Hydraulic telescopic rotary oil cylinder

Abstract

The invention relates to the technical field of rotary oil cylinders, and discloses a hydraulic telescopic rotary oil cylinder which comprises a hydraulic oil cylinder and further comprises a shaft core coaxially and fixedly installed on the hydraulic oil cylinder, and a first oil way and a second oil way which are used for feeding and discharging oil into the hydraulic oil cylinder are formed in the shaft core; the shaft core is sleeved with the rotating cylinder in a rotating mode, a rotation stopping shaft used for limiting rotation of the rotating cylinder is fixed to the rotating cylinder, two annular grooves communicated with the first oil way and the second oil way respectively are formed in the inner wall of the rotating cylinder, and oil holes communicated with the first oil way and the second oil way are further formed in the rotating cylinder; the shaft core and the rotary drum are in clearance fit, and a sealing oil film is formed in the clearance. The filtering piece is arranged in the oil return channel to filter backflow hydraulic oil, the thickening degree of the hydraulic oil after long-time use can be further reduced, the service life of the hydraulic oil is prolonged, and meanwhile the change of the thickening degree of the hydraulic oil can be monitored.

Description

Technical Field

[0001] The invention relates to the technical field of rotary oil cylinders, in particular to a hydraulic telescopic rotary oil cylinder. Background Art

[0002] The hydraulic rotary cylinder is a compact accessory that combines very high torque in a small space using hydraulic pressure and can be easily and accurately controlled. Therefore, the rotary cylinder has been successfully used in almost all fields requiring limited rotational motion and high torque.

[0003] At present, in the process of hot rolling coiler rolling strip steel, the rotating cylinder usually pushes and pulls the coil core shaft to drive the inclined slider, connecting plate and other parts to complete the expansion and contraction function of the fan plate, and the rotation is usually achieved by the reducer driving the coil core shaft to rotate, so as to complete the rolling use of the hot rolling coiler.

[0004] For example, Chinese patent publication number CN213144941U discloses a rotary cylinder for a hot rolling coiler. The rotary cylinder is matched through the clearance between the bushing and the rotating shaft so that the hydraulic oil forms a high-pressure oil film with sealing ability between the two under the action of oil pressure. However, since impurities or wear particles may be mixed into the hydraulic oil during its circulation due to the external environment or wear, it is necessary to ensure the cleanliness of the oil. Summary of the invention

[0005] The object of the present invention is to provide a hydraulic telescopic rotary cylinder to solve at least one technical problem existing in the above-mentioned prior art.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A hydraulic telescopic rotary cylinder, comprising a hydraulic cylinder, and further comprising:

[0008] An axis core is coaxially fixedly mounted on the hydraulic cylinder, and an oil circuit 1 and an oil circuit 2 are provided in the axis core for supplying and discharging oil into and out of the hydraulic cylinder;

[0009] A rotating drum is rotatably sleeved outside the shaft core, a stop shaft for limiting its rotation is fixed on the rotating drum, two annular grooves are respectively connected to the oil circuit 1 and the oil circuit 2 on the inner wall of the rotating drum, and an oil hole connected to the oil circuit 1 and the oil circuit 2 is also opened inside the rotating drum;

[0010] The shaft core and the drum are fitted with a gap, and a sealing oil film is formed in the gap. An oil return channel is also provided in the drum, and an oil return hole connected to the oil return channel is provided on the outer wall of the drum. The oil return channel is connected to the gap and forms a circulating oil circuit with the outside through the oil return hole.

[0011] The filter element is installed in the oil return passage, and the filter element can filter the return hydraulic oil in the oil return passage.

[0012] Preferably, the filter element includes a sleeve and a plug which are plugged into each other, and a spring is installed between the sleeve and the plug, the sleeve is fixedly installed on the inner wall of the oil return channel through a sealing ring, chamber two and chamber one are provided in the plug, and chamber two and chamber one are connected through a spiral flow channel, a through hole is provided at the partition between chamber two and chamber one, and a core shaft is rotatably installed in the through hole, a fin wheel is fixed at one end of the core shaft extending into chamber two, and the hydraulic oil flowing out of the spiral flow channel can impact the fins of the fin wheel in the same rotation direction, a filter screen is installed at the opening of chamber one, a through hole is provided in the middle of the filter screen, a scraper is installed at one end of the core shaft passing through the through hole, and the scraper is in contact with the plane of the filter screen.

[0013] Preferably, a slide groove is provided on the inner wall of the sleeve, a slider slidably installed in the slide groove is fixed on the outer wall of the insert tube, a mounting hole is also provided on the inner wall of the sleeve, and a displacement sensor for monitoring the axial movement distance of the insert tube is provided in the mounting hole.

[0014] Preferably, a filter bag is connected to the through hole of the filter screen in chamber one, and a through hole for the core shaft to pass through is provided inside the filter bag, and the plane of the filter screen is set as a concave cone.

[0015] Preferably, the chamber 1 is configured as a conical cavity, and the opening direction of the conical cavity faces the filter screen.

[0016] Preferably, the hydraulic cylinder includes a cylinder barrel and a piston rod, both ends of the cylinder barrel are seal-mounted through a cylinder head and a cylinder bottom, and the shaft core is coaxially fixedly connected to the cylinder bottom, the piston rod passes through the cylinder head and the cylinder bottom, and is seal-slidably connected to the penetration between the cylinder head and the cylinder bottom, the outer wall of the piston rod is fixed with a piston slidably mounted in the cylinder barrel, and the piston divides the cylinder barrel into two chambers, and the oil circuit one and the oil circuit two are respectively connected to the two chambers.

[0017] Preferably, an end cover and a bottom cover are fixed to both ends of the drum, and both the end cover and the bottom cover are designed to penetrate and seal with the shaft core.

[0018] Preferably, the end of the piston rod extending out of the shaft core is rotatably mounted with a rear rod end cover, a rear rod sleeve and a rear rod bottom cover which are arranged in sequence, and the rear rod end cover, the rear rod sleeve and the rear rod bottom cover are fixed to each other by bolts, a guide hole is opened on the rear rod end cover, a guide rod which slides with the guide hole is fixed to the outer wall of the bottom cover, a sensor shield is also fixed to the outer wall of the rear rod end cover, a sensor sleeve for installing a sensor is fixed to the outer wall of the bottom cover, and the sensor sleeve and the sensor shield are designed to slide together.

[0019] Preferably, the oil return channels and oil return holes are designed in multiple groups and are staggered.

[0020] Preferably, the diameter of the shaft core is 140 mm, and the matching error between the shaft core and the drum is 0.025-0.035 mm.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The present invention can further reduce the viscosity of the hydraulic oil after long-term use by arranging a filter in the oil return channel to filter the refluxed hydraulic oil, thereby extending its service life.

[0023] Second, the present invention can filter the hydraulic oil and use the flow of the hydraulic oil to drive the scraper to clean the filter, thereby extending the service life of the filter and reducing the number of maintenance times.

[0024] 3. The present invention monitors the distance moved by the cannula through a displacement sensor. When the displacement exceeds a preset value, it means that the pressure difference caused by the change in the viscosity of the hydraulic oil also exceeds the preset value, thereby reminding the maintenance personnel to replace the hydraulic oil, thereby achieving the effect of monitoring the change in the viscosity of the hydraulic oil. In addition, the cleaning effect of the scraper on the filter can further reduce the impact on the subsequent pressure difference monitoring results before and after the filter, making the monitoring results and data more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a front cross-sectional view of the present invention;

[0026] Figure 2 For the present invention Figure 1 A in the enlarged view;

[0027] Figure 3 is an enlarged stereoscopic view of the filter element of the present invention;

[0028] Figure 4 The exploded three-dimensional image of the filter element of the present invention Figure 1 ;

[0029] Figure 5 is a front cross-sectional view of the filter element of the present invention;

[0030] Figure 6 is a cross-sectional view of the sleeve, spring and cannula of the present invention;

[0031] Figure 7 For the present invention Figure 4 Cutaway stereogram of perspective;

[0032] Figure 8 The exploded three-dimensional image of the filter element of the present invention Figure 2 .

[0033] In the figure: 1. cylinder barrel; 2. cylinder head; 3. cylinder bottom; 4. piston rod; 5. piston; 6. shaft core; 7. rotating cylinder; 8. end cover; 9. bottom cover; 10. rear rod end cover; 11. rear rod sleeve; 12. rear rod bottom cover; 13. guide rod; 14. sensor sleeve; 15. sensor shield; 16. anti-rotation shaft; 17. oil circuit one; 18. oil circuit two; 19. annular groove; 20. oil hole; 21. oil return channel; 23. oil return hole; 24. sleeve; 25. insert tube; 26. spring; 27. filter screen; 28. core shaft; 29. ​​scraper; 30. filter bag; 31. displacement sensor; 32. chamber one; 33. chamber two; 34. spiral flow channel; 35. slide groove; 36. slider; 37. fin wheel. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] See also Figures 1 to 8 The present invention provides a hydraulic telescopic rotary cylinder, which includes a hydraulic cylinder and further includes:

[0036] A shaft core 6 is coaxially fixedly mounted on the hydraulic cylinder, and an oil passage 17 and an oil passage 2 18 are provided in the shaft core 6 for supplying and discharging oil into and out of the hydraulic cylinder;

[0037] The rotating drum 7 is rotatably sleeved outside the shaft core 6, and a stop shaft 16 is fixed on the rotating drum 7 for limiting its rotation. The inner wall of the rotating drum 7 is provided with two annular grooves 19 respectively connected with the oil passage 1 17 and the oil passage 2 18, and the inside of the rotating drum 7 is also provided with an oil hole 20 connected with the oil passage 1 17 and the oil passage 2 18;

[0038] There is a clearance fit between the shaft core 6 and the drum 7, and a sealing oil film is formed in the clearance. An oil return passage 21 is also provided in the drum 7, and an oil return hole 23 connected to the oil return passage 21 is provided on the outer wall of the drum 7. The oil return passage 21 is connected to the clearance and forms a circulating oil path with the outside through the oil return hole 23.

[0039] The filter element is installed in the oil return passage 21 , and the filter element can filter the return hydraulic oil in the oil return passage 21 .

[0040] When the hydraulic telescopic rotary cylinder is used in a hot rolling coiler, the hydraulic cylinder is connected to the external oil circuit via the oil hole 20, and the axial telescopic adjustment can be completed through the oil inlet and outlet of the oil circuit 17 and the oil circuit 2 18. At the same time, due to the rotational coordination between the shaft core 6 and the drum 7, not only can continuous rotation be achieved during operation, but also stable transmission of the hydraulic oil in the oil circuit 1 17 and the oil circuit 2 18 can be ensured. Moreover, the drum 7 can be prevented from rotating under the action of the stop shaft 16, and the stop shaft 16 can be connected to other installation parts.

[0041] During use, due to the pressure in the oil circuit 1 17 or the oil circuit 2 18, the hydraulic oil will be squeezed into the gap between the shaft core 6 and the drum 7 to form a sealing oil film, and a circulating oil circuit will be formed through the oil return channel 21 and the oil return hole 23. In this way, the sealing oil film can not only play a sealing role, but also the fluidity of the sealing oil film can take out the heat generated by friction, so as to play a certain cooling role.

[0042] Moreover, after long-term circulation, the hydraulic oil is easily mixed with foreign solid particles or fine debris generated by friction in the workshop environment, which will not only cause the hydraulic oil to become thicker, but also affect the normal circulation operation of the oil circuit. Therefore, a filter is provided in the return oil channel 21 to filter the returning hydraulic oil, which can further reduce the thickness of the hydraulic oil after long-term use, thereby extending its service life.

[0043] In one of the more preferred embodiments, a preferred implementation of a filter element is provided;

[0044] The filter element includes a sleeve 24 and a plug 25 which are plugged into each other, and a spring 26 is installed between the sleeve 24 and the plug 25. The sleeve 24 is fixedly installed on the inner wall of the oil return channel 21 through a sealing ring. A chamber 23 and a chamber 1 32 are provided in the plug 25, and the chamber 23 and the chamber 1 32 are connected through a spiral flow channel 34. A through hole is provided at the partition between the chamber 2 33 and the chamber 1 32, and a core shaft 28 is rotatably installed in the through hole. A fin wheel 37 is fixed at one end of the core shaft 28 extending into the chamber 2 33. The hydraulic oil flowing out of the spiral flow channel 34 can impact the fins of the fin wheel 37 in the same rotation direction. A filter screen 27 is installed at the opening of the chamber 1 32. A through hole is provided in the middle of the filter screen 27. A scraper 29 is installed at one end of the core shaft 28 passing through the through hole, and the scraper 29 is in contact with the plane of the filter screen 27.

[0045] See also Figure 2 , for the specific installation position of the filter, see Figure 4-5When the hydraulic oil flows back in the oil return channel 21, it will first pass through the filter screen 27 into the chamber 1 32, then flow into the chamber 1 32 through the spiral flow channel 34, and finally flow out from the sleeve 24 and the oil return hole 23, completing the reflux process;

[0046] The filter 27 can filter the particulate impurities in the hydraulic oil, and the hydraulic oil will impact the fins of the fin wheel 37 in the same rotation direction when flowing through the spiral flow channel 34. For details, please refer to Figure 6-7 Therefore, the fin wheel 37 will drive the core shaft 28 and the scraper 29 to rotate, so that the scraper 29 can be used to clean the surface of the filter 27 to prevent impurities from clogging the filter 27. In this way, while filtering the hydraulic oil, the flow of hydraulic oil can also drive the scraper 29 to clean the filter 27, thereby extending the service life of the filter 27 and reducing the number of maintenance times.

[0047] In one of the preferred embodiments, an implementation method for monitoring the viscosity of hydraulic oil is provided. Figure 5 , Figure 6 and Figure 8 ;

[0048] The inner wall of the sleeve 24 is provided with a slide groove 35 , and the outer wall of the insert tube 25 is fixed with a slider 36 slidably installed in the slide groove 35 . The inner wall of the sleeve 24 is also provided with a mounting hole, and a displacement sensor 31 for monitoring the axial movement distance of the insert tube 25 is provided in the mounting hole.

[0049] During the use of hydraulic oil, impurities in it are factors that cause it to become thicker. Similarly, oxidation, high-temperature decomposition, or emulsification of the hydraulic oil caused by the mixing of water will increase the thickening of the hydraulic oil. Although the above-mentioned hydraulic oil filtration can avoid the influence of impurities on the hydraulic oil, after long-term use, the hydraulic oil still needs to be replaced when the viscosity exceeds the preset value. Therefore, it is necessary to monitor the change of hydraulic oil viscosity. In this embodiment, a detection implementation method is mainly provided;

[0050] As the viscosity of the hydraulic oil increases, the filtering effect of the filter 27 will be affected, that is, the pressure drop will increase when passing through the filter 27, resulting in an increase in the pressure difference before and after the filter 27 (i.e., the filter element). Therefore, under the pressure of the hydraulic oil, the elastic force of the spring 26 will be overcome, thereby pushing the filter 27 (i.e., the cannula 25) to move axially. When the displacement sensor 31 detects that the distance moved by the cannula 25 exceeds the preset value, it can be explained that the pressure difference caused by the change in the viscosity of the hydraulic oil also exceeds the preset value, so that the maintenance personnel can be reminded to replace the hydraulic oil, thereby achieving the effect of monitoring the change in the viscosity of the hydraulic oil;

[0051] The sliding fit between the slide groove 35 and the slider 36 can limit and guide the insertion tube 25;

[0052] Moreover, it is worth noting that the blockage degree of the filter 27 will affect the pressure difference before and after the above-mentioned filter 27, that is, the higher the blockage degree of the filter 27, the greater the error of the pressure difference will be, and vice versa, the lower the blockage degree of the filter 27, the smaller the error of the pressure difference will be. Therefore, the above-mentioned self-cleaning process of the filter 27 can further reduce the impact on the subsequent pressure difference monitoring results before and after the filter 27, making the monitoring results and data more accurate.

[0053] In one of the more preferred embodiments, a filter bag 30 is connected to the through hole of the filter screen 27 located in the chamber 1 32, and a through hole is opened inside the filter bag 30 for the core shaft 28 to pass through, and the plane of the filter screen 27 is set to be a concave cone.

[0054] See also Figure 4 and Figure 5 The setting of the filter bag 30 can not only filter the hydraulic oil, but also mainly collect the particulate impurities. Due to the setting of the concave surface of the filter screen 27, the hydraulic oil can be guided to the middle, so that the scraper 29 will scrape the impurities from the filter screen 27 and flow into the filter bag 30 along with the hydraulic oil, thereby preventing the particulate impurities from clogging the filter screen 27 again. The filter bag 30 can be replaced during subsequent maintenance, and refer to Figure 3-4 The scraper 29 is arranged in a curved shape, so that during its rotation, it can further promote the flow of particulate impurities into the filter pocket 30, reducing the probability of them staying at the filter screen 27;

[0055] Moreover, the filter bag 30 is configured as a bag-shaped structure with a small opening and a large internal space, which can effectively prevent the impurities inside from flowing back to the filter screen 27.

[0056] In one of the more preferred embodiments, chamber 1 32 is configured as a conical cavity, and the opening direction of the conical cavity faces the filter screen 27 .

[0057] See also Figure 5 The conical cavity setting of chamber 1 32 can increase the flow rate of the hydraulic oil through the spiral flow channel 34, thereby making the rotation speed of the fin wheel 37 faster, and then the rotation speed of the scraper 29 is also accelerated, improving the cleaning efficiency and cleaning effect of the filter 27, and further reducing the impact on the subsequent hydraulic oil viscosity monitoring results.

[0058] In one of the more preferred embodiments, the hydraulic cylinder includes a cylinder barrel 1 and a piston rod 4, both ends of the cylinder barrel 1 are sealed and installed through a cylinder head 2 and a cylinder bottom 3, and the shaft core 6 is coaxially fixedly connected to the cylinder bottom 3, the piston rod 4 passes through the cylinder head 2 and the cylinder bottom 3, and is sealed and slidably connected to the penetration point between the cylinder head 2 and the cylinder bottom 3, the outer wall of the piston rod 4 is fixed with a piston 5 slidably installed in the cylinder barrel 1, and the piston 5 divides the cylinder barrel 1 into two chambers, and the oil circuit 1 17 and the oil circuit 2 18 are respectively connected to the two chambers.

[0059] The oil inlet and outlet in the two chambers through the oil passage 1 17 and the oil passage 2 18 can drive the piston 5 to move axially in the cylinder barrel 1, thereby ensuring that it can operate axially stably.

[0060] In one of the more preferred embodiments, an end cover 8 and a bottom cover 9 are respectively fixed to both ends of the rotating drum 7 , and both the end cover 8 and the bottom cover 9 are designed to penetrate and seal with the shaft core 6 .

[0061] In one of the more preferred embodiments, the end of the piston rod 4 extending out of the shaft core 6 is rotatably installed with a rear rod end cover 10, a rear rod sleeve 11 and a rear rod bottom cover 12 which are arranged in sequence, and the rear rod end cover 10, the rear rod sleeve 11 and the rear rod bottom cover 12 are fixed to each other by bolts, a guide hole is opened on the rear rod end cover 10, a guide rod 13 which slides with the guide hole is fixed to the outer wall of the bottom cover 9, a sensor shield 15 is also fixed to the outer wall of the rear rod end cover 10, a sensor sleeve 14 for installing a sensor is fixed to the outer wall of the bottom cover 9, and the sensor sleeve 14 and the sensor shield 15 are designed to slide together.

[0062] Through the sliding cooperation between the sensor sleeve 14 and the sensor shield 15, the sensor inside can control the position of the piston rod 4 in real time, which is conducive to the stable operation.

[0063] In one of the more preferred embodiments, the oil return channels 21 and the oil return holes 23 are designed in multiple groups and are staggered.

[0064] See also Figure 2 The design of multiple groups of oil return channels 21 can also enable multiple groups of internal filters to be designed. Monitoring the change of hydraulic oil viscosity using multiple groups of filters can make the detection result more objective and accurate.

[0065] In one of the more preferred embodiments, the diameter of the shaft core 6 is 140 mm, and the matching error between the shaft core 6 and the drum 7 is 0.025-0.035 mm.

[0066] The standard parts used in this embodiment can be purchased directly from the market, and the non-standard structural components recorded in the specification and the drawings can also be directly processed according to the existing technical common sense. At the same time, the connection method of each component adopts the mature conventional means in the prior art, and the machinery, parts and equipment all adopt the conventional models in the prior art, so no specific description will be given here.

[0067] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A hydraulic telescopic rotary cylinder, comprising a hydraulic cylinder, characterized in that: Also includes: A shaft core (6) is coaxially fixedly mounted on the hydraulic oil cylinder, and an oil circuit 1 (17) and an oil circuit 2 (18) are provided in the shaft core (6) for supplying and discharging oil into and out of the hydraulic oil cylinder; A rotating cylinder (7) is rotatably sleeved outside the shaft core (6), a stop shaft (16) is fixed on the rotating cylinder (7) for limiting its rotation, the inner wall of the rotating cylinder (7) is provided with two annular grooves (19) respectively connected to the first oil path (17) and the second oil path (18), and the interior of the rotating cylinder (7) is also provided with an oil hole (20) connected to the first oil path (17) and the second oil path (18); The shaft core (6) and the rotating cylinder (7) are fitted with a clearance, and a sealing oil film is formed in the clearance. An oil return passage (21) is also provided in the rotating cylinder (7), and an oil return hole (23) communicating with the oil return passage (21) is provided on the outer wall of the rotating cylinder (7). The oil return passage (21) is communicated with the clearance and forms a circulating oil circuit with the outside through the oil return hole (23). The filter element is installed in the oil return channel (21), and the filter element can filter the return hydraulic oil in the oil return channel (21).

2. The hydraulic telescopic rotary cylinder according to claim 1, characterized in that: The filter element comprises a sleeve (24) and a plug (25) which are plugged into each other, and a spring (26) is installed between the sleeve (24) and the plug (25), and the sleeve (24) is fixedly installed on the inner wall of the oil return channel (21) through a sealing ring, and a chamber 2 (33) and a chamber 1 (32) are provided in the plug (25), and the chamber 2 (33) and the chamber 1 (32) are communicated through a spiral flow channel (34), and a through hole is provided at the partition between the chamber 2 (33) and the chamber 1 (32), and the through hole is provided at the partition between the chamber 2 (33) and the chamber 1 (32). A core shaft (28) is rotatably mounted in the hole, and a fin wheel (37) is fixed to one end of the core shaft (28) extending into the second chamber (33). The hydraulic oil flowing out of the spiral flow channel (34) can impact the fins of the fin wheel (37) in the same rotation direction. A filter screen (27) is mounted at the opening of the first chamber (32). A through hole is opened in the middle of the filter screen (27). A scraper (29) is mounted on one end of the core shaft (28) passing through the through hole, and the scraper (29) is in contact with the plane of the filter screen (27).

3. The hydraulic telescopic rotary cylinder according to claim 2, characterized in that: The inner wall of the sleeve (24) is provided with a slide groove (35), the outer wall of the insert tube (25) is fixed with a slider (36) slidably installed in the slide groove (35), the inner wall of the sleeve (24) is also provided with a mounting hole, and a displacement sensor (31) for monitoring the axial movement distance of the insert tube (25) is arranged in the mounting hole.

4. The hydraulic telescopic rotary cylinder according to claim 2, characterized in that: A filter bag (30) is also connected to the through hole of the filter screen (27) located in the chamber 1 (32), and a through hole is provided inside the filter bag (30) for the core shaft (28) to pass through, and the plane of the filter screen (27) is set as a concave cone.

5. The hydraulic telescopic rotary cylinder according to claim 2, characterized in that: The chamber 1 (32) is configured as a conical chamber, and the opening direction of the conical chamber faces the filter screen (27).

6. The hydraulic telescopic rotary cylinder according to claim 1, characterized in that: The hydraulic cylinder comprises a cylinder barrel (1) and a piston rod (4). The two ends of the cylinder barrel (1) are sealed and installed through a cylinder head (2) and a cylinder bottom (3), and the shaft core (6) is coaxially fixedly connected to the cylinder bottom (3). The piston rod (4) penetrates the cylinder head (2) and the cylinder bottom (3) and is sealed and slidably connected to the penetration point between the cylinder head (2) and the cylinder bottom (3). The outer wall of the piston rod (4) is fixed with a piston (5) slidably installed in the cylinder barrel (1), and the piston (5) divides the cylinder barrel (1) into two chambers. The oil circuit 1 (17) and the oil circuit 2 (18) are respectively connected to the two chambers.

7. The hydraulic telescopic rotary cylinder according to claim 6, characterized in that: An end cover (8) and a bottom cover (9) are fixed to the two ends of the rotating drum (7), respectively. The end cover (8) and the bottom cover (9) are both designed to penetrate and seal with the shaft core (6).

8. The hydraulic telescopic rotary cylinder according to claim 7, characterized in that: The end of the piston rod (4) extending out of the shaft core (6) is rotatably mounted with a rear rod end cover (10), a rear rod sleeve (11) and a rear rod bottom cover (12) which are arranged in sequence, and the rear rod end cover (10), the rear rod sleeve (11) and the rear rod bottom cover (12) are fixed to each other by bolts, a guide hole is opened on the rear rod end cover (10), a guide rod (13) which is slidably matched with the guide hole is fixed to the outer wall of the bottom cover (9), a sensor shield (15) is also fixed to the outer wall of the rear rod end cover (10), and a sensor sleeve (14) for mounting a sensor is fixed to the outer wall of the bottom cover (9), and the sensor sleeve (14) and the sensor shield (15) are designed to be slidably matched.

9. The hydraulic telescopic rotary cylinder according to any one of claims 1 to 8, characterized in that: The oil return channels (21) and the oil return holes (23) are designed to be multiple groups and are staggered.

10. The hydraulic telescopic rotary cylinder according to any one of claims 1 to 8, characterized in that: The diameter of the shaft core (6) is 140 mm, and the matching error between the shaft core (6) and the rotating drum (7) is 0.025-0.035 mm.

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