Hydraulic oil cylinder and engineering machinery

Abstract

The utility model relates to a hydraulic oil cylinder, in order to solve the problem that dry grinding often occurs between a piston and the surface of an inner hole of a cylinder barrel when the hydraulic oil cylinder rapidly stretches out and draws back, the utility model provides a hydraulic oil cylinder and engineering machinery, and the hydraulic oil cylinder comprises the cylinder barrel, the piston located in the cylinder barrel and a piston rod with one end fixedly connected with the piston. The other end of the piston rod extends out of an inner hole of a guide sleeve fixed to the end of the cylinder barrel, and a piston supporting ring and a piston sealing ring are arranged on the circumferential surface of the piston. A piston lubricating oil groove surrounding the piston is formed in the circumferential surface of the piston, a piston lubricating oil channel communicated with the piston lubricating oil groove is formed in the piston, and the piston lubricating oil channel is communicated with the oil cylinder small cavity on the end face of the piston. According to the utility model, the piston is provided with the oil duct for communicating the small oil cylinder cavity with the piston lubricating oil groove on the circumferential surface of the piston, so that enough hydraulic oil is provided to timely and quickly form an oil film on the surface of the inner hole of the cylinder barrel, and the possibility of dry grinding of the piston support ring and the surface of the inner hole of the cylinder barrel is effectively reduced.

Description

Technical Field

[0001] This utility model relates to a hydraulic cylinder, and more specifically, to a hydraulic cylinder and engineering machinery. Background Technology

[0002] A hydraulic cylinder includes a cylinder barrel, a piston, and a piston rod. The piston is located inside the cylinder barrel, and one end of the piston rod is fixedly connected to the piston, while the other end extends out from the inner hole of a guide sleeve fixed at the end of the cylinder barrel.

[0003] The piston's circumferential surface has a clearance fit with the cylinder's inner wall. A support ring and a sealing ring are installed on the piston's circumferential surface. The support ring improves the hydraulic cylinder's load-bearing capacity and resistance to lateral forces, while the sealing ring reduces oil leakage between the large and small chambers of the cylinder. The support ring is usually located to one side of the sealing ring, which abuts tightly against the cylinder's inner wall. When the piston moves relative to the cylinder, the sealing ring wipes away or breaks the oil film on the cylinder's inner bore wall. Some hydraulic cylinders have multiple support rings on the piston. When the piston moves, the support rings contact the cylinder's inner bore wall; this contact and sliding action of the support rings also wipes away or breaks the oil film on the cylinder's inner bore wall.

[0004] When the piston slides relative to the cylinder, the support ring will come into contact with the inner wall of the cylinder bore, which has no oil film or an incomplete oil film, resulting in dry friction. Dry friction will cause rapid wear of the support ring and damage to the inner wall of the cylinder bore, shortening the maintenance cycle of the hydraulic cylinder, increasing maintenance costs, and even shortening the service life of the hydraulic cylinder.

[0005] In some engineering machinery or operating conditions, hydraulic cylinders need to extend and retract rapidly due to operational requirements. When the piston moves rapidly, the inner surface of the cylinder bore, where the oil film has been damaged or wiped away by the seals and support rings, comes into contact with the support rings before a new oil film can be formed. Therefore, in rapidly extending and retracting hydraulic cylinders, the inner surface of the cylinder bore and the support rings often experience dry friction and damage.

[0006] The piston rod extends from the inner hole of the guide sleeve. A support ring and a sealing ring are provided on the inner wall of the guide sleeve to cooperate with the piston rod. Dry friction often occurs between the guide sleeve and the piston rod when the hydraulic cylinder extends and retracts rapidly. Utility Model Content

[0007] The technical problem this utility model aims to solve is the frequent occurrence of dry friction between the piston and the inner bore surface of the cylinder during rapid extension and retraction of a hydraulic cylinder. The present invention provides a hydraulic cylinder and engineering machinery that reduces the dry friction between the piston support ring and the inner bore wall of the cylinder during rapid extension and retraction.

[0008] The technical solution of this utility model to achieve its purpose is: a hydraulic cylinder, which includes a cylinder barrel, a piston located inside the cylinder barrel, a piston rod fixedly connected to the piston at one end, and the other end of the piston rod extending out from the inner hole of a guide sleeve fixed at the end of the cylinder barrel. A piston support ring and a piston sealing ring are provided on the circumferential surface of the piston. A piston lubricating oil groove is provided on the circumferential surface of the piston, and a piston lubricating oil passage communicating with the piston lubricating oil groove is provided inside the piston. The piston lubricating oil passage communicates with the small cavity of the cylinder at the end face of the piston.

[0009] In the hydraulic cylinder of this utility model, the piston lubricating oil groove is arranged on the piston circumferential surface between the piston sealing ring and the piston support ring;

[0010] Alternatively, the piston support rings may include at least two rings spaced apart in the axial direction, and the piston lubricating oil grooves are arranged on the piston circumferential surface between two adjacent piston support rings.

[0011] Alternatively, the piston support ring may include at least two rings arranged at intervals in the axial direction, and the piston lubrication groove may include a first piston lubrication groove and at least one second piston lubrication groove. The first piston lubrication groove is arranged on the piston circumferential surface between the piston seal ring and the piston support ring; the second piston lubrication groove is arranged on the piston circumferential surface between two adjacent piston support rings.

[0012] In the hydraulic cylinder of this utility model, the piston lubrication oil passage is provided on the piston in multiple ways, and each piston lubrication oil passage is arranged in a centrally symmetrical manner on the piston.

[0013] In the hydraulic cylinder of this invention, the effective flow diameter of each piston lubrication oil passage is less than or equal to 2 mm.

[0014] In the hydraulic cylinder of this utility model, the piston sealing ring is arranged on the circumferential surface section of the piston adjacent to the large cavity of the cylinder.

[0015] In the hydraulic cylinder of this utility model, the piston has a copper-plated welding layer on each of the two circumferential surfaces of the piston sealing ring arrangement section.

[0016] In the hydraulic cylinder of this utility model, a guide sleeve lubricating oil groove, a guide sleeve support ring that mates with the circumferential surface of the piston rod, and a guide sleeve sealing ring are provided on the inner wall of the guide sleeve. The guide sleeve sealing ring is located on one side of the guide sleeve support ring in the piston rod extension direction, and the guide sleeve lubricating oil groove is located on one side of the guide sleeve sealing ring in the piston rod retraction direction. A guide sleeve lubricating oil passage communicating with the guide sleeve lubricating oil groove is provided inside the guide sleeve, and the guide sleeve lubricating oil passage communicates with the small cavity of the cylinder at the end face of the guide sleeve.

[0017] In the hydraulic cylinder of this utility model, the guide sleeve lubricating oil groove is arranged on the inner wall surface of the guide sleeve between the guide sleeve sealing ring and the guide sleeve support ring.

[0018] Alternatively, the guide sleeve support ring may include at least two rings arranged at intervals in the axial direction, and the guide sleeve lubricating oil groove is arranged on the inner wall of the guide sleeve between two adjacent guide sleeve support rings;

[0019] Alternatively, the guide sleeve support ring may include at least two rings arranged at intervals in the axial direction, and the guide sleeve lubrication groove may include a first guide sleeve lubrication groove and at least one second guide sleeve lubrication groove. The first guide sleeve lubrication groove is arranged on the inner wall of the guide sleeve between the guide sleeve sealing ring and the guide sleeve support ring; the second piston lubrication groove is arranged on the inner wall of the guide sleeve between two adjacent guide sleeve support rings.

[0020] In the hydraulic cylinder of this utility model, the guide sleeve lubrication oil passage is provided with multiple passages on the guide sleeve, and each passage of the guide sleeve lubrication oil passage is centrally symmetrically arranged on the guide sleeve; the effective flow diameter of each passage of the guide sleeve lubrication oil passage is less than or equal to 2 mm.

[0021] The technical solution of this utility model to achieve its purpose is: an engineering machine having the aforementioned hydraulic cylinder.

[0022] Compared with the prior art, this utility model provides an oil passage on the piston that connects the small cavity of the oil cylinder with the piston lubricating oil groove on the piston circumferential surface, so as to provide sufficient hydraulic oil to form an oil film on the inner surface of the cylinder barrel in a timely and rapid manner, effectively reducing the possibility of dry friction between the piston support ring and the inner surface of the cylinder barrel. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the hydraulic cylinder of this utility model.

[0024] Figure 2 This is a schematic diagram of the end face structure of the piston in the hydraulic cylinder of this utility model.

[0025] Figure 3 yes Figure 2 A schematic diagram of the rotating cross-section of the piston in direction A.

[0026] Component names and serial numbers in the diagram:

[0027] Cylinder 10, large chamber of oil cylinder 11, small chamber of oil cylinder 12.

[0028] Piston rod 20, pin 21.

[0029] Piston 30, piston seal ring 31, piston support ring 32, piston lubrication oil passage 33, support ring mounting groove 34, piston lubrication oil groove 35, first piston lubrication oil groove 351, second piston lubrication oil groove 352, seal ring mounting groove 36, copper stacking welding layer 37.

[0030] Guide sleeve 50, guide sleeve sealing ring 51, guide sleeve dustproof ring 52, guide sleeve support ring 53, guide sleeve lubrication oil passage 54, plug 55, starting oil passage 56, guide sleeve lubrication oil groove 57, first guide sleeve lubrication oil groove 571, second guide sleeve lubrication oil groove 572. Detailed Implementation

[0031] The specific implementation plan is described below with reference to the attached diagram.

[0032] like Figure 1 As shown, the hydraulic cylinder includes a cylinder barrel 10, a piston 30 located inside the cylinder barrel, and a piston rod 20 with one end fixedly connected to the piston. The other end of the piston rod 20 extends out from the inner hole of the guide sleeve 50 fixed at the end of the cylinder barrel 10. A piston support ring 32 and a piston sealing ring 31 are provided on the circumferential surface of the piston 30. A piston lubricating oil groove 35 is provided around the piston 30 on the circumferential surface of the piston. A piston lubricating oil passage 33 is provided inside the piston 30 and communicates with the piston lubricating oil groove 35. The piston lubricating oil passage 33 communicates with the small cavity 12 of the cylinder at the end face of the piston 30.

[0033] The piston 30 is arranged inside the cylinder 10, which divides the internal space of the cylinder 10 into a large cavity (rodless cavity) 11 and a small cavity (rod cavity) 12. A large cavity interface communicating with the large cavity of the cylinder is provided on the cylinder head, and a small cavity interface communicating with the small cavity of the cylinder is provided on the cylinder barrel.

[0034] like Figure 1 Figure 3 As shown, four piston support rings 32 and one piston seal ring 31 are provided on the circumferential surface of the piston 30. The four piston support rings 32 are arranged at intervals along the axial direction of the piston 30, and all piston support rings 32 are located on one side of the piston seal ring 31.

[0035] A sealing ring mounting groove 36 for accommodating the piston sealing ring 31 is arranged on the circumferential surface of the piston 30 near the large cylinder chamber 11. Support ring mounting grooves 34 for accommodating the piston support ring 32 are arranged on the side of the sealing ring mounting groove 36 facing the small cylinder chamber 12. Piston lubricating oil grooves 35 on the circumferential surface of the piston 30 include a first piston lubricating oil groove 351 and a second piston lubricating oil groove 352. The first piston lubricating oil groove 351 is located between the sealing ring mounting groove 36 and an adjacent support ring mounting groove 34, while the second piston lubricating oil groove 352 is located between two adjacent support ring mounting grooves 34 in the middle.

[0036] A piston lubrication passage 33 is provided inside the piston 30. The piston lubrication passage 33 communicates with both the first piston lubrication groove 351 and the second piston lubrication groove 352. Simultaneously, the piston lubrication passage 33 communicates with the small cavity of the oil cylinder at the end face of the piston 30. Preferably, the piston lubrication passage 33 has three passages, such as... Figure 2 As shown, three piston lubrication channels 33 are arranged centrally symmetrically on the piston 30. Optionally, the effective flow diameter of the piston lubrication channels 33 is less than or equal to 2 mm. The 2 mm effective flow diameter of the piston lubrication channels ensures sufficient oil flow to each piston lubrication groove, while also forming effective hydraulic damping to prevent excessive internal leakage caused by excessive pressure in the gap between the piston and cylinder.

[0037] In some embodiments, the piston lubricating oil groove 35 may be provided only on the circumferential surface between the sealing ring mounting groove 36 and the adjacent support ring mounting groove 34; or, the piston lubricating oil groove 35 may be provided only on the piston circumferential surface between two adjacent piston support rings.

[0038] In this embodiment, the piston 30 moves inside the cylinder 10. In the direction of movement of the piston 30, the piston support ring 32 or the piston sealing ring 31 scrapes off the oil film on the inner surface of the cylinder bore. The oil stored in the piston lubricating oil groove 35 on the piston circumferential surface can quickly form a new oil film on the inner wall of the cylinder bore, thereby avoiding dry friction between the support ring and the inner wall of the cylinder bore.

[0039] like Figure 1 As shown, one end of the piston rod 20 is fixedly connected to the piston 30 by a threaded connection. A pin 21 is provided at the connection point to fix the piston 30 and the piston rod 20, preventing the piston rod 20 from rotating relative to the piston 30. The other end of the piston 30 extends out from the inner hole of the guide sleeve at the end of the cylinder 10.

[0040] In the extension direction of the piston rod 20, multiple guide sleeve support rings 53, guide sleeve sealing rings 51, and guide sleeve dustproof rings 52 are sequentially arranged on the inner wall of the guide sleeve 50. A guide sleeve lubricating oil groove 57 is provided on the inner wall of the guide sleeve 50, and a guide sleeve lubricating oil channel 54 is provided inside the guide sleeve, communicating with the guide sleeve lubricating oil groove 57. The guide sleeve lubricating oil channel 54 communicates with the small cavity of the oil cylinder at the end of the guide sleeve.

[0041] like Figure 1 As shown, a second guide sleeve lubricating oil groove 572 is provided on the inner wall of the guide sleeve 50 between a pair of adjacent guide sleeve support rings 53. A first guide sleeve lubricating oil groove 571 is provided between the guide sleeve sealing ring 51 and the adjacent guide sleeve support ring 53. Both guide sleeve lubricating oil grooves are connected to the guide sleeve lubricating oil channel 54 inside the guide sleeve. The guide sleeve lubricating oil channel 54 is connected to the small cavity at the end of the guide sleeve.

[0042] In other embodiments, the guide sleeve lubricating oil groove 57 may be arranged only on the inner wall of the guide sleeve between the guide sleeve sealing ring 51 and the guide sleeve support ring 53; or the guide sleeve lubricating oil groove 57 may be arranged only on the inner wall of the guide sleeve between two adjacent guide sleeve support rings 53.

[0043] The guide sleeve lubrication channel 54 can be provided with multiple channels inside the guide sleeve. Each guide sleeve lubrication channel is arranged in a centrally symmetrical manner on the guide sleeve, and the effective flow diameter of each guide sleeve lubrication channel is less than or equal to 2 mm.

[0044] The guide sleeve lubrication passage 54 is formed by machining a connecting axial hole and a radial hole on the guide sleeve. A plug 55 is installed or welded to the radial outer end of the radial hole and the axial outer end (the shorter end facing away from the small cavity) of the axial hole. A radial starting oil passage is provided on the end face of the axial inner end (the end facing the small cavity) of the guide sleeve, and the end of the guide sleeve lubrication passage 54 is located in the starting oil groove.

[0045] This embodiment also provides an engineering machine having the aforementioned hydraulic cylinder. The engineering machine can be a loader, excavator, grader, etc.

[0046] In this embodiment, an oil passage is provided on the piston to connect the small cavity of the oil cylinder with the piston lubricating oil groove on the piston circumferential surface, so as to provide sufficient hydraulic oil to form an oil film on the inner surface of the cylinder barrel in a timely and rapid manner, effectively reducing the possibility of dry friction between the piston support ring and the inner surface of the cylinder barrel. Similarly, a guide sleeve lubricating oil groove and a guide sleeve lubricating oil passage are provided on the guide sleeve, which effectively reduces the possibility of dry friction between the guide sleeve support ring and the piston rod surface.

Claims

1. A hydraulic cylinder, comprising a cylinder barrel, a piston located within the cylinder barrel, a piston rod with one end fixedly connected to the piston, and the other end of the piston rod extending from the inner hole of a guide sleeve fixed to the end of the cylinder barrel, wherein a piston support ring and a piston sealing ring are disposed on the circumferential surface of the piston; characterized in that, A piston lubricating oil groove is provided around the piston on the circumferential surface of the piston, and a piston lubricating oil passage is provided inside the piston that communicates with the piston lubricating oil groove. The piston lubricating oil passage communicates with the small cavity of the oil cylinder at the end face of the piston.

2. The hydraulic cylinder according to claim 1, characterized in that, The piston lubricating oil groove is arranged on the piston circumferential surface between the piston seal ring and the piston support ring; Alternatively, the piston support rings may include at least two rings spaced apart in the axial direction, and the piston lubricating oil grooves are arranged on the piston circumferential surface between two adjacent piston support rings. Alternatively, the piston support ring may include at least two rings arranged at intervals in the axial direction, and the piston lubrication groove may include a first piston lubrication groove and at least one second piston lubrication groove. The first piston lubrication groove is arranged on the piston circumferential surface between the piston seal ring and the piston support ring; the second piston lubrication groove is arranged on the piston circumferential surface between two adjacent piston support rings.

3. The hydraulic cylinder according to claim 1 or 2, characterized in that, The piston lubrication passage is provided on the piston in multiple ways, and the piston lubrication passage is arranged in a centrally symmetrical manner on the piston.

4. The hydraulic cylinder according to claim 3, characterized in that, The effective flow orifice diameter of each piston lubrication passage is less than or equal to 2 mm.

5. The hydraulic cylinder according to claim 1 or 2, characterized in that, The piston seal ring is arranged on the circumferential surface section of the piston adjacent to the large chamber of the oil cylinder.

6. The hydraulic cylinder according to claim 5, characterized in that, The piston has a copper-plated weld layer on each of the two circumferential surfaces of the piston seal ring arrangement section.

7. The hydraulic cylinder according to claim 1, characterized in that, The inner wall of the guide sleeve is provided with a guide sleeve lubricating oil groove, a guide sleeve support ring that mates with the circumferential surface of the piston rod, and a guide sleeve sealing ring. The guide sleeve sealing ring is located on one side of the guide sleeve support ring in the piston rod extension direction, and the guide sleeve lubricating oil groove is located on one side of the guide sleeve sealing ring in the piston rod retraction direction. The guide sleeve is provided with a guide sleeve lubricating oil channel that communicates with the guide sleeve lubricating oil groove. The guide sleeve lubricating oil channel communicates with the small cavity of the oil cylinder at the end face of the guide sleeve.

8. The hydraulic cylinder according to claim 7, characterized in that, The guide sleeve lubricating oil groove is arranged on the inner wall surface of the guide sleeve between the guide sleeve sealing ring and the guide sleeve support ring; Alternatively, the guide sleeve support ring may include at least two rings arranged at intervals in the axial direction, and the guide sleeve lubricating oil groove is arranged on the inner wall of the guide sleeve between two adjacent guide sleeve support rings; Alternatively, the guide sleeve support ring may include at least two rings arranged at intervals in the axial direction, and the guide sleeve lubrication groove may include a first guide sleeve lubrication groove and at least one second guide sleeve lubrication groove. The first guide sleeve lubrication groove is arranged on the inner wall of the guide sleeve between the guide sleeve sealing ring and the guide sleeve support ring; the second piston lubrication groove is arranged on the inner wall of the guide sleeve between two adjacent guide sleeve support rings.

9. The hydraulic cylinder according to claim 7 or 8, characterized in that, The guide sleeve has multiple lubricating oil channels, and each lubricating oil channel is arranged symmetrically on the guide sleeve. The effective flow diameter of each lubricating oil channel is less than or equal to 2 mm.

10. An engineering machinery, characterized in that, A hydraulic cylinder having any one of claims 1 to 9.

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