Low-vibration single-tooth rotor, design method and dry compressor

Abstract

The invention relates to the field of compressors, in particular to a low-vibration single-tooth rotor, a design method and a dry compressor, a molded line comprises an epicycloid AB, a tooth crest arc BC, a line segment CD, a parabola DE, a tooth pitch arc EF, an envelope line FG of the parabola, an envelope line GH of the line segment, an epicycloid HI and a tooth bottom arc IA which are smoothly connected in sequence and form a closed loop; according to the improved design of the rotor, vibration in the working process of the compressor is greatly reduced, and working noise is reduced.

Description

Technical Field

[0001] The invention relates to the field of compressors, in particular to a low-vibration single-tooth rotor, a design method and a dry compressor. Background Art

[0002] As a dry compressor with good performance, single-tooth compressor is currently widely used in high-tech fields such as aerospace, electronics, and medicine. It realizes compression, intake, and exhaust processes through the synchronous and reverse high-speed rotation of two rotors that mesh with each other but do not directly contact each other. The design of the overall profile of the single-tooth compressor directly affects the performance of the compressor (such as compression ratio, operating noise, etc.).

[0003] The common rotor profiles in single-tooth compressors are as follows: Figure 3 As shown in the figure, the compressor has an outward-extending tooth arm structure, and the two sets of meshing rotors in the compressor have exactly the same tooth shape. Although the two sets of traditional symmetrical single-tooth rotors can achieve high-precision compression operations, they will produce large vibrations during operation. The outward-extending tooth arm structure is subjected to large stress and has uneven connection points, resulting in a poor stress state, and also produces large turbulence and working noise. These problems have been urgently needed to be solved. Summary of the invention

[0004] In order to avoid and overcome the technical problems existing in the prior art, the present invention provides a low-vibration single-tooth rotor, a design method and a dry compressor. The improved design of the rotor of the present invention greatly reduces the vibration of the compressor during operation and reduces the operating noise.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A low-vibration single-tooth rotor, whose profile includes an epicycloid AB, a tooth top arc BC, a line segment CD, a parabola DE, a tooth pitch arc EF, an envelope FG of the parabola, an envelope GH of the line segment, an epicycloid HI and a tooth bottom arc IA which are smoothly connected in sequence to form a closed loop.

[0007] As a further solution of the present invention: the coordinate equation of the epicycloid AB is:

[0008]

[0009] Among them, R 1 is the radius of the tooth top arc BC;

[0010] R 2 is the radius of the pitch arc EF;

[0011] The coordinate equation of the tooth top arc BC is:

[0012]

[0013] The coordinate equation of line segment CD is:

[0014]

[0015] Among them, α is the arc angle of the tooth top arc BC;

[0016] The two endpoints of line segment CD are point C and point D, the rotation axis of the rotor is point O, and γ is the angle between OC and OD;

[0017]

[0018] The coordinate equation of the parabola DE is:

[0019]

[0020] in,

[0021] l x =-R 2 sin(α+γ)cos2(α+γ);

[0022]

[0023] The coordinate equation of the pitch arc EF is:

[0024]

[0025] The coordinate equation of the parabola's envelope FG is:

[0026]

[0027] in,

[0028] The coordinate equation of the envelope GH of the line segment is:

[0029]

[0030] in,

[0031] The coordinate equation of the epicycloid HI is:

[0032]

[0033] The coordinate equation of the tooth bottom arc IA is:

[0034]

[0035] Among them, R 3 is the radius of the tooth bottom arc IA.

[0036] As a further embodiment of the present invention: R 3 =2R 2 -R 1 .

[0037] A design method for a low-vibration single-tooth rotor comprises the following steps:

[0038] S1. Determine the radius R of the rotor's tooth tip arc BC according to the design working conditions. 1 , Radius R of pitch arc EF 2 And the arc angle α of the tooth top arc BC; according to the radius R of the tooth top arc BC 1 and the radius R of the pitch arc EF 2 Determine the radius R of the tooth bottom arc IA 3 ;

[0039] S2. Build a plane rectangular coordinate system with the radius R of the tooth top arc BC 1 , Radius R of pitch arc EF 2 And the radius R of the tooth bottom arc IA 3 Draw the tooth addendum circle, tooth pitch circle and tooth bottom circle respectively. The centers of the tooth addendum circle, tooth pitch circle and tooth bottom circle coincide with each other. The center point O is used as the coordinate origin of the plane rectangular coordinate system. The line connecting one of the end points B of the tooth addendum arc BC and point O is used as the x-axis of the plane rectangular coordinate system. Draw the tooth addendum arc BC in the first quadrant of the plane rectangular coordinate system according to the arc angle α of the tooth addendum arc BC.

[0040] S3. Draw an epicycloid AB in a plane rectangular coordinate system according to its coordinate equation. The two endpoints of the epicycloid AB intersect with the tooth top circle and the tooth bottom circle at the x-axis of the plane rectangular coordinate system. The intersection of the epicycloid AB and the tooth bottom circle is one of the endpoints A of the tooth bottom arc IA.

[0041] S4. Draw a parabola DE and an envelope FG of the parabola in a plane rectangular coordinate system, take the intersection points E and F of the parabola DE and the envelope FG of the parabola with the pitch circle as the endpoints of the pitch arc EF, and determine the position of the pitch arc EF in the plane rectangular coordinate system;

[0042] S5. According to the coordinate equation of the envelope line GH of the line segment and the coordinate equation of the epicycloid HI, the envelope line GH and the epicycloid HI of the line segment are drawn in the plane rectangular coordinate system, and the intersection of the epicycloid HI and the tooth bottom circle is used as the other end point I of the tooth bottom circular arc IA to determine the position of the tooth bottom circular arc IA in the plane rectangular coordinate system; the tooth bottom circular arc IA, the epicycloid HI, the envelope line GH and the parabola FG are connected in sequence by smooth transition;

[0043] S6. Draw a tangent on the parabola DE, passing through point C, the end point of the tooth top arc BC. Take point C as the starting point, and the point of tangency between the tangent and the parabola DE is point D. Connect points C and D to close the rotor profile.

[0044] A dry compressor comprises two sets of screws driven by gears. The low-vibration single-tooth rotor is coaxially arranged on the two screws respectively and meshes with each other and rotates inversely synchronously.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] 1. The present invention significantly reduces the vibration of the compressor during operation, improves the dynamic balancing effect of the compressor rotor, and reduces gas turbulence and operating noise.

[0047] 2. The stress distribution of the present invention is reasonable, which overcomes the stress concentration caused by the unevenness of the original rotor tooth arm. The overall stress distribution is more uniform and continuous, has a greater bearing capacity, and can be applied to working environments with higher pressure and speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a schematic diagram of the structure of the present invention.

[0049] Figure 2 It is a schematic diagram of the meshing state of two groups of single-tooth rotors in the present invention.

[0050] Figure 3 This is a stress analysis diagram of the existing single-tooth rotor when it is working.

[0051] Figure 4 This is a stress analysis diagram of the single-tooth rotor of the present invention when it is working. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0053] See also Figures 1 to 4 In an embodiment of the present invention, a low-vibration single-tooth rotor, a design method and a dry compressor, whose profile includes an epicycloid AB, a tooth top arc BC, a line segment CD, a parabola DE, a tooth pitch arc EF, an envelope FG of the parabola, an envelope GH of the line segment, an epicycloid HI and a tooth bottom arc IA which are smoothly connected in sequence to form a closed loop.

[0054] The coordinate equation of the epicycloid AB is:

[0055]

[0056] Among them, R 1 is the radius of the tooth top arc BC;

[0057] R 2 is the radius of the pitch arc EF;

[0058] The coordinate equation of the tooth top arc BC is:

[0059]

[0060] The coordinate equation of line segment CD is:

[0061]

[0062] Among them, α is the arc angle of the tooth top arc BC;

[0063] The two endpoints of line segment CD are point C and point D, the rotation axis of the rotor is point O, and γ is the angle between OC and OD;

[0064]

[0065] The coordinate equation of the parabola DE is:

[0066]

[0067] in,

[0068] l x =-R 2 sin(α+γ)cos2(α+γ);

[0069]

[0070] The coordinate equation of the pitch arc EF is:

[0071]

[0072] The coordinate equation of the parabola's envelope FG is:

[0073]

[0074] in,

[0075] The coordinate equation of the envelope GH of the line segment is:

[0076]

[0077] in,

[0078] The coordinate equation of the epicycloid HI is:

[0079]

[0080] The coordinate equation of the tooth bottom arc IA is:

[0081]

[0082] Among them, R 3 is the radius of the arc IA at the bottom of the tooth, R 3 =2R 2 -R 1 .

[0083] When designing the above rotor, the following steps are included:

[0084] S1. Determine the radius R of the rotor's tooth tip arc BC according to the design working conditions. 1 , Radius R of pitch arc EF 2 And the arc angle α of the tooth top arc BC; according to the radius R of the tooth top arc BC 1 and the radius R of the pitch arc EF 2 Determine the radius R of the tooth bottom arc IA 3 ;

[0085] S2. Build a plane rectangular coordinate system with the radius R of the tooth top arc BC 1 , Radius R of pitch arc EF 2 And the radius R of the tooth bottom arc IA 3 Draw the tooth addendum circle, tooth pitch circle and tooth bottom circle respectively. The centers of the tooth addendum circle, tooth pitch circle and tooth bottom circle coincide with each other. The center point O is used as the coordinate origin of the plane rectangular coordinate system. The line connecting one of the end points B of the tooth addendum arc BC and point O is used as the x-axis of the plane rectangular coordinate system. Draw the tooth addendum arc BC in the first quadrant of the plane rectangular coordinate system according to the arc angle α of the tooth addendum arc BC.

[0086] S3. Draw an epicycloid AB in a plane rectangular coordinate system according to its coordinate equation. The two endpoints of the epicycloid AB intersect with the tooth top circle and the tooth bottom circle at the x-axis of the plane rectangular coordinate system. The intersection of the epicycloid AB and the tooth bottom circle is one of the endpoints A of the tooth bottom arc IA.

[0087] S4. Draw a parabola DE and an envelope FG of the parabola in a plane rectangular coordinate system, take the intersection points E and F of the parabola DE and the envelope FG of the parabola with the pitch circle as the endpoints of the pitch arc EF, and determine the position of the pitch arc EF in the plane rectangular coordinate system;

[0088] S5. According to the coordinate equation of the envelope line GH of the line segment and the coordinate equation of the epicycloid HI, the envelope line GH and the epicycloid HI of the line segment are drawn in the plane rectangular coordinate system, and the intersection of the epicycloid HI and the tooth bottom circle is used as the other end point I of the tooth bottom circular arc IA to determine the position of the tooth bottom circular arc IA in the plane rectangular coordinate system; the tooth bottom circular arc IA, the epicycloid HI, the envelope line GH and the parabola FG are connected in sequence by smooth transition;

[0089] S6. Draw a tangent on the parabola DE, passing through point C, the end point of the tooth top arc BC. Take point C as the starting point, and the point of tangency between the tangent and the parabola DE is point D. Connect points C and D to close the rotor profile.

[0090] like Figure 3 As shown, the maximum stress value of the existing rotor at the end of exhaust is 73.6MPa, while the maximum stress value of the rotor of the present invention under the same working condition is 32.2MPa, which is significantly lower than that of the existing rotor. The stress distribution of the rotor of the present invention is more continuous and uniform, more reasonable, and effectively improves the overall bearing capacity of the rotor. Since the two rotors are exactly the same and symmetrically arranged, the overall dynamic balancing effect is improved and the influence of the rotational inertia force is reduced.

[0091] When air is used as the conveying medium, under the same speed, pressure and flow conditions, when the compressor adopts the rotor of the present invention, the peak value of the working noise of the compressor is 79dB and the average value is 75dB; Figure 3 As shown in the prior art rotor, its peak working noise is 96dB and its average is 86dB. Since there are uneven points at the tooth arms of the prior art rotor, the airflow is prone to turbulence, resulting in whistling sounds. The optimized design of the rotor profile of the present invention greatly reduces the working noise of the compressor.

[0092] The basic principles of the present application are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present application are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present application. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, not for limitation, and the above details do not limit the present application to being implemented by adopting the above specific details.

[0093] The block diagrams of the devices, apparatuses, equipment, and systems involved in this application are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagram. As will be appreciated by those skilled in the art, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open words, referring to "including but not limited to", and can be used interchangeably with them. The words "or" and "and" used here refer to the words "and / or" and can be used interchangeably with them, unless the context clearly indicates otherwise. The words "such as" used here refer to the phrase "such as but not limited to", and can be used interchangeably with them.

Claims

1. A low-vibration single-tooth rotor, characterized in that: The profile includes an epicycloid AB, a tooth top arc BC, a line segment CD, a parabola DE, a tooth pitch arc EF, an envelope FG of the parabola, an envelope GH of the line segment, an epicycloid HI and a tooth bottom arc IA which are smoothly connected in sequence to form a closed loop.

2. A low vibration single-tooth rotor according to claim 1, characterized in that: The coordinate equation of the epicycloid AB is: Among them, R1 is the radius of the tooth top arc BC; R2 is the radius of the pitch arc EF; The coordinate equation of the tooth top arc BC is: The coordinate equation of line segment CD is: Among them, α is the arc angle of the tooth top arc BC; The two endpoints of line segment CD are point C and point D, the axis of rotation of the rotor is point O, and γ is the angle between OC and OD; The coordinate equation of the parabola DE is: in, l x =-R2 sin(α+γ)cos2(α+γ); The coordinate equation of the pitch arc EF is: The coordinate equation of the parabola's envelope FG is: in, The coordinate equation of the envelope GH of the line segment is: in, The coordinate equation of the epicycloid HI is: The coordinate equation of the tooth bottom arc IA is: Among them, R3 is the radius of the tooth bottom arc IA.

3. A low vibration single-tooth rotor according to claim 2, characterized in that: R3=2R2-R1.

4. A method for designing a low-vibration single-tooth rotor according to any one of claims 1 to 3, characterized in that: The steps include: S1. Determine the radius R1 of the rotor's tooth tip arc BC, the radius R2 of the tooth pitch arc EF, and the arc angle α of the tooth tip arc BC according to the design working condition requirements; determine the radius R3 of the tooth bottom arc IA according to the radius R1 of the tooth tip arc BC and the radius R2 of the tooth pitch arc EF; S2. Build a plane rectangular coordinate system, and draw the addendum circle, pitch circle and bottom circle respectively with the radius R1 of the addendum arc BC, the radius R2 of the pitch arc EF and the radius R3 of the bottom arc IA. The centers of the addendum circle, pitch circle and bottom circle coincide with each other, and the center O is used as the origin of the plane rectangular coordinate system; the line connecting one of the end points B of the addendum arc BC and point O is used as the x-axis of the plane rectangular coordinate system, and the addendum arc BC is drawn in the first quadrant of the plane rectangular coordinate system according to the arc angle α of the addendum arc BC; S3. Draw an epicycloid AB in a plane rectangular coordinate system according to its coordinate equation. The two endpoints of the epicycloid AB intersect with the tooth top circle and the tooth bottom circle at the x-axis of the plane rectangular coordinate system. The intersection of the epicycloid AB and the tooth bottom circle is one of the endpoints A of the tooth bottom arc IA. S4. Draw a parabola DE and an envelope FG of the parabola in a plane rectangular coordinate system, take the intersection points E and F of the parabola DE and the envelope FG of the parabola with the pitch circle as the endpoints of the pitch arc EF, and determine the position of the pitch arc EF in the plane rectangular coordinate system; S5. According to the coordinate equation of the envelope line GH of the line segment and the coordinate equation of the epicycloid HI, the envelope line GH and the epicycloid HI of the line segment are drawn in the plane rectangular coordinate system, and the intersection of the epicycloid HI and the tooth bottom circle is used as the other end point I of the tooth bottom circular arc IA to determine the position of the tooth bottom circular arc IA in the plane rectangular coordinate system; the tooth bottom circular arc IA, the epicycloid HI, the envelope line GH and the parabola FG are connected in sequence by smooth transition; S6. Draw a tangent on the parabola DE, passing through point C, the end point of the tooth top arc BC. Take point C as the starting point, and the point of tangency between the tangent and the parabola DE is point D. Connect points C and D to close the rotor profile.

5. A dry compressor, characterized in that: The dry compressor comprises two sets of screws driven by gears, and a low-vibration single-tooth rotor as claimed in any one of claims 1 to 3 is coaxially arranged on the two screws, meshing with each other and rotating synchronously in reverse.

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