Transport system with carriages with self-adjusting bearings

Abstract

The carrier (11) has a carrier body (12) which extends across the top surface of the track. A fixed bearing arrangement (14) comprises bearings (15a, 15b) for engaging a first side of the track and having an axis of rotation located in a fixed position on the carrier body. A self-adjusting bearing arrangement (19) comprises a moveable bearing (20) for engaging a second side of the track with the carrier body and mounting on a pivot arm (21) having pivot connections (24, 25). A biasing spring arrangement is arranged to act on the pivot arm to maintain contact between the moveable bearing and the second side of the track. The moveable bearing (20) is not driven. Both the moveable bearing (20) and the pivot connections (24, 25) of the pivot arm (21) are located at a first end of the pivot arm. The biasing spring is spaced from the pivot connections (24, 25) in a first direction. The moveable bearing (20) rotates about an axis which is offset from the pivot axis of the pivot arm in a second direction which is transverse to the first direction. This spacing in the first direction is five to twenty times the spacing in the second direction.

Description

Technical Field

[0001] The present invention relates to a transport system comprising a track and a carrier with bearings to engage with contours on opposite sides of the track. Background Technology

[0002] In transport systems comprising straight and curved track sections, the width is typically constant throughout both sections. A carrier with four bearings, centered on a trapezoid, is usually used. Its dimensions are carefully calculated to provide optimal fit when the carrier is fully positioned on both the straight and curved sections. As these carriers traverse between straight and curved sections, the fit on the tracks becomes looser, often resulting in gaps. These gaps are undesirable and become increasingly unacceptable with larger track systems. The dimensional stability of the carrier is likely to change due to these gaps. In some products, maintaining carrier stability throughout the track system, preserving gaps, and controlling air gaps are crucial.

[0003] Furthermore, although systems containing only straight tracks or circular tracks formed by arcs do not have the same transition, they are still affected by variations in manufacturing tolerances. This means that standard carriers must be manually reset to account for these variations. Additionally, the tracks themselves will wear down over the lifespan of any carrier-mounted track system. Consequently, the carriers may become loose and dimensionally unstable, which must be addressed through manual carrier reset. In systems with a large number of carriers, this will be time-consuming and may need to be done multiple times throughout the track system's lifespan.

[0004] In transport systems, loads are suspended from a carrier with drive wheels that engage the upper and / or lower surfaces of a track. It is well known to use spring-loaded wheels or rollers to maintain friction drive as the carrier travels along the track. For example, in EP 354 461-A1, when the drive wheel engages the upper surface of an I-beam track, the roller is pushed by a compression spring to engage the lower flange of the I-beam track. Alternatively, in US 3 774 548, the driven roller engages the lower surface of the track via a spring-loaded pivot arm. In both of these known arrangements, the amount of force applied by the spring is limited and insufficient to ensure constant clearance and dimensional stability in large track systems with heavy carriers and loads. This is particularly important in transport systems where all or part of the track is configured in a horizontal plane. Furthermore, this spring-loaded arrangement requires significant overhang on one side of the carrier, which can further compromise the potential stability of the transport system. Summary of the Invention

[0005] From one perspective, the present invention proposes a transportation system comprising:

[0006] The track (1) has a top surface (8) and opposing first side (9) and second side (10); a carrier (11) having a carrier body (12) extending across the top surface of the track; a fixed bearing arrangement (14) including bearings (15a, 15b) engaging with the first side of the track and having a rotation axis in a fixed position on the carrier body; a self-adjusting bearing arrangement (19) including a movable bearing (20) for engaging the second side of the track with the carrier body and mounted on a pivot arm (21) having pivoting connections (24, 25); and a biasing element (45) arranged to act on the pivot arm to maintain contact between the movable bearing and the second side of the track.

[0007] Among them, the self-adjusting bearing arrangement (19) is set as follows:

[0008] - The movable bearing (20) is not driven;

[0009] - The pivoting connections (24, 25) of the movable bearing (20) and the pivot arm (21) are both located at the first end of the pivot arm;

[0010] - The biasing element (45) is spaced apart from the pivoting connector (24, 25) of the pivot arm (21) in the first direction;

[0011] - The movable bearing (20) is offset from the pivot connector (24, 25) in a second direction, which is transverse to the first direction.

[0012] In a preferred embodiment, the second direction is substantially orthogonal to the first direction.

[0013] In a preferred embodiment, the biasing element (45) acts to push the pivot arm (21) in a direction opposite to the direction in which the movable bearing (20) deviates from the pivot connector (25, 25).

[0014] In a preferred embodiment, the distance A between the biasing element (45) and the pivot axis (y1) of the pivot arm (21) is greater than the distance B between the rotation axis (y2) of the bearing (20) and the pivot axis (y1).

[0015] In a preferred embodiment, an adjustable closing stop (46) is provided to restrict the pivoting movement of the movable bearing (20) toward the fixed bearing arrangement (14).

[0016] In a preferred embodiment, an adjustable opening stop (47) is provided to limit the pivoting movement of the movable bearing (20) away from the fixed bearing arrangement (14).

[0017] In a preferred embodiment, the bias element (45) acts against the adjustable stop (51) to change the preload of the bias element.

[0018] In one embodiment, the self-adjusting bearing arrangement (19) includes a single movable bearing (20) mounted on a pivot arm (21) with a biasing element (45).

[0019] In another embodiment, the self-adjusting bearing arrangement (19) includes a pair of movable bearings (20a, 20b) mounted on corresponding pivot arms (21a, 21b) having corresponding biasing elements (45). In a preferred configuration, the two pivot arms (21a, 21b) are left-right opposite. Attached Figure Description

[0020] To illustrate how the invention is practiced, the following description and the accompanying drawings are included by means of non-limiting examples. In the drawings:

[0021] Figure 1a and 1b This is a full view of the transportation system, which includes a three-bearing carrier.

[0022] Figure 2 This is an exploded view of a three-bearing carrier that can be used in this transportation system;

[0023] Figure 3 It is used for Figure 2 A top view of the pivot arm of the carrier;

[0024] Figure 4 This is a side view of the pivot arm;

[0025] Figure 5 This is an end view of the pivot arm;

[0026] Figure 6 This is a side view of the three-bearing carrier including the pivot arm;

[0027] Figure 7 This is a bottom view of a three-bearing carrier;

[0028] Figure 8 yes Figure 6 Section VIII-VIII;

[0029] Figure 9 Is with Figure 8 A similar cross-sectional view shows the bearing wheel at its minimum set interval;

[0030] Figure 10 Is with Figure 8 A similar cross-sectional view shows the bearing wheel at its maximum set interval;

[0031] Figure 11 Is with Figure 8 A similar cross-sectional view shows the bearing wheel locked at its maximum interval;

[0032] Figure 12 Is with Figure 8 A similar cross-sectional view shows the bearing wheels locked at their minimum interval;

[0033] Figure 13 It is similar to Figure 8 A cross-sectional view showing the modified positioning screw construction;

[0034] Figure 14 This is an overall view of the transportation system, which includes a four-bearing carrier.

[0035] Figure 15 This is a side view of a four-bearing carrier that can be used in this transport system;

[0036] Figure 16 This is a bottom view of the four-bearing carrier;

[0037] Figure 17 yes Figure 15 The cross section XVII-XVII. Detailed Implementation

[0038] Figure 1a and 1b A transportation system with a simple layout is shown for illustrative purposes. Figure 1a The track 1, including the straight section 2, is shown, while Figure 1b The diagram shows a circular track 1 including a curved section 5. Each track 1 has a top surface 8 and opposing first and second sides 9 and 10. The track width between sides 9 and 10 can be constant throughout the straight and curved sections, or it can vary for various reasons, as discussed herein. The transport system includes at least one carrier 11, which in this example is a three-bearing carrier with a carrier body 12 and three-bearing wheels 13. The carrier body 12 extends across the top surface 8 of the track, while the bearing wheels 13 engage with suitable profiles formed on the first side 9 and the second side 10. A triangular cross-section profile is generally used, but other profiles may also be used. The carrier body 12 protrudes at substantially the same distance on the opposing sides of the track. In the figure, the track 1 is shown in a horizontal orientation, but depending on the use, at least a portion of the track may be arranged in a vertical plane.

[0039] Figure 2An example of a three-bearing carrier is shown, which can be used in the transport system of Figure 1. The carrier body 12 is a flat metal plate, generally T-shaped in the three-bearing carrier shown. A fixed bearing arrangement 14 is provided at one end of the plate, comprising two fixed bearing wheels 15a and 15b for engaging a first side of a track. These bearing wheels have corresponding mounting screws 16a and 16b, which are received in threaded holes 17a and 17b such that the axes of rotation of the mounting screws 16a and 16b are fixed in a position on the carrier body 12. A self-adjusting bearing arrangement 19 is provided at the opposite end of the plate, comprising a single movable bearing wheel 20 for engaging a second side of the track. This bearing wheel 20 is rotatably mounted on an internally threaded bearing bolt 22, which is supported by a pivot arm 21, and the bearing wheel 20 is held on the bolt 22 by screws 23. The pivot arm 21 also carries a further internally threaded bolt 24, which provides a pivotal connection to the carrier 12 via a bearing sleeve 25 received in a hole 28 in the carrier body 12. The bolt 24 is pivotally secured by a further retaining screw 26 and a washer 27. As explained below, a biasing element, such as a compression spring (not shown), is arranged to act on the pivot arm 21 to maintain contact between the movable bearing wheel 20 and the second side of the track.

[0040] Figure 3-5 A preferred form of the pivot arm 21 is shown. The pivot arm comprises a long, flat metal plate 30 having a top surface 31 and a bottom surface 32. At one end of the plate 30, a bolt 24 protrudes from the top surface 31 to pivotally connect the arm to the carrier body 12 as described. At the same end, a bearing bolt 22 protrudes from the bottom surface 32 to carry a bearing wheel 20. At the opposite end of the plate 30, the top surface 31 carries an upright flange 34 extending longitudinally along the pivot arm. The flange 34 has a through hole 35 approximately halfway along its length for receiving a guide pin of the aforementioned biasing element. The end of the flange closest to the bolt 24 thickens at 36 to receive a threaded through hole 37 extending transversely to the arm 21.

[0041] Considering Figure 3 and Figure 4 The top and side views of the pivot arm show that the guide hole 35 for the bias spring is spaced apart from the central pivot axis of the bolt 24 by a distance A, which lies in a first direction extending longitudinally along the pivot arm. It can also be seen that, when viewed from the side of the pivot arm 30, the pivot axis of the bolt 24 coincides with the rotation axis of the bearing bolt 22. However, when viewed from the side, as shown... Figure 5In the end view of the pivot arm, the pivoting connection formed by bearing bolt 22 relative to bolt 24 is eccentrically mounted, such that the pivot axis y1 of bolt 24 is offset by a distance B from the rotation axis y2 of bearing bolt 22 along a second direction, which is transverse to, and more specifically, perpendicular to, the first direction. Furthermore, this second direction is opposite to the direction in which the bias spring acts on flange 34. Equally important, the eccentricity of the two bolts 22 and 24 is smaller relative to distance A, allowing the pivot arm to provide sufficient mechanical advantage to increase the force applied by the bias spring by 10 or 20 times. For a concrete example, if distance A is 25.0 mm and distance B is 4.0 mm, the ratio of A to B would be 6.25:1. To maintain a compact arrangement and sufficient spring force on the self-adjusting bearing wheel, distance A should be at least twice the distance B, preferably at least three times the distance B, and ideally at least five times the distance B. To maintain sufficient spring force, distance A should generally fall within five to twenty times the distance B. The smaller end of this range is suitable for smaller, lighter carriers requiring lighter preload, while the larger end is suitable for larger, heavier carriers requiring heavier preload. While achieving good mechanical advantage is generally desirable, it should be noted that the mechanical advantage should generally not exceed this specified range. Higher mechanical advantage will reduce the range of bearing movement, thereby decreasing the carrier's self-adjusting capability and making it unable to adapt to a wide range of track conditions. Excessive spring force also increases the risk of movable bearings locking and failing to self-adjust.

[0042] Figure 6 -8 shows something similar to Figure 2 The pivot arm 21 is shown mounted in a three-bearing carrier. The pivot arm 21 and the biasing element are arranged to extend over the top surface of the track during use. The pivot arm 21 and the bearing wheel 20 are shown in their nominal (floating) position when engaged with the track, the pressure applied by the biasing spring balanced by the reaction force between the bearing wheel and the track. In this configuration, the carrier is able to self-adjust to accommodate differences in track width, which may occur at the junction of straight and curved sections, and sometimes at other locations due to small variations in manufacturing tolerances within the transport system. It can be seen that the lower side of the carrier body 12 includes a cavity 40 that receives the flange 34 of the pivot arm 21, while a plate 30 is held below the carrier body. Bolts 24 and sleeves 2 are received in holes 28 to provide the described pivoting connection.

[0043] Cavity 40 communicates with three parallel holes 41-43 that pass through one side of the carrier body 12, opposite to the direction of bearing axis offset. The middle hole 42 is threaded and aligned with a through hole 35 in flange 34, allowing a partially threaded guide pin 44 to be inserted through the flange. The guide pin carries a compression spring 45, forming a biasing element. The biasing spring 45 is located in cavity 40 and acts between flange 34 and the opposing wall of the cavity. Hole 41, furthest from the movable bearing wheel 20, is also threaded and receives a closing positioning screw 46, which contacts flange 34 to position the support arm at its extreme positions under the action of spring 45. Figure 9 As shown. Therefore, this locating screw determines the closest interval between the bearing wheels in use. The third hole 43, closest to the movable bearing wheel 20, is unthreaded and aligns with the threaded through hole 37 in the flange 34 to provide an entry diameter for opening the locating screw 47, which is received in the hole 37. As... Figure 10 As shown, opening the locating screw allows the maximum spacing between the bearing wheels to be determined by contacting the opposing walls of the cavity 40. Opening the locating screw 47 can be used to position the bearing wheel 20 to its maximum extent so that the carrier cannot detach from the track when an excessive force sufficient to overcome the spring pressure is applied to the carrier during use.

[0044] The closing positioning screw 46 determines the minimum interval between the fixed and self-adjusting bearing wheels 15a, 15b, and 20, and can also be used to ensure that the bearing wheels are not closed too much, thus making it easier to assemble the carrier onto the track system. Furthermore, if the two positioning screws 46 and 47 are adjusted to lock the bearing wheels in a fully open configuration, as... Figure 11 As shown, the carrier can then be placed quickly and easily on the track without having to overcome spring pressure. Conversely, as Figure 12 As shown, adjusting the two locating screws to lock the bearing wheels in opposite fully closed directions allows the carrier to be locked in place, for example, to prevent movement during transport.

[0045] The magnitude of the spring pressure and the resulting bearing preload are determined by the spring constant of the bias spring 45. The spring can be easily changed through the bottom of the cavity 40 by unscrewing the threaded guide pin 44 to allow for different bearing preloads for specific applications.

[0046] Figure 13 Another method for positioning the spring force is illustrated. In this embodiment, another threaded hole 50 aligned with the guide pin 44 is provided on the opposite side of the carrier body 12. This hole 50 contains a loading positioning screw 51, which has a reverse hole at 52 to receive the end of the guide pin 44. The bias spring 45 is supported against the end of the positioning screw 51, rather than against the wall of the cavity 40. Therefore, the spring length and the force applied by the bias spring 45 can be adjusted using the loading positioning screw 51.

[0047] The locating screws 41 and 43, which limit the movement of arm 21, can also be used to limit the preload range that the bearings can have during their travel around the transport system. A carrier with the self-adjusting bearing wheel arrangement described herein is well-suited for use with a linear drive motor that has a limited amount of driving force. Being able to limit the preload limits the amount of force required to move the carrier, which can be useful in certain situations.

[0048] Regardless of the number of bearing wheels, the carrier should have a fixed side and a self-adjusting side. On the fixed side, the positions of all bearing wheels are fixed, but on the opposite side, the positions of all bearing wheels should be adjustable using a pivot arm arrangement. Figure 14-17 This demonstrates how to apply this to a four-bearing carrier. For ease of explanation, Figure 14 A transport system with another simple layout is shown. A circular track 1 is illustrated, comprising straight sections 2, 3, and 4 and curved sections 5, 6, and 7. The track has a top surface 8 and opposing first and second sides 9 and 10. The track width between sides 9 and 10 can be constant throughout the straight and curved sections or can vary as discussed herein. The transport system includes at least one carrier 11, in this example a four-bearing carrier, having a carrier body 12 and four bearing wheels 13. The carrier body 12 extends across the top surface 8 of the track, while the bearing wheels 13 engage with suitable profiles formed on the first side 9 and the second side 10. A triangular cross-section profile is generally used, but other profiles may also be used. The carrier body 12 protrudes at substantially equal distances on the opposing sides of the track. In the figure, track 1 is shown in a horizontal orientation, but depending on the application, at least a portion of the track may be arranged in a vertical plane. Reference Figure 15-17 Bearing wheels 15a and 15b are again secured in place on the carrier 11, but on the opposite sides of the carrier, bearing wheels 20a and 20b are mounted on corresponding pivot arms 21a and 21b. The arrangement of the pivot arms and their corresponding bias springs 45 and locating screws 46 and 47 is consistent with... Figure 3 Similar to section -8, but in this case, the two pivot arms 21a and 21b are left-right opposites, one being a mirror image of the other. Therefore, the pivot arms must move in opposite directions to move the bearing wheels toward or away from the fixed (bearing wheel) pair. This is done so that the locating screws and guide pins can enter from the adjacent end of the carrier in both cases. The four bearing wheels are positioned at the center of the trapezoid such that the pivot arms 21a and 21b, as well as the bearing wheels 20a and 20b, are in their nominal (floating) positions when engaged with the rail, as... Figure 16 As shown, the pressure applied by the bias spring 45 is balanced by the reaction force between the bearing wheel and the track. Note that in Figure 17In the diagram, positioning screws 46 and 47 are shown in the locked position, but will be adjusted during use to position the pivot arm to the required limits of movement under the action of the bias spring 45. The positions of the self-adjusting bearing wheels 20a and 20b can be adjusted to compensate for any loosening that may occur at the junction of the fixed-center four-bearing carrier in straight and curved sections, thus greatly improving the stability of the carrier at these points in the system.

[0049] The bias spring can be changed at the bottom of the carrier to allow different bearing wheel preloads as needed.

[0050] Therefore, it is understood that this embodiment allows for continuous changes in bearing position throughout the transport system, including at junctions between straight and curved sections, thereby maintaining the dimensional stability of the carrier. The carrier does not require precise individual adjustments to account for initial manufacturing tolerances, nor does it require periodic adjustments to account for wear. This is achieved without adversely affecting the dimensions and balance of the carrier. Furthermore, several useful adjustments are provided.

[0051] - Adjustable locating screws can be used to set a physical stop point at the innermost adjustment position of the bearing wheel. This prevents the wheel from closing too much, thus making it easy for the carrier to engage with the carrier / rail without excessively popping the wheel out.

[0052] - Adjustable locating screws can be used to set a physical stop at the outermost adjustment position of the bearing wheel. If the applied load exceeds the preload, this stop can prevent the bearing from moving too far outward, thus preventing the carrier from derailing.

[0053] - The spring can be replaced with a spring of different stiffness, depending on the required preload and adjustment range.

[0054] - The bias spring can be supported by an adjustable positioning screw. If this screw is moved, the preload of the mover can be adjusted within limits.

[0055] It should be noted that in current transport systems, the driving force is not transmitted to the carrier via self-adjusting bearings. For example, self-adjusting bearings can be used in rack-driven carriers, but the driving force is transmitted through a pinion running on a rack or gear, which positions itself adjacent to a fixed bearing.

[0056] Although this article describes the form of bearing wheels, the invention is also applicable to other forms of bearings, such as rollers.

[0057] Although the above description focuses on what is considered a new field and solves specific problems that have been identified, the features disclosed herein are intended to be used in any combination that can provide new and useful improvements in the field.

Claims

1. A transportation system, the transportation system comprising: The track (1) has a top surface (8) and opposing first side (9) and second side (10); a carrier (11) having a carrier body (12) extending across the top surface of the track; a fixed bearing arrangement (14) including bearings (15a, 15b) engaging the first side of the track and having an axis of rotation in a fixed position on the carrier body; a self-adjusting bearing arrangement (19) including a movable bearing (20) for engaging the second side of the track with the carrier body and mounted on a pivot arm (21) having pivoting connections (24, 25); and a biasing element (45) arranged to act on the pivot arm to maintain contact between the movable bearing and the second side of the track. The self-adjusting bearing arrangement (19) is configured as follows: -The movable bearing (20) is not driven; - The pivoting connectors (24, 25) of the movable bearing (20) and the pivoting arm (21) are both located at the first end of the pivoting arm; - The biasing element (45) is spaced apart from the pivoting connector (24, 25) of the pivoting arm (21) in a first direction; The movable bearing (20) is offset from the pivoting connector (24, 25) in a second direction, which is transverse to the first direction. The biasing element (45) is used to push the pivot arm (21) in a direction opposite to the direction in which the movable bearing (20) deviates from the pivot connector (25, 25).

2. The transportation system according to claim 1, characterized in that, The second direction is substantially orthogonal to the first direction.

3. The transportation system according to claim 1, characterized in that, The pivot arm (21) and the biasing element (45) extend on the top surface (8) of the track.

4. The transportation system according to claim 2, characterized in that, The pivot arm (21) and the biasing element (45) extend on the top surface (8) of the track.

5. The transportation system according to any one of claims 1 to 4, characterized in that, The biasing element (45) is contained within the cavity (40) of the carrier body (12).

6. The transportation system according to any one of claims 1 to 4, characterized in that, The distance A between the biasing element (45) and the pivot axis (y1) of the pivot arm (21) is greater than the distance B between the rotation axis (y2) of the bearing (20) and the pivot axis (y1).

7. The transportation system according to any one of claims 1 to 4, characterized in that, The distance A between the biasing element (45) and the pivot axis (y1) of the pivot arm (21) is greater than twice the distance B between the rotation axis (y2) of the bearing (20) and the pivot axis (y1).

8. The transportation system according to any one of claims 1 to 4, characterized in that, The distance A between the pivot axis (y1) of the bias element (45) and the pivot arm (21) is greater than three times the distance B between the rotation axis (y2) of the bearing (20) and the pivot axis (y1).

9. The transportation system according to any one of claims 1 to 4, characterized in that, The distance A between the pivot axis (y1) of the bias element (45) and the pivot arm (21) is greater than five times the distance B between the rotation axis (y2) of the bearing (20) and the pivot axis (y1).

10. The transportation system according to any one of claims 1 to 4, characterized in that, The pivot arm (21) has an upper part (31) and a lower part (32), and has a pivot bolt (24) protruding from the upper part and a bearing bolt (22) protruding from the lower part.

11. The transportation system according to claim 10, characterized in that, The upper part of the pivot arm carries a vertical flange (34).

12. The transportation system according to claim 11, characterized in that, The biasing element (45) acts against the flange (34).

13. The transportation system according to any one of claims 1 to 4, characterized in that, An adjustable closing stop (46) is provided to limit the pivoting movement of the movable bearing (20) toward the fixed bearing arrangement (14).

14. The transportation system according to any one of claims 1 to 4, characterized in that, An adjustable opening stop (47) is provided to limit the pivoting movement of the movable bearing (20) away from the fixed bearing arrangement (14).

15. The transportation system according to any one of claims 1 to 4, characterized in that, The biasing element (45) is positioned on the same side of the pivot arm (21) and the movable bearing (20).

16. The transportation system according to any one of claims 1 to 4, characterized in that, The biasing element (45) includes a compression spring supported on a guide pin (44).

17. The transportation system according to any one of claims 1 to 4, characterized in that, The biasing element (45) abuts against the adjustable stop (51) to change the preload of the biasing element.

18. The transportation system according to any one of claims 1 to 4, characterized in that, The self-adjusting bearing arrangement (19) includes a single movable bearing (20) mounted on a pivot arm (21) with a biasing element (45).

19. The transportation system according to any one of claims 1 to 4, characterized in that, The self-adjusting bearing arrangement (19) includes a pair of movable bearings (20a, 20b) mounted on corresponding pivot arms (21a, 21b) with corresponding bias elements (45).

20. The transportation system according to claim 19, characterized in that, The two pivot arms (21a, 21b) are opposite in orientation.

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