Patent Application
20250067029
The present disclosure relates to a shovel lip for earth moving machines. More specifically, the disclosure relates to optimising the structure of an excavation lip to improve the performance of an excavation shovel or bucket.
Earth moving machines such as hydraulic excavators, cable excavators, draglines or loaders are commonly used for mining, construction and other applications. In general, earth moving machines comprise a shovel or bucket in which the material is collected.
The shovels or buckets comprise a lip, welded to a surface of the shovel or bucket. The lip comprises a plurality of projections, called noses or adapters, on which a plurality of points or teeth are mounted. These points or teeth have the dual function of penetrating and scraping the ground, as well as protecting a portion of the front of the lip. The teeth or points are provided with a cavity with a geometry complementary to the geometry of the noses or projections of the lips so that the teeth or points engage in the noses or projections. More specifically, the engageable portions of the cavities of the teeth and the projections of the lip are provided with contact surfaces, which form the engaging area, which enable the transmission of forces from the tooth or point to the lip, enabling the flow of stresses from the tooth to the lip and then to the shovel or bucket, relieving the teeth and noses of the working stresses, which prolongs the useful life of points and noses as it takes longer to produce breaks or excessive wear on these elements.
In addition, the lip is also provided with other protective elements called shrouds. The shrouds are located on the front of the lip, specifically in the space between the noses. The shrouds also have the dual function of penetrating and scraping the ground, although to a lesser extent than the points, and they also have the function of protecting the lip area.
The lip, the shrouds and said teeth or points have direct contact with the ground and the excavated material, so these elements are subjected to high forces and great wear. Faced with prolonged wear, the teeth or points and the shrouds have to be replaced with new ones. To facilitate the assembly and disassembly of the teeth, the teeth are detachably fixed to the adapters or noses with the help of a fixing device and the shrouds are attached to the lip by welding or mechanically with the help of a pin.
The passage of the forces in the noses to the main body of the lip is conditioned by the geometric transition between both, i.e., by the type of geometry of the attachment between the noses and the main body.
For example, US2013008062A1, U.S. Pat. No. 9,903,092B2, WO2019/020844A1 and US2007/051022 describe lips wherein the cross section of the nose is considerably greater than the front cross section of the main body of the lip, i.e., the height of the nose is greater than the height of the front of the main body. These lips are mechanically rigid due to the considerable volume of the main body of the lip, although the attachment portions of the main body of the lip and the noses have a variable cross section to assimilate the difference in cross section between the nose and the front cross section of the main body. The portions with variable cross section concentrate the stresses and do not allow the forces to flow uniformly towards the shovel or bucket. Specifically, there are two critical areas so that the lip can properly withstand work forces.
Specifically, US2007/051022, provides a cutting lip of an excavation device such as a dragline bucket which, provided with at least a mounting nose, which is as integrally formed with a cutting lip. Said nose includes a pair of opposed tapered forwardly convergent side faces, a front face and upper and lower faces converging towards front face. Upper and lower faces each include planar rear bearing faces and planar forward bearing faces separated by a tapered generally planar intermediate face.
A first compromised area is the attachment or transition area of the noses or projections of the lip with the main body of the lip. The geometry of the main body of the lip is laminar, i.e., flat and elongated. The noses have a geometry complementary to an internal geometry of the tooth. On the one hand, these nose and tooth cross sections must be strong enough to absorb the forces produced at the tip of the tooth and transmit them to the main body of the lip without causing cracks or breaks in said nose and, on the other hand, said nose cross sections must allow good penetration, i.e., the nose cross section must be a cross section with a height balanced between its height with sufficient resistance and at the same time a cross section height that enables a good penetration. Therefore, the cross sections or attachment areas between the noses and the main body of the lip are areas that must adapt or compensate for the difference in height of the two sections, must enable the flow of stresses from the tip of the tooth to the lip, and preferably enable it without the appearance of extremely stress-concentrating points wherein, in the event of a prolongation of the force or a considerable increase in this force, these points become break points or cracks of the lip. In addition, a good penetration into the ground is also important for the energy consumption of the machine as it reduces the power required by the machine to break through the ground.
A second compromised area is the lateral ends of the lip. The lateral ends of the lip are attached to the side of the bucket or shovel. When the machine is working and the bucket is pulling out and loading material, the lip tends to flex due to the force and weight of the material. As the lips are fixed to the fixed sides of the bucket, stresses are produced in this lateral area of the lip that weaken the area, also being an area of high force concentrations that can become areas of breakage or the appearance of cracks.
Therefore, an objective of the present disclosure is to provide a shovel lip for earth moving machines that enables productivity to be increased by means of one or more of the following: reducing the time of load cycles, reducing energy consumption of the machine, increasing the penetration of the lip into the ground, and eliminating portions that can crack or break, also resulting in a lower maintenance cost.
A first aspect relates to a lip for an earth moving machine shovel including:
The main body includes a first portion, also referred to as the rear portion in the present disclosure, adapted to be coupled to the shovel, and a second portion, also referred to as the front portion or attack front of the lip in the present disclosure, which has a certain inclination relative to the first portion. The inclination, which is also called the angle of attack, enables the lip (typically teeth) to contact the ground at an angle of attack that improves penetration. Depending on the type of earth moving machine, the inclination can be, for example, but not limited to, between 10° to 12° (both limit values being included in the range); for some types of operations, the inclination is greater and can be, for example, 21°.
The noses are the elements to which the teeth or points are coupled, so the teeth or points must have a cavity with a geometry complementary to the geometry of the noses, which is protruding. The noses have a first side or end, also called the front or free end, and a second side or end, also called the rear end, fixed to the front of the main body. Each nose has two or more stabilisation surfaces, these stabilisation surfaces are the surfaces that at least partially contact the complementary surfaces of the tooth cavity and, in some embodiments, with surfaces of shrouds, which extend to the second end, specifically up to the attack front of the lip, creating a so-called constant transmission surface for the purposes of the present disclosure; the stabilisation surfaces of each nose can extend from the first end. The stabilisation surfaces are preferably located on the upper and lower surfaces of the nose and extending to the upper and lower surfaces of the attack front, that is to say, to a part between a pair of noses (but not necessarily extending throughout the entire portion between pairs of noses), and where the shrouds may be positioned, thus having constant transmission upper and lower surfaces. To this end, preferably, at least one transmission surface between each nose and the main body (which includes at least a portion of a stabilisation surface of the nose and a portion of the main body surface) has a slope variation of between 0° and 10° (both limit values being included in the range) in absolute value.
In some embodiments, each nose has at least two pairs of the transition or stabilisation surfaces, one pair in the upper surface of the nose and another pair in the lower surfaces of the nose. Each pair of stabilisation surfaces is separated by a rib, each stabilisation surface is positioned in the laterals/ends of upper and/or lower surface of the nose, side by side with the rib. This position of the pair of stabilisation surfaces related to the rib, allows for positioning the transition segment of the nose, secant or with 0° of inclination regarding the transition zone segment of the front portion of the lip, in height,
The transition or stabilisation surfaces include at least a portion of a stabilisation surface of the nose, in the direction that the noses protrude from the main body, and further they include a portion of the main body surface following the same protruding direction, and advantageously in a length direction of the main body, that is to say, through at least part of the portion of the main body surface between each pair of noses.
A transmission surface with a slope variation equal to or less than 10° is considered, for the purposes of the present disclosure, a constant transmission surface by causing the forces to propagate from the front portion of the lip towards the rear portion of the lip with smaller stress-concentrating areas or volumes. By reducing or minimising said stress-concentrating areas or volumes, the probability of a crack or break in the lip is also reduced as forces flow more homogeneously through the lip. The term “transmission surface” or “force transmission surface” has been used for the sake of clarity, however, it should be understood that such surface may simply be referred to as a surface without departing from the scope of the present disclosure.
The wider the area of the at least one transmission surface with little or no slope variation, the more effectively the forces propagate and the less likely it is to crack or break. Therefore, although the at least one transmission surface includes the surface of the lip closest to a secant plane that delimits the front portion of the main body from the rear portion of the nose, in preferred embodiments said at least one transmission surface extends beyond the area immediately contiguous to that delimited by the secant plane. In this sense, each transmission surface of the at least one transmission surfaces can include a surface of the respective nose that extends more than 10% of the length of the nose (the length being measured along an axis defined by the direction in which the nose protrudes from the main body), and/or may include a surface of the main body that extends more than 5% of the length of the main body (the length being measured along the same axis with which the length of the noses is measured). For the purposes of the present disclosure, although the terms “length of the noses” and “length of the main body” are used, these terms should not necessarily be interpreted as the maximum dimension of the noses and of the main body since they may not be the maximum dimension thereof. In fact, typically at least in the main body the dimension referred to herein as length is not the greatest and the same can happen with the noses. The term “width” can be used analogously to refer to the same dimension without departing from the scope of the present disclosure.
In some embodiments, the lip includes two lateral walls protruding from the main body.
In some embodiments, each transmission surface includes a stabilisation surface of the respective nose that extends between 25% and 75% (both limit values being included in the range) of the length of the nose. In some of these embodiments, the stabilisation surface of the respective nose extends more than 50% of the length of the nose.
In some embodiments, each transmission surface includes a main body surface extending between 10% and 50% (both limit values being included in the range) of the length of the main body. In some of these embodiments, the surface of the main body extends between 20% and 35% (both limit values being included in the range) of the length of the main body.
In some embodiments, the slope variation of each transmission surface of the at least one transmission surfaces is between 0° and 5° (both limit values being included in the range). In some of these embodiments, the slope variation of each transmission surface of the at least one transmission surfaces is between 0° and 1° (both limit values being included in the range). In some of these embodiments, the slope variation of each transmission surface of the at least one transmission surfaces is 0°, i.e., each transmission surface is contained in a single plane.
Fewer stress-concentrating areas or volumes exist and/or such areas or volumes are less significant, which further reduces the probability of a crack or break in the lip due to the forces and stresses to which the lip is subjected.
In some embodiments, each at least one transmission surface includes a first transmission surface and a second transmission surface. In these embodiments, both the first and second transmission surfaces have a slope variation as noted above. In some of these embodiments, the first transmission surface is a surface opposite the second transmission surface. For example, but not limited to, the first transmission surface is an upper surface of the main body and the respective nose, and the second transmission surface is a lower surface of the main body and the respective nose. In the context of the present disclosure, the upper and lower surfaces of the main body are the surfaces of the main body with the greatest extension, and the upper and lower surfaces of the noses are those extending from the upper and lower surfaces of the main body.
The existence of the first and second transmission surfaces with reduced slope variation makes it possible to achieve a propagation of forces towards the rear portion of the lip that is more effective and with less probability of cracks or breaks since the forces propagate through both surfaces. Depending on how the force is applied to the lip, especially during the excavation operation, sometimes the force is more intense on the first transmission surface and on other occasions the force is more intense on the second transmission surface, therefore, it is preferable to have both surfaces.
It is considered advantageous that the height of the nose tends to be the same as the height of the main body of the lip, avoiding a sudden change in cross section between the two elements of the lip. In other words, the upper and lower surfaces of the nose are a flat or substantially flat surface with the upper and lower surfaces of the main body of the lip.
In some embodiments, each at least one transmission surface includes first, second, third, and fourth transmission surfaces. In these embodiments, the four transmission surfaces have a slope variation as noted above. In some of these embodiments, the first and second transmission surfaces are surfaces opposite the third and fourth transmission surfaces. For example, but not limited to, the first and second transmission surfaces are an upper surface of the main body and of the respective nose, preferably one on each side of a reinforcing rib, and the third and fourth transmission surfaces are a lower surface of the main body and of the respective nose; in these examples, preferably one on each side of a reinforcing rib.
In some embodiments, at least one surface between one or both sides of each nose and the main body has a continuous transition geometry.
The continuous transitions between nose sides and a front surface of the main body mean that there is no cross-section change between these lip surfaces. In the context of the present disclosure, the term “continuous transition geometry” is understood as the geometry of a surface or contour wherein the slopes of tangent lines or normal vectors that define the respective surface do not present a discontinuity; i.e., if the slope of tangent lines or normal vectors taken at contiguous points of the surface with continuous transition geometry is calculated and represented, the evolution of the slope is in the form of a straight line or curve without discontinuities since the discontinuities are indicative of a sudden slope change (and therefore of curvature).
The attachments between the lateral portion(s) of the noses and the main body with continuous transition geometry reduce or minimise the stress that occurs on the surfaces of the attachments and that tend to produce cracks or breaks. The smaller the slope variation of the tangent lines or normal vectors, the better the mechanical behaviour of these surfaces.
In some embodiments, each nose comprises one or two reinforcing ribs. When the noses comprise two reinforcing ribs, each rib is on a different surface of the nose, particularly on opposite surfaces. Preferably, the reinforcing rib of each nose extends to the main body in the case of central noses, or to a lateral wall in the case of corner noses. Preferably, the reinforcing rib of each nose extends to the rear portion of the lip, which is the portion that is fixed to the shovel. The rear portion of the lip is subjected to lower stresses than the attack portion; in addition, the attachment of the rear portion to a larger element such as the shovel helps to dissipate the stresses towards the shovel, for this reason it is advantageous that the ribs extend to the rear portion of the lip, transferring the resistant structural cross section to the noses.
In some embodiments, on the two corner noses, a reinforcing rib extends to one of the lateral walls. In such embodiments, each lateral wall preferably has an attachment surface with a continuous transition geometry. The continuous transition geometry can have a curved profile; in such a case, the curved profile preferably has a surface with a radius of curvature such that it provides a smooth integration surface between the reinforcing rib of the respective nose and the respective lateral wall of the lip. Furthermore, the radius of curvature must enable the insertion of the point or tooth, i.e., the radius must enable a smooth transition surface and that the cavity of the point or tooth can be fully inserted into the nose. The dimension of the radius is determined by the height of the rib of the nose; if the nose is higher, the attachment area with the side is smaller and, consequently, the radius is smaller and the area worsens by concentrating more stresses. Preferably, the radius of curvature is equal to or greater than 1.8 times the maximum height of the nose; preferably, the radius of curvature is equal to or less than 3.0 times the maximum height of the nose. The lateral walls of the lip can be fixed to the side of the shovel once the lip is welded to the shovel.
In some embodiments, the reinforcing ribs protrude superiorly and inferiorly from the upper and lower surfaces of each nose. In this way, the resistant cross section of each nose is reinforced.
In some embodiments, a ratio of the maximum height of each nose divided by the maximum height of the main body has a value between 0.90 and 1.10. Preferably, the value of the ratio is between 0.95 and 1.05, more preferably it is between 0.98 and 1.02, and more preferably it is equal to 1.00.
In order to achieve a better penetration of the shovel, and more particularly of the teeth or points, in the ground to be excavated, it is important to have cross sections of noses as integrated to the lip as possible, i.e., that the noses have a height that is similar to the height of the main body of the lip.
It is preferable that the lip has a balanced behaviour between the resistance required to withstand the work forces and penetration of the teeth in the ground. For this reason, it is advantageous for the noses to be as short and low as possible and that, consequently, the teeth that are coupled to said noses to have a length and a height for improving penetration into the ground. The closer the height of the nose is to the height of the main body, the more the lip will penetrate into the ground. In addition, in those embodiments wherein the geometry of the noses is shorter, a reduction of the lever force of the teeth with the ground is achieved, increasing the material removal power of the machine and, as a consequence, reducing the times of the load cycle. In addition, a shorter nose geometry reduces the weight of the entire lip due to less volume and therefore less mass.
The maximum height of the noses is measured considering the reinforcing rib or ribs in the event of comprising them. The maximum height of the main body is measured without considering the lateral walls or reinforcing ribs of noses, in the event of comprising them, even though the ribs extend over the main body.
In some embodiments, a ratio of the maximum height of the main body divided by the height of the main body on the surface of a rear side adapted to be fixed to a surface of the shovel has a value between 1.60 and 2.00. Preferably, the value of the ratio is between 1.70 and 1.90, and more preferably it is between 1.75 and 1.85.
In some embodiments, a ratio of the maximum height of each nose divided by the height of the main body on the surface of a rear side adapted to be fixed to a surface of the shovel has a value between 1.60 and 2.00. Preferably, the value of the ratio is between 1.70 and 1.90, and more preferably it is between 1.75 and 1.85.
It is known in the field that the surface of the lips adapted to be fixed to the shovel has a height (which can also be referred to as a thickness) typically standard for a particular shovel size. The lip that meets one or both of the above ratios is lower than others that are known (which have a ratio greater than 2.00) due to the fact that the noses are flat or substantially flat with respect to the main body. As the lip is lower, the total volume and therefore the mass or weight of the lip is reduced. The energy consumption of the machine is lower when it moves the shovel due to the lower weight.
In addition, when the lip meets the ratio or ratios, a given shovel size being considered, the noses of the lip and/or teeth may have a reduction in thickness or height and/or in length of at least between 20% and 30% compared to noses and teeth of known lips with the smallest noses and teeth, and also a reduction of at least between 10% and 20% in mass of the lip and teeth than known lips and teeth.
In some embodiments, a ratio of the maximum height of each nose divided by the maximum thickness of each lateral wall has a value between 1.20 and 1.60. Preferably, the value of the ratio is between 1.30 and 1.50, and more preferably it is between 1.35 and 1.45.
In some embodiments, a ratio of the maximum height of the main body divided by the maximum thickness of each lateral wall has a value between 1.20 and 1.60. Preferably, the value of the ratio is between 1.30 and 1.50, and more preferably it is between 1.35 and 1.45.
It is known in the field that lateral walls have a typically standard thickness for a particular shovel size. The lip that meets one or both of the above ratios is narrower than others that are known (which have a ratio greater than 2.00) due to the fact that the noses are flat or substantially flat with respect to the main body.
In addition, when the lip meets the ratio or ratios, a given shovel size being considered, the noses of the lip and/or teeth may have a reduction in thickness or height and/or in length of at least between 20% and 30% compared to noses and teeth of known lips with the smallest noses and teeth, and also a reduction of at least between 10% and 20% in mass of the lip and teeth than known lips and teeth.
All limit values for the ranges indicated in relation to the previous ratios are also included in said ranges. It should be understood that the ratios can also be reversed without departing from the scope of the present disclosure, in which case the aforementioned values are raised to the power of −1.
In some embodiments, the lip further comprises a plurality of teeth removably couplable with the noses.
In some embodiments, the main body has portions between each pair of noses, each portion being adapted to receive a shroud.
The portions between each pair of noses are contact areas that normally make contact with the excavated material. To prolong the life of the lip, these portions are arranged so that a shroud can be removably coupled.
In some embodiments, the lip further comprises a plurality of shrouds that protect a front portion of the lip, the shrouds being at the front of the main body, specifically in the portions of the main body between each pair of noses.
In some embodiments, the lip further includes two shrouds at ends of the main body, particularly a shroud between each lateral wall and an adjacent edge of the main body.
In some embodiments, the lip further comprises a plurality of riser necks, and each riser neck follows a reinforcing rib of each respective nose.
In some embodiments, each riser neck is on a surface of the main body opposite the surface from which the lateral walls protrude, i.e., on the lower portion of the main body.
The riser necks are advantageously outside the area of their respective nose, not forming part of the section of the nose, ensuring that the steel in the noses is without flaws and that, if said necks are to be machined, the noses are not damaged.
In addition, by positioning the riser outside the perimeter of the nose during the manufacturing of the lip as explained below, the shrouds can also cover a greater area behind the nose, thus protecting more of the rear area of the nose.
In some embodiments, the lip is manufactured by means of a casting process, wherein the mould that reproduces the lip is fed by liquid steel at different points and has multiple risers; the marks left by the risers when they have cooled and have been cut from the lip are called riser necks. In the design of the lip, the risers are at points where the geometry of the part goes from a larger to a smaller cross section, to promote a uniform cooling of the steel, which does not leave deficiencies in the part. The areas where there is more cross section is in the noses of the lip, that is why in parts of this type the risers are located near the nose.
The areas of the riser necks are areas that have not cooled uniformly and the steel may contain more impurities, so the area around the neck may be flawed and the quality of that area may not be suitable. With more similar profiles between the noses and the main lip body, these necks can be moved away from the nose area, reducing the likelihood of the steel of the nose being flawed.
Once the lip is cooled, the mark or neck left by the riser must be machined, after cutting the riser from the lip, the neck must be ground so that the final lip is smooth and does not enlarge the cross section of the main body of the lip, and it is advantageous to remove any possible machining from the nose area as machining could damage the nose.
A second aspect relates to a lip for an earth moving machine shovel including:
The lip has one or more of the following ratios:
All limit values for the ranges indicated in relation to the previous ratios are also included in said ranges. It should be understood that the ratios can also be reversed without departing from the scope of the present disclosure, in which case the aforementioned values are raised to the power of −1.
The lip provides greater penetration to the shovel, and more particularly to the teeth or points, during the excavation operation carried out by the machine. Moreover, the lip with one more of the above ratios a lip is achieved with a behaviour in balance between the resistance required to withstand the work forces and the penetration of the teeth into the ground.
Furthermore, the lip has a low height, and the total volume and therefore the mass or weight of the lip are reduced, as well as the energy consumption of the machine.
In some embodiments, the lip further includes at least one transmission surface between each nose and the main body (including at least a portion of a stabilisation surface of the nose and a portion of the surface of the main body) with a slope variation of between 0° and 10°, and preferably between 0° and 5°, and more preferably between 0° and 1° (the limit values being included in the ranges) in absolute value, and more preferably it is 0°.
In some embodiments, at least one surface between one or both sides of each nose and the main body has a continuous transition geometry.
In some embodiments, each nose comprises one or two reinforcing ribs.
In some embodiments, the lip includes two lateral walls protruding from the main body.
In some embodiments, on the two corner noses, a reinforcing rib extends to one of the lateral walls. In such embodiments, each lateral wall preferably has an attachment surface with a continuous transition geometry.
In some embodiments, the reinforcing ribs protrude superiorly and inferiorly from the upper and lower surfaces of each nose.
In some embodiments, each nose has at least two pairs of the transition or stabilisation surfaces, one pair in the upper surface of the nose and another pair in the lower surfaces of the nose.
In some embodiments, the lip further comprises a plurality of teeth removably couplable with the noses.
In some embodiments, the main body has portions between each pair of noses, each portion being adapted to receive a shroud.
In some embodiments, the lip further comprises a plurality of shrouds that protect a front portion of the lip, the shrouds being at the front of the main body, specifically in the portions of the main body between each pair of noses.
In some embodiments, the lip further includes two shrouds at ends of the main body, particularly a shroud between each lateral wall and an adjacent edge of the main body.
In some embodiments, the lip further comprises a plurality of riser necks, and each riser neck follows a reinforcing rib of each respective nose.
In some embodiments, each riser neck is on a surface of the main body opposite the surface from which the lateral walls protrude, i.e., on the lower portion of the main body.
In some embodiments, the lip is manufactured by means of a casting process.
A third aspect relates to a shovel for an earth moving machine that includes a shovel body, and a lip according to the first aspect or the second aspect welded to the shovel body.
In some embodiments, the shovel body includes two lateral walls, each of the two lateral walls of the shovel body being welded to a different lateral wall of the lip.
A fourth aspect relates to an earth moving machine including a shovel according to the third aspect.
The machine has the ability to perform the excavation operation with a lower risk of lip breakage than with other lips of the state of the art. The lower risk is due to the more effective transmission of forces and stress flow from the points or teeth to the lip and shovel. Additionally, the lip assembly with the points or teeth produces a smaller lever arm with respect to other assemblies of the state of the art, which in turn also reduces the forces to which the shovel is subjected during its operation, and especially during excavation, which is the most demanding operation at a mechanical level.
Moreover, the machine may be able to carry out excavation more efficiently due to the shovel with the lip. In this regard, the lower thickness or height of the main body and the noses, and also of the teeth or points, leads to a reduction in weight, while shorter noses and teeth reduce the lever force of the teeth with the ground.
In some embodiments, the machine has an operating weight greater than or equal to 100 tonnes, although this lip could be installed on smaller machines.
A fifth aspect relates to a method for manufacturing a lip as described in the first aspect or the second aspect. The method includes: introducing molten steel into a lip mould through one or more openings in the mould, the mould including a plurality of risers; cooling or waiting at least until the molten steel introduced into the mould solidifies; removing the plurality of risers from the lip made with the mould, for example, by means of machining.
In some embodiments, the method further includes positioning the one or more openings of the mould outside an area or section of one or more noses of the lip. That is to say, in some embodiments, the one or more openings of the mould are outside an area or section of one or more noses. The opening or openings of the mould are at a location such that the molten steel is not introduced directly from the outside to where the noses of the lip are, and thus it is introduced, for example, on the main body of the lip that is manufactured
In some embodiments, a plurality of risers of the mould comprises at least as many risers as there are noses on the lip, and wherein each riser of the plurality is at the end of a reinforcing rib of a different nose, the end being located in the main body. Preferably, the reinforcing ribs on which the risers or the riser necks are located are the reinforcing ribs on a lower surface of the lip.
In some embodiments, a plurality of risers of the mould comprises at least as many risers as there are noses on the lip, and wherein each riser of the plurality is out of a section of noses of the lip, i.e. the risers are not part of the noses. Preferably, the risers or the riser necks are located on a lower surface of the lip.
In some embodiments, the manufactured lip is a lip as described in the first aspect or the second aspect.
As a complement to the description provided herein, and for the purpose of helping to make the features of the described aspects more readily understandable, in accordance with embodiments thereof, said description is accompanied by a set of drawings constituting an integral part of the same, wherein by way of illustration and not limitation, the following has been represented:
A detailed explanation of embodiments of the present disclosure is provided below, with the aid of the figures described above, only as non-limiting examples. To facilitate understanding of the explanation, each figure shows Cartesian axes that have been represented in such a way that they are common to all figures; it should be understood that it is possible to use a different configuration of Cartesian axes without departing from the scope of the present disclosure.
The term “main body” is used to denote the body or portion of the lip that has a volume greater than that of the lateral walls 2 and noses 3, and from which the lateral walls 2 and noses 3 protrude. In this example, the main body 1a-1d extends mainly along the X and Z axes (although a portion 1b extends with some inclination as explained later), and has a height or thickness that is measured by means of the normal vector of the main plane wherein the corresponding portion 1a, 1b is contained. Also the surface of the shovel to which the lip is fixed extends mainly along the X and Z axes. In this example, the axis α, dependent on the angle of attack as will be explained later, is the axis used to define the length of the noses 3 and of at least the portion of the main body 1b from which the noses protrude, although at least the longitudinal axis of the main body 1a-1d would be the axis X since it is the axis wherein the maximum dimension of the main body 1a-1d is contained for axes defined in such a way that a rectangular prism that encloses the main body in a tangential way has the smallest possible volume.
The main body has at least two distinguished portions 1a, 1b: a first portion 1a with a longer first side 1d adapted for attaching the lip to an earth moving machine shovel, typically by means of welding between the first side 1d and a surface of the shovel; and a second portion 1b defining an angle of attack with respect to the first portion 1a and with a longer second side 1c from which the noses 3 protrude; thus, the second portion 1b does not extend on a plane defined by the axes X and Z but on a plane defined by the axis X and the axis α, with Y and Z components in this case. In the context of the present disclosure, the first side 1d is considered a rear side or portion of the lip, and the second side 1c is considered a front side or portion of the lip. For the sake of clarity only, the front side 1c has been illustrated in the portions between noses 3, however, it should be understood that the front side 1c extends along one or more front faces (when there are several faces, said faces may define, for example, a delta geometry as can be seen in the embodiment of
As is known in the art, the main body 1a-1d is provided with the front portion 1b with an angle of attack relative to the rear portion 1b so that the surface of the shovel that is to make contact with a material to be excavated also has the angle of attack; said portion 1b is the one that supports or wherein the teeth and lip shrouds are fixed. The direction of the second portion 1b relative to the first portion 1a is illustrated by the axis α.
The lateral walls 2 protrude from one of the two larger surfaces of the first and second portions 1a, 1b. In this example, the surface from which the lateral walls 2 protrude is considered the upper surface of the main body. The lateral walls 2 are arranged on opposite sides on said surface, although not necessarily on the edge of the main body as there may be a gap relative to the edge, and are adapted to be fixed to the lateral walls of the shovel. In some embodiments such as the one illustrated, each lateral wall 2 is centred relative to the respective corner nose 3.
The noses 3 protrude from the main body 1b with respect to the front side 1c, preferably in the direction of an axis according to the angle of attack that the second portion 1b forms with respect to the first portion 1a (axis α), and with stabilisation or contact surfaces 9a, in this case at least upper ones, which together with one or more surfaces of the main body 1a, 1b produce flat or substantially flat transition surfaces 4a as explained and observable in more detail with reference to
The stabilisation surfaces 9a, 9b and the transition surfaces 4a, 4b can be on both sides of the respective reinforcing rib 6a, 6b. In this sense, in preferred embodiments, each nose 3 has two stabilisation surfaces 9a in the upper portion, each one on one side of the reinforcing rib 6a, and another two stabilisation surfaces 9b in the lower portion, each one on one side of the reinforcing rib 6b.
Furthermore, the lip is also preferably provided with transition surfaces 5 between the lateral portion of the noses 3 and the front side 1c of the main body 1b which are continuous as explained and observable in more detail with reference to
In embodiments such as that illustrated in
Preferably, the lip has reduced dimensions in terms of height, and/or reduced dimensions in terms of the direction in which the noses 3 protrude, in this case along the axis α. In such embodiments, the lip meets one or more of the following ratios:
As can be seen in
As described above, in some other embodiments, the lip meets one or more of the above ratios and does not have constant transmission surfaces, i.e., a surface between the noses and the main body has a slope variation greater than 10°.
With reference to
In this example, at least one upper transmission surface 4a extending between an upper stabilisation surface 9a of each nose 3 and an upper surface of the main body 1b has a slope variation of between 0° and 10°.
To calculate the slope variation, in this example a first point 30a is taken on the upper stabilisation surface 9a of each nose 3, and a second point 30b on the upper surface of the main body 1b; preferably both points are close to the aforementioned plane 20′ (and which by way of illustration is represented more simply with the axis 20), but may be further apart within the transmission surface. The first point 30a has a tangent 31a or a normal vector 32a on the surface, and the second point 30b has a tangent 31b or a normal vector 32b on the surface. In the case of tangents 31a, 31b, these are taken such that they are contained in the same plane or in parallel planes. The slope variation is calculated as the smallest angle formed by both normal vectors 32a, 32b or both tangents 31a, 31b.
Preferably, the slope variation less than or equal to 10° is given for a surface extension that includes points at a certain distance from the aforementioned plane. To this end, reference is made to
The distances 22, 24 are measured according to the direction in which the noses 3 protrude from the main body 1b. The distance 22 from the first additional axis 21 to the axis 20 shows the length of surface extension of the nose 3 up to where the reduced slope variation is located and is preferably between 25% and 75% of the length of the nose (along the axis α in this example). The distance 24 from the second additional axis 23 to the axis 20 shows the length of surface extension of the main body 1b up to where the reduced slope variation is located, and is preferably between 10% and 50% of the length of the main body 1b (along the axis α in this example), and/or reaches the start of the portion of the main body 1b that forms an angle of attack with respect to the remaining portion of the main body.
Also illustrated in
Referring to
Surfaces 4b with the same slope variation characteristics but in the lower portion of the lip can be additionally or alternatively provided.
The useful life of the lip is longer the smaller the slope variation in the transmission surfaces 4a, 4b; therefore, the lip has a superior mechanical behaviour when there is no slope variation and the surface is contained in the same plane.
The surfaces 5 have continuous transition geometry when normal vectors or lines tangent to different points on the surface do not have a slope variation with respect to adjacent points indicative of an abrupt jump, that is, the slope variation can be represented with a curve without discontinuities. The greater the radius of curvature of the surfaces 5, the less the tendency to create stress-concentrating areas or volumes.
The shrouds are coupled to the main body 1b, specifically on the front portion of the lip that is between the projections or noses 3. The points 7 are coupled on the noses 3, for this purpose the points 7 are provided with an internal cavity with a geometry complementary to the geometry of the nose 3. In this way, the points 7 are coupled on the noses 3, the internal contact surfaces of each point 7 make contact with the contact or stabilisation surfaces 9a, 9b of the nose 3 enabling the fluid passage of the forces from the contact area of the point with the ground, to the lip and then to the shovel.
The shrouds make contact with the main body 1a, 1b with contact areas on the upper and lower surfaces of the main body 1b. There is also another contact area between the shrouds and the main body 1b, particularly on the surface of the front side 1c of the main body 1b between the noses 3.
In these embodiments, each nose 3 includes a reinforcing rib 6b on the lower surface adjacent to two contact or stabilisation surfaces 9b. The lip also includes riser necks 10 on the main body 1a. Each riser neck 10 is away from the respective nose 3, i.e., the riser necks 10 are further back than known lip necks, that is to say out of the nose section. Each riser neck 10 may be at one end of a reinforcing rib 6b, as in the example of
As can be seen in
Despite having referred to specific examples of the invention, it is evident for a person skilled in the art that the lips that have been described and illustrated are susceptible to a number of variations and modifications, and that all the mentioned details can be replaced with other technically equivalent ones without departing from the scope of protection defined by the attached claims.
In this text, the word “comprises” and its variants (such as “comprising”, etc.) should not be understood in an exclusive sense, i.e. they do not exclude the possibility of that which is described including other elements, steps, etc.
Moreover, the invention is not limited to the specific embodiments described herein, but rather encompasses, for example, the variations that a person skilled in the art could make (for example, regarding the choice of materials, dimensions, components, configuration, etc.), within the scope of what may be deduced from the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| EP21383213.2 | Dec 2021 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/087632 | 12/22/2022 | WO |
