Roots pump capable of reducing pressure difference

Abstract

The utility model relates to the technical field of roots pumps, and discloses a roots pump capable of reducing pressure difference, which is characterized by comprising a front gear box and a pump shell, a front partition plate is hermetically connected between the front gear box and the pump shell, a front oil cavity is formed in the front gear box, a vacuum cavity is formed in the pump shell and comprises an air outlet, and the air outlet is communicated with the front oil cavity. In the operation process of the front-stage pump, the pressure in the vacuum cavity is quickly reduced, and the pressure in the front oil cavity is also reduced under the communication action of the first through hole and the second through hole, so that the pressure difference between the vacuum cavity and the front oil cavity is reduced, the situation that gas in the front cavity leaks towards the vacuum cavity is prevented, and the limit pressure of the vacuum cavity is prevented from being influenced; a first pressure difference one-way valve is arranged in the second through hole, when the vacuum degree in the front oil cavity reaches a certain value, a gas path between the first through hole and the second through hole can be cut off through the first pressure difference one-way valve, and oil gas in the front oil cavity is prevented from entering one side of the gas outlet.

Description

Technical Field

[0001] The utility model relates to the technical field of Roots pumps, and more particularly to a Roots pump capable of reducing pressure difference. Background Art

[0002] Roots pumps have the characteristics of fast start-up, low power consumption, low operation and maintenance costs, high pumping speed and high efficiency. They are insensitive to small amounts of water vapor and dust contained in the pumped gas. They have a large pumping rate within the pressure range of 100 to 1 Pa and can quickly remove suddenly released gases. Therefore, they are widely used in smelting, degassing, rolling in vacuum metallurgy, and vacuum distillation in the chemical, food, and pharmaceutical industries.

[0003] The Roots pump consists of a gear box and a pump casing. There is an oil seal between the gear box and the pump casing. When the current pump is working, the pressure in the vacuum chamber in the pump casing will drop rapidly, but the pressure in the gear box drops slowly due to the action of the oil seal, resulting in a large difference between the pressure in the gear box and the pressure in the vacuum pump. This will cause the gas in the gear box to leak into the vacuum chamber, affecting the ultimate pressure of the vacuum chamber. Utility Model Content

[0004] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a Roots pump with a reduced pressure difference, which is used to reduce the pressure difference between the gear box and the vacuum chamber.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a Roots pump for reducing pressure difference, comprising a front gear box and a pump casing, a front baffle being sealed between the front gear box and the pump casing, a front oil chamber being formed in the front gear box, a vacuum chamber being formed in the pump casing, the vacuum chamber including an air outlet, a first through hole being provided in the pump casing, the first through hole being connected to the air outlet, a second through hole being provided in the front baffle, one end of the second through hole being connected to the front oil chamber, the other end of the second through hole being connected to the first through hole, and a first pressure differential one-way valve being provided in the second through hole.

[0006] As a further improvement of the present invention, a first annular groove is provided on a side of the front partition facing the pump housing. The first annular groove is located at the connection between the first through hole and the second through hole. A first sealing ring is embedded in the first annular groove.

[0007] As a further improvement of the present invention, a first groove is provided on a side of the front partition plate facing the front oil chamber, the first groove is communicated with the second through hole, and a first filter element is fixedly connected in the first groove.

[0008] As a further improvement of the present invention, it further comprises a rear gear box, wherein a rear partition is sealedly connected between the rear gear box and the pump housing, and a rear oil chamber is formed in the rear gear box.

[0009] As a further improvement of the present invention, the rear oil chamber is communicated with the second through hole.

[0010] As a further improvement of the present invention, a third through hole is provided in the pump casing, the third through hole is connected to the air outlet, a fourth through hole is provided in the rear partition, the fourth through hole is connected to the third through hole, and a second pressure differential one-way valve is provided in the fourth through hole.

[0011] As a further improvement of the present invention, a second annular groove is provided on the side of the rear partition facing the pump housing. The second annular groove is located at the connection between the third through hole and the fourth through hole. A second sealing ring is embedded in the second annular groove.

[0012] As a further improvement of the present invention, a second groove is provided on a side of the rear partition plate facing the rear oil chamber, the second groove is communicated with the fourth through hole, and a second filter element is fixedly connected in the second groove.

[0013] The beneficial effects of the present invention are as follows: the air outlet is connected with the front oil chamber in the present invention. When the front-stage pump is in operation, the pressure in the vacuum chamber drops rapidly. The connection between the first through hole and the second through hole reduces the pressure in the front oil chamber, thereby reducing the pressure difference between the vacuum chamber and the front oil chamber, to prevent the gas in the front chamber from leaking toward the vacuum chamber, and to prevent the ultimate pressure of the vacuum chamber from being affected. A first pressure differential one-way valve is provided in the second through hole. When the vacuum degree in the front oil chamber reaches a certain value, the first pressure differential one-way valve can cut off the air path between the first through hole and the second through hole, thereby preventing the oil and gas in the front oil chamber from entering the air outlet side. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic cross-sectional structural diagram of the present utility model;

[0015] Figure 2 This utility model Figure 1 Schematic diagram of the enlarged structure at A in the middle;

[0016] Figure 3 This utility model Figure 1 Schematic diagram of the enlarged structure at B in the middle;

[0017] Figure 4 This utility model Figure 1 Schematic diagram of the enlarged structure at point C in the middle.

[0018] Figure markings: 1. Front gearbox; 11. Front oil chamber; 2. Pump housing; 21. Vacuum chamber; 22. Air outlet; 23. First through hole; 24. Third through hole; 3. Front partition; 31. Second through hole; 32. First sealing ring; 33. First groove; 34. First filter element; 4. First pressure differential one-way valve; 5. Rear gearbox; 51. Rear oil chamber; 6. Rear partition; 61. Fourth through hole; 62. Second sealing ring; 63. Second groove; 64. Second filter element; 7. Second pressure differential one-way valve. DETAILED DESCRIPTION

[0019] The present invention will be further described below in conjunction with the accompanying drawings and embodiments. Identical components are denoted by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "upper," and "lower" used in the following description refer to directions in the accompanying drawings, and the terms "bottom," "top," "inner," and "outer" refer to directions toward or away from the geometric center of a particular component, respectively.

[0020] Reference Figures 1 to 3 As shown, a Roots pump for reducing pressure difference in this embodiment includes a front gear box 1 and a pump housing 2. A front baffle 3 is sealed between the front gear box 1 and the pump housing 2. A front oil chamber 11 is formed in the front gear box 1, and a vacuum chamber 21 is formed in the pump housing 2. The vacuum chamber 21 includes an air outlet 22. The vacuum chamber 21 also includes an air inlet, and the air inlet is connected to the air outlet 22 through the vacuum chamber 21.

[0021] A first through hole 23 is provided in the pump housing 2, and the first through hole 23 is communicated with the air outlet 22. A second through hole 31 is provided in the front partition plate 3, and one end of the second through hole 31 is communicated with the front oil chamber 11, and the other end of the second through hole 31 is communicated with the first through hole 23, so that the air outlet 22 is communicated with the front oil chamber 11. When the current-stage pump is running, the pressure in the vacuum chamber 21 drops rapidly. Due to the communication between the first through hole 23 and the second through hole 31, the pressure in the front oil chamber 11 is also reduced, thereby reducing the pressure difference between the vacuum chamber 21 and the front oil chamber 11, thereby preventing the gas in the front chamber from leaking toward the vacuum chamber 21 and preventing the ultimate pressure of the vacuum chamber 21 from being affected.

[0022] Reference Figure 2 As shown, the first pressure differential check valve 4 is provided in the second through hole 31, wherein the second through hole 31 passes through the bottom of the front partition 3, and the first pressure differential check valve 4 is installed from the through hole, which facilitates the installation of the first pressure differential check valve 4;

[0023] When the vacuum degree in the front oil chamber 11 reaches a certain value, the first differential pressure one-way valve 4 can cut off the air path between the first through hole 23 and the second through hole 31 to prevent the oil and gas in the front oil chamber 11 from entering the side of the air outlet 22.

[0024] A first annular groove is formed on the side of the front partition plate 3 facing the pump housing 2. The first annular groove is located at the connection between the first through hole 23 and the second through hole 31. A first sealing ring 32 is embedded in the first annular groove. The provision of the first sealing ring 32 improves the sealing performance of the connection between the first through hole 23 and the second through hole 31, thereby preventing air leakage at the connection between the first through hole 23 and the second through hole 31.

[0025] The first annular groove may also be provided on the side of the pump housing 2 facing the front partition 3;

[0026] The inner diameter of the first sealing ring 32 is larger than the inner diameter of the first through hole 23 , and the inner diameters of the first through hole 23 and the second through hole 31 are the same.

[0027] A first groove 33 is provided on the side of the front partition 3 facing the front oil chamber 11. The first groove 33 is connected to the second through hole 31. A first filter element 34 is fixedly connected in the first groove 33. The first filter element 34 is used to filter oil and gas, which can prevent the oil and gas in the front oil chamber 11 from entering the side of the air outlet 22.

[0028] Reference Figure 1 As shown, the pump housing 2 further includes a rear gear box 5 , a rear partition plate 6 is sealed between the rear gear box 5 and the pump housing 2 , and a rear oil chamber 51 is formed in the rear gear box 5 .

[0029] In one embodiment, the rear oil chamber 51 is in communication with the second through hole 31 , wherein the rear oil chamber 51 is directly in communication with the second through hole 31 , that is, the rear oil chamber 51 is also in communication with the front oil chamber 11 ;

[0030] A communication hole is provided in the pump housing 2, one end of the communication hole is communicated with the second through hole 31, and the other end of the communication hole passes through the rear partition plate 6 and is communicated with the rear oil chamber 51;

[0031] A sealing ring may be installed at the connection between the communicating hole and the second through hole 31 to increase the sealing between the connecting hole and the second through hole 31 and prevent air leakage;

[0032] Of course, a sealing ring may also be installed at the connection between the communicating hole and the rear partition 6 to increase the sealing performance of the connection between the communicating hole and the rear partition 6 .

[0033] Reference Figure 4 As shown, in the second embodiment, a second differential pressure check valve 7 is separately provided between the rear partition plate 6 and the rear oil chamber 51, and the rear oil chamber 51 and the front oil chamber 11 are controlled separately;

[0034] A third through hole 24 is defined in the pump housing 2, the third through hole 24 being in communication with the air outlet 22, a fourth through hole 61 is defined in the rear partition plate 6, the fourth through hole 61 being in communication with the third through hole 24, a second differential pressure check valve 7 being disposed in the fourth through hole 61, wherein the fourth through hole 61 penetrates the rear partition plate 6, the second differential pressure check valve 7 being installed through the penetration, thereby facilitating the installation of the second differential pressure check valve 7;

[0035] When the vacuum degree of the rear oil chamber 51 reaches a certain value, the value can be consistent with the value at the front oil chamber 11; the second pressure differential one-way valve 7 cuts off the air path to prevent the oil and gas in the rear oil chamber 51 from entering the side of the air outlet 22.

[0036] A second annular groove is formed on the side of the rear partition plate 6 facing the pump housing 2. The second annular groove may also be formed on the side of the pump housing 2 facing the rear partition plate 6. The second annular groove is located at the junction of the third through hole 24 and the fourth through hole 61. A second sealing ring 62 is embedded in the second annular groove. The inner diameter of the second sealing ring 62 is larger than the inner diameters of the third through hole 24 and the fourth through hole 61. The inner diameter of the third through hole 24 is consistent with the inner diameter of the fourth through hole 61.

[0037] The second sealing ring 62 is provided to increase the sealing performance of the connection between the third through hole 24 and the fourth through hole 61 , thereby preventing air leakage at the connection.

[0038] A second groove 63 is provided on the side of the rear partition 6 facing the rear oil chamber. The second groove 63 is connected to the fourth through hole 61. A second filter element 64 is fixedly connected in the second groove 63. The second filter element 64 is used to filter oil and gas to prevent the oil and gas in the rear oil chamber from entering the side of the air outlet 22.

[0039] The first filter element 34 and the second filter element 64 may both be oil and gas filter elements.

[0040] The above are only preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions based on the concept of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, certain improvements and modifications that do not depart from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A Roots pump for reducing pressure difference, characterized in that: The invention comprises a front gearbox (1) and a pump housing (2), wherein a front baffle (3) is sealed between the front gearbox (1) and the pump housing (2), a front oil chamber (11) is formed in the front gearbox (1), a vacuum chamber (21) is formed in the pump housing (2), and the vacuum chamber (21) includes an air outlet (22), a first through hole (23) is provided in the pump housing (2), and the first through hole (23) is communicated with the air outlet (22), a second through hole (31) is provided in the front baffle (3), one end of the second through hole (31) is communicated with the front oil chamber (11), and the other end of the second through hole (31) is communicated with the first through hole (23), and a first differential pressure check valve (4) is provided in the second through hole (31).

2. A Roots pump for reducing pressure difference according to claim 1, characterized in that: A first annular groove is provided on a side of the front partition plate (3) facing the pump housing (2). The first annular groove is located at the connection between the first through hole (23) and the second through hole (31). A first sealing ring (32) is embedded in the first annular groove.

3. The Roots pump for reducing pressure difference according to claim 1, characterized in that: A first groove (33) is provided on a side of the front partition plate (3) facing the front oil chamber (11). The first groove (33) is communicated with the second through hole (31). A first filter element (34) is fixedly connected in the first groove (33).

4. The Roots pump for reducing pressure difference according to claim 1, characterized in that: It also includes a rear gear box (5), a rear partition plate (6) is sealed between the rear gear box (5) and the pump housing (2), and a rear oil chamber (51) is formed in the rear gear box (5).

5. A Roots pump for reducing pressure difference according to claim 4, characterized in that: The rear oil chamber (51) is communicated with the second through hole (31).

6. The Roots pump for reducing pressure difference according to claim 4, characterized in that: A third through hole (24) is provided in the pump housing (2), the third through hole (24) being in communication with the air outlet (22); a fourth through hole (61) is provided in the rear partition (6), the fourth through hole (61) being in communication with the third through hole (24); and a second differential pressure one-way valve (7) is provided in the fourth through hole (61).

7. The Roots pump for reducing pressure difference according to claim 6, characterized in that: A second annular groove is provided on a side of the rear partition plate (6) facing the pump housing (2). The second annular groove is located at the connection between the third through hole (24) and the fourth through hole (61). A second sealing ring (62) is embedded in the second annular groove.

8. The Roots pump for reducing pressure difference according to claim 6, characterized in that: A second groove (63) is provided on one side of the rear partition plate (6) facing the rear oil chamber. The second groove (63) is communicated with the fourth through hole (61). A second filter element (64) is fixedly connected in the second groove (63).

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