High-precision photoelectric turntable multi-stage composite sealing device

Abstract

The application relates to the technical field of photoelectric rotary table sealing, and discloses a high-precision photoelectric rotary table multistage composite sealing device.The sealing device comprises a rotating shaft, a bearing seat arranged on the rotating shaft, a bearing arranged on the bearing seat, a main sealing layer arranged outside the bearing and wrapping the bearing seat, a plurality of permanent magnets arranged around the rotating shaft in an alternating manner according to polarities and connected with the rotating shaft, magnetic fluid filled in an annular gap between the rotating shaft and the bearing seat, an auxiliary sealing layer arranged on the top of the main sealing layer and used for filling a gap and blocking liquid penetration, and a dynamic compensation mechanism arranged at the bottom of the main sealing layer and connected with the rotating shaft and used for adaptively adjusting sealing pre-tightening force.The sealing device has good sealing performance, can reduce friction loss, reduces the operation cost of equipment, and can effectively cope with shaft deformation through the dynamic compensation mechanism.

Description

Technical Field

[0001] This invention relates to the field of photoelectric turntable sealing technology, and more specifically to a high-precision photoelectric turntable multi-stage composite sealing device. Background Technology

[0002] In harsh environments such as oceans and rain / snow, the rotating parts of existing photoelectric turntables are susceptible to corrosion from salt spray and water vapor, and traditional static sealing devices cannot meet the dynamic sealing requirements. Traditional O-ring seals are prone to aging and failure after long-term friction, while single labyrinth seals are insufficient for sealing under high pressure. In existing technologies, some designs add waterproof plates to form water channels for drainage, but this does not solve the problem of continuous sealing during dynamic rotation.

[0003] Contact seals (such as O-rings) rely on preload to achieve a seal, resulting in high frictional resistance during rotation (coefficient of friction). Long-term operation leads to wear of the seal ring (wear rate 0.1mm / 1000 hours), and the rubber hardens and fails below -20℃, making it unsuitable for the shaft system. Radial runout. Non-contact seals (such as labyrinth seals and magnetic seals), labyrinth seals block liquid through multiple gaps, and their sealing effect is acceptable under normal pressure (leakage rate). However, under high-pressure environments (such as the 80℃ and 8MPa water pressure of the IP69K test), the leakage rate increases sharply. Furthermore, dust particles easily accumulate in the labyrinth groove, causing jamming. Magnetic seals, which form a sealing barrier through magnetic fluids or permanent magnets, can easily cause electromagnetic noise to the surrounding photoelectric turntable encoder during high-speed rotation. Combined seals (such as O-rings + labyrinths), while improving waterproofing, do not solve the problem of frictional heat accumulation (temperature rise) during dynamic rotation. This leads to accelerated aging of the seal ring and changes in the sealing gap caused by thermal expansion and contraction of the shaft system (shaft diameter change of ±0.15mm when the temperature difference is 50℃).

[0004] In marine environments, salt spray (5% NaCl concentration) causes corrosion of metal components (corrosion rate 0.05 mm / month), and traditional sealing materials (such as nitrile rubber) have a salt spray resistance life of only 500 hours; in high-altitude, low-pressure environments (air pressure... Under certain conditions, traditional sealing devices are prone to leakage of sealing grease due to internal and external pressure differences; in extremely cold environments (below -40℃), condensate freezes and expands, often causing the seal to break (breakage load ≤50N), resulting in insufficient adaptability to complex environments. Summary of the Invention

[0005] The purpose of this invention is to provide a high-precision photoelectric turntable multi-stage composite sealing device. This sealing device, through a main sealing layer, an auxiliary sealing layer, and a dynamic compensation mechanism, achieves a high airtight seal with low friction, long life, self-compensation, and maintenance-free operation under combined working conditions of dynamic rotation of the shaft, radial runout, temperature alternation, and pressure variation.

[0006] To achieve the above objectives, the present invention provides a high-precision photoelectric turntable multi-stage composite sealing device, comprising:

[0007] Rotation axis;

[0008] A bearing housing is disposed on the rotating shaft, and a bearing is fitted onto the bearing housing;

[0009] A main sealing layer, disposed on the outside of the bearing and enclosing the bearing housing, wherein the main sealing layer is a magnetohydrodynamic sealing ring, comprising:

[0010] Multiple permanent magnets, arranged in alternating polarities, are arranged around the rotation axis and connected to the rotation axis.

[0011] A magnetic fluid is used to fill the annular gap between the rotating shaft and the bearing housing.

[0012] An auxiliary sealing layer, disposed on top of the main sealing layer, is used to fill gaps and prevent liquid penetration;

[0013] A dynamic compensation mechanism is located at the bottom of the main sealing layer and connected to the rotating shaft, used to adaptively adjust the sealing preload.

[0014] Optionally, the auxiliary sealing layer includes:

[0015] A labyrinth groove base is fitted onto the top of the rotating shaft;

[0016] A three-pole labyrinth groove is disposed on the labyrinth groove base, and the groove of the three-pole labyrinth groove is filled with a hydrophobic medium.

[0017] A spiral guide channel, located at the center of the labyrinth base, is used to eject the infiltrated liquid.

[0018] Optionally, the auxiliary sealing layer includes a drain hole, which is inclinedly disposed on the labyrinth base to discharge the thrown-out liquid without retention.

[0019] Optionally, the dynamic compensation mechanism includes:

[0020] The disc spring assembly consists of multiple disc springs stacked evenly and is fitted onto the bottom of the rotating shaft;

[0021] A pressure ring is disposed at the bottom of the disc spring assembly and is used to connect the disc spring assembly to the rotating shaft.

[0022] Optionally, the sealing device further includes:

[0023] A temperature and humidity sensor is installed on the outside of the main sealing layer to detect temperature and humidity.

[0024] Optionally, the sealing device further includes:

[0025] A nano-electrothermal film is wound between the main sealing layer and the temperature and humidity sensor for heating to prevent condensate from freezing.

[0026] Optionally, the sealing device includes:

[0027] A miniature air knife is tilted at the entrance of the three-pole labyrinth groove for periodically blowing away dust.

[0028] Optionally, the sealing device includes:

[0029] A flange, located on the outside of the nano-electrothermal film, is used to connect to the photoelectric connector.

[0030] Optionally, the width of the annular gap is 0.2mm-0.3mm.

[0031] Optionally, the depths of the three-level maze grooves are 3mm, 4mm, and 5mm respectively, the step angle is 15°, and the distance between adjacent grooves is 2mm.

[0032] Through the above technical solution, the present invention provides a high-precision photoelectric turntable multi-stage composite sealing device. The sealing device is constructed by placing a bearing seat on a rotating shaft, mounting a bearing on the bearing seat, placing a main sealing layer outside the bearing and wrapping the bearing seat, the main sealing layer being a magnetic fluid sealing ring comprising multiple permanent magnets arranged in alternating polarities, surrounding the rotating shaft and connected to the rotating shaft, the magnetic fluid filling being disposed in the annular gap between the rotating shaft and the bearing seat, an auxiliary sealing layer being disposed on top of the main sealing layer to fill the gap and prevent liquid penetration, and a dynamic compensation mechanism being disposed at the bottom of the main sealing layer and connected to the rotating shaft to adaptively adjust the sealing preload. This invention effectively isolates liquids and gases through a composite design of a magnetofluid liquid film and a three-stage labyrinth groove, ensuring stable operation of the photoelectric turntable under high pressure. It can achieve non-contact dynamic sealing through the magnetofluid liquid film, reducing rotational energy consumption and component wear, and lowering equipment operating costs. Through a dynamic compensation mechanism and self-lubricating design, its service life is significantly extended, reducing the frequency of equipment maintenance. The disc spring assembly can automatically adjust the preload according to the thermal expansion and contraction of the shaft system, ensuring stable magnetofluid liquid film pressure and effectively coping with shaft deformation. Attached Figure Description

[0033] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings:

[0034] Figure 1 This is a schematic diagram of a high-precision photoelectric turntable multi-stage composite sealing device according to an embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram of a high-precision photoelectric turntable multi-stage composite sealing device according to an embodiment of the present invention;

[0036] Figure 3 This is a cross-sectional view of a high-precision photoelectric turntable multi-stage composite sealing device according to an embodiment of the present invention.

[0037] Explanation of reference numerals in the attached figures

[0038] Detailed Implementation

[0039] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0040] In embodiments of the present invention, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used to describe the relative positional relationships of components in relation to the directions shown in the accompanying drawings or in relation to the vertical, perpendicular, or gravitational directions.

[0041] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0042] like Figure 1 The diagram shown is a schematic representation of a high-precision photoelectric turntable multi-stage composite sealing device according to an embodiment of the present invention. Figure 2 The diagram shown is a schematic representation of a high-precision photoelectric turntable multi-stage composite sealing device according to an embodiment of the present invention. Figure 3 The figure shown is a cross-sectional view of a high-precision photoelectric turntable multi-stage composite sealing device according to an embodiment of the present invention. Figures 1 to 3 The sealing device includes a rotating shaft 4, a bearing housing 5, a main sealing layer 1, an auxiliary sealing layer 2, and a dynamic compensation mechanism 3. Specifically, the bearing housing 5 is mounted on the rotating shaft 4, and a bearing is sleeved on the bearing housing 5. The main sealing layer 1 is located outside the bearing and wraps around the bearing housing 5. The main sealing layer 1 is a magnetic fluid 12 sealing ring, including multiple permanent magnets 11 and magnetic fluid 12. The permanent magnets 11 constrain the magnetic fluid 12 to form a liquid film sealing band. In one embodiment of the invention, the rotating shaft 4 is made of 7-series aluminum alloy, and its surface is successively rough-ground, fine-ground, and finally nickel-plated using an environmentally friendly nickel plating process, with a film thickness of [missing information]. After nickel plating, the surface is ultra-fine ground to ensure that the surface hardness is not less than HV750. The permanent magnet 11 is a circumferential array of N52 neodymium iron boron magnets, forming a radial magnetic field with a magnetic induction intensity of 0.3-0.5T. Multiple permanent magnets 11 are arranged in alternating polarities and are connected to the rotation axis 4 around the rotation axis 4. In one embodiment of the present invention, there can be 8 permanent magnets 11.

[0043] The magnetic fluid 12 is filled in the annular gap between the rotating shaft 4 and the bearing seat 5. In one example of the present invention, the magnetic fluid 12 is a diester-based carrier nano-magnetic fluid 12, filling the annular gap between the rotating shaft 4 and the bearing seat 5, with a gap width of 0.2mm-0.3mm. The size of the sealing gap has a significant impact on the pressure-bearing capacity of the magnetic fluid 12 seal. Generally, the sealing capacity increases as the gap decreases. The sealing effect is better when the gap is 0.05-0.2mm, while when the gap is greater than 0.3mm, it can only withstand a very small pressure difference. Setting the gap to 0.2-0.3mm can reduce the requirements for processing and installation accuracy while ensuring a certain sealing performance. A slight increase in the annular sealing gap will lead to a significant increase in magnetic leakage at the annular sealing gap, reducing the magnetic attraction of the magnetic field to the magnetic fluid 12 filled in the annular sealing gap, thereby reducing the pressure-bearing value of the magnetic fluid 12 seal. A gap of 0.2-0.3mm can effectively reduce magnetic leakage, ensuring that the magnetic fluid 12 is subjected to sufficient magnetic force, thereby achieving a good sealing effect. If the clearance is too small, under conditions of low machining and installation precision, rigid contact wear can easily occur between the rotating shaft and the sealing teeth, which in turn increases the clearance and reduces the sealing performance. A clearance of 0.2-0.3mm can, to some extent, avoid rigid contact wear and extend the service life of the sealing components.

[0044] In one example of the present invention, eight sector-shaped N52 neodymium iron boron permanent magnets 11 are arranged with alternating polarities and embedded in the grooves of the inner wall of the bearing seat 5. The permanent magnets 11 are fixed with epoxy resin. After assembly, the radial magnetic field strength is tested. At a distance of 0.25 mm from the magnet surface, the magnetic induction intensity is stable at 0.3-0.5 T, and the circumferential magnetic field non-uniformity is... Magnetofluid 12 was selected as the diester-based carrier + nanoparticles. The particulate composition is injected into the annular gap between the permanent magnet 11 and the rotating shaft 4 through the injection hole on the side of the bearing housing 5. During the filling process, the shaft system is slowly rotated to ensure that the magnetofluid 12 is evenly distributed to form a complete liquid. The auxiliary sealing layer 2 is set on top of the main sealing layer 1 to fill the gap and prevent liquid penetration. The dynamic compensation mechanism 3 is set at the bottom of the main sealing layer 1 and connected to the rotating shaft 4 to adaptively adjust the sealing preload.

[0045] In this embodiment, the auxiliary sealing layer 2 includes a labyrinth base 25, a three-pole labyrinth 23, a spiral guide channel 22, and a drain hole 24. Specifically, the labyrinth base 25 is sleeved on the top of the rotating shaft 4, the three-pole labyrinth 23 is disposed on the labyrinth base 25, and the groove of the three-pole labyrinth 23 is filled with a hydrophobic medium 21. The spiral guide channel 22 is disposed at the center of the labyrinth base 25 for throwing out the infiltrated liquid, and the drain hole 24 is inclinedly disposed on the labyrinth base 25 for discharging the thrown-out liquid without retention. In one example of this invention, the three-stage labyrinth grooves 23 have depths of 3mm, 4mm, and 5mm respectively, a step angle of 15°, and a spacing of 2mm between adjacent grooves. The core purpose is to block media intrusion layer by layer through a stepped structure, while optimizing the fluid flow path to maximize sealing reliability and environmental adaptability. The progressively deeper stepped structure forms a "multi-level physical barrier." External media such as water vapor, salt spray, and dust must successively pass through the 3mm, 4mm, and 5mm deep grooves. Each level of the groove weakens the kinetic energy of the media through "retention and diversion," and deeper subsequent grooves can further intercept trace amounts of media that were not blocked by the previous level. Compared to grooves of equal depth, this significantly reduces the probability of media penetrating the sealing layer. The 15° tilt angle avoids an angle that is too small (e.g., This prevents the medium from accumulating at the bottom of the tank, and also prevents excessively large angles (such as...). The angle reduces the blocking effect caused by this. This angle guides the intruding liquid to flow quickly along the slope to the bottom drain hole 24, while reducing gas turbulence. Combined with the subsequent spiral guide groove 22, it accelerates media discharge and reduces the risk of corrosion. The 2mm spacing between adjacent grooves achieves a balance between "structural compactness" and "sealing independence." Too narrow a spacing (e.g.) This can lead to excessively thin walls between tanks, making them prone to deformation under long-term rotation or temperature differences, and excessively wide spacing (such as...). This would increase the overall volume of the sealing module and weaken the "cooperative interception" effect of the multi-level barriers. A 2mm spacing ensures that each level of the groove functions independently while maintaining the structural strength of the aluminum alloy groove.

[0046] In one example of the present invention, the hydrophobic medium 21 may be a hydrophobic silica gel, and the silica gel has a water absorption rate of... Operating temperature range It can effectively fill gaps and prevent liquid penetration. The spiral guide groove has a 5mm pitch, a 1mm depth, and a 45° helix angle. During rotation, the centrifugal force... The liquid that has seeped in can be thrown out along the spiral groove, resulting in high efficiency. The labyrinth base 25 is made of 6061-T6 aluminum alloy, with a 50μm thick polytetrafluoroethylene coating on the surface, and is resistant to salt spray corrosion for a certain period of time. Hour.

[0047] In this embodiment, the dynamic compensation mechanism 3 includes a disc spring assembly 31 and a pressure ring 32. Specifically, the disc spring assembly 31 is composed of multiple disc springs evenly stacked and sleeved on the bottom of the rotating shaft 4. The pressure ring 32 is disposed at the bottom of the disc spring assembly 31 and is used to connect the disc spring assembly 31 to the rotating shaft 4. In one example of the present invention, the disc spring assembly 31 is composed of two sets of 50CrVA springs, and the preload compensation range is... Adjust precision Disc springs 31 are evenly distributed circumferentially and connected to the rotating shaft 4 by pressure rings 32 and 32. The initial value of the spring preload can be set to... .

[0048] In this embodiment, the sealing device also includes a temperature and humidity sensor 6, which is disposed on the outside of the main sealing layer 1 and is used to detect temperature and humidity. The temperature and humidity sensor 6 is installed on the outer surface of the main sealing layer 1 and is connected to the MCU control module through a shielded wire to monitor the shaft temperature in real time. The temperature sampling frequency is 10Hz to ensure accurate temperature acquisition.

[0049] In this embodiment, the sealing device further includes a nano-electrothermal film 9, which is wound between the main sealing layer 1 and the temperature and humidity sensor 6 and fixed with high-temperature tape. The nano-electrothermal film 9 is connected to a thermostat via leads. In one example of the invention, the nano-electrothermal film 9 can be configured with a power density... ,thickness When the temperature and humidity sensor 6 (humidity accuracy) Dew point temperature was detected. Ambient temperature When the time comes, heating will start automatically, and the heating rate will be [missing information]. ,prevent The following condensation will freeze.

[0050] In this embodiment, the sealing device also includes a miniature air knife 7, which is inclinedly installed at the entrance of the tripolar labyrinth groove 23. The nozzle axis makes an angle of 30° with the tangent direction of the shaft system. It is connected to a nitrogen source through an air pipe, the jet pressure is adjusted to 0.3 MPa, and the blowing and scanning speed is measured by an anemometer. It is set to automatically blow clean once every 1 hour for regular dust removal.

[0051] In this embodiment, the sealing device also includes a flange 8, located on the outside of the nano-electrothermal film 9, for connecting the photoelectric connector. The photoelectric connector is fixedly connected by multiple bolts, facilitating easy assembly and disassembly. By adopting a standard flange 8 and threaded connection design, the disassembly time of the sealing assembly is ≤5 minutes, which facilitates equipment maintenance and component replacement, significantly reducing downtime for maintenance.

[0052] Through the above technical solution, the present invention provides a high-precision photoelectric turntable multi-stage composite sealing device. The sealing device is constructed by setting a bearing seat 5 on a rotating shaft 4, and a bearing being sleeved on the bearing seat 5. The main sealing layer 1 is set outside the bearing and wraps around the bearing seat 5. The main sealing layer 1 is a magnetic fluid 12 sealing ring, including multiple permanent magnets 11 arranged in alternating polarities, surrounding the rotating shaft 4 and connected to the rotating shaft 4. The magnetic fluid 12 fills the annular gap between the rotating shaft 4 and the bearing seat 5. The auxiliary sealing layer 2 is set on top of the main sealing layer 1 to fill the gap and prevent liquid penetration. The dynamic compensation mechanism 3 is set at the bottom of the main sealing layer 1 and connected to the rotating shaft 4 to adaptively adjust the sealing preload. This invention effectively isolates liquids and gases through a composite design of a magnetic fluid 12 liquid film and a three-stage labyrinth groove, ensuring stable operation of the photoelectric turntable under high pressure. It can achieve non-contact dynamic sealing through the magnetic fluid 12 liquid film, reducing rotational energy consumption and component wear, and lowering equipment operating costs. Through the dynamic compensation mechanism 3 and self-lubricating design, the service life is significantly improved, reducing the frequency of equipment maintenance. The disc spring assembly 31 can automatically adjust the preload according to the thermal expansion and contraction of the shaft system, ensuring stable pressure of the magnetic fluid 12 liquid film and effectively coping with shaft deformation.

[0053] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention. This includes combining various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not further describe the various possible combinations. However, these simple modifications and combinations should also be considered as part of the content disclosed in this invention and are all within the protection scope of this invention.

Claims

1. A high-precision photoelectric turntable multi-stage composite sealing device, characterized in that, The sealing device includes: Rotation axis; A bearing housing is disposed on the rotating shaft, and a bearing is fitted onto the bearing housing; A main sealing layer, disposed on the outside of the bearing and enclosing the bearing housing, wherein the main sealing layer is a magnetohydrodynamic sealing ring, comprising: Multiple permanent magnets, arranged in alternating polarities, are arranged around the rotation axis and connected to the rotation axis. A magnetic fluid is used to fill the annular gap between the rotating shaft and the bearing housing. An auxiliary sealing layer, disposed on top of the main sealing layer, is used to fill gaps and prevent liquid penetration; A dynamic compensation mechanism is located at the bottom of the main sealing layer and connected to the rotating shaft, used to adaptively adjust the sealing preload. The auxiliary sealing layer includes: A labyrinth groove base is fitted onto the top of the rotating shaft; A three-level labyrinth groove is provided on the labyrinth groove base, and the groove of the three-level labyrinth groove is filled with a hydrophobic medium. A spiral guide channel, located at the center of the labyrinth base, is used to eject the infiltrated liquid. The dynamic compensation mechanism includes: The disc spring assembly consists of multiple disc springs stacked evenly and is fitted onto the bottom of the rotating shaft; A pressure ring is disposed at the bottom of the disc spring assembly and is used to connect the disc spring assembly to the rotating shaft.

2. The sealing device according to claim 1, characterized in that, The auxiliary sealing layer includes: The drain hole is inclinedly set on the labyrinth groove base to discharge the thrown liquid without retention.

3. The sealing device according to claim 1, characterized in that, The sealing device further includes: A temperature and humidity sensor is installed on the outside of the main sealing layer to detect temperature and humidity.

4. The sealing device according to claim 3, characterized in that, The sealing device further includes: A nano-electrothermal film is wound between the main sealing layer and the temperature and humidity sensor for heating to prevent condensate from freezing.

5. The sealing device according to claim 1, characterized in that, The sealing device includes: A miniature air knife is tilted at the entrance of the three-stage labyrinth groove for periodically blowing away dust.

6. The sealing device according to claim 4, characterized in that, The sealing device includes: A flange, located on the outside of the nano-electrothermal film, is used to connect to the photoelectric connector.

7. The sealing device according to claim 1, characterized in that, The width of the annular gap is 0.2mm-0.3mm.

8. The sealing device according to claim 1, characterized in that, The depths of the three-level maze grooves are 3mm, 4mm, and 5mm respectively, the step angle is 15°, and the distance between adjacent grooves is 2mm.

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