Reciprocating compressor shafting modular geometric modeling method

Abstract

The invention discloses a design method for modular geometric modeling of a reciprocating compressor shaft system, which comprises the following steps of: realizing modeling of different body elements of the reciprocating compressor shaft system by using a universal ANSYS finite element calculation software APDL language, and combining various body elements to establish shaft system geometric models with different structures; according to the method, the working efficiency of parameterized geometric modeling of the reciprocating compressor shafting can be greatly improved, and an intelligent design means is provided for secondary development work of software.

Description

Technical Field

[0001] The invention belongs to the technical field of ANSYS modeling, and in particular relates to a method for modular geometric modeling of a shaft system of a reciprocating compressor. Background Art

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

[0003] The calculation technology of torsional vibration of reciprocating compressor rotor system is the technical bottleneck that restricts the development of reciprocating compressor to multi-row or high-speed. The geometric modeling of reciprocating compressor shaft system is one of the key links in the calculation of torsional vibration of rotor system. In the calculation of torsional resonance of reciprocating compressor rotor system, the parametric geometric modeling of shaft system accounts for more than 95% of the total workload. Figure 1 As shown, it is a typical 6-row reciprocating compressor shaft system geometry model in the prior art. In the process of modeling by ANSYS, each of the components of the cylinder and crank of different sizes needs to be modeled separately and then assembled. In this process, each unit body is provided with different key point numbers, line numbers, surface numbers, and body numbers. At the same time, the designer also needs to create different command streams according to different unit bodies for combination. The process is time-consuming and labor-intensive, and the work efficiency is low. Summary of the invention

[0004] The purpose of the embodiment of the present invention is to provide a modular geometric modeling method for the shaft system of a reciprocating compressor, so as to alleviate the technical problem of low efficiency of shaft system module modeling in the prior art.

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

[0006] A first aspect of the present invention provides a method for modular geometric modeling of a reciprocating compressor shaft system, comprising the following steps:

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

[0008] S200. According to the position of each volume element in the shaft system, the corresponding volume element model is adjusted to a corresponding size, and the geometric modeling of the reciprocating compressor shaft system is completed by superposition.

[0009] In some modified implementations of the first aspect of the present invention, in step S100, the volume element model includes a cylinder, a right step chamfered geometry, a left step chamfered geometry, a left crank geometry, a right crank geometry, an intermediate crank geometry, a left cone round chamfered geometry, a right cone round chamfered geometry, a left cone, a right cone, and a cylinder;

[0010] Cylinders and cylindrical bodies are drawn by the diameter D and axial length L of a circle or ring;

[0011] The left step chamfer geometry, right step chamfer geometry, left cone round chamfer geometry, and right cone round chamfer geometry are created by directly creating key point groups in the work plane, and then line elements are created from the key point groups, surface elements are created from the line elements, and then volume elements are formed from the surface elements through rotation;

[0012] The left crank geometry, the right crank geometry and the middle crank geometry are directly created by key points in the work plane, and then surface elements are created from the key point groups in turn, and then the surface elements are stretched to form volume elements, and then the Boolean operation in the ANSYS system is used to subtract two or more volume elements to complete the removal of large arcs and chamfers;

[0013] The left vertebra and the right vertebra are created by directly creating key point groups in the working plane, and then surface elements are created from the key points, and then the surface elements are rotated to form volume elements.

[0014] In some modified implementations of the first aspect of the present invention, modeling of the left step chamfered geometry, the right step chamfered geometry, the left cone round chamfered geometry, and the right cone round chamfered geometry includes the following steps:

[0015] S111. Create a first key point, a second key point, a third key point and a first center point in a key point group to form an arc cross section;

[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 first and second key points to form two straight lines;

[0018] S114. Create a surface by 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 endpoint a and endpoint b of the rotation axis of the surface in step S114, ie, the fourth key point and the fifth key point;

[0020] S116. Form a rotating body by rotating the created surface with the line connecting the fourth key point and the fifth key point as the rotation axis.

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

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

[0023] S1211 creates a first crank key point, a second crank key point, a third crank key point and a fourth crank key point that enclose a longitudinal section of the crank, wherein the first crank key point and the third crank key point and the second crank key point and the fourth crank key point are respectively coincident in the YZ plane, and 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 with the first crank keypoint, the second crank keypoint, the third crank keypoint and the fourth crank keypoint

[0025] S1213 forming a body by axially stretching the surface created in step S1212;

[0026] S122. The steps of cutting the created crank hexahedron are:

[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 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

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

[0030] S1224. Use the newly created cutting body to cut the crank hexahedron created in step S121.

[0031] In some modified implementations of the first aspect of the present invention, the creation step of the intermediate crank is the same as S121. In step S122, the segmentation requires the creation of two cutting bodies, and the chamfering of the upper and lower ends of the intermediate crank is completed respectively.

[0032] In some modified implementations of the first aspect of the present invention, the order of accumulating independent volume elements is: starting from the free end of the crankshaft, then modeling the motor shaft, and finally modeling the motor rotor.

[0033] 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 and different sizes in the geometric model of the reciprocating compressor shaft system into corresponding body elements. It is only necessary to complete the construction of the corresponding body element model according to the corresponding drawing instructions, coordinate system instructions and basic information of the body elements. Before the assembly step, it is adjusted to the corresponding size, which greatly shortens the time spent on modeling. At the same time, the basic information of the body element model includes the number of key points, lines, faces and bodies to ensure the information transmission between the elements of each independent body of the shaft system, thereby improving the accuracy of modeling.

[0034] Therefore, compared with the prior art, the shaft system geometric modeling method proposed in the present invention, on the one hand, does not need to define the key point number, line number, surface number, and body number required to create each unit body; on the other hand, it combines the command streams used to create different unit bodies, so that the time required to construct the shaft system geometric model is only one percent of the time consumed by conventional modeling, thereby greatly improving the work efficiency of shaft system modeling.

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

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the embodiments are briefly introduced below.

[0037] Figure 1 A schematic diagram of a geometric model of a shaft system of a six-row reciprocating compressor in a method for modular geometric modeling of a reciprocating compressor provided in Embodiment 1 of the present invention;

[0038] Figure 2 A schematic diagram of the decomposition of a shaft system model in a method for modular geometric modeling of a reciprocating compressor provided in the first embodiment of the present invention;

[0039] Figure 3 A schematic diagram of a 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 A schematic diagram of a right step chamfering process in a method for modular geometric modeling of a reciprocating compressor provided in the first embodiment of the present invention;

[0041] Figure 5 A schematic diagram of the key points of the left crank and the surfaces created therefrom in a method for modular geometric modeling of a reciprocating compressor provided in the first embodiment of the present invention;

[0042] Figure 6 A schematic diagram of a model created by a left crank in a method for modular geometric modeling of a reciprocating compressor provided in the first embodiment of the present invention;

[0043] Figure 7 A schematic diagram of creating a left crank chamfer in a method for modular geometric modeling of a reciprocating compressor provided in the first embodiment of the present invention;

[0044] Figure 8 A schematic diagram of creating an intermediate crank chamfer in a method for modular geometric modeling of a reciprocating compressor provided in the first embodiment of the present invention;

[0045] Fig. 9 A schematic diagram of creating a left vertebral body in a method for modular geometric modeling of a reciprocating compressor provided in the first embodiment of the present invention;

[0046] Fig.10 A schematic diagram of the basic process of creating a cylinder in a method for modular geometric modeling of a reciprocating compressor provided in the first embodiment of the present invention;

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

[0048] Fig.12 In a method for modular geometric modeling of a reciprocating compressor provided in embodiment 1 of the present invention Figure 1 Two-dimensional diagram of the equivalent shafting geometry of a reciprocating compressor.

[0049] In the figure: 1-cylinder, 2-left step chamfered geometry, 3-right step chamfered geometry, 4-left crank geometry, 5-middle crank geometry, 6-right crank geometry, 7-left cone chamfered geometry, 8-right cone chamfered geometry, 9-left cone, 10-right cone, 11-cylinder. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0052] Embodiment 1

[0053] This embodiment provides a method for modular geometric modeling of a reciprocating compressor, the method comprising the following steps:

[0054] S100. Segment the structures of the same shape and different sizes in the geometric model of the shaft system of the reciprocating compressor into corresponding volume elements, and establish a volume element model for each volume element, wherein the construction of the volume element model includes drawing instructions, coordinate system instructions and basic information of the volume element, wherein the basic information includes the number of key points, the number of lines, the number of faces and the number of volumes, and the basic information is used to realize information transmission between the elements of each independent volume of the shaft system;

[0055] S200. According to the position of each volume element in the shaft system, the corresponding volume element model is adjusted to a corresponding size, and the geometric modeling of the reciprocating compressor shaft system is completed by superposition.

[0056] like Figure 1 and Figure 2 As shown, the topological structure of the crankshaft system of the reciprocating compressor used in the present invention is relatively simple, and can be composed of a plurality of cylinders, left step chamfers, right step chamfers, left cranks, middle cranks, right cranks, left cone chamfers, right cone chamfers, left cones, right cones, cylinders and other unit structures arranged in an orderly manner, among which the cylinder has the highest repetition rate, and only the axial lengths and outer diameters of different cylinders are different. Each unit structure is as shown in FIG. Figure 2 As shown. These unit structures can all directly draw all the geometric models using the ANSYS software pre-processing modeling (Main Menu> Preprocessor> Modeling) function. The biggest feature of this modeling method is that it can realize parametric modeling and greatly improve the modeling efficiency. In order to achieve the equivalence of the inertial mass of each column and facilitate the meshing of the subsequent finite element model, no matter which method is used for the geometric modeling of the reciprocating compressor shaft system, it is necessary to construct each column of crank pins and other parts of the crankshaft, flywheel and other parts of the crankshaft, flywheel and motor shaft, motor shaft and motor rotor, etc. into independent body elements. Before the crankshaft shaft system is meshed, all independent body elements are glued (Glue) to make the entire crankshaft model a unified elastic body. It should be pointed out that ANSYS software sometimes has different construction methods to construct the same unit structure. This book only describes one of the methods. Taking the 6M type reciprocating compressor shaft system provided in this embodiment as an example, the ANSYS software pre-processing modeling function is used to perform geometric modeling of the shaft system in the human-computer interaction mode (GUI) and the command stream input mode.

[0057] 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 and different sizes in the geometric model of the reciprocating compressor shaft system into corresponding body elements. It is only necessary to complete the construction of the corresponding body element model according to the corresponding drawing instructions, coordinate system instructions and basic information of the body elements. Before the assembly step, it is adjusted to the corresponding size, which greatly shortens the time spent on modeling. At the same time, the basic information of the body element model includes the number of key points, lines, faces and bodies to ensure the information transmission between the elements of each independent body of the shaft system, thereby improving the accuracy of modeling.

[0058] Further, in step S100, the independent body elements include cylinder 1, right side round chamfered geometry, left side round chamfered geometry, left side crank geometry 4, right side crank geometry 6, middle crank geometry 5, left side cone round chamfered geometry 7, right side cone round chamfered geometry 8, left side cone, right side cone and cylinder 11;

[0059] The left round chamfered geometry, the right round chamfered geometry, the left cone round chamfered geometry 7, and the right cone round chamfered geometry 8 adopt the method of directly creating a key point group in the work plane, creating line elements from the key point group in turn, creating surface elements from the line elements, and then forming volume elements from the surface elements by rotation;

[0060] The left crank geometry 4, the right crank geometry 6 and the middle crank geometry 5 are directly created with key points in the work plane, and surface elements are created from the key point groups in turn, and then the surface elements are stretched to form volume elements, and then the Boolean operation in the ANSYS system is used to subtract two or more volume elements to complete the removal of large arcs and chamfers;

[0061] The left vertebra and the right vertebra are created by directly creating key point groups in the working plane, and then surface elements are created from the key points, and then the surface elements are rotated to form volume elements.

[0062] According to the characteristics of the shaft system unit structure, the creation methods of different shaft system unit structures can be summarized into four categories: First, create circular surface elements or ring elements directly in the work plane, and form volume elements by stretching, such as Figure 2The cylinder 1 and the cylinder 11 in the figure (drawn by the diameter D and the axial length L of the circle or the ring), the second is to directly create key points in the work plane, create line elements from the key points in turn, create surface elements from the line elements, and then form body elements by rotating the surface elements, the right step chamfer geometry 3, the left step chamfer geometry 2, the left crank geometry 4, the right crank geometry 6, the middle crank geometry 5, the left cone round chamfer geometry 7, the right cone round chamfer geometry 8, the left cone 9, and the right cone 10; the third is to directly create key points in the work plane, create surface elements from the key points in turn, and then form body elements by stretching the surface elements, and then use the Boolean operation (Booleans) in the ANSYS system to complete the removal of the large arc RH13 and the chamfer by subtracting (Subtract) two or more body elements, such as Figure 2 The left crank, middle crank, right crank, etc. in the figure (the outer contour of the crank is drawn by dimensions H, B and L, and the large chamfer and cut arc are drawn by parameters such as RH1, A2, LD, etc.); Fourth, directly create key points in the work plane, create surface elements from the key points in turn, and then form volume elements from the surface elements by rotation, such as Figure 2 The left cone, right cone, etc. in the figure (drawn by the diameter D and axial length L of each boundary point, etc.).

[0063] The following will introduce each independent volume element one by one:

[0064] (1) Cylinder model (D1, L1) The construction of the cylinder model includes three steps: first, draw a circular surface with a diameter of D1 and a coordinate point (0, 0) as the center in the work coordinate system (WP), and the command flow is shown in M3-1; second, stretch the circular surface to the right of the cylinder 1 with a length of L1, and the command flow is shown in M3-2; third, move the work coordinate system to the next axial position, and the command flow is shown in M3-3. Currently, the work coordinate system is moved to the right by a length of L1. When using key points to create an axis unit structure model, it is necessary to master the axial position of the work coordinate system WP, so use the command flow M3-4 to record the axial position of the current work plane from time to time.

[0065] The command flow of the cylindrical model (D1, L1) is as follows,

[0066]

[0067]

[0068] In the process of generating cylinder 1 by stretching the circular surface, the total number of key points (SUMPOINT) of the newly generated cylinder 1 is 8, the number of lines (SUMLINE) is 12, the total number of faces (SUMAREA) is 6, and the number of volumes (SUMVOLU) generated is 1. The command flow is shown in M3-5 to M3-8. Figure 2The various unit modeling methods are different. Some are operated on the built "body", some are operated on the built "surface", some are operated on the built "line", and some are operated on the built "key point". For example, the chamfer in the "crank model construction" is a subtraction operation on the "body", such as VOLU+1, VOLU+2, VOLU in the command flow M3-38~M3-40; the construction of the "cylinder model" is an operation on the built "surface", such as "AREA+1" in the command flow M3-2; in the construction process of various models that form unit bodies by rotating surfaces, such as the "left step chamfer model", operations are performed on the built "lines, key points", among which the operation command flow of "key points" is such as "POINT+1, POINT+2, POINT+3, POINT+4" in M3-17~M3-19, and the operation command flow of "lines" is such as "LINE+1, LINE+2, LINE+3" in M3-21~M3-22. Therefore, all unit modeling in this article must be accompanied by statistical figures of "point, line, surface, and volume" parameters. The command flow is shown in M3-9 to M3-12, where POINT is the total number of key points after drawing cylinder 1, LINE is the total number of lines, AREA is the total number of surfaces, and VOLU is the total number.

[0069] (2) Left step chamfer model (D1, AR1, C)

[0070] The modeling of the left step chamfered geometry 2, the right step chamfered geometry 3, the left cone round chamfered geometry 7 and the right cone round chamfered geometry 8 includes the following steps:

[0071] S111. Create a first key point, a second key point, a third key point and a first center point in a key point group to form an arc cross section;

[0072] S112. Draw an arc with the first center point as the center and the diameter.

[0073] S113. Connect the first key point and the third key point, respectively, and connect the third key point and the first key point to form two straight lines;

[0074] S114. Create a surface by 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;

[0075] S115. Create endpoint a and endpoint b of the rotation axis of the surface in step S114, ie, the fourth key point and the fifth key point;

[0076] S116. Form a rotating body by rotating the created surface with the line connecting the fourth key point and the fifth key point as the rotation axis.

[0077] The construction of the left step chamfer includes six steps: First, create key points 1, 3, 4 and center point 2 that enclose the arc section, such as Figure 3 (a) shows the command flow as shown in M3-13 to M3-16; (b) draws an arc with the first point as the center and the diameter D1 as shown in Figure 3 (a); the third is to connect the first key point and the third key point and the second key point and the third key point to form two straight lines, such as Figure 3 (a), the command flow is shown in M3-18 to M3-19; fourth, 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; three line segments create a surface, and each key point, line and surface is shown in Figure 3 (a), the command flow is shown in M3-20 to M3-23; the fifth is to create the two endpoints a and b of the "face" rotation axis, the fourth key point and the fifth key point, as shown in Figure 3 (b), the command flow is shown in M3-24 to M3-25, and the relative positions of the key points are shown in Figure 3 (b); Sixth, the created surface is rotated with the line connecting the fourth key point and the fifth key point as the rotation axis to form a rotating body. The command flow is shown in M3-15 to M-30. The chamfer created is shown in Figure 3 (c) as shown.

[0078] The command flow is as follows,

[0079]

[0080]

[0081] (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. You only need to replace the command stream M3-13 to M3-16 in the left step chamfer model with M3-32 to M3-35. The created right step chamfer section and key points are as follows: Figure 4 The command flow of M3-32 to M3-35 is as follows:

[0082]

[0083] (4) Left crank model (H1, H2, B1, L3, RH1, A2, LD1); the modeling steps are as follows:

[0084] S121. Create a crank hexahedron, the steps are:

[0085] S1211. Create a first crank key point, a second crank key point, a third crank key point and a fourth crank key point that enclose a longitudinal section of the crank, wherein the first crank key point and the third crank key point and the second crank key point and the fourth crank key point are respectively coincident in the YZ plane, and 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;

[0086] 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;

[0087] S1213. Forming a body by axially stretching the surface created in step S1212;

[0088] S122. The steps of cutting the created crank hexahedron are:

[0089] 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;

[0090] 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

[0091] S1223. Create a cutting volume by rotating the surface in step S1222;

[0092] S1224. Use the newly created cutting body to cut the crank hexahedron created in step S121.

[0093] Figure 5 and Figure 6 As shown, in step S121 and step S122, the construction of the left crank model includes the creation and cutting of the crank hexahedron. The basic methods of creating and cutting the crank hexahedron are introduced below.

[0094] ① Creation of the left crank hexahedron The creation of the left crank hexahedron includes three steps: First, create the key points that enclose the longitudinal section of the crank (the section perpendicular to the axial direction): the first crank key point, the second crank key point, the third crank key point and the fourth crank key point. The relative positions of the key points are as follows: Figure 5 As shown in the longitudinal section of Figure (b), it can be seen that the first crank key point and the third crank key point and the second crank key point and the fourth crank key point coincide with each other in the YZ plane, and the key points 1234 are all in the XY plane; second, the surface is created by 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 follows Figure 5 (c) as shown; the third is to create a body by axially stretching the surface. The command flow for creating the crank hexahedron on the left is as follows:

[0095]

[0096]

[0097] ② Cutting of the left crank hexahedron

[0098] It is additionally stated that Figure 6 In the figure, a represents the axonometric view 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.

[0099] like Figure 7 As shown, the cutting of the left crank hexahedron includes four steps: first, creating 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; second, creating 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. The created surface 12345 is shown in FIG. Figure 7 (a) as shown; third, create a cutting body by rotating the surface, the command flow is shown in M3-36; fourth, use the newly created cutting body to cut the "left crank hexahedron", the command flow is shown in M3-37~M3-40, and the GUI operation is shown in the figure; the relative relationship between the cutting body and the cut body is shown in Figure 7 As shown in (c), the new unit body created is Figure 7 (c) As shown. After the creation of the new unit body is completed, the new unit body will generate new body numbers, surface numbers, line numbers and key point numbers. In order to realize the parametric modeling of the module, all the current key point numbers, line numbers, surface numbers and body numbers need to be rearranged to ensure that they start from 1 and remain continuous, so the current model needs to be compressed.

[0100]

[0101]

[0102]

[0103] (5) Intermediate crank model (H1, B1, L5, RH1, A2, LD2)

[0104] The method of creating the middle crank is the same as that of the left crank, including the creation and cutting of the crank body. To create the command of the middle crank body, just replace M4-2, M4-4, and M4-5 in the command flow of creating the left crank body with M4-14, M4-15, and M4-16 respectively. The command flow of M4-6, M4-7, and M4-8 is as follows:

[0105] K,,B1 / 2,-H1,-L (M4-14)

[0106] K,,-B1 / 2,-H1,-L (M4-15)

[0107] VOFFST,AREA+1,L5,,(M4-16)

[0108] Different from the construction of the left crank, the middle crank model needs to create two cutting bodies to complete the chamfering of the upper and lower ends of the middle crank. The chamfering creation process is as follows: Figure 8 As shown, the intermediate crank model created is as follows Figure 2 (d) The command flow is as follows:

[0109]

[0110]

[0111]

[0112]

[0113] (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. You only need to replace M4-1 to M4-11 in the command flow of 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 flow of M4-1 to M4-13 is as follows:

[0114]

[0115] (7) Left cone chamfer model (D1, D5, AR1, C)

[0116] The method for creating the left cone chamfer is basically the same as that for 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 through calculation. You only need to replace the command flow M3-13~M3-16 in the left step chamfer model with M3-42~M3-45. The command flow is as follows:

[0117]

[0118]

[0119] (8) Left cone model (D5, D6, L8)

[0120] The creation method of the left cone model is similar to the creation method of the above-mentioned chamfers. It also creates multiple key points, then creates a rotation surface from the key points, and finally rotates the rotation surface into a cone along the rotation axis. The construction of the left cone includes six steps: the first is to create the key points that form the rotation surface. The command flow is shown in M3-46 to M3-49; the second is to create a rotation with key points. The command flow is shown in M3-50 to M3-55. The rotation surface created is shown in Fig. 9 (a); the third is to rotate the created rotation into a solid unit with the key point connection line as the rotation axis. The command flow is shown in M3-56 to M3-61. The created left cone is shown in Fig. 9 (b) and 9(c). The command flow is as follows,

[0121]

[0122]

[0123] (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. You only need to replace M3-47 and M3-48 with M4-31 and M4-32 respectively. The command flow is as follows: K,,,D5 / 2,-L8-L (M4-31)

[0124] K,,,D6 / 2,-L (M4-32)

[0125] (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. You only need to replace M3-43 and M3-44 with M4-33 and M4-34 respectively. The command flow is as follows,

[0126] K,,,D1 / 2+AR1,-SQRT(2*AR1*(D5-D1) / 2-((D5-D1)*(D5-D1) / 4))-L! *Dot(M4-33)

[0127] K,,,D1 / 2,-SQRT(2*AR1*(D5-D1) / 2-((D5-D1)*(D5-D1) / 4))-L(M4-34)

[0128] (11) Cylindrical model (D16, D15, L45)

[0129] The method of creating a cylinder model is very similar to that of a column. You only need to replace the command stream of M3-1 with M3-62, and change the variables from 2 to 3. The process of creating a cylinder is as follows: Fig.10 To facilitate cylinder modeling, the model is constructed using a symmetrical modeling method, as shown in command flow M3-63 to M3-64. The command flow for creating a cylinder model is as follows:

[0130] CYL4,0,0,D16 / 2,,D15 / 2 (M3-62)

[0131] VOFFST,AREA+1,-L45 / 2,,*! -L45 / 2 means stretching to the right (M3-63)

[0132] VOFFST,AREA+1,L45 / 2,,*! L45 / 2 means stretching to the left (M3-64)

[0133] SUMAREA=19

[0134] AREA=AREA+SUMAREA

[0135] After completing the construction of the above volume elements, the independent volume elements are accumulated to complete the geometric modeling of the reciprocating compressor shaft system. The accumulation order of the independent volume elements is: starting from the free end of the crankshaft, then the motor shaft modeling, and finally the motor rotor modeling.

[0136] The order of adding the elements of each body is as follows: starting from the free end of the crankshaft, then modeling the motor shaft, and finally building the model of the motor rotor.

[0137] The two-dimensional structure of a 6-row reciprocating compressor shaft system Fig.11 The diagram is a structural diagram of a crankshaft sequence. Figure 1 It can be seen that the entire shaft system is composed of crankshafts of multiple size sequences, which have the same structure and components, but different sizes. Therefore, it is necessary to adjust the established body elements to the appropriate size before assembly. The specific process is as follows:

[0138] Now Fig.12 Taking the shaft system geometry model shown in the figure as an example, the method and basic process of the shaft system geometry model are introduced in the form of GUI and command flow. Fig.12 In the figure, a is a schematic diagram of the 1st and 2nd crankshaft structures, b is a schematic diagram of the 2nd and 4th crankshaft structures; c is a schematic diagram of the 5th and 6th crankshaft structures; d is a schematic diagram of the motor shaft section structure; (e) is a schematic diagram of the crank structure dimensions and phase angles of each column; the construction of the reciprocating compressor shaft system geometry model starts from the free end of the crankshaft, then the motor shaft is modeled, and finally the motor rotor model is constructed. The command stream for the construction of the shaft system geometry model mainly consists of two parts: one part is the unit structure with parameter variables, and the other part is the creation and use of the local coordinate system. In the process of geometric parametric modeling of the reciprocating compressor crankshaft shaft system, it is necessary to Fig.12 The parameters of the central axis geometry model are defined in the macro file ParGeo6M.MAC (note: the macro file name cannot start with a number). The contents of the command stream are as follows:

[0139]

[0140]

[0141]

[0142]

[0143]

[0144] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for modular geometric modeling of a reciprocating compressor shaft system, characterized in that: The method comprises the following steps: S100. Segmenting the geometric model of the reciprocating compressor shaft system into corresponding volume elements with identical shapes and different sizes, and establishing a volume element model for each volume element. The volume element model construction includes drawing instructions, coordinate system instructions, and basic volume element information, including the number of key points, lines, faces, and volumes. This basic information is used to facilitate information transfer between the various volume elements of the shaft system. S200. According to the position of each body element in the shaft system, the corresponding body element model is adjusted to a corresponding size, and the geometric modeling of the reciprocating compressor shaft system is completed by superposition.

2. The method for modular geometric modeling of a reciprocating compressor shaft system according to claim 1, characterized in that: In step S100, the body element model includes a cylinder (1), a right step chamfered geometry (3), a left step chamfered geometry (2), a left crank geometry (4), a right crank geometry (6), an intermediate crank geometry (5), a left cone round chamfered geometry (7), a right cone round chamfered geometry (8), a left cone (9), a right cone (10), and a cylinder (11); The cylinder (1) and the cylindrical body (11) are drawn by the diameter D and the axial length L of the circle or the ring; The left step chamfer geometry (2), the right step chamfer geometry (3), the left cone round chamfer geometry (7), and the right cone round chamfer geometry (8) are formed by directly creating a key point group in the work plane, and then creating line elements from the key point group, creating surface elements from the line elements, and then forming volume elements from the surface elements by rotating them. The left crank geometry (4), the right crank geometry (6) and the middle crank geometry (5) are directly created in the work plane by creating key points, and then surface elements are created from the key point groups, and then the surface elements are stretched to form volume elements. Then, the Boolean operation in the ANSYS system is used to complete the removal of large arcs and chamfers by subtracting two or more volume elements. The left vertebra (9) and the right vertebra (10) are formed by directly creating a key point group in the working plane, creating surface elements from the key points in turn, and then forming volume elements from the surface elements through rotation.

3. The method for modular geometric modeling of a reciprocating compressor shaft system according to claim 2, characterized in that: The modeling of the left step chamfer geometry (2), the right step chamfer geometry (3), the left cone round chamfer geometry (7), and the right cone round chamfer geometry (8) includes the following steps: S111. Create the first key point, the second key point, the third key point and the first center point of the arc section in the key point group; S112. Draw an arc with the first center point as the center and the diameter as the center. S113. Connect the first key point and the third key point, and connect the third key point and the first and second key points to form two straight lines; S114. Create a surface by 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 endpoints a and b of the rotation axis of the surface in step S114, ie, the fourth key point and the fifth key point; S116. Form a rotating body by rotating the created surface with the line connecting the fourth key point and the fifth key point as the rotation axis.

4. The method for modular geometric modeling of a reciprocating compressor shaft system according to claim 2, characterized in that: The steps for modeling the left crank geometry (4), right crank geometry (6), and center crank geometry (5) are as follows: S121. Create a crank hexahedron, the steps are: S1211 creates a first crank key point, a second crank key point, a third crank key point, and a fourth crank key point that form a longitudinal section of the crank, wherein the first crank key point and the third crank key point, as well as the second crank key point and the fourth crank key point, are coincident in the YZ plane, and 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 creates a surface based on the first crank key point, the second crank key point, the third crank key point, and the fourth crank key point; S1213 forms a body by axially stretching the surface created in step S1212; S122. Cut the created crank hexahedron, The steps are: 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 volume by rotating the surface in step S1222; S1224. Use the newly created cutting body to cut the crank hexahedron created in step S121.

5. The method for modular geometric modeling of a reciprocating compressor shaft system according to claim 4, characterized in that: The steps for creating the middle crank are the same as S121. In step S122, the segmentation requires the creation of two cutting bodies, and the chamfering of the upper and lower ends of the middle crank is completed respectively.

6. The method for modular geometric modeling of a reciprocating compressor shaft system according to claim 2, characterized in that: The order of accumulating elements of each body is: starting from the free end of the crankshaft, then modeling the motor shaft, and finally building the model of the motor rotor.

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