CN113565806B

CN113565806B - Defoaming oil filter and hydraulic oil tank

Info

Publication number: CN113565806B
Application number: CN202110841458.XA
Authority: CN
Inventors: 杨胜清; 冀宏; 林博; 王素燕; 王云华; 李森林; 许琴; 张贺; 陈乾鹏; 孙飞
Original assignee: Lanzhou University of Technology; Guangxi Liugong Machinery Co Ltd
Current assignee: Lanzhou University of Technology; Guangxi Liugong Machinery Co Ltd
Priority date: 2021-07-26
Filing date: 2021-07-26
Publication date: 2023-03-21
Anticipated expiration: 2041-07-26
Also published as: CN113565806A

Abstract

The invention relates to a hydraulic oil tank, aiming at solving the problem of poor defoaming effect of the existing hydraulic oil tank; provided are a defoaming oil filter and a hydraulic oil tank, wherein the defoaming oil filter is composed of a plate-shaped oil filter, an upstream porous filter plate and a downstream porous filter plate which are respectively arranged at the upstream and downstream in the flowing direction of oil filter oil; the oil filter comprises a square frame and a square plate-shaped filter element fixedly arranged in the frame; vertical oil passing chambers are arranged between the upstream porous filter plate and the downstream porous filter plate and between the oil filters; the upstream porous filter plate and the downstream porous filter plate are both provided with oil passing hole groups, the oil passing resistance of the middle upper part of the upstream porous filter plate is smaller than that of the middle lower part of the upstream porous filter plate, and the oil passing resistance of the middle upper part of the downstream porous filter plate is larger than that of the middle lower part of the downstream porous filter plate. In the invention, the porous filter plate is arranged, so that the flowing direction of oil is changed, the flowing stroke is increased, enough time is provided for floating bubbles, and the defoaming efficiency is improved.

Description

Defoaming oil filter and hydraulic oil tank

Technical Field

The present invention relates to a hydraulic oil tank, and more particularly, to a defoaming oil filter and a hydraulic oil tank.

Background

The hydraulic oil tank is an important part of a hydraulic system of engineering machinery, and a filtering device is arranged in the hydraulic oil tank and plays a role in filtering return oil of the hydraulic system. The hydraulic oil tank plays the roles of storing, defoaming and assisting in heat dissipation of hydraulic oil at the same time.

Hydraulic oil acts as a power transfer medium, which generates a large number of bubbles in the oil during the compression and release cycles and as it flows from the lines into the hydraulic tank. Bubbles in the oil are the root cause of noise, vibration, cavitation and cavitation of a hydraulic system, a large amount of bubbles can cause low working efficiency of elements, the oil temperature of the system is increased, the efficiency of the whole machine is low, and meanwhile, the aging of the oil is accelerated. The defoaming of the hydraulic system needs to reduce the generation of bubbles on the one hand and improve the defoaming efficiency on the other hand, and the improvement of the defoaming efficiency for the hydraulic oil tank is to consider how to quickly eliminate the generated bubbles.

The hydraulic oil tank is generally composed of a tank body, an oil return filter, an oil suction filter, a liquid level meter, a breather and other parts. The box body is provided with an oil return filter cylinder, a partition plate and various flanges, and the oil return filter cylinder is internally provided with an oil return filter element and is connected with various oil return steel pipes, the partition plate, a filter cylinder oil outlet steel pipe and the like.

In the existing hydraulic oil tank, return oil of a hydraulic system is filtered by an oil return filter element and then sequentially enters an oil return cavity and an oil suction cavity, and defoaming mainly depends on bubbles to float naturally in the process. Because the diameter of the air cells in the oil is very small, the floating speed of the air cells is very slow, and even the air cells are in a suspension state, the existing defoaming effect is not ideal and poor.

Disclosure of Invention

The invention aims to solve the technical problem that the existing hydraulic oil tank is poor in defoaming effect, and provides a defoaming oil filter and a hydraulic oil tank, so that the defoaming effect is improved.

The technical scheme for realizing the purpose of the invention is as follows: provided is a defoaming oil filter characterized by consisting of a plate-like oil filter, an upstream porous filter plate and a downstream porous filter plate which are respectively arranged upstream and downstream in the oil filter flow direction of the oil filter; the oil filter comprises a square frame and a square plate-shaped filter element fixedly arranged in the frame; vertical oil passing chambers are arranged between the upstream porous filter plate and the downstream porous filter plate and between the oil filters; the upstream porous filter plate and the downstream porous filter plate are both provided with oil passing hole groups, the oil passing resistance of the middle upper part of the upstream porous filter plate is smaller than that of the middle lower part of the upstream porous filter plate, and the oil passing resistance of the middle upper part of the downstream porous filter plate is larger than that of the middle lower part of the downstream porous filter plate. In the invention, the porous filter plate is arranged, so that the flowing direction of oil is changed, the flowing stroke is increased, enough time is provided for floating bubbles, and the defoaming efficiency is improved.

In the defoaming oil filter, the oil passing holes in the oil passing hole groups on the upstream porous filter plate and the downstream porous filter plate are in a polygonal star shape, the middle part of the oil passing holes is a circular oil passing area, and a plurality of triangular oil passing areas with acute vertex angles and overlapped bottom edges with the circular oil passing area are uniformly distributed on the circumference of the circular oil passing area.

In the defoaming oil filter, the oil passing hole group on the upstream porous filter plate is arranged at the middle upper part of the upstream porous filter plate, and the oil passing hole group on the downstream porous filter plate is arranged at the middle lower part of the downstream porous filter plate; or the flow area of the single oil passing hole arranged at the upper part of the upstream porous filter plate in the oil passing hole group on the upstream porous filter plate is larger than that of the single oil passing hole arranged at the lower part of the upstream porous filter plate, and the flow area of the single oil passing hole arranged at the upper part of the downstream porous filter plate in the oil passing hole group on the downstream porous filter plate is smaller than that of the single oil passing hole arranged at the lower part of the downstream porous filter plate.

In the defoaming oil filter, the side surfaces of the upstream porous filter plate and the downstream porous filter plate are provided with rough surface structures for adsorbing bubbles; the rough surface structure is composed of a filter screen fixed on the side surface of the porous filter plate, or a plurality of concave pits or bulges with the radial size of 0.1mm-2mm arranged on the side surface of the porous filter plate. The rough surface structure has small space gaps or bulges, and is easy to adsorb fine bubbles, so that the fine bubbles grow up and float upwards.

In the defoaming oil filter, the frame comprises a frame body with a square accommodating space for accommodating the filter element, an installation flange arranged at the top of the frame body, and a filter element fixing frame which is arranged at the two sides of the upstream and downstream of the filter element and is fixedly connected with the frame body for fixing the filter element.

In the defoaming oil filter, the frame body is provided with an overflow oil passing hole communicated with spaces on two sides of the frame body at a position higher than the top of the filter element. When the filter element is seriously blocked by oil stains, the liquid level of an upstream cavity of the defoaming oil filter rises, and the oil overflows from an overflow oil hole on the upper part of the frame body to flow to a downstream cavity of the defoaming oil filter, so that the normal flow of oil in the box body from an oil return port to an oil suction port is ensured.

In the defoaming oil filter, the frame body is provided with a liquid level detection device mounting hole and an oil duct with a damping hole, the oil duct is used for communicating the two sides of the upstream and downstream of the frame body and is positioned at a position below the position of the overflow oil passing hole, and the liquid level detection device mounting hole is connected with the upstream end of the damping hole and extends towards the top of the frame body.

The technical scheme for realizing the purpose of the invention is as follows: the hydraulic oil tank comprises a tank body and is characterized by further comprising at least two sets of the defoaming oil filters, wherein an oil return port and an oil suction port are formed in the bottom of the tank body; and the upstream porous filter plate and the downstream porous filter plate of each defoaming oil filter are fixedly connected with the frame or the box body. In the invention, the hydraulic oil tank is divided into at least three chambers in the flow direction, the defoaming oil filter can realize the aggregation and combination of bubbles, so that the bubbles can float up quickly, meanwhile, the flow path of the main flow oil liquid is prolonged, and small bubbles float out of the liquid level in more sufficient time; the defoaming oil filter also has the functions of blocking and gathering bubbles, and the defoaming hydraulic oil tank has high efficiency in multiple aspects. The method specifically comprises the following steps:

1) The hydraulic oil tank is at least divided into a plurality of chambers by the transversely arranged filter, except the last oil return chamber, the other chambers have resistance in the flow direction, and the accumulation, combination and floating of bubbles are facilitated by the blocking action of the porous filter plate and the oil filter;

2) In the space surrounded by the porous filter plates, the upper porous filter plate and the lower porous filter plate are reasonably arranged, so that bubbles can float out of the liquid level in the flow direction; meanwhile, because the flow stroke is increased, enough time is provided for the floating of bubbles;

3) The plate-type oil filter without drastic change of the overflowing area is adopted, so that the oil flows stably in the oil tank, and stable flow field conditions are provided for floating of bubbles;

4) For the scheme of arranging the two oil filters, the first oil filter has the function of oil return filtration, the second oil filter has the function of oil absorption filtration, and after twice filtration, solid particles and bubbles in oil can be completely removed, so that the purity of the oil in an oil absorption chamber is ensured;

5) The plate filter is simple to process and manufacture, low in cost and convenient to maintain.

In the hydraulic oil tank, guide rails are arranged on the vertical edges of the two sides of each frame, vertical guide grooves corresponding to the guide rails on each frame are arranged on the side wall of the tank body, sealing rubber strips are arranged between the guide grooves and the guide rails, and a molded oil-resistant sealing gasket in sealing fit with a bottom plate of the tank body is arranged on the bottom edge of each frame. Furthermore, an oil return conduit is arranged in the oil return cavity, the lower end of the oil return conduit is connected with the oil return port, the upper end of the oil return conduit vertically extends upwards, the oil outlet is a wedge-shaped inclined port, and the wedge-shaped inclined port faces the direction far away from the defoaming oil filter.

Compared with the prior art, the invention changes the flowing direction of oil liquid by arranging the porous filter plate, increases the flowing stroke, provides enough time for air bubbles to float upwards and improves the defoaming efficiency.

Drawings

FIG. 1 is a front blanking view of a hydraulic tank of the present invention.

Fig. 2 is a bottom cross-sectional view of the hydraulic oil tank of the present invention.

Fig. 3 is a left side sectional view of the hydraulic oil tank of the present invention.

Fig. 4 is a schematic structural diagram of a hydraulic oil tank body of the invention.

Fig. 5 is a schematic view of the arrangement structure of the porous filter plate in the hydraulic oil tank of the invention.

Fig. 6 is a schematic view showing the structure of an oil filter in a hydraulic oil tank according to the present invention.

Fig. 7 is a schematic sectional view of an oil filter in a hydraulic oil tank of the present invention.

Fig. 8 is a schematic structural view of an oil filter frame in a hydraulic oil tank of the present invention.

FIG. 9 is a schematic view showing the structure of a molded oil-resistant gasket in the defoaming oil filter for a hydraulic oil tank according to the present invention.

Fig. 10 is a schematic structural view of a porous filter plate in a hydraulic oil tank according to the present invention.

Fig. 11 is a schematic diagram of the flow path of oil in the hydraulic oil tank of the present invention.

Fig. 12 is a schematic view showing another structure of the porous filter sheet in the hydraulic oil tank according to the present invention.

Fig. 13 is a side view and a partial enlarged view of the porous filter plate of fig. 12.

Fig. 14 is a schematic view showing a path of oil flow in the oil tank when the porous filter sheet of fig. 12 is installed.

Part names and serial numbers in the figure:

the oil filter comprises a box body 1, an oil filter 2, a cover plate 3, a breather 4, a liquid level meter 5, an oil return opening 6, an oil suction opening 7, an oil return conduit 10, an upstream porous filter plate 11, a downstream porous filter plate 12, a guide groove 13, a frame body 14, a guide rail 15, a bottom beam 16, a filter element fixing frame 17, a through hole 18, an overflow oil groove 19, a filter element 20, a mounting flange 21, an oil passage 22, a damping hole 23, a liquid level detection device mounting hole 24, a molded oil-resistant sealing gasket 26 and a rabbet 27.

Detailed Description

The following description of the embodiments refers to the accompanying drawings.

As shown in fig. 1 and fig. 2, the hydraulic oil tank in this embodiment includes a tank 1, two sets of defoaming oil filters are installed in the tank, an oil return port 6 and an oil suction port are disposed at the bottom of the tank 1, and the defoaming oil filters are sequentially arranged between the oil return port 6 and the oil suction port 7 in a hydraulic oil flowing direction and divide a tank cavity into an oil return cavity I communicated with the oil return port, an oil suction cavity IV communicated with the oil suction port, and a middle cavity III located between the oil return cavity and the oil suction cavity. The tank body 1 is provided with a liquid level meter 5.

As shown in fig. 3, 5 to 9, the defoaming oil filter is constituted by a plate-like oil filter 2, an upstream porous filter plate 11 and a downstream porous filter plate 12 which are arranged upstream and downstream in the oil flow direction of the oil filter 2, respectively. The oil filter 2 includes a rectangular frame, and a rectangular plate-like filter element 20 fixedly mounted in the frame. Vertical oil passing chambers are arranged between the upstream porous filter plate 11 and the downstream porous filter plate 12 and the oil filter 2; oil passing hole groups are arranged on the upstream porous filter plate 11 and the downstream porous filter plate 12, the oil passing resistance of the middle upper part of the upstream porous filter plate is smaller than the oil passing resistance of the middle lower part of the upstream porous filter plate, and the oil passing resistance of the middle upper part of the downstream porous filter plate is larger than the oil passing resistance of the middle lower part of the downstream porous filter plate.

As shown in fig. 6, the frame includes a frame body 14 having a square receiving space for receiving the filter cartridge, a mounting flange 21 provided at the top of the frame body 14, and a cartridge fixing frame 17 provided at both upstream and downstream sides of the filter cartridge and fixedly connected to the frame body for fixing the filter cartridge. In this embodiment, the filter element fixing frame 17 is plate-shaped, and the peripheral edge thereof is fixedly connected with the frame body, so as to reduce the resistance of the filter element fixing frame to the flow of oil, more through holes 18 are arranged on the filter element fixing frame, so that oil can pass through with smaller resistance. In specific implementation, the filter element fixing frame 17 can also adopt a grid structure.

The frame body 14 has a square space adapted to the shape of the filter insert, which is open at the bottom and closed at the open by a bottom beam 16 and fixes the filter insert to the frame body.

As shown in fig. 7, the top of the frame body 14 is provided with a liquid level detection device mounting hole 24 and an oil passage 22 having a damping hole 23, the oil passage 22 is used for communicating the upstream and downstream sides of the frame body 14 and is located at a position below the height of the overflow oil hole position, and the liquid level detection device mounting hole 24 is connected to the upstream end of the damping hole 23 and extends toward the top of the frame body 14. If the filter element is seriously blocked and the oil passing capacity of the filter element is weakened, the liquid level of a cavity on the upstream side of the oil filter is increased, when the liquid level is increased to the position of the oil passage 22, the oil flows from the upstream side to the downstream side of the oil filter through the oil passage, and due to the existence of the damping holes 23 in the oil passage 22, a stable liquid level is formed in the oil passage 22, so that a liquid level detection device arranged in a liquid level detection device mounting hole detects and sends out an alarm signal to prompt a worker to clean or replace the filter element.

As shown in fig. 6 and 8, an overflow oil groove 19 or an overflow oil hole is provided at the top of the frame body 14, so that when the filter element is blocked and the liquid level in the upstream chamber rises, the oil flows through the overflow oil groove 19 or the overflow oil hole to flow into the chamber downstream of the oil filter, thereby ensuring that the oil suction chamber has enough oil and cannot be emptied.

As shown in fig. 6, guide rails 15 are provided on the vertical sides of both sides of each frame. As shown in fig. 4, vertical guide grooves 13 corresponding to the guide rails on the frames are arranged on the side walls of the box body, and sealing rubber strips are arranged between the guide grooves 13 and the guide rails 15. The bottom edge of the frame is provided with a molded oil-proof sealing gasket 26 which is in sealing fit with the bottom plate of the box body. The oil-resistant seal 26 is formed as shown in fig. 9 and is provided with a tenon 27 which is fitted into a dovetail groove formed in the bottom sill 16.

As shown in fig. 1, 2 and 3, the oil filter 2 is mounted on the top plate of the tank by a mounting flange at the top thereof and sealed with a cover plate, and a breather 4 is mounted on the cover plate 3, and the breather 4 communicates with each chamber through an overflow oil sump 19 on each oil filter frame body.

As shown in fig. 5, two porous filter plates for each oil filter are disposed on the upstream side and the downstream side of the oil filter, respectively, and are fixedly connected to the tank. The structure of the upstream porous filter plate 11 is shown as 10, and the whole plate is provided with an oil through hole group, wherein the flow area of a single upper oil through hole 27 arranged at the middle upper part of the upstream porous filter plate in the oil through hole group is larger than the flow area of a single lower oil through hole 28 arranged at the middle lower part of the upstream porous filter plate, because the area of the lower hole is small, the oil through resistance at the middle upper part of the upstream porous filter plate is smaller than the oil through resistance at the middle lower part of the upstream porous filter plate, when oil flows through the upstream porous filter plate, more oil flows through the hole group at the upper part to form a main flow, and relatively less oil flows through the hole group at the lower part to form a secondary flow, as shown in fig. 11. The structure of the downstream porous filter plate is the same as that of the upstream porous filter plate, but the installation direction is opposite, namely, the oil passing resistance of the middle upper part of the downstream porous filter plate is larger than that of the middle lower part of the downstream porous filter plate, when oil flows through the upstream porous filter plate, more oil flows through the pore group of the lower part to form a main flow, and relatively less oil flows through the pore group of the upper part to form a secondary flow. In the present invention, the upstream porous filter sheet 11 may be provided with oil through holes 29 having a large pore size only at the upper portion thereof, as shown in fig. 12, and the downstream porous filter sheet may be provided with oil through holes having a large pore size only at the lower portion thereof, and the oil may flow through the upstream porous filter sheet as shown in fig. 14.

In this embodiment, the upper oil passing holes 27 and the lower oil passing holes 28 of the porous filter plate are in the shape of a polygon star, the center of which is a circular oil passing region, and a plurality of triangular oil passing holes with acute vertex angles are distributed around the circle, thereby forming polygon star-shaped holes, as shown in fig. 10, which are four-pointed star holes. The polygonal star-shaped holes form gaps with small sizes at the vertex angles, fine bubbles are easily absorbed by the gaps, the bubbles can float upwards conveniently after growing up, and the defoaming effect is enhanced.

The side surfaces of the upstream porous filter plate and the downstream porous filter plate can also be rough surface structures for adsorbing bubbles; the roughened surface structure is constituted by a screen fixed to the side surface of the porous filter plate, or by dimples or protrusions having a radial dimension of 0.1mm to 2mm provided on the side surface of the porous filter plate, as shown in fig. 13. The rough surface structure has small space gaps or bulges, and is easy to adsorb fine bubbles, so that the fine bubbles grow up and float upwards.

As shown in fig. 4, an oil return conduit 10 is arranged in the oil return cavity, the lower end of the oil return conduit 10 is connected with the oil return port 6, the upper end of the oil return conduit vertically extends upwards, the oil outlet is a wedge-shaped inclined port, and the wedge-shaped inclined port faces to the direction far away from the defoaming oil filter. The wedge-shaped inclined opening structure of the oil return conduit enables oil to diffuse in the direction far away from the oil filter when entering the oil return cavity, and impact on the oil filter is prevented.

As shown in fig. 11, in the present embodiment, the hydraulic oil tank is divided into an oil return chamber I, an intermediate chamber II, and an oil return chamber IV by the filter arranged transversely, and except for the last oil return chamber IV, the other chambers have resistance in the flow direction, and the accumulation, combination, and floating of bubbles are facilitated by the blocking action of the porous filter plate and the oil filter.

In a space II enclosed by the porous filter plates, the upper porous filter plate and the lower porous filter plate are reasonably arranged, so that bubbles can float out of the liquid level in the flow direction; meanwhile, the flow stroke is increased, so that enough time is provided for floating of bubbles.

The plate-type oil filter without drastic change of the overflowing area is adopted, so that the oil tank flows stably, and stable flow field conditions are provided for floating of bubbles.

To the scheme of laying two oil filters, first oil filter possesses the filterable effect of return oil, and the second oil filter possesses the filterable effect of oil absorption, filters the back through twice, can get rid of the solid particle and the bubble in the fluid completely, guarantees the purity of oil absorption cavity fluid.

The plate filter is simple to process and manufacture, low in cost and convenient to maintain.

Claims

1. A defoaming oil filter is characterized by comprising a plate-shaped oil filter, and porous filter plates respectively arranged at the upstream and the downstream in the flowing direction of oil filter oil; the oil filter comprises a square frame and a square plate-shaped filter element fixedly arranged in the frame; vertical oil passing chambers are arranged between the upstream porous filter plate and the downstream porous filter plate and between the oil filters; oil passing hole groups are arranged on the upstream porous filter plate and the downstream porous filter plate, the oil passing resistance of the middle upper part of the upstream porous filter plate is smaller than that of the middle lower part of the upstream porous filter plate, and the oil passing resistance of the middle upper part of the downstream porous filter plate is larger than that of the middle lower part of the downstream porous filter plate; the oil passing holes in the oil passing hole groups on the upstream porous filter plate and the downstream porous filter plate are in a multi-angle star shape, the middle parts of the oil passing holes are circular oil passing areas, and a plurality of triangular oil passing areas with acute vertex angles and overlapped bottom edges with the circular oil passing areas are uniformly distributed on the circumference of the circular oil passing areas.

2. The defoaming oil filter according to claim 1, wherein the group of oil-passing holes of the upstream porous filter plate is provided in an upper middle portion of the upstream porous filter plate, and the group of oil-passing holes of the downstream porous filter plate is provided in a lower middle portion of the downstream porous filter plate;

or the flow area of the single oil passing hole arranged at the upper part of the upstream porous filter plate in the oil passing hole group on the upstream porous filter plate is larger than that of the single oil passing hole arranged at the lower part of the upstream porous filter plate, and the flow area of the single oil passing hole arranged at the upper part of the downstream porous filter plate in the oil passing hole group on the downstream porous filter plate is smaller than that of the single oil passing hole arranged at the lower part of the downstream porous filter plate.

3. The defoaming oil filter according to claim 2, wherein the side surfaces of the upstream porous filter plate and the downstream porous filter plate have a rough surface structure that adsorbs bubbles;

the rough surface structure is composed of a filter screen fixed on the side surface of the porous filter plate, or a plurality of concave pits or bulges with the radial size of 0.1mm-2mm arranged on the side surface of the porous filter plate.

4. The defoaming oil filter of claim 2, wherein the frame comprises a frame body having a square receiving space for receiving the filter element, a mounting flange provided at the top of the frame body, and a filter element fixing frame provided at both upstream and downstream sides of the filter element and fixedly connected to the frame body for fixing the filter element.

5. The defoaming oil filter of claim 4, wherein the frame body is provided with an overflow oil passing hole communicating spaces on both sides of the frame body at a position higher than the top of the filter element.

6. The defoaming oil filter according to claim 5, characterized in that the frame body is provided with a liquid level detection device mounting hole and an oil passage having a damping hole for communicating both upstream and downstream sides of the frame body at a position below the level of the overflow oil passing hole, the liquid level detection device mounting hole being connected to the upstream end of the damping hole and extending toward the top of the frame body.

7. A hydraulic oil tank comprises a tank body and is characterized by further comprising at least two sets of defoaming oil filters according to any one of claims 1 to 6, wherein an oil return port and an oil suction port are arranged at the bottom of the tank body, and each defoaming oil filter is sequentially arranged between the oil return port and the oil suction port according to the flowing direction of hydraulic oil and divides a cavity of the tank body into an oil return cavity communicated with the oil return port, an oil suction cavity communicated with the oil suction port and at least one middle cavity positioned between the oil return cavity and the oil suction cavity; and the upstream porous filter plate and the downstream porous filter plate of each defoaming oil filter are fixedly connected with the frame or the box body.

8. The hydraulic oil tank is characterized in that guide rails are arranged on the vertical edges of two sides of each frame, vertical guide grooves corresponding to the guide rails on each frame are formed in the side wall of the tank body, sealing rubber strips are arranged between the guide grooves and the guide rails, and a formed oil-resistant sealing gasket in sealing fit with the bottom plate of the tank body is arranged on the bottom edge of each frame.

9. The hydraulic oil tank as claimed in claim 7, wherein an oil return conduit is arranged in the oil return cavity, the lower end of the oil return conduit is connected with the oil return port, the upper end of the oil return conduit extends vertically upwards, the oil outlet is a wedge-shaped inclined port, and the wedge-shaped inclined port faces away from the defoaming oil filter.