EP4644622A1

EP4644622A1 - Wear assembly of an earthmoving machine, and corresponding wear element and adapter

Info

Publication number: EP4644622A1
Application number: EP24382473.7A
Authority: EP
Inventors: Albert Gimeno Tordera
Original assignee: Metalogenia Research and Technologies SL
Current assignee: Metalogenia Research and Technologies SL
Priority date: 2024-04-30
Filing date: 2024-04-30
Publication date: 2025-11-05
Also published as: WO2025229034A1

Abstract

Wear assembly of an earthmoving machine, and corresponding wear element and adapter. The wear assembly is made up of an adapter and a wear element, wherein one of said adapter and wear element has a nose and the other one has a cavity. Both the nose and the cavity have contact surfaces which, in an assembled position of the nose in the cavity, are in contact with each other.

Description

Field of the Invention

The invention relates to a wear assembly of an earthmoving machine, comprising an adapter (in general, also referred to as a support element) and a wear element, wherein one of said adapter and wear element has a nose and the other of said adapter and wear element has a cavity wherein, in an assembled position, said nose is housed in said cavity, wherein said nose has contact surfaces which, in said assembled position, are in contact with corresponding contact surfaces in said cavity, wherein said cavity and said nose define a longitudinal direction, wherein said cavity and said nose define a first transverse direction which is perpendicular to said longitudinal direction and which is parallel to a direction of maximum stresses, and wherein said cavity and said nose define a second transverse direction which is perpendicular to said longitudinal direction and to said first transverse direction.
The invention also relates to a wear element of an earthmoving machine, suitable for being attached to an adapter, wherein one of said adapter and wear element has a nose and the other of said adapter and wear element has a cavity wherein, in an assembled position, said nose is housed in said cavity, wherein said nose has contact surfaces which, in said assembled position, are in contact with corresponding contact surfaces in said cavity, wherein said cavity and said nose define a longitudinal direction, wherein said cavity and said nose define a first transverse direction which is perpendicular to said longitudinal direction and which is parallel to a direction of maximum stresses, and wherein said cavity and said nose define a second transverse direction which is perpendicular to said longitudinal direction and to said first transverse direction.
The invention also relates to an adapter (in general, also referred to as a support element) of an earthmoving machine, suitable for supporting a wear element, wherein one of said adapter and wear element has a nose and the other of said adapter and wear element has a cavity wherein, in an assembled position, said nose is housed in said cavity, wherein said nose has contact surfaces which, in said assembled position, are in contact with corresponding contact surfaces in said cavity, wherein said cavity and said nose define a longitudinal direction, wherein said cavity and said nose define a first transverse direction which is perpendicular to said longitudinal direction and which is parallel to a direction of maximum stresses, and wherein said cavity and said nose define a second transverse direction which is perpendicular to said longitudinal direction and to said first transverse direction.

Prior Art

Earthmoving machines are used in excavation, loading, demolition, construction, mining, dredging and similar activities. In certain cases, these machines have a bucket or shovel to penetrate, pull out, pick up and load material. Given that the bucket or shovel withstands high stresses and impacts and a great deal of erosion and wear, the bucket or shovel has wear elements that serve both to protect the bucket or shovel and to improve the penetration of the bucket or shovel into the ground. In general, these wear elements can be of various types, depending on the activity for which the earthmoving machine is intended.
For example, in construction work the machines are smaller than in mining work or dragline excavators, where loads or mechanical requirements and stresses are greater. In construction work and in mining work with light loads, mostly a two-part wear assembly is used, an adapter secured to the machine lip, and a tooth coupled to the adapter. In general, the adapter is configured as a male part and the tooth is configured as a female part, but in some cases it is the other way around, and then the assembly is called a "reverse system".
In mining work where the loads to be withstood are larger and in dragline excavators, it is common to use three-part wear assemblies comprising a penetration member (tooth), an intermediate member (intermediate adapter) and a member welded to or cast onto the bucket (adapter). Three-part assemblies are used when the weight of the assembly is very large, so the increased number of elements makes it easier to handle. A three-part wear assembly is also useful because the ratio of usable wear material is increased. Additionally, the wear rate of the parts can be improved. In general, the intermediate element is provided with a male part in its front region and a female part in its rear region, the penetration element is configured as a female part and the adapter is configured as a male part. Nonetheless, sometimes also two-part assemblies are used in these cases.
The coupling between the different parts is maintained by means of an attachment system, usually a pin or a pin with a retainer that retains the pin in the assembled position, which can be vertical or lateral.
The service life of the coupling is limited due to:

Plastic deformation of the material due to reactions to counteract the forces exerted.
Fatigue: it is estimated that a tooth having a normal duration performs more than 50,000 duty cycles. As a result, the coupling must be designed to avoid defects that occur due to fatigue phenomena, such as cracks or other defects.
External wear of the parts due to the material flow, and internal wear due to the fine materials that are introduced between the two elements (tooth and adapter), so that the movements between the two elements produce an abrasive effect that gradually wears them down.

The engagement or contact area between the different elements of the wear assembly is formed by contact surfaces of the male and female parts, wherein the loads are transmitted from the tip of the wear element to the lip of the bucket through the adapter element.
When the machine is working, the tip of the tooth attacks the terrain in different directions, which causes stresses in the tooth that are transferred from the tip of the tooth to the contact surfaces that come into contact with the male part, i.e. from the tip to the adapter (or to the intermediate element in the case of a three-part assembly) and from the adapter to the bucket, so that the stresses are discharged from the assembly and also from the pin.
In traditional wear assemblies, the housing or cavity in the female part and the complementary nose of the male part are wedge-shaped. When a force is applied to the tooth, this wedge shape generates reaction forces on the adapter. These reaction forces tend to separate the tooth from the adapter, stressing the pin, sometimes breaking it, which can lead to a very dangerous situation because a disengagement of the pin can cause the tooth to also disengage, which can cause the tooth to end up inside a crusher. To remove a tooth from a crusher is a very risky and dangerous operation and should be avoided. It also affects the productivity of the operation. A broken tooth that it is not immediately detected, will wear out the nose of the adapter, reducing its functionality and most probably needing replacement.
Moreover, loads are transmitted in all directions, if the contact surfaces are not designed to support each other properly in any direction, they tend to deteriorate the wear assembly, in particular the contact or support surfaces between the elements of the wear assembly, with the pin accordingly suffering excessively as well.
Likewise, it should also be noted that, in use, the wear element, the adapter, the pin and the retainer form an assembly that is used as such. Depending on the terrain or the type of work in which the machine is working, the wear element suffers much more stresses, impact and wear during use so that its average life is less than that of the support element, and in some cases also less than that of the pin. Thus, for example, it is common for the average life of an adapter (which is a usual support element) to be 3 to 5 times longer (or even more) than the average life of a shovel tooth or bucket tooth (which is a common wear element) of an earthmoving machine. Therefore, it is common for the wear element to be attached to the adapter in a way that is easy to disassemble, usually by means of a pin (in general, an attachment system), and for these three elements (wear elements, adapter and pin) to be marketed not only as assemblies made up of the three components (or the adapter and wear element pair), but also separately.
The terms "concave", "convex", "inwardly" and "outwardly" appearing throughout the present description and claims are to be interpreted as explained below. Physical elements are bounded by surfaces. These surfaces have one side in contact with the material of the element itself and another side in contact with a material-free space. Thus, "inwardly" means toward the material part of the element, and "outwardly" means toward the material-free space in contact with the surface. By way of clarifying example, a cavity made on the outer surface of a ring would be referred to as an outwardly concave surface. The same cavity made on the inner surface of the ring would also be referred to as an outwardly concave surface, since "outwardly" indicates toward the material-free space which, in this case, would be the inner space of the ring.

Disclosure of the Invention

The invention is intended to overcome these drawbacks. That is, the object of the invention is to provide a coupling system between a wear element and an adapter which allows an optimum transmission of stresses. This purpose is achieved by means of a wear assembly of an earthmoving machine of the type indicated above, characterized in that said contact surfaces of said nose comprise at least a first outwardly concave segment and a second outwardly concave segment, wherein said first concave segment and said second concave segment extend according to said longitudinal direction and are symmetrical to each other according to a plane formed by said longitudinal direction and said first transverse direction, wherein between said first concave segment and said second concave segment there is a longitudinal protrusion, wherein each of said first and second concave segments extends an arc comprised between 50° and 110°, preferably between 60° and 90°, more preferably between 72° and 88°, and said contact surfaces of said cavity comprise at least a first outwardly convex segment and a second outwardly convex segment, wherein said first convex segment and said second convex segment extend according to said longitudinal direction and are symmetrical to each other according to a plane formed by said longitudinal direction and said first transverse direction, wherein between said first convex segment and said second convex segment there is a longitudinal recess suitable for housing said protrusion in said assembled position, wherein each of said first and second convex segments extends an arc comprised between 50° and 110°, preferably between 60° and 90°, more preferably between 72° and 88°, and is in contact, in said assembled position, with said first concave segment and said second concave segment, respectively. The contact surfaces are designed in such a way that they are suitable for withstanding loads and transmitting them to the adapter, thus preventing the wear element and the pin from being subjected to very high loads. It should be noted that the contact surfaces work when the wear element moves and, furthermore, the contact surfaces do not necessarily all work simultaneously. In fact, the contact surfaces work depending on the direction of the forces to which the wear element is subjected. Therefore, the fact that the contact surfaces are arc-shaped ensures that there is always contact between the corresponding contact surfaces. In addition, the arc shape also facilitates cleaning of the contact surfaces since they can be cleaned using rotary cleaning machines.
It must be taken into account that any wear assembly, made up of a wear element, an adapter (or in general, any support element on which the adapter is to be assembled), attachment means (such as pins, retainers or any other elements for attaching the wear element to the support element), etc., is designed from the outset taking into account all the elements making up the same. In other words, for example, when designing a wear element, it is taken into account on which support element it should be assembled, with which attachment means it should be attached, what its working conditions will be, etc. The same applies to the design of the other components of the assembly. Therefore, following the above example, the designer of the wear element will be aware of all the details of the remaining elements of the assembly, and will take them into account if they affect the design. In particular, the designer will be aware of all relevant dimensions of the "environment" of the wear element and will take them into account in the design. In addition, the designer shall take into account that the wear assembly will have a certain amount of wear during its service life. In this regard, the designer will also take into account how this wear affects the wear assembly and the relevant dimensions of the wear assembly. Therefore, it should be understood that all this information (data on the remaining components of the assembly, data on working conditions and wear, etc.) are part of the wear element itself (even if located in another physical entity), as they are preset values for the design of the wear element. The same applies for the remaining elements of the assembly.
Preferably, each of said first concave segment, second concave segment, first convex segment and second convex segment is a circular cylindrical surface, which makes it possible to ensure contact between the contact surfaces in any load application direction and, in addition, facilitates cleaning thereof.
Preferably, said nose has a front segment, close to the free end of said nose and a rear segment, away from said free end, wherein said at least first concave segment and second concave segment of said nose are in said rear segment, wherein said front segment has four front contact surfaces joined together by four outwardly concave clearance surfaces.
Preferably, said cavity has an internal segment, close to the bottom of said cavity and an outlet segment, away from said bottom, wherein said at least first convex segment and second convex segment of said cavity are in said outlet segment, wherein said internal segment has four internal contact surfaces, each in contact with a corresponding front contact surface in said assembled position, said internal contact surfaces being joined to each other by four outwardly concave clearance surfaces. Thus, between the concave clearance surfaces of the nose and the concave clearance surfaces of the cavity there is a space in which fines can be deposited, preventing these fines from getting between the contact surfaces and interfering with their proper operation, an also serving to absorb potential manufacturing defects (e.g., burrs or soils) and to detect wear. The concave clearance surfaces of the nose are also used as tooth wear detectors: during use, the wear element wears until a hole appears that can be detected by the user, but the nose has not suffered any wear yet thanks to the space between the concave clearance surfaces of the nose and the concave clearance surfaces of the cavity.
Preferably, said nose has an opening suitable for housing, in said assembled position, a pin going through a through opening arranged in a side wall of said cavity, wherein said nose has, next to said opening, a recess suitable for housing a retainer retaining said pin in said opening. Preferably, said opening and said through opening extend in a direction parallel to said second transverse axis. In this way, the adapter and the wear element can be attached in a removable manner.
Preferably, said contact surfaces of said nose additionally comprise a third outwardly concave segment and a fourth outwardly concave segment, wherein said third concave segment and said fourth concave segment extend according to said longitudinal direction and are symmetrical to each other according to a plane formed by said longitudinal direction and said first transverse direction, wherein between said third concave segment and said fourth concave segment there is a longitudinal protrusion, wherein each of said third and fourth concave segment extends an arc comprised between 50° and 110°, preferably between 60° and 90°, more preferably between 72° and 88°, and said contact surfaces of said cavity comprise at least a third outwardly convex segment and a fourth outwardly convex segment, wherein said third convex segment and said fourth convex segment extend according to said longitudinal direction and are symmetrical to each other according to a plane formed by said longitudinal direction and said first transverse direction, wherein between said third convex segment and said fourth convex segment there is a recess suitable for housing said protrusion in said assembled position, wherein each of said third and fourth convex segment extends an arc comprised between 50° and 110°, preferably between 60° and 90°, more preferably between 72° and 88°, and is in contact, in said assembled position, with said third concave segment and said fourth concave segment, respectively. As there are more contact surfaces with this specific shape, the assembly can withstand higher loads and is more responsive to forces with any direction.
Preferably, each of said third concave segment, fourth concave segment, third convex segment and fourth convex segment is a circular cylindrical surface, which improves the support of loads when the loads are not aligned and, in turn, facilitates cleaning thereof.
Preferably, said first convex segment and said third convex segment are symmetrical to each other according to a plane formed by said longitudinal direction and said second transverse direction, and in that said second convex segment and said fourth convex segment are symmetrical to each other according to a plane formed by said longitudinal direction and said second transverse direction.
Preferably, said nose is on said adapter and said cavity is on said wear element. In this case, preferably, said wear element has, on its outer surface, at least two outwardly concave surfaces, each of them in correspondence with one of said first and second convex segment of said cavity. More preferably, said wear element has, on its outer surface, four outwardly concave surfaces, each of them in correspondence with one of said first, second, third and fourth convex segment of said cavity. This is advantageous because a more constant cross-section of the wear element is achieved by avoiding corners which, in turn, are more prone to wear. Still more preferably, said outwardly concave surfaces of said outer surface extend an arc comprised between 50° and 110°, preferably between 60° and 90°, more preferably between 72° and 88°, and are preferably circular cylindrical surfaces. In this way, the penetration of the wear element into the ground is improved and, in addition, cleaning thereof is facilitated.
Preferably, in a cross-section of said nose, there is: [a] a first inflection point I1 at the junction of said first concave segment with said protrusion, [b] a second inflection point I2 at the junction of said second concave segment with said protrusion, and [c] two points of maximum width A1 and A2 each wherein a tangent to said cross-section is perpendicular to said second transverse direction, wherein between said points A1 and A2 there is a distance A, measured in the direction of said second transverse direction, between said point A1 and said point I1 there is a distance B, measured in the direction of said second transverse direction, and between said point I1 and said point I2 there is a distance C, measured in the direction of said second transverse direction, wherein the ratio between C and A is between 0.25 and 0.60. This is the optimum geometry for transmitting the loads from the wear element to the adapter, and the protrusion has a resistance capable of withstanding the stresses transmitted to it.
Preferably, said protrusion of said adapter has a longitudinal rib which serves as a wear indicator. This contacts the longitudinal recess of the wear element when the wear in the contact areas is excessive, leaving a mark on said longitudinal recess. This mark indicates that the adapter has very worn contact areas and that it is advisable to replace the adapters with new ones.
Preferably, one, and only one, of said protrusions has a longitudinal indentation.
Preferably, each protrusion has a longitudinal indentation.
More preferably, at least one of said longitudinal recesses of said cavity of said wear element comprises a longitudinal projection.
Preferably, said front surfaces of said nose comprise an upper front surface and a lower front surface, opposite said upper front surface, wherein one of said upper front surface and said lower front surface is outwardly concave and said other one is outwardly convex. In other preferred alternative said front surfaces of said nose comprise an upper front surface and a lower front surface, opposite said upper front surface, wherein both are flat surfaces. In a third preferred alternative said front surfaces of said nose comprise an upper front surface and a lower front surface, opposite said upper front surface, wherein both are outwardly concave.
More preferably, said cavity has an upper wall adjacent to said bottom and a lower wall adjacent to said bottom and opposite said upper wall, one of said upper wall and lower wall being outwardly concave and said other one being outwardly convex. The loads acting on the assembly may have different direction and intensity and accordingly generate reactions on the contact surfaces which tend to rotate the wear element (and remove it from the adapter). The combination of these concave and convex front surfaces together with the upper and lower front surfaces compensate for these reactions, since the V-shaped and Λ-shaped fit distributes the reactions generated during operation, so that retention of the wear element in the adapter is favored. In addition, the stresses to which the pin is subjected are also reduced.
The invention also relates to a wear element of an earthmoving machine of the type indicated above, characterized in that said contact surfaces of said nose comprise at least a first outwardly concave segment and a second outwardly concave segment, wherein said first concave segment and said second concave segment extend according to said longitudinal direction and are symmetrical to each other according to a plane formed by said longitudinal direction and said first transverse direction, wherein between said first concave segment and said second concave segment there is a longitudinal protrusion, wherein each of said first and second concave segments extends an arc comprised between 50° and 110°, preferably between 60° and 90°, more preferably between 72° and 88°, and said contact surfaces of said cavity comprise at least a first outwardly convex segment and a second outwardly convex segment, wherein said first convex segment and said second convex segment extend according to said longitudinal direction and are symmetrical to each other according to a plane formed by said longitudinal direction and said first transverse direction, wherein between said first convex segment and said second convex segment there is a longitudinal recess suitable for housing said protrusion in said assembled position, wherein each of said first and second convex segments extends an arc comprised between 50° and 110°, preferably between 60° and 90°, more preferably between 72° and 88°, and is in contact, in said assembled position, with said first concave segment and said second concave segment, respectively.
Preferably, each of said first concave segment, second concave segment, first convex segment and second convex segment is a circular cylindrical surface.
Preferably, said nose has a front segment, close to the free end of said nose and a rear segment, away from said free end, wherein said at least first concave segment and second concave segment of said nose are in said rear segment, wherein said front segment has four front contact surfaces joined together by four outwardly concave clearance surfaces.
Preferably, said cavity has an internal segment, close to the bottom of said cavity and an outlet segment, away from said bottom, wherein said at least first convex segment and second convex segment of said cavity are in said outlet segment, wherein said internal segment has four internal contact surfaces, each in contact with a corresponding front contact surface in said assembled position, said internal contact surfaces being joined to each other by four outwardly concave clearance surfaces.
Preferably, said nose has an opening suitable for housing, in said assembled position, a pin going through a through opening arranged in a side wall of said cavity, wherein said nose has, next to said opening, a recess suitable for housing a retainer retaining said pin in said opening.
Preferably, said opening and said through opening extend in a direction parallel to said second transverse axis.
Preferably, said contact surfaces of said nose further comprise, additionally, a third outwardly concave segment and a fourth outwardly concave segment, wherein said third concave segment and said fourth concave segment extend according to said longitudinal direction and are symmetrical to each other according to a plane formed by said longitudinal direction and said first transverse direction, wherein between said third concave segment and said fourth concave segment there is a longitudinal protrusion, wherein each of said third and fourth concave segment extends an arc comprised between 50° and 110°, preferably between 60° and 90°, more preferably between 72° and 88°, and said contact surfaces of said cavity comprise at least a third outwardly convex segment and a fourth outwardly convex segment, wherein said third convex segment and said fourth convex segment extend according to said longitudinal direction and are symmetrical to each other according to a plane formed by said longitudinal direction and said first transverse direction, wherein between said third convex segment and said fourth convex segment there is a longitudinal recess suitable for housing said protrusion in said assembled position, wherein each of said third and fourth convex segment extends an arc comprised between 50° and 110°, preferably between 60° and 90°, more preferably between 72° and 88°, and is in contact, in said assembled position, with said third concave segment and said fourth concave segment, respectively.
Preferably, each of said third concave segment, fourth concave segment, third convex segment and fourth convex segment is a circular cylindrical surface.
Preferably, said first convex segment and said third convex segment are symmetrical to each other according to a plane formed by said longitudinal direction and said second transverse direction, and in that said second convex segment and said fourth convex segment are symmetrical to each other according to a plane formed by said longitudinal direction and said second transverse direction.
Preferably, said nose is on said adapter and said cavity is on said wear element. In this case, preferably, said wear element has, on its outer surface, at least two outwardly concave surfaces, each in correspondence with one of said first and second convex segment of said cavity.
More preferably, said wear element has, on its outer surface, four outwardly concave surfaces, each of them in correspondence with one of said first, second, third and fourth convex segment of said cavity.
Preferably, said outwardly concave surfaces of said outer surface extend an arc comprised between 50° and 110°, preferably between 60° and 90°, more preferably between 72° and 88°, and are preferably circular cylindrical surfaces.
Preferably, in a cross-section of said nose, there is: [a] a first inflection point I1 at the junction of said first concave segment with said protrusion, [b] a second inflection point I2 at the junction of said second concave segment with said protrusion, and [c] two points of maximum width A1 and A2 each wherein a tangent to said cross-section is perpendicular to said second transverse direction, wherein between said points A1 and A2 there is a distance A, measured in the direction of said second transverse direction, between said point A1 and said point I1 there is a distance B, measured in the direction of said second transverse direction, and between said point I1 and said point I2 there is a distance C, measured in the direction of said second transverse direction, wherein the ratio between C and A is between 0.25 and 0.60.
Preferably, said longitudinal recess of said cavity of said wear element further has a longitudinal groove.
Preferably, at least one of said longitudinal recesses of said cavity of said wear element comprises a longitudinal projection.
Preferably, said cavity has an upper wall adjacent to said bottom and a lower wall adjacent to said bottom and opposite said upper wall, one of said upper wall and lower wall being outwardly concave and said other one being outwardly convex.
The invention also relates to an adapter of an earthmoving machine of the type indicated at the beginning characterized in that said contact surfaces of said nose comprise at least a first outwardly concave segment and a second outwardly concave segment, wherein said first concave segment and said second concave segment extend according to said longitudinal direction and are symmetrical to each other according to a plane formed by said longitudinal direction and said first transverse direction, wherein between said first concave segment and said second concave segment there is a longitudinal protrusion, wherein each of said first and second concave segments extends an arc comprised between 50° and 110°, preferably between 60° and 90°, more preferably between 72° and 88°, and said contact surfaces of said cavity comprise at least a first outwardly convex segment and a second outwardly convex segment, wherein said first convex segment and said second convex segment extend according to said longitudinal direction and are symmetrical to each other according to a plane formed by said longitudinal direction and said first transverse direction, wherein between said first convex segment and said second convex segment there is a longitudinal recess suitable for housing said protrusion in said assembled position, wherein each of said first and second convex segments extends an arc comprised between 50° and 110°, preferably between 60° and 90°, more preferably between 72° and 88°, and is in contact, in said assembled position, with said first concave segment and said second concave segment, respectively.
Preferably, each of said first concave segment, second concave segment, first convex segment and second convex segment is a circular cylindrical surface.
Preferably, said nose has a front segment, close to the free end of said nose and a rear segment, away from said free end, wherein said at least first concave segment and second concave segment of said nose are in said rear segment, wherein said front segment has four front contact surfaces joined together by four outwardly concave clearance surfaces.
Preferably, said cavity has an internal segment, close to the bottom of said cavity and an outlet segment, away from said bottom, wherein said at least first convex segment and second convex segment of said cavity are in said outlet segment, wherein said internal segment has four internal contact surfaces, each in contact with a corresponding front contact surface in said assembled position, said internal contact surfaces being joined to each other by four outwardly concave clearance surfaces.
Preferably, said nose has an opening suitable for housing, in said assembled position, a pin going through a through opening arranged in a side wall of said cavity, wherein said nose has, next to said opening, a recess suitable for housing a retainer retaining said pin in said opening.
More preferably, said opening and said through opening extend in a direction parallel to said second transverse axis.
Preferably, said contact surfaces of said nose additionally comprise a third outwardly concave segment and a fourth outwardly concave segment, wherein said third concave segment and said fourth concave segment extend according to said longitudinal direction and are symmetrical to each other according to a plane formed by said longitudinal direction and said first transverse direction, wherein between said third concave segment and said fourth concave segment there is a longitudinal protrusion, wherein each of said third and fourth concave segment extends an arc comprised between 50° and 110°, preferably between 60° and 90°, more preferably between 72° and 88°, and said contact surfaces of said cavity comprise at least a third outwardly convex segment and a fourth outwardly convex segment, wherein said third convex segment and said fourth convex segment extend according to said longitudinal direction and are symmetrical to each other according to a plane formed by said longitudinal direction and said first transverse direction, wherein between said third convex segment and said fourth convex segment there is a longitudinal recess suitable for housing said protrusion in said assembled position, wherein each of said third and fourth convex segment extends an arc comprised between 50° and 110°, preferably between 60° and 90°, more preferably between 72° and 88°, and is in contact, in said assembled position, with said third concave segment and said fourth concave segment, respectively.
More preferably, each of said third concave segment, fourth concave segment, third convex segment and fourth convex segment is a circular cylindrical surface.
Preferably, said first convex segment and said third convex segment are symmetrical to each other according to a plane formed by said longitudinal direction and said second transverse direction, and in that said second convex segment and said fourth convex segment are symmetrical to each other according to a plane formed by said longitudinal direction and said second transverse direction.
Preferably, said nose is in said adapter and said cavity is in said wear element.
Preferably, in a cross-section of said nose, there is: [a] a first inflection point I1 at the junction of said first concave segment with said protrusion, [b] a second inflection point I2 at the junction of said second concave segment with said protrusion, and [c] two points of maximum width A1 and A2 each wherein a tangent to said cross-section is perpendicular to said second transverse direction, wherein between said points A1 and A2 there is a distance A, measured in the direction of said second transverse direction, between said point A1 and said point I1 there is a distance B, measured in the direction of said second transverse direction, and between said point I1 and said point I2 there is a distance C, measured in the direction of said second transverse direction, wherein the ratio between C and A is between 0.25 and 0.60.
Preferably, said protrusion of said adapter has a longitudinal rib.
Preferably, one, and only one, of said protrusions has a longitudinal indentation.
Preferably, each protrusion has a longitudinal indentation.
Preferably, said front surfaces of said nose comprise an upper front surface and a lower front surface, opposite said upper front surface, wherein one of said upper front surface and said lower front surface is outwardly concave and said other one is outwardly convex.

Brief description of the drawings

Other advantages and features of the invention are apparent from the following description, in which a preferred embodiment of the invention is described in a non-limiting manner in reference to the attached drawings. In the figures:

Figure 1 is an exploded view of the assembly of a wear element and an adapter according to the invention.
Figure 2 is a perspective view of the adapter according to the invention.
Figure 3 is a cross-section of the nose of said adapter according to the invention, in which optimum dimensions thereof are detailed.
Figure 4 is a perspective view of the wear element according to the invention.
Figure 5 is a profile view of the adapter according to the invention.
Figure 6 is a top plan view of the adapter according to the invention.
Figure 7 is a cross-section of the adapter nose according to the invention.
Figure 8 is a section of a wear element assembled on an adapter by means of a pin according to the invention.
Figure 9 is a section of a wear element assembled on an adapter by means of a pin according to the invention.
Figure 10 is a partial section of a wear element assembled on an adapter by means of a pin according to the invention, in which the reaction forces of the contact surfaces according to the direction of the force applied at the nose tip of the adapter can be seen.
Figure 11 is a partial section of the wear element in Figure 10.
Figure 12 is a section of a wear element assembled in an adapter according to the invention, in which concave clearance surfaces of the wear element cavity can be seen.
Figure 13 is a section of a wear element, according to the invention, in which the cavity of said wear element can be seen.
Figure 14 is a perspective view of an adapter, according to the invention, in which the contact surfaces have been marked with shading.
Figure 15 is a perspective view of an adapter according to the invention.
Figure 16 is a perspective view of an adapter according to the invention, in which the protrusion has a rib.
Figure 17 is a top plan view of the adapter of Figure 16.
Figure 18 is a section of a wear element assembled on the nose of the adapter of Figure 17.
Figure 19 is a perspective view of an adapter according to the invention, in which the protrusion has an indentation.
Figure 20 is a top plan view of the adapter of Figure 19.
Figure 21 is a section of the nose of Figure 20, assembled with a wear element.
Figure 22 is a section of the nose of Figure 20, assembled with a wear element.
Figure 23 is a perspective view of an adapter according to the invention.
Figure 24 is a top plan view of the adapter of Figure 23.
Figure 25 is a section of the nose of Figure 24, assembled with a wear element.
Figure 26 is a section of the nose of Figure 20, assembled with a wear element.
Figure 27 is an upper perspective view of an adapter according to the invention.
Figure 28 is an upper perspective view of a variant of the adapter shown in Figure 27.
Figure 29 is a lower perspective view of the adapter of Figure 27.
Figure 30 is a lower perspective view of the adapter shown in Figure 28.
Figure 31 is an upper perspective view of a wear element according to the invention, in which the internal clearance surfaces 50 are flat.
Figure 32 is a lower perspective view of the wear element of Figure 31.
Figure 33 is a top plan view the adapter of Figure 27.
Figure 34 is a section of the nose of Figure 27, assembled with a wear element.
Figure 35 is a section of the nose of Figure 27, assembled with a wear element.
Figure 36 is a section of a variant of the nose of Figure 27, assembled with the wear element of Figure 31.
Figure 37 is a section of the variant of the nose of Figure 36, assembled with a wear element.
Figure 38 is a section of another variant of the nose of Figure 27, assembled with a wear element.
Figure 39 is a section of the variant of the nose of Figure 38, assembled with a wear element.
Figure 40 is a section of the nose of Figure 28, which is a variant of the nose of Figure 27, assembled with the wear element of Figure 31.
Figure 41 is a section of the variant of the nose of Figure 40, assembled with a wear element.

Detailed Description of Embodiments of the Invention

Figures 1 to 14 show a wear assembly 1 for an earthmoving machine according to the invention. This wear assembly comprises an adapter 2, which has a nose 6, and a wear element 4, which has a cavity 8. In an assembled position, the nose 6 is housed in the cavity 8. To attach the wear element 4 to the adapter 2 in the assembled position, the wear element 4 has two through openings 52, each arranged in a side wall of the cavity 8, and the nose 6 of the adapter 2 has an opening 32. The opening 32 and the through openings 52 extend in a direction parallel to a second transverse direction, defined below. As can be seen in Figure 10, in the assembled position, the through openings 52 and the opening 32 are aligned such that a pin 62 can be inserted through one of the through openings 52 until it is housed in the opening 32 of the nose 6 and in the two through openings 52. In addition, as can be seen in Figure 1, adjacent to the opening 32 of the nose 6 is a recess suitable for housing a retainer 60 that retains the pin 62 in the opening 32.
The cavity 8 and the nose 6 define a longitudinal direction (corresponding to the Z axis of Figure 1), a first transverse direction (corresponding to the Y axis of Figure 1) which is perpendicular to the longitudinal direction and which is parallel to a direction of maximum stresses (which is predefined by the expected working conditions for the wear assembly 1), and the second transverse direction (corresponding to the X axis of Figure 1) which is perpendicular to the longitudinal direction and to the first transverse direction.
First, as can be seen in Figure 2, the nose 6 of the adapter 2 has a front segment 22 and a rear segment 26. The front segment 22 is close to the free end 24 of the nose 6, and the rear segment 26 is away from the free end 24. Free end 24 is interpreted to mean the end of the nose 4 that first enters the cavity 8 of the wear element 4. As described below, both the front segment 22 and the rear segment 26 of the nose 6 have contact surfaces, which are also indicated by shading in Figure 14.
The front segment 22 of the nose 6 has four front contact surfaces 28 joined together by four outwardly concave clearance surfaces 30, and the rear segment 26 of the nose 6 has contact surfaces comprising a first outwardly concave segment 10, a second outwardly concave segment 12, a third outwardly concave segment 14, and a fourth outwardly concave segment 16.
The first concave segment 10 and the second concave segment 12 extend according to the longitudinal direction and are symmetrical to each other according to a plane formed by the longitudinal direction and the first transverse direction, i.e. according to the YZ plane. Each of the first and second concave segments 10, 12 extends, according to a transverse plane, parallel to the two transverse directions (a plane parallel to the XY plane), i.e. perpendicular to the longitudinal direction (direction according to the Z axis), an arc 20 comprised between 50° and 110°. Between the first concave segment 10 and the second concave segment 12 there is a longitudinal protrusion 18.
The third concave segment 14 and the fourth concave segment 16 extend according to the longitudinal direction and are symmetrical to each other according to a plane formed by the longitudinal direction and the first transverse direction. Each of the third 14 and fourth concave segment 16 extends, according to a transverse plane, parallel to the two transverse directions, i.e., perpendicular to the longitudinal direction, an arc 20 comprised between 50° and 110°. Between the third concave segment 14 and the fourth concave segment 16 there is another longitudinal protrusion 18.
Figure 3 depicts how the angles of the arcs 20 should be interpreted. In Figure 3, the angle of the arc is represented by the letter α. Each arc 20 has two inflection points P1, P2. At each of these inflection points there is a straight line tangent to the arc, and each tangent line has a perpendicular line. The angle formed by these two perpendicular lines is the angle that defines the arc.
The first concave segment 10 and the second concave segment 12 do not have to be symmetrical to the third concave segment 14 and the fourth concave segment 16, respectively, with respect to a plane formed by the longitudinal direction Z and the second transverse direction X, i.e. according to the ZX plane.
The longitudinal protrusions 18 are elements that provide strength to the assembly and reinforce the nose to withstand stresses received on the tooth or wear element. The protrusions 18 have a specific geometry that allows them to withstand stresses well. Furthermore, although it is not essential, it is optimal for the protrusions to have an outwardly convex surface.
As can be seen in Figure 3, the nose 6 has dimensions that are optimal. In a cross-section, perpendicular to the longitudinal direction of the nose 6, there is: a first inflection point I1 at the junction of the first concave segment 10 with the protrusion 18, a second inflection point I2 at the junction of the second concave segment 12 with the protrusion 18, and two points of maximum width A1 and A2 each wherein a tangent to the cross-section is perpendicular to the second transverse direction. Between points A1 and A2 there is a distance A measured in the direction of the second transverse direction. This distance A corresponds to the total width of the nose 6. Between point A1 and point I1 there is a distance B, measured in the direction of the second transverse direction. Between point I1 and point I2 there is a distance C, which corresponds to the width of the protrusion 18, measured in the direction of the second transverse direction. The ratio between C and A is between 0.25 and 0.60.
Furthermore, as can be seen in Figure 15, this geometry of the nose 6 allows vertical forces Fv and horizontal forces Fh to be transmitted from the free end of the nose 6, through the protrusion 18 of the nose 6, towards the lip of the mouth of the earthmoving machine. As a result of the longitudinal protrusion, the transmission of stresses originating from vertical forces Fv and horizontal forces Fh from the wear element to the adapter is improved.
Moreover, as can be seen in Figures 4 and 13, the cavity 8 of the wear element 4 has an internal segment and an outlet segment. The internal segment is close to the bottom 46 of the cavity 8 and the outlet segment is away from the bottom 46 of the cavity 8. That is, the outlet segment of the cavity 8 is where the nose 6 of the adapter 2 is introduced therein. As described below, both the internal segment and the outlet segment have contact surfaces which, in the assembled position, are in contact with the corresponding contact surfaces of the nose 6. That is, the contact surfaces of the outlet segment are in contact with the contact surfaces of the rear segment 26 of the nose 6, and the contact surfaces of the internal segment are in contact with the contact surfaces of the front segment 22 of the nose 6. Thus, as schematically depicted in Figure 10, the contact surfaces act as load-withstanding and load-transmitting surfaces, wherein the arrows indicate reaction forces. As mentioned above, the contact surfaces work when the wear element moves and, furthermore, the contact surfaces do not necessarily all work simultaneously. In fact, the contact surfaces work depending on the direction of the forces to which the wear element is subjected. Therefore, the fact that the contact surfaces are arc-shaped ensures that there is always contact between the corresponding contact surfaces.
In the internal segment of the cavity 8 there are arranged four internal contact surfaces 48 which are connected to each other by four outwardly concave clearance surfaces 50. In this way, between the outwardly concave clearance surfaces 30 of the nose 6 and the outwardly concave clearance surfaces 50 of the cavity 8, there is a space for fines (see Figure 12) and prevent them from being deposited in the contact areas. This space can also be used to check the wear of the wear element 4, as commented before.
Four contact surfaces comprising a first outwardly convex segment 36, a second outwardly convex segment 38, a third outwardly convex segment 40 and a fourth outwardly convex segment 42 are arranged in the outlet segment of the cavity 8.
The first convex segment 36 and the second convex segment 38 of the outlet segment of the cavity 8 extend according to the longitudinal direction and are symmetrical to each other according to a plane formed by the longitudinal direction and the first transverse direction. Each of the first 36 and second convex segments 38 extends according to a transverse plane, parallel to the two transverse directions, i.e. perpendicular to the longitudinal direction, an arc 20 comprised between 50° and 110°. Furthermore, as can be seen in Figure 4, between the first convex segment 36 and the second convex segment 38 there is a longitudinal recess 44. In the assembled position, the longitudinal recess 44 houses the corresponding protrusion 18 of the nose 6, and the first and second convex segments are in contact with the first and second concave segments of the nose 6, respectively.
The third convex segment 40 and the fourth convex segment 42 extend according to the longitudinal direction and are symmetrical to each other according to a plane formed by the longitudinal direction and the first transverse direction. Each of the third and fourth convex segments 42 extends according to a transverse plane, parallel to the two transverse directions, i.e. perpendicular to the longitudinal direction, an arc 20 comprised between 50° and 110°. In addition, between the third convex segment 40 and the fourth convex segment 42 there is another longitudinal recess 44. In the assembled position, the longitudinal recess 44 houses the corresponding protrusion 18 of the nose 6, and the third and fourth convex segments are in contact with the third and fourth concave segments of the nose 6, respectively.
Furthermore, the first convex segment 36 and the third convex segment 40 are symmetrical with respect to each other according to a plane formed by the longitudinal direction and the second transverse direction, and the second convex segment 38 and the fourth convex segment 42 are symmetrical with respect to each other according to a plane formed by the longitudinal direction and the second transverse direction.
As can be seen in Figures 8 and 9, the arcs 20 extending into the convex segments of the protruding segment of the cavity 8 are the same as the corresponding arcs 20 of the concave segments of the rear segment 26 of the nose 6. In addition, each of the concave segments of the rear segment 26 of the nose 6 and each of the convex segments of the protruding segment of the cavity 8 is a circular cylindrical surface.
Likewise, the wear element 4 also has on its outer surface, four outwardly concave surfaces 34, each corresponding to one of the first, second, third and fourth convex segments of the cavity 8. Each of them extends an arc comprised between 50° and 110° and is a circular cylindrical surface.
In this embodiment, a particular wear element 4 and adapter 2 assembly has been described. However, there are multiple variants. For example, the rear part 26 of the nose 6 of the adapter 2, instead of presenting four concave contact surfaces, may have only two concave contact surfaces joined by a longitudinal protrusion 18, and the cavity 8 would then have the respective contact surfaces. Similarly, the concave surfaces 34 arranged on the outer surface of the wear element 4 may be absent, or may be a number other than four.
Figures 16 to 18 show another embodiment according to the invention, in which at least one of the protrusions 18 has a longitudinal rib 54 protruding from the surface of the protrusion 18. In this embodiment, the longitudinal recess 44 of the cavity 8 of the wear element does not have a longitudinal groove. However, it could have a longitudinal groove suitable for housing the longitudinal rib 54 of the protrusion 18.
Figures 19 to 22 show another embodiment according to the invention, in which only one of the protrusions 18 has a longitudinal indentation 56, and the corresponding longitudinal recess 44 comprises a longitudinal projection 64 suitable for housing the longitudinal indentation 56 of the protrusion (see Figure 21). Furthermore, the nose 6 of the adapter comprises an outwardly convex upper front surface 28A and an outwardly concave lower front surface 28B, and the cavity 8 of the wear element has an outwardly concave upper wall 66 and an outwardly convex lower wall 68. Thus, the outwardly convex upper front surface 28A is housed in the outwardly concave upper wall 66 and the outwardly concave lower front surface 28B is housed in the outwardly convex lower wall 68 (see Figures 19 and 22). Although not depicted, the upper front surface 28A could be outwardly concave, the lower front surface 28B outwardly convex, the upper wall 66 outwardly convex and the lower wall 68 outwardly concave.
Figures 23 to 26 show another embodiment according to the invention, in which each of the protrusions 18 has an indentation 56.
Figures 27 to 30 and 33 to 41 show other embodiments according to the invention. In these embodiments, the rear segment 26 of the nose 6 has only two contact surfaces comprising outwardly concave segments, a first outwardly concave segment 10 and a second outwardly concave segment 12, that are in the lower part of the rear segment 26 of the nose 6. As in the previous embodiments, the first concave segment 10 and the second concave segment 12 extend according to the longitudinal direction and are symmetrical to each other according to a plane formed by the longitudinal direction and the first transverse direction, i.e. according to the YZ plane. Each of the first and second concave segments 10, 12 extends, according to a transverse plane, parallel to the two transverse directions (a plane parallel to the XY plane), i.e. perpendicular to the longitudinal direction (direction according to the Z axis), an arc 20 comprised between 50° and 110°. In fact, they correspond to the third concave segment 14 and the fourth concave segment 16 of the previous embodiments but, in order to be coherent with the nomenclature, and as there are only two of these concave segments, they have been named "first concave segment 10" and "second concave segment 12" for the description of these particular embodiments and figures. These embodiments combine some advantages that may be particularly useful in some cases: while having the advantages of having the two concave segments 10 and 12 they has also the advantage of having a greater contact surface 58 in the other side of the nose 6 (in the present example, in the upper side of the nose 6 (as seen in Figure 27)) although it could also be possible that the two concave segments 10 and 12 are in the upper side of the nose 6 and the greater contact surface 58 in the lower side of the nose 6). This greater contact surface 58 helps to reduce the local deformations in the contact surfaces and improves the reliability of the wear assembly and increases the durability of the nose of the adapter. It also allows to improve the design of the wear element so that the self-sharpening characteristic is enhanced.
In the case that the rear segment 26 of the nose 6 has only two contact surfaces comprising outwardly concave segments, as commented in the previous paragraph, and that the nose 6 also has a front segment 22, close to its free end 24 and a rear segment 26, away from the free end 24, wherein the first concave segment 10 and second concave segment 12 are in the rear segment 26, and the front segment 22 has four front contact surfaces 28 joined together by four clearance surfaces 30, it is possible to further introduce one of the following preferred solutions:

a) the clearance surfaces 30 that are in the opposite side of the nose 6 (according to plane XZ) of the side in which the first concave segment 10 and second concave segment 12 are (i.e., the clearance surfaces 30 that are in the upper part of the nose 6 in the example of Figures 27-31), are outwardly convex, and this outwardly convex surface extends not only along the front segment 22 but also along the rear segment 26. The corresponding internal clearance surfaces 50 in the internal segment of the cavity 8 are outwardly concave. This is the case shown in Figures 27, 29 and 33-35.
b) the clearance surfaces 30 that are in the opposite side of the nose 6 (according to plane XZ) of the side in which the first concave segment 10 and second concave segment 12 are, are flat (the section of the clearance surface with a plane parallel to the XY plane being a straight line), and this flat surface extends not only along the front segment 22 but also along the rear segment 26. The corresponding internal clearance surfaces 50 in the internal segment of the cavity 8 are also flat. This is the case shown in Figures 36-37.
c) the clearance surfaces 30 that are in the opposite side of the nose 6 (according to plane XZ) of the side in which the first concave segment 10 and second concave segment 12 are, are flat (the section of the clearance surface with a plane parallel to the XY plane being a straight line), and this flat surface extends not only along the front segment 22 but also along the rear segment 26. The corresponding internal clearance surfaces 50 in the internal segment of the cavity 8 are outwardly concave.
d) the clearance surfaces 30 that are in the opposite side of the nose 6 (according to plane XZ) of the side in which the first concave segment 10 and second concave segment 12 are, are outwardly concave, and this outwardly concave surface extends not only along the front segment 22 but also along the rear segment 26. The corresponding internal clearance surfaces 50 in the internal segment of the cavity 8 are outwardly convex. This is the case shown in Figures 38-39.
e) the clearance surfaces 30 that are in the opposite side of the nose 6 (according to plane XZ) of the side in which the first concave segment 10 and second concave segment 12 are, are outwardly concave, and this outwardly concave surface extends not only along the front segment 22 but also along the rear segment 26. The corresponding internal clearance surfaces 50 in the internal segment of the cavity 8 are flat. This is the case shown in Figures 40-41. In fact, Figures 28, 30-32 and 40-41 show a particularly preferred embodiment of the invention. It shares several characteristics with the embodiment of Figures 27, 29 and 33 to 39, but this particular shape of the clearance surfaces 30 and 50.

In the embodiments shown in Figures 27-41, the front contact surfaces 28 of the nose 6 that are perpendicular to the Y axis are both outwardly concave, and the corresponding internal contact surfaces 48 of the cavity 8 are both outwardly convex. In the embodiments of the remaining Figures these surfaces are flat. These two alternatives may be preferred solutions in specific cases. For example, the "flat alternative" is advantageous in the case of wear elements with vertical partition.
Furthermore, in this described embodiment, the wear element 4 and the adapter 2 are attached by a single pin 62 having the shape of a cylinder. As explained above, in the embodiment described, the pin is housed in the opening 32 of the nose 6 and in the two through openings 52 of the wear element 4. However, there are other variants. For example, two pins may be inserted, one through each through opening 52 of the wear element 4, or a single pin may be inserted into a through opening 52 and into the opening 32 of the nose 6. Also, the pin may be cylindrical in shape, in which case the axis of the pin will be substantially parallel to the axis of the opening 32 of the nose, or another shape such as, for example, a conical shape. In the latter case, the axis of the tapered pin will not be parallel to the axis of the opening 32 of the nose.
Finally, it is also contemplated that the cavity 8 could be arranged in the adapter 2 and that the wear element 4 could have the nose 6. In this case, all the features described above are maintained. The only difference is that the nose 6, instead of being in the adapter 2, is now in the wear element 4, and the cavity 8, instead of being in the wear element 4, is now in the adapter 2.

Claims

A wear assembly of an earthmoving machine, made up of an adapter (2) and a wear element (4), wherein one of said adapter (2) and wear element (4) has a nose (6) and the other of said adapter (2) and wear element (4) has a cavity (8) wherein, in an assembled position, said nose (6) is housed in said cavity (8), wherein said nose (6) has contact surfaces which, in said assembled position, are in contact with corresponding contact surfaces in said cavity (8), wherein said cavity (8) and said nose (6) define a longitudinal direction, wherein said cavity (8) and said nose (6) define a first transverse direction which is perpendicular to said longitudinal direction and which is parallel to a direction of maximum stresses, and wherein said cavity (8) and said nose (6) define a second transverse direction which is perpendicular to said longitudinal direction and to said first transverse direction, characterized in that said contact surfaces of said nose (6) comprise at least a first outwardly concave segment (10) and a second outwardly concave segment (12), wherein said first concave segment (10) and said second concave segment (12) extend according to said longitudinal direction and are symmetrical to each other according to a plane formed by said longitudinal direction and said first transverse direction, wherein between said first concave segment (10) and said second concave segment (12) there is a longitudinal protrusion (18), wherein each of said first and second concave segment (12) extends an arc (20) comprised between 50° and 110°, and said contact surfaces of said cavity (8) comprise at least a first outwardly convex segment (36) and a second outwardly convex segment (38), wherein said first convex segment (36) and said second convex segment (38) extend according to said longitudinal direction and are symmetrical to each other according to a plane formed by said longitudinal direction and said first transverse direction, wherein between said first convex segment (36) and said second convex segment (38) there is a longitudinal recess (44) suitable for housing said protrusion (18) in said assembled position, wherein each of said first and second convex segment (38) extends an arc (20) comprised between 50° and 110° and is in contact, in said assembled position, with said first concave segment (10) and said second concave segment (12), respectively.
The wear assembly according to claim 1, characterized in that each of said first concave segment (10), second concave segment (12), first convex segment (36) and second convex segment (38) is a circular cylindrical surface.
The wear assembly according to one of claims 1 or 2, characterized in that said nose (6) has a front segment (22), close to the free end (24) of said nose (6) and a rear segment (26), away from said free end (24), wherein said at least first concave segment (10) and second concave segment (12) of said nose (6) are in said rear segment (26), wherein said front segment (22) has four front contact surfaces (28) joined together by four outwardly concave clearance surfaces (30)and, preferably, said cavity (8) has an internal segment, close to the bottom (46) of said cavity (8) and an outlet segment, away from said bottom (46), wherein said at least first convex segment (36) and second convex segment (38) of said cavity (8) are in said outlet segment, wherein said internal segment has four internal contact surfaces (48), each in contact with a corresponding front contact surface in said assembled position, said internal contact surfaces (48) being joined together by four outwardly concave clearance surfaces (50).
The wear assembly according to any one of claims 1 to 3, characterized in that said contact surfaces of said nose (6) additionally comprise a third outwardly concave segment (14) and a fourth outwardly concave segment (16), wherein said third concave segment (14) and said fourth concave segment (16) extend according to said longitudinal direction and are symmetrical to each other according to a plane formed by said longitudinal direction and said first transverse direction, wherein between said third concave segment (14) and said fourth concave segment (16) there is a longitudinal protrusion (18), wherein each of said third and fourth concave segment (16) extends an arc (20) comprised between 50° and 110°, and said contact surfaces of said cavity (8) comprise at least a third outwardly convex segment (40) and a fourth outwardly convex segment (42), wherein said third convex segment (40) and said fourth convex segment (42) extend according to said longitudinal direction and are symmetrical to each other according to a plane formed by said longitudinal direction and said first transverse direction, wherein between said third convex segment (40) and said fourth convex segment (42) there is a longitudinal recess (44) suitable for housing said protrusion (18) in said assembled position, wherein each of said third and fourth convex segment (42) extends an arc (20) comprised between 50° and 110° and is in contact, in said assembled position, with said third concave segment (14) and said fourth concave segment (16), respectively and, preferably, each of said third concave segment (14), fourth concave segment (16), third convex segment (40) and fourth convex segment (42) is a circular cylindrical surface.
The wear assembly according to claim 4, characterized in that said first convex segment (36) and said third convex segment (40) are symmetrical to each other according to a plane formed by said longitudinal direction and said second transverse direction, and in that said second convex segment (38) and said fourth convex segment (42) are symmetrical to each other according to a plane formed by said longitudinal direction and said second transverse direction.
The wear assembly according to any one of claims 1 to 5, characterized in that said nose (6) is in said adapter (2) and said cavity (8) is in said wear element (4) and, preferably, said wear element (4) has, on its outer surface, at least two outwardly concave surfaces (34), each of them in correspondence with one of said first and second convex segment (38) of said cavity (8).
The wear assembly according to any one of claims 1 to 6, characterized in that, in a cross-section of said nose (6), there is: [a] a first inflection point I1 at the junction of said first concave segment (10) with said protrusion (18), [b] a second inflection point I2 at the junction of said second concave segment (12) with said protrusion (18), and [c] two points of maximum width A1 and A2 each wherein a tangent to said cross-section is perpendicular to said second transverse direction, wherein
between said points A1 and A2 there is a distance A, measured in the direction of said second transverse direction,

between said point A1 and said point I1 there is a distance B, measured in the direction of said second transverse direction, and

between said point I1 and said point I2 there is a distance C, measured in the direction of said second transverse direction,

wherein the ratio of C to A is between 0.25 and 0.60.
The wear assembly according to any one of claims 1 to 7, characterized in that said protrusion (18) of said adapter (2) has a longitudinal rib (54) and, preferably, said longitudinal recess (44) of said cavity (8) of said wear element further has a longitudinal groove.
The wear assembly according to claim 4 or any one of claims 5 to 7 when it depends on claim 4, characterized in that one, and only one, of said protrusions (18) has a longitudinal indentation (56).
The wear assembly according to claim 4 or any one of claims 5 to 7 when they depend on claim 4, characterized in that each protrusion (18) has a longitudinal indentation (56).
The wear assembly according to any one of claims 9 and 10, characterized in that at least one of said longitudinal recesses (44) of said cavity (8) of said wear element (4) comprises a longitudinal projection (64).
The wear assembly according to claim 3 or any one of claims 4 to 11 when they depend on claim 3, characterized in that said front surfaces (28) of said nose (6) comprise an upper front surface (28A) and a lower front surface (28B), opposite said upper front surface (28A), wherein one of said upper front surface (28A) and said lower front surface (28B) is outwardly concave and said other one is outwardly convex.
The wear assembly according to claim 3 or any one of claims 4 to 12 when they depend on claim 3, characterized in that said cavity (8) has an upper wall (66) adjacent to said bottom (46) and a lower wall (68) adjacent to said bottom (46) and opposite said upper wall (66), one of said upper wall (66) and lower wall (68) being outwardly concave and said other one being outwardly convex.
A wear element (4) of an earthmoving machine, suitable for being attached to an adapter (2), wherein one of said adapter (2) and wear element (4) has a nose (6) and the other of said adapter (2) and wear element (4) has a cavity (8) wherein, in an assembled position, said nose (6) is housed in said cavity (8), wherein said nose (6) has contact surfaces which, in said assembled position, are in contact with corresponding contact surfaces in said cavity (8), wherein said cavity (8) and said nose (6) define a longitudinal direction, wherein said cavity (8) and said nose (6) define a first transverse direction which is perpendicular to said longitudinal direction and which is parallel to a direction of maximum stresses, and wherein said cavity (8) and said nose (6) define a second transverse direction which is perpendicular to said longitudinal direction and to said first transverse direction, characterized in that said contact surfaces of said nose (6) comprise at least a first outwardly concave segment (10) and a second outwardly concave segment (12), wherein said first concave segment (10) and said second concave segment (12) extend according to said longitudinal direction and are symmetrical to each other according to a plane formed by said longitudinal direction and said first transverse direction, wherein between said first concave segment (10) and said second concave segment (12) there is a longitudinal protrusion (18), wherein each of said first and second concave segment (12) extends an arc (20) comprised between 50° and 110°, and said contact surfaces of said cavity (8) comprise at least a first outwardly convex segment (36) and a second outwardly convex segment (38), wherein said first convex segment (36) and said second convex segment (38) extend according to said longitudinal direction and are symmetrical to each other according to a plane formed by said longitudinal direction and said first transverse direction, wherein between said first convex segment (36) and said second convex segment (38) there is a longitudinal recess (44) suitable for housing said protrusion (18) in said assembled position, wherein each of said first and second convex segment (38) extends an arc (20) comprised between 50° and 110° and is in contact, in said assembled position, with said first concave segment (10) and said second concave segment (12), respectively.
An adapter (2) of an earthmoving machine, suitable for supporting a wear element (4), wherein one of said adapter (2) and wear element (4) has a nose (6) and the other of said adapter (2) and wear element (4) has a cavity (8) wherein, in an assembled position, said nose (6) is housed in said cavity (8), wherein said nose (6) has contact surfaces which, in said assembled position, are in contact with corresponding contact surfaces in said cavity (8), wherein said cavity (8) and said nose (6) define a longitudinal direction, wherein said cavity (8) and said nose (6) define a first transverse direction which is perpendicular to said longitudinal direction and which is parallel to a direction of maximum stresses, and wherein said cavity (8) and said nose (6) define a second transverse direction which is perpendicular to said longitudinal direction and to said first transverse direction, characterized in that said contact surfaces of said nose (6) comprise at least a first outwardly concave segment (10) and a second outwardly concave segment (12), wherein said first concave segment (10) and said second concave segment (12) extend according to said longitudinal direction and are symmetrical to each other according to a plane formed by said longitudinal direction and said first transverse direction, wherein between said first concave segment (10) and said second concave segment (12) there is a longitudinal protrusion (18), wherein each of said first and second concave segment (12) extends an arc (20) comprised between 50° and 110°, and said contact surfaces of said cavity (8) comprise at least a first outwardly convex segment (36) and a second outwardly convex segment (38), wherein said first convex segment (36) and said second convex segment (38) extend according to said longitudinal direction and are symmetrical to each other according to a plane formed by said longitudinal direction and said first transverse direction, wherein between said first convex segment (36) and said second convex segment (38) there is a longitudinal recess (44) suitable for housing said protrusion (18) in said assembled position, wherein each of said first and second convex segment (38) extends an arc (20) comprised between 50° and 110° and is in contact, in said assembled position, with said first concave segment (10) and said second concave segment (12), respectively.