A piston ring sealing structure of a vacuum pump

Abstract

The present invention discloses a piston ring sealing structure of a vacuum pump, comprising a rotating shaft, a dynamic ring, a piston ring, a static ring and an end cover. The dynamic ring is provided with a plurality of ring grooves, which are distributed along the axial direction. The piston ring is located in the ring grooves. The dynamic ring is also provided with an oil storage groove, which is distributed on the side of the oil storage groove. Lubricating oil is stored in the oil storage groove. The present invention can add lubricating oil to the movable part of the piston ring to realize a long-term oil lubrication and sealing structure.

Description

Technical Field

[0001] The present invention belongs to the technical field of vacuum pumps, and more particularly relates to a piston ring sealing structure of a vacuum pump. Background Art

[0002] A vacuum pump is a device or equipment that uses mechanical, physical, chemical, or physicochemical methods to evacuate the container to create a vacuum. In layman's terms, a vacuum pump is a device that uses various methods to improve, generate, and maintain a vacuum in a closed space.

[0003] An oil-free vacuum pump is a mechanical vacuum pump that does not require any oil for lubrication to operate.

[0004] Chinese patent publication number CN105889068 discloses a screw vacuum pump with a piston ring sealing structure, belonging to the technical field of screw pump sealing structures. It includes a pump body, the exhaust end of the pump body is connected to the front end cover, the exhaust ends of the active rotor and the passive rotor are connected to the front end cover via angular contact ball bearings, and exhaust end sealing structures are provided between the front end cover and the active rotor and the passive rotor; the intake end of the pump body is connected to the rear end cover, the suction ends of the active rotor and the passive rotor are connected to the rear end cover via deep groove ball bearings, and suction end sealing structures are provided between the rear end cover and the active rotor and the passive rotor. A mechanical seal mechanism is used at the exhaust end to ensure that the exhaust end bearings, gears and lubricating oil are clean; at the suction end, since the inlet pressure is lower than the atmospheric pressure, the rear end cover seal can be sealed with a piston ring, thereby ensuring that the screw pump can operate for a long time.

[0005] In the piston ring sealing structure of the above patent, the friction between the piston ring and the dynamic ring and the static ring is large and the piston ring is prone to wear. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the present invention provides a structure in which lubricating oil can be added to the movable part of the piston ring to achieve long-term oil lubrication and sealing.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a piston ring sealing structure for a vacuum pump, comprising a rotating shaft, a dynamic ring, a piston ring, a static ring and an end cover, wherein the dynamic ring is provided with a plurality of ring grooves, the plurality of ring grooves being distributed along the axial direction, the piston ring being located in the ring grooves, and the dynamic ring is also provided with an oil storage groove, the ring grooves being distributed on the side of the oil storage groove, and the oil storage groove stores lubricating oil.

[0008] Furthermore, an oil inlet hole is provided on the static ring, the oil inlet hole passes through the inner and outer side walls of the static ring, and the oil inlet hole is connected to the oil storage tank. An oil filling hole is provided on the end cover, and the oil filling hole is connected to the oil inlet hole. A plug is provided at the end of the end cover corresponding to the oil filling hole.

[0009] Furthermore, an oil distribution groove is provided on the outer circumferential surface of the static ring, the oil inlet hole is connected to the oil distribution groove, and the oil filling hole and the oil inlet hole are staggered in the circumferential direction.

[0010] Furthermore, there are multiple oil inlet holes, and the multiple oil inlet holes are evenly distributed along the circumference.

[0011] Furthermore, a first sealing ring groove is provided on the circumferential outer side surface of the piston ring.

[0012] Furthermore, a second sealing ring groove is provided on the axial side surface of the piston ring.

[0013] Furthermore, there are multiple first sealing ring grooves and / or second sealing ring grooves.

[0014] Furthermore, the two ends of the piston ring are respectively provided with a first side stop and a second side stop, the first side stop and the second side stop are respectively located on the two axial sides of the piston ring, the first side stop and the second side stop are arranged opposite to each other, and a cavity is formed between the first side stop and the second side stop, and the ends of the first side stop and the second side stop are both provided with anti-slip blocks extending into the interior of the cavity.

[0015] Compared with the prior art, the beneficial effects of the present invention are: the added oil storage tank continuously provides lubricating oil to the piston ring and the dynamic ring and static ring, and realizes a good oil seal structure. During operation, the lubricating oil can be more evenly distributed to the oil storage tank and the piston ring by using the oil filling hole and the oil distribution groove; the first sealing ring groove and the second sealing ring groove on the outer wall of the piston ring can accommodate lubricating oil to form a multi-channel sealing structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a side view of the vacuum pump;

[0017] Figure 2 for Figure 1 Section view at AA in the middle;

[0018] Figure 3 for Figure 2 Enlarged view of middle part B;

[0019] Figure 4 for Figure 1 Enlarged view of the middle CC;

[0020] Figure 5 for Figure 4 Enlarged view of the middle D part;

[0021] Figure 6 This is a three-dimensional structural diagram of the piston ring.

[0022] Figure numerals: 1, end cover; 11, oil filling hole; 12, plug; 2, rotating shaft; 31, dynamic ring; 311, oil storage tank; 32, static ring; 321, oil inlet hole; 322, oil distribution tank; 33, piston ring; 331, first sealing ring groove; 332, second sealing ring groove; 333, first side stop; 3331, anti-slip block; 334, second side stop. DETAILED DESCRIPTION

[0023] Reference Figures 1 to 6 An embodiment of the piston ring sealing structure of the vacuum pump of the present invention is further described.

[0024] In the description of the present invention, it should be noted that, for directional words, such as the terms "center", "horizontal (X)", "longitudinal (Y)", "vertical (Z)", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like, indicating directions and positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and cannot be understood as limiting the specific scope of protection of the present invention.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features. Therefore, the terms "first" and "second" may explicitly or implicitly refer to one or more of these features. Throughout the description of the present invention, "several" and "a number" mean two or more, unless otherwise specifically defined.

[0026] A piston ring sealing structure for a vacuum pump includes a rotating shaft 2, a dynamic ring 31, a piston ring 33, a static ring 32 and an end cover 1. The dynamic ring 31 is provided with a plurality of annular grooves distributed axially, and the piston ring 33 is located in the annular grooves. The dynamic ring 31 is also provided with an oil storage groove 311, and the annular grooves are distributed on the side of the oil storage groove 311. The oil storage groove 311 stores lubricating oil.

[0027] In a vacuum pump, one side of the dynamic ring 31 is a high-pressure area, and the other side is a low-pressure area. In this embodiment, the oil storage tank 311 is close to the side of the dynamic ring 31 corresponding to the high-pressure area, that is, there are a small number of ring grooves and piston rings 33 from the oil storage tank 311 to the high-pressure area, and there are more ring grooves and piston rings 33 from the oil storage tank 311 to the low-pressure area. During operation, the pressure in the high-pressure area causes the oil in the oil storage tank 311 to be squeezed toward the low-pressure area, so that the lubricating oil can fill more piston rings 33 and reduce the lubricating oil entering the low-pressure area as much as possible.

[0028] In this embodiment, the stationary ring 32 is preferably provided with an oil inlet hole 321, which passes through the inner and outer walls of the stationary ring 32 and is connected to the oil storage tank 311. The end cover 1 is provided with an oil filling hole 11, which is connected to the oil inlet hole 321. A plug 12 is provided at the end of the end cover 1 corresponding to the oil filling hole 11.

[0029] At this time, the depth and width of the oil storage tank 311 are small to reduce its capacity. Lubricating oil can be injected into the interior through the oil filling hole 11. The lubricating oil reaches the oil storage tank 311 through the oil inlet hole 321, and the lubricating oil can be replenished.

[0030] In this embodiment, an oil distribution groove 322 is preferably formed on the outer circumferential surface of the stationary ring 32 , the oil inlet hole 321 is connected to the oil distribution groove 322 , and the oil filling hole 11 and the oil inlet hole 321 are staggered in the circumferential direction.

[0031] There are multiple oil inlet holes 321 , and the multiple oil inlet holes 321 are evenly distributed along the circumference.

[0032] like Figure 1-5 As shown, in this embodiment, there are two oil inlet holes 321 on the static ring 32, and the two oil inlet holes 321 are symmetrically arranged. Preferably, the two oil inlet holes 321 are distributed above and below the static ring 32, and one oil filling hole 11 is provided on the end cover 1. This oil filling hole 11 is perpendicular to the line connecting the two oil inlet holes 321, and the oil filling hole 11 is arranged in the horizontal direction. When filling oil, lubricating oil is injected from the oil filling hole 11, and the lubricating oil reaches the oil distribution groove 322, flows along the oil distribution groove 322 and fills it. At the same time, the lubricating oil reaching the oil inlet hole 321 will pass through the static ring 32 and reach the oil storage tank 311.

[0033] like Figure 6 As shown, in this embodiment, the outer circumferential surface of the piston ring 33 is preferably provided with a first sealing ring groove 331 .

[0034] The first sealing ring groove 331 can accommodate lubricating oil, thereby increasing the sealing performance between the piston ring 33 and the stationary ring 32 and reducing the contact surface.

[0035] In this embodiment, a second sealing ring groove 332 is preferably formed on the axial side surface of the piston ring 33 .

[0036] The second sealing ring groove 332 can accommodate lubricating oil, thereby increasing the sealing performance between the piston ring 33 and the dynamic ring 31 and reducing the contact surface.

[0037] In this embodiment, a plurality of first sealing ring grooves 331 and / or second sealing ring grooves 332 may be provided.

[0038] In this embodiment, the piston ring 33 is preferably provided with a first side stop 333 and a second side stop 334 at both ends. The first side stop 333 and the second side stop 334 are respectively located on the two axial sides of the piston ring 33. The first side stop 333 and the second side stop 334 are arranged opposite to each other, and a cavity is formed between the first side stop 333 and the second side stop 334. The ends of the first side stop 333 and the second side stop 334 are both provided with an anti-slip block 3331 extending into the cavity.

[0039] The first side stop 333 and the second side stop 334 can ensure that there is no leakage point in the circumferential direction of the piston ring 33 when the piston ring 33 is extended or retracted, and the anti-slip stop block 3331 is provided to limit the maximum expansion amplitude of the piston ring 33.

[0040] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiment. 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, various 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 piston ring sealing structure for a vacuum pump, comprising a rotating shaft, a dynamic ring, a piston ring, a static ring and an end cover, characterized in that: The dynamic ring is provided with a plurality of annular grooves, which are distributed along the axial direction, and the piston ring is located in the annular grooves. The dynamic ring is also provided with an oil storage groove, which is distributed on the side of the oil storage groove, and the oil storage groove stores lubricating oil; The stationary ring is provided with an oil inlet hole, which passes through the inner and outer walls of the stationary ring and is connected to the oil storage tank. The end cover is provided with an oil filling hole, which is connected to the oil inlet hole. A plug is provided at the end of the end cover corresponding to the oil filling hole. An oil distribution groove is also provided on the outer circumferential surface of the stationary ring, the oil inlet hole is connected to the oil distribution groove, and the oil filling hole and the oil inlet hole are staggered in the circumferential direction; The piston ring is provided with a first side stop and a second side stop at both ends, respectively. The first side stop and the second side stop are respectively located on the two axial surfaces of the piston ring. The first side stop and the second side stop are arranged opposite to each other, and a cavity is formed between the first side stop and the second side stop. The ends of the first side stop and the second side stop are both provided with anti-slip blocks extending into the cavity.

2. The piston ring sealing structure of a vacuum pump according to claim 1, characterized in that: There are multiple oil inlet holes, and the multiple oil inlet holes are evenly distributed along the circumference.

3. The piston ring sealing structure of a vacuum pump according to claim 2, characterized in that: A first sealing ring groove is provided on the circumferential outer side surface of the piston ring.

4. The piston ring sealing structure of a vacuum pump according to claim 3, characterized in that: A second sealing ring groove is provided on the axial side surface of the piston ring.

5. The piston ring sealing structure of a vacuum pump according to claim 4, characterized in that: There are multiple first sealing ring grooves and / or second sealing ring grooves.

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