Mobile transport system
The mobile transport system addresses uneven surface navigation by using vertically movable drive units with adjustable spring force and offset design to reduce wear and maintenance costs.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- SEW EURODRIVE GMBH & CO KG
- Filing Date
- 2025-11-11
- Publication Date
- 2026-06-25
AI Technical Summary
Existing mobile transport systems face challenges in efficiently navigating uneven ground surfaces while minimizing maintenance and repair costs due to wear on spring elements.
A mobile transport system with vertically movable drive units mounted via spring elements, adjustable spring force, and offset drive units to distribute forces evenly across multiple spring elements, reducing wear and the need for immediate replacement.
The system effectively compensates for uneven surfaces, reduces wear on spring elements, and decreases maintenance costs by allowing adjustable spring force adjustment without immediate replacement.
Smart Images

Figure EP2025082576_25062026_PF_FP_ABST
Abstract
Description
[0001] Mobile transport system
[0002] Description:
[0003] The invention relates to a mobile transport system for transporting objects, in particular in a technical plant, comprising a base frame, a left drive unit and a right drive unit.
[0004] In technical facilities, such as production plants, mobile transport systems, especially autonomous mobile transport systems, are used to transport objects, such as small parts or boxes. These mobile transport systems move components from logistics areas, such as a material warehouse, to workstations where the components are processed.
[0005] From WO 2022 / 238005 A1, a generic mobile transport system is known which has several frames and a plurality of wheels arranged on the frames. The mobile transport system has drive wheels which can be driven by drive motors.
[0006] The invention is based on the objective of further developing a mobile transport system for transporting objects.
[0007] The problem is solved by a mobile transport system with the features specified in claim 1. Advantageous embodiments and further developments are the subject of the dependent claims.
[0008] A mobile transport system according to the invention for transporting objects comprises a base frame, a left drive unit, and a right drive unit. The drive units are mounted so as to be movable in a vertical direction relative to the base frame. One of the drive units moves vertically towards the base frame against a spring force. The mobile transport system has means for adjusting the spring force.
[0009] If the spring elements that generate the spring force become soft during operation of the mobile transport system, the spring preload can be increased, thereby...
[0010] ISI \ EIDOPAT 11.11.2025 Spring force is increased. Replacing the spring elements is not immediately necessary, thus advantageously reducing the costs for maintenance and repair of the mobile transport system.
[0011] According to an advantageous embodiment of the invention, the left drive unit and the right drive unit are arranged offset from each other in a transverse direction.
[0012] According to an advantageous embodiment of the invention, each of the drive units comprises a drive frame, a drive wheel, and a drive motor. The drive wheel is rotatably mounted about a drive axis extending in a transverse direction relative to the drive frame, and the drive motor drives the drive wheel about the drive axis.
[0013] According to an advantageous embodiment of the invention, the mobile transport system comprises a left yoke and a right yoke. The yokes are rigidly connected to the base frame, and the drive frames of the drive units are each coupled to the yokes by means of spring elements. The spring elements generate the spring force.
[0014] The drive units are thus suspended from the base frame by springs.
[0015] Uneven ground surfaces can thus be compensated for by spring action. Due to the arrangement of the spring elements, they are only subjected to vertical loads. This significantly reduces wear on the spring elements.
[0016] According to an advantageous embodiment of the invention, the spring elements are each designed as cylindrical spiral springs, which each project into bores in the yokes and into bores in the drive frame.
[0017] According to an advantageous embodiment of the invention, the means for adjusting the spring force comprise two adjusting plates. Each yoke is assigned an adjusting plate which is movable relative to the respective yoke in the vertical direction. The spring elements each bear against one of the adjusting plates.
[0018] According to an advantageous embodiment of the invention, the means for adjusting the spring force comprise at least two adjusting screws. The adjusting screws extend through the adjusting plates and are screwed into the yokes in such a way that a rotation of the adjusting screws causes a movement of the respective adjusting plate relative to the respective yoke in the vertical direction.
[0019] A turn of the adjusting screws thus causes a change in the preload of the spring elements and therefore a change in the spring force caused by the spring elements.
[0020] According to an advantageous embodiment of the invention, each of the drive frames of the drive units is coupled to one of the yokes by means of exactly two spring elements. The respective spring elements are arranged longitudinally spaced apart from one another, and the drive axis of the respective drive unit is arranged longitudinally between the spring elements.
[0021] This distributes the forces acting on the drive units when driving over an uneven surface across several spring elements.
[0022] According to an advantageous embodiment of the invention, the drive axis of the respective drive unit is arranged centrally in the longitudinal direction between the spring elements.
[0023] This ensures that forces acting on the spring elements when driving over an uneven surface are distributed evenly across the spring elements.
[0024] According to an alternative advantageous embodiment of the invention, each of the drive frames of the drive units is coupled to one of the yokes by means of exactly one spring element. A longitudinal axis of the spring element extending in the vertical direction intersects the drive axis of the respective drive unit.
[0025] The invention is not limited to the combination of features stated in the claims. For those skilled in the art, further meaningful combinations of claims and / or individual claim features and / or features of the description and / or the figures will arise, particularly from the problem statement and / or the problem arising from a comparison with the prior art. The invention will now be explained in more detail with reference to the figures. The invention is not limited to the embodiments shown in the figures. The figures represent the subject matter of the invention only schematically. They show:
[0026] Figure 1: a perspective view of the chassis of a mobile transport system,
[0027] Figure 2: a side view of part of the chassis of the mobile transport system,
[0028] Figure 3: a view of the underside of the chassis of the mobile transport system and
[0029] Figure 4: a sectional view of the part of the chassis from Figure 2.
[0030] Figure 1 shows a perspective view of the chassis of a mobile transport system. In this case, the mobile transport system is used to transport objects within a technical facility. The technical facility is an industrial application, such as a production plant. The transport system can also be used, for example, to deliver goods to a private residence in a city or residential area. In this case, the mobile transport system is an autonomously driving vehicle. In the illustration shown, the mobile transport system is located on a level surface within the technical facility.
[0031] The mobile transport system comprises a base frame 10. The base frame 10 has an approximately rectangular cross-section and extends predominantly in a longitudinal direction X and a transverse direction Y. The longitudinal direction X corresponds at least approximately to the usual direction of travel of the mobile transport system.
[0032] The transverse direction Y runs perpendicular to the longitudinal direction X. The longitudinal direction X and the transverse direction Y represent horizontal directions and run parallel to the flat ground on which the mobile transport system is located. A vertical direction Z is perpendicular to the flat ground and thus runs perpendicular to the longitudinal direction X and perpendicular to the transverse direction Y. Any direction perpendicular to the vertical direction Z represents a horizontal direction.
[0033] The mobile transport system comprises a left drive unit 21 and a right drive unit 21.
[0034] Drive unit 22. The left drive unit 21 and the right drive unit 22 are arranged offset from each other in the transverse direction Y. Each of the drive units 21, 22 has a drive frame 24, a drive wheel 25, and a drive motor 26. The drive wheel 25 is rotatably mounted about a drive axis extending in the transverse direction Y relative to the drive frame 24. Thus, the drive wheel 25 is also rotatable relative to the base frame 10.
[0035] The drive motor 26 drives the drive wheel 25 around the drive axle. The drive motor 26 is designed as a geared motor and includes a gearbox that transmits the rotation of a motor shaft to both the drive axle and the drive wheel 25. The drive wheel 25 rests on the ground.
[0036] The mobile transport system also includes an electrical energy storage device for supplying the drive units 21 and 22, as well as a control unit for controlling the drive units 21 and 22. The mobile transport system also includes a receiving unit to which energy can be inductively transferred from a charging unit. The charging unit is designed, for example, as a linear conductor or a coil. The energy inductively transferred from the charging unit to the receiving unit is used, for example, to charge the electrical energy storage device of the mobile transport system.
[0037] The mobile transport system also includes a communication device for wireless communication with a central server and with other mobile transport systems. Furthermore, the mobile transport system includes several laser scanners. The laser scanners are used for obstacle detection and for navigating the mobile transport system within the technical facility.
[0038] The mobile transport system includes additional support wheels (not shown here) which are rotatable relative to the base frame 10. The support wheels also rest on the ground. Each support wheel is also pivotable about a pivot axis extending in the vertical direction Z relative to the base frame 10.
[0039] The mobile transport system comprises a left yoke 11 and a right yoke 12. The left yoke 11 and the right yoke 12 are each rigidly connected to the base frame 10, in particular by bolting. Figure 2 shows a side view of a portion of the chassis of the mobile transport system. The left side is shown, on which the left drive unit 21 and the left yoke 11 are located. The right side is a mirror image of the left side. The right drive unit 22 is thus functionally identical to the left drive unit 21. The base frame 10 is not shown here.
[0040] The mobile transport system comprises several spring elements 40. The drive frame 24 of the left drive unit 21 is coupled to the left yoke 11 by means of two spring elements 40. The spring elements 40 are each designed as cylindrical coil springs, which each project into bores in the left yoke 11 and into bores in the drive frame 24.
[0041] The spring elements 40 are arranged at intervals from each other in the longitudinal direction X. The drive shaft of the left drive unit 21 is arranged in the longitudinal direction X between the spring elements 40. In particular, the drive shaft of the left drive unit 21 is arranged centrally in the longitudinal direction X between the spring elements 40.
[0042] The left drive unit 21 has a plurality of sliding rollers 90. The sliding rollers 90 are arranged on the drive frame 24. The sliding rollers 90 are each rotatable about a longitudinal axis X extending relative to the drive frame 24 of the left drive unit 21. The base frame 10 has a plurality of guide grooves 92 extending vertically Z (not shown here). The sliding rollers 90 of the left drive unit 21 run on the inner walls of the guide grooves 92 of the base frame 10.
[0043] The left drive unit 21 is thus mounted so as to be movable relative to the base frame 10 in the vertical direction Z. In particular, the left drive unit 21 is guided linearly relative to the base frame 10 in the vertical direction Z such that movement of the left drive unit 21 relative to the base frame 10 in the longitudinal direction X as well as in the transverse direction Y is prevented.
[0044] The movement of the left drive unit 21 in the vertical direction Z towards the base frame 10 and the left yoke 11 takes place against a spring force, whereby the spring elements 40 cause the said spring force.
[0045] Figure 3 shows a view of the underside of the chassis of the mobile transport system. The base frame 10 has a plurality of guide rails 94, each with a U-shaped cross-section. Each of the guide rails 94 has two parallel side legs and a base leg connecting the side legs. The side legs and the base leg of each guide rail 94 surround one of the guide grooves 92 on three sides.
[0046] The sliding rollers 90 of the drive units 21, 22 project in longitudinal direction X into the guide grooves 92 of the base frame 10 and, as already mentioned, run along the inner walls of the guide grooves 92.
[0047] Each of the drive units 21, 22 has a release lever attached to the respective drive motor 26. The release lever allows the gearbox of the respective drive motor 26 to be mechanically disconnected from the associated drive wheel 25, as well as mechanically coupled to the associated drive wheel 25. When the drive motor 25 is disconnected from the associated drive wheel 25, the drive wheel 25 is freely rotatable.
[0048] Figure 4 shows a sectional view of the part of the chassis from Figure 2. A cavity is formed in the first yoke 11, which is arranged facing upwards in the vertical direction Z, i.e., away from the left drive unit 21 and the ground. The cavity is open upwards in the vertical direction Z.
[0049] The mobile transport system comprises two adjustment plates 82, one of which is assigned to each of the yokes 11, 12. The adjustment plates 82 are arranged in the cavity of the first yoke 11 and in the cavity of the second yoke 12 (not shown). The adjustment plates 82 are movable relative to their respective yokes 11, 12 in the vertical direction Z.
[0050] The mobile transport system further comprises two adjusting screws 84, one adjusting screw 84 being assigned to each of the yokes 11, 12. The adjusting screws 84 extend through the adjusting plates 82 and are each screwed into one of the yokes 11, 12. A rotation of one of the adjusting screws 84 causes a movement of the respective adjusting plate 82 relative to the respective yoke 11, 12 in the vertical direction.
[0051] As already mentioned, the spring elements 40 protrude into bores in the left yoke 11. The spring elements 40 bear against the adjusting plate 82. A rotation of the adjusting screw 84 thus changes the preload of the spring elements 40 and therefore the spring force exerted by the spring elements 40.
[0052] The mobile transport system thus has means for adjusting the spring force caused by the spring elements 40. These means for adjusting the spring force comprise the two adjusting plates 82 and the two adjusting screws 84.
[0053] The mobile transport system further comprises several guide pins. Each of the spring elements 40 concentrically surrounds a guide pin. The guide pins are rigidly connected to the adjusting plates 82. The guide pins are guided linearly in the bores relative to the drive frames 24 in the vertical direction Z.
[0054] The mobile transport system also includes several locking screws, not shown here. Each locking screw extends through one of the yokes 11, 12 and is screwed into one of the drive frames 24. The locking screws are movable relative to the yokes 11, 12 in the vertical direction Z. The locking screws secure the drive units 21, 22 and prevent them from falling out of the base frame 10.
[0055] Reference symbol list
[0056] 10 basic frames
[0057] 11 left yoke
[0058] 12 right yoke
[0059] 21 left drive unit
[0060] 22 right drive unit
[0061] 24 drive frames
[0062] 25 drive wheel
[0063] 26 Drive motor
[0064] 40 spring element
[0065] 82 adjustment plates
[0066] 84 Adjusting screw
[0067] 90 sliding roller
[0068] 92 guide groove
[0069] 94 Running rail
[0070] X Longitudinal direction
[0071] Y transverse direction
[0072] Z Vertical direction
Claims
Patent claims:
1. Mobile transport system for transporting objects, comprising a base frame, a left drive unit and a right drive unit, characterized in that the drive units (21 , 22) are movably mounted relative to the base frame (10) in a vertical direction (Z), and that a movement of one of the drive units (21 , 22) in a vertical direction (Z) towards the base frame (10) is effected against a spring force, and that the mobile transport system has means for adjusting the spring force.
2. Mobile transport system according to claim 1, characterized in that the left drive unit (21) and the right drive unit (22) are arranged offset from each other in a transverse direction (Y).
3. Mobile transport system according to one of the preceding claims, characterized in that each of the drive units (21, 22) has a drive frame (24), a drive wheel (25) and a drive motor (26), and that the drive wheel (25) is rotatably mounted about a drive axis extending in a transverse direction (Y) relative to the drive frame (24), and that the drive motor (26) drives the drive wheel (25) about the drive axis.
4. Mobile transport system according to claim 3, characterized in that the mobile transport system comprises a left yoke (11) and a right yoke (12), and that the yokes (11, 12) are firmly connected to the base frame (10), and that the drive frames (24) of the drive units (21, 22) are each coupled to the yokes (11, 12) by means of spring elements (40), and that the spring elements (40) cause the spring force.
5. Mobile transport system according to claim 4, characterized in that the spring elements (40) are each designed as cylindrical spiral springs, which each project into bores in the yokes (11, 12) and into bores in the drive frame (24).
6. Mobile transport system according to one of claims 4 to 5, characterized in that the means for adjusting the spring force comprise two adjusting plates (82), and that each of the yokes (11, 12) is assigned an adjusting plate (82) which is movable relative to the respective yoke (11, 12) in the vertical direction (Z), and that the spring elements (40) each bear against one of the adjusting plates (82).
7. Mobile transport system according to claim 6, characterized in that the means for adjusting the spring force comprise at least two adjusting screws (84), and that the adjusting screws (84) extend through the adjusting plates (82) and are screwed into the yokes (11, 12) such that a rotation of the adjusting screws (84) causes a movement of the respective adjusting plate (82) relative to the respective yoke (11, 12) in the vertical direction (Z).
8. Mobile transport system according to one of claims 4 to 7, characterized in that each of the drive frames (24) of the drive units (21, 22) is coupled to one of the yokes (11, 12) by means of exactly two spring elements (40), and that the respective spring elements (40) are arranged spaced apart from each other in the longitudinal direction (X), and that the drive axis of the respective drive unit (21, 22) is arranged in the longitudinal direction (X) between the spring elements.
9. Mobile transport system according to claim 8, characterized in that the drive axis of the respective drive unit (21, 22) is arranged centrally between the spring elements (40) in the longitudinal direction (X).
10. Mobile transport system according to one of claims 4 to 7, characterized in that each of the drive frames (24) of the drive units (21 , 22) is coupled to one of the yokes (11, 12) by means of exactly one spring element (40), and that a longitudinal axis of the spring element (40) extending in the vertical direction (Z) intersects the drive axis of the respective drive unit (21, 22).