Sensor assembly for articulated joint of mining machine

Abstract

A sensor assembly (1) for determining a rotational relative position (P) of a first object (2) of a mining machine (14) with respect to a second object (3) of the mining machine (14), the second object (3) being rotatably attached to the first object (2) for relative rotation about a first axis of rotation (A1). The sensor assembly (1) comprises: a first mount (4) attachable to a first object (2); a second mount (5) attachable to a second object (3); and an angular position sensor (6) comprising a first member (7) and a second member (8) rotatably attached to the first member (7) for relative rotation about a second axis of rotation (A2). The first member (7) is attached to the first mount (4), and the first mount (4) is attachable to the first object (2) such that the second axis of rotation (A2) is aligned with the first axis of rotation (A1). The sensor assembly (1) further comprises an arm (9) connecting the second member (8) of the angular position sensor (6) to the second mount (5), where the arm (9) is attached to the second member (8) of the angular position sensor (6) such that, upon rotation of the arm (9) about the second axis of rotation (A2), the arm is able to rotate the second member (8) about the second axis of rotation (A2). Furthermore, a mining machine (4) comprising such a sensor assembly (1).

Description

Technical Field

[0001] The present disclosure relates to an articulated joint in a mining machine. In particular, the present disclosure relates to a sensor assembly for determining a rotational relative position of a first object in a mining machine relative to a second object in the mining machine. The first object and the second object may, for example, be a front frame and a rear frame, respectively, of a chassis of the mining machine. Other uses of the sensor assembly are also possible. Background Art

[0002] An articulated mining machine includes a joint between a first frame and a second frame of the vehicle. When driving and maneuvering the mining machine, the first frame rotates relative to the second frame about an axis of rotation defined by the joint. Information indicative of the relative position of the first frame relative to the second frame is useful when enabling autonomous or self-driving operation of the mining machine. Autonomous and self-driving operation of the mining machine is particularly advantageous for electric working machines, such as electric mining machines, which may be fully automated. It is also useful to monitor the position of other articulated joints in the mining machine, such as the tilt position of a dump box of a mining truck.

[0003] The joints of mining machines are often heavily loaded and therefore prone to wear, resulting in a gradual increase in play between components. Therefore, sensors attached between components that move relative to each other when rotating about the joint must cope with play, and as wear progresses, the readings output by the sensor may be affected by the play. Furthermore, play may result in excessive forces on the sensor, leading to sensor failure.

[0004] Therefore, there is a need to provide a robust and accurate sensor assembly for determining the rotational relative position of a first object of a mining machine relative to a second object of the mining machine, the second object being rotatably attached to the first object for relative rotation about a first axis of rotation. Summary of the invention

[0005] An object of the present disclosure is to provide a robust and accurate sensor assembly for determining the rotational relative position of a first object of a mining machine relative to a second object of the mining machine, the second object being rotatably attached to the first object for relative rotation about a first axis of rotation.

[0006] According to a first aspect of the present disclosure, this object is achieved by a sensor assembly as defined in the accompanying claim 1 , with alternative embodiments being defined in the dependent claims thereof.

[0007] The sensor assembly includes a first mounting member that can be attached to a first object and a second mounting member that can be attached to a second object. The sensor assembly further includes an angular position sensor, which includes a first member and a second member that can be rotatably attached to the first member to rotate relative to the second rotation axis. The angular position sensor is configured to provide an electronic indication of the rotational relative position of the second member relative to the first member around the second rotation axis. The first member is attached to the first mounting member, and the first mounting member can be attached to the first object so that the second rotation axis is aligned with the first rotation axis. The sensor assembly further includes an arm that connects the second member of the angular position sensor to the second mounting member. The arm is attached to the second member of the angular position sensor so that when the arm rotates around the second rotation axis, the arm can rotate the second member around the second rotation axis.

[0008] A typical use case of the sensor assembly is to determine the rotational position of an articulated joint of a mining machine, wherein the first object is a first frame of the mining machine, and the second object is a second frame of the mining machine rotatably attached to the first frame for relative rotation about a first rotation axis. In this use example, by definition, the first frame and the second frame also each include any portion of the articulated joint that rotatably attaches the first frame to the second frame. Specifically, Figure 1 The fixed central axis of an embodiment is fixedly attached to the remainder of the first frame, thereby effectively forming a part of the first frame.

[0009] Thus, the present sensor assembly may be used by mounting a first mount to a first frame and mounting a second mount to a second frame as shown in the figures. Preferably, the first mount should be mounted to the first frame such that the second axis of rotation is aligned with the first axis of rotation defined by the rotatable attachment between the first and second frames. As the first frame rotates relative to the second frame about the first axis of rotation, the second mount rotates relative to the first object along an approximately circular path about the first and second axes of rotation. Thus, the arm connecting the second mount to the second member of the angular position sensor rotates about the first and second axes of rotation, wherein the indication provided by the angular position sensor is directly related to the angle between the first and second frames of the mining machine.

[0010] By providing the angular position sensor on a first mount attached to a first object, the angular position sensor moves with the first object, thereby maintaining its alignment. The provision of an arm connecting the angular position sensor to the second object via a second mount enables a relatively large radial offset between the second axis of rotation and the second mount, making the system less sensitive to vibrations, as relatively large movements of the second mount are associated with relatively small changes in the angle of rotation of the angular position sensor, thereby providing more robust position detection. Moreover, the use of an arm enables great flexibility in the location of connecting the sensor assembly to the second object, wherein the sensor assembly can be easily adapted for use with different types of objects.

[0011] The arm may be connected to the second member of the angular position sensor via an intermediate member which is rotatably supported on the first mount for rotation about the second axis of rotation.

[0012] The intermediate member is rotatably supported on the first mounting member, thereby isolating the angular position sensor from forces from the arm, except for torque about the second axis of rotation. This protects the angular position sensor from excessive forces, prolongs the life of the angular position sensor, and further improves the motion accuracy of the second member of the angular position sensor by guiding the arm. As the rotatable attachment between the first object and the second object is worn, the radial play and axial play between the first object and the first object increase, which means that the second axis of rotation may increasingly deviate radially from the first axis of rotation. This radial deviation increases the tendency of the second mounting member to move radially toward or radially away from the first mounting member when the first object and the second object rotate relative to each other, which in turn increases the force on the arm.

[0013] The arm may be telescopic or otherwise configured to accommodate movement of the second mount toward and away from the second axis of rotation.

[0014] By making the arm retractable or configured to conform to movement of the second mount toward and away from the second axis of rotation, the second mount can be moved toward and away from the first mount without substantially causing excessive forces acting radially relative to the second axis of rotation on the intermediate member or the second member of the angular position sensor. Moreover, installation of the arm is easier because the adjustable length of the arm enables easier alignment of the first and second mounts to pre-positioned fastening means, such as holes or guides, on the first and second objects. Moreover, the self-adjusting length of the arm is particularly advantageous when wear of the rotatable attachment between the first and second objects results in a misalignment between the first and second axes of rotation.

[0015] The arm may comprise a plurality of sections telescopically engageable with each other.

[0016] The telescopic engagement between the sections provides a simple and robust means of accommodating changes in the distance between the first mount and the second mount.

[0017] The arm may be provided with a resilient dust protection, such as a hood, covering at least a portion of the plurality of sections.

[0018] The resilient dust guard is sealed to the first mount and the arm to form a sealed interior space around at least a portion of the plurality of segments.

[0019] The first mount may include a base plate for attachment to the first object and a cover or housing attached to the base plate by one or more mechanical connectors such that an interior space is formed between the base plate and the cover. The angular position sensor is attached to the cover / housing within the interior space of the first mount.

[0020] The arm may be connected to the second mount by a joint configured to enable relative rotation of the arm with respect to the second mount.

[0021] The joint connecting the arm to the second mount may comprise a ball joint, a hinge joint, a swivel joint or a resilient joint comprising a piece of resilient material connecting the arm to the second mount.

[0022] The arm may be connected to the second member of the angular position sensor by a hinge joint or a resilient joint comprising a piece of resilient material connecting the arm to the second member.

[0023] Aspects of the present disclosure relate to a mining machine comprising a sensor assembly as described above with reference to claim 1 , and alternative embodiments are defined in the dependent claims thereof.

[0024] The mining machine comprises a first object rotatably attached to a second object for rotation about a first rotation axis. Furthermore, the mining machine comprises a sensor assembly for determining a rotational relative position of the first object with respect to the second object, such as the sensor assembly described above.

[0025] The sensor assembly includes: a first mounting member attached to a first object; a second mounting member attached to a second object; an angular position sensor including a first member and a second member rotatably attached to the first object for relative rotation around a second rotation axis. The angular position sensor is configured to provide an electronic indication of the rotational relative position of the second member relative to the first member around the second rotation axis. The first member is attached to the first mounting member, and the first mounting member is attached to the first object so that the second rotation axis is aligned with the first rotation axis. Moreover, the sensor assembly includes an arm connecting the second member of the angular position sensor to the second mounting member. The arm is attached to the second member of the angular position sensor via a first joint, and the first joint is configured to enable the arm to rotate the second member around the second rotation axis when the arm rotates around the second rotation axis.

[0026] The first object may include a central shaft defining a first rotational axis, wherein the second object includes a bearing that rotatably supports the second object on the central shaft for rotation about the first rotational axis, and wherein the first mount is attached to an end portion of the central shaft.

[0027] The mining machine may include a first frame rotatably connected to a second frame for steering of the mining machine, wherein the first frame is a first object, and wherein the second frame is a second object.

[0028] As is obvious to one of ordinary skill in the art, the above aspects, the appended claims and / or the examples disclosed herein above and later below may be combined with each other as appropriate.

[0029] Additional features and advantages are disclosed in the following description, claims, and drawings, and in part will be apparent to those skilled in the art or may be learned by practicing the disclosure as described herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A side view of a mining machine in the form of a battery powered loader for use in mining operations is shown.

[0031] Figure 2 Shown also Figure 1 FIG. 1 is a top view of a loader shown in FIG. 1 while turning.

[0032] Figure 3 Shown in Figure 1 to Figure 2 A partial side view of a first frame and a second frame of a loader shown in FIG. 1 and mounted with a sensor assembly for determining relative rotation of the first frame relative to the second frame about an articulated joint.

[0033] Figure 4 Shown in Figure 3 Magnified partial view of the area A indicated in FIG.

[0034] Figure 5 Shown also Figure 4 , however the sensor assembly is mounted to the loader via a bracket rather than directly to the fixed axle of the articulated joint.

[0035] Figures 6 to 8 Various views of an embodiment of a sensor assembly are shown before it is assembled to a joint of a mining machine. DETAILED DESCRIPTION

[0036] The aspects set forth below represent information that enables one skilled in the art to practice the present disclosure. As mentioned above, an object of the present disclosure is to provide a robust and accurate sensor assembly for determining a rotational relative position of a first object of a mining machine relative to a second object of the mining machine, the second object being rotatably attached to the first object for relative rotation about a first rotation axis. Examples of mining machines are LHDs (loaders, haulers, dump trucks), concrete sprayers, drills and / or bolters, or other types of vehicles configured to perform work operations in a mining environment.

[0037] According to one aspect of the present disclosure, this object is achieved by a sensor assembly as described below.

[0038] Figure 1 to Figure 2 An articulated mining machine 14 is shown. Figures 2 to 3 As shown in , the chassis of the mining machine 14 comprises a first frame 2 in a rear part of the mining machine 14 rotatably connected to a first frame 3 in a front part of the mining machine 14 by an articulated joint defining a first rotation axis A1 . Figure 4 Show Figure 3 The enlarged area A of FIG. 1 shows the upper part of the articulated joint. The articulated joint also includes Figure 3 The similar lower part shown in the bottom part of FIG. Therefore, only the upper part will be described here. In alternative embodiments, the articulated joint may include only one such part, or include more than two such parts.

[0039] like Figure 4 As shown in , the first frame 2 comprises a cylindrical shaft 17 along a first axis of rotation A1. The shaft is fitted between an upper mounting 15 and a lower mounting 16, the two mountings 15, 16 forming part of the first frame 2. Furthermore, the shaft 17 is fixed to the upper plate 15 and the lower plate 16 so that the shaft 17 cannot rotate relative to the rest of the first frame 2. The second frame 3 comprises a connecting plate 18, which is provided with a bearing 19 suitable for fitting on the shaft 17 so that the second frame 3 can rotate around the first axis of rotation A1. The bearing 19 is held in place by an upper fixing plate 20 and a lower fixing plate 21, and the two fixing plates 20, 21 are attached to the connecting plate 18 by bolts.

[0040] The upper and lower mountings 15, 16 of the first frame include respective removable members 15a, 16a that can be attached to respective fixed portions 15b, 16b using bolts (not shown). Each respective removable member 15a, 16a and each respective fixed portion 15b, 16b are shaped to clamp the shaft 17 to the first frame 2 when the removable member 16b is mounted. Thus, after the bearing 19 and the shaft 17 have been assembled to the second frame 3, the shaft 17 is clamped to the first frame 2 by attaching the removable members 15a, 16a to the fixed portions 15b, 16b of the first frame 2.

[0041] In other embodiments, the joint between the first frame 2 and the second frame 3 may alternatively have any other suitable design.

[0042] To be able to determine the relative rotational position of the first frame 2 relative to the second frame 3 about the first rotational axis A1 , the sensor assembly 1 is mounted to the first frame 2 and the second frame 3 , ie to objects rotatable relative to each other about the first longitudinal axis A1 .

[0043] It should be understood that the sensor assembly is also applicable to any other joints between objects of the mining machine 14 that are rotatable relative to each other about the longitudinal axis for determining the relative rotational position of the objects about the longitudinal axis. For example, the sensor assembly may be used to monitor the movement of the joint between the chassis frame of the loader and the arm of the loader carrying the bucket, and to monitor the movement of the joint between the bucket and the arm carrying the bucket.

[0044] In the present exemplary embodiment, the sensor assembly 1 includes a first mount 4 attachable to the first frame 2 and a second mount 5 attachable to the second frame 3. The sensor assembly 1 further includes an angular position sensor 6, which includes a first member 7 and a second member 8, the second member 8 being rotatably attached to the first member 7 for relative rotation around the second rotation axis A2. The angular position sensor 6 is configured to provide an electronic indication of the rotational relative position of the second member 8 relative to the first member 7 around the second rotation axis A2. The first member 7 is attached to the first mount 4, and the first mount 4 is attached to the first object 2 so that the second rotation axis A2 is aligned with the first rotation axis A1. The sensor assembly 1 further includes an arm 9 connecting the second member 8 of the angular position sensor 6 to the second mount 5. The arm 9 is fixed to the second member 8 of the angular position sensor 6 so that when the arm 9 rotates around the second rotation axis A2, the arm can rotate the second member 8 around the second rotation axis A2. In other embodiments, the attachment of the arm 9 to the second member 8 can have any other suitable configuration as long as the arm can apply torque to the second member 8 around the first rotation axis A1. For example, the arm 9 may be attached to the second member 8 by means of splines allowing the arm 9 to move relative to the second member 8 along the first axis of rotation A1 .

[0045] like Figure 8 As shown in , the arm 9 is connected to the second member 8 of the angular position sensor 6 via an intermediate member 10 rotatably supported on the first mount 4 to rotate about the second rotation axis A2. In other embodiments, the intermediate member may alternatively be omitted and the arm is supported directly on the second member 8 of the angular position sensor 6. However, the provision of the intermediate member 10 supported by the first mount 4 isolates lateral forces on the arm, i.e., forces that are not parallel to the rotation axis A1, so that such lateral forces do not load the second member 8.

[0046] The arm 9 comprises a plurality of sections 9a, 9b that telescopically engage one another and thus accommodate movement of the second mount 5 towards and away from the second axis of rotation A2. In other embodiments, any other suitable design of the arm may be used instead, thereby allowing this accommodation of relative movement that varies the distance between the second mount 5 and the second axis of rotation A2. For example, the arm 9 may comprise a rigid rod pivotally connected to the second mount 5, wherein the rod freely passes through an opening of the first mount 4, the opening of the first mount 4 being shaped to prevent rotational play between the rod and the first mount 4 about the first longitudinal axis A1.

[0047] The arm 9 is provided with an elastic dust guard 11 in the form of a cover covering a portion of the plurality of sections 9a, 9b. The elastic dust guard 11 is sealed to the first mounting member 4 and the arm 9, thereby forming a sealed internal space around at least a portion of the plurality of sections 9a, 9b. In other embodiments, the dust guard 11 may alternatively be omitted.

[0048] The first mount 4 includes a base plate 12 attached to the first frame 2 using bolts. The first mount 4 further includes a cover or housing 13 attached to the base plate 12 by bolts so that an internal space is formed between the base plate 12 and the cover 13. The angular position sensor 6 is attached to the cover 13 within this internal space of the first mount 4, but in other embodiments may be attached to some other member or part of the first mount 4, as long as the first member 7 of the angular position sensor is fixed to the first mount 5, and thus to the first object 2.

[0049] The arm 9 is connected to the second mount 5 by a joint configured to enable the arm 9 to rotate relative to the second mount 5 about a rotation axis perpendicular to the first rotation axis A1. In this embodiment, the joint connecting the arm 9 to the second mount 5 is a hinge joint, but in other embodiments may alternatively include an elastic joint including an elastic material piece connecting the arm 9 to the second mount 5.

[0050] like Figure 8 As shown in FIG. 1 , the arm 9 is connected to the second member 8 of the angular position sensor 6 by a hinge joint 22. In other embodiments, any other suitable joint may be used instead of a hinge joint, such as an elastic joint comprising an elastic material piece connecting the arm 9 to the second member 8.

[0051] The sensor assembly may also be used to determine the rotational position of another joint by being mounted to the mining machine during manufacture of the mining machine, or the sensor assembly may be provided as a separate device for mounting anywhere on the mining machine.

[0052] The terms used herein are only used for the purpose of describing specific aspects and are not intended to limit the present disclosure. As used herein, the singular forms "a" and "the" are intended to also include plural forms, unless the context clearly states otherwise. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. It will be further understood that the terms "include" and / or "comprise" when used herein specify the presence of stated features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or their groups.

[0053] It will be understood that although the terms first, second, etc. can be used to describe various elements in this article, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, without departing from the scope of the present disclosure, the first element can be referred to as the second element, and similarly, the second element can be referred to as the first element.

[0054] Relative terms such as "below" or "above" or "up" or "lower" or "horizontal" or "vertical" may be used herein to describe the relationship of one element to another element as illustrated in the figures. It will be understood that these terms and the terms discussed above are intended to encompass different orientations of the device in addition to the orientation depicted in the figures. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there can be intervening elements. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements.

[0055] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present disclosure belongs. It will be further understood that the terms used herein should be interpreted as having a meaning consistent with their meaning in the context of this specification and the relevant art, and will not be interpreted in an idealized or overly formal sense unless explicitly defined as such herein.

[0056] It should be understood that the present disclosure is not limited to the aspects illustrated in the above description and drawings; on the contrary, those skilled in the art will recognize that many changes and modifications may be made within the scope of the present disclosure and the appended claims. In the drawings and description, aspects have been disclosed for illustrative purposes only and not for limiting purposes, and the scope of the inventive concept is set forth in the claims.

[0057]

[0058] Reference numerals list

Claims

1. A sensor assembly (1) for determining a rotational relative position (P) of a first object (2) of a mining machine (14) relative to a second object (3) of the mining machine (14), the second object (3) being rotatably attached to the first object (2) for relative rotation about a first rotation axis (A1), wherein the sensor assembly (1) comprises: a first mounting member (4) attachable to the first object (2); a second mounting member (5) attachable to the second object (3); An angular position sensor (6) comprising a first member (7) and a second member (8) rotatably attached to the first member (7) for relative rotation around a second rotation axis (A2), wherein the angular position sensor (6) is configured to provide an electronic indication of the rotational relative position of the second member (8) relative to the first member (7) about the second rotation axis (A2), wherein the first member (7) is attached to the first mounting member (4), and wherein the first mounting member (4) is attachable to the first object (2) such that the second axis of rotation (A2) is aligned with the first axis of rotation (A1), and The sensor assembly (1) further comprises an arm (9) connecting the second member (8) of the angular position sensor (6) to the second mounting member (5), wherein the arm (9) is attached to the second member (8) of the angular position sensor (6) such that when the arm (9) rotates around the second rotation axis (A2), the arm is able to cause the second member (8) to rotate around the second rotation axis (A2).

2. A sensor assembly (1) according to claim 1, wherein the arm (9) is connected to the second member (8) of the angular position sensor (6) via an intermediate member (10), and the intermediate member (10) is rotatably supported on the first mounting member (4) to rotate about the second rotation axis (A2).

3. A sensor assembly (1) according to any one of claims 1 or 2, wherein the arm (9) is retractable or configured to accommodate movement of the second mounting member (5) towards and away from the second rotation axis (A2).

4. The sensor assembly (1) according to claim 3, wherein the arm (9) comprises a plurality of sections (9a, 9b) which are telescopically engageable with each other.

5. A sensor assembly (1) according to claim 4, wherein the arm (9) is provided with a resilient dust protection (11), such as a cover, covering at least a part of the plurality of sections (9a, 9b).

6. A sensor assembly (1) according to claim 5, wherein the elastic dust protection device (10) is sealed to the first mounting member (4) and the arm (9) to form a sealed internal space around at least a part of the plurality of segments (9a, 9b).

7. A sensor assembly (1) according to any one of claims 1 to 6, wherein the first mounting member (4) comprises a substrate (12) for attaching to the first object (2) and a cover (13) attached to the substrate (12) via one or more mechanical connectors, such that an internal space is formed between the substrate (12) and the cover (13), wherein the angular position sensor (6) is attached to the cover (13) within the internal space of the first mounting member (4).

8. The sensor assembly (1) according to any one of claims 1 to 6, wherein the arm (9) is connected to the second mounting member (5) via a joint, and the joint is configured to enable the arm (9) to rotate relative to the second mounting member (5).

9. A sensor assembly (1) according to claim 8, wherein the joint connecting the arm (9) to the second mounting member (5) includes a ball joint, a hinge joint, a rotational joint or an elastic joint including an elastic material member connecting the arm (9) to the second mounting member (5).

10. A sensor assembly (1) according to any one of claims 1 to 9, wherein the arm (9) is connected to the second member (8) of the angular position sensor (6) by a hinge joint or an elastic joint, and the elastic joint includes an elastic material piece connecting the arm (9) to the second member (8).

11. A mining machine (14) comprising a first object (2) rotatably attached to a second object (3) for rotation about a first rotation axis (A1), wherein the mining machine comprises a sensor assembly (1) for determining a rotational relative position of the first object (2) relative to the second object (3), wherein the sensor assembly (1) comprises: a first mounting member (4) attached to the first object (2); a second mounting member (5) attached to the second object (3); An angular position sensor (6) comprising a first member (7) and a second member (8) rotatably attached to the first member (7) for relative rotation around a second rotation axis (A2), wherein the angular position sensor (6) is configured to provide an electronic indication of the rotational relative position of the second member (8) relative to the first member (7) about the second rotation axis (A2), wherein the first member (7) is attached to the first mount (4), and wherein the first mount (4) is attached to the first object such that the second axis of rotation (A2) is aligned with the first axis of rotation (A1), and The sensor assembly (1) further comprises an arm (9) connecting the second member (8) of the angular position sensor (6) to the second mounting member (5), wherein the arm (9) is attached to the second member (8) of the angular position sensor (6) such that when the arm (9) rotates around the second rotation axis (A2), the arm (9) is able to cause the second member (8) to rotate around the second rotation axis (A2).

12. The mining machine (14) of claim 10, wherein the first object comprises a central shaft defining the first rotation axis (A1), wherein the second object (3) comprises a bearing, the bearing rotatably supporting the second object (3) on the central shaft to rotate about the first rotation axis (A1), and wherein the first mount (4) is attached to an end portion of the central shaft.

13. The mining machine (14) according to any one of claims 10 to 12, wherein the mining machine (4) comprises a first frame (2) rotatably connected to a second frame (3) for steering of the mining machine (14), wherein the first frame (2) is the first object (2), and wherein the second frame (3) is the second object (3).

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