Screw vacuum pump rotor profile

Abstract

The utility model provides a screw vacuum pump rotor profile which comprises a master screw rotor profile and a slave screw rotor profile which are meshed with each other, the master screw rotor profile is provided with at least one group of claw-shaped end faces, and each claw-shaped end face is composed of an epicycloid segment AB, a tooth crest arc segment FA, a common epicycloid segment EF, an epicycloid segment CD and a tooth root circle segment DE. And the claw-shaped end surfaces of the driving screw rotor molded line and the driven screw rotor molded line are meshed with each other to generate an extrusion effect in the rotating process. According to the screw vacuum pump, the main screw rotor molded lines and the auxiliary screw rotor molded lines are arranged in a staggered mode and meshed with each other, the air transmission effect is enhanced through the characteristic of the special structure of the claw-shaped end face, and therefore the working efficiency of the screw vacuum pump is improved.

Description

Technical Field

[0001] This utility model belongs to the field of vacuum pump rotor profile technology, and particularly relates to a screw vacuum pump rotor profile. Background Technology

[0002] The screw vacuum pump rotor is a pair of meshing rotors that rotate in opposite directions. The rotors are not in contact with the housing and the two side plates. At the same time, the two rotors are also driven by synchronous gears to maintain a certain gap and not in contact. As the vacuum pump rotates, the space formed between the rotor and the housing completes the process of gas intake and exhaust from the inlet to the outlet, realizing the gas transportation.

[0003] Existing screw vacuum pump rotor profiles mostly adopt a smooth curve structure. Although the smooth curve can compress and push air, it cannot meet the vacuum requirements of the pump body when high vacuum is required. Utility Model Content

[0004] This invention provides a rotor profile for a screw vacuum pump, which aims to increase the air intake and compression ratio of the pump body and improve the overall vacuum level of the pump body.

[0005] This utility model is implemented as follows: a screw vacuum pump rotor profile includes a main screw rotor profile and a driven screw rotor profile that mesh with each other. The main screw rotor profile is provided with at least one set of claw-shaped end faces, which are composed of an epicycloid segment AB, a tooth tip arc segment FA, a normal epicycloid segment EF, an epicycloid segment CD, and a tooth root arc segment DE.

[0006] The coordinate equation of the epicycloid segment AB is:

[0007] x:-(Rf+Rt)*cos(t1)+Rf*cos(2*t1),

[0008] y:-(Rf+Rt)*cos(t1)+Rf*cos(2*t1);

[0009] The coordinate equation of the epicycloid segment CD is:

[0010] x: (Rf+Rt)*cos(t2)-Rf*cos(2*t2),

[0011] y: (Rf+Rt)*cos(t2)-Rf*cos(2*t2);

[0012] The coordinate equation of the epicycloid segment DE is:

[0013] x: Rf*cos(t3),

[0014] y: Rf*sin(t3);

[0015] The coordinate equation of the epicycloid segment EF is:

[0016] x:-(Rf+Rt)*cos(t4)+Rf*cos(2*t4),

[0017] y:-(Rf+Rt)*cos(t4)+Rf*cos(2*t4);

[0018] The coordinate equation of the epicycloid segment FA is:

[0019] x: Rt*cos(t5),

[0020] y: Rt*sin(t5);

[0021] Rt is the addendum circle radius, Rf is the dedendum circle radius, and t1, t2, t3, and t4 are all parameters.

[0022] Preferably, the claw-shaped end faces are a set and are disposed on the periphery of the rotor body. A pitch circle arc segment BC provides a transition connection between the epicycloid segment AB and the epicycloid segment CD.

[0023] The coordinate equation of the arc segment BC of the nodal circle is:

[0024] x: (Rf+Rt) / 2*cos(t6),

[0025] y: (Rf+Rt) / 2*sin(t6);

[0026] Preferably, there are three sets of claw-shaped end faces, and the claw-shaped end faces are arranged in a ring array on the profile of the main screw rotor.

[0027] Preferably, the distance from the tooth tip arc segment FA of one of the three sets of claw-shaped end faces to the rotation axis is smaller than the distance from the tooth tip arc segment FA of the other two sets of claw-shaped end faces to the rotation axis.

[0028] Preferably, the distance from the tooth tip arc segment FA to the rotation axis of the claw-shaped end face with the smaller distance is at least 3 to 5 mm smaller than the distance from the tooth tip arc segment FA to the rotation axis of the other two sets of claw-shaped end faces.

[0029] Preferably, the main screw rotor profile and the driven screw rotor profile have the same structure.

[0030] Preferably, the main screw rotor profile and the driven screw rotor profile are staggered and mesh with each other. The epicycloid segment AB, the tooth tip arc segment FA, and the ordinary epicycloid segment EF form a claw-shaped protrusion, while the ordinary epicycloid segment EF, the epicycloid segment CD, and the tooth root arc segment DE form a groove. During rotation, the claw-shaped protrusion on the main screw rotor profile extends into the groove on the driven screw rotor profile. As rotation continues, the claw-shaped protrusion on the driven screw rotor profile extends into the groove on the main screw rotor profile.

[0031] Compared with the prior art, the embodiments of this application have the following main advantages:

[0032] The main screw rotor profile and the driven screw rotor profile of the screw vacuum pump provided by this utility model are staggered and mesh with each other. The special structure of the claw-shaped end face increases the air intake and compression ratio of the pump body, thereby improving the vacuum degree of the entire pump body. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the rotor profile of a screw vacuum pump provided by this utility model.

[0034] Figure 2 This utility model provides a schematic diagram of the structure of a screw vacuum pump rotor profile with a set of claw-shaped end faces.

[0035] Figure 3 This utility model provides a schematic diagram of a screw vacuum pump rotor profile with a set of claw-shaped end faces, where the main screw rotor profile and the driven screw rotor profile mesh with each other.

[0036] Figure 4 This utility model provides a schematic diagram of a main screw rotor profile structure with three sets of claw-shaped end faces, which is a type of screw vacuum pump rotor profile.

[0037] Figure 5 This utility model provides a schematic diagram of the structure of a screw vacuum pump rotor profile in which a main screw rotor profile and a driven screw rotor profile with three sets of claw-shaped end faces mesh with each other.

[0038] Explanation of reference numerals in the attached figures:

[0039] 100, Main screw rotor profile; 200, Driven screw rotor profile. Detailed Implementation

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, not to describe a particular order.

[0041] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0042] This utility model embodiment provides a rotor profile for a screw vacuum pump, such as... Figures 1-5 As shown, the rotor profile of the screw vacuum pump includes: a main screw rotor profile 100 and a driven screw rotor profile 200 that mesh with each other. The main screw rotor profile 100 is provided with a set of claw-shaped end faces, which are composed of an epicycloid segment AB, a tooth tip arc segment FA, a normal epicycloid segment EF, an epicycloid segment CD, and a tooth root arc segment DE. The epicycloid segment AB and the epicycloid segment CD are connected by a pitch circle arc segment BC.

[0043] The coordinate equation of the epicycloid segment AB is:

[0044] x:-(Rf+Rt)*cos(t1)+Rf*cos(2*t1),

[0045] y:-(Rf+Rt)*cos(t1)+Rf*cos(2*t1);

[0046] The coordinate equation of the arc segment BC of the nodal circle is:

[0047] x: (Rf+Rt) / 2*cos(t6),

[0048] y: (Rf+Rt) / 2*sin(t6);

[0049] The coordinate equation of the epicycloid segment CD is:

[0050] x: (Rf+Rt)*cos(t2)-Rf*cos(2*t2),

[0051] y: (Rf+Rt)*cos(t2)-Rf*cos(2*t2);

[0052] The coordinate equation of the epicycloid segment DE is:

[0053] x: Rf*cos(t3),

[0054] y: Rf*sin(t3);

[0055] The coordinate equation of the epicycloid segment EF is:

[0056] x:-(Rf+Rt)*cos(t4)+Rf*cos(2*t4),

[0057] y:-(Rf+Rt)*cos(t4)+Rf*cos(2*t4);

[0058] The coordinate equation of the epicycloid segment FA is:

[0059] x: Rt*cos(t5),

[0060] y: Rt*sin(t5);

[0061] Rt is the addendum circle radius, Rf is the dedendum circle radius, and t1, t2, t3, t4, t5, and t6 are all parameters.

[0062] In this embodiment, the value range of t1 is -36.147° to 23.8°, the value range of t6 is -23.7° to 287.61°, the value range of t2 is 0 to 23.8°, the value range of t3 is -30° to 60°, the value range of t4 is -36° to 0, and the value range of t5 is -60.35° to 90°.

[0063] In this embodiment, the epicycloid segment AB, the tooth tip arc segment FA, and the ordinary epicycloid segment EF form a claw-shaped protrusion, while the ordinary epicycloid segment EF, the epicycloid segment CD, and the tooth root arc segment DE form a groove. The main screw rotor profile 100 and the driven screw rotor profile 200 have the same structure. During rotation, the claw-shaped protrusion on the main screw rotor profile 100 extends into the groove on the screw rotor profile. As rotation progresses, the claw-shaped protrusion on the driven screw rotor profile 200 extends into the groove on the main screw rotor profile 100.

[0064] The claw-shaped protrusions squeeze and push the material in the groove to complete the vacuum output. Due to the arc-shaped surface structure in the claw-shaped protrusions, the arc surface provides support for the material, and a greater thrust can be applied under the same torque to produce a stronger squeezing effect. Ultimately, the claw-shaped rotor will increase the air intake and compression ratio of the pump body with the help of the special structure of the claw-shaped end face, thereby improving the vacuum degree of the entire pump body.

[0065] It should be noted that the main screw rotor profile 100 rotates clockwise, while the driven screw rotor profile 200 rotates counterclockwise. The rotation direction is mainly set to match the claw-shaped protrusion.

[0066] In a further preferred embodiment of this utility model, the rotor profile of the screw vacuum pump includes: a main screw rotor profile 100 and a driven screw rotor profile 200 that mesh with each other. The main screw rotor profile 100 is provided with three sets of claw-shaped end faces. The claw-shaped end faces are composed of an epicycloid segment AB, a tooth tip arc segment FA, a normal epicycloid segment EF, an epicycloid segment CD, and a tooth root arc segment DE. The different claw-shaped end faces are connected by a pitch circle arc segment BC.

[0067] The coordinate equation of the epicycloid segment AB is:

[0068] x:-(Rf+Rt)*cos(t1)+Rf*cos(2*t1),

[0069] y:-(Rf+Rt)*cos(t1)+Rf*cos(2*t1);

[0070] The coordinate equation of the arc segment BC of the nodal circle is:

[0071] x: (Rf+Rt) / 2*cos(t6),

[0072] y: (Rf+Rt) / 2*sin(t6);

[0073] The coordinate equation of the epicycloid segment CD is:

[0074] x: (Rf+Rt)*cos(t2)-Rf*cos(2*t2),

[0075] y: (Rf+Rt)*cos(t2)-Rf*cos(2*t2);

[0076] The coordinate equation of the epicycloid segment DE is:

[0077] x: Rf*cos(t3),

[0078] y: Rf*sin(t3);

[0079] The coordinate equation of the epicycloid segment EF is:

[0080] x:-(Rf+Rt)*cos(t4)+Rf*cos(2*t4),

[0081] y:-(Rf+Rt)*cos(t4)+Rf*cos(2*t4);

[0082] The coordinate equation of the epicycloid segment FA is:

[0083] x: Rt*cos(t5),

[0084] y: Rt*sin(t5);

[0085] Rt is the addendum circle radius, Rf is the dedendum circle radius, and t1, t2, t3, t4, t5, and t6 are all parameters.

[0086] The distance from the tooth tip arc segment FA of one of the three sets of claw-shaped end faces to the rotation axis is smaller than that of the other two sets of claw-shaped end faces. During compression, if the lengths of the three sets of claw-shaped end faces are equal, material conveying may be interrupted. By controlling the length of the claw-shaped end faces and ensuring that the claw-shaped end faces not under compression are interconnected, interruptions can be avoided, thus minimizing the vibration and noise caused by these interruptions.

[0087] In a preferred embodiment of this invention, the distance from the tooth tip arc segment FA to the rotation axis of the claw-shaped end face with the smaller distance is at least 3 to 5 mm smaller than the distance from the tooth tip arc segment FA to the rotation axis of the other two sets of claw-shaped end faces.

[0088] It should be noted that, for the sake of simplicity, the foregoing embodiments are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to the present invention. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0089] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit the scope of protection of this utility model. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on these embodiments, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model. Although this utility model has been described in detail with reference to the above embodiments, those skilled in the art can still combine, add, delete, or otherwise adjust the features of the various embodiments of this utility model according to the circumstances without conflict or creative effort, thereby obtaining different technical solutions that do not fundamentally depart from the concept of this utility model. These technical solutions are also within the scope of protection of this utility model.

Claims

1. A screw vacuum pump rotor profile, comprising a main screw rotor profile and a driven screw rotor profile that mesh with each other, characterized in that, The main screw rotor profile is provided with at least one set of claw-shaped end faces, which are composed of an epicycloid segment AB, a tooth tip arc segment FA, a normal epicycloid segment EF, an epicycloid segment CD, and a tooth root arc segment DE; The coordinate equation of the epicycloid segment AB is: x:-(Rf+Rt)*cos(t1)+Rf*cos(2*t1), y:-(Rf+Rt)*cos(t1)+Rf*cos(2*t1); The coordinate equation of the epicycloid segment CD is: x: (Rf+Rt)*cos(t2)-Rf*cos(2*t2), y: (Rf+Rt)*cos(t2)-Rf*cos(2*t2); The coordinate equation of the epicycloid segment DE is: x: Rf*cos(t3), y: Rf*sin(t3); The coordinate equation of the epicycloid segment EF is: x:-(Rf+Rt)*cos(t4)+Rf*cos(2*t4), y:-(Rf+Rt)*cos(t4)+Rf*cos(2*t4); The coordinate equation of the epicycloid segment FA is: x: Rt*cos(t5), y: Rt*sin(t5); Rt is the addendum circle radius, Rf is the dedendum circle radius, and t1, t2, t3, t4, and t5 are all parameters.

2. The rotor profile of a screw vacuum pump as described in claim 1, characterized in that, The claw-shaped end faces are a set, and the outer pendulum segment AB and the outer pendulum segment CD are connected by a pitch circle arc segment BC.

3. The rotor profile of a screw vacuum pump as described in claim 2, characterized in that, The coordinate equation of the arc segment BC of the nodal circle is: x: (Rf+Rt) / 2*cos(t6) y: (Rf+Rt) / 2*sin(t6).

4. The rotor profile of a screw vacuum pump as described in claim 1, characterized in that, The claw-shaped end faces are in three groups, and the claw-shaped end faces are arranged in a ring array on the profile of the main screw rotor.

5. The rotor profile of a screw vacuum pump as described in claim 4, characterized in that, The distance from the tooth tip arc segment FA of one of the three sets of claw-shaped end faces to the rotation axis is smaller than the distance from the tooth tip arc segment FA of the other two sets of claw-shaped end faces to the rotation axis.

6. The rotor profile of a screw vacuum pump as described in claim 5, characterized in that, The distance from the tip arc segment FA to the rotation axis of the claw-shaped end face with the smaller distance is at least 3 to 5 mm smaller than the distance from the tip arc segment FA to the rotation axis of the other two sets of claw-shaped end faces.

7. The rotor profile of a screw vacuum pump as described in claim 3 or 6, characterized in that, The main screw rotor profile and the driven screw rotor profile have the same structure.

8. The rotor profile of a screw vacuum pump as described in claim 1, characterized in that, The main screw rotor profile and the driven screw rotor profile are staggered and mesh with each other.

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