CN210309770U - Universal wheel and transport device comprising same - Google Patents

Abstract

The application discloses universal wheel and including its conveyer. The universal wheel comprises a wheel body, a wheel body support connected with a wheel body shaft, an intermediate support arranged on the wheel body support, and a wheel seat arranged on the intermediate support, wherein the wheel body support and the intermediate support form a first revolute pair, the wheel seat and the intermediate support form a second revolute pair, a rotating shaft of the first revolute pair penetrates through an installation center of the intermediate support and deviates from a radial center of the wheel body, a rotating shaft of the second revolute pair deviates from an installation center of the intermediate support and deviates from a radial center of the wheel body, and the diameter of the wheel body is smaller than or equal to 50 cm. According to the utility model provides a universal wheel has two revolute pairs that are used for turning to, and when the universal wheel turned to, two revolute pair combined action have reduced the sliding distance of wheel body, and then have reduced the resistance that turns to of universal wheel.

Description

Universal wheel and transport device comprising same

Technical Field

The application relates to the field of transportation devices, in particular to a universal wheel. The application also relates to a transport device comprising such a castor.

Background

The casters, also known as casters, are capable of rotating 360 degrees in a horizontal plane to enable the equipment carried to move in various directions. The universal wheel is widely applied to electronic equipment, medical equipment, logistics equipment and the like.

In the prior art, the center of the universal wheel body has an eccentricity with the horizontal rotation center, so that when the equipment turns, the universal wheel deviates from the running direction of the equipment and swings back to the running direction of the equipment. However, during the swinging back of the universal wheel, the wheel body can slide relatively to the ground along the movement direction of the equipment to generate large steering resistance.

SUMMERY OF THE UTILITY MODEL

In order to solve the problem, the utility model provides an universal wheel. According to the utility model discloses an universal wheel has two revolute pairs that are used for turning to, has reduced the resistance that turns to of universal wheel.

According to the utility model discloses the universal wheel of first aspect includes: the wheel body, with the wheel body support of wheel body hub connection installs intermediate support on the wheel body support, and install wheel seat on the intermediate support, the wheel body support with intermediate support forms first revolute pair, the wheel seat with intermediate support forms the second revolute pair, the pivot of first revolute pair passes the installation center of intermediate support and skew the radial center of wheel body, the pivot of second revolute pair is skew the installation center of intermediate support and skew the radial center of wheel body, the diameter of wheel body is less than or equal to 50 cm.

In one embodiment, a horizontal distance between the rotating shaft of the first rotating pair and the radial center of the wheel body is a first eccentricity, a horizontal distance between the rotating shaft of the second rotating pair and the rotating shaft of the first rotating pair is a second eccentricity, and the first eccentricity is smaller than the second eccentricity.

In one embodiment, the ratio of the first eccentricity to the radius of the wheel is between 1:3 and 1: 1.

In one embodiment, a ratio of the second eccentricity to the first eccentricity is greater than 1:1 and less than or equal to 2: 1.

In one embodiment, the wheel body has two independently rotatable sub-wheels.

In one embodiment, a balance support is further provided on the intermediate support, and the balance support and the top surface of the wheel seat together form a support surface.

In one embodiment, the mounting center of the balance support and the rotating shaft of the second rotating pair are equidistant from the rotating shaft of the first rotating pair.

In one embodiment, the top of the balance support is provided with a rolling member.

In one embodiment, the wheel body bracket and the intermediate bracket are connected through angular contact ball bearings, and the wheel seat and the intermediate bracket are connected through thrust ball bearings.

According to the utility model discloses conveyer of second aspect, include the automobile body and install the automobile body below according to the above universal wheel.

Compared with the prior art, the beneficial effects of the utility model are as follows: the utility model discloses an universal wheel has wheel body support and middle support to form first revolute pair and wheel seat and middle support formation second revolute pair. Thus, when the universal wheel turns, the wheel body bracket can rotate and drive the middle bracket to rotate correspondingly, and meanwhile, the wheel body bracket is applied with rotation driving force. Under the combined action of the friction force between the wheel body and the ground and the rotation driving force received by the wheel body support, the wheel body support and the wheel body can also rotate in a compliant manner, so that the backswing of the wheel body support and the wheel body is realized, and the steering of the universal wheel is further realized. During the whole steering process, the wheel body mainly rotates, and basically does not slide, so that the steering resistance of the universal wheel is greatly reduced, and the abrasion of the wheel body is reduced.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

fig. 1 is a schematic view of the overall structure of a universal wheel according to an embodiment of the present invention.

Fig. 2 is a sectional view a-a of fig. 1.

Fig. 3(a) to 3(d) are schematic views illustrating a steering process of the universal wheel.

Fig. 4 is a schematic view of the overall structure of a transportation device according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the technical solutions of the present application will be described in detail and completely with reference to the following specific embodiments of the present application and the accompanying drawings. It should be apparent that the described embodiments are only some of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Fig. 1 schematically shows a universal wheel 10 according to an embodiment of the invention. As shown in fig. 1, the universal wheel 10 includes a wheel body 1, a wheel body support 2, an intermediate support 3 mounted on the wheel body support 2, and a wheel seat 4 mounted on the intermediate support 3. The wheel body bracket 2 is connected with the wheel body 1 through a rotating shaft 11 so that the wheel body 1 can rotate. The wheel base 4 may be used in connection with the body 41 (shown in fig. 4) of a transportation device. The wheel body bracket 2 and the middle bracket 3 form a first rotating pair, the wheel seat 4 and the middle bracket 3 form a second rotating pair, a rotating shaft 21 of the first rotating pair penetrates through the installation center of the middle bracket 3 and deviates from a radial center 23 of the wheel body 1, and a rotating shaft 22 of the second rotating pair deviates from the installation center of the middle bracket 3 and deviates from the radial center 23 of the wheel body 1. For example, the shaft 22 of the second revolute pair passes through the edge of the intermediate bracket 3. It should be understood that the mounting center of the intermediate bracket 3 is not necessarily the geometric center of the intermediate bracket 3. It will be appreciated that the mounting centre for the intermediate bracket 3 is not necessarily the geometric centre of the intermediate bracket 3. However, preferably, when the intermediate bracket 3 is a centrosymmetric shape, such as a circle, a square, etc., the installation center may be a geometric center, so that the force of the intermediate bracket 3 is balanced to contribute to the stability of the vehicle body 41. Further, in other embodiments, when the intermediate bracket 3 has an asymmetric shape, the installation center may be the center of the fitting position of the intermediate bracket 3.

When the wheel seat 4 receives steering force, the intermediate bracket 3 is driven to rotate similarly. While the intermediate bracket 3 rotates, a rotational driving force is applied to the wheel body bracket 2. Under the combined action of the friction force between the wheel body 1 and the ground and the rotational driving force, the wheel body bracket 2 and the wheel body 1 also rotate in compliance. In this way, the wheel body bracket 2 and the wheel body 1 swing back, and the universal wheel 10 is steered. It can be seen that the wheel body 1 mainly rotates without sliding substantially during the entire steering process, which greatly reduces the steering resistance of the universal wheel 10 and reduces the wear of the wheel body 1.

In one embodiment, the diameter of the wheel 1 is less than or equal to 50 cm. The inventor finds that the wheel body 1 with a smaller diameter, such as the wheel body 1 with the size of more than or equal to 2cm and less than or equal to 10cm, has smaller mass and flexible rotation, and is particularly suitable for smaller transportation devices or robots; and for the wheel body 1 with larger diameter, for example, the wheel body 1 with the size of more than 10cm and less than or equal to 50cm, the load capacity can reach several tons, which is suitable for large transportation devices or large robots with larger weight.

Preferably, the wheel body 1 has two sub-wheels 31, 32 capable of independently rotating, as shown in fig. 3 (a). When the universal wheel 10 is steered, the steering can be completed by rolling of the sub-wheels 31 and 32, which can further reduce the turning resistance of the universal wheel 10.

Preferably, the rotation shaft 21 of the first rotation pair and the rotation shaft 22 of the second rotation pair are parallel to each other, for example, both in the vertical direction. In this way, the universal wheel 10 can be adapted to most transportation devices, and the radial force applied to the first and second revolute pairs can be greatly reduced, which contributes to increasing the service life of the universal wheel 10.

Preferably, the wheel body support 2 and the intermediate support 3 are connected by angular contact ball bearings 6, and the wheel seat 4 and the intermediate support 3 are connected by thrust ball bearings 7. The inventors have found that the radial forces between the wheel seat 4 and the intermediate support 3 are small, whereas the radial forces between the wheel body support 2 and the intermediate support 3 are large, and that different bearings are used in order to withstand different radial forces. In this case, the connection of the wheel body support 2 to the intermediate support 3 can be realized in the following manner: a bearing chamber 26 is constructed on the intermediate bracket 3, then the angular ball bearing 6 is installed in the bearing chamber 26, and then the bolt 24 (corresponding to the rotary shaft 21) having one end connected to the wheel body bracket 2 is installed together with the angular ball bearing 6. For the connection of the wheel base 4 to the intermediate support 3: an insert rod 25 (corresponding to the rotating shaft 22) is formed on the wheel seat 4, and a bearing chamber 27 is formed at the edge of the intermediate bracket 3 (at a position deviated from the bearing chamber 26); the thrust ball bearing 7 is arranged in the bearing chamber 27, and the inserted rod 25 and the thrust ball bearing 7 are arranged together, so that the wheel seat 4 and the middle bracket 3 are connected.

As shown in FIG. 2, the horizontal distance between the rotating shaft 21 of the first rotating pair and the radial center 23 of the wheel body 1 is a first eccentricity D1, the horizontal distance between the rotating shaft 22 of the second rotating pair and the rotating shaft 21 of the first rotating pair is a second eccentricity D2, and the first eccentricity D1 is smaller than the second eccentricity D2. This makes the swing amplitude of the universal wheel 10 smaller than the swing amplitude of the vehicle body 41, and the turning of the universal wheel 10 is not hindered for the transportation device 40 using the universal wheel 10 as long as the size of the vehicle body 41 matches the width of the predetermined space. Thus, the user only needs to consider the vehicle body size and the use space width as a whole when using the transporting device 40, which greatly facilitates the use.

In a preferred embodiment, the ratio of the second eccentricity D2 to the first eccentricity D1 is greater than 1:1 and less than or equal to 2: 1. With this structure, when the universal wheel 10 is steered, the wheel seat 4 and the intermediate bracket 3 can be rotated with a small force, and thus the steering of the universal wheel 10 can be easily achieved. More importantly, with this structure, when the universal wheel 10 is steered, the swing amplitude of the vehicle body 41 is small, and the stability of the vehicle body 41 is high, which is very important for a transportation device for transporting precision equipment.

In another preferred embodiment, the ratio of the first eccentricity D1 to the radius R of the wheel 1 is between 1:3 and 1: 1. With this structure, the area occupied by the oscillation of the wheel body 1 when the universal wheel 10 is steered is small, so that the transportation apparatus 40 (shown in fig. 4) with such a universal wheel 10 can be used even in a narrow space.

Returning to fig. 1, a balance support 5 is also provided on the intermediate frame 3, the balance support 5 forming a support surface together with the top surface of the wheel seat 4. For example, the extension height of the balancing support 5 is equal to the extension height of the wheel seat 4. When the universal wheel 10 is applied to the transportation device 40, the balance support 5 and the wheel seat 4 simultaneously support the vehicle body 41 of the transportation device 40, thereby further improving the stability of the vehicle body 41 or the transportation device 40. In a preferred embodiment, the top of the balance support 5 is provided with rolling members 12. The rolling members 12 may be, for example, balls or rollers. The rolling members 12 can reduce the frictional force between the balance support 5 and the vehicle body 41 when the universal wheel 10 is steered, thereby reducing the steering resistance of the universal wheel 10.

In a preferred embodiment, the balancing support 5 and the wheel seat 4 are equidistant from the axis of rotation 21 of the first revolute pair. The intermediate frame 3 is formed like a seesaw with the rotation shaft 21 (or the bolt 24) as a fulcrum, and the balance support 5 and the wheel holder 4 are at both ends of the seesaw and are at the same distance from the rotation shaft 21 as a whole. In this way, the torque received by the thrust ball bearing 7 is reduced, thereby further improving the stability of the vehicle body 41 or the transportation device 40.

Fig. 3(a) to 3(d) schematically show the steering process of the universal wheel 10. In the state of fig. 3(a), the moving direction of the transporting device 40 is shown as V. In the state of fig. 3(a), the wheel body support 2, the intermediate support 3, and the wheel seat 4 of the universal wheel 10 are in a stressed state. The wheel base 4 is forced in the direction of movement V to rotate in the direction of movement V, and at the same time, it drives the intermediate frame 3 to rotate in the same direction. The rotation of the intermediate bracket 3 will apply a rotational driving force to the wheel body bracket 2. Under the combined action of the friction force between the wheel body 1 and the ground and the rotational driving force, the wheel body bracket 2 and the wheel body 1 also rotate in compliance, so that the wheel body 1 swings back towards the moving direction V, as shown in fig. 3(b) and 3 (c). Finally, the wheel body 1 and the wheel seat 4 rotate to the direction of the moving direction V, and the universal wheel 10 completes the steering, as shown in fig. 3 (d). During the entire steering process of the universal wheel 10, under the rotation of the intermediate bracket 3 and the wheel seat 4, the contact point of the wheel body 1 with the ground is maintained on the straight line L parallel to the moving direction V without slippage, and thus the steering resistance of the universal wheel 10 is greatly reduced. In addition, the wheel body 1 is provided with two sub-wheels 31 and 32 which can rotate independently, so that the steering of the universal wheel 10 can be completed through the rolling of the sub-wheels 31 and 32, and the rotation resistance of the universal wheel 10 can be further reduced.

Fig. 4 schematically shows a transport device 40 according to an embodiment of the invention. As shown in fig. 4, the transport device 40 comprises a vehicle body 41 and a universal wheel 10 according to the above mounted under the vehicle body 41. As shown in fig. 4, the transport device 40 has two universal wheels 10 and two orienting wheels 42. Under the combined action of the universal wheels 10 and the directional wheels 42, the transportation device 40 can be conveniently steered, the running precision of the transportation device 40 can be improved, and the use by a user is facilitated.

The above description is only an example of the present application and is not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims (10)

1. A universal wheel, comprising: the wheel body, a wheel body bracket connected with the wheel body shaft, a middle bracket arranged on the wheel body bracket, and a wheel seat arranged on the middle bracket, wherein the wheel body bracket and the middle bracket form a first revolute pair, and the wheel seat and the middle bracket form a second revolute pair,

the rotating shaft of the first rotating pair penetrates through the mounting center of the middle bracket and deviates from the radial center of the wheel body, the rotating shaft of the second rotating pair deviates from the mounting center of the middle bracket and deviates from the radial center of the wheel body,

the diameter of the wheel body is less than or equal to 50 cm.

2. The universal wheel of claim 1, wherein the horizontal distance between the rotational axis of the first revolute pair and the radial center of the wheel body is a first eccentricity, and the horizontal distance between the rotational axis of the second revolute pair and the rotational axis of the first revolute pair is a second eccentricity, and the first eccentricity is smaller than the second eccentricity.

3. The castor wheel of claim 2, wherein the ratio of the first eccentricity to the radius of the wheel body is between 1:3 and 1: 1.

4. A castor according to claim 2 or claim 3, wherein the ratio of the second eccentricity to the first eccentricity is greater than 1:1 and less than or equal to 2: 1.

5. A castor according to claim 1 or claim 2, wherein the body has two independently rotatable sub-wheels.

6. The universal wheel according to claim 1 or 2, wherein a balance support is further provided on the intermediate frame, and the balance support and the top surface of the wheel seat together form a support surface.

7. The universal wheel of claim 6, wherein the mounting center of the balance support and the axis of rotation of the second revolute pair are equidistant from the axis of rotation of the first revolute pair.

8. The universal wheel of claim 6, wherein the top of the balance support is provided with rolling members.

9. The universal wheel according to claim 6, wherein the wheel body holder and the intermediate holder are connected by angular contact ball bearings, and the wheel holder and the intermediate holder are connected by thrust ball bearings.

10. A transportation device comprising a vehicle body and a castor according to any preceding claim mounted beneath the vehicle body.

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