Multistage roots vacuum pump with internal flow channel

Abstract

The utility model discloses a multistage roots vacuum pump with an internal flow channel, and belongs to the technical field of roots vacuum pumps. Comprising a vacuum pump body, a driving gear and a driven gear which are meshed with each other are arranged on the vacuum pump body, and the driving gear is driven by a motor. The plurality of vacuum pump bodies are connected in series through gas paths, and the exhaust port of the previous-stage vacuum pump body is communicated with the gas inlet of the next-stage vacuum pump body. The multi-stage vacuum pump body which is detachably connected is adopted, so that maintenance and replacement are convenient.

Description

Technical Field

[0001] This application belongs to the technical field of Roots vacuum pumps, and particularly relates to a multi-stage Roots vacuum pump with an internal flow channel. Background Art

[0002] A Roots vacuum pump is a centrifugal exhaust pump commonly used in high-vacuum technology, mainly composed of two rotors. They rotate synchronously but do not contact inside the pump housing. When the Roots pump starts to operate, the rotation of the rotor causes the two rotors to rotate in the same direction, but they do not contact each other. Instead, gas is transferred from the suction side of one rotor to the discharge side of the other rotor. In this way, a continuous volume of gas is formed between the two rotors.

[0003] On December 24, 2021, a multi-stage Roots vacuum pump with the publication number of CN215292882U was authorized and announced in the Chinese patent. It includes a driving shaft, a driven shaft, and a number of end covers that are sequentially fitted. The driving shaft and the driven shaft rotate synchronously through a pair of synchronous gears meshing at their ends. The driving shaft and the driven shaft penetrate through all the end covers. The front side of each end cover is recessed backward, and a pump chamber is formed between the recessed part and the rear side of the previous end cover. A pair of Roots rotors are provided in each pump chamber, and the Roots rotors are respectively installed on the driving shaft and the driven shaft; the depth of the pump chamber decreases sequentially from front to back; a gas channel is also provided in each end cover, and the inlet of the gas channel communicates with the pump chamber on the front side, and the outlet communicates with the pump chamber on the rear side. In this patent, the multi-stage rotors are installed inside the same pump housing, and the maintenance and replacement are relatively cumbersome. Summary of the Utility Model

[0004] The technical problem to be solved by this application is: to overcome the deficiencies of the prior art and provide a multi-stage Roots vacuum pump with an internal flow channel. This application uses a multi-stage detachable vacuum pump body, which is convenient for maintenance and replacement.

[0005] The technical solution adopted by this application to solve the existing problems is:

[0006] A multi-stage Roots vacuum pump with an internal flow channel includes a vacuum pump body, on which a driving gear and a driven gear that mesh with each other are provided, and the driving gear is driven by a motor.

[0007] A number of vacuum pump bodies are connected in series in the gas path, and the exhaust port of the upper-stage vacuum pump body is connected to the intake port of the lower-stage vacuum pump body in a through manner.

[0008] Preferably, only the driving gear of one vacuum pump body is connected to the output shaft of the motor, and the gears between adjacent two vacuum pump bodies are connected through a speed increasing connection device, and the gear speeds of each vacuum pump body increase gradually in sequence.

[0009] Preferably, the speed increasing connection device includes two pulleys of different sizes and a timing belt connecting the two pulleys. The two pulleys are respectively connected to the driving gear or the driven gear of two adjacent vacuum pump bodies.

[0010] Preferably, two adjacent vacuum pump bodies are detachably connected.

[0011] Preferably, an intermediate body is connected through between two adjacent vacuum pump bodies, and a bypass pipe is connected through the outside of the intermediate body.

[0012] Preferably, a stop valve is connected in series on the bypass pipe.

[0013] Preferably, the stop valve is an electronically controlled valve with adjustable opening.

[0014] Compared with the prior art, the beneficial effects of the present application are as follows:

[0015] (1) By adopting multi-stage detachably connected vacuum pump bodies, it is convenient for maintenance and replacement.

[0016] (2) The multi-stage vacuum pump bodies are controlled by one motor, which reduces costs and simplifies the control process.

[0017] (3) A bypass pipe is provided between two adjacent stages of vacuum pumps. Since the negative pressures generated by each bypass pipe are different, a set of units can be matched with multiple negative pressure values. Description of the Drawings

[0018] The present application will be further described below with reference to the drawings and embodiments.

[0019] Figure 1 It is a structural diagram of a multi-stage Roots vacuum pump with an internal flow path of the present application.

[0020] Figure 2 is Figure 1 top view of.

[0021] In the figure: 1 - vacuum pump body, 2 - driving gear, 3 - driven gear, 4 - motor, 5 - speed increasing connection device, 6 - intermediate body, 7 - bypass pipe, 8 - stop valve. Detailed Embodiments

[0022] As certain terms are used in the description and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. The description and claims of this specification do not use the difference in names as a way to distinguish components, but use the difference in functions of components as the criterion for distinction. As used throughout the description and claims, "comprising" is an open-ended term and should be interpreted as "comprising but not limited to". "Substantially" means within an acceptable error range, and those skilled in the art can solve the technical problem within a certain error range and basically achieve the technical effect.

[0023] In the description of this application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "horizontal", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to this application.

[0024] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0025] The drawings are the best embodiments of the multi-stage Roots vacuum pump with an internal flow path. The following further describes this application in detail with reference to the drawings.

[0026] A multi-stage Roots vacuum pump with an internal flow path, consisting of Figure 1 and Figure 2 As shown, it includes a vacuum pump body 1. The vacuum pump body 1 is a prior art and mainly includes a pump casing and a rotor with a rotating shaft inside. On the vacuum pump body 1, there are a driving gear 2 and a driven gear 3 that mesh with each other. The driving gear 2 and the driven gear 3 are respectively coaxially connected to the rotors inside the vacuum pump body 1.

[0027] A number of vacuum pump bodies 1 are connected in series in the gas path. The exhaust port of the upper-stage vacuum pump body 1 is connected in communication with the intake port of the lower-stage vacuum pump body 1. The output air pressure of each stage of the vacuum pump body 1 gradually increases. To achieve this purpose, the rotational speed of the rotors inside each stage of the vacuum pump body 1 needs to gradually increase.

[0028] Therefore, in this embodiment, the following two methods are adopted:

[0029] 1. The driving gear 2 is driven by a motor 4. Each vacuum pump body 1 is provided with a motor 4, and the output power and rotational speed of each motor 4 are different;

[0030] 2. Only the driving gear 2 of one vacuum pump body 1 is connected to the output shaft of the motor 4. The gears between adjacent two vacuum pump bodies 1 are connected by a speed increasing connecting device 5, and the rotational speeds of the gears of each vacuum pump body 1 increase gradually in stages.

[0031] Compared with the first layout method, the second layout method only requires one motor 4, which can reduce costs and is more convenient to control by using one motor 4. Each stage of the vacuum pump body 1 starts and stops simultaneously. Therefore, the second layout method is preferred.

[0032] The speed increasing connecting device 5 includes two pulleys of different sizes and a synchronous belt connecting the two pulleys. The two pulleys are respectively connected to the driving gear 2 or the driven gear 3 of adjacent two vacuum pump bodies 1.

[0033] In order to achieve quick replacement and maintenance of each stage of the vacuum pump body, adjacent two vacuum pump bodies 1 are connected by bolts to achieve detachable connection.

[0034] In order to generate different vacuum degrees, in this embodiment, an intermediate body 6 is connected through between adjacent two vacuum pump bodies 1. The outside of the intermediate body 6 is connected through with a bypass pipe 7. A stop valve 8 is connected in series on the bypass pipe 7, and the stop valve 8 is an electric control valve with adjustable opening.

[0035] The embodiments of the present application have been described in detail above with reference to the accompanying drawings. However, the present application is not limited to the above embodiments. Within the knowledge scope of those of ordinary skill in the art to which the present application pertains, various changes can be made without departing from the purpose of the present application.

Claims

1. A multi-stage Roots vacuum pump with an internal flow channel, comprising a vacuum pump body (1), the vacuum pump body (1) being provided with a driving gear (2) and a driven gear (3) meshing with each other, the driving gear (2) being driven by a motor (4), characterized in that: The gas paths of the plurality of vacuum pump bodies (1) are connected in series, and the exhaust port of the upper vacuum pump body (1) is connected to the air inlet of the lower vacuum pump body (1); Only one driving gear (2) of a vacuum pump body (1) is connected to the output shaft of the motor (4), the gears between two adjacent vacuum pump bodies (1) are connected via a speed increasing connection device (5), and the gear speeds of the gears of each vacuum pump body (1) increase step by step; The speed increasing connection device (5) comprises two large and small pulleys and a synchronous belt connecting the two pulleys, the two pulleys being respectively connected to the driving gear (2) or the driven gear (3) of two adjacent vacuum pump bodies (1); Two adjacent vacuum pump bodies (1) are detachably connected.

2. A multi-stage Roots vacuum pump with an internal flow channel according to claim 1, characterized in that: An intermediate body (6) is connected through two adjacent vacuum pump bodies (1), and a bypass pipe (7) is connected through the outside of the intermediate body (6).

3. A multi-stage Roots vacuum pump with an internal flow channel according to claim 2, characterized in that: The bypass pipe (7) is connected in series with a stop valve (8).

4. A multi-stage Roots vacuum pump with an internal flow channel according to claim 3, characterized in that: The stop valve (8) is an electrically controlled valve with adjustable opening.

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