CN113340708B - Lifting device of pseudo-triaxial pressure-maintaining loading device - Google Patents
Lifting device of pseudo-triaxial pressure-maintaining loading device Download PDFInfo
- Publication number
- CN113340708B CN113340708B CN202110613979.XA CN202110613979A CN113340708B CN 113340708 B CN113340708 B CN 113340708B CN 202110613979 A CN202110613979 A CN 202110613979A CN 113340708 B CN113340708 B CN 113340708B
- Authority
- CN
- China
- Prior art keywords
- lifting
- pseudo
- block
- piston rod
- sliding block
- 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
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/02—Details
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/02—Details
- G01N3/04—Chucks
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
- G01N3/10—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces generated by pneumatic or hydraulic pressure
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
- Testing Of Devices, Machine Parts, Or Other Structures Thereof (AREA)
Abstract
The lifting device of the pseudo-triaxial pressure maintaining loading device comprises a plurality of lifting mechanisms and a driving device capable of driving the plurality of lifting mechanisms simultaneously, the lifting mechanisms are distributed at intervals in the circumferential direction, each lifting mechanism comprises a guide rail, a sliding block capable of sliding along the guide rail, a lifting block arranged on the sliding block in a relatively sliding mode and a transmission mechanism connected with the driving device, the upper end of each lifting block is fixedly connected with a lower cylinder cover of the pseudo-triaxial pressure maintaining loading device, the contact bottom surfaces of the lifting blocks and the sliding blocks are inclined surfaces, and when the driving device drives the sliding blocks to move along the guide rails through the transmission mechanisms, the sliding blocks and the lifting blocks slide relatively to enable the lifting blocks to move up and down. According to the lifting device of the pseudo-triaxial pressure-maintaining loading device, the lifting displacement of the cylinder body is accurately controlled through multi-stage transmission and the inclination angle of the contact bottom surface of the lifting block and the sliding block, so that a fidelity sample is always positioned at the center of the test chamber, and the accuracy of obtained experimental data is ensured.
Description
Technical Field
The invention relates to a lifting device, in particular to a lifting device of a pseudo-triaxial testing machine.
Background
Traditional pseudo-triaxial testing machine is when axial loading, and one end is fixed with the cylinder body, and the relative cylinder body of the other end removes and comes the loading, and the sensor depends on and measures axial or radial deformation on the sample. As shown in fig. 4, in the pseudo-triaxial dwell loading apparatus 4, the plurality of sensors 47 are located in the annular cavity 460 of the annular oil bag 46 and fixed to the oil bag holder 45, the oil bag holder 45 is connected to the cylinder body 40, and the fidelity sample 5 is located in the test chamber formed by the central hole of the annular oil bag 46 and held by the annular oil bag 46. The pseudo-triaxial pressure-maintaining loading device is generally vertically arranged on a uniaxial testing machine for loading test, the lower piston rod 44 is fixed, the upper piston rod 43 is loaded by the uniaxial testing machine, when the upper piston rod 43 is loaded, the fidelity sample 5 can move downwards under the action of the upper piston rod 43 to deform and deviate from the central position of a test chamber, so that the sensor 47 fixed on the cylinder body 40 and the fidelity sample 5 move relatively to influence the accuracy of experimental data. Therefore, in order to ensure that the fidelity sample 5 is always located at the central position of the test chamber, a lifting device for the pseudo-triaxial dwell loading device 4 needs to be developed, so that when the single-axis testing machine is loaded, the lifting device can simultaneously drive the cylinder body 40 of the pseudo-triaxial dwell loading device 4 to move, and the moving direction of the lifting device is consistent with the moving direction of the upper piston rod 44, so as to ensure that the fidelity sample 5 is always located at the central position of the test chamber. The deformation displacement may be in the order of micrometers to millimeters, taking into account the variability of rock deformation, and therefore the lifting device needs to be able to adjust the lifting displacement accurately over a large range.
Disclosure of Invention
The invention aims to solve the technical problem of providing a lifting device of a pseudo-triaxial pressure maintaining loading device, which has a compact structure and large bearing capacity and can realize accurate lifting of a cylinder body of the pseudo-triaxial pressure maintaining device relative to a lower piston rod.
The lifting device of the pseudo-triaxial pressure maintaining loading device comprises a plurality of lifting mechanisms and a driving device capable of driving the plurality of lifting mechanisms simultaneously, wherein the lifting mechanisms are distributed at intervals in the circumferential direction, each lifting mechanism comprises a guide rail, a sliding block capable of sliding along the guide rail, a lifting block capable of being installed on the sliding block in a relatively sliding mode and a transmission mechanism connected with the driving device, the upper end of each lifting block is fixedly connected with a lower cylinder cover of the pseudo-triaxial pressure maintaining loading device, the contact bottom surfaces of the lifting blocks and the sliding blocks are inclined surfaces, and when the driving device drives the sliding blocks to move along the guide rails through the transmission mechanisms, the sliding blocks and the lifting blocks slide relatively to enable the lifting blocks to move up and down.
The invention relates to a lifting device of a pseudo-triaxial pressure-maintaining loading device, wherein a transmission mechanism comprises a rack and a transmission gear set which are fixed on the side surface of a sliding block, a driving device comprises a central gear set and a motor reduction box, the central gear set is positioned at the center surrounded by a plurality of lifting mechanisms, the motor reduction box drives the central gear set through a worm set, and the central gear set drives the corresponding rack to move through the transmission gear set which is respectively matched with the central gear set.
The invention relates to a lifting device of a pseudo triaxial pressure maintaining loading device, wherein a central hole which can be in clearance fit with a lower piston rod of the pseudo triaxial pressure maintaining loading device is formed in a central transmission shaft of a central gear set.
The lifting device of the pseudo-triaxial pressure maintaining loading device comprises four groups of lifting mechanisms which are distributed at equal intervals along the circumferential direction.
According to the lifting device of the pseudo-triaxial pressure-maintaining loading device, the four lifting blocks and the sliding block are driven to move relatively by step through the step-by-step transmission of the worm group, the central gear group and the four gear transmission groups, and the lifting displacement of the four lifting blocks is accurately controlled by setting the inclination angle of the contact bottom surfaces of the lifting blocks and the sliding block, so that the accurate lifting displacement of a cylinder body of the pseudo-triaxial pressure-maintaining device relative to a lower piston rod is accurately controlled, a fidelity sample is ensured to be always positioned at the central position of a test cabin, and the fidelity sample cannot deviate from the central position due to the loading of a testing machine on an upper piston rod. The lifting device of the pseudo-triaxial pressure-maintaining loading device effectively ensures the accuracy of experimental data obtained by the pseudo-triaxial pressure-maintaining loading device during loading.
The lifting device of the pseudo-triaxial pressure-maintaining loading device of the invention is further explained with reference to the attached drawings.
Drawings
FIG. 1 is a schematic perspective view of a lifting device of a pseudo-triaxial pressure maintaining loading device according to the present invention;
FIG. 2 is a schematic diagram of the driving device and the transmission mechanism of the pseudo-triaxial pressure maintaining loading device of the present invention;
FIG. 3 is an assembly diagram of a lifting device and a pseudo-triaxial pressure maintaining loading device of the pseudo-triaxial pressure maintaining loading device according to the present invention;
fig. 4 is a cross-sectional view of a pseudo-triaxial dwell loading apparatus.
Detailed Description
As shown in fig. 1 and fig. 2, the lifting device of the pseudo-triaxial dwell loading device of the present invention includes a plurality of circumferentially distributed lifting mechanisms 1 and a driving device capable of driving the plurality of lifting mechanisms 1 simultaneously, and an upper end of each lifting mechanism 1 is used for being fixedly connected to a lower cylinder head 42 of the pseudo-triaxial dwell loading device 4. The driving device is used for driving the upper end of the lifting mechanism 1 to move up and down. The lifting mechanisms 1 of the present embodiment are four groups and are equally spaced in the circumferential direction. The lifting mechanism 1 comprises a guide rail 14, a slide block 12, a lifting block 11 and a transmission mechanism. The guide rail 14 is fixed on the bottom plate 33, and the bottom of the sliding block 12 is provided with a sliding groove matched with the guide rail 14, so that the sliding block 12 can slide on the guide rail 14. The lifting block 11 is arranged at the top of the sliding block 12, the top of the sliding block 12 is provided with a guide groove, the bottom of the lifting block 11 is provided with a guide block matched with the guide groove, and the lifting block 11 and the sliding block 12 can slide relatively; the contact bottom surfaces of the slide block 12 and the lifting block 11 are inclined surfaces with the same inclination angle. The upper end of the lifting block 11 is used for being fixedly connected with a lower cylinder cover 42 of the pseudo-triaxial pressure maintaining loading device 4. The bottom plate 33 is provided with a plurality of upright posts 36, and the top plate 32 is fixed at the upper ends of the upright posts 36; the outer side plate 34 surrounds the outer side surfaces of the top plate 32 and the bottom plate 33; the top plate 32 and the bottom plate 33 form a cylindrical housing with the outer plate 34. The top plate 32 is provided with a lifting hole 31 which is matched with the lifting block 11, and the lifting block 11 can move up and down in the lifting hole 31. The driving device drives the sliding block 12 to move along the guide rail 14 through the transmission mechanism, because the upper end of the lifting block 11 is fixedly connected with the lower cylinder cover of the pseudo-triaxial pressure maintaining loading device, the movement of the lifting block 11 in the horizontal direction is limited, so that the sliding block 12 and the lifting block 11 move relatively, and because the contact bottom surface of the sliding block 12 and the lifting block 11 is an inclined surface, the lifting block 11 moves upwards or downwards in the lifting hole 31. The drive means and transmission are secured between the top plate 32 and the bottom plate 33. The transmission mechanisms are four groups and are respectively provided with a group of lifting mechanisms 1 correspondingly. The transmission mechanism comprises a rack 15 fixed on the side of the slide block 12 and a transmission gear set 16 driving the rack 15 to move, wherein the transmission gear set 16 comprises an initial gear 161, a middle gear 163 engaged with the initial gear 161 and a tail gear 162, and the tail gear 162 and the middle gear 163 are positioned on the same transmission shaft. The drive means 2 comprises a central gear set 20 and a motor reduction gearbox 21 mounted between a top plate 32 and a bottom plate 33. The central gear set 20 includes a central drive shaft 201 and a worm gear 202 and a central gear 203 mounted on the central drive shaft 201. The central transmission shaft 201 is a hollow shaft with a central hole 6 fitted with the lower piston rod 44 of the pseudo-triaxial pressure maintaining loading unit 4. The motor reduction box 21 drives the worm wheel 202 of the central gear set 20 through the worm set 22, drives the central gear 203 to transmit power to the initial gear 161 of the transmission gear set 16 meshed with the central gear, the initial gear 161 drives the end gear 162 to rotate through the intermediate gear 163 meshed with the initial gear, the end gear 162 is meshed with the rack 15, and the slide block 12 is driven to move on the guide rail 14 through the rack 15.
As shown in fig. 4, the pseudo-triaxial dwell loading apparatus 4 includes a cylinder body 40, upper and lower cylinder heads 41, 42 fixed to upper and lower end surfaces of the cylinder body 40, respectively, and an oil sac device and upper and lower piston rods 43,44 located inside the cylinder body 40. The oil bag device includes an oil bag holder 45 and an annular oil bag 46 fixed in the oil bag holder 45. A plurality of sensors 47 are arranged in the annular inner cavity 460 of the annular oil bag 46, and the sensors 47 are fixed on the oil bag frame 45. The oil bag holder 45 is fitted into a groove in the inner wall of the cylinder 40. The fidelity sample 5 is positioned in a test chamber formed by the annular oil bag 46 and the upper and lower piston rods 43 and 44, and the fidelity sample 5 is clamped by the inner wall of the annular oil bag 46.
As shown in fig. 3, when the lifting device of the pseudo-triaxial pressure maintaining loading device of the present invention is used, the lower cylinder head 42 of the pseudo-triaxial pressure maintaining loading device 4 is fixed to the upper ends of the four lifting blocks 11 by bolts, and the lower piston rod 44 is ensured to extend into the central hole 6 in clearance fit therewith. After the installation is finished, a lower pressing disc of a loading testing machine enters from the lower end of a central hole 6 and abuts against the lower end face of a lower piston rod 44, the lower piston rod 44 is fixed, then an upper piston rod 43 of a pseudo-triaxial pressure maintaining loading device 4 is loaded through the loading testing machine, meanwhile, the rotating speed of a motor is controlled through a servo control system, the descending displacement of a lifting block 11 is measured through a monitoring device, the displacement direction of a cylinder body 40 of the pseudo-triaxial pressure maintaining loading device 4 is ensured to be the same as that of the upper piston rod 43, when the downward movement distance of the upper piston rod 43 under the loading of the testing machine is d, the lifting block 12 needs to be ensured to move downwards by d/2, and the fidelity sample 5 is ensured to be located in the central position of a testing cabin constantly. After the motor is started, the worm group 22 drives the central gear group 20, the central gear group 20 simultaneously drives four groups of transmission gear groups 16 matched with the central gear group, the tail end gear 162 of each group of transmission gear groups 16 respectively drives the sliding block 12 to move along the guide rail 14 through the rack 15 meshed with the tail end gear, and the sliding block 12 moves along the radial direction, so that relative displacement is generated between the lifting block 11 and the sliding block 12, the lifting block 11 is pushed to move upwards or downwards, and accurate lifting of a cylinder body of the pseudo-triaxial pressure maintaining device relative to a lower piston rod is realized. According to the inclination angle of the contact bottom surface of the lifting block 11 and the sliding block 12, the transmission ratio of the horizontal movement distance of the sliding block 12 to the vertical movement distance of the lifting block 11 can be calculated, and the precise lifting of the lifting block 11 is realized. The four groups of lifting mechanisms 1 can ensure the stability during lifting and reduce the bearing capacity of each sliding block 12.
According to the lifting device of the pseudo-triaxial pressure-maintaining loading device, the four lifting blocks and the sliding block are driven to move relatively by the step-by-step transmission of the worm group, the central gear group and the four gear transmission groups, and the lifting displacement of the four lifting blocks is realized by setting the inclination angle of the contact bottom surfaces of the lifting blocks and the sliding block, so that the accurate lifting displacement of a cylinder body of the pseudo-triaxial pressure-maintaining device relative to a lower piston rod is accurately controlled, a fidelity sample is ensured to be always positioned at the central position of a test cabin, and the fidelity sample cannot deviate from the central position due to the loading of a testing machine on an upper piston rod. The lifting device of the pseudo-triaxial pressure-maintaining loading device effectively ensures the accuracy of experimental data obtained by the pseudo-triaxial pressure-maintaining loading device during loading.
The above examples are only for describing the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention, and various modifications and improvements made to the technical solution of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.
Claims (3)
1. The utility model provides a pseudo-triaxial pressurize loading attachment's elevating gear which characterized in that: the lifting mechanism (1) is distributed at intervals in the circumferential direction, the lifting mechanism (1) comprises a guide rail (14), a sliding block (12) capable of sliding along the guide rail (14), a lifting block (11) capable of being installed on the sliding block (12) in a relatively sliding manner and a transmission mechanism connected with the driving device, the upper end of the lifting block (11) is fixedly connected with a lower cylinder cover (42) of a pseudo-triaxial pressure maintaining loading device (4), the contact bottom surfaces of the lifting block (11) and the sliding block (12) are inclined surfaces, and when the driving device drives the sliding block (12) to move along the guide rail (14) through the transmission mechanism, the sliding block (12) and the lifting block (11) slide relatively, so that the lifting block (11) moves up and down;
the transmission mechanism comprises a rack (15) and a transmission gear set (16) which are fixed on the side face of the sliding block (12), the driving device comprises a central gear set (20) and a motor reduction box (21), the central gear set (20) is located in the center surrounded by the plurality of lifting mechanisms (1), the motor reduction box (21) drives the central gear set (20) through a worm set (22), and the central gear set (20) drives the corresponding rack (15) to move through the transmission gear set (16) which is respectively matched with the central gear set;
a central hole (6) which can be in clearance fit with a lower piston rod (44) of the pseudo-triaxial pressure maintaining loading device (4) is formed in a central transmission shaft (201) of the central gear set (20);
the pseudo-triaxial pressure-maintaining loading device (4) comprises a cylinder body (40), an upper cylinder cover (41), a lower cylinder cover (42) and an oil sac device, an upper piston rod (43) and a lower piston rod (44), wherein the upper cylinder cover and the lower cylinder cover are respectively fixed on the upper end surface and the lower end surface of the cylinder body (40), and the oil sac device and the upper piston rod and the lower piston rod are positioned in the cylinder body (40);
the using method of the elevator device of the pseudo-triaxial pressure maintaining loading device comprises the following steps:
fixing a lower cylinder cover (42) of the pseudo-triaxial pressure-maintaining loading device (4) and the upper end of a lifting block (11) of the lifting device through bolts, and simultaneously ensuring that a lower piston rod (44) extends into a central hole (66) of the lifting device in clearance fit with the lower piston rod;
after the installation is finished, a lower pressing disc of a loading testing machine enters from the lower end of the central hole (6) and abuts against the lower end face of the lower piston rod (44), the lower piston rod (44) is fixed, then the upper piston rod (43) is loaded through the loading testing machine, meanwhile, the rotating speed of a motor is controlled through a servo control system, the descending displacement of the lifting block (11) is measured through a monitoring device, the displacement directions of the cylinder body (40) and the upper piston rod (43) are ensured to be the same, when the upper piston rod (43) moves downwards under the loading of the testing machine by a distance d, the lifting block (11) needs to be ensured to move downwards by d/2, and the fact that a fidelity sample (5) is always located in the central position of a testing cabin is ensured to be unchanged;
after the motor is started, the worm group (22) drives the central gear group (20), the central gear group (20) simultaneously drives the transmission gear group (16) matched with the central gear group, the tail end gear (162) of each transmission gear group (16) drives the sliding block (12) to move along the guide rail (14) through the rack (15) meshed with the tail end gear, and the sliding block (12) moves along the radial direction, so that the lifting block (11) and the sliding block (12) generate relative displacement, the lifting block (11) is pushed to move upwards or downwards, and the cylinder body of the pseudo-triaxial pressure maintaining loading device is accurately lifted relative to the lower piston rod;
according to the inclination angle of the contact bottom surface of the lifting block (11) and the sliding block (12), the transmission ratio of the horizontal movement distance of the sliding block (12) to the vertical movement distance of the lifting block (11) can be calculated, and the lifting block (11) can be accurately lifted.
2. The lifting device of a pseudo-triaxial dwell loading device according to claim 1, wherein: the bottom of the sliding block (12) is provided with a guide groove matched with the guide rail (14), and the top of the sliding block (12) is provided with a sliding groove matched with the bottom guide block of the lifting block (11).
3. The lift device of a pseudo-triaxial dwell loading device according to any one of claims 1-2, wherein: the lifting mechanisms (1) are four groups and are distributed at equal intervals along the circumferential direction.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202110613979.XA CN113340708B (en) | 2021-06-02 | 2021-06-02 | Lifting device of pseudo-triaxial pressure-maintaining loading device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202110613979.XA CN113340708B (en) | 2021-06-02 | 2021-06-02 | Lifting device of pseudo-triaxial pressure-maintaining loading device |
Publications (2)
Publication Number | Publication Date |
---|---|
CN113340708A CN113340708A (en) | 2021-09-03 |
CN113340708B true CN113340708B (en) | 2022-11-01 |
Family
ID=77474971
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN202110613979.XA Active CN113340708B (en) | 2021-06-02 | 2021-06-02 | Lifting device of pseudo-triaxial pressure-maintaining loading device |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN113340708B (en) |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3344805A1 (en) * | 1983-12-12 | 1985-06-13 | Expert Maschinenbau Gmbh, 6143 Lorsch | LIFT-TURNTABLE DEVICE |
JP3753770B2 (en) * | 1995-12-22 | 2006-03-08 | 東芝機械株式会社 | Three-dimensional tilting device |
CN2472220Y (en) * | 2001-02-28 | 2002-01-16 | 韩学海 | Liftable surface tension duct support |
KR20050073275A (en) * | 2004-01-09 | 2005-07-13 | 한국전기초자 주식회사 | Plunger clamping apparatus for glassware press-forming apparatus |
CN102635761A (en) * | 2012-04-27 | 2012-08-15 | 中国联合工程公司 | Adjustable sizing block |
CN205187760U (en) * | 2015-12-11 | 2016-04-27 | 合肥欣奕华智能机器有限公司 | Lifting system |
CN107792815A (en) * | 2017-11-29 | 2018-03-13 | 中国科学院沈阳自动化研究所 | A kind of single driving multi output elevating mechanism |
-
2021
- 2021-06-02 CN CN202110613979.XA patent/CN113340708B/en active Active
Also Published As
Publication number | Publication date |
---|---|
CN113340708A (en) | 2021-09-03 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN109282749B (en) | Hub detection device | |
CN110193837B (en) | Track inspection robot | |
US11460295B2 (en) | On-line space detection device for wheel inner rim | |
CN107084673B (en) | Device and method for measuring and detecting outer diameter and inner diameter of bullet train wheel | |
CN109969227B (en) | Wheel set detection device, high-speed railway wheel set detection device and moving wheel set detection device | |
CN110641159A (en) | Automatic marking detection robot for brake disc and marking and detection method thereof | |
CN209259566U (en) | A kind of jack device for aircraft wing jacking | |
CN113340708B (en) | Lifting device of pseudo-triaxial pressure-maintaining loading device | |
CN110980587A (en) | Wheel hub jacking and rotating device | |
CN117470162A (en) | Full-automatic detection machine and detection method for railway carriage bearings | |
CN116929946B (en) | Mobile communication equipment die-casting support stability testing arrangement | |
KR100579086B1 (en) | Gap measurement device of inner ring and outter ring of wheel bearing for vehicle | |
CN218973413U (en) | Automobile hub roundness detection device | |
CN202382717U (en) | Big power locomotive axle size measuring machine | |
CN116093011A (en) | Multi-degree-of-freedom motion platform for wafer detection | |
CN217133449U (en) | Precise assembling and adjusting equipment | |
CN115524106A (en) | Bearing retainer testing device and method | |
CN114485777A (en) | Detection equipment and detection method for bearing outer ring runout and rotation torque | |
CN210346640U (en) | Double-row angular contact ball bearing outer ring measuring structure | |
CN113600267A (en) | Crushing device and crushing method for measuring firmness coefficient of coal | |
CN220976496U (en) | Lifting mechanism | |
CN218155966U (en) | Detection apparatus for rotation accuracy | |
CN113310446B (en) | Brake disc runout degree detection positioning device | |
CN114682448B (en) | Accurate side roof machine that targets in place | |
CN218381560U (en) | Polishing grinding head test device |
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 |