CN108303241B - A kind of modularization oil-film damping test device and method - Google Patents
A kind of modularization oil-film damping test device and method Download PDFInfo
- Publication number
- CN108303241B CN108303241B CN201711497590.3A CN201711497590A CN108303241B CN 108303241 B CN108303241 B CN 108303241B CN 201711497590 A CN201711497590 A CN 201711497590A CN 108303241 B CN108303241 B CN 108303241B
- Authority
- CN
- China
- Prior art keywords
- oil
- oil film
- film
- test specimen
- damping
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M13/00—Testing of machine parts
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Testing Of Devices, Machine Parts, Or Other Structures Thereof (AREA)
Abstract
The invention discloses a kind of modularization oil-film damping test devices, cylindrical upper test specimen is sleeved in sleeve from the top down, upper test specimen and barrel contacts face keep clearance fit, are marked with oil liquid in the gap and form oil film, sleeve is supported and fixed on pedestal by the step of periphery；Upper test specimen upper surface shaft core position is fixedly installed with dynamic force snesor, and dynamic force snesor is fixedly connected with exciting rod upwards, is equipped with accelerometer one in upper test specimen upper surface；Sleeve upper surface is provided with non-contact micro-displacement sensor and accelerometer two.The invention also discloses a kind of modularization oil-film damping test methods.The device of the invention structure is simple, method is easy to implement, is of great significance to the popularization and application of scientific research oil-film damping mechanism and film damper.
Description
Technical field
The invention belongs to Structure dynamic characteristics the field of test technology, are related to a kind of modularization oil-film damping test device, this
Invention further relates to a kind of modularization oil-film damping test method.
Background technique
Vibration is often generated when mechanical equipment work, vibrates to the operating accuracy of mechanical equipment, reliability, use the longevity
Life etc., which can generate, to be seriously affected.Damping in structural system, such as oil-film damping, frictional damping, material damping, viscoelastic damping
To there is good inhibiting effect to the vibration in mechanical structure, therefore Proper Match damping resists elevating mechanism structural system
The job stability of vibration property and guarantee equipment is of great significance.
Oil-film damping is present in the oil liquid between two structural members with relative motion, when the two structural members do phase
To it is of reciprocating vibration when can produce oil-film damping power, to inhibit the vibration between the two structural members.When the two structural members
Generated damping is known as tangential damping when along the tangential vibrations of oil film；Generated damping is known as when along oil film normal vibration
Normal direction damping.In mechanical structure system, oil-film damping, this method usually are generated using the oil film formed between movement faying face
Simple and easy to do, damping is good, using relatively broad in mechanized equipment.
Although oil-film damping is widely applied in engineering, experience, oil film resistance are still leaned on to the design of film damper
There are which type of relationships for Buddhist nun's size and oil film thickness, viscosity, size, vibration frequency, vibration amplitude size etc., at present from theory
There is not specific saying yet to experiment, so that the rational design of film damper be made to lack effective scientific guidance, influences oil film
Damper effective exploitation and application.
Summary of the invention
The object of the present invention is to provide a kind of modularization oil-film damping test device, solution lacks effective oil film resistance at present
The problem of Buddhist nun's test method and device, breaks through the limitation of Experience Design, provides scientific basis to rationally design film damper.
It is a further object of the present invention to provide a kind of modularization oil-film damping test methods.
The technical solution adopted by the present invention is that a kind of modularization oil-film damping test device, cylindrical upper test specimen is from upper
It is sleeved in sleeve downwards, upper test specimen and barrel contacts face keep clearance fit, are marked with oil liquid in the gap and form oil film, sleeve
It is supported and fixed on pedestal by the step flange of periphery；Upper test specimen upper surface shaft core position is fixedly installed with dynamic force sensing
Device, dynamic force snesor are fixedly connected with exciting rod upwards, are equipped with accelerometer one in upper test specimen upper surface；In sleeve upper end
Face is provided with non-contact micro-displacement sensor and accelerometer two.
Another technical solution that the present invention uses is that a kind of modularization oil-film damping test method utilizes above-mentioned module
Carburetion film damping test device, follows the steps below to implement:
Establish following kinetics equation:
Wherein, f is extraneous exciting force, is measured by dynamic force snesor；fτFor the tangential damping force of oil film；M is upper test specimen
Quality；For the vibration acceleration of upper test specimen；CτIt is tangentially damped for oil film；For the Relative Vibration between upper test specimen and sleeve
Speed, abbreviation oil film tangential vibrations speed,
When extraneous exciting force f is simple harmonic quantity power, then enable:
fτ=Fτcosωt (3)
Wherein, FτFor the amplitude of the tangential damping force of oil film；ω is excited frequency；T is time variable；xτFor upper test specimen and set
Relative Vibration displacement between cylinder, the displacement of abbreviation oil film tangential vibrations；XτFor the amplitude of oil film tangential vibrations displacement；For oil film
Tangential vibrations displacement xτWith the tangential damping force f of oil filmτBetween phase difference,
Oil film tangential vibrations speed is obtained by formula (4)
Formula (3), (4), (5) are brought into formula (2), the calculating formula that oil film tangentially damps is obtained:
In formula (6),
Wherein, F is the amplitude of extraneous exciting force f；
In formula (6), formula (7), the quality m and excited frequency ω of upper test specimen be it is known,It is surveyed by accelerometer one
, extraneous amplitude of exciting force F is measured by dynamic force snesor；Oil film tangential vibrations are displaced XτPass through non-contact micro-displacement sensing
Device measures；Pass through fτPhase difference and x relative to fτIt is acquired relative to the phase difference of f, oil film is finally calculated by formula (6)
Tangential damping size.
The invention has the advantages that the test device is easily achieved the damping test under different oil film sizes, there is mould
Block feature, and do not influenced by surrounding structure, the damping value of target oil film can be gone out by measuring and calculation model separation, both
The tangential damping of oil film can be obtained, it is also possible to obtain the normal direction of oil film damps.Test method of the present invention and device are simple and easy to do,
Oil-film damping under the working conditions such as different oil film thicknesses, viscosity, size, vibration frequency, vibration amplitude can be effectively identified, to spy
The popularization and application of rope research oil-film damping mechanism and film damper are of great significance.
Detailed description of the invention
Fig. 1 is the tangential damping test system structure diagram of oil film；
Fig. 2 is the tangential damping test computation model figure of oil film；
Fig. 3 is oil film normal direction damping test system structure diagram；
Fig. 4 is oil film normal direction damping test computation model figure.
In figure, 1. exciting rods, 2. dynamic force snesors, 3. accelerometers one, test specimen on 4., 5. accelerometers two, 6. is non-
Contact micro-displacement sensor, 7. sleeves, 8. pedestals, 9. lower test specimens.
Specific embodiment
Invention is further described in detail with reference to the accompanying drawings and detailed description.
Referring to Fig.1, the structure of apparatus of the present invention is that cylindrical upper test specimen 4 is sleeved on from the top down in sleeve 7, upper examination
Part 4 and 7 contact surface of sleeve keep clearance fit, are marked with oil liquid in the gap and form oil film, along (close in 7 upper surface of sleeve
Gap side) it is provided with annular oil groove, wherein being perfused with oil liquid to keep continuing fuel feeding to oil film；The step that sleeve 7 passes through periphery
Flange is supported and fixed on pedestal 8；Upper 4 upper surface shaft core position of test specimen is fixedly installed with dynamic force snesor 2, dynamic force sensing
Device 2 is fixedly connected with exciting rod 1 upwards, is equipped with accelerometer 1 in upper 4 upper surface of test specimen；It is provided in 7 upper surface of sleeve
Non-contact micro-displacement sensor 6 and accelerometer 25.
When exciting rod 1 applies the exciting force of certain frequency to upper test specimen 4 by dynamic force snesor 2, upper test specimen 4 and set
Relative Vibration occurs between cylinder 7, at this moment the oil film between upper 7 inner wall of test specimen 4 and sleeve generates tangential damping force, to prevent the vibration
It is dynamic.The extraneous exciting force size that upper test specimen 4 is measured by dynamic force snesor 2 measures upper test specimen 4 by accelerometer 1
Vibration acceleration tests out the vibration displacement between upper test specimen 4 and sleeve 7 by non-contact micro-displacement sensor 6, passes through acceleration
Degree meter 25 tests out the vibration acceleration of sleeve 7.
Referring to Fig. 2, the method for the present invention establishes following kinetics equation based on above-mentioned device:
Wherein, f is extraneous exciting force, is measured by dynamic force snesor 2；fτFor the tangential damping force of oil film；M is upper test specimen
4 quality；For the vibration acceleration of upper test specimen 4；CτIt is tangentially damped for oil film；It is opposite between upper test specimen 4 and sleeve 7
Vibration velocity, abbreviation oil film tangential vibrations speed.
When extraneous exciting force f is simple harmonic quantity power, then enable:
fτ=Fτcosωt (3)
Wherein, FτFor the amplitude of the tangential damping force of oil film；ω is excited frequency；T is time variable；xτFor upper test specimen 4 and set
Relative Vibration displacement between cylinder 7, the displacement of abbreviation oil film tangential vibrations；XτFor the amplitude of oil film tangential vibrations displacement；For oil
Film tangential vibrations displacement xτWith the tangential damping force f of oil filmτBetween phase difference.
Oil film tangential vibrations speed is obtained by formula (4)
Formula (3), (4), (5) are brought into formula (2), the calculating formula that oil film tangentially damps is obtained:
In formula (6),
Wherein, F is the amplitude of extraneous exciting force f；
In formula (6), formula (7), the quality m and excited frequency ω of upper test specimen 4 be it is known,Pass through accelerometer 1
It measures, extraneous amplitude of exciting force F is measured by dynamic force snesor 2；Oil film tangential vibrations are displaced XτPass through non-contact micro-displacement
Sensor 6 measures；Pass through fτPhase difference and x relative to fτIt is acquired relative to the phase difference of f, therefore based on embodiment 1
Device and the numerical value of detection are finally calculated the tangential damping size of oil film by formula (6).
Lower test specimen 9 is set in the interior stepped hole of pedestal 8 on aforementioned device basic shown in FIG. 1 referring to Fig. 3, under
Between 9 upper surface of test specimen and the lower end surface of upper test specimen 4 inject oil liquid formed plane oil film, when upper test specimen 4 do when the vibrations are up and down, should
Plane oil film can produce normal direction damping force；Flanged annular oil groove is circumferentially offered in lower 9 upper surface of test specimen, wherein filling
Oil liquid is marked with to keep continuing fuel feeding to normal direction oil film；The cylindrical surface and its lower end that tangential oil film is generated in upper test specimen generate normal direction
The lower end surface of oil film keeps plumbness.Under the configuration state, it will generate simultaneously in upper 4 vibration processes of test specimen by upper test specimen 4
Oil film is formed by tangential damping force between sleeve 7, while being formed by normal direction by oil film between upper test specimen 4 and lower test specimen 9
Damping force, therefore the normal direction damping size of oil film can be just obtained after needing tangentially to damp the aforementioned oil film measured deduction.
Referring to Fig. 4, following kinetics equation is established:
Wherein, f is extraneous exciting force；fτFor the tangential damping force of oil film；fnFor oil film normal direction damping force；CnFor oil film normal direction
Damping；For the Relative Vibration speed between upper test specimen 4 and lower test specimen 9, abbreviation oil film normal direction vibration velocity,
When extraneous exciting force f is simple harmonic quantity power, since sleeve 7 and lower test specimen 9 are fixed on the same pedestal, and by upper
The up-down vibration of test specimen 4 generates tangential damping and normal direction damping simultaneously, therefore generates the vibration position of tangential damping with normal direction damping
Shifting be it is identical, it is unified to be indicated with oil film vibration displacement x, then obtain following expression:
fτ+fn=(Fn+Fτ)cosωt (10)
Oil film vibration speed is obtained by formula (11)
Wherein, Fτ、FnRespectively oil film tangentially with normal direction damping force amplitude；ω is excited frequency；T is time variable；X is
Oil film vibration displacement amplitude；For oil film vibration displacement x and oil-film damping power (fn+fτ) between phase difference；
Formula (2), formula (9), formula (12) are brought into formula (10), oil film normal direction Damping calculating formula is obtained:
In formula (13),
Wherein, F is the amplitude of extraneous exciting force f；
In formula (13), formula (14), the quality m and excited frequency ω of upper test specimen 4 be it is known,Pass through accelerometer
One 3 measure, and extraneous amplitude of exciting force F is measured by dynamic force snesor 2；Oil film vibration displacement X is passed by non-contact micro-displacement
Sensor 6 measures；Pass through (fτ+fn) acquired relative to the phase difference and x of f relative to the phase difference of f, therefore it is based on embodiment 2
Device and detection numerical value, by formula (13) calculate oil film normal direction damp size.
The device of the invention, by replace have different fit dimensions upper test specimen 4 and sleeve 7 can flexible combination go out not
With oil film thickness and different size oil-film damping test experiments schemes.It is by two clearance fits with the oil film tangentially damped
Oil liquid is added between cylindrical surface to be formed, by changing gap size, cylindrical surface size realizes different oil film thicknesses and different rulers
The test analysis of very little oil-film damping.
Claims (5)
1. a kind of modularization oil-film damping test device, it is characterised in that: cylindrical upper test specimen is sleeved on sleeve from the top down
In, upper test specimen and barrel contacts face keep clearance fit, are marked with oil liquid in the gap and form oil film, the step that sleeve passes through periphery
Flange is supported and fixed on pedestal；Upper test specimen upper surface shaft core position is fixedly installed with dynamic force snesor, dynamic force snesor
It is fixedly connected with exciting rod upwards, accelerometer one is installed in upper test specimen upper surface；It is provided in sleeve upper surface non-contact
Micro-displacement sensor and accelerometer two；
It is set with lower test specimen in the interior stepped hole of the pedestal, injects oil liquid between lower test specimen upper surface and upper test specimen lower end surface
Form plane oil film.
2. modularization oil-film damping test device according to claim 1, it is characterised in that: in the sleeve upper surface
Along annular oil groove is provided with, wherein being perfused with oil liquid to keep continuing fuel feeding to tangential oil film；
The lower test specimen upper surface circumferentially offers flanged annular oil groove, wherein being perfused with oil liquid to keep to normal direction
Oil film continues fuel feeding.
3. modularization oil-film damping test device according to claim 1, it is characterised in that: generated in the upper test specimen
The lower end surface that the cylindrical surface and its lower end of tangential oil film generate normal direction oil film keeps plumbness.
4. a kind of modularization oil-film damping test method, using modularization oil-film damping test device as claimed in claim 3,
It is characterized in that, follows the steps below to implement:
Establish following kinetics equation:
Wherein, f is extraneous exciting force, is measured by dynamic force snesor；fτFor the tangential damping force of oil film；M is the matter of upper test specimen
Amount；For the vibration acceleration of upper test specimen；CτIt is tangentially damped for oil film；Relative Vibration speed between upper test specimen and sleeve
Degree, abbreviation oil film tangential vibrations speed,
When extraneous exciting force f is simple harmonic quantity power, then enable:
fτ=Fτcosωt (3)
Wherein, FτFor the amplitude of the tangential damping force of oil film；ω is excited frequency；T is time variable；xτFor upper test specimen and sleeve it
Between Relative Vibration displacement, abbreviation oil film tangential vibrations displacement；XτFor the amplitude of oil film tangential vibrations displacement；It is tangential for oil film
Vibration displacement xτWith the tangential damping force f of oil filmτBetween phase difference,
Oil film tangential vibrations speed is obtained by formula (4)
Formula (3), (4), (5) are brought into formula (2), the calculating formula that oil film tangentially damps is obtained:
In formula (6),
Wherein, F is the amplitude of extraneous exciting force f；
In formula (6), formula (7), the quality m and excited frequency ω of upper test specimen be it is known,It is measured by accelerometer one, outside
Boundary amplitude of exciting force F is measured by dynamic force snesor；The amplitude X of oil film tangential vibrations displacementτIt is passed by non-contact micro-displacement
Sensor measures；Phase differencePass through the tangential damping force f of oil filmτPhase difference and oil film tangential vibrations relative to extraneous exciting force f
Displacement xτIt is acquired relative to the phase difference of extraneous exciting force f, the size that oil film tangentially damps finally is calculated by formula (6).
5. a kind of modularization oil-film damping test method, using modularization oil-film damping test device as claimed in claim 3,
It is characterized in that, follows the steps below to implement:
Establish following kinetics equation:
Wherein, f is extraneous exciting force；fτFor the tangential damping force of oil film；fnFor oil film normal direction damping force；CnFor the damping of oil film normal direction；For the Relative Vibration speed between upper test specimen and lower test specimen, abbreviation oil film normal direction vibration velocity,
It is unified to be indicated with oil film vibration displacement x when extraneous exciting force f is simple harmonic quantity power, then obtain following expression:
fτ+fn=(Fn+Fτ)cosωt (10)
Oil film vibration speed is obtained by formula (11)
Wherein, Fτ、FnRespectively oil film tangentially with normal direction damping force amplitude；ω is excited frequency；T is time variable；X is oil film
Vibration displacement amplitude；For oil film vibration displacement x and oil-film damping power (fn+fτ) between phase difference；
Formula (2), formula (9), formula (12) are brought into formula (10), oil film normal direction Damping calculating formula is obtained:
In formula (13),
Wherein, F is the amplitude of extraneous exciting force f；
In formula (13), formula (14), the quality m and excited frequency ω of upper test specimen be it is known,It is measured by accelerometer one,
Extraneous amplitude of exciting force F is measured by dynamic force snesor；Oil film vibration displacement amplitude X is surveyed by non-contact micro-displacement sensor
?；Phase differencePass through oil-film damping power (fτ+fn) relative to extraneous exciting force f phase difference and oil film vibration displacement x relative to
The phase difference of extraneous exciting force f acquires, and the size of oil film normal direction damping is calculated by formula (13).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711497590.3A CN108303241B (en) | 2017-12-28 | 2017-12-28 | A kind of modularization oil-film damping test device and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711497590.3A CN108303241B (en) | 2017-12-28 | 2017-12-28 | A kind of modularization oil-film damping test device and method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108303241A CN108303241A (en) | 2018-07-20 |
| CN108303241B true CN108303241B (en) | 2019-09-27 |
Family
ID=62868408
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711497590.3A Active CN108303241B (en) | 2017-12-28 | 2017-12-28 | A kind of modularization oil-film damping test device and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108303241B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111730410A (en) * | 2020-07-21 | 2020-10-02 | 湖北文理学院 | Static pressure and dynamic and static pressure main shaft oil film rigidity damping real-time measurement method and device, detection device, storage medium and system |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0186620A2 (en) * | 1984-12-24 | 1986-07-02 | Mitsubishi Jukogyo Kabushiki Kaisha | Method of controlling film thickness of mixture liquid layer of oil material and water in printing machines |
| CN103335843A (en) * | 2013-06-20 | 2013-10-02 | 上海大学 | Oil film stiffness and damping testing method based on experimental table of slide bearings |
| CN105675276A (en) * | 2016-01-13 | 2016-06-15 | 中国航空动力机械研究所 | Device and method for testing vibration damping property of elastic support extruded oil film damper |
| CN106768986A (en) * | 2017-02-22 | 2017-05-31 | 大连海事大学 | Fluid film lubrication damping test platform |
| CN106989917A (en) * | 2017-06-01 | 2017-07-28 | 中国航发湖南动力机械研究所 | Flexibly support the dynamic stiffness measurement device and its measuring method of squeeze film damper |
-
2017
- 2017-12-28 CN CN201711497590.3A patent/CN108303241B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0186620A2 (en) * | 1984-12-24 | 1986-07-02 | Mitsubishi Jukogyo Kabushiki Kaisha | Method of controlling film thickness of mixture liquid layer of oil material and water in printing machines |
| CN103335843A (en) * | 2013-06-20 | 2013-10-02 | 上海大学 | Oil film stiffness and damping testing method based on experimental table of slide bearings |
| CN105675276A (en) * | 2016-01-13 | 2016-06-15 | 中国航空动力机械研究所 | Device and method for testing vibration damping property of elastic support extruded oil film damper |
| CN106768986A (en) * | 2017-02-22 | 2017-05-31 | 大连海事大学 | Fluid film lubrication damping test platform |
| CN106989917A (en) * | 2017-06-01 | 2017-07-28 | 中国航发湖南动力机械研究所 | Flexibly support the dynamic stiffness measurement device and its measuring method of squeeze film damper |
Non-Patent Citations (1)
| Title |
|---|
| 切向油膜阻尼实验研究;王佳丽等;《第26届全国结构工程学术会议论文集（第Ⅰ册）》;20170930;第I-618页第2.1节以及图2 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108303241A (en) | 2018-07-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Guo et al. | Direct measurement of friction of a fluctuating contact line | |
| CN103822703B (en) | Unsmooth dynamic compensation method for ultralow-frequency horizontal vibration table guide rail | |
| Morooka et al. | Experiments with a steel catenary riser model in a towing tank | |
| US20090120168A1 (en) | Microfluidic downhole density and viscosity sensor | |
| CN205228620U (en) | Probe -type sensing module of testing vibration | |
| O'Loughlin et al. | MEMS accelerometers for measuring dynamic penetration events in geotechnical centrifuge tests | |
| CN108303241B (en) | A kind of modularization oil-film damping test device and method | |
| Ghemari et al. | Mechanical resonator sensor characteristics development for precise vibratory analysis | |
| Ja et al. | An experimental and theoretical method of calculating the damping ratio of the sucker rod column oscillation | |
| CN105478245A (en) | Identification method on basis of vibration detection of main shaft and for dynamic unbalance value of auxiliary shaft of double-freedom degree precision centrifugal machine | |
| Wang et al. | Dynamic response analysis of drill pipe considering horizontal movement of platform during installation of subsea production tree | |
| CN108318199A (en) | A kind of Machine Joint Surfaces normal direction basic characteristic parameter test device and method | |
| CN208432333U (en) | A kind of table top assembly | |
| Schiavi et al. | Simultaneous 3-axis MEMS accelerometer primary calibration: description of the test-rig and measurements | |
| CN105209901A (en) | Non-invasive method for measurement of physical properties of free flowing materials in vessels | |
| Tang et al. | Identification of hydrodynamic coefficients from experiment of vortex-induced vibration of slender riser model | |
| Shen et al. | Experimental analysis of dynamic oil film pressure of tilting-pad journal bearings | |
| Zheng et al. | Dynamic force transducer calibration based on electrostatic force | |
| CN103712794B (en) | Gear train assembly impact shock energy slippages rate detection system and method | |
| CN106768986B (en) | Fluid film lubrication damping test platform | |
| Strandberg | Experimental Investigation of Fluid-added Parameters on a Kaplan Runner | |
| Liu et al. | Design of Array MEMS Vector Vibration Sensor in the Location of Pipeline Inspection Gauge | |
| CN105241385B (en) | The method for real-time measurement of object vibration displacement in inertial space | |
| Ransom et al. | Identification of force coefficients from a gas annular seal-effect of transition flow regime to turbulence | |
| JPS6326854B2 (en) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |