Vacuum pump rotor and vacuum pump

Abstract

The embodiment of the present invention provides a vacuum pump rotor and a vacuum pump, which relate to the field of vacuum pumps. The end profile of the vacuum pump rotor includes: a curve L, the curve L includes a cycloid AB, a tooth root circle arc BC, an outer circle arc CD, an involute DE, an inner circle arc EF, and a tooth tip circle arc FA connected in sequence, the vacuum pump rotor is a screw rotor, the radius of the outer circle arc CD is r1, and the radius of the inner circle arc EF is r2, wherein the outer circle arc CD is tangent to the tooth root circle arc BC and the involute DE at the same time, and the inner circle arc EF is tangent to the involute DE and the tooth tip circle FA at the same time, therefore, the sharp point of the end profile of the vacuum pump rotor can be eliminated, and the end profile has a smooth transition, avoiding tool jumping during processing and causing processing difficulties.

Description

Technical Field

[0001] The present invention relates to the field of vacuum pumps, and in particular to a vacuum pump rotor and a vacuum pump. Background Art

[0002] The vacuum pump is an important part of industrial equipment. For example, the screw vacuum pump is a vacuum pump that uses a pair of screw rotors to rotate synchronously at high speed in opposite directions in the pump body to produce suction and exhaust. It is an updated product of the oil-sealed vacuum pump. It can remove gases containing a large amount of water vapor and a small amount of dust, and is widely used in modern industry. For the screw vacuum pump, the key technology is the intermeshing screw. The key to the intermeshing screw is the end profile. The end profile directly affects the performance of the screw vacuum pump, such as sealing, efficiency, area utilization factor, etc., and also determines the processing and manufacturing cost of the pump.

[0003] In the prior art, tool jumping is likely to occur during the manufacturing process of the vacuum pump rotor, causing processing difficulties. Summary of the invention

[0004] The invention provides a vacuum pump rotor and a vacuum pump, which can avoid tool jumping and reduce processing difficulty.

[0005] The embodiments of the present invention can be implemented as follows:

[0006] An embodiment of the present invention provides a vacuum pump rotor, wherein the end profile of the vacuum pump rotor comprises:

[0007] Curve L, wherein the curve L includes a cycloid AB, a tooth root circle arc BC, an outer circle arc CD, an involute DE, an inner circle arc EF, and a tooth tip circle arc FA connected in sequence, and the vacuum pump rotor is a screw rotor;

[0008] Wherein, the parametric equation of the cycloid AB is:

[0009] X1=R*sin(2*t)-2A*sin(t)

[0010] Y1=2A*cos(t)-R*cos(2*t), where X1 and Y1 are the rectangular coordinates of the point on the cycloid AB, R is the radius of the tooth tip circle, A is half of the center distance of the end rotor profiles of the two meshing vacuum pump rotors, and t is a preset value;

[0011] The parametric equation of the involute DE is:

[0012] X2=R0*sin(t+((Rm-Rg)^2 / R0^2-1)^0.5+arccos(R0 / (Rm-Rg)))+R0*t*cos(t-((Rm-Rg)^2 / R0^2-1)^0.5+arcsin(R0 / (Rm-Rg)))

[0013] Y2=-R0*cos(t-((Rm-Rg)^2 / R0^2-1)^0.5+arccos(R0 / (Rm-Rg)))+R0*t*sin(t-((Rm-Rg)^2 / R0^2-1)^0.5+arccos(R0 / (Rm-Rg))), wherein X2 and Y2 are the rectangular coordinates of the point on the involute DE, R0 is the base circle radius, Rm is the tooth top circle radius, Rg is the tooth root circle radius, and the value range of t is: [0, 1];

[0014] The radius of the outer circle arc CD is r1, the radius of the inner circle arc EF is r2, the distance between the outer circle O2 and the center O1 of the tooth tip circle is d1, the angle between the straight line from the center O2 to the center O1 and the extended line of the line connecting the points A and B of the cycloid AB is w1, the distance between the inner circle O3 and the center O1 of the tooth tip circle is d2, and the angle between the straight line from the center O3 to the center O1 and the extended line of the line connecting the points A and B of the cycloid AB is w2;

[0015] The outer circle arc CD is tangent to the tooth root circle arc BC and the involute DE at the same time, and the inner circle arc EF is tangent to the involute DE and the tooth addendum circle FA at the same time.

[0016] Optionally, in the parametric equation of the cycloid AB, the preset value t has a value range of: 0≤t≤arccos(2A / (2*R)).

[0017] Optionally, the base circle radius R0=(2*z)*r2 / pi, wherein z is a preset value.

[0018] Optionally, the value of z is 2 or 3.

[0019] Optionally, the tooth top circle radius Rm=A+r2.

[0020] Optionally, the tooth root circle radius Rg=A-r2.

[0021] Optionally, the number of the curve L is one, and the cycloid AB, the root circle arc BC, the outer circle arc CD, the involute DE, the inner circle arc EF, and the top circle arc FA are connected end to end in sequence to form the end surface profile of the single-head vacuum pump rotor, and the distance d1 is equal to the distance d2.

[0022] Optionally, the number of the curves L is two, and the two curves L are connected end to end in sequence to form an end profile of the double-headed vacuum pump rotor.

[0023] Optionally, the radius r1 of the outer arc CD is equal to the radius r2 of the inner arc EF.

[0024] An embodiment of the present invention further provides a vacuum pump, comprising a pump body and two of the above-mentioned vacuum pump rotors, wherein the two vacuum pump rotors mesh with each other;

[0025] Point A, tooth root circle arc BC, outer circle arc CD and involute DE of the end face profile of one of the vacuum pump rotors are respectively used to mesh with the cycloid AB, tooth top circle arc FA, inner circle arc EF and involute DE of the end face profile of the other vacuum pump rotor.

[0026] The beneficial effects of the vacuum pump rotor and the vacuum pump of the embodiment of the present invention include, for example:

[0027] An embodiment of the present invention provides a vacuum pump rotor, wherein the end profile of the vacuum pump rotor comprises: a curve L, wherein the curve L comprises a cycloid AB, a tooth root circle arc BC, an outer circle arc CD, an involute DE, an inner circle arc EF, and a tooth tip circle arc FA connected in sequence, wherein the vacuum pump rotor is a screw rotor, wherein the radius of the outer circle arc CD is r1, the radius of the inner circle arc EF is r2, the distance between the outer circle O2 and the center O1 of the tooth tip circle is d1, and the straight line from the center O2 to the center O1 and the line connecting the point A and the point B of the cycloid AB are d1. The angle of the extension line is w1, the distance between the inner circle O3 and the center O1 of the tooth top circle is d2, and the angle between the straight line from the center O3 to the center O1 and the extension line of the line connecting point A and point B of the cycloid AB is w2. Among them, the outer circle arc CD is tangent to the root circle arc BC and the involute DE at the same time, and the inner circle arc EF is tangent to the involute DE and the tooth top circle FA at the same time. Therefore, the sharp point of the end face profile of the vacuum pump rotor can be eliminated, and its end face profile has a smooth transition, avoiding tool jump during processing and causing processing difficulties.

[0028] An embodiment of the present invention also provides a vacuum pump, comprising a pump body and two of the above-mentioned vacuum pump rotors, the two vacuum pump rotors meshing with each other, wherein point A of the end face profile, tooth root circle arc BC, outer circle arc CD and involute DE of one vacuum pump rotor are respectively used to mesh with the cycloid AB, tooth top circle arc FA, inner circle arc EF and involute DE of the end face profile of the other vacuum pump rotor, which can avoid tool jump during processing and cause processing difficulties. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 A schematic diagram of the end profile of a vacuum pump rotor provided in an embodiment of the present invention;

[0031] Figure 2 It is a schematic diagram of the meshing of the end profile of a single-start screw rotor provided in an embodiment of the present invention;

[0032] Figure 3 A schematic diagram of the meshing of the end profiles of the double-headed screw rotor provided in an embodiment of the present invention;

[0033] Figure 4 It is a schematic diagram of the meshing of the end profiles of the three-start screw rotor provided in an embodiment of the present invention;

[0034] Figure 5 It is a schematic diagram of meshing of the end profiles of the four-start screw rotor provided in an embodiment of the present invention;

[0035] Figure 6 It is a schematic diagram of the meshing of the end profiles of the five-head screw rotor provided in the embodiment of the present invention. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0037] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. 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.

[0038] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0039] In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear to indicate an orientation or position relationship, they are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship in which the product of the invention is usually placed when used. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply 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 on the present invention.

[0040] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions and should not be understood as indicating or implying relative importance.

[0041] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0042] The vacuum pump is an important part of industrial equipment. For example, the screw vacuum pump is an exhaust device that uses a pair of screw rotors to rotate synchronously at high speed in opposite directions in the pump body to produce suction and exhaust. It is an updated product of the oil-sealed vacuum pump. It can extract gases containing a large amount of water vapor and a small amount of dust, and is widely used in modern industry. For the screw vacuum pump, the key technology is the intermeshing screws. The key to the intermeshing screws is the end profile. The end profile directly affects the performance of the screw vacuum pump, such as sealing, efficiency, area utilization coefficient, etc., and also determines the processing and manufacturing cost of the pump. In the prior art, the tool is prone to jump during the manufacturing process of the vacuum pump rotor, causing processing difficulties.

[0043] In view of this, the vacuum pump rotor and the vacuum pump provided in the embodiments of the present invention can solve this problem.

[0044] Please refer to Figure 1-Figure 6 , this embodiment provides a vacuum pump rotor and a vacuum pump, which will be described in detail below.

[0045] Please refer to Figure 1 and Figure 2 An embodiment of the present invention provides a vacuum pump, including a pump body (not shown) and two mutually meshing vacuum pump rotors. Specifically, the vacuum pump rotors are screw rotors. The end surface profiles of the two vacuum pump rotors are the same and both are installed in the pump body to facilitate transmission by synchronous gears.

[0046] In this embodiment, the vacuum pump rotor is a single-head screw rotor, and its end profile includes: a curve L, which includes a cycloid AB, a tooth root circle arc BC, an outer circle arc CD, an involute DE, an inner circle arc EF, and a tooth top circle arc FA connected in sequence.

[0047] Specifically, the number of curves L is one, and the cycloid AB, the tooth root circle arc BC, the outer circle arc CD, the involute DE, the inner circle arc EF, and the tooth top circle arc FA are connected end to end in sequence to form the end profile of the single-head vacuum pump rotor.

[0048] Point A, tooth root circle arc BC, outer circle arc CD and involute DE of the end face profile of one vacuum pump rotor are respectively used to mesh with the cycloid AB, tooth top circle arc FA, inner circle arc EF and involute DE of the end face profile of another vacuum pump rotor.

[0049] Among them, the radius of the outer circle arc CD is r1, the radius of the inner circle arc EF is r2, the distance between the outer circle O2 and the center O1 of the tooth top circle is d1, the angle between the straight line from the center O2 to the center O1 and the extension line of the line connecting point A and point B of the cycloid AB is w1, the distance between the inner circle O3 and the center O1 of the tooth top circle is d2, the angle between the straight line from the center O3 to the center O1 and the extension line of the line connecting point A and point B of the cycloid AB is w2. In this embodiment, the angle w1 and the angle w2 are both 135 degrees.

[0050] In addition, in the present embodiment, the distance d1 is equal to the distance d2, and the radius r1 of the outer circular arc CD is equal to the radius r2 of the inner circular arc EF, wherein the outer circular arc CD is tangent to both the tooth root circular arc BC and the involute DE, and the inner circular arc EF is tangent to both the involute DE and the tooth top circle FA. Therefore, the sharp points of the end face profile of the vacuum pump rotor can be eliminated, and the end face profile has a smooth transition, thereby avoiding tool jumping during processing and causing processing difficulties.

[0051] Among them, the parametric equation of the cycloid AB is specifically:

[0052] X1=R*sin(2*t)-2A*sin(t)

[0053] Y1=2A*cos(t)-R*cos(2*t), wherein X1 and Y1 are the rectangular coordinates of the point on the cycloid AB, R is the radius of the tooth top circle, A is half the center distance of the end rotor profiles of the two meshing vacuum pump rotors, and t is a preset value, the range of the preset value t is: 0≤t≤arccos(2A / (2*R)).

[0054] In addition, the parametric equation of the involute DE is:

[0055] X2=R0*sin(t+((Rm-Rg)^2 / R0^2-1)^0.5+arccos(R0 / (Rm-Rg)))+R0*t*cos(t-((Rm-Rg)^2 / R0^2-1)^0.5+arcsin(R0 / (Rm-Rg)))

[0056] Y2=-R0*cos(t-((Rm-Rg)^2 / R0^2-1)^0.5+arccos(R0 / (Rm-Rg)))+R0*t*sin(t-((Rm-Rg)^2 / R0^2-1)^0.5+arccos(R0 / (Rm-Rg))), where X2 and Y2 are the rectangular coordinates of the point on the involute DE, R0 is the base circle radius, Rm is the tooth top circle radius, and Rg is the tooth root circle radius. In the parametric equation of the involute DE, the value range of t is: [0, 1].

[0057] Among them, the base circle radius R0 = (2*z)*r2 / pi, where z is a preset value, and the value of z can be 2 or 3 or 4 or 5. The specific value is not limited here. In addition, the pitch circle radius in the end face profile is Rp, and the pitch circle radius Rp is equal to the value A, the top circle radius Rm = A+r2, and the root circle radius Rg = A-r2.

[0058] Please refer to Figure 3 There are two curves L, which are connected end to end in sequence to form the end profile of the double-headed vacuum pump rotor, which can solve the dynamic balance problem of the single-headed screw rotor and reduce the vibration during the rotation process.

[0059] Please continue to refer to Figure 4-Figure 6 The number of curves L can also be three, and the three curves L are connected end to end in sequence to form the end profile of the three-head screw rotor. When the number of curves L is four, the four curves L are connected end to end in sequence to form the end profile of the four-head screw rotor. When the number of curves L is five, the five curves L are connected end to end in sequence to form the end profile of the five-head screw rotor.

[0060] In summary, the end profile of the vacuum pump rotor includes: a curve L, which includes a cycloid AB, a tooth root circle arc BC, an outer circle arc CD, an involute DE, an inner circle arc EF, and a tooth top circle arc FA connected in sequence. The vacuum pump rotor is a screw rotor, the radius of the outer circle arc CD is r1, the radius of the inner circle arc EF is r2, the distance between the outer circle O2 and the center O1 of the tooth top circle is d1, and the angle between the straight line from the center O2 to the center O1 and the extension line of the line connecting point A and point B of the cycloid AB is The distance between the inner circle O3 and the center O1 of the tooth top circle is d2, and the angle between the straight line from the center O3 to the center O1 and the extension line of the line connecting the points A and B of the cycloid AB is w2. The outer circle arc CD is tangent to the tooth root circle arc BC and the involute DE at the same time, and the inner circle arc EF is tangent to the involute DE and the tooth top circle FA at the same time. Therefore, the sharp point of the end face profile of the vacuum pump rotor can be eliminated, and the end face profile has a smooth transition, which avoids the tool jumping during processing and causes processing difficulties.

[0061] The vacuum pump comprises a pump body and two vacuum pump rotors mentioned above, the two vacuum pump rotors mesh with each other, and point A of the end face profile, tooth root circle arc BC, outer circle arc CD and involute DE of one vacuum pump rotor are respectively used to mesh with the cycloid AB, tooth top circle arc FA, inner circle arc EF and involute DE of the end face profile of the other vacuum pump rotor, which can avoid tool jumping during processing and cause processing difficulties.

[0062] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A vacuum pump rotor, characterized in that: The end profile of the vacuum pump rotor includes: Curve L, wherein the curve L includes a cycloid AB, a tooth root circle arc BC, an outer circle arc CD, an involute DE, an inner circle arc EF, and a tooth tip circle arc FA connected in sequence, and the vacuum pump rotor is a screw rotor; Wherein, the parametric equation of the cycloid AB is: X1=R*sin(2*t)-2A*sin(t) Y1=2A*cos(t)-R*cos(2*t), where X1 and Y1 are the rectangular coordinates of the point on the cycloid AB, R is the radius of the tooth tip circle, A is half of the center distance of the end rotor profiles of the two meshing vacuum pump rotors, and t is a preset value; The parametric equation of the involute DE is: X2=R0*sin(t+((Rm-Rg)^2 / R0^2-1)^0.5arccos(R0 / (Rm-Rg)))+R0*t*cos(t-((Rm-Rg)^2 / R0^2-1)^0.5+arcsin(R0 / (Rm-Rg))) Y2=R0*cos(t-((Rm-Rg)^2 / R0^2-1)0.5+arccos(R0 / (Rm-Rg)))+R0*t*sin(t-((Rm-Rg)^2 / R0^2-1)^0.5+arccos(R0 / (Rm-Rg))), where X2 and Y2 are the rectangular coordinates of the point on the involute DE, R0 is the base circle radius, Rm is the tooth top circle radius, Rg is the tooth root circle radius, and the value range of t is: [0,1]; The radius of the outer circle arc CD is r1, the radius of the inner circle arc EF is r2, the distance between the outer circle O2 and the center O1 of the tooth tip circle is d1, the angle between the straight line from the center O2 to the center O1 and the extended line of the line connecting the points A and B of the cycloid AB is w1, the distance between the inner circle O3 and the center O1 of the tooth tip circle is d2, the angle between the straight line from the center O3 to the center O1 and the extended line of the line connecting the points A and B of the cycloid AB is w2; The outer circle arc CD is tangent to the tooth root circle arc BC and the involute DE at the same time, and the inner circle arc EF is tangent to the involute DE and the tooth addendum circle FA at the same time; The number of the curve L is one, the cycloid AB, the tooth root circle arc BC, the outer circle arc CD, the involute DE, the inner circle arc EF, and the tooth tip circle arc FA are connected end to end in sequence to form the end profile of the single-head vacuum pump rotor, and the distance d1 is equal to the distance d2; The radius r1 of the outer arc CD is equal to the radius r2 of the inner arc EF.

2. The vacuum pump rotor according to claim 1, characterized in that: In the parametric equation of the cycloid AB, the range of the preset value t is: 0≤t≤arccos(2A / (2*R)).

3. The vacuum pump rotor according to claim 1, characterized in that: The base circle radius R0=(2*z)*r2 / pi, wherein z is a preset value.

4. The vacuum pump rotor according to claim 3, characterized in that: The value of z is 2 or 3.

5. The vacuum pump rotor according to claim 1, characterized in that: The tooth top circle radius Rm=A+r2.

6. The vacuum pump rotor according to claim 5, characterized in that: The tooth root circle radius Rg=A-r2.

7. The vacuum pump rotor according to claim 1, characterized in that: The number of the curves L is two, and the two curves L are connected end to end in sequence to form the end profile of the double-headed vacuum pump rotor.

8. A vacuum pump, characterized in that: It comprises a pump body and two vacuum pump rotors according to any one of claims 1 to 7, wherein the two vacuum pump rotors are meshed with each other; Point A, tooth root circle arc BC, outer circle arc CD and involute DE of the end face profile of one of the vacuum pump rotors are respectively used to mesh with the cycloid AB, tooth top circle arc FA, inner circle arc EF and involute DE of the end face profile of the other vacuum pump rotor.

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