Engineering machinery hydraulic oil cylinder with low mechanical wear

Abstract

The invention relates to the technical field of hydraulic oil cylinders, in particular to an engineering machinery hydraulic oil cylinder with low mechanical wear. Comprising a cylinder barrel, a piston rod is slidably mounted in the cylinder barrel, a piston located in the cylinder barrel is mounted at the rear end of the piston rod, a rear oil inlet and a front oil inlet which are distributed front and back are fixedly connected to the top of the cylinder barrel, a guide assembly is mounted at the front end of the cylinder barrel, and a buffer assembly is further arranged in the cylinder barrel; the guide assembly comprises a sleeve installed at the front end of the cylinder barrel, a graphite block is installed in the sleeve and attached to the outer wall of the piston rod, and self-lubricating supporting of the guide assembly is combined with a multi-layer sealing structure, and the self-lubricating supporting structure is matched with the stroke tail end automatic throttling buffering design of the buffering assembly, so that the lubricity is improved; abrasion between the piston rod and the inner wall of the cylinder barrel is reduced, and the problems of serious abrasion, sealing failure and the like caused by dust and impurity invasion of an existing hydraulic oil cylinder are solved.

Description

Technical Field

[0001] This invention relates to the field of hydraulic cylinder technology, and more specifically, to a hydraulic cylinder for engineering machinery with low mechanical wear. Background Technology

[0002] Hydraulic cylinders, as core actuators of construction machinery, are widely used in equipment such as excavators, loaders, and cranes. They convert hydraulic energy into mechanical energy to achieve linear reciprocating motion. During the operation of construction machinery, hydraulic cylinders need to withstand high pressure and high frequency reciprocating loads for a long time, and the working environment is often harsh, with exposure to pollutants such as dust, mud, and gravel.

[0003] In harsh operating environments, when there is relative movement between the piston and the inner wall of the cylinder, and between the piston rod and the guide sleeve, the lubrication structure of traditional cylinders is prone to lubrication loss and untimely lubrication replenishment, resulting in insufficient lubrication, seal failure, and wear on the mating surfaces. This not only reduces the working efficiency of the cylinder, but in severe cases, it can even cause cylinder jamming and component damage, forcing the construction machinery to stop for maintenance, and significantly increasing the operating costs and risks. Summary of the Invention

[0004] This invention provides a low-mechanical-wear hydraulic cylinder for engineering machinery. It improves lubrication and reduces wear between the piston rod and the inner wall of the cylinder by combining the self-lubricating support of the guide component with a multi-layer sealing structure and the automatic throttling and buffering design at the end of the stroke of the buffer component. This solves the problems of severe wear and sealing failure caused by dust and impurities in existing hydraulic cylinders.

[0005] To achieve the above objectives, a low-mechanical-wear hydraulic cylinder for engineering machinery includes a cylinder barrel. The inner wall of the cylinder barrel is coated with a ceramic coating to reduce surface roughness and increase hardness. A piston rod is slidably mounted inside the cylinder barrel. The surface of the piston rod undergoes a composite treatment of nitriding and chromium plating to enhance wear resistance and corrosion resistance. A piston is mounted at the rear end of the piston rod and is located inside the cylinder barrel. A rear oil inlet and a front oil inlet are fixedly connected to the top of the cylinder barrel. The rear oil inlet and the front oil inlet are distributed front to back and are located on the front and rear sides of the piston.

[0006] To reduce friction between the outer wall of the piston rod and the front end of the cylinder, a guide assembly is installed at the front end of the cylinder.

[0007] Referring to the figure, the guide assembly includes a sleeve bolted to the front end of the cylinder. The sleeve has multiple inner cavities. A graphite block is slidably installed inside the inner cavity. The graphite block is used to provide continuous lubrication at the contact surface. A plug is threaded onto the top of the inner wall of the inner cavity. A spring is installed between the plug and the graphite block. The end of the graphite block away from the spring is in contact with the outer wall of the piston rod.

[0008] In use, the plug fixes the spring, which presses down on the graphite block with its elastic force. The graphite block is pressed tightly against the outer wall of the piston rod. The piston rod is supported by multiple graphite blocks at the front end of the cylinder. The uniform support of multiple graphite blocks can effectively reduce frictional resistance when the piston rod moves by utilizing the self-lubricating properties of graphite.

[0009] Based on the above, the buffer assembly includes a housing fixedly connected to the top of the cylinder, a connecting block that slides up and down inside the housing, baffles that are slidably installed inside both the rear oil inlet and the front oil inlet, the two baffles being symmetrically distributed, and two drive plates fixedly connected to the opposite surfaces of the two baffles, the drive plates being located inside the housing, the connecting block being located between the two drive plates, and a push rod fixedly connected to the outer wall of the push rod, the end of the push rod extending into the interior of the housing.

[0010] Both ends of the connecting block are fixedly connected to inclined blocks at their bottoms. The drive plate has an inclined groove inside. Both ends of the connecting block are equipped with rollers. The rollers are located inside the inclined grooves. The push rod is located at the bottom of the connecting block and the inclined blocks.

[0011] Referring to the diagram, when hydraulic oil enters through the rear inlet, a gap exists between the end of the baffle and the inner wall of the inlet. During its flow, the hydraulic oil pushes the baffle and its connected drive plate along direction F1. The drive plate, through the cooperation of the inclined groove and the roller, drives the inclined block downwards along direction F2, thereby pressing down the push rod and initiating piston movement. At this time, the baffle gradually opens, allowing hydraulic oil to smoothly enter the cylinder and push the piston to the other side.

[0012] When the piston rod extends to its maximum stroke, that is, when the piston is close to the front limit position, as shown in the figure, the push rod moves with the piston to contact and lift the front inclined block, causing it to move up in the F1 direction. Through the rolling of the roller in the inclined groove, the drive plate drives the baffle to move in the F2 direction, gradually closing the oil inlet channel.

[0013] This allows the flow area of ​​the oil inlet to be automatically reduced when the piston reaches the end of its stroke, whether it is extending or retracting, thus reducing the hydraulic oil flow rate and causing the piston speed to decrease smoothly, thereby reducing the impact on the end of the cylinder.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Through the guide assembly, during use, the graphite block is pushed to always fit tightly against the outer wall of the piston rod. The self-lubricating properties of the graphite block provide lubrication for the reciprocating motion of the piston rod. At the same time, the labyrinth seal structure formed by the convex ring and the cylinder groove, as well as the multi-layer rubber ring dynamic seal design on the inner wall of the sleeve, effectively prevent external dust and impurities from entering the mating surface. This solves the problem of severe wear on the piston rod and guide sleeve caused by insufficient lubrication and contaminant intrusion in traditional oil cylinders.

[0015] 2. Through the buffer assembly, when the piston reaches the end of its stroke, it pushes the push rod to drive the connecting block to move. Utilizing the oblique guiding effect of the inclined block, the roller and the inclined groove slide together to drive the drive plate to move horizontally. This controls the baffle to gradually reduce the flow area of ​​the oil inlet, thereby achieving automatic throttling and adjustment of the hydraulic oil flow. This makes the piston speed decrease smoothly, solving the problem of increased cylinder wear caused by excessive impact when the piston reaches the end of its stroke in traditional hydraulic cylinders. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a cross-sectional structural diagram of the present invention; Figure 3 for Figure 2 Enlarged structural diagram at point A in the middle; Figure 4 This is an enlarged structural schematic diagram of the buffer component in this invention; Figure 5 This is a schematic diagram showing the different operating postures of the piston rod in this invention; Figure 6 for Figure 5 Enlarged structural diagram at point B; Figure 7 for Figure 6 Enlarged structural diagram at point C.

[0017] The meanings of the labels in the diagram are as follows: 1. Cylinder; 11. Rear oil inlet; 12. Front oil inlet; 2. Piston rod; 21. Piston; 3. Guide assembly; 31. Sleeve; 311. Convex ring; 312. Rubber ring; 32. Inner cavity; 33. Graphite block; 34. Spring; 35. Plug; 4. Buffer assembly; 41. Housing; 42. Connecting block; 421. Inclined block; 422. Roller; 43. Baffle; 44. Drive plate; 441. Inclined groove; 45. Push rod. Detailed Implementation

[0018] The technical solutions of this invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0019] Due to insufficient lubrication, the mating surfaces between the piston 21 and cylinder 1 of the existing hydraulic cylinder suffer from severe mechanical wear, which in turn leads to seal failure, affecting the operating efficiency of the construction machinery and the service life of the cylinder.

[0020] Therefore, in view of the above-mentioned problems, the present invention provides a hydraulic cylinder for engineering machinery with low mechanical wear, with reference to... Figure 1-2 As shown, the cylinder includes a cylinder 1, the inner wall of which is coated with a ceramic coating to reduce surface roughness and increase hardness. A piston rod 2 is slidably installed inside the cylinder 1. The surface of the piston rod 2 is subjected to a composite treatment of nitriding and chrome plating to enhance wear resistance and corrosion resistance. A piston 21 is installed at the rear end of the piston rod 2. The piston 21 is located inside the cylinder 1. A rear oil inlet 11 and a front oil inlet 12 are fixedly connected to the top of the cylinder 1. The rear oil inlet 11 and the front oil inlet 12 are distributed front and rear, and are located on the front and rear sides of the piston 21.

[0021] To reduce friction between the outer wall of the piston rod 2 and the front end of the cylinder 1, a guide assembly 3 is installed at the front end of the cylinder 1.

[0022] refer to Figure 3 As shown, the guide assembly 3 includes a sleeve 31 bolted to the front end of the cylinder 1. The sleeve 31 has multiple inner cavities 32. Graphite blocks 33 are slidably installed inside the inner cavities 32 to provide continuous lubrication at the contact surfaces. A plug 35 is threaded onto the top of the inner wall of the inner cavity 32. A spring 34 is installed between the plug 35 and the graphite blocks 33. The end of the graphite block 33 away from the spring 34 is in contact with the outer wall of the piston rod 2.

[0023] In use, the plug 35 fixes the spring 34, which presses down on the graphite block 33 with its elastic force. The graphite block 33 is in close contact with the outer wall of the piston rod 2. The piston rod 2 is supported by multiple graphite blocks 33 at the front end of the cylinder 1. With the uniform support of multiple graphite blocks 33, the self-lubricating properties of graphite can be used to effectively reduce frictional resistance when the piston rod 2 moves.

[0024] However, the support of graphite block 33 will leave a gap between cylinder 1 and piston rod 2, which may cause insufficient sealing during the operation of the oil cylinder.

[0025] Therefore, refer to Figure 3As shown, a convex ring 311 is fixedly connected to the side of the sleeve 31 near the cylinder 1. The front end of the cylinder 1 has a groove corresponding to the convex ring 311. The convex ring 311 is located inside the groove. After installation, the convex ring 311 is embedded in the groove. The two form a labyrinth splicing structure, which can effectively improve the sealing performance at the connection between the cylinder 1 and the sleeve 31 and prevent external contaminants from entering.

[0026] Multiple rubber rings 312 are fixedly connected to the inner wall of the sleeve 31, and the inner wall of the rubber rings 312 is in contact with the outer wall of the piston rod 2.

[0027] Multiple rubber rings 312 are used to achieve multi-layer sealing between the front end of the cylinder 1 and the piston rod 2, thus achieving front-end sealing without affecting the forward and backward movement of the piston rod 2. This ensures the reliability of the dynamic seal at the front end when the piston rod 2 is in use, and prevents leakage from occurring in the oil cylinder during long-term operation.

[0028] When hydraulic oil enters through the rear inlet 11 or the front inlet 12 and pushes the piston 21 to the end of its stroke, the piston 21 may impact the inner wall of the cylinder 1, accelerating the wear of the inner wall of the cylinder, affecting stability and component life. To solve this problem, a buffer component 4 is integrated inside the cylinder 1.

[0029] refer to Figure 4 As shown, the buffer assembly 4 includes a housing 41 fixedly connected to the top of the cylinder 1. A connecting block 42 slides up and down inside the housing 41. Baffles 43 are slidably installed inside the rear oil inlet 11 and the front oil inlet 12. The two baffles 43 are symmetrically distributed. Two drive plates 44 are fixedly connected to the opposite surfaces of the two baffles 43. The drive plates 44 are located inside the housing 41. The connecting block 42 is located between the two drive plates 44. A push rod 45 is fixedly connected to the outer wall of the piston rod 2. The end of the push rod 45 extends into the interior of the housing 41.

[0030] Both ends of the connecting block 42 are fixedly connected to inclined blocks 421. The drive plate 44 has an inclined groove 441 inside. Both ends of the connecting block 42 are equipped with rollers 422. The rollers 422 are located inside the inclined groove 441. The push rod 45 is located at the bottom of the connecting block 42 and the inclined blocks 421.

[0031] For details, please refer to the following: Figure 5 and combined Figure 6 As shown, when hydraulic oil enters from the rear inlet 11, due to the gap between the end of the baffle 43 and the inner wall of the inlet, the hydraulic oil can push the baffle 43 and the connected drive plate 44 to move in the F1 direction during the flow. The drive plate 44, through the cooperation of the inclined groove 441 and the roller 422, drives the inclined block 421 to move downward in the F2 direction, thereby pressing down the push rod 45 to push the piston 21 to start actuation. At this time, the baffle 43 gradually opens, and the hydraulic oil smoothly enters the cylinder 1, pushing the piston 21 to move to the other side.

[0032] When piston rod 2 extends to its maximum stroke, that is, when piston 21 is close to its front limit position, refer to Figure 7 As shown, the push rod 45 moves with the piston to contact and lift the inclined block 421 at the front end, causing it to move up in the F1 direction. Through the rolling of the roller 422 in the inclined groove 441, the drive plate 44 drives the baffle 43 to move in the F2 direction, gradually closing the oil inlet channel.

[0033] This allows the piston 21 to automatically reduce the flow area of ​​the oil inlet and reduce the hydraulic oil flow when it reaches the end of its stroke, whether it is extending or retracting. This results in a smooth decrease in the piston 21's movement speed, thereby reducing the impact on the end of the cylinder 1.

[0034] Working principle: Hydraulic oil enters cylinder 1 through rear inlet 11 or front inlet 12, pushing piston 21 and causing piston rod 2 to extend and retract. During the oil inlet stage, hydraulic oil pushes baffle 43 and drive plate 44 to move. Through the cooperation of inclined groove 441 and roller 422, it drives connecting block 42 and push rod 45 to move, ensuring that piston 21 starts smoothly.

[0035] During operation, the preload of the spring 34 in the guide assembly 3 pushes the graphite block 33 to always be in close contact with the outer wall of the piston rod 2. When the piston rod 2 reciprocates, the graphite block 33 forms a continuous lubricating film through its self-lubricating properties. Combined with the uniform support of multiple graphite blocks 33, friction and wear are reduced. At the same time, the convex ring 311 of the sleeve 31 and the groove of the cylinder 1 form a labyrinth seal, and are sealed by multiple layers of rubber rings 312 to prevent hydraulic oil leakage.

[0036] When the piston 21 moves to the end of its stroke, the piston 21 pushes up the corresponding side push rod 45, driving the connecting block 42 and the inclined block 421 to move upward. Through the cooperation of the roller 422 and the inclined groove 441, the drive plate 44 is pulled, so that the baffle 43 gradually closes the oil inlet, reduces the flow area, reduces the hydraulic oil flow, and allows the piston 21 to descend slowly, reducing impact wear.

[0037] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A hydraulic cylinder for engineering machinery with low mechanical wear, comprising a cylinder barrel (1), wherein a piston rod (2) is slidably mounted inside the cylinder barrel (1), and a piston (21) located inside the cylinder barrel (1) is mounted at the rear end of the piston rod (2). A rear oil inlet (11) and a front oil inlet (12) distributed front and rear are fixedly connected to the top of the cylinder barrel (1), characterized in that: The cylinder (1) is equipped with a guide assembly (3) at the front end and a buffer assembly (4) is also provided inside the cylinder (1). The guide assembly (3) includes a sleeve (31) installed at the front end of the cylinder (1), and a graphite block (33) is installed inside the sleeve (31). The graphite block (33) is in contact with the outer wall of the piston rod (2). When the piston rod (2) moves, the self-lubricating properties of graphite are used to reduce the frictional resistance between the piston rod (2) and the cylinder (1), while the impact force of the piston rod (2) on the cylinder (1) is reduced by the buffer assembly (4).

2. The low-mechanical-wear hydraulic cylinder for engineering machinery according to claim 1, characterized in that: The sleeve (31) has multiple cavities (32) circumferentially arranged inside. A graphite block (33) is slidably installed in the cavity (32). A plug (35) is threaded on the top of the cavity (32). A spring (34) is installed between the plug (35) and the graphite block (33). The end of the graphite block (33) away from the spring (34) is in contact with the outer wall of the piston rod (2).

3. The low-mechanical-wear hydraulic cylinder for engineering machinery according to claim 1, characterized in that: The sleeve (31) is fixedly connected to a convex ring (311) on the side near the cylinder (1). The front end of the cylinder (1) is provided with a groove that matches the convex ring (311). The convex ring (311) is embedded in the groove to form a labyrinth-type sealing structure.

4. The low-mechanical-wear hydraulic cylinder for engineering machinery according to claim 1, characterized in that: The inner wall of the sleeve (31) is provided with a plurality of rubber rings (312) spaced apart along the axial direction, and the inner wall of the rubber rings (312) is in contact with the outer wall of the piston rod (2).

5. The low-mechanical-wear hydraulic cylinder for engineering machinery according to claim 1, characterized in that: The buffer assembly (4) includes a housing (41) fixed to the top of the cylinder (1), and a connecting block (42) is slidably installed inside the housing (41).

6. The low-mechanical-wear hydraulic cylinder for engineering machinery according to claim 5, characterized in that: Both the rear oil inlet (11) and the front oil inlet (12) are slidably installed with baffles (43), and two drive plates (44) are fixedly connected to the ends of the two baffles (43) away from the oil inlet (11) and the front oil inlet (12).

7. The low-mechanical-wear hydraulic cylinder for engineering machinery according to claim 6, characterized in that: The connecting block (42) is located between the two drive plates (44), and the piston rod (2) is fixedly connected to the outer wall of the piston rod (2) with a push rod (45).

8. The low-mechanical-wear hydraulic cylinder for engineering machinery according to claim 7, characterized in that: The drive plate (44) has a groove (441) inside, and rollers (422) are installed at both ends of the connecting block (42), with the rollers (422) located inside the groove (441).

9. The low-mechanical-wear hydraulic cylinder for engineering machinery according to claim 7, characterized in that: The bottom of both ends of the connecting block (42) is fixed with inclined blocks (421).

10. The low-mechanical-wear hydraulic cylinder for engineering machinery according to claim 9, characterized in that: The push rod (45) is located in the bottom area of ​​the connecting block (42) and the inclined block (421).

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