Claw rotor, end face profile drawing method, and vacuum pump

Abstract

This invention provides a claw rotor, a method for drawing end face profiles, and a vacuum pump, relating to the field of vacuum pump equipment technology. The claw rotor includes a first rotor and a second rotor; the end face profile of the first rotor includes a first circular arc segment AB, a first involute BC, a second circular arc segment CD, a third circular arc segment DE, a cycloid EF, a fourth circular arc segment FG, a fifth circular arc segment GH, and a second involute HA connected in sequence; the end face profile of the second rotor includes a first circular arc segment A'B', a first involute B'C', a second circular arc segment C'D', a third circular arc segment D'E', a cycloid E'F', a fourth circular arc segment F'G, a fifth circular arc segment G'H', and a second involute H'A' connected in sequence; the end face profiles of the first and second rotors are identical but have opposite rotation directions, improving the rotor matching and meshing degree, ensuring tight meshing between the two rotors during operation, improving processing efficiency and performance, and reducing processing costs.

Description

Technical Field

[0001] This invention relates to the field of vacuum pump equipment, and more specifically, to a claw rotor, a method for drawing end face profiles, and a vacuum pump. Background Technology

[0002] In fields such as panels, photovoltaics, and integrated circuits, the production process often generates toxic waste gases. The treatment of these waste gases usually requires the use of sealed containers, and currently, vacuum pumps are commonly used for this purpose.

[0003] However, due to unreasonable design, the rotors of existing vacuum pumps cannot fully mesh during operation, thus affecting the sealing performance of the vacuum pump. Summary of the Invention

[0004] This invention provides a claw rotor, a method for drawing end face profiles, and a vacuum pump, which can solve the problem that the two rotors cannot mesh tightly during rotation.

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

[0006] In a first aspect, the present invention provides a claw rotor, comprising a first rotor and a second rotor having the same end face profiles but opposite rotation directions;

[0007] The end face profile of the first rotor includes a first circular arc segment AB, a first involute BC, a second circular arc segment CD, a third circular arc segment DE, a cycloid EF, a fourth circular arc segment FG, a fifth circular arc segment GH, and a second involute HA connected end to end in sequence.

[0008] The end face profile of the second rotor includes a first circular arc segment A'B', a first involute B'C', a second circular arc segment C'D', a third circular arc segment D'E', a cycloid E'F', a fourth circular arc segment F'G', a fifth circular arc segment G'H', and a second involute H'A' connected end to end in sequence;

[0009] During the rotational meshing of the first rotor and the second rotor, the second involute HA meshes with the first involute B'C', the fifth arc segment GH meshes with the second arc segment C'D', the fourth arc segment FG meshes with the third arc segment D'E', and the intersection point F of the cycloid EF and the fourth arc segment FG meshes with the cycloid E'F'.

[0010] In the above embodiment, by rationally designing the first arc segment AB, the first involute BC, the second arc segment CD, the third arc segment DE, the cycloid EF, the fourth arc segment FG, the fifth arc segment GH, and the second involute HA connected end to end, and because the end face profiles of the first rotor and the second rotor are the same but rotate in opposite directions, during the rotation of the two rotors, the second involute HA meshes with the first involute B'C', the fifth arc segment GH meshes with the second arc segment C'D', the fourth arc segment FG meshes with the third arc segment D'E', and the intersection F of the cycloid EF and the fourth arc segment FG meshes with the cycloid E'F'. This ensures that each segment of the end face profiles of the two rotors can mesh during rotation. This not only achieves the symmetry of the profiles and the structural consistency of the first and second rotors, but also improves the matching meshing degree of the first and second rotors, and enables the two rotors to mesh tightly during operation, ensuring sealing performance and efficient transportation of the pumped gas. Therefore, it significantly improves processing efficiency and performance, and reduces processing costs.

[0011] In an optional implementation, the parametric equation of the third circular arc segment DE is:

[0012] Rg = Ar;

[0013] And / or:

[0014] Let the base circle radius be Ro, and the parametric equation of the base circle radius is:

[0015] Ro = (2 × z) × r / π;

[0016] In this system, the center of the first rotor is defined by the common center of the first arc segment AB, the third arc segment DE, and the fourth arc segment FG. A rectangular coordinate system is established with the center of the first rotor as the origin, any horizontal line passing through the origin as the x-axis, and any vertical line passing through the origin as the y-axis. Rg is the radius of the third arc segment DE, r is the radius of the second arc segment CD or the fifth arc segment GH, A is half the distance between the rotation centers of the first rotor and the second rotor, and A is also the radius of the first arc segment AB. z is the number of rotor blades.

[0017] In the above embodiment, the circle containing the third arc segment DE is the root circle of the rotor; the circle containing the second arc segment CD is the blade valley circle, and the circle containing the fifth arc segment GH is the blade peak circle, all with radius r. Therefore, the radius of the third arc segment DE and the base circle radius can be determined by the number of rotor blades, the radius of the rotor's root circle, the radius of the rotor's pitch circle, and the radii of the rotor's blade peak circle and blade valley circle.

[0018] In an optional implementation, the parametric equation of the second involute HA is:

[0019] X(t)=Ro×sin(t-((Rm-Rg)^2 / Ro^2-1)^0.5+arccos(Ro / (Rm-Rg)))-Ro×t×cos(t-((Rm-Rg)^2 / Ro^2-1)^0.5+arccos(Ro / (Rm-Rg)));

[0020] Y(t)=-Ro×cos(t-((Rm-Rg)^2 / Ro^2-1)^0.5+arccos(Ro / (Rm-Rg)))+Ro×t×sin(t-((Rm-Rg)^2 / Ro^2-1)^0.5+arccos(Ro / (Rm-Rg)));

[0021] In this system, the center of the first rotor is defined by the common center of the first arc segment AB, the third arc segment DE, and the fourth arc segment FG. A rectangular coordinate system is established with the center of the first rotor as the origin. t is a variable, Rm is the radius of the fourth arc segment FG, and z is the number of rotor blades.

[0022] In the above embodiment, a rectangular coordinate system is established with the center of the rotor, i.e. the center of the tooth tip circle, by using the number of rotor blades, the base circle radius, and the tooth tip circle radius. The shape of the second involute HA can be determined by continuously inputting the variable t according to the parametric equation of the second involute HA.

[0023] In an optional embodiment, the second involute HA and the first preset involute are symmetrically arranged about the first symmetry line, the first preset involute and the second preset involute are symmetrically arranged about the second symmetry line, and the intersection line segment of the second preset involute with the first arc segment AB and the second arc segment CD is the first involute BC.

[0024] The first and second lines of symmetry are both set at a 30° angle with respect to the y-axis.

[0025] In the above embodiments, the first involute BC and the second involute HA have the same shape. In other words, after the shape of the second involute HA is determined, the shape of the first involute BC can be determined in a symmetrical manner.

[0026] In an optional implementation, the parametric equation of the cycloid EF is:

[0027] X(t)=Rm×sin(2×t)-2A×sin(t);

[0028] Y(t)=2A×cos(t)-Rm×cos(2×t);

[0029] In this system, the center of the first rotor is defined by the common center of the first arc segment AB, the third arc segment DE, and the fourth arc segment FG. A rectangular coordinate system is established with the center of the first rotor as the origin. t is a variable, Rm is the radius of the fourth arc segment FG, and A is half the center distance between the first rotor and the second rotor.

[0030] In the above embodiment, the shape of the cycloid EF can be determined by continuously inputting the variable t according to the parametric equation of the cycloid EF, using the center distance between the first rotor and the second rotor and the radius of the fourth arc segment FG, and the rectangular coordinate system established with the center of the rotor, i.e. the center of the tooth tip circle.

[0031] In an optional implementation, the range of values ​​for t is:

[0032] 0≤t≤arccos(2A / (2×Rm)).

[0033] In the above embodiment, the specific segment of the cycloidal EF is determined based on the range of values ​​for t. By limiting the range of values ​​for t to between 0 and arccos(2A / (2×Rm)), the cycloidal EF and end face profile formed in this way can avoid the formation of a sharp point at this location during rotor rotation, thereby improving the meshing and sealing performance of the first and second rotors.

[0034] In an optional implementation, the fifth arc segment GH is tangent to the fourth arc segment FG at point G;

[0035] And / or, the fifth arc segment GH is tangent to the second involute HA at point H;

[0036] And / or, the second arc segment CD is tangent to the first involute BC at point C;

[0037] And / or, the second arc segment CD is tangent to the third arc segment DE at point D.

[0038] In the above embodiment, by making the two ends of the fifth arc segment tangent to the fourth arc segment and the second involute respectively, the resulting end face profile is a continuous and smooth curve; similarly, by making the two ends of the second arc segment CD tangent to the first involute BC and the third arc segment DE, the resulting end face profile is a continuous and smooth curve, thereby improving the meshing and sealing performance of the two rotors during operation.

[0039] In a second aspect, the present invention provides a method for drawing end face profiles, used to draw the end face profiles of a claw rotor as described in any of the foregoing embodiments, the end face profile drawing method comprising:

[0040] Draw the tooth tip circle with radius Rm and the tooth root circle with radius Rg, and make the tooth tip circle and the tooth root circle concentric. Establish a rectangular coordinate system with the common center of the tooth tip circle and the tooth root circle as the origin, any horizontal line passing through the origin as the x-axis, and any vertical line passing through the origin as the y-axis.

[0041] Draw the involute based on the first parametric equation, where the first parametric equation is:

[0042] X(t)=Ro×sin(t-((Rm-Rg)^2 / Ro^2-1)^0.5+arccos(Ro / (Rm-Rg)))-Ro×t×cos(t-((Rm-Rg)^2 / Ro^2-1)^0.5+arccos(Ro / (Rm-Rg)));

[0043] Y(t)=-Ro×cos(t-((Rm-Rg)^2 / Ro^2-1)^0.5+arccos(Ro / (Rm-Rg)))+Ro×t×sin(t-((Rm-Rg)^2 / Ro^2-1)^0.5+arccos(Ro / (Rm-Rg)));

[0044] t is a variable, Rg is the radius of the third arc segment DE, r is the radius of the second arc segment CD or the fifth arc segment GH, A is half the distance between the rotation center of the first rotor and the rotation center of the second rotor, and A is also the radius of the first arc segment AB, z is the number of rotor blades;

[0045] Draw the leaf peak circle and leaf valley circle with radius r;

[0046] Draw a nodal circle with a radius equal to half the center distance between the first rotor and the second rotor;

[0047] Draw the cycloid based on the second parametric equation, where the second parametric equation is:

[0048] X(t)=Rm×sin(2×t)-2A×sin(t);

[0049] Y(t)=2A×cos(t)-Rm×cos(2×t);

[0050] The center of the first rotor is defined by the common center of the first arc segment AB, the third arc segment DE, and the fourth arc segment FG. A rectangular coordinate system is established with the center of the first rotor as the origin, any horizontal line passing through the origin as the x-axis, and any vertical line passing through the origin as the y-axis. t is a variable, Rm is the radius of the fourth arc segment FG, and A is half the center distance between the first rotor and the second rotor.

[0051] Cutting is performed using the intersection points of the tooth tip circle, tooth root circle, involute, pitch circle, and cycloid as cutting points to form a first arc segment AB, a first involute BC, a second arc segment CD, a third arc segment DE, a cycloid EF, a fourth arc segment FG, a fifth arc segment GH, and a second involute HA that are connected end to end in sequence.

[0052] Thirdly, the present invention provides a vacuum pump comprising a claw rotor as described in any of the foregoing embodiments.

[0053] The beneficial effects of the claw rotor, end face profile drawing method, and vacuum pump provided in this invention embodiment include: by rationally designing the first arc segment AB, the first involute BC, the second arc segment CD, the third arc segment DE, the cycloid EF, the fourth arc segment FG, the fifth arc segment GH, and the second involute HA connected end to end, and because the end face profiles of the first rotor and the second rotor are the same and have opposite directions of rotation, the second involute HA meshes with the first involute B'C' during the rotation of the two rotors, and the fifth arc segment GH meshes with the second arc segment C'D'. The fourth arc segment FG meshes with the third arc segment D'E', and the intersection point F of the cycloid EF and the fourth arc segment FG meshes with the cycloid E'F', thus ensuring that each segment of the end face profile of the two rotors can mesh during rotation. This not only achieves the symmetry of the profile and the structural consistency of the first and second rotors, but also improves the matching meshing degree of the first and second rotors. It also enables the two rotors to mesh tightly during operation, ensuring sealing performance and efficient transportation of the pumped gas. Therefore, it significantly improves processing efficiency and performance, and reduces processing costs. Attached Figure Description

[0054] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0055] Figure 1 This is one of the schematic diagrams of the end face profile provided in the embodiments of the present invention;

[0056] Figure 2 This is the second schematic diagram of the end face profile provided in an embodiment of the present invention. Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0058] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0059] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0060] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0061] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0062] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0063] Vacuum pumps typically achieve gas intake, pressurization, and exhaust through the synchronous, high-speed, counter-rotating of two screw rotors. This causes periodic changes in the volume of the working chamber formed between the two screw rotors and the pump body's inner cavity. However, existing vacuum pumps have complex structures, and the design of involute and arc segments on the end face profiles of the two rotors is unreasonable, resulting in poor rotor meshing and weak sealing.

[0064] To address the above problems, this invention provides a vacuum pump, particularly suitable for claw-type vacuum pumps. The vacuum pump includes a pump body and a claw-type rotor disposed within the pump body. The claw-type rotor comprises a first rotor and a second rotor with identical end face profiles but opposite rotation directions. Gas transport is achieved through the suction and exhaust actions generated by the synchronous high-speed counter-rotation of the first and second rotors. It exhibits good meshing properties, excellent sealing performance, and high structural strength, making it suitable for applications requiring higher speeds, pressures, and temperatures, significantly improving adaptability and practicality.

[0065] For details, please refer to Figure 1 and Figure 2 The end face profile of the first rotor includes the first circular arc segment AB, the first involute BC, the second circular arc segment CD, the third circular arc segment DE, the cycloid EF, the fourth circular arc segment FG, the fifth circular arc segment GH, and the second involute HA, which are connected end to end in sequence; the end face profile of the second rotor includes the first circular arc segment A'B', the first involute B'C', the second circular arc segment C'D', the third circular arc segment D'E', the cycloid E'F', the fourth circular arc segment F'G', the fifth circular arc segment G'H', and the second involute H'A', which are connected end to end in sequence.

[0066] In this embodiment, during the rotational meshing of the first rotor and the second rotor, the second involute HA meshes with the first involute B'C', the fifth arc segment GH meshes with the second arc segment C'D', the fourth arc segment FG meshes with the third arc segment D'E', and the intersection point F of the cycloid EF and the fourth arc segment FG meshes with the cycloid E'F', thereby realizing the mutual meshing of the first rotor and the second rotor to complete the transport of gas.

[0067] It should be noted that, through a reasonable design, the first circular arc segment AB, the first involute BC, the second circular arc segment CD, the third circular arc segment DE, the cycloid EF, the fourth circular arc segment FG, the fifth circular arc segment GH, and the second involute HA are connected end to end. Since the end face profiles of the first and second rotors are the same and their rotation directions are opposite, during the rotation of the two rotors, the second involute HA meshes with the first involute B'C', the fifth circular arc segment GH meshes with the second circular arc segment C'D', the fourth circular arc segment FG meshes with the third circular arc segment D'E', and the intersection point F of the cycloid EF and the fourth circular arc segment FG meshes with the cycloid E'F'. This ensures that each segment of the end face profiles of the two rotors can mesh during rotation.

[0068] Therefore, the above configuration not only achieves symmetry in the profile and structural consistency between the first and second rotors, but also improves the meshing degree between them. This ensures tight meshing during operation, guaranteeing sealing performance and efficient transport of the pumped gas, thus significantly improving processing efficiency and performance while reducing processing costs. Furthermore, the first arc segment AB and the second arc segment CD are connected by the first involute BC, and the fifth arc segment GH and the first arc segment AB are connected by the second involute HA. This allows for a smoother transition between adjacent arc segments, further enhancing the meshing and sealing performance of the two rotors during rotation.

[0069] It should be noted that the end face profile of this claw rotor includes 5 circular arcs, 1 cycloid, and 2 involutes, namely, the first circular arc segment AB, the first involute BC, the second circular arc segment CD, the third circular arc segment DE, the cycloid EF, the fourth circular arc segment FG, the fifth circular arc segment GH, and the second involute HA connected end to end. Among them, the first involute BC, the second involute HA, and the cycloid EF are drawn using special parametric equations, and are not conventional circular arc segments. The end face profile formed in this way can make the entire end face profile smoothly connected, which is conducive to the meshing of the first rotor and the second rotor, thereby improving the meshing sealing and gas delivery efficiency.

[0070] Furthermore, the parametric equation of the third circular arc segment DE is:

[0071] Rg = Ar;

[0072] Where Rg is the radius of the third arc segment DE, r is the radius of the second arc segment CD or the fifth arc segment GH, A is half the center distance between the first rotor and the second rotor, and is also the radius of the first arc segment AB. The rotation center of the first rotor is the common center of the first arc segment AB, the third arc segment DE and the fourth arc segment FG.

[0073] It should be noted that the circle containing the third arc segment DE is the tip circle of the rotor; while the circle containing the second arc segment CD is the blade valley circle, and the circle containing the fifth arc segment GH is the blade peak circle, all with a radius of r. Therefore, the radius of the third arc segment DE can be determined by the radius of the rotor's tip circle and the radii of the rotor's blade peak circle and blade valley circle.

[0074] Furthermore, let the base circle radius be Ro, and the parametric equation of the base circle radius is:

[0075] Ro = (2 × z) × r / π;

[0076] The parametric equation for the second involute HA is:

[0077] X(t)=Ro×sin(t-((Rm-Rg)^2 / Ro^2-1)^0.5+arccos(Ro / (Rm-Rg)))-Ro×t×cos(t-((Rm-Rg)^2 / Ro^2-1)^0.5+arccos(Ro / (Rm-Rg)));

[0078] Y(t)=-Ro×cos(t-((Rm-Rg)^2 / Ro^2-1)^0.5+arccos(Ro / (Rm-Rg)))+Ro×t×sin(t-((Rm-Rg)^2 / Ro^2-1)^0.5+arccos(Ro / (Rm-Rg)));

[0079] The center of the first rotor is defined by the common center of the first arc segment AB, the third arc segment DE, and the fourth arc segment FG (e.g., ...). Figure 1 Point O is shown in the figure, and a rectangular coordinate system is established with the center of the first rotor as the origin. t is a variable, Ro is the radius of the base circle, Rm is the radius of the fourth circular arc segment FG, and z is the number of rotor blades.

[0080] In this embodiment, it should be noted that the number of rotor blades z is related to the rotor's own structure. In this implementation, the number of rotor blades z is usually 3. The base circle radius can be calculated from the number of rotor blades, the blade peak circle radius, or the blade valley circle radius. Therefore, by establishing a rectangular coordinate system with the rotor center (i.e., the center of the tooth tip circle) using the number of rotor blades, the base circle radius, and the tooth tip circle radius, the shape of the second involute HA can be determined by continuously inputting the variable t according to the parametric equation of the second involute HA.

[0081] In this embodiment, the shape of the second involute HA designed by the above parametric equation is more reasonable, and it can smoothly transition with the adjacent fifth arc segment GH and the first arc segment AB, so that the two rotors formed can smoothly transition between adjacent tooth surfaces.

[0082] Furthermore, the first involute BC is obtained by symmetrical processing of the second involute HA.

[0083] In this embodiment, the first involute BC and the second involute HA have the same profile. In other words, after the profile of the second involute HA is established, the profile of the first involute BC can be established in a symmetrical manner, so that the resulting rotor profile has better meshing and sealing properties, which is beneficial for the rotor to efficiently transport gas.

[0084] Specifically, the second involute HA and the first preset involute are symmetrically arranged about the first symmetry line, the first preset involute and the second preset involute are symmetrically arranged about the second symmetry line, and the intersection line of the second preset involute with the first arc segment AB and the second arc segment CD is the first involute BC; wherein, the first symmetry line and the second symmetry line are both set at a 30° angle about the y-axis.

[0085] In other words, after the second involute HA is established, the second involute HA is symmetrical about the first line of symmetry to obtain the first preset involute. Then, the first preset involute is symmetrical about the second line of symmetry to obtain the second preset involute. The first involute BC is obtained by intersecting the second preset involute through the first arc segment AB and the second arc segment CD. The first line of symmetry and the second line of symmetry are at a 60° angle, and both the first line of symmetry and the second line of symmetry are set at a 30° angle about the y-axis.

[0086] In this embodiment, the first involute BC obtained through the above design makes the end face shape more reasonable, and the first arc segment AB and the second arc segment CD are connected by the first involute BC, which makes the transition between the adjacent arc segments smoother, further improving the meshing performance and sealing performance of the two rotors during rotation.

[0087] Furthermore, the parametric equation of the cycloid EF is:

[0088] X(t)=Rm×sin(2×t)-2A×sin(t);

[0089] Y(t)=2A×cos(t)-Rm×cos(2×t);

[0090] Where t is a variable, Rm is the radius of the fourth arc segment FG, 2A is the center distance between the first rotor and the second rotor, and the rotation center of the first rotor is the common center of the first arc segment AB, the third arc segment DE and the fourth arc segment FG.

[0091] In this embodiment, the shape of the cycloid EF can be determined by continuously inputting the variable t according to the parametric equation of the cycloid EF, based on the center distance between the first rotor and the second rotor and the radius of the fourth arc segment FG, and the Cartesian coordinate system established with the center of the rotor, i.e. the center of the tooth tip circle. Thus, it is determined that the cycloid EF can make the formed rotor profile have better meshing and sealing properties, which is beneficial to the efficient gas transport of the rotor.

[0092] Furthermore, the range of t is 0 ≤ t ≤ arccos(2A / (2×Rm)). Therefore, based on the range of t, the specific line segment of the cycloidal EF is determined. By limiting the range of t to between 0 and arccos(2A / (2×Rm)), the cycloidal EF and end face profile formed in this way can avoid the formation of a sharp point at this point during rotor rotation, thus improving the meshing and sealing performance of the first and second rotors.

[0093] Furthermore, the radii of the second arc segment CD and the fifth arc segment GH are both r, and the fifth arc segment GH is tangent to the fourth arc segment FG at point G, and the fifth arc segment GH is tangent to the second involute HA at point H.

[0094] In this embodiment, the circle containing the fifth arc segment GH is obtained with radius r and the origin of the above coordinates as the center. The specific line segment of the fifth arc segment is determined by making the fifth arc segment GH tangent to the fourth arc segment FG.

[0095] Furthermore, by making the two ends of the fifth arc segment tangent to the fourth arc segment and the second involute respectively, the resulting end face profile is a continuous and smooth curve, thereby improving the meshing and sealing performance of the two rotors during operation.

[0096] Furthermore, the second arc segment CD is tangent to the first involute BC at point C, and the second arc segment CD is tangent to the third arc segment DE at point D.

[0097] In this embodiment, by making the two ends of the second arc segment CD tangent to the first involute BC and the third arc segment DE, the resulting end face profile is a continuous and smooth curve, thereby improving the meshing and sealing of the two rotors during operation, achieving higher gas conveying efficiency, and improving volume utilization.

[0098] In summary, the present invention comprises a first circular arc segment AB, a first involute BC, a second circular arc segment CD, a third circular arc segment DE, a cycloid EF, a fourth circular arc segment FG, a fifth circular arc segment GH, and a second involute HA, connected end-to-end in sequence; the end face profile of the second rotor includes a first circular arc segment A'B', a first involute B'C', a second circular arc segment C'D', a third circular arc segment D'E', a cycloid E'F', a fourth circular arc segment F'G', and a fifth circular arc segment HA, connected end-to-end in sequence. The arc segment G'H' and the second involute H'A' are connected, and the second involute HA meshes with the first involute B'C'. The fifth arc segment GH meshes with the second arc segment C'D', the fourth arc segment FG meshes with the third arc segment D'E', and the intersection F of the cycloidal EF and the fourth arc segment FG meshes with the cycloidal E'F'. The multiple curved segments transition smoothly, thereby improving the mechanical properties and meshing performance of the formed claw rotor, and giving it high strength and good sealing performance.

[0099] Furthermore, the present invention also provides a method for drawing end face profiles, used to draw the end face profiles of a claw rotor as described in the above embodiments. The method for drawing end face profiles includes:

[0100] Step S100: Draw the addendum circle with radius Rm and the dedendum circle with radius Rg; and make the addendum circle and the dedendum circle share the same center. Establish a rectangular coordinate system with the common center of the addendum circle and the dedendum circle as the origin. It should be noted that after determining the origin, the horizontal line can be used as the x-axis and the vertical line as the y-axis. As the rotor rotates, the coordinate system will rotate with the rotor after it has been determined.

[0101] In this embodiment, the tooth tip circle is drawn with Rm as the radius to draw the circle containing the fourth arc segment FG; the tooth root circle is drawn with Rg as the radius to draw the circle containing the third arc segment DE.

[0102] Step S200: Draw the involute according to the first parameter equation;

[0103] In this embodiment, a rectangular coordinate system is established with the rotor center, i.e., the tooth tip circle or tooth root circle, as the origin. The line shape of the first involute BC and the second involute HA is drawn through the first parametric equation.

[0104] Specifically, the equation for the first parameter is: X(t)=Rm×sin(2×t)-2A×sin(t);

[0105] Y(t)=2A×cos(t)-Rm×cos(2×t);

[0106] In this system, the center of the first rotor is defined by the common center of the first arc segment AB, the third arc segment DE, and the fourth arc segment FG. A rectangular coordinate system is established with the center of the first rotor as the origin. t is a variable, Rm is the radius of the fourth arc segment FG, and A is half the center distance between the first rotor and the second rotor.

[0107] It should be noted that the line shape of the segment containing the second involute HA can be determined by this equation. Specifically, after the second involute HA is established, the line shape of the segment containing the first involute BC is obtained by symmetrically processing the second involute HA.

[0108] Step S300: Draw the leaf peak circle and leaf valley circle with r as the radius.

[0109] In this embodiment, with the coordinate center as the origin, a first construction line (shown as a in the figure, which is the straight line containing the x-axis) and a second construction line (shown as b in the figure) are drawn. The first construction line is a horizontal line, and the second construction line is located in the first quadrant and is set at a 60° angle to the first construction line. With r as the radius, the centers of circles are determined on the first and second construction lines respectively to draw the leaf valley circle and the leaf peak circle, and the distance between the origin of the leaf valley circle and the leaf peak circle and the coordinate origin is A.

[0110] Step S400: Draw a nodal circle with a radius equal to half the center distance between the first rotor and the second rotor;

[0111] In this embodiment, the pitch circle is drawn by the rotor center distance to draw the circle containing the first arc segment AB.

[0112] Step S500: Draw the cycloid according to the second parameter equation;

[0113] In this embodiment, the line shape of the cycloid EF is drawn based on the second parameter equation.

[0114] Specifically, the second parameter equation is:

[0115] X(t)=Rm×sin(2×t)-2A×sin(t);

[0116] Y(t)=2A×cos(t)-Rm×cos(2×t);

[0117] In this system, the center of the first rotor is the common center of the first arc segment AB, the third arc segment DE, and the fourth arc segment FG. A rectangular coordinate system is established with the center of the first rotor as the origin. t is a variable, Rm is the radius of the fourth arc segment FG, and A is half the center distance between the first rotor and the second rotor. Therefore, the line shape of the cycloid EF segment can be determined by this parametric equation.

[0118] In step S600, the intersection points of the addendum circle, root circle, involute, blade peak circle, blade valley circle, pitch circle, and cycloid are used as cutting points to cut off excess curves, forming the first arc segment AB, the first involute BC, the second arc segment CD, the third arc segment DE, the cycloid EF, the fourth arc segment FG, the fifth arc segment GH, and the second involute HA connected end to end. This completes the drawing of the end face profile. The entire profile adopts a fully parametric design, which is convenient for processing. The first and second rotors formed by the end face profile drawn in this way can self-mesh, with a high area utilization coefficient, which significantly improves the working efficiency and performance of the vacuum pump.

[0119] In summary, the embodiments of the present invention provide a one-claw rotor, an end face profile drawing method, and a vacuum pump. The end face profiles of the first rotor and the second rotor are the same but rotate in opposite directions to achieve profile symmetry and structural consistency of the first rotor and the second rotor, thereby improving the matching and meshing degree of the first rotor and the second rotor, enabling the two rotors to mesh tightly during operation, significantly improving processing efficiency and performance, and reducing processing costs.

[0120] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of protection described in the claims.

Claims

1. A claw-type rotor, characterized in that, Includes a first rotor and a second rotor with the same end face profile but opposite rotation directions; The end face profile of the first rotor includes a first circular arc segment AB, a first involute BC, a second circular arc segment CD, a third circular arc segment DE, a cycloid EF, a fourth circular arc segment FG, a fifth circular arc segment GH, and a second involute HA connected end to end in sequence. The end face profile of the second rotor includes a first circular arc segment A'B', a first involute B'C', a second circular arc segment C'D', a third circular arc segment D'E', a cycloid E'F', a fourth circular arc segment F'G', a fifth circular arc segment G'H', and a second involute H'A' connected end to end in sequence; During the rotational meshing of the first rotor and the second rotor, the second involute HA meshes with the first involute B'C', the fifth arc segment GH meshes with the second arc segment C'D', the fourth arc segment FG meshes with the third arc segment D'E', and the intersection point F of the cycloid EF and the fourth arc segment FG meshes with the cycloid E'F'. The parametric equation for the third circular arc segment DE is: Rg=Ar; And / or, the base circle radius is set to Ro, and the parametric equation of the base circle radius is: Ro = (2 × z) × r / π; Wherein, the center of the first circular arc segment AB, the third circular arc segment DE, and the fourth circular arc segment FG is the center of the first rotor, and a rectangular coordinate system is established with the center of the first rotor as the origin, any horizontal line passing through the origin as the x-axis, and any vertical line passing through the origin as the y-axis. Rg is the radius of the third circular arc segment DE, r is the radius of the second circular arc segment CD or the fifth circular arc segment GH, A is half the distance between the rotation center of the first rotor and the rotation center of the second rotor, and A is also the radius of the first circular arc segment AB, and z is the number of rotor blades; The parametric equation for the second involute HA is: X(t)=Ro×sin(t-((Rm-Rg)^2 / Ro^2-1)^0.5+arccos(Ro / (Rm-Rg)))-Ro×t×cos(t-((Rm-Rg)^2 / Ro^2-1)^0.5+arccos(Ro / (Rm-Rg))); Y(t)=-Ro×cos(t-((Rm-Rg)^2 / Ro^2-1)^0.5+arccos(Ro / (Rm-Rg)))+Ro×t×sin(t-((Rm-Rg)^2 / Ro^2-1)^0.5+arccos(Ro / (Rm-Rg))); The center of the first rotor is defined by the common center of the first arc segment AB, the third arc segment DE, and the fourth arc segment FG. A rectangular coordinate system is established with the center of the first rotor as the origin, any horizontal line passing through the origin as the x-axis, and any vertical line passing through the origin as the y-axis. t is a variable, Rm is the radius of the fourth arc segment FG, and z is the number of rotor blades. The second involute HA and the first preset involute are symmetrically arranged about the first symmetry line, the first preset involute and the second preset involute are symmetrically arranged about the second symmetry line, and the intersection line segment of the second preset involute with the first arc segment AB and the second arc segment CD is the first involute BC. The first and second lines of symmetry are both set at a 30° angle with respect to the y-axis.

2. The claw rotor according to claim 1, characterized in that, The parametric equation of the cycloid EF is: X(t)=Rm×sin(2×t)-2A×sin(t); Y(t)=2A×cos(t)-Rm×cos(2×t); In this system, the center of the first rotor is defined by the common center of the first arc segment AB, the third arc segment DE, and the fourth arc segment FG. A rectangular coordinate system is established with the center of the first rotor as the origin. t is a variable, Rm is the radius of the fourth arc segment FG, and A is half the center distance between the first rotor and the second rotor.

3. The claw rotor according to claim 2, characterized in that, The range of values ​​for t is: 0≤t≤arccos(2A / (2×Rm)).

4. The claw rotor according to claim 1, characterized in that, The fifth arc segment GH is tangent to the fourth arc segment FG at point G; And / or, the fifth arc segment GH is tangent to the second involute HA at point H; And / or, the second arc segment CD is tangent to the first involute BC at point C; And / or, the second arc segment CD is tangent to the third arc segment DE at point D.

5. A method for drawing end face profiles, used to draw the end face profiles of a claw rotor as described in any one of claims 1-4, characterized in that, The method for drawing end face profiles includes: Draw the addendum circle with radius Rm and the dedendum circle with radius Rg, and make the addendum circle and the dedendum circle share the same center. Establish a rectangular coordinate system with the common center of the addendum circle and the dedendum circle as the origin, with any horizontal line passing through the origin as the x-axis and any vertical line passing through the origin as the y-axis. Draw the involute based on the first parametric equation, where the first parametric equation is: X(t)=Ro×sin(t-((Rm-Rg)^2 / Ro^2-1)^0.5+arccos(Ro / (Rm-Rg)))-Ro×t×cos(t-((Rm-Rg)^2 / Ro^2-1)^0.5+arccos(Ro / (Rm-Rg))); Y(t)=-Ro×cos(t-((Rm-Rg)^2 / Ro^2-1)^0.5+arccos(Ro / (Rm-Rg)))+Ro×t×sin(t-((Rm-Rg)^2 / Ro^2-1)^0.5+arccos(Ro / (Rm-Rg))); t is a variable, Rg is the radius of the third arc segment DE, r is the radius of the second arc segment CD or the fifth arc segment GH, A is half the distance between the rotation center of the first rotor and the rotation center of the second rotor, and A is also the radius of the first arc segment AB, z is the number of rotor blades; Draw the leaf peak circle and leaf valley circle with radius r; Draw a nodal circle with a radius equal to half the center distance between the first rotor and the second rotor; Draw the cycloid based on the second parametric equation, where the second parametric equation is: X(t)=Rm×sin(2×t)-2A×sin(t); Y(t)=2A×cos(t)-Rm×cos(2×t); The center of the first rotor is defined by the common center of the first arc segment AB, the third arc segment DE, and the fourth arc segment FG. A rectangular coordinate system is established with the center of the first rotor as the origin, any horizontal line passing through the origin as the x-axis, and any vertical line passing through the origin as the y-axis. t is a variable, Rm is the radius of the fourth arc segment FG, and A is half the center distance between the first rotor and the second rotor. Cutting is performed using the intersection points of the tooth tip circle, tooth root circle, involute, blade peak circle, blade valley circle, pitch circle, and cycloid as cutting points to form the first arc segment AB, the first involute BC, the second arc segment CD, the third arc segment DE, the cycloid EF, the fourth arc segment FG, the fifth arc segment GH, and the second involute HA, which are connected end to end in sequence.

6. A vacuum pump, characterized in that, Including the claw rotor as described in any one of claims 1-4.

Images