A two-degree-of-freedom parallel joint mechanism

Abstract

The present application relates to a two-degree-of-freedom parallel joint mechanism, which comprises a fixed device, a cross hinge structure, a first driver and a second driver. The two drivers are fixed to the fixed device, and the axes of the output shafts are perpendicular. The output shaft of the first driver can drive the cross hinge structure to rotate continuously, and the rotation angle depends on the rotation angles of the two drivers. The extension of the output shaft axis of the second driver intersects with the center of the cross hinge, and the output shaft of the cross hinge is a moving platform. The two-degree-of-freedom parallel joint mechanism can obtain a larger rotation angle range, and the moving platform can rotate continuously (the rotation angle can be infinite) under the drive of the first driver. The output shaft of the cross hinge can swing ±90 degrees around another axis (orthogonal to the previous axis) under the drive of the second driver, and the rotation angle depends only on the rotation angle of the second driver. The rotation of the moving platform in two directions can be carried out respectively or simultaneously.

Description

Technical Field

[0001] This invention relates to the field of multi-degree-of-freedom joint technology, and particularly to a two-degree-of-freedom parallel joint mechanism. Background Technology

[0002] Two-degree-of-freedom (DOF) joint mechanisms refer to joint mechanisms with two rotational degrees of freedom, particularly those with two perpendicularly intersecting axes. The prototypes of such joint mechanisms are derived from the human and animal bodies, such as the neck, ankle, shoulder, waist, and hip joints of humans and other walking animals. Two-DOF joint mechanisms are widely used in robotics, five-axis machining centers, radar or camera pose adjusters, etc. Therefore, improving the various performance characteristics of two-DOF joints while simplifying their structure is one of the technical problems that needs to be solved.

[0003] Compared to traditional serial joint mechanisms, parallel joint mechanisms offer advantages such as high precision and strong load-bearing capacity. Existing two-degree-of-freedom parallel joint mechanisms all have two chains, and the moving platform has degrees of freedom to rotate around two axes, such as... Figures 1-3 As shown, these existing two-degree-of-freedom parallel joint mechanisms can realize that the moving platform has two rotational degrees of freedom, but the rotation angle range is small and it is difficult to reach ±90 degrees. Moreover, the joint structure is relatively complex and the number of passive pairs is large, making it difficult to meet the more demanding application requirements. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a two-degree-of-freedom parallel joint mechanism with a large rotation range, a small number of passive pairs, and a simple structure.

[0005] The technical solution of the present invention is: a two-degree-of-freedom parallel joint mechanism, including a fixing device, a cross hinge structure, a first driver, a second driver, and a joint mechanism output shaft. The relative positions of the output shafts of the first driver and the second driver are fixed to each other by the fixing device. The characteristic is that the output shaft of the first driver drives the joint mechanism output shaft to rotate around a first axis through the cross hinge structure, and the output shaft of the second driver drives the joint mechanism output shaft to rotate around a second axis.

[0006] Furthermore, the cross-hing structure includes two orthogonally arranged first U-shaped frames and second U-shaped frames, and a cross structure connecting the two U-shaped frames. The output shaft of the first driver and the output shaft of the joint mechanism are respectively connected to the first U-shaped frame and the second U-shaped frame.

[0007] Furthermore, the output shaft of the first driver is connected to the first rotating shaft, driving the first U-shaped frame to rotate, thereby causing the second U-shaped frame and the output shaft of the joint mechanism to rotate around the first axis, realizing the first degree of freedom of rotational motion.

[0008] Furthermore, the output shaft of the second driver is connected to the second rotating shaft, and the second rotating shaft is connected to the output shaft of the joint mechanism through a connecting rod. The connecting rod and the output shaft of the joint mechanism are connected through a rotating pair (bearing). The rotation of the output shaft of the second driver drives the connecting rod and the output shaft of the joint mechanism to rotate around the second axis, thereby realizing the second degree of freedom rotational motion.

[0009] Furthermore, the first axis mentioned above coincides with the axis of the output shaft of the first driver, and the second axis mentioned above coincides with the axis of the output shaft of the second driver.

[0010] Furthermore, the output shaft of the joint mechanism can rotate continuously around the first axis.

[0011] Furthermore, the output shaft of the joint mechanism can swing around the second axis.

[0012] Furthermore, the output shaft of the first driver and the first rotating shaft are integrated into one structure, and the output shaft of the second driver and the second rotating shaft are integrated into one structure.

[0013] Furthermore, the connecting rod is L-shaped.

[0014] Furthermore, the intersection of the output shafts of the first driver and the second driver coincides with the center of the cross-hing structure.

[0015] Furthermore, the first rotating shaft is coaxially arranged with the output shaft of the joint mechanism, and its axis passes through the center of the cross hinge structure.

[0016] The present invention has the following beneficial effects: The two-degree-of-freedom parallel joint mechanism of the present invention has a simple structure and can obtain a large rotational angle range, especially the rotational angle of one of the rotational degrees of freedom can be infinite; the rotational angle range of the second rotational degree of freedom is ±90 degrees, and this swing angle is decoupled from the first rotational degree of freedom, that is, it depends only on the rotational angle of the second actuator. The rotation in the two directions can be performed separately or simultaneously. In addition to being used for joint driving in fields such as robotics, the two-degree-of-freedom parallel joint mechanism of the present invention can also be used in various processing equipment because the output shaft can rotate continuously with the first actuator. The first actuator can be used as a spindle motor to control the spindle speed; the first actuator can also drive the wheels, and the entire mechanism can realize the control of the wheel posture. In addition, it can also be used for driving two-degree-of-freedom platforms, with strong versatility and good social and economic benefits. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of existing technology. Figure 1 .

[0018] Figure 2 This is a schematic diagram of existing technology. Figure 2 .

[0019] Figure 3 This is a schematic diagram of existing technology. Figure 3 .

[0020] Figure 4 This is a schematic diagram of the structure of the present invention before movement.

[0021] Figure 5 This is a schematic diagram of the mechanism posture of the present invention rotating only around the first axis.

[0022] Figure 6 This is a schematic diagram of the mechanism posture of the present invention, which rotates only around the second axis.

[0023] Figure 7 This is a schematic diagram of the mechanism of the present invention that rotates simultaneously around the first axis and the second axis.

[0024] Figure 8 This is a schematic diagram illustrating an application example of the present invention in the hip joint of a robot dog. Detailed Implementation

[0025] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; or internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0028] like Figure 4As shown, a two-degree-of-freedom parallel joint mechanism includes a fixing device 2, a cross-hing structure 7, a first actuator 1, and a second actuator 3. The output shafts of the first actuator 1 and the second actuator 3 intersect, preferably orthogonal. The output shafts of the first actuator 1 and the second actuator 3 are fixed in relative position by the fixing device 2. The output shaft of the first actuator 1 can drive the cross-hing structure 7 to rotate continuously. The fixing device can take various forms; the joint mechanism can be fixed to other components by the fixing device 2, or the fixing device 2 can be integrally formed with other components.

[0029] The cross hinge structure 7 includes two orthogonally arranged first U-shaped frames and second U-shaped frames, and a cross structure connecting the two U-shaped frames. The first U-shaped frame and the second U-shaped frame are respectively connected to the first rotating shaft 8 and the joint mechanism output shaft 6. The first rotating shaft 8 and the joint mechanism output shaft 6 are preferably coaxially arranged, and their axis preferably passes through the center of the cross structure.

[0030] The output shaft of the first driver 1 is connected to the first rotating shaft 8, or the output shaft of the first driver 1 can directly drive the first U-shaped frame to rotate as the first rotating shaft 8, thereby driving the second U-shaped frame and the joint mechanism output shaft 6 to rotate around the first axis, realizing the first degree of freedom rotational motion. The first axis may coincide with the axis of the output shaft of the first driver 1 or may not coincide with it.

[0031] The output shaft of the second driver 3 or the second rotating shaft 9 connected to the output shaft is connected to the output shaft 6 of the joint mechanism via the connecting rod 4. The connecting rod 4 and the output shaft 6 of the joint mechanism are connected by a rotating pair, preferably a bearing 5. The rotation of the output shaft of the second driver 3 drives the connecting rod 4 and the output shaft 6 of the joint mechanism to rotate around the second axis. The second axis may or may not coincide with the axis of the output shaft of the second driver 3, thereby realizing the second degree of freedom rotational motion.

[0032] The connecting rod 4 is preferably L-shaped, but it can also be other shapes, such as U-shaped, S-shaped, etc.

[0033] The first degree of freedom is preferably the roll degree of freedom, and the second degree of freedom is preferably the pitch degree of freedom.

[0034] The first driver 1 can drive the joint mechanism output shaft 6 to rotate continuously around the first axis multiple times. At the same time, the joint mechanism output shaft 6 can be driven by the second driver 3 to swing around the second axis, or it can remain still.

[0035] The rotation of the joint mechanism output shaft 6 around the second axis and its rotation angle depend only on the output of the second driver 3, and the rotation angle can reach ±90 degrees.

[0036] The intersection of the output shaft of the first driver 1 and the output shaft of the second driver 3 is preferably coincided with the center of the cross structure.

[0037] The first and second drivers mentioned above can be electric motors, pneumatic swing cylinders, or hydraulic swing cylinders.

[0038] like Figure 5-7 As shown, the schematic diagram of the two-degree-of-freedom parallel joint mechanism of the present invention before and after movement shows that the movements of the first degree of freedom and the second degree of freedom do not interfere with each other, and the two rotations can be performed individually or simultaneously.

[0039] like Figure 8 The image shows an application example of the two-degree-of-freedom parallel joint mechanism of the present invention on the hip joint of a robot dog's thigh. That is, the two-degree-of-freedom parallel joint mechanism is the hip joint, which can realize the rolling and pitching movements of the robot dog's thigh.

[0040] The two-degree-of-freedom parallel joint mechanism of the present invention can be used not only for joint driving of robots, but also for any application that requires two rotational degrees of freedom at the same time. It has strong versatility and good social and economic benefits.

[0041] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A two-degree-of-freedom parallel decoupled joint mechanism, comprising a fixing device (2), a cross hinge structure (7), a first actuator (1), a second actuator (3), and a joint mechanism output shaft (6), wherein the relative positions of the output shafts of the first actuator (1) and the second actuator (3) are fixed to each other by the fixing device (2), characterized in that: The output shaft of the first driver (1) drives the output shaft (6) of the joint mechanism to rotate around the first axis through the cross hinge structure (7), and the output shaft of the second driver (3) drives the output shaft (6) of the joint mechanism to rotate around the second axis. The cross hinge structure (7) includes two orthogonally arranged first U-shaped frames and second U-shaped frames, and a cross structure connected between the two U-shaped frames. The first U-shaped frames and the second U-shaped frames are respectively connected to the output shaft of the first driver (1) and the output shaft (6) of the joint mechanism. The joint mechanism is capable of: the first axis coinciding with the axis of the output shaft of the first driver (1), the second axis coinciding with the axis of the output shaft of the second driver (3), and the intersection of the output shaft of the first driver (1) and the output shaft of the second driver (3) coinciding with the center of the cross hinge structure, and the rotation of the joint mechanism output shaft (6) around the first axis and around the second axis does not interfere with each other; The output shaft of the second driver (3) is connected to the second rotating shaft (9). The second rotating shaft (9) is connected to the output shaft (6) of the joint mechanism via a connecting rod (4). The connecting rod (4) and the output shaft (6) of the joint mechanism are connected via a rotating pair (5), which is a bearing.

2. The two-degree-of-freedom parallel decoupling joint mechanism according to claim 1, characterized in that: The output shaft of the first driver (1) is connected to the first rotating shaft (8), driving the first U-shaped frame to rotate, thereby causing the second U-shaped frame and the output shaft (6) of the joint mechanism to rotate around the first axis, realizing the first degree of freedom rotational motion.

3. The two-degree-of-freedom parallel decoupling joint mechanism according to claim 2, characterized in that: The rotation of the output shaft of the second driver (3) drives the connecting rod (4) and the output shaft (6) of the joint mechanism to rotate around the second axis, thereby realizing the second degree of freedom of rotational motion.

4. A two-degree-of-freedom parallel decoupling joint mechanism according to claim 1, 2, or 3, characterized in that: The output shaft (6) of the joint mechanism can rotate continuously around the first axis in one or more turns.

5. A two-degree-of-freedom parallel decoupling joint mechanism according to claim 2 or 3, characterized in that: The output shaft of the first driver (1) is integrated with the first rotating shaft (8), and / or the output shaft of the second driver (3) is integrated with the second rotating shaft (9).

6. A two-degree-of-freedom parallel decoupling joint mechanism according to claim 1, 2, or 3, characterized in that: The connecting rod (4) is L-shaped.

7. A two-degree-of-freedom parallel decoupling joint mechanism according to claim 2 or 3, characterized in that: The first rotating shaft (8) is coaxially arranged with the output shaft (6) of the joint mechanism, and its axis passes through the center of the cross structure.

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