Roots pump

Abstract

The utility model provides a lobe pump, relates to lobe pump technical field, including pump body and end cover, the end cover is provided at the both ends of pump body, the inside of pump body is provided with the shaft body, and the upper end of shaft body passes through the end cover, the outside of shaft body and end cover is provided with the end cover bushing, and the top of end cover bushing is provided with the oil flinger, and the oil flinger is provided with the oil flinger. The oil flinger surrounds the outer side of the shaft body; a groove is formed in the top of the end cover bushing, a first sealing ring is filled in the groove, and the oil flinger is pressed above the first sealing ring; the groove is additionally formed in the face, adjacent to the oil flinger, of the end cover lining, the first sealing ring is placed in the groove, the elastic O-shaped ring is placed below the first sealing ring, the oil flinger is used for limiting the first sealing ring in the groove, and under the condition that the first sealing ring is abraded, the first sealing ring is sealed by the elastic O-shaped ring through the elasticity enhancing property of the elastic O-shaped ring. The first sealing ring and the oil flinger are always kept sealed, and lubricating oil is prevented from entering the pump body.

Description

Technical Field

[0001] The utility model relates to the technical field of Roots pumps, in particular to a Roots pump. Background Art

[0002] Roots pump is a vacuum pump without internal compression, usually with a very low compression ratio. Therefore, high and medium vacuum pumps require a fore-stage pump. It relies on the pushing effect of a pair of blade-shaped rotors rotating synchronously and counter-rotating in the pump chamber to move the gas, thereby achieving the purpose of exhaust. In the structure of the Roots vacuum pump, there are small gaps between the rotors and between the rotor and the inner wall of the pump casing, so that they do not contact each other. The working principle of the Roots pump is similar to that of the Roots blower. When the rotor rotates continuously, the exhausted gas is sucked from the air inlet into the space between the rotor and the pump casing, and then discharged through the exhaust port. After the air is sucked in, the space is in a fully closed state, so the gas in the pump chamber There is no compression and expansion, but when the top of the rotor turns over the edge of the exhaust port, the space is connected to the exhaust side. Due to the high gas pressure on the exhaust side, part of the gas will rush back into the space, causing the gas pressure to suddenly increase. As the rotor continues to rotate, the gas is eventually discharged out of the pump. The structural composition of the Roots vacuum pump mainly depends on the arrangement of the two rotors in the pump body. Common structural arrangements include vertical and horizontal. In the vertical structure, the axes of the two rotors are installed horizontally, but the plane they form is perpendicular to the horizontal plane; in the horizontal structure, the axes of the two rotors are installed horizontally, and the plane they form is in the horizontal direction.

[0003] The existing Roots pump is sealed at the shaft body, and a dynamic seal is generated by the rotation of a sealing ring and a sealing ring bushing. The sealing ring adopts an open metal ring, which is easy to corrode and cannot maintain a sealing effect in a static state. There is a gap between the end cover bushing and the oil throwing plate. This gap will cause lubricating oil to enter the pump body when the front end oil seal fails, thereby reducing the sealing effect. Therefore, the utility model proposes a Roots pump to solve the problems existing in the prior art. Utility Model Content

[0004] In view of the above problems, the utility model proposes a Roots pump. When the first sealing ring of the Roots pump is worn, the elastic property of the elastic O-ring is used to keep the first sealing ring and the oil-slinging plate sealed at all times to prevent lubricating oil from entering the pump body.

[0005] To achieve the purpose of the utility model, the utility model is implemented by the following technical scheme: a Roots pump, comprising a pump body and end covers, the end covers are arranged at both ends of the pump body, a shaft body is arranged inside the pump body, and the upper end of the shaft body passes through the end covers, an end cover bushing is arranged between the outer side of the shaft body and the end cover, and an oil slinging plate is arranged above the end cover bushing, and the oil slinging plate surrounds the outer side of the shaft body;

[0006] The top of the end cover bushing is provided with a groove, and the interior of the groove is filled with a first sealing ring, the oil-slinging plate is pressed above the first sealing ring, and an elastic O-ring is provided between the bottom of the first sealing ring and the bottom of the groove.

[0007] A further improvement is that a sealing ring bushing is provided between the inner side of the end cover bushing and the shaft body, and the sealing ring bushing surrounds the outer side of the shaft body.

[0008] A further improvement is that an inner cavity is provided between the sealing ring bushing and the end cover bushing, and the interior of the inner cavity is filled with a second sealing ring.

[0009] A further improvement is that the first sealing ring and the second sealing ring are both made of composite self-lubricating material.

[0010] A further improvement is that a bearing seat is provided above the point where the shaft body and the end cover pass through, and the bearing seat surrounds the outside of the shaft body, and a positioning sleeve is provided below the inner side of the bearing seat and between the shaft body.

[0011] A further improvement is that the positioning bushing surrounds the outer side of the shaft body, an embedded groove is provided below the inner side of the bearing seat, and an oil seal is filled between the embedded groove and the positioning bushing.

[0012] The beneficial effects of the utility model are:

[0013] 1. The utility model adds a groove on the surface adjacent to the end cover bushing and the oil-slinging plate, a first sealing ring is placed in the groove, an elastic O-ring is placed below the first sealing ring, and the first sealing ring is limited in the groove by the oil-slinging plate. When the first sealing ring is worn, the elastic property of the elastic O-ring is utilized to keep the first sealing ring and the oil-slinging plate sealed at all times, thereby preventing lubricating oil from entering the pump body.

[0014] 2. In addition to the first sealing ring, the utility model provides a sealing ring bushing between the inner side of the end cover bushing and the shaft body, and fills a second sealing ring between the sealing ring bushing and the end cover bushing. The sealing ring design using an open metal ring is cancelled and replaced with a sealing ring body made of a graphite ring or a polytetrafluoroethylene ring or other composite self-lubricating material, which has corrosion resistance and self-lubricating properties, so that the sealing surface fits tightly, achieving a better sealing effect than an open metal ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the main body of the utility model;

[0016] Figure 2 For the utility model Figure 1 Schematic diagram of the structure at point A in the middle.

[0017] Among them: 1. Pump body; 2. End cover; 3. Shaft body; 4. End cover bushing; 5. Oil throwing pan; 6. Groove; 7. Elastic O-ring; 8. First sealing ring; 9. Sealing ring bushing; 10. Second sealing ring; 11. Bearing seat; 12. Positioning bushing; 13. Oil seal. DETAILED DESCRIPTION

[0018] In order to deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with an embodiment. The embodiment is only used to explain the present invention and does not constitute a limitation on the protection scope of the present invention.

[0019] Embodiment 1

[0020] according to Figure 1 , 2 As shown, this embodiment proposes a Roots pump, comprising a pump body 1 and an end cover 2, wherein the end cover 2 is arranged at both ends of the pump body 1, a shaft body 3 is arranged inside the pump body 1, and the upper end of the shaft body 3 passes through the end cover 2, an end cover bushing 4 is arranged between the outer side of the shaft body 3 and the end cover 2, and an oil slinger 5 is arranged above the end cover bushing 4, and the oil slinger 5 surrounds the outer side of the shaft body 3;

[0021] The top of the end cover bushing 4 is provided with a groove 6, and the inside of the groove 6 is filled with a first sealing ring 8, the oil-slinging plate 5 is pressed on the top of the first sealing ring 8, and an elastic O-ring 7 is provided between the bottom of the first sealing ring 8 and the bottom of the groove 6. When in use, a groove 6 is added to the surface of the end cover bushing 4 adjacent to the oil-slinging plate 5, the first sealing ring 8 is placed in the groove 6, and the elastic O-ring 7 is placed below the first sealing ring 8. The oil-slinging plate 5 is used to limit the first sealing ring 8 in the groove 6. In the event that the first sealing ring 8 is worn, the elastic property of the elastic O-ring 7 is used to keep the first sealing ring 8 and the oil-slinging plate 5 sealed at all times to prevent lubricating oil from entering the pump body.

[0022] A sealing ring bushing 9 is provided between the inner side of the end cover bushing 4 and the shaft body 3, and the sealing ring bushing 9 surrounds the outer side of the shaft body 3. An inner cavity is provided between the sealing ring bushing 9 and the end cover bushing 4, and the interior of the inner cavity is filled with a second sealing ring 10. The first sealing ring 8 and the second sealing ring 10 are both graphite rings or polytetrafluoroethylene rings or other composite self-lubricating materials. In addition to the first sealing ring 8, a sealing ring bushing 9 is provided between the inner side of the end cover bushing 4 and the shaft body 3, and a second sealing ring 10 is filled between the sealing ring bushing 9 and the end cover bushing 4. The sealing ring design using an open metal ring is cancelled and replaced with a sealing ring body made of a graphite ring or polytetrafluoroethylene ring or other composite self-lubricating materials, which has anti-corrosion and self-lubricating properties, so that the sealing surface fits tightly, achieving a better sealing effect than an open metal ring.

[0023] Embodiment 2

[0024] according to Figure 1 , 2 As shown, this embodiment proposes a Roots pump, comprising a pump body 1 and an end cover 2, wherein the end cover 2 is arranged at both ends of the pump body 1, a shaft body 3 is arranged inside the pump body 1, and the upper end of the shaft body 3 passes through the end cover 2, an end cover bushing 4 is arranged between the outer side of the shaft body 3 and the end cover 2, and an oil slinger 5 is arranged above the end cover bushing 4, and the oil slinger 5 surrounds the outer side of the shaft body 3;

[0025] The top of the end cover bushing 4 is provided with a groove 6, and the inside of the groove 6 is filled with a first sealing ring 8, the oil-slinging plate 5 is pressed on the top of the first sealing ring 8, and an elastic O-ring 7 is provided between the bottom of the first sealing ring 8 and the bottom of the groove 6. When in use, a groove 6 is added to the surface of the end cover bushing 4 adjacent to the oil-slinging plate 5, the first sealing ring 8 is placed in the groove 6, and the elastic O-ring 7 is placed below the first sealing ring 8. The oil-slinging plate 5 is used to limit the first sealing ring 8 in the groove 6. In the event that the first sealing ring 8 is worn, the elastic property of the elastic O-ring 7 is used to keep the first sealing ring 8 and the oil-slinging plate 5 sealed at all times to prevent lubricating oil from entering the pump body.

[0026] A bearing seat 11 is provided above the point where the shaft body 3 and the end cover 2 pass through, and the bearing seat 11 surrounds the outside of the shaft body 3, and a positioning bushing 12 is provided between the lower inner side of the bearing seat 11 and the shaft body 3. The positioning bushing 12 surrounds the outside of the shaft body 3, and an embedded groove is provided below the inner side of the bearing seat 11, and an oil seal 13 is filled between the embedded groove and the positioning bushing 12. The positioning bushing 12 cooperates with the oil seal 13 to seal the front end connection of the shaft body 3 to prevent lubricating oil from entering the pump body.

[0027] The Roots pump has a groove 6 on the surface adjacent to the end cover bushing 4 and the oil-slinging plate 5, a first sealing ring 8 is placed in the groove 6, an elastic O-ring 7 is placed below the first sealing ring 8, and the first sealing ring 8 is limited in the groove 6 by the oil-slinging plate 5. In the case of wear of the first sealing ring 8, the elastic property of the elastic O-ring 7 is used to keep the first sealing ring 8 and the oil-slinging plate 5 sealed at all times to prevent the lubricating oil from entering the pump body. In addition to the first sealing ring 8, this product has a sealing ring bushing 9 between the inner side of the end cover bushing 4 and the shaft body 3, and a second sealing ring 10 is filled between the sealing ring bushing 9 and the end cover bushing 4. The sealing ring design using an open metal ring is cancelled and replaced with a sealing ring body made of a graphite ring, a PTFE ring, or other composite self-lubricating material, which has anti-corrosion and self-lubricating properties, so that the sealing surface fits tightly, achieving a better sealing effect than an open metal ring.

[0028] The above shows and describes the basic principles, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions are only for explaining the principles of the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the utility model to be protected. The scope of protection claimed by the utility model is defined by the attached claims and their equivalents.

Claims

1. A Roots pump, comprising a pump body (1) and an end cover (2), characterized in that: The end covers (2) are arranged at both ends of the pump body (1); a shaft body (3) is arranged inside the pump body (1); the upper end of the shaft body (3) passes through the end covers (2); an end cover bushing (4) is arranged between the outer side of the shaft body (3) and the end cover (2); an oil slinger (5) is arranged above the end cover bushing (4); and the oil slinger (5) surrounds the outer side of the shaft body (3); A groove (6) is provided at the top of the end cover bushing (4), and a first sealing ring (8) is filled inside the groove (6). The oil-slinging pan (5) is pressed above the first sealing ring (8), and an elastic O-ring (7) is provided between the bottom of the first sealing ring (8) and the bottom of the groove (6).

2. A Roots pump according to claim 1, characterized in that: A sealing ring bushing (9) is provided between the inner side of the end cover bushing (4) and the shaft body (3), and the sealing ring bushing (9) surrounds the outer side of the shaft body (3).

3. A Roots pump according to claim 2, characterized in that: An inner cavity is provided between the sealing ring bushing (9) and the end cover bushing (4), and the interior of the inner cavity is filled with a second sealing ring (10).

4. A Roots pump according to claim 3, characterized in that: The first sealing ring (8) and the second sealing ring (10) are both made of composite self-lubricating materials.

5. A Roots pump according to claim 1, characterized in that: A bearing seat (11) is provided above the point where the shaft body (3) and the end cover (2) penetrate each other, and the bearing seat (11) surrounds the outside of the shaft body (3). A positioning bushing (12) is provided below the inside of the bearing seat (11) and between the shaft body (3).

6. A Roots pump according to claim 5, characterized in that: The positioning bushing (12) surrounds the outer side of the shaft body (3); an embedded groove is provided below the inner side of the bearing seat (11); and an oil seal (13) is filled between the embedded groove and the positioning bushing (12).

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