High-precision leak-free grading machine based on bidirectional air-tight structure
By employing a bidirectional gas-sealing structure and carbon ring adaptive adjustment technology on the classifier, the problem of traditional sealing structures being prone to failure at high speeds has been solved, achieving efficient gas isolation and carbon ring protection, and improving the safety and efficiency of metal powder manufacturing.
Patent Information
- Application Number
- CN202511280109.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-09
- Publication Date
- 2025-11-04
- Estimated Expiration
- 2045-09-09
AI Technical Summary
In existing technologies, traditional sealing structures are prone to failure at high speeds, failing to effectively prevent external air infiltration and internal inert gas leakage. This limits the efficiency and safety of metal powder manufacturing, and the carbon rings are easily damaged at high temperatures, affecting the sealing effect.
A high-precision, leak-free classifier based on a bidirectional gas-tight structure is adopted. By constructing a precision annular gas chamber at the end of the rotating shaft, combined with carbon ring sealing technology and a shape memory metal adjustment plate, and utilizing a pressurized gas and temperature sensing system, the carbon ring can be adaptively adjusted and its stability monitored, thus avoiding carbon ring damage and leakage.
It effectively prevents external air from seeping in, prevents internal gas leakage, reduces the risk of carbon ring damage, improves equipment utilization and product quality, and ensures safe production.
Smart Images
Figure CN120755083B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of ultrafine powder sorting equipment technology, and in particular to a high-precision leak-free classifier based on a bidirectional air-tight structure. Background Technology
[0002] In the graded purification process of metal powders (such as titanium alloys, high-temperature alloys, and additive manufacturing powders), maintaining an ultra-low oxygen environment within the process chamber is a core requirement for ensuring safe production and product quality. The infiltration of even trace amounts of oxygen can trigger metal dust explosions or cause powder surface oxidation and failure. Currently, the industry commonly uses multi-layer skeleton oil seals (rubber or PTFE) to achieve dynamic sealing at the rotating shaft end. This technology has systemic defects: when the shaft speed exceeds 3000 rpm, the temperature rise at the oil seal friction interface can reach over 120°C, causing the sealing material to soften and deform, leading to rapid sealing failure; the debris generated by the aging of rubber materials at high temperatures can directly contaminate high-value powder materials; the sealing components require replacement every 500-800 hours of operation, significantly reducing equipment utilization; most critically, traditional structures cannot simultaneously and effectively prevent the infiltration of external air (causing excessive oxygen content) and the leakage of internal inert protective gases (such as nitrogen and argon) (leading to a surge in operating costs). These technical bottlenecks severely restrict the efficiency and safety of high-end metal powder manufacturing.
[0003] The bidirectional gas-tight technology solves the above problems by innovating the sealing principle. This technology constructs a precision annular gas chamber structure at the end of the classifier's rotating shaft and combines it with carbon ring sealing technology to continuously introduce compressed air at a pressure 0.1-0.3 MPa higher than the process chamber. By precisely controlling the gas flow rate and pressure, a stable centripetal high-speed airflow barrier is formed in the shaft clearance. This airflow barrier achieves a bidirectional sealing function: effectively preventing ambient air from permeating into the process chamber internally, and preventing the inert protective gas within the process chamber from leaking outwards.
[0004] However, in actual applications, as the processing progresses, the temperature inside the air cavity rises due to friction, causing the carbon ring to expand due to heat. The inner diameter and elastic modulus of the carbon ring both increase. During the process of the carbon ring swinging or displacing, the carbon ring is more likely to collide with the side wall of the air cavity, and the collision is more likely to cause damage to the carbon ring, ultimately leading to sealing failure. Summary of the Invention
[0005] The purpose of this invention is to provide a high-precision, leak-free classifier based on a bidirectional gas-tight structure to solve the above-mentioned problems.
[0006] This invention is achieved through the following technical solution:
[0007] A high-precision, leak-free classifier based on a bidirectional airtight structure includes a housing. The housing contains a bearing cavity and a classification cavity. A classification rotor is housed within the classification cavity. The classification rotor is coaxially fixedly connected to a main shaft. The main shaft is driven by a drive component. The classification rotor is used to classify particles, and the drive component drives the main shaft to rotate. A seal is provided on the outer wall of the main shaft to prevent communication between the classification cavity and the bearing cavity. The seal includes a housing fitted onto the main shaft, and the housing contains several sealing chambers. Several shape-memory metal adjustment plates are provided on the side walls of the sealing chambers. The adjustment plates are used to change the... The sealed chamber is described in terms of its shape. Each sealed chamber contains several carbon rings, and the outer walls of each carbon ring have several spherical protrusions. Each carbon ring includes a fitting section and a redundant section. The carbon rings are fitted to the sidewall of the spindle via the fitting section. The projection of the fitting section of the carbon rings installed in the same sealed chamber onto the horizontal plane is equal in length to the circumference of the spindle. Both the redundant section and the fitting section are provided with elastic elements, which are fixedly connected to the sidewall of the sealed chamber. The sidewall of the sealed chamber is provided with several nozzles for pumping pressurized gas into the sealed chamber. The sealed chamber is connected to a chip collection groove for collecting graphite debris generated by the carbon rings.
[0008] Compared with the prior art, the present invention has the following advantages and beneficial effects:
[0009] This design, through the adjustment plate, allows the volume of the sealed chamber to change with temperature. Compared to existing technologies where the sealed chamber maintains a constant position for the carbon ring, this design, under normal temperatures, allows the sealed chamber sidewall to clamp the carbon ring when its inner wall is in contact with the spindle. This prevents the carbon ring from swinging, colliding with the spindle, and causing spindle damage. It also avoids the carbon ring breaking under high temperatures where the sealed chamber's inner wall still restricts its position. Furthermore, the design incorporates a protrusion that allows the inner wall of the carbon ring to slightly detach from the spindle after high-temperature expansion. This causes the carbon ring to oscillate under the kinetic energy transferred from the outside, guiding surrounding graphite debris and reducing the probability of graphite debris adhering to the carbon ring or the sealed chamber sidewall, thus minimizing the impact of graphite debris on the subsequent operation of the carbon ring.
[0010] Furthermore, it also includes a control system, which is used to collect temperature field information of the outer shell, obtain the distribution of the carbon ring inside the sealed chamber based on the temperature field information, and drive the movement of the carbon ring by controlling the opening and closing of each of the nozzles according to the distribution of the carbon ring.
[0011] Beneficial effects: This solution collects temperature field information from the outer shell and uses this information to determine the distribution of carbon rings within the sealed chamber. Based on changes in the carbon ring distribution, it determines whether the carbon rings are vibrating or displacing. Compared to existing technologies, this solution does not negatively impact the operation of the seals during data collection and can continuously monitor the stability of the carbon rings, effectively preventing seal failure due to vibration, displacement, or excessively high temperatures.
[0012] Furthermore, the elastic element is a rectangular cross-section spring, and all springs are made of metal.
[0013] Beneficial effects: This solution uses a rectangular cross-section spring as the elastic element. Compared with other types of carbon rings with the same outer diameter, the rectangular cross-section carbon ring can withstand a larger load, effectively avoiding the failure of the elastic element during the operation of the carbon ring, which would lead to the failure of the carbon ring seal. At the same time, compared with disc springs, the spring used in this solution can deform axially on the spindle, so that the carbon ring can still dampen it during axial movement or oscillation.
[0014] At the same time, a metal spring is used, taking advantage of the good thermal conductivity of metal, to transfer the heat generated by the carbon ring to the outer shell, thereby cooling the carbon ring and preventing it from overheating and causing failure.
[0015] Furthermore, the inner wall of the carbon ring is provided with a bushing, and the bushing is interference-fitted with the main shaft.
[0016] Beneficial effects: Compared to solutions without bushings, the bushing design can prevent excessive friction between the carbon ring and the spindle, which could lead to spindle wear and leakage of the seal. It can also compensate for some of the deformation caused by the thermal expansion of the spindle, preventing the spindle from jamming with the seal after thermal expansion.
[0017] Furthermore, a cooling assembly is provided inside the housing. The cooling assembly is used to adjust the temperature of the gas at the input end of the nozzle. The control system is also used to determine the temperature distribution in each of the sealed chambers based on the temperature field information, and to control the opening and closing of the nozzles and the operation of the cooling assembly based on the temperature distribution in the sealed chambers.
[0018] Beneficial effects: Through the design of the cooling component, this solution can adjust the temperature of the gas output from the nozzle in real time compared with the existing technology, so as to avoid the carbon ring from breaking due to sudden heating and cooling. At the same time, it can also cool down the carbon ring in time, further preventing the carbon ring from failing due to excessive temperature.
[0019] Furthermore, the projections of the mating segments of the carbon rings installed in the same sealed chamber on the same plane do not overlap.
[0020] Beneficial effects: Compared to existing technologies, this solution avoids the possibility of complete contact between the mating sections of the carbon rings when they vibrate or shift, which could damage the mating sections and lead to carbon ring failure. This effectively improves the stability of the seal.
[0021] Furthermore, the sidewalls of the carbon ring installed in the same sealed chamber are not parallel to the spray angle of the nozzle.
[0022] Beneficial effects: Compared with the design of using a nozzle with the spray angle parallel to the sidewall of the carbon ring, this solution can avoid the situation where the gas sprayed by the nozzle can only drive the carbon ring radially but cannot drive the carbon ring axially, thus making it impossible to adjust the position and angle of the carbon ring. At the same time, it can also avoid the excessive radial movement of the carbon ring during the operation of the nozzle, which would cause the carbon ring to press against or detach from the main shaft, thereby affecting the working effect of the carbon ring.
[0023] Furthermore, a gasket is provided between each carbon ring and the adjacent carbon ring, and the gaskets are all made of elastic material.
[0024] Beneficial effects: The design of the liner in this solution buffers collisions between carbon rings and adjacent carbon rings, further preventing the carbon rings from completely failing during collisions. At the same time, the liner design can also dampen the carbon rings through its own phase change, further absorbing the kinetic energy of the carbon rings.
[0025] Furthermore, the control system is also used to collect distance information between the inner wall of the carbon ring and the main shaft, and to determine whether the carbon ring vibrates based on the distance information, and to control the nozzle to work when the carbon ring vibrates.
[0026] Beneficial effects: This solution determines whether the carbon ring is in a suitable position by obtaining the distance information between the carbon ring and the outer wall of the spindle, and supplements the carbon ring position obtained by the temperature field based on the distance information, thereby improving the accuracy of the obtained carbon ring position and avoiding system misjudgment or omission.
[0027] Furthermore, the outer casing has several windows. The control system emits ultrasonic waves into the outer casing and receives ultrasonic waves reflected by the outer casing. It also obtains the reflection time and amplitude of the emitted ultrasonic waves and acquires distance information based on the reflection time and amplitude. When the amplitude is less than the set minimum amplitude and the reflection time is less than the set time, the distance information is zero, and the carbon ring is stable, so the working state of the nozzle is not adjusted. When the reflection time is greater than the set time, the distance information is greater than zero, the carbon ring moves, and the nozzle at the corresponding position is controlled to adjust the position of the carbon ring. When the amplitude is greater than the set minimum amplitude, the carbon ring vibrates or the carbon ring breaks into pieces. At this time, the nozzle is controlled to increase its working power.
[0028] Beneficial effects: In this solution, ultrasonic waves are emitted into the outer shell, and the reflection time and amplitude of the reflected ultrasonic waves are used to determine whether the carbon ring has shifted and whether there are graphite debris in the sealed chamber. When graphite debris appears or the carbon ring shifts, the graphite debris is promptly expelled and the carbon ring is adjusted to reduce the time that graphite debris stays in the sealed chamber and reduce the damage to the carbon ring caused by graphite debris. Attached Figure Description
[0029] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:
[0030] Figure 1 This is a schematic diagram of the structure of the present invention;
[0031] Figure 2 This is a cross-sectional view of the sealing element in this invention;
[0032] Figure 3 for Figure 2 Enlarged view of point A in the middle;
[0033] Figure 4 This is a schematic diagram of the carbon ring portion in this invention;
[0034] Figure 5 This is a top view of the carbon ring portion in this invention.
[0035] The reference numerals in the attached figures represent: 1. Housing; 11. Grading chamber; 12. Bearing chamber; 2. Seal; 21. Outer shell; 22. Adjusting plate; 23. Spring; 24. Carbon ring; 241. Redundant section; 242. Fitting section; 25. Gasket; 26. Protrusion; 3. Motor; 4. Main shaft; 41. Bushing; 5. Grading rotor. Detailed Implementation
[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments and accompanying drawings. The illustrative embodiments and descriptions of this invention are for illustrative purposes only and are not intended to limit the invention. It should be noted that this invention is already in the actual research and development stage.
[0037] Example 1
[0038] like Figures 1 to 5As shown, this embodiment includes a housing 1, within which a bearing cavity 12 and a grading cavity 11 are formed. A grading rotor 5 is housed within the grading cavity 11. A main shaft 4 is coaxially and fixedly connected to the grading rotor 5. A driving component, specifically a motor 3, is driven by the main shaft 4. The motor 3 is bolted to the outer top wall of the housing 1 and coaxially and fixedly connected to the main shaft 4 via a coupling. The grading rotor 5 is used to grade particles, and the driving component drives the main shaft 4 to rotate. A sealing element 2 is provided on the outer wall of the main shaft 4 to prevent the grading cavity 11 from contacting the bearing cavity 12 with the main shaft 4. The bearing cavity 12 is connected. The seal 2 includes a housing 21, which is sleeved on the spindle 4. The housing 21 has several sealing chambers inside. Several shape-memory metal adjusting plates 22 are welded and fixed to the side walls of the sealing chambers. Initially, among the adjusting plates 22 located in the same sealing chamber, one adjusting plate 22 is straight and bends after reaching its threshold temperature, while the remaining adjusting plates 22 are arc-shaped and become straight after reaching their threshold temperature. The adjusting plates 22 are used to change the shape of the sealing chamber. Several carbon rings 24 are provided inside each sealing chamber. In this embodiment, all carbon rings 24... The carbon rings 24 are elliptical in shape, and each outer wall of the carbon ring 24 has several spherical protrusions 26 integrally formed. Gaskets 25 are provided between adjacent carbon rings 24 within the same sealed chamber. All gaskets 25 are made of elastic material. A bushing 41 is provided on the inner wall of each carbon ring 24, and the bushing 41 is interference-fitted with the main shaft 4. Each carbon ring 24 includes a fitting section 242 and a redundant section 241. All carbon rings 24 are fitted to the side wall of the main shaft 4 through the fitting section 242. The projection of the fitting section 242 of the carbon rings 24 installed in the same sealed chamber onto the horizontal plane is proportional to the circumference of the main shaft 4. The mating sections 242 of the carbon rings 24, which are of equal length and installed in the same sealed chamber, do not overlap on the same plane. Both the redundant section 241 and the mating section 242 are provided with elastic elements, which are springs 23. The springs 23 are all made of metal. In this embodiment, the springs 23 are made of copper. The elastic elements are welded and fixed to the side wall of the sealed chamber. The side wall of the sealed chamber is provided with several nozzles. The nozzles are used to pump pressurized gas into the sealed chamber. The sealed chamber is connected to a chip collection groove (not shown in the figure). The chip collection groove is used to collect graphite debris generated by the carbon rings 24.
[0039] The carbon ring 24 installed on the same side wall of the sealed chamber is not parallel to the spray angle of the nozzle.
[0040] The specific implementation method is as follows: When using this device, connect the input end and output end of the housing 1 to the upstream and downstream production lines of the classifier respectively, and connect the storage tank containing a suitable pressurized inert gas to the nozzle. Then start the classifier. During the operation of the classifier, the motor 3 drives the classifying rotor 5 to rotate through the main shaft 4 to classify the material passing through the housing 1.
[0041] During this process, the seal 2 seals the connection between the main shaft 4 and the side wall of the bearing cavity 12, preventing external contaminants from entering the grading chamber 11 through the gap between the side wall of the main shaft 4 and the side wall of the bearing cavity 12, causing material contamination and leakage, and affecting the final output of the material.
[0042] As the main shaft 4 rotates, the graphite crystal layer on the inner wall of the carbon ring 24 is displaced with the movement of the main shaft 4, thereby achieving self-lubrication. While maintaining the connection between the closed graded cavity 11 and the bearing cavity 12, the influence on the movement of the main shaft 4 is greatly reduced. At the same time, since the carbon ring 24 has a good thermal conductivity, it can quickly dissipate the heat generated by friction with the main shaft 4 to avoid affecting the main shaft 4.
[0043] Since the movement of materials within this production line primarily relies on the high-pressure inert gas flowing within the line, when materials move into the classification chamber 11, the high-pressure inert gas causes a pressure increase within the chamber, leading to a greater pressure difference between the classification chamber 11 and the sealed chamber. This increases the risk of leakage. To mitigate this, a nozzle can be opened to pump pressurized inert gas into the sealed chamber, increasing the pressure and preventing the high-pressure gas from the classification chamber 11 from entering and causing damage to the carbon ring 24, as well as material contamination or leakage. Furthermore, during this process, the friction between the carbon ring 24 and the main shaft 4 generates heat, and the high-pressure gas is pumped in. Temperature and pressure fluctuations occur within the sealed chamber. Due to deformation of the carbon ring 24 or turbulent excitation, the circular carbon ring 24 used in traditional solutions may oscillate or vibrate, potentially colliding with the sealed chamber or the main shaft 4, causing damage to the carbon ring 24. This could lead to sealing failure of the subsequent seal 2, ultimately affecting the quality of the finished product.
[0044] When the temperature inside the sealed chamber is at room temperature, below the threshold temperature of the shape memory metal, the regulating plate 22 does not undergo significant deformation. At this time, the side wall of the sealed chamber restricts the axial movement of the carbon ring 24, allowing it to move only radially. This is the most stable temperature for the carbon ring 24, and the inner wall of the carbon ring 24 is in contact with the outer wall of the main shaft 4, making it less prone to violent oscillation. Simultaneously, the amplitude of the carbon ring 24 is small, resulting in low kinetic energy. Therefore, even if the carbon ring 24 experiences minor vibrations and collides with the side wall of the sealed chamber, the damage is minimal. Thus, by restricting the movement of the carbon ring 24 through the side wall of the sealed chamber, the potential for repeated collisions between the carbon ring 24 and the side wall due to continuous vibration is reduced, thereby lowering... The probability of damage to the low-carbon ring 24 is reduced. When the carbon ring 24 moves radially, its kinetic energy is transferred to the elastic element, which enables the elastic element to dampen the carbon ring 24. At the same time, as the carbon ring 24 moves radially, it rubs against the adjacent pad 25. Since the pad 25 is fixed to the adjacent carbon ring 24 on only one side, there is a certain gap between the other side of the pad 25 and the adjacent carbon ring 24. When the carbon ring 24 moves radially, it rubs against the adjacent pad 25. During the friction, the layered crystals on the sidewall surface of the carbon ring 24 are displaced, forming a dynamic graphite transfer film. That is, the self-lubricating properties of the carbon ring 24 are used to achieve lubrication between the carbon ring 24 and the pad 25, reducing the wear of the carbon ring 24 during radial movement.
[0045] Simultaneously, as the temperature inside the sealed chamber rises, upon reaching the threshold temperature of the shape memory metal, the adjusting plate 22 deforms. With this deformation, the internal volume of the sealed cavity increases. Simultaneously, as the temperature rises, the carbon ring 24 expands due to heat. Due to the design of the elastic element, as the carbon ring 24 deforms, the elastic element continuously pushes the contact section of the carbon ring 24 towards the main shaft 4, preventing potential sealing failure caused by the contact section of the carbon ring 24 detaching from the main shaft 4 for an extended period. Because the carbon ring 24 is elliptical, its inner wall cannot completely contact the side wall of the main shaft 4. As the internal area of the sealed chamber increases, the carbon ring 24 is more prone to movement. However, due to the design of the redundant section 241, the probability of the inner wall of the carbon ring 24 colliding with the side wall of the main shaft 4 decreases during movement. In the above process, the kinetic energy transfer on the carbon ring 24... The elastic element converts kinetic energy into its own elastic potential energy, damping the carbon ring 24 and preventing it from moving violently, which would affect the overall stability of the seal 2. Simultaneously, as the carbon ring 24 vibrates, the spherical protrusion 26, which contacts the side wall of the sealing chamber, rolls. At this time, the carbon ring 24 tilts, and due to its weight, its center of gravity shifts from the vertical position. Gravity generates a restoring torque, causing the carbon ring 24 to oscillate back and forth. During this process, the elastic element continuously converts the kinetic energy transmitted by the carbon ring 24 into elastic potential energy and heat energy, absorbing the kinetic energy of the carbon ring 24. Simultaneously, the oscillation of the carbon ring 24 guides the powder and debris generated by the carbon ring 24 within the sealing chamber. During this process, the nozzle continuously pumps pressurized inert gas into the sealing chamber, which carries the powder and debris into the chip collection groove.
[0046] This solution can adjust the state of the carbon ring 24 according to the temperature changes inside the sealed chamber, thereby reducing damage to the carbon ring 24 and its impact on subsequent sealing performance. Compared to existing technologies that only use pressurized gas to drive out powder and debris inside the sealed chamber, this solution uses the protrusion 26 to enable the carbon ring 24 to oscillate back and forth during movement. This oscillation of the carbon ring 24 loosens the powder and debris, improving the cleaning efficiency of the pressurized gas. At the same time, the oscillation of the carbon ring 24 also prevents powder and debris from getting stuck between carbon rings 24 or between the carbon ring 24 and the side wall of the sealed chamber. This would prevent uneven stress on the carbon ring 24 during subsequent operation, which could lead to high-frequency vibration or thermal runaway, causing the seal 2 to fail and affecting the processing of metal powder. Compared to existing technologies that pump constant-pressure gas into the seal 2, this solution reduces the risk of carbon ring 24 instability due to temperature changes causing pressure fluctuations inside the seal chamber, or carbon ring 24 wear aggravated or separating from the main shaft 4 due to pressure differences between the inside and outside of the seal chamber during production. Furthermore, this solution, through the design of the elliptical carbon ring 24 and the use of contact sections 242 located at different positions on the main shaft 4, disrupts the smooth flow of gas along the main shaft 4 axis, gradually buffering the kinetic energy of the leaking gas. During this process, the gas kinetic energy is converted into heat energy, and the gas pressure gradually decreases, reducing the pressure difference between the leaking gas and the other end of the seal 2. This makes it more difficult for leaked gas to overcome resistance and pass through the seal 2, thereby reducing the probability of gas penetration. In the above process, as the carbon ring 24 and the sealing chamber increase, the probability of gas penetration gradually decreases. In the end, only a very small amount of leaked gas can pass through the seal 2 to reach the bearing cavity 12, achieving effective sealing. That is, by increasing the leakage path, the leakage of particles inside the stage chamber 11 is reduced and the gas in the bearing cavity 12 is prevented from entering the stage chamber 11. Compared with the prior art, after the carbon ring 24 is heated and expanded, the pressurized gas ejected by the elastic element and the nozzle can keep the contact section 242 of the carbon ring 24 in contact with the main shaft 4, which greatly reduces the sealing failure that may be caused by the deformation of the carbon ring 24.
[0047] Furthermore, due to the properties of graphite, graphite powder easily rubs against each other under the action of pressurized gas, generating static electricity. The charged graphite powder is then attracted to the elastic element or carbon ring 24. Due to the lubricating properties of graphite, after collisions with the carbon ring 24 or spindle 4, the graphite powder may also adhere to the carbon ring 24, causing wear as operation continues and potentially leading to seal failure. This solution, by causing the carbon ring 24 to oscillate, utilizes inertia to enhance the cleaning effect of the pressurized air, making it easier for graphite particles to detach from the carbon ring 24 and the elastic element, thereby reducing the impact of graphite powder on the operation of the carbon ring 24.
[0048] Meanwhile, by designing the carbon ring 24's mating section 242 within the same sealed chamber to not overlap, as the device operates, if the carbon ring 24 collides with an adjacent carbon ring 24 due to vibration, the mating section 242 of the carbon ring 24 in this design can only collide with the redundant section 241 of the adjacent carbon ring 24. Furthermore, since the carbon ring 24 is elliptical, the mating section 242 of the carbon ring 24 does not completely overlap with the redundant section 241 of the adjacent carbon ring 24, thereby reducing the area of damage to the mating section 242 during the collision and reducing the probability of the carbon ring 24 completely failing during the collision.
[0049] In this design, by arranging the nozzle at an angle to the side wall of the carbon ring 24, the pressurized gas ejected from the nozzle is prevented from acting on the carbon ring 24 radially. This prevents the pressurized gas from only driving the carbon ring 24 radially without being able to drive it axially, which would make it difficult to adjust the tilt angle of the carbon ring 24. It could also cause the carbon ring 24 to detach from the main shaft 4, affecting the normal operation of the carbon ring 24.
[0050] Example 2
[0051] The difference from the above embodiments is that it also includes a control system. In this solution, the control system includes a controller and several infrared thermal imagers. The controller is fixedly connected to the outer wall of the housing 1 by bolts, and the infrared imagers and nozzles are electrically connected to the controller. The infrared thermal imaging observation positions are all different. The infrared thermal imagers are used to collect thermal maps of the housing 21 from various angles. In other embodiments, fiber optic cables and sensors can also be used to obtain temperature information of the housing 21 from several angles. After the controller obtains the thermal maps of the housing 21 from various angles, it can obtain the temperature field information of the housing 21 by combining the data calibration formula of the thermal imager in the prior art. Based on the temperature field information, the distribution of the carbon ring 24 inside the sealed chamber is obtained. Based on the distribution of the carbon ring 24, the opening and closing of each of the nozzles is controlled to drive the movement of the carbon ring 24.
[0052] The housing 1 is also equipped with a cooling assembly. In this design, the nozzle is connected to the gas storage tank via a hose. The cooling assembly includes a cooling pipe, a water pump, and a water storage tank. One end of the cooling pipe is connected to the water pump, and the other end is connected to the water storage tank. The output end of the water pump is connected to the water storage tank. The cooling pipe is wound inside the gas storage tank. The cooling assembly is used to adjust the temperature of the gas at the input end of the nozzle. The water pump is electrically connected to the controller. The water pump is also used to determine the temperature distribution in each of the sealed chambers based on the temperature field information, and to control the opening and closing of the nozzle and the operation of the water pump based on the temperature distribution in the sealed chamber.
[0053] The specific implementation method is as follows: During the use of this solution, the infrared thermal imager continuously acquires thermal maps of the outer shell 21 from different angles and constructs the temperature field of the outer shell 21. Since the carbon rings 24 are distributed in different positions in the sealed chamber, that is, the mass distribution inside the outer shell 21 is uneven, the outer shell 21 will have different temperatures on the thermal maps of different positions. Based on the different temperatures of the outer shell 21 at different angles, the position of each carbon ring 24 inside the outer shell 21 can be deduced, that is, the position of the carbon rings 24 can be basically located by the temperature field. When the seal 2 remains stable, the carbon rings 24 remain relatively stationary. The temperature changes at various positions of the outer shell 21 within the temperature field are small and slow. However, when a carbon ring 24 is displaced due to changes in air pressure or temperature, the temperature at the corresponding position of the carbon ring 24 changes rapidly. That is, when the temperature change rate at the position corresponding to a certain carbon ring 24 exceeds a set value according to the temperature field, it is determined that the carbon ring 24 has been displaced. At this time, the controller controls the nozzle corresponding to the carbon ring 24 to increase or decrease the working power to adjust the position of the carbon ring 24 and assist the carbon ring 24 in resetting.
[0054] This solution acquires the mass distribution at different locations inside the outer shell 21 by collecting the temperature field of the outer shell 21, thereby inferring the position of the carbon ring 24. Based on the rate of change of the position of the carbon ring 24, it determines whether the carbon ring 24 has shifted due to changes in air pressure difference and temperature. If the carbon ring 24 shifts, it assists in resetting the carbon ring 24. Compared with the prior art, this solution can consume the kinetic energy of the carbon ring 24 by converting it into heat energy, thus avoiding damage caused by continuous oscillation of the carbon ring 24 and preventing instability inside the seal 2, which would affect the sealing effect of the seal 2.
[0055] Example 3
[0056] The difference from the above embodiments is that the control system is also used to collect distance information between the inner wall of the carbon ring 24 and the main shaft 4. In other embodiments, a laser detector or the like can be used to emit a laser into the gap between the main shaft 4 and the carbon ring 24. The distance information between the carbon ring 24 and the main shaft 4 is determined based on the laser blocking situation, and the carbon ring 24 is determined to vibrate based on the distance information. When the distance information is intermittently or continuously greater than zero, the carbon ring 24 vibrates, and the nozzle is controlled to work when the carbon ring 24 vibrates.
[0057] The outer casing 21 has several windows. The control system also includes an ultrasonic detector (not shown in the figure). In this embodiment, the ultrasonic detector used is an ultrasonic detector with a multi-probe array system. The number of probes is greater than or equal to the number of carbon rings 24 being monitored. The probes are evenly arranged along the axis of the main shaft 4. The ultrasonic detector is electrically connected to the controller. The ultrasonic detector is fixedly connected to the top wall of the bearing cavity 12 by bolts. The transmitter of the ultrasonic detector emits ultrasonic waves into the outer casing 21. At the same time, the receiver of the ultrasonic detector receives the ultrasonic waves reflected by the outer casing 21. The controller obtains the reflection time and amplitude of the emitted ultrasonic waves. Based on the reflection time and amplitude, it obtains distance information. When the amplitude is less than the set minimum amplitude and the reflection time is less than the set time, the distance information is zero, and the carbon ring 24 is stable. The working state of the nozzle is not adjusted. When the reflection time is greater than the set time, the distance information is greater than zero, and the carbon ring 24 moves. The nozzle at the corresponding position is controlled to work and adjust the position of the carbon ring 24. When the amplitude is greater than the set minimum amplitude, the carbon ring 24 vibrates or the carbon ring 24 breaks. At this time, the nozzle is controlled to increase its working power.
[0058] The specific implementation method is as follows: When using this solution, during the operation of the device, an ultrasonic detector continuously emits ultrasonic waves into the housing 21 through the viewing window along the side wall of the main shaft 4. When the carbon ring 24 is stable, the ultrasonic waves are reflected when they pass the side wall of the nearest bonding section 242. At this time, the time for the ultrasonic waves to return to the receiver after reflection is relatively short. When the carbon ring 24 vibrates and shifts, the ultrasonic waves can pass through the gap between the nearest bonding section 242 and the main shaft 4. At this time, the time for the ultrasonic waves to reach the receiver after reflection changes. When debris appears in the sealed chamber, the ultrasonic amplitude changes due to the obstruction of the debris. When the debris is small, the area of ultrasonic wave reflection by the debris is small, and the amplitude is large. When the debris is large (such as the carbon ring 24 breaking), the time for the ultrasonic waves to be obstructed during the movement of the debris in the sealed chamber is longer, which reduces the ultrasonic amplitude, but it is still greater than the case where the ultrasonic waves are completely emitted through the carbon ring 24.
[0059] Therefore, during the use of this device, the internal state of the sealed chamber can be judged based on the ultrasonic reflection time and amplitude. While determining whether debris exists inside the sealed chamber, it can also determine whether the carbon ring 24 is maintained in the appropriate position. If debris is present in the sealed chamber or the carbon ring 24 has shifted, the nozzle is used to expel the debris and simultaneously help the carbon ring 24 return to its proper position. Compared to existing technologies, this solution is convenient and fast. Through redundant data acquisition, the accuracy of the obtained carbon ring 24 position is improved, reducing the probability of misjudgment or missed judgment.
[0060] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A high-precision leak-free classifier based on a bidirectional air-tight structure, comprising a housing (1), wherein a bearing cavity (12) and a classification cavity (11) are provided in the housing (1), a classification rotor (5) is provided in the classification cavity (11), the classification rotor (5) is coaxially fixedly connected to a main shaft (4), the main shaft (4) is driven by a driving component, the classification rotor (5) is used to classify particles, the driving component is used to drive the main shaft (4) to rotate, and a sealing component (2) is provided on the outer wall of the main shaft (4), the sealing component (2) is used to prevent the classification cavity (11) from communicating with the bearing cavity (12), characterized in that: The sealing element (2) includes a housing (21), which is fitted onto the main shaft (4). The housing (21) contains several sealing chambers. Several shape-memory metal adjustment plates (22) are provided on the side walls of each sealing chamber. The adjustment plates (22) are used to change the shape of the sealing chamber. Several carbon rings (24) are provided inside each sealing chamber. Several spherical protrusions (26) are provided on the outer side walls of each carbon ring (24). Each carbon ring (24) includes a fitting section (242) and a redundant section (241). Each carbon ring (24) passes through the fitting section. (242) The projection of the fitting section (242) of the carbon ring (24) installed in the same sealed chamber on the horizontal plane is equal to the circumference of the main shaft (4). The redundant section (241) and the fitting section (242) are both provided with elastic elements. The elastic elements are fixedly connected to the side wall of the sealed chamber. The side wall of the sealed chamber is provided with several nozzles. The nozzles are used to pump pressurized gas into the sealed chamber. The sealed chamber is connected to a chip collection groove. The chip collection groove is used to collect graphite chips generated by the carbon ring (24).
2. The high-precision leak-free classifier based on a bidirectional gas-tight structure according to claim 1, characterized in that: It also includes a control system, which is used to collect temperature field information of the outer shell (21), and obtain the distribution of the carbon ring (24) inside the sealed chamber according to the temperature field information, and drive the movement of the carbon ring (24) by controlling the opening and closing of each of the nozzles according to the distribution of the carbon ring (24).
3. A high-precision, leak-free classifier based on a bidirectional gas-tight structure according to claim 1, characterized in that: The elastic element is a rectangular cross-section spring (23), and the spring (23) is made of metal.
4. A high-precision, leak-free classifier based on a bidirectional gas-tight structure according to claim 1, characterized in that: The inner wall of the carbon ring (24) is provided with a bushing (41), and the bushing (41) is interference-fitted with the main shaft (4).
5. A high-precision, leak-free classifier based on a bidirectional gas-tight structure according to claim 2, characterized in that: The housing (1) is also provided with a cooling component, which is used to adjust the temperature of the gas at the input end of the nozzle. The control system is also used to determine the temperature distribution in each of the sealed chambers based on the temperature field information, and to control the opening and closing of the nozzles and the operation of the cooling component based on the temperature distribution in the sealed chambers.
6. A high-precision, leak-free classifier based on a bidirectional gas-tight structure according to claim 1, characterized in that: The projections of the mating segments (242) of the carbon ring (24) installed in the same sealed chamber on the same plane do not overlap.
7. A high-precision, leak-free classifier based on a bidirectional gas-tight structure according to claim 1, characterized in that: The sidewall of the carbon ring (24) installed in the same sealed chamber is not parallel to the spray angle of the nozzle.
8. A high-precision leak-free classifier based on a bidirectional gas-tight structure according to claim 1, characterized in that: Each carbon ring (24) is provided with a gasket (25) between itself and the adjacent carbon ring (24), and the gaskets (25) are all made of elastic material.
9. A high-precision, leak-free classifier based on a bidirectional gas-tight structure according to claim 2, characterized in that: The control system is also used to collect distance information between the inner wall of the carbon ring (24) and the main shaft (4), and to determine whether the carbon ring (24) vibrates based on the distance information, and to control the nozzle to work when the carbon ring (24) vibrates.
10. A high-precision, leak-free classifier based on a bidirectional gas-tight structure according to claim 9, characterized in that: The outer shell (21) has several windows. The control system emits ultrasonic waves into the outer shell (21) and receives ultrasonic waves reflected by the outer shell (21). It also obtains the reflection time and amplitude of the emitted ultrasonic waves and obtains distance information based on the reflection time and amplitude. When the amplitude is less than the set minimum amplitude, and the reflection time is less than the set time, the distance information is zero. In this case, the carbon ring (24) is stable and the working state of the nozzle is not adjusted. When the reflection time is greater than the set time, the distance information is greater than zero and the carbon ring (24) moves. The control system adjusts the position of the carbon ring (24) by controlling the nozzle at the corresponding position. When the amplitude is greater than the set minimum amplitude, the carbon ring (24) vibrates or the carbon ring (24) breaks. At this time, the control system increases the working power of the nozzle.
Citation Information
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