Patent Application
20240191477
This application claims priority to Chilean Patent application No. CL 202203482, filed Dec. 7, 2022, the entire contents of which are incorporated herein by reference.
The invention is developed in the field of wear monitoring and control for electric excavator shovels, specifically, it refers to a set for monitoring and preventing wear of bushings and pins in pivoting connections in buckets of electric shovels.
Maintenance corresponds to those actions carried out on equipment, device, object, etc., with the objective of maintaining, repairing and/or restoring them to preserve them in adequate conditions that allow them to fulfill their function and, thus, ensure productivity and availability, reducing the probability of occurrence of failures that may occur during use.
Developing an appropriate maintenance strategy is essential to maximize the benefit of an activity, prolong the useful life, maintain the reliability of the equipment, prevent a production process from stopping, and reduce occupational risks. Lack of maintenance and/or inappropriate maintenance can generate critical failures, causing both unscheduled stoppages that affect the productivity and availability of equipment and risk situations that can generate accidents and affect people's health.
For certain equipment, an alternative to ensure its preservation is to replace critical parts, pieces or elements, previously identified, whose condition is essential to ensure its correct functioning. In many cases, these critical elements are subject to wear and tear, which is why they deteriorate during use. The timing of replacement of parts, pieces or elements is important in economic terms, being necessary to ensure that the costs associated with a preventive replacement are lower than the costs associated with an unforeseen failure or stoppage and that the replacement timing is adequate or optimal. Carrying out a replacement at inappropriate times or a component is in an operational state, a greater expense will be incurred that will increase production or operation costs over the years. On the contrary, replacing parts, pieces or elements over prolonged periods of time can put the quality and productivity of an operation at risk, as well as increase the probability of accidents.
Options to reduce replacement costs consist of implementing monitoring systems or programs to track the status of a component in order to detect when its replacement is necessary and/or reduce the wear to which the component is subjected to extend its useful life and the time in which replacement is necessary.
In particular, in electric excavator shovels, a critical element for its operation corresponds to the bushings in the pivoting connections of the shovel, where the wear of the bushings can cause critical failures in the operation, generating unscheduled stops that affect its productivity and availability, in addition, if there is a risk of accident. Currently, the state of a bushing, to determine its wear, is verified by removing the components or parts where they are installed, making it necessary to stop the operation of the blade, affecting the availability of the equipment since the process of disassembly and assembly of these parts is a complex task in terms of time and resources.
Among the causes of wear of the bushings in excavator shovels, is the interaction between pins and bushings in pivoting connections in the bucket of the shovel, when they rotate on their own axis during the movement of said bucket, where a bushing It has a pin inserted so that, during rotation, a relative movement is produced between the contact surfaces, generating wear on the bushing, where the wear generated by this rotation is mainly responsible for the premature deterioration of the bushings.
By virtue of the above, to ensure the operation and availability of the excavator shovel, it is necessary to implement a system that allows monitoring the status of a bushing, which does not interrupt the operation of the shovel, to determine the appropriate replacement time, in addition, to reduce the wear of said bushing to extend its useful life, reducing downtime.
Among the solutions available in the state of the art for monitoring the condition of bushings, document CL202101477 can be cited, which describes a wear or thickness monitoring kit for a bushing installed in an earth-moving machine, preferably in an ear of a bucket, where said bushing comprises on its external mantle, at least one shallow rectangular channel, where the kit comprises: at least one measurement module located in the rectangular channel that measures the wear of the bushing, being connected to a data acquisition module to determine the status of the bushing and define the management of maintenance, replacement or removal of the monitored bushing.
Another document that can be cited is document U.S. Pat. No. 6,080,982 which discloses wear detectors for a bearing element or bushing, which comprise: at least one package of fiber optic lines, where part of the optical fibers is embedded in a portion of element wear; a light emitter, connected to a first end of the fiber optic line and a light receiver, connected to a second end of the fiber optic line. The light emitter emits a first amount of light that is received by the light receiver, where a decrease in the light received occurs depending on the deterioration of the fiber optic line part embedded in the bearing element.
On the other hand, in the state of the art there are documents aimed at reducing the wear of the bushing, it is relevant to cite the document U.S. Pat. No. 9,587,375 that describes a shovel bucket with a padlock or padlock connected to a tongue or ear of the bucket by means of a pin that includes a bushing, wherein said pin is connected to an arm arranged perpendicular to the axis of rotation of the pin, wherein the end of the arm is arranged between connecting elements that restrict the movement of the pin.
In this way, none of the previous documents teaches a set of monitoring and prevention of wear of bushings and pins in connections in buckets of electric shovels that allows restricting the rotation of the pins to reduce premature wear of bushings and monitor the condition of the bushings without using electronic means or performing direct inspection of the component.
The invention refers to a set of monitoring and prevention of wear of bushings and pins in connections in buckets of electric shovels that has the objective of monitoring the condition of bushings to inform the moment of replacement of the component, in addition, to reduce wear by which is subjected to extend its useful life. The assembly comprises devices for locking pins in the bucket connections of electric excavator shovels, such as handles (bail) or padlocks (padlock), restricting the movement of the pins that interact with the bushings during the operation of the electric shovel bucket, preventing that rotate on their own axis so that rotational friction does not occur between said pin and the bushing, reducing wear. The set also includes wear indicators for the bushings of electric excavator shovels that use handles (bail) or padlocks (padlock), allowing you to monitor and report the wear status of the bushings, to schedule maintenance, replace components and avoid critical failure of components that may generate unscheduled stoppages.
The invention discloses a set for monitoring and preventing wear of bushings (4) and pins (2) in connections in buckets (16) of electric shovels.
The set comprises at least one pin-locking device (1) for the bushings (4) of electric excavator shovels that use padlocks (11) or handles (12), restricting the movement of the pins (2) that interact with the bushings (4) during the operation of the buckets (16) of electric excavator shovels, preventing them from rotating on their own axis (3); and wear indicators for the bushings (4) of shovels (16) electric excavators that use padlocks (11) or handles (12), to monitor and report the state of wear of said bushings, allowing the useful life of the buckets to be extended (16) and the components installed on it, thus improving the performance of the blade.
The pin locking devices (1) for an electric shovel bucket (16) restrict the movement of the pins (2) that interact with the bushings (4) during the operation of the bucket (16), preventing them from rotating on their own axis. (3) so that rotational friction does not occur between said pin (2) and bushing (4), reducing wear on said bushings (4) preventing their premature deterioration.
A pin-locking device (1) for electric excavator shovels with padlocks (11) or handles (12) are installed in each of the connections of the bucket (16) with the padlocks (11) or the handles (12). The connections of the bucket (16) with the padlocks (11) or the handles (12) comprise a pin (2) that connects an ear (6) of the bucket (16), by installing it in a housing of said ear (6), with the connection elements of a padlock (11) or handle (12); two removable shackles (9), at one of the ends of the pin (2), joined together by bolts in housings (10) at the ends of the removable shackles (9), which restrict the longitudinal movement of the pin (2); and a fin (8) or retaining arm located at the other end of the pin (2), being arranged perpendicular to the axis (3) of rotation of the pin (2), which comprises a rim that surrounds and joins said end of the pin (2) and a fin edge portion (8) that projects from said flange to connect or engage and be retained by a pin-locking device (1). The shackles (9) are removable, allowing the pin (2) to be inserted into the housing in the ear (6) of the bucket (16). A bushing (4) that receives rotational friction is included between the pin (2) and the ear (6) of the bucket (16) and padlock (11) or handle (12) connection elements. Once the pin (2) is in its final position, the shackles (9) are installed to prevent longitudinal movement of the pin (2), where the shackles (9) have a larger diameter than the bushing (4). of the bucket (16). The pin locking device (1) comprises retention elements attached to the bucket (16) that receive and retain the fin edge portion (8), restricting the longitudinal movement of the pin (2) and the rotational movement of the pin by limiting the movement of the fin edge portion (8) between said retaining elements.
In one embodiment, when the bucket (16) uses padlocks (11), the connection elements correspond to two guide straps (7), being installed in the upper front part of the bucket (16), on the outside of each connection of the bucket (16) bucket (16) between a lug (6) and padlock (11), the guide straps (7) being separated from each other, so that it allows receiving and retaining the fin edge portion (8). The guide straps (7) have a curved hexahedral shape, comprising a straight portion and a curved portion that deviates from the longitudinal axis of said straight portion, favoring the distribution of loads when the fin (8) is retained and allows relief. of the fin edge portion (8) allowing said fin (8) to be easily inserted/removed from the curved portion of the guide straps, ensuring that the fin (8) is retained in the straight portion and does not get stuck in an inappropriate position of the connecting elements. The guide straps (7) are arranged symmetrically on the upper front part of the bucket (16) so that they are separated from each other in such a way that the straight portions are parallel to each other and the curved portions deviate in opposite directions. The separation distance (B) of the guide straps (7) is between 1.04 to 1.08 times the width (C) of the extreme edge portion of the fin (8) so that there is a play that allows a certain degree of movement of the fin. fin (8) between the guide straps (7) without said fin (8) being able to free itself from them. The play between the guide straps (7) and the fin (8) is included because due to the wear of the bushing (4) during the operation of the blade, the position of the pin (2) may vary so that the portion of fin edge (8) moves between the guide straps and can be loaded on one of said guide straps (7), transferring loads that can cause the detachment of one of these, therefore, the play between the guide straps (7) and the fin (8) allows safe movement of the fin (8) preventing the locks from receiving the loads of the pin when its location changes due to wear.
In another embodiment, when the bucket (16) uses handles (12), the connection elements correspond to a fork-shaped piece (14) that is installed on the outer face of the connection ear (6) of the handle (12) of the bucket (16). This location does not obstruct the installation and removal of the pin (2) and does not affect the assembly and removal of the handle (12), in addition, the fork (14) is not exposed to the flow of material or being hit by rocks when loading the bucket (16), avoiding wear. The fork (14) comprises a first straight end and an opposite end that corresponds to a “C”-shaped opening mouth that allows receiving and retaining the fin edge portion (8) of the pin (2). The fork (14) is placed in the bucket (16) so that the straight end is attached to the outer face of the ear (6) of the bucket (16) so that the opening mouth is perpendicular to the edge portion of fin (8), being parallel to the axis of rotation of the pin (2). The opening (A) of the mouth of the fork (14) is between 1.04 to 1.08 times the width (C) of the end edge portion of the fin (8) so that there is a play that allows some movement of the fin (8) between said fork (14) without said fin (8) being able to be released from it. The play between the opening (A) of the fork mouth (14) and the fin (8) is included because, due to the wear of the bushing (4) during the operation of the blade, the position of the pin (2) can vary so that the fin edge portion (8) moves in the opening (A) and can be loaded on one of the edges, transferring loads that can generate the detachment of the fork (14), therefore, the Play between the opening (A) of the mouth of the fork (14) and the fin (8) allows safe movement of the fin (8) preventing the locks from receiving the loads of the pin when its location changes due to wear.
The C-shaped mouth of the fork (14) may have a partially inclined mouth, so that two mouth portions are defined in which the opening (A) in one mouth portion is larger than in the other portion, presenting a relief or relief angle to insert/remove the edge of the fin (8) easily and ensuring that said edge of the fin (8) is retained in the mouth of the fork. In particular, as shown in
The locking of the pin (2) occurs because the fin (8) is inserted either between the guide straps (7) or in the fork-shaped piece (14) depending on the type of bucket (16) used. Both the guide straps (7) and the fork-shaped piece (14) have a greater separation (A, B) than the width (C) of the end of the fin edge portion (8), producing play between both. During operation, the end of the fin edge portion (8) tends to rotate between the guide straps (7) or at the mouth of the fork-shaped piece (14), due to the normal operation of the blade or due to effect of the wear of the bushing (4), so that, in operation, the pin (2) experiences a small play movement that prevents the transfer of the load to the pin-locking device (1), without said pin (2) is released from the connecting elements. The particular shape of the connection elements allows the distribution of loads, preventing them from detaching from their installation position.
In one embodiment, the connection elements are joined to the bucket (16) by welding, being manufactured from high resistance steel.
The Wear Indicators for electric excavator shovels with locks (11) or handles (12) allow you to monitor the level of wear of the bushings (4) at the connections of the bucket (16) with the locks (11) or the handles (12).
A first wear indicator (15) is installed on each of the two connections of the bucket (16) with the padlocks (11) or the handles (12). Each of the first wear indicators (15) comprises a status plate (18) comprising at least three colors, these being a first color (20), a second color (21) and a third color (22), located in the external side of the connection ears (6) of a bucket (16); and an indicator element welded to the padlock (11) or to the handle (12), depending on the type of bucket (16), so that said indicator element moves together with the padlock (11) or handle (12). The indicator element will allow viewing or signaling at least one color of the status plate (18) representing a level of wear of the bushings (4). When there is wear in the bushing (4) in a connection ear (6), a displacement of the position of the elements in the bucket connections (16) is generated, due to the variation in the thickness of the bushing (4), so that a change occurs in the position of the indicator element, since it is attached to the padlock (11) or handle (12), the color or colors that are displayed or signaled are modified to represent the level of wear of the bushing (4). In one embodiment, the status plate (18) corresponds to a metal plate, hexahedral in shape, preferably straight with rectangular faces, where one of its largest faces is divided into at least three sections to include the three colors (20, 21, 22) that represent the wear levels and the opposite major face is attached to the bucket (16). The three sections divide the largest face of the state plate (18) transversely, said sections being able to have different lengths, where the section that includes the first color (20) is adjacent to one end of the state plate (18), the section that includes the third color (22) is adjacent to the other end of the status plate (18) and the section that includes the second color (21) is between the sections that include the first color (20) and to the third color (22), respectively. The length of each section is related to the thickness of the bushing (4) so that they represent a range of the amount of thickness of the bushing (4) that has been worn or that has been reduced relative to the thickness without wear. In one embodiment, the length of the status plate (18) corresponds to at least the thickness of the wall of the bushing (4). In one embodiment, the first color (20), the second color (21) and the third color (22) are, respectively, green, yellow and red.
In one embodiment, when the bucket (16) uses handles (12), a first wear indicator (15) is installed in each of the connections of the bucket (16) with the handles (12), as shown in the
In one embodiment, when the bucket (16) uses padlocks (11), a first wear indicator (15) is installed in each of the connections of the bucket (16) with the padlocks (11), as shown in the
The arrangement of the first wear indicator (15) with respect to the operating position of the padlock (11) or handle (12) at 45° is used since in said position the greatest wear can be seen due to the direction of wear (24) product of the rotation (25) of the lock (12) or handle (11) during the operation of the bucket (16).
Each color of the status plate (18) is related to the thickness of the upper or outer face of the bushing (4) that is experiencing wear. In this way, the indicator element will display or signal: the first color (20) when the outer face of the bushing (4) has a thickness between 85 to 100% of its thickness without wear; the second color (21) when the outer face of the bushing (4) has a thickness between 70 to 85% of its thickness without wear; and the third color (22) when the thickness of the outer face of the bushing (4) has a thickness less than 70% of its thickness without wear. In the case in which the bushing (4) has an outer face with a wear-free thickness of 35 mm, the indicator element displays or signals the first color (20) when said face has a thickness between 35 to 30 mm, the second color (21) when said face has a thickness between 30 to 25 mm, and the third color (22) when said face has a thickness less than 25 mm (wear greater than 10 mm).
In an alternative embodiment, the indicator element will display or signal; the first color (20) when the outer face of the bushing (4) has a thickness between 85 to 100% of its thickness without wear; the second color (21) when the outer face of the bushing (4) has a thickness between 25 to 85% of its thickness without wear; and the third color (22) when the thickness of the outer face of the bushing (4) has a thickness less than 25% of its thickness without wear.
In one embodiment, a second wear indicator (26) can also be included on the front of a door (30) of the buckets (16) to monitor wear on bushings (27) at the connections between the door (30) and the bucket (16). In this embodiment, the second wear indicator (26) is located on each side of the bucket (16), specifically, in at least one contact area between an edge of the door (27) and an edge of the bucket (16), comprising the second wear indicator (26) a bucket plate (28) and a door plate (29), identical, placed near the edge of the bucket (16) and the door (27), respectively. Both the bucket plate (28) and the door plate (29) include a horizontal reference line, which are aligned in an initial state without wear of the bushings (27). When wear occurs in the bushings (27), a displacement of the door occurs with respect to the bucket, so that the door plate (29) will move with respect to the location of the bucket plate (28), so that the reference lines of each plate will be misaligned, indicating wear. The bucket plates (28) and the door plate (29) have dimensions such that when the horizontal reference line of the door plate (29) is below the lower end of the bucket plate (28), it will be an indicator that the bushings (27) are in a state of severe or critical wear, requiring replacement of the bushing (27) to avoid critical failure. The distance between the horizontal reference line and one end of the bucket plate (28) and the door plate (29) is at most 70% of the thickness of the outer face of the bushing (27) when it is without wear, preferably being equal to 70% of the thickness of the outer face of the bushing (27) to indicate a state of severe or critical wear when the horizontal reference line of the door plate (29) is below the lower end of the bucket plate (28).
In an alternative embodiment, the distance between the horizontal reference line and one end of the bucket plate (28) and the door plate (29) is at most 25% of the thickness of the outer face of the bushing (27) when it is without wear, preferably being equal to 25% of the thickness of the outer face of the bushing (27) to indicate a state of severe or critical wear when the horizontal reference line of the door plate (29) is below of the lower end of the bucket plate (28). In one embodiment, the plates (28, 29) will be at the height of the rim that divides the bucket (16) in half, and on both sides (right and left), being an easily accessible area when the bucket (16) is at rest, having a suitable surface to mount every second wear indicator (26). This allows the separation distance between the bucket plate (28) and door plate (29) to be measured manually in order to verify the state of wear of the bushing (27).
Alternatively, the door plate (29) corresponds to a status plate (18) such as that of the first wear indicator (15), being arranged so that the longitudinal axis of the status plate (18) is perpendicular to the line horizontal line of the bucket plate (28), so that said horizontal line of the bucket plate (28) indicates one of the colors (20, 21, 22) of the status plate (18) depending on the level of wear in the bushing (27). As wear occurs, the door plate (29) will move with respect to its initial position allowing a particular color to be indicated depending on the wear of the bushing (27). In this way, the horizontal line of the bucket plate (28) points: to the first color (20) of the status plate (18) when the bushing (27) does not show wear or has a low level of wear; to the second color (21) of the status plate (18) when the bushing (27) shows normal wear; and indicates the third color (22) of the status plate (18) when the bushing (27) presents severe or critical wear, making it necessary to replace the bushing (27) to avoid critical failure of the ear (6) of the bucket. (16).
In one embodiment, the first wear indicator (15) can also be installed in any connection in buckets (16) of electric shovels or other device that comprise pins that interact with bushings, allowing monitoring and reporting the state of wear of said bushings, to prolong the useful life of connections and avoid critical failure. The elements of the first wear indicator (15) are equivalent to those used in connections in buckets (16) of electric shovels, being arranged in an equivalent manner to how it is installed in the connections of the bucket (16) with padlocks (11) or handles (12), where the status plate (18) is located near and on the external side of the connection comprising a pin and bushing, being oriented in a position in which its longitudinal axis is parallel to the direction of wear of the bushing, and the indicator element is attached to the connection that comprises a pin and bushing, so that said indicator element moves together with said connection when a displacement is generated due to wear of the bushing. The longitudinal axis of the status plate (18) can coincide or be strictly parallel to the direction of wear of the bushing. The indicator element will allow displaying or signaling at least one color of the status plate (18) representing a level of wear of the bushings equivalent to the buckets (16) of electric shovels.
The indicator element is attached to the edge of the connection comprising a pin and bushing so that its longitudinal axis is perpendicular or coincides with the direction of wear of the bushing. In the case that the longitudinal axis of the indicator element is perpendicular to the direction of wear of the bushing, the indicator element corresponds to a tip (19) and the status plate (18) is arranged so that its longitudinal axis is perpendicular to the axis longitudinal of the indicator element, where said tip (19) overlaps the status plate (18), without contacting it, so that said tip (19) indicates one of the colors (20, 21, 22) of the status plate status (18) depending on the level of wear on the bushing. Alternatively, in the case where the longitudinal axis of the indicator element coincides with the wear direction of the bushing, the indicator element corresponds to an indicator plate (23) and the status plate (18) is arranged so that its longitudinal axis coincides with the direction of wear of the bushing, where the indicator plate (23) overlaps the state plate (18), without contacting it, at least partially covering said state plate (18) allowing the colors (20, 21) to be displayed (22) of this depending on the level of wear on the bushing.
The particular configuration of the first wear indicator (15) in connections that include pin and bushing will depend on the space available around said connections.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202203482 | Dec 2022 | CL | national |
