type dynamic sealing device for ventilator motor shaft

Abstract

The invention belongs to the field of coal mine underground ventilation safety, and particularly relates to an anti-explosion draw-out type ventilator motor shaft dynamic sealing device which comprises a main lip, an auxiliary lip and an auxiliary lip. The motor shaft is sleeved with the oil accumulation lip, the oil accumulation lip is arranged at the end, away from the center of the motor shaft, of the motor shaft, the two ends of the oil cavity framework are connected with the main lip and the end, away from the motor shaft, of the oil accumulation lip respectively, and therefore an oil accumulation cavity is formed among the main lip, the oil cavity framework, the oil accumulation lip and the motor shaft; the lubricating grease is filled in the oil accumulation cavity; the auxiliary lip can be arranged on the motor shaft in a sleeving mode, is arranged on the side, away from the oil accumulation cavity, of the oil accumulation lip and faces the end, away from the center of the motor shaft, of the oil accumulation lip so that impurities can be blocked outside. The oil accumulation cavity is ingeniously formed between the main lip and the oil accumulation lip and filled with lubricating grease, a unique self-lubricating system is constructed, and the defects of a traditional O-shaped ring seal in the aspects of high temperature, abrasion and unstable adsorption are overcome.

Description

Technical Field

[0001] The present invention belongs to the field of mine underground ventilation safety, and particularly relates to a dynamic seal device for the motor shaft of an explosion-proof exhaust ventilator. Background Art

[0002] In coal mine underground mining operations, there are potential risks of gas outburst or ejection in areas such as coal roadways, semi-coal rock roadways, rock roadways with gas outburst, gas ejection areas, and outburst coal seams. When the gas concentration in the roadway reaches the explosion limit, a highly dangerous explosive gas environment will be formed. For the operation safety in such highly dangerous environments, the national standard has formulated strict safety standards for electrical equipment used in explosive gas environments. Generally, it is required that such equipment has at least two independent protections to reach the equipment protection level (EPL) Ma level. This means that even if one of the protection measures fails, the equipment can still maintain the reliability of its safety performance through additional protection mechanisms.

[0003] Among Ma-level explosion-proof equipment, a common implementation method is to use an explosion-proof exhaust ventilator with internal positive pressure protection. This type of ventilator usually combines a double protection design of an explosion-proof enclosure and filling positive pressure non-explosive gas inside the enclosure to meet the requirements of Ma-level explosion-proof equipment. Among them, maintaining the stability of the positive pressure inside the enclosure is one of the key stages to ensure the safe operation of the equipment. As the motor shaft, which is the core component of the ventilator, its dynamic rotary seal directly affects the effect of maintaining positive pressure. During the high-speed rotation of the motor shaft, the dynamic seal must effectively prevent gas leakage, maintain the temperature rise of the friction pair within the range specified by the national standard, and at the same time be able to maintain stable performance in the environment of high temperature, high humidity and a large amount of dust impurities in coal mines. At present, traditional motor shaft dynamic seal technologies mostly adopt the O-ring seal scheme. However, this technology has deficiencies in practical applications and is difficult to fully meet the high safety requirements of Ma-level explosion-proof equipment. The following is a specific analysis of the main problems of the traditional O-ring seal:

[0004] High-temperature problem: Obvious frictional heat is generated between the O-ring and the motor shaft during high-speed rotation, resulting in a sharp rise in the surface temperature of the motor shaft. This temperature rise may exceed the strict limit of the surface temperature of the equipment in the "GB3836 Electrical Apparatus for Explosive Atmospheres" standard, which not only affects the stability of the sealing material but also may pose a threat to the overall safety of the equipment.

[0005] Fatigue and aging: As an elastomer material, the O-ring is extremely prone to wear and aging under the long-term action of friction and mechanical fatigue. Once damage appears on the surface of the O-ring, its sealing performance will significantly decline, resulting in an increased risk of gas leakage. This not only affects the internal positive pressure protection ability of the ventilator but also may endanger the explosion performance of the equipment.

[0006] Adsorption: In the underground environment of coal mines, the air often contains fine particles such as coal ash. Due to the material characteristics of the O-ring, the surface adsorbs these coal ash particles, resulting in a rough or uneven sealing interface, which in turn affects the sealing effect. Long-term accumulation of coal ash particles may also increase the risk of O-ring damage, further undermining the integrity of the entire internal positive pressure system.

[0007] This defect limits the application of traditional O-ring seals in high-risk environments, which not only reduces the reliability and safety of explosion-proof exhaust ventilators, but also increases the maintenance frequency and potential risks of the equipment. Therefore, developing a motor shaft dynamic seal technology that can overcome the above problems has become a technical problem that needs to be solved urgently.

[0008] Based on this, the present invention aims to provide a novel explosion-proof exhaust fan motor shaft dynamic sealing device to solve the following technical defects of traditional O-ring sealing:

[0009] Reduce temperature rise: By optimizing the sealing design, the heat generated by the high-speed friction between the sealing ring and the motor shaft can be effectively reduced, ensuring that the surface temperature of the motor shaft meets the requirements of GB3836 standard and enhancing the safety of the equipment.

[0010] Improve wear resistance and service life: Improve the wear resistance and anti-aging performance of the sealing material, so that it can still maintain a good sealing effect after long-term use, extend the service life of the seal and reduce maintenance requirements.

[0011] Prevent unexpected impacts: Optimize the sealing structure to avoid the adsorption of particles such as fly ash on the sealing surface, ensure the cleanliness of the sealing surface and the stability of the sealing performance.

[0012] By solving the above problems, the present invention will significantly improve the safety performance of the Ma-class explosion-proof exhaust ventilator with internal positive pressure protection, provide reliable protection for the safe operation of the ventilation system in coal mines, reduce the equipment operation cost, and promote the widespread application of related technologies in high-risk environments. This not only has important technical innovation significance, but also has important practical value for the safety of miners' lives and improving production efficiency. Summary of the invention

[0013] In view of this, an object of the present invention is to provide an explosion-proof extraction fan motor shaft dynamic sealing device to solve the shortcomings of traditional O-ring sealing in terms of high temperature, wear and unstable adsorption.

[0014] In order to achieve the above object, the present invention provides the following technical solutions:

[0015] An explosion-proof extraction fan motor shaft dynamic sealing device, comprising:

[0016] The main lip can be sleeved on the motor shaft;

[0017] An oil-accumulating lip and an oil cavity skeleton, the oil-accumulating lip can be sleeved on the motor shaft and is arranged at one end far from the center of the motor shaft, and both ends of the oil cavity skeleton are respectively connected to one end of the main lip and the oil-accumulating lip far from the motor shaft to form an oil-accumulating cavity between the main lip, the oil cavity skeleton, the oil-accumulating lip and the motor shaft;

[0018] Lubricating grease, filled in the oil-accumulating cavity;

[0019] A secondary lip, which can be sleeved on the motor shaft and is arranged on the side of the oil-accumulating lip far from the oil-accumulating cavity and faces one end far from the center of the motor shaft to block impurities outside.

[0020] Further, the main lip is made of wear-resistant fluororubber.

[0021] Further, a retaining spring is sleeved on the main lip for automatic compensation after it wears.

[0022] Further, a bracket is embedded in the secondary lip, the bracket is in an inverted U shape and clamps the main lip, the oil cavity skeleton and the oil-accumulating lip inside.

[0023] The beneficial effects of the present invention are as follows:

[0024] The present invention proposes an explosion-proof extraction type ventilator motor shaft dynamic sealing device, and its core innovation adopts a double-sealing design combining a main lip and a secondary lip. This structure significantly enhances the sealing performance of the device and is particularly suitable for ventilation equipment in high-risk environments such as coal mines. The main lip is made of wear-resistant rubber material and undertakes the main sealing task to effectively isolate the positive-pressure gas inside the motor housing and the external explosive environment; the secondary lip serves as an auxiliary barrier to specifically shield external dust, particles and other additional dangers to protect the cleanliness and safety of the main sealing area. This double protection design not only improves the reliability of the seal, but also greatly reduces the risk caused by seal damage, providing a practical guarantee for the safe operation of the equipment.

[0025] The present device cleverly sets an oil-accumulating cavity between the main lip and the oil-accumulating lip and fills it with lubricating grease to construct a unique self-lubricating system. This innovative design makes the lubricating grease evenly distributed on the sealing contact surface when the motor shaft rotates, effectively reducing the friction between the main lip and the motor shaft, reducing the temperature rise during operation, and solving the deficiencies of traditional O-ring seals in terms of high temperature, wear and unstable adsorption; in addition, the lubricating grease can continuously provide lubrication support when the main lip is fatigued, further extending the service life of the seal. This self-lubricating mechanism not only reflects the technical advancement, but also ensures the stability and durability of the device in high-temperature and high-risk environments, showing its excellent practical value.

[0026] To further enhance the durability of the sealing performance, a hoop spring is installed on the main lip in the present invention. This design can automatically compensate for the wear amount after the main lip wears, always maintain a tight fit with the motor shaft, and ensure that the sealing effect does not decay due to long-term use. At the same time, the device adopts an inverted U-shaped skeleton design, which provides a strong support for the overall structure and ensures the stability and durability of each component. The combination of this automatic compensation and structural optimization not only reflects the high-efficiency innovation of the technical solution but also significantly improves the wear-resistant mechanism and reliability of the sealing device. In summary, through double sealing, self-lubricating system and automatic compensation, the present invention provides strong technical support for the safe operation of the explosion-proof extraction ventilator, and has extremely high practicality and promotion value.

[0027] Other advantages, objectives and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be described in detail preferably with reference to the accompanying drawings, where:

[0029] Figure 1 It is a schematic structural diagram of a dynamic sealing device for the motor shaft of an explosion-proof extraction ventilator in the embodiment.

[0030] Reference numerals: motor shaft 1, auxiliary lip 2, oil-accumulating lip 3, bracket 4, grease 5, end cover 6, oil chamber skeleton 7, hoop spring 8, main lip 9. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] The following specific examples illustrate the embodiments of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the drawings provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0032] Among them, the drawings are only for illustrative purposes, showing only schematic diagrams, not physical diagrams, and should not be construed as a limitation to the present invention; in order to better illustrate the embodiments of the present invention, some components in the drawings will be omitted, enlarged or reduced, and do not represent the dimensions of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0033] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc. indicating the orientation or positional relationship, it is based on the orientation or positional relationship shown in the accompanying drawings. This is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the accompanying drawings are only for illustrative purposes and cannot be construed as a limitation of the present invention. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0034] Please refer to Figure 1 , which is an explosion-proof extraction type ventilator motor shaft dynamic sealing device (hereinafter referred to as the sealing device), used to ensure the safe operation of the ventilator in an explosive gas environment such as a coal mine. This sealing device is installed between the motor shaft 1 and the end cover 6, and mainly consists of components such as the main lip 9, oil accumulating lip 3, oil cavity skeleton 7, lubricating grease 5, auxiliary lip 2, bracket 4, and hoop spring 8 to achieve the rotary dynamic sealing of the motor shaft 1.

[0035] The core components of this sealing device include the main lip 9, oil accumulating lip 3, and auxiliary lip 2, all of which are sleeved on the motor shaft 1. The main lip 9 is located at the device close to the center of the motor shaft 1 and provides the main sealing function. The oil accumulating lip 3 is arranged at one end far from the center of the motor shaft 1 and is connected to the main lip 9 through the oil cavity skeleton 7. The two ends of the oil cavity skeleton 7 are respectively connected to the main lip 9 and the oil accumulating lip 3, thus forming a closed oil accumulating cavity between the main lip 9, oil cavity bracket 7, oil accumulating lip 3, and motor shaft 1. The lubricating grease 5 is filled inside this oil accumulating cavity for lubrication and temperature reduction. The auxiliary lip 2 is sleeved on the motor shaft 1 and is located on the side of the oil accumulating lip 3 far from the oil accumulating cavity, used to block external coal ash and other impurities from entering the sealing area.

[0036] In addition, the sealing device also includes a bracket 4 and a hoop spring 8. The bracket 4 is arranged in the auxiliary lip 2, presenting an inverted U-shaped structure, and clamping and supporting the main lip 9, oil cavity skeleton 7, and auxiliary lip 3 to provide overall structural support. The hoop spring 8 is sleeved on the main lip 9 and is used for automatic compensation after the main lip 9 is worn to ensure the durability of the sealing performance.

[0037] Specifically, the materials, shapes, and functions of each component are as follows:

[0038] Main lip 9: Made of wear-resistant rubber, it has good wear resistance and high-temperature resistance. Its shape is designed to fit tightly with the motor shaft 1 to ensure reliable sealing when the motor shaft 1 rotates at high speed. The hoop spring 8 sleeved on the main lip 9 can automatically adjust the fitting pressure between the main lip 9 and the motor shaft 1 when the main lip 9 is worn due to long-term use, compensate for the wear amount, and maintain the sealing effect.

[0039] The grease reservoir lip 3: It is sleeved on the motor shaft 1 and located in the middle of the sealing device. Together with the oil chamber skeleton 7 and the main lip 9, it forms the boundary of the grease reservoir chamber, preventing the leakage of the grease 5. A gap is designed between the grease reservoir lip 3 and the main lip 9, allowing a small amount of grease 5 to flow from the grease reservoir chamber to the connection between the main lip 9 and the motor shaft 1, playing a role in lubrication and heat conduction.

[0040] The oil chamber skeleton 7: Connects the main lip 9 and the grease reservoir chamber 3, constituting the side wall of the grease reservoir chamber. It is usually made of metal or high-strength plastic to provide sufficient rigidity and structure. Its design ensures that the grease reservoir chamber can accommodate and support the grease 5.

[0041] The grease 5: Fills the grease reservoir chamber. A high-temperature and wear-resistant grease is selected, which can reduce the friction between the main lip 9 and the motor shaft 1, lower the temperature rise, and extend the service life of the main lip 9.

[0042] The auxiliary lip 2: It is the key to positioning the sealing device. It is arranged at the tail far from the center of the motor shaft 1, and its main function is to block external impurities such as coal ash.

[0043] The bracket 4: It is embedded and installed in the auxiliary lip 2, in an inverted U shape, usually made of metal material. It clamps and supports the main lip 9, the oil chamber skeleton 7 and the grease reservoir lip 3, providing the overall rigidity and installation stability of the sealing device.

[0044] The retaining spring 8: It is sleeved on the main lip 9 and is an elastic element. It can automatically compensate after the main lip 9 wears, ensuring the fitting pressure between the main lip 9 and the motor shaft 1, thus maintaining the sealing performance.

[0045] The installation steps of this sealing device are as follows:

[0046] Pre-fill the grease 5 into the grease reservoir chamber formed by the main lip 9, the grease reservoir lip 3 and the oil chamber skeleton 7 to ensure that the grease reservoir chamber is filled with the grease 5.

[0047] Set the entire sealing device on the motor shaft 1 and embed it in the preset position between the motor shaft 1 and the end cover 6. During installation, the auxiliary lip 2 should face the outside.

[0048] The working principle of this sealing device is as follows:

[0049] After the sealing device is installed, when the motor shaft 1 rotates at a high speed, the main lip 9 is in close contact with the motor shaft 1, forming the first sealing barrier to prevent gas leakage. A lubricating film is formed between the grease 5 in the grease reservoir chamber and the motor shaft 1, and it cools the friction between the main lip 9 and the motor shaft 1, extending the service life of the main lip 9.

[0050] When the main lip 9 is fatigued due to long-term use, the hoop spring 8 automatically compensates for the wear amount, ensuring good contact between the main lip 9 and the motor shaft 1 and maintaining the sealing performance. The secondary lip 2 serves as a second line of defense, closing the outside to protect the sealing effects of the main lip 9 and the oil accumulating lip 3.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the present technical solution, and they should all be covered within the scope of the claims of the present invention.

Claims

1. An explosion-proof extraction fan motor shaft dynamic sealing device, characterized in that: include: The main lip can be sleeved on the motor shaft; An oil accumulation lip and an oil chamber frame, wherein the oil accumulation lip can be sleeved on the motor shaft and arranged at an end away from the center of the motor shaft, and the two ends of the oil chamber frame are respectively connected to the main lip and the end of the oil accumulation lip away from the motor shaft, so as to form an oil accumulation chamber between the main lip, the oil chamber frame, the oil accumulation lip and the motor shaft; Lubricating grease, filled in the oil accumulation chamber; The auxiliary lip can be sleeved on the motor shaft and arranged on a side of the oil accumulation lip away from the oil accumulation chamber and toward an end away from the center of the motor shaft to block impurities out.

2. The explosion-proof extraction fan motor shaft dynamic sealing device according to claim 1 is characterized in that: The main lip is made of wear-resistant fluororubber.

3. The explosion-proof extraction fan motor shaft dynamic sealing device according to claim 1 is characterized in that: A hoop spring is sleeved on the main lip to automatically compensate after the main lip is worn.

4. The explosion-proof extraction fan motor shaft dynamic sealing device according to claim 1 is characterized in that: A bracket is embedded in the auxiliary lip, the bracket is in an inverted U shape, and clamps the main lip, the oil chamber skeleton and the oil accumulation lip therein.

5. The explosion-proof extraction fan motor shaft dynamic sealing device according to claim 1 is characterized in that: The sealing device is installed between the motor shaft and the end cover.

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