Method for estimating the temperature of a rotating device, a temperature estimation device, and a program.

Abstract

The present invention provides a temperature estimation method for estimating the temperatures of a plurality of parts constituting a device. The temperature estimation method includes: a setting step for setting a heat balance formula based on a thermal circuit network model specified in correspondence with the plurality of parts; an acquisition step for acquiring information related to heat generation of the device during operation; a calculation step for calculating the temperature of at least one of the plurality of parts by using the heat balance formula and the information acquired in the acquisition step; and an output step for outputting the temperature calculated in the calculation step.

Description

Technical Field

[0001] The present invention relates to a method for estimating the temperature of a rotating device, a temperature estimation device, and a program.

Background Art

[0002] In mechanical devices such as bearing devices and sliding devices, the temperature of each part changes with its operation. Conventionally, in order to appropriately control the operation state of a mechanical device, it is required to appropriately perform temperature management of the mechanical device. For example, in a bearing device, a configuration is used in which lubrication is promoted by using a lubricant (for example, lubricating oil or grease) on the contact surface between members. Since the lubrication performance of the lubricant changes depending on the temperature, it is required to grasp the temperature, but it is difficult to directly measure the temperature of the lubricant. In addition, depending on the installation position and size of the device, it is difficult to measure the temperature of each component constituting the device.

[0003] For example, in Patent Document 1, a configuration is shown in which the internal temperature of a turbocharger is estimated using a neural network. Further, in Patent Document 2, a configuration is disclosed in which the temperature is estimated based on temperature information measured at different positions for a part where the temperature cannot be directly measured.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] For example, a machine or device may consist of multiple parts, and it may be necessary to obtain temperature information for each of these parts. While thermocouples and infrared sensors are used to measure the temperature of machines, there are structural limitations to applying these methods to measuring the temperature of each individual part inside the device. Furthermore, installing temperature sensors or other measuring devices for each of these multiple parts increases costs and device size. In particular, measuring the temperature of parts sealed inside the device, such as the lubricant mentioned above, is difficult.

[0006] In view of the above issues, the present invention aims to provide a method that enables the estimation of the temperature of each part constituting a mechanical device using a relatively simple configuration. [Means for solving the problem]

[0007] To solve the above problems, the present invention has the following configuration. That is, a temperature estimation method for estimating the temperature of multiple parts constituting a device, A setting step of setting a heat balance equation based on a thermal circuit network model defined for the aforementioned multiple parts, A step of acquiring information related to heat generation during the operation of the device, A calculation step that uses the heat balance formula and the information obtained in the acquisition step to calculate the temperature of at least one of the multiple parts, An output step that outputs the temperature calculated in the above calculation step, It has.

[0008] Another embodiment of the present invention has the following configuration: a temperature estimation device for estimating the temperature of multiple parts constituting a device, A setting means for setting a heat balance equation based on a thermal circuit network model defined for the aforementioned multiple parts, An acquisition means for acquiring information related to heat generation during the operation of the device, A calculation means that uses the heat balance equation and the information acquired by the acquisition means to calculate the temperature of at least one of the multiple parts, An output means that outputs the temperature calculated by the calculation means, It has.

[0009] Another embodiment of the present invention has the following configuration: namely, a program, On the computer, A setting process for setting a heat balance equation based on a thermal circuit network model defined for multiple parts constituting the device, A step of acquiring information related to heat generation during the operation of the device, A calculation step that uses the heat balance formula and the information obtained in the acquisition step to calculate the temperature of at least one of the multiple parts, An output step that outputs the temperature calculated in the above calculation step, Make it run. [Effects of the Invention]

[0010] This invention makes it possible to estimate the temperature of each part constituting a mechanical device using a relatively simple configuration. [Brief explanation of the drawing]

[0011] [Figure 1] A diagram showing an example configuration of a temperature estimation system according to one embodiment of the present invention. [Figure 2] A schematic diagram illustrating a thermal network method model relating to one embodiment of the present invention. [Figure 3] Schematic diagram illustrating a thermal network method model according to one embodiment of the present invention. [Figure 4] A block diagram showing an example of the functional configuration of a temperature estimation device according to one embodiment of the present invention. [Figure 5] Flowchart of the temperature estimation process related to one embodiment of the present invention. [Figure 6] A graph showing an example of temperature estimation results related to one embodiment of the present invention. [Modes for carrying out the invention]

[0012] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings and other documents. The embodiments described below are merely examples for illustrating the present invention and are not intended to be interpreted as limiting the invention. Furthermore, not all configurations described in each embodiment are necessarily essential for solving the problems of the present invention. In addition, in each drawing, the same components are given the same reference numeral to indicate their correspondence.

[0013] <First Embodiment> The first embodiment of the present invention will be described below. In this embodiment, a bearing device including a rolling bearing that performs rolling behavior while being lubricated by a lubricant will be used as an example. Examples of rolling bearings to which the temperature estimation method of the present invention can be applied include deep groove ball bearings, angular contact ball bearings, tapered roller bearings, cylindrical roller bearings, and self-aligning roller bearings. However, it is not limited to these, and can also be applied to other bearings and rotating devices such as gear devices. Furthermore, it can also be applied to sliding devices that experience sliding due to linear motion (for example, linear bushings and self-lubricating bushings). As will be described in detail later, this embodiment can be applied to any device to which a heat transfer model using the thermal network method (hereinafter also referred to as the "thermal network model" or simply the "model") can be identified.

[0014] Figure 1 shows an example configuration of a temperature estimation system 1 to which the temperature estimation method according to this embodiment can be applied. The temperature estimation system 1 includes a measuring device 100 for performing temperature estimation, a mechanical device 200 to be estimated, a torque sensor 300, and a rotation sensor 400. In this embodiment, the measuring device 100 and the mechanical device 200 are described as separate entities, but they may be configured as an integrated unit. Furthermore, a control device (not shown) for controlling the mechanical device 200 may be configured to include the measuring device 100.

[0015] The measuring device 100 is comprised of a control unit 101, a storage unit 102, an IF (Interface) unit 103, a UI (User Interface) unit 104, and a communication unit 105. The measuring device 100 may be configured as a general-purpose information processing device such as a PC (Personal Computer), or it may be configured as a device dedicated to measurement.

[0016] The control unit 101 may consist of a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a DSP (Digital Single Processor), or a dedicated circuit. The storage unit 102 consists of volatile and non-volatile storage media such as an HDD (Hard Disk Drive), ROM (Read Only Memory), and RAM (Random Access Memory), and can input and output various types of information in response to instructions from the control unit 101.

[0017] The IF unit 103 is an interface for connecting to external devices, and in this embodiment, it is configured to enable data transmission and reception with the torque sensor 300 and the rotation sensor 400. The UI unit 104 accepts user input and displays various information such as measurement results. For example, the UI unit 104 is composed of a speaker, a light, or a display device such as a liquid crystal display, and outputs to the user based on instructions from the control unit 101. The output method by the UI unit 104 is not particularly limited, but for example, it may be a visual output via screen output or an auditory output via sound. The communication unit 105 is a network interface for communicating with external devices.

[0018] In this embodiment, the machine device 200 is configured to include a bearing device to be measured. The bearing device includes a bearing unit 201 composed of two rolling bearings. One rolling bearing includes rolling elements 203 such as balls, and an outer ring 202 and an inner ring 204 that form the rolling surfaces of the rolling elements 203. Lubricant is filled around the rolling elements 203 to lubricate the components. The outer ring 202 is a fixed ring and is fixed to the housing 205. The inner ring 204 is a rotating ring and is connected to the main shaft 206 and configured to rotate integrally with the main shaft 206. The main shaft 206 rotates when driving force is transmitted from the motor 208 via a belt 207. The motor 208 generates a predetermined driving force based on a control signal and provides it to the main shaft 206. The bearing device is configured to be subjected to loads in predetermined directions (radial load, axial load).

[0019] The torque sensor 300 detects the torque value around the spindle 206 and provides it to the measuring device 100. The rotation sensor 400 detects the rotational speed of the spindle 206 and provides it to the measuring device 100. The detection results of the torque sensor 300 and the rotation sensor 400 are associated with time. The detection timing and detection parameters of the torque sensor 300 and the rotation sensor 400 may be controlled by the measuring device 100.

[0020] [Thermal Network Model] The thermal network model used in the temperature estimation method according to this embodiment will be described below with reference to Figures 2 and 3. The thermal network method is one of the thermal design methods, and it performs thermal design by focusing on the similarity between heat transfer and electrical conduction. Since the thermal network method is well known, a detailed explanation will be omitted, and the description will focus on the configuration according to this embodiment.

[0021] In this embodiment, the bearing device within the mechanical device 200 shown in Figure 1 is used as the target of measurement using the temperature estimation method. Figure 2 is a schematic diagram showing the bearing unit 201 of the bearing device. In this example, since the bearing unit 201 has two rolling bearings, we will focus on one more rolling bearing as shown by the dashed line in Figure 2(a) for explanation.

[0022] First, as a preliminary step for the temperature estimation method according to this embodiment, a model is defined according to the configuration of the object to be measured. In the example in Figure 2, nodes N1 to N8 and N11 to N22 are set corresponding to each part that makes up the rolling bearing. The setting of the nodes may be arbitrarily set depending on the part for which temperature estimation is to be performed and the physical properties of the material that makes up the part. Also, in Figure 2, each line connecting the nodes indicates the path of heat conduction or heat transfer (convection). For example, in Figure 2(a), the solid line connecting N2 to N7 indicates heat conduction between nodes. Also, in Figure 2(a), the dashed lines connecting N1 to N2, 4, N6, and N7 respectively indicate convective heat transfer between nodes. Similarly, in Figure 2(b), the dashed lines connecting N13 to N12, N14, and N21 respectively indicate convective heat transfer between nodes. Although not shown in Figure 2(b), node N13, which corresponds to the lubricant, is connected via convective heat transfer not only to node N14, which corresponds to the rolling element 203, but also to nodes N15 to N20, which also correspond to the rolling element 203.

[0023] A simplified representation of a part of the model set up in Figure 2 can be shown as in Figure 3. Here, a heat flow Q is applied to node N5 set for the rolling element 203. f We will explain assuming that the following is input. In other words, the following equation (4) is given by the heat flow Q. f This is set. This assumes that friction occurs around the rolling element 203 as the rolling bearing rotates, generating heat. However, the location where heat flow occurs is not particularly limited and can be set arbitrarily according to the configuration of the object being measured. Note that in Figure 3, multiple nodes corresponding to the rolling element 203 are shown together as N5. Therefore, they are also defined together in the following formula.

[0024] Then, by defining heat balance equations for these contact points and solving the simultaneous differential equations, it becomes possible to calculate the temperature of each part. In this embodiment, more specifically, the following equations (1) to (8) can be defined as heat balance equations corresponding to the configurations in Figures 2 and 3. Equations (1) to (8) correspond, in order, to the end of the spindle 206 (N2), the bearing position of the spindle 206 (N3), the inner ring 204 (N4), the rolling element 203 (N5), the outer ring 202 (N6), the housing 205 (N7), air (N1), and the lubricant 210 (N13). The subscripts of each parameter correspond to each part. For example, shaft1 (or simply "1") corresponds to node N2 of the spindle 206, and shaft2 (or simply "2") corresponds to node N3 of the spindle 206.

[0025]

number

[0026]

number

[0027]

number

[0028]

number

[0029]

number

[0030]

number

[0031]

number

[0032]

number

[0033] T: Temperature [K] Q f :Heat flow [W] R: Thermal resistance [Ω] c: Specific heat [J / kg·K] m: Mass [kg] ∂: Partial derivative

[0034] The number of heat balance equations increases depending on the nodes to be defined, i.e., the parts whose temperature we want to estimate. Also, the heat flow Q f It is calculated using the following formula (9).

[0035]

number

[0036] M: Torque [N·m] N: rotational speed [min -1 ]

[0037] Furthermore, corresponding to the heat conduction and convection heat transfer in Figure 2, the following equation can be defined. Heat conduction occurs between nodes N2 and N3 set on the main shaft 206, and the thermal resistance can be expressed by the following equation (10).

[0038]

number

[0039] L: Length [m] A: Cross-sectional area [m 2 ] k: Thermal conductivity [W / (m·k)]

[0040] Heat conduction (cylindrical) occurs between node N3 set on the main spindle 206 and node N4 set on the inner ring 204, and between node N6 set on the outer ring 202 and node N7 set on the housing 205, and the thermal resistance can be expressed by the following equation (11).

[0041]

number

[0042] r0: Radius of the inner member (main shaft 206 or outer ring 202) [m] r i Radius of the outer member (inner ring 204 or housing 205) [m] L: Length [m] k: Thermal conductivity [W / (m·k)]

[0043] Heat conduction occurs between node N4 set on the inner ring 204 and node N5 set on the rolling element 203, and between node N6 set on the outer ring 202 and node N5 set on the rolling element 203, and the contact thermal resistance can be expressed using the following equations (12) and (13).

[0044]

number

[0045] R c :Contact thermal resistance [K / W] e: Eccentricity of the contact ellipse a: Major axis of the contact ellipse [m] b: Minor axis of the contact ellipse [m] k: Thermal conductivity [W / (m·k)] K: Complete elliptic integral of the first kind

[0046] Between the node N13 set on the lubricant 210 and the node N12 set on the outer ring 202, and between the node N13 set on the lubricant 210 and the node N21 set on the inner ring 204, forced convection occurs, and the thermal resistance can use the following formulas (14) to (16). Formulas (14) to (16) are defined as a state where a fluid (in this example, lubricant 210) is filled between the double cylinders. Using formulas (15) and (16), the Nusselt number N u is calculated to obtain the heat transfer coefficient h between the lubricant and the inner and outer rings. Then, from the heat transfer coefficient h and the heat transfer area A in formula (14), the thermal resistance R between the lubricant and the inner and outer rings, that is, R oil_inner and R oil_outer are respectively derived. Note that the Nusselt number is a dimensionless number obtained by dimensionlessizing the heat transfer coefficient h. In this embodiment, the Nusselt number for which the heat transfer coefficient h and the similarity law hold is used.

[0047]

Number

[0048] R: Thermal resistance of convective heat transfer between the lubricant and the inner and outer rings [K / W] (in this example, R oil_inner , R oil_outer ) D: Representative length [m] k: Thermal conductivity of the fluid (lubricant) [W / (m·k)] T a : Taylor number R e : Reynolds number Gap: Gap between the inner and outer rings [m] Dio: Diameter of the outer side of the inner ring [m] h: Heat transfer coefficient between the lubricant and the inner and outer rings [W / m 2 ·K] A: Heat transfer area between the lubricant and the inner and outer rings [m 2 N u : Nusselt number P r : Prandtl number of the lubricant

[0049] ​Forced convection occurs between node N13 set on the lubricant 210 and node N14 set on the rolling element 203, and the thermal resistance can be expressed using the following equations (17) to (20). Using equations (18) to (20), the heat transfer coefficient h between the lubricant and the rolling element can be expressed. v Then, in equation (17), the heat transfer coefficient h v From the heat transfer area A, the thermal resistance R between the lubricant and the rolling element is, i.e., R oil_ball This is derived.

[0050]

number

[0051] R: Thermal resistance of convective heat transfer between lubricant and rolling elements [K / W] (In this example, R oil_ball ) h v : Heat transfer coefficient between rolling element and lubricant [W / (m 2 (K) D: Characteristic length [m] (Here, the diameter of the rolling element) k: Thermal conductivity of the fluid (lubricant) [W / (m·k)] u: kinematic viscosity coefficient of the lubricant [m 2 / s] v: Typical velocity [m / s] (Here, the orbital velocity of the rolling element) α: Temperature diffusivity [m 2 / s] P r : Number of Prandtl lubricants A: Heat transfer area between lubricant and rolling element [m²] 2 ]

[0052] Natural convection occurs between node N1, which is set in the air, and node N6, which is set in the outer ring 202, and the thermal resistance can be expressed using the following equations (21) to (24).

[0053]

number

[0054] R: Thermal resistance of heat transfer by natural convection between air and the outer ring (In this example, R air_outer) g: Gravitational acceleration [m / s 2 ] B: Coefficient of volumetric expansion of air [1 / K] T w Outer ring temperature [K] T a Air temperature [K] L air_outer : Representative length [m] (here, the width of the outer ring) u air : The kinematic viscosity of air [m 2 / s] k air Thermal conductivity of air [W / (m·k)] P r : Prandtl number of air G r Grashof number N u Nusselt number h: Heat transfer coefficient between air and outer ring [W / (m 2 (K) A: Heat transfer area between air and outer ring [m²] 2 ]

[0055] Using equations (22) to (24), the Nusselt number N u By calculating this, the heat transfer coefficient h between the air and the outer ring can be determined. Then, using equation (21), the thermal resistance R between the air and the outer ring can be obtained from the heat transfer coefficient h and the heat transfer area A, i.e., R air_outer The following is derived. In this embodiment, with respect to equation (23) above, an example is shown in which it is set by approximating it to the following equations (25) and (26) for a vertical plate, based on the content described in "Heat Transfer Engineering", Maruzen Publishing, Japan Society of Mechanical Engineers, 2005, p. 90.

[0056]

number

[0057] Natural convection occurs between node N1, which is set in the air, and node N7, which is set in the housing 205, and the thermal resistance can be expressed using the following equations (27) to (30).

[0058]

number

[0059] R: Thermal resistance of heat transfer by natural convection between air and housing (in this example, R air_housing ) g: Gravitational acceleration [m / s 2 ] B: Coefficient of volumetric expansion of air [1 / K] T wh Housing temperature [K] T a Air temperature [K] L air_housing :Representative length [m] u air : The kinematic viscosity of air [m 2 / s] k air Thermal conductivity of air [W / (m·k)] P r : Prandtl number of air G r Grashof number N u Nusselt number h: Heat transfer coefficient between air and housing [W / (m 2 (K) A: Heat transfer area between air and housing [m²] 2 ]

[0060] Using equations (28) to (30), the Nusselt number N u By calculating this, the heat transfer coefficient h between the air and the housing can be determined. Then, using equation (27), the thermal resistance R between the air and the housing can be obtained from the heat transfer coefficient h and the heat transfer area A, i.e., R air_housing The following is derived. Regarding equation (27) above, similar to equation (23), it is set by approximating it to equations (25) and (26) for the vertical plate above, based on the content described in "Heat Transfer Engineering," Maruzen Publishing, Japan Society of Mechanical Engineers, 2005, p. 90.

[0061] Forced convection occurs between node N1, which is set in the air, and node N4, which is set in the inner ring 204, and the thermal resistance can be expressed using the following equations (31) to (33).

[0062]

number

[0063] v: Typical velocity [m / s] (in this case, the rotational speed of the inner ring) N: Inner wheel rotation speed [rpm] D ii Inner ring diameter [m] L air_inner : Representative length [m] (Here, the difference between the outer diameter of the inner ring and the inner diameter of the inner ring) u air : The kinematic viscosity of air [m 2 / s] Re air_inner : Reynolds number k air Thermal conductivity of air [W / (m·k)] P r : Prandtl number of air

[0064] Note that the Nusselt number N u The following conditions will be used to differentiate between cases.

[0065]

number

[0066] For example, the relationships between the Nusselt number, Reynolds number, and Prandtl number are detailed in Dalila Belmiloud et al., “Thermo-dynamical modelisation of the degradation of a ball bearing in variables use conditions”, 2020, Vol.21, No.6, Mechanics & Industry, and Xu Hao et al., “Thermal-Fluid-Solid Coupling in Thermal Characteristics Analysis of Rolling Bearing System Under Oil Lubrication”, March 2020, Vol.142, Journal of Tribology.

[0067] Forced convection occurs between node N1, which is set to the air, and node N2, which is set to the main shaft 206, and the thermal resistance can be expressed using the following equations (34) to (36).

[0068]

number

[0069] v: Typical velocity [m / s] (in this case, the rotational speed of the inner ring) D ii Inner ring diameter [m] u air : The kinematic viscosity of air [m 2 / s] Re air_1 : Reynolds number h: Heat transfer coefficient [W / (m 2 (K) A: Heat transfer area [m²] 2 ]

[0070] The Nusselt number formula can be modified according to the Reynolds number, and in this embodiment, Becker's formula is used in formula (35). An example of a Nusselt number formula is the formula shown in Bariq Ozerdem, “MEASUREMENT OF CONVECTIVE HEAT TRANSFER COEFFICIENT FOR A HORIZONTAL CYLINDER ROTATING IN QUIESCENT AIR”, International Communications in Heat and Mass Transfer, April 2000, Vol.27, No.3, pp.389-395. Therefore, the method according to this embodiment can be selected and used from the formulas shown in the above-mentioned document depending on the object to be measured.

[0071] By solving the above system of differential equations, it is possible to estimate the temperature of a specific part of the object being measured, depending on its configuration. In particular, it becomes possible to estimate the temperature of parts that cannot be directly measured, such as the lubricant inside a rolling bearing, relatively easily.

[0072] [Functional Configuration] Figure 4 is a block diagram showing an example of the functional configuration of the measuring device 100 according to this embodiment. The data acquisition unit 111 acquires measurement data for the mechanical device 200 (bearing device) from the torque sensor 300 and the rotation sensor 400. The model holding unit 112 holds a thermal network model that is predefined by the user or the like in relation to the object to be measured. For example, a mathematical formula defined in relation to the thermal network model may be held. The thermal network model used may be configured to be specified by the user when estimating the temperature.

[0073] The parameter holding unit 113 holds various parameters that are substituted into the thermal network model when performing temperature estimation. For example, it may hold the mass m and specific heat c of each part, which are predetermined according to the configuration of the bearing device. The various parameters may be configured to be specified by the user when performing temperature estimation. The temperature calculation unit 114 calculates the temperature of each part of the object to be measured using the thermal network model that is predetermined according to the object to be measured.

[0074] The calculation result output control unit 115 performs output control based on the temperature of each part calculated by the temperature calculation unit 114. This output control may be, for example, output in a way that is recognizable to the user via the UI unit 104, or it may be configured to control the operation of the bearing device control unit (not shown). For example, if the temperature of a predetermined part within the bearing device exceeds a predetermined threshold, the unit may instruct the bearing device to stop operating. The calculation result recording unit 116 records the temperature of each part calculated by the temperature calculation unit 114 as history information in the storage unit 102. At this time, the calculation result recording unit 116 may also record the operating conditions of the bearing device in addition to the measurement data.

[0075] [Processing flow] Figure 5 is a flowchart of the temperature estimation process according to this embodiment. This process is performed by the measuring device 100, and may be implemented, for example, by the control unit 101 of the measuring device 100 reading a program for implementing the process according to this embodiment from the storage unit 102 and executing it. Furthermore, this process flow may be executed continuously while the measuring device 100 is operating, or it may be executed at any time based on user instructions.

[0076] In S501, the measuring device 100 sets the heat balance equation corresponding to the thermal network model of the object being measured. As described above, the heat balance equations corresponding to the thermal network model are predetermined and are used by switching between them depending on the object being measured. Here, known parameters among the various variables included in the heat balance equation may also be obtained. The heat balance equation and various parameters corresponding to the thermal network model may be set based on specifications from the user.

[0077] In step S502, the measuring device 100 acquires the rotational speed of the bearing device via the rotation sensor 400.

[0078] In step S503, the measuring device 100 acquires the torque of the bearing device via the torque sensor 300.

[0079] In S504, the measuring device 100 substitutes the acquired parameters, rotational speed, and torque into the heat balance equation obtained in S501 and solves the simultaneous equations to estimate the temperature of each part that makes up the object being measured.

[0080] In S505, the measuring device 100 outputs the temperature measured in S504 as the estimated result. The output method is not particularly limited and may be output visually or audibly so that the user can recognize it. Alternatively, it may be recorded as history information in the storage unit 102, or it may be notified to an external device (not shown).

[0081] In S506, the measuring device 100 determines whether the temperature estimation process is complete. For example, it may determine to terminate this processing flow if the operation of the measuring device 100 stops or if the user gives an instruction to terminate the temperature estimation process. If it is determined that the temperature estimation process is complete (YES in S506), the processing of the measuring device 100 ends. On the other hand, if it is determined that the temperature estimation process is not complete (NO in S506), the processing of the measuring device 100 returns to S502 and the process is repeated.

[0082] [test] The following describes the results of tests conducted using the temperature estimation method described above. The test conditions were as follows. The general configuration of the apparatus is shown in Figure 1.

[0083] (Test conditions) Bearing used: Deep groove ball bearing (Model number: 608) Rotation speed: 2400 [min -1 ] Axial load: 30 [N] Radial load: 0 [N] Amount of lubricant enclosed: 80 [mg] (Lubricant used) Base oil: Polyalphaolefin oil (PAO) Thickener: Urea group Kinematic viscosity: 46[mm 2 / s] (at 40℃), 7.8[mm 2 / s] (below 100℃) Consistency: 243

[0084] (Test results) Figure 6 shows the test results obtained under the above test conditions. Here, two graphs are shown side by side. In each graph, the horizontal axis represents time [hours], showing the time elapsed since the start of rotation of the bearing device. The vertical axis of the upper graph represents the torque value [N·mm], showing the change in torque (plot 601) over time. The vertical axis of the lower graph represents temperature [°C], showing the change in temperature of each part over time.

[0085] In the graph below, plot 615 shows the temperature (measured value) of the outer ring 202 of the rolling bearing included in the bearing device being measured. Graphs 611, 612, 613, and 614 show the estimated temperatures of each part, estimated using the temperature estimation method described above. Specifically, graphs 611, 612, 613, and 614 show the estimated temperatures of the rolling elements 203, inner ring 204, lubricant 210, and outer ring 202, respectively. Now, let's focus on plot 615, which is the measured value of the outer ring 202, and graph 614, which is the estimated temperature of the outer ring. When comparing these, similar values ​​are calculated, and especially from about one hour after the start of rotation, almost identical values ​​are obtained.

[0086] Based on the results described above, it can be concluded that temperature estimation is possible with the same accuracy even for the rolling elements 203, inner ring 204, and lubricant 210, for which direct temperature measurement is difficult. Therefore, it can be concluded that graphs 611 to 613 also achieve the same level of accuracy as graph 614.

[0087] As described above, the configuration of this embodiment makes it possible to estimate the temperature of various parts of a measurement target that are difficult to measure directly, using a simple configuration. In particular, even for parts that are sealed inside the device, such as lubricants, and are difficult to measure directly during operation, the temperature of the desired part can be easily estimated by defining a heat balance equation based on the corresponding thermal network model.

[0088] <Other Embodiments> The method according to the present invention is applicable to devices other than rotating devices that involve rotational motion. For example, it can be applied to sliding devices in which slippage occurs between two members. More specifically, a heat balance equation may be defined assuming a first member, a second member, a lubricant supplied between the first and second members, and the air around the first and second members of the sliding device. Information related to heat generation may be obtained, such as the velocity V (relative velocity between members) during sliding, the load W (load in a predetermined direction at the contact point between members), and the friction coefficient μ. The temperature of each part is then estimated using this information and a predetermined heat balance equation. In this case, the heat flow Q used in the heat balance equation can be determined by the equation Q = μWV[W]. Therefore, in addition to rotating devices that perform rotational motion, even in sliding devices that perform sliding motion, by defining a heat balance equation based on a thermal network model corresponding to each part as described above, it becomes possible to easily estimate the temperature of a desired part in which direct temperature measurement is difficult.

[0089] Furthermore, the present invention can also be realized by supplying a program or application for realizing the functions of one or more embodiments described above to a system or device using a network or storage medium, and having one or more processors in the computer of that system or device read and execute the program.

[0090] Alternatively, it may be implemented by a circuit that performs one or more functions (for example, an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array)).

[0091] Thus, the present invention is not limited to the embodiments described above. It is also intended and within the scope of protection to be provided for the combination of each configuration of the embodiments, as well as for modifications and applications by those skilled in the art based on the description in the specification and well-known technology.

[0092] As described above, the following matters are disclosed in this specification: (1) A temperature estimation method for estimating the temperatures of multiple parts (e.g., 202, 203, 204, 205, 206, 210) that constitute a device (e.g., 200, 201), A setting step of setting a heat balance equation based on a thermal circuit network model defined for the aforementioned multiple parts, A step of acquiring information related to heat generation during the operation of the device, A calculation step that uses the heat balance formula and the information obtained in the acquisition step to calculate the temperature of at least one of the multiple parts, An output step that outputs the temperature calculated in the above calculation step, A method for estimating temperature, characterized by having the following features. This configuration makes it possible to estimate the temperature of each component of a machine using a relatively simple setup. In particular, it makes it possible to estimate the temperatures of multiple components that cannot be directly measured during operation using a simple configuration.

[0093] (2) The acquisition step acquires the torque and rotational speed of the device during rotational operation as information related to the heat generation, The temperature estimation apparatus according to (1), wherein the calculation step calculates the temperature of at least one of the plurality of parts using the heat balance formula and the torque and rotational speed obtained in the acquisition step. This configuration makes it possible to estimate the temperature of each component of a rotating mechanical device using a relatively simple setup.

[0094] (3) The acquisition step acquires the speed, load, and friction coefficient of the device during sliding as information related to the heat generation, The temperature estimation apparatus according to (1), wherein the calculation step calculates the temperature of at least one of the plurality of parts using the heat balance formula and the velocity, load, and friction coefficient obtained in the acquisition step. This configuration makes it possible to estimate the temperature of each component of a device that experiences slippage, using a relatively simple setup.

[0095] (4) The device is a bearing device, The temperature estimation method according to (1) or (2), wherein the plurality of parts include at least one of an outer ring (e.g., 202), an inner ring (e.g., 203), rolling elements (e.g., 203), a main shaft (e.g., 206), a housing (e.g., 205), and a lubricant (e.g., 210) sealed in the bearing device. This configuration allows for the measurement of a bearing device and enables temperature estimation for multiple parts of the bearing device according to its configuration.

[0096] (5) The device is a sliding device, The temperature estimation method according to (1) or (3), wherein the plurality of parts include a first member and a second member that experience sliding motion. This configuration allows for the measurement of a sliding device and enables temperature estimation for multiple parts of the device according to its configuration.

[0097] (6) The thermal network model has nodes set corresponding to the parts where the temperature is to be estimated, A temperature estimation method according to any one of (1) to (5), wherein the formulas for calculating heat conduction and heat transfer used in the heat balance formula are defined according to the set nodes and the configuration of the apparatus. This configuration allows for temperature estimation for multiple parts of the device using a heat balance equation corresponding to a thermal network model that is appropriate for the device's configuration.

[0098] (7) A temperature estimation device (e.g., 100) for estimating the temperatures of multiple parts (e.g., 202, 203, 204, 205, 206, 210) that constitute a device (e.g., 200, 201), Setting means (for example, 112, 113, 114) for setting a heat balance equation based on a thermal circuit network model defined corresponding to the aforementioned multiple parts, The device includes an acquisition means (for example, 300, 400, 111) for acquiring information related to heat generation during operation, A calculation means (for example, 114) that uses the heat balance equation and the information acquired by the acquisition means to calculate the temperature of at least one of the multiple parts, Output means (for example, 115, 116) that output the temperature calculated by the calculation means, A temperature estimation device characterized by having the following features. This configuration makes it possible to estimate the temperature of each component of a machine using a relatively simple setup. In particular, it makes it possible to estimate the temperatures of multiple components that cannot be directly measured during operation using a simple configuration.

[0099] (8) A computer (for example, 100) A setting step involves setting up a heat balance equation based on a thermal network model defined for multiple parts (e.g., 202, 203, 204, 205, 206, 210) that constitute a device (e.g., 200), and A step of acquiring information related to heat generation during the operation of the device, A calculation step that uses the heat balance formula and the information obtained in the acquisition step to calculate the temperature of at least one of the multiple parts, An output step that outputs the temperature calculated in the above calculation step, A program to execute. This configuration makes it possible to estimate the temperature of each component of a machine using a relatively simple setup. In particular, it makes it possible to estimate the temperatures of multiple components that cannot be directly measured during operation using a simple configuration.

[0100] Although various embodiments have been described above with reference to the drawings, it goes without saying that the present invention is not limited to these examples. It is clear to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally also fall within the technical scope of the present invention. Furthermore, the components of the above embodiments may be combined in any way without departing from the spirit of the invention.

[0101] Although various embodiments have been described above, it goes without saying that the present invention is not limited to these examples. It is clear to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally also fall within the technical scope of the present invention. Furthermore, the components in the above embodiments may be combined in any way without departing from the spirit of the invention.

[0102] This application is based on Japanese Patent Application No. 2023-025262 filed on February 21, 2023, and Japanese Patent Application No. 2023-085526 filed on May 24, 2023, the contents of which are incorporated by reference in this application. [Explanation of symbols]

[0103] 1…Temperature estimation system 100... Measuring device 101... Control Unit 102...Storage section 103...IF (Interface) section 104...UI (User Interface) Department 105... Communications Department 200…Mechanical equipment 201...Bearing Unit 202…Outer ring 203... Rolling element 204...Internal 205… Housing 206…Spindle 207... belt 208...motor 210... Lubricant 300... Torque sensor 400... Rotation sensor

Claims

1. A temperature estimation method for estimating the temperature of multiple parts that make up a device, A setting step of setting a heat balance equation based on a thermal circuit network model defined for the aforementioned multiple parts, A step of acquiring information related to heat generation during the operation of the device, A calculation step that uses the heat balance formula and the information obtained in the acquisition step to calculate the temperature of at least one of the multiple parts, The system includes an output step that outputs the temperature calculated in the calculation step, The aforementioned device is a bearing device that includes a rolling bearing with a lubricant sealed inside, The aforementioned multiple parts include an outer ring, an inner ring, rolling elements, a main shaft, a housing, and the lubricant. The thermal network model includes nodes corresponding to the lubricant, and these nodes are connected by convective heat transfer to at least the nodes corresponding to the outer ring and the nodes corresponding to the inner ring. The acquisition step acquires the torque and rotational speed during the rotational operation of the device as information related to the heat generation. The calculation step involves inputting the heat flow calculated from the acquired torque and rotational speed into the heat balance equation as input to the nodes corresponding to the rolling elements, and calculating the temperature of at least one of the multiple parts as the temperature of the lubricant. The temperature estimation method is characterized in that the output step outputs at least the calculated temperature of the lubricant.

2. In the aforementioned thermal network model, nodes are set corresponding to the parts where the temperature is to be estimated. The temperature estimation method according to claim 1, wherein the formulas for calculating heat conduction and heat transfer used in the heat balance formula are defined according to the set nodes and the configuration of the apparatus.

3. A temperature estimation device that estimates the temperature of multiple parts that make up a device, A setting means for setting a heat balance equation based on a thermal circuit network model defined for the aforementioned multiple parts, An acquisition means for acquiring information related to heat generation during the operation of the device, A calculation means that uses the heat balance equation and the information acquired by the acquisition means to calculate the temperature of at least one of the multiple parts, The output means has an output that outputs the temperature calculated by the calculation means, The aforementioned device is a bearing device that includes a rolling bearing with a lubricant sealed inside, The aforementioned multiple parts include an outer ring, an inner ring, rolling elements, a main shaft, a housing, and the lubricant. The thermal network model includes nodes corresponding to the lubricant, and these nodes are connected by convective heat transfer to at least the nodes corresponding to the outer ring and the nodes corresponding to the inner ring. The acquisition means acquires the torque and rotational speed during the rotational operation of the device as information related to the heat generation. The calculation means provides the heat flow calculated from the acquired torque and rotational speed as input to the nodes corresponding to the rolling elements in the heat balance equation, and calculates the temperature of at least one of the plurality of parts as the temperature of the lubricant. The temperature estimation device is characterized in that the output means outputs at least the calculated temperature of the lubricant.

4. On the computer, A setting process for setting a heat balance equation based on a thermal circuit network model defined for multiple parts constituting the device, A step of acquiring information related to heat generation during the operation of the device, A calculation step that uses the heat balance formula and the information obtained in the acquisition step to calculate the temperature of at least one of the multiple parts, The system executes an output step that outputs the temperature calculated in the calculation step, The aforementioned device is a bearing device that includes a rolling bearing with a lubricant sealed inside, The aforementioned multiple parts include an outer ring, an inner ring, rolling elements, a main shaft, a housing, and the lubricant. The thermal network model includes nodes corresponding to the lubricant, and these nodes are connected by convective heat transfer to at least the nodes corresponding to the outer ring and the nodes corresponding to the inner ring. The acquisition step acquires the torque and rotational speed during the rotational operation of the device as information related to the heat generation. The calculation step involves inputting the heat flow calculated from the acquired torque and rotational speed into the heat balance equation as input to the nodes corresponding to the rolling elements, and calculating the temperature of at least one of the multiple parts as the temperature of the lubricant. The output step is a program that outputs at least the calculated temperature of the lubricant.

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