A stick-slip rotating platform with a fully symmetrical structure

Abstract

A stick-slip rotating platform with a fully symmetrical structure comprises a piezoelectric stack driver, a base, a ring, a frame, a motion transmission mechanism, a stick-slip mechanism and a stage; the motion transmission mechanism comprises a rhombus amplifying mechanism and two rockers that are symmetrically arranged; the rhombus amplifying mechanism is driven by a piezoelectric stack driver arranged in the long axis direction, the output end of each rhombus amplifying mechanism is connected to a rocker through a flexible hinge, one end of each rocker is fixed to the inner surface of the ring, and the other ends of the two rockers are fixed to the base, the two rockers are arranged in a central symmetrical manner, a plurality of stick-slip mechanisms are evenly fixed to the frame along the circumferential direction, a stick-slip arc plate is extended to the stage toward the base, the output end of the stick-slip mechanism contacts the outer surface of the stick-slip arc plate, and the inner surface of the stick-slip arc plate is in frictional contact with the outer surface of the ring. The invention has a compact structure and low control difficulty, and is suitable for the fields of micro-manipulation robots and micro-electromechanical systems.

Description

Technical Field

[0001] The invention relates to a micro-motion platform, in particular to a stick-slip rotating platform with a fully symmetrical structure. Background Art

[0002] As a key component of micro-electromechanical systems, micro-motion platforms are widely used to load precision instruments or their key components such as common optical lenses, precision micro-manipulators and micro-grippers. Therefore, micro-motion platforms need to have multi-dimensional motion and extremely high resolution.

[0003] Compared with electrostatic comb drive, electrothermal drive and shape memory alloy drive, piezoelectric stack drive has the advantages of high resolution, large driving force, wide frequency response range, fast response speed and good dynamic characteristics, so it is particularly suitable for driving micro-motion platforms. In the field of micro-assembly technology, micro-motion platforms are often required to drive micro-grippers to move from micron level to millimeter level. Therefore, the micro-motion platform should have a large stroke. In addition, in order to better perform high-precision assembly, the position of the micro-motion platform needs to be monitored online and feedback controlled.

[0004] The stick-slip phenomenon refers to the fact that the sliding speed of the interface under the action of constant traction is generally constant or approximately constant, but in some cases, the sliding speed fluctuates greatly. If the friction force or sliding speed fluctuates with the sliding distance or time. In the sticking stage, the static friction force gradually increases to a certain value. Once the external force is sufficient to overcome this friction force, the interface slips. During the stick-slip process, the friction force and time relationship curve is jagged. This typical stick-slip can only occur when the static friction factor is significantly greater than the sliding friction factor. Stick-slip can occur repeatedly or randomly. If the slope of the dynamic friction factor with the sliding speed is negative at a certain speed, then resonance occurs. Summary of the invention

[0005] In order to overcome the shortcomings of the prior art, the present invention provides a stick-slip rotating platform with a fully symmetrical structure and capable of rotating a stage with a single input.

[0006] A stick-slip rotating platform with a fully symmetrical structure comprises a piezoelectric stack driver, a base, a ring, a frame, a motion transmission mechanism, a stick-slip mechanism and a stage;

[0007] A piezoelectric stack driver, a motion transmission mechanism, a circular ring and a stick-slip mechanism are arranged in the frame; the motion transmission mechanism comprises a symmetrically distributed rhombus amplifying mechanism and two rockers; the rhombus amplifying mechanism is driven by the piezoelectric stack driver arranged in the long axis direction, the output end of each rhombus amplifying mechanism is connected to a rocker through a flexible hinge, one end of each rocker is fixed to the inner surface of the circular ring, and the other ends of the two rockers are fixed to the base, the two rockers are arranged in a centrally symmetrical manner, a plurality of stick-slip mechanisms are evenly fixed to the frame along the circumferential direction, a stick-slip arc plate is extended from the stage toward the base, the output end of the stick-slip mechanism is in contact with the outer surface of the stick-slip arc plate, and the inner surface of the stick-slip arc plate is in frictional contact with the outer surface of the circular ring.

[0008] Compared with the prior art, the present invention has the following beneficial effects:

[0009] A diamond-shaped amplifying mechanism and a pair of rockers are used to amplify the output displacement of the piezoelectric stack driver, and the stage rotation is realized by a stick-slip mechanism. A piezoelectric stack driver is used to provide driving displacement for the stage, which reduces the control difficulty and reduces the system error. The amplifying mechanism is connected by a flexible hinge and is processed by wire cutting, so that the entire flexible hinge and the amplifying mechanism are a whole. The present invention has the advantages of compact structure, small size, high guiding accuracy, easy to ensure processing accuracy and no need for assembly. The present invention is suitable for micro-manipulation robot systems and micro-electromechanical systems.

[0010] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments: BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a three-dimensional diagram of the sticky-slip rotating platform with a fully symmetrical structure of the present invention after the base is removed;

[0012] Figure 2 is a structural diagram of the stick-slip rotating platform with a fully symmetrical structure of the present invention after the base is removed;

[0013] Figure 3 is a structural diagram of the sticky-slip rotating platform with a fully symmetrical structure of the present invention after the cover plate is removed;

[0014] Figure 4 is a stereoscopic diagram of a stick-slip rotating platform having a fully symmetrical structure according to the present invention;

[0015] Figure 5 is an exploded view of the stick-slip rotating platform with a fully symmetrical structure of the present invention;

[0016] Figure 6 It is a schematic diagram of the structural movement principle of the present invention. DETAILED DESCRIPTION

[0017] like Figure 1-Figure 2As shown, a stick-slip rotating platform with a fully symmetrical structure comprises a piezoelectric stack driver 1, a base 2, a ring 3, a frame 4, a motion transmission mechanism A, a stick-slip mechanism B and a stage 5;

[0018] The frame 4 is provided with a piezoelectric stack driver 1, a motion transmission mechanism A, a ring 3 and a stick-slip mechanism B;

[0019] The motion transmission mechanism A comprises a symmetrically distributed rhombus amplifying mechanism A1 and two rockers A2; the rhombus amplifying mechanism A1 is driven by a piezoelectric stack driver 1 arranged in the long axis direction, the output end of each rhombus amplifying mechanism A1 is connected to a rocker A2 through a flexible hinge 6, one end of each rocker A2 is fixed to the inner surface of the ring 3, and the other ends of the two rockers A2 are fixed to the base 2, the two rockers A2 are arranged in a central symmetrical manner, a plurality of stick-slip mechanisms B are evenly fixed to the frame 4 along the circumferential direction, the stage 5 extends toward the base 2 with a stick-slip arc plate 51, the output end of the stick-slip mechanism B contacts the outer surface of the stick-slip arc plate 51, and the inner surface of the stick-slip arc plate 51 is in frictional contact with the outer surface of the ring 3. The contact friction between the stick-slip arc plate 51 and the ring 3 is greater than the contact friction between the output end of the stick-slip mechanism B and the stick-slip arc plate 51.

[0020] The motion transmission mechanism A transforms the deformation of the piezoelectric stack driver 1 , drives the annular output member 3 , and finally transmits it to the stage 5 through the stick-slip mechanism B to realize the rotational displacement of the stage 5 .

[0021] In one embodiment, each side of the diamond-shaped magnifying mechanism A1 is a single-circular flexible hinge structure.

[0022] In another embodiment, each rocker A2 is a single circular flexible hinge structure, that is, a symmetrical arch amplifier structure based on a single groove circular flexible hinge, the diamond-shaped amplifier mechanism A1 is driven by the piezoelectric stack driver 1, and the diamond-shaped amplifier mechanism A1 and the double rocker A2 can simultaneously achieve high lateral stiffness and compact structure, and protect the piezoelectric stack driver 1.

[0023] Since the diamond-shaped amplifying mechanism A1 is connected to the rocker A2 through the flexible hinge 6, when the piezoelectric stack driver 1 pushes the diamond-shaped amplifying mechanism A1, the displacement is transmitted to a rocker A2, giving a tangential force to the ring 3. Since the two rockers A2 are centrally symmetrical, the two tangential forces are in opposite directions, thereby pushing the ring 3 to rotate in the circumferential direction. Since the stick-slip mechanism B is attached to the outer surface of the ring 3 and since multiple stick-slip mechanisms B (for example, 4 stick-slip mechanisms B) are centrally symmetrical, the stage 5 is driven to rotate.

[0024] like Figure 2 As shown, each of the stick-slip mechanisms B comprises a bolt B1, a nut B and two arc-shaped pieces B3;

[0025] The two arc pieces B3 are bent toward each other, one end of the two arc pieces B3 contacts the outer arc surface of the stick-slip arc plate 51, the inner arc surface of the stick-slip arc plate 51 matches and abuts against the outer surface of the ring 3, the other ends of the two arc pieces B3 are fixed on the base 2, the two arc pieces B3 are penetrated by bolts B1, and are fastened by nuts B2. The stick-slip arc plate 51 is made integrally with the stage 5.

[0026] like Figure 1 , Figure 2 and Figure 6 As shown, since the diamond-shaped amplifying mechanism A1 is connected to the rocker A2 through the flexible hinge 6, when the piezoelectric stack driver 1 pushes the diamond-shaped amplifying mechanism A1, the displacement is transmitted to the rocker A2, and the rocker A2 deforms to exert a tangential force on the ring 3. Since the two rockers A2 are centrally symmetrical, the two tangential forces are opposite (such as Figure 6 As shown by the arrow, the ring 3 is pushed to rotate in the circumferential direction, and the bolt B1 and the nut B2 are adjusted so that the arc piece B3 acts on the stick-slip arc plate 51, so that the stick-slip arc plate 51 is pressed against the outer surface of the ring 3 and is in frictional contact with the ring 3 (as shown in FIG. Figure 6 As shown by the arrow, since multiple stick-slip mechanisms B (for example, 4 stick-slip mechanisms B) are symmetrically arranged, the stage 5 is driven to rotate. The contact friction between the stick-slip arc plate 51 and the ring 3 is greater than the contact friction between the arc piece B3 and the stick-slip arc plate 51.

[0027] In order to increase the rotation stability of the ring 3, the outer surface of the ring 3 is connected to the frame 4 via a flexible hinge 6. Further, the flexible hinge 6 is a double-cut straight circular flexible hinge.

[0028] like Figure 3-Figure 5 As shown, the stick-slip rotating platform is further provided with a cover plate 8, and the cover plate 8, the frame 4 and the base 2 are connected together by screws 9. The loading platform 5 is arranged in the center hole of the cover plate 8 and can rotate.

[0029] The present invention has been disclosed as above with preferred implementation cases, but it is not used to limit the present invention. Any technician familiar with the profession can make slight changes or modifications to equivalent implementation cases with equivalent changes by using the above-disclosed structures and technical contents without departing from the scope of the technical solution of the present invention, which still fall within the scope of the technical solution of the present invention.

Claims

1. A stick-slip rotating platform with a fully symmetrical structure, characterized in that: It comprises a piezoelectric stack driver (1), a base (2), a ring (3), a frame (4), a motion transmission mechanism (A), a stick-slip mechanism (B) and a stage (5); A piezoelectric stack driver (1), a motion transmission mechanism (A), a circular ring (3) and a stick-slip mechanism (B) are arranged in the frame (4); The motion transmission mechanism (A) comprises a rhombus amplifying mechanism (A1) and two rocking arms (A2) which are symmetrically arranged. The rhombus amplifying mechanism (A1) is driven by a piezoelectric stack driver (1) arranged in the long axis direction. The output end of each rhombus amplifying mechanism (A1) is connected to a rocking arm (A2) via a flexible hinge (6). One end of each rocking arm (A2) is fixedly connected to the inner surface of the ring (3). The other ends of the two rocking arms (A2) are fixedly connected to the base (2). The two rocking arms (A2) are arranged symmetrically around the center. A plurality of stick-slip mechanisms (B) are evenly fixedly connected to the frame (4) along the circumferential direction. The stage (5) is provided with a stick-slip arc plate (51) extending in the direction of the base (2). The output end of the mechanism (B) contacts the outer surface of the stick-slip arc plate (51), and each of the stick-slip mechanisms (B) comprises a bolt (B1), a nut (B) and two arc plates (B3); the two arc plates (B3) are bent toward each other, one end of the two arc plates (B3) contacts the outer arc surface of the stick-slip arc plate (51), the inner arc surface of the stick-slip arc plate (51) matches the outer surface of the circular ring (3) and abuts against the outer surface of the circular ring (3), the other ends of the two arc plates (B3) are fixed to the base (2), the two arc plates (B3) are provided with bolts (B1) and are fastened by nuts (B2), and the inner surface of the stick-slip arc plate (51) is in frictional contact with the outer surface of the circular ring (3).

2. The stick-slip rotating platform with a fully symmetrical structure according to claim 1, characterized in that: Each side of the diamond-shaped enlarging mechanism (A1) is a single-circular flexible hinge structure.

3. A stick-slip rotating platform with a fully symmetrical structure according to claim 1 or 2, characterized in that: Each rocker (A2) is a single-circular flexible hinge structure.

4. The stick-slip rotating platform with a fully symmetrical structure according to claim 1, characterized in that: The outer surface of the circular ring (3) is connected to the frame (4) via a flexible hinge (6).

5. The stick-slip rotating platform with a fully symmetrical structure according to claim 1 or 4, characterized in that: The flexible hinge (6) is a double-cut straight circular flexible hinge.

6. The stick-slip rotating platform with a fully symmetrical structure according to claim 1, characterized in that: The stick-slip arc plate (51) and the loading platform (5) are integrally manufactured.

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