Vacuum pump

Abstract

The utility model relates to a vacuum pump and relates to the technical field of vacuum pumps. The utility model provides a vacuum pump which comprises a vacuum pump body and an oil separator. The exhaust channel, the exhaust port and the first gas port are formed in the main shaft, the oil separator is arranged in the exhaust channel, oil gas entering the oil cavity from the first gas port can be separated and filtered through the oil separator, oil liquid in the oil gas can be separated out, and the oil gas with oil liquid such as lubricating oil is prevented from entering the working cavity; the vacuum pump is prevented from being damaged; meanwhile, pressure balance between the working cavity of the vacuum pump body and the oil cavity of the oil tank can be achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to vacuum pump technical field, specifically, relate to a kind of vacuum pump. BACKGROUND

[0002] The multistage Roots vacuum pump in the related art is increasingly widely applied in semiconductor, photovoltaic industry.

[0003] The inventor found that, when the vacuum pump works, the cavity is in a high vacuum degree negative pressure state, while the oil tank and the gear box are generally in a standard atmospheric pressure state. If the vacuum pump is not designed with a pressure balancing structure, the lubricating oil in the oil tank and the gear box will move to the working cavity due to pressure, eventually causing the performance of the vacuum pump to decline and be damaged. SUMMARY

[0004] The utility model discloses a vacuum pump, which can balance the pressure of the working cavity of the vacuum pump body and the oil cavity of the oil tank, and prevent oil gas containing lubricating oil from entering the working cavity.

[0005] The embodiment of the utility model can be implemented as follows:

[0006] The utility model provides a kind of vacuum pump, comprising: vacuum pump body, the vacuum pump body includes cavity, oil tank and the main shaft being arranged in the cavity, working cavity is equipped in the cavity, the oil tank is located at one side of the cavity, the first end of the main shaft extends from the cavity and is located in the oil cavity of the oil tank, the sealing space that the main shaft is formed with exhaust passage, first gas port and exhaust port, the first gas port is connected with the oil cavity and the exhaust passage, the exhaust port is connected with the exhaust passage and the sealing space, the sealing space is communicated with the working cavity under the action of pressure by the assembly gap of the sealing element;

[0007] Oil separator, the oil separator is located between the first gas port and the exhaust port in the exhaust passage, to separate the oil gas from the oil cavity flowing to the sealing space.

[0008] Optionally, the oil separator includes a body, a fixed portion, and a separation portion. The body has a hollow passage therethrough. The separation portion and the fixed portion are both arranged on the body. The separation portion is located between the inlet of the hollow passage and the first gas port. The fixed portion is fixedly connected with the inner wall of the exhaust passage. The oil gas flows through the first gas port, the separation portion, and the hollow passage in sequence.

[0009] Optionally, the separation portion includes a plurality of spiral vanes extending along the circumference of the body in a serpentine manner. The spiral vanes form a spiral passage therebetween for the oil gas to pass through.

[0010] Optionally, the fixed part is arranged at a side of the separation part away from the entrance of the hollow channel, and the first air port is located between the fixed part and the separation part.

[0011] Optionally, the main shaft is further provided with a second air port in communication with the oil cavity for discharging oil, and the second air port and the first air port are arranged at two sides of the separation part, respectively.

[0012] Optionally, the flow area of the second air port is smaller than the flow area of the first air port; and / or

[0013] the body extends to the second air port, and at least part of the body shields the second air port, and the body is spaced apart from the second air port; and / or

[0014] the body extends to the second air port, and the body shields the second air port and exceeds the second air port by at least 3 mm, and the body is spaced apart from the second air port.

[0015] Optionally, the oil tank is provided with a nitrogen purging hole for introducing nitrogen, and the nitrogen purging hole is in communication with the oil cavity.

[0016] Optionally, the vacuum pump further comprises a filter element, and the filter element is arranged in the exhaust channel and located between the oil separator and the exhaust port.

[0017] Optionally, a limiting step is arranged in the exhaust channel, and the filter element is pressed between the oil separator and the limiting step.

[0018] Optionally, a one-way valve is further included, and the one-way valve is arranged between the exhaust port and the oil cavity in the flow direction of the oil gas.

[0019] The beneficial effects of the vacuum pump provided by the embodiments of the utility model include:

[0020] By arranging the exhaust channel, the exhaust port and the first air port on the main shaft, and arranging the oil separator in the exhaust channel, the oil gas entering from the first air port can be separated and filtered by the oil separator, and the oil in the oil gas can be separated out, so that the oil gas containing lubricating oil and other oil is prevented from entering the working cavity, thereby preventing damage to the vacuum pump; at the same time, the pressure balance between the working cavity of the vacuum pump body and the oil cavity of the oil tank can also be realized. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical scheme of the embodiments of the present application, the drawings used in the embodiments will be briefly introduced as follows, and it should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor on the premise of not paying creative labor.

[0022] Figure 1 The partial sectional view of the vacuum pump provided for the present embodiment is shown in the figure.

[0023] Figure 2 The structural schematic diagram of the oil separator under the first perspective provided for the present embodiment is shown in the figure.

[0024] Figure 3 The structural schematic diagram of the oil separator under the second perspective provided for the present embodiment is shown in the figure.

[0025] Figure 4 The structural schematic diagram of the filter under the first perspective provided for the present embodiment is shown in the figure.

[0026] Icon: 100-vacuum pump body; 101-sealing space; 102-working cavity; 110-main shaft; 111-exhaust passage; 112-exhaust port; 113-first gas port; 114-second gas port; 115-end cover; 116-limiting step; 130-mounting seat; 132-shaft sleeve; 133-sealing element; 134-limiting boss; 200-oil separator; 201-hollow passage; 210-body; 220-fixed part; 230-separation part; 231-vane; 300-oil tank; 310-oil cavity; 320-nitrogen purging hole; 400-filter; 410-cylindrical body; 420-filter screen. DETAILED DESCRIPTION

[0027] The inventor has found that when the vacuum pump is working, the cavity is in a high-vacuum negative pressure state, while the oil tank and the gear box are generally in a standard atmospheric pressure state. If the vacuum pump is not designed with a pressure balancing structure, the lubricating oil in the oil tank and the gear box will move to the working cavity due to the pressure relationship, which will eventually cause the performance of the vacuum pump to decline and be damaged.

[0028] In view of the above problems, the present application provides a vacuum pump which can separate oil gas, balance the pressure of the working cavity 102 of the vacuum pump, and separate the oil in the oil gas, so as to avoid the oil gas containing lubricating oil and other oil entering the working cavity 102.

[0029] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be described clearly and completely in combination with the drawings in the embodiments of the utility model below. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. The components of the embodiments of the utility model described and shown in the drawings can be arranged and designed in various different configurations.

[0030] Therefore, the following detailed description of the embodiments of the utility model provided in the drawings is not intended to limit the scope of the claimed utility model, but only represents selected embodiments of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the utility model.

[0031] It should be noted that: similar signs and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0032] In the description of the utility model, it should be noted that if the terms "upper", "lower", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly placed when the utility model product is used, only for the convenience of describing the utility model and simplifying the description, and it is not intended to indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, therefore, it cannot be understood as a limitation on the utility model.

[0033] In addition, if the terms "first", "second" and the like appear, they are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0034] It should be noted that the features in the embodiments of the utility model can be combined with each other without conflict.

[0035] The overall structure, working principle and technical effects of the vacuum pump provided by the utility model will be described in detail below through embodiments and in combination with the drawings.

[0036] In the present embodiment, a vacuum pump is proposed, which is applied to a vacuum pump group and its pumping system.

[0037] Please refer to Figure 1The utility model provides a kind of vacuum pump, including vacuum pump body 100 and oil separator 200;Vacuum pump body 100 is equipped with working cavity 102 and the main shaft 110 being rotatably arranged to working cavity 102, the first end of main shaft 110 extends vacuum pump body 100 and is located in the oil cavity 310 of oil tank 300;The first end of main shaft 110 is equipped with exhaust passage 111 and the exhaust port 112 and first gas port 113 communicated with exhaust passage 111, exhaust port 112 is communicated under the connection gap of sealing element 133 with working cavity 102 by pressure, first gas port 113 is communicated with oil cavity 310;Oil separator 200 is arranged in exhaust passage 111 and is relative to first gas port 113, and oil separator 200 is used to separate the oil gas entering from first gas port 113.

[0038] It can be understood that by setting oil separator 200 in exhaust passage 111, oil separator 200 is arranged relative to first gas port 113, oil gas entering from first gas port 113 is separated to make separated oil discharge, and separated gas passes through hollow passage 201, exhaust passage 111 and exhaust port 112, and enters working cavity 102 through the connection gap of sealing element 133 under pressure.

[0039] Therefore, by setting exhaust passage 111, exhaust port 112 and first gas port 113 on main shaft 110, when the pressure of oil cavity 310 is greater than the pressure of working cavity 102, working cavity 102 and oil cavity 310 of vacuum pump body 100 can be connected through assembly gap, so that working cavity 102 and oil cavity 310 of vacuum pump body 100 can maintain pressure balance.

[0040] In the embodiment, the vacuum pump includes an oil tank 300.

[0041] In the embodiment, please refer to Figure 1 Oil tank 300 is sealingly connected to the first end of vacuum pump body 100, and the first end of main shaft 110 is located in oil cavity 310.

[0042] In the embodiment, the vacuum pump further comprises a one-way valve arranged between the oil cavity 310 and the exhaust port 112 in the flow direction of the oil gas; for example, the one-way valve can be arranged in at least one of the first gas port 113, the exhaust passage 111, the exhaust port 112 and the sealing space 101, so that the oil cavity 310 is in one-way communication with the working chamber 102, and the gas in the working chamber 102 is prevented from flowing reversely into the oil cavity 310, thereby preventing the lubricating oil in the oil cavity 310 from being contaminated. The specific structure and specific arrangement position of the one-way valve can be not limited in the application as long as the gas in the working chamber 102 can be prevented from flowing to the oil cavity 310.

[0043] In the embodiment, the oil tank 300 is provided with a nitrogen purging hole 320 for introducing nitrogen; one end of the nitrogen purging hole 320 is in communication with a nitrogen source, and the other end is in communication with the oil cavity 310, so that the nitrogen purging hole 320 can deliver nitrogen to the oil cavity 310 for pressurization, so as to ensure the pressure balance between the oil cavity 310 and the working chamber 102, and prevent the process gas in the working chamber 102 from flowing to the oil cavity 310.

[0044] In the embodiment, the nitrogen purging hole 320 and the nitrogen source can be provided with a flow regulating valve, so that the purging flow can be adjusted. Further, the flow regulating valve can also be a one-way valve to realize one-way flow of the nitrogen source to the oil cavity 310.

[0045] In the embodiment, the vacuum pump comprises a vacuum pump body 100.

[0046] In the embodiment, the vacuum pump body 100 comprises a cavity, an oil tank 300 and a main shaft 110 penetrating the cavity; the cavity is provided with a working chamber 102, the oil tank 300 is arranged on one side of the cavity, the first end of the main shaft 110 extends out of the cavity and is located in the oil cavity 310 of the oil tank 300, the sealing space 101 accommodating the sealing member 133 is formed between the cavity and the main shaft 110, the exhaust passage 111, the first gas port 113 and the exhaust port 112 are formed in the main shaft 110, the first gas port 113 is in communication with the oil cavity 310 and the exhaust passage 111, the exhaust port 112 is in communication with the exhaust passage 111 and the sealing space 101, and the sealing space 101 is in communication with the working chamber 102 under the pressure action through the assembly gap of the sealing member 133.

[0047] In the embodiment, please refer to Figure 1 The cavity comprises a pump body and a mounting seat 130; the pump body is provided with a working chamber 102 comprising a plurality of stages of chambers, and the mounting seat 130 is sealingly arranged at both ends of the pump body. The oil tank 300 is sealingly fixed with the opposite mounting seat 130.

[0048] The main shaft 110 penetrates the pump body and the mounting seat 130 at both ends, and is rotationally connected with the mounting seat 130. The middle part of the main shaft 110 is provided with an eccentric rotor located in the working chamber 102. The first end of the main shaft 110 penetrates the mounting seat 130 and is located in the oil cavity 310. The second end of the main shaft 110 is in transmission connection with the output shaft of the driving unit.

[0049] It can be understood that the output shaft of the driving unit drives the main shaft 110 to rotate, and the rotation of the main shaft 110 drives the eccentric rotor to compress the gas in the working chamber 102.

[0050] In the embodiment, the mounting seat 130 and the main shaft 110 form a sealing space 101 accommodating the sealing member 133; the sealing space 101 can be jointly defined by the mounting seat 130, the shaft sleeve 132 and the main shaft 110. At the sealing space 101, the main shaft 110 is rotationally connected with the mounting seat 130 through the shaft sleeve 132, and the sealing member 133 seals the assembly gap between the shaft sleeve 132 and the mounting seat 130. The sealing member 133 can be a lip seal ring, etc., and is used to prevent the process gas in the working chamber 102 from leaking. When the pressure of the oil cavity 310 is greater than that of the working chamber 102, the oil containing oil liquid in the oil cavity 310 is separated by the oil separator 200, and the gas can enter the working chamber 102 through the assembly gap between the sealing member 133, the cavity and the main shaft 110, so as to balance the pressure of the oil cavity 310 and the working chamber 102.

[0051] In the embodiment, please refer to Figure 1 The cavity forms a shaft hole for the main shaft 110 to pass through, and the shaft sleeve 132 is sleeved on the main shaft 110. The cavity is connected with the main shaft 110 through the shaft sleeve 132, so as to realize the rotational connection. The shaft hole is provided with the sealing space 101 and the limiting boss 134 surrounding the main shaft 110 and the shaft sleeve 132. The sealing member 133 is arranged in the sealing space 101 and abuts against the limiting boss 134, so as to seal the assembly gap between the shaft sleeve 132 and the cavity, and prevent the process gas in the working chamber 102 from flowing out of the assembly gap.

[0052] In the embodiment, the first end of the main shaft 110 extends out of the mounting seat 130 on one side of the pump body and is located in the oil tank 300 correspondingly. The first end of the main shaft 110 is provided with a coaxial exhaust passage 111, an exhaust port 112 in communication with the exhaust passage 111 and a first gas port 113. The exhaust port 112 is in communication with the working chamber 102. The first gas port 113 is in communication with the oil cavity 310 and the exhaust passage 111. The exhaust port 112 is in communication with the exhaust passage 111 and the sealing space 101.

[0053] Further, please refer to Figure 1The second air port 114 is arranged on the main shaft 110 and communicates with the oil cavity 310 and the exhaust passage 111, and is used for discharging oil. The oil separated by the oil separator 200 can be discharged into the oil cavity 310 through the second air port 114, mixed with the oil in the oil cavity 310, and reused. The oil gas in the oil cavity 310 can also partially enter the exhaust passage 111 through the second air port 114.

[0054] In some embodiments, the exhaust passage 111 can be coaxially arranged with the main shaft 110. In other embodiments, the axis of the exhaust passage 111 can be inclined relative to the axis of the main shaft 110. That is, the exhaust passage 111 can be inclined relative to the axis of the main shaft 110 towards the position of the second air port 114. The oil separator 200 arranged in the exhaust passage 111 can also be inclined towards the second air port 114, thereby facilitating the separation and discharge of the oil.

[0055] In some embodiments, the second air port 114 can also be inclined to facilitate the discharge of the oil. Alternatively, the exhaust passage 111, the oil separator 200, and the second air port 114 can all be arranged with a taper of 10°-25° to guide the ejection of the oil.

[0056] In some embodiments, the exhaust port 112, the first air port 113, and the second air port 114 can include multiple ports. The multiple exhaust ports 112, the first air ports 113, and the second air ports 114 are arranged at equal angles along the main shaft 110.

[0057] In this embodiment, the flow area of the second air port 114 is smaller than the flow area of the first air port 113. In this way, the oil gas in the oil cavity 310 can mainly enter the exhaust passage 111 through the first air port 113 and a small amount of oil gas can enter the exhaust passage 111 through the second air port 114, so that most of the oil gas can be separated by the oil separator 200. Alternatively, the diameter of the first air port 113 can be 5mm-8mm, for example, the diameter of the first air port 113 can be 5mm, 6mm, 7mm, or 8mm. Alternatively, the diameter of the second air port 114 can be 1mm-5mm, for example, the diameter of the second air port 114 can be 1mm, 2mm, 3mm, 4mm, or 5mm.

[0058] In this embodiment, please refer to Figure 1 The exhaust passage 111 is formed as a blind hole penetrating through the first end of the main shaft 110. The first end of the main shaft 110 is provided with an end cover 115 to cover the blind hole and form the exhaust passage 111. The end cover 115 can be fixed to the first end of the main shaft 110 by a connecting member, which can be a bolt or the like.

[0059] As shown in Figure 1As shown, the oil separator 200 is located within the exhaust channel 111 and between the first air port 113 and the exhaust port 112, for separating the oil and gas flowing from the oil chamber 310 to the sealed space 101. It can be understood that the oil separator 200 is located within the exhaust channel 111, and the main shaft 110 drives the oil separator 200 to rotate, thereby separating the oil and gas entering from the first air port 113 into oil and gas. This ensures that the oil chamber 310 and the working chamber 102 are connected and pressure balanced, while preventing oil and gas containing lubricating oil or other liquids from entering the working chamber 102 of the vacuum pump body 100 through the assembly gap.

[0060] In this embodiment, please refer to Figure 2 and Figure 3 The oil separator 200 includes a body 210, a fixing part 220, and a separating part 230. The body 210 is provided with a hollow channel 201 through which the body 210 is provided. The separating part 230 and the fixing part 220 are both provided on the body 210. The separating part 230 is located between the inlet of the hollow channel 201 and the first air port 113. The fixing part 220 is fixedly connected to the inner wall of the exhaust channel 111. Oil and gas flow sequentially through the first air port 113, the separating part 230, and the hollow channel 201 before entering the exhaust channel 111. Thus, oil and gas enter the exhaust channel 111 through the first air port 113 and flow to the separating part 230. Oil and gas are separated by the separating part 230. The separated gas flows to the hollow channel 201 and then to the downstream exhaust channel 111, and then to the sealed space 101 to achieve pressure balance between the working chamber 102 and the oil chamber 310.

[0061] In this embodiment, the fixing part 220 is located on the side of the separating part 230 away from the inlet of the hollow channel 201, and the first air port 113 is located between the fixing part 220 and the separating part 230. Thus, the fixing part 220 not only achieves a fixed connection with the main shaft 110, but also guides the oil and gas flow entering from the first air port 113 towards the separating part 230, allowing the separated gas to flow towards the hollow channel 201. The fixing part 220 can be interference-fitted with the sidewall of the exhaust channel 111, and further, the fixing part 220 can be formed as a cylindrical structure that can fit against the inner wall of the exhaust channel 111.

[0062] The separation section 230 includes a plurality of vanes 231 extending circumferentially along the body 210, and a spiral channel is formed between the vanes 231 to allow oil and gas to pass through.

[0063] Please refer to Figure 1 The second air inlet 114 and the first air inlet 113 are respectively located on both sides of the separation section 230.

[0064] It can be understood that the main shaft 110 drives the separation part 230 with the plurality of rotating vanes 231 to rotate, and the oil gas forms a rotating airflow in the spiral channel between the rotating vanes 231, so that the oil in the oil gas is thrown out due to gravity, thereby realizing separation of the oil gas entering from the first gas port 113 into oil and gas, and the oil can be discharged from the second gas port 114.

[0065] In the embodiment, the body 210 extends to the second gas port 114 and at least partially blocks the second gas port 114, and the body 210 is spaced apart from the second gas port 114, so that when the oil gas entering from the second gas port 114 enters the exhaust channel 111, the oil gas can be prevented from directly entering the hollow channel 201 due to the blocking of the body 210, and a certain oil gas separation effect can also be achieved; further, the second gas port 114 can be provided corresponding to the end of the separation part 230, so that the oil gas entering from the second gas port 114 can also be separated by the separation part 230, and the spacing of the body 210 from the second gas port 114 is also conducive to the discharge of the oil.

[0066] In the embodiment, the body 210 extends to the second gas port 114, the body 210 blocks the second gas port 114 and exceeds the second gas port 114 by at least 3 mm, and the body 210 is spaced apart from the second gas port 114, so that the oil gas entering from the second gas port 114 can be prevented from directly flowing to the hollow channel 201, and the blocking time of the body 210 on the oil gas entering from the second gas port 114 can be prolonged, further improving the oil separation effect of the body 210.

[0067] In the embodiment, the body 210 exceeds the second gas port 114 by at least 3 mm, which can be understood with reference to Figure 1 The distance L between the end of the body 210 provided at one end of the separation part 230 and the second gas port 114 is at least 3 mm.

[0068] In the embodiment, the oil separator 200 can be pressed into the exhaust channel 111 of the main shaft 110 by interference.

[0069] In the embodiment, the vacuum pump further comprises a filter 400.

[0070] In the embodiment, the filter 400 is arranged in the exhaust channel 111, and the filter 400 is located between the exhaust port 112 and the oil separator 200, and the filter 400 can be used to filter impurities and oil, so as to prevent the impurities from entering the working chamber 102 through the exhaust channel 111, so as to ensure the cleanliness of the working area of the vacuum pump body 100, and further separate the oil and gas in the gas, reduce the content of the oil in the gas, and also Figure 1As shown, the oil gas entering the second gas port 114 enters the exhaust passage 111, and the oil content is high, so that the gas entering the hollow passage 201 also contains part of the oil, and the gas flowing out of the hollow passage 201 is filtered by the filter 400, which can further ensure the cleanliness of the gas.

[0071] In the embodiment, please refer to Figure 1 In order to cooperate with the limiting installation filter 400 and the oil separator 200, the main shaft 110 is provided with a ring-shaped limiting step 116 along the exhaust passage 111, so that the filter 400 can be pressed between the oil separator 200 and the limiting step 116.

[0072] In the embodiment, please refer to Figure 4 The filter 400 includes a cylindrical body 410 and a filter screen 420, and the first end of the cylindrical body 410 is fixed with the filter screen 420, wherein the first end of the cylindrical body 410 of the filter 400 is limited to be arranged at the limiting step 116, and the second end is connected with the oil separator 200.

[0073] The filter 400 and the oil separator 200 can be pressed into the exhaust passage 111 of the main shaft 110 and be limited and pressed at the limiting step 116.

[0074] The working principle and process of the vacuum pump provided by the embodiment of the utility model are as follows:

[0075] The vacuum pump body 100 has two working conditions, and the working principle and process are introduced as follows according to the two working conditions:

[0076] The first condition: the vacuum pump body 100 is in the working condition of vacuum pumping operation, the pressure in the oil cavity 310 of the oil tank 300 is close to a standard atmospheric pressure, at this time, the pressure in the oil cavity 310 is greater than the working cavity 102 pressure of the vacuum pump body 100. The pressure difference will make the working pressure of the sealing element 133 and the bearing, the shaft sleeve 132 and other components become larger, and the service life of the vacuum pump body 100 is shortened. Therefore, the pressure in the oil cavity 310 is allowed to release to the working cavity 102, but at this time, the gas in the oil tank 300 contains oil such as lubricating oil, and the lubricating oil and other oil entering the working cavity 102 will cause damage to the vacuum pump, so it is necessary to filter, and in the application, the oil separator 200 is arranged to separate the oil gas in the oil cavity 310, so as to prevent the oil from entering the working cavity 102 with the gas and damaging the vacuum pump.

[0077] Therefore, in the working condition of the vacuum pump body 100 in the vacuum pumping operation: since the pressure in the oil cavity 310 is greater than the pressure of the working cavity 102 of the vacuum pump body 100, the pressure in the oil cavity 310 is released into the working cavity 102. Under the action of the pressure, the oil gas enters from the first gas port 113; wherein the main shaft 110 is in a rotating state of working, and the main shaft 110 drives the separation part 230 on the internal oil separator 200 to separate the oil gas, and separates the oil gas into oil and gas.

[0078] Further, the separated gas enters the sealed space 101 from the hollow channel 201, the exhaust channel 111 and the exhaust port 112, and under the action of the pressure, the working cavity 102 communicates with the sealed space 101 through the assembly gap of the sealing element 133; then the gas further enters the working cavity 102 through the assembly gap, so as to balance the pressure of the working cavity 102 and the oil cavity 310, wherein the first gas port 113 and the second gas port 114 can simultaneously realize gas inlet, and the separated oil can also move along the separation part 230 to the second gas port 114 and be thrown out from the second gas port 114.

[0079] The second case: in the broken gas operation state of the vacuum pump body 100 in the broken vacuum, the vacuum state in the vacuum pump needs to be broken, so the pressure of the working cavity 102 of the vacuum pump body 100 will rise sharply. Under the action of the pressure, the process gas in the working cavity 102 has a tendency to move towards the oil cavity 310, and the process gas entering the oil cavity 310 will cause the fluorine oil of the oil tank 300 to fail rapidly, causing abnormal wear of the bearing and other parts.

[0080] Therefore, in the working condition of the vacuum pump body 100 in the broken gas operation state of the broken vacuum: in order to prevent the process gas from flowing from the working cavity 102 to the oil cavity 310, the pressure of the working cavity 102 of the vacuum pump body 100 needs to be not higher than the external pressure, so nitrogen needs to be supplied unidirectionally through the nitrogen purging hole 320 to pressurize the oil cavity 310, so as to ensure that the pressure of the working cavity 102 and the pressure of the oil cavity 310 quickly reach balance. Under the pressurization of the nitrogen purging hole 320, the oil gas in the oil cavity 310 will enter the first gas port 113; wherein the main shaft 110 is in a rotating state of working, and the main shaft 110 drives the separation part 230 on the internal oil separator 200 to separate the oil gas, and separates the oil gas into oil and gas.

[0081] Further, the separated oil moves along the separation part 230 to the second gas port 114 and is thrown out from the second gas port 114, and the clean gas after separation can flow to the working cavity 102 through the assembly gap to maintain the pressure balance of the working cavity 102 and the oil cavity 310.

[0082] In summary, the vacuum pump provided by the embodiment of the present application is characterized in that the exhaust passage 111, the exhaust port 112 and the first gas port 113 are arranged on the main shaft 110, so that the working cavity 102 of the vacuum pump body 100 and the oil cavity 310 of the oil tank 300 are connected in communication under the action of pressure, and the working cavity 102 of the vacuum pump body 100 and the oil cavity 310 of the oil tank 300 are balanced in pressure; the oil separator 200 is arranged in the exhaust passage 111, and the oil separator 200 can separate the oil gas entering from the first gas port 113, so that the oil in the oil gas is separated out, and the oil gas with oil such as lubricating oil is prevented from entering the working cavity 102.

[0083] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, and all the changes or replacements should be covered within the protection scope of the present application.

Claims

1. A vacuum pump, characterized by, The vacuum pump body (100) comprises a cavity, an oil tank (300) and a main shaft (110) penetrating the cavity, the cavity is internally provided with a working chamber (102), the oil tank (300) is arranged at one side of the cavity, a first end of the main shaft (110) extends out of the cavity and is located in an oil cavity (310) of the oil tank (300), a sealing space (101) accommodating a sealing element (133) is formed between the cavity and the main shaft (110), an exhaust passage (111), a first gas port (113) and an exhaust port (112) are formed in the main shaft (110), the first gas port (113) communicates the oil cavity (310) and the exhaust passage (111), the exhaust port (112) communicates the exhaust passage (111) and the sealing space (101), the sealing space (101) is communicated with the working chamber (102) under the action of pressure through the assembly gap of the sealing element (133); The oil separator (200) is arranged in the exhaust passage (111) and located between the first gas port (113) and the exhaust port (112) to separate oil gas flowing from the oil cavity (310) to the sealing space (101). The oil separator (200) comprises a body (210), a fixed part (220) and a separation part (230), the body (210) is provided with a hollow passage (201) penetrating the body (210), the separation part (230) and the fixed part (220) are arranged on the body (210), the separation part (230) is located between the inlet of the hollow passage (201) and the first gas port (113), the fixed part (220) is fixedly connected with the inner wall of the exhaust passage (111), and the oil gas sequentially flows through the first gas port (113), the separation part (230) and the hollow passage (201).

2. Vacuum pump according to claim 1, characterized in that The separation part (230) comprises a plurality of spiral vanes (231) extending in a meandering manner along the circumference of the body (210), and a spiral passage is formed between the spiral vanes (231) for the oil gas to pass through.

3. Vacuum pump according to claim 2, characterized in that The fixed part (220) is arranged on the side of the separation part (230) away from the inlet of the hollow passage (201), and the first gas port (113) is located between the fixed part (220) and the separation part (230).

4. Vacuum pump according to claim 2, characterized in that The main shaft (110) is further provided with a second gas port (114) communicating with the oil cavity (310) for oil discharge, and the second gas port (114) and the first gas port (113) are arranged on the two sides of the separation part (230), respectively.

5. The vacuum pump of claim 2, wherein, The flow area of the second gas port (114) is smaller than the flow area of the first gas port (113); and / or 6. Vacuum pump according to claim 5, characterized in that The body (210) extends to the second gas port (114), at least part of the body (210) shields the second gas port (114), and the body (210) is spaced apart from the second gas port (114); and / or ​ The body (210) extends to the second gas port (114), the body (210) blocks the second gas port (114) and exceeds the second gas port (114) by at least 3mm, and the body (210) is spaced apart from the second gas port (114).

7. The vacuum pump of claim 1, wherein, The oil tank (300) is provided with a nitrogen purging hole (320) for introducing nitrogen, and the nitrogen purging hole (320) communicates with the oil cavity (310).

8. The vacuum pump of claim 1, wherein, The vacuum pump further comprises a filter (400) arranged in the exhaust passage (111) and located between the oil separator (200) and the exhaust port (112).

9. Vacuum pump according to claim 8, characterized in that A limiting step (116) is arranged in the exhaust passage (111), and the filter (400) is pressed between the oil separator (200) and the limiting step (116).

10. The vacuum pump of claim 1, wherein, A one-way valve is further included, which is arranged between the exhaust port (112) and the oil cavity (310) in the flow direction of the oil gas.

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