Filter and engineering machinery having the filter

Abstract

The present invention provides a filter and an engineering machinery having the filter, wherein the filter comprises: an annular mounting cylinder, the annular mounting cylinder is suitable for being fixed on an external structure, an overflow structure is arranged on the side wall of the annular mounting cylinder, and a first oil inlet is formed in the middle of the annular mounting cylinder; a filter element assembly, a second oil inlet is arranged on the top of the filter element assembly, the annular mounting cylinder is sleeved on the upper part of the filter element assembly so that the first oil inlet and the second oil inlet are connected, the filter element assembly and the annular mounting cylinder can move relative to each other in the radial direction, the filter element assembly has a first position and a second position, when the filter element assembly is in the first position, the side wall of the filter element assembly blocks the overflow structure, and when the filter element assembly is in the second position, the side wall of the filter element assembly avoids the overflow structure; an elastic reset member, suitable for applying an elastic force toward the first position to the filter element assembly. The technical solution of the present invention solves the defect that the replacement steps of the filter of the engineering machinery in the prior art are complicated.

Description

Technical Field

[0001] The invention relates to the technical field of filtering equipment, and in particular to a filter and an engineering machine having the filter. Background Art

[0002] For construction machinery, in order to prevent the hydraulic oil from bringing impurities into the oil tank during the oil return process, a filter is installed in the oil return line. Figure 1 As shown, the filter includes a filter element assembly 1' and a bypass valve 2' arranged above the filter element assembly 1'. When the filter element in the filter element assembly 1' is blocked, the hydraulic oil can flow in from the bypass valve 2' to prevent the return oil circuit from being blocked. However, in the above structure, when replacing the filter, the bypass valve 2' needs to be disassembled, and then the filter element assembly 1' can be replaced, and the replacement steps are cumbersome. At the same time, since the filter element assembly 1' is a non-detachable structure, its outer shell and the internal filter element are discarded together during replacement, resulting in waste. Summary of the invention

[0003] Therefore, the technical problem to be solved by the present invention is to overcome the defect of complicated replacement steps of the filter of the engineering machinery in the prior art, thereby providing a filter and an engineering machinery having the filter.

[0004] In order to solve the above problems, the present invention provides a filter, comprising: an annular mounting cylinder, the annular mounting cylinder is suitable for being fixed on an external structure, an overflow structure is arranged on the side wall of the annular mounting cylinder, and a first oil inlet is formed in the middle of the annular mounting cylinder; a filter element assembly, a second oil inlet is arranged on the top of the filter element assembly, the annular mounting cylinder is sleeved on the upper part of the filter element assembly to connect the first oil inlet and the second oil inlet, the filter element assembly and the annular mounting cylinder can move relative to each other in the radial direction, the filter element assembly has a first position and a second position, when the filter element assembly is in the first position, the side wall of the filter element assembly blocks the overflow structure, and when the filter element assembly is in the second position, the side wall of the filter element assembly avoids the overflow structure; an elastic reset member, suitable for applying an elastic force toward the first position to the filter element assembly.

[0005] Optionally, the overflow structure is a plurality of overflow grooves, and the plurality of overflow grooves are arranged at intervals along the circumference of the annular mounting cylinder.

[0006] Optionally, the filter further comprises a limiting structure, which is disposed between the annular mounting cylinder and the filter element assembly, and is suitable for limiting the relative position between the annular mounting cylinder and the filter element assembly.

[0007] Optionally, the limiting structure includes: a first limiting protrusion and a second limiting protrusion, the first limiting protrusion and the second limiting protrusion are arranged on the inner wall of the annular mounting cylinder from top to bottom, and the overflow structure is located between the first limiting protrusion and the second limiting protrusion; a third limiting protrusion is arranged on the outer wall of the filter element assembly, and the third limiting protrusion is located between the first limiting protrusion and the second limiting protrusion.

[0008] Optionally, a first annular groove is provided on the inner side wall of the annular mounting cylinder, and the filter further comprises an elastic retaining ring, which is provided in the first annular groove, and a portion of the elastic retaining ring protruding from the first annular groove forms a first limiting protrusion.

[0009] Optionally, a second annular groove is arranged on the outer end surface of the third limiting protrusion, and the filter element assembly further includes a sealing ring arranged in the second annular groove.

[0010] Optionally, the elastic return member is a spring, the spring is sleeved outside the filter element assembly, and two ends of the spring are respectively in contact with the second limiting protrusion and the third limiting protrusion.

[0011] Optionally, the filter element assembly includes: a cylinder, a plurality of oil return holes are arranged on the side wall of the cylinder, and a second oil inlet is formed at the upper end of the cylinder; a filter element is arranged in the cylinder; an end cover is arranged at the bottom end of the cylinder; a connecting ring is arranged at the upper end of the cylinder, and a limiting structure is arranged between the annular mounting cylinder and the connecting ring.

[0012] The present invention also provides an engineering machine, comprising the above-mentioned filter.

[0013] Optionally, the engineering machinery includes an oil tank, an oil filter cavity is arranged in the oil tank, an inner wall of the oil filter cavity is provided with a mounting boss, an outer wall of the annular mounting cylinder is provided with a mounting convex edge, and the mounting convex edge is limited above the mounting boss. The engineering machinery also includes a clamping piece, and two ends of the clamping piece are respectively abutted against the bottom wall of the oil filter cavity and the annular mounting cylinder.

[0014] The present invention has the following advantages:

[0015] By utilizing the technical solution of the present invention, when the filter is filtering, the hydraulic oil enters the filter element assembly from the first oil inlet and the second oil inlet for filtering. At this time, the filter element assembly is in the first position under the action of the elastic reset member, and the overflow structure of the annular mounting cylinder is closed. When blockage occurs in the filter element assembly, the oil pressure of the hydraulic oil increases, and the pressure exerted by the hydraulic oil on the filter element assembly overcomes the elastic force of the elastic reset member, and pushes the filter element assembly from the first position to the second position. At this time, the overflow structure on the annular mounting cylinder is opened, and the hydraulic oil can flow through the overflow structure, thereby preventing the return oil from being blocked. In the above structure, the overflow structure is integrated on the filter, so there is no need to set a bypass valve, which reduces the assembly steps during replacement and improves the work efficiency of the operator. Therefore, the technical solution of the present invention solves the defect of cumbersome replacement steps of the filter of engineering machinery in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 A schematic diagram of installing a filter in the prior art is shown;

[0018] Figure 2 It shows a schematic diagram of the assembly of the filter of the present invention installed in the oil filter cavity;

[0019] Figure 3 Shows Figure 2 Schematic diagram of the filter in the figure;

[0020] Figure 4 Shows Figure 3 A schematic diagram of the structure of the annular mounting cylinder of the middle filter;

[0021] Figure 5 Shows Figure 2 A schematic diagram of the structure of the connecting ring of the filter;

[0022] Figure 6 Shows Figure 2 A schematic cross-sectional view of the filter (elastic reset member is not shown);

[0023] Figure 7 Shows Figure 6 A partial enlarged schematic diagram of the upper left portion of the middle filter; and

[0024] Figure 8 Shows Figure 2Schematic diagram of the installation and coordination of the middle filter and the oil filter chamber.

[0025] Description of reference numerals:

[0026] 1', filter element assembly; 2', bypass valve; 10, annular mounting cylinder; 11, first oil inlet; 12, first annular groove; 13, mounting convex edge; 20, overflow structure; 30, filter element assembly; 31, second oil inlet; 32, sealing ring; 33, cylinder; 34, end cover; 35, connecting ring; 36, filter element; 40, elastic reset member; 50, limiting structure; 51, first limiting convex portion; 52, second limiting convex portion; 53, third limiting convex portion; 531, second annular groove; 60, elastic retaining ring; 100, oil filter chamber; 200, pressing member; 300, mounting boss. DETAILED DESCRIPTION

[0027] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0029] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0031] like Figure 2 , Figure 3 , Figure 6 and Figure 7 As shown, the filter of this embodiment includes an annular mounting cylinder 10, a filter element assembly 30 and an elastic reset member 40. Among them, the annular mounting cylinder 10 is suitable for being fixed on the external structure, an overflow structure 20 is arranged on the side wall of the annular mounting cylinder 10, and a first oil inlet 11 is formed in the middle of the annular mounting cylinder 10. A second oil inlet 31 is arranged on the top of the filter element assembly 30, and the annular mounting cylinder 10 is sleeved on the upper part of the filter element assembly 30 so that the first oil inlet 11 and the second oil inlet 31 are connected. In addition, the filter element assembly 30 and the annular mounting cylinder 10 can move relative to each other in the radial direction, so that the filter element assembly 30 has a first position and a second position. Further, when the filter element assembly 30 is in the first position, the side wall of the filter element assembly 30 blocks the overflow structure 20, and when the filter element assembly 30 is in the second position, the side wall of the filter element assembly 30 avoids the overflow structure 20. The elastic reset member 40 is suitable for applying an elastic force toward the first position to the filter element assembly 30.

[0032] By using the technical solution of this embodiment, when the filter is filtering, the hydraulic oil enters the filter element assembly 30 from the first oil inlet 11 and the second oil inlet 31 for filtering. At this time, the filter element assembly 30 is in the first position under the action of the elastic reset member 40, and the overflow structure 20 of the annular mounting cylinder 10 is closed. When blockage occurs in the filter element assembly 30, the oil pressure of the hydraulic oil increases, and the pressure exerted by the hydraulic oil on the filter element assembly 30 overcomes the elastic force of the elastic reset member 40, and pushes the filter element assembly 30 from the first position to the second position. At this time, the overflow structure 20 on the annular mounting cylinder 10 is opened, and the hydraulic oil can flow through the overflow structure 20, thereby preventing the return oil from being blocked. In the above structure, the overflow structure is integrated on the filter, so there is no need to set a bypass valve, which reduces the assembly steps during replacement and improves the work efficiency of the operator. Therefore, the technical solution of this embodiment solves the defect of cumbersome replacement steps of the filter of engineering machinery in the prior art.

[0033] It should be noted that the above-mentioned "annular mounting cylinder 10 is suitable for being fixed on an external structure" means that the annular mounting cylinder 10 is fixed in the cavity to be filtered. Specifically speaking of the oil tank of the engineering machinery, the annular mounting cylinder 10 is fixed in the oil cavity of the oil return pipeline. The above-mentioned fixation can be achieved by conventional methods such as clamping, welding, and fastener connection. Of course, the structures that need to be filtered in other equipment and electrical appliances can be regarded as the above-mentioned "external structure".

[0034] Combination Figure 2 , Figure 3 and Figure 6The annular mounting cylinder 10 in this embodiment is in the form of a sleeve structure, and the upper end opening of the sleeve structure forms the above-mentioned first oil inlet 11, and the above-mentioned overflow structure 20 is arranged on the side wall of the sleeve structure. The filter element assembly 30 is in the form of a cylindrical structure, and the top of the filter element assembly 30 has an opening, that is, the filter element assembly 30 takes in oil from the top. The overall outer diameter of the filter element assembly 30 is smaller than the inner diameter of the annular mounting cylinder 10, so that the annular mounting cylinder 10 can be sleeved outside the filter element assembly 30, and the two can move in the radial direction. Since the annular mounting cylinder 10 is fixedly arranged, those skilled in the art can understand that in Figure 2 In the embodiment, the filter element assembly 30 can move upward or downward relative to the annular mounting cylinder 10.

[0035] Combination Figure 2 and Figure 6 As shown, when the filter element assembly 30 is filtering normally, the hydraulic oil enters the filter element assembly 30 along the first oil inlet 11 and the second oil inlet 31 for filtering. At this time, the elastic reset member 40 applies an upward elastic force to the filter element assembly 30, so that the side wall of the filter element assembly 30 blocks the overflow structure 20 (that is, the filter element assembly 30 is in the first position), and the hydraulic oil entering from the first oil inlet 11 will enter the filter element assembly 30 for filtering. When the filter element assembly 30 is blocked, the hydraulic oil cannot be discharged from the filter element assembly 30, so that the pressure applied by the hydraulic oil to the filter element assembly 30 increases and overcomes the elastic force of the elastic reset member 40. The pressure of the hydraulic oil pushes the filter element assembly 30 downward and avoids the overflow structure 20, so that the overflow structure 20 is opened (fully opened or partially opened), and the hydraulic oil entering from the first oil inlet 11 can flow out from the overflow structure 20, thereby preventing the oil circuit from being blocked.

[0036] like Figure 4 As shown, in the technical solution of this embodiment, the overflow structure 20 is a plurality of overflow grooves, and the plurality of overflow grooves are arranged at intervals along the circumference of the annular mounting tube 10. Specifically, the overflow groove is a square window structure, and the overflow groove is arranged on the side wall of the annular mounting tube 10. There are a plurality of overflow grooves arranged at intervals along the circumference, thereby ensuring the overflow effect. Of course, the overflow structure 20 is not limited to the above-mentioned overflow groove structure, for example, the overflow structure 20 can be an overflow hole.

[0037] like Figures 3 to 7As shown, in the technical solution of this embodiment, the filter also includes a limiting structure 50, which is arranged between the annular mounting cylinder 10 and the filter element assembly 30, and the limiting structure 50 is suitable for limiting the relative position between the annular mounting cylinder 10 and the filter element assembly 30. The function of the limiting structure 50 is to enable the filter element assembly 30 to move between the first position and the second position relative to the annular mounting cylinder 10, while ensuring that the two will not separate. That is, when the filter element assembly 30 is filtering normally, the limiting structure 50 can keep the filter element assembly 30 in the first position, and the filter element assembly 30 will not fall out of the annular mounting cylinder 10 upward. When the filter element assembly 30 is blocked, the filter element assembly 30 is pushed downward by the hydraulic oil, and the limiting structure 50 can keep the filter element assembly 30 in the second position, and the filter element assembly will not fall out of the annular mounting cylinder 10 downward.

[0038] like Figure 3 , Figure 5 as well as Figure 7 As shown, the limiting structure 50 includes a first limiting protrusion 51, a second limiting protrusion 52 and a third limiting protrusion 53. The first limiting protrusion 51 and the second limiting protrusion 52 are arranged on the inner side wall of the annular mounting cylinder 10 from top to bottom, and the overflow structure 20 is located between the first limiting protrusion 51 and the second limiting protrusion 52. The third limiting protrusion 53 is arranged on the outer side wall of the filter element assembly 30, and the third limiting protrusion 53 is located between the first limiting protrusion 51 and the second limiting protrusion 52. According to the above structure, when the filter element assembly 30 is in the first position, the third limiting protrusion 53 abuts against the first limiting protrusion 51 upward; when the filter element assembly 30 is in the second position, the third limiting protrusion 53 abuts against the second limiting protrusion 52 downward. That is, the filter element assembly 30 can move up and down within the range between the first limiting protrusion 51 and the second limiting protrusion 52 relative to the annular mounting cylinder 10. Furthermore, by arranging the overflow structure 20 between the first limiting protrusion 51 and the second limiting protrusion 52, the entire overflow structure 20 can be blocked when the filter element assembly 30 is in the first position, and the entire overflow structure 20 can be avoided when the filter element assembly 30 is in the second position.

[0039] like Figure 3 , Figure 4 as well as Figure 7 As shown, in the technical solution of this embodiment, a first annular groove 12 is provided on the inner side wall of the annular mounting cylinder 10, and the filter further includes an elastic retaining ring 60, which is provided in the first annular groove 12, and the portion of the elastic retaining ring 60 protruding from the first annular groove 12 forms a first limiting convex portion 51. Specifically, the two ends of the elastic retaining ring 60 are not closed, that is, it has an opening. At the same time, the two ends of the elastic retaining ring 60 are bent upward, so as to facilitate the operator to squeeze the elastic retaining ring 60 inward and deform it. At the same time, from Figure 4It can also be seen that the upper end surface of the first annular groove 12 has a groove, and the groove is used to place the end bending part of the above-mentioned elastic ring 60. Based on the above structure, the installation process of the above-mentioned elastic ring is as follows: the operator squeezes the two end protrusions of the elastic ring 60, thereby causing the elastic ring 60 to deform and shrink; the elastic ring 60 is placed in the first annular groove 12, and the two end protrusions of the elastic ring 60 are placed in the groove of the upper end surface of the first annular groove 12; the two end protrusions of the elastic ring 60 are loosened, and the elastic ring restores its shape under the action of its own elasticity, and then is stuck in the first annular groove 12. When removing the elastic ring 60, the above steps can be reversed.

[0040] According to the above structure, it can be seen that the installation and removal of the elastic ring 60 are very convenient, so when the filter element assembly 30 needs to be maintained or replaced, the elastic ring 60 is removed, and then the filter element assembly 30 is moved upward to separate the filter element assembly 30 and the annular installation cylinder 10. Similarly, the operation of installing the filter element assembly 30 is also very convenient.

[0041] Of course, the structure of the first limiting protrusion 51 is not limited to the above-mentioned elastic retaining ring 60 . For example, the first limiting protrusion 51 may also be an annular rib integrally provided on the side wall of the annular mounting tube 10 .

[0042] like Figure 4 and Figure 7 As shown, in this embodiment, the second limiting protrusion 52 is an annular rib arranged at the bottom of the inner wall of the annular mounting tube 10.

[0043] like Figure 3 , Figure 5 and Figure 7 As shown, in the technical solution of this embodiment, a second annular groove 531 is provided on the outer end surface of the third limiting protrusion 53, and the filter element assembly 30 further includes a sealing ring 32 disposed in the second annular groove 531. Specifically, the sealing ring 32 is used to seal the gap between the third limiting protrusion 53 and the annular mounting cylinder 10, so that when the filter element assembly 30 is in the first position, the hydraulic oil will not flow to the overflow structure 20 along the gap between the third limiting protrusion 53 and the annular mounting cylinder 10.

[0044] like Figure 3As shown, in the technical solution of this embodiment, the elastic reset member 40 is a spring, and the spring is sleeved outside the filter element assembly 30, and the two ends of the spring are respectively in contact with the second limiting convex portion 52 and the third limiting convex portion 53. Specifically, the diameter of the spring is larger than the outer diameter of the filter element assembly 30, and smaller than the inner diameter of the annular mounting cylinder 10, so that the spring can be arranged between the filter element assembly 30 and the annular mounting cylinder 10, thereby making the overall structure of the filter more compact. Of course, the arrangement of the elastic reset member 40 is not limited to the above-mentioned manner. For example, the elastic reset member 40 can be arranged on the outside of the filter element assembly 30 and located at the bottom of the filter element assembly 30, and exert an upward elastic force toward the filter element assembly 30. That is, the elastic reset member 40 can exert an elastic force toward the first position toward the filter element assembly 30, and the setting position and setting method thereof can be flexibly adjusted by those skilled in the art according to actual needs.

[0045] like Figure 3 and Figure 6 As shown, the filter element assembly 30 includes a barrel 33, a filter element 36, an end cover 34 and a connecting ring 35. Among them, a plurality of oil return holes are arranged on the side wall of the barrel 33, and the upper end of the barrel 33 forms a second oil inlet 31. The filter element 36 is arranged in the barrel 33. The end cover 34 is arranged at the bottom end of the barrel 33. The connecting ring 35 is arranged at the upper end of the barrel 33, and the limiting structure 50 is arranged between the annular mounting barrel 10 and the connecting ring 35.

[0046] Furthermore, combined with Figures 2 to 4 It can be seen that in this embodiment, a handle is provided on the upper surface of the annular mounting cylinder 10. The two ends of the handle are connected to the annular mounting cylinder 10 through the shaft hole structure, so that the handle can swing. When the filter needs to be removed and the filter element 36 needs to be replaced, the handle can be pulled upward (such as Figure 2 As shown), the annular mounting cylinder 10 and the filter element assembly 30 can be taken out. When the filter is working, the handle is laid flat to prevent the handle from interfering with the oil inlet.

[0047] Specifically, the filter element assembly 30 in this embodiment is a filtering method with oil inlet at the top and oil outlet at the side. The filter element 36 is a cylindrical structure, and the filter element 36 is placed in the cylinder 33. A plurality of oil return holes are arranged in an array on the side wall of the cylinder 33 to form a mesh structure. The above filtering method allows oil return holes to be set in the entire radial direction of the cylinder 33, thereby reducing the difficulty of processing. Figure 1, the filtering method of the filter in the prior art is oil inlet from the side and oil outlet from the bottom, so the filtered impurities are located between the side wall of the filter cylinder and the internal filter element. In the process of replacing the filter and removing it, the return hydraulic oil will drive the impurities to move downward. If a filter hole is also set at the bottom of the filter side wall, the impurities will flow out of the filter hole and be brought back to the oil tank. Therefore, the filter hole of the filter in the prior art needs to be designed in combination with the hydraulic oil level of the oil return line of the oil tank, that is, the lowest filter hole needs to be higher than the highest liquid level, which increases the difficulty of design and processing. In the present embodiment, the hydraulic oil is filtered by the method of oil inlet from the top and oil outlet from the side, so the impurities are concentrated inside the filter element. Therefore, when the filter is removed, the impurities will not flow out through the oil return holes on the filter element and the cylinder 33, so the setting position of the oil return hole is not restricted, reducing the difficulty of design and processing.

[0048] At the same time, for the above structure, when the filter needs to be maintained, the filter element 36 of the cylinder 33 can be taken out and replaced. The annular mounting cylinder 10, cylinder 33, end cover 34 and connecting ring 35 do not need to be discarded and can be used for a long time, thereby reducing waste.

[0049] Furthermore, the end cap 34 is welded to the bottom of the cylinder 33 and is used to block the bottom of the cylinder 33. The connecting ring 35 is welded to the upper part of the side wall of the cylinder 33, and the third limiting protrusion 53 is arranged on the outer side wall of the connecting ring 35. The above structure reduces the overall processing difficulty of the filter element assembly 30. Of course, those skilled in the art can understand that the above cylinder 33, the end cap 34 and the connecting ring 35 can also be made by integral molding.

[0050] This embodiment also provides an engineering machine, which includes the above-mentioned filter. Figure 2 and Figure 8 As shown, further, the engineering machinery includes an oil tank, and an oil filter chamber 100 is arranged in the oil tank. The inner side wall of the oil filter chamber 100 is provided with a mounting boss 300, and the outer side wall of the annular mounting cylinder 10 is provided with a mounting flange 13, and the mounting flange 13 is limited above the mounting boss 300. The engineering machinery also includes a pressing member 200, and the two ends of the pressing member 200 are respectively abutted against the end wall of the oil filter chamber 100 and the annular mounting cylinder 10. Specifically, the top of the oil filter chamber 100 is provided with an opening, and a cover is provided at the opening. The above-mentioned filter is put into the oil filter chamber 100 from the opening, and the mounting flange 13 of the annular mounting cylinder 10 is abutted against the mounting boss 300 in the oil filter chamber 100. Then the pressing member 200 (a spring in this embodiment) is placed above the annular mounting cylinder 10, and the cover is pressed on the opening, and the cover is installed by screws.

[0051] Of course, the above-mentioned filter is not limited to use in engineering machinery, and any vehicle, equipment, electrical appliance, etc. that uses a filter can adopt the above-mentioned filter structure.

[0052] Combined with the above structure, the filter in this embodiment has the following advantages:

[0053] 1. The return oil filter of this embodiment can ensure that all impurities are retained inside the filter element during return oil filtration and will not flow back to the oil tank, thus avoiding secondary contamination of the hydraulic oil. At the same time, it reduces the difficulty of design and processing;

[0054] 2. The annular mounting cylinder 10 of the filter is provided with a bypass valve function, so there is no need to provide a bypass valve, thus reducing product costs;

[0055] 3. The filter element has no inner and outer cylinder structure, which can reduce waste;

[0056] 4. During maintenance, the annular mounting cylinder 10, the cylinder body 33, the end cover 34 and the connecting ring 35 do not need to be discarded, thereby saving costs, reducing waste, and being beneficial to environmental protection.

[0057] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A filter, characterized in that: include: An annular mounting cylinder (10), the annular mounting cylinder (10) being suitable for being fixed on an external structure, an overflow structure (20) being provided on a side wall of the annular mounting cylinder (10), and a first oil inlet (11) being formed in the middle of the annular mounting cylinder (10); A filter element assembly (30), wherein a second oil inlet (31) is arranged at the top of the filter element assembly (30), the annular mounting cylinder (10) is sleeved on the upper part of the filter element assembly (30) so that the first oil inlet (11) and the second oil inlet (31) are in communication, the filter element assembly (30) and the annular mounting cylinder (10) are relatively movable in a radial direction, the filter element assembly (30) having a first position and a second position, when the filter element assembly (30) is in the first position, the side wall of the filter element assembly (30) blocks the overflow structure (20), and when the filter element assembly (30) is in the second position, the side wall of the filter element assembly (30) avoids the overflow structure (20); an elastic return member (40) adapted to exert an elastic force on the filter element assembly (30) toward the first position, The filter further comprises a limiting structure (50), wherein the limiting structure (50) is arranged between the annular mounting cylinder (10) and the filter element assembly (30), and the limiting structure (50) is suitable for limiting the relative position between the annular mounting cylinder (10) and the filter element assembly (30). The limiting structure (50) comprises: a first limiting protrusion (51) and a second limiting protrusion (52), wherein the first limiting protrusion (51) and the second limiting protrusion (52) are arranged on the inner side wall of the annular mounting cylinder (10) from top to bottom, and the overflow structure (20) is located between the first limiting protrusion (51) and the second limiting protrusion (52); A third position-limiting protrusion (53) is provided on the outer side wall of the filter element assembly (30), and the third position-limiting protrusion (53) is located between the first position-limiting protrusion (51) and the second position-limiting protrusion (52). A first annular groove (12) is provided on the inner side wall of the annular mounting cylinder (10), and the filter further comprises an elastic retaining ring (60), wherein the elastic retaining ring (60) is arranged in the first annular groove (12), and a portion of the elastic retaining ring (60) protruding from the first annular groove (12) forms the first limiting protrusion (51); A second annular groove (531) is provided on the outer end surface of the third limiting protrusion (53), and the filter element assembly (30) further comprises a sealing ring (32) provided in the second annular groove (531).

2. The filter according to claim 1, characterized in that The overflow structure (20) is a plurality of overflow grooves, and the plurality of overflow grooves are arranged at intervals along the circumference of the annular mounting cylinder (10).

3. The filter according to claim 1, characterized in that The elastic return member (40) is a spring, which is sleeved outside the filter element assembly (30), and two ends of the spring are respectively in contact with the second limiting protrusion (52) and the third limiting protrusion (53).

4. The filter according to claim 1, characterized in that The filter element assembly (30) comprises: A cylinder (33), wherein a plurality of oil return holes are arranged on a side wall of the cylinder (33), and the upper end of the cylinder (33) forms the second oil inlet (31); A filter element (36) disposed in the cylinder (33); An end cover (34) is arranged at the bottom end of the cylinder (33); The connecting ring (35) is arranged at the upper end of the cylinder (33), and the limiting structure (50) is arranged between the annular mounting cylinder (10) and the connecting ring (35).

5. An engineering machine, characterized in that: Comprising the filter according to any one of claims 1 to 4.

6. The construction machine according to claim 5, characterized in that: The engineering machinery comprises an oil tank, an oil filter cavity (100) is arranged in the oil tank, a mounting boss (300) is arranged on the inner side wall of the oil filter cavity (100), a mounting flange (13) is arranged on the outer side wall of the annular mounting cylinder (10), the mounting flange (13) is limited above the mounting boss (300), and the engineering machinery further comprises a pressing member (200), two ends of the pressing member (200) are respectively in contact with the end wall of the oil filter cavity (100) and the annular mounting cylinder (10).

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