Sealing structure of vane rotary cylinder

Abstract

This utility model relates to a sealing structure for a vane-type rotary cylinder, including an upper housing and a detachable lower housing disposed on one side of the upper housing. A shaft through-hole is provided in the middle of both the upper and lower housings, and an output shaft is rotatably disposed inside the shaft through-hole. Both the upper and lower housings have annular chamfers at their joints. A shaped seal adapted to the shape of the chamfer is provided inside the gap between adjacent chamfers. The end of the shaped seal away from the chamfer is pressed and fixed between the upper and lower housings. This utility model achieves effective axial and radial sealing of the output shaft by designing the shaped seal to form an adaptive and tight fit with the annular chamfer of the housing. This fundamentally eliminates internal oil leakage between the high and low pressure chambers and external leakage at the housing joint surface, thereby ensuring the accuracy of the rotation angle control of the vane-type rotary cylinder.

Description

Technical Field

[0001] This utility model relates to the field of swing hydraulic cylinder technology, specifically to a sealing structure for a vane-type rotary cylinder. Background Technology

[0002] The vane-type oscillating cylinder employs a radially arranged vane structure. When hydraulic oil acts on the vane surface, it drives the drive shaft to achieve rotational motion. Its core advantages lie in its low moment of inertia, sensitive response, and uniform torque output with minimal pulsation during operation, making it suitable for applications requiring rapid and precise oscillation. Compared to the rack and pinion type, the vane structure avoids the mechanical losses associated with rack and pinion reciprocating motion. However, it carries the risk of hydraulic oil leakage and is generally unsuitable for low-speed applications due to limitations in sealing performance.

[0003] Authorization number CN119435501B discloses a swing-type hydraulic actuator. According to its specification and drawings, the design forms a sealed cavity through an end cover, cylinder wall, and hollow rotating shaft. Stator blades and rotor blades divide the sealed cavity into high-pressure and low-pressure chambers. During the bolt connection of the end cover and cylinder wall, the wedge-shaped surfaces of the end face seal ring and the axial combined seal ring are used to pre-tighten the two seals. An annular tensioning oil chamber is provided on the end cover. The pressure of the oil chamber is changed by adjusting the depth of the pressure regulating screw according to the working environment requirements, causing the inner wall of the end cover to deform inward, providing a second pre-tightening for the end face seal ring and the axial combined seal ring. The axial combined seal ring is provided with an annular seal, a wedge ring, a drum spring, and a second O-ring.

[0004] However, this solution has certain limitations: 1. O-rings or rings, as a type of line seal, primarily seal the contact line after compression. At the mating gap between the cylinder head and cylinder arm end faces, it is difficult to form a complete sealing surface. High-pressure oil easily forms an "internal leakage channel" along this microscopic gap, leading to oil leakage between the high and low pressure chambers and reduced efficiency; 2. There is an unavoidable microscopic height difference between the two mating end faces of the cylinder head and cylinder arm. After assembly, this unevenness is transmitted internally, causing the hollow bearing to experience additional eccentric force, resulting in uneven wear and affecting rotational smoothness and service life. Summary of the Invention

[0005] This invention addresses the aforementioned deficiencies in the design by proposing a sealing structure for a vane-type rotary cylinder. By designing a shaped seal that fits tightly and adaptively with the annular chamfer of the housing, it achieves effective dual sealing of the output shaft in both the axial and radial directions. This fundamentally eliminates internal oil leakage between the high and low pressure chambers and external leakage at the housing mating surface, thereby ensuring the accuracy of the vane-type oscillating cylinder's rotation angle control.

[0006] The objective of this invention is achieved through the following technical solution: a sealing structure for a vane-type rotary cylinder, comprising an upper housing and a lower housing detachably disposed on one side of the upper housing. A shaft through hole is provided in the middle of the upper housing and the lower housing. An output shaft is rotatably disposed inside the shaft through hole. An annular chamfer is provided at the connection between the upper housing and the lower housing. A non-circular seal adapted to the shape of the annular chamfer is provided in the gap between adjacent annular chamfers. The end of the non-circular seal away from the annular chamfer is squeezed and fixed between the upper housing and the lower housing.

[0007] Preferably, the lower housing has an annular inner groove on the surface near the annular chamfer, and the bottom of the upper housing has an annular boss that fits the annular inner groove. After the annular boss is inserted into the annular inner groove, it can press the end of the irregular seal away from the annular chamfer.

[0008] Preferably, the irregularly shaped seal includes a first annular body, a horizontal body, and a second annular body. The first annular body extends downward integrally from the surface of the horizontal body, and the second annular body with an isosceles trapezoidal cross-section extends integrally from the end of the horizontal body near the output shaft. The waist surface of the isosceles trapezoid on the second annular body is adapted to the inner wall of the annular chamfer.

[0009] Preferably, the width of the first annular body is smaller than the width of the annular inner groove, and an annular sealing ring is also provided inside the annular inner groove. After the annular boss is inserted into the annular inner groove, the first annular body of the irregular seal and the annular sealing ring are squeezed and deformed against each other. The setting of the annular sealing ring further increases the sealing effect between the upper shell and the lower shell.

[0010] Preferably, the upper and lower housings are further provided with a columnar inner groove coaxial with the through hole of the rotating shaft. The diameter of the columnar inner groove is larger than the diameter of the through hole of the rotating shaft. A stator plate is fixedly installed inside the columnar inner groove. A blade is also fixedly installed on the side wall of the output shaft. The second annular side wall of the irregular seal is attached to the stator plate and the blade. The volume of oil between the side wall of the stator plate and the side wall of the blade determines the rotation angle of the output shaft.

[0011] Preferably, the outer diameters of the upper and lower housings are the same, the axis of the second annular body coincides with the axis of the output shaft, and the bottom surface of the isosceles trapezoid on the second annular body is adapted to and fits against the sidewalls of the stator plate and blades. During the rotation of the output shaft, the sidewalls of the stator plate and blades are always in contact with the bottom surface of the isosceles trapezoid of the second annular body.

[0012] Preferably, both the irregularly shaped seal and the annular sealing ring are made of deformable rubber material. This design allows the irregularly shaped seal to deform and create a sealing function when subjected to compression.

[0013] 1. The second annular body of the irregularly shaped seal adopts an isosceles trapezoidal cross-section, which fits the annular chamfer to form a wedge effect. When under pressure, the second annular body undergoes flexible deformation. During the rotation of the output shaft, the sidewalls of the blades and stator plate constantly press against the bottom surface of the second annular body, generating sealing forces in both radial and axial directions. The sealing pressure adaptively increases with the oil pressure, requiring no external adjustment; it automatically fills the gap between the annular chamfers, completely blocking the end-face leakage channel between the high and low pressure chambers; this design avoids the gap leakage problem that is prone to occur in dynamic sealing by traditional O-rings or flat gaskets. 2. By moving the dynamic sealing surface from the outside to the inside of the cylinder housing (i.e., the second annular body directly contacts the end face of the rotating blade), the risk of multiple leakage points in traditional seals is reduced. This inward-moving design brings the sealing surface closer to the core area of ​​the oil cavity, directly responding to the action of high-pressure oil, thus improving the sealing accuracy and response speed. 3. By using annular chamfers and irregularly shaped seals, a sealing surface is set inside the cylinder, reducing the extremely high flatness requirements for the mating surfaces of the upper and lower housings and simplifying the assembly process; the structure is simple and reliable, and manufacturing and assembly are friendly; compared with technologies that require complex oil chambers and adjustment mechanisms, the problem can be solved by irregularly shaped seals, resulting in a simple structure; while improving sealing reliability, it also effectively controls manufacturing costs, improving the economy and reliability of the product. 4. The annular boss pressing into the annular inner groove will pre-compress the annular sealing ring in the annular inner groove; after being compressed, the annular sealing ring undergoes elastic deformation and simultaneously squeezes the first annular body to deform. Since the first annular body of the irregular seal is also deformed and pressed into the annular inner groove, and the horizontal body of the irregular seal is tightly pressed between the joint end faces of the upper and lower housings, the clamping force of the upper and lower housings is effectively transmitted and distributed to the entire irregular seal, ensuring that its position is fixed and will not move under oil pressure or vibration. Attached Figure Description

[0014] Figure 1 This is a perspective view of the present utility model; Figure 2 This is an exploded view of the present invention; Figure 3 This is a cross-sectional view of the present invention; Figure 4 This is a perspective view of the present invention after the upper shell has been removed; Figure 5 This is an exploded view of the present invention.

[0015] The markings in the diagram are: 1. Upper housing; 11. Annular boss; 2. Lower housing; 21. Annular inner groove; 3. Through hole of the rotating shaft; 4. Output shaft; 41. Blade; 5. Annular chamfer; 6. Irregular seal; 61. First annular body; 62. Horizontal body; 63. Second annular body; 7. Annular sealing ring; 8. Columnar inner groove; 9. Stator plate. Detailed Implementation

[0016] The present invention will be further described below with reference to the embodiments shown in the accompanying drawings: like Figure 1 , Figure 2 and Figure 4 As shown, a sealing structure for a vane-type rotary cylinder includes an upper housing 1 and a lower housing 2 that is detachably disposed on one side of the upper housing 1. The upper housing 1 and the lower housing 2 are connected by bolts (not shown in the figure). This installation structure is a conventional technical means in the field and will not be described in detail here.

[0017] The upper housing 1 and the lower housing 2 are provided with a rotating shaft through hole 3 in the middle. An output shaft 4 is rotatably provided inside the rotating shaft through hole 3. The upper housing 1 and the lower housing 2 are also provided with a columnar inner groove 8 coaxial with the rotating shaft through hole 3. The diameter of the columnar inner groove 8 is larger than the diameter of the rotating shaft through hole 3. A stator plate 9 is fixedly installed inside the columnar inner groove 8. A blade 41 is also fixedly installed on the side wall of the output shaft 4. The volume of oil between the side wall of the stator plate 9 and the side wall of the blade 41 determines the rotation angle of the output shaft 4. The cavity formed by the upper housing 1 and the lower housing 2 in the vane-type swing cylinder is a fixed pressure vessel. The internally fixed stator plate 9 is the core static partition, which divides the columnar inner groove 8 into two independent working oil chambers.

[0018] In the vane-type oscillating cylinder, the output shaft 4 is the power output element. The vane 41 fixed on it is the core element that drives the output shaft 4 to rotate. The vane 41 rotates with the output shaft 4 and further divides the oil chamber separated by the stator plate 9 into an oil inlet chamber and an oil return chamber.

[0019] When pressurized oil enters the sealed oil chamber formed by the stator plate 9, blades 41, upper housing 1, and lower housing 2 from one oil port, the oil pressure acts directly on the side surface of blades 41. Since the stator plate 9 is fixed, the oil pressure cannot push it; therefore, the reaction force is entirely used to push blades 41, thereby driving the output shaft 4 to generate rotational torque. As blades 41 rotate, the volume of the oil chamber on the opposite side decreases, and the oil within is squeezed out and discharged back to the oil tank from the other oil port.

[0020] The volume of oil between the sidewall of stator plate 9 and the sidewall of blade 41 determines the rotation angle of output shaft 4. By controlling the volume of oil entering the oil chamber, the displacement of the blades, i.e., the rotation angle of output shaft 4, can be precisely controlled. This is the basis for achieving precise position control.

[0021] In this embodiment, please continue to refer to Figure 2 and Figure 3 The upper housing 1 and the lower housing 2 are provided with annular chamfers 5 at the connection. The gap between adjacent annular chamfers 5 is provided with a non-circular seal 6 adapted to the shape of the annular chamfer 5. The end of the non-circular seal 6 away from the annular chamfer 5 is squeezed and fixed between the upper housing 1 and the lower housing 2. Specifically, the irregular-shaped seal 6 includes a first annular body 61, a horizontal body 62, and a second annular body 63. The first annular body 61 extends integrally downward from the surface of the horizontal body 62. The second annular body 63, with an isosceles trapezoidal cross-section, extends integrally from the end of the horizontal body 62 near the output shaft 4. The waist surface of the isosceles trapezoid on the second annular body 63 is adapted to the inner wall of the annular chamfer 5. The sidewall of the second annular body 63 of the irregular-shaped seal 6 is attached to the stator plate 9 and the blade 41. The upper housing 1 and the lower housing 2 have the same outer diameter. The axis of the second annular body 63 coincides with the axis of the output shaft 4. The bottom surface of the isosceles trapezoid on the second annular body 63 is adapted to and fits against the side wall of the stator plate 9 and the blade 41. During the rotation of the output shaft 4, the side wall of the stator plate 9 and the blade 41 always fits against the bottom surface of the isosceles trapezoid of the second annular body 63. During implementation, as the output shaft 4 rotates, the sidewalls of the stator plate 9 and the blade 41 are always in contact with the bottom surface of the isosceles trapezoid of the second annular body 63; this ensures that the sidewalls of the second annular body 63 are always in a state of compression deformation with the right-angled side. During the rotation of the output shaft 4, the irregular seal 6 provides a sealing base for the output shaft 4 in both axial and radial directions. When the second annular body 63 at the end of the irregular seal 6 is compressed, it can produce a significant wedge effect. The flexible deformation of the second annular body 63 can perfectly fill the gap between the entire adjacent annular chamfer 5, completely blocking the potential end face leakage channel and fundamentally preventing internal oil leakage between the high and low pressure chambers.

[0022] Furthermore, due to the isosceles trapezoidal design of the cross-section of the second annular body 63, the sealing surface generated by the second annular body 63 has inward movement and adaptive compensation, resulting in a better self-tightening effect while improving lifespan and stability; the dynamic sealing surface is moved forward to the interior of the entire upper housing 1 and lower housing 2, that is, the end face of the rotating blade 41 is directly and tightly fitted and slid against the side wall surface of the second annular body 63.

[0023] To further enhance the sealing between the upper housing 1 and the lower housing 2, a second sealing structure is provided: the lower housing 2 is provided with an annular inner groove 21 on the surface near the annular chamfer 5, and the bottom of the upper housing 1 is provided with an annular boss 11 adapted to the annular inner groove 21. The width of the first annular body 61 is smaller than the width of the annular inner groove 21. The annular inner groove 21 is also provided with an annular sealing ring 7. The first annular body 61 of the irregular sealing member 6 can be installed inside the annular inner groove 21. Whenever the upper housing 1 and the lower housing 2 are installed, that is, after the annular boss 11 is inserted into the annular inner groove 21: the first annular body 61 of the irregular seal 6 and the annular sealing ring 7 are squeezed and deformed against each other, and the top surface of the horizontal body 62 of the irregular seal 6 is squeezed at the joint between the upper housing 1 and the lower housing 2, resulting in deformation. When the upper housing 1 and the lower housing 2 are tightened with bolts, the annular boss 11 is pressed into the annular inner groove 21. This process pre-compresses the annular sealing ring 7 in the annular inner groove 21. After being compressed, the annular sealing ring 7 undergoes elastic deformation and simultaneously deforms the first annular body 61. The annular sealing ring 7 and the first annular body 61 then perfectly fill all the microscopic unevenness and gaps between the annular inner groove 21 and the annular boss 11. Its function is to block the leakage path between the mating surfaces of the upper housing 1 and the lower housing 2, preventing oil from leaking outward from the inside along the housing gaps.

[0024] Because the first annular body 61 of the irregular seal 6 is also deformed and pressed into the annular inner groove 21, and the top surface of the horizontal body 62 of the irregular seal 6 is deformed by pressure, the sealing effect of the housing mating surface area is further enhanced; the horizontal body 62 of the irregular seal 6 is tightly pressed between the mating end faces of the upper housing 1 and the lower housing 2; the clamping force of the upper housing 1 and the lower housing 2 is effectively transmitted and distributed to the entire irregular seal 6, ensuring that its position is fixed and will not move under oil pressure or vibration.

[0025] The working principle and usage method of this utility model.

[0026] Place the annular sealing ring 7 into the annular inner groove 21 of the lower housing 2. Then, place the irregularly shaped sealing member 6 at the annular chamfer 5 of the lower housing 2, ensuring that the isosceles trapezoidal waist surface of its second annular body 63 matches the inner wall of the annular chamfer 5. Next, align the annular boss 11 of the upper housing 1 with the annular inner groove 21 of the lower housing 2, so that the upper housing 1 and the lower housing 2 are joined. During this process, the bottom surface of the second annular body 63 of the irregularly shaped sealing member 6 must be aligned and matched with the side wall positions of the stator plate 9 and the blades 41. Finally, use bolts to fasten the upper housing 1 and the lower housing 2 together.

[0027] Under the preload of the bolts, the annular boss 11 is pressed into the annular inner groove 21, causing the annular sealing ring 7 and the first annular body 61 of the irregular seal 6 to undergo compression deformation, achieving a static seal at the housing mating surface. Simultaneously, the horizontal body 62 of the irregular seal 6 is compressed and deformed, while the second annular body 63, due to its isosceles trapezoidal structure, undergoes adaptive deformation, tightly fitting the stator plate 9 and the sidewalls of the blade 41. When pressurized oil enters the oil chamber to drive the output shaft 4 and the blade 41 to rotate, the bottom surface of the second annular body 63 of the irregular seal 6 always maintains a dynamic sliding seal with the end face of the rotating blade 41 and the fixed sidewall of the stator plate 9, preventing internal oil leakage and ensuring that the swing cylinder rotates at a precise angle according to the injected oil volume.

[0028] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to replace them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. A sealing structure of a vane-type rotary oil cylinder, comprising an upper housing (1) and a lower housing (2) detachably provided on one side of the upper housing (1), characterized in that, The upper housing (1) and the lower housing (2) are provided with a rotating shaft through hole (3) in the middle. The rotating shaft through hole (3) is provided with an output shaft (4) that can rotate inside. The upper housing (1) and the lower housing (2) are provided with an annular chamfer (5). The gap between adjacent annular chamfers (5) is provided with a shaped seal (6) adapted to the shape of the annular chamfer (5). The end of the shaped seal (6) away from the annular chamfer (5) is squeezed and fixed between the upper housing (1) and the lower housing (2).

2. The seal structure of a vane-type rotary oil cylinder according to claim 1, characterized by The lower housing (2) is provided with an annular inner groove (21) on the surface near the annular chamfer (5). The bottom of the upper housing (1) is provided with an annular boss (11) adapted to the annular inner groove (21). After the annular boss (11) is inserted into the annular inner groove (21), it can press the irregular seal (6) away from the annular chamfer (5).

3. The seal structure of a vane-type rotary oil cylinder according to claim 2, characterized by The irregular seal (6) includes a first annular body (61), a horizontal body (62), and a second annular body (63). The first annular body (61) extends downward integrally from the surface of the horizontal body (62). The second annular body (63) with an isosceles trapezoidal cross-section extends integrally from the end of the horizontal body (62) near the output shaft (4). The waist surface of the isosceles trapezoid on the second annular body (63) is adapted to the inner wall of the annular chamfer (5).

4. The sealing structure of the vane-type rotary cylinder according to claim 3, characterized in that, The width of the first annular body (61) is smaller than the width of the annular inner groove (21). The annular inner groove (21) is also provided with an annular sealing ring (7). After the annular boss (11) is inserted into the annular inner groove (21), the first annular body (61) of the irregular seal (6) and the annular sealing ring (7) are squeezed and deformed against each other.

5. The sealing structure of the vane-type rotary cylinder according to claim 4, characterized in that, The upper housing (1) and the lower housing (2) are also provided with a columnar inner groove (8) coaxial with the shaft through hole (3). The diameter of the columnar inner groove (8) is larger than the diameter of the shaft through hole (3). A stator plate (9) is fixedly installed inside the columnar inner groove (8). A blade (41) is also fixedly installed on the side wall of the output shaft (4). The side wall of the second annular body (63) of the irregular seal (6) is attached to the stator plate (9) and the blade (41). The volume of oil between the side wall of the stator plate (9) and the side wall of the blade (41) determines the rotation angle of the output shaft (4).

6. The sealing structure of the vane-type rotary cylinder according to claim 5, characterized in that, The outer diameters of the upper housing (1) and the lower housing (2) are the same. The axis of the second annular body (63) coincides with the axis of the output shaft (4). The bottom surface of the isosceles trapezoid on the second annular body (63) is adapted to and fits against the side wall of the stator plate (9) and the blade (41). During the rotation of the output shaft (4), the side wall of the stator plate (9) and the blade (41) always fits against the bottom surface of the isosceles trapezoid of the second annular body (63).

7. The sealing structure of the vane-type rotary cylinder according to claim 6, characterized in that, The irregular seal (6) and the annular seal (7) are both made of rubber that can deform.

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