A hydraulic swing cylinder

Abstract

The present invention belongs to the technical field related to hydraulic components, and discloses a hydraulic swing cylinder comprising: a housing, an output shaft, a piston rod, and a driven rod; the output shaft is rotatably arranged in the inner center portion of the housing and the end portion extends out of the housing; the piston rod is slidably arranged in the housing along the axial direction; the axial direction of the piston rod is parallel to the axial direction of the output shaft, and closed hydraulic cavities are formed between the two ends of the piston rod and the housing, respectively; a sliding track arranged in a spiral is provided on the outer wall of the output shaft; the first end of the driven rod is connected to the piston rod, and the second end of the driven rod is set as a spherical end, which is matched and plugged into the sliding track. The present invention adopts a transmission form in which the spherical end of the driven rod is engaged with the spiral sliding track, which increases the contact area during the transmission process, is conducive to reducing stress concentration, is not easy to get stuck during the transmission process, is conducive to reducing wear, and can better adapt to water-lubricated environments.

Description

Technical Field

[0001] The present invention belongs to the technical field related to hydraulic components, and more specifically, relates to a hydraulic swing cylinder. Background Art

[0002] At present, the main methods of swing hydraulic cylinders are gear meshing, gear and rack meshing, vane-type or spiral pair coordination to achieve rotation and swinging motion. Gear meshing and gear rack swing hydraulic cylinders use the meshing motion between teeth to achieve torque output. Under water lubrication, it is easy to produce bite wear, which seriously reduces the life of the swing cylinder. In addition, in high-precision application fields, it is necessary to adjust the gap between teeth to eliminate the rotation error caused by machining accuracy. The operation is cumbersome and the work efficiency is low. The vane-type swing cylinder bears a small load, has low volumetric efficiency, and has internal motion gaps. It is difficult to seal dynamically and is prone to leakage under high-pressure environments, which will seriously affect performance. It is suitable for a few low-pressure mechanisms. The spiral swing hydraulic cylinder uses the meshing between multiple spiral pairs. This method requires high machining precision of the spiral pairs and also has the problem of easy jamming under water lubrication conditions and relatively severe wear.

[0003] Most existing oscillating hydraulic cylinders are prone to seizure and severe wear under water lubrication conditions, leading to serious performance degradation. Existing traditional oscillating cylinders are not suitable for use in conditions with poor lubrication, such as water lubrication. Summary of the Invention

[0004] In response to the above defects or improvement needs of the prior art, the present invention provides a hydraulic swing cylinder, which is used to solve the problem that most existing swing hydraulic cylinders are prone to jamming and severe wear under water lubrication conditions, resulting in serious performance degradation, and that existing traditional swing cylinders are not suitable for use under poor lubrication conditions such as water lubrication, thereby realizing stable transmission of the hydraulic swing cylinder under water lubrication conditions.

[0005] To achieve the above-mentioned purpose, according to the present invention, a hydraulic swing cylinder is provided, comprising: an outer shell, an output shaft, a piston rod and a driven rod; the output shaft is rotatably arranged in the inner center part of the outer shell and the end portion extends out of the outer shell, the piston rod is slidably arranged in the inner shell along the axial direction, the axial direction of the piston rod is parallel to the axial direction of the output shaft, and closed hydraulic cavities are respectively formed between the two ends of the piston rod and the outer shell, a sliding track arranged in a spiral line is provided on the outer wall of the output shaft, the first end of the driven rod is connected to the piston rod, and the second end of the driven rod is set to a spherical end, and the spherical end is matched and plugged with the sliding track.

[0006] According to the hydraulic swing cylinder provided by the present invention, a plurality of piston rods are provided inside the housing on the periphery of the output shaft, and any of the piston rods is axially connected to a plurality of driven rods, and any of the driven rods is matched and plugged into the sliding track.

[0007] According to the hydraulic swing cylinder provided by the present invention, the output shaft includes a mating shaft segment, the sliding track is arranged on the outer wall of the mating shaft segment, the sliding track extends from one end of the mating shaft segment to the other end, and the sliding track is provided with a cutout at at least one end of the mating shaft segment.

[0008] According to the hydraulic swing cylinder provided by the present invention, the outer shell includes a shell, a first end cover and a second end cover, the first end cover and the second end cover are connected to the two ends of the shell, the first end cover and the second end cover are respectively provided with a first accommodating groove at the corresponding positions of the output shaft, the output shaft is rotatably connected to the groove wall of the first accommodating groove through a bearing, and the end of the output shaft passes through the groove bottom of the first accommodating groove on the second end cover.

[0009] According to the hydraulic swing cylinder provided by the present invention, the groove wall of the first accommodating groove is stepped, and the bearing is arranged in contact with the step surface.

[0010] According to the hydraulic swing cylinder provided by the present invention, the first end cover and the second end cover are respectively provided with second accommodating grooves at corresponding positions of the piston rod, the end of the piston rod is inserted into the second accommodating groove, and a sliding sealing structure is provided between the end of the piston rod and the groove wall of the second accommodating groove.

[0011] According to the hydraulic swing cylinder provided by the present invention, a first flow channel is provided inside the first end cover, a first end of the first flow channel is connected to the outside of the housing, and a second end of the first flow channel is connected to the second receiving groove on the first end cover;

[0012] A second flow channel is provided inside the second end cover, a first end of the second flow channel is communicated with the outside of the shell, and a second end of the second flow channel is communicated with the second accommodating groove on the second end cover.

[0013] According to the hydraulic swing cylinder provided by the present invention, the first section of the first flow channel is connected to the outer surface of the first end cover; a connecting flow channel is provided inside the outer shell, one end of the connecting flow channel is connected to the second flow channel, and the other end of the connecting flow channel is connected to the outer surface of the first end cover.

[0014] According to the hydraulic swing cylinder provided by the present invention, a first through hole is provided at the inner center portion of the shell, the output shaft is arranged in the first through hole, a second through hole is also provided inside the shell, the piston rod is arranged in the second through hole, the first through hole and the second through hole have a connecting portion, and the connecting portion is arranged along the axial direction of the first through hole.

[0015] According to the hydraulic swing cylinder provided by the present invention, connecting flanges are respectively provided at both ends of the shell, the first end cover and the second end cover are respectively connected to the connecting flanges by bolts, and the outer wall of the shell is set to a shape that avoids the bolts.

[0016] In general, compared with the prior art, the hydraulic swing cylinder provided by the present invention is:

[0017] 1. The transmission form adopts the meshing of the spherical end of the driven rod and the spiral sliding track. Compared with the transmission form of teeth, the contact area during the transmission process is increased, which is conducive to reducing stress concentration, making it less likely to get stuck during the transmission process, and helping to reduce wear. It can better adapt to water lubrication environment, so that the transmission process still has good transmission performance under water lubrication conditions or other poor lubrication conditions;

[0018] 2. The multi-rod drive design not only makes the radial force on the output shaft more uniform, but also makes the output shaft force transmission more uniform, thereby improving the stability and reliability of the system; the multi-rod drive design can also reduce the impact of problems such as poor sealing and high leakage of a single rod, which is conducive to improving the safety factor of the swing cylinder;

[0019] 3. The hydraulic flow channel is integrated into the end cover and the inside of the shell to realize the pipeless drive of the swing cylinder, making the structure more compact, the sealing performance of the swing cylinder more reliable, and the disassembly and maintenance of the swing cylinder convenient, which can adapt to deep-sea working conditions. At the same time, the flow channel interface is concentrated on the first end cover, which can facilitate the connection and layout of the pipeline, for example, reducing the pipeline layout problems in the construction of the robotic arm. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the overall structure of the hydraulic swing cylinder provided by the present invention;

[0021] Figure 2 This is a first axial cross-sectional view of the hydraulic swing cylinder provided by the present invention;

[0022] Figure 3 is a second axial cross-sectional view of the hydraulic swing cylinder provided by the present invention;

[0023] Figure 4 Schematic diagram of the sliding track of the output shaft provided by the present invention;

[0024] Figure 5 This is a schematic diagram of the assembly of the piston rod and the driven rod provided by the present invention;

[0025] Figure 6 This is a schematic diagram of the meshing transmission between the piston rod and the output shaft provided by the present invention;

[0026] Figure 7 is a side view schematic diagram of the second end cover provided by the present invention;

[0027] Figure 8 The present invention provides Figure 7 Schematic diagram of the cross section of the middle oo plane;

[0028] Figure 9 is a schematic cross-sectional view of a housing provided by the present invention;

[0029] Figure 10 is a longitudinal sectional view of the hydraulic swing cylinder provided by the present invention;

[0030] Figure 11 This is a schematic diagram of the installation process of the piston rod and output shaft provided by the present invention;

[0031] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0032] 1-first end cover; 1.1-first flow channel; 2-guide ring; 3-Glay ring; 4-piston rod; 5-driven rod; 5.1-spherical end; 6-housing; 6.1-mounting hole; 6.2-second through hole; 6.3-connecting flow channel; 6.4-first through hole; 6.5-connecting part; 7-second end cover; 7.1-second flow channel; 8-bearing; 9-output shaft; 9.1-sliding track; 9.2-mating shaft section; 9.3-connecting shaft section; 10-first interface; 11-second interface; 12-first accommodating groove; 13-second accommodating groove; 14-bolt. DETAILED DESCRIPTION

[0033] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0034] See also Figure 1 and Figure 2The present invention provides a hydraulic swing cylinder, which includes: an outer shell, an output shaft 9, a piston rod 4 and a driven rod 5; the output shaft 9 is rotatably arranged in the inner center part of the outer shell and the end thereof extends out of the outer shell, the piston rod 4 is slidably arranged in the inner shell along the axial direction, the axial direction of the piston rod 4 is parallel to the axial direction of the output shaft 9, and closed hydraulic cavities are respectively formed between the two ends of the piston rod 4 and the outer shell, and a sliding track 9.1 arranged in a spiral line is provided on the outer wall of the output shaft 9, the first end of the driven rod 5 is connected to the piston rod 4, and the second end of the driven rod 5 is set to a spherical end 5.1, and the spherical end 5.1 is matched and plugged with the sliding track 9.1.

[0035] The outer shell is the encapsulated component of the hydraulic oscillating cylinder. The output shaft 9, piston and driven rod 5 are all arranged inside the outer shell. The outer shell is a closed structure except for the part where the output shaft 9 passes through and some other parts that need to be opened. A accommodating cavity can be provided inside the outer shell to accommodate the output shaft 9 and realize the rotation of the output shaft 9. Sliding channels are provided inside the outer shell at least at the corresponding two end parts of the piston rod 4. At least the two end parts of the piston rod 4 can be matched with the sliding channels for sliding connection. The sliding channels and the ends of the piston rod 4 can be enclosed to form a closed hydraulic chamber. The closed hydraulic chamber is filled with hydraulic medium, so that under the push of the hydraulic medium, the piston rod 4 can slide back and forth along the axial direction.

[0036] The piston rod 4 is connected to the output shaft 9 through the driven rod 5. Specifically, the sliding track 9.1 on the outer wall of the output shaft 9 extends in a spiral from one end of the output shaft 9 to the other end, that is, the sliding track 9.1 has a rising angle in the axial direction of the output shaft 9. The sliding track 9.1 is a groove structure on the outer wall of the output shaft 9. The driven rod 5 is vertically connected to the piston rod 4, and the spherical end 5.1 of the driven rod 5 is inserted into the sliding track 9.1, and the shape and size of the sliding track 9.1 match the spherical end 5.1. As a result, the spherical end 5.1 of the driven rod 5 and the sliding track 9.1 are similarly meshed and connected, which can play a role in fixed positioning and transmission.

[0037] During operation, the hydraulic medium passes through the closed hydraulic chamber to push the piston rod 4 to move. The piston rod 4 drives the driven rod 5 to move linearly, forming a radial component of force of the driven rod 5 on the helical sliding track 9.1 of the output shaft 9, thereby realizing the conversion of the linear motion of the piston rod 4 into the rotational motion of the output shaft 9.

[0038] The hydraulic swing cylinder provided by the present invention adopts a transmission form in which the spherical end 5.1 of the driven rod 5 is meshed with the spiral sliding track 9.1. Compared with the transmission form of teeth, the contact area during the transmission process is increased, which is beneficial to reducing stress concentration, making it less likely to get stuck during the transmission process, and is beneficial to reducing wear. It can better adapt to the water lubrication environment, so that the transmission process still has good transmission performance under water lubrication conditions or other poor lubrication conditions.

[0039] Further, refer to Figure 3 and Figure 4 The cross-section of the sliding track 9.1 is circular, matching the spherical end 5.1 and wrapping around it. The spherical end 5.1 is larger than a hemisphere; accordingly, the cross-section of the sliding track 9.1 is larger than a semicircle. A spherical deep-hole spiral groove design allows the sphere of the driven rod 5 to be wrapped within the spiral track, forming a spherical meshing surface. Combined with the radial positioning of the driven rod 5 and the piston rod 4, the driven rod 5 radially limits the output shaft 9, achieving stable torque output of the swing cylinder.

[0040] In addition, the present invention adopts a spherical meshing transmission mode to replace the traditional rack and pinion transmission, thereby better eliminating the problem of inaccurate positioning caused by the gap between teeth, making the rotation more accurate.

[0041] Further, refer to Figure 2 and Figure 5 The interior of the housing is provided with a plurality of piston rods 4 on the periphery of the output shaft 9, and any of the piston rods 4 is axially connected to a plurality of driven rods 5, and any of the driven rods 5 is matched and plugged into the sliding track 9.1.

[0042] That is, multiple piston rods 4 are spaced apart around the periphery of the output shaft 9, and each of the multiple piston rods 4 is in transmission connection with the output shaft 9 via the driven rod 5. Furthermore, the multiple piston rods 4 can be evenly distributed around the periphery of the output shaft 9. The symmetrical distribution of multiple piston rods 4 and the multi-rod drive design not only ensure a more uniform radial force distribution and force transmission on the output shaft 9, thereby improving the stability and reliability of the system, but also mitigates the effects of problems such as poor sealing and high leakage from a single rod, thereby improving the safety factor of the swing cylinder.

[0043] Further, refer to Figure 5 , each piston rod 4 is connected to a plurality of follower rods 5, and the plurality of follower rods 5 are matched and plugged with the sliding track 9.1, that is, the spherical ends 5.1 of the plurality of follower rods 5 are all located inside the sliding track 9.1, such as Figure 6 As shown. A hole can be opened in the side wall of the piston rod 4. The follower rod 5 is based on a cylinder, with one end machined into a spherical shape. The cylindrical end of the follower rod 5 is fixed in the hole in the middle of the piston rod 4, with the spherical end facing outward, intermeshing with the spiral sliding track 9.1 of the output shaft 9. The follower rod 5 and the opening in the piston rod 4 can be fixedly connected by means of threads or interference fit, and the specific connection structure is not limited. When the piston rod 4 slides axially, it can drive the output shaft 9 to rotate. During the rotation of the output shaft 9, the spherical ends 5.1 of the multiple follower rods 5 all slide in the sliding track 9.1.

[0044] Furthermore, the multiple piston rods 4 move synchronously. The closed hydraulic chambers of the multiple piston rods 4 can be interconnected, so that the hydraulic medium can synchronously push the multiple piston rods 4 to move, thereby acting on the output shaft 9 at the same time, thereby improving the rotation stability of the output shaft 9.

[0045] Further, refer to Figure 4 and Figure 6 The output shaft 9 includes a mating shaft section 9.2, and the sliding track 9.1 is provided on the outer wall of the mating shaft section 9.2. That is, the output shaft 9 is divided into multiple shaft sections along the axial direction. The mating shaft section 9.2 is used to provide the sliding track 9.1 for meshing and transmission with the driven rod 5. On the mating shaft section 9.2, the sliding track 9.1 extends from one end of the mating shaft section 9.2 to the other end, and the sliding track 9.1 is provided with a notch at at least one end of the mating shaft section 9.2. That is, the sliding track 9.1 extends all the way to the end of the mating shaft section 9.2 and has a notch at the end position. The spherical end 5.1 of the driven rod 5 can be screwed into the sliding track 9.1 through this notch for assembly.

[0046] Furthermore, the output shaft 9 also includes a connecting shaft section 9.3, which can be set at both ends of the mating shaft section 9.2. The cross-sectional size of the mating shaft section 9.2 can be larger than the cross-sectional size of the connecting shaft section 9.3. The connecting shaft section 9.3 is used to install and fix the output shaft 9 inside the shell.

[0047] Furthermore, the helix angle of the sliding track 9.1 is greater than the friction angle between the output shaft 9 and the driven rod 5. The output shaft 9 is a cylindrical body with a circular spiral cutout to form a spiral sliding track 9.1 with a lead angle. The helix angle of the sliding track 9.1 on the output shaft 9 is greater than the friction angle between the output shaft 9 and the driven rod 5 to avoid self-locking and ensure that the output shaft 9 can be smoothly pushed to rotate, that is:

[0048]

[0049] Where: φ is the helix angle; is the equivalent friction angle; f v is the equivalent friction coefficient of the helical pair.

[0050] Further, refer to Figure 1 and Figure 2The outer shell includes a shell body 6, a first end cover 1, and a second end cover 7. The first end cover 1 and the second end cover 7 are connected to both ends of the shell body 6. The first end cover 1, the shell body 6, and the second end cover 7 are sequentially connected to form the outer shell. The first end cover 1 and the second end cover 7 have a certain thickness to facilitate the provision of the first receiving groove 12 and the second receiving groove 13. Specifically, the first end cover 1 and the second end cover 7 are respectively provided with a first receiving groove 12 at positions corresponding to the output shaft 9. The output shaft 9 is rotatably connected to the groove wall of the first receiving groove 12 via a bearing 8, and the end of the output shaft 9 passes through the groove bottom of the first receiving groove 12 on the second end cover 7.

[0051] That is, the output shaft 9 passes through the shell 6, one end is inserted into the first receiving groove 12 on the first end cover 1 and is rotatably connected to the first receiving groove 12, and the other end is inserted into the first receiving groove 12 on the second end cover 7 and passes through the bottom of the first receiving groove 12, so that the end passes through the outside of the shell.

[0052] Further, refer to Figure 2 and Figure 3 The wall of the first receiving groove 12 is stepped, and the bearing 8 is disposed in contact with the stepped surface. This allows the output shaft 9 to be axially fixed and rotatably disposed. The bearing 8 may be a tapered roller bearing 8.

[0053] Furthermore, an opening is provided at the bottom of the first receiving groove 12 of the second end cap 7, through which the end of the output shaft 9 extends, and a rotational sealing structure is provided between the end of the output shaft 9 and the wall of the opening. A Glyd ring 3 can be provided on the wall of the opening, and the output shaft 9 passes through the opening, and is rotationally sealed by the Glyd ring 3 on the inner wall of the opening.

[0054] Further, refer to Figure 2 The first end cover 1 and the second end cover 7 are respectively provided with second accommodating grooves 13 at the corresponding positions of the piston rod 4, the end of the piston rod 4 is inserted into the second accommodating groove 13, and a sliding sealing structure is provided between the end of the piston rod 4 and the groove wall of the second accommodating groove 13.

[0055] The first end cover 1 is provided with a second receiving groove 13 at the corresponding position of any piston rod 4. Similarly, the second end cover 7 is provided with a second receiving groove 13 at the corresponding position of any piston rod 4. One end of the piston rod 4 is inserted into the second receiving groove 13 on the first end cover 1, and the other end is inserted into the second receiving groove 13 on the second end cover 7. A grid ring 3 and a guide ring 2 are provided between each end of the piston rod 4 and the corresponding second receiving groove 13, and the grid ring 3 and the guide ring 2 located at both ends are used to achieve sealing and guiding functions. A closed hydraulic cavity is formed between the end of the piston rod 4 and the second receiving groove 13. Control the accuracy of the second end cover 7 and the second receiving groove 13 on the first end cover 1, select appropriate grid ring 3 and guide ring 2 sizes, and seal the cavities at both ends of the piston rod 4 well.

[0056] Further, refer to Figure 2 , a first flow channel 1.1 is provided inside the first end cover 1, the first end of the first flow channel 1.1 is connected to the outside of the shell, and the second end of the first flow channel 1.1 is connected to the second receiving groove 13 on the first end cover 1; the first flow channel 1.1 is connected to each second receiving groove 13 on the first end cover 1. Specifically, a first interface 10 may be provided on the outer surface of the first end cover 1, and the first interface 10 is connected to the first flow channel 1.1, so that the first end of the first flow channel 1.1 is connected to the outside of the shell. The hydraulic medium can flow into the first flow channel 1.1 through the first interface 10, and then flow into the each second receiving groove 13 on the first end cover 1, pushing one end of each piston rod 4; the hydraulic medium in each second receiving groove 13 on the first end cover 1 can also flow out through the first interface 10.

[0057] refer to Figure 7 and Figure 8 A second flow channel 7.1 is provided inside the second end cover 7. The first end of the second flow channel 7.1 communicates with the exterior of the housing, and the second end of the second flow channel 7.1 communicates with the second receiving groove 13 on the second end cover 7. In other words, hydraulic medium can flow into each second receiving groove 13 on the second end cover 7 through the second flow channel 7.1, pushing the other end of each piston rod 4. The hydraulic medium in each second receiving groove 13 on the second end cover 7 can also flow out of the housing through the second flow channel 7.1.

[0058] Further, refer to Figure 3 and Figure 8 , the first section of the first flow channel 1.1 is connected to the outer surface of the first end cover 1; a connecting flow channel 6.3 is provided inside the shell, one end of the connecting flow channel 6.3 is connected to the second flow channel 7.1, and the other end of the connecting flow channel 6.3 is connected to the outer surface of the first end cover 1.

[0059] A first port 10 can be provided on the outer surface of the first end cap 1 to communicate with the first flow channel 1.1. Similarly, a second port 11 can be provided on the outer surface of the first end cap 1 to communicate with the second flow channel 7.1. Specifically, a connecting flow channel 6.3 can be provided axially within the housing. The connecting flow channel 6.3 is used to connect the second flow channel 7.1 located within the second end cap 7 to the second port 11 on the outer surface of the first end cap 1. The connecting flow channel 6.3 can extend through the housing 6, with one end connected to the second flow channel 7.1 and the other end passing through the first end cap 1 to connect to the second port 11.

[0060] The present invention integrates the hydraulic flow channels into the end caps and housing 6, achieving a pipeless drive system for the oscillating cylinder. This results in a more compact structure, more reliable sealing performance, and easier disassembly and maintenance of the oscillating cylinder, making it suitable for deep-sea operations. Furthermore, the flow channel interfaces are concentrated on the first end cap 1, facilitating pipe connection and layout, reducing piping layout issues during, for example, robotic arm construction.

[0061] Further, refer to Figure 9 and Figure 10 The housing 6 has a first through-hole 6.4 extending through the center thereof. The output shaft 9 is disposed in the first through-hole 6.4. The housing 6 also has a second through-hole 6.2 extending therethrough. The piston rod 4 is disposed in the second through-hole 6.2. The first through-hole 6.4 and the second through-hole 6.2 are connected by a connecting portion 6.5, which is arranged axially along the first through-hole 6.4. The driven rod 5 passes through the connecting portion 6.5, which restricts the rotational movement of the driven rod 5, limiting its linear movement to the axial direction.

[0062] Furthermore, the two ends of the housing 6 are provided with connecting flanges, the first end cover 1 and the second end cover 7 are connected to the connecting flanges by bolts 14, and the outer wall of the housing 6 is designed to avoid the bolts 14. Figure 9 and Figure 10 The housing 6 is provided with connecting flanges at both ends, each with mounting holes 6.1. The first end cap 1 and the second end cap 7 are respectively connected and fixed to the housing 6 at the mounting holes 6.1 by bolts 14. Sealing rings may be provided between the first end cap 1 and the second end cap 7 and the housing 6 to achieve a sealed connection. The outer wall of the housing 6 between the two ends can be cut according to the position of the bolts 14, so that the outer wall and the mounting holes 6.1 avoid each other, facilitating the connection of the bolts 14. This also helps to reduce the overall size of the housing, reducing the installation space and weight, making the swing cylinder suitable for applications with high volume and weight requirements, and improving applicability.

[0063] refer to Figure 9The housing 6 is an annular structure with openings at both ends. The middle section of the outer wall is cut into a cross shape, providing space for mounting holes 6.1, which allow the bolts 14 to be installed. The housing 6 is connected to the first end cap 1 and the second end cap 7. The outer wall of the middle section of the housing 6 can be cut to form connecting flanges at both ends, which helps to reduce the size. The first through hole 6.4 forms an axial cavity, through which the output shaft 9 is installed; the second through hole 6.2 forms a piston cavity, through which the piston rod 4 passes. The connecting portion 6.5 between the first through hole 6.4 and the second through hole 6.2 is used to limit the rotation of the driven rod 5. The connecting channel 6.3 is used to transmit the hydraulic medium.

[0064] The location of the receiving grooves on first end cap 1 corresponds to the position of the through-holes in housing 6. The central first receiving groove 12 secures the tapered roller bearing 8, thereby axially securing the output shaft 9. The surrounding second receiving grooves 13 secure the piston rod 4, forming a sealed space with the guide ring 2 and Gly ring 3. The first flow channel 1.1 communicates with the surrounding second receiving grooves 13 on the first end cap 1 to drive the movement of the piston rod 4.

[0065] The position of the receiving groove on the second end cover 7 also corresponds to the through hole of the housing 6. Similar to the first end cover 1, one end of the piston rod 4 is dynamically sealed by the grid ring 3 in the second receiving groove 13, and axially positioned by the tapered roller bearing 8 in the first receiving groove 12, and the grid ring 3 dynamically seals the output shaft 9.

[0066] Furthermore, the hydraulic medium is water. The lubricating medium may also be water. The present invention utilizes a water hydraulic drive, avoiding the pollution problems associated with conventional oil hydraulic drives due to oil leakage. Adapting to water lubrication conditions, the present invention achieves oil-free operation of the swing cylinder, making it suitable for environmentally friendly and pollution-free applications such as ecosystem sampling operations and the nuclear energy industry.

[0067] Furthermore, the present invention provides a hydraulic swing cylinder with simple structure, good sealing, easy operation and high rotation accuracy, which has better adaptability under water lubrication conditions and can be used in water hydraulic drive and full water lubrication environment. Figure 1 and Figure 2 The hydraulic swing cylinder of the present invention includes a first end cover 1, a guide ring 2, a grid ring 3, a piston rod 4, a driven rod 5, a housing 6, a second end cover 7, a tapered roller bearing 8, and an output shaft 9. The first end cover 1 and the second end cover 7 are fixed at opposite ends of the housing 6. One end of the piston rod 4 is arranged in the first end cover 1, and the other end passes through the housing 6 and extends into the second end cover 7. The guide ring 2 and the grid ring 3 are sleeved on both ends of the piston rod 4. The first end cover 1 is provided with a first flow channel 1.1, and the second end cover 7 is provided with a second flow channel 7.1; a hole is punched in the middle of the outer wall of the piston rod 4 for fixing the driven rod 5 that drives the output shaft 9 to rotate; one end of the output shaft 9 is arranged in the first end cover 1, and the other end passes through the housing 6 and then passes out of the second end cover 7.

[0068] Figure 5This is an assembly drawing of the piston rod 4. The grid ring 3 and the guide ring 2 are installed at both ends of the piston rod 4 to achieve sealing and guiding of the piston rod 4. The middle section of the piston rod 4 is punched according to the meshing position of the driven rod 5. The number of holes can be set according to actual needs. Then the driven rod 5 is fixed in the middle section hole of the piston rod 4 with the spherical end 5.1 facing outward. The present invention is assembled with four piston rods 4 as an example, but is not limited to four. The positions of the holes on the other three piston rods 4 are determined according to the pitch of the spiral cut on the output shaft 9. The four piston rods 4 can be evenly and symmetrically distributed on the periphery of the output shaft 9. At this time, the number of holes in the middle of the other three piston rods 4 is the same as that of the piston rod 4, and the relative positions of the holes are staggered by 0.25, 0.5, and 0.75 pitches in the axial direction, respectively. When the four piston rods 4 overlap at one end face, the spherical surface of the driven rod 5 can mesh with the circular spiral cut of the output shaft 9, i.e., the sliding track 9.1.

[0069] Figure 10 This is a longitudinal cross-sectional view of the structure of the present invention, showing the meshing of the spherical end 5.1 of the driven rod 5 with the helical section of the output shaft 9. The helical section of the output shaft 9 has a lift angle. When the lift force is greater than the friction force, the linear motion of the piston rod 4 drives the output shaft 9 through the driven rod 5 to generate rotational motion.

[0070] The embodiment of the present invention changes the transmission mode of traditional gear meshing and adopts spherical meshing for transmission. One end of the driven rod 5 is set to be spherical, and the surface of the output shaft 9 is scanned and cut with a circular cross-section along a spiral track according to which the lift force is greater than the friction force, forming a track that the driven rod 5 can mesh with, thereby realizing the output of converting linear motion into rotation.

[0071] The present invention utilizes a linear-to-oscillating transmission method with spherical engagement of bosses. This differs from traditional gear meshing by replacing the linear contact meshing motion of the gear rack with the surface contact motion of the cam roller. This increases the contact surface area, reduces contact stress, and effectively avoids jamming. It also effectively improves stress concentration and short service life, particularly when driven by water hydraulics, reducing the effects of low lubrication on the kinematic pair. The symmetrically distributed structure of multiple piston rods (4) and the multi-rod drive design mitigate the effects of single-rod sealing problems such as poor sealing and high leakage, thereby increasing the safety factor of the oscillating cylinder. Furthermore, the multi-rod drive design offsets the radial force of the oscillating cylinder, making the output shaft (9) transmit force more evenly and improving the stability and reliability of the system.

[0072] The implementation principle of the hydraulic swing cylinder provided by the present invention is as follows: when the staff installs the hydraulic swing cylinder, they first install the guide ring 2 and the grid ring 3 at both ends of the piston rod 4, and then fix the driven rod 5 in the hole in the middle section of the piston rod 4. The assembly result is as follows: Figure 5As shown, the piston rod 4 is vertically connected to the driven rod 5. The same operation is performed to assemble four piston rods 4. The driven rod 5 on the assembled piston rod 4 is installed into the piston cavity of the housing 6 along the connecting portion 6.5 between the first through hole 6.4 and the second through hole 6.2 inside the housing 6. Similarly, the remaining three piston rods 4 are placed in the remaining three piston cavities. The assembly result is shown as follows. Figure 11 shown.

[0073] The output shaft 9 is installed into the tapered roller bearing 8 away from the key end. The bearings 8 are installed relative to each other, and then the tapered roller bearing 8 is installed into the first end cover 1 to form the axial positioning of the output shaft 9. The housing 6 is then docked with the first end cover 1. During docking, the end cover and the housing 6 are axially aligned. At the same time, during the process of pressing the four piston rods 4 in, the end faces of the four piston rods 4 are kept aligned. From the spiral cut at one end of the output shaft 9, the spherical end of the driven rod 5 is meshed with the spiral cut of the output shaft 9. The spherical surface of the driven rod 5 and the spiral cut of the output shaft 9 are meshed with each other, and slowly pressed into the second receiving groove 13 of the first end cover 1 to a depth exceeding the grid ring 3 of the piston rod 4. When the end face of the housing 6 fits the screw hole surface of the first end cover 1, it is connected and fixed with screws.

[0074] Finally, press the tapered roller bearing 8 into the middle of the second end cover 7. After installing the grid ring 3, align the piston rod 4 extending from the front shell 6 with the second receiving groove 13 around the second end cover 7, and slowly press it in until the end face of the shell 6 fits with the end face of the second end cover 7, and then fix it with screws.

[0075] Optionally, the housing 6 and the end cover can be made of 17-4PH material, the driven rod 5 and the output shaft 9 can be made of cemented carbide, and the meshing surfaces of the driven rod 5 and the output shaft 9 are sprayed with carbon film to reduce meshing friction.

[0076] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A hydraulic swing cylinder, characterized in that: include: A housing, an output shaft, a piston rod, and a driven rod; the output shaft is rotatably disposed in the central portion of the housing, with its end extending out of the housing; the piston rod is axially slidably disposed within the housing; the axial direction of the piston rod is parallel to the axial direction of the output shaft, and closed hydraulic cavities are respectively formed between the two ends of the piston rod and the housing; a sliding track arranged in a spiral is provided on the outer wall of the output shaft; the first end of the driven rod is connected to the piston rod, and the second end of the driven rod is configured as a spherical end, which is mated and plugged into the sliding track; A plurality of piston rods are provided on the periphery of the output shaft inside the housing, and any of the piston rods is axially connected to a plurality of driven rods, and any of the driven rods is matched and plugged into the sliding track.

2. The hydraulic swing cylinder according to claim 1, characterized in that: The output shaft includes a mating shaft segment, the sliding track is arranged on the outer wall of the mating shaft segment, the sliding track extends from one end of the mating shaft segment to the other end, and the sliding track is provided with a cutout at at least one end of the mating shaft segment.

3. The hydraulic swing cylinder according to claim 1 or 2, characterized in that: The housing includes a shell, a first end cover and a second end cover, the first end cover and the second end cover are connected to both ends of the shell, the first end cover and the second end cover are respectively provided with a first accommodating groove at positions corresponding to the output shaft, the output shaft is rotatably connected to the groove wall of the first accommodating groove through a bearing, and the end of the output shaft passes through the groove bottom of the first accommodating groove on the second end cover.

4. The hydraulic swing cylinder according to claim 3, characterized in that: The groove wall of the first accommodating groove is in a step shape, and the bearing is arranged in contact with the step surface.

5. The hydraulic swing cylinder according to claim 3, characterized in that: The first end cover and the second end cover are respectively provided with second accommodating grooves at corresponding positions to the piston rod, the end of the piston rod is inserted into the second accommodating groove, and a sliding sealing structure is provided between the end of the piston rod and the groove wall of the second accommodating groove.

6. The hydraulic swing cylinder according to claim 5, characterized in that: A first flow channel is provided inside the first end cover, a first end of the first flow channel is connected to the outside of the housing, and a second end of the first flow channel is connected to the second receiving groove on the first end cover; A second flow channel is provided inside the second end cover, a first end of the second flow channel is communicated with the outside of the shell, and a second end of the second flow channel is communicated with the second accommodating groove on the second end cover.

7. The hydraulic swing cylinder according to claim 6, characterized in that: The first section of the first flow channel is connected to the outer surface of the first end cover; a connecting flow channel is provided inside the shell, one end of the connecting flow channel is connected to the second flow channel, and the other end of the connecting flow channel is connected to the outer surface of the first end cover.

8. The hydraulic swing cylinder according to claim 4, characterized in that: A first through hole is provided at the inner center portion of the shell, and the output shaft is arranged in the first through hole. A second through hole is also provided inside the shell, and the piston rod is arranged in the second through hole. The first through hole and the second through hole have a connecting portion, and the connecting portion is arranged along the axial direction of the first through hole.

9. The hydraulic swing cylinder according to claim 4, characterized in that: Both ends of the shell are provided with connecting flanges respectively, the first end cover and the second end cover are connected to the connecting flanges respectively by bolts, and the outer wall of the shell is designed to avoid the bolts.

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