Crawler undercarriage roller assembly with temperature monitoring

Abstract

A tracked undercarriage roller assembly (17) comprising: a roller body (18) having a through cavity (19) delimited by a radially inner surface (20); a shaft (22) inserted into the through cavity (19) of the roller body (18); a bushing (32) extending from a first axial end (32a) to a second axial end (32b) and radially interposed between the roller body (18) and the shaft (22); an annular chamber (34) at least partially filled with a lubricant and radially interposed between the shaft (22) and the bushing (32); a housing seat (37) obtained in the shaft (22) and comprising an inlet portion (39) facing an axial end surface (22d) of the shaft (22) and a measuring portion (40) placed inside the shaft (22) in an axial position between the first axial end (32a) and the second axial end (32b) of the bushing (32), wherein the inlet portion (39) and the measuring portion (40) are aligned with each other along the axial direction. A temperature transducer (41) is placed inside the housing seat (37) at the measuring portion (40), wherein the measuring portion (40) is placed at a radial distance of 8 mm to 50 mm from the bushing (32).

Description

Technical Field

[0001] The present invention relates to a tracked underframe roller assembly with temperature monitoring, i.e., a tracked underframe roller assembly whose operating temperature is monitored. Background Technology

[0002] Tracked underframes are typically used to operate machinery such as earthmoving machinery, mining machinery, and crushing machinery, to allow the machinery to move frequently on uneven ground or with poor grip.

[0003] Tracked underframes typically include two chain assemblies spaced apart and arranged parallel to each other, configured to receive drive torque and transmit it to the ground. Each chain assembly includes multiple underframe components, which typically include a closed-loop chain on a drive wheel and an idler wheel (or idler paddle) operably connected to a tensioner assembly. The underframe components further include multiple roller assemblies between the drive wheel and the idler wheel, configured to guide the chain during movement. The roller assemblies typically include one or more upper roller assemblies and multiple lower roller assemblies.

[0004] Chains typically consist of multiple links, where a link is an individual component of the chain that is hinged to other components. Typically, each link consists of a pair of plates facing each other. The links are interconnected by pins. Each pin is usually inserted into a hole set in one of the plates and connects the two links together.

[0005] The grounding contactor is typically mounted on a chain link and makes direct contact with the ground. Its function is to release traction to the ground and increase the contact surface between the machine and the ground. The type of grounding contactor used depends on the ground surface where the machine will operate, the environmental conditions in which the machine will operate, and the specifications recommended by the machine manufacturer.

[0006] Each roller assembly typically includes a roller body through which a shaft passes. The roller assembly is defined by a radially inner surface facing the shaft, and more particularly by an outer surface facing the shaft. The roller body is rotatable about the shaft, which is fixed relative to a base mounted on the base. The roller assembly includes a bushing fitted onto the outer surface of the shaft to be inserted between the shaft and the inner surface of the roller body. The roller body and shaft are made of metal, typically steel, and the bushing is configured to reduce friction between the roller body and the shaft. The bushing is typically made of a non-ferrous material (such as bronze) or a bimetallic alloy and is lubricated to further reduce friction between the bushing contact surfaces and the roller body and / or between the bushing and the shaft.

[0007] The underframe is typically subjected to very harsh operating conditions, which can stem from the machine’s total weight, the high power transmitted from the machine’s engine to the ground, and / or the construction and composition of the terrain on which the machine must operate.

[0008] In particular, the applicant has observed that some underframe components are subjected to high stress during operation of large earthmoving machinery. A particularly critical underframe component is the lower roller assembly, which absorbs loads transmitted by the machine and serves as a guide chain. Typically, large excavators have multiple lower roller assemblies, for example, 8 to 32. When the excavator moves, the lower roller assemblies rotate, causing a significant increase in internal temperature, which may reach a critical value that affects the functional integrity of these components.

[0009] The applicant has noted that improper lubrication of the bushing increases friction, which can lead to damage to the roller assembly due to bushing wear (which gradually reduces in thickness), or cause the bushing to grip on the shaft and / or the roller body.

[0010] The applicant has noted that by measuring the bushing temperature, it is possible to identify abnormal lubrication, particularly since the temperature of the lubricant increases with the increase of the bushing temperature.

[0011] US application 2013 / 0255354 discloses a monitoring device in a chassis assembly having a roller assembly including a shaft and a bushing. In one example, the monitoring device has a temperature sensor located inside the roller assembly to measure the bushing temperature. Specifically, an opening is provided in the shaft, formed parallel to the shaft to a depth sufficient to overlap with the bushing, and has an outwardly oriented portion reaching the outer surface of the shaft. The temperature sensor is inserted into the opening and is arranged in the portion oriented towards the shaft surface. The document mentions that the output signal is transmitted to a computer via a wireless transmitter, or the data is accessed via a port connected to the monitoring device.

[0012] The applicant has observed that the opening in the shaft leading to the outer surface of the shaft allows the temperature sensor to be positioned in direct or substantially direct contact with the bushing, thereby effectively measuring the temperature of the bushing.

[0013] However, the applicant has demonstrated that such an opening can cause lubricant to leak into the opening itself, potentially damaging the temperature sensor and reducing the amount of lubricant available between the bushing and the shaft. This second situation could even lead to premature degradation of the roller assembly due to lack of or insufficient lubricant.

[0014] The applicant has noted that indications of inadequate lubrication of the bushing can be related not only to the temperature of the bushing but also to the temperature of the shaft portion located near the bushing.

[0015] The applicant has observed that by arranging a temperature transducer in the shaft of the roller assembly such that the sensor is close to the bushing but not directly facing or in contact with it, it is possible to measure a temperature proportional to (although not precisely corresponding to) the actual temperature of the bushing, thereby allowing the identification of abnormal increases in bushing temperature. Summary of the Invention

[0016] This invention relates to a tracked underframe roller assembly, comprising:

[0017] A roller body having a cavity defined by a radially inner surface;

[0018] A shaft is inserted into the cavity of the roller body;

[0019] A bushing extends from a first axial end to a second axial end and is radially inserted between the roller body and the shaft;

[0020] An annular chamber, which is at least partially filled with lubricant and radially inserted between the shaft and the bushing;

[0021] A receiving seat is obtained in the shaft and includes an inlet portion facing the axial end face of the shaft and a measuring portion, the measuring portion being placed within the shaft in an axial position between a first axial end and a second axial end of the bushing, wherein the inlet portion and the measuring portion are aligned with each other along the axial direction;

[0022] A temperature transducer located inside the housing, at the measuring section;

[0023] The measuring part is placed at a radial distance of 8 mm to 50 mm from the bushing.

[0024] A housing is placed in the shaft, and a temperature transducer is inserted into the measuring portion of the housing so that the temperature of the shaft at the measuring portion of the housing can be detected.

[0025] As is known, the shafts of tracked underframe roller assemblies are typically made of ferrous alloys (such as steel), so the shafts have such thermal conductivity that the portion of the shaft placed near the bushing changes temperature as the bushing temperature changes.

[0026] The applicant has observed that, depending on the size of the roller assembly and the material actually used to manufacture the shaft, a radial distance from the bushing at a temperature of 8 mm to 50 mm allows for the detection of sudden or abnormal increases in bushing temperature.

[0027] An increase in temperature exceeding a predetermined threshold detected by the temperature transducer can be associated with an abnormal increase in the temperature of the bushing, which may be caused, for example, by leakage of lubricant from the annular chamber, excessive friction of the bushing on the shaft, or, in any case, by exceeding the bushing's functional range.

[0028] This allows for intervention to restore the function of the roller assembly before irreversible damage occurs.

[0029] Furthermore, by arranging the inlet portion to face the axial end face of the shaft, with the inlet portion and the measuring portion aligned between them along the axial direction, it is possible to prevent lubricant from leaking from the annular chamber toward the housing or toward the temperature transducer, since the housing is obtained entirely inside the shaft without any opening toward the bushing.

[0030] The lubricant can be, for example, lubricating oil or grease.

[0031] The terms “axial,” “axially,” “radial,” and “radially” are used with reference to the axis of rotation of the roller assembly.

[0032] Specifically, the terms "axial" and "axially" refer to a reference / quantity arranged / measured or extended in a direction parallel to or coinciding with the axis of rotation of the roller assembly.

[0033] The terms “radial” and “radially” refer to a reference / quantity arranged / measured or extended in a direction perpendicular to the axis of rotation of the roller assembly.

[0034] The terms “radial interior” and “radial exterior” refer to positions closer to or further away from the aforementioned axis of rotation, respectively.

[0035] The terms "axially inward / axially outward" refer to the positions of points that are closer to and further away from roller assemblies placed along the axis of rotation and equidistant from the axial ends of the shaft, respectively.

[0036] The term "transducer" refers to a device that interacts directly with the quantity being measured; that is, the first element of a measurement chain that converts a physical quantity into an electrical signal related to the quantity being measured.

[0037] Preferably, the measuring portion is placed at a radial distance of 10 mm to 40 mm from the bushing, and more preferably at 12 mm to 30 mm, for example, about 15 mm.

[0038] Preferably, the receiving seat is an axially symmetrical blind cavity with an axis of symmetry parallel to the axial direction.

[0039] Therefore, the housing can be obtained by piercing the shaft until the desired depth is reached for inserting the temperature transducer into the shaft.

[0040] Preferably, the blind cavity has a straight extension and does not include multiple deviated portions or branches that branch radially from an axis of symmetry parallel to the axial direction.

[0041] This prevents the housing from reaching the radial outer surface of the shaft or directly facing the bushing or the annular chamber containing the lubricant, thus avoiding possible leakage of lubricant from the annular chamber.

[0042] Preferably, the radial extension of the inlet portion is greater than the radial extension of the measuring portion.

[0043] Preferably, the inlet portion has a radial extension that is almost twice the radial extension of the measuring portion.

[0044] Preferably, an electronic sensor module is provided, configured to generate a measurement signal in wireless mode, the measurement signal including data representing temperature; the electronic sensor module is placed in the entrance portion of the housing.

[0045] Preferably, the electronic sensor module includes: circuit components, an electronic processor, a power supply, and a wireless transmitter operatively connected to the electronic processor to receive corresponding measurement signals including data representing temperature. The wireless transmitter generates corresponding measurement signals in wireless mode, these measurement signals including data representing temperature.

[0046] Preferably, the electronic processor of the electronic sensor module is configured to receive measurement signals from the temperature transducer.

[0047] For example, an operator far from the tracked vehicle with the roller assembly will be able to remotely view data related to the current temperature of the shaft portion near the bushing, which connects a mobile terminal or personal computer to a Wi-Fi network to which the electronic sensor module is connected.

[0048] Preferably, the inlet portion includes an annular groove engaged by a stop ring, the annular groove being axially located outside the electronic sensor module, such that the electronic sensor module is axially held in the inlet portion by the stop ring.

[0049] The electronic sensor module is thus held within the housing, thereby preventing potential damage to the electronic sensor module and ensuring its proper operation when the roller assembly is used.

[0050] Preferably, a sealing plug is provided for the entrance portion of the receiving seat. The sealing plug is preferably inserted axially between the stop ring and the electronic sensor module.

[0051] The sealing plug prevents liquids, mud, dirt, or other substances from entering the container.

[0052] Preferably, the stop ring is removable from the annular groove in the inlet portion of the receiver.

[0053] The retaining ring holds the plug in the operating position; however, it allows the plug to be removed if access to the housing is required to inspect or replace the temperature transducer and / or electronic sensor module.

[0054] Preferably, the temperature transducer is connected to the electronic sensor module via a wire.

[0055] Preferably, the temperature transducer is a thermistor with resistance, the resistance of which decreases as the temperature increases.

[0056] As the temperature of the shaft portion near the bushing increases, the resistance of the thermistor decreases. Therefore, in the event of a thermistor failure (such as in the case of electrical breakdown between the thermistor and the electronic sensor module), the detected resistance value will significantly deviate from the expected resistance value, thus providing an immediate indication of the thermistor failure.

[0057] Preferably, a pin is provided to be inserted into the radial cavity of the shaft so that the shaft is integrated with the base frame; the receiving seat does not cross the radial cavity of the shaft.

[0058] The pin has the following function: to engage the shaft to the base frame (or to a base component integrated with the base frame) to hold the roller assembly in place and allow the roller body to rotate about the shaft.

[0059] The pins are typically removable to remove the roller assembly from the undercarriage chassis.

[0060] If the temperature transducer is connected to the electronic sensor module via wires and if the housing crosses the pin, removing the pin will permanently damage the connection between the temperature transducer and the electronic sensor module because the pin will be pierced by the electrical connector. Furthermore, by preventing the housing from crossing the pin, positioning the temperature transducer within the housing can be performed even when the roller assembly is not yet mounted on the base frame.

[0061] Preferably, the roller body includes an opening that allows the external environment to be in fluid communication with an annular chamber filled with lubricant; the opening is closed by a plug. Attached Figure Description

[0062] Other features and advantages of the invention will become clearer from the following description of preferred embodiments of the invention with reference to the accompanying drawings. In these drawings:

[0063] Figure 1 This is a schematic side view of a tracked underframe;

[0064] Figure 2This is a cross-sectional view of the tracked underframe roller assembly according to the present invention;

[0065] Figure 2A yes Figure 2 Enlarged views of some details of the roller assembly;

[0066] Figure 3 yes Figure 2 A partially exploded perspective view of the roller assembly details; and

[0067] Figure 4 yes Figure 2 A schematic diagram of some components of the roller assembly. Detailed Implementation

[0068] Figure 1 This is a schematic side view showing some components of the tracked underframe. The tracked underframe 10 includes two track assemblies 11, in... Figure 1 Only one track assembly is visible in the figure. Each track assembly 11 includes a chain 12, a return wheel 14, and a drive wheel 16. The chain 12 includes multiple links 13 interconnected by pins and bushings (not shown). The return wheel 14 is partially hidden by the crankcase 15 in the figure. Multiple roller assemblies 17 are arranged between the return wheel 14 and the drive wheel 16. Specifically, one or more upper roller assemblies and multiple lower roller assemblies are arranged to contact the links 13 and adapt to guide the movement of the chain 12.

[0069] The lower roller assembly 17 is arranged in the lower part of the track assembly 11 and configured to transmit load between the track and the underframe (not shown). The upper roller assembly 17 is configured to guide the chain between the drive wheel 16 and the return wheel 14, and is typically present in a lower number than the lower roller assemblies. The number of lower roller assemblies 17 varies depending on the type and weight of the machine.

[0070] According to this disclosure, at least the lower or upper roller assembly 17 includes a sensor device for monitoring temperature.

[0071] Figure 2 This is a cross-sectional view of the roller assembly 17 according to an embodiment. In this embodiment, the roller assembly 17 is a roller assembly of the lower roller. The cross-section is a longitudinal plane that is transverse to the link 13 of the chain 11 and therefore transverse to the direction of movement of the tracked undercarriage, passing through the axis of rotation X of the roller assembly 17.

[0072] The roller assembly 17 includes a roller body 18, which includes a cylindrical cavity 19 extending from a first axial end 18a to a second axial end 18b.

[0073] The roller body 18 is defined by a radial inner surface 20 and a radial outer surface 21. The radial inner surface typically has a cylindrical shape facing the cylindrical cavity 19, and the shape of the radial outer surface is determined by the type of track 12 with which the roller assembly 17 must interact.

[0074] The roller body 18 is made of low-alloy steel, which is boron alloyed and has undergone at least heat treatment. Low-alloy steel is steel in which elements other than iron and carbon are present, and in which such other elements are not present in amounts higher than 5%.

[0075] The roller assembly 17 further includes a shaft 22 inserted into a cylindrical cavity 19 of the roller body 18. The shaft is substantially cylindrical in shape, extends between a first axial end 22a and a second axial end 22b, and has a radially outer surface 23 facing the radially inner surface 20 of the roller body 18.

[0076] Shaft 22 is preferably made of low alloy steel, which is boron alloyed and has undergone at least heat treatment.

[0077] The axial extension of shaft 22 is greater than the axial extension of roller body 18. In other words, the axial distance between the first axial end 22a and the second axial end 22b of shaft 22 is greater than the distance measured along the same direction between the first axial end 18a and the second axial end 18b of roller body 18.

[0078] Shaft 22 extends axially beyond the first axial end 18a and the second axial end 18b of roller body 18. Specifically, the axial extension beyond the first axial end 18a of roller body 18 is substantially equal to the axial extension of shaft 22 beyond the second axial end 18b of roller body 18, such as... Figure 2 As shown.

[0079] The shaft portion 22 extending outward from the first axial end 18a of the roller body 18 is integrated with the base frame or with the base frame component, which is integrated with the base frame.

[0080] For this purpose, a support member 24 is provided, which is integrated with the base frame or with a base component. The base component, integrated with the base frame, has an internal cavity 25 into which a shaft portion 22 is inserted. The internal cavity extends axially outward from the first axial end 18a of the roller body 18. Figure 2 As shown.

[0081] To integrate shaft 22 with support member 24, shaft 22 includes a radial cavity 26 that intersects shaft 22 in the radial direction. Two radially opposing through holes are formed in support member 24, which can be aligned between themselves and with the radial cavity 26 of shaft 22. Pin 27 is inserted into radial cavity 26, passing through radial cavity 26 and intersecting the two through holes of support member 24. Therefore, any axial movement of shaft 22 relative to support member 24 and any rotation about the axis of rotation X can be prevented.

[0082] Similarly, the shaft portion 22 extending axially outward from the second axial end 18b of the roller body 18 is integrated with the base frame or with a base component that is integrated with the base frame.

[0083] For this purpose, an additional support 28 is provided, which is integrated with the base frame or with a base component. This base component has an internal cavity 29 into which the shaft portion 22 is inserted. The internal cavity extends axially outward from the second axial end 18b of the roller body 18. Figure 2 As shown.

[0084] To integrate shaft 22 with the additional support member 28, shaft 22 includes a radial cavity 30 that intersects shaft 22 in the radial direction. Two radially opposing through holes are formed in the additional support member 28, which can be aligned between themselves and with the radial cavity 30 of shaft 22. An additional pin 31 is inserted into the radial cavity 30 such that it passes through the radial cavity 30 and intersects with the two through holes of support member 28. Therefore, any axial movement of shaft 22 relative to the additional support member 28 and any rotation about the axis of rotation X can be prevented.

[0085] The roller body 18 is rotatable relative to the shaft 22 about the rotation axis X. To reduce friction between the roller body 18 and the shaft 22, a bushing 32 is provided, which is radially inserted between the roller body 18 and the shaft 22, such as... Figure 2 As shown in the image.

[0086] The bushing 32 is made of brass, bronze, copper, or other preferred metal material, which is more malleable than the material used to manufacture the shaft 22 and the roller body 18. The bushing material 32 also has good thermal conductivity, for example, above 15 W / m℃.

[0087] In a preferred embodiment of the invention, the bushing 32 rotates integrally with the roller body 18 and thus rotates relative to the shaft 22.

[0088] like Figure 2As shown, the bushing 32 extends through an axial extension of the roller body 18 between a first axial end 32a and a second axial end 32b. The bushing 32 includes a radially inner surface 33 directly facing the shaft 22. An annular cavity 34 is defined between the radially inner surface 33 of the bushing 32 and the radially outer surface 22c of the shaft 22. The annular cavity 34 is filled with a lubricant (such as oil or grease) to further reduce friction between the shaft 22 and the bushing 32.

[0089] The annular shaft 34 is in fluid communication with a reservoir 35 obtained in the roller body 18 through one or more radial holes 33a in the bushing 33. The reservoir 35 also has an annular shape and is in fluid communication with a channel (not shown) obtained in the roller body 18, the channel extending radially between the reservoir 35 and the radially outer surface 21 of the roller body 18. The channel serves to allow lubricant to be introduced into the reservoir 35 and thus into the annular chamber 34. The channel is sealed by a leak-proof plug (not shown).

[0090] At the first annular end 18a and the second annular end 18b of the roller body 18, corresponding hydraulic sealing rings 36 are arranged to prevent lubricant leakage between the bushing 33 and the supports 24, 28 of the shaft 22. At two portions of the shaft 22 extending axially outward from the first axial end 18a and the second axial end 18b of the roller body 18, corresponding hydraulic sealing washers are further provided, which are placed between the shaft 22 and the supports 24, 28 to prevent lubricant leakage between the shaft 22 and the supports 24, 28.

[0091] The receiving seat 37 is obtained inside the shaft 22 and is defined by a blind cavity 38 in the shaft 22. The blind cavity 38 has an axially symmetrical portion about an axis of symmetry parallel to the axis of rotation X.

[0092] The receiving seat 37 extends axially downward from the inlet portion 39 to the measuring portion 40. The inlet portion 39 is positioned at the axial end face 22d of the shaft 22, which is situated within the first axial end portion 22a of the shaft 22. The inlet portion 39 is open to define an opening for the cavity 38.

[0093] The measuring part 40 is placed deep downward inside the shaft 22, specifically axially positioned at the bushing 32. For example... Figure 2 As shown, the measuring part 40 is axially positioned between the first axial end 32a and the second axial end 32b of the bushing 32.

[0094] The inlet portion 39 and the measuring portion 40 are aligned along the axial direction, such that the blind cavity 38 is parallel to the axis of rotation X.

[0095] The measuring portion 40 is spaced apart from the radial outer surface 23 of the shaft 22 in the radial direction. The measuring portion 40 does not contact the radial outer surface 23 of the shaft 22 and is not open on the radial outer surface 23 of the shaft 22.

[0096] like Figure 2A As better shown, the measuring portion 40 is placed at a radial distance RD of 8 mm to 50 mm from the bushing 32.

[0097] The radial distance RD is measured in the radial direction between a point in the inner cavity 38 that is radially closer to the bushing 32 and the radial inner surface 33 of the bushing 32, such as... Figure 2A As shown in the image.

[0098] Temperature transducer 41 is inserted into the measuring portion 40 of the housing 37.

[0099] Temperature transducer 41 is configured to generate an electrical signal representing the measured temperature. For example, temperature transducer 41 is a thermal probe, preferably an NTC (Negative Temperature Coefficient) probe, which causes resistance to decrease as temperature increases. Preferably, temperature transducer 41 is adapted to measure temperatures up to about 200°C.

[0100] An electronic sensor module 42 is arranged in the inlet section 39. The electronic sensor module 42 is configured to generate measurement signals in a wireless mode. These measurement signals include data representing temperature as measured by the temperature transducer 41.

[0101] As in Figure 2A As better shown in the diagram, the inlet portion 39 has a radial extension that is greater than the radial extension of the measuring portion 40, in order to accommodate the electronic sensor module 42.

[0102] In a preferred embodiment of the invention, the radial extension of the inlet portion 39 is approximately twice the radial extension of the measuring portion 40.

[0103] The axial extension of the inlet portion 39 is chosen to be substantially accommodated by mounting the electronic sensor module 42.

[0104] The electronic sensor module 42 and the temperature transducer 41 are electrically connected by a wire 43.

[0105] As in Figure 4 As schematically shown, the electronic sensor module 42 includes a connector 44 for connection to a wire 43.

[0106] The sensor electronics module 42 includes a circuit component 45 operatively connected to a wire 43 to capture signals from a temperature transducer 41 and generate an output electrical signal representing the measured temperature.

[0107] The circuitry 45 of the electronic sensor module 42 includes circuitry for managing signals from the temperature transducer 41. This circuitry may include conditioning circuitry for the analog signals from the temperature transducer 41 and a possible amplifier for converting the input signals into voltage or current, analog or digital output signals. Typically, the electrical signals output from the circuitry are digital electrical signals. For this purpose, the circuitry 45 may include an analog-to-digital converter (A / D). The electrical signals output from the first circuitry include data representing instantaneous temperature measured by the temperature transducer 41 in shaft 22.

[0108] The electronic sensor module 42 includes an electronic processor 46, particularly a microprocessor, which is associated with a memory that receives measurement signals from circuit components 45 and stores these measurement signals to transmit them to a wireless transmitter 47 for wireless transmission via an antenna 48.

[0109] Wireless transmitter 47 is configured to generate radio frequency (RF) signals. Specifically, wireless transmitter 47 is an RF transmitter configured to receive a measurement signal including temperature data from processor 46 and generate a corresponding RF signal including temperature data. Wireless transmitter 47 is operatively connected to antenna 45 for transmitting RF signals.

[0110] The electronic sensor module 42 further includes a power source 49, such as a button battery, to power the circuit assembly 45 and the microprocessor 46.

[0111] Preferably, the electronic sensor module 42 is inserted into the container 50 arranged within the inlet portion 39 of the receiving seat 37, such as... Figure 2A As shown in the diagram. The container 50 provides greater protection for the circuit components and electronic devices included in the electronic sensor module 42. In a preferred embodiment, the container 50 is a vibration-absorbing synthetic rubber shell with a front opening 51 having an axially outer surface 22d facing the shaft 22. Figure 3 The container 50 may be filled with epoxy resin to further suppress external stress and prevent the electronic sensor module 42 from leaking.

[0112] The container 50 is sealed by a sealing plug 52, which preferably tightly seals the front opening 51 and fits into the inlet opening 39 of the receiving seat 37 to seal the blind cavity 38. The sealing plug 52 is made of a material that is transmissive to the transmission of radio signals via the antenna 48. The sealing plug 52 is axially located outside the electronic sensor module 42. The sealing plug 52 is axially outside the container 50.

[0113] The inlet portion 39 of the receiving seat 37 includes an annular groove 53 obtained in the blind cavity 38 and positioned at the surface 22d of the axial end 22a of the shaft 22. The annular groove 53 is configured to receive and retain a stop ring 54. The stop ring 54 is preferably made of steel and is an elastic ring, wherein the elasticity is given by the fact that the outer circumference of the ring is incomplete. The stop ring 54 is axially outside the electronic sensor module 42. The stop ring 54 is axially outside the sealing plug 52. The stop ring 54 is axially outside the container 50.

[0114] Starting from the axial inner position, a stop ring 54 is provided to be fitted in an annular groove 53 (the annular groove is placed in the same axial position as the stop ring 54), followed by a sealing plug 52, and then an electronic sensor module 42 housed in a container 50.

[0115] The receiving seat 39 extends in the radial direction to receive the stop ring 54, the sealing plug 52 and the container 50.

[0116] like Figure 2 and Figure 2A As shown, the receiving seat 37 does not intersect with the radial cavity 26, that is, it does not cross the radial cavity 26, which intersects the shaft 22 in the radial direction and receives the pin 27. The blind cavity 38 is not in fluid communication and does not cross the radial cavity 26, which intersects the shaft 22 in the radial direction and receives the pin 27.

[0117] Those skilled in the art will recognize that different features of the embodiments described above can be combined to obtain further embodiments, all of which fall within the scope of the invention as defined by the appended claims.

Claims

1. A tracked underframe roller assembly (17), comprising: Roller body (18) having a cavity (19) defined by a radial inner surface (20); Shaft (22), said shaft (22) is inserted into said cavity (19) of said roller body (18); Bushing (32), which extends from a first axial end (32a) to a second axial end (32b) and is radially inserted between the roller body (18) and the shaft (22); An annular chamber (34) is at least partially filled with a lubricant radially inserted between the shaft (22) and the bushing (32); A receiving seat (37) is obtained in the shaft (22) and includes an inlet portion (39) at the axial end face (22d) of the shaft (22) and a measuring portion (40), the measuring portion being placed within the shaft (22) at an axial position between the first axial end (32a) and the second axial end (32b) of the bushing (32), wherein the inlet portion (39) and the measuring portion (40) are aligned with each other in the axial direction; Temperature transducer (41), the temperature transducer (41) is located inside the housing (37) at the measuring part (40); The measuring part (40) is placed at a radial distance of 8 mm to 50 mm from the bushing (32).

2. The roller assembly (17) according to claim 1, wherein, The receiving seat (37) is an axially symmetrical blind cavity (38) with an axis of symmetry parallel to the axial direction.

3. The roller assembly (17) according to any one of the preceding claims, the roller assembly including an electronic sensor module (42) configured to output a measurement signal in a wireless mode, the measurement signal including data representing temperature; the electronic sensor module (42) being placed in the inlet portion (39) of the receiving seat (37).

4. The roller assembly (17) according to claim 3, wherein, The inlet portion (39) includes an annular groove (53) engaged by a stop ring (54), the annular groove (53) being axially located outside the electronic sensor module (42), such that the electronic sensor module (42) is axially held in the inlet portion (39) by the stop ring (54).

5. The roller assembly (17) according to claim 4, the roller assembly comprising a closure plug (52) for the inlet portion (39) of the receiving seat (37); the closure plug (52) being axially inserted between the stop ring (54) and the electronic sensor module (42).

6. The roller assembly (17) according to claim 1, wherein, The radial extension of the inlet portion (39) is greater than the radial extension of the measuring portion (40).

7. The roller assembly (17) according to claim 3, wherein, The temperature transducer (41) is connected to the electronic sensor module (42) via a wire (43).

8. The roller assembly (17) according to claim 1, wherein the roller assembly includes pins (27, 31) inserted into radial cavities (26, 30) of the shaft (22) to integrate the shaft (22) with the base chassis; and the receiving seat (37) does not intersect the radial cavities (26, 30) of the shaft (22).

9. The roller assembly (17) according to claim 1, wherein, The temperature transducer (41) is a thermistor with resistance, the resistance of which decreases as the temperature increases.

10. The roller assembly (17) according to claim 1, wherein, The roller body (18) includes an opening that allows the external environment to be in fluid communication with the annular chamber (34) filled with lubricant; the opening is closed by a plug.

Images