Wheel assembly and movable electronic device

Abstract

To provide a wheel assembly and a movable electronic device that enable a follower wheel to have a small diameter for achieving miniaturization of a service robot, and exhibit the excellent ability to ride over obstacles.SOLUTION: A wheel assembly includes a frame, at least one movable wheel and at least one guide wheel. The frame includes a seat portion and a support portion connected to each other. The movable wheel is rotatably disposed on the support portion, and the movable wheel has a first edge located opposite to the seat portion. The guide wheel is rotatably disposed on the support portion. The guide wheel has a second edge located opposite to the seat portion, and the second edge of the guide wheel is located closer to the seat portion than the first edge of the movable wheel.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to wheel assemblies and mobile electronic devices. [Background technology]

[0002] Service robots such as autonomous mobile robots or automated guided vehicles generally need to navigate in narrow environments, and are therefore designed to be compact so as not to create a feeling of oppression.

[0003] To miniaturize a service robot, its chassis must be made smaller. A smaller chassis requires a smaller turning radius for the driven wheels to avoid interference with surrounding components when turning. The turning radius of a driven wheel depends on its outer diameter and the distance from its center to the driven wheel's rotation axis. Therefore, the smaller the outer diameter of a service robot's driven wheels, the smaller the achievable size of the service robot. However, by reducing the outer diameter of the driven wheels, the contact point between the driven wheels and an obstacle moves closer to the center of the driven wheels, thereby reducing the lifting force applied to the driven wheels. Therefore, one of the key issues in this technical field is how to enable the driven wheels to have a small diameter to achieve the miniaturization of a service robot while still having excellent obstacle climbing capabilities. Summary of the Invention

[0004] The present disclosure provides a wheel assembly and a movable electronic device that enable the driven wheel to have a small diameter to achieve miniaturization of the service robot while still having excellent ability to climb over obstacles.

[0005] One embodiment of the present disclosure provides a wheel assembly. The wheel assembly includes a frame, at least one movable wheel, and at least one guide wheel. The frame includes a base and a support connected to each other. The movable wheel is rotatably disposed on the support, and has a first edge located opposite the base. The guide wheel is rotatably disposed on the support. The guide wheel has a second edge located opposite the base, and the second edge of the guide wheel is located closer to the base than the first edge of the movable wheel.

[0006] Another embodiment of the present disclosure provides a movable electronic device. The movable electronic device includes a main body and a plurality of wheel assemblies. The wheel assemblies are respectively disposed at different positions on the main body, and each wheel assemblies includes a frame, a movable wheel, and a guide wheel. The frame includes a base portion and a support portion connected to each other, and the base portion is attached to the main body. The movable wheel is rotatably disposed on the support portion, and the movable wheel has a first edge located opposite the base portion. The guide wheel is rotatably disposed relative to the support portion. The guide wheel has a second edge located opposite the base portion, and the second edge of the guide wheel is located closer to the base portion than the first edge of the movable wheel.

[0007] Yet another embodiment of the present disclosure provides a movable electronic device. The movable electronic device includes a main body, a drive source, a drive wheel, and a plurality of wheel assemblies. The drive source is disposed on the main body. The drive wheel is connected to the drive source. The wheel assemblies are disposed at different positions on the main body, and each wheel assemblies includes a frame, a movable wheel, and a guide wheel. The frame includes a base and a support connected to each other, and the base is attached to the main body. The movable wheel is rotatably disposed on the support, and the movable wheel has a first edge located opposite the base. The guide wheel is rotatably disposed on the support. The guide wheel has a second edge located opposite the base, and the second edge of the guide wheel is located closer to the base than the first edge of the movable wheel. The drive source is configured to drive the drive wheel to drive the wheel assemblies, thereby moving the main body.

[0008] According to the wheel assembly and the movable electronic device, the guide wheel and the movable wheel are rotatably arranged on the support part of the frame, and the second edge of the guide wheel is located closer to the base part of the frame than the first edge of the movable wheel so that the guide wheel can contact the obstacle before the movable wheel contacts the obstacle, thereby lifting the entire movable electronic device. Therefore, the movable wheel that contacts the obstacle can obtain a larger lifting force so as to easily climb up onto the obstacle. As a result, even if the movable wheel has a small diameter due to the miniaturization requirement of the movable electronic device, the guide wheel enables the movable wheel to climb up onto the obstacle. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view of a movable electronic device according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a perspective view of the wheel assembly of FIG. 1. [Figure 3] FIG. 3 is a side view of the wheel assembly of FIG. 2. [Figure 4] FIG. 3 is a bottom view of the wheel assembly of FIG. 2. [Figure 5] 2 is a side view of the movable electronic device of FIG. 1 when in contact with an obstacle. [Figure 6] FIG. 6 is a close-up view of the guide wheel of the wheel assembly of FIG. 5 when in contact with an obstacle. [Figure 7] FIG. 6 is a close-up view of the movable wheel of the wheel assembly of FIG. 5 when in contact with an obstacle. [Figure 8] 3 is a curve graph showing the relationship between the outer diameter of the guide wheel in FIG. 2 and the ratio of the lift force to the reverse force. [Figure 9] FIG. 10 is a side view of a wheel assembly according to a second embodiment of the present disclosure. [Figure 10] 10 is a curve graph showing the relationship between the outer diameter of the guide wheel in FIG. 9 and the ratio of the lift force to the reverse force. [Figure 11] FIG. 10 is a side view of a wheel assembly according to a third embodiment of the present disclosure. [Figure 12]12 is a curve graph showing the relationship between the outer diameter of the guide wheel in FIG. 11 and the ratio of the lift force to the reverse force. [Figure 13] FIG. 10 is a perspective view of a wheel assembly according to a fourth embodiment of the present disclosure. [Figure 14] FIG. 10 is a perspective view of a wheel assembly according to a fifth embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present disclosure will become better understood from the detailed description given herein and the accompanying drawings, which are given by way of illustration only and are therefore not intended to limit the disclosure.

[0011] In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are shown in schematic form to simplify the drawings.

[0012] Furthermore, terms used in this disclosure, such as technical and scientific terms, have their own meanings and are understandable to those skilled in the art, unless the terms are further defined in this disclosure. That is, the terms used in the following paragraphs should be read in the meanings commonly used in the relevant technical field and will not be overly explained, unless the terms have a specific meaning in this disclosure.

[0013] Referring to FIG. 1, FIG. 1 is a perspective view of a movable electronic device according to a first embodiment of the present disclosure.

[0014] In this embodiment, the movable electronic device 1 is a service robot such as an autonomous mobile robot or an automated guided vehicle. The movable electronic device 1 includes a main body 10 and a plurality of wheel assemblies 20. In addition, the movable electronic device 1 may further include a plurality of drive wheels 30 and a plurality of drive sources 40.

[0015] The main body 10 includes a housing 11 and multiple electronic components, such as a circuit board and a battery, located within the housing 11. The number of wheel assemblies 20 may be, for example, but is not limited to, four. The wheel assemblies 20 are located at the four corners of the bottom of the housing 11, respectively, and are partially exposed to the outside from the housing 11. The number of drive wheels 30 may be, for example, but is not limited to, two. One of the drive wheels 30 is located between two of the wheel assemblies 20, and the other of the drive wheels 30 is located between the other two of the wheel assemblies 20. The drive source 40 may be, for example, a motor, and the number thereof may be, for example, but is not limited to, two. The drive source 40 is located at the bottom of the housing 11 and is connected to each of the two drive wheels 30 to drive the drive wheels 30 to rotate relative to the housing 11 and move the entire movable electronic device 1. In one embodiment, the number of drive sources and the number of drive wheels may be one, and the drive source and the drive wheel may be located at the center of the housing.

[0016] In this embodiment, all the wheel assemblies 20 have the same structure, so the following paragraphs will specifically introduce only one of them. Referring to Figures 1-4, Figure 2 is a perspective view of the wheel assembly of Figure 1, Figure 3 is a side view of the wheel assembly of Figure 2, and Figure 4 is a bottom view of the wheel assembly of Figure 2.

[0017] The wheel assembly 20 includes a frame 21, two movable wheels 22, and a guide wheel 23. The wheel assembly 20 may further include a first shaft 24 and a second shaft 25. The frame 21 includes a pedestal 211 and a support 212. The pedestal 211 is disposed within the housing 11. The support 212 includes a base 2121 and two arms 2122. The base 2121 of the support 212 is rotatably disposed on the pedestal 211. The two arms 2122 protrude from the base 2121 and are spaced apart from each other. The two movable wheels 22 are coaxially and rotatably disposed between the two arms 2122 via the first shaft 24. The guide wheel 23 is rotatably disposed between the two arms 2122 via the second shaft 25. The rotation axis P1 of the two movable wheels 22 (i.e., the central axis of the first shaft 24) and the rotation axis P2 of the guide wheel 23 (i.e., the central axis of the second shaft 25) are perpendicular to the rotation axis P of the base 2121 of the support part 212 relative to the pedestal part 211. The rotation axis P1 of the two movable wheels 22 is parallel to the rotation axis P2 of the guide wheel 23, does not overlap with the rotation axis P2 of the guide wheel 23, and is located closer to the pedestal part 211 than the rotation axis P2 of the two movable wheels 22. In other words, the distance T2 from the rotation axis P2 of the guide wheel 23 to the pedestal part 211 is shorter than the distance T1 from the rotation axis P1 of the movable wheel 22 to the pedestal part 211.

[0018] In this embodiment, the guide wheels 23 are partially positioned between the movable wheels 22 and do not contact the movable wheels 22. The guide wheels 23 are positioned within a rotation range R formed by the movable wheels 22, which rotate relative to the base 211 via the support parts 212. In a direction parallel to the rotation axis P1 of the movable wheels 22 (i.e., in the angle of view of FIG. 3 ), the movable wheels 22 partially overlap the guide wheels 23. Furthermore, the outer diameter D1 of the movable wheels 22 is, for example, but not limited to, larger than the outer diameter D2 of the guide wheels 23. Each of the movable wheels 22 has a first edge 221 positioned on the opposite side from the base 211. In each of the movable wheels 22, the first edge 221 is positioned at the position of the outer contour 222 of the movable wheel 22 that is located furthest from the base 211. The guide wheel 23 has a second edge 231 located opposite the base 211, and the second edge 231 is located at a position on the outer contour 232 of the guide wheel 23 that is located farthest from the base 211. The second edge 231 of the guide wheel 23 is located closer to the base 211 than the first edge 221 of the movable wheel 22. A distance T3 from the second edge 231 of the guide wheel 23 to the base 211 is longer than a distance T1 from the rotation axis P1 of the movable wheel 22 to the base 211. Furthermore, a reference point RP is defined to be located on the outer contour 222 of the movable wheel 22, and the reference point RP is located farther from the base 211 than the rotation axis P1 of the movable wheel 22 and closer to the base 211 than the first edge 221. A line L1 connecting the reference point RP and the rotation axis P1 of the movable wheel 22 forms an angle θ of approximately 45 degrees with a line L2 connecting the first edge 221 and the rotation axis P1 of the movable wheel 22. A distance T3 from the second edge 231 of the guide wheel 23 to the base portion 211 is shorter than a distance T4 from the reference point RP to the base portion 211.

[0019] 5 to 7, FIG. 5 is a side view of the movable electronic device of FIG. 1 when it is in contact with an obstacle, FIG. 6 is an enlarged view of the guide wheel of the wheel assembly of FIG. 5 when it is in contact with an obstacle, and FIG. 7 is an enlarged view of the movable wheel of the wheel assembly of FIG. 6 when it is in contact with an obstacle.

[0020] When the movable electronic device 1 encounters an obstacle O while traveling, the guide wheel 23 of the wheel assembly 20 located at the front of the movable electronic device 1 contacts the obstacle O before the movable wheel 22. At this moment, the acting force applied to the obstacle O by the guide wheel 23 generates a reaction force applied to the guide wheel 23, and this reaction force (represented, for example, by arrow f) consists of a vertical lift force (represented, for example, by arrow fy) and a horizontal reversal force (represented, for example, by arrow fx). When the driving source 40 (shown in FIG. 1 ) is operated, the above-mentioned lift force raises the entire movable electronic device 1 through the guidance of the guide wheel 23 so that the guide wheel 23 rides over the obstacle O, and then the movable wheel 22 comes into contact with the obstacle O. As a result, the movable wheel 22 that comes into contact with the obstacle O can obtain a larger lift force so that it can easily ride over the obstacle O. Therefore, even if the movable wheel 22 has a small diameter due to the requirement of miniaturization of the movable electronic device 1, the guide wheel 23 enables the movable wheel 22 to ride over the obstacle O.

[0021] In this embodiment, the distance T3 from the second edge 231 of the guide wheel 23 to the base portion 211 is longer than the distance T1 from the rotation axis P1 of the movable wheel 22 to the base portion 211, the distance T3 from the second edge 231 of the guide wheel 23 to the base portion 211 is shorter than the distance T4 from the reference point RP to the base portion 211, and the rotation axis P2 of the guide wheel 23 is located closer to the base portion 211 than the rotation axis P1 of the movable wheel 22, thereby allowing the guide wheel 23 to further assist the movable wheel 22 in climbing over the obstacle O more efficiently.

[0022] Specifically, since the wheel assembly 20 is further provided with a guide wheel 23, there are two cases that need to be analyzed: one is when the guide wheel 23 comes into contact with an obstacle O (for example, as shown in FIG. 6 ), and the other is when the movable wheel 22 comes into contact with the obstacle O (for example, as shown in FIG. 7 ). In the case where the guide wheel 23 comes into contact with the obstacle O, the maximum acting force that the driving source 40 applies to move the entire movable electronic device 1 without slipping is “F”, the outer diameter D1 of the movable wheel 22 is 38.1 mm, the height H of the obstacle O is 25 mm, the difference between the distance T2 from the rotation axis P2 of the guide wheel 23 to the base part 211 and the distance T1 from the rotation axis P1 of the movable wheel 22 to the base part 211 is 4 mm, and the diameter D2 of the guide wheel 23 is “r”. The lifting force applied to the guide wheel 23 can be calculated by the following formula:

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number

[0023] In this embodiment, the guide wheel 23 is located within a rotation range R formed by the movable wheel 22 that rotates relative to the base 211 via the support portion 212, which makes it possible to prevent the guide wheel 23 from interfering with components positioned around the guide wheel 23. Note that if the above-mentioned problem does not occur, the guide wheel may be partially located outside the range formed by the movable wheel that rotates relative to the base via the support portion.

[0024] On the other hand, the movable wheel 22 is not limited to overlapping the guide wheel 23 in a direction parallel to the rotation axis P1 of the movable wheel 22. In some other embodiments, the movable wheel may not overlap the guide wheel in a direction parallel to the rotation axis of the movable wheel.

[0025] 9 and 10, FIG. 9 is a side view of a wheel assembly according to a second embodiment of the present disclosure, and FIG. 10 is a curve graph showing the relationship between the outer diameter of the guide wheel of FIG. 9 and the ratio of lift force to reversal force.

[0026] The wheel assembly 20a of this embodiment is similar to the wheel assembly 20 of the previous embodiment, and the main difference between them is the position of the guide wheel. Therefore, the following paragraphs will mainly introduce the difference, and the same parts between them will not be introduced again below.

[0027] In this embodiment, the rotation axis P1 of the movable wheel 22a is located neither closer nor farther from the base 211a than the rotation axis P2 of the guide wheel 23a. That is, the distance T2 from the rotation axis P2 of the guide wheel 23a to the base 211a is equal to the distance T1 from the rotation axis P1 of the movable wheel 22a to the base 211a. In this configuration, assuming other parameters are the same as those in the previous embodiment, the relationship between the lifting force provided by the guide wheel 23a and the outer diameter D2 of the guide wheel 23a, and the relationship between the lifting force provided by the movable wheel 22a after the guide wheel 23a is assisted and the outer diameter D2 of the guide wheel 23a, can be understood from FIG. 10. As shown in FIG. 10, the two lines representing the above relationship intersect at a position corresponding to the outer diameter D2 of the guide wheel 23a, which is 22.4 mm. When the outer diameter D2 of the guide wheel 23a is 22.4 mm, the lifting force provided by the movable wheel 22a can be up to approximately 0.72 F. As a result, compared to the lift force of 0.37 F obtained by the movable wheel of the wheel assembly without guide wheels, the lift force obtained by the movable wheel 22a with the assistance of the guide wheels 23a can be improved by approximately 95%.

[0028] 11 and 12, FIG. 11 is a side view of a wheel assembly according to a third embodiment of the present disclosure, and FIG. 12 is a curve graph showing the relationship between the outer diameter of the guide wheel of FIG. 11 and the ratio of lift force to reversal force.

[0029] The wheel assembly 20b of this embodiment is similar to the wheel assembly 20 of the previous embodiment, and the main difference between them is the position of the guide wheel. Therefore, the following paragraphs will mainly introduce the difference, and the same parts between them will not be introduced again below.

[0030] In this embodiment, the rotation axis P2 of the guide wheel 23b is positioned farther from the base 211b than the rotation axis P1 of the movable wheel 22b. The distance T2 from the rotation axis P2 of the guide wheel 23b to the base 211b is longer than the distance T1 from the rotation axis P1 of the movable wheel 22b to the base 211b. In this configuration, assuming that the difference between the distance T2 from the rotation axis P2 of the guide wheel 23b to the base 211b and the distance T1 from the rotation axis P1 of the movable wheel 22b to the base 211b is 4 mm and the other parameters are the same as in the previous embodiment, the relationship between the lifting force obtained by the guide wheel 23b and the outer diameter D2 of the guide wheel 23b, and the relationship between the lifting force obtained by the movable wheel 22b after the assistance of the guide wheel 23b and the outer diameter D2 of the guide wheel 23b can be understood from FIG. 12. 12, the two lines representing the above relationship intersect at a position corresponding to the outer diameter D2 of the guide wheel 23b, which is 16.8 mm. When the outer diameter D2 of the guide wheel 23b is 16.8 mm, the lifting force obtained by the movable wheel 22b can be up to approximately 0.64 F. As a result, compared to the lifting force of 0.37 F obtained by the movable wheel of the wheel assembly without the guide wheel 23b, the lifting force obtained by the movable wheel 22b with the assistance of the guide wheel 23b can be improved by approximately 73%.

[0031] In the above embodiment, the outer diameters of the guide wheels in the cases shown in Figures 3, 9, and 11 are set to 23 mm, 22.4 mm, and 16.8 mm, respectively. Therefore, it can be understood that there is a negative correlation between the distance from the rotation axis of the guide wheel to the base and the outer diameter of the guide wheel. In other words, when designing the guide wheel, the outer diameter of the guide wheel is set to become smaller as the guide wheel is positioned farther away from the base.

[0032] Reference is now made to FIG. 13, which is a perspective view of a wheel assembly according to a fourth embodiment of the present disclosure.

[0033] The wheel assembly 20c of this embodiment is similar to the wheel assembly 20 of the previous embodiment, and the main difference between them is the number of movable wheels and guide wheels. Therefore, the following paragraphs will mainly introduce the differences, and the same parts between them will not be introduced again.

[0034] In this embodiment, the wheel assembly 20c includes one moving wheel 22c and two guide wheels 23c. The guide wheel 23c is coaxially and rotatably disposed on the support 212c, and the moving wheel 22c is partially located between the two guide wheels 23c.

[0035] Reference is now made to FIG. 14, which is a perspective view of a wheel assembly according to a fifth embodiment of the present disclosure.

[0036] The wheel assembly 20d of this embodiment is similar to the wheel assembly 20 of the previous embodiment, and the main difference between them is the number of movable wheels and guide wheels. Therefore, the following paragraphs will mainly introduce the differences, and the same parts between them will not be repeated below.

[0037] In this embodiment, the wheel assembly 20d includes only one moving wheel 22d and only one guide wheel 23d.

[0038] According to the wheel assembly and the movable electronic device, the guide wheel and the movable wheel are rotatably arranged on the support part of the frame, and the second edge of the guide wheel is located closer to the base part of the frame than the first edge of the movable wheel so that the guide wheel can contact the obstacle before the movable wheel contacts the obstacle, thereby lifting the entire movable electronic device. Therefore, the movable wheel that contacts the obstacle can obtain a larger lifting force so as to easily climb up onto the obstacle. As a result, even if the movable wheel has a small diameter due to the miniaturization requirement of the movable electronic device, the guide wheel enables the movable wheel to climb up onto the obstacle.

[0039] Furthermore, the guide wheel is located within a rotation range R formed by the movable wheel that rotates relative to the base part via the support part, thereby preventing the guide wheel from interfering with components located around the guide wheel.

[0040] It will be apparent to those skilled in the art that various modifications and variations can be made to the present disclosure. The specification and examples are to be considered as exemplary embodiments only, with the scope of the present disclosure being indicated by the following claims and their equivalents.

Claims

1. a frame including a base portion and a support portion connected to each other; At least one movable wheel rotatably disposed on the support, the at least one movable wheel having a first edge positioned opposite the base; At least one guide wheel rotatably disposed on the support, the at least one guide wheel having a second edge positioned opposite the base, the second edge of the at least one guide wheel being positioned closer to the base than the first edge of the at least one movable wheel; A wheel assembly comprising:

2. 2. The wheel assembly of claim 1, wherein the distance from the second edge of the at least one guide wheel to the base is longer than the distance from the rotation axis of the at least one movable wheel to the base, and (1) the rotation axis of the at least one guide wheel is located closer to the base than the rotation axis of the at least one movable wheel, (2) the distance from the rotation axis of the at least one movable wheel to the base is substantially equal to the distance from the rotation axis of the at least one guide wheel to the base, or (3) the rotation axis of the at least one guide wheel is located farther from the base than the rotation axis of the at least one movable wheel.

3. The main body and a plurality of wheel assemblies respectively disposed at different positions on the body, each of which comprises: a frame including an interconnected base and support, the base attached to the body; a movable wheel rotatably disposed on the support portion, the movable wheel having a first edge positioned opposite the base portion; a guide wheel rotatably disposed on the support portion, the guide wheel having a second edge positioned on the opposite side to the base portion, the second edge of the guide wheel being positioned closer to the base portion than the first edge of the movable wheel; a plurality of wheel assemblies comprising: A movable electronic device comprising:

4. The movable electronic device according to claim 3 , wherein the support portion is rotatably disposed on the base portion, and the guide wheel is located within a rotation range formed by the movable wheel that rotates relative to the base portion via the support portion.

5. The main body and a drive source disposed in the main body; a drive wheel connected to the drive source; a plurality of wheel assemblies respectively disposed at different positions on the body, each of which comprises: a frame including an interconnected base and support, the base attached to the body; a movable wheel rotatably disposed on the support portion, the movable wheel having a first edge positioned opposite the base portion; a guide wheel rotatably disposed on the support portion, the guide wheel having a second edge positioned on the opposite side to the base portion, the second edge of the guide wheel being positioned closer to the base portion than the first edge of the movable wheel; a plurality of wheel assemblies comprising: Equipped with The drive source is configured to drive the drive wheels to drive the plurality of wheel assemblies and move the body.

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