Hub type electric omnidirectional wheel

Abstract

The invention discloses a hub type electric omnidirectional wheel which comprises a hub, a plurality of large-section wheels, a plurality of small-section wheels and a motor mechanism. The large-section wheels and the small-section wheels are staggered and distributed in the circumferential direction of the hub at intervals and are connected front and back to form a circumferential wheel; the motor mechanism is installed in the hub in an embedded mode so as to drive the hub to rotate. Through the design that the large and small section wheels are distributed at intervals in a staggered mode and rotate freely in the axial direction, in the process that the motor mechanism drives the omni-directional wheel to rotate circumferentially, the large and small section wheels can move circumferentially along with the hub and can also rotate freely in the axial direction, omni-directional rotation is achieved, the movement flexibility of the wheel is greatly improved, and the application range of the wheel is greatly widened. And the robot can move more flexibly in a complex space environment.

Description

Technical Field

[0001] The present invention relates to the technical field of mobile devices, and particularly to a hub-type electric omnidirectional wheel. Background Art

[0002] An omnidirectional wheel is a special wheel that can rotate in multiple directions. While it rotates around the main shaft, the knuckle wheels evenly distributed on the circumference can also axially rotate relative to the circumferential small shaft of the omnidirectional wheel. Installing it as a support wheel on a mobile device can achieve the omnidirectional movement of the device. In 2008, Masaaki Kumagai and Takaya Ochiai of Tohoku Gakuin University in Japan developed BallIP (Balanced Robot on a Ball) by driving a ball wheel with three omnidirectional wheels. The three omnidirectional wheels on it are respectively connected to drive motors at the shaft ends. Because the knuckle wheels of the omnidirectional wheel can rotate axially freely, the frictional drive control of the three omnidirectional wheels on the ball wheel in three directions does not affect each other. When driving the three omnidirectional wheels according to a certain rule, the arbitrary direction rotation control of the ball wheel can be achieved through the frictional action of the circumferential knuckle wheels. The omnidirectional wheels of a new energy electric vehicle that can move omnidirectionally can also be like this, relying on three omnidirectional wheels to drive the ball wheel to roll omnidirectionally. However, the wheels of an automobile are different from the walking wheels of small and medium-sized robots. They need to bear a greater load. Therefore, the scheme of connecting a motor to one end of the omnidirectional wheel shaft is obviously not very realistic. Inspired by the hub motor, the hub motor can be combined with the omnidirectional wheel. This technical scheme can not only solve the disadvantages of the external motor, but also optimize the overall structure and increase the overall efficiency. In summary, developing a hub-type electric omnidirectional wheel has important practical significance for solving the above problems. Summary of the Invention

[0003] The purpose of the present invention is to provide a hub-type electric omnidirectional wheel to solve the problems raised in the above background art. To achieve the above purpose, the present invention provides the following technical solutions:

[0004] A hub-type electric omnidirectional wheel includes a hub, a plurality of large knuckle wheels, a plurality of small knuckle wheels, and a motor mechanism; the large knuckle wheels and the small knuckle wheels are arranged in a staggered manner at intervals along the circumferential direction of the hub, and are connected front and back to form a circumferential wheel; the motor mechanism is embedded in the hub to drive the hub to rotate.

[0005] Both the large knuckle wheels and the small knuckle wheels are provided as cylindrical wheel shapes with a middle circular section radius larger than the two end circular section radii, and the circular section radii on both sides of the middle circular section are symmetrical.

[0006] Further, both ends of the large knuckle wheels are provided with concave portions, and both ends of the small knuckle wheels are respectively placed in the concave portions of the front and back large knuckle wheels.

[0007] Further, both the large pitch wheels and the small pitch wheels are provided in six numbers.

[0008] Further, the radius of the middle circular section plane of the large pitch wheel is about twice that of the small pitch wheel.

[0009] Further, the length of the rotating shaft of the small pitch wheel is about three times that of the rotating shaft of the large pitch wheel.

[0010] Further, tread patterns are also provided on the large pitch wheels and the small pitch wheels.

[0011] Further, the motor mechanism includes a fixed shaft, an inner stator assembly, an outer rotor assembly, and a bearing assembly; the inner stator assembly is fixedly connected to the fixed shaft; the outer rotor assembly is rotatably connected to the fixed shaft through the bearing assembly; the outer rotor assembly is sleeved on the inner stator assembly and rotates relative to the inner stator assembly; the hub is fixedly connected to the outer rotor assembly.

[0012] Further, the inner stator assembly includes a stator core and a coil 422 wound around the stator core; the outer rotor assembly includes a housing and a plurality of permanent magnets, and the plurality of permanent magnets are circumferentially distributed inside the housing; the housing and the plurality of permanent magnets are sleeved on the stator core, and the housing is fixedly connected to the hub.

[0013] Further, a wheel speed sensor is provided in the motor mechanism.

[0014] The beneficial effects of the present invention are as follows: Through the design of the staggered distribution of the large and small pitch wheels and the axial free rotation, during the circumferential rotation of the omnidirectional wheel driven by the motor mechanism, the large and small pitch wheels can not only perform circumferential movement along with the hub, but also perform axial free rotation, realizing omnidirectional rotation, greatly improving the flexibility and application range of the wheel movement, and being able to move more flexibly in a complex space environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0016] Figure 1 It is a schematic structural diagram of the present invention.

[0017] Figure 2 It is a schematic structural diagram of the hub of the present invention.

[0018] Figure 3This is a schematic structural diagram of the large sprocket of the present invention.

[0019] Figure 4 This is a schematic structural diagram of the small sprocket of the present invention.

[0020] Figure 5 This is a schematic structural diagram of the motor mechanism of the present invention.

[0021] It should be noted that the drawings are not necessarily drawn to scale, but are only shown in a schematic manner that does not affect the reader's understanding. Detailed implementation manners

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0023] In the present invention, the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal", etc. is based on the orientation or positional relationship shown in the accompanying drawings. These terms are mainly used to better describe the present invention and its embodiments, and are not used to limit that the indicated devices, elements or components must have a specific orientation, or be constructed and operated in a specific orientation.

[0024] Moreover, in addition to being able to represent the orientation or positional relationship, some of the above terms may also be used to represent other meanings. For example, the term "upper" may also be used to represent a certain attachment relationship or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in the present invention can be understood according to specific circumstances.

[0025] In addition, the terms "installed", "set", "provided with", "connected", "connected to" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or there is an internal connection between two devices, elements or components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] In addition, terms such as "first", "second", etc. are mainly used to distinguish different devices, components or constituent parts (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance and quantity of the indicated devices, components or constituent parts. Unless otherwise specified, the meaning of "a plurality" is two or more.

[0027] It should also be understood that the terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include the plural forms.

[0028] It should be further understood that the term "and / or" used in the specification of the present invention and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0029] As Figure 1 shown, a hub-type electric omnidirectional wheel according to an embodiment of the present application mainly includes a hub 1, six large sprockets 2, six small sprockets 3 and a motor mechanism 4.

[0030] As Figure 2 shown, the hub 1 is made of a suitable metal material by casting or machining to produce a hexagonal hub 1, ensuring that the dimensional accuracy and strength of the hub 1 meet the design requirements. On the circumferential direction of the hub 1, twelve rotating shafts evenly distributed are precisely machined at the designed positions, and these rotating shafts respectively correspond to six groups of large and small sprockets, providing a basis for the installation of the large and small sprockets, so that each large and small sprocket can rotate relative to the hub 1. It should be noted that in other embodiments, the number of the rotating shafts, large sprockets 2 and small sprockets 3 can also be synchronously changed, and as long as they are arranged in a staggered manner to form an omnidirectional wheel structure as in this embodiment.

[0031] As Figure 1 shown, the large sprockets 2 and the small sprockets 3 are arranged in a staggered manner along the circumferential direction of the hub 1 at intervals, and are installed on the hub 1 through the rotating shafts, ensuring that the large sprockets 2 and the small sprockets 3 can rotate freely and independently relative to the hub 1 respectively. Through this unique layout of the large and small sprockets, the large sprockets 2 and the small sprockets 3 are connected front and back into a circumferential wheel, and then a single-row omnidirectional wheel structure is constructed. This arrangement not only has a compact structure, but also can achieve omnidirectional movement through the coordinated rotation of the large and small sprockets.

[0032] The motor mechanism 4 is embedded in the hub 1. Its function is to drive the hub to rotate, thereby driving the large and small pitch wheels on the outer periphery of the hub 1 to rotate to achieve omnidirectional movement. The principle is as follows: Through the design of the large and small pitch wheels being spaced apart and axially freely rotatable, when the motor mechanism 4 drives the hub 1 of the omnidirectional wheel to rotate circumferentially, the large and small pitch wheels can not only perform circumferential movement along with the hub 1, but also perform axial free rotation. This characteristic enables the wheel body to achieve omnidirectional rotation, greatly improving the flexibility of the wheel movement, and enabling it to move more flexibly in a complex space environment. Whether it is turning in a narrow passage or in a scenario where rapid direction change is required, it can easily cope, greatly improving the mobility and application range of the equipment.

[0033] The core principle of the hub-type electric omnidirectional wheel of this application to achieve omnidirectional rotation lies in its unique layout and rotation characteristics of the large and small pitch wheels. During the process of the motor mechanism driving the omnidirectional wheel to rotate circumferentially, the hub 1 drives the large pitch wheel 2 and the small pitch wheel 3 to perform circumferential movement. At the same time, since the large pitch wheel 2 and the small pitch wheel 3 rotate relative to the hub 1 respectively, and they can also perform axial free rotation. By combining the axial rotation and circumferential rotation of the large and small pitch wheels, the wheel can be moved in a specific direction. The synergistic effect of this circumferential and axial rotation enables the wheel to move in any direction within the plane, thus achieving the effect of omnidirectional rotation.

[0034] In the specific implementation process of this application, referring to Figure 3 and Figure 4 , the structural designs of the large pitch wheel 2 and the small pitch wheel 3 are as follows:

[0035] The radius of the middle circular section of the large pitch wheel 2 and the small pitch wheel 3 is greater than the radius of the two end circular sections, presenting an overall cylindrical wheel shape with a higher middle and lower ends. And, the radii of the circular sections on both sides of the middle circular section are symmetrical, that is, the dimensions at both ends are symmetrical. This shape design helps to make the contour line at the connection of the large and small pitch wheels more continuous during wheel rotation, making the rotation process smoother and reducing vibrations caused by irregular shapes.

[0036] At the same time, concave portions 21 are provided at both ends of the large pitch wheel 2, and the two ends of the small pitch wheel 3 are respectively and cleverly placed in the concave portions 21 of the two large pitch wheels 2 in the front and back. Such a design enables the ends of the small pitch wheels 3 arranged on both sides of the large pitch wheel 2 to be inclined towards the concave portions 21 of the large pitch wheel 2. Through reasonable angular arrangement, the contour line at the connection of the large and small pitch wheels is successfully made continuous. The large and small pitch wheels are staggered and arranged on the hub 1, making the outer periphery of the hub 1 a complete circumferential wheel. Thus, the function of the omnidirectional wheel can be achieved with only a single hub 1, effectively reducing the vibration problem caused by the load alternating pulsation due to discontinuous contour lines. During the operation of the wheel, the influence of vibration on the equipment is reduced, the operation stability is significantly improved, the service life of the equipment is extended, and at the same time, the operation comfort of the equipment equipped with this wheel is also improved.

[0037] In addition, to ensure the continuity of the contour line at the connection of the large and small pitch wheels, in the embodiments of the present application, on the basis of designing six groups of large and small pitch wheels, the sizes of the large and small pitch wheels are also reasonably designed. Among them, the radius of the middle circular section of the large pitch wheel 2 is approximately twice that of the middle circular section of the small pitch wheel 3. The length of the rotating shaft of the small pitch wheel 3 is approximately three times that of the rotating shaft of the large pitch wheel 2. Through this precise size matching, the large and small pitch wheels rotate more smoothly when cooperating, further optimizing the performance of the omnidirectional wheel.

[0038] Triangular arrow-shaped treads are also provided on the large pitch wheel 2 and the small pitch wheel 3. This tread design can significantly increase the friction between the wheel and the ground. In actual application scenarios, whether driving on a smooth ground or a rough ground, the triangular arrow-shaped treads can provide better grip for the wheel, ensuring the stability and reliability of the wheel during omnidirectional movement, effectively preventing the wheel from slipping, and ensuring safe and stable operation in different environments.

[0039] In the specific implementation process of the present application, refer to Figure 5 , the structural design of the motor mechanism 4 is as follows:

[0040] The motor mechanism 4 includes a fixed shaft 41, an inner stator assembly 42, an outer rotor assembly 43, and a bearing assembly 44.

[0041] The fixed shaft 41 is the central fixed shaft 41 of the electric omnidirectional wheel. When the electric omnidirectional wheel is running, the fixed shaft 41 will be fixed. Its function is to bear the load of the hub 1 type electric omnidirectional wheel, and the fixed position of the fixed shaft 41 determines the forward and backward rotation directions of the electric omnidirectional wheel.

[0042] As an example, the inner stator assembly 42 includes a stator core 421 and a winding coil 422 wound around the stator core 421. The stator core 421 in the inner stator assembly 42 is fixedly connected to the fixed shaft 41 through a specific connection method to ensure the stability of the stator core 421 during motor operation. The bearing assembly 44 includes two groups, which are precisely arranged on both sides of the inner stator assembly 42 respectively. The outer rotor assembly 43 is connected to the fixed shaft 41 through the bearing assembly 44 and can rotate freely relative to the fixed shaft 41. The outer rotor assembly 43 is sleeved on the inner stator assembly 42 and can rotate freely relative to the inner stator assembly 42.

[0043] As an example, the outer rotor assembly 43 includes a housing 431 and a plurality of permanent magnets 432. The plurality of permanent magnets 432 are circumferentially distributed and embedded in the inner side of the housing 431. The housing 431 and the plurality of permanent magnets 432 are jointly sleeved on the stator core 421. The housing 431 in the outer rotor assembly 43 is fixedly connected to the hub 1 through a reliable connection method to ensure that the rotation of the outer rotor assembly 43 can effectively drive the hub type electric omnidirectional wheel to rotate.

[0044] When an electric current is applied to the coil 422 of the inner stator assembly 42, a magnetic field is generated around it due to the principle of electromagnetic induction. The permanent magnet 432 in the outer rotor assembly 43 is in this magnetic field. According to the Lorentz force law, the magnetic field will exert a force on the permanent magnet 432. Since the permanent magnet 432 is embedded inside the housing 431 of the outer rotor assembly 43, and the outer rotor assembly 43 is connected to the fixed shaft 41 through the bearing assembly 44 and can rotate relative to the inner stator assembly 42. Through the action of the magnetic field force on the permanent magnet 432, the outer rotor assembly 43 is driven to rotate around the inner stator assembly 42 and the fixed shaft 41. Also, because the housing 431 in the outer rotor assembly 43 is fixedly connected to the hub 1, the rotation of the outer rotor assembly 43 thus drives the entire hub-type electric omnidirectional wheel to rotate around the fixed shaft 41, thereby realizing the drive of the electric omnidirectional wheel. This drive method has a high energy conversion efficiency and can provide stable power output for the omnidirectional wheel. By controlling the direction of the current applied to the winding coil 422, the direction of the generated magnetic field is controlled, and further the forward and reverse rotation directions of the hub-type electric omnidirectional wheel are controlled.

[0045] In order to reduce the vibration problem caused by the discontinuous contour in the prior art omnidirectional wheels, generally two omnidirectional wheel hubs need to be spliced, and the knuckle wheels on the hubs are offset from each other to achieve the omnidirectional rotation function of the omnidirectional wheel. The hub-type electric omnidirectional wheel of this application only needs one hub to achieve the omnidirectional rotation of the omnidirectional wheel and can electronically control the rotation direction of the omnidirectional wheel. In the omnidirectional wheels of new energy electric vehicles, the friction drive ball wheel can achieve the rotation of the ball wheel in any direction and thus can achieve the omnidirectional movement of the vehicle.

[0046] In order to monitor the rotational speed of the electric omnidirectional wheel in real time, a wheel speed sensor is provided in the motor mechanism 4. The wheel speed sensor can accurately detect the rotational speed of the outer rotor assembly, and thus reflect the actual running speed of the electric omnidirectional wheel, providing data support for accurately controlling the motion state of the wheel. This information is of great significance for controlling the running state of the electric omnidirectional wheel, achieving precise speed adjustment and motion control, and further improving the stability and controllability of the motor drive.

[0047] For the embodiments of the present invention, it should also be noted that, without conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other to obtain new embodiments.

[0048] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. The protection scope of the present invention shall be subject to the protection scope of the claims. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art, without departing from the technical solution of the present invention, may make some changes or modifications to the above-disclosed technical content to form equivalent embodiments with equivalent changes. However, as long as it does not depart from the technical solution content of the present invention, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A hub-type electric omnidirectional wheel, characterized in that: The invention comprises a wheel hub (1), a plurality of large-segment wheels (2), a plurality of small-segment wheels (3) and a motor mechanism (4); the large-segment wheels (2) and the small-segment wheels (3) are arranged in a staggered manner along the circumferential direction of the wheel hub (1) at intervals from each other and are connected front and back to form a circumferential wheel; the motor mechanism (4) is embedded and installed in the wheel hub (1) to drive the wheel hub (1) to rotate.

2. The hub-type electric omnidirectional wheel according to claim 1, characterized in that: The large section wheel (2) and the small section wheel (3) are both arranged in the shape of a cylindrical wheel with a radius of a middle circular section larger than a radius of a circular section at both ends, and the radii of the circular sections at both ends of the middle circular section are symmetrical.

3. The hub-type electric omnidirectional wheel according to claim 1, characterized in that: Both ends of the large segment wheel (2) are provided with inner recesses (21), and both ends of the small segment wheel (3) are respectively placed in the inner recesses (21) of the front and rear large segment wheels (2).

4. The hub-type electric omnidirectional wheel according to claim 1, characterized in that: The number of the large segment wheels (2) and the number of the small segment wheels (3) are both six.

5. The hub-type electric omnidirectional wheel according to claim 4, characterized in that: The radius of the middle circular section of the large segment wheel (2) is approximately twice the radius of the middle circular section of the small segment wheel (3).

6. The hub-type electric omnidirectional wheel according to claim 4, characterized in that: The length of the rotation axis of the small segment wheel (3) is approximately three times that of the rotation axis of the large segment wheel (2).

7. The hub-type electric omnidirectional wheel according to claim 1, characterized in that: The large segment wheel (2) and the small segment wheel (3) are also provided with tread patterns.

8. The hub-type electric omnidirectional wheel according to claim 1, characterized in that: The motor mechanism (4) comprises a fixed shaft (41), an inner stator assembly (42), an outer rotor assembly (43) and a bearing assembly (44); the inner stator assembly (42) is fixedly connected to the fixed shaft (41); the outer rotor assembly (43) is rotatably connected to the fixed shaft (41) via the bearing assembly (44); the outer rotor assembly (43) is sleeved on the inner stator assembly (42) and rotates relative to the inner stator assembly (42); and the wheel hub (1) is fixedly connected to the outer rotor assembly (43).

9. The hub-type electric omnidirectional wheel according to claim 8, characterized in that: The inner stator assembly (42) comprises a stator core (421) and a coil 422() wound on the stator core (421); the outer rotor assembly (43) comprises a shell (431) and a plurality of permanent magnets (432), wherein the plurality of permanent magnets (432) are circumferentially distributed on the inner side of the shell (431); the shell (431) and the plurality of permanent magnets (432) are sleeved on the stator core (421), and the shell (431) is fixedly connected to the wheel hub (1).

10. The hub-type electric omnidirectional wheel according to claim 1, characterized in that: A wheel speed sensor is arranged in the motor mechanism (4).

Images