Double-degree-of-freedom knuckle bearing

Abstract

The utility model relates to the technical field of bearings, in particular to a double-degree-of-freedom knuckle bearing which comprises a bearing outer ring and a bearing inner ring, the bearing outer ring is used for being arranged on the outer side of the bearing inner ring in a sleeved mode, a square groove is formed in the inner wall of the bearing outer ring, and the square groove is arranged in the radial direction of the inner wall ring of the bearing outer ring. A pin is connected into the square groove in a sliding mode, the pin can slide along the square groove, the pin is in transmission connection with the bearing inner ring, and the bearing inner ring makes deflection motion in the direction perpendicular to the axis with the pin as the axis. According to the double-degree-of-freedom knuckle bearing, deflection movement of the bearing inner ring with the pin as the axis is achieved, deflection of the bearing inner ring is limited on the same axis through the pin, the bearing can only flexibly move on the two degrees of freedom, and the adaptability and flexibility of the knuckle bearing to a robot which only needs two-dimensional rotation are enhanced.

Description

Technical Field

[0001] The utility model relates to the technical field of bearings, in particular to a spherical plain bearing with two degrees of freedom. Background Art

[0002] A spherical plain bearing is a kind of spherical sliding bearing, whose sliding contact surfaces are an inner spherical surface and an outer spherical surface. During movement, it can rotate or swing at any angle within a certain range. Spherical plain bearings are widely used in industries such as engineering hydraulic cylinders, forging machine tools, construction machinery, automation equipment, automotive shock absorbers, and water conservancy machinery.

[0003] However, in bionic robots, when a spherical plain bearing is installed at the ankle joint of the robot's foot, the spherical plain bearing only requires rotation or swing in two dimensions, and multi-directional swing and rotation will instead affect the rotation and swing of the ankle. Summary of the Utility Model

[0004] To solve the problem that when a spherical plain bearing is installed at the ankle joint of the robot's foot in the prior art, the spherical plain bearing only requires rotation or swing in two dimensions, and multi-directional swing and rotation will instead affect the rotation and swing of the ankle, this application provides a spherical plain bearing with two degrees of freedom, and the specific solution is as follows.

[0005] A spherical plain bearing with two degrees of freedom includes an outer bearing ring and an inner bearing ring. The outer bearing ring is used to sleeved on the outside of the inner bearing ring. A square groove is formed on the inner wall of the outer bearing ring. The square groove is arranged along the circumferential direction of the inner wall of the outer bearing ring. A pin is slidably connected in the square groove. The pin can slide along the square groove. The pin is drivingly connected with the inner bearing ring. The inner bearing ring takes the pin as the axis and swings in a direction perpendicular to the axis.

[0006] By adopting the above technical solution, the spherical plain bearing with two degrees of freedom realizes the swinging movement of the inner bearing ring with the pin as the axis. By restricting the swing of the inner bearing ring to one axis with the pin, the bearing can only move flexibly in two degrees of freedom, enhancing the adaptability and flexibility of the spherical plain bearing for robots that only require rotation in two dimensions. During specific installation, the outer bearing ring can be designed integrally with the assembly seat, which can reduce weight and space occupancy.

[0007] Optionally, the pins are respectively arranged on both sides of the outer bearing ring, and the pins are symmetrically arranged along the center of the outer bearing ring.

[0008] By adopting the above technical solution, arranging the pins on both sides of the outer bearing ring and symmetrically along the center can ensure the balanced swing of the inner bearing ring on the pins, improving the stability and service life of the spherical plain bearing.

[0009] Optionally, blind holes are provided on both sides of the inner ring of the bearing corresponding to the pins, and the pins are used to be embedded in the blind holes and have an interference fit with the inner ring of the bearing.

[0010] By adopting the above technical solution, there is an interference fit between the pins and the blind holes, making the connection between the inner ring of the bearing and the pins more firm and reliable, avoiding unnecessary loosening or detachment during relative movement, and improving the working stability and service life of the entire spherical bearing.

[0011] Optionally, an assembly auxiliary hole is also provided on the outer ring of the bearing corresponding to the shape of the pins. The assembly auxiliary hole penetrates through the outer ring of the bearing and communicates with the square groove, and the assembly auxiliary hole is for the pins to extend into.

[0012] By adopting the above technical solution, with the design of adding the assembly auxiliary hole, the pins can be inserted into the square groove more conveniently, thus simplifying the assembly process and improving the assembly efficiency; at the same time, the pins can be accurately aligned and inserted into the square groove, and this design ensures the position accuracy of the pins during installation, further enhancing the overall stability of the device.

[0013] Optionally, a nylon plug is provided in the assembly auxiliary hole. The nylon plug is detachably connected to the outer ring of the bearing, and the nylon plug is used to block the assembly auxiliary hole.

[0014] By adopting the above technical solution, setting the nylon plug to be detachably connected to the outer ring of the bearing and blocking the assembly auxiliary hole can not only block the pins in the square groove, reduce the situation of the pins coming out, but also effectively prevent external impurities from entering the inside of the assembly auxiliary hole, ensure the stability during the pin assembly process, and is convenient for maintenance and disassembly at the same time.

[0015] Optionally, two key grooves are also provided on the inner ring of the bearing. The key grooves are symmetrically arranged along the axis of the inner ring of the bearing, and the key grooves are perpendicular to the blind holes.

[0016] By adopting the above technical solution, the key grooves can cooperate with the installation of the bionic robot, thereby improving the convenience and stability during installation.

[0017] Optionally, a sealing ring is also provided between the inner ring and the outer ring of the bearing. The sealing rings are respectively arranged on both sides of the outer ring of the bearing.

[0018] By adopting the above technical solution, since lubricating grease usually needs to be applied between the inner ring and the outer ring of the bearing, setting the sealing ring can not only prevent dust, but also play a role in preventing the lubricating grease from overflowing.

[0019] Optionally, a notch is also provided on the outer ring of the bearing. The notch is for the inner ring of the bearing to be inserted into.

[0020] By adopting the above technical solutions, a notch design on the outer ring of the bearing is added, which facilitates the installation and disassembly of the inner ring of the bearing and improves the assembly efficiency.

[0021] In summary, the present application has at least the following beneficial effects:

[0022] 1. The present application solves the problem that when a spherical plain bearing is installed at the ankle joint of a robot foot in the prior art, the spherical plain bearing only rotates or swings in two dimensions, and the multi-directional swing and rotation will instead affect the rotation and swing of the ankle. The present application realizes the yaw movement of the inner ring relative to the outer ring in a direction perpendicular to the axis by providing a square groove on the inner wall of the outer ring and slidably connecting a pin in the square groove, and making the pin drive-connected to the inner ring, thereby realizing the two-degree-of-freedom movement of the spherical plain bearing, and being able to better cooperate with the installation on a bionic robot.

[0023] 2. The present application also simplifies the assembly process and reduces the manufacturing cost by providing an assembly auxiliary hole on the outer ring that communicates with the square groove, which facilitates the installation and disassembly of the pin.

[0024] 3. The present application further reduces the leakage of grease and can also play a dust-proof role by providing a sealing ring and a nylon plug to seal the outer ring of the bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a cross-sectional view in this embodiment.

[0026] Figure 2 is a cross-sectional view in this embodiment.

[0027] Figure 3 is a cross-sectional view in this embodiment.

[0028] Figure 4 is a front view of the outer ring of the bearing in this embodiment.

[0029] DESCRIPTION OF THE REFERENCE NUMERALS:

[0030] 1. Outer ring of the bearing; 12. Square groove; 121. Pin; 13. Assembly auxiliary hole; 131. Nylon plug; 14. Sealing ring; 15. Notch;

[0031] 2. Inner ring of the bearing; 21. Blind hole; 22. Keyway. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] The following further details the present application through specific embodiments in conjunction with the accompanying drawings.

[0033] A spherical plain bearing with two degrees of freedom, as Figure 1 and Figure 2As shown in the figure, it includes an outer bearing ring 1 and an inner bearing ring 2. The outer bearing ring 1 is used to sleeved on the outside of the inner bearing ring 2. A square groove 12 is provided on the inner wall of the outer bearing ring 1. The square groove 12 is arranged along the circumferential direction of the inner wall of the outer bearing ring 1. A pin 121 is slidably connected in the square groove 12. The pin 121 can slide along the square groove 12. The pin 121 is in transmission connection with the inner bearing ring 2. The inner bearing ring 2 swings with the pin 121 as the axis and perpendicular to the axis direction. In specific implementation, the outer bearing ring 1 and the assembly seat for assembling the robot leg can be designed as an integral body, which can reduce the weight and space occupation. Since the pin 121 forms a limit with the square groove 12 and also forms a limit with the inner bearing ring 2, the pin 121 can slide along the square groove 12 but cannot swing. The inner bearing can rotate circumferentially with the pin 121, but can only swing with the pin 121 as the axis. Thus, the spherical plain bearing as a whole can only rotate and swing in two dimensions, which better meets the working requirements of the bionic robot. In other embodiments, the pin 121 can also be replaced by a ball. The ball can also play a role in limiting the inner bearing ring 2, and the ball can also enable the inner bearing ring 2 to swing along the axis of its ball center.

[0034] As Figure 1 shown, the pins 121 are respectively arranged on both sides of the outer bearing ring 1. The pins 121 are symmetrically arranged along the center of the outer bearing ring 1. In specific implementation, the pins 121 on both sides limit the outer bearing ring 1 at the same time, reducing the situation that the inner bearing ring 2 falls off the pins 121 and affects the swing. In other embodiments, a limiting groove can also be provided in the square groove 12 to limit the pins 121, reducing the situation of the pins 121 falling off and further improving the stability after installation.

[0035] As Figure 1 and Figure 3 shown, blind holes 21 corresponding to the pins 121 are provided on both sides of the inner bearing ring 2. The pins 121 are used to be embedded in the blind holes 21 and are in interference fit with the inner bearing ring 2. In specific implementation, after the pins 121 are inserted into the blind holes 21, the rotation of the inner bearing can be further restricted, improving the stability of the transmission connection.

[0036] As Figure 1As shown, an assembly auxiliary hole 13 corresponding to the shape of the pin 121 is also provided on the outer ring 1 of the bearing. The assembly auxiliary hole 13 penetrates through the outer ring 1 of the bearing and communicates with the square groove 12. The assembly auxiliary hole 13 is for the pin 121 to extend into. A nylon plug 131 is arranged in the assembly auxiliary hole 13. The nylon plug 131 is detachably connected to the outer ring 1 of the bearing, and the nylon plug 131 is used to block the assembly auxiliary hole 13. During specific implementation, one of the pins 121 needs to be installed first, then the inner ring 2 of the bearing is installed, and subsequently the nylon plug 131 is installed, thus completing the installation, improving the convenience and stability of the installation, and also being able to achieve a dust-proof effect. In other embodiments, the pin 121 and the outer ring 1 of the bearing can also be directly integrally cast.

[0037] As Figure 1 and Figure 3 shown, two key grooves 22 are also provided on the inner ring 2 of the bearing. The key grooves 22 are symmetrically arranged along the axis of the inner ring 2 of the bearing, and the key grooves 22 are perpendicular to the blind hole 21. During specific implementation, the key grooves 22 can cooperate with the installation of bionic robot parts.

[0038] As Figure 1 shown, a sealing ring 14 is also arranged between the inner ring 2 and the outer ring 1 of the bearing. The sealing rings 14 are respectively arranged on both sides of the outer ring 1 of the bearing. During specific implementation, the sealing ring 14 can block dust and also block the leakage of grease, improving stability.

[0039] As Figure 4 shown, a notch 15 is also provided on the outer ring 1 of the bearing. The notch 15 is for the inner ring 2 of the bearing to be inserted. During specific implementation, the notch 15 facilitates the insertion of the inner ring 2 of the bearing.

[0040] Working principle: The spherical plain bearing only needs two-dimensional rotation or swing. Multi-directional swing and rotation will instead cause problems that the rotation and swing of the ankle are affected. In this application, by providing a square groove 12 on the inner wall of the outer ring and slidingly connecting a pin 121 in the square groove 12, and making the pin 121 drive-connected to the inner ring, a yaw motion of the inner ring relative to the outer ring in a direction perpendicular to the axis is realized, thus realizing the two-way degree-of-freedom motion of the spherical plain bearing.

[0041] The above are the preferred embodiments of this application. The protection scope of this application is not limited thereby. Therefore, all equivalent changes made according to the structure, shape, and principle of this application should be covered within the protection scope of this application.

Claims

1. A spherical plain bearing with two degrees of freedom, characterized in that: It includes an outer bearing ring (1) and an inner bearing ring (2). The outer bearing ring (1) is used to sleeved on the outside of the inner bearing ring (2). A square groove (12) is formed on the inner wall of the outer bearing ring (1). The square groove (12) is arranged radially along the inner wall of the outer bearing ring (1). A pin (121) is slidably connected in the square groove (12). The pin (121) can slide along the square groove (12). The pin (121) is in transmission connection with the inner bearing ring (2). The inner bearing ring (2) swings with the pin (121) as the axis and perpendicular to the axis direction.

2. The spherical plain bearing with two degrees of freedom according to claim 1, characterized in that: The pins (121) are respectively arranged on both sides of the outer bearing ring (1). The pins (121) are symmetrically arranged along the center of the outer bearing ring (1).

3. The spherical plain bearing with two degrees of freedom according to claim 2, characterized in that: Blind holes (21) are correspondingly arranged on both sides of the inner bearing ring (2) corresponding to the pins (121). The pins (121) are used to be embedded in the blind holes (21) and have an interference fit with the inner bearing ring (2).

4. A spherical plain bearing with two degrees of freedom according to claim 3, characterized in that: An assembly auxiliary hole (13) is also formed on the outer bearing ring (1) corresponding to the shape of the pin (121). The assembly auxiliary hole (13) penetrates through the outer bearing ring (1) and is communicated with the square groove (12). The assembly auxiliary hole (13) is for the pin (121) to extend into.

5. A spherical plain bearing with two degrees of freedom according to claim 4, characterized in that: A nylon plug (131) is arranged in the assembly auxiliary hole (13). The nylon plug (131) is detachably connected to the outer bearing ring (1). The nylon plug (131) is used to block the assembly auxiliary hole (13).

6. A spherical plain bearing with two degrees of freedom according to claim 3, characterized in that: Two key grooves (22) are also formed on the inner bearing ring (2). The key grooves (22) are symmetrically arranged along the axis of the inner bearing ring (2). The key grooves (22) are perpendicular to the blind holes (21).

7. A spherical plain bearing with two degrees of freedom according to claim 1, characterized in that: A sealing ring (14) is also arranged between the inner bearing ring (2) and the outer bearing ring (1). The sealing rings (14) are respectively arranged on both sides of the outer bearing ring (1).

8. A spherical plain bearing with two degrees of freedom according to claim 1, characterized in that: A notch (15) is also formed on the outer bearing ring (1). The notch (15) is for the inner bearing ring (2) to be inserted.

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