CN220980003U

CN220980003U - Lifting point longitudinally moving oil cylinder

Info

Publication number: CN220980003U
Application number: CN202322792506.8U
Authority: CN
Inventors: 黎雄坚
Original assignee: Smk Hydraulic Cylinder Co ltd
Current assignee: Smk Hydraulic Cylinder Co ltd
Priority date: 2023-10-18
Filing date: 2023-10-18
Publication date: 2024-05-17
Anticipated expiration: 2033-10-18

Abstract

The utility model discloses a lifting point longitudinal moving oil cylinder which comprises a cylinder barrel, a piston rod, a cylinder bottom, a cylinder cover, a piston, a first oil hole, a second oil hole, a first lifting lug and a second lifting lug, wherein the cylinder barrel is transversely arranged, the piston rod is installed in the cylinder barrel and can move leftwards or rightwards relative to the cylinder barrel, the piston is sleeved on the tail end of the left end of the piston rod, the right end of the cylinder barrel is movably provided with the cylinder cover, the left end of the cylinder barrel is provided with the cylinder bottom, the first oil hole penetrates through the cylinder bottom to be communicated with the inside of the cylinder barrel, the second oil hole penetrates through the cylinder barrel at the left end of the cylinder cover, a first sealing device is arranged between the inner periphery of the cylinder cover and the piston rod, a second sealing device is arranged between the outer periphery of the piston and the cylinder barrel, a third sealing device is arranged between the inner periphery of the piston and the piston rod, the first lifting lug is connected to the tail end of the right end of the piston rod, and the second lifting lug is connected to the left end of the cylinder bottom. The utility model has the advantages of simple structure, high running stability, high precision, good safety and durability and convenient installation and replacement.

Description

Lifting point longitudinally moving oil cylinder

Technical Field

The utility model relates to the technical field of hydraulic cylinders, in particular to a lifting point longitudinal movement oil cylinder.

Background

The hydraulic cylinder is a hydraulic actuator that converts hydraulic energy into mechanical energy and performs linear reciprocating motion (or swinging motion). The device has simple structure and reliable operation. When it is used to realize reciprocating motion, it can eliminate speed reducer, and has no transmission clearance and smooth motion, so that it can be widely used in hydraulic systems of various machines. The output force of the hydraulic cylinder is in direct proportion to the effective area of the piston and the pressure difference between two sides of the effective area of the piston; the hydraulic cylinder basically consists of a cylinder barrel, a cylinder cover, a piston rod, a sealing device, a buffer device and an exhaust device. The device can be divided into linear reciprocating motion type and rotary swing type according to the motion mode; the working principle of the hydraulic cylinder doing linear reciprocating motion is as follows: by utilizing the two one-way valves, after the hydraulic cylinder reaches the end point, the lower part of the one-way valve is communicated with the other oil inlet pipe, and oil is turned to the other oil inlet pipe to push the oil cylinder. Because the two one-way valves are communicated, the labor is saved in any aspect, and the oil flows into any oil pipe until the hydraulic pressure at the two ends is balanced.

The lifting point longitudinal moving oil cylinder is a hydraulic cylinder for hoisting equipment and is mainly used for adjusting the height position of a lifting point. The design and selection should consider the actual demand of hoisting equipment, and the requirement of the lifting point longitudinal movement oil cylinder mainly comprises the following points:

Load carrying capacity: the lifting point longitudinal moving oil cylinder needs to be capable of bearing the maximum load required by the lifting equipment, and the bearing capacity of the lifting point longitudinal moving oil cylinder is designed and selected according to actual requirements.

Stability: the lifting point longitudinally moving oil cylinder needs to be kept stable in the working process, shaking or tilting is avoided, and the structural design of the lifting point longitudinally moving oil cylinder needs to have enough rigidity and stability.

Precision: the lifting point longitudinally moving cylinder needs to have higher precision so as to ensure the accurate position adjustment of the lifting point in the vertical direction, and the precision is required to be in the millimeter level.

Safety: the lifting point longitudinally moving oil cylinder needs to have reliable safety protection measures, such as overload protection, pressure loss prevention and the like, so as to ensure the safety in the working process.

Durability: the lifting point longitudinally moving cylinder needs to have high durability and can maintain stable and reliable working performance in long-time use.

The existing lifting point longitudinal moving oil cylinder has the following defects in the use process: firstly, the integral hydraulic buffer performance is poor, vibration and pause are generated during operation, the operation is unstable, meanwhile, the stability of a piston rod is poor, the phenomenon of bending or deformation often occurs during use, and even the cylinder bottom is damaged, so that the integral oil cylinder is scrapped, and the safety is low; secondly, when the working environment is relatively bad, the lifting point longitudinally moving oil cylinder needs to bear the erosion of dust, oil stain and the like in the air, the stability of the running oil cylinder is easy to be disordered when the working is frequent and the maintenance is inconvenient, even oil leakage occurs, and the precision is poor; the installation and replacement are inconvenient, the bottom, the piston rod and the like of the existing oil cylinder are required to be fixed on external parts, and the existing lifting point longitudinally-moving oil cylinder is inconvenient to fix or replace.

In summary, there is a need in the market for a lifting point vertical movement cylinder which meets the market demands, has high operation stability, high precision, good safety and durability, and is convenient to install and replace.

Disclosure of utility model

According to the defects of the prior art, the utility model provides the lifting point longitudinal moving oil cylinder which is simple in structure, high in operation stability, high in precision, good in safety and durability and convenient to install and replace.

In order to solve the technical problems, the technical scheme of the utility model is as follows: the utility model provides a hoisting point is indulged and is moved hydro-cylinder, includes cylinder, piston rod, cylinder bottom, cylinder cap, piston, first oilhole, second oilhole, first lug and second lug, the cylinder transversely sets up, and the piston rod is installed in the cylinder to can be moved left or right for the cylinder, the piston cup joints in the left end terminal side of piston rod, the cylinder cap is installed to the right-hand member of cylinder, the cylinder bottom is installed to the left end of cylinder, first oilhole runs through the cylinder bottom and is linked together with the cylinder inside for power oil gets into between cylinder and the piston, promote the piston and move right for the cylinder, the second oilhole wears to locate on the cylinder of cylinder cap left end for power oil gets into the cylinder inner periphery, promotes the piston and moves left for the cylinder, is equipped with first sealing device between the inner periphery of cylinder cap and the piston rod for prevent that power oil from excessive and outside impurity get into the cylinder inside, be equipped with second sealing device between the periphery of piston and the cylinder, be equipped with third sealing device between the inner periphery of piston and the piston rod, second sealing device and third sealing device cooperate and be used for preventing that power oil from revealing through the piston when moving, first lifting lug is connected in the right end of cylinder bottom for treating the cylinder bottom to move, be used for fixing in the cylinder bottom.

As a further illustration of the utility model:

Preferably, the cylinder cover is fixed at the right end of the cylinder barrel through a plurality of hexagon socket head cap bolts uniformly distributed on the periphery of the cylinder barrel, and the cylinder bottom is welded at the left end of the cylinder barrel.

Preferably, the inner periphery of the left end of the piston is provided with a piston buffer pad with a shape matched with the tail side of the left end of the piston rod, so that the piston is prevented from damaging or crashing the cylinder bottom in the working process.

Preferably, the first oil hole and the second oil hole have the same diameter and are communicated through an external oil pipe for the inlet and outlet of power oil.

Preferably, the first sealing device sequentially comprises a first piston rod guide sleeve, a second piston rod guide sleeve, a first sealing ring, a piston rod supporting ring, a second sealing ring, a third piston rod guide sleeve and a third sealing ring from left to right, wherein the first piston rod guide sleeve, the second piston rod guide sleeve and the third piston rod guide sleeve are mutually matched and used for guiding the piston rod to move left and right relative to the cylinder barrel, the first sealing ring is a Style sealing ring, the second sealing ring is a Y-shaped sealing ring, the third sealing ring is an O-shaped dustproof sealing ring, and the first sealing ring, the second sealing ring and the third sealing ring are mutually matched and used for preventing power oil from overflowing and external impurities from entering the cylinder barrel.

Preferably, the second sealing device sequentially comprises a first piston guide ring, a fourth sealing ring, a second piston guide ring, a fifth sealing ring and a third piston guide ring from left to right, the first piston guide ring, the second piston guide ring and the third piston guide ring are used for supporting and guiding the piston to move left and right relative to the cylinder barrel, the fourth sealing ring and the fifth sealing ring are gray rings, the third sealing device sequentially comprises a first O-shaped sealing ring and a second O-shaped sealing ring from left to right, and the fourth sealing ring, the fifth sealing ring, the first O-shaped sealing ring and the second O-shaped sealing ring are mutually matched to prevent power oil from leaking through the piston when the piston moves.

Preferably, the first lug and second lug are axisymmetric setting, and first lug is the U type that the middle part was equipped with first circular through-hole, and the shape phase-match of first lug left end and piston rod right-hand member end side, the second lug is the spindle that the middle part was equipped with the circular through-hole of second, and the second lug right-hand member is with cylinder bottom shape phase-match, and the diameter of first circular through-hole is the same with the circular through-hole of second.

Preferably, the diameter of the outer circumference of the cylinder barrel is 530.0 mm-570.0 mm, the diameter of the inner circumference of the cylinder barrel is 430.0 mm-470.0 mm, the diameter of the piston rod is 240.0 mm-260.0 mm, the diameters of the inner circumferences of the first circular through hole and the second circular through hole are 190.0 mm-210.0 mm, the lengths from the hole center of the first circular through hole to the right end side of the piston rod and the hole center of the second circular through hole to the cylinder bottom are equal, the lengths from the hole center of the first circular through hole to the hole center of the second circular through hole are 260.0 mm-280.0 mm, the length from the hole center of the first circular through hole to the hole center of the second circular through hole is 3180.0 mm-3220.0 mm in a static state, the working stroke of the piston is 2080.0 mm-2120.0 mm, the working pressure is 23 MPa-27 MPa, and the test pressure is 30 MPa-35 MPa.

Preferably, the first lifting lug and the piston rod are of an integrated structure, and the second lifting lug and the cylinder bottom are of an integrated structure.

The beneficial effects of the utility model are as follows:

the inner periphery of the left end of the piston is provided with the piston buffer pad which is matched with the left end side of the piston rod in shape, so that the damage or the collision of the bottom of the cylinder in the working process of the piston is prevented, and the safety and the durability are good.

The second sealing device sequentially comprises a first piston rod guide sleeve, a second piston rod guide sleeve, a first sealing ring, a piston rod supporting ring, a second sealing ring, a third piston rod guide sleeve and a third sealing ring from left to right, wherein the first piston rod guide sleeve, the second piston rod guide sleeve and the third piston rod guide sleeve are mutually matched to guide the piston rod to move left and right relative to the cylinder barrel, so that the phenomena of poor sealing effect, short service life and the like caused by uneven pressure bearing caused by non-axial stress of the piston rod on the piston rod sealing are prevented, the first sealing ring is a Style sealing ring which is single-acting and is formed by combining a rubber O-shaped ring and a polytetrafluoroethylene ring, the O-shaped ring is a force application element and provides enough sealing force, the sealing device is suitable for sealing for the piston rod of a hydraulic cylinder and has low friction force, the second sealing ring is a Y-shaped sealing ring, the cross section of the second sealing ring is Y-shaped, the second sealing ring is a typical lip-shaped sealing ring and is widely applied to reciprocating sealing devices, the third sealing ring is an O-shaped dustproof sealing ring, the first sealing ring, the second sealing ring and the third sealing ring are mutually matched and are used for preventing power oil from overflowing and external impurities from entering the cylinder barrel and preventing oil leakage, the precision of working is ensured, the second sealing device sequentially comprises a first piston guiding ring, a fourth sealing ring, a second piston guiding ring, a fifth sealing ring and a third piston guiding ring from left to right, the first piston guiding ring, the second piston guiding ring and the third piston guiding ring are used for supporting and guiding the piston to move left and right relative to the cylinder barrel, the guiding piston does linear motion, the hydraulic buffering performance is stronger, the piston is prevented from being deviated due to uneven stress to cause internal leakage, service life is reduced, stability and operation reliability in the operation process are guaranteed, the defect that the lifting point longitudinal movement oil cylinder in the prior art is poor in precision is overcome, the fourth sealing ring and the fifth sealing ring are gray rings, the gray rings are formed by combining rubber O-shaped rings and polytetrafluoroethylene rings, the O-shaped rings apply force, the gray rings are double-acting piston seals, friction force is low, no crawling exists, starting force is small, high pressure resistance is achieved, the third sealing device sequentially comprises a first O-shaped sealing ring and a second O-shaped sealing ring from left to right, and the fourth sealing ring, the fifth sealing ring, the first O-shaped sealing ring and the second O-shaped sealing ring are mutually matched to be used for preventing power oil from leaking through the piston when the piston moves.

And thirdly, the diameters of the first oil hole and the second oil hole are the same, and the first oil hole and the second oil hole are communicated through the external oil pipe, so that in the operation process, the inlet power oil and the outlet power oil are two oil holes with the same diameter, and the stability is further improved.

Fourth, the first lug of the utility model is connected to the right end side of the piston rod, is used for hoisting the thing to be moved longitudinally, the second lug is connected to the left end of the cylinder bottom, is used for fixing the cylinder bottom, the first lug and second lug are axisymmetrically arranged, the first lug is U-shaped with the first round through hole in the middle, and the left end of the first lug is matched with the shape of the right end side of the piston rod, the second lug is spindle-shaped with the second round through hole in the middle, and the right end of the second lug is matched with the shape of the cylinder bottom.

Drawings

FIG. 1 is a schematic diagram of the overall structure of the present utility model.

In the figure: 1. a cylinder; 2. a piston rod; 3. a cylinder bottom; 4. a cylinder cover; 5. a piston; 6. a first oil hole; 7. a second oil hole; 8. a first lifting lug; 9. the second lifting lug; 11. an inner hexagon bolt; 12. a piston cushion pad; 13. an oil pipe; 14. a first piston rod guide sleeve; 15. a second piston rod guide sleeve; 16. a first seal ring; 17. a piston rod support ring; 18. a second seal ring; 19. a third piston rod guide sleeve; 20. a third seal ring; 21. a first piston guide ring; 22. a fourth seal ring; 23. a fifth seal ring; 24. a third piston guide ring; 25. a first O-ring seal; 26. a first circular through hole; 27. and a second circular through hole.

Detailed Description

The structural and operational principles of the present utility model will be described in further detail below with reference to the accompanying drawings.

As shown in fig. 1, the utility model relates to a lifting point longitudinal moving oil cylinder, which comprises a cylinder barrel 1, a piston rod 2, a cylinder bottom 3, a cylinder cover 4, a piston 5, a first oil hole 6, a second oil hole 7, a first lifting lug 8 and a second lifting lug 9, wherein the cylinder barrel 1 is transversely arranged, the piston rod 2 is arranged in the cylinder barrel 1 and can move leftwards or rightwards relative to the cylinder barrel 1, the piston 5 is sleeved on the left end tail side of the piston rod 2, the cylinder cover 4 is movably arranged at the right end of the cylinder barrel 1, the cylinder bottom 3 is arranged at the left end of the cylinder barrel 1, the first oil hole 6 penetrates through the cylinder bottom 3 and is communicated with the inside of the cylinder barrel 1, power oil enters between the cylinder barrel 1 and the piston 5, the piston 5 is pushed to move rightwards relative to the cylinder barrel 1, the second oil hole 7 penetrates through the cylinder barrel 1 at the left end of the cylinder cover 4, the power oil enters the inner periphery of the cylinder barrel 1, the piston 5 is pushed leftwards relative to the cylinder barrel 1, a first sealing device is arranged between the inner periphery of the cylinder cover 4 and the piston rod 2 and is used for preventing power oil from overflowing and external impurities from entering the inside the cylinder barrel 1, a second sealing device is arranged between the outer periphery of the piston 5 and the cylinder barrel 1, the piston 5 and the cylinder barrel 1 is movably provided with a second sealing device, and the inner periphery of the piston 5 is used for sealing the piston rod 5 is connected with the third lifting lug 5 through the cylinder bottom 3 when the cylinder bottom is used for being in the vertical sealing connection with the cylinder bottom 3, which is used for sealing the cylinder end 3.

As shown in fig. 1, the cylinder cover 4 is fixed to the right end of the cylinder 1 by a plurality of hexagon socket head cap bolts 11 uniformly distributed on the outer periphery of the cylinder 1, and the cylinder bottom 3 is welded to the left end of the cylinder 1. The inner periphery of the left end of the piston 5 is provided with a piston buffer pad 12 with the shape matched with the left end side of the piston rod 2, so that the piston 5 is prevented from damaging or crashing the cylinder bottom 3 in the working process. The first oil hole 6 and the second oil hole 7 have the same diameter and are communicated through an external oil pipe 13 for the inlet and outlet of power oil.

As shown in fig. 1, the first sealing device sequentially includes, from left to right, a first piston rod guiding sleeve 14, a second piston rod guiding sleeve 15, a first sealing ring 16, a piston rod supporting ring 17, a second sealing ring 18, a third piston rod guiding sleeve 19 and a third sealing ring 20, where the first piston rod guiding sleeve 14, the second piston rod guiding sleeve 15 and the third piston rod guiding sleeve 19 are mutually matched to guide the piston rod 2 to move left and right relative to the cylinder 1, the first sealing ring 16 is a stele sealing ring, the second sealing ring 18 is a Y sealing ring, the third sealing ring 20 is an O-shaped dustproof sealing ring, and the first sealing ring 16, the second sealing ring 18 and the third sealing ring 20 are mutually matched to prevent power oil from overflowing and external impurities from entering the cylinder 1. The second sealing device sequentially comprises a first piston guide ring 21, a fourth sealing ring 22, a second piston 5 guide ring, a fifth sealing ring 23 and a third piston guide ring 24 from left to right, the first piston guide ring 21, the second piston 5 guide ring and the third piston guide ring 24 are used for supporting and guiding the piston 5 to move left and right relative to the cylinder barrel 1, the fourth sealing ring 22 and the fifth sealing ring 23 are gray rings, the third sealing device sequentially comprises a first O-shaped sealing ring 25 and a second O-shaped sealing ring from left to right, and the fourth sealing ring 22, the fifth sealing ring 23, the first O-shaped sealing ring 25 and the second O-shaped sealing ring are mutually matched to prevent power oil from leaking through the piston 5 when the piston 5 moves.

As shown in fig. 1, the first lifting lug 8 and the second lifting lug 9 are axisymmetrically arranged, the first lifting lug 8 is in a U shape with a first circular through hole 26 in the middle, the left end of the first lifting lug 8 is matched with the shape of the right end of the piston rod 2, the second lifting lug 9 is in a spindle shape with a second circular through hole 27 in the middle, the right end of the second lifting lug 9 is matched with the shape of the cylinder bottom 3, and the diameters of the first circular through hole 26 and the second circular through hole 27 are the same.

Further, the diameter of the outer periphery of the cylinder barrel 1 is 530.0 mm-570.0 mm, the diameter of the inner periphery of the cylinder barrel 1 is 430.0 mm-470.0 mm, the diameter of the piston rod 2 is 240.0 mm-260.0 mm, the diameters of the inner periphery of the first circular through hole 26 and the second circular through hole 27 are 190.0 mm-210.0 mm, the lengths from the center of the first circular through hole 26 to the right end of the piston rod 2 and the length from the center of the second circular through hole 27 to the cylinder bottom 3 are equal, the lengths from the center of the first circular through hole 26 to the center of the second circular through hole 27 are all 260.0 mm-280.0 mm, the lengths from the center of the first circular through hole 26 to the center of the second circular through hole 27 are 3180.0 mm-3220.0 mm, the working stroke of the piston 5 is 2080.0 mm-2120.0 mm, the working pressure is 23 MPa-27 MPa, and the test pressure is 30 MPa-35 MPa. In this embodiment, the diameter of the outer circumference of the cylinder 1 is 550.0mm, the diameter of the inner circumference of the cylinder 1 is 450.0mm, the diameter of the piston rod 2 is 250.0mm, the diameters of the inner circumferences of the first circular through hole 26 and the second circular through hole 27 are 200.0mm, the lengths from the center of the first circular through hole 26 to the right end of the piston rod 2 and the center of the second circular through hole 27 are equal to the length from the center of the cylinder bottom 3, the lengths from the center of the first circular through hole 26 to the center of the second circular through hole 27 are 270.0mm, in a static state, the length from the center of the first circular through hole 26 to the center of the second circular through hole 27 is 3200.0mm, the working stroke of the piston 5 is 2100.0mm, the working pressure is 25MPa, and the test pressure is 30 MPa-35 MPa.

Further, the first lifting lug 8 and the piston rod 2 are of an integral structure, and the second lifting lug 9 and the cylinder bottom 3 are of an integral structure.

The embodiments described by referring to the drawings are exemplary and intended to be illustrative of the application and are not to be construed as limiting the application. In the description of the present application, it should be understood that the azimuth or positional relationship indicated by the terms "left", "right", etc. are based on the azimuth or positional relationship shown in the drawings, and are merely for convenience of describing the present application and simplifying the description, and do not indicate or imply that the apparatus or element referred to must have a specific azimuth, be constructed and operated in a specific azimuth, and thus should not be construed as limiting the present application. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first", "a second", etc. may explicitly or implicitly include one or more such feature.

In the foregoing, only the preferred embodiment of the present utility model is described, and any minor modifications, equivalent changes and modifications made to the above embodiments according to the technical solutions of the present utility model fall within the scope of the technical solutions of the present utility model.

Claims

1. The utility model provides a hoisting point moves hydro-cylinder longitudinally which characterized in that: including cylinder, piston rod, cylinder bottom, cylinder cap, piston, first oilhole, second oilhole, first lug and second lug, the cylinder transversely sets up, and the piston rod is installed in the cylinder to can be for the cylinder left or right removal, the piston cup joints in the left end terminal side of piston rod, the cylinder cap is installed to the right-hand member movable of cylinder, the cylinder bottom is installed to the left end of cylinder, first oilhole runs through the cylinder bottom and is linked together with the cylinder inside for between power oil entering cylinder and the piston, promote the piston right-hand member for the cylinder, the second oilhole wears to locate on the cylinder of cylinder left end for power oil gets into the cylinder inner periphery, promotes the piston left-hand member for the cylinder, is equipped with first sealing device between the inner periphery of cylinder cap and the piston rod for prevent power oil excessive and outside impurity entering cylinder inside, be equipped with second sealing device between the periphery of piston and the cylinder, be equipped with third sealing device between the inner periphery of piston and the piston rod, second sealing device and third sealing device cooperate and be used for preventing that power oil from revealing through the piston when the piston moves, first connecting in the right end terminal side of piston rod for hoist and treat to move the thing, left side of cylinder bottom is used for fixing the cylinder bottom.

2. The lifting point longitudinal displacement cylinder as claimed in claim 1, wherein: the cylinder cover is fixed to the right end of the cylinder through a plurality of hexagon socket head cap bolts uniformly distributed on the periphery of the cylinder, and the cylinder bottom is welded to the left end of the cylinder.

3. The lifting point longitudinal displacement cylinder as claimed in claim 2, wherein: the inner periphery of the left end of the piston is provided with a piston buffer cushion with the shape matched with the left end side of the piston rod, so that the piston is prevented from damaging or crashing the bottom of the cylinder in the working process.

4. The lifting point longitudinal shifting cylinder as set forth in claim 3, wherein: the first oil hole and the second oil hole have the same diameter and are communicated through an external oil pipe for power oil to enter and exit.

5. The lifting point longitudinal shifting cylinder as set forth in claim 4, wherein: the first sealing device sequentially comprises a first piston rod guide sleeve, a second piston rod guide sleeve, a first sealing ring, a piston rod supporting ring, a second sealing ring, a third piston rod guide sleeve and a third sealing ring from left to right, wherein the first piston rod guide sleeve, the second piston rod guide sleeve and the third piston rod guide sleeve are mutually matched and used for guiding the piston rod to move left and right relative to the cylinder barrel, the first sealing ring is a Style sealing ring, the second sealing ring is a Y-shaped sealing ring, the third sealing ring is an O-shaped dustproof sealing ring, and the first sealing ring, the second sealing ring and the third sealing ring are mutually matched and used for preventing power oil from overflowing and external impurities from entering the cylinder barrel.

6. The lifting point longitudinal shifting cylinder as set forth in claim 5, wherein: the second sealing device comprises a first piston guide ring, a fourth sealing ring, a second piston guide ring, a fifth sealing ring and a third piston guide ring in sequence from left to right, wherein the first piston guide ring, the second piston guide ring and the third piston guide ring are used for supporting and guiding the piston to move left and right relative to the cylinder barrel, the fourth sealing ring and the fifth sealing ring are gray rings, the third sealing device comprises a first O-shaped sealing ring and a second O-shaped sealing ring in sequence from left to right, and the fourth sealing ring, the fifth sealing ring, the first O-shaped sealing ring and the second O-shaped sealing ring are mutually matched to prevent power oil from leaking through the piston when the piston moves.

7. The lifting point longitudinal shifting cylinder as set forth in claim 6, wherein: the first lug and second lug are axisymmetric setting, and first lug is the U type that the middle part was equipped with first circular through-hole, and the shape phase-match of first lug left end and piston rod right-hand member end side, the second lug is the spindle type that the middle part was equipped with the circular through-hole of second, and the second lug right-hand member is with cylinder bottom shape phase-match, and the diameter of first circular through-hole is the same with the circular through-hole of second.

8. The lifting point longitudinal shifting cylinder as set forth in claim 7, wherein: the diameter of the outer circumference of the cylinder barrel is 530.0-570.0 mm, the diameter of the inner circumference of the cylinder barrel is 430.0-470.0 mm, the diameter of the piston rod is 240.0-260.0 mm, the diameters of the inner circumferences of the first circular through hole and the second circular through hole are 190.0-210.0 mm, the lengths from the hole center of the first circular through hole to the right end of the piston rod to the tail end of the second circular through hole are equal to the lengths from the hole center of the second circular through hole to the cylinder bottom and are 260.0-280.0 mm, the lengths from the hole center of the first circular through hole to the hole center of the second circular through hole in a static state are 3180.0-3220.0 mm, the working stroke of the piston is 2080.0-2120.0 mm, the working pressure is 23-27 MPa, and the test pressure is 30-35 MPa.

9. The lifting point vertical movement cylinder according to any one of claims 1 to 8, characterized in that: the first lifting lug and the piston rod are of an integrated structure, and the second lifting lug and the cylinder bottom are of an integrated structure.