An oil cylinder with a self-lubricating system

Abstract

The present invention discloses an oil cylinder with a self-lubricating system, which comprises a piston seat, a cylinder barrel, a piston rod and a plunger rod. Two groups of piston sealing rings are arranged on the outer wall of the piston seat and enclose a lubricating area with the inner wall of the cylinder barrel. An annular filling groove is also arranged on the outer wall of the piston seat, and an annular oil filtering cavity and an annular compression cavity are arranged on the inner side. The annular oil filtering cavity is divided into an oil collecting area and an oil storage area by an annular filter screen, and the annular compression cavity is divided into an oil injection area and an acting area by an annular piston. Lubricating oil is filled in the lubricating area and the annular oil filtering cavity. The oil collecting area collects the lubricating oil, and the oil storage area replenishes the filtered lubricating oil to the oil injection area and injects it into the lubricating area through the annular filling groove. The plunger rod is fixed at the center of the rear end cover, and a sliding through groove is communicated with the acting area. When the plunger rod slides, it compresses the gas medium to push the annular piston to inject the lubricating oil into the lubricating area, realizing the recycling of the lubricating oil. The present invention significantly improves the performance and reliability of the oil cylinder.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic cylinders, and more specifically, to a cylinder with a self-lubricating system. Background Art

[0002] As a common hydraulic actuator, hydraulic cylinders are widely used in the fields of construction machinery, aerospace, and automotive manufacturing. Their core function is to drive the telescopic movement of the piston rod through the injection and discharge of hydraulic oil, thereby achieving the attitude adjustment or power output of mechanical devices. However, during the long-term operation of traditional hydraulic cylinders, the friction problem between the piston and the inner wall of the cylinder barrel has always been a technical bottleneck that is difficult to overcome. Due to the direct contact between the piston and the cylinder barrel, especially under working conditions of high pressure, high speed, or frequent reciprocating motion, it is easy to cause an increase in friction loss, which in turn leads to problems such as equipment wear, seal failure, and even cylinder jamming. This not only reduces the service life of the hydraulic cylinder but also increases the maintenance cost and downtime risk.

[0003] To solve the above problems, in the prior art, an external lubrication system or regular manual lubricating oil injection is usually adopted to reduce the friction between the piston and the cylinder barrel. However, the external lubrication system has a complex structure, occupies a large space, and requires additional power sources and control devices, increasing the complexity and cost of the system. The method of manual lubricating oil injection has problems such as uneven lubrication and untimely injection, making it difficult to meet the usage requirements of high precision and high reliability. In addition, traditional lubrication methods are also prone to a decrease in lubrication effect due to impurities mixed in the lubricating oil, and even block the oil circuit, further exacerbating equipment wear. Summary of the Invention

[0004] Aiming at the above deficiencies existing in the prior art, the purpose of the present invention is to provide a cylinder with a self-lubricating system. Through innovative structural design and integration of the lubrication system, it effectively solves the technical problems of traditional cylinders in lubrication, and has multiple beneficial effects such as efficient lubrication, reduced friction, recycling of lubricating oil, compact structure, and improved sealing performance, significantly improving the performance and reliability of the cylinder.

[0005] The technical solution adopted by the present invention to achieve the above purpose is: a cylinder with a self-lubricating system, including a cylinder barrel, a front end cover, a rear end cover that are assembled in a matching manner, and a piston seat and a piston rod that are fixedly combined. The front end cover and the rear end cover are hermetically assembled at the front and rear ends of the cylinder barrel. The piston seat is slidably installed in the cylinder barrel, and the piston rod is slidably inserted and connected with the front end cover.

[0006] Two groups of piston sealing rings are hermetically assembled on the outer wall of the piston seat. The piston sealing rings, the inner wall of the cylinder barrel, and the outer wall of the piston seat enclose a lubricating area. An annular filling groove is arranged on the outer wall of the piston seat between the two groups of piston sealing rings. An annular oil filtering cavity and an annular compression cavity are sequentially arranged from outside to inside on the inner side of the piston seat. The annular oil filtering cavity is separated into an oil collecting area and an oil storage area by an annular filter screen assembled therein. The annular compression cavity is separated into an oil injection area and an acting area by an annular piston assembled therein.

[0007] Lubricating oil is filled in the lubricating area and the annular oil filtering cavity. The oil collecting area is in communication with the lubricating area and is used to collect the lubricating oil in the lubricating area. The oil storage area is in communication with the oil injection area and is used to supplement the filtered lubricating oil into the oil injection area. The oil injection area is in communication with the annular filling groove and is used to inject the lubricating oil in the oil injection area into the lubricating area through the annular filling groove.

[0008] It further includes a plunger rod fixed at the axis of the rear end cover. A sliding through groove is arranged at the axis of the piston seat and the piston rod. A gas medium is filled in the sliding through groove and the acting area. The plunger rod is slidably installed in the sliding through groove, and the front end of the sliding through groove is in communication with the acting area.

[0009] Based on the above technical solution, in order to facilitate the machining of the annular oil filtering cavity and the annular compression cavity in the piston seat and realize the stable installation of the annular filter screen and the annular piston therein respectively, the following technical solution is provided:

[0010] The piston seat includes a front seat body, an annular seat, and a rear seat body that are sequentially arranged and fixedly combined. The piston rod is fixedly connected to the front side end of the front seat body. The annular seat is hermetically attached to the front seat body and the rear seat body. An outer sleeve is fixedly connected to the inner side end of the front seat body. An inner ring groove and an outer ring groove are sequentially arranged from inside to outside at the inner side end of the rear seat body. An inner sleeve arranged inside the inner ring groove is also fixedly connected to the inner side end of the rear seat body. The inner sleeve is arranged inside the outer sleeve and is hermetically abutted against the front seat body. The outer sleeve, the inner sleeve, and the inner ring groove enclose the annular compression cavity. The annular seat, the outer sleeve, and the outer ring groove enclose the annular oil filtering cavity. The annular filter screen is nested and installed at the port of the outer ring groove.

[0011] Based on the above technical solution, in order to realize the communication of each chamber in the piston seat and ensure the stable flow of the lubricating oil according to the design requirements, the following technical solution is provided:

[0012] The annular filling groove is arranged on the outer side wall of the annular seat. The piston sealing ring is nested and installed at the connection between the annular seat and the front seat body and the rear seat body. Radial through grooves are formed on the annular seat on both sides of the annular filling groove and are used to communicate the lubrication area and the oil collecting area. The radial through grooves are arranged inside the piston sealing ring.

[0013] Multiple groups of connection passages A distributed in an annular array are formed on the rear seat body. The connection passages A are in communication with the outer ring groove and the inner ring groove. Multiple groups of connection passages B distributed in an annular array are formed on the rear seat body and the annular seat. The connection passages B are in communication with the inner ring groove and the annular filling groove.

[0014] Based on the above technical solutions, in order to limit the lubricating oil in the oil storage area to flow unidirectionally into the oil injection area through the connection passage A and limit the lubricating oil in the oil injection area to flow unidirectionally into the annular filling groove through the connection passage B, the following technical solutions are provided:

[0015] A one-way valve A is assembled at the connection between the connection passage A and the outer ring groove. The one-way valve A is used to control the unidirectional flow of the lubricating oil in the oil storage area into the oil injection area. A one-way valve B is assembled at the connection between the connection passage B and the inner ring groove. The one-way valve B is used to control the unidirectional flow of the lubricating oil in the oil injection area into the annular filling groove.

[0016] Based on the above technical solutions, in order to ensure that the plunger rod can be installed in the sliding through groove in a sliding combination manner and the relative displacement of the plunger rod can apply a force to the gas medium in the acting area and the sliding through groove, the following technical solutions are provided:

[0017] The sliding through groove is formed at the axis of the front seat body, the rear seat body, and the piston rod. An axial through groove is formed in the piston rod around the sliding through groove. The axial through groove is connected to the acting area and is in communication with the front end of the sliding through groove.

[0018] Based on the above technical solutions, in order to facilitate the machining of the axial through groove and realize the communication between the axial through groove and the front end of the sliding through groove, the following technical solutions are provided:

[0019] An assembly seat is arranged at the front end of the piston rod. A threaded column A rotatably connected to the front end of the sliding through groove is fixedly connected to the inner side end of the assembly seat. An annular through groove is formed in the inner side end of the assembly seat around the threaded column A. The annular through groove is in communication with the axial through groove. An axial sinking groove is formed in the inner side wall of the sliding through groove at the front end of the piston rod. A radial connection groove is also formed in the inner side end of the assembly seat. The radial connection groove is in communication with the annular through groove and the axial sinking groove.

[0020] Based on the above technical solutions, to ensure that the piston rod and the rear end cover can be respectively connected to the acting component, the following technical solutions are provided:

[0021] A front connecting piece is installed on the assembly seat in a matching manner, a rear connecting piece is fixedly connected to the rear side end of the rear end cover, and a front assembly through hole and a rear assembly through hole are respectively formed in the front connecting piece and the rear connecting piece.

[0022] Based on the above technical solutions, to ensure that the front connecting piece can be connected and combined with the assembly seat, and at the same time facilitate its disassembly and assembly for the assembly of the piston rod, the following technical solutions are provided:

[0023] A threaded column B is fixedly connected to the front side end of the assembly seat, a positioning cover is screwed on the threaded column B, a rotating seat is rotatably installed in the positioning cover, a threaded column C arranged outside the positioning cover is fixedly connected to the rotating seat, and the front connecting piece is kept screwed with the threaded column C.

[0024] Based on the above technical solutions, to add or discharge hydraulic oil to both sides of the piston seat in the cylinder barrel through the front end cover and the rear end cover, the following technical solutions are provided:

[0025] An oil supply interface A is formed in the front end cover, an oil supply interface B is formed in the rear end cover, and both the oil supply interface A and the oil supply interface B are in communication with the inner cavity of the cylinder barrel and the external environment.

[0026] Advantages of the present invention:

[0027] 1. Efficient lubrication and friction reduction: By providing an annular filling groove, an annular oil filtering cavity and an annular compression cavity on the piston seat, automatic filling and recycling of lubricating oil are realized. When the piston seat contracts, the plunger rod pushes the gas medium to squeeze the annular piston, and injects the lubricating oil into the lubrication area through the annular filling groove, effectively reducing the friction between the piston seat and the inner wall of the cylinder barrel, and avoiding rigid collision and equipment wear.

[0028] 2. Recycling and filtering of lubricating oil: Through the design of the annular oil filtering cavity and the annular filter screen, the lubricating system realizes automatic filtering and recycling of lubricating oil. The lubricating oil in the lubrication area enters the oil collecting area under pressure, is filtered by the filter screen and then enters the oil storage area, and then flows back to the oil injection area through the connecting passage, ensuring the cleanliness and fluidity of the lubricating oil and extending the service life of the lubricating oil.

[0029] 3. Compact structure and high integration: The lubrication system is integrated inside the piston seat. Through the split piston seat design (front seat body, annular seat, rear seat body) and the modular assembly method, efficient integration of the lubrication system is realized. This design not only simplifies the overall structure of the oil cylinder, but also reduces the manufacturing and maintenance costs.

[0030] 4. One-way flow control and improved sealing: By setting one-way valve A and one-way valve B in connecting passage A and connecting passage B, the one-way flow of lubricating oil is ensured, and the backflow and leakage of lubricating oil are avoided. At the same time, through the design of sealing components A and sealing components B, the sealing performance of the piston rod and the plunger rod is further improved, ensuring the stable operation of the lubrication system.

[0031] 5. Wide application range and high reliability: The lubrication system of this solution is suitable for a variety of working conditions, especially in scenarios of high pressure, high speed or frequent reciprocating motion. It can effectively reduce friction loss and improve the operating reliability and service life of the cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural schematic diagram of the present invention;

[0033] Figure 2 It is a structural schematic diagram of another perspective of the present invention;

[0034] Figure 3 It is a schematic diagram of the structure of the present invention in a cutaway state;

[0035] Figure 4 It is a cross-sectional schematic diagram of the present invention;

[0036] Figure 5 A detailed schematic diagram of the piston seat;

[0037] Figure 6 for Figure 5 Schematic diagram of the structure in disassembled state;

[0038] Figure 7 It is a structural schematic diagram of the front end of the piston rod;

[0039] Figure 8 for Figure 7 Schematic diagram of the structure with key components disassembled.

[0040] In the figure: 1 cylinder barrel, 2 front end cover, 21 sealing assembly A, 22 oil supply interface A, 3 rear end cover, 31 rear connecting piece, 311 rear assembly through port, 32 oil supply interface B, 41 piston seat, 411 piston sealing ring, 412 annular filling groove, 4131 annular filter screen, 4132 oil collecting area, 4133 oil storage area, 4141 annular piston, 4142 oil injection area, 4143 acting area, 415 lubricating area, 416 front seat body, 4161 outer sleeve, 417 annular seat, 4171 radial through groove, 418 rear seat body, 4181 inner ring groove, 4182 outer ring groove, 4183 inner sleeve, 4191 connecting passage A, 4192 connecting passage B, 4193 sealing plug, 4194 one-way valve A, 4195 one-way valve B, 42 piston rod, 421 axial through groove, 422 axial sinking groove, 43 sliding through groove, 431 sealing assembly B, 44 assembly seat, 441 threaded post A, 442 annular through groove, 443 radial connecting groove, 444 threaded post B, 445 positioning cover, 446 rotating seat, 447 threaded post C, 45 front connecting piece, 451 front assembly through port, 5 plunger rod. Detailed implementation manner

[0041] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. Embodiment

[0042] Please refer to Figures 1 - 5 , an oil cylinder with a self-lubricating system, including a supporting combination of a cylinder barrel 1, a front end cover 2, a rear end cover 3, and a fixed combination of a piston seat 41 and a piston rod 42. The front end cover 2 and the rear end cover 3 are hermetically assembled at the front and rear ends of the cylinder barrel 1. The piston seat 41 is slidably installed in the cylinder barrel 1, and the piston rod 42 is slidably inserted into the front end cover 2.

[0043] Both the front end cover 2 and the rear end cover 3 are hermetically attached to the inner wall of the end of the cylinder barrel 1 and are fixedly combined through a bolt assembly provided on the periphery, so as to form a sealed piston cavity in the cylinder barrel 1. The piston seat 41 and the piston rod 42 are assembled into the cylinder barrel 1 before the front end cover 2 and the rear end cover 3, and the outer wall of the piston seat 41 is hermetically attached to the inner wall of the cylinder barrel 1, and the piston rod 42 is hermetically attached to the front end cover 2. By injecting or discharging hydraulic oil at both ends of the cylinder barrel 1, the sliding of the piston seat 41 and the piston rod 42 in the cylinder barrel 1 can be controlled, thereby adjusting the telescopic posture of the oil cylinder.

[0044] Two groups of piston sealing rings 411 are hermetically assembled on the outer wall of the piston seat 41. The piston sealing rings 411, the inner wall of the cylinder barrel 1, and the outer wall of the piston seat enclose a lubrication area 415. An annular filling groove 412 arranged between the two groups of piston sealing rings 411 is formed on the outer wall of the piston seat 41. An annular oil filtering cavity and an annular compression cavity are sequentially arranged inside the piston seat 41 from outside to inside. The annular oil filtering cavity is divided into an oil collecting area 4132 and an oil storage area 4133 by an annular filter screen 4131 assembled therein. The annular compression cavity is divided into an oil injection area 4142 and an acting area 4143 by an annular piston 4141 assembled therein.

[0045] Lubricating oil is filled in the lubrication area 415 and the annular oil filtering cavity. The oil collecting area 4132 is in communication with the lubrication area 415 and is used to collect the lubricating oil in the lubrication area 415. The oil storage area 4133 is in communication with the oil injection area 4142 and is used to supplement the filtered lubricating oil into the oil injection area 4142. The oil injection area 4142 is in communication with the annular filling groove 412 and is used to inject the lubricating oil in the oil injection area 4142 into the lubrication area 415 through the annular filling groove 412.

[0046] It further includes a plunger rod 5 fixed at the center of the rear end cover 3. A sliding through groove 43 is formed at the center of the piston seat 41 and the piston rod 42. A gas medium is filled in the sliding through groove 43 and the acting area 4143. The plunger rod 5 is slidably installed in the sliding through groove 43, and the front end of the sliding through groove 43 is in communication with the acting area 4143.

[0047] When the piston seat 41 and the piston rod 42 contract and move, that is, when the piston seat 41 and the piston rod 42 move towards the rear end cover 3, the plunger rod 5 moves into the sliding through groove 43 to squeeze the gas medium (the gas medium can use stable nitrogen or helium, and the filling pressure is controlled), so as to push the annular piston 4141 to move towards the oil injection area 4142, and then convey the lubricating oil in the oil injection area 4142 to the lubrication area 415 through the annular filling groove 412, so as to lubricate the gap between the outer wall of the piston seat 41 and the inner wall of the cylinder barrel 1 and the piston sealing rings 411, realize the smooth operation of the piston seat 41 in the cylinder barrel 1, and avoid rigid collision between the cylinder barrel 1 and the piston seat 41, which may cause equipment damage or affect the service life.

[0048] While the lubricating oil is filled into the lubrication area 415, the original lubricating oil containing impurities in the lubrication area 415 enters the oil collecting area 4132 of the annular oil filtering cavity under the action of pressure. The lubricating oil entering the oil collecting area 4132 can enter the oil storage area 4133 through the annular filter screen 4131 for filtering and storage.

[0049] When the piston seat 41 and the piston rod 42 perform an elongation movement, that is, the piston seat 41 and the piston rod 42 move towards the side of the rear end cover 3, at this time, the plunger rod 5 will extend out of the sliding through groove 43, so that the pressure on the side of the acting area 4143 is reduced. Under the action of the pressure difference, the annular piston 4141 moves towards the side of the acting area 4143, and the lubricating oil in the oil storage area 4133 will flow back to the oil injection area 4142. Thus, the reciprocating movement can realize the circulating flow of the lubricating oil, and further realize the full lubrication of the piston seat 41 and the inner wall of the cylinder barrel 1. Embodiment

[0050] Please refer to Figures 3 - 6 , for the convenience of machining the annular oil filtering cavity and the annular compression cavity in the piston seat 41, and realizing the stable installation of the annular filter screen 4131 and the annular piston 4141 therein respectively, the following technical solutions are provided:

[0051] The piston seat 41 includes a front seat body 416, an annular seat 417, and a rear seat body 418 that are arranged in sequence and fixedly combined. The piston rod 42 is fixedly connected to the front side end of the front seat body 416. The annular seat 417 is in sealed fit with the front seat body 416 and the rear seat body 418. An outer sleeve 4161 is fixedly connected to the inner side end of the front seat body 416. The inner side end of the rear seat body 418 is provided with an inner ring groove 4181 and an outer ring groove 4182 that are arranged in sequence from the inside to the outside. The inner side end of the rear seat body 418 is also fixedly connected with an inner sleeve 4183 arranged inside the inner ring groove 4181. The inner sleeve 4183 is arranged inside the outer sleeve 4161 and is in sealed contact with the front seat body 416. The outer sleeve 4161, the inner sleeve 4183, and the inner ring groove 4181 enclose an annular compression cavity. The annular seat 417, the outer sleeve 4161, and the outer ring groove 4182 enclose an annular oil filtering cavity. The annular filter screen 4131 is nested and installed at the port of the outer ring groove 4182.

[0052] The piston seat 41 is designed as a three-section split structure, which can facilitate the machining of the annular oil filtering cavity and the annular compression cavity in the piston seat 41, and realize the effective assembly of the annular filter screen 4131 and the annular piston 4141. The front seat body 416, the annular seat 417, and the rear seat body 418 are fixedly combined by means of bolts, and sealing rings are installed at each joint part to ensure the sealing effect of the connection part.

[0053] The annular oil filtering cavity is fixedly clamped by the outer ring groove 4182 and the annular seat 417 and the outer sleeve 4161 to realize the stable installation in the annular filter screen 4131 and the filtration of the lubricating oil.

[0054] To realize the communication of each chamber in the piston seat 41 and ensure the stable flow of the lubricating oil according to the design requirements, the following technical solutions are provided:

[0055] The annular filling groove 412 is arranged on the outer side wall of the annular seat 417. A piston seal ring 411 is nested and installed at the connection between the annular seat 417 and the front seat body 416 and the rear seat body 418. Radial through grooves 4171 are formed on the annular seat 417 on both sides of the annular filling groove 412 and are used to connect the lubrication area 415 and the oil collecting area 4132. The radial through grooves 4171 are arranged inside the piston seal ring 411.

[0056] Multiple groups of connection passages A4191 distributed in an annular array are formed on the rear seat body 418. The connection passages A4191 are in communication with the outer ring groove 4182 and the inner ring groove 4181. Multiple groups of connection passages B4192 distributed in an annular array are formed on the rear seat body 418 and the annular seat 417. The connection passages B4192 are in communication with the inner ring groove 4181 and the annular filling groove 412.

[0057] The radial through grooves 4171 are arranged on both sides of the annular filling groove 412 and inside the piston seal ring 411. After the lubricating oil is input into the lubrication area 415 through the annular filling groove 412, the original lubricating oil is blocked by the piston seal ring 411 and flows into the oil collecting area 4132 along the radial through grooves 4171 for filtering treatment.

[0058] The connection passages A4191 and the connection passages B4192 are all drilled radially along the outer side of the rear seat body 418 or the annular seat 417, and axially drilled on the end faces of the rear seat body 418 and the annular seat 417 to connect the drilled holes, so as to realize the communication between the oil injection area 4142, the oil storage area 4133 and the annular filling groove 412.

[0059] During the assembly stage, the openings of the radial drill holes on the rear seat body 418 are blocked by the sealing plugs 4193 to prevent the leakage of lubricating oil.

[0060] To restrict the lubricating oil in the oil storage area 4133 from flowing unidirectionally into the oil injection area 4142 through the connection passage A4191, and restrict the lubricating oil in the oil injection area 4142 from flowing unidirectionally into the annular filling groove 412 through the connection passage B4192, the following technical solutions are provided:

[0061] A one-way valve A4194 is assembled at the connection between the connection passage A4191 and the outer ring groove 4182. The one-way valve A4194 is used to control the unidirectional flow of the lubricating oil in the oil storage area 4133 into the oil injection area 4142. A one-way valve B4195 is assembled at the connection between the connection passage B4192 and the inner ring groove 4181. The one-way valve B4195 is used to control the unidirectional flow of the lubricating oil in the oil injection area 4142 into the annular filling groove 412.

[0062] An assembly interface is provided at the connection of the connecting passage A4191, the connecting passage B4192 with the inner ring groove 4181 and the outer ring groove 4182. The one-way valve A4194 and the one-way valve B4195 are fixed in the corresponding assembly interfaces by screwing, and can control the one-way flow of lubricating oil. Embodiment

[0063] Please refer to Figures 3 - 6 、 Figure 8 , to ensure that the plunger rod 5 can be installed in the sliding through groove 43 in a sliding combination manner, and the gas medium in the acting area 4143 and the sliding through groove 43 can be applied with a force through the relative displacement of the plunger rod 5. The following technical solutions are provided for this:

[0064] The sliding through groove 43 is opened to the axes of the front seat body 416, the rear seat body 418, and the piston rod 42. An axial through groove 421 is opened in the piston rod 42 and is arranged outside the sliding through groove 43. The axial through groove 421 is connected to the acting area 4143 and is kept in communication with the front end of the sliding through groove 43.

[0065] When the plunger rod 5 slides relative to the sliding through groove 43, the pressure change of the gas medium can act on the acting area 4143 through the axial through groove 421 to drive the annular piston 4141 to slide stably in the annular compression chamber.

[0066] A sealing component A21 that is hermetically fitted with the piston rod 42 is assembled inside the front end cover 2. A sealing component B431 that is hermetically fitted with the plunger rod 5 is assembled at the rear side end of the sliding through groove 43 (in the rear seat body 418). The sealing component A21 and the sealing component B431 are both composed of a combination of multiple types of sealing rubber rings, and can ensure the sealing effect when the piston rod 42 and the plunger rod 5 slide.

[0067] To facilitate the machining of the axial through groove 421 and to achieve the communication between the axial through groove 421 and the front end of the sliding through groove 43, the following technical solutions are provided for this:

[0068] An assembly seat 44 is provided at the front side end of the piston rod 42. A threaded column A441 that is screwed with the front side end of the sliding through groove 43 is fixedly connected to the inner side end of the assembly seat 44. An annular through groove 442 is opened in the inner side end of the assembly seat 44 and is arranged outside the threaded column A441. The annular through groove 442 is kept in communication with the axial through groove 421. An axial sunk groove 422 is opened in the front side end of the piston rod 42 and is arranged on the inner wall of the sliding through groove 43. A radial connection groove 443 is further opened in the inner side end of the assembly seat 44. The radial connection groove 443 is kept in communication with the annular through groove 442 and the axial sunk groove 422.

[0069] The provision of the axial sink 422 can, while ensuring the normal screwed connection combination of the threaded post A 441 and the sliding through slot 43, also cooperate with the radial connection slot 443 to achieve the communication between the sliding through slot 43 and the annular through slot 442, and the annular through slot 442 can achieve the communication of the axial through slot 421. The distribution and design of each groove structure can be drilled and processed separately on the corresponding components, thereby ensuring the communication effect between the sliding through slot 43 and the annular compression chamber in the piston seat 41.

[0070] A sealing ring needs to be additionally installed at the joint between the assembly seat 44 and the front end of the piston rod 42 to ensure the sealing effect at the joint, and thus ensure the airtight effect of the sliding through slot 43 and the acting area 4143. Embodiment

[0071] Please refer to Figures 1 - 4 、 Figure 7 In order to ensure that the piston rod 42 and the rear end cover 3 can be respectively connected to the acting components, the following technical solutions are provided:

[0072] A front connecting piece 45 is installed on the assembly seat 44 in a matching manner, and a rear connecting piece 31 is fixedly connected to the rear side end of the rear end cover 3. Front assembly through openings 451 and rear assembly through openings 311 are respectively provided on the front connecting piece 45 and the rear connecting piece 31.

[0073] The provision of the front assembly through opening 451 and the rear assembly through opening 311 can be connected and combined with the acting components in a hinged manner to achieve the attitude adjustment of the associated components during the telescopic movement of the oil cylinder.

[0074] On the basis of the above technical solution, in order to ensure that the front connecting piece 45 can be connected and combined with the assembly seat 44, and at the same time facilitate its disassembly and assembly to facilitate the assembly of the piston rod 42, the following technical solutions are provided:

[0075] A threaded post B 444 is fixedly connected to the front side end of the assembly seat 44. A positioning cover 445 is screwed onto the threaded post B 444. A rotating seat 446 is rotatably installed in the positioning cover 445. A threaded post C 447 arranged outside the positioning cover 445 is fixedly connected to the rotating seat 446. The front connecting piece 45 is kept screwed with the threaded post C 447.

[0076] The screwed connection combination of the positioning cover 445 and the threaded post B 444 can effectively position the rotating seat 446, and then the front connecting piece 45 can be installed and combined through the threaded post C 447. The front connecting piece 45 can be assembled onto the assembly seat 44 in a manner of freely rotating around the axis to ensure that the front connecting piece 45 can be effectively connected to the acting components. Embodiment

[0077] Please refer to Figure 3 、 Figure 4, in order to realize filling or discharging hydraulic oil to both sides of the piston seat 41 in the cylinder barrel 1 through the front end cover 2 and the rear end cover 3, the following technical solutions are provided:

[0078] An oil supply interface A22 is provided in the front end cover 2, and an oil supply interface B32 is provided in the rear end cover 3. Both the oil supply interface A22 and the oil supply interface B32 are in communication with the inner cavity of the cylinder barrel 1 and the external environment.

[0079] Both the oil supply interface A22 and the oil supply interface B32 are processed into an L-shaped structure by drilling, and are respectively connected to the side wall and the end wall of the front end cover 2 and the rear end cover 3, providing a stable filling or oil discharging interface while not affecting the stable operation of other components. After being connected to the hydraulic oil system, it can effectively control the telescopic posture of the oil cylinder.

[0080] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claimed rights.

[0081] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An oil cylinder with a self-lubricating system, comprising a cylinder barrel (1), a front end cover (2), a rear end cover (3) which are assembled in a matching manner, and a piston seat (41) and a piston rod (42) which are fixedly combined. The front end cover (2) and the rear end cover (3) are hermetically assembled at the front and rear ends of the cylinder barrel (1). The piston seat (41) is slidably installed in the cylinder barrel (1), and the piston rod (42) is slidably inserted into the front end cover (2). It is characterized in that: Two groups of piston sealing rings (411) are hermetically assembled on the outer wall of the piston seat (41). The piston sealing rings (411), the inner wall of the cylinder barrel (1), and the outer wall of the piston seat (41) enclose a lubrication area (415). An annular filling groove (412) is arranged on the outer wall of the piston seat (41) between the two groups of piston sealing rings (411). An annular oil filtering cavity and an annular compression cavity are sequentially arranged from outside to inside on the inner side of the piston seat (41). The annular oil filtering cavity is divided into an oil collecting area (4132) and an oil storage area (4133) by an annular filter screen (4131) assembled therein. The annular compression cavity is divided into an oil injection area (4142) and an acting area (4143) by an annular piston (4141) assembled therein. The piston seat (41) includes a front seat body (416), an annular seat (417), and a rear seat body (418) which are sequentially arranged and fixedly combined. An outer sleeve (4161) is fixedly connected to the inner end of the front seat body (416). An inner ring groove (4181) and an outer ring groove (4182) are sequentially arranged from inside to outside on the inner end of the rear seat body (418). An inner sleeve (4183) arranged inside the inner ring groove (4181) is also fixedly connected to the inner end of the rear seat body (418). The outer sleeve (4161), the inner sleeve (4183), and the inner ring groove (4181) enclose the annular compression cavity. The annular seat (417), the outer sleeve (4161), and the outer ring groove (4182) enclose the annular oil filtering cavity. Radial through grooves (4171) which are arranged on both sides of the annular filling groove (412) and used to connect the lubrication area (415) and the oil collecting area (4132) are arranged on the annular seat (417). A plurality of connecting passages A (4191) which are annularly arrayed are arranged on the rear seat body (418). The connecting passages A (4191) are in communication with the outer ring groove (4182) and the inner ring groove (4181). A plurality of connecting passages B (4192) which are annularly arrayed are arranged on the rear seat body (418) and the annular seat (417). The connecting passages B (4192) are in communication with the inner ring groove (4181) and the annular filling groove (412). It further includes a plunger rod (5) fixed at the axis of the rear end cover (3). A sliding through groove (43) is provided at the axis of the piston seat (41) and the piston rod (42). A gas medium is filled in the sliding through groove (43) and the acting area (4143). The plunger rod (5) is slidably installed in the sliding through groove (43), and the front end of the sliding through groove (43) is in communication with the acting area (4143).

2. The oil cylinder with a self-lubricating system according to claim 1, wherein: The piston rod (42) is fixedly connected to the front side end of the front seat body (416). The annular seat (417) is in sealing fit with the front seat body (416) and the rear seat body (418). The inner sleeve (4183) is arranged inside the outer sleeve (4161) and is in sealing abutment with the front seat body (416). The annular filter screen (4131) is nested and installed at the port of the outer ring groove (4182).

3. The oil cylinder with a self-lubricating system according to claim 2, characterized in that: The annular filling groove (412) is arranged on the outer side wall of the annular seat (417). A piston seal ring (411) is nested and installed at the connection of the annular seat (417) with the front seat body (416) and the rear seat body (418). The radial through groove (4171) is arranged inside the piston seal ring (411).

4. The oil cylinder with a self-lubricating system according to claim 3, characterized in that: A one-way valve A (4194) is assembled at the connection of the connection passage A (4191) and the outer ring groove (4182). The one-way valve A (4194) is used to control the one-way flow of lubricating oil in the oil storage area (4133) into the oil injection area (4142). A one-way valve B (4195) is assembled at the connection of the connection passage B (4192) and the inner ring groove (4181). The one-way valve B (4195) is used to control the one-way flow of lubricating oil in the oil injection area (4142) into the annular filling groove (412).

5. The oil cylinder with a self-lubricating system according to claim 3, characterized in that: The sliding through groove (43) is provided at the axis of the front seat body (416), the rear seat body (418), and the piston rod (42). An axial through groove (421) is provided in the piston rod (42) and is arranged outside the sliding through groove (43). The axial through groove (421) is connected to the acting area (4143) and is in communication with the front end of the sliding through groove (43).

6. The oil cylinder with a self-lubricating system according to claim 5, characterized in that: An assembly seat (44) is provided at the front side end of the piston rod (42). A threaded post A (441) which is in rotary connection with the front side end of the sliding through groove (43) is fixedly connected to the inner side end of the assembly seat (44). An annular through groove (442) is provided in the inner side end of the assembly seat (44) and is arranged outside the threaded post A (441). The annular through groove (442) is in communication with the axial through groove (421). An axial sink (422) is provided in the inner wall of the sliding through groove (43) at the front side end of the piston rod (42). A radial connection groove (443) is further provided in the inner side end of the assembly seat (44). The radial connection groove (443) is in communication with the annular through groove (442) and the axial sink (422).

7. An oil cylinder with a self-lubricating system according to claim 6, characterized in that: A front connecting piece (45) is fitted and installed on the assembly seat (44), and a rear connecting piece (31) is fixedly connected to the rear side end of the rear end cover (3). Front assembly through holes (451) and rear assembly through holes (311) are respectively formed in the front connecting piece (45) and the rear connecting piece (31).

8. The hydraulic cylinder with a self-lubricating system according to claim 7, characterized in that: A threaded post B (444) is fixedly connected to the front side end of the assembly seat (44). A positioning cover (445) is screwed onto the threaded post B (444). A rotating seat (446) is rotatably installed in the positioning cover (445). A threaded post C (447) arranged outside the positioning cover (445) is fixedly connected to the rotating seat (446). The front connecting piece (45) is kept screwed with the threaded post C (447).

9. The oil cylinder with a self-lubricating system according to claim 1, characterized in that: An oil supply interface A (22) is formed in the front end cover (2), and an oil supply interface B (32) is formed in the rear end cover (3). Both the oil supply interface A (22) and the oil supply interface B (32) are in communication with the inner cavity of the cylinder barrel (1) and the external environment.

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