Screw vacuum pump rotor profile with noise reduction effect

Abstract

The screw vacuum pump rotor profile with the noise reduction effect comprises a main screw rotor and an auxiliary screw rotor which are meshed with each other, the main screw rotor is formed by sequentially connecting three sets 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; the three groups of claw-shaped end surfaces are connected through pitch circular arc sections; and a channel is arranged between the epicycloid section AB and the common epicycloid section EF in one of the three groups of claw-shaped end surfaces. The pair of mutually meshed claw type rotors is adopted, the claw type end faces enable the two rotors to be communicated with each other under the help of the channel, the situation that contact between claw type protrusions and a shell of the screw vacuum pump is interrupted is avoided, and after the two rotors are communicated, the situation that an interval is generated and an air inlet space is enlarged is avoided, namely the air inlet amount of the rotors is increased. And meanwhile, the noise in the operation process of equipment can be reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of the rotor profile of a screw vacuum pump, and particularly relates to a rotor profile of a screw vacuum pump with a noise reduction effect. Background Art

[0002] The rotor of a screw vacuum pump rotates in opposite directions through a pair of meshing rotors. There are clearances between the rotors and the casing and the two side plates without contact. At the same time, a certain clearance is also maintained between the two rotors through the drive of a synchronous gear without contact. As the rotors rotate, the space formed between the rotors and the casing completes the process of inhaling and delivering gas from the inlet to the outlet, realizing the transportation of gas.

[0003] In order to maintain high intake air volume and compression ratio, during actual operation, the outer edge of a single claw of the rotor usually has a very small clearance with the casing. Due to the small clearance, insufficient air supply will occur during operation, resulting in certain vibrations and relatively large noise when the pump body rotates at high speed. Content of the Utility Model

[0004] The utility model provides a rotor profile of a screw vacuum pump with a noise reduction effect, aiming to solve the problem that the clearance between the outer edge of the rotor and the casing is usually small at present, and during high-speed rotation, gas is easily spaced by the claw-shaped rotor, resulting in insufficient air supply at the air inlet, vibrations and noise.

[0005] The utility model is realized as follows. A rotor profile of a screw vacuum pump with a noise reduction effect includes a main screw rotor and a slave screw rotor that mesh with each other. The circumferential side of the main screw rotor is formed by connecting three groups of claw-shaped end faces in sequence. The claw-shaped end face is composed of an involute segment AB, a tooth top arc segment FA, a common involute segment EF, an involute segment CD, and a root circle segment DE; the three groups of claw-shaped end faces are connected by a pitch circle arc segment;

[0006] A channel is provided between the involute segment AB and the common involute segment EF in one of the three groups of claw-shaped end faces.

[0007] Preferably, the coordinate equation of the involute segment AB is:

[0008] x: -(Rf + Rt) * cos(t1) + Rf * cos(2 * t1),

[0009] y: -(Rf + Rt) * sin(t1) + Rf * sin(2 * t1);

[0010] The coordinate equation of the involute segment CD is:

[0011] x: (Rf + Rt) * cos(t2) - Rf * cos(2 * t2),

[0012] y: (Rf + Rt) * cos(t2) - Rf * cos(2 * t2);

[0013] The coordinate equation of the epicycloid segment DE is:

[0014] x: Rf * cos(t3),

[0015] y: Rf * sin(t3);

[0016] The coordinate equation of the epicycloid segment EF is:

[0017] x: -(Rf + Rt) * cos(t4) + Rf * cos(2 * t4),

[0018] y: -(Rf + Rt) * sin(t4) + Rf * sin(2 * t4);

[0019] The coordinate equation of the epicycloid segment FA is:

[0020] x: Rt * cos(t5),

[0021] y: Rt * sin(t5);

[0022] Rt is the addendum circle radius, Rf is the dedendum circle radius, and t1, t2, t3, t4, and t5 are all parameter variables.

[0023] Preferably, the addendum circle radii of the three sets of claw-shaped end faces are the same.

[0024] Preferably, the coordinate equation of the pitch circle arc segment is:

[0025] x: (Rf + Rt) / 2 * cos(t6),

[0026] y: (Rf + Rt) / 2 * sin(t6);

[0027] t6 is a parameter variable.

[0028] Preferably, the structures of the main screw rotor and the slave screw rotor are the same.

[0029] Preferably, the main screw rotor and the slave screw rotor are arranged in a staggered manner and are meshed and connected to each other.

[0030] Preferably, the epicycloid segment AB, the addendum circle 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 dedendum circle segment DE form a groove. During rotation, the claw-shaped protrusion on the main screw rotor extends into the groove on the slave screw rotor during rotation. As the rotation progresses, the claw-shaped protrusion on the slave screw rotor extends into the groove on the main screw rotor.

[0031] Compared with the prior art, the embodiments of the present application mainly have the following beneficial effects:

[0032] The profile of the rotor of the screw vacuum pump with noise reduction effect provided by the present utility model has a channel between the outer swing line segment AB and the ordinary outer swing line segment EF in one of the three claw-shaped end faces. When rotating, when the claw protrusions and grooves mesh with each other, the claw-shaped end faces communicate with each other between the two rotors with the help of the channel, and there will be no interruption due to the contact between the claw protrusions and the shell of the screw vacuum pump. After the two rotors are connected, the interval is avoided, the intake space is increased, that is, the intake volume of the rotor is increased, and at the same time, the noise during the operation of the equipment can be reduced. Description of the Drawings

[0033] Figure 1 It is a schematic structural diagram of the main screw rotor of the profile of the rotor of the screw vacuum pump with noise reduction effect provided by the present utility model.

[0034] Figure 2 It is a schematic structural diagram of the end face of the main screw rotor of the profile of the rotor of the screw vacuum pump with noise reduction effect provided by the present utility model.

[0035] Figure 3 It is a schematic structural diagram of the internal structure of the main screw rotor of the profile of the rotor of the screw vacuum pump with noise reduction effect provided by the present utility model.

[0036] Figure 4 It is a schematic structural diagram of the main screw rotor and the secondary screw rotor of the profile of the rotor of the screw vacuum pump with noise reduction effect provided by the present utility model.

[0037] Description of the Reference Numerals:

[0038] 100, main screw rotor; 110, channel; 200, secondary screw rotor. Detailed Embodiments

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs; the terms used in the description of the present application are only for the purpose of describing specific embodiments, and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the description and claims of this application and the above description of the drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the description and claims of this application or the above drawings are used to distinguish different objects, rather than to describe a specific order.

[0040] References to "embodiments" in this document mean that the specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of this application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment each time, nor are they independent or alternative embodiments mutually exclusive of other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0041] An embodiment of the utility model provides a profile of a screw vacuum pump rotor with a noise reduction effect, as Figures 1-4 shown. The profile of the screw vacuum pump rotor with a noise reduction effect includes a main screw rotor 100 and a slave screw rotor 200 that mesh with each other. The main screw rotor 100 is formed by sequentially connecting three groups of claw-shaped end faces. The claw-shaped end face is composed of an outer cycloid segment AB, a tooth top arc segment FA, a common outer cycloid segment EF, an outer cycloid segment CD, and a tooth root circle segment DE; the three groups of claw-shaped end faces are connected by pitch circle arc segments;

[0042] A channel 110 is provided between the outer cycloid segment AB and the common outer cycloid segment EF in one of the three groups of claw-shaped end faces;

[0043] The outer cycloid segment AB, the tooth top arc segment FA, and the common outer cycloid segment EF form a claw-shaped protrusion, while the common outer cycloid segment EF, the outer cycloid segment CD, and the tooth root circle segment DE form a groove. During rotation, the claw-shaped protrusion on the main screw rotor 100 extends into the groove on the slave screw rotor 200 during rotation. As the rotation progresses, the claw-shaped protrusion on the slave screw rotor 200 extends into the groove on the main screw rotor 100;

[0044] A channel 110 is opened on the outer cycloid segment AB and the common outer cycloid segment EF of the claw-shaped protrusion as a flow channel for materials. When the claw-shaped protrusion and the groove mesh with each other during rotation, the other claw-shaped end faces are connected to each other with the help of the channel 110, enabling the materials to be in a flowing state and preventing interruption due to the contact between the claw-shaped protrusion and the housing. Since the materials are connected, the occurrence of material gaps is avoided, thereby reducing the noise during the operation of the equipment;

[0045] It should be noted that the channel 110 is opened on the claw-shaped protrusion. The main screw rotor 100 and the slave screw rotor 200 have the same structure, and the claw-shaped end faces with the channel 110 on the main screw rotor 100 and the slave screw rotor 200 are arranged in a staggered manner to achieve different connection effects respectively;

[0046] As a preferred embodiment in this embodiment, the coordinate equation of the outer cycloid segment AB is:

[0047] x: -(Rf + Rt) * cos(t1) + Rf * cos(2 * t1),

[0048] y: -(Rf + Rt)*cos(t1) + Rf*cos(2*t1);

[0049] The coordinate equation of the outer cycloid segment CD is as follows:

[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 outer cycloid segment DE is as follows:

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

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

[0055] The coordinate equation of the outer cycloid segment EF is as follows:

[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 outer cycloid segment FA is as follows:

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

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

[0061] The coordinate equation of the pitch circle arc segment is as follows:

[0062] x: (Rf + Rt) / 2*cos(t6),

[0063] y: (Rf + Rt) / 2*sin(t6);

[0064] The three sets of claw-shaped end faces are connected by the pitch circle arc segment;

[0065] In this embodiment, Rt is the addendum circle radius, Rf is the dedendum circle radius, t1, t2, t3, t4, t5, and t6 are all parameter variables, and the addendum circle radius Rt and the dedendum circle radius Rf in the three sets of claw-shaped end faces are the same.

[0066] As a preferred implementation manner in this embodiment, the structures of the main screw rotor 100 and the slave screw rotor 200 are the same, and the main screw rotor 100 and the slave screw rotor 200 are arranged in a staggered manner and meshed with each other;

[0067] In this embodiment, it should be noted that the main screw rotor 100 rotates counterclockwise, and the driven screw rotor 200 rotates clockwise. Here, the rotation direction is mainly set to cooperate with the claw-shaped protrusions.

[0068] It should be noted that for the foregoing embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the present invention is not limited by the described action sequence, because according to the present invention, some steps may be carried out in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0069] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting the protection scope of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all embodiments. Based on these embodiments, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art can still, without conflict and without creative efforts, combine, add, delete or make other adjustments to the features in the embodiments of the present invention according to the circumstances, so as to obtain different technical solutions that essentially do not depart from the concept of the present invention. These technical solutions also belong to the scope of protection of the present invention.

Claims

1. A rotor profile of a screw vacuum pump with a noise reduction effect, characterized in that, It includes a main screw rotor and a slave screw rotor that mesh with each other. The circumferential side of the main screw rotor is formed by three groups of claw-shaped end faces connected in sequence. The claw-shaped end face is composed of an outer cycloid segment AB, a tooth top arc segment FA, a common outer cycloid segment EF, an outer cycloid segment CD, and a tooth root circle segment DE. The three groups of claw-shaped end faces are connected by pitch circle arc segments. There is a channel between the outer cycloid segment AB and the common outer cycloid segment EF in one of the three groups of claw-shaped end faces.

2. The rotor profile of a screw vacuum pump with a noise reduction effect according to claim 1, wherein, The coordinate equation of the outer cycloid 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 outer cycloid 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 outer cycloid segment DE is: x: Rf*cos(t3), y: Rf*sin(t3); The coordinate equation of the outer cycloid 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 outer cycloid segment FA is: x: Rt*cos(t5), y: Rt*sin(t5); Rt is the tooth top circle radius, Rf is the tooth root circle radius, and t1, t2, t3, t4, and t5 are all parameter variables.

3. The rotor profile of a screw vacuum pump with a noise reduction effect as described in claim 2, wherein The coordinate equation of the pitch circle arc segment is: x: (Rf + Rt) / 2*cos(t6), y: (Rf + Rt) / 2*sin(t6); t6 is a parameter variable.

4. The rotor profile of a screw vacuum pump with noise reduction effect according to claim 3, characterized in that, The structures of the main screw rotor and the slave screw rotor are the same.

5. The rotor profile of a screw vacuum pump with a noise reduction effect as described in claim 4, wherein The main screw rotor and the slave screw rotor are arranged in a staggered manner and mesh with each other.

6. The rotor profile of a screw vacuum pump with noise reduction effect as described in claim 5, characterized in that, The outer cycloid segment AB, the tooth top arc segment FA, and the common outer cycloid segment EF form a claw-shaped protrusion, while the common outer cycloid segment EF, the outer cycloid segment CD, and the tooth root circle segment DE form a groove. During rotation, the claw-shaped protrusion on the main screw rotor extends into the groove on the slave screw rotor during rotation. As the rotation progresses, the claw-shaped protrusion on the slave screw rotor extends into the groove on the main screw rotor.

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