JP3979526B2 - Rotating machine thermal analysis method, rotating machine thermal analysis apparatus, computer program, and recording medium - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for performing thermal analysis of a rotating machine using a finite element method, a thermal analysis apparatus for the rotating machine, a computer program for realizing a computer as the thermal analysis apparatus, and a recording medium.
[0002]
[Prior art]
The rotating machine is an important part that is incorporated and used in various devices, and has been repeatedly improved for higher performance. As a rotating machine is used, it generates heat due to current flowing in the coil, eddy current generated in the magnet, and iron loss, and the internal temperature rises. In order to know the conditions of use of this, it is necessary to perform a thermal analysis that calculates the generation and transfer of heat inside the rotating machine during operation.
[0003]
Thermal analysis of rotating machines has been conventionally performed using the finite element method. In the finite element method, a two-dimensional or three-dimensional shape model representing the shape to be analyzed is created using a CAD system or the like. Generate a mesh that represents the model with a combination of polygonal or polyhedral elements, and perform numerical calculations on the mesh. FIG. 6 is a cross-sectional view showing an example of the structure of a rotating machine and a cross-sectional view showing an example of a mesh generated for performing thermal analysis. FIG. 6A is a cross-sectional view of the rotating machine cut along a plane perpendicular to the rotation axis of the rotor R. As shown in the figure, there is a space between the stator S and the rotor R of the rotating machine. In order to perform the accurate thermal analysis, it is necessary to calculate the air flow in the space G. FIG. 6B is a conventional mesh generated for performing thermal analysis. Since enormous calculation costs are required to calculate the air flow, conventionally, the combined portion of the rotating rotor R and the space G is regarded as a concentric heating element, and the shape of the stator S Is generated, and thermal analysis is performed on the stator S without calculating the air flow.
[0004]
[Problems to be solved by the invention]
In the conventional thermal analysis method, the rotating rotor R is modeled concentrically while ignoring the uneven shape of the rotor R, so that there is a problem that thermal analysis cannot be performed on the rotor R. In particular, in a rotating machine that uses a permanent magnet for the rotor R, the performance of the permanent magnet changes depending on the temperature, so that a detailed thermal analysis of the rotor R is required.
[0005]
The present invention has been made in view of such circumstances, and the object of the present invention is to use a finite element method in a thermal analysis of a rotating machine to obtain a circle centered on the rotation axis of the rotor in a space. The part that can be drawn represents the rotation of the rotor by assuming that the temperature is uniform in the circumferential direction, and a method of performing thermal analysis using a mesh that represents the shape of the stator and rotor, A thermal analysis apparatus, a computer program for realizing a computer as the thermal analysis apparatus, and a recording medium are provided.
[0006]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a thermal analysis method for a rotating machine using a computer including a storage unit and a calculation unit, and a stator constituting the rotating machine, a rotor, and a shape of a space between the stator and the rotor. Is stored in the storage unit and a thermal analysis of the rotating machine by the finite element method is performed in the arithmetic unit, and is included in the space unit. Then, for each of a plurality of circles centered on the rotation axis of the rotor, the calculation unit extracts a plurality of nodes located on the circumference, and calculates the temperature at each of the extracted nodes for each of the circles. The portion is constrained within a predetermined range.
[0007]
A thermal analysis apparatus for a rotating machine according to a second aspect of the present invention includes a stator, a rotor, and a space portion between the stator and the rotor constituting the rotating machine. A device for performing thermal analysis of a rotating machine by a finite element method using a mesh expressed in combination, wherein each of a plurality of circles included in the space portion and centering on a rotation axis of a rotor is arranged on the circumference And a means for constraining the temperature at each of the extracted nodes within a predetermined range for each of the circles.
[0008]
A computer program according to a third invention is a combination of a plurality of elements including a stator constituting a rotating machine, a rotor, and a shape of a space between the stator and the rotor. A computer program for performing a thermal analysis of a rotating machine by a finite element method using a mesh expressed in the above, wherein each of a plurality of circles included in the space portion and centered on a rotation axis of a rotor is included in the computer. And a step of extracting a plurality of nodes located on the circumference and a step of causing the computer to constrain the temperature at each of the extracted nodes within a predetermined range for each of the circles. To do.
[0009]
According to a fourth aspect of the present invention, there is provided a computer-readable recording medium comprising a plurality of nodes in the shape of a stator constituting a rotating machine, a rotor, and a space between the stator and the rotor. A computer-readable recording medium on which a computer program for performing thermal analysis of a rotating machine using a finite element method is recorded using a mesh expressed by a combination of a plurality of elements, A procedure for extracting a plurality of nodes located on the circumference of each of a plurality of circles centered on the rotation axis of the rotor included in the space portion, and a plurality of extracted about each of the circles by a computer And a computer program including a procedure for constraining the temperature at each of the nodes within a predetermined range.
[0010]
In the present invention, a stator that constitutes a rotating machine, a rotor, and a mesh that expresses the shape of the space between the stator and the rotor by a combination of a plurality of elements, are included in the space. For a plurality of nodes located on a circle centered on the rotation axis of the rotor, the temperature at the nodes located on the same circle is substantially uniformly restricted, and thermal analysis is performed by a finite element method. During rotation of the rotating machine, the air in the space is agitated in the circumferential direction and the temperature in the circumferential direction is considered to be uniform. Therefore, the rotation of the rotating machine is restricted by uniformly restraining the temperature at the nodes in the circumferential direction. And the thermal analysis during rotation of the rotating machine can be performed while maintaining the shapes of the stator and the rotor.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof.
FIG. 1 is a block diagram showing the configuration of the thermal analysis apparatus of the present invention. Reference numeral 1 in the figure denotes a thermal analysis apparatus according to the present invention, a CPU 11 that performs calculations, a RAM 12 that stores temporary information generated along with the calculations, an external storage device 13 such as a CD-ROM drive, a hard disk, and the like. And the internal storage device 14, the computer program 20 according to the present invention is read from the recording medium 2 such as a CD-ROM by the external storage device 13, and the read computer program 20 is stored in the internal storage device 14. The computer program 20 is loaded into the RAM 12, and the CPU 11 executes processing necessary for the thermal analysis device 1 based on the computer program 20. The thermal analysis apparatus 1 includes an input device 15 such as a keyboard or a mouse, and an output device 16 such as a liquid crystal display or a CRT display, and is configured to receive operations from an operator such as data input. .
[0012]
The thermal analysis apparatus 1 includes a communication interface (not shown), downloads the computer program 20 according to the present invention from an external server apparatus (not shown) connected to the communication interface, and executes processing by the CPU 11. May be.
[0013]
FIG. 2 is a flowchart showing a processing flow of the thermal analysis apparatus 1. First, the thermal analysis device 1 receives a shape model expressing the shape of a rotating machine that is an analysis target of thermal analysis from the input device 15 operated by an operator (S1), and the stator S, the rotor R, and the space A mesh expressing the shape of the part G by a combination of a plurality of elements is generated (S2). 3 and 4 are sectional views showing a shape model of the rotating machine and an example of the generated mesh. 3A is a cross-sectional view of the shape model of the rotating machine cut perpendicular to the rotation axis A of the rotor R, and FIG. 3B is a cross-sectional view of the mesh perpendicular to the rotation axis A of the rotor R. A quarter of the cross section is shown. FIG. 4A is a cross-sectional view of the shape model taken along line IV-IV shown in FIG. 3A in parallel to the rotation axis A, and FIG. 4B shows the rotation of the rotor R through the mesh. A half of a cross section cut along a plane including the axis A is shown. The rotating machine includes a stator S in which a coil is wound around a stator iron core, a rotor R having a magnet around the iron core, and a space G between the stator S and the rotor R. In the generated mesh, each shape is expressed by a combination of a plurality of elements.
[0014]
Next, the thermal analysis device 1 extracts a plurality of nodes located on the circle for each of a plurality of circles included in the space G and centering on the rotation axis A (S3). FIG. 5 is a cross-sectional view of the mesh showing a part of the extracted nodes. FIG. 5A shows a part of the cross-sectional view obtained by cutting the mesh along a plane perpendicular to the rotation axis A. As shown in the drawing, nodes a0, a1, a2, a3,... Located on a circle included in the space G and centered on the rotation axis A are extracted, and nodes b0, b1 located on other circles are extracted. , B2, b3,... Are extracted. FIG. 5B shows a part of a cross-sectional view obtained by cutting the mesh along a plane including the rotation axis A. As shown in the drawing, a circle including each of the nodes c0, d0, e0, f0,. For each, a plurality of nodes located on each circle are extracted.
[0015]
Next, the thermal analysis device 1 determines a constraint condition for uniformly constraining the temperatures of the extracted nodes for each circle (S4). In the example shown in FIG. 5A, assuming that the temperature at the node x is T (x), T (a0) = T (a1) = T (a2) = T (a3) =... And T (b0) = T (b1) = T (b2) = T (b3) =... The temperature constraint condition is determined so that the temperatures of the nodes located on the respective circles coincide with each other. Note that, under the constraint condition, the temperature value is variable, and the temperature value is generally different between circles that exist in a direction perpendicular or parallel to the rotation axis A. Next, the thermal analysis apparatus 1 solves an equation of heat generation or transfer by a finite element method using the generated mesh under a predetermined temperature constraint condition, so that the stator S and the rotor R are Thermal analysis is performed (S5), and the process is terminated.
[0016]
In addition, although the process which receives a shape model and produces | generates a mesh was shown in the above-mentioned process, you may use the process which receives the mesh produced | generated with the other apparatus and performs thermal analysis.
[0017]
As described in detail above, the air in the space G is agitated in the circumferential direction under the condition of uniformly constraining the temperatures of a plurality of nodes on the circle centered on the rotation axis A included in the space G, so that the space G Therefore, by performing a thermal analysis on the stator S and the rotor R based on the above conditions, the stator S and the rotor can be expressed. Thermal analysis of a rotating rotating machine can be performed using a mesh expressing the shape of R. Since the thermal analysis can be performed while maintaining the shape of the rotor R, it is possible to perform a detailed thermal analysis of the rotor R, which is impossible with the conventional thermal analysis method, and a higher performance rotating machine. It can be applied to the design of Further, since it is not necessary to rotate the mesh of the rotor R in order to express the rotation of the rotating machine, the calculation of the thermal analysis can be performed in a short time.
[0018]
In this embodiment, a process of uniformly constraining the temperatures of a plurality of nodes on the circle is used, but it is not necessary to strictly constrain to a uniform value. A process of constraining the temperature within a predetermined range such as setting the deviation within 1% of the value may be used. In this case as well, thermal analysis of the rotating rotating machine can be performed using a mesh that similarly represents the shape of the rotor R.
[0019]
【The invention's effect】
In the present invention, the air in the space portion is agitated in the circumferential direction by restraining the temperature at the node of the space portion between the stator and the rotor constituting the rotating machine substantially uniformly in the circumferential direction. The rotation of the rotating machine is expressed in a circumferential direction. Therefore, the finite element method is used for the thermal analysis of the rotating machine using the mesh that maintains the shape of the stator and rotor. This makes it possible to perform detailed thermal analysis of the rotor, which was impossible in the past. Moreover, since it is not necessary to rotate the mesh of the rotor in order to express the rotation, the present invention has an excellent effect that the calculation of the thermal analysis can be performed in a short time.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a thermal analysis apparatus of the present invention.
FIG. 2 is a flowchart showing a flow of processing of a thermal analysis apparatus.
FIG. 3 is a cross-sectional view showing a shape model of a rotating machine and an example of a generated mesh.
FIG. 4 is a cross-sectional view showing a shape model of a rotating machine and an example of a generated mesh.
FIG. 5 is a cross-sectional view of a mesh showing a part of extracted nodes.
FIG. 6 is a cross-sectional view showing an example of the structure of a rotating machine, and a cross-sectional view showing an example of a mesh generated for performing thermal analysis.
[Explanation of symbols]
1 Thermal analysis device 11 CPU
2 Recording medium 20 Computer program S Stator R Rotor A Rotating shaft G Space

Claims (4)

Using a computer having a storage unit and a calculation unit, a combination of a plurality of elements composed of a plurality of nodes and a stator constituting the rotating machine, a rotor, and a space portion between the stator and the rotor Is a method for storing the mesh expressed in the storage unit, and performing the thermal analysis of the rotating machine by the finite element method in the calculation unit,
For each of a plurality of circles centered on the rotation axis of the rotor included in the space portion, the arithmetic unit extracts a plurality of nodes located on the circumference,
A thermal analysis method for a rotating machine, characterized in that, with respect to each of the circles, a calculation unit constrains a temperature at each of a plurality of extracted nodes within a predetermined range. Rotation by the finite element method using a mesh that expresses the shape of the stator that constitutes the rotating machine, the rotor, and the space between the stator and the rotor by a combination of multiple elements composed of multiple nodes An apparatus for performing thermal analysis of a machine,
Means for extracting a plurality of nodes located on the circumference of each of a plurality of circles centered on the rotation axis of the rotor included in the space portion;
A thermal analysis apparatus for a rotating machine, comprising: means for constraining a temperature at each of a plurality of extracted nodes within a predetermined range for each of the circles. Using a mesh that expresses the shape of the stator that constitutes the rotating machine, the rotor, and the space between the stator and the rotor as a combination of a plurality of elements composed of a plurality of nodes. A computer program for performing thermal analysis of a rotating machine by an element method,
A procedure for causing a computer to extract a plurality of nodes located on the circumference of each of a plurality of circles included in the space portion and centered on a rotation axis of a rotor;
A computer program comprising: a step of causing a computer to constrain the temperature at each of a plurality of extracted nodes within a predetermined range for each of the circles. Using a mesh that expresses the shape of the stator that constitutes the rotating machine, the rotor, and the space between the stator and the rotor as a combination of a plurality of elements composed of a plurality of nodes. A computer-readable recording medium in which a computer program for performing thermal analysis of a rotating machine by an element method is recorded,
A procedure for causing a computer to extract a plurality of nodes located on the circumference of each of a plurality of circles included in the space portion and centered on a rotation axis of a rotor;
A computer-readable recording medium comprising a computer recorded with a computer program including a procedure for constraining the temperature at each of a plurality of extracted nodes within a predetermined range for each of the circles. .

Images