A negative pressure type oil-gas separation device

Abstract

The present invention relates to a negative pressure type oil-gas separation device, which solves the deficiencies of existing similar technologies at home and abroad. The technical solution is as follows: It includes a housing, an air outlet pipe, a cover plate, a partition plate, a filter screen and an oil collector. An air inlet is provided on the upper side wall of the housing, and an oil return port is provided at the lower end of the housing. The interior of the housing is divided into a pre-filter cavity and a post-filter cavity by the filter screen. An oil collector is arranged at the lower part of the housing. An air compensation inlet is provided on the cover plate. A retaining ring is formed by the upward protrusion of the upper surface of the partition plate. The cavity between the partition plate and the cover plate is divided into an outer cavity and an inner cavity by the retaining ring. The outer cavity is provided with a downward-introducing filter screen air compensation hole corresponding to the position of the filter screen, and the inner cavity is provided with a downward-introducing pressure difference compensation hole. The upper surface of the filter screen abuts against the lower surface of the partition plate, and the lower surface of the filter screen abuts against the upper surface of the oil collector. The air outlet pipe extends into the U-shaped circle of the oil collector inside the filter screen. An oil collecting chamber is provided inside the oil collector. The oil collector is provided with an oil collecting hole corresponding to the lower surface of the filter screen, and the oil collecting hole is communicated with the oil collecting chamber.

Description

Technical Field

[0001] The present invention relates to an oil-gas separation device, and particularly to a negative-pressure oil-gas separation device. Background Art

[0002] As is well known, the mixed gas discharged from the crankcase of an internal combustion engine contains engine oil. During the recovery combustion process, it will adsorb on various components of the internal combustion engine, forming carbon deposits, reducing the working performance of the internal combustion engine, accelerating the wear of the internal combustion engine and wasting engine oil, reducing the working efficiency of the engine, shortening its lifespan, and at the same time discharging more harmful gases to pollute the environment. Therefore, it is necessary to recover the engine oil in the mixed gas. Thus, someone has designed an oil-gas separation device, such as an oil-gas separation device with the patent number 95218800.7, which sets a spiral separation tube in a sealed housing. The mixed gas discharged from the crankcase hits the separation tube, and the engine oil temporarily adheres to the separation tube and flows out along the separation tube. Although the invention has a simple structure, it can only separate large-droplet engine oil and has a poor separation effect on mist-like engine oil. Someone has also designed an oil-gas separation device for a diesel engine (patent number: 97202028.4), which has upper and lower boxes, a core shaft and filter plates. There are spacer sleeves between the filter plates and a filter mesh device is adopted. This utility model has made great improvements over the previous technology. It mainly separates oil and gas through the filtering action of the filter mesh. However, the filter plates or filter meshes are also prone to blockage. Under the continuous negative pressure of the internal combustion engine, the pressure of the crankcase cannot be adjusted and balanced. The adsorption force of the mist-like engine oil on the filter plates or filter meshes is not large, so the mist-like engine oil cannot be separated better. Others have also designed other oil-gas separation devices such as mazes and negative-pressure control, but they all have technical problems such as inability to adjust and balance the crankcase pressure and inability to efficiently separate mist-like engine oil, and are very prone to block the filter mesh, with a short service life, and cannot meet the technical requirements of the internal combustion engine in different periods and working conditions. When the oil-gas separation device completely fails due to the blockage of the filter mesh, the user cannot discover it in time and carry out cleaning and maintenance, which is very likely to cause damage to the internal combustion engine and cause significant losses to the user. Summary of the Invention

[0003] The present invention mainly aims at the technical problems existing in the prior art, such as high crankcase pressure, kinetic energy consumption (fuel consumption), too low oil-gas separation efficiency, too high engine oil consumption, potential safety hazards, short service life, and inability to meet the development needs of emission regulations. It provides a "negative-pressure oil-gas separation device" that can not only effectively reduce the crankcase pressure (fuel saving), improve the oil-gas separation efficiency, but also greatly reduce the engine oil consumption and carbon deposit deposition. At the same time, without moving parts, aging parts, and fatigue parts, it has a "self-cleaning" function, is safe and reliable in use, and has a long service life, so as to meet the needs of national VI and above emission regulations and respond to the country's energy conservation and emission reduction strategy.

[0004] The technical solution adopted by the present invention to solve its technical problems is as follows: A negative pressure type oil-gas separation device includes a housing, an air outlet pipe, a cover plate, a partition plate, a filter screen and an oil collector. An air inlet is provided on the upper side wall of the housing, and an oil return port is provided at the lower end of the housing. The interior of the housing is divided into a pre-filter cavity and a post-filter cavity by the filter screen. An oil collector is arranged at the lower part of the housing. An air compensation inlet is provided on the cover plate. The upper surface of the partition plate bulges upward to form a retaining ring. The cavity between the partition plate and the cover plate is divided into an outer cavity and an inner cavity by the retaining ring. The outer cavity is provided with a downward-introduced filter screen air compensation hole corresponding to the position of the filter screen, and the inner cavity is provided with a downward-introduced pressure difference compensation hole. The upper surface of the filter screen abuts against the lower surface of the partition plate, and the lower surface of the filter screen abuts against the upper surface of the oil collector. The air outlet pipe extends into the inner side of the filter screen. An oil collection chamber is provided inside the oil collector. The oil collector is provided with an oil collection hole corresponding to the lower surface of the filter screen, and the oil collection hole is communicated with the oil collection chamber. In the present invention, the overall negative pressure separation method is adopted to fully separate the crankcase mixed oil and gas. In the present invention, after the oil and gas enter from the air inlet, they first pass through a labyrinth for preliminary centrifugal separation, and then enter the filter screen, and the filter screen performs adhesion separation; the compensation air enters the filter screen and the post-filter cavity through the air compensation hole on the partition plate, forming the intersection and cooling of two gas streams, improving the separation effect of the filter screen. When the compensation air enters the filter screen under the action of negative pressure, since the flow direction of the air is the same as the gravity direction of the engine oil, it can accelerate the downward flow rate of the engine oil, prevent the filter screen from being saturated with engine oil, and improve the passing performance of the crankcase mixed gas on the filter screen; on the other hand, the combination of the air intersection technology and the filter screen technology can intercept smaller-sized engine oil particles, and under the condition of the same density filter screen, it can greatly improve the separation efficiency of the oil and gas. The retaining ring provided on the partition plate can prevent the engine oil from being sucked back from above the partition plate, and the flow-limiting compensation hole provided on the retaining ring plays a role in compensating the air in the inner cavity. After the air is introduced, under the action of the negative pressure at the bottom end of the air outlet pipe, the air moves downward from the pressure difference compensation hole to form a wind wall effect, increasing the pressure difference between the pre-filter cavity and the post-filter cavity, and at the same time blocking the movement of the liquid engine oil towards the air outlet pipe; the setting of the oil collector plays a role in collecting and returning the engine oil on the filter screen. During operation, the oil collector introduces negative pressure from the negative pressure through hole, so that a negative pressure is formed inside the oil collection chamber. Under the action of the negative pressure, the engine oil moves downward to enter the oil collection hole and into the oil collection chamber. The setting of the oil return passage balance hole makes the negative pressure values of the oil return passage, the pre-filter cavity and the oil collection chamber remain relatively balanced. In this way, it is beneficial for the liquid engine oil collected in the oil collection chamber to pass through the oil hole and then naturally flow back through the oil return port. On the other hand, the air entering from the air compensation hole and the pressure difference compensation hole converges with the filtered crankcase mixed gas, and under the action of the negative pressure at the bottom of the air outlet pipe, it then flows upward along the air outlet pipe until it is sucked out of the air outlet.The present invention realizes the functions of compensating gas cooling and separating oil and gas by changing the flow direction of the gas and using the principle of negative pressure separation. The separation effect is excellent. At the same time, the oil collector is used to forcibly absorb the liquid oil adhered to the bottom of the filter screen, preventing the liquid oil from being sucked out from the air outlet pipe, greatly improving the separation efficiency and service life of the filter screen, and achieving the effect of lifelong use.

[0005] Preferably, an oil collector support seat is arranged upward on the inner wall of the lower part of the shell, and the oil collector is mounted on the oil collector support seat.

[0006] Preferably, the oil collector includes an integrally formed filter screen support seat, an oil collector conical part and a U-shaped ring. The oil collector conical part is located below the middle of the filter screen support seat. The interior of the filter screen support seat and the oil collector conical part forms an oil collecting chamber. A circle of oil collecting holes are opened at the position of the filter screen support seat corresponding to the filter screen. One end of the oil collecting hole communicates with the filter screen, and the other end of the oil collecting hole communicates with the oil collecting chamber. A number of oil collecting holes abut against the bottom of the filter screen, and the liquid oil adhered to the filter screen is sucked through the action of negative pressure, so that the liquid oil quickly enters the oil collector through the oil collecting holes.

[0007] Preferably, in the U-shaped ring, an oil collector negative pressure through hole is opened at the inner bottom, and a convex platform for blocking the reverse suction of liquid oil is formed by the downward protrusion of the hole wall of the oil collector negative pressure through hole. In this way, the negative pressure of the air outlet pipe and the filtered cavity is introduced into the oil collecting chamber through the negative pressure through hole, so that the oil collecting chamber forms a negative pressure, and then the liquid oil adhered to the bottom of the filter screen is collected through the oil collecting holes.

[0008] Preferably, an oil return channel is arranged in the oil collecting chamber. The oil return channel is composed of two longitudinally parallel fixed wall plates and a right-angled insertion plate. The fixed wall plates are connected to the conical inner wall of the oil collector conical part. One end of the right-angled insertion plate is vertically inserted into the groove provided by the two fixed wall plates, and an oil passing hole is left at the bottom. The other end of the right-angled insertion plate is embedded in the upper plane of the fixed wall plate. A number of balance holes are opened in the upper partition of the channel. Balance holes and oil return holes are opened on the conical surface of the oil collector conical part. The balance holes are in the upper part of the oil return channel, the oil return holes are in the middle of the oil return channel, and the oil passing holes are at the bottom of the oil collecting chamber. The balance holes and the oil return holes are both arranged in the oil return channel, and the oil passing holes communicate the oil collecting chamber and the oil return channel.

[0009] Preferably, the partition plate includes a circular plate body, a circular labyrinth ring and a retaining ring. The outer edge of the plate body abuts against the inner side wall of the upper part of the housing. The upper surface of the plate body bulges upward to form a retaining ring, and the top end of the retaining ring abuts against the lower surface of the cover plate. The lower surface of the plate body bulges downward to form a circular labyrinth ring. The cavity between the lower part of the housing and the partition plate is divided to form a circular labyrinth. An air outlet is provided at the center of the cover plate, and a corresponding through hole is also provided at the center of the partition plate. The air outlet pipe penetrates through the cover plate and the partition plate and extends into the U-shaped ring of the oil collector inside the filter screen. The extended part of the air outlet pipe and the U-shaped ring are in clearance non-contact fit. The labyrinth ring and the tangential air intake play a role in centrifugally separating liquid oil.

[0010] Preferably, the partition plate is turned up with a hem at the position where the air outlet pipe is attached. The top end of the hem fits against the lower surface of the cover plate. A number of flow-limiting compensation holes are provided at the top of the retaining ring and fit against the lower plane of the cover plate. The flow-limiting compensation holes communicate the inner cavity and the outer cavity. The upper end of the pressure difference compensation hole communicates with the inner cavity, and the lower end communicates with the filtered cavity. The function of the pressure difference compensation hole is to increase the pressure difference between the pre-filter cavity and the filtered cavity, improve the performance of the filter screen in adhering to the misty engine oil, and block the liquid oil from entering the filtered cavity.

[0011] Preferably, the pressure difference compensation holes provided on the plate body are arranged at intervals in a circular shape with the center of the partition plate as the center of the circle. The filter screen air compensation holes provided on the plate body are also arranged at intervals in a circular shape with the center of the partition plate as the center of the circle. The pressure difference compensation holes are all located inside the retaining ring, and the filter screen air compensation holes are all located outside the retaining ring. With such a setting in the present invention, the balanced and reasonable configuration of the compensation air is ensured.

[0012] Preferably, a closed outer circulation chamber is provided on the side wall of the upper part of the housing. A safety valve and a safety through hole are provided on the side wall of the upper part of the housing corresponding to the outer circulation chamber. A circulation through hole is provided above the safety valve. The outer circulation chamber communicates with the outer cavity through the circulation through hole. The pre-filter cavity communicates with the outer circulation chamber through the safety through hole and the safety valve. The safety valve is a balanced safety component for the pressure of the housing. Although the present invention generally does not need to be equipped with a safety valve, in the event of excessive pressure in the pre-filter cavity under extreme or special conditions, the safety valve opens, and the safety operation of the present invention can still be maintained through the outer circulation chamber. At the same time, after the outer circulation, the air is returned to the housing, and the efficiency of the internal oil-gas separation will not be reduced.

[0013] Preferably, an auxiliary filter screen is provided on the upper surface of the partition plate. Adding an auxiliary filter screen in the present invention can further improve the separation efficiency.

[0014] The substantial effects of the present invention are as follows: In the present invention, an overall negative pressure separation method is adopted to efficiently separate oil and gas. In the present invention, after the oil and gas enter from the cross-section of the housing air inlet, they first pass through a labyrinth for preliminary centrifugal separation, and then enter a filter screen for efficient separation; the compensation air enters the upper end of the filter screen and the post-filter cavity through the compensation holes on the partition plate. When the compensation air enters the filter screen under the action of negative pressure, since the flow direction of the air is consistent with the gravity direction of the oil, it can accelerate the downward flow rate of the oil, prevent the filter screen from being saturated with oil, and improve the gas permeability of the filter screen; on the other hand, the combination of the air cross technology and the filter screen technology can intercept smaller particle-size oil particles, and under the condition of the same density filter screen, it can greatly improve the separation efficiency of oil and gas. The retaining ring provided on the partition plate can prevent the oil from being sucked back from above the partition plate, and the flow-limiting compensation holes opened on the retaining ring play a role in compensating the air in the inner cavity. After the air is introduced, under the action of the negative pressure at the bottom end of the air outlet pipe, the compensation air moves downward to form a wind wall effect, blocking the movement of the oil towards the air outlet pipe. The setting of the oil collector serves to collect the oil on the filter screen. During operation, the negative pressure through holes of the oil collector introduce negative pressure, and a negative pressure is formed inside the oil collection chamber. Under the action of the negative pressure, the oil moves downward to enter the oil collection hole and into the oil collection chamber. The setting of the balance holes in the oil return passage enables the pressure in the oil return passage to be balanced with the pressures in the oil collection chamber and the pre-filter cavity, facilitating the natural outflow of the liquid oil in the oil collection chamber from the oil return hole. Finally, the filtered gas after multi-stage separation of the crankcase mixture and the compensation air converge and flow upward along the air outlet pipe from the bottom of the air outlet pipe until they are sucked out of the air outlet. By changing the flow direction of the gas and utilizing the principle of negative pressure separation, the present invention realizes the functions of cross, cooling, and combined fiber adhesion separation of the compensation gas and the oil and gas mixture, with excellent separation effects. At the same time, by enhancing the reflux of the liquid oil through the oil collector, the situation of the liquid oil being sucked out from the air outlet pipe is eliminated, forming a "self-cleaning" effect of the filter screen. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic structural diagram of the present invention;

[0016] Figure 2 is a schematic structural diagram of the partition plate in the present invention;

[0017] Figure 3 is a schematic side view structural diagram of the oil collector in the present invention;

[0018] Figure 4 is a schematic side view internal structure diagram of the oil collector in the present invention;

[0019] Figure 5 is a schematic front view structural diagram of the oil collector in the present invention.

[0020] In the figure: 1. Housing, 11. Air inlet, 12. Oil return port, 13. Oil collector support seat, 14. Air compensation inlet, 2. Exhaust pipe, 3. Cover plate, 4. Partition plate, 41. Filter screen air compensation hole, 42. Differential pressure compensation hole, 43. Flow limiting compensation hole, 44. Circular labyrinth, 5. Filter screen, 6. Oil collector, 61. Filter screen support seat, 62. Oil collector conical part, 63. Oil collecting chamber, 64. Right-angled plug board, 65. Oil collecting hole, 66. Balance hole, 67. Oil collector negative pressure through hole, 68. Oil return hole, 69. Oil passing hole, 60. U-ring, 7. Safety valve, 71. Safety through hole, 72. Circulation through hole. Detailed implementation manners

[0021] The technical solution of the present invention will be further specifically described below through specific embodiments in combination with the accompanying drawings.

[0022] Embodiment:

[0023] A negative pressure type oil-gas separation device (see attached Figure 1 , attached Figure 2 , attached Figure 3 , attached Figure 4 and attached Figure 5),including a housing 1, an air outlet pipe 2, a cover plate 3, a partition plate 4, a filter screen 5 and an oil collector 6. An air inlet 11 is provided on the upper side wall of the housing, and an oil return port 12 is provided at the lower end of the housing. The interior of the housing is divided into a pre-filter cavity and a post-filter cavity by the filter screen. An oil collector is arranged at the lower part of the housing. An air compensation inlet 14 is provided on the cover plate. The upper surface of the partition plate bulges upward to form a retaining ring. The cavity between the partition plate and the cover plate is divided into an outer cavity and an inner cavity by the retaining ring. The outer cavity is provided with a downward-introducing filter screen air compensation hole 41 corresponding to the position of the filter screen, and the inner cavity is provided with a downward-introducing pressure difference compensation hole 42. The upper surface of the filter screen abuts against the lower surface of the partition plate, and the lower surface of the filter screen abuts against the upper surface of the oil collector. The air outlet pipe extends into the inner side of the filter screen and faces the oil collector. An oil collecting chamber 63 is provided inside the oil collector. The oil collector is provided with an oil collecting hole 65 corresponding to the lower surface of the filter screen, and the oil collecting hole communicates with the oil collecting chamber. An oil collector support seat 13 is provided on the inner side wall of the lower part of the housing, and the oil collector is mounted on the oil collector support seat. The oil collector includes an integrally formed filter screen support seat 61, an oil collector conical part 62 and a U-shaped ring 60. The oil collector conical part is located below the filter screen support seat. The interior of the filter screen support seat and the oil collector conical part is the oil collecting chamber. The filter screen support seat is provided with a circle of oil collecting holes corresponding to the position of the filter screen. One end of the oil collecting hole communicates with the filter screen, and the other end communicates with the oil collecting chamber. The inner side bottom of the U-shaped ring is provided with an oil collector negative pressure through hole 67, and the hole wall of the oil collector negative pressure through hole bulges downward to form a convex platform for blocking the back suction of liquid oil. An oil return channel is provided in the oil collecting chamber. The oil return channel is composed of two longitudinally parallel fixed wall plates and a right-angled inserting plate 64. The fixed wall plates are connected to the conical inner wall of the oil collector conical part. One end of the right-angled inserting plate is vertically inserted into the groove provided by the two fixed wall plates, and an oil passing hole 69 is left at the bottom. The other end of the right-angled inserting plate is embedded in the upper plane of the fixed wall plate. A plurality of balance holes 66 are provided in the upper partition plate of the channel. Balance holes and an oil return hole 68 are provided on the conical surface of the oil collector conical part. The balance holes are above the oil return channel, the oil return hole is in the middle of the oil return channel, and the oil passing hole is at the bottom of the oil collecting chamber. The balance holes and the oil return hole are both provided in the oil return channel, and the oil passing hole communicates the oil collecting chamber and the oil return channel. The partition plate includes a circular plate body, a circular labyrinth ring and a retaining ring. The outer edge of the plate body abuts against the inner side wall of the upper part of the housing. The upper surface of the plate body bulges upward to form a retaining ring. The top of the retaining ring abuts against the lower surface of the cover plate. The lower surface of the plate body bulges downward to form a circular labyrinth ring. The cavity between the lower part of the housing and the partition plate is divided to form a circular labyrinth 44. An air outlet is provided in the center of the cover plate, and a corresponding through hole is also provided in the center of the partition plate. The air outlet pipe penetrates through the cover plate and the partition plate and extends into the inner side of the filter screen and into the U-shaped ring.The partition is turned up with a hem at the position where it fits the air outlet pipe. The top end of the hem fits the lower surface of the cover plate. A number of flow-limiting compensation holes 43 are opened at the top of the retaining ring and fit the lower plane of the cover plate. The flow-limiting compensation holes communicate the inner cavity and the outer cavity. The upper end of the pressure difference compensation hole communicates with the inner cavity, and the lower end communicates with the filtered cavity. An auxiliary filter screen is arranged on the upper surface of the partition. A closed outer circulation chamber is opened on the side wall of the upper part of the housing. A safety valve 7 is opened on the side wall of the upper part of the housing corresponding to the outer circulation chamber. A circulation through hole 72 is opened above the safety valve. The outer circulation chamber communicates with the outer cavity through the circulation through hole. The pre-filter cavity communicates with the outer circulation chamber through the safety through hole 71 and the safety valve. The pressure difference compensation holes opened on the plate body are arranged at intervals in a circular shape with the center of the partition as the center. The filter screen air compensation holes opened on the plate body are also arranged at intervals in a circular shape with the center of the partition as the center. The pressure difference compensation holes are all located inside the retaining ring, and the filter screen air compensation holes are all located outside the retaining ring.

[0024] In this embodiment, the overall negative pressure separation method is adopted to separate the oil and gas. In this embodiment, after the oil and gas enter from the air inlet, they first pass through the maze for preliminary centrifugal separation, and then enter the filter screen. The filter screen performs efficient separation. The compensation air enters the filter screen and the filtered cavity through the compensation holes on the partition. When the compensation air enters the filter screen under the action of negative pressure, since the flow direction of the air is consistent with the gravity direction of the oil, it can accelerate the downward flow speed of the oil, prevent the filter screen from being saturated with oil, and improve the air permeability of the filter screen. On the other hand, the combination of the air cross technology and the filter screen technology can intercept smaller particle size oil particles. Under the condition of the same density filter screen, it can greatly improve the separation efficiency of the oil and gas. The retaining ring arranged on the partition can prevent the oil from being sucked back from above the partition. The flow-limiting compensation holes opened on the retaining ring play the role of compensating the air in the inner cavity. After the air is introduced, under the action of the negative pressure at the bottom end of the air outlet pipe, the compensation air moves downward to form a wind wall effect, blocking the movement of the oil towards the air outlet pipe. The setting of the oil collector plays the role of collecting the oil on the filter screen. During operation, the negative pressure through hole of the oil collector introduces negative pressure, and a negative pressure is formed inside the oil collecting chamber. Under the action of the negative pressure, the oil moves downward to enter the oil collecting hole and enter the oil collecting chamber. The setting of the balance hole of the oil return passage makes the pressure of the oil return passage balance with the pressures of the oil collecting chamber and the pre-filter cavity, which is beneficial for the liquid oil in the oil collecting chamber to naturally flow out from the oil return hole. Finally, the filtered gas after multi-stage separation of the crankcase mixture and the compensation air converge and flow upward along the air outlet pipe from the bottom of the air outlet pipe until it is sucked out of the air outlet. This embodiment changes the flow direction of the gas and uses the principle of negative pressure separation to realize the functions of cross, cooling and fiber adhesion separation of the compensation gas and the oil and gas mixture, and the separation effect is excellent. At the same time, the oil collector enhances the return of the liquid oil, preventing the liquid oil from being sucked out of the air outlet pipe, and forming a "self-cleaning" effect of the filter screen.

[0025] The above-described embodiments are only a preferred solution of the present invention and do not impose any formal restrictions on the present invention. There are other variations and modifications without exceeding the technical solutions recorded in the claims.

Claims

1. A negative pressure type oil-gas separation device, comprising a housing, an air outlet pipe, a cover plate, a partition plate, a filter screen and an oil collector. An air inlet is provided on the upper side wall of the housing, and an oil return port is provided at the lower end of the housing. The interior of the housing is divided into a pre-filter cavity and a post-filter cavity by the filter screen, and it is characterized in that: An oil collector is provided at the lower part of the housing. An air compensation inlet is provided on the cover plate. The upper surface of the partition plate bulges upward to form a retaining ring. The cavity between the partition plate and the cover plate is divided into an outer cavity and an inner cavity by the retaining ring. The outer cavity is provided with a downward-introducing filter screen air compensation hole corresponding to the position of the filter screen, and the inner cavity is provided with a downward-introducing differential pressure compensation hole. The upper surface of the filter screen abuts against the lower surface of the partition plate, and the lower surface of the filter screen abuts against the upper surface of the oil collector. The air outlet pipe extends into the inner side of the filter screen and faces the oil collector. An oil collection chamber is provided inside the oil collector. The oil collector is provided with an oil collection hole corresponding to the lower surface of the filter screen, and the oil collection hole communicates with the oil collection chamber. An oil collector support seat is provided upward on the inner wall of the lower part of the housing. The oil collector includes an integrally formed filter screen support seat, an oil collector conical part, and a U-shaped ring.

2. The negative pressure type oil-gas separation device according to claim 1, wherein: The oil collector is mounted on the oil collector support seat.

3. The negative pressure type oil-gas separation device according to claim 1, wherein: The oil collector conical part is located below the filter screen support seat. The interior of the filter screen support seat and the oil collector conical part is the oil collection chamber. The filter screen support seat is provided with a circle of oil collection holes corresponding to the position of the filter screen. One end of the oil collection hole communicates with the filter screen, and the other end of the oil collection hole communicates with the oil collection chamber.

4. The negative pressure type oil-gas separation device according to claim 1, wherein: For the U-shaped ring, an oil collector negative pressure through hole is provided at the inner bottom thereof, and a convex platform for blocking the reverse suction of liquid oil is formed by the downward bulge of the hole wall of the oil collector negative pressure through hole.

5. The negative pressure type oil-gas separation device according to claim 1, wherein: An oil return channel is provided in the oil collection chamber. The oil return channel is composed of two longitudinally parallel fixed wall plates and a right-angled insertion plate. The fixed wall plates are connected to the conical inner wall of the oil collector conical part. One end of the right-angled insertion plate is vertically inserted into the groove provided by the two fixed wall plates, and an oil passing hole is left at the bottom. The other end of the right-angled insertion plate is inserted into the upper plane of the fixed wall plate. A plurality of balance holes are provided on the upper partition plate of the channel. Balance holes and oil return holes are provided on the conical surface of the oil collector conical part. The balance holes are at the upper part of the oil return channel, the oil return holes are at the middle part of the oil return channel, the oil passing hole is at the bottom of the oil collection chamber. The balance holes and the oil return holes are both provided in the oil return channel. The oil passing hole communicates the oil collection chamber and the oil return channel.

6. The negative pressure type oil-gas separation device according to claim 1, characterized in that: The partition plate includes a circular plate body, a circular labyrinth ring, and a retaining ring. The outer edge of the plate body abuts against the inner side wall of the upper part of the housing. The upper surface of the plate body bulges upward to form a retaining ring. The top of the retaining ring abuts against the lower surface of the cover plate. The lower surface of the plate body bulges downward to form a circular labyrinth ring. The cavity between the lower part of the housing and the partition plate is divided to form a circular labyrinth. An air outlet is provided at the center of the cover plate, and a corresponding through hole is also provided at the center of the partition plate. The air outlet pipe passes through the cover plate and the partition plate and extends into the inner side of the filter screen and into the U-shaped ring.

7. The negative pressure type oil-gas separation device according to claim 1, characterized in that: A folded edge is turned up upward at the position where the partition plate fits the air outlet pipe. The top of the folded edge fits the lower surface of the cover plate. A plurality of flow-limiting compensation holes are provided at the top of the retaining ring and fit the lower plane of the cover plate. The flow-limiting compensation holes communicate the inner cavity and the outer cavity. The upper end of the differential pressure compensation hole communicates with the inner cavity, and the lower end communicates with the filtered cavity.

8. The negative pressure type oil-gas separation device according to claim 6, characterized in that: The differential pressure compensation holes formed on the plate body are arranged at intervals in a circular shape with the center of the partition plate as the center of the circle. The filter screen air compensation holes formed on the plate body are also arranged at intervals in a circular shape with the center of the partition plate as the center of the circle. The differential pressure compensation holes are all located inside the retaining ring, and the filter screen air compensation holes are all located outside the retaining ring.

9. The negative pressure type oil-gas separation device according to claim 1, wherein: A closed outer circulation chamber is formed on the side wall of the upper part of the housing. A safety valve and a safety through hole are formed on the side wall of the upper part of the housing corresponding to the outer circulation chamber. A circulation through hole is formed above the safety valve. The outer circulation chamber is communicated with the outer cavity through the circulation through hole. The pre-filter cavity is communicated with the outer circulation chamber through the safety through hole and the safety valve.

10. The negative pressure type oil-gas separation device according to claim 1, wherein: An auxiliary filter screen is arranged on the upper surface of the partition plate.

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