Nitrogen thrust balancing cylinder

Abstract

The utility model provides a nitrogen gas thrust balance cylinder, including cylinder, middle bushing, piston rod, first connecting assembly and second connecting assembly, cylinder is equipped with inner chamber, cylinder has cylinder first end and cylinder second end, the middle bushing is inserted in cylinder first end and is sealed with cylinder cooperation, one end of piston rod passes through middle bushing and stretches into the inner chamber, the other end stretches out cylinder second end, first connecting assembly is installed in cylinder first end, second connecting assembly is installed on piston rod and is located one end of piston rod far from cylinder first end, the one end of piston rod that stretches into the inner chamber is equipped with piston boss, piston boss is matched with the inner chamber, and the piston boss is equipped with the air hole, and the air hole is along the axis direction of piston rod and is through piston boss. The setting of the air hole of this nitrogen gas thrust balance cylinder can make the air in the cavity flow smoothly, avoid the back pressure produced when the piston rod rebounds too fast, and ensure the stability of force.

Description

Technical Field

[0001] This utility model relates to the field of elastic component technology, and in particular to a nitrogen thrust balance cylinder. Background Technology

[0002] Nitrogen thrust balancing cylinder is a new type of elastic component that uses high-pressure nitrogen as the working medium. It has the advantages of large elastic force, long stroke, stable operation, long service life (generally up to five million times of extension and retraction), smooth elastic force curve, and no need for pre-tensioning. It is used to balance the torque of robot arms.

[0003] Existing nitrogen thrust balancing cylinders generally include a cylinder body, a piston rod, a guide sleeve, and a first connecting part and a second connecting part located at opposite ends of the cylinder body and piston rod. The cylinder body defines a cavity with an open front end. The guide sleeve is inserted into the opening of the cylinder body, and the piston rod is movably inserted into the guide sleeve. The cylinder body cavity, guide sleeve, and piston rod form a sealed gas chamber filled with high-pressure nitrogen. The first and second connecting parts are respectively connected to corresponding parts of the robot arm. During operation, as the robot arm extends and retracts, it drives the piston rod to move, thereby compressing the high-pressure nitrogen inside the cylinder body and generating a reaction force to balance the torque of the robot arm.

[0004] However, existing nitrogen thrust balance cylinders still have shortcomings. For example, when the piston rod is compressed, it will compress the nitrogen in the cylinder, thereby creating a spring force. After the pressure is released or reduced, the nitrogen in the cylinder will push the piston rod to pop out quickly again. If the rebound speed of the nitrogen spring is too fast, it will easily generate back pressure, resulting in unstable force. Previous nitrogen thrust balance cylinders often neglected the protection of the piston rod. Since nitrogen thrust balance cylinders are often used in production workshops, if dust, flying iron filings, flowing machine oil and other contaminants from the production workshop enter the gap between the piston rod and the guide sleeve or the gap between the guide sleeve and the cylinder body, it can easily cause jamming between the components during relative movement, affecting the working reliability of the nitrogen spring and damaging its sealing performance. Utility Model Content

[0005] The purpose of this invention is to provide a nitrogen thrust balance cylinder that can solve the above problems.

[0006] A nitrogen thrust balancing cylinder includes a cylinder body, a middle sleeve, a piston rod, a first connecting assembly, and a second connecting assembly. The cylinder body has an inner cavity and has a first cylinder end and a second cylinder end. The middle sleeve is inserted into the second cylinder end and is sealed to the cylinder body. One end of the piston rod passes through the middle sleeve and extends into the inner cavity from the second cylinder end, while the other end of the piston rod extends out of the second cylinder end. The first connecting assembly is installed at the first cylinder end, and the second connecting assembly is installed on the piston rod and located at the end of the piston rod away from the first cylinder end.

[0007] The piston rod has a piston protrusion at one end that extends into the inner cavity. The piston protrusion matches the inner cavity. The piston protrusion has an air passage hole that passes through the piston protrusion along the axial direction of the piston rod.

[0008] Preferably, an outer dustproof component is provided between the middle sleeve and the cylinder body, and an inner dustproof component is provided between the piston rod and the middle sleeve, and both the outer and inner dustproof components are fixed to the middle sleeve.

[0009] Preferably, a retaining ring is provided between the middle sleeve and the cylinder body, the retaining ring being disposed near the outer dustproof component and located on the side of the outer dustproof component near the first connecting assembly.

[0010] Preferably, a first seal is provided between the intermediate sleeve and the cylinder body, and a second seal is provided between the intermediate sleeve and the piston rod.

[0011] Preferably, a first wear-resistant band is provided between the piston and the cylinder body, and a second wear-resistant band is provided between the intermediate sleeve and the piston rod. The first wear-resistant band is located at the protrusion of the piston rod, and the second wear-resistant band is located on both sides of the second seal.

[0012] Preferably, the first connecting assembly includes a rear bearing housing mounted on the first end of the cylinder, a first self-aligning roller bearing mounted in the rear bearing housing, and a first bearing pressure plate that locks the self-aligning roller bearing in the rear bearing housing.

[0013] Preferably, the piston rod is covered with a dustproof cloth cover, and the two ends of the dustproof cloth cover are respectively connected to the cylinder body and the second connecting assembly.

[0014] Preferably, the second connecting assembly includes a front bearing housing, a second self-aligning roller bearing mounted in the front bearing housing, and a second bearing pressure plate that locks the second self-aligning roller bearing in the front bearing housing.

[0015] Preferably, the first end of the cylinder is further provided with a valve core hole that communicates with the inner cavity.

[0016] Preferably, the second connecting assembly is connected to the piston rod via a connecting block.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] 1. This utility model provides a piston protrusion at one end of the piston rod that extends into the inner cavity. The piston protrusion matches the inner cavity of the cylinder. An air passage is provided on the piston protrusion, which passes through the piston protrusion along the axial direction of the piston rod. The air passage allows for smooth airflow within the cavity, preventing back pressure from being generated when the piston rod rebounds too quickly, thus ensuring stable force.

[0019] 2. This utility model provides a foldable dustproof cloth cover over the piston rod. The two ends of the dustproof cloth cover are connected to the cylinder body and the second connecting component, respectively. The dustproof cloth cover can further prevent external dust, debris and other impurities from entering the gap between the middle sleeve and the piston rod, and the gap between the middle sleeve and the cylinder body. This avoids contaminants from entering the gap between the piston rod and the guide sleeve or the gap between the guide sleeve and the cylinder body, which could cause jamming between the components during relative movement, thus affecting the working reliability of the nitrogen spring and damaging its sealing performance. Attached Figure Description

[0020] Figure 1 This is a simplified cross-sectional view of an embodiment of the nitrogen thrust balance cylinder of this utility model;

[0021] Figure 2 for Figure 1 Enlarged view of point B.

[0022] The following is a description of the attached figures:

[0023] Cylinder body 10, intermediate sleeve 20, piston rod 30, first connecting assembly 40, second connecting assembly 50, cylinder first end 101, cylinder second end 102, valve core hole 103, first seal 104, snap ring 105, outer dustproof part 106, piston protrusion 301, vent hole 302, first wear-resistant belt 303, piston rod seal 304, second seal 305, inner dustproof part 306, second wear-resistant belt 307, dustproof cloth cover 308, rear bearing seat 411, first self-aligning roller bearing 412, first bearing pressure plate 413, front bearing seat 511, second self-aligning roller bearing 512, second bearing pressure plate 513, connecting block 514. Detailed Implementation

[0024] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0025] Please refer to Figure 1This embodiment provides a nitrogen thrust balancing cylinder, including a cylinder body 10 with an inner cavity, a middle sleeve 20 inserted into the inner cavity of the cylinder body 10, a piston rod 30 partially inserted into the middle sleeve 20, a first connecting assembly 40 installed at one end of the cylinder body 10, and a second connecting assembly 50 installed at one end of the piston rod 30. The inner cavity of the cylinder body 10 is filled with nitrogen. The piston rod 30 extends partly into the inner cavity of the cylinder body 10 through the middle sleeve 20 and partly extends out of the inner cavity of the cylinder body 10. The piston rod 30 is connected to a robotic arm (various common robotic arms) that needs to balance gravity. The first connecting assembly 40 and the second connecting assembly 50 are respectively connected to the robotic arm. When the robotic arm is subjected to gravity, it will generate a downward pulling force on the piston rod 30. At this time, the pressure generated by the nitrogen in the cylinder body 10 acts on the piston rod 30 through the piston, generating an upward force. When these two forces are equal in magnitude and opposite in direction, a force balance is achieved, enabling the robotic arm to maintain any position and realize the levitation and stable handling of heavy objects.

[0026] The cylinder body 10 has a first cylinder end 101 and a second cylinder end 102. The first cylinder end 101 is connected to a first connecting assembly 40 and has a valve core hole 103 for connecting to an external nitrogen source pipeline. Nitrogen enters the inner cavity of the cylinder body 10 through the valve core hole 103, causing it to push the piston rod 30 to move towards the second cylinder end. A middle sleeve 20 is installed inside the second cylinder end 102. The middle sleeve 20 and the cylinder body 10 are sealed together by a first sealing element 104. In this embodiment, the first sealing element 104 is an O-ring. A retaining spring 105 and an outer dustproof component 106 are also installed between the middle sleeve 20 and the cylinder body 10. In this embodiment, both the retaining spring 105 and the outer dustproof component 106 are located near the second end 102 of the cylinder, and the retaining spring 105 is located on the side of the outer dustproof component 106 that is close to the first connecting assembly 40. The retaining spring 105 is used to further fix the middle sleeve 20 in the cylinder body 10 so that its position does not deviate. The outer dustproof component 106 can block external dust, debris and impurities from entering between the middle sleeve 20 and the cylinder body 10.

[0027] One end of the piston rod 30 passes through the intermediate sleeve 20 and extends into the inner cavity of the cylinder body 10 from the second cylinder end 102, while the other end extends out of the second cylinder end 102 of the cylinder body 10. Specifically, the end of the piston rod 30 that extends into the inner cavity is provided with a piston protrusion 301, which matches the inner cavity of the cylinder body 10. The piston protrusion 301 is provided with a vent hole 302, which passes through the piston protrusion 301 along the axial direction of the piston rod 30. The vent hole 302 allows for smooth airflow within the cavity, preventing back pressure from being generated when the piston rod 30 rebounds too quickly, thus ensuring stable force.

[0028] A first wear-resistant band 303 is provided between the piston rod 30 and the cylinder body 10. In this embodiment, the first wear-resistant band 303 is located at the piston protrusion 301. The inner wall of the cylinder body 10 is kept smooth by injecting lubricating oil or other means to prevent the first wear-resistant band 303 from rubbing against the inner wall of the cylinder body 10 and generating powder, which could cause the piston rod 30 to become stuck.

[0029] A piston rod seal 304, a second seal 305, and an inner dustproof component 306 are provided between the piston rod 30 and the middle sleeve 20. In this embodiment, the second seal 305 is a combined sealing ring. The second seal 305 and the piston rod seal 304 are located on the inner side of the inner dustproof component 306. The outer dustproof component 106 and the inner dustproof component 306 are both located near the second end 102 of the cylinder and are arranged opposite to each other. They respectively provide dustproof seals for the gap between the piston rod 30 and the middle sleeve 20 and the gap between the middle sleeve 20 and the cylinder body 10, preventing external dust, debris, and other impurities from entering and affecting the life and movement performance of the piston rod 30 and the middle sleeve 20. A second wear-resistant band 307 is also provided between the piston rod 30 and the middle sleeve 20. The second wear-resistant band 307 is located on both sides of the second seal 305. The first wear-resistant band 303 and the second wear-resistant band 307 serve to guide the movement of the piston rod 30, while avoiding severe wear between the piston rod 30 and the middle sleeve 20, increasing the piston rod 30's resistance to eccentric loads, and improving its service life and performance.

[0030] The piston rod 30 is covered with a dustproof cloth cover 308. The two ends of the dustproof cloth cover 308 are connected to the cylinder body 10 and the second connecting component 50, respectively, which can further prevent external dust, debris and other impurities from entering the gap between the middle sleeve 20 and the piston rod 30, and the gap between the middle sleeve 20 and the cylinder body 10.

[0031] The second end 102 of the cylinder body 10 is also connected to a first connecting assembly 40. The first connecting assembly 40 includes a rear bearing housing 411 installed on the first end 101 of the cylinder, a first self-aligning roller bearing 412 and a first bearing pressure plate 413 installed on the rear bearing housing 411, and the first bearing pressure plate 413 is used to lock the first self-aligning roller bearing 412 on the rear bearing housing 411.

[0032] The second connecting assembly 50 is mounted on the piston rod 30 and located at the end of the piston rod 30 away from the first end 101 of the cylinder. The second connecting assembly 50 includes a front bearing seat 511 mounted on the second end 102 of the cylinder, a second self-aligning roller bearing 512 and a second bearing pressure plate 513 mounted on the front bearing seat 511. The second bearing pressure plate 513 is used to lock the second self-aligning roller bearing 512 on the front bearing seat 511. In this embodiment, the second connecting assembly 50 is connected to the piston rod 30 through a connecting block 514. The second connecting assembly 50 and the connecting block 514, and the connecting block 514 and the piston rod 30 are respectively locked together by screws.

[0033] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A nitrogen thrust balancing cylinder, characterized in that, The device includes a cylinder body, a middle sleeve, a piston rod, a first connecting assembly, and a second connecting assembly. The cylinder body has an inner cavity and has a first cylinder end and a second cylinder end. The middle sleeve is inserted into the second cylinder end and is sealed to the cylinder body. One end of the piston rod passes through the middle sleeve and extends into the inner cavity from the second cylinder end, while the other end of the piston rod extends out of the second cylinder end. The first connecting assembly is installed on the first cylinder end, and the second connecting assembly is installed on the piston rod and located at the end of the piston rod away from the first cylinder end. The piston rod has a piston protrusion at one end that extends into the inner cavity. The piston protrusion matches the inner cavity. The piston protrusion has an air passage hole that passes through the piston protrusion along the axial direction of the piston rod.

2. The nitrogen thrust balance cylinder according to claim 1, characterized in that, An outer dustproof component is provided between the middle sleeve and the cylinder body, and an inner dustproof component is provided between the piston rod and the middle sleeve. Both the outer and inner dustproof components are fixed to the middle sleeve.

3. A nitrogen thrust balance cylinder according to claim 2, characterized in that, A retaining ring is provided between the middle sleeve and the cylinder body. The retaining ring is located near the outer dustproof component and is situated on the side of the outer dustproof component closest to the first connecting assembly.

4. A nitrogen thrust balance cylinder according to claim 1, characterized in that, A first seal is provided between the middle sleeve and the cylinder body, and a second seal is provided between the middle sleeve and the piston rod.

5. A nitrogen thrust balance cylinder according to claim 4, characterized in that, A first wear-resistant band is provided between the piston and the cylinder body, and a second wear-resistant band is provided between the middle sleeve and the piston rod. The first wear-resistant band is located at the protrusion of the piston rod, and the second wear-resistant band is located on both sides of the second seal.

6. A nitrogen thrust balance cylinder according to claim 1, characterized in that, The first connecting assembly includes a rear bearing housing mounted on the first end of the cylinder, a first self-aligning roller bearing mounted in the rear bearing housing, and a first bearing pressure plate that locks the self-aligning roller bearing in the rear bearing housing.

7. A nitrogen thrust balance cylinder according to claim 1, characterized in that, The piston rod is covered with a dustproof cloth cover, and the two ends of the dustproof cloth cover are respectively connected to the cylinder body and the second connecting assembly.

8. A nitrogen thrust balance cylinder according to claim 1, characterized in that, The second connecting assembly includes a front bearing housing, a second self-aligning roller bearing mounted in the front bearing housing, and a second bearing pressure plate that locks the second self-aligning roller bearing in the front bearing housing.

9. A nitrogen thrust balance cylinder according to claim 1, characterized in that, The first end of the cylinder is also provided with a valve core hole that communicates with the inner cavity.

10. A nitrogen thrust balance cylinder according to claim 1, characterized in that, The second connecting assembly is connected to the piston rod via a connecting block.

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