A hydraulic rock drill piston-bush film thickness observation device

Abstract

The application discloses a kind of hydraulic rock drill plunger-bush film thickness observation equipment, and the observation equipment is equipped with crankcase on the top of oil pan on bottom plate;Motor is used to drive crankshaft rotation;Cylinder body is fixedly installed on the top of crankcase;Upper bushing, glass ring and lower bushing are loosely fitted on the inner wall of cylinder body;Upper oil retaining ring, test ring and lower oil retaining ring are installed on the outer circumferential surface of plunger with gap cooperation with the inner wall of bushing;Cylinder body is provided with window;The inner surface of glass ring is provided with a layer of chromium film;High-speed camera is oppositely arranged with glass ring in window by microscope;Laser emitted by laser source is vertically shot to glass ring by objective lens of microscope;Laser is reflected on the surface of test ring on both sides of oil film and the surface of chromium film respectively, and forms mutually superimposed bright and dark stripes reflected to microscope, and imaging on the photosensitive element of high-speed camera.The observation equipment is used to realize non-contact, dynamic and high-precision observation and prediction of oil film thickness.

Description

Technical Field

[0001] This invention belongs to the field of mining equipment technology, specifically relating to a hydraulic rock drill plunger-liner film thickness observation device. Background Technology

[0002] Rock drills operate in harsh environments characterized by high pressure, high speed, high frequency, and strong vibration. As a critical component, the plunger-bushing friction pair frequently experiences excessive wear and failure, thus often being a key factor limiting the lifespan of the rock drill. The lubricating oil film, acting as the insulating medium between the friction pairs, bears the heavy responsibility of lubrication, load bearing, and wear resistance; its thickness directly determines the friction state. However, because oil film thickness is typically in the nanometer to micrometer range, its precise measurement has always been a research hotspot and challenge in the fields of tribology and mechanical engineering.

[0003] Currently, domestic and international methods for measuring oil film thickness mainly focus on the following areas: 1. Electrical measurement was the earliest method applied to oil film thickness monitoring, mainly including the resistance method and the capacitance method. The resistance method uses the resistance difference between metal contact and oil film isolation to estimate the oil film thickness, suitable for studying boundary and mixed lubrication states. The capacitance method treats the oil film as a dielectric layer and estimates its thickness through capacitance changes; it has a simple structure and is suitable for real-time monitoring. However, electrical methods are generally sensitive to the material's conductivity and dielectric constant, and have limited environmental adaptability.

[0004] 2. Optical interferometry is one of the most accurate methods for measuring oil film thickness, with resolution down to the nanometer level. This method utilizes the reflection of light at the interface between the oil film and the substrate to form interference fringes, thereby obtaining the oil film thickness distribution. Optical methods are widely used in academic research, such as measuring the thickness distribution of elastohydrodynamic lubricating oil films. However, its application in closed friction pairs (such as plunger pairs and bearing inner surfaces) is limited due to the need for transparent windows or specially designed samples. The propagation characteristics of ultrasound at solid-liquid-solid interfaces are closely related to oil film thickness. By analyzing the echo amplitude, phase, or propagation time, non-destructive testing of oil film thickness can be achieved.

[0005] 3. Ultrasonic methods have advantages such as strong penetration, insensitivity to ambient light, and suitability for in-situ measurements, making them particularly suitable for oil film monitoring under high pressure and strong vibration environments. Therefore, they have become a research hotspot in recent years. However, this method places high demands on sensor placement, signal processing algorithms, and environmental noise suppression. X-ray and neutron transmission methods utilize the absorption characteristics of oil films for X-rays or neutrons to achieve thickness measurement. These methods offer advantages such as non-contact and high precision, but the testing equipment is expensive and the experimental conditions are demanding, limiting them mainly to laboratory research and making it difficult to extend to engineering fields.

[0006] Among the existing rock drill performance testing rigs, most testing equipment is geared towards research on the dynamics and vibration characteristics, durability and life testing, and hydraulic control strategy verification of rock drills. Research on lubrication testing of the plunger-bushing friction pair is still lacking.

[0007] In summary, to make the test conditions closer to the actual working conditions of a rock drill, this invention proposes a plunger-bulb film thickness observation device for a hydraulic rock drill, based on the optical interferometry method suitable for applied basic research. Summary of the Invention

[0008] This invention provides a plunger-bushing film thickness observation device for hydraulic rock drills. This device enables non-contact, dynamic, and high-precision observation and prediction of oil film thickness, and is of great significance in the material and lubrication design, life assessment, and verification of new control methods for reciprocating surface contact friction pairs.

[0009] To achieve the above objectives, the present invention adopts the following specific technical solution: A hydraulic rock drill plunger-bushing film thickness observation device, wherein an oil pan and a motor are fixedly installed on a base plate; A crankcase is fixedly mounted on the top of the oil pan; the crankshaft is rotatably mounted in the crankcase; the motor is connected to the crankshaft drive and is used to drive the crankshaft to rotate. The plunger-bushing assembly includes a cylinder block fixedly mounted at the bottom of the crankcase; a bushing consisting of an upper bushing, a glass ring, and a lower bushing connected sequentially from top to bottom is loosely fitted on the inner wall of the cylinder block; three annular grooves are spaced apart on the outer circumference of the plunger, with an upper oil baffle ring installed in the upper annular groove, a test ring installed in the middle annular groove, and a lower oil baffle ring installed in the lower annular groove; the upper oil baffle ring, the test ring, and the lower oil baffle ring are all clearance-fitted with the inner wall of the bushing; a connecting rod connects the plunger and the crankshaft; a window is provided in the cylinder block; a thin chromium film is provided on the inner surface of the glass ring; The cylinder block is equipped with an oil supply nozzle for spraying lubricating oil onto the top of the plunger; A high-speed camera is positioned opposite a microscope and a glass ring inside a window. A laser emitted from a laser source is directed perpendicularly to the glass ring through the objective lens of the microscope. The laser is reflected off the test ring surface and the chromium film surface on both sides of the oil film and interferes with each other, forming superimposed bright and dark fringes reflected back to the microscope. These fringes are then imaged on the photosensitive element of the high-speed camera. The thickness of the oil film is determined based on the wavelength of the laser, the order of the interference fringes, and the brightness information.

[0010] Furthermore, the gaps between the upper and lower oil baffle rings and the inner wall of the bushing allow the space between the upper and lower oil baffle rings to be filled with lubricating oil.

[0011] Furthermore, the inner wall of the cylinder is provided with a retaining ring for limiting the bottom end face of the lower bushing.

[0012] Furthermore, the cylinder block has multiple windows evenly distributed circumferentially; The height of the window covers the piston's stroke. The glass ring is located within the plunger's stroke.

[0013] Furthermore, it also includes a motor mount that is fixedly installed between the base plate and the motor.

[0014] Furthermore, the big end of the connecting rod is clearance-fitted with the crankshaft, while the small end of the connecting rod is fixedly connected to the plunger via a piston pin.

[0015] Furthermore, the two ends of the crankshaft are mounted to the crankcase via bearings and are fixedly connected to the output shaft of the motor via a coupling.

[0016] Furthermore, it also includes optical platforms for supporting high-speed cameras, microscopes, and laser sources.

[0017] Furthermore, a flange is provided at the bottom of the cylinder block, and the flange is connected to the crankcase by fasteners.

[0018] Furthermore, it also includes an electronic control system for controlling the motor, laser source, and high-speed camera.

[0019] Compared with the prior art, the technical solution of the present invention has the following beneficial effects: The film thickness observation device of this invention has a bushing inside the cylinder, consisting of an upper bushing, a glass ring, and a lower bushing connected sequentially from top to bottom. A section of the bushing at a certain position is replaced by a transparent coated glass ring of the same size and precision as the bushing. A window is provided around the circumference of the cylinder. An observation system consisting of a high-speed camera and a microscope is used to observe the film thickness between the plunger and the glass ring through the window of the cylinder. By rotating the cylinder, film thickness observation can be achieved at a certain height throughout the entire circumference. By installing upper and lower bushings at different heights, the height position of the glass ring can be adjusted to change the observation position along the plunger stroke height direction. In this way, through multiple disassembly and assembly measurements, the oil film thickness at any position throughout the entire stroke and circumference can be measured, establishing an oil film thickness distribution throughout the entire height and circumference.

[0020] The aforementioned film thickness observation equipment utilizes optical interferometry to overcome the limitations of traditional electrical and ultrasonic methods in closed friction pairs. It achieves high-precision film thickness prediction by dynamically analyzing interference fringes. By controlling parameters such as rotational speed, temperature, pressure, and lubricating oil viscosity, it obtains the distribution and evolution of oil film thickness under different working conditions. The constructed film thickness observation equipment is suitable for studying the film thickness measurement of rock drill plunger-bushing friction pairs and can be used for friction pair material selection and lubrication scheme design, thereby improving the service life of rock drills.

[0021] In the aforementioned film thickness observation equipment, the cylinder block and crankcase are fixedly installed, making disassembly and assembly convenient. This allows for the simulation of the actual plunger ring-bushing lubrication condition while avoiding the impact of strong, accidental differences caused by combustion on film thickness measurement. Attached Figure Description

[0022] Figure 1 This is a three-dimensional structural schematic diagram of the hydraulic rock drill plunger-bulb film thickness observation device of the present invention; Figure 2 This is a schematic diagram of the plunger-bushing assembly.

[0023] Figure label: 1-Motor; 2-Motor mount; 3-Base plate; 4-Oil pan; 5-Crankcase; 6-Plunger-bulb assembly; 7-Laser source; 8-Microscope; 9-High-speed camera; 10-Cylinder block; 11-Plunger; 12-Upper bushing; 13-Glass ring; 14-Lower bushing; 15-Upper oil baffle ring; 16-Test ring; 17-Lower oil baffle ring; 18-Connecting rod. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] This invention addresses the challenge of measuring the film thickness of the plunger-bushing friction pair in rock drills, primarily solving the following three technical problems: Traditional rock drill testing equipment focuses on vibration and impact characteristics, material durability testing, and hydraulic control strategies, lacking testing devices for film thickness detection; Analyzing the lubrication state at different contact positions based on oil film variation patterns allows for optimization of the design of materials and lubrication schemes for the rock drill plunger-bushing friction pair; By controlling rotational speed, temperature, and viscosity, the influence of various operating parameters on the plunger-bushing friction pair can be studied.

[0026] This embodiment provides a hydraulic rock drill plunger-bulb film thickness observation device, such as... Figure 1 and Figure 2 As shown in the structure, the observation device includes a motor 1, a motor mount 2, a base plate 3, an oil pan 4, a crankcase 5, a crankshaft (not shown in the figure), a plunger-bulb assembly 6, a laser source 7, a microscope 8, and a high-speed camera 9; wherein: The base plate 3 serves as the foundation of the entire observation equipment, located at the bottom of the equipment. The oil pan 4 and the motor 1 are fixedly mounted on the base plate 3. To facilitate the installation of the motor 1 and the crankshaft, a motor mount 2 is fixedly installed between the base plate 3 and the motor 1. The motor mount 2 is fixedly connected to the base plate 3 and provides a mounting base for the motor 1.

[0027] A crankcase 5 is fixedly mounted on the top of the oil pan 4, and the oil pan 4 is used to collect the lubricating oil in the crankcase 5. The crankshaft is rotatably mounted in the crankcase 5, and both ends of the crankshaft are mounted in the crankcase 5 by bearings and are fixedly connected to the output shaft of the motor 1 by a coupling. The motor 1 is driven by the crankshaft and is used to drive the crankshaft to rotate.

[0028] like Figure 2 As shown, the plunger-bushing assembly 6 includes a cylinder block 10, a plunger 11, an upper bushing 12, a glass ring 13, a lower bushing 14, an upper oil baffle ring 15, a test ring 16, a lower oil baffle ring 17, and a connecting rod 18. The cylinder block 10 is arranged vertically and its bottom end is fixedly mounted on the top of the crankcase 5. The cylinder block 10 and the crankcase 5 can be connected by threads, or a flange can be provided at the bottom end of the cylinder block 10, and the flange can be fixedly connected to the crankcase 5 by bolts, screws, and other fasteners.

[0029] The cylinder body 10 has a loosely fitted bushing on its inner wall. The bushing consists of an upper bushing 12, a glass ring 13, and a lower bushing 14 connected sequentially from top to bottom. The inner wall of the cylinder body 10 is provided with a retaining ring (not shown in the figure) for limiting the bottom end face of the lower bushing 14. The retaining ring also supports the bottom end of the lower bushing 14. The inner diameter of the retaining ring is larger than the inner diameter of the lower bushing 14 to avoid the retaining ring affecting the reciprocating movement of the plunger 11. The outer circumferential surface of the plunger 11 is provided with three annular grooves (not shown in the figure) at intervals. The three annular grooves are distributed vertically at intervals, namely the first annular groove on the upper side, the second annular groove in the middle, and the third annular groove on the lower side. An upper oil baffle ring 15 is installed in the first annular groove on the upper side, a test ring 16 is installed in the second annular groove in the middle, and a lower oil baffle ring 17 is installed in the third annular groove on the lower side. The upper oil baffle ring 15, test ring 16, and lower oil baffle ring 17 are all clearance-fitted with the inner wall of the bushing, ensuring gaps between the upper oil baffle ring 15 and the inner wall of the bushing, the test ring 16 and the inner wall of the bushing, and the lower oil baffle ring 17 and the inner wall of the bushing. Through design and calculation, by controlling the gaps between the upper oil baffle ring 15 and the inner wall of the bushing, and between the lower oil baffle ring 17 and the inner wall of the bushing, the space between the upper oil baffle ring 15 and the lower oil baffle ring 17 can be filled with lubricating oil; that is, the cavity between the upper oil baffle ring 15 and the lower oil baffle ring 17, where the test ring 16 is located, is filled with lubricating oil. The cross-sectional shape of the upper oil baffle ring 15, test ring 16, and lower oil baffle ring 17 is rectangular.

[0030] Connecting rod 18 connects the plunger 11 and the crankshaft; the large end of connecting rod 18 is clearance-fitted with the crankshaft, and the small end of connecting rod 18 is fixedly connected to the plunger 11 via a piston pin. The rotation of the crankshaft driven by motor 1 is converted into the reciprocating linear motion of the plunger 11 in the vertical direction through connecting rod 18.

[0031] The cylinder block 10 has windows, which are elongated openings running vertically and extending through the wall thickness of the cylinder block 10, allowing light to pass through and directly view the upper oil baffle ring 15, test ring 16, and lower oil baffle ring 17 inside the glass ring 13. Multiple windows, such as three or four, are evenly distributed circumferentially on the cylinder block 10. The height of the windows covers the stroke of the plunger 11; that is, the top dead center and bottom dead center of the plunger 11 are both within the height range of the windows. The glass ring 13 is located within the stroke of the plunger 11, that is, between the top dead center and bottom dead center of the plunger 11. A thin chromium film is provided on the inner surface of the glass ring 13.

[0032] The cylinder block 10 is provided with an oil supply nozzle for spraying lubricating oil onto the top of the plunger 11. The oil supply nozzle can be connected to an oil pump via an oil pipe to obtain the required lubricating oil.

[0033] The high-speed camera 9 is positioned opposite the glass ring 13 within the window of the microscope 8, allowing the thickness of the oil film between the test ring 16 and the glass ring 13 to be detected through the microscope 8, the window, and the glass ring 13. A laser emitted from the laser source 7 is directed perpendicularly to the glass ring 13 through the objective lens of the microscope 8. The emission direction of the laser source 7 is perpendicular to the optical axis of the microscope 8. A semi-transparent mirror can be placed inside the microscope 8 to reflect the laser emitted from the laser source 7, while allowing light reflected from the lubricating oil film to pass through and enter the high-speed camera 9. The laser light is reflected from the surfaces of the test ring 16 and the chromium film on both sides of the oil film, and then interferes with each other, forming superimposed bright and dark fringes reflected back to the microscope 8. These fringes are then imaged on the photosensitive element of the high-speed camera 9. The oil film thickness is determined based on the laser wavelength, the order of the interference fringes, and the brightness information.

[0034] To support the observation system and automatically control the film thickness observation equipment, the aforementioned observation equipment also includes an optical platform and an electronic control system. The optical platform supports the high-speed camera 9, microscope 8, and laser source 7, and can be a lifting platform fixedly mounted on the base plate 3. The electronic control system can be fixedly mounted on the base plate 3 and is connected to the motor 1, laser source 7, and high-speed camera 9 for signal control.

[0035] The aforementioned observation device has a bushing inside the cylinder 10 consisting of an upper bushing 12, a glass ring 13, and a lower bushing 14 connected sequentially from top to bottom. A section of the bushing at a certain position is replaced by a transparent coated glass ring 13 of the same size and precision as the bushing. A window is provided around the circumference of the cylinder 10. The film thickness between the plunger 11 and the glass ring 13 is observed through the window of the cylinder 10 using an observation system consisting of a high-speed camera 9 and a microscope 8. By rotating the cylinder 10, the film thickness can be observed at a certain height throughout the entire circumference. By installing upper bushings 12 and lower bushings 14 at different heights, the height position of the glass ring 13 can be adjusted to change the observation position along the stroke height direction of the plunger 11. In this way, through multiple disassembly and assembly measurements, the oil film thickness at any position throughout the entire stroke and circumference can be measured, establishing the oil film thickness distribution throughout the entire height and circumference.

[0036] The aforementioned observation equipment utilizes optical interferometry to overcome the limitations of traditional electrical and ultrasonic methods in closed friction pairs. It achieves high-precision film thickness prediction by dynamically analyzing interference fringes. By controlling parameters such as rotational speed, temperature, pressure, and lubricating oil viscosity, it obtains the distribution and evolution of oil film thickness under different working conditions. The constructed film thickness observation equipment is suitable for studying the film thickness measurement of rock drill plunger-bushing friction pairs and can be used for friction pair material selection and lubrication scheme design, thereby improving the service life of rock drills.

[0037] In the aforementioned observation equipment, the cylinder block 10 and crankcase 5 are fixedly installed, making disassembly and assembly convenient. This allows for the simulation of the actual plunger ring-bushing lubrication condition while avoiding the impact of strong, accidental differences caused by combustion on film thickness measurement.

[0038] The installation process of the above-mentioned observation equipment is as follows: First, the lower bushing 14 is installed into the cylinder 10 through the top opening of the cylinder 10, all the way to the bottom retaining ring. Then, the glass ring 13 is installed into the cylinder 10 in the same way until the bottom end face of the glass ring 13 contacts the top end face of the lower bushing 14. Finally, the upper bushing 12 is installed. The fit between the lower bushing 14, glass ring 13, and upper bushing 12 and the cylinder 10 is a loose fit. The upper oil retaining ring 15, test ring 16, and lower oil retaining ring 17 of the plunger 11 are all rectangular rings, which are installed into the three annular grooves of the plunger 11 in sequence. The gaps between the upper oil retaining ring 15, test ring 16, and lower oil retaining ring 17 and the bushing are very small. Finally, the plunger 11 assembly, formed by assembling the piston pin, connecting rod 18, plunger 11, upper oil retaining ring 15, test ring 16, and lower oil retaining ring 17, is installed from the direction of the lower bushing 14 using plunger ring calipers.

[0039] The operation of the aforementioned observation equipment is as follows: Before the observation begins, the oil supply nozzle at the top of the cylinder block 10 will spray oil from the direction of the upper bushing 12 towards the top of the plunger 11. Since there are gaps between the upper baffle ring 15 and the bushing, between the test ring 16 and the bushing, and between the lower baffle ring 17 and the bushing, lubricating oil will flow sequentially into the cavities between the upper baffle ring 15 and the test ring 16, and between the test ring 16 and the lower baffle ring 17, and finally flow out from the gap between the lower baffle ring 17 and the bushing. The design purpose of the upper baffle ring 15 and the lower baffle ring 17 is to fill the gaps between them and the test ring 16 with sufficient lubricating oil, so that the test ring 16 is in a fully lubricated state, thus simulating the lubrication state of the plunger-bushing friction pair in the hydraulic chamber. When the motor 1 starts, the plunger 11 will drive the upper baffle ring 15, the test ring 16, and the lower baffle ring 17 to reciprocate. By controlling the oil injection quantity, the amount of oil flowing into the upper baffle ring 15 and the amount of oil flowing out of the lower baffle ring 17 are balanced. The oil film thickness at the position where the test ring 16 passes through the glass ring 13 can be observed using the observation system. By adjusting the height of the upper and lower bushings 14 and the rotation of the bushings, the film thickness in the moving contact area in the entire axial and circumferential directions can be observed.

[0040] The working principle of the above-mentioned observation equipment is as follows: A uniform thin chromium film is coated on the inner surface of the glass ring 13. When the test ring 16 passes through the inner surface of the glass ring 13, the oil film fills the tiny gap between the test ring 16 and the chromium film. At this time, a laser perpendicular to the contact area is emitted from the objective lens of the observation system. The laser is reflected on the upper and lower surfaces of the oil film (the surface of the test ring 16 and the surface of the chromium film) and interferes with each other, forming superimposed bright and dark fringes that are reflected back to the observation system and finally imaged on the photosensitive element of the high-speed camera 9. The thickness of the oil film can be determined based on the wavelength of the laser, the order of the interference fringes, and the brightness information.

[0041] Obviously, those skilled in the art can make various modifications and variations to the embodiments of the present invention without departing from the spirit and scope of the invention. Therefore, if these modifications and variations fall within the scope of the claims of the present invention and their equivalents, the present invention also intends to include these modifications and variations.

[0042] In summary, the above are merely preferred embodiments of the present invention and are 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 plunger-bulb film thickness observation device for a hydraulic rock drill, characterized in that, The observation equipment has an oil pan and a motor fixedly mounted on the base plate; A crankcase is fixedly mounted on the top of the oil pan; the crankshaft is rotatably mounted in the crankcase; the motor is connected to the crankshaft drive and is used to drive the crankshaft to rotate. The plunger-bushing assembly includes a cylinder block fixedly mounted at the bottom of the crankcase; a bushing consisting of an upper bushing, a glass ring, and a lower bushing connected sequentially from top to bottom is loosely fitted on the inner wall of the cylinder block; three annular grooves are spaced apart on the outer circumference of the plunger, with an upper oil baffle ring installed in the upper annular groove, a test ring installed in the middle annular groove, and a lower oil baffle ring installed in the lower annular groove; the upper oil baffle ring, the test ring, and the lower oil baffle ring are all clearance-fitted with the inner wall of the bushing; a connecting rod connects the plunger and the crankshaft; a window is provided in the cylinder block; a thin chromium film is provided on the inner surface of the glass ring; The cylinder block is equipped with an oil supply nozzle for spraying lubricating oil onto the top of the plunger; A high-speed camera is positioned opposite a microscope and a glass ring inside a window. A laser emitted from a laser source is directed perpendicularly to the glass ring through the objective lens of the microscope. The laser is reflected off the test ring surface and the chromium film surface on both sides of the oil film and interferes with each other, forming superimposed bright and dark fringes reflected back to the microscope. These fringes are then imaged on the photosensitive element of the high-speed camera. The thickness of the oil film is determined based on the wavelength of the laser, the order of the interference fringes, and the brightness information.

2. The hydraulic rock drill plunger-bulb film thickness observation device as described in claim 1, characterized in that, The gaps between the upper and lower oil baffle rings and the inner wall of the bushing allow the space between the upper and lower oil baffle rings to be filled with lubricating oil.

3. The hydraulic rock drill plunger-bulb film thickness observation device as described in claim 1, characterized in that, The inner wall of the cylinder is provided with a retaining ring for limiting the bottom end face of the lower bushing.

4. The hydraulic rock drill plunger-bulb film thickness observation device as described in claim 1, characterized in that, The cylinder block has multiple windows evenly distributed circumferentially. The height of the window covers the piston's stroke. The glass ring is located within the plunger's stroke.

5. The hydraulic rock drill plunger-bulb film thickness observation device as described in claim 1, characterized in that, It also includes a motor mount that is fixedly installed between the base plate and the motor.

6. The hydraulic rock drill plunger-bulb film thickness observation device as described in claim 1, characterized in that, The big end of the connecting rod is clearance-fitted with the crankshaft, while the small end of the connecting rod is fixedly connected to the plunger via a piston pin.

7. The hydraulic rock drill plunger-bulb film thickness observation device as described in claim 1, characterized in that, The crankshaft is mounted on the crankcase at both ends by bearings and is fixedly connected to the output shaft of the motor by a coupling.

8. The hydraulic rock drill plunger-bulb film thickness observation device as described in claim 1, characterized in that, It also includes optical platforms for supporting high-speed cameras, microscopes, and laser sources.

9. The hydraulic rock drill plunger-bulb film thickness observation device as described in claim 1, characterized in that, A flange is provided at the bottom of the cylinder block, and the flange is connected to the crankcase by fasteners.

10. The hydraulic rock drill plunger-bulb film thickness observation device as described in any one of claims 1-9, characterized in that, It also includes an electronic control system for controlling the motor, laser source, and high-speed camera.

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