High-load high-precision universal joint

Abstract

The utility model provides a high-load high-precision universal joint, which relates to the technical field of universal joints, and comprises a mounting seat and a rotating body, the rotating body comprises a ball body and rotating rods, and the rotating rods are symmetrically connected to two sides of the ball body and are integrally formed with the ball body; a bearing hole which is coaxial with the ball and penetrates through the ball is formed in the ball, a first needle bearing is arranged in the bearing hole, and the surfaces, located at the two ends of the bearing hole, of the ball are planes flush with the end face of the first needle bearing. The axis of the rotating rod perpendicularly intersects with the axis of the bearing hole, a receding opening matched with the ball is formed in the bottom of the mounting base, a mounting hole matched with the end, away from the ball, of the rotating rod and communicated with the receding opening is further formed in the mounting base, and the end, away from the ball, of the rotating rod is mounted in the corresponding mounting hole through a second needle bearing coaxial with the rotating rod. A mounting rod is arranged on the side, away from the receding opening, of the mounting base, and in the normal state, the axes of the mounting rod, the rotating rod and the first needle bearing perpendicularly intersect with one another. The utility model has the characteristics of high precision, high load, high sensitivity and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of universal joints, in particular to a high-load and high-precision universal joint. Background Technique

[0002] In the connection of the body limbs of a humanoid robot, a roller screw structure is required to drive the screw for linear motion, so that the screw drives the output rod to move synchronously, realizing the output of thrust or tension. Among them, a universal joint such as a spherical bearing or a cross bearing is usually used at one end of the output rod far from the screw to connect with other link structures, so as to realize the movement of the body limbs of the humanoid robot through overall linkage. However, in the actual use process, due to the excessive degrees of freedom of the spherical bearing and the cross bearing, when pushing and pulling forces are output, there will be shaking at other angles, sacrificing a certain axial accuracy and not fully meeting the required axial accuracy requirements. Therefore, it is necessary to design a high-load and high-precision universal joint to avoid sacrificing axial accuracy, with the characteristics of high precision, high load, high sensitivity, etc., to meet the usage requirements in the connection of the body limbs of the humanoid robot. Content of the Utility Model

[0003] The purpose of the utility model is to provide a high-load and high-precision universal joint, which has degrees of freedom in two directions, avoids axial accuracy deviation when pushing and pulling forces are output, has the characteristics of high precision, high load, high sensitivity, etc., and can meet the usage requirements in the connection of the body limbs of the humanoid robot.

[0004] The above technical purpose of the utility model is achieved through the following technical solutions:

[0005] A high-load and high-precision universal joint includes a mounting seat and a rotating body. The rotating body includes a sphere and rotating rods symmetrically connected to both sides of the sphere, and the rotating rods are integrally formed with the sphere. A bearing hole coaxial with and penetrating the sphere is provided in the sphere. A first needle roller bearing is provided in the bearing hole, and the surfaces of the sphere at both ends of the bearing hole are planes flush with the end faces of the first needle roller bearing. The axis of the rotating rod is perpendicular to and intersects with the axis of the bearing hole. A relief opening for mating with the sphere is provided at the bottom of the mounting seat. An installation hole for mating with the end of the rotating rod far from the sphere and communicating with the relief opening is also provided on the mounting seat. The end of the rotating rod far from the sphere is installed in the corresponding installation hole through a second needle roller bearing coaxial with it. An installation rod is provided on one side of the mounting seat far from the relief opening, and normally, the axes of the installation rod, the rotating rod, and the first needle roller bearing are perpendicular to and intersect with each other.

[0006] By adopting the above technical solution, the mounting seat is connected to an external structure such as a lead screw through a mounting rod, and two rotating rods are installed on the mounting seat through two second needle bearings, so that the entire rotating body can rotate around the second needle bearings, and the external output mechanism is connected to the sphere through the first needle bearing, and when the lead screw drives the mounting seat to move as a whole to output thrust and pull, the external mechanism performs circular motion around the first needle bearing. In this way, the entire universal joint has two degrees of freedom when in use: rotation around the axis of the first needle bearing and rotation around the axis of the second needle bearing, thereby ensuring that there will be no shaking in other directions when outputting push and pull forces, resulting in loss of axial accuracy. The first needle bearing and the second needle bearing are used for transmission, which has high transmission accuracy, strong load capacity, and a small starting torque, which makes the sensitivity also high, thereby meeting the use requirements in the connection of the limbs of the humanoid robot.

[0007] Further, the first needle roller bearing includes a first needle roller cage coaxial therewith, the outer ring of the first needle roller cage is installed in the bearing hole, the inner ring of the first needle roller cage is equipped with a plurality of first needle rollers in a circular array around its axis, and the plurality of first needle rollers are arranged along the axis direction of the first needle roller bearing, and when the first needle roller bearing is connected to the output mechanism, the outer walls of the plurality of first needle rollers are rollingly connected to the outer wall of the output mechanism.

[0008] By adopting the above technical solution, the first needle roller bearing includes a first needle roller cage and a plurality of first needle rollers. The first needle roller cage is used to realize the installation and axial limitation of the plurality of first needle rollers, and the entire first needle roller bearing has no inner ring. After installation, the output mechanism is directly connected to the first needle roller in a rolling manner, which can not only reduce the volume and weight of the first needle roller bearing, but also improve the transmission accuracy and reduce the loss.

[0009] Furthermore, both ends of the first needle roller retainer are respectively provided with limit retaining rings cooperating therewith, and the limit retaining rings are installed on the plane of the sphere.

[0010] By adopting the above technical solution, the limit rings at both ends of the first needle roller retainer realize axial limitation of the first needle roller bearing from both ends, thereby avoiding axial displacement of the first needle roller bearing during use. The plane of the sphere facilitates the installation of the limit ring, and the large installation contact surface can ensure the limiting stability.

[0011] Furthermore, the second needle roller bearing includes a second needle roller retainer coaxial therewith, the outer ring of the second needle roller retainer is interference mounted in the corresponding mounting hole, the inner ring of the second needle roller retainer is arrayed with a plurality of second needle rollers around its axis, the plurality of second needle rollers are arranged along the axis direction of the second needle roller bearing, and the outer walls of the plurality of second needle rollers are rollingly connected to the outer walls of the corresponding rotating rods.

[0012] By adopting the above technical solution, the second needle roller bearing includes a second needle roller cage and a number of second needle rollers. The second needle roller cage is used to realize the installation and axial limit of the number of second needle rollers, and the whole second needle roller bearing has no inner ring. The number of second needle rollers is directly in rolling connection with the outer wall of the corresponding rotating rod, which can not only reduce the volume and weight of the second needle roller bearing, but also improve the transmission accuracy and reduce the loss. Among them, the outer ring of the second needle roller cage is installed in the corresponding installation hole by interference fit, which can prevent the second needle roller bearing from axially shifting, and there is no need to additionally set other axial limit structures.

[0013] Further, the mounting seat includes a first mounting body, a second mounting body and a third mounting body. One of the mounting holes and the mounting rod are both arranged on the first mounting body. The second mounting body and the third mounting body are symmetrically arranged and divide the other mounting hole into two halves symmetrically. The second mounting body and the third mounting body are installed and connected between them, and the second mounting body or the third mounting body is integrally formed with the first mounting body.

[0014] By adopting the above technical solution, the second mounting body and the third mounting body are symmetrically arranged and installed and connected, and one of them is integrally formed with the first mounting body. In this way, the whole mounting seat is a split structure, which is convenient for installing the rotating body on the mounting seat, and the split structure of this kind can ensure the overall strength of the mounting seat, and is more convenient for the installation and connection between the second mounting body or the third mounting body and the first mounting body.

[0015] Further, at least two groups of mutually matching positioning holes and at least two groups of mutually matching locking holes are provided on the second mounting body and the third mounting body. A pin is inserted into the positioning hole, and a screw is installed in the locking hole, and at least two groups of locking holes are respectively located on the upper and lower sides of the corresponding mounting hole.

[0016] By adopting the above technical solution, under the combined action of at least two groups of positioning holes and pins, the positioning of the second mounting body and the third mounting body is realized, which is convenient for locking the screw into the locking hole to realize the fixed connection between the second mounting body and the third mounting body.

[0017] Further, an adjusting gasket is provided between the mating surfaces of the second mounting body and the third mounting body, and the adjusting gasket is located on the upper and lower sides of the corresponding mounting hole.

[0018] By adopting the above technical solution, the locking degree of the mating surfaces of the second mounting body and the third mounting body is ensured by using the adjusting gasket, so as to ensure the installation hole after the combination of the second mounting body and the third mounting body for the precise assembly of the second needle roller bearing.

[0019] Further, the mounting rod is a threaded rod or a smooth rod. When the mounting rod is a threaded rod, a positioning protrusion is provided at the outer thread near the tail end of the mounting seat. When the mounting rod is a smooth rod, a positioning groove coaxial with it is provided around one end near the mounting seat.

[0020] By adopting the above technical solution, when the mounting rod is a threaded rod, it is connected to an external driving structure such as a lead screw through a threaded connection, and when the mounting rod is a smooth rod, it is connected to an external driving structure such as a lead screw through a key, a pin, etc. The positioning protrusion or the positioning groove realizes the positioning of the mounting rod during installation, ensuring the installation accuracy of the mounting rod.

[0021] In summary, the utility model has the following beneficial effects:

[0022] 1. In the utility model, the mounting seat is connected to an external structure such as a lead screw through a mounting rod, and two rotating rods are mounted on the mounting seat through two second needle roller bearings, so that the entire rotating body can rotate around the second needle roller bearing, and the external output mechanism is connected to the spherical body through the first needle roller bearing. When the lead screw drives the mounting seat to move as a whole to output thrust and pull, the external mechanism performs circular motion around the first needle roller bearing; the entire universal joint has two degrees of freedom of rotation around the axis of the first needle roller bearing and the axis of the second needle roller bearing when in use, thereby ensuring that there will be no shaking in other directions when outputting push and pull forces, resulting in loss of axial precision, and the use of the first needle roller bearing and the second needle roller bearing for transmission has high transmission precision, strong load capacity, and a small starting torque, which makes the sensitivity also high, so it can meet the use requirements in the connection of the limbs of the humanoid robot;

[0023] 2. The mounting seat in the utility model includes a first mounting body, a second mounting body and a third mounting body, and the second mounting body and the third mounting body are symmetrically arranged and installed and connected, and one of them is integrally formed with the first mounting body, so that the entire mounting seat is a split structure, which is convenient for installing the rotating body on the mounting seat, and the split structure of this structure can ensure the overall strength of the mounting seat, and is more convenient for the installation and connection of the second mounting body or the third mounting body with the first mounting body. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the overall structure of a high-load and high-precision universal joint, in which the mounting rod is a threaded rod;

[0025] Figure 2 It is a schematic diagram of the exploded structure of a high-load and high-precision universal joint;

[0026] Figure 3 This is a cross-sectional view of a high-load, high-precision universal joint;

[0027] Figure 4 It is a schematic diagram of the overall structure of a high-load and high-precision universal joint, in which the mounting rod is a bare rod.

[0028] In the figure, 1 is the mounting base; 11 is the first mounting body; 12 is the second mounting body; 13 is the third mounting body; 14 is the relief opening; 15 is the mounting hole; 16 is the positioning hole; 17 is the locking hole; 18 is the pin; 19 is the screw; 2 is the rotating body; 3 is the sphere; 31 is the bearing hole; 4 is the rotating rod; 5 is the first needle roller bearing; 51 is the first needle roller cage; 52 is the first needle roller; 6 is the limit retaining ring; 7 is the second needle roller bearing; 71 is the second needle roller cage; 72 is the second needle roller; 8 is the mounting rod; 81 is the positioning protrusion; 82 is the positioning groove; 9 is the adjusting shim. Detailed implementation mode

[0029] The following further elaborates on the present utility model in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0030] A high-load and high-precision universal joint, as Figure 1 and Figure 2 shown, includes a mounting base 1 and a rotating body 2. The rotating body 2 includes a sphere 3 and rotating rods 4 symmetrically connected to both sides of the sphere 3, and the rotating rods 4 are integrally formed with the sphere 3. A bearing hole 31 coaxial with and penetrating the sphere 3 is provided in the sphere 3. A first needle roller bearing 5 is provided in the bearing hole 31, and the surfaces of the sphere 3 at both ends of the bearing hole 31 are planes flush with the end faces of the first needle roller bearing 5. The axis of the rotating rod 4 is perpendicular to and intersects the axis of the bearing hole 31. A relief opening 14 for mating with the sphere 3 is provided at the bottom of the mounting base 1, and a mounting hole 15 for mating with the end of the rotating rod 4 away from the sphere 3 and communicating with the relief opening 14 is further provided on the mounting base 1. The end of the rotating rod 4 away from the sphere 3 is installed in the corresponding mounting hole 15 through a second needle roller bearing 7 coaxial with it. A mounting rod 8 is provided on the side of the mounting base 1 away from the relief opening 14, and normally, the axes of the mounting rod 8, the rotating rod 4, and the first needle roller bearing 5 are perpendicular to and intersect each other.

[0031] As Figure 1 shown, when the present utility model is in use, the mounting base 1 is connected to an external structure such as a lead screw through the mounting rod 8. The two rotating rods 4 are installed on the mounting base 1 through two second needle roller bearings 7, so that the entire rotating body 2 can rotate around the second needle roller bearing 7. The external output mechanism is connected to the sphere 3 through the first needle roller bearing 5. When the lead screw drives the entire mounting base 1 to move to output thrust and pull, the external mechanism makes a circular motion around the first needle roller bearing 5.

[0032] In this embodiment, as Figure 3As shown, the first needle roller bearing 5 has no inner ring and includes a first needle roller cage 51 coaxial with it. The outer ring of the first needle roller cage 51 is installed in the bearing hole 31. A number of first needle rollers 52 are installed circumferentially around the axis of the inner ring of the first needle roller cage 51, and the number of first needle rollers 52 is arranged along the axis direction of the first needle roller bearing 5. When the first needle roller bearing 5 is connected to the output mechanism, the outer walls of the number of first needle rollers 52 are in rolling connection with the outer wall of the output mechanism. And as Figure 1 and Figure 2 shown, to achieve the axial limit of the first needle roller bearing 5, limit retaining rings 6 are respectively provided at both ends of the first needle roller cage 51 and are installed on the plane of the sphere 3 and are matched with it.

[0033] Similarly, as Figure 2 and Figure 3 shown, the second needle roller bearing 7 also has no inner ring and includes a second needle roller cage 71 coaxial with it. The outer ring of the second needle roller cage 71 is installed in the corresponding mounting hole 15. A number of second needle rollers 72 are installed around the axis of the inner ring of the second needle roller cage 71, and the number of second needle rollers 72 is arranged along the axis direction of the second needle roller bearing 7, and the outer walls of the number of second needle rollers 72 are in rolling connection with the outer wall of the corresponding rotating rod 4. Among them, the outer ring of the second needle roller cage 71 is in interference fit with the corresponding mounting hole 15, directly achieving the axial limit of the second needle roller bearing 7 without the need to additionally set other limiting structures.

[0034] As Figure 1 and Figure 2 shown, to facilitate the assembly of the rotating body 2 and the mounting seat 1, in this embodiment, the mounting seat 1 includes a first mounting body 11, a second mounting body 12 and a third mounting body 13. The left mounting hole 15 and the mounting rod 8 are both arranged on the first mounting body 11. The second mounting body 12 and the third mounting body 13 are symmetrically arranged and divide the right mounting hole 15 symmetrically into two halves. The second mounting body 12 and the third mounting body 13 are installed and connected between them, and the second mounting body 12 or the third mounting body 13 is integrally formed with the first mounting body 11. In this embodiment, the second mounting body 12 is integrally formed with the first mounting body 11, and the third mounting body 13 is independently separated. In this way, the mounting seat 1 is a two-piece split structure, which ensures the overall strength of the mounting seat 1 and is more convenient for the installation and connection of the third mounting body 13 and the first mounting body 11. Among them, in this embodiment, the mounting seat 1 is integrally in a U-shaped structure with an open bottom, and the two corners at the top are rounded structures, and the vertical part with the mounting hole 15 is circular in side view with a top notch.

[0035] Among them, as Figure 1 and Figure 2As shown in the figure, at least two sets of cooperating positioning holes 16 are provided on the second mounting body 12 and the third mounting body 13. A pin 18 is inserted through the positioning holes 16. With the cooperation of the pin 18 and the positioning holes 16, the positioning connection between the second mounting body 12 and the third mounting body 13 is achieved. At least two sets of cooperating locking holes 17 are also provided on the second mounting body 12 and the third mounting body 13, and the locking holes 17 are respectively located on the upper and lower sides of the corresponding mounting holes 15. Screws 19 are installed in the locking holes 17. With the cooperation of the screws 19 and the locking holes 17, the fixed installation between the second mounting body 12 and the third mounting body 13 is achieved. Of course, in other embodiments, after the second mounting body 12 and the third mounting body 13 are positioned by the pin 18, the second mounting body 12 can also be directly welded to the first mounting body 11 and the third mounting body 13, and in this case, the locking holes 17 and the screws 19 need to be provided.

[0036] In addition, as Figure 1 and Figure 2 shown, adjusting shims 9 are provided between the mating surfaces of the second mounting body 12 and the third mounting body 13, and the adjusting shims 9 are respectively located on the upper and lower sides of the corresponding mounting holes 15. The adjusting shims 9 are used to ensure the locking degree of the mating surfaces of the second mounting body 12 and the third mounting body 13, so as to ensure that the mounting holes 15 are within the combined second mounting body 12 and the third mounting body 13 for the precise assembly of the second needle roller bearing 7.

[0037] As Figure 1 and Figure 4 shown, to facilitate the connection of the present utility model to an external drive mechanism such as a lead screw through the mounting rod 8, the mounting rod 8 can be a threaded rod or a smooth rod. When the mounting rod 8 is a threaded rod, it is connected to the external drive structure through a threaded connection. When the mounting rod 8 is a smooth rod, it is connected to the external drive mechanism through connection methods such as keys and pins. Among them, as Figure 1 shown, when the mounting rod 8 is a threaded rod, a positioning protrusion 81 is provided at the end of the external thread of the mounting rod 8 close to the mounting seat 1. As Figure 4 shown, when the mounting rod 8 is a smooth rod, a positioning groove 82 coaxial with it is provided around one end of the mounting rod 8 close to the mounting seat 1. The positioning protrusion 81 or the positioning groove 82 is used to achieve the positioning of the mounting rod 8 during installation, and ensure the installation accuracy of the mounting rod 8.

[0038] The working principle and usage method of the present utility model:

[0039] The mounting seat 1 is connected to an external structure such as a lead screw through a mounting rod 8, and two rotating rods 4 are mounted on the mounting seat 1 through two second needle bearings 7, so that the entire rotating body 2 can rotate around the second needle bearings 7, and the external output mechanism is connected to the sphere 3 through the first needle bearing 5. When the lead screw drives the mounting seat 1 to move as a whole to output thrust and pull, the external mechanism performs a circular motion around the first needle bearing 5. In this way, the entire universal joint has two degrees of freedom when in use: rotation around the axis of the first needle bearing 5 and rotation around the axis of the second needle bearing 7, thereby ensuring that there will be no shaking in other directions when outputting push and pull forces, resulting in loss of axial precision. The first needle bearing 5 and the second needle bearing 7 are used for transmission, which has high transmission precision, strong load capacity, and a small starting torque, which makes the sensitivity also high, and can meet the use requirements in the connection of the limbs of the humanoid robot.

[0040] The above description shows and describes the preferred embodiments of the utility model. As mentioned above, it should be understood that the utility model is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the utility model concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not depart from the spirit and scope of the utility model, and should be within the scope of protection of the claims attached to the utility model.

Claims

1. A high-load and high-precision universal joint, characterized in that: The invention comprises a mounting seat (1) and a rotating body (2), wherein the rotating body (2) comprises a sphere (3) and a rotating rod (4) symmetrically connected to both sides of the sphere (3), and the rotating rod (4) and the sphere (3) are integrally formed; a bearing hole (31) coaxial with the sphere (3) and penetrating the sphere (3) is provided in the sphere (3), a first needle roller bearing (5) is provided in the bearing hole (31), and the surfaces of the sphere (3) located at both ends of the bearing hole (31) are planes flush with the end faces of the first needle roller bearing (5); the axis of the rotating rod (4) intersects perpendicularly with the axis of the bearing hole (31), and the mounting seat (1) is provided with a plurality of rotating rods (4) and a plurality of rotating rods (4) extending from the sphere (3) to the sphere (3). The bottom of the seat (1) is provided with a clearance opening (14) matched with the sphere (3); the mounting seat (1) is also provided with a mounting hole (15) matched with the end of the rotating rod (4) away from the sphere (3) and connected with the clearance opening (14); the end of the rotating rod (4) away from the sphere (3) is mounted in the corresponding mounting hole (15) through a second needle roller bearing (7) coaxial with the rotating rod (4); a mounting rod (8) is provided on the side of the mounting seat (1) away from the clearance opening (14); and in a normal state, the axes of the mounting rod (8), the rotating rod (4) and the first needle roller bearing (5) intersect each other perpendicularly.

2. A high-load and high-precision universal joint according to claim 1, characterized in that: The first needle roller bearing (5) comprises a first needle roller retainer (51) coaxial therewith, the outer ring of the first needle roller retainer (51) is installed in the bearing hole (31), the inner ring of the first needle roller retainer (51) is provided with a plurality of first needle rollers (52) in a circular array around its axis, and the plurality of first needle rollers (52) are arranged along the axis direction of the first needle roller bearing (5), and when the first needle roller bearing (5) is connected to an output mechanism, the outer walls of the plurality of first needle rollers (52) are rollingly connected to the outer wall of the output mechanism.

3. A high-load and high-precision universal joint according to claim 2, characterized in that: The first needle roller retainer (51) is provided with two ends thereof with respective stop rings (6) which cooperate therewith, and the stop rings (6) are installed on the plane of the sphere (3).

4. A high-load and high-precision universal joint according to claim 1, characterized in that: The second needle roller bearing (7) comprises a second needle roller retainer (71) coaxial therewith, the outer ring of the second needle roller retainer (71) is interference-mounted in the corresponding mounting hole (15), the inner ring of the second needle roller retainer (71) is arrayed with a plurality of second needle rollers (72) around its axis, the plurality of second needle rollers (72) are arranged along the axis of the second needle roller bearing (7), and the outer walls of the plurality of second needle rollers (72) are rollingly connected to the outer walls of the corresponding rotating rods (4).

5. A high-load and high-precision universal joint according to claim 1, characterized in that: The mounting seat (1) comprises a first mounting body (11), a second mounting body (12) and a third mounting body (13), wherein one of the mounting holes (15) and the mounting rod (8) are both arranged on the first mounting body (11), the second mounting body (12) and the third mounting body (13) are symmetrically arranged to symmetrically divide the other mounting hole (15) into two halves, the second mounting body (12) and the third mounting body (13) are mounted and connected, and the second mounting body (12) or the third mounting body (13) is integrally formed with the first mounting body (11).

6. A high-load and high-precision universal joint according to claim 5, characterized in that: The second mounting body (12) and the third mounting body (13) are provided with at least two groups of mutually matching positioning holes (16) and at least two groups of mutually matching locking holes (17), the positioning holes (16) are provided with pins (18), the locking holes (17) are provided with screws (19), and the at least two groups of locking holes (17) are respectively located at the upper and lower sides of the corresponding mounting holes (15).

7. A high-load and high-precision universal joint according to claim 6, characterized in that: An adjustment gasket (9) is provided between the fitting surfaces of the second mounting body (12) and the third mounting body (13), and the adjustment gasket (9) is located at the upper and lower sides of the corresponding mounting hole (15).

8. The high-load and high-precision universal joint according to claim 1, characterized in that: The mounting rod (8) is a threaded rod or a smooth rod. When the mounting rod (8) is a threaded rod, a positioning protrusion (81) is provided at the tail end of the external thread close to the mounting seat (1). When the mounting rod (8) is a smooth rod, a positioning groove (82) coaxial with the mounting seat (1) is provided at one end close to the mounting seat (1).

Images