Trundle assembly and self-walking robot

Abstract

The utility model relates to the field of robots, in particular to a trundle assembly and a self-walking robot, the trundle assembly comprises a supporting frame and a moving wheel set, the supporting frame is connected with a transmission shaft, and the transmission shaft can drive the supporting frame to freely rotate in the horizontal plane; the moving wheel set comprises main wheels and auxiliary wheels, the main wheels and the auxiliary wheels are arranged on the supporting frame in a rolling mode, and the main wheels and the auxiliary wheels are distributed in the advancing direction of the moving wheel set at intervals; at least one part of the main wheel in the width direction of the main wheel is concaved inwards in the radial direction to form a receding space, the auxiliary wheel is partially located in the receding space, the at least one part of the main wheel in the width direction of the main wheel is concaved inwards in the radial direction to form the receding space, and therefore the grinding force of the trundle assembly on a supporting face below the trundle assembly is reduced. And the damage to the supporting surface is reduced.

Description

Technical Field

[0001] The present application relates to the field of robotics technology, and in particular to a caster assembly and a self-propelled robot. Background Art

[0002] Self-propelled robots, such as lawn mowing robots, travel along a planned path. Since the self-propelled robots will stay for a long time at the turning position in the path and will also perform steering and other actions, the caster assembly of the self-propelled robot will exert a relatively large pressure on the turning position. Especially when mowing the lawn, the self-propelled robot exerts a relatively large pressure on the grass at the turning position. In the long run, it is easy to cause the grass in this area (the turning position in the path) to be crushed to death, resulting in damage to the supporting surface. Therefore, how to reduce the crushing pressure or crushing area under the self-propelled robot when walking and turning has become a technical problem that needs to be solved. Utility Model Content

[0003] The main purpose of the present application is to propose a caster assembly and a self-propelled robot to solve the technical problem that the existing self-propelled robots have excessively large rolling pressure or rolling area when walking or turning.

[0004] To achieve the above objectives, in a first aspect, an embodiment of the present application provides a caster assembly, comprising:

[0005] A support frame, to which a transmission shaft is connected, and the transmission shaft can drive the support frame to rotate freely in a horizontal plane;

[0006] A moving wheel set, comprising a main wheel and a secondary wheel, wherein both the main wheel and the secondary wheel are rollingly arranged on the support frame, and the main wheel and the secondary wheel are spaced apart in the traveling direction of the moving wheel set;

[0007] Wherein, at least a portion of the main wheel in the width direction is radially concave to form an avoidance space, and the secondary wheel portion is located in the avoidance space.

[0008] The caster assembly provided in the embodiment of the present application includes a support frame and a moving wheel group, the support frame is connected to a transmission shaft, and the transmission shaft can drive the support frame to rotate freely in a horizontal plane; the moving wheel group includes a main wheel and a secondary wheel, the main wheel and the secondary wheel are both rollingly arranged on the support frame, and the main wheel and the secondary wheel are spaced apart in the traveling direction of the moving wheel group; at least a portion of the main wheel in the width direction is radially concave to form an avoidance space, and the secondary wheel portion is located in the avoidance space, and by arranging at least a portion of the main wheel in the width direction to be radially concave to form the avoidance space, the rolling pressure of the caster assembly on the supporting surface below is reduced, thereby reducing damage to the supporting surface.

[0009] In an optional embodiment, the main wheel includes a ground contacting portion for contacting the ground, and suspended portions located on both sides of the ground contacting portion, radial dimensions of the two suspended portions are smaller than radial dimensions of the ground contacting portion, and the avoidance space is formed at the two suspended portions.

[0010] In an optional embodiment, the suspended portion includes a first annular portion, a second annular portion, and a third annular portion connected in sequence, the first annular portion is arranged close to the ground contact portion and connected thereto, the third annular portion is away from the ground contact portion and its radial dimension is smaller than the radial dimension of the first annular portion, and the second annular portion is concave relative to the first annular portion and the third annular portion.

[0011] In an optional embodiment, the main wheel is constructed as a left half shell and a right half shell connected to each other, the ground contacting portion is formed at the middle position between the left half shell and the right half shell, and the two suspended portions are respectively formed at the non-connecting portions of the left half shell and the right half shell.

[0012] In an optional embodiment, the auxiliary wheels include two, the two auxiliary wheels are spaced apart along the width direction of the main wheel, and the two auxiliary wheels are respectively partially located in the two avoidance spaces in the traveling direction of the caster assembly.

[0013] In an optional embodiment, the support frame includes a bracket, a first mounting portion bent on both sides thereof, and a second mounting portion connected to the first mounting portion, both of the second mounting portions extend along the travel direction of the caster assembly, the main wheel is located between the two first mounting portions, and the secondary wheel is located between the two second mounting portions.

[0014] In an optional embodiment, the bracket is provided with a moving arm for moving debris on the surface of the main wheel, and the moving arm is located above the main wheel and extends toward the surface of the main wheel by a preset length.

[0015] In an optional embodiment, on the orthographic projection plane perpendicular to the extension direction of the central axis of the main wheel, the angle between the tangent line of the main wheel and the secondary wheel near the bottom and the horizontal line is 0-35°.

[0016] In an optional implementation, the distance between the wheel center of the secondary wheel and the central axis of the transmission shaft is a first value, and the ratio of the diameter of the secondary wheel to the first value is 0.5-2.5.

[0017] In an optional embodiment, the wheel centers of the main wheel and the secondary wheel are not at the same height, the height difference between the wheel centers of the main wheel and the secondary wheel is a second value, the ratio of the diameter of the main wheel to the second value is 40-75, and the ratio of the diameter of the secondary wheel to the second value is 20-30.

[0018] In an optional embodiment, the lowest end of the secondary wheel is higher than the lowest end of the main wheel, the main wheel can roll relative to the ground to move the caster assembly along the direction of travel, and the secondary wheel is configured to contact an obstacle to lift the main wheel before the main wheel contacts the obstacle.

[0019] In a second aspect, an embodiment of the present application provides a self-propelled robot, comprising a chassis and the above-mentioned caster assembly, wherein the caster assembly is rotatably connected to the chassis via the transmission shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments are briefly introduced below.

[0021] Figure 1 is a structural schematic diagram of a self-propelled robot provided in an embodiment of the present application;

[0022] Figure 2 It is a rear view structural schematic diagram of the first main wheel provided in an embodiment of the present application;

[0023] Figure 3 is a rear view structural schematic diagram of a second main wheel provided in an embodiment of the present application;

[0024] Figure 4 is a rear view structural schematic diagram of a third main wheel provided in an embodiment of the present application;

[0025] Figure 5 This is a schematic diagram of the top view structure of the third main wheel and auxiliary wheel provided in the embodiment of the present application Figure 1 ;

[0026] Figure 6 The following is a schematic diagram of a partial three-dimensional structure of a caster assembly provided in an embodiment of the present application. Figure 1 ;

[0027] Figure 7 This is a schematic diagram of the top view structure of the third main wheel and auxiliary wheel provided in the embodiment of the present application Figure 2 ;

[0028] Figure 8 This is a schematic diagram of the fourth main wheel and secondary wheel structure provided in the embodiment of the present application from a bottom view. Figure 2 ;

[0029] Fig. 9 This is a schematic diagram of the structural disassembly of a main wheel provided in an embodiment of the present application;

[0030] Fig.10 is a structural schematic diagram of a support frame provided in an embodiment of the present application;

[0031] Fig.11A side view of a caster assembly provided in an embodiment of the present application Figure 1 ;

[0032] Fig.12 The three-dimensional structure diagram of a caster assembly provided in an embodiment of the present application is shown in FIG. Figure 1 ;

[0033] Fig.13 A top view of a caster assembly provided in an embodiment of the present application Figure 1 ;

[0034] Fig.14 A side view of a caster assembly provided in an embodiment of the present application Figure 2 ;

[0035] Fig.15 A side view of a caster assembly provided in an embodiment of the present application Figure 3 ;

[0036] Fig.16 A simplified side view of a caster assembly provided in an embodiment of the present application Figure 1 ;

[0037] Fig.17 A side view of a caster assembly provided in an embodiment of the present application Figure 4 .

[0038] Description of Figure Numbers:

[0039] Self-propelled robot 1000; chassis 200; caster assembly 100; moving wheel group 30; support frame 21; transmission shaft 22; main wheel 31; secondary wheel 32; first fixed axis 311; first wheel center O1; second fixed axis 321; second wheel center O2; central axis L0; ground contact portion 312; suspended portion 313; receiving space 314; first receiving space 314a; second receiving space 314b; avoidance space 315; first avoidance space 315a; second avoidance space 315b; first suspended portion 313a; second suspended portion 313b; first annular portion 316; second annular portion 317; third annular portion 318; first roller 322; second roller 323; diameter D2 of secondary wheel; angle θ1; tangent line L2; horizontal line L3; diameter D1 of main wheel; bracket 211; first mounting portion 212; second mounting portion 213. DETAILED DESCRIPTION

[0040] The technical solution of the present application will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the embodiments described in the present application are only a part of the embodiments, not all of the embodiments. Based on the embodiments provided in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0041] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it mutually exclusive, independent, or alternative to other embodiments. It can be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0042] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example: a component or device including one or more parts is not limited to the one or more parts listed, but optionally includes one or more parts that are not listed but inherent to the exemplified product, or one or more parts that it should have based on the described function.

[0043] See also Figure 1 The embodiment of the present application provides a self-propelled robot 1000. The self-propelled robot 1000 includes a chassis 200 and a caster assembly 100. The chassis 200 is used to carry the main structure of the self-propelled robot 1000, for example, other functional components such as batteries and circuit boards. The caster assembly 100 is arranged at the bottom of the chassis 200 to achieve walking.

[0044] See also Figure 2 The embodiment of the present application provides a caster assembly 100. The caster assembly 100 includes a support frame 21 and a moving wheel set 30.

[0045] See also Figure 2 The moving wheel set 30 includes a main wheel 31. The main wheel 31 is for the self-propelled robot 1000 to contact the ground.

[0046] Optionally, the main wheel 31 is a driving wheel, and specifically, the rotating shaft of the main wheel 31 is electrically connected to a motor. The motor drives the main wheel 31 to roll, so as to drive the self-propelled robot 1000 to walk.

[0047] Optionally, the main wheel 31 is a driven wheel. For example, the main wheel 31 rolls under the propulsion force to drive the self-propelled robot 1000 to walk. Optionally, the main wheel 31 is arranged on the front end side of the chassis, and the main wheel 31 is a universal wheel so that the main wheel 31 can flexibly turn.

[0048] At least a portion of the main wheel 31 in its width direction is radially concave to form a space for avoiding a position. In other words, a portion of the rolling surface of the main wheel 31 contacts the ground, and another portion is suspended and spaced from the ground.

[0049] The self-propelled robot 1000 travels along a planned path. Since the self-propelled robot 1000 stays at a turning position in the path for a relatively long time and also performs actions such as turning, the caster assembly of the self-propelled robot 1000 exerts relatively large pressure on the turning position. Especially when mowing the lawn, the self-propelled robot 1000 exerts relatively large pressure on the grass at the turning position. Over time, this may easily lead to problems such as the grass in this area (the turning position in the path) being crushed to death.

[0050] Based on the above-mentioned problems, in the embodiment of the present application, the main wheel 31 is designed to be radially concave in at least a portion in the width direction thereof to form an avoidance space 315, so that a portion of the rolling surface of the main wheel 31 contacts the ground, and the other portion with the avoidance space 315 is suspended and spaced from the ground. This portion will not cause crushing pressure on the supporting surface below, or this portion has a small pressure on the grass of the supporting surface, thereby reducing the crushed area of ​​the grass below and reducing the damaged area of ​​the grass.

[0051] Furthermore, by setting the width direction of the main wheel 31 to have a certain size, the structural strength of the main wheel 31 in the width direction can be effectively improved, thereby improving the supporting force of the main wheel 31 in the width direction.

[0052] In an optional implementation, the roller surface of the main wheel 31 is a cylindrical surface, and the number of the avoidance spaces 315 is one or more.

[0053] For example, see Figure 2 The number of the avoidance space 315 is one, and one avoidance space 315 is arranged at the axial center position of the cylindrical main wheel 31, so that the main wheel 31 has a symmetrical structure, thereby improving the supporting stability of the main wheel 31.

[0054] For another example, see Figure 3 There are two avoidance spaces 315 , and the two avoidance spaces 315 are symmetrically arranged on both sides of the axial center of the cylindrical main wheel 31 , so that the main wheel 31 has a symmetrical structure, thereby improving the supporting stability of the main wheel 31 .

[0055] For another example, the number of the avoidance spaces 315 is three, one of which is located at the axial center of the cylindrical main wheel 31, and the other two avoidance spaces 315 are symmetrically located on both sides of the axial center of the cylindrical main wheel 31, so that the main wheel 31 has a symmetrical structure, thereby improving the support stability of the main wheel 31.

[0056] In another alternative embodiment, see Figure 4 The roller surface of the main wheel 31 may also include a conical surface with a large diameter in the middle and small diameters at both ends.

[0057] Among them, the contact area between the main wheel 31 and the ground can be determined by designing the width dimension of the avoidance space 315 in the axial direction. If the width dimension of the avoidance space 315 in the axial direction is too large, the contact area between the main wheel 31 and the ground may be too small, which in turn causes the main wheel 31 to exert a greater pressure per unit area on the ground, which may easily cause damage to the ground. If the width dimension of the avoidance space in the axial direction is too small, the contact area between the main wheel 31 and the bottom surface may be too large, which in turn causes the main wheel 31 to press the ground too large. When walking on the grass, the rolling area of ​​the grass is too large, especially at the turning position, the self-propelled robot 1000 may easily cause the rolling pressure of the grass at the turning position to be too large and the rolling area to be large, which may cause damage to the grass. Based on this, for example, the ratio of the width of the main wheel 31 in axial contact with the ground to the axial width of the main wheel 31 is 1:2 to 1:10. By properly setting the ratio of the width of the main wheel 31 axially contacting the ground to the axial width of the main wheel 31 , it is possible to avoid the main wheel 31 applying too much pressure per unit area on the ground and causing damage to the ground, and it is also possible to avoid the main wheel 31 pressing too large an area on the ground, resulting in too large a crushing area on the grass when walking on the grass.

[0058] For further information, see Figure 5 The moving wheel set 30 also includes a secondary wheel 32.

[0059] The main wheel 31 and the secondary wheel 32 are both rollingly arranged on the support frame 21. That is, the main wheel 31 and the secondary wheel 32 can roll freely on the support frame 21.

[0060] See also Figure 5 , the main wheel 31 and the secondary wheel 32 are spaced apart in the traveling direction of the moving wheel set 30. Optionally, the main wheel 31 contacts the ground. In an optional embodiment, the secondary wheel 32 contacts the ground, and the main wheel 31 and the secondary wheel 32 are used in combination to increase the walking stability of the moving wheel set 30 in the traveling direction.

[0061] Optionally, the secondary wheel 32 is suspended. By designing the secondary wheel 32 at a suitable height above the ground, the secondary wheel 32 can assist the main wheel 31 and increase the obstacle-crossing height of the mobile wheel set 30 in the traveling direction.

[0062] Optionally, the secondary wheel 32 is arranged in the corresponding avoidance space 315, which can effectively prevent the gap between the surface of the secondary wheel 32 and the surface opposite to the main wheel 31 from being too small, thereby preventing the main wheel 31 and the secondary wheel 32 from getting stuck or stuck due to grass being entangled in the gap between the main wheel 31 and the secondary wheel 32. Even if grass is entangled in the gap between the main wheel 31 and the secondary wheel 32, since the gap between the main wheel 31 and the secondary wheel 32 has a sufficient safety distance, it is not easy for the grass to block the gap between the main wheel 31 and the secondary wheel 32.

[0063] Furthermore, the secondary wheel 32 is partially located in the avoidance space 315 , and the secondary wheel 32 and the main wheel 31 are embedded with each other to reduce the movement interference with other structures of the chassis 200 .

[0064] Optionally, when the self-propelled robot 1000 is a lawn mowing robot, a blade disc assembly and a blade disc guard covering the blade disc assembly are further provided below the chassis 200. The blade disc guard occupies a relatively large space below the chassis 200, and a certain interference distance (safety distance) needs to be reserved between the blade disc guard and the activity space of the caster assembly 100. Therefore, it is necessary to perform a structural design of the caster assembly 100 to reduce the motion interference between the caster assembly 100 and other structures below the chassis 200, such as the blade disc guard. In this embodiment, by arranging the secondary wheel 32 to be partially located in the avoidance space 315, the secondary wheel 32 and the main wheel 31 are mutually embedded, and the overall size of the secondary wheel 32 and the main wheel 31 is reduced, thereby effectively avoiding motion interference between the caster assembly and other structures (such as the blade disc assembly) of the self-propelled robot 1000.

[0065] Optional, see Figure 6 A transmission shaft 22 is connected to the support frame 21. The transmission shaft 22 can drive the support frame 21 to rotate freely in a horizontal plane.

[0066] The caster assembly provided in the embodiment of the present application includes a support frame 21 and a moving wheel group 30. The support frame 21 is connected to a transmission shaft 22, and the transmission shaft 22 can drive the support frame 21 to rotate freely in a horizontal plane. The moving wheel group 30 includes a main wheel 31 and a secondary wheel 32. The main wheel 31 and the secondary wheel 32 are both rollingly arranged on the support frame 21, and the main wheel 31 and the secondary wheel 32 are spaced apart in the traveling direction of the moving wheel group 30. At least a portion of the main wheel 31 in the width direction is radially concave to form an avoidance space 315, and a portion of the secondary wheel 32 is located in the avoidance space 315. By arranging at least a portion of the main wheel 31 in the width direction to be radially concave to form the avoidance space 315, the rolling pressure or rolling area of ​​the caster assembly on the supporting surface below can be reduced, thereby reducing damage to the supporting surface.

[0067] In an alternative embodiment, see Figure 7 The main wheel 31 includes a ground contacting portion 312 for contacting the ground, and two suspended portions 313 located on both sides of the ground contacting portion 312. The two suspended portions 313 extend from the ground contacting portion 312 toward one side of the support frame 21. The cross-sectional area of ​​one end of the suspended portion 313 away from the ground contacting portion 312 is smaller than the cross-sectional area of ​​the ground contacting portion 312. The radial dimensions of the two suspended portions 313 are smaller than the radial dimensions of the ground contacting portion 312.

[0068] Optionally, the ground contact portion 312 is located at the center of the main wheel 31, and the suspended portions 313 are located on both sides of the axial direction of the ground contact portion 312. The two suspended portions 313 can be symmetrically arranged on both sides of the ground contact portion 312.

[0069] See also Figure 7 The ground contact portion 312 and the suspended portion 313 are both in annular shape. The ground contact portion 312 has a larger diameter, so it contacts the ground. At least part of the suspended portion 313 has a smaller diameter than the ground contact portion 312.

[0070] In this embodiment, by providing a ground contact portion 312 with a larger diameter in the middle of the main wheel 31 and suspended portions 313 with a smaller diameter on both sides, the main wheel 31 has a ground contact area of ​​a suitable size and a smaller grass pressing area. In addition, the width of the main wheel 31 is wider, so that a stronger supporting force can be provided in the width direction.

[0071] Optional, see Figure 7 The outer contour surface of the suspended portion 313 is a conical surface. The diameter of the suspended portion 313 changes uniformly along the axial direction.

[0072] Specifically, the suspended portion 313 includes a first suspended portion 313a axially arranged with the ground contact portion 312. The radial radius of the first suspended portion 313a is smaller than the radial radius of the ground contact portion 312. The radial radius of at least part of the first suspended portion 313a gradually increases in the direction approaching the ground contact portion 312. The outer surface of the first suspended portion 313a is concave compared to the outer surface of the ground contact portion 312 to form a first accommodating space 314a for accommodating the secondary wheel 32. The design of the first suspended portion 313a can reduce grass pressure. The radial size of the first suspended portion 313a gradually decreases in the direction away from the ground contact portion 312, and the distance between the first suspended portion 313a and the ground gradually increases in the direction away from the ground contact portion 312, so that the pressure on the grass gradually decreases.

[0073] For more details, please refer to Figure 7, the number of the suspended parts 313 is two, and the two suspended parts 313 further include a second suspended part 313b. The second suspended part 313b is located on the side of the ground contacting part 312 away from the first suspended part 313a. The radial radius of the second suspended part 313b is smaller than the radial radius of the ground contacting part 312. The radial radius of at least part of the second suspended part 313b gradually increases in the direction approaching the ground contacting part 312. The outer surface of the second suspended part 313b is concave compared to the outer surface of the ground contacting part 312 to form a second accommodating space 314b for accommodating the secondary wheel 32. The design of the second suspended part 313b can reduce grass pressure. The radial size of the second suspended part 313b in the direction away from the ground contacting part 312 gradually decreases, and the distance between the second suspended part 313b and the ground gradually increases in the direction away from the ground contacting part 312, and the pressure on the grass gradually decreases.

[0074] For optional reference, see Figure 8 , the outer contour surface of the suspended portion 313 is a concave curved surface. The diameter of the suspended portion 313 increases non-uniformly along the axial direction. In this way, the space of the first receiving space 314a and the second receiving space 314b is larger, and the gap between the suspended portion 313 and the secondary wheel 32 is increased, which can reduce the problem of grass being entangled in the gap between the suspended portion 313 and the secondary wheel 32 when the self-propelled robot 1000 is used as a lawn mowing robot, causing the main wheel 31 and the secondary wheel 32 to get stuck or jammed.

[0075] For details, please refer to Figure 7 The first suspended portion 313a is concave relative to the ground contact portion 312 and forms a first receiving space 314a on one side of the ground contact portion 312, and the second suspended portion 313b is concave relative to the ground contact portion 312 and forms a second receiving space 314b on the other side of the ground contact portion 312.

[0076] In an alternative embodiment, see Figure 7 The auxiliary wheels 32 include two. The two auxiliary wheels 32 are spaced apart along the width direction of the main wheel 31. The two auxiliary wheels 32 are respectively partially located in the two receiving spaces 314 (the first receiving space 314a and the second receiving space 314b) in the traveling direction F1 of the caster assembly 100.

[0077] For details, please refer to Figure 7 The secondary wheel 32 includes a first roller 322 and a second roller 323. The first roller 322 and the second roller 323 are respectively located at the front sides of the main wheel 31 in the travel direction F1. In the travel direction F1 of the caster assembly 100, the first roller 322 and the second roller 323 are at least partially located in the receiving space 314 where the suspended portion 313 is contracted relative to the ground contacting portion 312.

[0078] Further, the avoidance space 315 is formed at the two suspended parts 313. Specifically, the first avoidance space 315a is provided at the first suspended part 313a and communicates with the first receiving space 314a, and the second avoidance space 315b is provided at the second suspended part 313b and communicates with the second receiving space 314b.

[0079] See also Figure 7 , a portion of the first roller 322 is disposed in the first receiving space 314a and the first avoiding space 315a, and a portion of the second roller 323 is disposed in the second receiving space 314b and the second avoiding space 315b. That is, in the axial direction of the main wheel 31, a portion of the first roller 322, the ground contact portion 312, and a portion of the second roller 323 are disposed in sequence.

[0080] Optionally, the suspended portion 313 includes a first annular portion 316, a second annular portion 317, and a third annular portion 318 connected in sequence. The first annular portion 316 is arranged close to the ground contact portion 312 and connected to the ground contact portion 312. The third annular portion 318 is away from the ground contact portion 312 and its radial dimension is smaller than the radial dimension of the first annular portion 316. The second annular portion 317 is concave relative to the first annular portion 316 and the third annular portion 318. The outer peripheral surface of the second annular portion 317 is a concave arc surface, and the space surrounded by the concave arc surface is the avoidance space 315. In other words, the boundary line of the cross section passing through the central axis of the main wheel 31 at the avoidance space 315 is an arc line concave toward the central axis of the main wheel 31.

[0081] Taking the outer contour surface of the suspended portion 313 as a conical surface as an example, the radial dimension of the first annular portion 316 gradually increases in a direction close to the ground contacting portion 312. The second annular portion 317 is located on a side of the second annular portion 317 away from the first annular portion 316. The radial dimension of the third annular portion 318 gradually increases in a direction close to the ground contacting portion 312.

[0082] Optionally, the first suspended portion 313a and the second suspended portion 313b are symmetrical structures.

[0083] In other embodiments, the second annular portion 317 may be connected to the ground contact portion 312. In other embodiments, the second annular portion 317 may also be provided at both axial ends of the main wheel 31.

[0084] For further details, please refer to Figure 7 The first roller 322 and the second roller 323 are at least partially located in the avoidance space 315 where the suspended portion 313 is contracted relative to the ground contacting portion 312 .

[0085] Specifically, the upper right corner of the first roller 322 (with Figure 7The upper left corner of the second roller 323 (with reference to Figure 7 (referenced in the text) is arranged in the second avoiding space 315b.

[0086] Optional, see Fig. 9 The main wheel 31 is constructed of a left half shell 31a and a right half shell 31b connected to each other. The ground contact portion 312 is formed at the middle position between the left half shell 31a and the right half shell 31b. The two suspended portions 313 are respectively formed at the non-jointed parts of the left half shell 31a and the right half shell 31b.

[0087] Optionally, the two auxiliary wheels 32 (the first roller 322 and the second roller 323 ) are respectively partially located in the two avoidance spaces 315 (the first avoidance space 315 a and the second avoidance space 315 b ) in the traveling direction of the caster assembly 100 .

[0088] In this implementation, please refer to Figure 7 and Figure 8 , the main wheel 31 and the secondary wheel 32 have a partial overlapping area on the orthographic projection plane parallel to the traveling direction F1. When overcoming obstacles, the secondary wheel 32 can increase the obstacle overcoming height of the caster assembly 100, so as to increase the overall obstacle overcoming height of the caster assembly 100, so that the self-propelled robot 1000 has a better obstacle overcoming ability. In addition, the main wheel 31 and the secondary wheel 32 are compactly arranged in the forward direction, which reduces the overall size of the main wheel 31 and the secondary wheel 32 in the forward direction, thereby reducing the size of the caster assembly 100 in the forward direction, reducing the rotation space formed by the caster assembly 100 when rotating, and avoiding interference with other structures (such as the cutter head assembly) of the self-propelled robot 1000.

[0089] See also Figure 1 and Figure 6 The transmission shaft 22 is arranged in a direction perpendicular to the chassis 200 and also in a height direction of the self-propelled robot 1000. The transmission shaft 22 can rotate freely relative to the chassis 200 and the support frame 21. In other words, the caster assembly 100 is rotatably connected to the chassis 200 through the transmission shaft 22. The transmission shaft 22 is used to make the support frame 21 rotate horizontally. In other words, the rotation of the transmission shaft 22 drives the support frame 21 to rotate horizontally.

[0090] See also Figure 6 and Fig.10 The support frame 21 further includes a bracket 211, two first mounting portions 212 bent and arranged on both sides thereof, and a second mounting portion 213 connected to the first mounting portion 212. The bracket 211 is arranged in a horizontal direction. The transmission shaft 22 vertically penetrates the bracket 211, and each first mounting portion 212 is arranged obliquely compared to the transmission shaft 22.

[0091] See also Fig.10 and Fig.11 One end of the two second mounting portions 213 is respectively connected to one end of the two first mounting portions 212 away from the bracket 211. Both of the two second mounting portions 213 extend along the travel direction F1 of the caster assembly 100.

[0092] Optional, see Fig.10 and Fig.11 The support frame 21 further includes a first fixed shaft 311 and a second fixed shaft 321, wherein two ends of the first fixed shaft 311 are fixedly connected between the two first mounting portions 212, and two ends of the second fixed shaft 321 are fixedly connected between the two second mounting portions 213. The main wheel 31 is located between the two first mounting portions. The secondary wheel 32 is located between the two second mounting portions.

[0093] Optional, see Fig.10 and Fig.11 The first fixed axis 311 and the second fixed axis 321 are perpendicular to the advancing direction and also perpendicular to the extending direction of the transmission axis 22 .

[0094] See also Fig.10 and Fig.11 Specifically, the main wheel 31 is arranged on the first fixed shaft 311. In other words, the first fixed shaft 311 runs through the center of the main wheel 31. The main wheel 31 can rotate freely around the first fixed shaft 311. The secondary wheel 32 is arranged on the second fixed shaft 321. In other words, the second fixed shaft 321 runs through the center of the secondary wheel 32. The secondary wheel 32 can rotate freely around the second fixed shaft 321.

[0095] See also Fig.10 and Fig.11 , the first fixed shaft 311 is connected to the wheel center position of the main wheel 31 in the side view. The wheel center of the main wheel 31 is the first wheel center O1. The first wheel center O1 is the center position of the outer contour circle of the main wheel 31 in the side view. The second fixed shaft 321 is connected to the wheel center position of the secondary wheel 32 in the side view. The wheel center of the secondary wheel 32 is the second wheel center O2. The second wheel center O2 is the center position of the outer contour circle of the secondary wheel 32 in the side view.

[0096] See also Fig.12 The main wheel 31 and the secondary wheel 32 have two rotational degrees of freedom, one of which is that the main wheel 31 and the secondary wheel 32 can rotate horizontally together with the support frame 21 ( Fig.12 The arrow around the transmission shaft 22 is one of the directions of rotation, and it can also rotate in the opposite direction), and the other degree of rotational freedom is that the main wheel 31 and the secondary wheel 32 can roll relative to the support frame 21. Fig.12The arrow around the first fixed axis 311 indicates one of the directions, and the reverse rotation is also possible. Fig.12 The arrow around the second fixed axis 321 is one of the turns, and it can also rotate in the opposite direction. The rolling axes of the main wheel 31 and the secondary wheel 32 are all in the horizontal direction. The main wheel 31 and the secondary wheel 32 can form a universal wheel assembly.

[0097] See also Fig.13 , the first fixed axis 311 and the second fixed axis 321 are spaced apart along the travel direction F1 of the caster assembly 100. In other words, the main wheel 31 and the secondary wheel 32 are spaced apart along the travel direction F1 of the caster assembly 100. In other words, the first fixed axis 311 of the main wheel 31 is parallel to the second fixed axis 321 of the secondary wheel 32. The section of the main wheel 31 perpendicular to the first fixed axis 311 is parallel or coplanar with the section of the secondary wheel 32 perpendicular to the second fixed axis 321.

[0098] See also Fig.11 , the first mounting portion 212 extends obliquely from the bracket 211 toward the side away from the secondary wheel 32. The two ends of the first mounting portion 212 are not on the same vertical line, so that the wheel center of the main wheel 31 deviates from the central axis L0 of the transmission shaft 22, so the main wheel 31 is eccentrically designed. Since the main wheel 31 is heavier than the secondary wheel 32, the center of gravity of the caster assembly 100 is biased toward the side where the secondary wheel 32 is located. During the forward movement, under the action of inertia, the center of gravity of the caster assembly 100 will move backward. Since the caster assembly 100 can rotate freely in the horizontal direction, the secondary wheel 32 will remain in front of the main wheel 31 during the forward movement, that is, the automatic self-centering effect is achieved.

[0099] See also Fig.11 The other ends of the two second mounting portions 213 extend toward the side away from the main wheel 31, and the second mounting portions 213 can extend in a horizontal direction or in an inclined direction. The wheel center O2 of the secondary wheel 32 is offset from the center axis L0 of the transmission shaft 22, so the secondary wheel 32 is eccentrically designed to better match the main wheel 31.

[0100] Optional, see Fig.10 The bracket 211 is provided with a lever arm 214 for moving debris on the surface of the main wheel 31. The lever arm 214 is located above the main wheel 31 and extends toward the surface of the main wheel 31 by a preset length. The lever arm 214 extends from the forward side of the bracket 211 toward the main wheel 31 by a preset length and is spaced from the surface of the main wheel 31. The present application does not specifically limit the preset length.

[0101] In this embodiment, a lever arm 214 is provided to move the debris on the surface of the main wheel 31 , so as to prevent the debris on the surface of the main wheel 31 from affecting the rolling of the main wheel 31 .

[0102] Furthermore, the spacing between the lever arm 214 and the surface of the main wheel 31 is greater than or equal to 5 mm, which effectively prevents the main wheel 31 from being entangled by debris or foreign objects sticking to the surface, causing the gap between the lever arm 214 and the main wheel 31 to be blocked, thereby causing the main wheel 31 to get stuck or jammed.

[0103] In an alternative embodiment, see Fig.14 On the orthographic projection plane perpendicular to the extension direction of the central axis of the main wheel 31 (the central axis of the main wheel 31 is the central axis of the first fixed axis 311), the angle θ1 between the tangent line L2 near the bottom of the main wheel 31 and the secondary wheel 32 and the horizontal line L3 is 0-35°.

[0104] Optionally, taking the side view of the main wheel 31 and the secondary wheel 32 as an example, an angle θ1 between a bottom tangent line L2 of the main wheel 31 and the secondary wheel 32 and a horizontal line L3 is 0-35°.

[0105] For example, the angle θ1 between the bottom tangent line L2 of the main wheel 31 and the secondary wheel 32 and the horizontal line L3 is 0°, or 5°, or 10°, or 15°, or 20°, or 25°, or 30°, or 35°. It can be understood that the angle θ1 between the bottom tangent line L2 of the main wheel 31 and the secondary wheel 32 and the horizontal line L3 can also be other values ​​in addition to the above values, as long as the angle θ1 between the bottom tangent line L2 of the main wheel 31 and the secondary wheel 32 and the horizontal line L3 is 0-35°. Since the bottom of the secondary wheel 32 is suspended, the angle θ1 between the bottom tangent line L2 of the main wheel 31 and the secondary wheel 32 and the horizontal line L3 is greater than or equal to 0, which is conducive to the subsequent obstacle crossing height of the secondary wheel 32 being higher than the obstacle crossing height of the main wheel 31, thereby improving the obstacle crossing effect of the secondary wheel 32. When the angle θ1 between the bottom tangent line L2 of the main wheel 31 and the secondary wheel 32 and the horizontal line L3 is greater than 35°, the height difference between the bottom of the secondary wheel 32 and the bottom of the main wheel 31 is too large, which causes the bottom of the secondary wheel 32 to be too high compared to the main wheel 31, and the auxiliary obstacle crossing effect cannot be achieved or the auxiliary obstacle crossing effect is poor.

[0106] The present application reasonably sets the angle θ1 between the bottom tangent line L2 of the main wheel 31 and the secondary wheel 32 and the horizontal line L3, which is beneficial to achieving the obstacle crossing effect of the secondary wheel 32 and increasing the obstacle crossing height of the caster assembly 100.

[0107] In an alternative embodiment, see Fig.15 The distance between the wheel center O2 of the secondary wheel 32 and the center axis L0 of the transmission shaft 22 is a first value N1. The ratio of the diameter D2 of the secondary wheel 32 to the first value N1 is 0.5-2.5.

[0108] It can be understood that the secondary wheel 32 is an eccentric wheel. The distance between the wheel center O2 of the secondary wheel 32 and the center axis L0 of the transmission shaft 22 can be understood as the eccentricity of the secondary wheel 32 mentioned above.

[0109] For example, the ratio of the diameter D2 of the secondary wheel 32 to the first value N1 is 0.5, or 0.6, or 0.7, or 0.8, or 0.9, or 1, or 1.1, or 1.2, or 1.3, or 1.4, or 1.5, or 1.6, or 1.7, or 1.8, or 1.9, or 2, or 2.1, or 2.2, or 2.3, or 2.4, or 2.5. It can be understood that the ratio of the diameter D2 of the secondary wheel 32 to the first value N1 can also be other values ​​in addition to the above values, as long as the ratio of the diameter D2 of the secondary wheel 32 to the first value N1 is 0.5-2.5. When the ratio of the diameter D2 of the secondary wheel 32 to the first value N1 is less than 0.5, the secondary wheel 32 and the first fixed shaft 311 of the main wheel 31 will form motion interference. When the ratio of the diameter D2 of the secondary wheel 32 to the first value N1 is greater than 2.5, the distance between the secondary wheel 32 and the first fixed axis 311 of the main wheel 31 is relatively large, which in turn causes the size of the secondary wheel 32 and the main wheel 31 in the forward direction to increase, and the rotation space of the caster assembly 100 is relatively large. The present application reasonably sets the size of the eccentricity of the secondary wheel 32 so that the secondary wheel 32 and the first fixed axis 311 of the main wheel 31 do not form motion interference, and can also make the size of the secondary wheel 32 and the main wheel 31 in the forward direction relatively small, and the rotation space of the caster assembly 100 is relatively small, thereby avoiding motion interference with the structure near the caster assembly 100 in the self-propelled robot 1000.

[0110] In an alternative embodiment, see Fig.16 , the wheel centers O2 of the main wheel 31 and the secondary wheel 32 are not at the same height. The height difference between the wheel centers O2 of the main wheel 31 and the secondary wheel 32 is L1. The ratio of the diameter D1 of the main wheel 31 to the L1 is 40-75. The ratio of the diameter D2 of the secondary wheel 32 to the L1 is 20-30.

[0111] For example, the ratio of the diameter D1 of the main wheel 31 to the L1 is 40, 45, 50, 55, 60, 65, 70, or 75. For example, the ratio of the diameter D2 of the secondary wheel 32 to the L1 is 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30.

[0112] It can be understood that the ratio of the diameter D1 of the main wheel 31 to the L1 can also be other values ​​besides the above values, as long as the ratio of the diameter D1 of the main wheel 31 to the L1 is 40-75. The ratio of the diameter D2 of the secondary wheel 32 to the L1 can also be other values ​​besides the above values, as long as the ratio of the diameter D2 of the secondary wheel 32 to the L1 is 20-30.

[0113] By reasonably setting the ratio of the diameter D1 of the main wheel 31 to the diameter L1, and the ratio of the diameter D2 of the secondary wheel 32 to the diameter L1, the obstacle crossing height of the caster assembly 100 can be increased, and the caster assembly 100 can move more smoothly in the process of crossing obstacles, and the caster assembly 100 is also less shaken.

[0114] In an alternative embodiment, see Fig.17 , the lowest end of the secondary wheel 32 is higher than the lowest end of the main wheel 31. The main wheel 31 is used to drive the caster assembly 100 to move along the travel direction F1. In other words, the bottom of the secondary wheel 32 can be suspended. The main wheel 31 can roll relative to the ground to drive the caster assembly 100 to move along the travel direction F1. The secondary wheel 32 is configured to contact an obstacle to lift the main wheel 31 before the main wheel 31 contacts the obstacle, thereby assisting the main wheel 31 to cross the obstacle.

[0115] For example, when the main wheel 31 is the front wheel and the driven wheel, and the self-propelled robot 1000 is a device with a center of gravity that is biased to the rear (because heavier structures such as the motor, the cutter head, and the battery are all located at the rear side of the self-propelled robot 1000), since the center of gravity of the self-propelled robot 1000 is biased to the rear, the weight borne by the main wheel 31 as the front wheel is relatively small, so that the grip force (friction between the main wheel 31 and the ground) of the main wheel 31 is relatively small, so when the main wheel 31 crosses an obstacle that is higher than 1 / 3 of the diameter of the main wheel 31, it may slip and be unable to cross. Therefore, the maximum height h1 of the obstacle that the main wheel 31 can cross is one-third of the diameter of the main wheel 31. Correspondingly, the maximum height h1 of the obstacle that the secondary wheel 32 can cross is one-third of the diameter of the secondary wheel 32.

[0116] See also Figure 8 , the height h3 (relative to the horizontal plane) of the 1 / 3 diameter position on the secondary wheel 32 is greater than the height h1 (relative to the horizontal plane) of the 1 / 3 diameter position on the main wheel 31. In this way, the secondary wheel 32 can increase the maximum height of the obstacle that the caster assembly 100 can cross, for example, the obstacle crossing height of the caster assembly 100 is increased from the 1 / 3 diameter position of the main wheel 31 to the sum of the lowest end height of the secondary wheel 32 and the 1 / 3 diameter of the secondary wheel 32. The obstacle crossing height of the caster assembly 100 is increased by (1 / 3D2+h4-1 / 3D1). h2 is the height of the secondary wheel 32 from the ground.

[0117] The height h2 of the auxiliary wheel 32 from the ground is less than the height of the 1 / 3 diameter position on the main wheel 31, so that the auxiliary wheel 32 can assist the main wheel 31 in overcoming obstacles, so that the main wheel 31 has better passability, and the main wheel 31 can pass over obstacles more smoothly, which can effectively increase the overall obstacle-crossing height of the caster assembly 100, improve the obstacle-crossing ability of the caster assembly 100, and enable the main wheel 31 to easily overcome obstacles with the help of the auxiliary wheel.

[0118] Optionally, a maximum axial distance (along the extension direction of the second fixed axis 321 ) between the two secondary wheels 32 is greater than, equal to, or less than a width of the main wheel 31 .

[0119] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present application, and these improvements and modifications are also regarded as the scope of protection of the present application.

Claims

1. A caster assembly, characterized in that: include: A support frame, to which a transmission shaft is connected, and the transmission shaft can drive the support frame to rotate freely in a horizontal plane; A moving wheel set, comprising a main wheel and a secondary wheel, wherein both the main wheel and the secondary wheel are rollingly arranged on the support frame, and the main wheel and the secondary wheel are spaced apart in the traveling direction of the moving wheel set; Wherein, at least a portion of the main wheel in the width direction is radially concave to form an avoidance space, and the secondary wheel portion is located in the avoidance space.

2. The caster assembly according to claim 1, characterized in that: The main wheel comprises a ground contacting portion for contacting the ground, and suspended portions located at both sides of the ground contacting portion, the radial dimensions of the two suspended portions are both smaller than the radial dimensions of the ground contacting portion, and the avoidance space is formed at the two suspended portions.

3. The caster assembly according to claim 2, characterized in that: The suspended portion includes a first annular portion, a second annular portion, and a third annular portion connected in sequence, the first annular portion is arranged close to the ground contact portion and connected thereto, the third annular portion is away from the ground contact portion and its radial dimension is smaller than the radial dimension of the first annular portion, and the second annular portion is concave relative to the first annular portion and the third annular portion.

4. The caster assembly according to claim 2, characterized in that: The main wheel is constructed of a left half shell and a right half shell connected to each other, the ground contacting portion is formed at the middle position between the left half shell and the right half shell, and the two suspended portions are respectively formed at the non-jointed portions of the left half shell and the right half shell.

5. The caster assembly according to claim 1, characterized in that: The auxiliary wheels include two, the two auxiliary wheels are arranged at intervals along the width direction of the main wheel, and the two auxiliary wheels are respectively partially located in the two avoidance spaces in the traveling direction of the caster assembly.

6. The caster assembly according to claim 1, characterized in that: The support frame includes a bracket, a first mounting portion bent on both sides thereof, and a second mounting portion connected to the first mounting portion, the two second mounting portions both extend along the travel direction of the caster assembly, the main wheel is located between the two first mounting portions, and the secondary wheel is located between the two second mounting portions.

7. The caster assembly according to claim 6, characterized in that: The bracket is provided with a moving arm for moving debris on the surface of the main wheel. The moving arm is located above the main wheel and extends toward the surface of the main wheel by a preset length.

8. The caster assembly according to claim 1, characterized in that: On the orthographic projection plane perpendicular to the extension direction of the central axis of the main wheel, the angle between the tangent line of the main wheel and the secondary wheel close to the bottom and the horizontal line is 0-35°.

9. The caster assembly according to claim 1, characterized in that: The distance between the wheel center of the secondary wheel and the central axis of the transmission shaft is a first value, and the ratio of the diameter of the secondary wheel to the first value is 0.5-2.

5.

10. The caster assembly according to claim 1, characterized in that: The wheel centers of the main wheel and the secondary wheel are not at the same height, the height difference between the wheel centers of the main wheel and the secondary wheel is a second value, the ratio of the diameter of the main wheel to the second value is 40-75, and the ratio of the diameter of the secondary wheel to the second value is 20-30.

11. The caster assembly according to any one of claims 1 to 10, characterized in that: The lowest end of the secondary wheel is higher than the lowest end of the main wheel, the main wheel can roll relative to the ground to move the caster assembly along the travel direction, and the secondary wheel is configured to contact an obstacle to lift the main wheel before the main wheel contacts the obstacle.

12. A self-propelled robot, characterized in that: It comprises a chassis and a caster assembly as claimed in any one of claims 1 to 11, wherein the caster assembly is rotatably connected to the chassis via the transmission shaft.

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