Work Machine Parts

Abstract

The invention describes a work machine part 40 having a cavity 42 formed in the part and having an extension axis A1, an opening 44 for the cavity 42 arranged on an outer surface 41 of the part, and a support 47 inserted in the cavity 42 with an axial extension axis B1 parallel to said extension axis A1 of the cavity 42. The support 47 has at a first axial end 47a a top surface 48 and at least one receiving seat 53 configured to receive a wear sensor 60. The receiving seat 53 has a top wall 54a arranged at a distance along the axial extension axis B1 from the top surface 48 of the support 53. The wear sensor 60 is received in the receiving seat 53.

Description

[Technical field]

[0001] The present invention relates to a component for a work machine, such as an earthmoving machine, a mining machine, or a demolition machine. [Background technology]

[0002] Such types of machines are typically mounted on a mobile structure known as a chassis to enable the machine to be moved over ground that is often uneven or loose.

[0003] The undercarriage typically has two chain assemblies that are spaced apart from one another, arranged in parallel, and configured to receive and transmit torque to the ground.

[0004] Each chain assembly includes a number of undercarriage pieces, typically having a closed loop chain on drive and idler wheels operatively connected to a tensioning section, and further including a number of rollers between the drive and idler wheels configured to guide the chain during its motion and to absorb loads transmitted by the machine.

[0005] A chain generally has a number of joints that are rotatably connected to each other at each end. Each joint has a pair of links facing each other. The links of each joint are generally interconnected by a pin and a bush. Each pin is generally inserted into a hole in the link to connect two links together. A bush is generally located radially outside the pin to separate the links of the joint from each other and protect the pin from the external environment and to mesh with the drive wheel. The joints are generally equipped with a sole that has the role of releasing traction to the ground by directly contacting the ground and increasing the contact surface between the machine and the ground. The type of sole used depends on the ground on which the machine needs to operate, the environmental conditions in which the machine needs to operate, and the specifications suggested by the machine manufacturer.

[0006] The undercarriage is typically subjected to extremely stressful operating conditions due to both the overall weight of the machine and the high power delivered to the ground by the machine's engine, as well as the influence of the topography and composition of the ground on which the machine will operate.

[0007] Thus, undercarriage components, such as buckets, rippers, loaders, bucket tines, loader tines, and other parts of the work machine, such as ripper tines, are subjected to high mechanical stresses that can result in damage and wear (or abrasion) to the components themselves.

[0008] Wear and tear is one of the factors that may result in downtime for repair intervention or replacement of parts of the work machine to ensure correct operation of the work machine.

[0009] The applicant has confirmed that accurate planning of machine downtimes allows the machine's performance in terms of production to be optimized. In particular, the applicant has confirmed that in order to optimize the productive performance of the working machine, the working machine should be stopped and undergo repair interventions or replacement of parts before wear phenomena cause the machine to break down, resulting in a forced and sudden stop. At the same time, the applicant has also confirmed that in optimizing the productive performance of the working machine, machine downtimes for repair or replacement of parts that are not effectively damaged or are not close to being effectively damaged cannot be predicted, since this would unduly lengthen the total machine downtime.

[0010] The applicant has noted that in order to be able to predict damage resulting from excessive wear of one or more parts of the work machine and to be able to avoid situations in which parts that still work properly have to be replaced or repaired, it is important to be able to know the current wear status of the parts, i.e. the parts that are most subject to wear.

[0011] Applicant has hypothesized that by knowing the average operating life of each part (in terms of machine operating hours) for each type of machine and part, and for each type of machine operating condition, and using statistical considerations of the wear rates of the parts, it may be possible to predict the wear conditions of work machine parts.

[0012] However, the Applicant has determined that such statistical considerations are unreliable, since there are too many variables to take into account, often interrelated, in order for significant data to be obtained and for the wear state of each component to be able to be effectively estimated.

[0013] The applicant has therefore realised that in order to be able to effectively predict damage and at the same time reduce the number of machine downtimes to a minimum and ensure the correct operation of the machine, it is appropriate for the wear state of one or more parts of the working machine to be directly measurable.

[0014] Therefore, the applicant has attempted to perform periodic reviews of the wear status of the parts through visual or instrumental inspection of the parts by qualified personnel.

[0015] The Applicant has determined that for obvious safety reasons, such periodic inspections require interruption of machine operation with limited but necessary machine downtime required to carry out the inspections.

[0016] Furthermore, based on the applicant's experience, visual or instrumental inspection of parts, such as for example undercarriage parts, is not always possible, as such parts may not be directly accessible (e.g., if there are pins or elements inside the rollers) or may be covered with mud, dirt, etc., which are very often present in a typical machine operating environment.

[0017] US 2015 / 0081166 describes a system for monitoring wear of an undercarriage component having a sensor device with a probe configured to measure information regarding the wear. The probe may be a resistor having one or more resistors configured to vary a resistance value associated with the probe as the probe wears. The variation in resistance value is associated with an amount of material removed from the undercarriage component due to wear. The probe is positioned in proximity to or in contact with the undercarriage component.

[0018] On behalf of the same applicant, document WO 2021 / 105941 describes a work machine part having a cavity formed in the part, having an extension axis and bounded by a side wall, an opening for the cavity arranged on an outer surface of the part, a wear sensor housed in the cavity and having a first axial end arranged in the opening for the cavity, and a support inserted into the cavity with the first axial end aligned with the first axial end of the wear sensor. The support is connected to the side wall of the cavity and is constrained to the side wall of the cavity. The wear sensor is physically connected to the support and is constrained to the support in at least the axial direction.

[0019] Applicant believes that systems such as those described in U.S. Patent Application Publication No. 2015 / 0081166 and WO 2021 / 105941 can provide an indication of the current wear condition of work machine components.

[0020] The applicant has noted that wear sensors such as those described in WO 2021 / 105941 must be constantly and directly exposed to erosive agents along with the work machine component whose wear state is being monitored in order to wear and provide a corresponding electrical signal indicative of the degree of wear. [Prior art documents] [Patent documents]

[0021] [Patent Document 1] US Patent Application Publication No. 2015 / 0081166 [Patent Document 2] International Publication No. 2021 / 105941 Summary of the Invention

[0022] Applicant has noted, however, that wear sensors are inherently much less tolerant to wear than the work machine components whose wear conditions are being monitored.

[0023] Furthermore, based on the applicant's experience, the wear sensor is precisely designed to wear out immediately when exposed to erosive forces that cause wear of mechanical parts, such as debris, stone chips, or other objects of various natures, shapes, and sizes.

[0024] However, the applicant has discovered that in some unfavorable cases, when the erosive forces causing wear to the mechanical component reach the wear sensor, the wear sensor may be eroded further than the mechanical component and may actually wear out before the mechanical component, resulting in an overestimation of the actual wear status of the work machine component.

[0025] Accordingly, applicant has realised that in order to obtain a reliable and reliable indication of the wear condition of a work machine component, it is necessary to ensure that the wear sensor is not able to wear out prior to the work machine component whose wear condition is being monitored.

[0026] The applicant has discovered that by exposing the wear sensor to erosive forces that cause wear of the work machine component only when such erosive forces actually wear the machine component, the wear sensor will be prevented from wearing out before the work machine component.

[0027] SUMMARY OF THE DISCLOSURE Accordingly, the present invention is directed to a work machine component having a cavity formed in the component and having an elongated axis, and an opening for the cavity located on an exterior surface of the component.

[0028] A support is provided having an axial extension axis parallel to the extension axis of the cavity, inserted into the cavity, and having an upper surface at a first axial end.

[0029] The support has at least one housing seat cavity formed therein and configured to receive a wear sensor, the housing seat having an upper wall spaced apart from an upper surface of the support along the axial extension axis.

[0030] The wear sensor is housed in the housing seat.

[0031] The applicant has determined that wear on the surface of the work machine component causes wear on the support. The applicant has realized that by providing a seat for the wear sensor, which has an upper wall, the wear sensor is not exposed to erosive forces as long as such an upper wall of the seat is present. Only when the upper wall of the seat is eroded due to wear is the wear sensor exposed to erosive forces and capable of being worn away, providing an indication of the wear status of the work machine component.

[0032] Therefore, the wear sensor cannot provide any incidental signal of wear, since it can only be exposed to erosive forces when the actual wear threshold of the work machine component is reached.

[0033] The term "work machine part" or "part" means a part of a work machine that is subject to loads, stresses, and strains that can cause wear to the part itself. Examples of work machine parts are buckets, rippers, loaders, bucket tines, loader tines, ripper tines, and undercarriage parts.

[0034] The term "chassis part" means any one of the following chassis parts: drive wheel, idler wheel, pin, bushing, link, link plate, roller, or bottom.

[0035] The cavity in the part has an elongation axis along which the cavity is formed. Such elongation axis may coincide with the axis of symmetry of the cavity if the cavity is substantially cylindrical.

[0036] The terms "axial," "axially," "radial," "radially," "circumferential," and "circumferentially" are used with reference to the support.

[0037] In particular, the terms "axial" and "axially" are meant as a measure / size disposed / measured or extending in a direction substantially parallel to the elongated axis of the support.

[0038] The terms "radial" and "radially" are meant as a reference / size disposed / measured or extending in a direction substantially perpendicular to an elongated axis of the support and lying in a plane perpendicular to such elongated axis.

[0039] The terms "circumferential" and "circumferentially" are meant as a measure / size disposed / measured or extending in a substantially angular direction about an axis of extension of the support and lying in a plane perpendicular to such axis of extension.

[0040] The terms "radially inner / outer" are meant as closer or further away, respectively, from said axis of extension of the support.

[0041] Preferably, the axis of extension of the support is perpendicular to the surface of the work machine component being monitored for wear.

[0042] The term "sensor" is meant as a device that directly interacts with the system being measured, i.e., the first element in the measurement chain that converts a process variable into a measurable signal.

[0043] The term "wear" refers to the gradual loss of material from the surface of a body. When referring to a part, the term refers to the gradual loss of material from the surface of the part.

[0044] The expression "mechanical properties", when referring to a body or structure, means at least one of mechanical resistance (defined as the ability to withstand static stress), resilience (defined as the ability to withstand dynamic stress), hardness (defined as the resistance to localized plastic deformation), and fatigue resistance (defined as the ability to withstand cyclic stress).

[0045] The present invention may have at least one of the following preferred features.

[0046] Preferably, the accommodating seat has an abutment wall facing in the direction of the first axial end, and the wear sensor has a measuring portion arranged axially between the upper wall and the abutment wall.

[0047] The applicant has found that following wear of the upper wall of the receiving seat and the resulting exposure of the wear sensor to the external environment, the wear sensor may be accidentally moved inside the receiving seat before indicating wear of the component. This possibility makes the detection of wear of the component less reliable. Providing abutment walls facing in the direction of the first axial end and arranging the measuring part of the wear sensor between the abutment walls makes it possible for the abutment walls to stop the measuring part during the detection of wear of the component.

[0048] Preferably, the abutment wall has an angle with respect to the axial extension axis between 45° and 135°, preferably between 60° and 120°, more preferably between 75° and 105°, even more preferably between 85° and 95°, such as 90°.

[0049] Preferably, the abutment wall is radially parallel to the top wall.

[0050] Therefore, as a result of wear of the upper wall, external forces apply stress to the measuring part that is in direct contact with the abutment wall.

[0051] Preferably, the measuring portion may be subject to wear.

[0052] Preferably, such a measurement sensor is configured to detect a state of wear of the work machine component directly as a result of degradation of the measurement part.

[0053] Preferably, the accommodating seat has a radial recess defined between an upper wall and an abutment wall, the radial recess extending radially toward the axial extension axis, and the measuring portion being inserted into the radial recess.

[0054] By inserting the measuring portion into the radial recess, the possibility of the measuring portion moving is reduced.

[0055] Preferably, the radial recess is a hole extending towards the axial extension axis.

[0056] Preferably, the hole is cylindrical.

[0057] Preferably, the bore extends radially to the axial extension axis.

[0058] Preferably, the receiving seat has an axial channel extending parallel to the axial extension axis from the radial recess to a second axial end of the support axially opposite the first axial end.

[0059] Preferably, said seat has an "L" shape, said axial channel and said radial recess forming respective lines of said "L" shape.

[0060] Preferably, said axial channel is a groove formed in a side surface of the support.

[0061] Preferably, the groove is axially straight.

[0062] Preferably, the seat has an edge between the radial recess and the axial channel.

[0063] Preferably, said edge is a sharp edge.

[0064] Preferably, said edge is defined between said abutment wall and said axial channel.

[0065] Preferably, said edge defines an angle comprised between 45° and 135°, preferably between 75° and 105°, even more preferably between 85° and 95°, in particular around 90°.

[0066] Preferably, said edge is defined between said abutment wall and an abutment wall of an axial channel.

[0067] Preferably, the wear sensor forms a curve at the edge.

[0068] The applicant has found that forming the curvature of the measurement sensor at the edge of the receiving seat serves to influence the measurable electrical characteristic of the measurement sensor when the support wears down to the abutment wall.

[0069] Preferably, the curved portion is formed between the conductive portion and the measuring portion.

[0070] Preferably, the receiving seat has a base opening.

[0071] Preferably, the base opening is located at the second end of the support.

[0072] Preferably, said base opening is perpendicular to said axial extension axis.

[0073] Preferably, the wear sensor comprises a conductive portion coupled to a measuring portion.

[0074] Preferably, said conductive portion is housed in said axial channel.

[0075] Preferably, the conductive portion extends through the base opening.

[0076] Preferably, said measuring portion extends radially.

[0077] Preferably, the conductive portion extends in an axial direction.

[0078] Preferably, the cavity has an internal thread.

[0079] Preferably, the support has an external thread.

[0080] Preferably, the external threads of the support are engaged with the internal threads of the cavity.

[0081] Preferably, the female and male threads are configured to allow the support to be screwed into the cavity up to the limit switch position.

[0082] Preferably the support is permanently retained in place in the cavity.

[0083] Preferably, said predetermined position corresponds to said limit switch position.

[0084] Preferably, the support has a handle configured to enable the support to be rotated within the cavity by a tool shaped corresponding to the handle.

[0085] Preferably, the operation portion has an operation recess that opens on the upper surface.

[0086] Preferably, the operating recess comprises a hexagonal hole.

[0087] Preferably, said top surface is aligned with an outer surface of the component.

[0088] Preferably, said upper surface is aligned with an outer surface of the component at a predetermined position on the support.

[0089] The support has a top surface which is aligned with the surface of the work machine part being monitored for wear, so that as the surface of the undercarriage part wears, the support also wears from its top surface.

[0090] Preferably, said upper wall is located a predetermined distance from an upper surface of the support along said axial extension axis.

[0091] The applicant has found that by positioning such an upper wall of the accommodating seat at a predetermined distance in the direction of the axial extension axis of the support, it is possible to select such predetermined distance to correspond to a predetermined degree of wear of the support (and therefore the work machine part) indicating replacement of the work machine part or any predetermined wear threshold of the work machine part.

[0092] Preferably, said top wall is located a predetermined distance from an outer surface of the component along said axial extension axis.

[0093] Preferably, said predetermined distance is measured at a predetermined location on the support.

[0094] Preferably, the predetermined distance of the upper wall from the upper surface of the support and / or the outer surface of the part is greater than 0.5 centimeters, preferably between 0.5 centimeters and 5 centimeters, preferably between 0.5 centimeters and 3 centimeters, preferably between 0.5 centimeters and 2 centimeters, for example 1 centimeter.

[0095] Preferably, the support has a plurality of receiving seats formed therein.

[0096] Preferably, a plurality of wear sensors are provided, each wear sensor of the plurality of wear sensors being inserted into a corresponding receiving seat.

[0097] Preferably, each wear sensor is connected to a device for processing or conditioning the signal coming from the wear sensor.

[0098] Preferably, each of the plurality of receiving seats has a respective upper wall spaced a distance along the axial extension axis from an upper surface of the support.

[0099] Preferably, each upper wall is located at a distance along said axial extension axis from an upper surface of the support and / or from an outer surface of the component.

[0100] Preferably, each of the plurality of receiving seats has an abutment wall facing towards the first axial end.

[0101] Preferably, each wear sensor of the plurality of wear sensors has a measuring portion arranged axially between an upper wall and an abutment wall of the respective receiving seat.

[0102] Preferably, each of the plurality of accommodating seats has a radial recess defined between a respective upper wall and a respective abutment wall, the radial recess extending radially toward the axial extension axis.

[0103] Preferably, the measuring portion of each wear sensor is inserted into a radial recess in the respective receiving seat.

[0104] Preferably, each of the plurality of receiving seats has a respective axial channel extending parallel to the axial extension axis from a respective radial recess towards a second axial end of the support axially opposite the first axial end.

[0105] Preferably, each axial channel is a groove formed in a side of the support.

[0106] Preferably, each wear sensor of the plurality of wear sensors has a respective conductive portion electrically connected to a respective measuring portion, and the conductive portion of each sensor is accommodated in an axial channel of a respective accommodation seat.

[0107] Preferably, the predetermined distances of the upper walls of the plurality of receiving seats are different from one another.

[0108] Preferably, the different predetermined distances are selected such that each predetermined distance corresponds to a predetermined degree of wear on the work machine component.

[0109] Preferably, at least one of said predetermined distances is selected to correspond to a predetermined maximum degree of wear on the work machine component.

[0110] Preferably, it is envisaged that the work machine part will be replaced when said maximum degree of wear of the work machine part has been reached.

[0111] Preferably, said maximum degree of wear of the work machine component is less than a detrimental degree of wear of the work machine component.

[0112] Preferably, each seat of the plurality of seats is spaced a certain distance in the circumferential direction from the other seats.

[0113] Preferably, each of the plurality of receiving seats is equidistant in the circumferential direction from two circumferentially adjacent receiving seats.

[0114] In one embodiment, the at least one receiving seat is a groove formed in a side surface of the support.

[0115] Preferably, each seat has said top wall and two side walls.

[0116] Preferably, each seat extends in the axial direction.

[0117] Preferably, the two side walls are substantially straight.

[0118] Preferably, each seat has a support wall bounded by said top wall and said two side walls.

[0119] Preferably, each of the receiving seats is open in the radial direction.

[0120] Preferably, each receiving seat is radially open along the entire extension of said two side walls.

[0121] Preferably, each receiving seat has a base opening on axially opposite sides of the top wall.

[0122] Preferably, each wear sensor is restrained in a respective receiving seat.

[0123] Preferably, each wear sensor is glued in its respective receiving seat.

[0124] Preferably, each wear sensor comprises a measuring portion which can be worn and which is arranged to change a measurable electrical characteristic of the wear sensor when it erodes.

[0125] Preferably, erosion of the wear sensor changes said measurable electrical property.

[0126] Preferably, the measurable electrical property may be electrical resistance, capacitance or inductance, considered individually or in combination.

[0127] Preferably, the measurable electrical property is electrical resistance.

[0128] Preferably, the mechanical properties of the support are different from the mechanical properties of the wear sensor.

[0129] Preferably, each wear sensor is an electrical conductor.

[0130] Preferably, the wear sensor is a single wire of conductive material.

[0131] Preferably, the wear sensor is a single wire of conductive material forming a U-bend in the top wall of the receiving seat.

[0132] Preferably, the measurement portion comprises the U-bend.

[0133] Preferably, when the support is worn away to the point where the top wall of the receiving seat is removed, said U-bend of the single wire of conductive electrical material is exposed to erosive forces.

[0134] Preferably, said single wire of conductive electrical material is configured to break at said U-bend when exposed to an erosive force.

[0135] Preferably, said single wire of conductive electrical material may comprise a single filament or multiple filaments woven or twisted together.

[0136] Preferably, said single wire of electrically conductive material comprises a sheath of electrically insulating material completely surrounding the filament or filaments of electrically conductive material.

[0137] Preferably, the ratio between the resistance to local plastic deformation of the material constituting the support and the resistance to local plastic deformation of the material of the part surrounding the cavity is less than 1.6, wherein the resistances to local plastic deformation of the support and the part are measured on the Brinell scale under the same test conditions, or the ultimate tensile strength of the material constituting the support is less than 160% of the ultimate tensile strength of the part surrounding the cavity.

[0138] One example of test conditions that can be used to measure hardness according to the Brinell scale can be found in standard ISO 6506-1:2015.

[0139] The resistance of a material to concentrated plastic deformation is its hardness.

[0140] If the hardness of the substrate (or part) cannot be measured on the Brinell scale using the same test conditions for measuring the hardness of the part (or substrate), or if it is not possible to accurately determine the hardness of the substrate or part using the Brinell scale, it is preferable to refer to the ratio between the ultimate tensile strength of the material constituting the substrate and the ultimate tensile strength of the material constituting the part in order to compare the two hardnesses.

[0141] The ultimate tensile strength for metallic materials is preferably determined in accordance with standard ISO 6892-1: 2016. The ultimate tensile strength for plastic or polymeric materials is preferably determined in accordance with standard ISO 527-1: 2019.

[0142] Applicants have found that if the hardness of the support is too high relative to the hardness of the part, the support (which will experience less wear against the outer surface of the part) may be exposed axially beyond the outer surface of the part.

[0143] Preferably, the ratio of the resistance to local plastic deformation of the material constituting the support to the resistance to local plastic deformation of the material of the part surrounding the cavity is 0.20 or more, more preferably 0.35 or more, more preferably 0.55 or more, more preferably 0.80 or more, more preferably 0.95 or more, wherein the resistances to local plastic deformation of the support and the part are measured using the Brinell scale under identical test conditions, or the ultimate tensile strength of the material constituting the support is 20% or more, more preferably 35% or more, more preferably 55% or more, more preferably 80% or more, more preferably 95% or more of the ultimate tensile strength of the material of the part surrounding the cavity.

[0144] Preferably, the ratio of the resistance to local plastic deformation of the material constituting the support to the resistance to local plastic deformation of the material of the part surrounding the cavity is 1.40 or less, more preferably 1.30 or less, more preferably 1.25 or less, more preferably 1.15 or less, more preferably 1.05, wherein the resistances to local plastic deformation of the support and the part are measured using the Brinell scale under the same test conditions, or the ultimate tensile strength of the material constituting the support is 140% or less, more preferably 130% or less, more preferably 125% or less, more preferably 115% or less, more preferably 105% or less of the ultimate tensile strength of the material of the part surrounding the cavity.

[0145] Preferably, the ratio between the resistance to local plastic deformation of the material constituting the support and the resistance to local plastic deformation of the material of the part surrounding the cavity is equal to 1, where the resistances to local plastic deformation of the support and the part are measured using the Brinell scale under identical test conditions, or the ultimate tensile strength of the material constituting the support is greater than or equal to 100% of the ultimate tensile strength of the part surrounding the cavity.

[0146] Preferably, the support is made of a metal. Examples of metals that can be used to make the support include steel, stainless steel, bronze, brass, cast iron, and aluminum alloys.

[0147] Preferably, the support and the part are made of the same material.

[0148] In some embodiments of the present invention, the support may be made of polymeric materials such as aliphatic polyamides (such as nylon and ertalon) and aromatic polyamides (such as Kevlar®).

[0149] In practice, the applicant has found that during normal use of the component, the support is subjected to dynamic loads (as well as static loads) which may cause undesirable vibrations in the support.

[0150] By constructing the support from a polymeric material, such vibrations can be reduced.

[0151] Preferably, the support has a radial cross-section taken along a radial plane passing through said upper surface and having an area less than or equal to an area subtended by the cavity in a cross-section taken along a radial plane passing through said opening to the cavity.

[0152] Preferably, the support has a radial cross-section, taken along a radial plane passing through said upper surface, which has an area, in a cross-section taken along a radial plane passing through said opening to the cavity, of at least 95% of the area bounded by the cavity.

[0153] Preferably, said radial cross-sectional area is constant along the axial extension of the support between the upper surface and the upper wall of said at least one receiving seat.

[0154] Preferably, at least between the upper surface of the support and the upper wall of the receiving seat closest to the upper surface, the support has a radial cross section having a constant area and a constant shape.

[0155] Preferably, the base opening of each seat is configured to allow at least one electrical conductor to pass therethrough.

[0156] Preferably, each wear sensor is inserted into a respective receiving seat such that said wear sensor is housed within an axial projection of the upper surface of the support.

[0157] Preferably, the radial height of said two side walls of each seat is at least equal to the diameter of said single wire of conductive material.

[0158] Preferably, the circumferential distance between said two side walls of each receiving seat is at least equal to twice the diameter of a single wire of conductive material.

[0159] Preferably, the wear sensor does not rub against the cavity wall, at least when the support is inserted into the cavity.

[0160] Preferably, the support has a substantially cylindrical shape between the upper surface and an upper wall of the receiving seat furthest from the upper surface.

[0161] Preferably, the cavity has the shape of a cylinder with a constant diameter.

[0162] According to a first variant embodiment of the invention, the support preferably comprises an insert extending between the base opening and the second axial end of the support.

[0163] Preferably, the insert has a radial cross-section which, measured at any point along the axial extension of the support, has an area which is less than the area of ​​a radial cross-section of the support taken along a radial plane passing through said upper surface.

[0164] Preferably, said radial cross section of the insert has an area smaller than the area of ​​the radial cross section of the cavity measured at the same point.

[0165] Preferably, the support has a substantially cylindrical shape at the insert.

[0166] Preferably, the support has the shape of a first cylinder in the insert and a second cylinder superimposed on said first cylinder.

[0167] According to a second variant embodiment, the support has a radial cross-section, which, measured at any point along the axial extension of the support, is substantially constant along the entire axial extension of the support.

[0168] Preferably, said radial cross section of the insert has a diameter equal to the diameter of the radial cross section of the cavity measured at the same point reduced by at least twice the diameter of said single wire of conductive material.

[0169] Preferably, the support extends axially for the entire axial length of the cavity.

[0170] Preferably, the volume of the support is at least equal to 75% of the volume of the cavity.

[0171] Preferably, the volume of the support is at least equal to 90% of the volume of the cavity.

[0172] Preferably, the volume of the support is at least equal to 95% of the volume of the cavity.

[0173] Preferably, the seat is filled with epoxy resin.

[0174] Preferably, the support is constrained to the sidewalls of the cavity by the use of said epoxy resin. One example of an epoxy resin that can be used is a two-part epoxy thixotropic resin that is heat resistant and chemically resistant, such as the Elantas ADH 50.50 product.

[0175] In this case, the support is preferably inserted into the cavity with a radial clearance.

[0176] Preferably, the radial gap between the support and the cavity is less than 2 millimeters in length.

[0177] Preferably, the radial gap between the support and the cavity is less than 1.5 millimeters in length.

[0178] Preferably, the radial gap between the support and the cavity is less than 1.0 millimeter in length.

[0179] Preferably, the radial gap between the support and the cavity has a length of less than 0.5 millimeters.

[0180] The radial clearance between the support and the cavity refers to the radial displacement of the support between two diametrically opposed positions where at each position the support contacts the side wall of the cavity.

[0181] Alternatively, the support is inserted into the cavity with mechanical interference, in other words, along at least one radial plane, the maximum radial dimension of the support is preferably greater than the minimum radial dimension of the cavity.

[0182] Further features and advantages of the present invention will become more apparent from the following description of preferred embodiments thereof, which proceeds with reference to the accompanying drawings. [Brief description of the drawings]

[0183] [Figure 1] 1 is a schematic cross-sectional view of a portion of a work machine component according to the present invention, according to a first embodiment; [Diagram 2] 1 is a schematic cross-sectional view of a portion of a work machine component according to the present invention, according to a first embodiment; [Figure 1A] 4 is a schematic cross-sectional view of a portion of a work machine component according to the present invention, according to a second embodiment; FIG. [Figure 2A] 4 is a schematic cross-sectional view of a portion of a work machine component according to the present invention, according to a second embodiment; FIG. [Diagram 3] FIG. 3 is a perspective view of a detail of the work machine component of FIG. 2. [Figure 4] FIG. 4 is a bottom view of the detail of FIG. 3. [Diagram 5] FIG. 4 is a front view of a detail of FIG. 3. [Figure 6] FIG. 4 is a side view of a detail of FIG. 3. [Figure 7] FIG. 3 is a front view of a detail of the part of FIG. 2. [Figure 8] FIG. 2B is a front view of a detail of the part of FIG. 2A. [Figure 9] FIG. 3 is a schematic diagram of an electrical circuit that may be used in the components of FIGS. 2 and 2A. [Figure 10] 4 is a schematic cross-sectional view of a portion of a work machine component according to the present invention, according to a third embodiment; FIG. [Figure 10A] 4 is a schematic cross-sectional view of a portion of a work machine component according to the present invention, according to a third embodiment; FIG. [Figure 11] FIG. 10B is a front view of a detail of the work machine component of FIG. 10A. [Figure 12] 10B are cross-sectional views of a detail of FIG. 10A, each taken along a different cut plane. [Figure 13] 10B are cross-sectional views of a detail of FIG. 10A, each taken along a different cut plane. [Figure 14] 10B are cross-sectional views of a detail of FIG. 10A, each taken along a different cut plane. [Figure 15] FIG. 10B is a top view of a detail of FIG. 10A. [Figure 16] FIG. 10B is a bottom view of the detail of FIG. 10A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0184] 1, 2, 1A and 2A, all of which are accompanied by reference numeral 10, there are shown collectively first and second embodiments of a work machine component in accordance with the present invention.

[0185] Work machine component 10 may be, for example, an undercarriage component, to which reference is made below as an example of a work machine component. Undercarriage component 10 may be, for example, a drive wheel, an idler wheel, a pin, a bushing, a link, a link plate, a roller, or a bottom of an undercarriage.

[0186] As shown in Figures 1 and 1A, undercarriage part 10 has an exterior surface 11 that is intended to interact with a work surface (not shown), which may be, for example, the exterior surface of another undercarriage part or the ground.

[0187] The exterior surface 11 of the undercarriage component 10 is the surface that is monitored for a condition of wear.

[0188] In the undercarriage part 10 a cavity 12 is obtained which is bounded by a side wall 13. The cavity 12 may for example be formed by drilling with a drill bit and may have a substantially cylindrical shape.

[0189] The cavity 12 has an opening 14 therefor disposed on the outer surface 11 of the component 10 .

[0190] Cavity 12 further has a bottom wall 15 opposite opening 14, which may be truncoconical as depicted in Figures 1 and 1A. Such a truncoconical shape is obtained by drilling cavity 12 with a drill bit.

[0191] Bottom wall 15 may be closed (as shown in FIG. 1) or open (as shown in FIG. 1A), i.e., bottom wall 15 may be a continuous wall or a wall having openings 15a.

[0192] In other embodiments not shown, the shape of the cavity 12 may be a rectilinear prism with a polygonal base, an oblique prism with a polygonal base, or a truncated pyramid.

[0193] The cavity 12 preferably has a constant radial cross section along its axial progression.

[0194] The cavity 12 has an extension axis A along which the cavity itself extends. The extension axis A passes through the opening 14 and extends into the bottom wall 15. If the cavity is substantially cylindrical (as shown in FIG. 1), the extension axis A coincides with the axis of symmetry of the cavity 12.

[0195] A passage channel 16 is provided in the bottom wall 15 .

[0196] When the bottom wall 15 is closed, the passage channel 16 reaches the side wall 13 of the cavity 12, as shown in FIGS.

[0197] If the bottom wall is open, the passage channel extends from an opening 15a in the bottom wall 15, as shown in Figures 1A and 2A.

[0198] In either case, the passage channel 16 communicates the cavity 12 with a further surface (not shown) of the work machine component 10 and is preferably obtained by drilling.

[0199] The undercarriage part 10 further comprises a support 17 which is inserted into the cavity 12, as shown in FIG.

[0200] The support 17 has a first axial end 17a and a second axial end 17b opposite the first axial end 17a. The support 17 has a substantially flat upper surface 18. The upper surface 18 is arranged at the first axial end 17a. Opposite to the upper surface 18, the support 17 has a base surface 19. The base surface 19 is arranged at the second axial end 17b. The base surface 19 is shaped correspondingly to the bottom wall 15 of the cavity 12. In the embodiment shown, the base surface 19 is substantially frusto-conical.

[0201] In the embodiment shown in FIGS. 3-7, the support 17 has an insert 20 that extends from the base surface 19 towards the top surface 18. As shown in FIG.

[0202] The support 17 further has a receiving portion 21 extending from the insertion portion 20 and reaching the upper surface 18 .

[0203] As shown in FIG. 3, the insertion portion 20 has a radial dimension smaller than the radial dimension of the receiving portion 21.

[0204] The support 17 extends along an axial extension axis B. In a preferred embodiment of the invention, such axial extension axis B defines an axis of symmetry of the support 17.

[0205] The container 21 is substantially cylindrical in shape and generally defines a first cylinder.

[0206] The insert 20 is substantially cylindrical in shape and generally defines a second cylinder.

[0207] The first cylinder is axially overlapped with the second cylinder.

[0208] In the embodiment shown in FIG. 8, the support 17 only has a receiving portion 21 which extends from the upper surface 18 to the base surface 19 .

[0209] Furthermore, in this embodiment, the receiving portion 21 is substantially cylindrical in shape.

[0210] In both embodiments, the support 17 has a side surface 22 which extends into the receiving portion 21 .

[0211] Preferably, the support 17 is made of a material having mechanical properties similar to those of the undercarriage component 10 .

[0212] In a first preferred embodiment of the invention, the undercarriage component 10 may be made of a wear-resistant steel, for example a steel with a low carbon content (between 0.2% and 0.45% by weight). The ultimate tensile strength is between about 1450 MPa and about 1930 MPa. The hardness is between about 420 HWB and 530 HBW10 / 3000. Examples of steels that may be used are boron steels of the type 37MnB4 or 25MnB5 with an average carbon content.

[0213] The support 17 may be made of the same material as the undercarriage part 10 .

[0214] In another embodiment, the support 17 may be made of stainless steel having an ultimate tensile strength of between about 650 and about 800 MPa and a hardness of between about 200 and about 270 HBW10 / 3000.

[0215] In this immediately preceding embodiment, the ratio between the hardness of the support 17 and the hardness of the undercarriage component 10 is between about 0.38 and about 0.64. The ratio between the ultimate tensile strength of the support 17 and the ultimate tensile strength of the undercarriage component 10 is between about 0.34 and about 0.55.

[0216] In a further embodiment, the support 17 is made of a thermoplastic material, such as, for example, Eltalon PA6 or PA66, having an ultimate tensile strength comprised between 54 MPa and 61 MPa.

[0217] In this case, the material of the support 17 does not have similar mechanical properties as the material of the chassis part.

[0218] The support 17 has at least one receiving seat 23. In a preferred embodiment of the invention, the support 17 has a plurality of receiving seats 23. In the exemplary embodiment shown in the accompanying drawings, three receiving seats 23 are provided.

[0219] Each receiving seat 23 is delimited in the axial direction by an upper wall 24 which is located at a predetermined distance D1, D2, D3 from the upper surface 18 of the support 17.

[0220] Such predetermined distances D1, D2, D3 are equidistant from one another in the axial direction.

[0221] The predetermined distance D1 of the upper wall 24 closest to the upper surface 18 of the support 17 may be equal to the distance separating any two upper walls 24 in the axial direction, greater than the distance separating any two upper walls 24 in the axial direction, or less than the distance separating any two upper walls 24 in the axial direction.

[0222] On the opposite side to the top wall 24 , each seat 23 has a base opening 25 .

[0223] 3 to 7, the base opening 25 is located in the insert 20 of the support 17. In other words, the side wall 26 extends in the axial direction until it reaches the insert 20.

[0224] In the embodiment of FIG. 8, base opening 25 is located in base surface 19 .

[0225] Between the top wall 24 and the base opening 25, each receiving seat 23 has two side walls 26. A load-bearing wall 27 is defined between the side walls 26 and the top portion 24.

[0226] 3-7, the bearing wall 27 is substantially axially aligned with the insert 20 of the support 17. In other words, the side wall 26 extends radially within the support 17 (and in particular within the receiving portion 21) until it reaches the ideal axial projection of the insert 20.

[0227] 8, the sidewall 26 extends radially within the support 17 a quantity greater than the ideal axial projection of the passage channel 16. In other words, the sidewall 26 lies on the surface of a first ideal cylinder of a smaller radius than a second ideal cylinder defined by the axial projection of the passage channel 16.

[0228] In either embodiment, each seat 23 is open radially outwardly.

[0229] Preferably, each receiving seat 23 has a substantially straight extension parallel to the radial extension axis B of the support 17 .

[0230] As illustrated in the accompanying drawings, and as better depicted in FIG. 4, the receiving seats 23 are equidistant from one another in the circumferential direction.

[0231] The receiving seat 17 is produced from a corresponding groove formed in the side surface 22 of the support 17. Such a groove is formed in the receiving part 21 of the support 17.

[0232] The upper wall 24 of each receiving seat 23 is disposed at a predetermined distance D1, D2, D3 from the upper surface 18 of the support 17.

[0233] Such predetermined distances D1, D2, D3 are different from each other.

[0234] The upper wall 24 of the receiving seat 23 is located at different distances from the upper surface 18 of the support 17 .

[0235] In the exemplary embodiment shown in the accompanying drawings, in which three receiving seats 23 are provided, the upper wall 24 of the first receiving seat 23 is located at a first predetermined distance D1 (shown in FIG. 2), the upper wall 24 of the second receiving seat 23 is located at a second predetermined distance D2 (shown in FIG. 5) and the upper wall 24 of the third receiving seat 23 is located at a third predetermined distance D3 (shown in FIG. 6) from the upper surface 18 of the support 17.

[0236] None of the receiving seats 23 are open in the axial direction relative to the upper surface 18 of the support body 17 .

[0237] An upper wall 24 of the receiving seat 23 closes the receiving seat 23 in the axial direction relative to the upper surface 18 of the support 17 .

[0238] The support 17 has a radial cross-section taken along a radial plane that remains constant (in area and shape) as one moves axially from the upper surface 18 to the upper wall 24 of the support 17 closest to the upper surface 18.

[0239] As shown in FIGS. 2, 7 and 8, each wear sensor 30 is housed within a respective seat 23.

[0240] Each wear sensor 30 comprises a measuring portion 31 which can be worn and which is configured to change a measurable electrical characteristic of the wear sensor when it erodes.

[0241] The measuring unit 31 is disposed on the upper wall 24 of the receiving seat 23 .

[0242] In a preferred embodiment of the present invention, each wear sensor 30 is an electrical conductor having a single wire 32 of conductive material surrounded by a sheath of electrically insulating material.

[0243] For example, the single wire of conductive material 32 may be an electrical cable having a core of a metallic material, such as copper or aluminum, surrounded by a layer of electrical insulation. Illustratively, the single wire of conductive material 32 may be a single-core American wire gauge (AWG) 28.

[0244] The wear sensor 30 is at least partially received in the receiving seat 23 such that it does not protrude radially beyond the dimensions of the upper surface 18 of the support 17 .

[0245] In particular, a wire 32 of conductive material forming the wear sensor 30 is arranged in the receiving seat 23 so as to create a U-bend 33 in the upper wall 24. Such U-bend 33 defines a measuring portion 31.

[0246] To form the U-bend 33 , a wire 32 of conductive material is bent and inserted into the receiving seat 23 so as to define two sections joined by said U-bend 33 .

[0247] Each wire 32 of conductive material is retained within its respective seat 23 through the use of an adhesive.

[0248] As shown diagrammatically, each wire 32 of conductive material exits a respective receiving seat 23 at an exit opening 25 .

[0249] In the embodiment of FIG. 7, each wire 32 of conductive material is disposed in an exit opening 25 that contacts the insert 20 of the support 17 .

[0250] In the embodiment of FIGS. 2A and 8, each wire 32 of conductive material is disposed within the passage channel 16 at the exit opening 25. As shown in FIG.

[0251] In either embodiment, on the opposite side to the measuring portion 31, each wear sensor 30 is connected to one or more connectors 34 (illustrated in FIG. 8) so that it can be inserted into a measurement circuit for a measurable electrical characteristic of the wear sensor 30.

[0252] In a preferred embodiment of the present invention, such measurable electrical property of wear sensor 30 is electrical resistance.

[0253] 8, all the wires 32 of conductive material are electrically connected to one another at one end to have a common electrical pole 35. By measuring the electrical conductivity (or electrical resistance) between the common electrode 35 and the other free end of each wire 32 of conductive material, it is possible to determine the electrical continuity of each wire 32 of conductive material.

[0254] The connectors 34 may be connected to a signal processing or conditioning device (not shown) configured to determine the electrical continuity of each wire 32 of conductive material.

[0255] As shown, the support 17 and the wear sensor 30 (or multiple wear sensors 30 if multiple wear sensors 30 are provided) are inserted into the cavity 12 .

[0256] The support 17 is inserted into the cavity 12 with the upper surface 18 aligned with the exterior surface 11 of the work machine component 10 being monitored for wear.

[0257] A base surface 19 of the support 17 is disposed in contact with the bottom wall 15 of the cavity 12 .

[0258] The support 17 is inserted into the cavity 12 with a minimal radial gap, which is filled with epoxy resin, which also fills the receiving seat 23 with the wear sensor 30 therein.

[0259] In the embodiment of FIGS. 3 to 7, the epoxy resin also fills the radial space between the insert 20 of the support 17 and the wall 13 of the cavity 12 .

[0260] 3 to 7, the cavities 12 have radial cross sections that are identical to one another (along planes that are parallel to one another and perpendicular to the extension axis A), while the support 17 has radial cross sections that are different between the insertion part 20 and the accommodation part 21 (along planes that are parallel to one another and perpendicular to the extension axis B). In particular, the radial cross section at the insertion part 20 has an area that is smaller than the area of ​​the radial cross section at the accommodation part 21.

[0261] In other words, the radial space between the receiving portion 21 and the wall 13 of the cavity 12 is greater than the radial space between the insert portion 20 and the wall 13 of the cavity 12 .

[0262] During insertion of the support 17 into the cavity 12 , the wear sensor 30 is completely housed radially in its footprint on the upper surface 18 of the support 17 and therefore does not rub against the walls of the cavity 12 .

[0263] The wear sensor 30 is completely housed radially within a groove that defines the receiving seat 23 .

[0264] As shown diagrammatically in FIG. 2, the portion of the wear sensor 30 that leaves the outlet opening 25 of the receiving seat 23 reaches the insert 20 of the support 17 and enters the passage channel 16 of the component 10 .

[0265] In the embodiment of FIG. 2A, the portion of the wear sensor 30 that exits the exit opening 25 of the receiving seat 23 enters the passage channel 16 of the component 10 .

[0266] The connector 34 is preferably housed within the access channel 16 .

[0267] In use, wear of the outer surface 11 of the component 10 causes wear of the support 17 starting from the top surface 18. As long as the wear of the support 17 does not reach the top wall 24 of the receiving seat 23, which is closest to the top surface 18, the wear sensor 30 is not exposed to erosive forces.

[0268] In this operating condition, the measuring part 31 of the wear sensors 30 ensures electrical continuity and the electrical resistance of each wear sensor 30 has a finite value.

[0269] When the wear of the support 17 reaches the top wall 24 of the receiving seat 23 closest to the top surface 18, such top wall 24 is worn away and exposes the corresponding wear sensor 30 to erosive forces. This causes a change in the electrical state of the measuring part 31 of the corresponding wear sensor 30. In particular, the electrical continuity of the wear sensor 30 is interrupted and its electrical resistance becomes infinite.

[0270] A change in the electrical state of the measuring portion 31 of the wear sensor 30 occurs as a result of a breakage of the U-bend 33 of the wire 32 of conductive material caused by erosive forces.

[0271] When the top wall 24 is worn away and exposes the corresponding wear sensor 30 to erosive forces, the entire receiving seat 23 is exposed to the erosive forces as it is no longer bounded above by the top wall 24 .

[0272] The upper walls 24 of the receiving seats 23, which are positioned at a greater distance from the upper surface 18 compared to the already eroded upper walls 24, prevent the erosion forces from reaching the wear sensors 30 housed in the corresponding receiving seats 23.

[0273] If wear of the outer surface 11 of the component 10 continues, the support 17 will wear accordingly.

[0274] When the wear of the support 17 reaches a further upper wall 24 of a further receiving seat 23, such upper wall 24 is worn away and exposes the corresponding wear sensor 30 to erosive forces. This causes a change in the electrical state of the measuring part 31 of the wear sensor 30. In particular, the electrical continuity of the wear sensor 30 is interrupted and its electrical resistance becomes infinite.

[0275] The wearing process of the outer surface 11 of the component 10 continues, as does the wearing of the support 17, until the top wall 24 of the support 17 which is furthest from the top surface 18 of the support 17 is also worn away and exposes the corresponding wear sensor 30 to erosive forces. As mentioned above, this causes a change in the electrical state of the measuring portion 31 of the wear sensor 30.

[0276] By selecting predetermined distances D1, D2, D3 of the upper wall 24 from the upper surface 18 of the support 17 such that each distance corresponds to an indicated wear value of the component 10, it is thus possible to monitor the wear status of the component 10.

[0277] 10-16, a third embodiment of a work machine component in accordance with the present invention is shown generally and generally designated by the reference numeral 40. As shown in FIG.

[0278] Work machine component 40 is similar to work machine component 10 of Figures 1 and 2, except as described differently below.

[0279] As shown in FIG. 10, work machine part 40 has an exterior surface 41 that is intended to interact with a work surface (not shown), which may be, for example, the exterior surface of another undercarriage part or the ground.

[0280] The exterior surface 41 of the work machine component 40 is the surface that is monitored for a condition of wear.

[0281] In the work machine part 40 a cavity 42 is formed which is bounded by a side wall 43. The cavity 42 may be obtained, for example, by drilling with a drill bit and may have a substantially cylindrical shape.

[0282] The cavity 42 has an opening 44 therefor disposed on the outer surface 41 of the component 40 .

[0283] The cavity 42 may have a bottom wall 45 opposite the opening 44 .

[0284] Cavity 42 preferably has a substantially constant radial cross section along its axial extension, subject to the presence of surface irregularities such as, for example, threads.

[0285] The cavity 42 has an extension axis A1 along which the cavity 42 extends. If the cavity is substantially cylindrical (as in the embodiment shown in FIG. 10), the extension axis A1 coincides with the axis of symmetry of the cavity 42.

[0286] A passage channel 46 is provided which terminates at the bottom wall 45 into the side wall 43 of the cavity 42.

[0287] The passage channel 46 is transverse, and preferably perpendicular, to the extension axis A1.

[0288] In the embodiment of FIG. 10, the cavity 42 has an internal thread (not shown) on the side wall 43 .

[0289] In the alternative embodiment, bottom wall 45 and passage channel 46 may be constructed similarly to bottom wall 15 and passage channel 16 of the embodiment of Figures 1, 2, 1A, and 2A.

[0290] The work machine component 40 further includes a support 47, shown in Figures 11-16, which is inserted into the cavity 42.

[0291] The support 47 is rigidly held in place within the cavity 42 .

[0292] The support 47 has a first axial end 47a and a second axial end 47b opposite the first axial end 47a. The support 47 has a substantially flat upper surface 48. The upper surface 48 is disposed at the first axial end 47a.

[0293] On the upper surface 48 , the support 47 has an operating portion 48 a by which the support 47 can be rotated with a tool having a shape corresponding to the operating portion 48 a in order to tighten and loosen the support 47 in the cavity 42 .

[0294] The operating portion 48a has an operating recess 48b opening at said top surface. In the embodiment shown, the operating recess 48b is a hexagonal hole that can be engaged by a corresponding standard hexagonal wrench.

[0295] Opposite to the top surface 48, the support 47 has a base surface 49. The base surface 49 is disposed at the second axial end 47b. In the embodiment shown, the base surface 49 is substantially flat.

[0296] The support 47 extends along an axial extension axis B1. In a preferred embodiment of the invention, such axial extension axis B1 defines an axis of symmetry of the support 47. The support 47 is substantially cylindrical in shape.

[0297] The support 47 has a side 52 that extends from the base surface 49 to the top surface 48. The support 47 has external threads (not shown) on the side 52 that are configured to engage the internal threads of the cavity 42 to capture the support 47 within the cavity 42.

[0298] The female threads of cavity 42 and the male threads of support 47 are configured to allow support 47 to be threaded into cavity 42 up to a limit switch position (e.g., as shown in Figures 10 and 10A) where support 47 cannot be further threaded into cavity 42. In the embodiment shown in Figures 10-16, the limit switch position coincides with the predetermined position.

[0299] Preferably, the support 47 is made of a material having mechanical properties similar to those of the undercarriage component 40 .

[0300] In a first preferred embodiment of the invention, the undercarriage component 40 may be made of a wear-resistant steel, for example a steel with a low carbon content (between 0.2% and 0.45% by weight). The ultimate tensile strength is between about 1450 MPa and about 1930 MPa. The hardness is between about 420 HWB and 530 HBW10 / 3000. Examples of steels that may be used are boron steels of the type 37 MnB4 or 25 MnB5 with an average carbon content.

[0301] The support 47 may be made of the same material as the undercarriage part 40 .

[0302] In another embodiment, the support 47 may be made of stainless steel having an ultimate tensile strength of between about 650 and about 800 MPa and a hardness of between about 200 and about 270 HBW10 / 3000.

[0303] In this immediately preceding embodiment, the ratio between the hardness of the support 47 and the hardness of the undercarriage component 40 is between about 0.38 and about 0.64. The ratio between the ultimate tensile strength of the support 47 and the ultimate tensile strength of the undercarriage component 40 is between about 0.34 and about 0.55.

[0304] In a further embodiment, the support 47 is made of a thermoplastic material, such as, for example, Eltalon PA6 or PA66, having an ultimate tensile strength comprised between 54 MPa and 61 MPa.

[0305] In this case, the material of the support 47 does not have similar mechanical properties as the material of the chassis part.

[0306] The support 47 has at least one receiving seat 53. In a preferred embodiment of the invention, the support 47 has a plurality of receiving seats 53. In the exemplary embodiment shown in the accompanying drawings, three receiving seats 53 are provided.

[0307] Each receiving seat 53 has a radial recess 53a extending radially toward, and preferably up to, the axial extension axis B1. In the embodiment shown, the radial recess is a cylindrical hole having a cylindrical axis perpendicular to the axial extension axis B1.

[0308] Each seat 53 further has an axial channel 53b extending parallel to the axial extension axis B1. The axial channel 53b extends from the radial recess 53a toward the second axial end 47b of the support 47. The axial channel 53b is perpendicular to the radial recess 53a. The axial channel 53b is a straight axial groove formed in the side surface 52 of the support 47.

[0309] The receiving seat 53 has an "L" shape, with the axial channel 53b and the radial recess forming respective lines of said "L" shape.

[0310] Each receiving seat 53 is axially separated by an upper wall 54a. The upper wall 54a is arranged in the radial recess 53a and separates the radial recess 53a in the axial direction toward the first axial end 47a.

[0311] Each of the receiving seats 53 further has an abutment wall 54b. The abutment wall 54b faces the first axial end 47a. The abutment wall 54b is disposed on the side of the radial recess 53a opposite the upper wall 54a. The abutment wall 54b divides the radial recess 53a toward the second axial end 47b. The abutment wall 54b has an angle of 90° with respect to the axial extension axis B1.

[0312] The upper wall 54a and the abutment wall 54b define respective semi-cylindrical surfaces which bound the radial recess 53a from axially opposite sides.

[0313] The abutment wall 54b is radially parallel to the top wall 54a. In other words, a cutting plane passing through the axial extension axis B1 and cutting the abutment wall 54b and the top wall 54a, such as the cutting planes in the perspectives of Figures 13, 14 and 15, defines respective cutting segments in the abutment wall 54b and the top wall 54a that are parallel to each other.

[0314] Opposite the top wall 54a, each seat 53 has a base opening 55 at the second axial end 47b. The base opening 55 is disposed in the base surface 49. The base opening 55 lies in a plane perpendicular to the axial extension axis B1.

[0315] Between the top wall 54a and the base opening 55, each receiving seat 53 has two side walls 56. The side walls 56 define an axial channel 53b. A bearing wall 57 is defined between the side walls 56 and the top wall 54a. The bearing wall 57 defines the axial channel 53b toward the axial extension axis B. Each receiving seat 53 opens radially outward.

[0316] Between the radial recess 53a and the axial channel 53b, the receiving seat has an edge 58, preferably a sharp edge.

[0317] As shown in FIG. 16, the receiving seats 53 are equidistant from one another in the circumferential direction.

[0318] As shown in FIG. 10A, each wear sensor 60 is housed within a respective seat 53 .

[0319] Each wear sensor 60 comprises a measuring portion 61 that can be worn and is configured to change a measurable electrical characteristic of the wear sensor 60 when it erodes.

[0320] The measuring portion 61 is arranged in the radial recess 53a between the upper wall 54a and the abutment wall 54b. The measuring portion 61 is oriented in the radial direction.

[0321] Each wear sensor 60 further includes a conductive portion 61a electrically connected to the measuring portion and disposed in the axial channel 53b. The conductive portion 61a is oriented in the axial direction.

[0322] Each wear sensor 60 forms a curved portion 61b, preferably of about 90°, between the conductive portion 61a and the measuring portion 61. The curved portion 61b is disposed at the edge 58.

[0323] In a preferred embodiment of the present invention, each wear sensor 60 is an electrical conductor having a single wire 62 of conductive material surrounded by a sheath of electrically insulating material.

[0324] For example, the single wire of conductive material 62 may be an electrical cable having a core of a metallic material, such as copper or aluminum, surrounded by a layer of electrical insulation. Illustratively, the single wire of conductive material 62 may be a single-core American Wire Gauge (AWG) 28.

[0325] The wear sensor 60 is at least partially received in the receiving seat 53 such that it does not protrude radially beyond the dimensions of the upper surface 48 of the support 47 .

[0326] In particular, a wire 62 of conductive material forming the wear sensor 60 is arranged in the receiving seat 53 so as to create a U-bend 63 between the top wall 54a and the abutment wall 54b within the radial recess 53a. Such a U-bend 63 defines a measuring portion 61.

[0327] To form the U-bend 63, a wire 62 of conductive material is bent and inserted into the receiving seat 53 so as to define two sections joined by said U-bend 63. Portions of the two sections of the wire 62 are inserted into the radial recess 53a and the axial channel 53b, defining the measuring portion 61, the conductive portion 61a and the curved portion 61b.

[0328] Each wire 62 of conductive material is retained within a respective seat 63 through the use of an adhesive.

[0329] As shown diagrammatically, each wire 62 of conductive material exits a respective seat 63 at base opening 55. In particular, each wire 62 exits from its respective seat 63 axially.

[0330] Each wire 62 of conductive material exits from the exit opening 55 and passes through a passage channel 46. Between the exit opening 55 and the passage channel, the wire 62 forms a 90° bend.

[0331] Similar to what is depicted in FIG. 8 with reference to measurement sensor 30, on the opposite side to the measuring portion 61, each wear sensor 60 is connected to one or more connectors so that it can be inserted into a measurement circuit for a measurable electrical characteristic of the wear sensor 60.

[0332] In a preferred embodiment of the present invention, such measurable electrical property of wear sensor 60 is electrical resistance.

[0333] All the wires 62 of conductive material are electrically connected to one another at one end to have a common electrode, and by measuring the conductivity (or electrical resistance) between said common electrode and the other free end of each wire 62 of conductive material it is possible to determine the electrical continuity of each wire 62 of conductive material.

[0334] The connector may be connected to a signal processing or conditioning device (not shown) configured to determine the electrical continuity of each wire 62 of conductive material.

[0335] The connector is preferably housed within the passage channel 46 .

[0336] As shown, the support 47 and wear sensor 60 (or multiple wear sensors 60, if multiple wear sensors 60 are provided) are inserted into the cavity 42. In particular, the support 47 is threadedly engaged with the cavity 42, with the male threads of the support 47 engaging the female threads of the cavity 42.

[0337] In the preferred embodiment shown, when the support 47 is inserted in place in the cavity 42, the upper surface 48 is aligned with the exterior surface 41 of the work machine component 10 whose wear condition is to be monitored.

[0338] In an alternative embodiment not shown, the support 47 may be placed in place with the upper surface 48 not aligned with the outer surface 41. For example, the upper surface 48 may be recessed within the cavity 42.

[0339] The upper wall 54a of each seat 53 is disposed a predetermined axial distance D1a, D2a, D3a from the outer surface 41 of the work machine component 10 being monitored for wear.

[0340] In the illustrated embodiment, where the upper surface 48 is aligned with the outer surface 41 at a predetermined position, the predetermined axial distance D1a, D2a, D3a of each upper wall 54a from the outer surface 41 of the work machine component 10 corresponds to the distance of the upper wall 54a from the upper surface 48 of the support 47 (as shown in Figures 10A, 12, 13, 14).

[0341] Such predetermined distances D1a, D2a, D3a are different from one another. The upper wall 54a of the receiving seat 53 is located at different axial distances from the outer surface 41 of the working machine component 10.

[0342] In the embodiment with three accommodating seats 53 shown in the accompanying drawings, the upper wall 54a of the first accommodating seat 53 is located at a first predetermined distance D1a (shown in Figure 12), the upper wall 24 of the second accommodating seat 53 is located at a second predetermined distance D2a (shown in Figure 13) and the upper wall 54a of the third accommodating seat 53 is located at a third predetermined distance D3a (shown in Figure 14) from the outer surface 41 of the working machine part 10.

[0343] Such predetermined distances D1a, D2a, D3a are equidistant from one another in the axial direction.

[0344] The predetermined distance D1a of the upper wall 54a closest to the upper surface 48 of the support 47 may be equal to the distance separating any two upper walls 54a in the axial direction, greater than the distance separating any two upper walls 54a in the axial direction, or less than the distance separating any two upper walls 54a in the axial direction.

[0345] None of the receiving seats 53 are open in the axial direction relative to the upper surface 48 of the support body 47 .

[0346] An upper wall 54 a of the receiving seat 53 closes the receiving seat 53 in the axial direction relative to the upper surface 48 of the support 47 .

[0347] The support 47 has a radial cross-section taken along a radial plane that remains constant (in area and shape) as one moves axially from the upper surface 48 until one reaches the upper wall 54a, which is closest to the upper surface 48 of the support 47, except for any surface irregularities caused, for example, by the male screw threads.

[0348] The receiving seat 53 is filled with epoxy resin together with the wear sensor 60 therein. If a radial gap exists between the cavity 42 and the support 47, such radial gap may also be filled with epoxy resin.

[0349] The wear sensor 60 is completely housed radially within the receiving seat 53 .

[0350] In use, wear of the outer surface 41 of the component 40 causes wear of the support 47 starting from the top surface 48. As long as the wear of the support 47 does not reach the top wall 54a of the seat 53, which is closest to the top surface 48, the wear sensor 60 is not exposed to erosive forces.

[0351] In this operating condition, the measuring part 61 of the wear sensors 60 ensures electrical continuity and the electrical resistance of each wear sensor 60 has a finite value.

[0352] When wear of the support 47 reaches the top wall 54a of the receiving seat 53 closest to the upper surface 48, such top wall 54a is worn away and exposes the corresponding wear sensor 60 to the erosive forces.

[0353] The measuring portion 61 of the sensor 60 is held in an abutting position at an abutment wall 54b which counteracts external forces acting on the measuring portion 61 and pushing it axially towards the second end 47b.

[0354] Wear or eventual breakage of the measuring part 61 changes the electrical state of the measuring part 61 of the corresponding wear sensor 60. In particular, the electrical continuity of the wear sensor 60 is interrupted and its electrical resistance becomes infinite.

[0355] A change in the electrical state of the measuring portion 61 of the wear sensor 60 may occur as a result of either a breakage of the U-bend 63 or a breakage of the bent portion 61b of the wire 62 of conductive material caused by erosive forces.

[0356] When the upper wall 54a is worn away and exposes the corresponding wear sensor 60 to erosive forces, the entire receiving seat 53 is exposed to the erosive forces since it is no longer bounded above by the upper wall 54a.

[0357] The upper walls 54a of the receiving seats 53, which are positioned at a greater distance from the upper surface 48 than the already eroded upper walls 54a, prevent the erosion forces from reaching the wear sensors 60 housed in the corresponding receiving seats 53.

[0358] As wear of the outer surface 41 of the component 40 continues, the support 47 will wear accordingly.

[0359] When the wear of the support 47 reaches the further upper wall 54a of the further receiving seat 53, such upper wall 54a is worn away and exposes the corresponding wear sensor 60 to erosive forces. This causes a change in the electrical state of the measuring part 61 of the wear sensor 60. In particular, the electrical continuity of the wear sensor 60 is interrupted and its electrical resistance becomes infinite.

[0360] The wearing process of the outer surface 41 of the component 40 continues, as does the wearing of the support 47, until the top wall 54a of the support 47 which is furthest from the top surface 48 of the support 47 is also worn away and exposes the corresponding wear sensor 60 to erosive forces. As mentioned above, this causes a change in the electrical state of the measuring portion 61 of the wear sensor 60.

[0361] By selecting predetermined distances D1a, D2a, D3a of the axial upper wall 54 of the outer surface 41 of the part 40 (having the support 47 in place) such that each distance corresponds to an indicated wear value of the part 40, it is then possible to monitor the wear status of the part 40.

[0362] The present invention has been described with reference to some preferred embodiments thereof. Various modifications may be made to the above-mentioned embodiments while still remaining within the scope of protection of the invention, as defined by the appended claims.

Claims

1. A work machine component (10, 40), comprising: a cavity (12, 42) formed in said part and having an elongated axis (A, A1); an opening (14, 44) for said cavity (12, 42) arranged on the outer surface (11, 41) of said part; a support (17, 47) inserted into the cavity (12, 42), the support (17, 47) having an axial extension axis (B, B1) parallel to the extension axis (A, A1) of the cavity (12, 42), the support (17, 47) having an upper surface (18, 48) at a first axial end (17a, 47a) and at least one receiving seat (23, 53) formed on the support (17, 47), the at least one receiving seat (23, 53) configured to receive a wear sensor (30, 60), the receiving seat (23, 53) having an upper wall (24, 54a) disposed at a distance along the axial extension axis (B, B1) from the upper surface (18, 48) of the support (17, 47); A wear sensor (30, 60) accommodated in the accommodation seat (23, 53); A work machine component (10, 40) having:

2. 2. The work machine component (40) according to claim 1, wherein the accommodating seat (53) has an abutment wall (54b) facing the first axial end (47a), and the wear sensor (60) has a measuring portion (61) arranged axially between the upper wall (54a) and the abutment wall (54b).

3. 3. The work machine component (40) according to claim 2, wherein the accommodating seat (53) has a radial recess (53a) defined between the upper wall (54a) and the abutment wall (54b), the radial recess (53a) extending radially toward the axial extension axis (B1), and the measuring portion (61) is inserted into the radial recess (53a).

4. 4. The work machine component (40) according to claim 3, wherein the receiving seat (53) has an axial channel (53b) extending parallel to the axial extension axis (B1) from the radial recess (53a) toward a second axial end (47b) of the support (48) that is axially opposite to the first axial end (47a).

5. The work machine component (40) of claim 4, wherein the axial channel (53b) is a groove formed in a side surface (52) of the support (47).

6. 5. The work machine component (40) of claim 4, wherein the wear sensor (60) has a conductive portion (61 a) electrically connected to the measuring portion (61), the conductive portion (61 a) being housed in the axial channel (53 b).

7. 2. The work machine component (10) according to claim 1, wherein the at least one receiving seat (23) is a groove formed in a side surface (22) of the support (17).

8. 8. The work machine component (10, 40) according to any one of claims 1 to 7, wherein the cavity (12, 42) has an internal thread, and the support (17, 47) has an external thread that engages with the internal thread of the cavity (12, 42).

9. 8. The work machine component (10, 40) according to any one of claims 1 to 7, wherein the upper surface (18, 48) is aligned with the outer surface (11, 41) of the component (10, 40), and the upper wall (24, 54) is positioned at a predetermined distance (D1, D1a) along the axial extension axis (B, B1) from the upper surface (18, 48) of the support (23, 53).

10. 2. The work machine component (10, 40) of claim 1, wherein the support (17, 47) has a plurality of receiving seats (23, 53) formed therein, each receiving seat (23, 53) having a respective upper wall (24, 54a) positioned at a distance from the upper surface (18, 48) of the support (17, 47) along the axial extension axis (B, B1), and the work machine component (10, 40) has a plurality of wear sensors (30, 60), each wear sensor (30, 60) of the plurality of wear sensors (30, 60) inserted into a corresponding receiving seat (23, 53).

11. 11. The work machine component (40) according to claim 10, wherein each of the plurality of accommodating seats (53) has an abutment wall (54b) facing the first axial end (47a), and each of the plurality of wear sensors (60) has a measuring portion (61) arranged in the axial direction between the upper wall (54a) and the abutment wall (54b) of the respective accommodating seat (53).

12. 12. The work machine component (40) according to claim 11, wherein each of the plurality of accommodating seats (53) has a radial recess (53 a) defined between a respective upper wall (54 a) and a respective abutment wall (54 b), the radial recess (53 a) extending radially toward the axial extension axis (B1), and the measuring portion (61) of each of the wear sensors (60) being inserted into the radial recess (53 a).

13. 13. The work machine component (40) according to claim 12, wherein each of the plurality of accommodating seats (53) has an axial channel (53 b) extending parallel to the axial extension axis (B1) from the respective radial recess (53 a) toward a second axial end (47 b) of the support (48) that is axially opposite to the first axial end (47 a).

14. A work machine component (40) according to claim 13, wherein each axial channel (53b) is a groove formed in a side surface (52) of the support (47).

15. 15. The work machine component (40) according to claim 13 or 14, wherein each wear sensor (60) of the plurality of wear sensors (60) has a conductive portion (61 a) electrically connected to the respective measuring portion (61), and the conductive portion (61 a) is housed in the axial channel (53 b) of the housing seat (53) of the respective wear sensor (60).

16. The working machine component (10, 40) according to any one of claims 10 to 14 when dependent on claim 9, wherein each respective upper wall (24, 54a) is disposed at a predetermined distance (D1, D2, D3; D1a, D2a, D3a) along the axial extension axis (B, B1) from the upper surface (18, 48) of the support body (17, 47), and the predetermined distances (D1, D2, D3; D1a, D2a, D3a) of the upper walls (24, 54a) of the plurality of receiving seats (23, 53) are different from one another.

17. 11. The work machine component (10) according to claim 10, wherein each of the plurality of receiving seats (23) is a groove formed in a side surface (22) of the support (17), and each groove is disposed at a circumferential distance from the other grooves.

18. 8. The work machine component (10, 40) according to any one of claims 1 to 7, wherein the support (17, 47) has a radial cross section taken along a radial plane passing through the upper surface (18, 48), the radial cross section having an area substantially equal to an area bounded by the cavity (12, 42) in a cross section taken along a radial plane passing through the opening (14, 44) for the cavity (12, 42).

19. 19. The work machine component (10, 40) of claim 18, wherein the area of ​​the radial cross section is constant along the axial extension of the support (17, 47) between the upper surface (18, 48) and the upper wall (24, 54a) of the at least one receiving seat (23, 53).

20. 8. The work machine component (10, 40) according to any one of claims 1 to 7, wherein the at least one receiving seat (23, 53) has a base opening (25, 55) axially opposite the top wall (24, 54), the base opening (25, 55) being configured to allow at least one electrical conductor to pass therethrough.

21. 21. The work machine component (10) of claim 20, wherein the support (17) has an insert (20) extending between the base opening (25) and a second axial end (17b) of the support (17), the insert (20) having a radial cross-section measured at any point along the axial extension of the support (17) that has an area smaller than an area of ​​the radial cross-section of the support (17) taken along a radial plane passing through the top surface (18).

22. The work machine component (10, 40) according to any one of claims 1 to 7, wherein the support (17, 47) is made of metal.

23. The work machine component (10, 40) according to any one of claims 1 to 7, wherein the wear sensor (30, 60) is glued in the receiving seat (23, 53).

24. 24. The work machine component (10, 40) of claim 23, wherein the receiving seat (23, 53) is filled with epoxy resin.

25. The work machine component (10, 40) of any one of claims 1 to 7, wherein the wear sensor (30, 60) comprises a single wire (32, 62) of electrically conductive material surrounded by a sheath of electrically insulating material.

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