Method for calculating evaporation amount of lubricant, calculation device, and program

Abstract

This method for calculating the evaporation amount of a lubricant within a mechanical device to the exterior includes: a calculation step in which the evaporation amount of the lubricant is calculated using a calculation formula defined so as to include a container shape parameter defined by modeling the configuration within the machine device as a container in which the lubricant is accommodated, a physical property parameter of the lubricant, an environmental parameter from the area around the lubricant, and a parameter regarding time; and an output step in which the evaporation amount calculated in the calculation step is output.

Description

Method, device, and program for calculating evaporation amount of lubricant

[0001] The present invention relates to a method, a device, and a program for calculating an evaporation amount of a lubricant.

[0002] Conventionally, lubricants are used in mechanical devices such as bearing devices and sliding devices to reduce friction during operation. The amount of lubricant in a mechanical device can vary depending on the device configuration and the passage of time. If the amount of lubricant changes, it will affect the operation of the mechanical device, so managing the amount of lubricant in the mechanical device is important for ensuring proper operation of the mechanical device.

[0003] For example, Patent Document 1 discloses a configuration for preventing lubricating oil from entering the bearing space by oil plating in an open-type rolling bearing. With this configuration, Patent Document 1 suppresses fluctuations in the amount of lubricant in the bearing space, maintaining the lubricated state of the bearing space while suppressing torque fluctuations.

[0004] Japanese Patent Application Publication No. 2007-107588

[0005] It is assumed that the lubricant in the mechanical device evaporates over time and leaks out of the mechanical device. As a result, the amount of lubricant in the mechanical device decreases as a result of the lubricant leaking out due to evaporation, which may affect the operation of the mechanical device. While Patent Document 1 takes into account the intrusion of lubricant into the bearing space, it does not take into account fluctuations in the amount of lubricant due to evaporation.

[0006] In view of the above-mentioned problems, an object of the present invention is to provide a method for calculating the amount of evaporation of lubricant in a mechanical device.

[0007] In order to solve the above problems, the present invention has the following configuration: A method for calculating an amount of evaporation of a lubricant from inside a mechanical device to the outside, the method comprising: a calculation step of calculating the amount of evaporation of the lubricant using a calculation formula defined including container shape parameters defined by modeling the internal configuration of the mechanical device as a container that contains the lubricant, physical property parameters of the lubricant, environmental parameters around the lubricant, and time parameters; and an output step of outputting the amount of evaporation calculated in the calculation step.

[0008] Another aspect of the present invention has the following configuration: A calculation device for calculating an amount of evaporation of lubricant from inside a mechanical device to the outside, comprising: calculation means for calculating the amount of evaporation of the lubricant using a calculation formula defined including container shape parameters defined by modeling the internal configuration of the mechanical device as a container that contains the lubricant, physical property parameters of the lubricant, environmental parameters around the lubricant, and time parameters; and output means for outputting the amount of evaporation calculated by the calculation means.

[0009] Another aspect of the present invention has the following configuration: a program causing a computer to execute: a calculation step of calculating an amount of evaporation of the lubricant to the outside using a calculation formula defined including container shape parameters defined by modeling the internal configuration of a mechanical device as a container that contains a lubricant, physical property parameters of the lubricant, environmental parameters around the lubricant, and time parameters; and an output step of outputting the amount of evaporation calculated in the calculation step.

[0010] According to the present invention, it is possible to calculate the amount of evaporation of lubricant in a mechanical device.

[0011] A conceptual diagram for explaining a change in the amount of lubricant according to one embodiment of the present invention. An explanatory diagram for explaining an example of measurement results of a lubricant according to one embodiment of the present invention. An explanatory diagram for explaining an example of measurement results of a lubricant according to one embodiment of the present invention. An explanatory diagram for explaining a case where a calculation method according to one embodiment of the present invention is applied to a rolling bearing. A model ... graph showing an example of measurement results of the amount of fluctuation of a rolling bearing by a calculation method according to one embodiment of the present invention. A block diagram showing an example configuration of an information processing device capable of executing a calculation method according to one embodiment of the present invention.

[0012] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. Note that the embodiment described below is one embodiment for explaining the present invention and is not intended to be interpreted as limiting the present invention. Furthermore, not all of the configurations described in each embodiment are necessarily essential configurations for solving the problems of the present invention. Furthermore, in each drawing, the same components are assigned the same reference numerals to indicate corresponding relationships.

[0013] <First embodiment> A first embodiment of the present invention will be described below. In this embodiment, a rolling bearing will be described as an example of a mechanical device that contains a lubricant and uses it for its operation. However, the present invention is not limited to this, and as will be described later, the present invention can be applied to any device that has a path through which the lubricant evaporates and flows out.

[0014] In the case of rolling bearings, an open configuration is assumed in which a path to the external space is formed around the lubricant. Examples of types of rolling bearings include deep groove ball bearings, angular contact ball bearings, tapered roller bearings, cylindrical roller bearings, and self-aligning roller bearings. Other mechanical devices that use lubricants include gear devices, reduction gears, rotating devices such as windmills, sliding devices that perform sliding motion, and motors, and the present invention can also be applied to these devices.

[0015] [Change in Amount of Lubricant] Figure 1 is a conceptual diagram for explaining the change in the amount of lubricant in the mechanical device according to this embodiment. The lubricant according to this embodiment has the property of evaporating over time. The lubricant is also assumed to be contained in a container of a predetermined shape, and in the example of Figure 1, a cylindrical container is used as an example.

[0016] In FIG. 1, the vertical axis indicates the height of the lubricant liquid surface, and the base of the container is used as the reference. The height of the lubricant liquid surface at the initial time (t=0) is defined as z ０ The liquid level of the lubricant at the time t has elapsed is z ｔ The height of the opening of the container that contains the lubricant is z ｏｕｔ In other words, the lubricant evaporates over time and flows out of the container through the opening. As a result, when time t has passed, the liquid level reaches z ０ From Z ｔ Changes to.

[0017] The relationship between the liquid level and time as shown in FIG. 1 can be expressed by the following equation (1).

[0018]

[0019] M: Molecular weight of lubricant [g / mol] D: Diffusion coefficient [m ２ / s] ρ: density of lubricant [g / m ３ ] R: Gas constant [J・K －１ mol －１ ] T: Temperature [K] P ｖａｐ : Saturated vapor pressure at temperature T [Pa] t: Time [s] z ｔ : Liquid level height at time t [m] z ０ : Liquid level height at initial time [m] z: Liquid level height at any time [m] (z ｔ <z<z ０ ) z ｏｕｔ : Height of the container opening [m] S(z): Cross-sectional area of ​​the container at z [m ２ The relationship between the amount of evaporation of the lubricant and time can be expressed by the following formula (2).

[0020]

[0021] w: Evaporation amount [g] ρ: Density of lubricant [g / m ３ ] z ｔ : Liquid level height at time t [m] z ０ : Liquid level height at initial time [m] z: Liquid level height at any time [m] (z ｔ <z<z ０ ) S(z): Cross-sectional area of ​​the container at z [m ２ ]

[0022] The change in the liquid level and the amount of evaporation are predicted by equations (1) and (2). In this embodiment, the outflow of the lubricant to the outside of the container due to evaporation or the like is referred to as "evaporation." On the other hand, if the lubricant is in a vaporized state but remains in the container, it is treated as not having evaporated.

[0023] Furthermore, when the amount of evaporation of the lubricant is small, i.e., when the drop in the lubricant liquid level can be ignored, i.e., under the conditions shown in the following equation (3), equations (1) and (2) can be combined into the following equation (4).

[0024]

[0025]

[0026] w: Evaporation amount [g] z ｏｕｔ : Height of container opening [m] z ０ : Liquid level height at initial time [m] M: Molecular weight of lubricant [g / mol] D: Diffusion coefficient [m ２ / s] R: gas constant [J·K －１ mol －１ ] T: Temperature [K] P ｖａｐ : saturated vapor pressure at temperature T [Pa] t: time [s] z: liquid level height at any time [m] (z ｔ <z<z ０ ) S(z): Cross-sectional area of ​​the container at z [m ２ ]

[0027] In equation (4), attention will be focused on three parts. First, in equation (4), the following parts are parameters relating to the shape of a container that contains the lubricant (hereinafter referred to as "container shape parameters").

[0028]

[0029] In addition, in formula (4), "MDP ｖａｐ " is a parameter related to the physical properties of the lubricant vapor (hereinafter referred to as "physical property parameters"). In addition, in equation (4), "RT" is a parameter related to the environment around the lubricant (hereinafter referred to as "environmental parameters").

[0030] That is, by specifying the dimensions of the container in which the lubricant is stored and the physical properties of the lubricant in advance in equation (4), it is possible to calculate the amount of evaporation of the lubricant. In this embodiment, equations (1) and (2) are referred to as "non-approximation equations," and equation (4) is referred to as "approximation equation," and the measurement results of each will be described. Note that the non-approximation equation and the approximation equation also include a time parameter, more specifically, a parameter indicating the elapsed time from a reference point.

[0031] In the case of a formula without approximation, the container shape parameters are shown on the right side of formula (1), and the physical property parameters and environmental parameters are shown on the left side.

[0032] 2 and 3 are diagrams illustrating a comparison between the calculated values ​​obtained by the method according to the present embodiment and the measured values, using two examples of container shapes. Here, hexane was used as the lubricant and the test temperature was set to 25°C.

[0033] 2(a) shows an example of the shape of a container containing a lubricant. In the example of the container shown in FIG. 2(a), the main body is cylindrical, and the opening is cylindrical with a smaller diameter than the main body. When the radius of the main body of the container is r １ and the radius of the opening is r ０ (<r １ ) The height of the main body is L １ and the height to the top of the container is L ０ (>L １ ) Therefore, the length of the opening in the height direction is L ０ -L １ Furthermore, the lubricant is contained in the container, and the initial liquid level of the lubricant is z ０(<L １ ) For the sake of simplicity, the thickness of the container is ignored here.

[0034] Figure 2(b) is a graph showing an example of calculated values ​​using the method according to this embodiment and actual measured values ​​based on the configuration of Figure 2(a). In Figure 2(b), the vertical axis represents the amount of evaporation [g], and the horizontal axis represents time [h]. Plot 201 represents the actual measured values. Dashed line 202 represents the calculated values ​​using the above formula (3). Solid line 203 represents the calculated values ​​using the above formulas (1) and (2).

[0035] As shown in FIG. 2, the method according to this embodiment makes it possible to calculate the amount of evaporation over time with high accuracy relative to the actual measured value.

[0036] Fig. 3(a) shows another example of the shape of a container containing a lubricant. In the example of the container shown in Fig. 3(a), the main body has a tapered shape like an Erlenmeyer flask, narrowing toward the opening, and the opening has a tapered shape that widens toward the top, opposite to the main body. The radius of the bottom of the container is r ２ and the radius of the connecting portion between the main body and the opening is r １ (<r ２ ), the radius of the container opening is r ０ (>r １ ) The height of the main body is L １ and the height to the top of the container is L ０ (>L １ ) Therefore, the length of the opening in the height direction is L ０ -L １ Furthermore, the lubricant is contained in the container, and the initial liquid level of the lubricant is z ０ (<L １ ) For the sake of simplicity, the thickness of the container is ignored here.

[0037] Figure 3(b) is a graph showing an example of calculated values ​​using the method according to this embodiment and actual measured values ​​based on the configuration of Figure 3(a). In Figure 3(b), the vertical axis represents the amount of evaporation [g], and the horizontal axis represents time [h]. Plot 301 represents the actual measured values. Dashed line 302 represents the calculated values ​​using the above formula (3). Solid line 303 represents the calculated values ​​using the above formulas (1) and (2).

[0038] As in the example shown in Figure 2, even if the shape of the container changes, the method of this embodiment can be applied and it is possible to calculate the amount of evaporation over time with high accuracy based on the actual measured value.

[0039] [Example of Application to Mechanical Device] An example of application of the above-described calculation method to a mechanical device will be described below, taking a rolling bearing as an example of the mechanical device to be predicted.

[0040] FIG. 4 is a conceptual diagram of a rolling bearing for calculating the amount of lubricant evaporation according to this embodiment. As shown in FIG. 4( a), the rolling bearing 400 includes an outer ring 401, an inner ring 402, rolling elements 403, a cage 404, a seal 405, and a lubricant 406. The lubricant 406 is filled to reduce friction between the outer ring 401 and the rolling elements 403 and between the inner ring 402 and the rolling elements 403, and to provide lubrication. The seal 405 is configured to prevent impurities such as dust from entering the rolling bearing 400. Due to the rotational movement of the rolling bearing 400, a gap is provided between the seal 405 and the inner ring 402, and the lubricant 406 can leak out, i.e., evaporate, from this gap.

[0041] In this embodiment, the inner ring 402 is a rotating ring and the outer ring 401 is a fixed ring, but the opposite configuration may also be used. Also, the seal 405 may be installed on the inner ring 402 side, with a gap provided between the outer ring 401 and the seal 405.

[0042] Figure 4(b) shows a model of a container that stores lubricant 406 in rolling bearing 400. In this embodiment, as indicated by frame line 410, the portion of rolling bearing 400 that is surrounded by outer ring 401, inner ring 402, and seal 405 is assumed to be the main body of the container. Furthermore, as indicated by frame line 411, the gap formed between inner ring 402 and seal 405 is assumed to be the opening of the container. Although Figure 4 shows a partially simplified view, the area of ​​the gap formed between inner ring 402 and seal 405 corresponds to the area of ​​the uppermost surface of the opening of the container.

[0043] FIG. 5 shows an example of an enlarged view of a portion of the inner ring 402 and seal 405 of a rolling bearing 400. Here, an example of a single-row deep groove ball bearing (number: 608) is shown. As indicated by the arrow in FIG. 5(a), a lubricant flow path (opening) is formed in the gap between the inner ring 402 and the seal 405, and the lubricant flows out through this flow path. FIG. 5(b) shows a model of the container shape based on the configurations of FIG. 4(a) and FIG. 5(a). This example is similar to that shown in FIG. 2(a).

[0044] FIG. 6 is another example showing an enlarged view of a portion of the inner ring 402 and seal 405 in the rolling bearing 400. Here, an example of a single-row deep groove ball bearing (number: 6203) is shown. The shape of the flow path (opening) formed between the inner ring 402 and the seal 405 is different from the example in FIG. 5. FIG. 6(b) is a model of the container shape based on the configurations in FIG. 4(a) and FIG. 6(a). The model is different from FIG. 5 in the shape of the opening, and the diameter r corresponds to the change in the diameter and length of the flow path. ０ , r １ , r ２ and length L ０ , L １ , L ２ is set.

[0045] The modeling, i.e., container shape parameters, can be defined depending on the configuration of the machine being predicted.

[0046] [Test Result Example] Figure 7 is a graph illustrating the calculation results by the method according to this embodiment and the actual measured values ​​based on the rolling bearing model shown in Figures 5 and 6. In Figure 7, the vertical axis represents the evaporation amount ratio (the ratio of the evaporation amount to the total initial lubricant amount), and the horizontal axis represents time [h]. This example shows the calculation results without approximation using the above formulas (1) and (2).

[0047] The test conditions are as follows. In this example, an organic solvent is used as the lubricant to ignore changes in physical property parameters due to oxidation. The rolling bearing used in the test is in a stationary state. (Physical properties of organic solvent) Organic solvent: hexane Molecular weight: 86.18 [g / mol] Saturated vapor pressure (21°C): 1.7 x 10 ４ [Pa] Saturated vapor pressure (25°C): 2.0 x 10 ４ [Pa] Collision diameter: 0.53 [nm] (Test environment and physical properties) Atmosphere: Air Molecular weight: 28.96 [g / mol] Collision diameter: 0.3617 [nm] Atmospheric pressure: 1.01325 × 10 ５ [Pa] Temperature: Room temperature [℃]

[0048] FIG. 7(a) corresponds to the example of the single-row deep groove ball bearing (number: 608) shown in FIG. 5. Here, the results are for a room temperature of 21°C. The solid line 701 shows the calculation results using the method according to this embodiment. The plot 702 shows the actual measured values ​​of the amount of evaporation. FIG. 7(b) corresponds to the example of the single-row deep groove ball bearing (number: 6203) shown in FIG. 6. Here, the results are for a room temperature of 25°C. The solid line 711 shows the calculation results using the method according to this embodiment. The plot 712 shows the actual measured values ​​of the amount of evaporation.

[0049] As shown in FIG. 7, it is possible to predict the evaporation amount of lubricant with high accuracy.

[0050] The method according to the present embodiment can measure the evaporation amount of lubricant contained in a machine device that has already been manufactured. Another application is predicting the amount of evaporation in order to meet the target evaporation amount conditions during the design of a machine device. Therefore, the method according to the present embodiment is not particularly limited in terms of the type of device to be used or the timing of its use.

[0051] Whether to use the non-approximation formulas (1) and (2) or the approximation formula (4) may be switched based on the conditions for calculation. For example, when higher accuracy is required, the non-approximation formula may be used.

[0052] According to the above formula (4), the container shape parameter uses the reciprocal of the integral of the cross-sectional area of ​​the path. Therefore, as the path narrows, the parameter increases, and the effect of a narrow path becomes greater. For example, when designing a mechanical device, if the goal is to reduce the amount of lubricant evaporation, the gap between the seal and the inner ring can be designed so that the lubricant flow path becomes narrower, that is, so that the container shape parameter increases.

[0053] 8 is a diagram showing an example of the configuration of an information processing device capable of measuring or predicting evaporation of a lubricant in a mechanical device using the method according to this embodiment. The information processing device 800 includes a processing unit 801, a storage unit 802, an external IF (Interface) 803, a display unit 804, an operation unit 805, and a communication unit 806. The information processing device 800 may be configured as a general-purpose information processing device such as a PC (Personal Computer), or may be configured as a dedicated device.

[0054] The processing unit 801 may be configured with a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a DSP (Digital Single Processor), a dedicated circuit, or the like. The storage unit 802 is configured with volatile and non-volatile storage media such as an HDD (Hard Disk Drive), a ROM (Read Only Memory), or a RAM (Random Access Memory), and is capable of inputting and outputting various information in response to instructions from the processing unit 801. The processing unit 801 can implement the above-described calculation method by reading and executing programs, applications, and various data related to the calculation method according to this embodiment from the storage unit 802.

[0055] The storage unit 802 stores, for example, the calculation formulas shown in the above formulas (1), (2), and (4) and various parameters of the mechanical device to be measured. More specifically, container shape parameters, physical property parameters, environmental parameters, etc.

[0056] The external IF 803 is an interface for connecting to an external device. For example, when the method according to this embodiment is used during measurement, it may be connected to a sensor for measuring information such as the temperature and atmospheric pressure in the environment surrounding the measurement target. The display unit 804 is a unit for outputting results obtained by the method according to this embodiment, and outputs the results to the user in response to instructions from the processing unit 801. The operation unit 805 is a unit for receiving input of parameters and various instructions from the user. The communication unit 806 is a network interface for communicating with an external device, and may be configured to output results obtained by the method according to this embodiment to the outside, for example.

[0057] For example, in this embodiment, as described above, it is possible to use a non-approximation formula and an approximation formula. Therefore, the user may input a switching instruction via the operation unit 805 so that calculation can be performed using either of these formulas. Furthermore, the device may be configured to be able to receive, via the operation unit 805 or the communication unit 806, a plurality of dimensional information models of the lubricant surroundings in the mechanical device to be measured.

[0058] As described above, the configuration of this embodiment makes it possible to provide a method for calculating the amount of evaporation of lubricant in a mechanical device.

[0059] <Other Embodiments> Furthermore, in the present invention, a program or application for realizing the functions of one or more of the above-described embodiments can be supplied to a system or device using a network or a storage medium, etc., and one or more processors in a computer of the system or device can read and execute the program.

[0060] Alternatively, the functions may be realized by a circuit that realizes one or more functions (for example, an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array)).

[0061] As such, the present invention is not limited to the above-described embodiments, and the present invention also contemplates the mutual combination of the various components of the embodiments, as well as modifications and applications by those skilled in the art based on the description in the specification and well-known techniques, and these modifications and applications are included in the scope of protection sought.

[0062] As described above, the present specification discloses the following: (1) A method for calculating an amount of evaporation of lubricant from a mechanical device to the outside, the method comprising: a calculation step of calculating the amount of evaporation of the lubricant using a calculation formula defined including container shape parameters defined by modeling the configuration inside the mechanical device as a container that contains the lubricant, physical property parameters of the lubricant, environmental parameters around the lubricant, and time parameters; and an output step of outputting the amount of evaporation calculated in the calculation step. This configuration makes it possible to provide a technique for calculating the amount of evaporation of lubricant from a mechanical device.

[0063] (2) The calculation method according to (1), wherein the calculation formula is defined by the following formula:

[0064]

[0065] w: Evaporated mass [g] M: Molecular weight of lubricant [g / mol] D: Diffusion coefficient [m ２ / s] ρ: density of lubricant [g / m ３ ] R: Gas constant [J・K －１ mol －１ ] T: Temperature [K] P ｖａｐ : Saturated vapor pressure at temperature T [Pa] t: Time [s] z ｔ : Liquid level height at time t [m] z ０ : Liquid level height at initial time [m] z: Liquid level height at any time [m] (z ｔ <z<z ０ ) z ｏｕｔ : Height of the container opening [m] S(z): Cross-sectional area of ​​the container at z [m ２ According to this configuration, it is possible to calculate the amount of evaporation of the lubricant in the mechanical device with higher accuracy.

[0066] (3) The calculation method according to (1), wherein the calculation formula is defined by the following formula:

[0067]

[0068] w: Evaporation mass [g] z ｏｕｔ : Height of container opening [m] z ０ : Liquid level height at initial time [m] M: Molecular weight of lubricant [g / mol] D: Diffusion coefficient [m ２ / s] R: gas constant [J·K －１ mol －１ ] T: Temperature [K] P ｖａｐ : saturated vapor pressure at temperature T [Pa] t: time [s] z: liquid level height at any time [m] S(z): cross-sectional area of ​​the container at z [m ２ According to this configuration, it is possible to calculate the evaporation amount of the lubricant in the mechanical device using a simpler calculation formula.

[0069] (4) The calculation method according to any one of (1) to (3), wherein the evaporation amount of the lubricant is the amount of lubricant that has flowed out of the container. With this configuration, it is possible to calculate the evaporation amount taking into account the lubricant that has evaporated and remained in the device.

[0070] (5) The calculation method according to any one of (1) to (4), wherein the mechanical device is one of a rolling bearing, a rotating device, and a sliding device. With this configuration, it is possible to calculate the evaporation amount for various mechanical devices that use lubricant.

[0071] (6) A method for designing a mechanical device using the calculation method according to any one of (1) to (5), comprising a receiving step of receiving designation of container shape parameters defined by modeling an internal configuration of the mechanical device as a container for storing the lubricant. With this configuration, it is possible to design the mechanical device in consideration of the evaporation amount of the lubricant at the design stage.

[0072] (7) A method for measuring an evaporation amount of a lubricant in a mechanical device using the calculation method according to any one of (1) to (5), the method including an acquisition step of acquiring environmental parameters around the lubricant in the mechanical device, physical property parameters of the lubricant, and time parameters. With this configuration, it is possible to measure the evaporation amount of a lubricant in an existing mechanical device without actually measuring it.

[0073] (8) A calculation device for calculating an amount of evaporation of lubricant from inside a mechanical device to the outside, the calculation device comprising: a calculation means for calculating the amount of evaporation of the lubricant using a calculation formula defined including container shape parameters defined by modeling the configuration inside the mechanical device as a container for containing the lubricant, physical property parameters of the lubricant, environmental parameters around the lubricant, and time parameters, and an output means for outputting the amount of evaporation calculated by the calculation means. With this configuration, it is possible to provide a device for calculating the amount of evaporation of lubricant from inside a mechanical device.

[0074] (9) A program for causing a computer to execute the following steps: a calculation step of calculating the amount of evaporation of the lubricant to the outside using a calculation formula defined including container shape parameters defined by modeling the internal configuration of a mechanical device as a container for storing a lubricant, physical property parameters of the lubricant, environmental parameters around the lubricant, and time parameters; and an output step of outputting the evaporation amount calculated in the calculation step. With this configuration, it is possible to provide a function for calculating the amount of evaporation of the lubricant in the mechanical device.

[0075] Although various embodiments have been described above with reference to the drawings, it goes without saying that the present invention is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications or alterations within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present invention. Furthermore, the components of the above-described embodiments may be combined in any manner without departing from the spirit of the invention.

[0076] This application is based on a Japanese patent application (Patent Application No. 2023-088047) filed on May 29, 2023, the contents of which are incorporated herein by reference.

[0077] The present invention has the effect of making it possible to calculate the amount of evaporation of lubricant inside a mechanical device, and can be used for calculating, measuring, and designing the amount of evaporation of lubricant in mechanical devices such as rolling bearings, rotating devices, sliding devices, and motors, particularly in devices that have a path through which the lubricant evaporates and flows out to the outside.

[0078] 400: Rolling bearing 401: Outer ring 402: Inner ring 403: Rolling element 404: Cage 405: Seal 406: Lubricant 800: Information processing device 801: Processing unit 802: Storage unit 803: External IF 804: Display unit 805: Operation unit 806: Communication unit

Claims

1. A method for calculating an amount of evaporation of a lubricant from inside a mechanical device to the outside, comprising: a calculation step of calculating the amount of evaporation of the lubricant using a calculation formula defined including container shape parameters defined by modeling the internal configuration of the mechanical device as a container in which the lubricant is contained, physical property parameters of the lubricant, environmental parameters around the lubricant, and time parameters; and an output step of outputting the amount of evaporation calculated in the calculation step.

2. The calculation method according to claim 1, wherein the calculation formula is defined by the following formula: w: Evaporation mass [g] M: Molecular weight of lubricant [g / mol] D: Diffusion coefficient [m ２ / s] ρ: density of lubricant [g / m ３ ] R: Gas constant [J K －１ Mol －１ ] T: Temperature [K] P ｖａｐ : Saturated vapor pressure at temperature T [Pa] t: Time [s] z ｔ z : Liquid level height at time t [m] ０ : Liquid level height at initial time [m] z: Liquid level height at any time [m] (z ｔ <z<z ０ ) z ｏｕｔ : Height of the container opening [m] S(z): Cross-sectional area of ​​the container at z [m ２ ] 3. The calculation method according to claim 1, wherein the calculation formula is defined by the following formula: w: Evaporation mass [g] z ｏｕｔ z: Height of container opening [m] ０ : Liquid level height at initial time [m] M: Molecular weight of lubricant [g / mol] D: Diffusion coefficient [m ２ / s] R: Gas constant [J·K －１ Mol －１ ] T: Temperature [K] P ｖａｐ : Saturated vapor pressure at temperature T [Pa] t: Time [s] z: Liquid level at any time [m] S(z): Cross-sectional area of ​​the container at z [m ２ ] 4. The calculation method according to claim 1, wherein the amount of evaporated lubricant is the amount that has flowed out from the container.

5. The calculation method according to claim 1, wherein the mechanical device is one of a rolling bearing, a rotating device, and a sliding device.

6. A method for designing a mechanical device using the calculation method according to any one of claims 1 to 5, comprising a receiving step of receiving designation of container shape parameters defined by modeling the internal configuration of the mechanical device as a container for storing the lubricant.

7. A method for measuring an amount of evaporation of a lubricant in a mechanical device using the calculation method according to any one of claims 1 to 5, the method comprising an acquisition step of acquiring environmental parameters around the lubricant in the mechanical device, physical property parameters of the lubricant, and time parameters.

8. A calculation device for calculating an amount of evaporation of a lubricant from inside a mechanical device to the outside, comprising: a calculation means for calculating the amount of evaporation of the lubricant using a calculation formula defined including container shape parameters defined by modeling a configuration inside the mechanical device as a container in which the lubricant is contained, physical property parameters of the lubricant, environmental parameters around the lubricant, and time parameters; and an output means for outputting the amount of evaporation calculated by the calculation means.

9. A program for causing a computer to execute the following steps: a calculation step of calculating an amount of evaporation of the lubricant to the outside using a calculation formula defined including container shape parameters defined by modeling the internal configuration of a mechanical device as a container for storing a lubricant, physical property parameters of the lubricant, environmental parameters around the lubricant, and time parameters; and an output step of outputting the amount of evaporation calculated in the calculation step.