Low noise hydraulic cylinder with adjustable end stroke and method of assembly

Abstract

This invention discloses a low-noise hydraulic cylinder with adjustable end stroke and its assembly method, belonging to the field of ship vibration reduction and noise reduction technology. The cylinder includes a bow end cap, cylinder barrel, piston, connecting rod, buffer sleeve, stern end cap, and structures such as a reversing oil passage, a buffer oil passage, a reversing oil chamber, and a buffer oil chamber. The buffer sleeve is fitted onto both sides of the connecting rod, forming a closed buffer oil chamber in cooperation with the end cap, cylinder barrel, and piston. During operation, the oil flow rate and pressure of the buffer oil chamber are controlled by adjusting the oil pressure at the buffer port, achieving precise adjustment of the piston and connecting rod end stroke, avoiding rigid collision between the piston and the end cap, and suppressing impact noise at the source. This invention has a compact structure, reliable sealing, and convenient assembly, significantly reducing vibration impact and operating noise, improving the stealth of ships, and is suitable for scenarios with high vibration reduction and noise reduction requirements, such as the opening and closing of ship hull covers.

Description

Technical Field

[0001] This invention belongs to the field of ship vibration reduction and noise reduction technology, specifically relating to a low-noise hydraulic cylinder with adjustable end stroke and its assembly method. Background Technology

[0002] Hydraulic cylinders are typically used to power the opening and closing of ship hull covers. Traditional hydraulic cylinders cannot precisely control the end stroke of the piston and connecting rod. During operation, the piston is prone to strong collisions with the cylinder end cap, generating transient impacts and high-bandwidth, high-intensity transient noise. This noise can easily become a characteristic signal for sonar detection, reducing the ship's stealth and posing a risk of detection and identification. Therefore, there is an urgent need to develop hydraulic cylinders with adjustable end strokes and reduced impact noise. Summary of the Invention

[0003] (a) Purpose of the invention This invention aims to solve the problems of non-adjustable end stroke of traditional hydraulic cylinders, large impact from piston-end cap collision, and high operating noise. It provides a hydraulic cylinder with adjustable end stroke that can significantly reduce vibration and impact noise, as well as its assembly method, thereby improving the stealth of ship operations.

[0004] (II) Technical Solution (1) Low-noise hydraulic cylinder with adjustable end stroke The hydraulic cylinder includes: bow end cap, reversing oil passage, buffer oil passage, dustproof ring, end cap sealing ring, cylinder barrel sealing ring, cylinder barrel, bolt, piston, connecting rod, buffer sleeve, buffer sealing ring, piston sealing ring, buffer oil chamber, reversing oil port, reversing oil port threaded joint, buffer oil port, buffer oil port threaded joint, reversing oil chamber, and stern end cap.

[0005] The bow end cover is a hollow cylindrical structure with through holes evenly arranged along the axis for fastening with cylinder bolts. The bow end cover is machined with reversing oil passages and buffer oil passages. Three annular grooves are opened on the inner side to install dustproof rings and end cover sealing rings respectively, and two annular grooves are opened on the outer side to install cylinder sealing rings.

[0006] The cylinder is a hollow cylindrical structure with threaded holes at both ends corresponding to the through holes of the bow end cap. It is fastened to the bow end cap and stern end cap by bolts.

[0007] The bolts are countersunk bolts, used for fastening the bow end cap, stern end cap, and cylinder.

[0008] The piston has a cylindrical structure with an outer diameter that matches the inner diameter of the cylinder. Two annular grooves are opened on the outer side to install piston seals.

[0009] The buffer sleeves are circular ring-shaped structures, and there are two in total. They are respectively fitted onto the connecting rods on both sides of the piston, and two circular grooves are opened on the outer side to install the buffer sealing rings.

[0010] The buffer oil chamber is formed by the bow end cap, cylinder, piston, connecting rod, buffer sleeve, and buffer oil port. The oil discharge state of the buffer oil chamber is controlled by adjusting the oil pressure of the buffer oil port, so as to achieve precise control of the end stroke.

[0011] The reversing oil port and buffer oil port are high-pressure cylindrical pipelines, which are connected to the bow end cap through corresponding threaded joints. The reversing oil port is connected to the reversing oil chamber and is used to drive the piston and connecting rod to move axially.

[0012] The reversing oil chamber is formed by the bow end cover, cylinder, piston, and connecting rod, and is connected to the reversing oil passage and reversing oil port.

[0013] The stern cap has the same structure and composition as the bow cap.

[0014] The end cap seal ring, cylinder seal ring, buffer seal ring, and piston seal ring are all made of rubber and are used in conjunction with silicone grease, providing oil-resistant sealing performance.

[0015] (2) Working principle When the hydraulic cylinder is working, external hydraulic oil enters the reversing oil chamber through the reversing port and reversing oil passage. By changing the pressure difference on both sides of the piston, it pushes the piston and connecting rod to move axially. When the buffer sleeve gradually enters the bow / stern cover along with the connecting rod, the bow / stern cover, cylinder, piston, connecting rod, buffer sleeve, and buffer port together form a closed buffer oil chamber. By adjusting the hydraulic oil pressure at the buffer port, the discharge flow and pressure of the hydraulic oil in the buffer oil chamber can be precisely controlled, thereby damping the movement of the piston and connecting rod, finely limiting and adjusting the end stroke of the piston and connecting rod, avoiding rigid collision between the piston and the bow / stern cover, suppressing transient impact and impact noise from the source, and achieving low-noise operation.

[0016] (3) Hydraulic cylinder assembly method Step 1: Apply silicone grease to the cylinder sealing ring and embed it into the outer annular groove of the bow end cover. Fit the cylinder into the bow end cover and align the bolt holes. Tighten the bolts diagonally in sequence.

[0017] Step 2: Fit the two buffer sleeves onto the connecting rod and weld them securely. Apply silicone grease to the buffer sealing ring and then embed it into the outer annular groove of the buffer sleeve.

[0018] Step 3: Install the dust seal and end cap seal ring into the inner annular groove of the bow end cap in sequence. Apply silicone grease to the piston seal ring and install it into the annular groove of the piston. Slide the connecting rod, piston, buffer sleeve and buffer seal ring into the cylinder from the right side, so that the connecting rod passes through the bow end cap and the piston is close to the bow end cap.

[0019] Step 4: Secure the stern cap to the right side of the cylinder as described above.

[0020] Step 5: Install the reversing port and buffer port onto the bow cap and stern cap respectively using the reversing port threaded connector and the buffer port threaded connector.

[0021] Step 6: Connect the reversing port and buffer port to the external hydraulic oil source to complete the assembly.

[0022] Beneficial effects This invention forms a buffer oil chamber by cooperating with the buffer sleeve and end cap. By adjusting the hydraulic oil pressure at the buffer port, the end stroke of the piston and connecting rod can be precisely controlled, avoiding direct collision between the piston and the bow and stern end caps. This significantly reduces transient vibration and impact noise, solving the defects of traditional hydraulic cylinders, such as non-adjustable stroke and high noise, and significantly improving the stealth of ships. All seals are made of rubber and used in conjunction with silicone grease, which is oil-resistant and provides reliable sealing. The hydraulic cylinder has a compact structure and is easy to assemble, making it suitable for scenarios with high requirements for vibration reduction and noise reduction, such as the opening and closing of ship hull cover plates. Attached Figure Description

[0023] Figure 1 This is a cross-sectional view of the low-noise hydraulic cylinder with adjustable end stroke according to an embodiment of the present invention. Figure 2 This is a cross-sectional view of the low-noise hydraulic cylinder with adjustable end stroke as described in an embodiment of the present invention. Figure 3 This is a cross-sectional view of the low-noise hydraulic cylinder with adjustable end stroke as described in an embodiment of the present invention.

[0024] Correspondence of reference numerals in the attached diagram: 1-Bow end cap, 2-Reversing oil passage, 3-Buffer oil passage, 4-Dustproof ring, 5-End cap sealing ring, 6-Cylinder sealing ring, 7-Cylinder, 8-Bolt, 9-Piston, 10-Connecting rod, 11-Buffer sleeve, 12-Buffer sealing ring, 13-Piston sealing ring, 14-Buffer oil chamber, 15-Reversing oil port threaded connector, 16-Reversing oil port, 17-Buffer oil port threaded connector, 18-Buffer oil port, 19-Reversing oil chamber, 20-Stern end cap. Detailed Implementation

[0025] The present invention will now be described in detail with reference to the accompanying drawings and embodiments, which can be used as a reference for those skilled in the art.

[0026] The low-noise hydraulic cylinder with adjustable end stroke described in this embodiment includes: bow end cap 1, reversing oil passage 2, buffer oil passage 3, dustproof ring 4, end cap sealing ring 5, cylinder sealing ring 6, cylinder 7, bolt 8, piston 9, connecting rod 10, buffer sleeve 11, buffer sealing ring 12, piston sealing ring 13, buffer oil chamber 14, reversing oil port threaded connector 15, reversing oil port 16, buffer oil port threaded connector 17, buffer oil port 18, reversing oil chamber 19, and stern end cap 20.

[0027] The bow end cover 1 is a hollow cylindrical structure with a maximum outer diameter of 160 mm and a length of 160 mm. It has 8 through holes evenly arranged along the axis, with the through holes 65 mm away from the axis. The reversing oil passage 2 is a cylindrical hole with a diameter of 10 mm, and the buffer oil passage 3 is a cylindrical hole with a diameter of 5 mm. The first inner annular groove is 5 mm deep and 10 mm wide for installing the dustproof ring 4, and the other two annular grooves are 5 mm deep and 5 mm wide for installing the end cover sealing ring 5. Two annular grooves are opened on the outer side for installing the cylinder sealing ring 6.

[0028] The cylinder 7 is a hollow cylindrical structure with a maximum outer diameter of 160mm, a length of 500mm, a wall thickness of 20mm in the middle, and a wall thickness of 30mm at both ends; each end has 8 threaded holes 65mm from the axis, corresponding to the through hole of the bow end cover 1.

[0029] Bolt 8 consists of 16 M10 countersunk bolts with a thread length of 80mm. Eight bolts are used to fasten the bow end cap 1 to the cylinder 7, and eight bolts are used to fasten the stern end cap 20 to the cylinder 7.

[0030] Piston 9 has a cylindrical structure with a diameter of 100mm and a length of 40mm; the two outer circular grooves are 5mm deep and 5mm wide, used to install piston seal ring 13.

[0031] The buffer sleeve 11 is annular, 10mm thick and 30mm long, and there are two of them, which are respectively fitted onto the connecting rods 10 on both sides of the piston 9; the two outer annular grooves of each are 5mm deep and wide, and are used to install the buffer sealing ring 12.

[0032] The buffer oil chamber 14 is formed by the bow end cover 1, cylinder 7, piston 9, connecting rod 10, buffer sleeve 11, and buffer oil port 18. Adjusting the oil pressure of the buffer oil port 18 can precisely control the end stroke of the piston 9 and reduce impact noise.

[0033] The reversing port 16 is a cylindrical pipeline with a pressure rating of 20MPa, a diameter of 10mm, and a wall thickness of 4mm. It is connected to the bow end cap 1 through the reversing port threaded connector 15.

[0034] The buffer port 18 is a cylindrical pipeline with a pressure rating of 20MPa, a diameter of 5mm, and a wall thickness of 3mm. It is connected to the bow end cap 1 through the buffer port threaded connector 17.

[0035] The reversing oil chamber 19 is formed by the bow end cover 1, cylinder 7, piston 9, and connecting rod 10, and is connected to the reversing oil passage 2 and reversing oil port 16. The piston 9 and connecting rod 10 are driven to move axially by oil pressure.

[0036] The stern cap 20 has the same structure and composition as the bow cap 1.

[0037] The end cap sealing ring 5, cylinder sealing ring 6, buffer sealing ring 12, and piston sealing ring 13 are all made of rubber and are used in conjunction with silicone grease. They are oil-resistant and provide reliable sealing.

[0038] The hydraulic cylinder assembly steps in this embodiment are as follows: Step 1: Apply silicone grease to the two cylinder sealing rings 6 and embed them into the outer annular groove of the bow end cover 1. Fit the cylinder 7 onto the right side of the bow end cover 1 and align it with the bolt holes. Tighten the eight bolts 8 from the left side of the bow end cover 1 and tighten them diagonally in sequence.

[0039] Step 2: The two buffer sleeves 11 are fitted onto the connecting rod 10 and welded securely. The four buffer sealing rings 12 are coated with silicone grease and then embedded into the outer annular groove of the buffer sleeve 11.

[0040] Step 3: Install the dustproof ring 4 into the first annular groove inside the bow end cover 1. Apply silicone grease to the two end cover sealing rings 5 ​​and install them into the remaining two annular grooves. Apply silicone grease to the piston sealing ring 13 and install it into the annular groove of the piston 9. Insert the connecting rod 10, piston 9, buffer sleeve 11, and buffer sealing ring 12 from the right side of the cylinder 7 and push them to the left until the connecting rod 10 passes through the bow end cover 1 and the piston 9 approaches the bow end cover 1.

[0041] Step 4: Secure the stern cap 20 to the right side of the cylinder 7 following the steps described above.

[0042] Step 5: The reversing port 16 is installed on the upper side of the bow end cover 1 through the reversing port threaded connector 15, and the buffer port 18 is installed on the lower side of the bow end cover 1 through the buffer port threaded connector 17; the stern end cover 20 is installed with the reversing port 16 and the buffer port 18 in the same manner.

[0043] Step 6: Connect the reversing port 16 and the buffer port 18 to the external hydraulic oil source to complete the assembly.

[0044] In this embodiment, the hydraulic cylinder precisely controls the end stroke of the piston 9 by adjusting the oil pressure at the buffer oil port 18, which greatly reduces the transient impact between the piston 9 and the end cover, effectively reduces operating noise, and meets the requirements of ship vibration reduction, noise reduction and concealment.

Claims

1. A low-noise hydraulic cylinder with adjustable end stroke, characterized in that, include: Bow end cap, cylinder, piston, connecting rod, buffer sleeve, and stern end cap; The bow end cap and stern end cap are respectively fastened to both ends of the cylinder by bolts; The piston is disposed inside the cylinder and connected to one end of the connecting rod, the other end of which passes through the bow end cap; The buffer sleeve is fitted onto the connecting rod; The bow end cover is equipped with independent reversing oil passages and buffer oil passages; The buffer oil chamber is formed by the bow end cover, cylinder, piston, connecting rod, and buffer sleeve, and is connected to the external oil passage through the buffer oil port; The space enclosed by the bow end cap, cylinder, piston, connecting rod, and buffer sleeve constitutes a buffer oil chamber, which is connected to the buffer oil passage. By regulating the hydraulic oil pressure at the buffer oil port connected to the buffer oil passage, the oil discharge state of the buffer oil chamber can be controlled, thereby adjusting the end stroke of the piston and connecting rod.

2. The low-noise hydraulic cylinder with adjustable end stroke according to claim 1, characterized in that, There are two buffer sleeves, which are respectively fitted onto the connecting rods on both sides of the piston. When the piston moves close to either end cap, the buffer sleeve on that side cooperates with the corresponding end cap to form a closed chamber for the buffer oil cavity.

3. The low-noise hydraulic cylinder with adjustable end stroke according to claim 2, characterized in that, The piston has an annular groove on its outer side for installing a piston seal ring; each buffer sleeve has an annular groove on its outer side for installing a buffer seal ring; the bow end cap and stern end cap have annular grooves on their inner sides for installing end cap seal rings, and annular grooves on their outer sides for installing cylinder seal rings.

4. The low-noise hydraulic cylinder with adjustable end stroke according to claim 1, characterized in that, The reversing oil passage is connected to the reversing oil port via a reversing oil port threaded connector; the buffer oil passage is connected to the buffer oil port via a buffer oil port threaded connector.

5. The low-noise hydraulic cylinder with adjustable end stroke according to any one of claims 1 to 4, characterized in that, The bow cap and stern cap are hollow cylindrical structures with multiple through holes evenly spaced along their axis for the bolts to pass through; the cylinder barrel has threaded holes at both ends that match the positions of the through holes.

6. The assembly of the low-noise hydraulic cylinder with adjustable end stroke according to any one of claims 1-5, characterized in that, Includes the following steps: Step 1: Apply silicone grease to the cylinder sealing ring and embed it into the outer annular groove of the bow end cover. Fit the cylinder into the bow end cover and align the bolt holes. Tighten the bolts diagonally in sequence. Step 2: Fit the two buffer sleeves onto the connecting rod and weld them securely. Apply silicone grease to the buffer sealing ring and then embed it into the outer annular groove of the buffer sleeve. Step 3: Install the dustproof ring and end cap sealing ring in sequence into the inner annular groove of the bow end cap. Insert the connecting rod, piston, buffer sleeve and buffer sealing ring from the right side of the cylinder, so that the connecting rod passes through the bow end cap and the piston approaches the bow end cap. Step 4: Secure the stern cap to the right side of the cylinder as described above; Step 5: Install the reversing port and buffer port onto the bow end cap and stern end cap respectively using the reversing port threaded connector and the buffer port threaded connector; Step 6: Connect the reversing port and buffer port to the external hydraulic oil source to complete the assembly.

7. The assembly of the hydraulic cylinder according to claim 6, characterized in that, In steps 1 and 4, the bow cap and stern cap are tightened diagonally in sequence using multiple bolts.

8. The assembly of the hydraulic cylinder according to claim 6, characterized in that, In step 2, the two buffer sleeves are respectively fastened to the connecting rod on both sides of the piston by welding.

9. The assembly of the hydraulic cylinder according to claim 6, characterized in that, In step 3, before installing the piston, the piston seal ring is first installed in the annular groove on the outside of the piston.

10. The assembly of the hydraulic cylinder according to claim 6, characterized in that, In steps 1-3, silicone grease must be applied before installing the cylinder seal ring, buffer seal ring, end cap seal ring, and piston seal ring.

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