Vacuum pump with dynamic pressure sealing structure

Abstract

The utility model relates to the field of electric vacuum pumps, in particular to a vacuum pump with a dynamic pressure sealing structure. A vacuum pump with a dynamic pressure sealing structure comprises a cylinder body and a cylinder cover buckled on the cylinder body, a cylinder hole is formed in the cylinder body and used for containing a first piston, an annular sealing seat is arranged on the surface of the side, facing the cylinder cover, of the cylinder body, an annular groove is formed in the annular sealing seat, and the annular groove is coaxial with the cylinder hole and surrounds the cylinder hole; a sealing ring is arranged in the annular groove; in the process that the floating top plate floats in the axial direction of the cylinder hole, the edge of the floating top plate extrudes the sealing ring or is separated from the sealing ring. Compared with the mode that a one-way valve is arranged in the prior art, only by arranging the floating top plate, the sealing ring and the elastic piece, the sealing function can be achieved when the air pressure in the cylinder hole is the first air pressure, and the exhaust function can be achieved when the air pressure in the cylinder hole is the second air pressure; therefore, the technical problems existing in the prior art are solved.

Description

Technical Field

[0001] This utility model relates to the field of electric vacuum pumps, and in particular to a vacuum pump with a dynamic pressure sealing structure. Background Technology

[0002] An electric vacuum pump is a device that uses electricity to generate, maintain, or enhance a vacuum in a closed system. Essentially, it is a small air pump whose core function is to "pump air," removing air from a specific container or pipeline to create a vacuum environment below atmospheric pressure.

[0003] In existing technology, a one-way valve is installed at the cylinder bore of the vacuum pump. The one-way valve guides the cylinder bore to the cavity of the cylinder head in one direction, so that the first piston can discharge gas through the one-way valve during its upward stroke. However, the one-way valve has a complex structure and high cost, which does not meet the current demand for cost reduction. Therefore, it is necessary to propose a new sealing structure that is simple in structure and can achieve the sealing function when the gas pressure in the cylinder bore reaches the first gas pressure, and achieve the exhaust function when the gas pressure in the cylinder bore reaches the second gas pressure. Utility Model Content

[0004] The purpose of this invention is to address the aforementioned deficiencies in the prior art by providing a vacuum pump with a dynamic pressure sealing structure.

[0005] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0006] A vacuum pump with a dynamic pressure sealing structure includes a cylinder body and a cylinder head that is fastened to the cylinder body.

[0007] The cylinder body is provided with a cylinder bore for accommodating the first piston. An annular sealing seat is provided on the side surface of the cylinder body facing the cylinder head. The annular sealing seat is provided with an annular groove. The annular groove is coaxial with the cylinder bore and surrounds the cylinder bore. A sealing ring is provided in the annular groove.

[0008] It also includes a floating top plate, which floats on the cylinder bore along the axial direction of the cylinder bore. The outer tangent diameter of the floating top plate is larger than the radial diameter of the cylinder bore. During the process of the floating top plate floating along the axial direction of the cylinder bore, the edge of the floating top plate squeezes the sealing ring or separates from the sealing ring.

[0009] It also includes a support column, the axis of which coincides with the axis of the cylinder bore. The floating top plate has a first hole at its center, and the floating top plate is coaxially sleeved on the support column through the first hole and fixedly connected.

[0010] It also includes an elastic sheet with a second hole in the center. The elastic sheet is coaxially sleeved on the support column and fixedly connected through the second hole. The floating top plate is located between the elastic sheet and the cylinder hole.

[0011] The side surface of the cylinder cover facing the cylinder hole is provided with an annular mounting groove, the axis of the annular mounting groove is coaxial with the axis of the cylinder hole, and the circumferential outer surface of the elastic sheet abuts to the circumferential groove side wall of the annular mounting groove along the radial direction of the support column.

[0012] The groove bottom wall of the annular mounting groove is provided with an annular rubber pad, and the edge of the elastic sheet away from the side of the floating top plate abuts to the annular rubber pad.

[0013] Further, one of the groove side walls of the annular groove is provided with an acute angle groove formed by radial recessing of the groove side wall of the annular groove, the cross section of the groove bottom wall of the acute angle groove is in the shape of an acute angle, and the acute angle groove is used to accommodate the deformed part of one side of the sealing ring when the edge of the floating top plate extrudes the sealing ring.

[0014] Further, the other groove side wall of the annular groove is at a right angle with the groove bottom wall of the annular groove.

[0015] Further, along the axial direction of the cylinder hole, the height of the groove side wall where the acute angle groove of the annular groove is located is greater than the height of the other groove side walls of the annular groove.

[0016] Further, it further comprises a locking nut, a pressing sheet, a base, from the direction of the cylinder cover pointing to the cylinder hole, the locking nut, the pressing sheet, the elastic sheet, the base and the floating top plate are sequentially sleeved and fixed on the support column.

[0017] Further, the cylinder cover is provided with a let-in groove, and the end of the support column away from the first piston is inserted into the slot of the let-in groove.

[0018] Further, the surface of the first piston facing the cylinder cover is provided with a pushing top, and the first piston lifts the floating top plate through the pushing top.

[0019] Further, between the cylinder body and the cylinder cover, a sealing structure is arranged, and the sealing structure comprises a lower sealing pad, a middle pressing plate and an upper sealing pad which are sequentially and closely arranged from the direction of the cylinder body pointing to the cylinder cover.

[0020] Compared with the prior art, the advantages of the utility model lie in that:

[0021] I. In this utility model, the floating top plate, sealing ring, and elastic sheet form a novel sealing structure. Specifically, when the gas pressure inside the cylinder bore is at the first gas pressure, the elastic sheet abuts against the cylinder head, thereby providing a downward preset force to the floating top plate, ensuring tight contact between the floating top plate and the sealing ring, achieving a sealing effect. This ensures that the gas can only push the floating top plate open when the gas pressure inside the cylinder bore is sufficiently high, i.e., when the gas pressure inside the cylinder bore is at the second gas pressure, allowing the gas to escape from the gap between the floating top plate and the sealing ring. Compared to the existing technology that uses a one-way valve, this utility model achieves a sealing function when the gas pressure inside the cylinder bore is at the first gas pressure and an exhaust function when the gas pressure inside the cylinder bore is at the second gas pressure, all using only a floating top plate, sealing ring, and elastic sheet. Furthermore, the structure is simpler. Therefore, this utility model solves the technical problems existing in the prior art.

[0022] II. In this utility model, during the movement from the lower vertex to the upper vertex, the cylinder bore is under positive pressure. The floating top plate moves upward away from the sealing ring. During this process, the groove wall of the acute-angle groove plays a limiting role for the sealing ring. To prevent the floating top plate and the sealing ring from adhering to each other, causing the floating top plate to move upward together and resulting in the separation of the sealing ring from the annular sealing seat, this utility model, through the setting of the acute-angle groove, ensures that the sealing ring is always confined within the annular groove of the annular sealing seat, avoiding sealing failure caused by the sealing ring coming off the annular sealing seat.

[0023] Third, in this utility model, the sealing seat and the cylinder body are rigidly connected, which is prone to slight gas leakage; in this utility model, the combination of the upper sealing gasket, the middle pressure plate and the lower sealing gasket between the cylinder body and the cylinder head can effectively resist this part of gas leakage, and ultimately ensure the vacuum degree of the vacuum pump.

[0024] IV. In this utility model, the pusher is set on the surface of the first piston facing the cylinder head. Before the first piston reaches the top dead center, the pusher has already contacted the floating top plate. The crankshaft drives the first piston to continue moving upward, and the pusher pushes the floating top plate open. That is, because the pusher is set, the compressed gas and the pusher work together to push the floating top plate open, avoiding the situation where the gas pressure decreases at the end of the pumping process, and even if the first piston reaches the top dead center, the pressure of its compressed air is still insufficient to push open the floating top plate. Attached Figure Description

[0025] Figure 1 This is a cross-sectional schematic diagram of a vacuum pump with a dynamic pressure sealing structure according to this utility model;

[0026] Figure 2 yes Figure 1 Enlarged view of region A in the middle;

[0027] Figure 3is a structural schematic diagram of the elastic sheet, the annular mounting groove and the annular rubber pad;

[0028] Figure 4 is a structural schematic diagram of the annular sealing seat;

[0029] Figure 5 is Figure 4 is an enlarged schematic diagram of the B area in the middle;

[0030] Figure 6 is a structural schematic diagram of the lower sealing pad, the middle pressing plate and the upper sealing pad;

[0031] Figure 7 is Figure 6 is an enlarged schematic diagram of the C area in the middle;

[0032] Figure 8 is a schematic diagram of the floating top plate and the sealing ring being separated;

[0033] Figure 9 is a schematic diagram of the floating top plate extruding the sealing ring.

[0034] In the figure, the marks are as follows: cylinder body 1, cylinder cover 2, cylinder hole 3, first piston 4, annular sealing seat 5, annular groove 6, sealing ring 7, floating top plate 8, support 9, elastic sheet 10, annular mounting groove 11, annular rubber pad 12, acute angle groove 13, locking nut 14, pressing sheet 15, base 16, accommodation groove 17, pushing top 18, lower sealing pad 19, middle pressing plate 20, upper sealing pad 21, stepped surface 22. DETAILED DESCRIPTION

[0035] The utility model technical scheme will be further described in a non-restrictive manner in combination with the preferred embodiments and the drawings thereof. In the description of the utility model, it should be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "lateral", "length h", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" are based on the orientations or positional relationships shown in the drawings. In addition, the terms "first" and "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" can explicitly or implicitly include at least one of the features. In the description of the utility model, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise specifically limited. The embodiments described below by referring to the drawings are exemplary and are intended to explain the utility model, and cannot be understood as limiting the utility model.

[0036] Example 1

[0037] The vacuum pump with dynamic pressure sealing structure of the embodiment has three cylinder bodies and three piston connecting rod assemblies, any one of the cylinder bodies is arranged corresponding to one of the piston connecting rod assemblies, the three piston connecting rod assemblies are further connected with a crankshaft assembly arranged in the box body, the crankshaft assembly is driven to rotate by a motor, thereby driving the three piston connecting rod assemblies to reciprocate up and down, and then realizing the pumping function; the embodiment takes the piston of one of the cylinder bodies and the piston connecting rod assembly as an example to illustrate the improvement of the embodiment on the prior art.

[0038] As shown in Figures 1-5 The embodiment provides a vacuum pump with dynamic pressure sealing structure, which comprises a cylinder body 1 and a cylinder cover 2 buckled on the cylinder body 1. The cylinder body 1 is provided with a cylinder hole 3 for accommodating a first piston 4. An annular sealing seat 5 is arranged on the side surface of the cylinder body 1 facing the cylinder cover 2. The annular sealing seat 5 is provided with an annular groove 6 coaxial with the cylinder hole 3 and surrounding the cylinder hole 3. A sealing ring 7 is arranged in the annular groove 6. The vacuum pump further comprises a floating top plate 8 which can float along the axial direction of the cylinder hole 3 and cover the cylinder hole 3. The diameter of the circumscribed circle of the floating top plate 8 is greater than the radial diameter of the cylinder hole 3. During the floating process of the floating top plate 8 along the axial direction of the cylinder hole 3, the edge of the floating top plate 8 extrudes or separates from the sealing ring 7. The vacuum pump further comprises a support 9, the axis of the support 9 coincides with the axis of the cylinder hole 3, the center of the floating top plate 8 is provided with a first hole, and the floating top plate 8 is coaxially sleeved on the support 9 through the first hole and fixedly connected. The vacuum pump further comprises an elastic sheet 10, the center of the elastic sheet 10 is provided with a second hole, the elastic sheet 10 is coaxially sleeved on the support 9 through the second hole and fixedly connected, and the floating top plate 8 is located between the elastic sheet 10 and the cylinder hole 3. The side surface of the cylinder cover 2 facing the cylinder hole 3 is provided with an annular mounting groove 11, the axis of the annular mounting groove 11 is coaxial with the axis of the cylinder hole 3, along the radial direction of the support 9, the circumferential outer surface of the elastic sheet 10 abuts to the circumferential groove side wall of the annular mounting groove 11. The groove bottom wall of the annular mounting groove 11 is provided with an annular rubber pad 12, and the edge of the elastic sheet 10 away from the floating top plate 8 abuts to the annular rubber pad 12.

[0039] The cylinder body 1 and the cylinder cover 2 are connected in a split type, the cylinder cover 2 is buckled on the cylinder body 1, the cylinder hole 3 is used for accommodating the first piston 4, the first piston 4 reciprocates in the cylinder hole 3 to inhale or exhaust; the annular sealing seat 5 is arranged on the cylinder body 1, preferably coaxially arranged with the cylinder hole 3; the floating top plate 8 is preferably an annular plate structure, and the diameter of the circumscribed circle thereof is greater than the radial diameter of the cylinder hole 3, so that the floating top plate 8 can completely cover the cylinder hole 3 when closed, and can leave a gap with the cylinder body 1 when opened, so that the gas in the cylinder hole 3 can escape; the edge of the floating top plate 8 extrudes the sealing ring 7, thereby achieving the sealing effect, and the edge of the floating top plate 8 separates from the sealing ring 7, thereby making the gas escape from the gap between the edge of the floating top plate 8 and the sealing ring 7.

[0040] The shape of the elastic sheet 10 is preferably such that the edge thereof is curved away from the cylinder hole 3, and the circumferential outer surface of the edge abuts against the circumferential groove side wall of the annular mounting groove 11, thereby ensuring that the radial position of the elastic sheet 10 is coaxial with the cylinder hole 3 through the circumferential groove side wall of the annular mounting groove 11. The side of the edge of the elastic sheet 10 away from the floating top plate 8 abuts against the annular rubber pad 12, thereby enabling the cylinder head 2 to transmit a downward preset force to the floating top plate 8 through the annular rubber pad 12, the elastic sheet 10, and the support column 9 along the axial direction, so that the floating top plate 8 can be pushed away to cause the gas to escape only when the gas pressure in the cylinder hole 3 is large enough.

[0041] The elastic sheet 10 and the floating top plate 8 are respectively fixedly connected to the support column 9. Specifically, the vacuum pump with the dynamic pressure sealing structure further comprises a locking nut 14, a pressing sheet 15, and a base 16. From the direction in which the cylinder head 2 points to the cylinder hole 3, the locking nut 14, the pressing sheet 15, the elastic sheet 10, the base 16, and the floating top plate 8 are sequentially sleeved and fixed on the support column 9. During the process of installation, the bottom of the support column 9 is provided with a stepped surface 22, and the top of the support column 9 is provided with a thread. The base 16, the elastic sheet 10, and the pressing sheet 15 are sequentially sleeved on the support column 9 and are supported by the stepped surface 22, and finally the locking nut 14 is screwed on the thread of the support column 9 to be threadedly connected, so as to tightly limit the pressing sheet 15, the elastic sheet 10, and the base 16 between the locking nut 14 and the stepped surface 22.

[0042] Preferably, the cylinder head 2 is provided with a make-way groove 17, and the end of the support column 9 away from the first piston 4 is inserted into the slot of the make-way groove 17. In this way, the cylinder head 2 does not interfere with the support column 9.

[0043] As Figures 8-9As shown, when the first piston 4 moves downward during use, the cylinder hole 3 inhales gas, at this time, the downward elastic force of the elastic sheet 10 forces the floating top plate 8 to move downward and abut against the sealing ring 7, and after abutting, the sealing ring 7 deforms, and the deformation stops when the connecting rod piston assembly moves downward to the lower vertex. In this process, the sealing ring 7 and the floating top plate 8 change from line sealing to multi-line sealing and face sealing, which ensures the effective sealing of the gas inhalation process of the cylinder hole 3. When the first piston 4 moves from the lower vertex to the upper vertex, the gas in the cylinder hole 3 is forced to compress, and the compressed gas exerts force on three places, i.e., the cylinder hole wall, the floating top plate 8 and the end face of the first piston 4; but the cylinder hole wall is a rigid structure, and the gas force cannot cause displacement; the end face of the first piston 4 is continuously provided with power by the crankshaft, and the gas force cannot cause displacement; the floating top plate 8 is mainly pressed downward by the elastic force of the elastic sheet 10, and when the gas in the cylinder hole 3 is continuously compressed by the first piston 4, the unit area force increases, and finally, the force of the compressed gas forces the floating top plate 8 to change the displacement direction and move upward, thereby pushing open the floating top plate 8, and the floating top plate 8 and the sealing ring 7 are separated from each other, and the gas escapes from the gap between the floating top plate 8 and the sealing ring 7 and enters the cavity of the cylinder head 2.

[0044] In the prior art, a one-way valve is arranged at the cylinder hole of the vacuum pump, the one-way valve guides the cylinder hole to the cavity of the cylinder head, and thus the first piston discharges the gas through the one-way valve during the upward stroke; however, the one-way valve has a complex structure and high cost, which does not meet the current economic demand for cost reduction, and therefore, how to propose a new sealing structure with a simple structure and capable of achieving the sealing function when the gas pressure in the cylinder hole is the first gas pressure and achieving the exhaust function when the gas pressure in the cylinder hole is the second gas pressure, and the structure is simpler.

[0045] In the embodiment, the floating top plate 8, the sealing ring 7 and the elastic sheet 10 form a new sealing structure, specifically, when the gas pressure in the cylinder hole is the first gas pressure, the elastic sheet 10 abuts against the cylinder head 2, thereby providing the floating top plate 8 with a downward preset force, so that the floating top plate 8 tightly contacts the sealing ring 7, achieving the sealing effect; and only when the gas pressure in the cylinder hole 3 is large enough, i.e., when the gas pressure in the cylinder hole 3 is the second gas pressure, the gas can push open the floating top plate 8, and the gas escapes from the gap between the floating top plate 8 and the sealing ring 7. Compared with the prior art of arranging a one-way valve, the embodiment only needs to arrange the floating top plate 8, the sealing ring 7 and the elastic sheet 10 to achieve the sealing function when the gas pressure in the cylinder hole is the first gas pressure and achieve the exhaust function when the gas pressure in the cylinder hole is the second gas pressure, and the structure is simpler; therefore, the embodiment solves the technical problems in the prior art.

[0046] Specifically, when the gas pressure is lower than the first threshold value, the pressure of the gas is a first gas pressure, and when the gas pressure is higher than the first threshold value, the pressure of the gas is a second gas pressure. The specific value of the first threshold value can be set according to the actual working condition, and is not limited herein, for example, 120 KPa.

[0047] As shown in Figure 5 Further, the embodiment further includes the following technical solutions: one of the groove side walls of the annular groove 6 is provided with an acute-angle groove 13, the acute-angle groove 13 is formed by the radial recess of the groove side wall of the annular groove 6, the cross section of the groove bottom wall of the acute-angle groove 13 is in the shape of an acute angle, and the acute-angle groove 13 is used to accommodate a deformed part of one side of the sealing ring 7 when the floating top plate 8 extrudes the sealing ring 7 at the edge. Preferably, along the axial direction of the cylinder hole 3, the height of the groove side wall where the acute-angle groove 13 of the annular groove 6 is located is greater than the height of the other groove side walls of the annular groove 6.

[0048] During the movement of the first piston 4 from the upper dead point to the lower dead point, the cylinder hole 3 is in a negative pressure state, the floating top plate 8 is displaced downward and extrudes the sealing ring 7, and a part of the sealing ring 7 is deformed and filled into the acute-angle groove 13; during the movement from the lower dead point to the upper dead point, the cylinder hole 3 is in a positive pressure state, the floating top plate 8 is displaced upward away from the sealing ring 7, and in this process, the groove wall of the acute-angle groove 13 plays a limiting role on the sealing ring 7, so as to avoid the adhesion of the floating top plate 8 and the sealing ring 7, which causes the floating top plate 8 to displace upward together with the sealing ring 7, resulting in the separation of the sealing ring 7 from the annular sealing seat 5; the acute-angle groove 13 provided in the embodiment makes the sealing ring 7 always be limited in the annular groove 6 of the annular sealing seat 5, so as to avoid the sealing failure caused by the disengagement of the sealing ring 7 from the annular sealing seat 5.

[0049] Further, the other groove side wall of the annular groove 6 is at a right angle with the groove bottom wall of the annular groove 6. During the process that the floating top plate 8 extrudes the sealing ring 7 downward, the other deformed part of the sealing ring 7 is filled into the right angle.

[0050] As shown in Figures 6-7 Further, the embodiment further includes the following technical solutions: a sealing structure is arranged between the cylinder body 1 and the cylinder cover 2, and the sealing structure includes a lower sealing gasket 19, a middle pressing plate 20 and an upper sealing gasket 21 which are sequentially and closely arranged in the direction from the cylinder body 1 to the cylinder cover 2. The annular sealing seat 5 and the cylinder body 1 are rigidly connected, and a small amount of gas leakage is prone to occur; in the embodiment, the combination of the upper sealing gasket 21, the middle pressing plate 20 and the lower sealing gasket 19 between the cylinder body 1 and the cylinder cover 2 can effectively resist the gas leakage, so as to finally ensure the vacuum degree of the vacuum pump.

[0051] In order to avoid that in the end of pumping, the gas pressure is too small, and even if the first piston 4 reaches the top dead center, the pressure of the gas is still insufficient to push open the floating top plate 8, the embodiment further comprises the technical scheme that the surface of the first piston 4 towards the cylinder cover 2 is provided with a pushing top 18, and the first piston 4 pushes open the floating top plate 8 through the pushing top 18. In the embodiment, the pushing top 18 is arranged on the surface of the first piston 4 towards the cylinder cover 2, and before the first piston 4 reaches the top dead center, the pushing top 18 has contacted with the floating top plate 8, the crankshaft drives the first piston 4 to continue to move upwards, and the pushing top 18 pushes open the floating top plate 8, that is, due to the arrangement of the pushing top 18, the compressed gas and the pushing top 18 jointly push open the floating top plate 8, and the situation that in the end of pumping, the gas pressure is reduced, and even if the first piston 4 reaches the top dead center, the pressure of the compressed air is still insufficient to push open the floating top plate 8 is avoided.

[0052] The above-mentioned embodiments only express several implementation manners of the utility model, the description is more specific and detailed, but it cannot be understood as the limitation of the patent range of the utility model. It should be pointed out that for ordinary skilled persons in the art, on the premise of not departing from the concept of the utility model, a plurality of deformations and improvements can be made, which all belong to the protection range of the utility model. Therefore, the protection range of the utility model patent should be subject to the appended claims.

Claims

1. A vacuum pump with dynamic pressure sealing structure, comprising a cylinder body (1) and a cylinder cover (2) buckled on the cylinder body (1), characterized in that, a cylinder hole (3) is arranged in the cylinder body (1), the cylinder hole (3) is used for accommodating a first piston (4), a ring-shaped sealing seat (5) is arranged on the side surface of the cylinder body (1) facing the cylinder cover (2), the ring-shaped sealing seat (5) is provided with a ring-shaped groove (6), the ring-shaped groove (6) is coaxial with the cylinder hole (3) and is arranged around the cylinder hole (3), and a sealing ring (7) is arranged in the ring-shaped groove (6); a floating top plate (8) is further arranged, the floating top plate (8) is coaxially arranged on the cylinder hole (3) and can float along the axial direction of the cylinder hole (3), the diameter of the circumscribed circle of the floating top plate (8) is greater than the radial diameter of the cylinder hole (3), and the edge of the floating top plate (8) extrudes or separates from the sealing ring (7) during the floating of the floating top plate (8) along the axial direction of the cylinder hole (3); a support column (9) is further arranged, the axis of the support column (9) is coincident with the axis of the cylinder hole (3), the center of the floating top plate (8) is provided with a first hole, and the floating top plate (8) is coaxially arranged on the support column (9) through the first hole and is fixedly connected; an elastic sheet (10) is further arranged, the center of the elastic sheet (10) is provided with a second hole, the elastic sheet (10) is coaxially arranged on the support column (9) through the second hole and is fixedly connected, and the floating top plate (8) is located between the elastic sheet (10) and the cylinder hole (3); the side surface of the cylinder cover (2) facing the cylinder hole (3) is provided with a ring-shaped mounting groove (11), the axis of the ring-shaped mounting groove (11) is coaxial with the axis of the cylinder hole (3), the circumferential outer surface of the elastic sheet (10) abuts to the circumferential groove side wall of the ring-shaped mounting groove (11) along the radial direction of the support column (9); the groove bottom wall of the ring-shaped mounting groove (11) is provided with a ring-shaped rubber pad (12), and the edge of the elastic sheet (10) away from the floating top plate (8) abuts to the ring-shaped rubber pad (12).

2. The vacuum pump having a dynamic pressure seal structure according to claim 1, characterized by, one of the groove side walls of the ring-shaped groove (6) is provided with an acute-angle groove (13), the acute-angle groove (13) is formed by the radial recess of the groove side wall of the ring-shaped groove (6), the cross section of the groove bottom wall of the acute-angle groove (13) is in the shape of an acute angle, and the acute-angle groove (13) is used for accommodating the deformed part of one side of the sealing ring (7) when the edge of the floating top plate (8) extrudes the sealing ring (7).

3. The vacuum pump having a dynamic pressure seal structure according to claim 2, characterized by, the other groove side wall of the ring-shaped groove (6) is at a right angle with the groove bottom wall of the ring-shaped groove (6).

4. The vacuum pump having a dynamic pressure seal structure according to claim 3, characterized by, along the axial direction of the cylinder hole (3), the height of the groove side wall where the acute-angle groove (13) of the ring-shaped groove (6) is located is greater than the height of the other groove side walls of the ring-shaped groove (6).

5. The vacuum pump having a dynamic pressure seal structure according to claim 4, characterized by, a locking nut (14), a pressing sheet (15) and a base (16) are further arranged, from the direction in which the cylinder cover (2) points to the cylinder hole (3), the locking nut (14), the pressing sheet (15), the elastic sheet (10), the base (16) and the floating top plate (8) are sequentially arranged on the support column (9) and are fixedly connected.

6. The vacuum pump having a dynamic pressure seal structure according to claim 5, characterized by, the cylinder cover (2) is provided with a giving-up groove (17), and one end of the support column (9) away from the first piston (4) is inserted into the slot opening of the giving-up groove (17).

7. The vacuum pump with dynamic pressure seal according to any one of claims 1 to 6, characterized in that The first piston (4) is provided with a pushing part (18) on the surface facing the cylinder cover (2), and the first piston (4) pushes up the floating top plate (8) through the pushing part (18).

8. The vacuum pump with dynamic pressure seal according to any one of claims 1 to 6, characterized in that Between the cylinder body (1) and the cylinder cover (2), a sealing structure is arranged, which comprises a lower sealing gasket (19), a middle pressing plate (20) and an upper sealing gasket (21) arranged in close contact in sequence in the direction from the cylinder body (1) to the cylinder cover (2).

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