Transformation wheel and robot system

Abstract

Transformation wheel (10), in particular for a robot (12) with a central rotating element (14), having several spokes (16) which are movably connected to the rotating element (14), wherein the spokes (16) can be moved by the rotating element (14) from at least a first position to a second position, wherein the diameter of the transformation wheel (10) increases when the spokes (16) are moved from the first position to the second position, characterized in that a self-locking mechanism (18) is provided and wherein the spokes (16) are fixed in the first position and / or the second position by the self-locking mechanism (18), characterized in that the self-locking mechanism (18) comprises a gear (20), and that the gear (20) comprises at least one gear (22) and a worm gear (24).that the worm gear (24) is in engagement with the gear (22) and that when the worm gear (24) rotates, the spokes (16) can be moved from the first position to the second position.

Description

[0001] The invention relates to a transformation wheel, in particular for a robot with a central rotation element, with a plurality of spokes which are movably connected to the rotation element, wherein the spokes can be moved by the rotation element from at least a first position to a second position, wherein the diameter of the transformation wheel increases when the spokes are moved from the first position to the second position.

[0002] In addition, the invention relates to a robot system comprising a robot and a transformation wheel arranged on the robot.

[0003] A variety of devices are known in the prior art that improve the mobility of vehicles or wheeled devices. It is becoming increasingly important that the vehicles and devices function reliably and efficiently even on different surface conditions.

[0004] Wheel size is an important parameter that determines the traversing performance of the vehicle or device. Limitations of this kind can be reduced by introducing mobility elements into the system. These can be used to deploy the locomotion mechanism from a stowed configuration. The use of inflatable or foldable wheels, which can achieve large diameters and thus offer high off-road capability while still being compatible with launch restrictions, is also common.

[0005] In this regard, devices are known from the prior art in which the wheels can be transformed in such a way that a spoke adjustment is carried out, whereby the diameter of the wheels is increased.

[0006] CN 1 11 110 465 A, for example, shows a wheelchair robot designed to climb steps. The robot has four transformation wheels with adjustable spokes, allowing the diameter of the transformation wheels to be adjusted. This allows people in the wheelchair to remain in a horizontal sitting position while climbing the steps and not be forced to sit reclined in the wheelchair due to the incline of the steps. Several motors are provided to operate the wheelchair. One motor is used to adjust the spokes.

[0007] CN 1 11 532 353 A discloses a planetary gear with an adjustable tread that can be used for stair climbing. The spokes of the gear are connected to each other and can be pivoted simultaneously to increase the diameter of the gear.

[0008] CN 1 11 532 327 A also discloses a planetary gear arrangement, wherein a plurality of gears are arranged on a frame and are movable along the frame by means of a plurality of threaded rods which can rotate through a central rotation element, so that the gears can have a smaller or larger distance from the center of the frame.

[0009] A disadvantage of the aforementioned transformation wheels is that the spoke adjustment motor must apply a continuous torque to keep the spokes in the moved position, which requires a high energy expenditure.

[0010] The invention is therefore based on the object of specifying a transformation wheel and a robot system in which an energy-efficient use of the transformation wheel can be ensured.

[0011] This object is achieved in the present invention by the features of the characterizing part of patent claim 1, according to which a self-locking mechanism is provided, and wherein the self-locking mechanism fixes the spokes in the first position and the second position, respectively. The self-locking mechanism holds the spokes in the corresponding position without the need for an additional force acting against a movement of the spokes, for example, from the second position to the first position.

[0012] The central rotation element is an element located at the center of the transformation wheel, which also lies on the rotation axis of the transformation wheel. It is conceivable that the spokes, or parts of the spokes, extend in a star shape from the central rotation element. By rotating the rotation element, the rotational movement is converted, using suitable means, into a movement that moves the spokes from the first position to the second position.

[0013] The spokes can be known from the prior art, extending in a star shape from the rotating element. However, other spoke designs are also conceivable. A spoke, as defined by the invention, is an element arranged between the central rotating element and the wheel's tread. A spoke itself can also be part of the wheel's tread.

[0014] When moving the spokes from the first position to the second position, the diameter of the transformation wheel increases. Between the first and second positions, there may be additional positions in which the diameter of the transformation wheel is smaller than in the second position but larger than in the first position. The diameter of the transformation wheel is at its maximum in the second position.

[0015] The movement of the spokes from the first position to the second position can be accomplished in different ways. One conceivable option is for the spokes to be extendable. Using a kind of telescopic mechanism, the spokes can then be moved radially outward, away from the central rotating element, thereby increasing the overall diameter of the transformation wheel.

[0016] The self-locking mechanism secures the spokes in their respective positions. This means that a force continues to act on the spokes at this moment, allowing them to be moved back into a different position. With the current technology, this force must be continuously applied by a motor. However, the self-locking mechanism of the gear system supports the spoke in its respective position, eliminating the need for additional force from the motor. Therefore, the force that counteracts the retraction of the spoke is caused by friction in the gear system.

[0017] Further preferred embodiments of the invention emerge from the remaining features mentioned in the subclaims.

[0018] According to the invention, the self-locking mechanism comprises a gearing, the gearing comprises at least one gear and a worm gear, the worm gear engages the gear, and upon rotation of the worm gear, the spokes can be moved from the first position to the second position. In this way, the self-locking mechanism is practically realized. The worm gear, as a combination of a toothed gear and a helical gear, has a self-locking mechanism that holds the spokes in the second position and the first position, respectively.

[0019] The direction of rotation can also be influenced by choosing the pitch of the worm gear or the gear arrangement. For example, a "positive" direction of rotation of the rotating element can cause the spokes to extend, while if the pitch of the worm is negated, a positive direction of rotation of the rotating element causes the spokes to retract.

[0020] In a further advantageous embodiment of the transformation wheel according to the invention, it is provided that the rotation element is designed as a bevel gear, that the bevel gear engages with several ring gears, and that the spokes can be moved from the first position to the second position by rotating the ring gears. By designing the central rotation element as a bevel gear and correspondingly designing the ring gears, a rotational movement of the central rotation element can be converted into a rotary movement offset by approximately 90 degrees. The orientation of the ring gears makes it possible for the spokes connected to the ring gears via suitable means to be moved from the first position to the second position. This means that, accordingly, upon rotation of the rotation element, the spokes can be moved from the first position to the second position.By appropriately selecting the angles of the gear teeth of the two meshing elements, angles other than 90 degrees can be achieved. The axes, which extend approximately radially from the center of the rotating element, do not necessarily have to originate from the center of the rotating element. An offset of the axes is conceivable, for example, in a hypoid gear.

[0021] Alternatively, in a further embodiment of the transformation wheel according to the invention, the rotation element is designed as a ring gear, the ring gear engages with several bevel gears, and the spokes can be moved from the first position to the second position by rotating the bevel gears. Analogous to the aforementioned embodiment, by designing the central rotation element as a ring gear and correspondingly designing the bevel gears, a rotational movement of the central rotation element can be converted into a rotary movement offset by approximately 90 degrees. The bevel gears can then rotate on an axis that extends radially from the center of the rotation element. The axes, which extend approximately radially from the center of the rotation element, do not necessarily have to originate from the center of the rotation element. An offset of the axes is conceivable, for example in a hypoid gear.

[0022] The orientation of the bevel gears allows the spokes, which are connected to the bevel gears by suitable means, to be moved from the first position to the second position. This means that, when the rotating element rotates, the spokes can be moved from the first position to the second position. By appropriately selecting the angle of the teeth of the two meshing elements, angles other than 90 degrees can also be achieved.

[0023] In order to be able to implement a size scaling of the transformation wheel relatively easily, a further embodiment of the invention provides at least one coupling element, wherein the coupling element is arranged between the rotational element and the worm wheel, and wherein a rotational movement can be transmitted from the rotational element to the worm wheel via the coupling element. The coupling element can, for example, be an intermediate piece that acts as a transition part between the rotational element and a respective spoke. The coupling element can also be part of the spoke. It is conceivable that the coupling element is arranged on a ring gear or bevel gear, so that the coupling element rotates when the ring gear or bevel gear rotates.In this way, an extension of the crown wheel or the bevel gear is realized, whereby the diameter of the transformation wheel for the first position of the spokes can be adjusted to the desired size, depending on the length of the coupling element.

[0024] In an advantageous embodiment of the transformation wheel according to the invention, it is provided that the spokes are at least partially pivotable about a pivot point from the first position to the second position. The spokes can also be only partially pivoted about the pivot point. This means that part of the spoke is fixed and another part can be pivoted about the pivot point by means of a joint. By pivoting the spokes, the spokes can be moved from the first position to the second position, thus increasing the diameter of the transformation wheel. The spokes can be folded in in the first position and unfolded in the second position. The further the spokes are unfolded, the larger the diameter of the transformation wheel.

[0025] Additionally, in a further embodiment of the invention, three spokes are provided, wherein the spokes are arranged at an angle of at least 60 degrees to one another. By using three spokes, the diameter of the transformation wheel in the second position can be maximized. When the spokes are arranged at an angle of at least 60 degrees to one another, the spokes form a triangle. It is also conceivable that only the pivotable part of the spokes is arranged at an angle of 60 degrees to one another, so that the pivotable part of the spokes forms a triangle. The sides of the triangle each have a length that cannot be surpassed by other geometric shapes.

[0026] To improve the usability of the transformation wheel, a further embodiment provides an electric drive. The electric drive allows the rotating element to rotate. The electric drive thus enables the spokes to be moved from the first position to the second position. Using suitable control elements, the diameter of the transformation wheel can also be increased remotely. Remote control can be performed either by a user or by an automated remote control unit.

[0027] Additionally or alternatively, a further embodiment of the transformation wheel according to the invention provides a rotary motor. The transformation wheel is rotatable by the rotary motor. Analogous to an electric drive, a rotary motor can be provided that is responsible for driving the transformation wheel. The independent possibility of driving the transformation wheel and increasing the diameter of the transformation wheel by an additional motor provides the greatest possible flexibility in the operation of the transformation wheel. It is conceivable that the electric drive could also be used as an auxiliary means of driving the transformation wheel. Accordingly, it is also possible for the rotary motor to be used to support the increase in the diameter of the transformation wheel, i.e., to move the spokes from the first position to the second position.

[0028] The aforementioned object is also achieved by a robot system comprising a robot and at least one transformation wheel arranged on the robot. The transformation wheel is designed according to the invention. The above statements regarding the transformation wheel also apply accordingly to the robot system according to the invention.

[0029] Robots are available in various designs. Many robots are designed like vehicles for locomotion. Common robots have four wheels and, using appropriate controls, can transport loads from one position to another. Mobile robots are often used on level surfaces. Things become more complicated when the robot has to negotiate inclines such as stairs.

[0030] For this purpose, the robot can be equipped with several transformation wheels and, for example, a chassis. With appropriate control units, the robot can be moved to different positions using the transformation wheels. The transformation wheels also allow it to negotiate difficult surfaces, such as steps. By increasing the diameter of the robot's transformation wheels at suitable locations, the robot can be used to climb stairs in such a way that the robot, or rather the robot's chassis, only requires minimal tilt.

[0031] The various embodiments of the invention mentioned in this application can be advantageously combined with one another, unless otherwise stated in the individual case.

[0032] The invention is explained below in exemplary embodiments with reference to the accompanying drawings. They show: Fig. 1 a schematic representation of an embodiment of a transformation wheel according to the invention, Fig. 2 the schematic representation of the embodiment of the transformation wheel according to Fig. 1 with extended spokes and Fig. 3 a schematic representation of a robot with multiple transformation wheels.

[0033] Fig. 1 shows a schematic representation of an embodiment of a transformation wheel 10. The transformation wheel 10 can, for example, be mounted on a Fig. 3. The transformation wheel 10 has a central rotation element 14. The rotation element 14 lies in the axis of rotation of the transformation wheel 10, even if it does not simultaneously correspond to the hub of the transformation wheel 10. The rotation element 14 serves to move spokes 16 of the transformation wheel 10 from a first position to a second position by means of a rotational movement. In the Fig. In the state shown in Figure 1, the spokes 16 are in the first position.

[0034] By moving the spokes 16 from the first position to the second position, the diameter of the transformation wheel 10 is increased. In this way, the transformation wheel 10 can be adapted to different surface conditions depending on the situation. If the transformation wheel 10 is mounted on a vehicle, for example, the vehicle can initiate various maneuvers by increasing the diameter of the transformation wheel(s) 10.

[0035] To hold the spokes 16 in the corresponding position, a self-locking mechanism 18 is provided. Thanks to the self-locking mechanism 18, no force needs to be applied to the spokes 16 to hold them in the respective position. Once the spokes 16 have been moved into the first position or the second position, they remain in that position. The self-locking mechanism 18 comprises a gear 20, wherein the gear 20 has at least one gear 22 and a worm gear 24. The worm gear 24 engages with the gear 22. A rotational movement of the worm gear 24 also causes the gear 22 to rotate.

[0036] In this embodiment, three spokes 16 are provided, wherein the spokes 16 are arranged at an angle of less than 90 degrees to each other in the first position. By using three spokes 16, the diameter of the transformation wheel 10 can be maximized in the second position. Each spoke 16 is connected to a gear 22. When the gear 22 rotates, the spokes 16 perform a rotary movement and can be pivoted outward, thereby increasing the diameter of the transformation wheel 10.

[0037] In this embodiment, the rotating element 14 is designed as a ring gear 26. Three bevel gears 28 mesh with the ring gear 26. By rotating the bevel gears 28, the spokes can be moved from the first position to the second position. By designing the central rotating element 14 as a ring gear 26 and correspondingly designing the bevel gears 28, a rotational movement of the central rotating element 14 can be converted into a rotational movement of the bevel gears 28 offset by approximately 90 degrees.

[0038] The bevel gears 28 then rotate on an axis extending radially from the center of the rotating element 14. The orientation of the bevel gears 28 allows the spokes 16 connected to the bevel gears 28 to be moved from the first position to the second position. This means that, accordingly, upon rotation of the rotating element 14, the spokes 16 can be moved from the first position to the second position.

[0039] To enable comparatively simple scaling of the transformation wheel 10, coupling elements 30 are provided. Each coupling element 30 is arranged between the rotating element 14 and the worm wheel 24. A rotational movement from the rotating element 14 is transmitted to the worm wheel 24 via the coupling element 30. Consequently, in this exemplary embodiment, the coupling element is an intermediate piece that functions as a transition part between the rotating element 14 and each spoke 16.

[0040] A coupling element 30 is arranged on each bevel gear 28, so that the coupling element 30 rotates when the ring gear 26 or the bevel gear 28 rotates. This results in an extension of the respective bevel gear 28. The smallest diameter of the transformation wheel 10, for the first position of the spokes 16, can thus be adjusted to the desired size depending on the length of the coupling element 30. The spokes 16 can each be pivoted about a pivot point 32 from the first position to the second position.

[0041] Fig. 2 shows the transformation wheel 10 according to Fig. 1, with the spokes 16 in the second position. The spokes 16 are pivoted about the pivot point 32, so that the enlarged diameter of the transformation wheel 10 and the resulting enlarged running surface of the transformation wheel 10 are described by the ends of the pivoted spokes 16.

[0042] Additionally, an electric drive 34 is provided. The electric drive 34 is connected to the rotating element 14 such that the rotating element 14 can be driven and rotated by the electric drive. The electric drive 34 enables the spokes 16 to be moved from the first position to the second position. Furthermore, a rotary motor 36 is provided. The transformation wheel 10 is rotatable by the rotary motor 36. The independent possibility of driving the transformation wheel 10 by the rotary motor 36 and increasing the diameter of the transformation wheel 10 by the electric drive provides the greatest possible flexibility in the operation of the transformation wheel 10. The electric drive 34 can also be used as an auxiliary means for driving the transformation wheel 10.

[0043] Overall, the spokes 16 are moved from the first position to the second position and vice versa as follows: The electric drive 34 serves to rotate the rotating element 14 or the ring gear 26. The movement of the ring gear 26 causes the bevel gears 28 to rotate accordingly. Since the coupling elements 30 are connected to the bevel gears 28, these also rotate. On the sides of the coupling element 30 opposite the bevel gears 28, the coupling elements 30 are connected to the worm gears 24, which also rotate accordingly. The rotation of the worm gears 24 allows the gears 22 to rotate, which ultimately pivots the spokes 16 about the pivot point 32.

[0044] Fig.3 shows a robot system 38 with a robot 12. The robot 12 has four transformation wheels 10. Using appropriate control units (not shown here), the robot 12 can be moved to various positions using the transformation wheels 10. The transformation wheels 10 also allow it to negotiate difficult surfaces. By individually enlarging the diameter of the transformation wheels 10 of the robot 12 at a suitable location, the robot 12 can be used to climb stairs in such a way that the robot 12, or rather the chassis of the robot 12, only needs to be tilted minimally. List of reference symbols 10 Transformation Wheel 12 robots 14 Rotation element 16 spokes 18 Self-locking mechanism 20 gearboxes 22 gear 24 Worm gear 26 ring gear 28 bevel gear 30 coupling element 32 Pivot point 34 Electric drive 36 rotary engine 38 Robot system

Claims

[1] Transformation wheel (10), in particular for a robot (12) with a central rotation element (14), with a plurality of spokes (16) which are movably connected to the rotation element (14), wherein the spokes (16) can be moved by the rotation element (14) from at least a first position to a second position, wherein the diameter of the transformation wheel (10) increases when the spokes (16) are moved from the first position to the second position, characterized by , wherein a self-locking mechanism (18) is provided and wherein the spokes (16) are fixed in the first position and / or the second position by the self-locking mechanism (18), characterized bythat the self-locking mechanism (18) comprises a gear (20), that the gear (20) comprises at least one gear (22) and a worm wheel (24), that the worm wheel (24) is in engagement with the gear (22) and that upon rotation of the worm wheel (24) the spokes (16) can be moved from the first position into the second position. [2] Transformation wheel (10) according to claim 1, characterized by that the rotation element (14) is designed as a bevel gear, that the bevel gear is in engagement with a plurality of ring gears (26) and that by rotation of the ring gears (26) the spokes (16) can be moved from the first position into the second position. [3] Transformation wheel (10) according to claim 1, characterized by that the rotation element (14) is designed as a ring gear, that the ring gear engages with several bevel gears (28) and that by rotation of the bevel gears the spokes can be moved from the first position to the second position. [4] Transformation wheel (10) according to one of claims 1 to 3, characterized by that at least one coupling element (30) is provided, that the coupling element (30) is arranged between the rotation element (14) and the worm wheel (24) and that a rotational movement can be transmitted from the rotation element (14) to the worm wheel (24) via the coupling element (30). [5] Transformation wheel (10) according to one of claims 1 to 4, characterized by that the spokes (16) can be pivoted at least partially about a respective pivot point (32) from the first position to the second position. [6] Transformation wheel (10) according to one of claims 1 to 5, characterized by that three spokes (16) are provided and that the spokes (16) are arranged at an angle to each other of at least 60 degrees. [7] Transformation wheel (10) according to one of claims 1 to 6, characterized bythat an electric drive (34) is provided and that the rotary element (14) is rotatable by the electric drive (34). [8] Transformation wheel (10) according to one of claims 1 to 7, characterized by that a rotary motor (36) is provided and that the transformation wheel (10) is rotatable by the rotary motor (36). [9] Robot system (38) with a robot (12) and at least one transformation wheel (10) arranged on the robot (12) according to one of claims 1 to 8.

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