Oil return filter and crane

Abstract

The application discloses a hydraulic oil return filter and a crane in the technical field of hydraulic oil return filter, and aims to solve the problem of poor bubble discharge effect and hydraulic oil overflow to the exhaust pipe in the prior art. The hydraulic oil return filter comprises a spiral guide plate, and when the spiral guide plate rotates, the hydraulic oil is driven to rotate and flow to an oil outlet. When the hydraulic oil rotates, all bubbles including small bubbles gather at the central axis of a filter channel and move to a centrifugal cavity. The intermediate small and two large internal shapes of the centrifugal cavity and a contraction channel make a high pressure area at the connection of the centrifugal cavity and the contraction channel, and a low pressure area is formed at one end of the centrifugal cavity close to a return oil port. All bubbles including small bubbles gather at the central position of the one end of the centrifugal cavity close to the return oil port and are discharged through the exhaust pipe based on the pressure difference. The hydraulic oil return filter can effectively discharge small bubbles, and when the bubbles are discharged, the hydraulic oil is not easy to overflow the exhaust pipe because the hydraulic oil has a movement trend of moving away from the central axis of the filter channel.

Description

Technical Field

[0001] This invention relates to a return oil filter and a crane, belonging to the field of hydraulic oil return oil filtration technology. Background Technology

[0002] Hydraulic systems use hydraulic oil as the working medium to transmit power to mechanisms. The quality of the hydraulic oil directly affects the stability and reliability of the hydraulic system. Return oil filters can effectively filter out contaminants such as metal particles generated by component wear and rubber impurities in seals, but they cannot remove air bubbles mixed in with the hydraulic oil. During normal operation, gas mixing with the hydraulic oil can cause phenomena such as increased oil temperature, cavitation, and cavitation, leading to vibration and noise in the hydraulic system and reducing its reliability and operational stability. Existing hydraulic oil-gas separators are ineffective at filtering small air bubbles and easily cause hydraulic oil to overflow into the exhaust pipe. In fact, existing return oil filters can only be used with strict vertical placement and cannot be laid flat or even upside down, thus requiring high installation standards and hindering the utilization of internal space in construction machinery. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a return oil filter with good bubble removal effect and hydraulic oil that does not overflow into the exhaust pipe, as well as a crane and a crane using the return oil filter and crane.

[0004] To achieve the above objectives, the present invention is implemented using the following technical solution: In a first aspect, the present invention provides a return oil filter, including an oil outlet and an oil return port, and further including a filter channel communicating with the oil return port. A spiral guide plate is provided in the filter channel, and when the spiral guide plate rotates in the filter channel, it drives hydraulic oil to flow from the oil return port into the oil outlet. The filter channel forms a centrifugal chamber at one end away from the oil return port. The cross-sectional area of ​​the centrifugal chamber gradually shrinks from near the oil return port to away from the oil return port and is connected to the shrinkage channel at one end away from the oil return port. The cross-sectional area of ​​the shrinkage channel gradually expands from near the oil return port to away from the oil return port and is connected to the oil outlet at one end away from the oil return port. It also includes an exhaust pipe for discharging air bubbles, the exhaust pipe being connected to the center of the centrifuge chamber near the oil return port.

[0005] In some embodiments of the first aspect, the exhaust pipe is also connected to a hydraulic oil tank.

[0006] In some embodiments of the first aspect, the end of the centrifugal chamber near the oil return port is adjacent to the spiral guide plate.

[0007] In some embodiments of the first aspect, the spiral guide plate is in the shape of an Archimedean spiral, the spiral guide plate includes at least one first spiral blade, the first spiral blade being spirally extended along the axial direction of the filter channel; the exhaust pipe includes a central shaft tube fitted into the rotation center of the spiral guide plate, the central shaft tube being connected to one end of the centrifugal chamber near the oil return port.

[0008] In some embodiments of the first aspect, the wall of the central tube is made of an oleophobic material and is densely covered with one-way venting holes, which only allow air bubbles to flow from the outside of the central tube into the interior.

[0009] In some embodiments of the first aspect, the central tube is provided with a one-way vent valve that only allows air bubbles to flow out from the filter channel to the other end of the central tube.

[0010] In some embodiments of the first aspect, an air pump is provided inside the exhaust pipe.

[0011] In some embodiments of the first aspect, at least one baffle is fitted axially into the central tube.

[0012] In some embodiments of the first aspect, the air deflector is in the shape of an Archimedean spiral, and the air deflector includes a second spiral blade that is staggered in position with the first spiral blade, the spiral extension direction of the second spiral blade matching that of the first spiral blade.

[0013] Secondly, the present invention also provides a crane, wherein the hydraulic system of the crane includes the return oil filter described in any one of the first aspects.

[0014] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: The return oil filter provided by this invention drives the hydraulic oil to rotate and flow towards the outlet when the spiral guide plate rotates. When the hydraulic oil rotates, all bubbles, including small bubbles, gather at the central axis of the filter channel and move towards the centrifugal chamber. The flow channel shape formed by the centrifugal chamber and the contraction channel, which is smaller in the middle and larger at both ends, creates a high-pressure zone at the connection between the centrifugal chamber and the contraction channel, and a low-pressure zone at the end of the centrifugal chamber near the return oil port. All bubbles, including small bubbles, gather at the center of the centrifugal chamber near the return oil port and are discharged through the exhaust pipe based on the pressure difference. The return oil filter provided by this invention can effectively discharge small bubbles. Since the hydraulic oil is in a rotating centrifugal state and has a tendency to move away from the central axis of the filter channel, the hydraulic oil is not easy to overflow from the exhaust pipe when discharging bubbles. Therefore, the return oil filter does not need to maintain a strictly vertical arrangement with the return oil port facing upwards. The crane provided by this invention includes the return oil filter provided by this invention, and therefore has the same technical effect. Attached Figure Description

[0015] Figure 1This is a cross-sectional structural diagram of the oil return filter provided in an embodiment of the present invention; Figure 2 yes Figure 1 A schematic diagram of a non-transparent surface structure; Figure 3 yes Figure 1 A rendered schematic diagram of the structure surrounding the central spiral guide plate; Figure 4 yes Figure 3 A rendering diagram of the structure surrounding the central axis tube; Figure 5 yes Figure 1 Schematic diagram of the structure of the spiral guide plate and exhaust pipe; Figure 6 yes Figure 1 A schematic diagram of the cross-sectional structure of the spiral guide plate and the exhaust pipe; In the diagram: 1-rectifier; 2-exhaust pipe; 2.1-central shaft pipe; 3-centrifugal chamber; 4-contraction channel; 5-spiral guide plate; 5.1-first spiral blade; 6-oil return port; 7-filter channel; 8-oil outlet; 9-one-way breather valve; 10-air pump; 11-Laval nozzle; 12-air baffle; 12.1-second spiral blade. Detailed Implementation

[0016] The technical solution of this application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments and specific features in the embodiments are detailed descriptions of the technical solution of this application, rather than limitations thereof. In the absence of conflict, the embodiments and technical features in the embodiments can be combined with each other. Example 1

[0017] Existing technologies address the problem of poor air bubble filtration in hydraulic system return oil filters by employing an "oil turbulence device that rotates the hydraulic oil, causing air bubbles to aggregate and be discharged based on centrifugal force." However, this solution has two drawbacks: firstly, it is only effective against large air bubbles and fails to remove small ones; secondly, the vigorous rotation and splashing of hydraulic oil can easily cause it to overflow into the exhaust pipe. In fact, existing return oil filters can only be used with a strictly vertical orientation and cannot be laid flat or even upside down. When the return oil filter is placed upside down, the hydraulic oil will flow backward into the exhaust pipe, thus requiring high installation standards and hindering the utilization of internal space in construction machinery.

[0018] This embodiment provides a return oil filter for hydraulic systems in engineering machinery to solve the problems of poor bubble removal, difficulty in removing small bubbles, and hydraulic oil overflowing into the exhaust pipe in the prior art.

[0019] refer to Figure 1 , Figure 5 and Figure 6The return oil filter provided in this embodiment includes an oil outlet 8 and an oil return port 6. The oil return port 6 recovers the hydraulic oil in the hydraulic system from which air bubbles need to be removed, and the oil outlet 8 sends the hydraulic oil with air bubbles removed back to the hydraulic system (such as a hydraulic oil tank). It also includes a filter channel 7 connected to the oil return port 6. In this embodiment, the filter channel 7 is tubular, and a spiral guide plate 5 is provided in the filter channel 7. When the spiral guide plate 5 rotates in the filter channel 7, it drives the hydraulic oil to flow from the oil return port 6 into the oil outlet 8, and also drives the hydraulic oil to rotate.

[0020] The filter channel 7 forms a centrifugal chamber 3 at the end opposite to the return port 6. The cross-sectional area of ​​the centrifugal chamber 3 gradually contracts from near the return port 6 to far away from the return port 6 and connects with the contraction channel 4 at the end opposite to the return port 6. The cross-sectional area of ​​the contraction channel 4 gradually expands from near the return port 6 to far away from the return port 6 and connects with the outlet port 8 at the end opposite to the return port 6. After passing through the spiral guide plate 5, the hydraulic oil is in a state of rotation and flowing towards the outlet port 8. Due to the narrowing flow channel structure formed by the centrifugal chamber 3 and the contraction channel 4, a high-pressure zone is generated at the connection point of the centrifugal chamber 3 and the contraction channel 4. The centrifugal chamber 3 generates a low-pressure zone relative to the high-pressure zone at the connection point of the centrifugal chamber 3 and the contraction channel 4. The pressure distribution gradually decreases from the end of the centrifugal chamber 3 opposite to the return port 6 to the end near the return port 6.

[0021] During the process of hydraulic oil flowing from the spiral guide plate 5 to the centrifugal chamber 3, the hydraulic oil is subjected to centrifugal force. The bubbles gradually converge towards the central axis of the filter channel 7, the rotation center of the spiral guide plate 5, and the central axis of the centrifugal chamber 3 (in the prior art, the baffle and turbulence holes of the oil flow turbulence device will break large bubbles into small bubbles, but the prior art oil flow turbulence device does not have the ability to gather small bubbles). During the process of large bubbles converging towards the center under centrifugal force, since the plane of the spiral guide plate 5 used in this embodiment is nearly parallel to the direction of movement of the large bubbles (in the prior art, the baffle of the oil flow turbulence device is perpendicular to the direction of convergence of large bubbles towards the center under centrifugal force, breaking the large bubbles, while the turbulence holes will cut the large bubbles), the large bubbles will be difficult to break and will play the role of absorbing small bubbles; and the pressure difference from the end of the centrifugal chamber 3 away from the return oil port 6 to the end near the return oil port 6 will promote the movement of bubbles towards the end of the centrifugal chamber 3 away from the return oil port 6, and will also promote the separation of small bubbles from the hydraulic oil. Finally, the large bubbles and small bubbles will gather at the center position of the end of the centrifugal chamber 3 away from the return oil port 6. The spiral guide vane 5 can be selected in various forms, such as shaftless pump blades or propellers.

[0022] It also includes an exhaust pipe 2 for expelling air bubbles, which is connected to the center of the centrifugal chamber 3 near the return port 6. Based on the pressure difference between the end of the centrifugal chamber 3 away from the return port 6 and the end near the return port 6, the air bubbles are pushed into the exhaust pipe 2 due to the pressure difference, which is more effective than the prior art in expelling air bubbles. Furthermore, also based on the pressure difference between the end of the centrifugal chamber 3 away from the return port 6 and the end near the return port 6, combined with the effect of the spiral guide plate 5 driving the hydraulic oil to the outlet 8 and the centrifugal effect of the rotating hydraulic oil, the hydraulic oil tends to move away from the exhaust pipe 2, which solves the problem of hydraulic oil easily overflowing into the exhaust pipe in the prior art. Precisely because the movement of air bubbles is based on the pressure difference, the return oil filter provided in this embodiment does not have to be installed vertically, and can be laid flat or inverted with the return port 6 facing down. The spiral guide plate 5 can be driven to rotate by a motor or driven to rotate by a gear set of engineering machinery.

[0023] Hydraulic oil flow direction: return port 6 → filter channel 7 (including spiral guide plate 5) → centrifugal chamber 3 → contraction channel 4 → outlet port 8. Bubble flow direction: return port 6 → filter channel 7 (including spiral guide plate 5) → centrifugal chamber 3 → (return) exhaust pipe 2. Example 2

[0024] This embodiment provides a return oil filter, which is a further improvement on the return oil filter provided in Embodiment 1. For details not covered in the technical solution, please refer to Embodiment 1.

[0025] The oil return filter provided in this embodiment is a further improved technical solution compared to Embodiment 1: The exhaust pipe 2 is also connected to the hydraulic oil tank, specifically to the top of the hydraulic oil tank, to balance the internal pressure.

[0026] refer to Figure 1 The centrifugal chamber 3 is adjacent to the spiral guide plate 5 at one end near the return oil port 6. The spiral guide plate 5 drives the hydraulic oil to accelerate and rotate, and then seamlessly connects with the centrifugal chamber 3 to ensure that the functions of the centrifugal chamber 3 and the spiral guide plate 5 do not interfere with each other. If the spiral guide plate 5 goes deep into the centrifugal chamber 3, it will cause interference bubbles to accumulate at the center of the centrifugal chamber 3 near the return oil port 6. If the spiral guide plate 5 is a certain distance away from the centrifugal chamber 3 near the return oil port 6, the rotation of the hydraulic oil will be reduced.

[0027] refer to Figure 1 , Figure 3 , Figure 4 , Figure 5 and Figure 6The spiral guide plate 5 is in the shape of an Archimedean spiral. The spiral guide plate 5 includes at least one first spiral blade 5.1. The first spiral blade 5.1 extends spirally along the axial direction of the filter channel 7, forming an Archimedean spiral shape (refer to the blades of an Archimedean spiral pump). The first spiral blade 5.1 provides a gentler flow than a shaftless pump impeller or propeller during the rotation and flow of hydraulic oil towards the oil outlet 8, better protecting large air bubbles and preventing their rupture. It also provides a pre-installed mounting position for the central shaft tube 2.1 compared to a propeller. The exhaust pipe 2 includes a central shaft tube 2.1 that fits into the center of rotation of the spiral guide plate 5. The central shaft tube 2.1 is connected to the end of the centrifugal chamber 3 near the return oil port 6. (Reference) Figure 1 In this embodiment, the central tube 2.1 is adjacent to the end of the centrifuge chamber 3 near the oil return port 6, neither extending deep into the centrifuge chamber 3 nor retracting into the spiral guide plate 5, thus achieving better bubble collection. The constriction channel 4, which encloses the spiral guide plate 5 and the central tube 2.1, forms the rectifier 1.

[0028] Alternatively, the wall of the central tube 2.1 can be made of an oleophobic material and densely covered with one-way vents. These vents allow air bubbles that do not enter through the end inlet of the central tube 2.1 to be drawn in from the outer wall. The vents only allow air bubbles to flow from the outside of the central tube 2.1 into the interior. Based on the pressure difference, the air bubbles will rapidly travel along the wall of the central tube 2.1 towards the depth of the exhaust pipe 2. The exhaust pipe 2 is shaped like a blind end, inserted into the rectifier 1 of the constriction channel 4 and entering the rotating central axis of the spiral guide plate 5.

[0029] refer to Figure 1 The central tube 2.1 is equipped with a one-way vent valve 9 that only allows air bubbles to flow out from the filter channel 7 to the other end of the central tube 2.1. The exhaust pipe 2 is equipped with an air pump 10. In this way, when the return oil filter provided in this embodiment is laid flat or the return oil port 6 is inverted with downwards, it can prevent the hydraulic oil from flowing back due to the unexpected stop of the spiral guide plate 5 or the stop of the return oil filter.

[0030] refer to Figure 3 , Figure 4 , Figure 5 and Figure 6 At least one baffle plate 12 is inserted into the central tube 2.1 along the axial direction. When the oil return filter is placed with the oil return port 6 facing upward, the baffle plate 12 blocks the rise of air bubbles that have not entered through the end inlet of the central tube 2.1 (the rise of air bubbles may cause air bubbles to accumulate on the top of the oil return filter). In conjunction with the setting that "the tube wall of the central tube 2.1 is made of oleophobic material and densely covered with one-way vent holes", the air bubbles that have not entered through the end inlet of the central tube 2.1 are absorbed.

[0031] Further, refer to Figure 5 and Figure 6The air baffle 12 is also in the shape of an Archimedean spiral. The air baffle 12 includes a second spiral 12.1 that is staggered with the position of the first spiral 5.1. The spiral extension direction of the second spiral 12.1 matches that of the first spiral 5.1. When the first spiral 5.1 rotates, the second spiral 12.1 assists in guiding the hydraulic oil to form a rotating flow of hydraulic oil.

[0032] refer to Figure 2 The centrifugal chamber 3 and the contraction channel 4 can be replaced by an integrated Laval nozzle 11.

[0033] The return oil filter provided in this embodiment can be applied to the filtration of air bubbles in the hydraulic oil of engineering machinery, thereby improving the service life of the hydraulic system.

[0034] Finally, the present invention also provides a crane, the hydraulic system of which includes a return oil filter provided in either Embodiment 1 or Embodiment 2, and also possesses the technical effects mentioned in Embodiment 1 or Embodiment 2 compared to existing cranes.

[0035] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0036] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "connected," "linked," "located in," "equipped with," "located in," "installed," "set," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0037] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An oil return filter, comprising an oil outlet (8) and an oil return port (6), characterized in that, It also includes a filter channel (7) connected to the return port (6), and a spiral guide plate (5) is provided in the filter channel (7). When the spiral guide plate (5) rotates in the filter channel (7), it drives hydraulic oil to flow from the return port (6) into the outlet port (8). The filter channel (7) forms a centrifugal chamber (3) at one end away from the oil return port (6). The cross-sectional area of ​​the centrifugal chamber (3) gradually shrinks from near the oil return port (6) to away from the oil return port (6) and is connected to the contraction channel (4) at one end away from the oil return port (6). The cross-sectional area of ​​the contraction channel (4) gradually expands from near the oil return port (6) to away from the oil return port (6) and is connected to the oil outlet (8) at one end away from the oil return port (6). It also includes an exhaust pipe (2) for discharging air bubbles, the exhaust pipe (2) being connected to the center of one end of the centrifuge chamber (3) near the oil return port (6); The spiral guide plate (5) is in the shape of an Archimedean spiral. The spiral guide plate (5) includes at least one first spiral blade (5.1). The first spiral blade (5.1) is spirally extended along the axial direction of the filter channel (7). The exhaust pipe (2) includes a central shaft tube (2.1) fitted into the rotation center of the spiral guide plate (5). The central shaft tube (2.1) is connected to one end of the centrifuge chamber (3) near the oil return port (6).

2. The return oil filter according to claim 1, characterized in that, The exhaust pipe (2) is also connected to the hydraulic oil tank.

3. The return oil filter according to claim 1, characterized in that, The centrifugal chamber (3) is adjacent to the spiral guide plate (5) at one end near the oil return port (6).

4. The return oil filter according to claim 1 or 3, characterized in that, The wall of the central tube (2.1) is made of an oleophobic material and is covered with one-way venting holes, which only allow air bubbles to flow into the interior from the outside of the central tube (2.1).

5. The return oil filter according to claim 1 or 3, characterized in that, The central tube (2.1) is provided with a one-way vent valve (9) that allows air bubbles to flow out from the filter channel (7) to the other end of the central tube (2.1).

6. The return oil filter according to claim 5, characterized in that, An air pump (10) is installed inside the exhaust pipe (2).

7. The return oil filter according to claim 1 or 3, characterized in that, At least one air baffle (12) is fitted into the central tube (2.1) along the axial direction.

8. The return oil filter according to claim 7, characterized in that, The air baffle (12) is in the shape of an Archimedean spiral. The air baffle (12) includes a second spiral (12.1) that is staggered with the first spiral (5.1). The spiral extension direction of the second spiral (12.1) matches that of the first spiral (5.1).

9. A crane, characterized in that, The hydraulic system of the crane includes a return oil filter as described in any one of claims 1 to 8.

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