CN113565806B - Defoaming oil filter and hydraulic oil tank - Google Patents

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

Anti-foaming oil filter and hydraulic tank

technical field

The invention relates to a hydraulic oil tank, more specifically, to an anti-foaming oil filter and a hydraulic oil tank.

Background technique

The hydraulic oil tank is an important part of the hydraulic system of construction machinery, and a filter device is installed in it to filter the return oil of the hydraulic system. The hydraulic oil tank plays the role of storage, defoaming and auxiliary heat dissipation for hydraulic oil at the same time.

As the power transmission medium, hydraulic oil will generate a large number of air bubbles in the oil during the cycle of compression and release and when it flows from the pipeline into the hydraulic oil tank. Air bubbles in the oil are the source of noise, vibration, cavitation, and cavitation in the hydraulic system. A large number of air bubbles will reduce the working efficiency of the components, increase the oil temperature of the system, and reduce the efficiency of the whole machine. At the same time, it will also accelerate the aging of the oil. . The defoaming of the hydraulic system, on the one hand, needs to reduce the generation of bubbles, and on the other hand, it needs to improve the defoaming efficiency. For the hydraulic oil tank, to improve the defoaming efficiency is to consider how to quickly eliminate the generated bubbles.

The hydraulic oil tank is usually composed of tank body, oil return filter, oil suction filter, liquid level gauge, breather and other components. The oil return filter cartridge, separator and various flanges are arranged in the box body, and the oil return filter element is installed in the oil return filter cartridge and connected with various oil return steel pipes, baffles, filter cartridge oil outlet steel pipes, etc.

In the existing hydraulic oil tank, the return oil of the hydraulic system enters the oil return chamber and the oil suction chamber successively after being filtered by the oil return filter element. During this process, the defoaming mainly depends on the natural floating of the air bubbles. Because the pore diameter of the air bubbles in the oil is very small, its floating speed is very slow, and even in a suspended state, so the existing defoaming effect is not ideal, and the defoaming effect is poor.

Contents of the invention

The technical problem to be solved by the present invention is to provide a defoaming oil filter and a hydraulic oil tank to improve the defoaming effect in view of the poor defoaming effect of the existing hydraulic oil tank.

The technical solution of the present invention for realizing its purpose is as follows: provide a kind of defoaming oil filter, it is characterized in that by the oil filter of sheet shape, arrange respectively in the upstream and downstream upstream of the oil filter oil flow direction Porous filter plate and downstream porous filter plate; the oil filter includes a square frame, a square plate-shaped filter element fixedly installed in the frame; between the upstream porous filter plate and the downstream porous filter plate and the oil filter Both have vertical oil passage chambers; both the upstream porous filter plate and the downstream porous filter plate are provided with groups of oil passage holes; The oil passage resistance of the middle and upper parts of the downstream porous filter plate is greater than the oil passage resistance of the middle and lower parts. In the present invention, by arranging a porous filter plate, the oil flow direction is changed, the flow stroke is increased, enough time is provided for the bubbles to float up, and the defoaming efficiency is improved.

In the above-mentioned defoaming oil filter, the oil holes in the oil hole group on the upstream porous filter plate and the downstream porous filter plate are multi-pointed stars, the middle part of which is a circular oil passage area, and the circumference of the circular oil passage area is Evenly distributed a plurality of triangular oil-through areas whose vertex angles are acute angles and whose base overlaps with the circular oil-through area.

In the above-mentioned defoaming oil filter, the oil passage group on the upstream porous filter plate is arranged on the middle and upper part of the upstream porous filter plate, and the oil passage group on the downstream porous filter plate is arranged on the middle and lower part of the downstream porous filter plate or the flow area of a single oil hole arranged in the upper part of the upstream porous filter plate in the group of oil holes on the upstream porous filter plate is greater than the flow area of a single oil hole arranged in the lower part of the upstream porous filter plate, said The flow area of a single oil hole arranged in the middle and upper part of the downstream porous filter plate in the group of oil holes on the downstream porous filter plate is smaller than that of a single oil hole arranged in the middle and lower part of the downstream porous filter plate.

In the above-mentioned defoaming oil filter, the sides of the upstream porous filter plate and the downstream porous filter plate have a rough surface structure for absorbing air bubbles; the rough surface structure is made of a filter screen fixed on the side of the porous filter plate, or It consists of a number of pits or protrusions with a radial size of 0.1mm-2mm arranged on the side of the porous filter plate. The rough surface structure has small space gaps or protrusions, which are easy to absorb small air bubbles and make the small air bubbles grow up and float up.

In the above-mentioned defoaming oil filter, the frame includes a frame body with a square accommodation space for accommodating the filter element, a mounting flange arranged on the top of the frame body, arranged on both upstream and downstream sides of the filter element and fixedly connected to the frame body Filter holder for holding the filter.

In the above-mentioned defoaming oil filter, the frame body is provided with an overflow oil hole connecting the space on both sides of the frame body at a position higher than the top of the filter element. When the filter element is seriously clogged by oil, the liquid level in the upstream chamber of the defoaming oil filter rises, and overflows from the overflow oil hole on the upper part of the frame body to the downstream chamber of the defoaming oil filter to ensure that the oil in the box is Normal flow from tank to suction.

In the above-mentioned defoaming oil filter, the frame body is provided with a liquid level detection device installation hole and an oil passage with a damping hole, and the oil passage is used to connect the upstream and downstream sides of the frame body and is located at the overflow oil hole position At a position below the height, the installation hole of the liquid level detection device is connected to the upstream end of the damping hole and extends to the top of the frame body.

The technical scheme of the present invention for realizing its object is as follows: provide a kind of hydraulic oil tank, comprise tank body, it is characterized in that also comprising at least two sets of above-mentioned defoaming oil filters, oil return port and oil suction port are arranged on the box body At the bottom, the defoaming oil filters are arranged sequentially between the oil return port and the oil suction port according to the flow direction of the hydraulic oil, and the tank cavity is divided into an oil return chamber connected with the oil return port, and an oil return chamber connected with the oil suction port. The oil suction chamber, at least one intermediate chamber between the oil return chamber and the oil suction chamber; the upstream porous filter plate and the downstream porous filter plate of each defoaming oil filter are fixedly connected to the frame or to the box body. In the present invention, by dividing the hydraulic oil tank into at least three chambers in the flow direction, the defoaming oil filter can realize the accumulation and merging of air bubbles, and then quickly float up, while the flow path of the mainstream oil is extended, and the small air bubbles have More time to surface; the anti-foaming oil filter also has the function of blocking and accumulating air bubbles, which together form an efficient anti-foaming hydraulic oil tank. Specifically:

1) The hydraulic oil tank is divided into at least several chambers by the filter arranged horizontally. Except for the last oil return chamber, other chambers have resistance in the flow direction. Through the blocking effect of the porous filter plate and the oil filter, Facilitate the aggregation, merging and floating of air bubbles;

2) In the space surrounded by the porous filter plate, through the reasonable arrangement of the upstream and downstream porous filter plates, it is beneficial for the bubbles to float out of the liquid surface in the flow direction; at the same time, due to the increased flow stroke, it provides enough time for the bubbles to float up ;

3) The plate type oil filter without drastic change of the flow area is adopted to make the flow in the oil tank stable and provide a stable flow field condition for the floating of the air bubbles;

4) For the plan of placing two oil filters, the first oil filter has the function of oil return filtration, and the second oil filter has the function of oil suction filtration. After two times of filtration, the oil in the oil can be completely removed. Solid particles and air bubbles ensure the purity of the oil in the oil absorption chamber;

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

In the above-mentioned hydraulic oil tank, guide rails are provided on the vertical sides of the two sides of each frame, vertical guide grooves corresponding to the guide rails on the frames are provided on the side walls of the box, and a guide rail is provided between each guide groove and the guide rails. There is a sealing rubber strip, and a formed oil-resistant sealing gasket sealingly matched with the bottom plate of the box body is installed on the bottom edge of the frame. Further, an oil return conduit is arranged in the oil return cavity, the lower end of the oil return conduit is connected to the oil return port, the upper end extends vertically upwards and the oil outlet is a wedge-shaped oblique opening, and the wedge-shaped oblique opening faces away from the defoaming filter oil direction of the device.

Compared with the prior art, the present invention adopts a porous filter plate to change the flow direction of the oil, increase the flow stroke, provide enough time for the bubbles to float up, and improve the defoaming efficiency.

Description of drawings

Fig. 1 is a hidden front view of the hydraulic oil tank of the present invention.

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

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

Fig. 4 is a schematic diagram of the structure of the hydraulic oil tank of the present invention.

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

Fig. 6 is a structural schematic diagram of the oil filter in the hydraulic oil tank of the present invention.

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

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

Fig. 9 is a schematic structural view of the formed oil-resistant sealing gasket in the defoaming oil filter in the hydraulic oil tank of the present invention.

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

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

Fig. 12 is another structural schematic diagram of the porous filter plate in the hydraulic oil tank of the present invention.

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

Fig. 14 is a schematic diagram of the oil flow path in the oil tank when the porous filter plate in Fig. 12 is installed.

Part names and serial numbers in the figure:

Box body 1, oil filter 2, cover plate 3, breather 4, liquid level gauge 5, oil return port 6, oil suction port 7, oil return conduit 10, upstream porous filter plate 11, downstream porous filter plate 12, guide groove 13. Frame body 14, guide rail 15, bottom beam 16, filter element fixing frame 17, through hole 18, overflow oil tank 19, filter element 20, mounting flange 21, oil passage 22, damping hole 23, liquid level detection device installation hole 24, forming oil-resistant gasket 26, tenon 27.

Detailed ways

The specific implementation will be described below in conjunction with the accompanying drawings.

As shown in Figure 1 and Figure 2, the hydraulic oil tank in this embodiment includes a box body 1, and two sets of defoaming oil filters are installed in the box body, and the oil return port 6 and the oil suction port are arranged at the bottom of the box body 1. The oil bubble filter is arranged sequentially between the oil return port 6 and the oil suction port 7 according to the flow direction of the hydraulic oil and divides the tank cavity into an oil return chamber I connected with the oil return port and an oil suction chamber IV connected with the oil suction port , The intermediate chamber III between the oil return chamber and the oil suction chamber. A liquid level gauge 5 is installed on the tank body 1 .

As shown in Figure 3 and Figure 5-9, the anti-foaming oil filter consists of a plate-shaped oil filter 2, an upstream porous filter plate 11 and a downstream porous filter plate 11 arranged upstream and downstream in the oil flow direction of the oil filter 2, respectively. Filter plate 12 constitutes. The oil filter 2 includes a square frame and a square plate-shaped filter element 20 fixedly installed in the frame. There are vertical oil passage chambers between the upstream porous filter plate 11 and the downstream porous filter plate 12 and the oil filter 2; oil passage groups are arranged on the upstream porous filter plate 11 and the downstream porous filter plate 12, and the upstream porous filter plate The oil passage resistance of the middle and upper part of the plate is smaller than the oil passage resistance of the lower part, and the oil passage resistance of the middle and upper part of the downstream porous filter plate is greater than the oil passage resistance of the lower part of the plate.

As shown in Figure 6, the frame includes a frame body 14 with a square accommodation space for accommodating the filter element, a mounting flange 21 arranged on the top of the frame body 14, arranged on both upstream and downstream sides of the filter element and fixedly connected with the frame body The filter element holder 17 for fixing the filter element. In this embodiment, the filter element fixing frame 17 is plate-shaped, and its peripheral edges are fixedly connected with the frame body. In order to reduce the resistance of the filter element fixing frame to the oil flow, more through holes 18 are arranged on the filter element fixing frame so that Oil passes through with less 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 element, the bottom of which is open, and the bottom beam 16 is connected and closed at the open place and the filter element is fixed on the frame body.

As shown in Figure 7, the top of the frame body 14 is provided with a liquid level detection device installation hole 24 and an oil passage 22 with a damping hole 23. The oil passage 22 is used to connect the upstream and downstream sides of the frame body 14 and is located in the overflow oil hole. At the position below the position height, the installation hole 24 of the liquid level detection device 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 severely clogged, its oil flow capacity will be weakened, and the liquid level in the upstream chamber of the oil filter will rise. When the liquid level rises to the position of the oil passage 22, the oil will flow from the upstream to the downstream of the oil filter through the oil passage. The existence of the damping hole 23 in the oil passage 22 forms a stable liquid level in the oil passage 22, so that the liquid level detection device installed in the installation hole of the liquid level detection device can detect and send an alarm signal to prompt the staff to clean the filter element or replace.

As shown in Figures 6 and 8, an overflow oil tank 19 or an overflow oil hole is provided on the top of the frame body 14. When the filter element is blocked and the liquid level in the upstream chamber rises, the oil will flow through the overflow Oil groove 19 or overflow through the chamber downstream of the oil hole flow channel oil filter, ensure that the oil suction cavity has enough oil liquid and can not suck empty.

As shown in FIG. 6 , guide rails 15 are provided on the vertical edges on both sides of each frame. As shown in FIG. 4 , vertical guide grooves 13 corresponding to the guide rails on the frames are provided on the side walls of the box body, and sealing strips are provided between the guide grooves 13 and the guide rails 15 . The bottom edge of the frame is equipped with a formed oil-resistant gasket 26 that is sealingly matched with the bottom plate of the box body. The structure of the molded oil-resistant gasket 26 is shown in FIG. 9 , and a tenon 27 matching the dovetail groove on the bottom beam 16 is arranged on it.

As shown in Figure 1, Figure 2 and Figure 3, the oil filter 2 is installed on the top plate of the box body through the mounting flange on the top, and is sealed with a cover plate, and a respirator 4 is installed on the cover plate 3, the respirator 4 communicate with each cavity through the overflow oil groove 19 on each oil filter frame body.

As shown in Fig. 5, two porous filter plates for each oil filter are respectively arranged on the upstream side and the downstream side of the oil filter, and are fixedly connected with the box body. The structure of the upstream porous filter plate 11 is shown in 10, and the entire plate is provided with oil hole groups, wherein the flow area of the single upper oil hole 27 arranged in the upper middle part of the upstream porous filter plate in the oil hole group is larger than that set at the The flow area of the single lower oil passage hole 28 in the lower part of the upstream porous filter plate, due to the small area of the lower hole, the oil passage resistance of the middle and upper part of the upstream porous filter plate is smaller than the oil passage resistance of the lower part of the upstream porous filter plate, when the oil flows through the upstream porous filter plate , more oil flows through the upper pore group to form the main flow, while relatively less oil flows through the lower pore group to form the secondary flow, as shown in Figure 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, that is, on the downstream porous filter plate, the oil passage resistance of the middle and upper parts is greater than that of the lower part, and when the oil flows through the upstream porous filter plate, More oil flows through the lower pore group, forming the main flow, while relatively less oil flows through the upper pore group, forming the secondary flow. In the present invention, the upstream porous filter plate 11 can also only be provided with oil passing round holes 29 with larger apertures in its upper part, as shown in Figure 12, and the downstream porous filter plate can also be provided with larger apertures in its lower part. Oil holes, when oil flows through the upstream porous filter plate, its flow path is shown in Figure 14.

In this embodiment, the upper oil hole 27 and the lower oil hole 28 on the porous filter plate are in the shape of a polygonal star, the central part of which is a circular oil passage area, and a plurality of sharp-angled holes are distributed around the circle. Oil is passed through the triangle to form a multi-pointed star-shaped hole, as shown in Figure 10, which is a four-pointed star hole. The multi-pointed star-shaped holes form small gaps at the top corners, which are easy to absorb small air bubbles, and facilitate the floating of bubbles after they grow up, enhancing the defoaming effect.

The side surfaces of the upstream porous filter plate and the downstream porous filter plate of the present invention can also be a rough surface structure for absorbing air bubbles; Concaves or protrusions with a radial dimension of 0.1mm-2mm, as shown in FIG. 13 . The rough surface structure has small space gaps or protrusions, which are easy to absorb small air bubbles and make the small air bubbles grow up and float up.

As shown in Figure 4, an oil return conduit 10 is arranged in the oil return chamber, the lower end of the oil return conduit 10 is connected to the oil return port 6, the upper end extends vertically upwards and the oil outlet is a wedge-shaped inclined opening, and the wedge-shaped inclined opening faces away from the defoaming Orientation of the oil filter. The wedge-shaped oblique structure of the oil return conduit allows the oil to diffuse away from the oil filter when it enters the oil return chamber, preventing impact on the oil filter.

As shown in Figure 11, in this embodiment, the hydraulic oil tank is divided into an oil return chamber I, an intermediate chamber II, and an oil return chamber IV by a filter arranged horizontally in this embodiment. Except for the last oil return chamber IV, the other chambers are in the flow direction There is a resistance effect, and the blocking effect of the porous filter plate and the oil filter is beneficial to the accumulation, merging and floating of the air bubbles.

In the space II surrounded by the porous filter plate, through the reasonable arrangement of the upstream and downstream porous filter plates, it is beneficial for the bubbles to float out of the liquid surface in the flow direction; at the same time, due to the increased flow stroke, it provides enough time for the bubbles to float up.

The plate type oil filter without drastic change of flow area makes the flow in the oil tank stable and provides a stable flow field condition for the floating of air bubbles.

For the plan of placing two oil filters, the first oil filter has the function of oil return filtration, and the second oil filter has the function of oil suction filtration. After two times of filtration, solid particles in the oil can be completely removed. and air bubbles to ensure the purity of the oil in the oil absorption chamber.

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

Claims (9)

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.

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