Caster wheel mechanism and mobile vehicle

Abstract

This application discloses a universal wheel mechanism and a mobile vehicle, relating to the field of vehicle wheel assembly technology. It includes a wheel bracket, a wheel assembly, and a locking element. The wheel assembly is rotatably connected to the wheel bracket and has a spline groove. The locking element is movably connected to the wheel bracket. The locking element is circumferentially fixed to the wheel bracket and has an external spline structure. When the locking element moves down to the locked position, the external spline structure inserts into the spline groove, preventing the wheel assembly from rotating relative to the wheel bracket. A first radial fit clearance exists between the addendum circle of the external spline structure and the root circle of the spline groove, and a second radial fit clearance exists between the root circle of the external spline structure and the addendum circle of the spline groove. This solution sets a radial fit clearance between the external spline structure and the spline groove, reducing friction on non-working surfaces, lowering the insertion and extraction resistance and wear of the locking element, improving smoothness of operation, and achieving weight reduction.

Description

Technical Field

[0001] This application relates to the field of vehicle wheel assembly technology, and in particular to a universal wheel mechanism and a mobile vehicle. Background Technology

[0002] Casters are widely used in various mobile vehicles; in order to switch the wheel assembly between a rotatable state and a locked state, existing casters are usually equipped with a corresponding locking structure.

[0003] However, in actual switching operations, the locking mechanisms on existing casters generally suffer from high operating resistance, insufficient smoothness of movement, and severe wear after long-term use, which adversely affects the overall lifespan of the product and the user experience. Summary of the Invention

[0004] The main purpose of this application is to propose a universal wheel mechanism that aims to solve the technical problems of existing universal wheels, such as high operating resistance, insufficient smoothness of movement, and severe wear after long-term use.

[0005] To achieve the above objectives, the universal wheel mechanism proposed in this application includes: Wheel bracket; A wheel assembly is rotatably connected to the wheel bracket about a vertical axis; the wheel assembly is provided with an upward-opening spline groove; A locking element is movably connected to the wheel bracket in the vertical direction; the locking element and the wheel bracket are fixed relative to each other in the circumferential direction, and the locking element is provided with an external spline structure; When the locking member moves downward relative to the wheel bracket to the locking position, the external spline structure is inserted into the spline groove to prevent the wheel assembly from rotating relative to the wheel bracket; There is at least one first radial fit clearance between the tooth tip cylindrical surface of the external spline structure and the tooth root cylindrical surface of the spline groove; and / or, there is at least one second radial fit clearance between the tooth root cylindrical surface of the external spline structure and the tooth tip cylindrical surface of the spline groove.

[0006] In one embodiment, at least one first recess is provided on the tooth tip cylindrical surface of the external spline structure.

[0007] In one embodiment, at least one second recess is provided on the cylindrical surface of the spline tooth tip.

[0008] In one embodiment, the first recess is provided through the axial direction of the external spline structure.

[0009] In one embodiment, the second recess is provided through the bottom wall of the spline groove extending upwards.

[0010] In one embodiment, the caster wheel mechanism further includes a fixed base; the fixed base is fixed in the wheel bracket, and the fixed base is provided with at least two vertically penetrating guide holes at intervals; The locking component includes a connecting frame; the connecting frame includes a main frame and at least two spaced guide posts, the main frame is used to be mounted on the fixed base, the upper end of the guide post is connected to the main frame, the lower end of the guide post is detachably connected to the external spline structure, and at least two of the guide posts are slidably fitted into at least two guide through holes.

[0011] In one embodiment, the omnidirectional wheel mechanism further includes a reset elastic element, which is connected to the wheel bracket and the locking element; the elastic force provided by the reset elastic element is used to drive the locking element downward to the locking position.

[0012] In one embodiment, the caster wheel mechanism further includes a traction cable; a first end of the traction cable is connected to the locking member, and a second end of the traction cable is used to connect to the operating member; The traction cable is used to pull the locking member upward under the drive of the operating member, so as to disengage the external spline structure from the spline groove.

[0013] In one embodiment, the top surface of the locking member is provided with a connecting groove extending in a horizontal direction, and at least one end of the connecting groove is through the member; the connecting groove has a first groove segment and a second groove segment, the first groove segment is located above the second groove segment, and the groove width of the first groove segment is smaller than the groove width of the second groove segment. The first end of the traction cable passes through the first groove; the first end of the traction cable is provided with a limiting block, which is detachably snapped into the second groove; the width of the limiting block is greater than the groove width of the first groove.

[0014] In one embodiment, the caster wheel mechanism further includes a connecting seat and a limiting sleeve; the connecting seat is detachably connected to the wheel bracket, the connecting seat is located above the locking member, and the connecting seat has a first arm and a second arm spaced apart in the horizontal direction, the gap between the first arm and the second arm forming a limiting groove; The limiting sleeve is connected to the limiting groove; the traction cable is slidably inserted into the inner cavity of the limiting sleeve in the vertical direction.

[0015] In one embodiment, the limiting groove has a third groove segment and a fourth groove segment, the third groove segment being located above the fourth groove segment, and the groove width of the third groove segment being smaller than the groove width of the fourth groove segment; The limiting sleeve has a first sleeve portion and a second sleeve portion connected sequentially along the axial direction; the outer diameter of the first sleeve portion is smaller than the outer diameter of the second sleeve portion, and the outer diameter of the second sleeve portion is larger than the groove width of the third groove segment; the first sleeve portion is engaged in the third groove segment, and the second sleeve portion is engaged in the fourth groove segment.

[0016] In one embodiment, one end of the connecting groove extends through to the first side of the locking member to form an assembly opening, and the other end of the connecting groove is closed. The first arm and the second arm extend downward to the outer side of the first side; the limiting groove has a fifth groove segment, which is disposed opposite to the assembly opening, and the width of the fifth groove segment is smaller than the width of the limiting block.

[0017] In one embodiment, the radial depth of the first radial fit gap is 1 mm to 1.2 mm.

[0018] In one embodiment, the radial depth of the second radial fit gap is 1 mm to 1.2 mm.

[0019] In one embodiment, the radial depth of the first recess is 1.3 mm to 2 mm.

[0020] In one embodiment, the radial depth of the second recess is 1.3 mm to 2.5 mm.

[0021] In one embodiment, the circumferential width of the first recess is 2 mm to 3.6 mm.

[0022] In one embodiment, the circumferential width of the second recess is 1.5 mm to 2.5 mm.

[0023] This application also proposes a mobile vehicle comprising a frame and a caster mechanism as described above; the caster mechanism is connected to the frame.

[0024] The universal wheel mechanism proposed in this application has at least one radial fit clearance (including a first radial fit clearance and / or a second radial fit clearance) between the outer spline structure of the locking member and the spline groove of the wheel assembly. This creates a certain clearance space between the non-working surfaces of the outer spline structure and the spline groove, reducing unnecessary contact area between them, lowering frictional resistance during insertion and removal, improving the smoothness of the locking member's movement, reducing wear on the locking member and wheel assembly, and extending their service life. Furthermore, by setting the aforementioned radial fit clearance, the weight of the locking member and wheel assembly can be reduced, facilitating the overall lightweight design of the universal wheel mechanism and making it easier to manufacture. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0026] Figure 1 A three-dimensional structural schematic diagram of an embodiment of the universal wheel mechanism provided in this application; Figure 2 An exploded view of an embodiment of the caster mechanism provided in this application; Figure 3 A three-dimensional schematic diagram of the internal structure of the universal wheel mechanism provided in this application when it is in the unlocked state; Figure 4 A schematic diagram of the internal cross-sectional structure of the universal wheel mechanism provided in this application when it is in the unlocked state; Figure 5 A schematic diagram of the internal three-dimensional structure of the caster mechanism provided in this application when it is in the locked state; Figure 6 A schematic diagram of the internal cross-sectional structure of the caster mechanism provided in this application when it is in the locked state; Figure 7 This is a schematic diagram showing the fit between the external spline structure and the spline groove in one embodiment of the universal wheel mechanism provided in this application; Figure 8 A three-dimensional structural schematic diagram of the locking element in one embodiment of the caster wheel mechanism provided in this application; Figure 9 A three-dimensional structural schematic diagram of the traction cable in one embodiment of the universal wheel mechanism provided in this application; Figure 10 A three-dimensional structural diagram of the connecting seat in one embodiment of the universal wheel mechanism provided in this application.

[0027] Explanation of icon numbers: 1000, First radial clearance; 2000, First recess; 3000, Second radial clearance; 4000, Second recess; 1. Wheel bracket; 2. Wheelset; 21. Spline groove; 3. Locking components; 31. External spline structure; 32. Connecting bracket; 321. Main frame; 322. Guide column; 3211. Connecting groove; 3212. First side surface; 32111, First slot section; 32112, Second slot section; 32113, Assembly opening; 4. Fixture; 41. Guide through hole; 5. Reset elastic element; 6. Traction cable; 61. Limit block; 7. Connecting base; 71. First arm body; 72. Second arm body; 73. Limiting groove; 731. Third section; 732. Fourth section; 733. Fifth section; 8. Limiting sleeve; 81. First sleeve section; 82. Second sleeve section.

[0028] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0029] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0030] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0031] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0032] Casters are widely used in various mobile vehicles; in order to switch the wheel assembly between a rotatable state and a locked state, existing casters are usually equipped with a corresponding locking structure.

[0033] However, in actual switching operations, the locking mechanisms on existing casters generally suffer from high operating resistance, insufficient smoothness of movement, and severe wear after long-term use, which adversely affects the overall lifespan of the product and the user experience.

[0034] To address the aforementioned issues, this application provides a universal wheel mechanism. Please refer to [link / reference]. Figure 1 , Figure 3 , Figure 5 and Figure 7 and for reference Figure 2 , Figure 4 and Figure 6 The omnidirectional wheel mechanism includes: Wheel bracket 1; Wheel assembly 2 is rotatably connected to wheel bracket 1 about a vertical axis; wheel assembly 2 is provided with an upward-facing spline groove 21; The locking member 3 is movably connected to the wheel bracket 1 in the vertical direction; the locking member 3 and the wheel bracket 1 are fixed relative to each other in the circumferential direction, and the locking member 3 is provided with an external spline structure 31; When the locking member 3 moves downward relative to the wheel bracket 1 to the locking position, the external spline structure 31 is inserted into the spline groove 21 to prevent the wheel set 2 from rotating relative to the wheel bracket 1. There is at least one first radial fit clearance 1000 between the tooth tip cylindrical surface of the external spline structure 31 and the tooth root cylindrical surface of the spline groove 21; and / or, there is at least one second radial fit clearance 3000 between the tooth root cylindrical surface of the external spline structure 31 and the tooth tip cylindrical surface of the spline groove 21.

[0035] In this embodiment, the wheel bracket 1 can be configured as a hollow shell structure to accommodate the corresponding mechanical parts using its internal cavity; the wheel bracket 1 is used to be fixedly connected to the frame of a mobile vehicle (such as a stroller, trolley or walker) to serve as the basic support component of the entire omnidirectional wheel mechanism.

[0036] The wheel assembly 2 is rotatably connected to the lower end of the wheel bracket 1 via a bearing structure, allowing the wheel assembly 2 to freely rotate relative to the wheel bracket 1 in a horizontal plane around a vertical axis. The top of the wheel assembly 2 has an upward-facing spline groove 21, which is oriented towards the inner cavity of the wheel bracket 1 for the locking member 3 to be inserted from above. Specifically, the spline groove 21 is an internal spline structure, with multiple grooves distributed circumferentially on its inner wall, forming a convex tooth between adjacent grooves.

[0037] The inner cavity of the wheel bracket 1 can be provided with limiting and guiding structures such as guide holes and guide grooves. The locking member 3 can be set in the inner cavity of the wheel bracket 1 and cooperate with the limiting and guiding structures, so that the locking member 3 only has the vertical degree of freedom of movement relative to the wheel bracket 1, while the horizontal degree of freedom of movement and the rotational degree of freedom about the vertical axis of the locking member 3 are constrained. That is, the locking member 3 cannot rotate relative to the wheel bracket 1 about the vertical axis. Specifically, there are many ways to achieve circumferential relative fixation between the locking member 3 and the wheel bracket 1. For example, the upper end of the locking member 3 can be set to a non-circular cross-sectional shape, and a matching hole of the same shape can be opened in the wheel bracket 1; or anti-rotation structures such as key connections and guide planes can be used to restrict the circumferential rotation of the locking member 3 relative to the wheel bracket 1. These are not listed here.

[0038] The lower end of the locking member 3 is provided with an external spline structure 31; the external spline structure 31 has multiple protruding teeth distributed along the circumferential direction, and a tooth groove is formed between two adjacent protruding teeth; the shape of the protruding teeth of the external spline structure 31 is adapted to the shape of the tooth groove of the spline groove 21, and the shape of the tooth groove of the external spline structure 31 is adapted to the shape of the protruding teeth of the spline groove 21, so that the external spline structure 31 can be inserted into the spline groove 21 and form a spline fit.

[0039] Based on the above settings, such as Figure 5 and Figure 6 As shown, when the locking member 3 moves downward relative to the wheel bracket 1 to the locked position, the external spline structure 31 is inserted downward into the spline groove 21; at this time, the protruding teeth of the external spline structure 31 are inserted into the tooth grooves of the spline groove 21 one by one, and the protruding teeth of the spline groove 21 are inserted into the tooth grooves of the external spline structure 31 one by one; the side surfaces of the protruding teeth and the side surfaces of the tooth grooves contact each other and form a constraint in the circumferential direction, which can prevent the wheel assembly 2 from rotating relative to the locking member 3 around the vertical axis; and since the upper end of the locking member 3 is circumferentially fixed to the wheel bracket 1, the wheel assembly 2 cannot rotate relative to the wheel bracket 1 around the vertical axis, and the universal wheel mechanism is in a locked state at this time. Figure 3 and Figure 4 As shown, when the locking member 3 moves upward to the unlocked position, the external spline structure 31 will disengage from the spline groove 21. At this time, the external spline structure 31 no longer forms a circumferential constraint on the wheel assembly 2, and the wheel assembly 2 can rotate freely relative to the wheel bracket 1 around the vertical axis.

[0040] Based on the above basic structure, this embodiment further defines the mating relationship between the external spline structure 31 and the spline groove 21. Specifically, in an optional implementation, such as Figure 7As shown, there is at least one first radial fit clearance 1000 between the tooth tip cylindrical surface of the external spline structure 31 and the tooth root cylindrical surface of the spline groove 21; wherein, the tooth tip cylindrical surface of the external spline structure 31 refers to the outer cylindrical surface where the top of at least one protruding tooth on the external spline structure 31 is located, and the tooth root cylindrical surface of the spline groove 21 refers to the inner cylindrical surface where the bottom of the tooth groove in the spline groove 21 that engages with the protruding tooth is located. By setting the first radial fit clearance 1000, direct rigid contact between the tooth tip of the external spline structure 31 and the tooth root of the spline groove 21 can be avoided at the fit position, thereby reducing the friction in the local fit area, reducing the wear at the contact position, and reducing the axial resistance when the locking member 3 performs insertion and extraction actions. It should be noted that this embodiment does not require that all the protrusions of the external spline structure 31 have the first radial fit clearance 1000 with the corresponding tooth groove of the spline groove 21. It is only necessary to ensure that at least one protrusion of the external spline structure 31 meets the clearance condition with the corresponding tooth groove in the spline groove 21.

[0041] Because a first radial clearance 1000 is provided between the external spline structure 31 and the spline groove 21, a certain clearance space can be formed between the tooth tip of the external spline structure 31 and the tooth root of the spline groove 21. This makes it less likely for the tooth tip to scrape against the tooth root during movement, thereby improving the smoothness of the movement of the locking member 3. In addition, by setting the first radial clearance 1000, the material weight of the locking member 3 and the wheel assembly 2 can be reduced, which is conducive to achieving the overall lightweighting of the universal wheel mechanism, thus making it easier to manufacture.

[0042] As another optional specific implementation, such as Figure 7 As shown, at least one second radial fit clearance 3000 exists between the root cylindrical surface of the external spline structure 31 and the tip cylindrical surface of the spline groove 21. The root cylindrical surface of the external spline structure 31 refers to the outer cylindrical surface where the bottom of at least one tooth groove on the external spline structure 31 is located, and the tip cylindrical surface of the spline groove 21 refers to the inner cylindrical surface where the top of the protruding tooth in the spline groove 21 that engages with the tooth groove is located. By setting the second radial fit clearance 3000, direct rigid contact between the root of the external spline structure 31 and the tip of the spline groove 21 can be avoided at this fit position, thereby reducing friction in this local fit area, reducing wear at the contact position, and reducing the axial resistance of the locking member 3 during insertion and extraction. It should be noted that this embodiment does not require that all the tooth grooves of the external spline structure 31 have the second radial fit clearance 3000 with the corresponding protrusion of the spline groove 21, but only needs to ensure that at least one tooth groove of the external spline structure 31 meets the clearance condition with the corresponding protrusion in the spline groove 21.

[0043] Because a second radial clearance 3000 is provided between the external spline structure 31 and the spline groove 21, a certain clearance space can be formed between the tooth root of the external spline structure 31 and the tooth tip of the spline groove 21. This makes it less likely for the tooth tip to scrape against the tooth root during movement, thereby improving the smoothness of the movement of the locking member 3. In addition, by setting the second radial clearance 3000, the material weight of the locking member 3 and the wheel assembly 2 can be reduced, which is conducive to achieving the overall lightweighting of the universal wheel mechanism, thus making it easier to manufacture.

[0044] In practical applications, a first radial fit clearance 1000 can be separately provided between the external spline structure 31 and the spline groove 21, and a second radial fit clearance 3000 can also be separately provided between the external spline structure 31 and the spline groove 21. Furthermore, the external spline structure 31 and the spline groove 21 can also be configured as follows: Figure 7 The diagram shows that a first radial fit clearance of 1000 and a second radial fit clearance of 3000 are set simultaneously, but this is not limited here.

[0045] It should be noted that the aforementioned radial fit clearances are all set on non-working surfaces such as tooth tip and tooth root, and do not affect the circumferential snap fit between the external spline structure 31 and the spline groove 21. That is, the side of the convex tooth and the side of the groove still maintain an appropriate meshing relationship, which can ensure the circumferential locking accuracy and load-bearing capacity in the locked state.

[0046] Therefore, this embodiment provides at least one radial fit clearance (including a first radial fit clearance 1000 and / or a second radial fit clearance 3000) between the outer spline structure 31 of the locking member 3 and the spline groove 21 of the wheel set 2. This creates a certain clearance space between the non-working surfaces of the outer spline structure 31 and the spline groove 21, reducing unnecessary contact area between them, lowering frictional resistance during insertion and removal, improving smoothness of movement, reducing wear on the locking member 3 and the wheel set 2, and extending service life. Furthermore, by providing the aforementioned radial fit clearance, the weight of the locking member 3 and the wheel set 2 can be reduced, facilitating the overall lightweight design of the universal wheel mechanism and making it easier to manufacture.

[0047] In one implementation, please refer to Figure 1 , Figure 3 , Figure 5 and Figure 7 and for reference Figure 2 , Figure 4 and Figure 6 The external spline structure 31 has at least one first recess 2000 on the tooth tip cylindrical surface.

[0048] With the first radial clearance 1000 provided, the external spline structure 31 further includes at least one first recess 2000 on the tooth tip cylindrical surface. The first recess 2000 is recessed radially inward from the tooth tip cylindrical surface of the external spline structure 31, and can be specifically configured as a groove, cavity, hole, or other structure. By providing the first recess 2000, the area where the tooth tip cylindrical surface of the external spline structure 31 and the tooth root cylindrical surface of the spline groove 21 may come into contact can be further reduced. Even if the first radial clearance 1000 is smaller at a certain position due to machining tolerance factors, the area where the first recess 2000 is located can still remain in a non-contact state, thereby further reducing the insertion and extraction resistance of the locking member 3 and improving the smoothness of the locking member 3's movement. Furthermore, when there is a lubricating medium in the mating interface between the protruding teeth of the external spline structure 31 and the tooth groove of the spline groove 21, the first recess 2000 can be used to store a certain amount of lubricating medium and continuously release it during the repeated insertion and removal of the locking member 3, thereby maintaining good lubrication performance between the external spline structure 31 and the spline groove 21 during use.

[0049] Because a first radial clearance 1000 is provided between the external spline structure 31 and the spline groove 21, and a first recess 2000 is provided on the cylindrical surface of the tooth tip of the external spline structure 31, a certain clearance space can be formed between the tooth tip of the external spline structure 31 and the tooth root of the spline groove 21. This makes it less likely for the tooth tip to scrape against the tooth root during movement. Even if there are a small amount of dust, debris, or other foreign objects in the spline groove 21, these foreign objects can be pushed into the first recess 2000 for temporary accommodation, and will not accumulate on the mating path to form a blockage, thereby further improving the smoothness of movement of the locking member 3. In addition, by setting the first radial clearance 1000 and the first recess 2000, the material weight of the locking member 3 and the wheel assembly 2 can be further reduced, which is conducive to achieving the overall lightweighting of the universal wheel mechanism, thus making it easier to manufacture.

[0050] In one implementation, please refer to Figure 1 , Figure 3 , Figure 5 and Figure 7 and for reference Figure 2 , Figure 4 and Figure 6 At least one second recess 4000 is provided on the tooth tip cylindrical surface of the spline groove 21.

[0051] With the second radial clearance 3000 provided, at least one second recess 4000 is further provided on the tooth tip cylindrical surface of the spline groove 21; the second recess 4000 is recessed radially outward from the tooth tip cylindrical surface of the spline groove 21, and the second recess 4000 can be specifically configured as a groove, cavity, hole, or other structure. By providing the second recess 4000, the area where the tooth root cylindrical surface of the external spline structure 31 and the tooth tip cylindrical surface of the spline groove 21 may come into contact can be further reduced; even if the second radial clearance 3000 is small at a certain position due to machining tolerance factors, the area where the second recess 4000 is located can still remain in a non-contact state, thereby further reducing the insertion and extraction resistance of the locking member 3 and improving the smoothness of the movement of the locking member 3. Furthermore, when there is a lubricating medium in the mating interface between the tooth groove of the external spline structure 31 and the convex tooth of the spline groove 21, the second recess 4000 can be used to store a certain amount of lubricating medium and continuously release it during the repeated insertion and removal of the locking member 3, thereby maintaining good lubrication performance between the external spline structure 31 and the spline groove 21 during use.

[0052] Because a second radial clearance 3000 is provided between the external spline structure 31 and the spline groove 21, and a second recess 4000 is provided on the cylindrical surface of the tooth tip of the spline groove 21, a certain clearance space can be formed between the tooth root of the external spline structure 31 and the tooth tip of the spline groove 21. This makes it less likely for the tooth tip to scrape against the tooth root during movement. Even if there are a small amount of dust, debris, or other foreign objects in the spline groove 21, these foreign objects can be pushed into the second recess 4000 for temporary accommodation, and will not accumulate on the mating path to form a blockage, thereby further improving the smoothness of movement of the locking member 3. In addition, by providing the second radial clearance 3000 and the second recess 4000, the material weight of the locking member 3 and the wheel assembly 2 can be further reduced, which is conducive to achieving the overall lightweighting of the universal wheel mechanism, making it easier to manufacture.

[0053] It should be noted that the first recess 2000 and the second recess 4000 are both located on non-working surfaces such as the tooth tip and tooth root, and do not affect the circumferential engagement between the external spline structure 31 and the spline groove 21. That is, the side of the convex tooth and the side of the groove still maintain an appropriate meshing relationship, which can ensure the circumferential locking accuracy and load-bearing capacity in the locked state.

[0054] In one embodiment, refer to Figure 2 and Figure 7 The first recess 2000 is provided to penetrate along the axial direction of the outer spline structure 31.

[0055] By setting the first recess 2000 as an axially penetrating structure, the clearance space between the tooth tip cylindrical surface of the external spline structure 31 and the tooth root cylindrical surface of the spline groove 21 can be further expanded, so that the non-contact area between the tooth tip part and the tooth root part is continuously distributed along the axial direction. This further reduces the area that may come into contact between the tooth tip part and the tooth root part, thereby further reducing the frictional resistance and wear degree between the external spline structure 31 and the spline groove 21, and further improving the smoothness of the movement of the locking member 3.

[0056] In one embodiment, refer to Figure 2 and Figure 7 The second recess 4000 is provided by extending upward through the bottom wall of the spline groove 21.

[0057] By setting the second recess 4000 as an axially penetrating structure, the clearance space between the tooth root cylindrical surface of the external spline structure 31 and the tooth tip cylindrical surface of the spline groove 21 can be further expanded, so that the non-contact area between the tooth tip part and the tooth root part is continuously distributed along the axial direction. This further reduces the area that may come into contact between the tooth tip part and the tooth root part, thereby further reducing the frictional resistance and wear between the external spline structure 31 and the spline groove 21, and further improving the smoothness of the movement of the locking member 3.

[0058] In one embodiment, refer to Figure 2 , Figure 4 and Figure 6 The universal wheel mechanism also includes a fixed base 4; the fixed base 4 is fixed in the wheel bracket 1, and at least two vertical through guide holes 41 are provided on the fixed base 4 at intervals; The locking component 3 includes a connecting frame 32; the connecting frame 32 includes a main frame 321 and at least two spaced guide posts 322. The main frame 321 is used to mount on the fixed base 4. The upper end of the guide post 322 is connected to the main frame 321, and the lower end of the guide post 322 is detachably connected to the external spline structure 31. At least two guide posts 322 are slidably fitted in at least two guide through holes 41.

[0059] In this embodiment, the fixing seat 4 can be fixed to the inner cavity of the wheel bracket 1 by means of screw fastening, snap-fit, etc.; the fixing seat 4 is provided with at least two vertical through guide holes 41 at intervals.

[0060] The locking member 3 includes a connecting frame 32 located at the upper end of the locking member 3. The connecting frame 32 consists of a main frame 321 and at least two spaced guide posts 322. The main frame 321 is mounted on the top surface of the fixed base 4. The upper ends of the guide posts 322 are fixedly connected to the main frame 321 or integrally formed therefrom. The lower ends of the guide posts 322 pass downward through the corresponding guide holes 41 on the fixed base 4 and are detachably connected to the external spline structure 31, for example, by means of threaded connection or pin connection. Each guide post 322 forms a sliding fit with the corresponding guide hole 41, so that the locking member 3 can only move in the vertical direction, while the horizontal movement and rotation about the vertical axis of the locking member 3 are constrained.

[0061] By setting at least two guide posts 322, the locking member 3 receives multi-point guidance during its up-and-down movement, effectively preventing skewing and jamming, thereby improving the movement stability of the locking member 3. Furthermore, the detachable connection between the guide posts 322 and the external spline structure 31 allows for the individual replacement of the worn external spline structure 31 after long-term use, without requiring the replacement of the entire locking member 3. The contact between the main frame 321 and the fixed base 4 limits the lower limit position of the locking member 3, ensuring that the external spline structure 31 stops moving downwards after reaching the locking position.

[0062] In one embodiment, refer to Figures 2 to 6 The universal wheel mechanism also includes a reset elastic element 5, which is connected to the wheel bracket 1 and the locking element 3. The elastic force provided by the reset elastic element 5 is used to drive the locking element 3 to move downward to the locking position.

[0063] The reset elastic element 5 can be an elastic element such as a spring, torsion spring, or elastic gel. Taking a spring as an example, the reset elastic element 5 can be arranged around the connecting frame 32, with its upper end connected to the fixed base 4 and its lower end connected to the upper end face of the external spline structure 31; for example... Figure 3 and Figure 4 As shown, when the locking member 3 moves upward relative to the fixed seat 4 to the unlocked position under the action of external force, the reset elastic member 5 is compressed and stores elastic potential energy; as Figure 5 and Figure 6 As shown, when the external force is removed, the reset elastic element 5 releases the stored elastic potential energy, causing the locking element 3 to move automatically downward until the locking element 3 is reset to the locked position.

[0064] By setting the reset elastic element 5, the universal wheel mechanism can remain locked under normal conditions, meaning that the wheel assembly 2 cannot rotate freely. Only when the operator actively applies an upward external force can the external spline structure 31 be driven upward to disengage from the spline groove 21. Once the external force is released, the locking element 3 will automatically reset to the locked position under the elastic action of the reset elastic element 5, thereby enabling the universal wheel mechanism to have a normally closed locking function, improving the safety of the mobile vehicle when it is parked, and avoiding the uncertainty that exists when the locking element 3 is reset by relying solely on gravity.

[0065] In one embodiment, refer to Figures 2 to 6 The omnidirectional wheel mechanism also includes a traction cable 6; the first end of the traction cable 6 is connected to the locking member 3, and the second end of the traction cable 6 is used to connect to the operating member; The traction cable 6 is used to pull the locking member 3 upward under the drive of the operating member, so that the external spline structure 31 disengages from the spline groove 21.

[0066] Specifically, the traction cable 6 is a flexible transmission element, typically made of steel wire rope or synthetic fiber rope. The lower end of the traction cable 6 is connected to the locking member 3, for example, it can be fixed to the main frame 321 of the locking member 3; the upper end of the traction cable 6 is used to connect the operating element, which can refer to foot pedals, rotary handles, brake levers, pull rings, etc., installed on the mobile vehicle.

[0067] When the operating element is triggered (e.g., when the foot pedal is pressed or the handle is pulled), the traction cable 6 is pulled, applying an upward force to the locking element 3; under the action of this force, such as Figure 3 and Figure 4 As shown, the locking member 3 overcomes the elastic force of the reset elastic member 5 and its own weight, moving upward to the unlocked position, causing the external spline structure 31 to disengage from the spline groove 21, allowing the wheel assembly 2 to return to a free-rotating state; when the operating member is released, as... Figure 5 and Figure 6 As shown, the reset elastic element 5 will drive the locking element 3 to automatically reset downwards to the locked position.

[0068] By setting the traction cable 6, the operating component can be positioned away from the swivel wheel mechanism, enabling remote control of the locking component 3 without requiring the user to bend over or reach near the wheel assembly 2, thereby improving ease of use and safety.

[0069] In one embodiment, refer to Figure 4 , Figure 6 , Figure 8 and Figure 9The top surface of the locking member 3 is provided with a connecting groove 3211 extending in a horizontal direction, and at least one end of the connecting groove 3211 is provided through; the connecting groove 3211 has a first groove segment 32111 and a second groove segment 32112, the first groove segment 32111 is located above the second groove segment 32112, and the groove width of the first groove segment 32111 is smaller than the groove width of the second groove segment 32112; The first end of the traction cable 6 is inserted into the first groove section 32111; the first end of the traction cable 6 is provided with a limiting block 61, which is detachably snapped into the second groove section 32112; the width of the limiting block 61 is greater than the groove width of the first groove section 32111.

[0070] Specifically, at least one end of the connecting groove 3211 extends through to the side of the locking member 3 to form an opening. The connecting groove 3211 is vertically divided into upper and lower sections, namely, a first groove section 32111 located at the top and a second groove section 32112 located at the bottom; the groove width of the first groove section 32111 is smaller than the groove width of the second groove section 32112; the lower end of the traction cable 6 passes through the first groove section 32111 and extends downward to the second groove section 32112; a limiting block 61 is fixed to the lower end of the traction cable 6, the width of which is greater than the groove width of the first groove section 32111, and the... The width of the limiting block 61 is less than or equal to the width of the second groove 32112. The limiting block 61 is detachably engaged in the second groove 32112. Since the width of the first groove 32111 is less than the width of the limiting block 61, the limiting block 61 cannot pass upward through the first groove 32111 and disengage from the connecting groove 3211. This ensures a reliable connection between the lower end of the traction cable 6 and the locking member 3, so that the tension provided by the traction cable 6 can be stably transmitted to the locking member 3.

[0071] In practical applications, the limiting block 61 can slide horizontally into the second groove section 32112 from the through end of the connecting groove 3211, and slide horizontally outward from the second groove section 32112. This enables quick installation and disassembly between the traction cable 6 and the locking component 3, and makes it easier to adjust and replace the traction cable 6.

[0072] In one embodiment, refer to Figures 2 to 6 and for reference Figure 9 and Figure 10 The universal wheel mechanism also includes a connecting seat 7 and a limiting sleeve 8; the connecting seat 7 is detachably connected to the wheel bracket 1, the connecting seat 7 is located above the locking member 3, the connecting seat 7 has a first arm 71 and a second arm 72 spaced apart in the horizontal direction, and the spaced area between the first arm 71 and the second arm 72 forms a limiting groove 73. The limiting sleeve 8 is connected in the limiting groove 73; the traction cable 6 is slidably inserted into the inner cavity of the limiting sleeve 8 in the vertical direction.

[0073] Specifically, the connecting seat 7 can be detachably connected to the fixed seat 4 by means of threaded connection, pin connection, snap-fit ​​connection, etc. The connecting seat 7 has a first arm body 71 and a second arm body 72 arranged at intervals in the horizontal direction, and the interval area between the first arm body 71 and the second arm body 72 forms a limiting groove 73; the limiting groove 73 is arranged through in the vertical direction and has a lateral opening, which allows the traction cable 6 and the limiting sleeve 8 to be installed horizontally from the side.

[0074] During actual assembly, the traction cable 6 can be first horizontally inserted into the limiting groove 73 through the lateral opening between the first arm 71 and the second arm 72. Then, the limiting sleeve 8, which is pre-fitted onto the traction cable 6, can be horizontally inserted into the limiting groove 73 through the same lateral opening and fixed. Based on the structural design of the limiting groove 73, the traction cable 6 and the limiting sleeve 8 can be inserted into the limiting groove 73 from the side after all other components have been assembled, which avoids interference problems during assembly and improves assembly convenience.

[0075] Based on the above configuration, the limiting sleeve 8 can provide a fixed fulcrum for the traction cable 6, so as to stably keep the lower end of the traction cable 6 in the area above the locking member 3. The limiting sleeve 8 provides a precise vertical guide for the traction cable 6, so that the lower end of the traction cable 6 always moves in the vertical direction when it is pulled, thereby stably transmitting the pulling force to the locking member 3 and driving the locking member 3 to move upward stably.

[0076] In one embodiment, refer to Figure 9 and Figure 10 The limiting groove 73 has a third groove segment 731 and a fourth groove segment 732. The third groove segment 731 is located above the fourth groove segment 732, and the groove width of the third groove segment 731 is smaller than the groove width of the fourth groove segment 732. The limiting sleeve 8 has a first sleeve portion 81 and a second sleeve portion 82 connected sequentially along the axial direction; the outer diameter of the first sleeve portion 81 is smaller than the outer diameter of the second sleeve portion 82, and the outer diameter of the second sleeve portion 82 is larger than the groove width of the third groove section 731; the first sleeve portion 81 is engaged in the third groove section 731, and the second sleeve portion 82 is engaged in the fourth groove section 732.

[0077] Specifically, the limiting sleeve 8 can be configured as a stepped cylindrical structure. During assembly, the limiting sleeve 8 can be inserted into the limiting groove 73 from the side, so that the first sleeve part 81 is engaged in the third groove section 731, and the second sleeve part 82 is engaged in the fourth groove section 732. After the limiting sleeve 8 moves to the end of the limiting groove 73, it is fixed in the current position by means of fastening, snapping, or bonding. Since the outer diameter of the second sleeve part 82 is larger than the groove width of the third groove section 731, it can form an axial limiting effect on the limiting sleeve 8, so that the limiting sleeve 8 cannot be disengaged upward from the limiting groove 73. Thus, the limiting sleeve 8 can be reliably axially positioned in the limiting groove 73 without the need for additional fasteners, simplifying the assembly process.

[0078] In one embodiment, refer to Figures 8 to 10 and for reference Figure 2 , Figure 3 and Figure 5 One end of the connecting groove 3211 extends through to the first side 3212 of the locking member 3 to form an assembly opening 32113, and the other end of the connecting groove 3211 is closed. The first arm body 71 and the second arm body 72 extend downward to the outer side of the first side 3212; the limiting groove 73 has a fifth groove segment 733, which is opposite to the assembly opening 32113, and the groove width of the fifth groove segment 733 is smaller than the width of the limiting block 61.

[0079] like Figure 8 As shown, the connecting groove 3211 is provided on the main frame 321. The vertical sidewall of the main frame 321 forms the first side 3212 of the locking member 3. One end of the connecting groove 3211 extends through the first side 3212 to form an assembly opening 32113. The other end of the connecting groove 3211 is closed. The limiting block 61 can be horizontally inserted into the second groove section 32112 of the connecting groove 32111 from the assembly opening 32113, and the limiting block 61 slides along the second groove section 32112 to the closed end of the connecting groove 32111 to complete the positioning.

[0080] like Figure 10As shown, the first arm 71 and the second arm 72 have horizontal extensions above the locking member 3 and vertical extensions bent downwards. The vertical extensions of the two arms are opposite to the first side 3212 of the locking member 3. The section of the limiting groove 73 corresponding to the horizontal extensions of the two arms is the horizontal extension section of the limiting groove 73, and the section of the limiting groove 73 corresponding to the vertical extensions of the two arms is the vertical extension section of the limiting groove 73. Based on this, the horizontal extension section of the limiting groove 73 can be divided vertically into the third section 731 and the fourth section 732 in the above embodiment. The vertical extension section of the limiting groove 73 constitutes the fifth section 733. The fifth section 733 is opposite to the assembly opening 32113 of the connecting groove 3211, and the width of the fifth section 733 is smaller than the width of the limiting block 61.

[0081] Based on the above configuration, during the actual assembly process, the traction cable 6 can pass through the fifth slot 733. That is, the traction cable 6 is first passed through the fifth slot 733 before the limiting block 61 is inserted into the connecting slot 3211, thus avoiding interference problems caused by the arm obstructing the assembly process. In the assembled state, as follows... Figure 2 , Figure 8 , Figure 9 and Figure 10 As shown, the limiting block 61 is located in the second groove segment 32112 of the connecting groove 3211, and the side of the limiting block 61 facing the assembly opening 32113 is directly opposite the fifth groove segment 733. Since the groove width of the fifth groove segment 733 is smaller than the width of the limiting block 61, the limiting block 61 cannot move horizontally out through the fifth groove segment 733 at the assembly opening 32113, thereby ensuring that the limiting block 61 is constrained in the connecting groove 3211, and realizing reliable anti-detachment of the end of the traction cable 6.

[0082] In one embodiment, refer to Figure 7 The radial depth D1 of the first radial fit clearance 1000 is 1mm~1.2mm.

[0083] In one embodiment, refer to Figure 7 The radial depth D2 of the second radial fit clearance 3000 is 1mm~1.2mm.

[0084] In actual processing and assembly, if the radial depth of the first radial fit clearance 1000 is too small, it will be difficult to effectively accommodate foreign objects and will also easily cause unnecessary contact friction due to processing tolerances. If the radial depth of the first radial fit clearance 1000 is too large, it may lead to a decrease in the radial positioning accuracy between the external spline structure 31 and the spline groove 21, and will result in an insufficient lateral contact area between the protrusion and the groove, thereby adversely affecting the circumferential meshing stability between the external spline structure 31 and the spline groove 21.

[0085] Through testing, it has been verified that in this embodiment, the radial depth D1 of the first radial fit clearance 1000 is limited to 1mm~1.2mm. This allows the external spline structure 31 to maintain a high degree of smoothness of movement, while maintaining good alignment accuracy between the external spline structure 31 and the spline groove 21, and avoiding excessive weakening of the circumferential meshing stability between the external spline structure 31 and the spline groove 21.

[0086] Similarly, the radial depth D2 of the second radial fit clearance 3000 is also limited to 1mm~1.2mm to achieve the same technical effect, which will not be elaborated here.

[0087] In one embodiment, refer to Figure 7 The radial depth D3 of the first recess 2000 is 1.3mm~2mm.

[0088] In one embodiment, refer to Figure 7 The radial depth D4 of the second recess 4000 is 1.3mm~2.5mm.

[0089] The radial depth of the first recess 2000 on the tooth tip cylindrical surface of the external spline structure 31 determines the volume of debris it can provide and the degree of clearance between the tooth tip cylindrical surface and the tooth root cylindrical surface. If the radial depth of the first recess 2000 is too small, its capacity to accommodate foreign objects is insufficient. When dust, debris, or other impurities fall into the spline groove 21, these foreign objects may still be squeezed into the gap between the tooth tip and the tooth root, resulting in greater insertion and extraction resistance. At the same time, there is still a high probability of contact between the tooth tip cylindrical surface and the tooth root cylindrical surface, making it difficult to effectively reduce friction and wear. On the other hand, if the radial depth of the first recess 2000 is too large, it will excessively weaken the radial thickness of the protruding teeth of the external spline structure 31, increasing the probability of deformation and breakage of the protruding teeth of the external spline structure 31 when subjected to circumferential locking loads, which will adversely affect the reliability and service life of the locking mechanism.

[0090] Through testing, it has been verified that the radial depth D3 of the first recess 2000 in this embodiment is limited to 1.3mm~2mm. Within this depth range, the first recess 2000 can provide sufficient chip space to prevent foreign matter from accumulating on the mating path between the tooth and the tooth groove. At the same time, it can reduce the unnecessary contact area between the tooth tip cylindrical surface and the tooth root cylindrical surface, thereby reducing insertion and extraction resistance and wear. On the other hand, it can avoid substantial weakening of the structural strength of the tooth of the external spline structure 31, and ensure long-term reliability.

[0091] Similarly, for the second recess 4000 located on the cylindrical surface of the tooth tip of the spline groove 21, if its radial depth is too small, the chip-holding and clearance effects will be insufficient, making it difficult to improve the smoothness of the movement of the locking member 3; if its radial depth is too large, it may weaken the radial thickness of the protruding tooth of the spline groove 21, thereby causing local deformation and cracking problems. Through experimental verification, this embodiment limits the radial depth D4 of the second recess 4000 to 1.3mm~2.5mm; this depth range ensures good drag reduction effect and reduces wear, while avoiding substantial weakening of the structural strength of the protruding tooth of the spline groove 21, thus ensuring long-term reliability.

[0092] In one embodiment, refer to Figure 7 The circumferential width L1 of the first recess 2000 is 2mm~3.6mm.

[0093] In one embodiment, refer to Figure 7 The circumferential width L2 of the second recess 4000 is 1.5mm~2.5mm.

[0094] For the first recess 2000 located on the tooth tip cylindrical surface of the external spline structure 31, its circumferential width determines its arc length in the circumferential direction, thus affecting the chip volume and the degree of clearance between the tooth tip cylindrical surface and the tooth root cylindrical surface. If the circumferential width of the first recess 2000 is too small, the number of foreign objects that the first recess 2000 can accommodate is limited, and foreign objects are prone to accumulate between the tooth tip and the tooth root, resulting in greater insertion and extraction resistance; at the same time, an excessively small circumferential width makes it difficult to effectively reduce the contact area between the tooth tip cylindrical surface and the tooth root cylindrical surface, and the effect of reducing friction and wear is not significant. On the other hand, if the circumferential width of the first recess 2000 is too large, it will excessively weaken the structural strength of the protruding teeth of the external spline structure 31, thereby reducing the circumferential load-bearing capacity of the spline mating structure in the locked state.

[0095] Through testing, it has been verified that the circumferential width L1 of the first recess 2000 in this embodiment is limited to 2mm~3.6mm. Within this width range, the first recess 2000 can provide sufficient space for debris, allowing dust, debris, and other impurities to easily enter the first recess 2000 and avoid being squeezed onto the mating path. At the same time, it can reduce unnecessary contact area between the tooth tip cylindrical surface and the tooth root cylindrical surface, thereby reducing insertion and extraction resistance and wear. On the other hand, it can avoid excessive reduction of the structural strength of the convex teeth of the external spline structure 31, ensuring the stability and durability of the spline mating structure under circumferential loads.

[0096] Similarly, for the second recess 4000 located on the cylindrical surface of the tooth tip of the spline groove 21, if its circumferential width is too small, the chip-carrying and drag-reduction effects will be poor, making it difficult to improve the smoothness of the movement of the locking member 3; if its circumferential width is too large, it will excessively weaken the structural strength of the protruding teeth of the spline groove 21. Through experimental verification, this embodiment limits the circumferential width L2 of the second recess 4000 to 1.5mm~2.5mm, which can ensure good chip-carrying and drag-reduction effects while avoiding substantial weakening of the structural strength of the protruding teeth of the spline groove 21, thereby achieving a reasonable balance between locking smoothness and long-term reliability.

[0097] This application also provides a mobile vehicle; please refer to [link / reference]. Figures 1 to 10 The mobile vehicle includes a frame and a caster mechanism as described in any of the above embodiments; the caster mechanism is connected to the frame.

[0098] In this embodiment, the mobile vehicle can refer to a stroller, walker, or other tool that has the function of carrying people and walking; the frame can refer to the main body of the mobile vehicle, such as the body of a stroller or a walker, etc., and is not limited here.

[0099] The specific structure of the caster wheel mechanism can be referred to the above embodiments. Since this mobile vehicle adopts all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be elaborated further here.

[0100] The above description is merely an exemplary embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the technical concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A universal wheel mechanism, characterized in that, include: Wheel bracket (1); The wheel assembly (2) is rotatably connected to the wheel bracket (1) about a vertical axis; the wheel assembly (2) is provided with an upward-facing spline groove (21); A locking member (3) is movably connected to the wheel bracket (1) in the vertical direction; the locking member (3) and the wheel bracket (1) are fixed relative to each other in the circumferential direction, and the locking member (3) is provided with an external spline structure (31); When the locking member (3) moves downward relative to the wheel bracket (1) to the locking position, the external spline structure (31) is inserted into the spline groove (21) to prevent the wheel set (2) from rotating relative to the wheel bracket (1); There is at least one first radial fit clearance (1000) between the tooth tip cylindrical surface of the external spline structure (31) and the tooth root cylindrical surface of the spline groove (21); and / or, there is at least one second radial fit clearance (3000) between the tooth root cylindrical surface of the external spline structure (31) and the tooth tip cylindrical surface of the spline groove (21).

2. The universal wheel mechanism according to claim 1, characterized in that, The external spline structure (31) has at least one first recess (2000) on the tooth tip cylindrical surface; And / or, at least one second recess (4000) is provided on the tooth tip cylindrical surface of the spline groove (21).

3. The universal wheel mechanism according to claim 2, characterized in that, The first recess (2000) is provided through the axial direction of the external spline structure (31); And / or, the second recess (4000) is provided through the bottom wall of the spline groove (21) upward.

4. The universal wheel mechanism according to claim 1, characterized in that, The universal wheel mechanism also includes a fixed seat (4); the fixed seat (4) is fixed in the wheel bracket (1), and the fixed seat (4) is provided with at least two vertically penetrating guide holes (41) at intervals; The locking member (3) includes a connecting frame (32); the connecting frame (32) includes a main frame (321) and at least two spaced guide posts (322). The main frame (321) is used to be mounted on the fixed base (4). The upper end of the guide post (322) is connected to the main frame (321), and the lower end of the guide post (322) is detachably connected to the external spline structure (31). At least two of the guide posts (322) are correspondingly slidably fitted in at least two guide through holes (41).

5. The universal wheel mechanism according to claim 1, characterized in that, The universal wheel mechanism also includes a reset elastic element (5), which is connected to the wheel bracket (1) and the locking element (3); the elastic force provided by the reset elastic element (5) is used to drive the locking element (3) to move downward to the locking position.

6. The universal wheel mechanism according to claim 1, characterized in that, The universal wheel mechanism also includes a traction cable (6); the first end of the traction cable (6) is connected to the locking member (3), and the second end of the traction cable (6) is used to connect to the operating member; The traction cable (6) is used to pull the locking member (3) upward under the drive of the operating member, so that the external spline structure (31) disengages from the spline groove (21).

7. The universal wheel mechanism according to claim 6, characterized in that, The top surface of the locking member (3) is provided with a connecting groove (3211) extending in a horizontal direction, and at least one end of the connecting groove (3211) is through-hole; the connecting groove (3211) has a first groove segment (32111) and a second groove segment (32112), the first groove segment (32111) is located above the second groove segment (32112), and the groove width of the first groove segment (32111) is smaller than the groove width of the second groove segment (32112); The first end of the traction cable (6) is inserted into the first groove section (32111); the first end of the traction cable (6) is provided with a limiting block (61), which is detachably snapped into the second groove section (32112); the width of the limiting block (61) is greater than the groove width of the first groove section (32111).

8. The universal wheel mechanism according to claim 7, characterized in that, The universal wheel mechanism also includes a connecting seat (7) and a limiting sleeve (8); the connecting seat (7) is detachably connected to the wheel bracket (1), the connecting seat (7) is located above the locking member (3), the connecting seat (7) has a first arm body (71) and a second arm body (72) spaced apart in the horizontal direction, and the spaced area between the first arm body (71) and the second arm body (72) forms a limiting groove (73); The limiting sleeve (8) is connected in the limiting groove (73); the traction cable (6) is slidably inserted in the inner cavity of the limiting sleeve (8) in the vertical direction.

9. The universal wheel mechanism according to claim 8, characterized in that, The limiting groove (73) has a third groove segment (731) and a fourth groove segment (732), the third groove segment (731) is located above the fourth groove segment (732), and the groove width of the third groove segment (731) is smaller than the groove width of the fourth groove segment (732); The limiting sleeve (8) has a first sleeve portion (81) and a second sleeve portion (82) connected sequentially along the axial direction; the outer diameter of the first sleeve portion (81) is smaller than the outer diameter of the second sleeve portion (82), and the outer diameter of the second sleeve portion (82) is larger than the groove width of the third groove segment (731); the first sleeve portion (81) is engaged in the third groove segment (731), and the second sleeve portion (82) is engaged in the fourth groove segment (732).

10. The universal wheel mechanism according to claim 8, characterized in that, One end of the connecting groove (3211) extends through to the first side (3212) of the locking member (3) to form an assembly opening (32113), and the other end of the connecting groove (3211) is closed. The first arm body (71) and the second arm body (72) extend downward to the outside of the first side surface (3212); the limiting groove (73) has a fifth groove segment (733), the fifth groove segment (733) is disposed opposite to the assembly opening (32113), and the groove width of the fifth groove segment (733) is smaller than the width of the limiting block (61).

11. The caster wheel mechanism according to any one of claims 1 to 10, characterized in that, The radial depth of the first radial fit clearance (1000) is 1mm~1.2mm; And / or, the radial depth of the second radial fit clearance (3000) is 1mm~1.2mm.

12. The caster wheel mechanism according to any one of claims 2 to 10, characterized in that, The radial depth of the first recess (2000) is 1.3mm~2mm; And / or, the radial depth of the second recess (4000) is 1.3mm to 2.5mm.

13. The caster wheel mechanism according to any one of claims 2 to 10, characterized in that, The circumferential width of the first recess (2000) is 2mm~3.6mm; And / or, the circumferential width of the second recess (4000) is 1.5mm~2.5mm.

14. A mobile vehicle, characterized in that, The mobile vehicle includes a frame and a caster mechanism as described in any one of claims 1 to 13; the caster mechanism is connected to the frame.

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