Mobile transport system

Abstract

The invention relates to a mobile transport system for transporting objects, comprising a chassis (12), a first rocker (81) which is pivotally mounted about a first rocker axis (91) relative to the chassis, a second rocker (82) which is pivotally mounted about a second rocker axis (92) relative to the chassis, a first front wheel (21) and a first rear wheel (31) which are rotatably mounted on the first rocker, and a second front wheel (22) and a second rear wheel (32) which are rotatably mounted on the second rocker. The mobile transport system additionally comprises a first hydraulic cylinder (41), a first working piston (43) which can be moved therein, a second hydraulic cylinder (42), and a second working piston (44) which can be moved therein. The hydraulic cylinders are hinged to the chassis. A first piston rod (45) which is connected to the first working piston is hinged to the first rocker such that when the first working piston is moved relative to the first hydraulic cylinder, the first rocker is pivoted about the first rocker axis, and a second piston rod (46) which is connected to the second working piston is hinged to the second rocker such that when the second working piston is moved relative to the second hydraulic cylinder, the second rocker is pivoted about the second rocker axis.

Description

[0001] Mobile transport system

[0002] Description:

[0003] The invention relates to a mobile transport system for transporting objects, which comprises a chassis, a first swing arm which is pivotally mounted about a first swing axis relative to the chassis, a second swing arm which is pivotally mounted about a second swing axis relative to the chassis, a first front wheel and a first rear wheel which are rotatably mounted on the first swing arm, and a second front wheel and a second rear wheel which are rotatably mounted on the second swing arm.

[0004] Mobile transport systems of this type are used, for example, in NASA's Mars rovers. Such a mobile transport system comprises a landing gear designed as a rocker-bogie system. The landing gear comprises two rocker arms to suspend the wheels. This allows the landing gear to compensate for uneven ground. The two rocker arms are connected to the chassis via a mechanical differential. This ensures that the chassis moves relatively little, even with large vertical movements of the individual wheels attached to the rocker arms.

[0005] DE 102020 007 712 A1 discloses a mobile transport system for transporting objects. It comprises a vehicle frame, a pendulum frame, and a tilting frame. Two wheels are mounted on each frame. The frames can be pivoted relative to each other about various axes. The chassis of the mobile transport system allows it to compensate for uneven ground.

[0006] The invention is based on the object of developing a mobile transport system for transporting objects.

[0007] The object is achieved by a mobile transport system having the features specified in claim 1. Advantageous embodiments and further developments are the subject of the subclaims.

[0008] A mobile transport system according to the invention for transporting objects comprises a chassis, a first swing arm pivotably mounted relative to the chassis about a first swing axis, a second swing arm pivotably mounted relative to the chassis about a second swing axis, a first front wheel and a first rear wheel rotatably mounted on the first swing arm, and a second front wheel and a second rear wheel rotatably mounted on the second swing arm. The mobile transport system further comprises a first hydraulic cylinder and a first working piston displaceable therein, as well as a second hydraulic cylinder and a second working piston displaceable therein. The hydraulic cylinders are articulated to the chassis.A first piston rod connected to the first working piston is articulated to the first rocker arm such that upon displacement of the first working piston relative to the first hydraulic cylinder, the first rocker arm pivots about the first oscillation axis. A second piston rod connected to the second working piston is articulated to the second rocker arm such that upon displacement of the second working piston relative to the second hydraulic cylinder, the second rocker arm pivots about the second oscillation axis.

[0009] The hydraulic system of the mobile transport system according to the invention allows the rockers to pivot around the pivot axes in such a way that all wheels always maintain contact with the ground on which the mobile transport system is located. When driving over uneven surfaces, corresponding pivoting movements of the pivot axes occur relative to the chassis. The chassis of the mobile transport system is always statically determined. The hydraulic cylinders require relatively little installation space compared to a mechanical differential.

[0010] According to an advantageous embodiment of the invention, the mobile transport system comprises a first angle sensor for detecting a pivot angle of the first rocker arm about the first pivot axis relative to the chassis, and a second angle sensor for detecting a pivot angle of the second rocker arm about the second pivot axis relative to the chassis. Detecting the pivot angle of one of the rockers enables corresponding control of the other rocker arm using a suitable actuator. This enables active control of the chassis of the mobile transport system.

[0011] According to a preferred embodiment of the invention, the working pistons separate the hydraulic cylinders into an upper region and a lower region. The upper regions and the lower regions are filled with a fluid, and the piston rods each extend through the lower region. When a working piston in one of the hydraulic cylinders is displaced, one of the said regions is enlarged, while the other of the said regions is simultaneously reduced. According to an advantageous embodiment of the invention, the upper regions of the hydraulic cylinders are connected to one another by means of an upper hydraulic line, and the lower regions of the hydraulic cylinders are connected to one another by means of a lower hydraulic line. The hydraulic lines enable the fluid in the working pistons to flow back and forth between the upper regions and between the lower regions.As a result, the swing arms pivot in opposite directions relative to the chassis.

[0012] According to an advantageous development of the invention, an upper valve is provided in the upper hydraulic line, which, in an open position, hydraulically connects the upper regions of the hydraulic cylinders to one another, and which, in a closed position, hydraulically separates the upper regions of the hydraulic cylinders from one another. According to an advantageous development of the invention, a lower valve is provided in the lower hydraulic line, which, in an open position, hydraulically connects the lower regions of the hydraulic cylinders to one another, and which, in a closed position, hydraulically separates the lower regions of the hydraulic cylinders from one another. By closing one of said valves, a flow of fluid between the upper regions and between the lower regions is prevented. This also prevents pivoting movements of the rocker arms relative to the chassis.The valves thus act like a switchable differential lock.

[0013] According to an advantageous development of the invention, the mobile transport system has a pump which is connected to the upper hydraulic line and to the lower hydraulic line, and which is configured to pump a fluid from the upper hydraulic line to the lower hydraulic line and from the lower hydraulic line to the upper hydraulic line. The pumping of the fluid from the upper hydraulic line to the lower hydraulic line and from the lower hydraulic line to the upper hydraulic line causes pivoting movements of the rockers relative to the chassis synchronously and in the same pivoting direction. This allows the alignment of the chassis relative to the ground to be adjusted. For example, when driving uphill, fluid is pumped from the upper hydraulic line to the lower hydraulic line, and when driving downhill, fluid is pumped from the lower hydraulic line to the upper hydraulic line.This allows the chassis to be aligned such that a transport surface of the mobile transport system remains in an at least approximately horizontal position. According to a preferred embodiment of the invention, the first oscillation axis extends in a transverse direction, and / or the second oscillation axis extends in the transverse direction. Preferably, the first oscillation axis and the second oscillation axis are aligned with one another.

[0014] According to an advantageous embodiment of the invention, the front wheels are arranged offset from the rear wheels in a longitudinal direction, and the swing axles are arranged in the longitudinal direction between the front and rear wheels. The longitudinal direction runs perpendicular to the transverse direction.

[0015] According to an advantageous development of the invention, the front wheels and / or the rear wheels are each steerable about a steering axis extending in a vertical direction. The vertical direction runs at right angles to the longitudinal direction and at right angles to the transverse direction.

[0016] According to a preferred embodiment of the invention, the front wheels and / or the rear wheels are each rotatable about an axis of rotation extending in a horizontal direction. Horizontal directions extend perpendicular to the vertical direction. In particular, the longitudinal direction and the transverse direction represent horizontal directions.

[0017] According to an advantageous embodiment of the invention, the mobile transport system comprises a first drive motor for driving the first front wheel and / or the first rear wheel and a second drive motor for driving the second front wheel and / or the second rear wheel, wherein the first drive motor is arranged on the first swing arm, and the second drive motor is arranged on the second swing arm. Preferably, transmissions are also provided, via which the drive motors drive the wheels. The transmissions are also arranged on the swing arms. The drive motors and the transmissions can thus be arranged in a space-saving manner.

[0018] According to an advantageous embodiment of the invention, the mobile transport system has a first braking device for braking the first front wheel and / or the first rear wheel and a second braking device for braking the second front wheel and / or the second rear wheel, wherein the first braking device is arranged on the first swing arm and the second braking device is arranged on the second swing arm. The braking devices are preferably electromagnetically actuated. The invention is not limited to the combination of features of the claims. Those skilled in the art will recognize further useful combinations of claims and / or individual claim features and / or features of the description and / or the figures, in particular from the task and / or the task posed by comparison with the prior art.

[0019] The invention will now be explained in more detail with reference to the accompanying drawings. The invention is not limited to the exemplary embodiments shown in the drawings. The drawings only represent the subject matter of the invention schematically. They show:

[0020] Figure 1 : a schematic perspective view of a mobile transport system on a flat floor,

[0021] Figure 2: a schematic view of a hydraulic system of the mobile transport system on the flat ground,

[0022] Figure 3: a schematic perspective view of the mobile transport system when driving over an uneven floor,

[0023] Figure 4: a schematic view of the hydraulic system of the mobile transport system when driving over the uneven ground,

[0024] Figure 5: a side view of the mobile transport system when driving downhill and

[0025] Figure 6: a schematic view of the hydraulic system of the mobile transport system when driving downhill.

[0026] Figure 1 shows a schematic perspective view of a mobile transport system on a flat floor. 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 or a paint shop. The transport system can also be used, for example, to deliver goods to a private recipient's home in a city or residential area. The mobile transport system is an autonomously driving vehicle.

[0027] A transverse direction Y runs at right angles to a vertical direction Z. A longitudinal direction X runs at right angles to the vertical direction Z and at right angles to the transverse direction Y. The longitudinal direction X and the transverse direction Y represent horizontal directions. Every direction perpendicular to the vertical direction Z represents a horizontal direction. The longitudinal direction X corresponds at least approximately to the usual direction of travel of the mobile transport system. The mobile transport system comprises a chassis 12, a first rocker 81 and a second rocker 82. The first rocker 81 is pivotally mounted about a first rocker axis 91 relative to the chassis 12. The second rocker 82 is pivotally mounted about a second rocker axis 92 relative to the chassis 12. The first rocker axis 91 runs in the transverse direction Y. The second rocker axis 92 also runs in the transverse direction Y. The first rocker axis 91 and the second rocker axis 92 are aligned with one another.

[0028] The mobile transport system also includes a first front wheel 21, a first rear wheel 31, a second front wheel 22, and a second rear wheel 32. The first front wheel 21 and the first rear wheel 31 are rotatably mounted on the first swing arm 81. The second front wheel 22 and the second rear wheel 32 are rotatably mounted on the second swing arm 82. The front wheels 21, 22 are arranged offset from the rear wheels 31, 32 in the longitudinal direction X. The swing axes 91, 92 are arranged between the front wheels 21, 22 and the rear wheels 31, 32 in the longitudinal direction X.

[0029] The first front wheel 21 and the first rear wheel 31 are each steerable relative to the first swing arm 81 about a steering axis extending in the vertical direction Z. The first front wheel 21 and the first rear wheel 31 are each rotatable relative to the first swing arm 81 about a rotation axis extending in a horizontal direction. In the illustration shown here, the said rotation axes extend in the transverse direction Y. Depending on a steering movement of the first front wheel 21 and the first rear wheel 31 about the said pivot axes, the rotation axes may extend in a different horizontal direction.

[0030] The second front wheel 22 and the second rear wheel 32 are each steerable relative to the second swing arm 82 about a steering axis extending in the vertical direction Z. The second front wheel 22 and the second rear wheel 32 are each rotatable relative to the second swing arm 82 about a rotation axis extending in a horizontal direction. In the illustration shown here, the said rotation axes extend in the transverse direction Y. Depending on a steering movement of the second front wheel 22 and the second rear wheel 32 about the said pivot axes, the rotation axes may extend in a different horizontal direction.

[0031] The mobile transport system has a first drive motor (not shown here) for driving the first front wheel 21 and the first rear wheel 31. The first drive motor is arranged on the first swing arm 81. The mobile transport system also has a second drive motor (not shown here) for driving the second front wheel 22 and the second rear wheel 32. The second drive motor is arranged on the second swing arm 82.

[0032] The mobile transport system has a first braking device (not shown here) for braking the first front wheel 21 and the first rear wheel 31. The first braking device is arranged on the first swing arm 81. The mobile transport system also has a second braking device (not shown here) for braking the second front wheel 22 and the second rear wheel 32. The second braking device is arranged on the second swing arm 82. The said braking devices are electromagnetically actuated.

[0033] The mobile transport system has an electrical energy storage device (not shown here). The mobile transport system also has a receiving unit (not shown here), which is arranged on the chassis 12 and 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 serves, for example, to charge the electrical energy storage device of the mobile transport system.

[0034] The mobile transport system has a first angle sensor for detecting a pivot angle of the first rocker arm 81 about the first pivot axis 91 relative to the chassis 12. The mobile transport system also has a second angle sensor for detecting a pivot angle of the second rocker arm 82 about the second pivot axis 92 relative to the chassis 12. The mobile transport system further has an inclination sensor for detecting an inclination of the ground, i.e., a slope or gradient.

[0035] The mobile transport system comprises a first hydraulic cylinder 41 and a first working piston 43 that can be moved therein. A first piston rod 45 is connected to the first working piston 43. The first hydraulic cylinder 41 is articulated to the chassis 12. The first piston rod 45 is articulated to the first rocker 81. When the first working piston 43 is moved relative to the first hydraulic cylinder 41, the first rocker 81 is pivoted about the first rocker axis 91. The mobile transport system comprises a second hydraulic cylinder 42 and a second working piston 44 that can be moved therein. A second piston rod 46 is connected to the second working piston 44. The second hydraulic cylinder 42 is articulated to the chassis 12. The second piston rod 46 is articulated to the second rocker 82. When the second working piston 44 is displaced relative to the second hydraulic cylinder 42, the second swing arm 82 is pivoted about the second swing axis 92.

[0036] The first hydraulic cylinder 41 and the second hydraulic cylinder 42 are connected to each other by means of an upper hydraulic line 53 and a lower hydraulic line 54.

[0037] Figure 2 shows a schematic view of a hydraulic system of the mobile transport system on level ground. The hydraulic system includes the first hydraulic cylinder 41, the first working piston 43, the first piston rod 45, the second hydraulic cylinder 42, the second working piston 44, the second piston rod 46, the upper hydraulic line 53, the lower hydraulic line 54, and a pump 55.

[0038] The first working piston 43 separates the first hydraulic cylinder 41 into an upper region 51 and a lower region 52. The first piston rod 45 extends through the lower region 52 and penetrates a lower end face of the first hydraulic cylinder 41. The upper region 51 and the lower region 52 of the first hydraulic cylinder 41 are filled with a fluid, in particular hydraulic oil.

[0039] The second working piston 44 separates the second hydraulic cylinder 42 into an upper region 51 and a lower region 52. The second piston rod 46 extends through the lower region 52 and penetrates a lower end face of the second hydraulic cylinder 42. The upper region 51 and the lower region 52 of the second hydraulic cylinder 42 are filled with a fluid, in particular hydraulic oil.

[0040] The upper region 51 of the first hydraulic cylinder 41 and the upper region 51 of the second hydraulic cylinder 42 are connected to one another via the upper hydraulic line 53. The lower region 52 of the first hydraulic cylinder 41 and the lower region 52 of the second hydraulic cylinder 42 are connected to one another via the lower hydraulic line 54. The hydraulic lines 53, 54 are also filled with the fluid. The first rocker arm 81 and the second rocker arm 82 are coupled to one another via the hydraulic system in such a way that a pivoting movement of the first rocker arm 81 about the first rocker axis 91 in a first pivoting direction causes a pivoting movement of the second rocker arm 82 about the second rocker axis 92 in a second pivoting direction opposite to the first pivoting direction.

[0041] The pump 55 is connected to the upper hydraulic line 53 and to the lower hydraulic line 54. The pump 55 is configured to pump fluid from the upper hydraulic line 53 to the lower hydraulic line 54 and from the lower hydraulic line 54 to the upper hydraulic line 53.

[0042] In the illustration shown here, the mobile transport system is located on a level floor. The contact points of the wheels 21, 22, 31, 32 with the floor are in the same plane. The working pistons 43, 44 are located approximately in the center of the hydraulic cylinders 41, 42. The piston rods 45, 46 protrude equally far from the lower end faces of the hydraulic cylinders 41, 42.

[0043] Figure 3 shows a schematic perspective view of the mobile transport system traveling over an uneven surface. For example, the first front wheel 21 travels over an obstacle and is thereby raised in the vertical direction Z. The first swing arm 81 is pivoted about the first swing axis 91, and the first rear wheel 31 is thereby lowered in the vertical direction Z.

[0044] Via the aforementioned coupling by the hydraulic system, the second swing arm 82 is pivoted about the second swing axis 92. As a result, the second front wheel 22 is lowered in the vertical direction Z, and the second rear wheel 32 is raised in the vertical direction Z. The contact points of the wheels 21, 22, 31, 32 with the ground are thus no longer in one plane.

[0045] Figure 4 shows a schematic view of the hydraulic system of the mobile transport system when traveling over uneven ground. Due to the pivoting movement of the first rocker 81 about the first rocker axis 91, the first piston rod 45 is pushed further into the first hydraulic cylinder 41. This reduces the size of the upper region 51 of the first hydraulic cylinder 41 and enlarges the size of the lower region 52 of the first hydraulic cylinder 41. As a result, fluid flows from the upper region 51 of the first hydraulic cylinder 41 through the upper hydraulic line 53 to the upper region 51 of the second hydraulic cylinder 42. Fluid also flows from the lower region 52 of the second hydraulic cylinder 42 through the lower hydraulic line 54 to the lower region 52 of the first hydraulic cylinder 41. This enlarges the size of the upper region 51 of the second hydraulic cylinder 42 and reduces the size of the lower region 52 of the second hydraulic cylinder 42.This pushes the second piston rod 46 further out of the second hydraulic cylinder 42. This causes the second rocker arm 82 to pivot about the second pivot axis 92.

[0046] Figure 5 shows a side view of the mobile transport system traveling downhill. The inclination sensor detects the inclination of the ground, in this case a slope. Using the hydraulic system, the rockers 81, 82 are pivoted about the pivot axes 91, 92 relative to the chassis 12 such that the front wheels 21, 22 are lowered in the vertical direction Z and the rear wheels 31, 32 are raised in the vertical direction Z. A transport surface of the mobile transport system thus remains in an approximately horizontal position.

[0047] Figure 6 shows a schematic view of the hydraulic system of the mobile transport system during downhill travel. When the incline sensor detects the gradient, pump 55 is activated to pump fluid from the lower hydraulic line 54 to the upper hydraulic line 53.

[0048] As a result, fluid flows through the upper hydraulic line 53 to the upper regions 51 of the hydraulic cylinders 41, 42. Fluid also flows from the lower regions 52 of the hydraulic cylinders 41, 42 to the lower hydraulic line 54. As a result, the upper regions 51 of the hydraulic cylinders 41, 42 are enlarged and the lower regions 52 of the hydraulic cylinders 42 are reduced.

[0049] As a result, the piston rods 45, 46 are pushed further out of the hydraulic cylinders 41, 42. As a result, the rockers 81, 82 are pivoted about the rocker axes 91, 92 relative to the chassis 12. The front wheels 21, 22 are lowered in the vertical direction Z, and the rear wheels 31, 32 are raised in the vertical direction Z. List of reference symbols

[0050] 12 chassis

[0051] 21 first front wheel

[0052] 22 second front wheel

[0053] 31 first rear wheel

[0054] 32 second rear wheel

[0055] 41 first hydraulic cylinder

[0056] 42 second hydraulic cylinder

[0057] 43 first working piston

[0058] 44 second working piston

[0059] 45 first piston rod

[0060] 46 second piston rod

[0061] 51 upper area

[0062] 52 lower area

[0063] 53 upper hydraulic line

[0064] 54 lower hydraulic line

[0065] 55 Pump

[0066] 81 first wing

[0067] 82 second swing arm

[0068] 91 first swing axis

[0069] 92 second swing axis

[0070] X Longitudinal direction

[0071] Y transverse direction

[0072] Z vertical direction

Claims

Patent claims:

1. A mobile transport system for transporting objects, comprising a chassis (12), a first swing arm (81) pivotally mounted about a first swing axis (91) relative to the chassis (12), a second swing arm (82) pivotally mounted about a second swing axis (92) relative to the chassis (12), a first front wheel (21) and a first rear wheel (31) rotatably mounted on the first swing arm (81), and a second front wheel (22) and a second rear wheel (32) rotatably mounted on the second swing arm (82), characterized in that the mobile transport system comprises a first hydraulic cylinder (41) and a first working piston (43) displaceable therein, as well as a second hydraulic cylinder (42) and a second working piston (44) displaceable therein, and in that the hydraulic cylinders (41, 42) are articulated to the chassis (12).and that a first piston rod (45) connected to the first working piston (43) is articulated on the first rocker (81) in such a way that upon displacement of the first working piston (43) relative to the first hydraulic cylinder (41), the first rocker (81) is pivoted about the first oscillation axis (91), and that a second piston rod (46) connected to the second working piston (44) is articulated on the second rocker (82) in such a way that upon displacement of the second working piston (44) relative to the second hydraulic cylinder (42), the second rocker (82) is pivoted about the second oscillation axis (92).

2. Mobile transport system according to claim 1, characterized in that the mobile transport system has a first angle sensor for detecting a pivot angle of the first rocker (81) about the first pivot axis (91) relative to the chassis (12) and a second angle sensor for detecting a pivot angle of the second rocker (82) about the second pivot axis (92) relative to the chassis (12).

3. Mobile transport system according to one of the preceding claims, characterized in that the working pistons (43, 44) separate the hydraulic cylinders (41, 42) into an upper region (51) and a lower region (52), and that the upper regions (51) and the lower regions (52) are filled with a fluid, and that the piston rods (45, 46) each extend through the lower region (52).

4. Mobile transport system according to claim 3, characterized in that the upper regions (51) of the hydraulic cylinders (41, 42) are connected by means of an upper hydraulic line (53) are connected to each other, and the lower regions (52) of the hydraulic cylinders (41, 42) by means of a lower hydraulic line (54) are interconnected.

5. Mobile transport system according to claim 4, characterized in that an upper valve is provided in the upper hydraulic line (53), which in an open position hydraulically connects the upper regions (51) of the hydraulic cylinders (41, 42) to one another, and which in a closed position hydraulically separates the upper regions (51) of the hydraulic cylinders (41, 42) from one another, and / or that a lower valve is provided in the lower hydraulic line (54), which in an open position hydraulically connects the lower regions (52) of the hydraulic cylinders (41, 42) to one another, and which in a closed position hydraulically separates the lower regions (52) of the hydraulic cylinders (41, 42) from one another.

6. Mobile transport system according to one of claims 4 to 5, characterized in that the mobile transport system has a pump (55) which is connected to the upper hydraulic line (53) and to the lower hydraulic line (54) and which is designed to convey a fluid from the upper hydraulic line (53) to the lower hydraulic line (54) and from the lower hydraulic line (54) to the upper hydraulic line (53).

7. Mobile transport system according to one of the preceding claims, characterized in that the first oscillation axis (91) runs in a transverse direction (Y), and / or that the second oscillation axis (92) runs in the transverse direction (Y), and / or that the first oscillation axis (91) and the second oscillation axis (92) are aligned with one another.

8. Mobile transport system according to one of the preceding claims, characterized in that the front wheels (21, 22) are arranged offset in a longitudinal direction (X) to the rear wheels (31, 32), and that the swing axes (91, 92) are arranged in the longitudinal direction (X) between the front wheels (21, 22) and the rear wheels (31, 32).

9. Mobile transport system according to one of the preceding claims, characterized in that the front wheels (21, 22) and / or the rear wheels (31, 32) are each steerable about a steering axis extending in a vertical direction (Z).

10. Mobile transport system according to one of the preceding claims, characterized in that the front wheels (21, 22) and / or the rear wheels (31, 32) are each rotatable about an axis of rotation extending in a horizontal direction.

11. Mobile transport system according to one of the preceding claims, characterized in that the mobile transport system has a first drive motor for driving the first front wheel (21) and / or the first rear wheel (31) and a second drive motor for driving the second front wheel (22) and / or the second rear wheel (32), wherein the first drive motor is arranged on the first swing arm (81) and the second drive motor is arranged on the second swing arm (82).

12. Mobile transport system according to one of the preceding claims, characterized in that the mobile transport system has a first braking device for braking the first front wheel (21) and / or the first rear wheel (31) and a second braking device for braking the second front wheel (22) and / or the second rear wheel (32), wherein the first braking device is arranged on the first swing arm (81) and the second braking device is arranged on the second swing arm (82).

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