CN219388163U - Shell positioning structure of multistage dry vacuum pump - Google Patents

Abstract

The utility model discloses a shell positioning structure of a multistage dry vacuum pump, which comprises a low-pressure end plate, a multistage middle shell, a high-pressure end plate and a motor end cover which are sequentially arranged; and the low-pressure end plate, the middle shell, the high-pressure end plate and the motor end cover are all provided with through positioning pin holes, and the long positioning pins sequentially penetrate through all the positioning pin holes. According to the utility model, the long positioning pins are used as positioning references for installation, all the shell parts are equivalent to the two long positioning pins, no turn-over machining error exists, the overall error of the shell parts is greatly reduced, the installation precision of the dry vacuum pump is improved, and the normal operation of a machine is ensured.

Description

Shell positioning structure of multistage dry vacuum pump

Technical Field

The utility model relates to the technical field of dry vacuum pumps, in particular to a shell positioning structure of a multistage dry vacuum pump.

Background

The dry vacuum pump is widely applied to equipment such as semiconductors, photovoltaics, aerospace, panel manufacturing, various scientific research instruments and the like. The main flow of dry vacuum pumps include screw vacuum pumps, multi-stage claw-Roots compound vacuum pumps, multi-stage Roots vacuum pumps, screw Roots compound vacuum pumps, and the like. The screw vacuum pump has a simple structure, but the screw rotor has a complex shape, and the manufacturing of the screw vacuum pump requires high-precision equipment and has lower processing efficiency. The multi-stage claw type vacuum pump, the multi-stage claw type Roots type composite vacuum pump and the multi-stage Roots type vacuum pump (hereinafter referred to as multi-stage dry type vacuum pump) are relatively simple in shape of the shell and the rotor, and the vertical machining center with slightly better precision can machine the shell and the rotor, but because the shell is stacked step by step, the accumulated error can cause poor equipment stability, the accumulated error is required to be within a design value range, the precision requirement on machining equipment can be greatly improved, and the production cost is greatly increased.

The existing shell is installed and positioned by using a shorter positioning pin, and is installed in a positioning pin hole which is machined on a surface needing to be installed precisely and matched with a pin hole on the plane of another matched part. Typically one face requires 2 locating pins for locating. In this way, for a multistage dry vacuum pump, the shells which are stacked and mounted step by step need to be provided with positioning pin holes on both sides for positioning and mounting with the adjacent shells except for the two ends of the shell in the middle part. The positioning pin holes on two sides are required to be turned over for processing, so that two errors of a secondary positioning error and a machine tool error exist, on one hand, the processing difficulty is improved, and on the other hand, the accumulated error is increased.

Taking the five-stage dry Roots vacuum pump currently on the market as an example, as shown in FIG. 3, for such a dry pump, there are cases that need to be positioned with a short positioning pin 16 at the time of installation: an existing low pressure end plate 21, an existing primary housing 22, an existing secondary housing 23, an existing tertiary housing 24, an existing quaternary housing 25, an existing penta-stage housing 26, an existing high pressure end plate 27, an existing motor end cap 28. Wherein the low pressure end plate is positioned on only one side, the existing primary shell 22, the existing secondary shell 23, the existing tertiary shell 24, the existing quaternary shell 25, the existing five-stage shell 26, the existing high pressure end plate 27 and the existing motor end cover 28 are positioned on both sides by utilizing the short positioning pins 29, and the second positioning pin holes 30 are machined on both sides. The accumulated error is analyzed as follows: under the condition that the size errors of the pin holes and other size errors are not considered, the position errors of the pin holes on each side of each part are 0.01mm, and the positions errors of the pin holes on the two sides are in different directions, namely, the position errors of the pin holes on the two sides are 0.02mm (the references of the low-pressure end plate and the high-pressure end plate are bearing holes, the references of the primary shell, the secondary shell, the tertiary shell, the quaternary shell and the penta-level shell are working cavities, and the references of the motor end cover are motor positioning flanges). The error of the bearing hole of the low-pressure end plate relative to the motor positioning flange of the motor end cover is 0.14mm by taking the motor end cover as a reference part, and the error is enough to influence the normal operation of the machine.

Disclosure of Invention

In order to solve the problems, the utility model provides a shell positioning structure of a multistage dry vacuum pump, which can reduce error generation and ensure normal operation of a machine.

For this purpose, the technical scheme of the utility model is as follows: a shell positioning structure of a multistage dry vacuum pump comprises a low-pressure end plate, a multistage middle shell, a high-pressure end plate and a motor end cover which are sequentially arranged; and the low-pressure end plate, the middle shell, the high-pressure end plate and the motor end cover are all provided with through positioning pin holes, and the long positioning pins sequentially penetrate through all the positioning pin holes.

The above-mentioned scheme is based on and is a preferable scheme of the above-mentioned scheme: the low-pressure end plate, the middle shell, the high-pressure end plate and the motor end cover are respectively provided with two through positioning pin holes, the two positioning pin holes are distributed up and down to form two positioning channels, and a long positioning pin penetrates through each positioning channel. Each shell is positioned by an upper long positioning pin and a lower long positioning pin, so that subsequent installation is facilitated.

The above-mentioned scheme is based on and is a preferable scheme of the above-mentioned scheme: the length-diameter ratio of the long locating pin is 8-30. The diameter of the long locating pin is larger than that of the common locating pin, so that the long locating pin is not easy to deform.

The above-mentioned scheme is based on and is a preferable scheme of the above-mentioned scheme: the long locating pin is made of quenched steel or hard alloy. When the long locating pin is made of steel, heat treatment is needed, so that the long locating pin has higher hardness and rigidity and deformation resistance; or the long locating pin can be directly made of hard alloy, and has higher hardness and rigidity.

The above-mentioned scheme is based on and is a preferable scheme of the above-mentioned scheme: the middle shell comprises a first-stage shell, a second-stage shell and a third-stage shell, and the long locating pin sequentially penetrates through the low-voltage end plate, the first-stage shell, the second-stage shell, the third-stage shell, the high-voltage end plate and the locating pin hole on the motor end cover. The three-stage dry Roots vacuum pump can adopt the positioning structure.

The above-mentioned scheme is based on and is a preferable scheme of the above-mentioned scheme: the middle shell comprises a first-stage shell, a second-stage shell, a third-stage shell and a fourth-stage shell, and the long locating pin sequentially penetrates through the low-voltage end plate, the first-stage shell, the second-stage shell, the third-stage shell, the fourth-stage shell, the high-voltage end plate and the locating pin hole on the motor end cover. The four-stage dry Roots vacuum pump can adopt the positioning structure.

The above-mentioned scheme is based on and is a preferable scheme of the above-mentioned scheme: the middle shell comprises a first-stage shell, a second-stage shell, a third-stage shell, a fourth-stage shell and a fifth-stage shell, and the long locating pin sequentially penetrates through the low-voltage end plate, the first-stage shell, the second-stage shell, the third-stage shell, the fourth-stage shell, the fifth-stage shell, the high-voltage end plate and the locating pin hole on the motor end cover. The five-stage dry Roots vacuum pump can adopt the positioning structure.

Compared with the prior art, the utility model has the beneficial effects that: the long locating pins are used as locating references for installation, and all shell parts are equivalent to the two long locating pins; the low-pressure end plate, the multi-stage middle shell, the high-pressure end plate and the motor end cover are provided with the through two positioning pin holes, so that the turnover machining error does not exist, the overall error of the shell part is greatly reduced, the installation accuracy of the dry vacuum pump is improved, and the normal operation of the machine is ensured.

Drawings

The following is a further detailed description of embodiments of the utility model with reference to the drawings

FIG. 1 is a schematic diagram of the structure of the present utility model;

FIG. 2 is a schematic view of the primary housing of the present utility model;

FIG. 3 is a schematic diagram of a prior art structure;

fig. 4 is a schematic structural view of a prior art primary housing.

Marked in the figure as: a low-pressure end plate 1, a first-stage shell 2, a second-stage shell 3, a third-stage shell 4, a fourth-stage shell 5, a fifth-stage shell 6, a high-pressure end plate 7, a motor end cover 8, a driving rotor 9, a driven rotor 10, a bearing 11, a synchronous gear 12, a rotor driving shaft 13, a first positioning pin hole 14 and a long positioning pin 15;

an existing low pressure end plate 21, an existing primary housing 22, an existing secondary housing 23, an existing tertiary housing 24, an existing quaternary housing 25, an existing penta-stage housing 26, an existing high pressure end plate 27, an existing motor end cap 28, short dowel pins 29, and second dowel holes 30.

Detailed Description

In the description of the present utility model, it should be noted that, for the azimuth words such as the terms "center", "transverse (X)", "longitudinal (Y)", "vertical (Z)", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., the azimuth and positional relationships are based on the azimuth or positional relationships shown in the drawings, only for convenience of describing the present utility model and simplifying the description, but do not indicate or imply that the apparatus or element to be referred to must have a specific azimuth, be constructed and operated in a specific azimuth, and should not be construed as limiting the specific protection scope of the present utility model.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features. Thus, the definition of "a first", "a second" feature may explicitly or implicitly include one or more of such feature, and in the description of the present utility model, the meaning of "a number", "a number" is two or more, unless otherwise specifically defined.

See the drawings. Take five-stage dry Roots vacuum pumps currently on the market as an example.

The dry vacuum pump comprises a low-pressure end plate 1, a first-stage shell 2, a second-stage shell 3, a third-stage shell 4, a fourth-stage shell 5, a fifth-stage shell 6, a high-pressure end plate 7 and a motor end cover 8 which are sequentially arranged; the inside of the dry vacuum pump is provided with a driving rotor 9 and a driven rotor 10, both sides of the driving rotor 9 and the driven rotor 10 are rotatably arranged on the low-pressure end plate 1 and the high-pressure end plate 7 through bearings 11, the driving rotor 9 and the driven rotor 10 are driven by a synchronous gear 12, and one end of the driving rotor 9 extends out of a motor end cover 8 and is connected with a rotor driving shaft 13.

The low-pressure end plate 1, the first-stage shell 2, the second-stage shell 3, the third-stage shell 4, the fourth-stage shell 5, the fifth-stage shell 6, the high-pressure end plate 7 and the motor end cover 8 are respectively provided with two through first positioning pin holes 14, the two first positioning pin holes 14 are distributed up and down to form two positioning channels, and a long positioning pin 15 penetrates through each positioning channel. Each shell is positioned by an upper long positioning pin 15 and a lower long positioning pin 15, so that subsequent installation is facilitated.

The long dowel 15 is made of quenched steel or cemented carbide. When the long locating pin is made of steel, heat treatment is needed, so that the long locating pin has higher hardness and rigidity and deformation resistance; or the long locating pin can be directly made of hard alloy, and has higher hardness and rigidity.

The length-diameter ratio of the long positioning pin 15 is 8-30. The diameter of the long locating pin is larger than that of the common locating pin, so that the long locating pin is not easy to deform.

Assuming that the error of the position degree of each side pin hole of each part is 0.01mm, respectively machining second positioning pin holes on two sides of a shell in the prior art; the two sides are in different directions, namely the position degree error of the second positioning pin holes on the two sides is 0.02mm, the references of the low-pressure end plate and the high-pressure end plate are bearing holes, the references of the primary shell, the secondary shell, the tertiary shell, the quaternary shell and the quaternary shell are working cavities, and the references of the motor end cover are motor positioning flanges. And taking the motor end cover as a reference part, and the error of the bearing hole of the low-voltage end plate relative to the motor positioning flange of the motor end cover is 0.14mm.

In this embodiment, only the first positioning pin hole is directly formed on each housing, and the motor end cover is used as a reference part, so that the error of the bearing hole of the low-voltage end plate relative to the top positioning flange of the motor end cover is 0.02mm. Therefore, compared with the positioning of a plurality of short positioning pins in the prior art, the positioning mode of the long positioning pins adopted by the embodiment has smaller error and ensures that the machine can normally run.

The above description is only a preferred embodiment of the present utility model, and the protection scope of the present utility model is not limited to the above examples, and all technical solutions belonging to the concept of the present utility model belong to the protection scope of the present utility model. It should be noted that modifications and adaptations to the present utility model may occur to one skilled in the art without departing from the principles of the present utility model and are intended to be within the scope of the present utility model.

Claims (7)

1. A shell positioning structure of a multistage dry vacuum pump comprises a low-pressure end plate, a multistage middle shell, a high-pressure end plate and a motor end cover which are sequentially arranged; the method is characterized in that: and the low-pressure end plate, the middle shell, the high-pressure end plate and the motor end cover are all provided with through positioning pin holes, and the long positioning pins sequentially penetrate through all the positioning pin holes.

2. The housing positioning structure of a multi-stage dry vacuum pump as claimed in claim 1, wherein: the low-pressure end plate, the middle shell, the high-pressure end plate and the motor end cover are respectively provided with two through positioning pin holes, the two positioning pin holes are distributed up and down to form two positioning channels, and a long positioning pin penetrates through each positioning channel.

3. The housing positioning structure of a multi-stage dry vacuum pump as claimed in claim 1, wherein: the length-diameter ratio of the long locating pin is 8-30.

4. The housing positioning structure of a multi-stage dry vacuum pump as claimed in claim 1, wherein: the long locating pin is made of quenched steel or hard alloy.

5. The housing positioning structure of a multi-stage dry vacuum pump as claimed in claim 1, wherein: the middle shell comprises a first-stage shell, a second-stage shell and a third-stage shell, and the long locating pin sequentially penetrates through the low-voltage end plate, the first-stage shell, the second-stage shell, the third-stage shell, the high-voltage end plate and the locating pin hole on the motor end cover.

6. The housing positioning structure of a multi-stage dry vacuum pump as claimed in claim 1, wherein: the middle shell comprises a first-stage shell, a second-stage shell, a third-stage shell and a fourth-stage shell, and the long locating pin sequentially penetrates through the low-voltage end plate, the first-stage shell, the second-stage shell, the third-stage shell, the fourth-stage shell, the high-voltage end plate and the locating pin hole on the motor end cover.

7. The housing positioning structure of a multi-stage dry vacuum pump as claimed in claim 1, wherein: the middle shell comprises a first-stage shell, a second-stage shell, a third-stage shell, a fourth-stage shell and a fifth-stage shell, and the long locating pin sequentially penetrates through the low-voltage end plate, the first-stage shell, the second-stage shell, the third-stage shell, the fourth-stage shell, the fifth-stage shell, the high-voltage end plate and the locating pin hole on the motor end cover.