EP4673284A1

EP4673284A1 - Wheel assembly

Info

Publication number: EP4673284A1
Application number: EP23925577.1A
Authority: EP
Inventors: Jaeyeob JUNG; Jong-Won Kim; Sang-Goo JEONG
Original assignee: Bear Robotics Inc
Current assignee: Bear Robotics Inc
Priority date: 2023-02-28
Filing date: 2023-12-05
Publication date: 2026-01-07
Also published as: JP2026509190A; WO2024182032A1; KR20250153248A

Abstract

According to one aspect of the present invention, there is provided a wheel assembly provided at a lower part of a mobile object. The wheel assembly includes a main frame configured to connect a driving wheel and a steering wheel such that the driving wheel and the steering wheel are integrally formed; a support member disposed below a part of the main frame to which the steering wheel is coupled, and configured to surround at least a part of the steering wheel from above the steering wheel; and an elastic member disposed between the part of the main frame to which the steering wheel is coupled and the support member.

Description

WHEEL ASSEMBLY

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63/448,864 filed on February 28, 2023, the entire contents of which are herein incorporated by reference.

FIELD OF THE INVENTION

[0002] The present invention relates to a wheel assembly.

BACKGROUND

[0003] With the development of robot technology, service robots as well as industrial robots are attracting more attention and demand. The service robots are being applied to various fields of daily life, and among these service robots, autonomously driving serving robots for transporting food ordered by a customer to a table in a restaurant or the like are also known. The serving robots are receiving rapidly increasing attention due to their advantages of maximizing the efficiency of restaurant management and improving the quality of customer service.

[0004] Typically, a lower part of a serving robot may be provided with a wheel assembly for movement of the robot. The wheel assembly may partially employ a rockerbogie structure, which may comprise a driving wheel and a steering wheel (or caster). However, the conventional wheel assembly employing the rocker-bogie structure has a problem that it is very susceptible to foreign objects such as insects penetrating into the interior of the serving robot through the steering wheel, because it is difficult to maintain hermeticity between the steering wheel and the main body of the serving robot.

SUMMARY OF THE INVENTION

[0005] One object of the present invention is to solve all the above-described problems in the prior art. [0006] Another object of the invention is to achieve hermeticity between a steering wheel and a main body of a serving robot, thereby preventing foreign objects such as insects from penetrating into an interior of the serving robot through the steering wheel.

[0007] The representative configuration of the invention to achieve the above objects is described below.

[0008] According to one aspect of the invention, there is provided a wheel assembly provided at a lower part of a mobile object, comprising: a main frame configured to connect a driving wheel and a steering wheel such that the driving wheel and the steering wheel are integrally formed; a support member disposed below a part of the main frame to which the steering wheel is coupled, and configured to surround at least a part of the steering wheel from above the steering wheel; and an elastic member disposed between the part of the main frame to which the steering wheel is coupled and the support member.

[0009] In addition, there are further provided other wheel assemblies to implement the invention.

[0010] According to the invention, it is possible to achieve hermeticity between a steering wheel and a main body of a serving robot, thereby preventing foreign objects such as insects from penetrating into an interior of the serving robot through the steering wheel.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG. 1 shows a wheel assembly according to one embodiment of the invention.

[0012] FIG. 2 is a view of the wheel assembly according to one embodiment of the invention as seen from a front side of a mobile object.

[0013] FIG. 3 is a view of the wheel assembly according to one embodiment of the invention as seen from a right side of the mobile object.

[0014] FIG. 4 is a view of the wheel assembly according to one embodiment of the invention as seen from a bottom side of the mobile object.

[0015] FIG. 5 shows a situation in which a main frame according to one embodiment of the invention rotates toward the front side of the mobile object.

[0016] FIG. 6 shows a situation in which the main frame according to one embodiment of the invention rotates toward a rear side of the mobile object.

DETAILED DESCRIPTION OF THE INVENTION

[0017] In the following detailed description of the present invention, references are made to the accompanying drawings that show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It is to be understood that the various embodiments of the invention, although different from each other, are not necessarily mutually exclusive. For example, specific shapes, structures and characteristics described herein may be implemented as modified from one embodiment to another without departing from the spirit and scope of the invention. Furthermore, it shall be understood that the positions or arrangements of individual elements within each embodiment may also be modified without departing from the spirit and scope of the invention. Therefore, the following detailed description is not to be taken in a limiting sense, and the scope of the invention is to be taken as encompassing the scope of the appended claims and all equivalents thereof. In the drawings, like reference numerals refer to the same or similar elements throughout the several views.

[0018] Hereinafter, various preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings to enable those skilled in the art to easily implement the invention.

[0019] FIG. 1 shows a wheel assembly 100 according to one embodiment of the invention. FIG. 2 is a view of the wheel assembly 100 according to one embodiment of the invention as seen from a front side of a mobile object. Further, FIG. 3 is a view of the wheel assembly 100 according to one embodiment of the invention as seen from a right side of the mobile object. Furthermore, FIG. 4 is a view of the wheel assembly 100 according to one embodiment of the invention as seen from a bottom side of the mobile object.

[0020] Referring to FIGS. 1 to 4, the wheel assembly 100 according to one embodiment of the invention may be provided at a lower part of the mobile object, and may include various components for movement of the mobile object. Here, the mobile object may refer to an object that moves autonomously or heteronomously, and may include, for example, an autonomously driving transport means such as a serving robot that is required to move from one place to another.

[0021] Specifically, according to one embodiment of the invention, the wheel assembly 100 may include a driving wheel 110 and a steering wheel 120 as the components for movement of the mobile object.

[0022] Here, the driving wheel 110 may be disposed at each of the left and right sides of the lower part of the mobile object, and may be connected to a motor and rotationally driven by the driving force of the motor. The mobile object may be moved forward, backward, leftward, and rightward by the rotational drive of the driving wheel 110.

[0023] Further, the steering wheel 120 may be disposed at a position closer to the front side of the mobile object than the driving wheel 110, and the number of steering wheels 120 may correspond to the number of the driving wheels 110. The steering wheel 120 may be configured such that it is not directly connected to the motor but rotated together with the driving wheel 110 by the rotational drive of the driving wheel 110. The steering wheel 120 may function to ensure that balance of the mobile object is maintained upon the rotational drive of the driving wheel 110, which may further improve the driving stability of the mobile object. According to another embodiment of the invention, an additional wheel that functions the same as the steering wheel 120 may be disposed at one side of the lower part of the mobile object (e.g., at a position closer to a rear side of the mobile object than the driving wheel 110). However, only the wheel disposed at a position closer to the front side of the mobile object than the driving wheel 110 as described above will be referred to herein as the steering wheel 120.

[0024] Meanwhile, according to one embodiment of the invention, the wheel assembly 100 may include a main frame 130, a support member 140, and an elastic member 150 in addition to the driving wheel 110 and the steering wheel 120.

[0025] First, the main frame 130 may function to connect the driving wheel 110 and the steering wheel 120 such that the driving wheel 110 and the steering wheel 120 are integrally formed. For example, a pair of main frames 130 may be provided, wherein the main frame 130 at one side may connect the driving wheel 110 disposed at the left side of the lower part of the mobile object and the steering wheel 120 disposed at the front left side of the lower part of the mobile object such that the driving wheel 110 and the steering wheel 120 are integrally formed, while the main frame 130 at the other side may connect the driving wheel 110 disposed at the right side of the lower part of the mobile object and the steering wheel 120 disposed at the front right side of the lower part of the mobile object such that the driving wheel 110 and the steering wheel 120 are integrally formed.

[0026] According to one embodiment of the invention, each of the main frames 130 may include a part to which the steering wheel 120 is coupled and a part to which the driving wheel 110 is coupled, and a protrusion 131 may be formed between the part to which the steering wheel 120 is coupled and the part to which the driving wheel 110 is coupled. The protrusion 131 may protrude toward the ground when the wheel assembly 100 is disposed at the mobile object, and a downwardly directed end of the protrusion 131 may be rotatably coupled to a main body of the mobile object. Specifically, the main frame 130 may be configured to be rotatable about the downwardly directed end of the protrusion 131 within a predetermined range. Here, the main frame 130 may rotate in a plane parallel to the driving wheel 110 within a range corresponding to conditions of a road surface (e.g., an angle of inclination of the road surface or a size of an obstacle present on the road surface).

[0027] Meanwhile, according to one embodiment of the invention, the support member 140 may be disposed below the part of the main frame 130 to which the steering wheel 120 is coupled. A lower part of the support member 140 may be fixedly coupled to the main body of the mobile object in close contact therewith, and the support member 140 may be configured to surround at least a part of the steering wheel 120 from above the steering wheel 120. Here, the support member 140 may be formed in a cup shape, wherein the term "cup shape" may refer to a shape having a circular horizontal cross-section and a hollow interior. According to one embodiment of the invention, the steering wheel 120 may include a connecting rod 121 that may be coupled to the main frame 130 passing through the cup-shaped support member 140.

[0028] According to one embodiment of the invention, the main frame 130 may be configured to be rotatable according to the conditions of the road surface as described above, which requires that the main frame 130 and the support member 140 be spaced apart at a predetermined interval. In this case, foreign objects such as insects may easily penetrate into the interior of the mobile object through the space formed between the main frame 130 and the support member 140. According to the invention, the elastic member 150 is disposed between the main frame 130 (specifically, the part of the main frame 130 to which the steering wheel 120 is coupled) and the support member 140 in order to resolve this problem.

[0029] Specifically, according to one embodiment of the invention, the elastic member 150 may be formed with a height corresponding to the interval between the main frame 130 and the support member 140, and disposed between the main frame 130 and the support member 140. When the elastic member 150 is disposed between the main frame 130 and the support member 140, a lower part of the elastic member 150 may be configured to be in close contact with the support member 140, and an upper part of the elastic member 150 may be configured to be in close contact with the main frame 130.

[0030] According to one embodiment of the invention, the elastic member 150 may be formed in a cup shape like the support member 140, wherein the term "cup shape" may refer to a shape having a circular horizontal cross-section and a hollow interior as described above. According to one embodiment of the invention, the connecting rod 121 of the steering wheel 120 may be coupled to the main frame 130 passing through the cup-shaped support member 140 and then through the cup-shaped elastic member 150.

[0031] According to one embodiment of the invention, the elastic member 150 may be configured to be resilient. Specifically, the elastic member 150 may change its shape when an external force is applied by an action of the main frame 130 (e.g., a rotation toward the front side of the mobile object), but may be configured to be resilient to the shape change (e.g., may be formed of an elastic material such as silicone, polyurethane, or rubber) so that it is restored to its original shape when the external force is removed.

[0032] Meanwhile, according to one embodiment of the invention, the lower part of the elastic member 150 may be fixedly coupled to an upper part of the support member 140 in close contact therewith, whereas the upper part of the elastic member 150 may be configured to be in close contact with the main frame 130 but not fixedly coupled thereto.

[0033] Specifically, the part of the main frame 130 to which the steering wheel 120 is coupled may be configured to be in close contact with the upper part of the elastic member 150 but capable of disengaging from the upper part of the elastic member 150 according to the action of the main frame 130. For example, the close contact between the main frame 130 and the elastic member 150 is not released when the main frame 130 rotates toward the front side of the mobile object (see FIG. 5), whereas the close contact between the main frame 130 and the elastic member 150 may be released when the main frame 130 rotates toward the rear side of the mobile object (see FIG. 6). When the close contact between the main frame 130 and the elastic member 150 is released as above, the part of the main frame 130 to which the steering wheel 120 is coupled disengages from the upper part of the elastic member 150.

[0034] As described above, the wheel assembly 100 according to one embodiment of the invention may be provided with the elastic member 150 between the main frame 130 and the support member 140, so that hermeticity is achieved between the steering wheel 120 and the main body of the mobile object while maintaining the driving performance of the mobile object.

[0035] Although the present invention has been described above in terms of specific items such as detailed elements as well as the limited embodiments and the drawings, they are only provided to help more general understanding of the invention, and the present invention is not limited to the above embodiments. It will be appreciated by those skilled in the art to which the present invention pertains that various modifications and changes may be made from the above description.

[0036] Therefore, the spirit of the present invention shall not be limited to the abovedescribed embodiments, and the entire scope of the appended claims and their equivalents will fall within the scope and spirit of the invention.

Claims

1. A wheel assembly provided at a lower part of a mobile object, comprising: a main frame configured to connect a driving wheel and a steering wheel such that the driving wheel and the steering wheel are integrally formed; a support member disposed below a part of the main frame to which the steering wheel is coupled, and configured to surround at least a part of the steering wheel from above the steering wheel; and an elastic member disposed between the part of the main frame to which the steering wheel is coupled and the support member.

2. The wheel assembly of Claim 1, wherein the support member and the elastic member are formed in a cup shape, respectively.

3. The wheel assembly of Claim 1, wherein the support member and the elastic member are fixedly coupled in close contact with each other.

4. The wheel assembly of Claim 1, wherein the part of the main frame to which the steering wheel is coupled is configured to be in close contact with an upper part of the elastic member but capable of disengaging from the upper part of the elastic member according to an action of the main frame.

5. The wheel assembly of Claim 1, wherein the elastic member is capable of changing its shape as an external force is applied by an action of the main frame, and is configured to be resilient to the shape change.

6. The wheel assembly of Claim 1, wherein the main frame includes a protrusion formed between the part to which the steering wheel is coupled and a part to which the driving wheel is coupled.

7. The wheel assembly of Claim 6, wherein the main frame is configured to be rotatable about a downwardly directed end of the protrusion within a predetermined range.