A Method for Modular Geometric Modeling of the Shafting of a Reciprocating Compressor

Abstract

The invention discloses a design method for modular geometric modeling of a reciprocating compressor shafting. The modeling of different volume elements of the reciprocating compressor shafting is realized by using the APDL language of the general ANSYS finite element calculation software, and geometric models of shaftings with different structures are established by combining various volume elements. This method can greatly improve the working efficiency of parametric geometric modeling of the reciprocating compressor shafting and provide an intelligent design means for the secondary development of software.

Description

Technical Field

[0001] The present invention belongs to the technical field of ANSYS modeling, and particularly relates to a method for modular geometric modeling of a reciprocating compressor shafting. Background Art

[0002] ANSYS is a multi-purpose finite element method computer design program that can be used to solve problems such as structures, fluids, electricity, electromagnetic fields, and collisions. Therefore, it can be applied to the following industrial fields: aerospace, automotive industry, biomedicine, bridges, buildings, electronic products, heavy machinery, microelectromechanical systems, sports equipment, etc.

[0003] The calculation technology of torsional vibration of the reciprocating compressor rotor system is a technical bottleneck restricting the development of reciprocating compressors towards multi-columns or high speeds. The geometric modeling of the reciprocating compressor shafting is one of the key links in the calculation of torsional vibration of the rotor system; in the calculation of torsional resonance of the reciprocating compressor rotor system, parametric geometric modeling of the shafting accounts for more than 95% of the total workload. As Figure 1 shown, it is a typical geometric model of a 6-column reciprocating compressor shafting in the prior art. During the process of modeling through ANSYS, it is necessary to separately model each component of different sizes, such as cylinders and cranks, and then assemble them. During this process, each unit body has different key point numbers, line numbers, surface numbers, and body numbers. At the same time, designers also need to create different command flows according to different unit bodies for combination, which is time-consuming and laborious, and the work efficiency is low. Summary of the Invention

[0004] The purpose of the embodiments of the present invention is to provide a method for modular geometric modeling of a reciprocating compressor shafting to alleviate the technical problem of low modeling efficiency of the shafting module in the prior art.

[0005] To solve the above technical problem, the embodiments of the present invention provide the following technical solutions:

[0006] A method for modular geometric modeling of a reciprocating compressor shafting provided in the first aspect of the present invention includes the following steps:

[0007] S100. Divide the structures with the same shape but different sizes in the geometric model of the reciprocating compressor shafting into corresponding volume elements, and establish a volume element model for each volume element. The construction of the volume element model includes drawing instructions, coordinate system instructions, and basic information of the volume element. The basic information includes the number of key points, lines, surfaces, and volumes, and the basic information is used to realize information transmission between the elements of each independent body of the shafting;

[0008] S200. According to the positions of the respective volume elements in the shafting, adjust the corresponding volume element models to the corresponding sizes, and then complete the geometric modeling of the reciprocating compressor shafting by superposition.

[0009] In some modified embodiments of the first aspect of the present invention, in step S100, the solid element model includes a cylinder, a right stepped chamfered geometric body, a left stepped chamfered geometric body, a left crank geometric body, a right crank geometric body, an intermediate crank geometric body, a left conical circular chamfered geometric body, a right conical circular chamfered geometric body, a left cone, a right cone, and a cylindrical body;

[0010] The cylinder and the cylindrical body are drawn using the respective diameters D and axial lengths L of a circle or a circular ring;

[0011] The left stepped chamfered geometric body, the right stepped chamfered geometric body, the left conical circular chamfered geometric body, and the right conical circular chamfered geometric body are created by directly creating a key point group in the working plane, sequentially creating line elements from the key point group, creating surface elements from the line elements, and then forming solid elements by rotating the surface elements;

[0012] The left crank geometric body, the right crank geometric body, and the intermediate crank geometric body are created by directly creating key points in the working plane, sequentially creating surface elements from the key point group, forming solid elements by stretching the surface elements, and then using Boolean operations in the ANSYS system to complete the excision of large arcs and chamfers by subtracting two or more solid elements;

[0013] The left cone and the right cone are created by directly creating a key point group in the working plane, sequentially creating surface elements from the key points, and then forming solid elements by rotating the surface elements.

[0014] In some modified embodiments of the first aspect of the present invention, the modeling of the left stepped chamfered geometric body, the right stepped chamfered geometric body, the left conical circular chamfered geometric body, and the right conical circular chamfered geometric body includes the following steps:

[0015] S111. Create a first key point, a second key point, a third key point, and a first center point that enclose an arc cross-section in the key point group;

[0016] S112. Draw an arc with the first center point as the center and the diameter;

[0017] S113. Connect the first key point and the third key point, and connect the third key point and the second key point respectively to form two straight lines;

[0018] S114. Create a surface from the arc, the straight line formed by the first key point and the third key point, and the straight line formed by the second key point and the third key point;

[0019] S115. Create the end points a and b of the rotation axis of the surface in step S114, that is, the fourth key point and the fifth key point;

[0020] S116. Rotate the created surface around the line connecting the fourth key point and the fifth key point to form a rotating body.

[0021] In some modified embodiments of the first aspect of the present invention, the modeling steps of the left crank geometric body, the right crank geometric body, and the middle crank geometric body are as follows:

[0022] S121. Create a crank hexahedron, and the steps are as follows:

[0023] S1211. Create the first crank key point, the second crank key point, the third crank key point, and the fourth crank key point that enclose the crank longitudinal section. In the YZ plane, the first crank key point and the third crank key point coincide, and the second crank key point and the fourth crank key point coincide. Moreover, the first crank key point, the second crank key point, the third crank key point, and the fourth crank key point are all in the XY plane;

[0024] S1212. Create a surface using the first crank key point, the second crank key point, the third crank key point, and the fourth crank key point.

[0025] S1213. Form a solid by axially stretching the surface created in step S1212;

[0026] S122. Cut the created crank hexahedron, and the steps are as follows:

[0027] S1221. Create the first cutting key point, the second cutting key point, the third cutting key point, the fourth cutting key point, and the fifth cutting key point that enclose the cutting section;

[0028] S1222. Create a surface using the first cutting key point, the second cutting key point, the third cutting key point, the fourth cutting key point, and the fifth cutting key point.

[0029] S1223. Create a cutting solid by rotating the surface in step S1222;

[0030] S1224. Cut the crank hexahedron created in step S121 with the newly created cutting solid.

[0031] In some modified embodiments of the first aspect of the present invention, the creation steps of the middle crank are the same as S121. In step S122, 2 cutting solids need to be built for splitting, and chamfers are respectively completed at the upper and lower ends of the middle crank.

[0032] In some modified embodiments of the first aspect of the present invention, the accumulation order of each independent body element is as follows: start constructing from the free end of the crankshaft, then model the motor shaft, and finally construct the model of the motor rotor.

[0033] Compared with the prior art method of modeling each component separately and then assembling them, the present invention divides the structures with the same shape but different sizes in the geometric model of the reciprocating compressor shafting into corresponding volume elements. Only by following the corresponding drawing instructions, coordinate system instructions, and the basic information of the volume elements can the construction of the corresponding volume element models be completed. Before the assembly step, the size is adjusted to the corresponding size, greatly shortening the time spent on modeling. At the same time, the number of key points, lines, faces, and volumes in the basic information of the volume element model ensures the information transfer between the elements of each independent body of the shafting, improving the accuracy of modeling.

[0034] Therefore, compared with the prior art, the shafting geometric modeling method proposed by the present invention, on the one hand, does not require defining the key point numbers, line numbers, face numbers, and volume numbers required for creating each unit body, and on the other hand, combines the command streams used for creating different unit bodies, making the time required to construct the shafting geometric model only 1% of the time consumed by conventional modeling, greatly improving the work efficiency of shafting modeling.

[0035] The present invention alleviates the technical problem of low modeling work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments.

[0037] Figure 1 Schematic diagram of the geometric model of the shafting of a 6-column reciprocating compressor in a method for modular geometric modeling of a reciprocating compressor provided in Embodiment 1 of the present invention;

[0038] Figure 2 Schematic diagram of the decomposition of the shafting model in a method for modular geometric modeling of a reciprocating compressor provided in Embodiment 1 of the present invention;

[0039] Figure 3 Schematic diagram of the left step chamfering process in a method for modular geometric modeling of a reciprocating compressor provided in Embodiment 1 of the present invention;

[0040] Figure 4 Schematic diagram of the right step chamfering process in a method for modular geometric modeling of a reciprocating compressor provided in Embodiment 1 of the present invention;

[0041] Figure 5 Schematic diagram of the key points of the left crank and the created faces in a method for modular geometric modeling of a reciprocating compressor provided in Embodiment 1 of the present invention;

[0042] Figure 6 Schematic diagram of the model created by the left crank in a method for modular geometric modeling of a reciprocating compressor provided in Embodiment 1 of the present invention;

[0043] Figure 7 Schematic diagram of the creation of the chamfer on the left crank in a method for modular geometric modeling of a reciprocating compressor provided in Embodiment 1 of the present invention;

[0044] Figure 8 Schematic diagram of the creation of the chamfer on the middle crank in a method for modular geometric modeling of a reciprocating compressor provided in Embodiment 1 of the present invention;

[0045] Figure 9 Schematic diagram of the creation of the left cone in a method for modular geometric modeling of a reciprocating compressor provided in Embodiment 1 of the present invention;

[0046] Figure 10 Schematic diagram of the basic process of creating a cylinder in a method for modular geometric modeling of a reciprocating compressor provided in Embodiment 1 of the present invention;

[0047] Figure 11 Schematic diagram of the single-row structure of the crankshaft in a method for modular geometric modeling of a reciprocating compressor provided in Embodiment 1 of the present invention;

[0048] Figure 12 In a method for modular geometric modeling of a reciprocating compressor provided in Embodiment 1 of the present invention Figure 1 equivalent shafting geometric two-dimensional drawing of the reciprocating compressor.

[0049] In the figure: 1 - cylinder, 2 - left stepped chamfer geometric body, 3 - right stepped chamfer geometric body, 4 - left crank geometric body, 5 - middle crank geometric body, 6 - right crank geometric body, 7 - left cone round chamfer geometric body, 8 - right cone round chamfer geometric body, 9 - left cone, 10 - right cone, 11 - cylinder body. Detailed implementation manners

[0050] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0051] To make the above objects, features, and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Embodiment

[0052] This embodiment provides a method for modular geometric modeling of a reciprocating compressor, and the method includes the following steps:

[0053] S100. Divide the structures with the same shape but different sizes in the geometric model of the reciprocating compressor shafting into corresponding volume elements, and establish a volume element model for each volume element. The construction of the volume element model includes drawing instructions, coordinate system instructions, and the basic information of the volume element. The basic information includes the number of key points, lines, faces, and volumes, and the basic information is used to realize the information transfer between the elements of each independent body of the shafting;

[0054] S200. According to the positions of the respective volume elements in the shafting, after adjusting the corresponding volume element models to the corresponding sizes, complete the geometric modeling of the reciprocating compressor shafting by means of superposition.

[0055] As Figure 1 and Figure 2 shown, the topological structure of the crankshaft shafting of the reciprocating compressor adopted in the present invention is relatively simple and can be composed of an orderly arrangement of several unit structures such as cylinders, left stepped chamfers, right stepped chamfers, left cranks, middle cranks, right cranks, left conical chamfers, right conical chamfers, left cones, right cones, cylinders, etc. Among them, the cylinder has the highest repetition rate, only the axial lengths and outer diameters of different cylinders are different, and each unit structure is shown in Figure 2. For these unit structures, the entire geometric model can be directly drawn by using the preprocessing modeling (Main Menu>Preprocessor>Modeling) function of ANSYS software. The biggest feature of this modeling method is that parametric modeling can be realized, which greatly improves the modeling efficiency. In order to realize the equivalence of the inertia mass of each column and facilitate the mesh division of the subsequent finite element model, no matter which method is used for the geometric modeling of the reciprocating compressor shafting, it is necessary to construct the crank pins of each column and other parts of the crankshaft, the flywheel and other parts of the crankshaft, the flywheel and the motor shaft, the motor shaft and the motor rotor, etc. into independent volume elements, and bond (Glue) all the independent volume elements before dividing the mesh of the crankshaft shafting, so that the entire crankshaft model becomes a unified elastic body. It should be particularly noted that there are sometimes different construction methods for ANSYS software to construct the same unit structure, and only one method is described in this book. Taking the shafting of a certain 6M type reciprocating compressor provided in this embodiment as an example, the geometric modeling of the shafting is carried out by using the preprocessing modeling function of ANSYS software in the human-computer interaction mode (GUI) and the command stream input mode respectively.

[0056] Compared with the method of modeling each component separately and then assembling them in the prior art, the present invention divides the structures with the same shape but different sizes in the geometric model of the reciprocating compressor shafting into corresponding volume elements. Only by following the corresponding drawing instructions, coordinate system instructions and the basic information of the volume elements can the construction of the corresponding volume element models be completed. Before the assembly step, adjust to the corresponding size, which greatly shortens the time spent on modeling. At the same time, the key point number, line number, face number and volume number in the basic information of the volume element model ensure the information transmission between the elements of each independent body of the shafting, improving the accuracy of modeling.

[0057] Further, in step S100, the independent volume elements include cylinder 1, right circular chamfer geometry, left circular chamfer geometry, left crank geometry 4, right crank geometry 6, middle crank geometry 5, left conical circular chamfer geometry 7, right conical circular chamfer geometry 8, left cone, right cone and cylinder body 11;

[0058] For the left circular chamfer geometry, right circular chamfer geometry, left conical circular chamfer geometry 7 and right conical circular chamfer geometry 8, key point groups are directly created in the working plane, line elements are created from the key point groups in sequence, face elements are created from the line elements, and then the volume elements are formed by rotating the face elements;

[0059] For the left crank geometry 4, right crank geometry 6 and middle crank geometry 5, key points are directly created in the working plane, face elements are created from the key point groups in sequence, and then the volume elements are formed by stretching the face elements. Then, the excision of the large arc and chamfer is completed by the Boolean operation in the ANSYS system through the subtraction of two or more volume elements;

[0060] For the left cone and right cone, key point groups are directly created in the working plane, face elements are created from the key points in sequence, and then the volume elements are formed by rotating the face elements.

[0061] According to the characteristics of the shafting unit structure, the creation methods of different unit structures of the shafting can be summarized into four major categories: one is to directly create circular face elements or circular ring elements in the working plane and form volume elements by stretching, such as Figure 2The cylinder 1 and the cylindrical body 11 in it (drawn by the diameters D of circles or circular rings and the axial length L), second, directly create key points in the working plane, successively create line elements from the key points, create surface elements from the line elements, and then create volume elements by rotating the surface elements, the right-step chamfered geometric body 3, the left-step chamfered geometric body 2, the left crank geometric body 4, the right crank geometric body 6, the middle crank geometric body 5, the left conical circular chamfered geometric body 7, the right conical circular chamfered geometric body 8, the left cone 9, the right cone 10; third, directly create key points in the working plane, successively create surface elements from the key points, and then create volume elements by stretching the surface elements, and then use the Boolean operation (Booleans) in the ANSYS system to complete the excision of the large arc RH13 and the chamfer by subtracting (Subtract) two or more volume elements, such as Figure 2 The left crank, middle crank, right crank, etc. in it (where the outer contour of the crank is drawn by the dimensions H, B, and L, and the large chamfer and the cut arc are drawn by parameters such as RH1, A2, LD, etc.); fourth, directly create key points in the working plane, successively create surface elements from the key points, and then create volume elements by rotating the surface elements, such as Figure 2 The left cone, right cone, etc. in it (drawn by the diameter D and the axial length L of each boundary point, etc.).

[0062] Each independent volume element will be introduced one by one below:

[0063] (1) Cylindrical model (D1, L1) The construction of the cylindrical model includes three steps: first, draw a circular surface with a diameter D1 with the coordinate point (0, 0) as the center in the working coordinate system (WP), and the command stream is as shown in M3-1; second, stretch the circular surface to the right by a length of L1 to form the cylinder 1, and the command stream is as shown in M3-2; third, move the working coordinate system to the next axial position, and the command stream is as shown in M3-3. Currently, the working coordinate system is moved to the right by a length of L1. When creating the axis system unit structure model using key points, it is necessary to master the axial position of the working coordinate system WP. Therefore, use the command stream M3-4 to record the axial position of the current working plane at all times.

[0064] The command stream of the cylindrical model (D1, L1) is as follows,

[0065] CYL4,0,0,D1 / 2 *! Draw a circle with a diameter of D1 with the point (0, 0) as the center (M3-1)

[0066] VOFFST,AREA+1,-L1,, *! -L1 means stretching to the right, L1 means stretching to the left (M3-2)

[0067] wpoff, 0, 0, -L1 *! -L1 means moving right, L1 means moving left (M3-3)

[0068] L = L + L1 *! Record the position of the working coordinate system (WP) on the axis (M3-4)

[0069] SUMPOINT = 8 (M3-5)

[0070] SUMLINE = 12 (M3-6)

[0071] SUMAREA = 6 (M3-7)

[0072] SUMVOLU = 1 (M3-8)

[0073] POINT = POINT + SUMPOINT (M3-9)

[0074] LINE = LINE + SUMLINE (M3-10)

[0075] AREA = AREA + SUMAREA (M3-11)

[0076] VOLU = VOLU + SUMVOLU (M3-12)

[0077] In the process of generating a cylinder 1 by stretching a circular surface, the total number of key points (SUMPOINT) of the newly generated cylinder 1 is 8, the total number of lines (SUMLINE) is 12, the total number of faces (SUMAREA) is 6, the number of generated volumes (SUMVOLU) is 1, and the command stream is as shown in M3-5 to M3-8. Due to different unit modeling methods in Figure 2, some operations are performed on the already built "volume", some on the already built "face", some on the already built "line", and some on the already built "key point". For example, the chamfering in "crank model construction" is a subtraction operation on the "volume", such as VOLU+1, VOLU+2, VOLU in the command stream M3-38 to M3-40; the construction of the "cylinder model" is an operation on the already built "face", such as "AREA+1" in the command stream M3-2; in the various model construction processes of forming unit volumes by rotating faces, such as the "left step chamfer model", operations are performed on the already built "line and key point", where the operation command stream for the "key point" is "POINT+1, POINT+2, POINT+3, POINT+4" in M3-17 to M3-19, and the operation command stream for the "line" is "LINE+1, LINE+2, LINE+3" in M3-21 to M3-22. Therefore, all unit modeling in this article should be accompanied by statistical figures of "point, line, face, volume" parameters, and the command stream is as shown in M3-9 to M3-12, where POINT is the total number of key points after drawing the cylinder 1, LINE is the total number of lines, AREA is the total number of faces, and VOLU is the total number of volumes.

[0078] (2)Left step chamfer model (D1, AR1, C)

[0079] The modeling of the left step chamfer geometry 2, the right step chamfer geometry 3, the left conical circular chamfer geometry 7, and the right conical circular chamfer geometry 8 includes the following steps:

[0080] S111. Create the first key point, the second key point, the third key point, and the first center point that enclose the arc section in the key point group;

[0081] S112. Draw an arc with the first center point as the center and the diameter;

[0082] S113. Connect the first key point and the third key point, and connect the third key point and the first key point respectively to form two straight lines;

[0083] S114. Create a face from the arc, the straight line formed by the first key point and the third key point, and the straight line formed by the second key point and the third key point;

[0084] S115. Create the end points a and b of the rotation axis of the surface in step S114, i.e., the fourth key point and the fifth key point;

[0085] S116. Rotate the created surface about the line connecting the fourth key point and the fifth key point to form a solid of revolution.

[0086] The construction of the left step chamfer includes six steps: First, create the key points 1, 3, 4 that enclose the circular arc section and the center point 2, as shown in Figure 3 Figure (a), and the command stream is as shown in M3-13~M3-16; Second, draw an arc with the first dot as the center and diameter D1, as shown in Figure 3(a); Third, connect the first key point and the third key point and the second key point and the third key point respectively to form two straight lines, as shown in Figure 3 Figure (a), and the command stream is as shown in M3-18~M3-19; Fourth, create a surface from the arc, the straight line formed by the first key point and the third key point, and the straight line formed by the second key point and the third key point; Create a surface from three line segments, and each key point, line, and surface is as shown in Figure 3(a), and the command stream is as shown in M3-20~M3-23; Fifth, create the two end points a and b of the rotation axis of the "surface", the fourth key point and the fifth key point, as shown in Figure 3 Figure (b), and the command stream is as shown in M3-24~M3-25, and the relative positions of the key points are as shown in Figure 3 Figure (b); Sixth, rotate the created surface about the line connecting the fourth key point and the fifth key point to form a solid of revolution, and the command stream is as shown in M3-15~M-30, and the created chamfer is as shown in Figure 3 Figure (c).

[0087] The command stream is as follows,

[0088] K, ,,D1 / 2+AR1,-L, *! Variables D1 and AR1 (M3-13)

[0089] K, ,,D1 / 2+AR1,AR1-L, *! Variables D1 and AR1 (M3-14)

[0090] K, ,,D1 / 2,AR1 -L, *! Variables D1 and AR1 (M3-15)

[0091] K, ,,D1 / 2,-L, *! Variable D1 (M3-16)

[0092] LARC,POINT+1,POINT+3,POINT+2,AR1, *! AR1 (M3-17)

[0093] LSTR, POINT+1, POINT+4 (M3-18)

[0094] LSTR, POINT+4, POINT+3 (M3-19)

[0095] FLST,2,3,4 (M3-20)

[0096] FITEM,2,LINE+1 (M3-21)

[0097] FITEM,2,LINE+2

[0098] FITEM,2,LINE+3 (M3-22)

[0099] AL,P51X (M3-23)

[0100] K, ,,C*R, (M3-24)

[0101] K, ,,C*R,-L1 (M3-25)

[0102] *! Chamfer on the axis C = 0, chamfer on the crank pins in odd columns C = 1, chamfer on the crank pins in even columns C = -1

[0103] FLST,2,1,5,ORDE,1 (M3-26)

[0104] FITEM,2,AREA+1 (M3-27)

[0105] FLST,8,2,3 (M3-28)

[0106] FITEM,8, POINT+5 (M3-29)

[0107] FITEM,8, POINT+6 (M3-30)

[0108] VROTAT,P51X, , , , , ,P51X, ,360, , (M3-31)

[0109] SUMPOINT=15

[0110] SUMLINE=24

[0111] SUMAREA=16

[0112] SUMVOLU=4

[0113] POINT=POINT+SUMPOINT

[0114] LINE=LINE+SUMLINE

[0115] AREA = AREA + SUMAREA

[0116] VOLU = VOLU + SUMVOLU

[0117] (3)Right step chamfer model (D3, AR1, C) The creation method of the right step chamfer is exactly the same as that of the left step chamfer. Only the command streams M3-13 to M3-16 in the left step chamfer model need to be replaced with M3-32 to M3-35. The cross-section and key points of the created right step chamfer are as Figure 4 shown. The command streams of M3-32 to M3-35 are as follows,

[0118] K, ,,D3 / 2+AR1,-L, *! Create key point 1 (M3-35)

[0119] K, ,,D3 / 2+AR1,-AR1-L, *! Create key point 2, which is the center point (M3-32)

[0120] K, ,,D3 / 2,-AR1-L, *! Create key point 3 (M3-33)

[0121] K, ,,D3 / 2,-L, *! Create key point 3 (M3-34)

[0122] (4)Left crank model (H1, H2, B1, L3, RH1, A2, LD1); The modeling steps are as follows:

[0123] S121. Create a crank hexahedron, and the steps are as follows,

[0124] S1211. Create the first crank key point, the second crank key point, the third crank key point, and the fourth crank key point that enclose the longitudinal section of the crank. In the YZ plane, the two points of the first crank key point and the third crank key point coincide, and the two points of the second crank key point and the fourth crank key point coincide. Moreover, the first crank key point, the second crank key point, the third crank key point, and the fourth crank key point are all in the XY plane;

[0125] S1212. Create a surface with the first crank key point, the second crank key point, the third crank key point, and the fourth crank key point;

[0126] S1213. Form a solid by axially stretching the surface created in step S1212;

[0127] S122. Cut the created crank hexahedron, and the steps are as follows,

[0128] S1221. Create the first cutting key point, the second cutting key point, the third cutting key point, the fourth cutting key point, and the fifth cutting key point that enclose the cutting section.

[0129] S1222. Create a surface using the first cutting key point, the second cutting key point, the third cutting key point, the fourth cutting key point, and the fifth cutting key point.

[0130] S1223. Create a cutting body by rotating the surface in step S1222.

[0131] S1224. Cut the crank hexahedron created in step S121 with the newly created cutting body.

[0132] Figure 5 and Figure 6 As shown in and, in steps S121 and S122, the construction of the left crank model includes the creation and cutting of the crank hexahedron. The basic methods for creating and cutting the crank hexahedron are introduced separately below.

[0133] ① Creation of the left crank hexahedron The creation of the left crank hexahedron includes three steps: First, create the first crank key point, the second crank key point, the third crank key point, and the fourth crank key point that enclose the crank longitudinal section (the section perpendicular to the axis). The relative positions of the key points are as Figure 5 shown. As can be seen from the longitudinal section in Figure (b), in the YZ plane, the first crank key point and the third crank key point coincide, and the second crank key point and the fourth crank key point coincide. All the 1234 key points are in the XY plane. Second, create a surface using the first crank key point, the second crank key point, the third crank key point, and the fourth crank key point. The created surface is as Figure 5 shown in (c). Third, create a body by axially stretching the surface. The command stream for creating the left crank hexahedron is as follows:

[0134] K, ,B1 / 2,H1,-L, (M4-1)

[0135] K, ,B1 / 2,-H2,-L, (M4-2)

[0136] K, ,-B1 / 2,H1,-L, (M4-3)

[0137] K, ,-B1 / 2,-H2,-L, (M4-4)

[0138] FLST,2,4,3

[0139] FITEM,2,POINT+1

[0140] FITEM,2,POINT+2

[0141] FITEM,2,POINT+4

[0142] FITEM,2,POINT+3

[0143] A,P51X

[0144] VOFFST,AREA+1,L3, , (M4-5)

[0145] SUMPOINT=8

[0146] SUMLINE=12

[0147] SUMAREA=6

[0148] SUMVOLU=1

[0149] POINT=POINT+SUMPOINT

[0150] LINE=LINE+SUMLINE

[0151] AREA=AREA+SUMAREA

[0152] VOLU=VOLU+SUMVOLU

[0153] ②Cutting of the left crank hexahedron

[0154] It should be noted that Figure 6 in which, a represents the axonometric drawing of the left crank, b represents the schematic diagram of the longitudinal section of the left crank, and c represents the schematic diagram of the longitudinal section of the left crank

[0155] As Figure 7 shown, the cutting of the left crank hexahedron includes four steps: First, create key points enclosing the cutting section, namely the first cutting key point, the second cutting key point, the third cutting key point, the fourth cutting key point, and the fifth cutting key point; Second, create a surface with the five key points of the first cutting key point, the second cutting key point, the third cutting key point, the fourth cutting key point, and the fifth cutting key point. The created surface 12345 is shown in Figure 7(a); Third, create a cutting body by rotating the surface, and the command stream is shown as M3-36; Fourth, cut the "left crank hexahedron" with the newly created cutting body, and the command stream is shown as M3-37~M3-40, and the GUI operation is shown as follows; The relative relationship between the cutting body and the body to be cut is as Figure 7As shown in (c), the newly created element is shown in Figure 7 (c). After the creation of the new element, new body numbers, face numbers, line numbers, and key point numbers will be generated. To achieve parametric modeling of the module, it is necessary to re-number all the current key point numbers, line numbers, face numbers, and body numbers to ensure that they start from 1 and are continuous. Therefore, it is necessary to compress the current model.

[0156] K, ,H1-(L3-LD1)*TANH(A2),,-L (M4-6)

[0157] K, ,1.2*H1,,-L (M4-7)

[0158] K, ,1.2*H1,,-L3-L (M4-8)

[0159] K, ,H1,,-L3-L (M4-9)

[0160] K, ,H1,,-(L3-LD1)-L (M4-10)

[0161] LSTR, POINT+1, POINT+2

[0162] LSTR, POINT+2, POINT+3

[0163] LSTR, POINT+3, POINT+4

[0164] LSTR, POINT+4, POINT+5

[0165] LSTR, POINT+5, POINT+1

[0166] FLST,2,5,4

[0167] FITEM,2,LINE+1

[0168] FITEM,2,LINE+2

[0169] FITEM,2,LINE+3

[0170] FITEM,2,LINE+4

[0171] FITEM,2,LINE+5

[0172] AL,P51X

[0173] K, ,,,

[0174] K, ,,,-L3(M4-11)

[0175] FLST,2,1,5,ORDE,1

[0176] FITEM,2,AREA+1

[0177] FLST,8,2,3

[0178] FITEM,8,POINT+6

[0179] FITEM,8,POINT+7

[0180] VROTAT,P51X,,,,,,P51X,,-180,, (M3-36)

[0181] FLST,3,2,6,ORDE,2 (M3-37)

[0182] FITEM,3,VOLU+1 (M3-38)

[0183] FITEM,3,VOLU+2 (M3-39)

[0184] VSBV, VOLU,P51X (M3-40)

[0185] NUMCMP,ALL (M3-41)

[0186] wpoff,0,R,-L3 (M4-12)

[0187] L=L+L3(M4-13)

[0188] SUMPOINT=7

[0189] SUMLINE=8

[0190] SUMAREA=3

[0191] POINT=POINT+SUMPOINT

[0192] LINE=LINE+SUMLINE

[0193] AREA=AREA+SUMAREA

[0194] (5)Intermediate crank model (H1, B1, L5, RH1, A2, LD2)

[0195] The method for creating the middle crank is the same as that for constructing the left crank, including the creation and cutting of the crank body. To create the command for the middle crank body, only need to replace M4-2, M4-4, and M4-5 in the command stream for creating the left crank body with M4-14, M4-15, and M4-16 respectively. The command streams of M4-6, M4-7, and M4-8 are as follows:

[0196] K, ,B1 / 2,-H1,-L (M4-14)

[0197] K, ,-B1 / 2,-H1,-L (M4-15)

[0198] VOFFST,AREA+1,L5, , (M4-16)

[0199] Different from the construction of the left crank, the middle crank model needs to create two cutting bodies to complete the chamfers at the upper and lower ends of the middle crank respectively. The process of creating the chamfers is as Figure 8 shown, and the created middle crank model is as Figure 8 shown in (c). The command stream is as follows:

[0200] K, ,H1,,-L

[0201] K, ,1.2*H1,,-L

[0202] K, ,1.2*H1,,-L5-L

[0203] K, ,H1-(L5-LD2)*TANH(A2),,-L5-L

[0204] K, ,H1,,-LD2-L

[0205] LSTR, POINT+1, POINT+2

[0206] LSTR, POINT+2, POINT+3

[0207] LSTR, POINT+3, POINT+4

[0208] LSTR, POINT+4, POINT+5

[0209] LSTR, POINT+5, POINT+1

[0210] FLST,2,5,4

[0211] FITEM,2,LINE+1

[0212] FITEM,2,LINE+2

[0213] FITEM,2,LINE+3

[0214] FITEM,2,LINE+4

[0215] FITEM,2,LINE+5

[0216] AL,P51X

[0217] K, ,,0*R,

[0218] K, ,,0*R,-L5

[0219] FLST,2,1,5,ORDE,1

[0220] FITEM,2,AREA+1

[0221] FLST,8,2,3

[0222] FITEM,8,POINT+6

[0223] FITEM,8,POINT+7

[0224] VROTAT,P51X, , , , , ,P51X, ,-180, ,

[0225] SUMPOINT=17

[0226] SUMLINE=25

[0227] SUMAREA=13

[0228] POINT=POINT+SUMPOINT

[0229] LINE=LINE+SUMLINE

[0230] AREA=AREA+SUMAREA

[0231] K, ,H1-(L5-LD2)*TANH(A2),,-L

[0232] K, ,1.2*H1,,-L

[0233] K, ,1.2*H1,,-L5-L

[0234] K, ,H1,,-L5-L

[0235] K, ,H1,,-(L5-LD2)-L

[0236] LSTR, POINT+1, POINT+2

[0237] LSTR, POINT+2, POINT+3

[0238] LSTR, POINT+3, POINT+4

[0239] LSTR, POINT+4, POINT+5

[0240] LSTR, POINT+5, POINT+1

[0241] FLST,2,5,4

[0242] FITEM,2,LINE+1

[0243] FITEM,2,LINE+2

[0244] FITEM,2,LINE+3

[0245] FITEM,2,LINE+4

[0246] FITEM,2,LINE+5

[0247] AL,P51X

[0248] K, ,,0*R,

[0249] K, ,,0*R,-L5

[0250] FLST,2,1,5,ORDE,1

[0251] FITEM,2,AREA+1

[0252] FLST,8,2,3

[0253] FITEM,8,POINT+6

[0254] FITEM,8,POINT+7

[0255] VROTAT,P51X, , , , , ,P51X, ,180, ,

[0256] SUMPOINT=17

[0257] SUMLINE=25

[0258] SUMAREA=13

[0259] POINT=POINT+SUMPOINT

[0260] LINE=LINE+SUMLINE

[0261] AREA = AREA + SUMAREA

[0262] FLST, 3, 4, 6, ORDE, 2

[0263] FITEM, 3, VOLU + 1

[0264] FITEM, 3, -(VOLU + 4)

[0265] VSBV, VOLU, P51X

[0266] NUMCMP, ALL

[0267] wpoff, 0, -2*R, -L5

[0268] L = L + L5

[0269] SUMPOINT = -20

[0270] SUMLINE = -34

[0271] SUMAREA = -20

[0272] POINT = POINT + SUMPOINT

[0273] LINE = LINE + SUMLINE

[0274] AREA = AREA + SUMAREA

[0275] (6)Right crank model (H1, H2, B1, L6, RH1, A2, LD1) The creation method of the right crank is the same as that of the left crank. Only need to replace M4-1 to M4-11 in the command stream for creating the "left crank model" with M4-17 to M4-27, replace M3-39 with M4-28, and replace M4-12 and M4-13 with M4-29 and M4-30 respectively. The command streams of M4-1 to M4-13 are as follows:

[0276] K, , B1 / 2, H2, -L (M4-17)

[0277] K, , B1 / 2, -H1, -L (M4-18)

[0278] K, , -B1 / 2, H2, -L (M4-19)

[0279] K, , -B1 / 2, -H1, -L (M4-20)

[0280] VOFFST, AREA + 1, L6, , (M4-21)

[0281] K, ,H1,,-L (M4-22)

[0282] K, ,1.2*H1,,-L (M4-23)

[0283] K, ,1.2*H1,,-L5-L (M4-24)

[0284] K, ,H1-(L6-LD1)*TANH(A2),,-L6-L (M4-25)

[0285] K, ,H1,,-LD1-L (M4-26)

[0286] K, ,,,-L5 (M4-27)

[0287] VROTAT,P51X, , , , , ,P51X, ,180, , (M4-28)

[0288] wpoff,0,R,-L6 (M4-29)

[0289] L = L + L6 (M4-30)

[0290] (7) Left cone chamfer model (D1, D5, AR1, C)

[0291] The creation method of the left cone chamfer is basically the same as that of the left step chamfer. The only difference is that the coordinate values of the center point and the third cutting key point need to be obtained by calculation. Only need to replace the command stream M3-13~M3-16 in the left step chamfer model with M3-42~M3-45. The command stream is as follows.

[0292] K, ,,D5 / 2, -L (M3-42)

[0293] K, ,,D1 / 2+AR1,SQRT(2*AR1*(D5-D1) / 2-((D5-D1)*(D5-D1) / 4))-L *! Center point (M3-43)

[0294] K, ,,D1 / 2,SQRT(2*AR1*(D5-D1) / 2-((D5-D1)*(D5-D1) / 4)) -L (M3-44)

[0295] K, ,,D1 / 2, -L (M3-45)

[0296] (8) Left cone model (D5, D6, L8)

[0297] The creation method of the left cone model is similar to the creation methods of the above various chamfers. It also creates multiple key points, then creates a rotating surface from the key points, and finally rotates the rotating surface along the rotation axis to form a cone. The construction of the left cone includes six steps: First, create each key point that encloses the rotating surface, and the command stream is shown in M3-46~M3-49; Second, create a rotation with the key points, and the command stream is shown in M3-50~M3-55, and the created rotating surface is as shown in Figure 9 Figure (a); Third, rotate the created rotation into a solid element with the connection line of the key points as the rotation axis, and the command stream is shown in M3-56~M3-61, and the created left cone is as shown in Figure 9 Figures (b) and 9(c). The command stream is as follows,

[0298] K, ,,,-L8-L (M3-46)

[0299] K, ,,D6 / 2,-L8-L (M3-47)

[0300] K, ,,D5 / 2, -L (M3-48)

[0301] K, ,,, -L (M3-49)

[0302] FLST,2,4,3 (M3-50)

[0303] FITEM,2,POINT+1 (M3-51)

[0304] FITEM,2,POINT+2 (M3-52)

[0305] FITEM,2,POINT+3 (M3-53)

[0306] FITEM,2,POINT+4 (M3-54)

[0307] A,P51X (M3-55)

[0308] FLST,2,1,5,ORDE,1 (M3-56)

[0309] FITEM,2,AREA+1 (M3-57)

[0310] FLST,8,2,3 (M3-58)

[0311] FITEM,8,POINT+1 (M3-59)

[0312] FITEM,8,POINT+4 (M3-60)

[0313] VROTAT,P51X,,,,,,P51X,,360,, (M3-61)

[0314] wpoff,0,0,-L8

[0315] L = L + L8

[0316] SUMPOINT = 10

[0317] SUMLINE = 21

[0318] SUMAREA = 16

[0319] SUMVOLU = 4

[0320] POINT = POINT + SUMPOINT

[0321] LINE = LINE + SUMLINE

[0322] AREA = AREA + SUMAREA

[0323] VOLU = VOLU + SUMVOLU

[0324] (9)Right cone model (D5, D6, L8) The creation method of the right cone model is exactly the same as that of the left cone, only need to replace M3-47 and M3-48 with M4-31 and M4-32 respectively. The command stream is as follows,

[0325] K, ,,D5 / 2,-L8-L (M4-31)

[0326] K, ,,D6 / 2, -L (M4-32)

[0327] (10)Right cone chamfer model (D1, D5, AR1, C) The creation method of the right cone chamfer is exactly the same as that of the left cone chamfer, only need to replace M3-43 and M3-44 with M4-33 and M4-34 respectively. The command stream is as follows,

[0328] K, ,,D1 / 2+AR1,-SQRT(2*AR1*(D5-D1) / 2-((D5-D1)*(D5-D1) / 4))-L!*Dot (M4-33)

[0329] K, ,,D1 / 2,-SQRT(2*AR1*(D5-D1) / 2-((D5-D1)*(D5-D1) / 4))-L (M4-34)

[0330] (11)Cylinder model (D16, D15, L45)

[0331] The method for creating a cylinder model is very similar to that of a cylinder. Only the command stream of M3-1 needs to be replaced with M3-62, and the number of variables changes from 2 to 3. The process of creating a cylinder is as Figure 10 shown; for the convenience of cylinder modeling, the model construction adopts a symmetric modeling method, as shown in the command streams M3-63 to M3-64. The command stream for creating the cylinder model is as follows,

[0332] CYL4,0,0,D16 / 2, ,D15 / 2 (M3-62)

[0333] VOFFST,AREA+1,-L45 / 2, , *! -L45 / 2 means stretching to the right (M3-63)

[0334] VOFFST,AREA+1,L45 / 2, , *! L45 / 2 means stretching to the left (M3-64)

[0335] SUMAREA=19

[0336] AREA=AREA+SUMAREA

[0337] After completing the construction of the above volume elements, add up the individual volume elements to complete the geometric modeling of the reciprocating compressor shafting. The order of adding up the individual volume elements is: start from the free end of the crankshaft, then model the motor shaft, and finally model the motor rotor.

[0338] The order of adding up each volume element is: start from the free end of the crankshaft, then model the motor shaft, and finally model the motor rotor.

[0339] The two-dimensional view of a 6-column reciprocating compressor shafting is as Figure 11 shown, which is the structural diagram of a column of crankshaft sequences. Combining Figure 1 it can be seen that the entire shafting is composed of crankshafts with multiple dimensional sequences. Their structures are the same, the components they form are the same, only the dimensions are different. Therefore, after adjusting the established volume elements to the appropriate dimensions, assembly is required. The specific process is as follows:

[0340] Taking the shafting geometric model shown in Figure 12 as an example, the method and basic process of the shafting geometric model are introduced in the ways of GUI and command stream respectively. In Figure 12In it, a is the schematic diagram of the crankshaft structure of the 1st and 2nd columns, b is the schematic diagram of the crankshaft structure of the 2nd and 4th columns; c is the schematic diagram of the crankshaft structure of the 5th and 6th columns; d is the schematic diagram of the motor shaft section structure; (e) is the schematic diagram of the structural dimensions and phase angles of the crank of each column. The geometric model of the reciprocating compressor shafting is constructed starting from the free end of the crankshaft, then the motor shaft is modeled, and finally the model of the motor rotor is constructed. The command stream for constructing the geometric model of the shafting mainly consists of two parts: one part is the unit structure with parameter variables, and the other part is the creation and use of local coordinate systems, etc. During the process of parametric modeling of the geometric parameters of the reciprocating compressor crankshaft shafting, each parameter of the geometric model in Figure 12 needs to be defined in the macro file ParGeo6M.MAC (note: the macro file name cannot start with a number). The content of this command stream is as follows,

[0341] / PREP7 !* Start executing the Preprocessor (preprocessing) command

[0342] ParGeo6M !* Read in all the parameters defined in the ParGeo6M.MAC file

[0343] !* The following is the content for drawing the crankshaft of the 1st and 2nd columns

[0344] Cylindrical model (D1, L1) !* The main shaft of the 1st column

[0345] Left step chamfer model (D1, AR1, 0)

[0346] Cylindrical model (D2, L2)

[0347] Left crank model (H1, H2, B1, L3, RH1, A2, LD1)

[0348] Cylindrical model (D4, L2)

[0349] Right step chamfer model (D3, AR1, 1)

[0350] Cylindrical model (D3, L4) !* The crank pin of the 1st column

[0351] Left step chamfer model (D3, AR1, 1)

[0352] Cylindrical model (D4, L2)

[0353] Middle crank model (H1, B1, L5, RH1, A2, LD2)

[0354] Cylindrical model (D4, L2)

[0355] Right step chamfer model (D3, AR1, -1)

[0356] Cylindrical model (D3, L4)! * Second column crankpin

[0357] Left stepped chamfer model (D3, AR1, -1)

[0358] Cylindrical model (D4, L2)

[0359] Right crank model (H1, H2, B1, L6, RH1, A2, LD1)

[0360] Cylindrical model (D4, L2)

[0361] Right stepped chamfer model (D1, AR1, 0)

[0362] Cylindrical model (D1, L7)! * Second column main shaft

[0363] Left conical chamfer model (D1, D5, AR1, 0)

[0364] Left conical model (D5, D6, L8)

[0365] Cylindrical model (D6, L9)

[0366] Right conical model (D5, D6, L8)

[0367] ! * The following is the content for drawing the crankshaft of the third and fourth columns

[0368] wprot,ALPHA! * Rotate the origin of the current working plane WP by the angle ALPHA

[0369] CSWPLA,11,0,1,1,! * Create the working plane WP coordinate system as the local coordinate system 11, CSYS,11,! * Change the local coordinate system 11 to the active coordinate system, CHA-CS-SP

[0370] L = 0

[0371] Right conical chamfer model (D1, D5, AR1, 0)

[0372] Cylindrical model (D1, L7)! * Third column main shaft

[0373] Left stepped chamfer model (D1, AR1, 0)

[0374] Cylindrical model (D2, L2)

[0375] Left crank model (H1, H2, B1, L6, RH1, A2, LD1)

[0376] Cylindrical model (D4, L2)

[0377] Right stepped chamfer model (D3, AR1, 1)

[0378] Cylindrical model (D3, L4)! * The third column crank pin

[0379] Left stepped chamfer model (D3, AR1, 1)

[0380] Cylindrical model (D4, L2)

[0381] Middle crank model (H1, B1, L5, RH1, A2, LD2)

[0382] Cylindrical model (D4, L2)

[0383] Right stepped chamfer model (D3, AR1, -1)

[0384] Cylindrical model (D3, L4)! * The fourth column crank pin

[0385] Left stepped chamfer model (D3, AR1, -1)

[0386] Cylindrical model (D4, L2)

[0387] Right crank model (H1, H2, B1, L6, RH1, A2, LD1)

[0388] Cylindrical model (D4, L2)

[0389] Right stepped chamfer model (D1, AR1, 0)

[0390] Cylindrical model (D1, L7)! * The fourth column main shaft

[0391] Left conical chamfer model (D1, D5, AR1, 0)

[0392] Left conical model (D5, D6, L8)

[0393] Cylindrical model (D6, L11)! * Compared with the first and second column crankshafts, L9 becomes L11

[0394] Right conical model (D5, D6, L8)

[0395] ! * The following is the content for drawing the fifth and sixth column crankshafts

[0396] wprot,ALPHA! * Rotate the origin of the current working plane WP by ALPHA angle again

[0397] CSWPLA,12,0,1,1,! * Create the working plane WP coordinate system as the local coordinate system 12

[0398] CSYS,12,! * Change the local coordinate system 12 to the active coordinate system

[0399] L = 0

[0400] Right cone chamfer model (D1, D5, AR1, 0)

[0401] Cylinder model (D1, L7) !* 5th column main shaft

[0402] Left step chamfer model (D1, AR1, 0)

[0403] Cylinder model (D2, L2)

[0404] Left side crank model (H1, H2, B1, L6, RH1, A2, LD1)

[0405] Cylinder model (D4, L2)

[0406] Right step chamfer model (D3, AR1, 1)

[0407] Cylinder model (D3, L4) !* 5th column crank pin

[0408] Left step chamfer model (D3, AR1, 1)

[0409] Cylinder model (D4, L2)

[0410] Middle crank model (H1, B1, L5, RH1, A2, LD2)

[0411] Cylinder model (D4, L2)

[0412] Right step chamfer model (D3, AR1, -1)

[0413] Cylinder model (D3, L4) !* 6th column crank pin

[0414] Left step chamfer model (D3, AR1, -1)

[0415] Cylinder model (D4, L2)

[0416] Right side crank model (H1, H2, B1, L12, RH1, A2, LD1)

[0417] Cylinder model (D2, L2)

[0418] Right step chamfer model (D1, AR1, 0)

[0419] Cylinder model (D1, L13) !* 6th column main shaft

[0420] Cylinder model (D7, L14)

[0421] Cylinder model (D8, L15)

[0422] Left step chamfer model (D8, AR2, 0)

[0423] Cylindrical model (D9, L20)

[0424] Cylindrical model (D22, L21) !* Determine D22 according to the equivalent flywheel

[0425] !* The following is the content for drawing the motor shaft

[0426] wprot, -2*ALPHA !* Rotate the origin of the current working plane WP by -2*ALPHA angle

[0427] CSWPLA, 13, 0, 1, 1, !* Create the working plane WP coordinate system as the local coordinate system 13

[0428] CSYS, 13, !* Change the local coordinate system 13 to the active coordinate system

[0429] L = 0

[0430] Cylindrical model (D9, L22)

[0431] Right step chamfer model (D10, AR3, 0)

[0432] Cylindrical model (D10, L23)

[0433] Cylindrical model (D11, L24)

[0434] Cylindrical model (D12, L25) !* Motor bearing

[0435] Cylindrical model (D13, L26)

[0436] Left cone model (D13, D14, L27)

[0437] Cylindrical model (D14, L28)

[0438] Cylindrical model (D16, L29)

[0439] Right cone model (D16, D17, L30)

[0440] Cylindrical model (D17, L31)

[0441] Cylindrical model (D18, L32)

[0442] Cylindrical model (D19, L33)

[0443] Cylindrical model (D27, L34)

[0444] !* The following is the content for drawing the motor rotor

[0445] wpoff,0,0,L35! * Move the working plane WP to the axial symmetry center of the motor rotor

[0446] Cylinder model (D16, D15, L45)

[0447] Cylinder model (D15, D20, L36)

[0448] Cylinder model (D20, D21, L42)

[0449] Cylinder model (D21, D26, L45)

[0450] CSYS,0! * Activate the global Cartesian coordinate system

[0451] WPAVE,0,0,0! * Move the working plane WP to the origin of the global Cartesian coordinate system

[0452] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method for modular geometric modeling of a reciprocating compressor shafting, characterized in that, The method includes the following steps: S100. Divide the structures with the same shape but different sizes in the geometric model of the reciprocating compressor shafting into corresponding volume elements, and establish a volume element model for each volume element. The construction of the volume element model includes drawing instructions, coordinate system instructions, and basic information of the volume element. The basic information includes the number of key points, lines, faces, and volumes, and the basic information is used to realize the information transfer between the volume elements of the shafting; S200. According to the positions of the volume elements in the shafting, after adjusting the corresponding volume element models to the corresponding sizes, complete the geometric modeling of the reciprocating compressor shafting by superposition.

2. The method for modular geometric modeling of the reciprocating compressor shafting according to claim 1, characterized in that In step S100, the volume element model includes a cylinder (1), a right stepped chamfered geometric body (3), a left stepped chamfered geometric body (2), a left crank geometric body (4), a right crank geometric body (6), a middle crank geometric body (5), a left conical circular chamfered geometric body (7), a right conical circular chamfered geometric body (8), a left cone (9), a right cone (10), and a cylindrical body (11); The cylinder (1) and the cylindrical body (11) are drawn by the diameters D and the axial length L of a circle or a ring; The left stepped chamfered geometric body (2), the right stepped chamfered geometric body (3), the left conical circular chamfered geometric body (7), and the right conical circular chamfered geometric body (8) are created by directly creating a key point group in the working plane, creating line elements from the key point group in sequence, creating surface elements from the line elements, and then forming volume elements by rotating the surface elements; The left crank geometric body (4), the right crank geometric body (6), and the middle crank geometric body (5) are created by directly creating key points in the working plane, creating surface elements from the key point group in sequence, then forming volume elements by stretching the surface elements, and then using the Boolean operation in the ANSYS system to cut off the large arc and chamfer by subtracting two or more volume elements; The left cone (9) and the right cone (10) are created by directly creating a key point group in the working plane, creating surface elements from the key points in sequence, and then forming volume elements by rotating the surface elements.

3. The method for modular geometric modeling of the reciprocating compressor shafting according to claim 2, characterized in that, The modeling of the left stepped chamfered geometric body (2), the right stepped chamfered geometric body (3), the left conical circular chamfered geometric body (7), and the right conical circular chamfered geometric body (8) includes the following steps: S111. Create the first key point, the second key point, the third key point, and the first center point that enclose the arc section in the key point group; S112. Draw an arc with the first center point as the center and the diameter; S113. Connect the first key point and the third key point respectively, and connect the third key point and the second key point to form two straight lines; S114. Create a surface from the arc, the straight line formed by the first key point and the third key point, and the straight line formed by the second key point and the third key point; S115. Create the end point a and the end point b of the rotation axis of the surface in step S114, that is, the fourth key point and the fifth key point; S116. Rotate the created surface with the connection line of the fourth key point and the fifth key point as the rotation axis to form a rotating body.

4. The method for modular geometric modeling of a reciprocating compressor shafting according to claim 2, characterized in that, The modeling steps of the left crank geometric body (4), the right crank geometric body (6) and the middle crank geometric body (5) are as follows: S121. Create a crank hexahedron, and the steps are as follows: S1211. Create the first crank key point, the second crank key point, the third crank key point and the fourth crank key point that enclose the crank longitudinal section. In the YZ plane, the first crank key point and the third crank key point coincide, and the second crank key point and the fourth crank key point coincide. Moreover, the first crank key point, the second crank key point, the third crank key point and the fourth crank key point are all in the XY plane; S1212. Create a surface with the first crank key point, the second crank key point, the third crank key point and the fourth crank key point; S1213. Form a solid by axially stretching the surface created in step S1212; S122. Cut the created crank hexahedron, and the steps are as follows: S1221. Create the first cutting key point, the second cutting key point, the third cutting key point, the fourth cutting key point and the fifth cutting key point that enclose the cutting section; S1222. Create a surface with the first cutting key point, the second cutting key point, the third cutting key point, the fourth cutting key point and the fifth cutting key point; S1223. Create a cutting solid by rotating the surface in step S1222; S1224. Cut the crank hexahedron created in step S121 with the newly created cutting solid.

5. The method for modular geometric modeling of a reciprocating compressor shafting according to claim 4, characterized in that The creation steps of the middle crank are the same as those of S121. In step S122, 2 cutting solids need to be built for splitting, and chamfers are completed at the upper and lower ends of the middle crank respectively.

6. The method for modular geometric modeling of a reciprocating compressor shafting according to claim 2, characterized in that, The cumulative order of each body element is: start from the free end of the crankshaft, then model the motor shaft, and finally build the model of the motor rotor.

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