Machine component and monitoring system

Abstract

A machine component 40 includes: a housing 41; a bearing 42 that is disposed in the housing 41 and rotatably supports the shaft member 31 with respect to the housing 41; and a temperature sensor 43b that is disposed on the outer surface of the housing 41 and detects the temperature of the housing 41. When the housing 41 is viewed along the axial direction of the bearing 42, the temperature sensor 43b overlaps a portion where the stress generated by the force acting from the bearing 42 in the housing 41 becomes maximum.

Description

Machinery and Monitoring Systems

[0001] The present disclosure relates to machine components and monitoring systems.

[0002] Patent Document 1 discloses a bearing unit for a conveying device as an example of a mechanical component, which includes a housing, a bearing disposed in the housing, a sensor for detecting the condition of the bearing, and a transmitter for wirelessly transmitting information detected by the sensor.

[0003] The bearing, sensor, and transmitter are disposed within a housing. The sensor is, for example, a temperature sensor that detects the temperature of the bearing. If the condition of the bearing changes, the temperature of the bearing rises, which can cause an abnormality in the bearing. The mechanical component of Patent Document 1 can contribute to detecting an abnormality in the bearing based on the temperature detected by the temperature sensor.

[0004] JP 2013-11312 A

[0005] The mechanical component of Patent Document 1 further includes a cover that covers the sensor and transmitter inside the housing, and a seal member that prevents dust and other particles from entering between the housing and the cover. The presence of the sensor and other components inside the housing increases the number of components in the mechanical component of Patent Document 1, making it difficult to simplify the design. Furthermore, for mechanical components that have bearings, there is a demand for early detection of bearing abnormalities.

[0006] The present disclosure aims to simplify the configuration of a mechanical component having a bearing and a monitoring system including the mechanical component, and to enable early detection of an abnormality in the bearing.

[0007] A mechanical component according to one aspect of the present disclosure comprises a housing, a bearing disposed in the housing and rotatably supporting a shaft member relative to the housing, and a temperature sensor disposed on the outer surface of the housing and detecting the temperature of the housing, wherein when the housing is viewed along the axial direction of the bearing, the temperature sensor overlaps with a portion of the housing where the stress generated by the force acting from the bearing is greatest.

[0008] According to this, the temperature sensor is disposed on the outer surface of the housing. This simplifies the configuration inside the housing and the configuration of the mechanical component. Furthermore, when a state change in a bearing progresses due to a load from the shaft member, the temperature of the portion where the state change is progressing rises. The heat from the bearing is transferred to the housing. The temperature of the portion of the housing in contact with the portion of the bearing where the state change is progressing rises earlier than other portions of the housing. Furthermore, the portion of the housing in contact with the portion of the bearing where the state change is progressing corresponds to the portion where the stress generated by the force acting from the bearing is greatest. Therefore, the temperature detected by the temperature sensor rises earlier in response to the temperature rise of the bearing and the housing. Therefore, the mechanical component can contribute to earlier detection of bearing abnormalities based on the temperature detected by the temperature sensor.

[0009] Furthermore, in a mechanical component according to one aspect of the present disclosure, the axis of the bearing is inclined relative to the direction of gravity when the housing is attached to the workpiece, and when the housing is viewed along the axial direction of the bearing when the housing is attached to the workpiece, the temperature sensor is located below the axis of the bearing in the direction of gravity.

[0010] According to this, the portion of the housing located below the axis of the bearing in the direction of gravity corresponds to the portion where the stress generated by the force acting from the bearing is greatest. Therefore, the temperature detected by the temperature sensor reliably rises early in response to temperature increases in the bearing and the housing. This contributes to reliably detecting bearing abnormalities early based on the temperature detected by the temperature sensor.

[0011] Furthermore, a mechanical component according to one aspect of the present disclosure includes an RFID tag that is configured integrally with the temperature sensor and transmits the temperature detected by the temperature sensor to a reader / writer.

[0012] This allows the mechanical component to output the temperature detected by the temperature sensor with a simple configuration.

[0013] A monitoring system according to one aspect of the present disclosure comprises a mechanical device including a plurality of the above-described mechanical components, the reader / writer, and a terminal device electrically connected to the reader / writer and configured to store the detected temperature of the temperature sensor.

[0014] With this, the reader / writer quickly acquires the temperatures detected by the temperature sensors from multiple mechanical components. Therefore, the terminal device can easily acquire the temperatures detected by the multiple temperature sensors via the reader / writer. Therefore, even when the monitoring system includes multiple mechanical components, it can quickly detect bearing abnormalities with a simple configuration.

[0015] FIG. 1 is a diagram illustrating the configuration of a monitoring system. FIG. 2 is a front view of a mechanical component. FIG. 3 is a cross-sectional view of the mechanical component taken along line III-III shown in FIG. 2. FIG. 4 is a plan view of a temperature detection device. FIG. 5 is an enlarged cross-sectional view of the temperature detection device shown in FIG. 3. FIG. 6 is a block diagram of an RFID tag. FIG. 7 is a cross-sectional view of a temperature detection device in a mechanical component according to a first modified example of the embodiment of the present disclosure. FIG. 8 is a cross-sectional view of a temperature detection device in a mechanical component according to a second modified example of the embodiment of the present disclosure. FIG. 9 is a cross-sectional view of a temperature detection device in a mechanical component according to a third modified example of the embodiment of the present disclosure. FIG. 10 is a cross-sectional view of a temperature detection device in a mechanical component according to a fourth modified example of the embodiment of the present disclosure.

[0016] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings, but the present disclosure is not limited thereto. The components of each embodiment and each modified example described below can be combined as appropriate. In addition, some components may not be used.

[0017] <Monitoring System 1> Fig. 1 is a diagram showing the configuration of a monitoring system 1. The monitoring system 1 is a system that monitors a mechanical component 40 that includes a bearing 42, which will be described later. The monitoring system 1 includes a mechanical device 2, a reader / writer 3, and a terminal device 4. Note that the monitoring system 1 may include multiple mechanical devices 2.

[0018] The machine 2 is a roller conveyor that transports industrial products along a transport direction W. The machine 2 includes a pair of support bases 10 and a plurality of roller units 20. The support bases 10 correspond to the "receiving member." In this embodiment, the number of roller units 20 is ten, but it goes without saying that the number is not limited to ten.

[0019] The pair of support bases 10 support a plurality of roller devices 20. The pair of support bases 10 are shaped like rectangular parallelepipeds extending along the conveying direction W.

[0020] The roller device 20 includes a roller member 30 and a pair of mechanical components 40 .

[0021] The roller member 30 includes a shaft member 31 and a roller 32. The shaft member 31 has a cylindrical shape extending along a central axis.

[0022] The rollers 32 are cylindrical and disposed on the circumferential surface of the shaft member 31, and rotate integrally with the shaft member 31. Both ends of the shaft member 31 are exposed from the rollers 32.

[0023] The pair of mechanical components 40 support the roller member 30 so as to be rotatable relative to one another. Specifically, the pair of mechanical components 40 support both ends of the shaft member 31 so as to be rotatable relative to one another. The mechanical components 40 are plummer blocks. The mechanical components 40 include a bearing 42 (described later) and an RFID (Radio Frequency Identification) tag 43a that is integral with a temperature sensor 43b. Details of the mechanical components 40 will be described later.

[0024] The pair of mechanical components 40 are fixed to the pair of support bases 10 using, for example, fixing bolts, and thereby the plurality of roller devices 20 are supported by the pair of support bases 10. The plurality of roller devices 20 are arranged such that the central axes of the shaft members 31 are parallel to each other and perpendicular to the conveying direction W.

[0025] The reader / writer 3 performs wireless communication with an RFID tag 43a provided on the mechanical component 40. The reader / writer 3 is portable by the user. The reader / writer 3 is electrically connected to the terminal device 4 by wire or wirelessly.

[0026] The user operates the reader / writer 3, which transmits a carrier wave toward the RFID tag 43a. In response, the RFID tag 43a transmits the temperature detected by the temperature sensor 43b (hereinafter referred to as the temperature detected by the temperature sensor 43b) to the reader / writer 3. The reader / writer 3 acquires the temperature detected by the temperature sensor 43b and transmits it to the terminal device 4.

[0027] The reader / writer 3 can simultaneously communicate wirelessly with multiple RFID tags 43 a. This allows the reader / writer 3 to acquire the temperatures detected by the multiple temperature sensors 43 b in a relatively short time. The reader / writer 3 then transmits the temperatures detected by the multiple temperature sensors 43 b to the terminal device 4.

[0028] The terminal device 4 is a computer, and includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an internal storage unit, an input interface, and an output interface. The CPU, ROM, RAM, and internal storage unit are connected via an internal bus. The ROM stores programs such as the BIOS. The internal storage unit is, for example, a hard disk drive (HDD) or flash memory, and stores operating system programs and application programs. The CPU uses the RAM as a work area and executes programs stored in the ROM or internal storage unit to realize various functions.

[0029] The terminal device 4 acquires the temperature detected by the temperature sensor 43b from the reader / writer 3. The terminal device 4 detects an abnormality in the bearing 42 of the mechanical component 40 before a failure occurs in the bearing 42, based on the temperature detected by the temperature sensor 43b.

[0030] An abnormality in the bearing 42 occurs when the load acting from the shaft member 31 causes a change in the condition of the bearing 42 (for example, aging). If an abnormality in the bearing 42 is overlooked, the bearing 42 will fail, leading to failure of the mechanical component 40. In other words, the terminal device 4 detects an abnormality in the bearing 42 that occurs before the bearing 42 fails.

[0031] As the state change of the bearing 42 progresses, the temperature detected by the temperature sensor 43b rises (details will be described later). If the temperature detected by the temperature sensor 43b is equal to or higher than a predetermined temperature, the terminal device 4 determines that there is an abnormality in the bearing 42. Based on the determination result of the terminal device 4, the user investigates the mechanical component 40 determined to have an abnormality.

[0032] The user can periodically check the temperature detected by the temperature sensor 43b using the terminal device 4, thereby detecting an abnormality in the bearing 42 at an early stage.

[0033] As described above, according to this embodiment, the monitoring system 1 includes the mechanical device 2 including a plurality of mechanical components 40, the reader / writer 3, and the terminal device 4 electrically connected to the reader / writer 3 and storing the temperatures detected by the temperature sensors 43b. In this manner, the reader / writer 3 acquires the temperatures detected by the temperature sensors 43b from the plurality of mechanical components 40 in a relatively short time. Therefore, the terminal device 4 can easily acquire the temperatures detected by the plurality of temperature sensors 43b via the reader / writer 3. Therefore, even when the monitoring system 1 includes a plurality of mechanical components 40, it is possible to quickly detect an abnormality in the bearings 42 with a simple configuration.

[0034] <Mechanical component 40> In the following description, the Z direction shown in the drawing is the up-down direction of the mechanical component 40, the X direction is the left-right direction of the mechanical component 40, and the Y direction is the front-rear direction of the mechanical component 40. The X direction, Y direction, and Z direction are perpendicular to each other. Note that the X, Y, and Z directions are merely examples, and the present disclosure is not limited to these directions.

[0035] Fig. 2 is a front view of the mechanical component 40. Fig. 3 is a cross-sectional view of the mechanical component 40 taken along line III-III shown in Fig. 2. The mechanical component 40 includes a housing 41, a bearing 42, and a temperature detection device 43.

[0036] The housing 41 has a main body 41a and a flange 41b formed integrally therewith. The main body 41a has a first through-hole 41a1 through which the shaft member 31 passes.

[0037] The flange portions 41b are located on both sides of the main body portion 41a in the X direction. The flange portions 41b have second through holes 41b1 through which bolts for attaching the mechanical component 40 to the support base 10 pass.

[0038] Furthermore, the lower surface (the surface on the -Z side) of the housing 41 corresponds to the mounting surface F1 that comes into contact with the support base 10. The mounting surface F1 is flat. The mounting surface F1 is perpendicular to the Z direction. When the mechanical component 40 is attached to the support base 10, the Z direction is approximately parallel to the direction of gravity. Therefore, when the mechanical component 40 is attached to the support base 10, the mounting surface F1 is approximately perpendicular to the direction of gravity and faces downward in the direction of gravity.

[0039] The bearing 42 is disposed in the housing 41 and supports the shaft member 31 rotatably relative to the housing 41. The axis Ax of the bearing 42 extends along the Y direction. That is, the axis Ax of the bearing 42 is approximately perpendicular to the direction of gravity when the housing 41 is attached to the support base 10. Note that in this specification, the axis Ax being inclined with respect to the direction of gravity includes the axis Ax being perpendicular to the direction of gravity. The axis Ax of the bearing 42 is approximately parallel to the central axis of the shaft member 31.

[0040] The bearing 42 is a ball bearing. However, the bearing 42 may be a roller bearing. The bearing 42 is disposed in the first through hole 41a1. The bearing 42 includes an outer ring 42a, an inner ring 42b, and a plurality of balls 42c.

[0041] The outer ring 42a fits into an annular groove 41a2 formed on the inner circumferential surface of the first through-hole 41a1. The outer ring 42a is fixed to the housing 41. The inner ring 42b is located inside the outer ring 42a. The shaft member 31 is fixed to the inner ring 42b so as to be rotatable integrally therewith. A plurality of balls 42c are arranged between the outer ring 42a and the inner ring 42b.

[0042] When the shaft member 31 rotates relative to the housing 41, the inner ring 42b rotates relative to the outer ring 42a. At this time, the plurality of balls 42c roll relative to the outer ring 42a and the inner ring 42b.

[0043] The temperature detector 43 is disposed on the outer surface of the housing 41 and detects the temperature of the housing 41. The temperature detector 43 is disposed on the front surface F2 (the surface on the +Y side) of the outer surface of the housing 41. Furthermore, when the housing 41 is viewed along the axial direction of the bearing 42 with the housing 41 attached to the support base 10, the temperature detector 43 is located below the axis Ax of the bearing 42 in the direction of gravity. The axial direction of the bearing 42 is the direction in which the axis Ax extends.

[0044] When the housing 41 is attached to the support base 10 as described above, the mounting surface F1 of the housing 41 is substantially perpendicular to the direction of gravity and faces downward in the direction of gravity. Therefore, as shown in FIG. 2 , the temperature detection device 43 is located on the front surface F2 of the housing 41 within an arrangement region R1 on the −Z side of the axis Ax of the bearing 42. The arrangement region R1 corresponds to the region on the front surface F2 of the housing 41 in FIG. 2 where a range H1 between the mounting surface F1 and an imaginary line L that passes through the axis Ax of the bearing 42 and is parallel to the X direction, and a range H2 of the bearing 42 in the X direction overlap. In this embodiment, the temperature detection device 43 is located in a partial region R2 of the arrangement region R1 that is on the −Z side of the outer circumferential surface of the bearing 42 in the Z direction.

[0045] Furthermore, when the housing 41 is viewed along the axial direction of the bearing 42 with the housing 41 attached to the support base 10, at least the temperature sensor 43b (described later) of the temperature detection device 43 must overlap with the placement area R1 (or partial area R2).

[0046] Fig. 4 is a plan view of the temperature detecting device 43. Fig. 5 is an enlarged cross-sectional view of the temperature detecting device 43 shown in Fig. 3. Fig. 6 is a block diagram of the RFID tag 43a.

[0047] The temperature detection device 43 includes an RFID tag 43a, a temperature sensor 43b, a cover member 43c, and an adhesive member 43d. The RFID tag 43a is integral with the temperature sensor 43b.

[0048] The RFID tag 43a is a passive RFID tag. The RFID tag 43a includes a substrate 43a1 shown in FIG. 5. The substrate 43a1 may be made of a resin substrate, a ceramic substrate, a plastic substrate, or the like. The conductive portion of the substrate 43a1 is formed by metal plating the surface of the substrate. The conductive portion may be formed of a conductive foil. The conductive portion may also be formed by screen printing, inkjet printing, or the like using a polymer-type conductive ink. The substrate 43a1 is provided with a temperature sensor 43b, an antenna 43e shown in FIG. 6, and a control circuit 43f.

[0049] The temperature sensor 43b detects the temperature of the housing 41. That is, the temperature detected by the temperature sensor 43b corresponds to the temperature detected by the temperature detection device 43.

[0050] 5, the temperature sensor 43b is disposed on the main surface 43a2 of the substrate 43a1. When the temperature detection device 43 is disposed in the housing 41, the temperature sensor 43b faces the outer surface (front surface F2) of the housing 41. There is a space between the temperature sensor 43b and the outer surface of the housing 41. This prevents vibrations from the mechanical component 40 from being transmitted to the temperature sensor 43b, thereby preventing damage to the temperature sensor 43b.

[0051] The control circuit 43f shown in FIG. 6 is electrically connected to the temperature sensor 43b and the antenna 43e. The antenna 43e receives a carrier wave from the reader / writer 3. A known structure is applied to the antenna 43e. For example, the inverted F antenna structure described in Japanese Patent No. 4990858 can be applied to the antenna 43e. In this case, the antenna 43e can communicate even when the temperature detection device 43 is attached to the surface of a metal member. The control circuit 43f is driven by power generated by the carrier wave.

[0052] The control circuit 43f acquires the temperature detected by the temperature sensor 43b and stores it in the memory area 43f1. The control circuit 43f transmits the temperature detected by the temperature sensor 43b stored in the memory area 43f1 to the reader / writer 3 via the antenna 43e.

[0053] Furthermore, the control circuit 43f transmits identification information (e.g., an identification number) that identifies the mechanical component 40 in association with the temperature detected by the temperature sensor 43b to the reader / writer 3. The identification information is stored in advance in the memory area 43f1 by the reader / writer 3. The terminal device 4 stores the temperature detected by the temperature sensor 43b in association with the identification information. Thus, the terminal device 4 can identify the mechanical component 40 that has been determined to have an abnormality in the bearing 42.

[0054] The control circuit 43f can be an IC chip equipped with the temperature sensor 43b. In this case, the control circuit 43f is integrated with the temperature sensor 43b, which allows the RFID tag 43a to be miniaturized.

[0055] 5 protects the RFID tag 43a. The cover member 43c is flat and includes an arrangement surface 43c1. The arrangement surface 43c1 is flat. The arrangement surface 43c1 has a recess 43c2 in which the RFID tag 43a is arranged. In a plan view of the cover member 43c, the recess 43c2 is located in the center of the cover member 43c.

[0056] Furthermore, when the RFID tag 43a is placed in the recess 43c2, the placement surface 43c1 of the cover member 43c and the main surface 43a2 of the substrate 43a1 are on the same plane. In other words, when the RFID tag 43a is placed in the recess 43c2, the placement surface 43c1 is present around the entire periphery of the main surface 43a2 of the substrate 43a1. Note that the placement surface 43c1 of the cover member 43c and the main surface 43a2 of the substrate 43a1 may be on different planes. Furthermore, when the RFID tag 43a is placed in the recess 43c2, the temperature sensor 43b protrudes from the placement surface 43c1.

[0057] The cover member 43c is made of a thermoplastic resin. Specifically, the cover member 43c is made of a nylon resin that is waterproof and oil-resistant. Therefore, the cover member 43c is waterproof and oil-resistant. The fact that the cover member 43c is waterproof and oil-resistant means that changes in the properties of the cover member 43c caused by water, oil, grease, and the like used in the mechanical component 40 are suppressed during use of the mechanical component 40, and problems do not occur in the operation of the temperature sensor 43b and the RFID tag 43a.

[0058] The adhesive member 43d is disposed on the mounting surface 43c1 of the cover member 43c and adheres the RFID tag 43a and the cover member 43c to the outer surface (front surface F2) of the housing 41. The adhesive member 43d is also disposed on the main surface 43a2 of the substrate 43a1. The adhesive member 43d has a third through-hole 43d1 inside which the temperature sensor 43b is located. This allows the temperature sensor 43b to face the outer surface of the housing 41 across a space. Furthermore, the third through-hole 43d1 reduces the space between the temperature sensor 43b and the outer surface of the housing 41. This allows the temperature sensor 43b to accurately detect the temperature of the housing 41.

[0059] The adhesive member 43d is a double-sided tape. The adhesive member 43d is waterproof. The adhesive member 43d is a so-called waterproof tape. The fact that the adhesive member 43d is waterproof means that changes in the properties of the adhesive member 43d caused by water during use of the mechanical component 40 are suppressed, and problems do not occur in the operation of the temperature sensor 43b and the RFID tag 43a.

[0060] The adhesive member 43d is disposed on the arrangement surface 43c1 of the cover member 43c around the entire periphery of the RFID tag 43a, thereby ensuring watertightness between the cover member 43c and the outer surface of the housing 41 and preventing water from adhering to the temperature sensor 43b and the RFID tag 43a.

[0061] Next, the operation of the mechanical component 40 when an abnormality occurs in the bearing 42 will be described.

[0062] 1 conveys industrial products, a load acts on the bearing 42 from the shaft member 31 in the downward direction of gravity. The load from the shaft member 31 generates frictional forces between the balls 42c and the inner ring 42b and between the balls 42c and the outer ring 42a. If the frictional forces cause the condition of the bearing 42 to change progressively, abnormalities such as damage to the bearing 42 may occur. If the abnormality in the bearing 42 progresses, failures such as seizure of the bearing 42 may occur.

[0063] Furthermore, as the state of the bearing 42 continues to change due to the frictional force, the temperature of the bearing 42 increases. The part of the bearing 42 where the temperature is the greatest is the same as the part where the frictional force is the greatest, i.e., the part where the load from the shaft member 31 is the greatest.

[0064] The load of the shaft member 31 is transmitted to the housing 41 via the bearing 42. The part of the housing 41 where the stress generated by the force acting from the bearing 42 is greatest corresponds to the part that comes into contact with the part of the bearing 42 where the load acting from the shaft member 31 is greatest.

[0065] Furthermore, the heat of the bearing 42 is transferred to the housing 41. The part of the housing 41 where the temperature is the highest corresponds to the part of the housing 41 that comes into contact with the part of the bearing 42 where the temperature of the bearing 42 is the highest.

[0066] As described above, the part of the bearing 42 where the temperature is the highest is the same part where the load from the shaft member 31 is the greatest. Therefore, the part of the housing 41 where the temperature is the highest is the same part where the stress generated by the force acting from the bearing 42 is the greatest. Therefore, the temperature of the part of the housing 41 where the stress generated by the force acting from the bearing 42 is the greatest rises earlier than the temperature of other parts.

[0067] In this embodiment, a load in the downward direction of gravity (toward the −Z side along the Z direction) acts on the bearing 42 from the shaft member 31. Therefore, the part of the housing 41 where the stress generated by the force acting from the bearing 42 is greatest is the part on the −Z side of the axis Ax.

[0068] As described above, the temperature detection device 43 is located in the arrangement region R1 on the front surface F2 of the housing 41, on the −Z side of the axis Ax of the bearing 42. In other words, when the housing 41 is viewed along the axial direction of the bearing 42, the temperature detection device 43 overlaps with the part of the housing 41 where the stress generated by the force acting from the bearing 42 is greatest.

[0069] Therefore, when the temperature of the bearing 42 and the temperature of the housing 41 rise due to the load from the shaft member 31, the detected temperature of the temperature detection device 43 rises early in response to the rise in temperature of the housing 41 because it is located in the above-mentioned placement area R1.

[0070] As described above, the temperature detected by the temperature detector 43 is stored in the terminal device 4 via the reader / writer 3. Furthermore, if the temperature detected by the temperature detector 43 is equal to or higher than a predetermined temperature, the terminal device 4 determines that there is an abnormality in the bearing 42. Therefore, by positioning the temperature detector 43 in the above-described arrangement region R1, an abnormality in the bearing 42 can be detected early.

[0071] As described above, according to this embodiment, the mechanical component 40 includes the housing 41, the bearing 42 disposed in the housing 41 and rotatably supporting the shaft member 31 relative to the housing 41, and the temperature sensor 43b disposed on the outer surface of the housing 41 and detecting the temperature of the housing 41. When the housing 41 is viewed along the axial direction of the bearing 42, the temperature sensor 43b overlaps with the portion of the housing 41 where the stress generated by the force acting from the bearing 42 is greatest. This arrangement simplifies the configuration within the housing 41 and the configuration of the mechanical component 40. Furthermore, as the load from the shaft member 31 causes a change in the state of the bearing 42, the temperature rises in the portion where the change in state is occurring. The heat from the bearing 42 is transferred to the housing 41. The temperature of the portion of the housing 41 in contact with the portion of the bearing 42 where the change in state is occurring rises earlier than that of other portions of the housing 41. Furthermore, the portion of the housing 41 that comes into contact with the portion of the bearing 42 where the state change is progressing corresponds to the portion where the stress generated by the force acting from the bearing 42 is greatest. Therefore, the temperature detected by the temperature sensor 43b rises early in response to the temperature rise of the bearing 42 and the housing 41. Therefore, the mechanical component 40 can contribute to early detection of an abnormality in the bearing 42 by the temperature detected by the temperature sensor 43b.

[0072] Furthermore, the axis Ax of the bearing 42 is inclined with respect to the direction of gravity when the housing 41 is attached to the support base 10. When the housing 41 is viewed along the axial direction of the bearing 42 with the housing 41 attached to the support base 10, the temperature sensor 43b is located below the axis Ax of the bearing 42 in the direction of gravity. Accordingly, the portion of the housing 41 located below the axis Ax of the bearing 42 in the direction of gravity corresponds to the portion where the stress generated by the force acting from the bearing 42 is greatest. Therefore, the detected temperature of the temperature sensor 43b reliably rises early when the temperature of the bearing 42 rises. Therefore, the mechanical component 40 can reliably contribute to early detection of an abnormality in the bearing 42 by the detected temperature of the temperature sensor 43b.

[0073] The mechanical component 40 also includes an RFID tag 43a that is integrated with a temperature sensor 43b and transmits the temperature detected by the temperature sensor 43b to the reader / writer 3. This allows the mechanical component 40 to output the temperature detected by the temperature sensor 43b with a simple configuration.

[0074] Next, a monitoring system 1 and a mechanical component 40 according to a modified example of the embodiment of the present disclosure will be described, focusing mainly on the differences from the monitoring system 1 and the mechanical component 40 of the above-described embodiment.

[0075] For example, the mechanical device 2 is not limited to a roller conveyor, but may be any device that includes a plurality of mechanical components 40 each including a bearing 42.

[0076] Furthermore, the mechanical component 40 is not limited to a plummer block, but may be any mechanical component that includes a bearing 42.

[0077] The RFID tag 43a may also be an active RFID tag, in which case the RFID tag 43a further includes a power source.

[0078] The adhesive member 43d may also be elastic. In this case, the adhesive member 43d includes, for example, an elastic sheet-like base material and adhesive layers disposed on both sides of the base material. The base material is formed of, for example, a foamed resin such as foamed polyethylene. When the mechanical device 2 is operating, the elasticity of the adhesive member 43d can suppress vibrations transmitted from the housing 41 to the temperature sensor 43b and the RFID tag 43a.

[0079] The adhesive member 43d may be a hardened adhesive (for example, an epoxy adhesive) or a butyl tape that is waterproof and oil-resistant.

[0080] The temperature detector 43 may not include the adhesive member 43d. In this case, the temperature detector 43 is fixed to the housing 41 by, for example, a bolt.

[0081] The cover member 43c may be shaped to cover a part of the main surface 43a2 of the substrate 43a1 while exposing the temperature sensor 43b.

[0082] Furthermore, the arrangement region R1 may be located on the front surface F2 of the housing 41 at a position other than the -Z side of the axis Ax of the bearing 42. As described above, when the housing 41 is viewed along the axial direction of the bearing 42, the temperature sensor 43b overlaps with a portion of the housing 41 where the stress generated by the force acting from the bearing 42 is greatest. For example, the position of the arrangement region R1 on the front surface F2 of the housing 41 varies depending on the orientation of the mechanical component 40 attached to the support base 10. For example, when the mechanical component 40 is attached to the support base 10, if the attachment surface F1 is perpendicular to the direction of gravity and faces upward in the direction of gravity, the arrangement region R1 is located on the +Z side of the axis Ax of the bearing 42 on the front surface F2 of the housing 41. Furthermore, the position of the arrangement region R1 on the front surface F2 of the housing 41 varies depending on the direction of the load acting from the shaft member 31 on the bearing 42. For example, when the direction of the load acting on the bearing 42 from the shaft member 31 is from the −X side to the +X side along the X direction, the arrangement region R1 is located on the +X side of the axis Ax of the bearing 42 on the front surface F2 of the housing 41, regardless of the attitude of the mechanical component 40. Note that the mechanical component 40 may be attached to the support base 10 with the axis Ax of the bearing 42 extending in the direction of gravity.

[0083] FIG. 7 is a cross-sectional view of a temperature detection device 43 in a mechanical component 40 according to a first modified example of the embodiment of the present disclosure.

[0084] The mechanical component 40 according to the first modification further includes a thermally conductive paste 143g. The thermally conductive paste 143g is, for example, a silicon-based thermally conductive grease. Needless to say, the thermally conductive paste 143g is not limited to a silicon-based paste, and any paste-like material may be used. The thermally conductive paste 143g may also be a thermosetting resin (for example, an epoxy resin) containing particles of Ag or other materials with a relatively high thermal conductivity.

[0085] The thermally conductive paste 143g is filled into the third through hole 43d1 with the temperature detection device 43 disposed in the housing 41. As a result, the temperature sensor 43b and the housing 41 are thermally connected via the thermally conductive paste 143g.

[0086] In the mechanical component 40 according to the first modification, heat from the housing 41 is more efficiently transferred to the temperature sensor 43b via the thermally conductive paste 143g than in the mechanical component 40 according to the above embodiment.

[0087] 8 is a cross-sectional view of a temperature detection device 43 in a mechanical component 40 according to a second modified example of the embodiment of the present disclosure. In this second modified example, the adhesive member 243d does not have a third through-hole 43d1. The adhesive member 243d covers the entire RFID tag 43a. As a result, the temperature sensor 43b is covered by the adhesive member 243d. As a result, the temperature sensor 43b and the housing 41 are thermally connected via the adhesive member 243d.

[0088] In the mechanical component 40 according to the second modification, heat from the housing 41 is more efficiently transferred to the temperature sensor 43b via the adhesive member 243d than in the mechanical component 40 according to the above embodiment. The adhesive member 243d may contain particles of Ag or other materials with relatively high thermal conductivity. In this case, heat from the housing 41 is more efficiently transferred to the temperature sensor 43b via the adhesive member 243d.

[0089] 9 is a cross-sectional view of a temperature detection device 43 in a mechanical component 40 according to a third modified example of the embodiment of the present disclosure. In this third modified example, the housing 41 has a recess 341a3 into which the temperature sensor 43b fits. The shape of the recess 341a3 is not particularly limited as long as it can accommodate the temperature sensor 43b. The shape of the recess 341a3 is preferably such that the temperature sensor 43b is in close proximity to but not in contact with the recess 341a3 even when the mechanical component 40 is in operation. The recess 341a3 may be filled with the above-mentioned thermally conductive paste 143g.

[0090] 9, the adhesive member 43d is omitted. In the third modified example, the adhesive member 43d may be, for example, a cured cyanoacrylate adhesive. In this case, the thickness of the adhesive member 43d can be reduced.

[0091] In the mechanical component 40 of the third modified example, the temperature sensor 43b is located inside the recess 341a3, so that the temperature sensor 43b can detect the temperature of the housing 41 with higher accuracy.

[0092] 10 is a cross-sectional view of a temperature detection device 444 in a mechanical component 40 according to a fourth modified example of the embodiment of the present disclosure. The temperature detection device 444 of the fourth modified example does not include an RFID tag 43a or a cover member 43c. The temperature detection device 444 of the fourth modified example includes a substrate 444a, a temperature sensor 444b, and an adhesive member 444c. The temperature sensor 444b is disposed on a main surface 444a1 of the substrate 444a. The substrate 444a includes a terminal that outputs the detected temperature of the temperature sensor 444b.

[0093] In this case, the monitoring system 1 does not include the reader / writer 3, and the terminal device 4 acquires the temperature detected by the temperature sensor 444b by electrically connecting to the terminal of the board 444a. The board 444a may also include a display unit that displays the temperature detected by the temperature sensor 444b. In this case, the user may check the temperature detected by the temperature sensor 444b on the display unit and input it into the terminal device 4.

[0094] The adhesive member 444c adheres the substrate 444a to the housing 41. The adhesive member 444c is, for example, a double-sided tape. The temperature detection device 444 may include a cover member that protects the substrate 444a.

[0095] REFERENCE SIGNS LIST 1 Monitoring system 2 Mechanical device 3 Reader / writer 4 Terminal device 10 Support base (mounted member) 31 Shaft member 40 Mechanical part 41 Housing 42 Bearing 43a RFID tag 43b Temperature sensor Ax Axis of bearing

Claims

1. A mechanical component comprising: a housing; a bearing disposed in the housing and supporting a shaft member rotatably relative to the housing; and a temperature sensor disposed on the outer surface of the housing and detecting the temperature of the housing, wherein when the housing is viewed along the axial direction of the bearing, the temperature sensor overlaps with a portion of the housing where the stress generated by the force acting from the bearing is greatest.

2. A mechanical component as described in claim 1, wherein the axis of the bearing is inclined with respect to the direction of gravity when the housing is attached to the workpiece, and when the housing is viewed along the axial direction of the bearing with the housing attached to the workpiece, the temperature sensor is located below the axis of the bearing in the direction of gravity.

3. The mechanical part according to claim 1, further comprising an RFID tag that is integrated with the temperature sensor and transmits the temperature detected by the temperature sensor to a reader / writer.

4. A monitoring system comprising: a mechanical device including a plurality of mechanical parts as claimed in claim 3; the reader / writer; and a terminal device electrically connected to the reader / writer and storing the temperature detected by the temperature sensor.

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