Gear shape design device, gear shape design method, and gear shape design program

Abstract

To provide a gear shape design device capable of automatically designing gears, a gear shape design method, and a gear shape design program gear shape design device.SOLUTION: A gear shape design device 1 includes an information acquisition unit 4 configured to acquire specification information including information on the material of a gear and peripheral information on other gears that mesh with the gear when the gear is mounted, and a part of a plurality of pieces of shape information of the gear, and a calculation unit 6 configured to calculate at least a part of shape information other than the gear shape information acquired by the information acquisition unit 4, which is gear shape information satisfying a predetermined performance index indicating gear performance, based on the specification information and the shape information acquired by the information acquisition unit 4.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a gear shape design device, a gear shape design method, and a gear shape design program gear shape design device.

Background Art

[0002] Conventionally, various studies have been made on the shape of gears that are frequently used as power transmission mechanisms. When designing the shape of a gear, currently, efforts are being continuously made to calculate the optimal gear shape by using methods such as mechanism analysis by modeling the equation of motion, FEM analysis using numerical analysis by the finite element method, and simulation for high-speed and high-precision dynamic evaluation of tooth surface rigidity by dedicated software alone or in combination (for example, Non-Patent Document 1).

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, there is still no established technology for automatically designing the optimal gear shape according to the operator's intention. In practice, the gear design is carried out by setting variable values to various values using simulation and repeating trial and error.

[0005] In view of such circumstances, the present invention has been made, and an object thereof is to provide a gear shape design device, a gear shape design method, and a gear shape design program gear shape design device capable of automatically designing a gear.

Means for Solving the Problems

[0006] In order to solve the above problems, in one aspect of the present invention, an information acquisition unit that acquires a part of specification information including information on the material of a gear and peripheral information on other gears that mesh with the gear when the gear is mounted, and shape information of the gear, and based on the specification information and shape information acquired by the information acquisition unit, a calculation unit that calculates at least a part of shape information of a gear that satisfies a predetermined performance index indicating the performance of the gear and that is different from the shape information of the gear acquired by the information acquisition unit.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0008] Hereinafter, embodiments of the present invention will be described in detail. In the embodiment, a detailed description will be given by taking as an example the design of spur gears used in the speed reduction mechanism of an open-loop 6-axis robot arm by a gear shape design device. In recent years, with the increase in the number of work processes using robot arms, the opportunity for humans and robot arms to work at a close distance has increased. In this case, the noise during the drive of spur gears used in robot arms, especially the noise during the meshing of two spur gears in a speed reduction mechanism that performs shoulder rotation or shoulder swivel with a large output (for example, a spur gear on the crank side and an input gear on the motor side), often becomes a problem. Therefore, in the embodiment, a detailed example of calculating the optimal gear shape for reducing noise by focusing on the noise of spur gears will be described.

[0009] The outline of a gear shape design device will be described. The gear shape design device outputs information regarding the shape of an optimal gear having desired performance when an operator inputs requirement information regarding the shape of the gear. That is, if the operator inputs only the shape conditions (partial information) that the gear must satisfy at the current stage to the gear shape design device, the gear shape design device outputs information regarding the remaining shape of the gear.

[0010] At this time, a gear manufactured based on the information output from the gear shape design device satisfies a predetermined performance index. The performance index is a numerical value indicating the performance of the gear. Examples of the performance of the gear include, in addition to the noise described above, vibration of the gear, efficiency, transmission accuracy, etc. In order to reduce the noise during gear drive, it is conceivable to reduce the fluctuation of the meshing stiffness during gear drive or reduce the meshing transmission error during gear drive. Taking this into account, the gear shape design device outputs shape information in which one or both of the meshing stiffness fluctuation or the meshing transmission error become less than a desired value. The performance index may be a value input by the operator to the gear shape design device, or may be determined in advance and stored in the gear shape design device.

[0011] Hereinafter, embodiments will be described. FIG. 1 is a block diagram of a gear shape design device. As shown in FIG. 1, the gear shape design device 1 includes an input unit 2, an information acquisition unit 4, a calculation unit 6, an output unit 8, and a storage unit 10.

[0012] The input unit 2 is an interface for the operator to perform various operations. The input unit 2 is constituted by an input device of a computer operated by the operator and is used for the operator to input information to the gear shape design device 1. Information input to the gear shape design device 1 includes gear design information. The gear design information is information including gear shape information and gear specification information.

[0013] The shape information of a gear is information including information on the overall shape of the gear to be designed and information on the shape of each individual tooth. The information on the overall shape of the gear includes information on the diameter of the gear and the type of the gear. The tooth shape information includes information on the dimensions and shape of the teeth. Examples of the tooth shape information include the amount of crowning of the teeth and the amount of tooth profile modification.

[0014] The specification information of a gear is information including information on the material of the gear and peripheral information on other gears that mesh with the gear to be designed when the gear is mounted. When the gear is mounted in combination with other gears such as those of a speed reduction mechanism, it is important to take into account the coupling method between the gear and the drive shaft, the module, the number of teeth, and the tooth thickness of the gear in relation to the peripheral members. Therefore, the specification information of the gear includes information on the coupling method between the gear and the drive shaft, information on the module of the gear, information on the number of teeth, and information on the tooth thickness. Also, when the gear to be designed is a spur gear (a gear that meshes with the input gear of a speed reduction mechanism) used in a speed reducer, the number of spur gears can be included in the specification information of the gear. Constraint information may also be included in the specification information. The constraint information includes information on manufacturing constraints and information on structural constraints. The manufacturing constraint is a constraint related to the manufacturing equipment of the gear, and is a constraint related to a shape that is difficult to realize with the equipment available when manufacturing the gear. The structural constraints include dimensional constraints and durability constraints. The dimensional constraint is a constraint related to the dimensions of the space for housing the gear. The durability constraint is a constraint related to the mechanical strength of the gear. The peripheral information is information on the gear that meshes with the gear to be designed (sometimes simply referred to as the "opposing gear"). Examples of the peripheral information include the number of teeth, the tooth thickness, the module, and the shape information of the opposing gear.

[0015] The information acquisition unit 4 acquires the shape information and the specification information input to the input unit 2 from the input unit 2 and supplies them to the calculation unit 6. When a performance index is input to the input unit 2, the information acquisition unit 4 acquires the performance index from the input unit 2.

[0016] Based on the shape information and specification information supplied from the information acquisition unit 4, the calculation unit 6 calculates at least a part of the remaining shape information (that is, at least a part of the shape information other than the shape information supplied from the information acquisition unit 4). The shape information calculated by the calculation unit 6 may be only the shape information not input by the operator (that is, only the remaining shape information), or may be information regarding the overall shape of the gear, such as a design drawing of the gear (for example, 2D or 3D CAD drawing information) created by integrating the input shape information and the remaining shape information. The method for calculating the shape information by the calculation unit 6 will be described later.

[0017] The output unit 8 is an interface that outputs the shape information calculated by the calculation unit 6 to the operator. As the output unit 8, image display means such as a monitor or image forming means such as a printer can be used.

[0018] The storage unit 10 is composed of a storage medium that stores predetermined information. The information stored in the storage unit 10 is read by the calculation unit 6. In the storage unit 10, a database associating the shape information of gears designed in the past, the specification information, and the performance index is stored. The database is created in advance and stored in the storage unit 10. In constructing the database, the gears designed by the gear shape design device 1 may be actually manufactured, and the results of measuring the performance index using the manufactured gears may be collected, or the performance index may be measured by performing a simulation on the gears designed by the gear shape design device 1. That is, the database is constructed from the feedback data of the gears designed by the gear shape design device 1. The database may include information on gears that have exhibited the desired performance index in addition to information on gears that have not exhibited the desired performance index, that is, gears that have malfunctioned. Also, the performance index of gears not designed by the gear shape design device 1 may be measured or simulated and included in the database. Further, an information update unit (not shown) capable of acquiring information from the outside may be provided so that the database can be sequentially updated.

[0019] Next, the calculation unit 6 will be described in more detail. The calculation unit 6 calculates the remaining shape information based on the shape information and specification information acquired by the information acquisition unit 4 and the database stored in the storage unit 10. At this time, the calculation unit 6 calculates the shape information such that the performance index (in this example, "meshing stiffness variation") is equal to or less than a desired value. The calculation unit 6 may read out the performance index or the threshold value of the performance index stored in advance in the storage unit 10, or may acquire the performance index or the threshold value of the performance index input by the operator via the input unit 2 by the information acquisition unit 4. The calculation unit 6 refers to the database stored in the storage unit 10 and extracts gears that satisfy the shape information and specification information acquired by the information acquisition unit 4 from the database. Further, the calculation unit 6 extracts gears among the extracted gears whose meshing stiffness variation is equal to or less than a desired value. The calculation unit 6 supplies the shape information of the extracted gears to the output unit 8 as a calculation result. At this time, the calculation unit 6 may supply only the shape information of the gear with the least meshing stiffness variation to the output unit 8. Further, the calculation unit 6 may supply the shape information obtained by listing the shape information of a plurality of gears in ascending order of meshing stiffness variation to the output unit 8.

[0020] Hereinafter, the operation of the gear shape design device 1 will be described with reference to FIG. 2. FIG. 2 is a flowchart showing a series of operations by the gear shape design device.

[0021] When the shape information and the specification information are input to the input unit 2 by the operator, the gear shape design device 1 starts a series of processes. At this time, it is assumed that only the information regarding the overall shape of the gear is input as the shape information. In step S1, the gear shape design device 1 acquires the input shape information and specification information by the information acquisition unit 4. Next, in step S2, the gear shape design device 1 calculates the shape information of the gear. This process is that the calculation unit 6 refers to the database stored in the storage unit 10 and calculates the remaining shape information (shape information other than the overall shape of the gear, that is, tooth shape information) with reference to the performance index. Next, in step S3, the gear shape design device 1 outputs the calculated shape information. Thereby, the operator can be provided with the shape information that satisfies the desired performance index.

[0022] FIG. 3 is a block diagram of a control program for a gear shape design device. The control program is stored in a predetermined storage medium and includes commands for operating each part of the gear shape design device when executed by the gear shape design device.

[0023] Referring to FIGS. 1 and 3, the control program 20 for the gear shape design device includes an acquisition instruction unit 22 that causes the information acquisition unit 4 to acquire the shape information and specification information input to the input unit 2, a calculation instruction unit 24 that causes the calculation unit 6 to calculate the shape information, and an output instruction unit 26 that causes the output unit 8 to output the shape information. When the control program 20 is executed by the gear shape design device 1, the gear shape design device 1 calculates the shape information according to the flow shown in FIG. 2.

[0024] As described above, according to the embodiment, the remaining shape information can be output by inputting a part of the plurality of shape information. The output shape information satisfies the desired performance index. Therefore, it is not necessary to repeatedly perform analysis to obtain an optimal gear, or at least the number of times of analysis can be significantly reduced.

[0025] Next, a modification of the embodiment will be described.

[0026] In the above-described embodiment, the calculation unit 6 may calculate manufacturing condition information regarding the manufacturing conditions of the gear. The manufacturing condition information is information regarding the conditions when actually manufacturing the designed gear. The manufacturing conditions are information including the allowable tolerance of the gear, the machining conditions of the gear, and the surface treatment conditions of the gear. The manufacturing conditions are stored in the database in the storage unit 10 together with the shape information, specification information, and performance index of the gears designed in the past. The calculation unit 6 supplies the manufacturing condition information associated with the calculated shape information to the output unit 8 together with the shape information.

[0027] Further, the operator may be able to input the manufacturing condition information into the input unit 2. In this case, the information acquisition unit 4 acquires the manufacturing conditions input into the input unit 2 and supplies them to the calculation unit 6. The calculation unit 6 extracts gears that satisfy the manufacturing conditions (gears with manufacturing conditions that match the input manufacturing conditions) when extracting gears from the database. Thereby, the shape information of the gears manufactured under the manufacturing conditions specified by the operator can be provided to the operator.

[0028] As another modification example, the calculation unit 6 may be realized by artificial intelligence. In this case, the calculation unit 6 constructs a learned model using the above-described database. When the shape information and the specification information acquired by the information acquisition unit 4 are input into the calculation unit 6, the calculation unit 6 executes the learned model to calculate the shape information that satisfies the desired performance index.

[0029] When the calculation unit 6 is realized by artificial intelligence, when the operator inputs a plurality of information included in the shape information and the specification information into the input unit 2, the operator may be able to classify each information into an essential condition (must condition) or a desired condition (want condition). For example, when inputting the tooth crowning amount (shape information) and the gear material (specification information) into the input unit 2, these information are classified as must conditions, and the remaining information is classified as want conditions. In this case, the calculation unit 6 calculates a result that satisfies the must condition and is weighted by the want condition. Thereby, the shape information of the gear that satisfies the performance index and at least satisfies the want condition can be output.

[0030] As another modification example, the calculation unit 6 may be configured to use a calculation model that calculates the shape information of the gear (that is, the remaining shape information) from the must condition. In this case, the calculation unit 6 has one or more calculation models. The calculation unit 6 selects a calculation model that satisfies the must condition and satisfies the desired performance index, and calculates the remaining shape information by executing the selected calculation model. The want condition may be used as a weighting coefficient when executing the calculation model.

[0031] In the embodiment, the design information is classified into shape information and specification information, and the shape information and the specification information are further classified into more detailed information. However, the method of classifying the shape information and the specification information is not limited to the example of the embodiment, and the classification method may be changed according to the needs of the design site, and as long as the design information that has not been determined at the stage of using the gear shape design device can be calculated as a result.

[0032] Each block can be realized by electronic elements such as a computer's CPU and mechanical parts in terms of hardware, and can be realized by a computer program or the like in terms of software. Here, however, functional blocks realized by their cooperation are depicted. Therefore, it is understood by those skilled in the art that these functional blocks can be realized in various forms by a combination of hardware and software.

[0033] In addition, any combination of the above components, or those obtained by mutually substituting the components and expressions of the present invention among a method, an apparatus, a program, a temporary or non-temporary storage medium recording the program, a system, etc. are also effective as aspects of the present invention.

Explanation of Reference Numerals

[0034] 1 Gear shape design device; 2 Input unit; 4 Information acquisition unit; 6 Calculation unit; 8 Output unit; 10 Storage unit; 20 Control program; 22 Acquisition instruction unit; 24 Calculation instruction unit; 26 Output instruction unit

Claims

An information acquisition unit that acquires specification information including information on the material of a gear for a speed reducer and peripheral information on other gears that mesh with the gear when the gear is mounted, a part of the plurality of shape information of the gear, and a performance index indicating the performance of the gear; A storage unit that stores a database associating the shape information of the gear designed in the past, the specification information, and a performance index indicating the performance of the gear; A calculation unit that refers to the database, extracts the gear that satisfies a part of the specification information and the shape information of the gear acquired by the information acquisition unit and whose performance index is equal to or less than a predetermined value, and outputs, as a calculation result, at least a part of the shape information of the extracted gear that is different from the shape information of the gear acquired by the information acquisition unit; The gear is a spur gear; The specification information includes information on the number of the spur gears; The performance index is at least one of a meshing transmission error and a meshing stiffness variation, a gear shape design device.

2. The information acquisition unit acquires constraint information regarding at least one of a structural constraint of the gear and a manufacturing constraint of the gear; The calculation unit according to claim 1, wherein the calculation unit calculates the remaining of the plurality of shape information in consideration of the constraint information.

3. The gear shape design device according to claim 1 or 2, further comprising an output unit that outputs the shape information obtained by the calculation unit.

4. The calculation unit according to any one of claims 1 to 3, wherein the calculation unit calculates manufacturing condition information regarding manufacturing conditions of the gear.

5. The specification information according to any one of claims 1 to 4, wherein the specification information includes at least one of information on a coupling method with a drive shaft of the gear, information on the number of teeth of the gear, information on a module of the gear, and information on a tooth thickness of the gear.

6. The gear shape design device according to any one of claims 1 to 5, wherein the shape information includes at least one of a crowning amount of teeth of the gear and a tooth profile dressing amount of the teeth. A step of acquiring specification information including information on the material of a gear for a speed reducer and peripheral information on other gears that mesh with the gear when the gear is mounted, a part of the shape information of the gear, and a performance index indicating the performance of the gear; Referring to the database in the storage unit that stores a database associating the shape information of the previously designed gear, the specification information, and a performance index indicating the performance of the gear, extracting the gear that satisfies a part of the specification information and the shape information of the obtained gear and whose performance index is equal to or less than a predetermined value, and outputting, as a calculation result, at least a part of the shape information of the extracted gear that is different from the shape information of the gear obtained, The gear is a spur gear, The specification information includes information regarding the number of the spur gears, The performance index is at least one of a contact transmission error and a contact stiffness variation, and is a gear shape design method.

8. A control program for a gear shape design device including an information acquisition unit, a storage unit, and a calculation unit, Causing a computer to An acquisition instruction unit that causes the information acquisition unit to acquire the specification information including information regarding the material of the gear that is a spur gear for a speed reducer and peripheral information regarding other gears that mesh with the gear when the gear is mounted, the specification information including information regarding the number of the spur gears, a part of the plurality of shape information of the gear, and the performance index indicating the performance of the gear, the performance index being at least one of a contact transmission error and a contact stiffness variation, A calculation instruction unit that causes the calculation unit to calculate the shape information, the calculation unit referring to the database in the storage unit that stores a database associating the shape information of the previously designed gear, the specification information, and a performance index indicating the performance of the gear, extracting the gear that satisfies a part of the specification information and the shape information of the gear obtained by the information acquisition unit and whose performance index is equal to or less than a predetermined value, and outputting, as a calculation result, at least a part of the shape information of the extracted gear that is different from the shape information of the gear obtained by the information acquisition unit, A control program for causing the computer to function as such.

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