A video displacement recognition system for an oil pump

Abstract

The present application relates to the technical field of video displacement recognition, and particularly relates to a video displacement recognition system for an oil pump. The video displacement recognition system is arranged on a fixed shaft rod near the end of the other end of the driving rod, and the video displacement recognition system is arranged corresponding to the scale mark, so that the scale mark is recognized, and then the displacement data of the driving rod in the oil pump is obtained. The video displacement recognition system for the oil pump fills the technical blank of domestic video displacement meters. The image recognition technology and the Internet of Things technology are combined to serve new displacement monitoring sensors in various industrial fields. Compared with traditional pull wire sensors, the video displacement recognition system has the following obvious advantages: the test precision is not affected by the test length, the test frequency can reach 100 Hz, the monitoring precision can reach 0.1 mm, and the imported high-precision pull wire displacement sensor can be effectively replaced.

Description

Technical Field

[0001] This invention relates to the field of video displacement recognition technology, and in particular to a video displacement recognition system for oil pumps. Background Technology

[0002] With the increasing demand for digitalization and intelligentization in pumping products, fire trucks, and other applications, hydraulic cylinder displacement detection has become a crucial point for digital data acquisition and fault monitoring. Currently, imported wire sensors are mainly used, which suffer from high prices and high failure rates, becoming a bottleneck in the digital closed-loop control of pumping products. Therefore, the industry urgently needs a digital, stable video displacement recognition system for oil pumps. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a video displacement recognition system for oil pumps.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A video displacement recognition system for an oil pump, the oil pump including a hollow fixed shaft and a drive rod with one end passing through the fixed shaft and coaxially arranged with the fixed shaft, an oil storage space being formed between the inner side wall of the fixed shaft and the outer side wall of the drive rod, the drive rod having a scale mark arranged along the axial direction of the drive rod, and the video displacement recognition system being located at the end of the fixed shaft near the other end of the drive rod and being arranged corresponding to the scale mark.

[0005] The beneficial effects of this invention are as follows: This invention provides a video displacement recognition system for oil pumps. By providing scale markings along the axial direction of the drive rod on the drive rod, and by placing the video displacement recognition system at the end of a fixed shaft near the other end of the drive rod, with the system corresponding to the scale markings, the system can recognize the scale markings and thus obtain the displacement data of the drive rod in the oil pump. This video displacement recognition system for oil pumps fills a technological gap in domestic video displacement gauges. It combines image recognition technology and Internet of Things (IoT) technology to provide a new type of displacement monitoring sensor serving various industrial fields. Compared with traditional wire-guided sensors, it has the following significant advantages: testing accuracy is not affected by the testing length, the testing frequency can reach 100 Hz, and the monitoring accuracy can reach 0.1 mm, effectively replacing imported high-precision wire-guided displacement sensors. Attached Figure Description

[0006] Figure 1 This is an exploded view of the structure of a video displacement recognition system for an oil pump according to the present invention; Figure 2 This is a schematic diagram illustrating the application of a video displacement recognition system for an oil pump according to the present invention. Figure 3 This is a schematic diagram of the structure of an optical lens for a video displacement recognition system for an oil pump according to the present invention; Figure 4 This is an MTF diagram of an optical lens for a video displacement recognition system for an oil pump according to the present invention. Figure 5 This is a distortion diagram of an optical lens for a video displacement recognition system for an oil pump according to the present invention. Label Explanation: 1. First lens; 2. Second lens; 3. Third lens; 4. Fourth lens; 5. Fifth lens; 6. Sixth lens; 7. Seventh lens; 11. Fixed shaft; 12. Drive rod; 121. Scale markings; 13. Limiting cylinder; 131. Through groove; 14. Optical lens; 15. Outer cover; 16. Rubber gasket; 17. Frosted glass; 18. Interface board; 19. Main control board; 20. Sensor board; 21. Base; 22. Fill light board; 23. Sealing ring; 24. Top cover. Detailed Implementation

[0007] To explain in detail the technical content, objectives, and effects of the present invention, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0008] Please refer to Figures 1 to 5 The present invention provides a video displacement recognition system for an oil pump. The oil pump includes a hollow fixed shaft and a drive rod with one end passing through the fixed shaft and coaxially arranged with the fixed shaft. An oil storage space is formed between the inner side wall of the fixed shaft and the outer side wall of the drive rod. The drive rod is provided with a scale mark arranged along the axial direction of the drive rod. The video displacement recognition system is located at the end of the fixed shaft near the other end of the drive rod and is arranged corresponding to the scale mark.

[0009] As can be seen from the above description, the beneficial effects of the present invention are as follows: This invention provides a video displacement recognition system for oil pumps. By providing scale markings along the axial direction of the drive rod on the drive rod, and by placing the video displacement recognition system at the end of a fixed shaft near the other end of the drive rod, with the system corresponding to the scale markings, the system can recognize the scale markings and thus obtain the displacement data of the drive rod in the oil pump. This video displacement recognition system for oil pumps fills a technological gap in domestic video displacement gauges. It combines image recognition technology and IoT technology to provide a new type of displacement monitoring sensor for various industrial fields. Compared with traditional wire-driven sensors, it has the following significant advantages: testing accuracy is not affected by the testing length, the testing frequency can reach 100 Hz, and the monitoring accuracy can reach 0.1 mm, effectively replacing imported high-precision wire-driven displacement sensors. Furthermore, wire-driven displacement sensors have a high failure rate in actual use; the displacement gauge in this solution does not require mechanical movement, and real-time detection is achieved through image recognition technology. The module can operate 24 / 7, significantly reducing the failure rate.

[0010] Furthermore, the video displacement recognition system includes a limiting cylinder and a video displacement recognition device. The limiting cylinder is sleeved on the drive rod and is fixedly connected to the end of the fixed shaft near the other end of the drive rod. The limiting cylinder is provided with a through groove corresponding to the scale mark, and the video displacement recognition device is installed in the through groove.

[0011] As can be seen from the above description, the video displacement recognition system is applied to the oil pump through the specific structural design described above, which is achieved by the cooperation of the limiting cylinder, the fixed shaft, and the drive rod.

[0012] Furthermore, sealing rings are embedded at both ends of the limiting cylinder that contact the drive rod to keep the limiting cylinder isolated from the oil storage space.

[0013] As can be seen from the above description, through the specific structural design, the limiting cylinder and the oil storage space can be kept isolated. Even if there is relative movement between the drive rod and the fixed shaft, the limiting cylinder and the oil storage space will always remain isolated, that is, oil will not enter the interior of the limiting cylinder, thus avoiding affecting the recognition function of the video displacement recognition system, such as the recognition accuracy.

[0014] Furthermore, the video displacement recognition device includes an optical lens positioned toward the scale markings; The optical lens includes a first lens, a second lens, a third lens, an aperture stop, a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged sequentially along the incident direction of light. The first lens is a meniscus lens, the second lens is a biconcave lens, the third lens is a biconvex lens, the fourth and fifth lenses form a closely spaced cemented group, the sixth lens is a biconvex lens, and the seventh lens is a meniscus lens. The air gap between the first lens and the second lens is 1mm to 2mm, the air gap between the second lens and the third lens is 0mm to 1mm, the air gap between the third lens and the aperture is 0mm to 1mm, the air gap between the aperture and the fourth lens is 0mm to 1mm, the air gap between the fifth lens and the sixth lens is 0mm to 1mm, and the air gap between the sixth lens and the seventh lens is 1mm to 2mm.

[0015] As described above, the optical lens includes a first lens, a second lens, a third lens, an aperture stop, a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged sequentially along the incident light direction, i.e., a six-group, seven-element structure, meeting the usage requirements. The optical system has a center field-of-view MTF value greater than 0.2 at 250 lp / mm, an edge field-of-view MTF value greater than 0.2 at 200 lp / mm, an Fno of 2.6, a relative illumination greater than 50%, a total optical length less than 15 mm, a short object distance of 20 mm, a horizontal object height of 35 mm, and an optical distortion of 15%, making it suitable for 1 / 2.7" chips used in video displacement meters.

[0016] Furthermore, the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, and seventh lens further satisfy the following optical conditions: 1.4 <n1<1.5,70<v1<80; 1.5 <n2<1.6,40<v2<50; 2.0 <n3<2.1,20<v3<30; 1.7 <n4<1.8,20<v4<30; 1.5 <n5<1.6,60<v5<70; 1.5 <n6<1.6,60<v6<70; 1.6 <n7<1.7,30<v7<40; Where n1-n7 are the refractive indices of the first lens to the seventh lens, respectively, and v1-v7 are the Abbe coefficients of the first lens to the seventh lens, respectively.

[0017] Furthermore, the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, and seventh lens further satisfy the following optical conditions: The radius of curvature of the side of the first lens away from the second lens is in the range of 4mm to 6mm, and the radius of curvature of the side of the first lens closer to the second lens is in the range of 2mm to 3mm. The radius of curvature of the side of the second lens away from the third lens ranges from -30mm to -20mm, and the radius of curvature of the side of the second lens closer to the third lens ranges from 3mm to 10mm. The radius of curvature of the side of the third lens away from the fourth lens is in the range of 0mm to 10mm, and the radius of curvature of the side of the third lens close to the fourth lens is in the range of -10mm to -5mm. The radius of curvature of the side of the fourth lens away from the fifth lens is in the range of -5mm to -4mm, and the radius of curvature of the side of the fourth lens closer to the fifth lens is in the range of 2mm to 3mm. The radius of curvature of the side of the fifth lens away from the sixth lens is in the range of 2mm to 3mm, and the radius of curvature of the side of the fifth lens close to the sixth lens is in the range of -5mm to -3mm. The radius of curvature of the side of the sixth lens away from the seventh lens is in the range of 5mm to 10mm, and the radius of curvature of the side of the sixth lens close to the seventh lens is in the range of -10mm to -5mm. The radius of curvature of the side of the seventh lens closest to the sixth lens is in the range of -7mm to -3mm, and the radius of curvature of the side of the seventh lens furthest from the sixth lens is -7.1mm.

[0018] Furthermore, the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, and seventh lens further satisfy the following optical conditions: The center thickness of the first lens ranges from 0 mm to 1 mm; The center thickness of the second lens ranges from 0 mm to 1 mm; The center thickness of the third lens ranges from 1 mm to 2 mm; The center thickness of the fourth lens ranges from 1 mm to 2 mm; The center thickness of the fifth lens ranges from 2mm to 3mm; The center thickness of the sixth lens ranges from 1 mm to 2 mm; The center thickness of the seventh lens ranges from 0 mm to 1 mm.

[0019] Furthermore, the combined focal length of the first lens, second lens, third lens, aperture, fourth lens, fifth lens, sixth lens, and seventh lens is 4mm, and the total optical length of the optical lens is less than 15mm.

[0020] Furthermore, the video displacement recognition device also includes a cover with an opening at one end, the opening of the cover being opposite to the through groove and a rubber gasket being provided at the connection between the cover and the through groove; the cover contains an interface board, a main control board, a sensor board, a base, and a supplementary light board. The interface board, sensor board, fill light board and optical lens are electrically connected to the main control board respectively; The optical lens passes through the fill light plate and is fixedly connected to the base, which is mounted on the sensor plate.

[0021] Furthermore, the video displacement recognition device also includes frosted glass, which is laid inside a rubber gasket and covers the through groove. A through hole is provided in the center of the frosted glass for the front end of the optical lens to be embedded.

[0022] As can be seen from the above description, the specific structural design enables the assembly of the optical lens and its related auxiliary configurations, such as the interface board, main control board, sensor board, and fill light board.

[0023] Please refer to Figures 1 to 5 Embodiment 1 of the present invention is as follows: This invention provides a video displacement recognition system for an oil pump. The oil pump includes a hollow fixed shaft 11 and a drive rod 12. The fixed shaft 11 is a cylindrical tube, and the drive rod 12 is a telescopic rod of an oil cylinder. The drive rod 12 is coaxially arranged with the fixed shaft, with one end passing through the fixed shaft 11 and the other end fixedly connected to a drive mechanism. An oil storage space is formed between the inner side wall of the fixed shaft 11 and the outer side wall of the drive rod 12, and oil is filled into the oil storage space. The drive rod 12 is provided with a scale mark 121 arranged along the axial direction of the drive rod. The video displacement recognition system is located at the end of the fixed shaft near the other end of the drive rod and is arranged corresponding to the scale mark.

[0024] Specifically, a scale line is engraved every 30mm (or 10mm, 20mm or 40mm) on the drive rod 12 (hydraulic piston rod), and a number is engraved between two scale lines to indicate the position information of the marking line before the number.

[0025] The video displacement recognition system includes a limiting cylinder 13 and a video displacement recognition device. The limiting cylinder 13 is sleeved on the drive rod and is fixedly connected to the end of the fixed shaft near the other end of the drive rod. The limiting cylinder 13 is provided with a through groove 131 corresponding to the scale mark, and the video displacement recognition device is installed in the through groove.

[0026] The video displacement recognition device includes an optical lens 14 facing the scale mark and a cover with an opening at one end. The opening of the cover is opposite to the through groove, and a rubber gasket 16 is provided at the connection between the cover and the through groove. The cover contains a frosted glass 17, an interface board 18, a main control board 19, a sensor board 20, a base 21, and a supplementary light board 22. The cover is injection molded and includes an outer cover 15 and a top cover 24. The outer cover has openings at both ends, and the top cover is placed on one of the openings at both ends of the outer cover. The edge of the other opening at both ends of the outer cover has an outwardly extending edge with a mounting hole. Screws are threadedly connected to the screw holes on the end face of the through groove of the limiting cylinder through the mounting holes.

[0027] The interface board 18, sensor board 20, fill light board 22 and optical lens 14 are electrically connected to the main control board 19 respectively; the optical lens 14 passes through the fill light board 22 and is fixedly connected to the base 21, and the base 21 is mounted on the sensor board 20.

[0028] The frosted glass 17 is laid inside the rubber gasket 16 and covers the through groove 131. The frosted glass 17 has a through hole in the center for the front end of the optical lens to be embedded.

[0029] The top layer of the overall structure inside the enclosure is the interface board, where power and network cables are connected. The next layer is the main control board, housing the electronic components. The layer below that is the sensor board, which has Φ2.1mm through holes spaced 20mm apart. The final layer is the supplementary lighting layer, containing a ring light source for illumination. The boards are separated by brass pillars and connected by ribbon cables, a simple and convenient design that takes up little space. The outer enclosure also has a recess in the middle to limit the frosted glass. The frosted glass has a φ14.5mm circular hole in the center to avoid interference with industrial lenses (i.e., optical lenses). The main function of the frosted glass is to prevent glare caused by strong light. The outer enclosure's interface is at the bottom, allowing for customization of new models according to the corresponding test items.

[0030] Both ends of the limiting cylinder that contact the drive rod are fitted with sealing rings 23 to keep the limiting cylinder isolated from the oil storage space. Even if there is relative movement between the drive rod and the fixed shaft, the limiting cylinder and the oil storage space remain isolated, meaning that oil will not enter the limiting cylinder, thus avoiding affecting the recognition function of the video displacement recognition system, such as recognition accuracy.

[0031] like Figure 3, said optical lens 14 comprises a first lens 1, a second lens 2, a third lens 3, a diaphragm, a fourth lens 4, a fifth lens 5, a sixth lens 6 and a seventh lens 7 arranged in sequence along the light incident direction; that is, a six-group seven-piece structure is adopted to meet the use requirements. In the present optical system, the MTF value of the central field of view is greater than 0.2 at 250 lp / mm, the MTF values of the edge field of view are all greater than 0.2 at 200 lp / mm, Fno is 2.6, the relative illumination is greater than 50%, the total optical length is less than 15mm, the working object distance is short at 20mm, the horizontal object height is 35mm, and the optical distortion is 15%, which is suitable for the 1 / 2.7 chip used in video displacement meters.

[0032] The first lens 1 is a meniscus lens, the second lens 2 is a biconcave lens, the third lens 3 is a biconvex lens, the fourth lens 4 and the fifth lens 5 form a closely connected cemented group, the sixth lens 6 is a biconvex lens, and the seventh lens 7 is a meniscus lens; The air gap between the first lens 1 and the second lens 2 ranges from 1 mm to 2 mm, the air gap between the second lens 2 and the third lens 3 ranges from 0 mm to 1 mm, the air gap between the third lens 3 and the diaphragm ranges from 0 mm to 1 mm, the air gap between the diaphragm and the fourth lens 4 ranges from 0 mm to 1 mm, the air gap between the fifth lens 5 and the sixth lens 6 ranges from 0 mm to 1 mm, and the air gap between the sixth lens 6 and the seventh lens 7 ranges from 1 mm to 2 mm.

[0033] The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens further satisfy the following optical conditions: 1.4 < n1 < 1.5, 70 < v1 < 80; the radius of curvature of the side surface (S1 surface) of the first lens away from the second lens ranges from 4 mm to 6 mm, and the radius of curvature of the side surface (S2 surface) of the first lens close to the second lens ranges from 2 mm to 3 mm; the central thickness of the first lens ranges from 0 mm to 1 mm; In this embodiment, n1 is 1.49, v1 is 70.4, the radius of curvature of the S1 surface is 4.3, and the radius of curvature of the S2 surface is 2.19.

[0034] 1.5 < n2 < 1.6, 40 < v2 < 50; the radius of curvature of the side surface (S3 surface) of the second lens away from the third lens ranges from -30 mm to -20 mm, and the radius of curvature of the side surface (S4 surface) of the second lens close to the third lens ranges from 3 mm to 10 mm; the central thickness of the second lens ranges from 0 mm to 1 mm; In this embodiment, n2 is 1.57, v1 is 42.8, the curvature radius of the S3 surface is -21.73, and the curvature radius of the S4 surface is 3.27.

[0035] 2.0 < n3 < 2.1, 20 < v3 < 30; the curvature radius of the side surface of the third lens away from the fourth lens (S5 surface) ranges from 0 mm to 10 mm, the curvature radius of the side surface of the third lens close to the fourth lens (S6 surface) ranges from -10 mm to -5 mm; the central thickness of the third lens ranges from 1 mm to 2 mm; In this embodiment, n3 is 2.00, v3 is 29.1, the curvature radius of the S5 surface is 4.3, and the curvature radius of the S6 surface is -7.65.

[0036] 1.7 < n4 < 1.8, 20 < v4 < 30; the curvature radius of the side surface of the fourth lens away from the fifth lens (S8 surface) ranges from -5 mm to -4 mm, the curvature radius of the side surface of the fourth lens close to the fifth lens (S9 surface) ranges from 2 mm to 3 mm; the central thickness of the fourth lens ranges from 1 mm to 2 mm; In this embodiment, n4 is 1.72, v4 is 29.5, the curvature radius of the S8 surface is -4.05, and the curvature radius of the S9 surface is 3.

[0037] 1.5 < n5 < 1.6, 60 < v5 < 70; the curvature radius of the side surface of the fifth lens away from the sixth lens (S9 surface) ranges from 2 mm to 3 mm, the curvature radius of the side surface of the fifth lens close to the sixth lens (S10 surface) ranges from -5 mm to -3 mm; the central thickness of the fifth lens ranges from 2 mm to 3 mm; In this embodiment, n5 is 1.59, v5 is 68.3, the curvature radius of the S9 surface is 3, and the curvature radius of the S10 surface is -3.57.

[0038] 1.5 < n6 < 1.6, 60 < v6 < 70; the curvature radius of the side surface of the sixth lens away from the seventh lens (S11 surface) ranges from 5 mm to 10 mm, the curvature radius of the side surface of the sixth lens close to the seventh lens (S12 surface) ranges from -10 mm to -5 mm; the central thickness of the sixth lens ranges from 1 mm to 2 mm; In this embodiment, n6 is 1.59, v6 is 68.3, the curvature radius of the S11 surface is 6.94, and the curvature radius of the S12 surface is -6.94.

[0039] 1.6 < n7 < 1.7, 30 < v7 < 40; the radius of curvature of the side surface (S13 surface) of the seventh lens that is close to the sixth lens ranges from -7mm to -3mm, and the radius of curvature of the side surface (S14 surface) of the seventh lens that is away from the sixth lens is -7.1mm. The central thickness of the seventh lens ranges from 0mm to 1mm.

[0040] In this embodiment, n7 is 1.65, v7 is 33.8, the radius of curvature of the S13 surface is -3.9, and the radius of curvature of the S14 surface is -7.1.

[0041] Wherein, n1-n7 are sequentially the refractive indices of the first lens to the seventh lens, and v1-v7 are sequentially the Abbe numbers of the first lens to the seventh lens.

[0042] The combined focal length of the first lens, the second lens, the third lens, the stop, the fourth lens, the fifth lens, the sixth lens and the seventh lens is 4mm, and the total optical length of the optical lens is less than 15mm.

[0043] In this embodiment, the total optical length is 15mm, Fno is 2.6, the maximum object height in the horizontal direction is 35mm, the relative illumination is 50%, and the distortion is 15%.

[0044] The data of the specific embodiment is shown in Table 1 below:

[0045] Table 1 As Figures 4 to 5 , the present invention has the following advantages: The optical lens for video displacement meter provided by the present invention adopts a six-group seven-element structure, the center field MTF value is 0.4 at 250lp / mm, the edge field MTF value is 0.2 at 200lp / mm, and the distortion is 15%. Under a short total optical length, the lens centering coefficient is > 0.1, the opening angle is < 60°, all thicknesses are > 0.6mm, which is easy to process.

[0046] In summary, the present invention provides a video displacement recognition system for an oil pump. This system utilizes a scale marking on the drive rod arranged axially along the drive rod, and positions the video displacement recognition system at the end of a fixed shaft near the other end of the drive rod, corresponding to the scale marking. This allows for the recognition of the scale marking and the acquisition of displacement data for the drive rod within the oil pump. This video displacement recognition system for an oil pump fills a technological gap in domestic video displacement gauges. It combines image recognition technology with IoT technology to provide a new type of displacement monitoring sensor for various industrial fields. Compared to traditional wire-driven sensors, it offers significant advantages: test accuracy is unaffected by test length, test frequency can reach 100 Hz, and monitoring accuracy can reach 0.1 mm, effectively replacing imported high-precision wire-driven displacement sensors. Furthermore, wire-driven displacement sensors have a high failure rate in practical use; the displacement gauge in this solution does not require mechanical movement, and real-time detection is achieved through image recognition technology. The module can operate 24 / 7, significantly reducing the failure rate.

[0047] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A video displacement recognition system for an oil pump, the oil pump comprising a hollow fixed shaft and a drive rod having one end passing through the fixed shaft and coaxially arranged with the fixed shaft, wherein an oil storage space is formed between the inner sidewall of the fixed shaft and the outer sidewall of the drive rod, characterized in that, The drive rod is provided with scale markings arranged along the axial direction of the drive rod, and the video displacement recognition system is located at the end of the fixed shaft near the other end of the drive rod and is set accordingly to the scale markings; The video displacement recognition system includes a limiting cylinder and a video displacement recognition device. The limiting cylinder is sleeved on the drive rod and is fixedly connected to the end of the fixed shaft near the other end of the drive rod. The limiting cylinder is provided with a through groove corresponding to the scale mark, and the video displacement recognition device is installed in the through groove. The video displacement recognition device includes an optical lens that is oriented toward the scale markings; The optical lens consists of a first lens, a second lens, a third lens, an aperture stop, a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged sequentially along the incident direction of light. The first lens is a meniscus lens, the second lens is a biconcave lens, the third lens is a biconvex lens, the fourth and fifth lenses form a closely spaced cemented group, the sixth lens is a biconvex lens, and the seventh lens is a meniscus lens. The air gap between the first lens and the second lens is 1mm to 2mm, the air gap between the second lens and the third lens is 0mm to 1mm, the air gap between the third lens and the aperture is 0mm to 1mm, the air gap between the aperture and the fourth lens is 0mm to 1mm, the air gap between the fifth lens and the sixth lens is 0mm to 1mm, and the air gap between the sixth lens and the seventh lens is 1mm to 2mm.

2. A video displacement recognition system for an oil pump according to claim 1, wherein, Both ends of the limiting cylinder that contact the drive rod are fitted with sealing rings to keep the limiting cylinder isolated from the oil storage space.

3. A video displacement recognition system for an oil pump as defined in claim 1, wherein, The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens further satisfy the following optical conditions: 1.4 <n1<1.5,70<v1<80; 1.5 <n2<1.6,40<v2<50; 2.0 <n3<2.1,20<v3<30; 1.7 <n4<1.8,20<v4<30; 1.5 <n5<1.6,60<v5<70; 1.5 <n6<1.6,60<v6<70; 1.6 <n7<1.7,30<v7<40; Where n1-n7 are the refractive indices of the first lens to the seventh lens, respectively, and v1-v7 are the Abbe coefficients of the first lens to the seventh lens, respectively.

4. The video displacement recognition system for an oil pump according to claim 1, characterized in that, The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens further satisfy the following optical conditions: The radius of curvature of the side of the first lens away from the second lens is in the range of 4mm to 6mm, and the radius of curvature of the side of the first lens closer to the second lens is in the range of 2mm to 3mm. The radius of curvature of the side of the second lens away from the third lens ranges from -30mm to -20mm, and the radius of curvature of the side of the second lens closer to the third lens ranges from 3mm to 10mm. The radius of curvature of the side of the third lens away from the fourth lens is in the range of 0mm to 10mm, and the radius of curvature of the side of the third lens close to the fourth lens is in the range of -10mm to -5mm. The radius of curvature of the side of the fourth lens away from the fifth lens is in the range of -5mm to -4mm, and the radius of curvature of the side of the fourth lens closer to the fifth lens is in the range of 2mm to 3mm. The radius of curvature of the side of the fifth lens away from the sixth lens is in the range of 2mm to 3mm, and the radius of curvature of the side of the fifth lens close to the sixth lens is in the range of -5mm to -3mm. The radius of curvature of the side of the sixth lens away from the seventh lens is in the range of 5mm to 10mm, and the radius of curvature of the side of the sixth lens close to the seventh lens is in the range of -10mm to -5mm. The radius of curvature of the side of the seventh lens closest to the sixth lens is in the range of -7mm to -3mm, and the radius of curvature of the side of the seventh lens furthest from the sixth lens is -7.1mm.

5. A video displacement recognition system for an oil pump as defined in claim 1, wherein, The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens further satisfy the following optical conditions: The center thickness of the first lens ranges from 0 mm to 1 mm; The center thickness of the second lens ranges from 0 mm to 1 mm; The center thickness of the third lens ranges from 1 mm to 2 mm; The center thickness of the fourth lens ranges from 1 mm to 2 mm; The center thickness of the fifth lens ranges from 2mm to 3mm; The center thickness of the sixth lens ranges from 1 mm to 2 mm; The center thickness of the seventh lens ranges from 0 mm to 1 mm.

6. A video displacement recognition system for an oil pump as defined in claim 1, wherein, The combined focal length of the first lens, second lens, third lens, aperture, fourth lens, fifth lens, sixth lens, and seventh lens is 4mm, and the total optical length of the optical lens is less than 15mm.

7. A video displacement recognition system for an oil pump as defined in claim 1, wherein, The video displacement recognition device also includes a cover with an opening at one end, the opening of the cover being opposite to the through groove and a rubber gasket being provided at the connection between the cover and the through groove; the cover contains an interface board, a main control board, a sensor board, a base, and a supplementary light board. The interface board, sensor board, fill light board and optical lens are electrically connected to the main control board respectively; The optical lens passes through the fill light plate and is fixedly connected to the base, which is mounted on the sensor plate.

8. A video displacement recognition system for an oil pump according to claim 7, wherein, The video displacement recognition device also includes frosted glass, which is laid inside a rubber gasket and covers the through groove. A through hole is provided in the center of the frosted glass for the front end of the optical lens to be embedded.

Images