Single-motor multi-degree-of-freedom mechanical limb structure controlled by piezoelectric ceramics

Abstract

The utility model provides a single-motor multi-degree-of-freedom mechanical limb structure controlled by piezoelectric ceramics, relates to the technical field of mechanical arms, and aims to solve the technical problem that a single-motor multi-degree-of-freedom mechanical limb structure in the prior art is large in size. A single-motor multi-degree-of-freedom mechanical limb structure controlled by piezoelectric ceramics comprises two piezoelectric ceramic assemblies and a support, each piezoelectric ceramic assembly comprises a piezoelectric ceramic piece, a yoke plate element, a ratchet wheel, a conversion element, a connecting shaft and a reset piece, and the connecting shaft is rotationally connected with an upper driven gear and a lower driven gear which are coaxially arranged; the conversion element is rotationally connected with the support, a plurality of abutting faces are distributed at the top end of the conversion element in the circumferential direction at equal intervals and sequentially comprise the first abutting face, the second abutting face and the third abutting face in the clockwise or anticlockwise direction, the bottom end of the connecting shaft abuts against one abutting face, and the ratchet wheel is connected to the bottom end of the conversion element. The piezoelectric ceramic piece rotates the ratchet wheel and the conversion element through the yoke plate element.

Description

Technical Field

[0001] The utility model relates to the technical field of mechanical arms, in particular to a single-motor multi-degree-of-freedom mechanical limb structure controlled by piezoelectric ceramics. Background Art

[0002] As an automated equipment, the robot arm is widely used in mechanical manufacturing and processing. It can clamp products to realize the handling or processing of products. Due to the needs of production, the robot arm has multiple degrees of freedom, generally in the three directions of X, Y, and Z. Therefore, the robot arm is more flexible to use and has more functions. At present, the angle or position adjustment of the robot arm in multiple degrees of freedom is mostly achieved by multiple motors. For example, three motors are set and equipped with corresponding transmission mechanisms. The three motors are combined with the transmission mechanism to drive the robot arm to adjust the angle or position in three directions. This kind of robot arm control structure not only requires the use of three motors, but also the corresponding transmission materials are increased accordingly, resulting in a higher overall cost. Chinese patent CN117532652A discloses a single-motor multi-degree-of-freedom mechanical limb structure, which controls four driven gears to mesh with the driving gear respectively through four sets of electromagnets and corresponding transmission mechanisms, and the four driven gears control the rotation of the auxiliary arm in four directions. Although the above patent can use a single motor control to achieve the freedom of the robot arm in the three directions of X, Y, and Z, each driven gear needs to be equipped with a set of electromagnets and a corresponding transmission mechanism, resulting in the overall size of the mechanism still being relatively large. Utility Model Content

[0003] In view of the deficiencies of the prior art, the purpose of the present invention is to provide a single-motor multi-degree-of-freedom mechanical limb structure controlled by piezoelectric ceramics, so as to solve the technical problem of the large size of the single-motor multi-degree-of-freedom mechanical limb structure in the prior art.

[0004] In order to solve the above technical problems, the utility model provides a single-motor multi-degree-of-freedom mechanical limb structure controlled by piezoelectric ceramics, including a driving motor, a mounting seat, a main arm, a sub-arm, a universal joint, a driving gear and four driven gears. The main arm and the sub-arm are rotatably connected through a universal joint. The driving motor is connected to the mounting seat and drives the main arm and the driving gear to rotate. The four driven gears are respectively used to drive the sub-arm to rotate in four directions. It also includes two groups of piezoelectric ceramic components and brackets. Each group of piezoelectric ceramic components includes a piezoelectric ceramic sheet, a connecting plate element, a ratchet, a conversion element, a connecting shaft and a reset member. The driving gear and each driven gear axis are vertically arranged, the connecting shaft is vertically arranged and vertically slidably connected to the bracket, and two upper and lower coaxial driven gears are rotatably connected on the connecting shaft. The conversion element is rotatably connected to the bracket and the rotation axis is vertically arranged. The top of the conversion element is equidistantly distributed with a plurality of abutment surfaces along the circumferential direction, and the plurality of abutment surfaces rotate clockwise or counterclockwise. The needle direction includes a first abutment surface, a second abutment surface and a third abutment surface in sequence. The heights of the first abutment surface, the second abutment surface and the third abutment surface are increased in sequence. Adjacent abutment surfaces are connected by arc surfaces. The bottom end of the connecting shaft abuts on one of the abutment surfaces. The ratchet is connected to the bottom end of the conversion element. The middle part of the connecting plate element is rotatably connected to the bracket. The piezoelectric ceramic piece is connected to the bracket. The upper end of the connecting plate element is connected to the ratchet. The lower end of the connecting plate element is connected to the piezoelectric ceramic piece. Each time the piezoelectric ceramic piece is energized, the connecting plate element is driven to rotate and the ratchet is driven by the connecting plate element to rotate one tooth groove. The number of teeth of the ratchet is the same as the total number of abutment surfaces. When the bottom end of the connecting shaft abuts against the first abutment surface, the two driven gears are separated from the driving gear. When the bottom end of the connecting shaft abuts against the second abutment surface, the driven gear located above is meshed with the driving gear. When the bottom end of the connecting shaft abuts against the third abutment surface, the driven gear located below is meshed with the driving gear. The reset member is used to drive the connecting plate element to reset.

[0005] After adopting the above structure, the utility model has the following advantages for a single-motor multi-degree-of-freedom mechanical limb structure controlled by piezoelectric ceramics: the structure and working principle of the driven gear controlling the rotation of the auxiliary arm are the same as those of the prior art, the four driven gears correspond to the four directions of rotation of the auxiliary arm, and the two driven gears on the same connecting shaft correspond to the rotation of the auxiliary arm in two opposite directions. The piezoelectric ceramic piece will deflect each time it is energized, driving the connecting plate element to rotate, and when the connecting plate element rotates, it drives the ratchet to rotate one tooth groove. Since the number of teeth on the ratchet is the same as the number of abutment surfaces, the rotation of the ratchet by one tooth groove corresponds to the rotation of the conversion element by an angle of an abutment surface. For example, when the bottom end of the connecting shaft is aligned with the first When the abutment surfaces abut against each other, in the process of the ratchet wheel rotating through a tooth groove, the connecting shaft is first lifted by the arc surface between the first abutment surface and the second abutment surface. After the ratchet wheel rotates through a tooth groove, the bottom end of the connecting shaft abuts against the second abutment surface. The bottom end of the connecting shaft abuts against different abutment surfaces corresponding to the meshing of different driven gears and driving gears. The driven gear driven by the driving gear drives the meshing driven gear to rotate, thereby controlling the rotation of the auxiliary arm. Therefore, the piezoelectric ceramic sheet can be used to make the bottom end of the connecting shaft located on abutment surfaces of different heights, thereby realizing the rotation of the robotic arm in three degrees of freedom controlled by a single motor. A group of piezoelectric ceramic components can simultaneously control the meshing or separation of two driven gears and the driving gear, thereby reducing the overall volume.

[0006] As an improvement, the connecting shaft includes a main shaft and a secondary shaft, the bottom end of the main shaft abuts against the abutment surface, the secondary shaft is connected to the main shaft, and the two driven gears are rotatably connected to the secondary shaft.

[0007] As an improvement, the utility model also includes a vertically arranged first spring, which is compressed between the top end of the connecting shaft and the bracket; with this structure, the first spring applies a downward elastic force to the connecting shaft, and the auxiliary connecting shaft can abut against the new abutment surface each time the abutment surface is switched.

[0008] As an improvement, the upper end of the connecting plate element is connected to a first cone angle, and the lower end of the connecting plate element is connected to a second cone angle. The first cone angle is against the ratchet, and the second cone angle is against the piezoelectric ceramic piece. With this structure, the first cone angle and the second cone angle are respectively connected to the ratchet and the piezoelectric ceramic piece, which makes it easier for the piezoelectric ceramic piece to stably control the rotation of the connecting plate element, and also makes it easier for the connecting plate element to stably control the rotation of the ratchet.

[0009] As an improvement, the reset member is a horizontally arranged second spring, one end of the second spring is against the upper part of the connecting plate element, and the other end of the second spring is against the bracket; with this structure, the connecting plate element is in a vertical state in the initial state, and when the connecting plate element is deflected by the control of the piezoelectric ceramic sheet, the length of the second spring changes and generates an elastic force on the connecting plate element to cause the connecting plate element to rotate to the initial state. After the piezoelectric ceramic sheet is reset, the connecting plate element is also automatically reset under the action of the elastic force of the second spring.

[0010] As an improvement, a protrusion is provided on the upper side wall of the connecting plate element, and a groove is provided in the protrusion, and one end of the second spring abuts against the groove; with this structure, the protrusion and the groove limit the second spring, thereby improving the stability of the connection between the second spring and the connecting plate element.

[0011] As an improvement, six abutment surfaces are provided at the top of the conversion element, and the six abutment surfaces are respectively the first first abutment surface, the first second abutment surface, the first third abutment surface, the second first abutment surface, the second second abutment surface and the second third abutment surface in a clockwise or counterclockwise direction, and the number of ratchet teeth is six; adopting this structure, by setting six abutment surfaces on the conversion element, compared with setting only three abutment surfaces, the angle required for the ratchet to rotate each time is reduced, thereby improving the stability of the piezoelectric ceramic sheet and the connecting plate element in driving the ratchet to rotate. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a three-dimensional structural schematic diagram of the utility model.

[0013] Figure 2 It is a three-dimensional structural schematic diagram of the piezoelectric ceramic component part of the utility model.

[0014] Figure 3 It is a three-dimensional structural schematic diagram of the conversion element and the ratchet in the utility model.

[0015] Figure 4 It is a three-dimensional structural schematic diagram of the conversion element in the utility model.

[0016] Figure numerals: 1. mounting seat; 3. main arm; 4. auxiliary arm; 5. universal joint; 6. driving gear; 7. driven gear; 8. piezoelectric ceramic sheet; 9. connecting plate element; 10. ratchet; 11. conversion element; 12. connecting shaft; 121. main shaft; 122. auxiliary shaft; 14. first abutting surface; 15. second abutting surface; 16. third abutting surface; 17. arc surface; 18. first cone angle; 19. second cone angle; 20. protrusion; 21. groove. DETAILED DESCRIPTION

[0017] The following is a detailed description of a single-motor multi-degree-of-freedom mechanical limb structure controlled by piezoelectric ceramics according to the present invention in conjunction with the accompanying drawings.

[0018] like Figures 1 to 4As shown, a single-motor multi-degree-of-freedom mechanical limb structure controlled by piezoelectric ceramics includes a driving motor, a mounting base 1, a main arm 3, a secondary arm 4, a universal joint 5, a driving gear 6 and four driven gears 7. The main arm 3 and the secondary arm 4 are rotatably connected through the universal joint 5. The driving motor is connected to the mounting base 1 and drives the main arm 3 and the driving gear 6 to rotate. The four driven gears 7 are respectively used to drive the secondary arm 4 to rotate in four directions. Specifically, the universal joint 5 has a first rotating shaft and a second rotating shaft that are perpendicular to each other. A fixed pulley is respectively connected to the first rotating shaft and the second rotating shaft, and the four fixed pulleys are respectively connected to the four driven gears 7. The specific connection structure and working principle are all existing technologies and will not be repeated here.

[0019] In addition, the utility model also includes two groups of piezoelectric ceramic components and brackets (not shown in the figure), each group of piezoelectric ceramic components includes a piezoelectric ceramic sheet 8, a connecting plate element 9, a ratchet 10, a conversion element 11, a connecting shaft 12 and a reset member, the axis of the driving gear 6 and each driven gear 7 are vertically arranged, the connecting shaft 12 is vertically arranged and vertically slidably connected to the bracket, and the connecting shaft 12 is rotatably connected to two upper and lower coaxial driven gears 7; Figure 2 As shown, the connecting shaft 12 includes a main shaft 121 and a secondary shaft 122 . The secondary shaft 122 is connected to the main shaft 121 , and the two driven gears 7 are rotatably connected to the secondary shaft 122 .

[0020] like Figure 2 As shown, the conversion element 11 is rotatably connected to the bracket and the rotation axis is vertically arranged. The top of the conversion element 11 has a plurality of abutment surfaces equidistantly distributed along the circumferential direction, such as Figure 4 As shown, the plurality of abutment surfaces include a first abutment surface 14, a second abutment surface 15 and a third abutment surface 16 in a clockwise or counterclockwise direction, the heights of the first abutment surface 14, the second abutment surface 15 and the third abutment surface 16 are successively increased, and the adjacent abutment surfaces are connected by arc surfaces 17, the bottom end of the connecting shaft 12 abuts against one of the abutment surfaces, specifically, the bottom end of the main shaft 121 in the connecting shaft 12 abuts against the abutment surface, the ratchet 10 is connected to the bottom end of the conversion element 11, and the number of teeth of the ratchet 10 is the same as the total number of abutment surfaces; specifically, the top end of the conversion element 11 is provided with six abutment surfaces equidistantly distributed along the circumferential direction, and the six abutment surfaces are respectively the first first abutment surface 14, the first second abutment surface 15, the first third abutment surface 16, the second first abutment surface 14, the second second abutment surface 15 and the second third abutment surface 16 in a clockwise or counterclockwise direction, and in this embodiment, they are arranged in the counterclockwise direction, as shown in FIG. Figure 3As shown, the ratchet 10 has six teeth. In addition, the maximum height of the arc surface 17 in this embodiment is higher than the height of the adjacent abutment surface. For example, the maximum height of the arc surface 17 between the first first abutment surface 14 and the first second abutment surface 15 is greater than the height of the first second abutment surface 15. Therefore, there is a step difference between the arc surface 17 and the second abutment surface 15. In the process of the bottom end of the connecting shaft 12 moving from the first abutment surface 14 to the second abutment surface 15, the connecting shaft 12 first rises and then falls. Therefore, in order to keep the connecting shaft 12 always able to abut on the abutment surface vertically to ensure the stability of the structure, the connecting shaft 12 is connected to a vertically arranged first spring, and the first spring is compressed between the top end of the connecting shaft 12 and the bracket. Specifically, the first spring is compressed between the top end of the main shaft 121 and the bracket.

[0021] like Figure 2 As shown, the middle part of the connecting plate element 9 is rotatably connected to the bracket, and the rotation axis is horizontally arranged. The piezoelectric ceramic piece 8 is connected to the bracket. The piezoelectric ceramic piece 8 will deflect once after being energized, and will reset after the power is stopped; the upper end of the connecting plate element 9 is connected to the ratchet 10, and the lower end of the connecting plate element 9 is connected to the piezoelectric ceramic piece 8. Specifically, the upper end of the connecting plate element 9 is connected with a first cone angle 18, and the lower end of the connecting plate element 9 is connected with a second cone angle 19. The first cone angle 18 is against the ratchet 10, and the second cone angle 19 is against the piezoelectric ceramic piece 8; each time the piezoelectric ceramic piece 8 is energized, the connecting plate element 9 is driven to rotate and the ratchet 10 is driven by the connecting plate element 9 to rotate one tooth groove. In this embodiment, each time the piezoelectric ceramic piece 8 is energized, the ratchet 10 and the conversion element 11 are Rotate clockwise, when the bottom end of the connecting shaft 12 abuts against the first abutting surface 14, the two driven gears 7 are separated from the driving gear 6, when the bottom end of the connecting shaft 12 abuts against the second abutting surface 15, the driven gear 7 located above is meshed with the driving gear 6, and when the bottom end of the connecting shaft 12 abuts against the third abutting surface 16, the driven gear 7 located below is meshed with the driving gear 6, and the reset member is used to drive the connecting plate element 9 to reset; the reset member in this embodiment is a horizontally arranged second spring, one end of the second spring abuts against the upper part of the connecting plate element 9, and the other end of the second spring abuts against the bracket, a protrusion 20 is provided on the upper side wall of the connecting plate element 9, a groove 21 is provided in the protrusion 20, and one end of the second spring abuts in the groove 21.

[0022] The four driven gears 7 correspond to the four directions of rotation of the auxiliary arm 4. The two driven gears 7 on the same connecting shaft 12 correspond to the rotation of the auxiliary arm 4 in two opposite directions. The piezoelectric ceramic piece 8 will deflect each time it is energized, driving the connecting plate element 9 to rotate. When the connecting plate element 9 rotates, it drives the ratchet 10 to rotate one tooth groove. Since the number of teeth of the ratchet 10 is the same as the number of abutment surfaces, the rotation of the ratchet 10 by one tooth groove corresponds to the angle of the conversion element 11 rotating through one abutment surface. For example, when the bottom end of the connecting shaft 12 abuts against the first abutment surface 14, during the process of the ratchet 10 rotating through one tooth groove, the connecting shaft 12 is first lifted by the arc surface 17 between the first abutment surface 14 and the second abutment surface 15, and then the ratchet 10 rotates through one After the tooth groove, the bottom end of the connecting shaft 12 abuts against the second abutting surface 15. At this time, the state in which the two driven gears 7 are separated from the driving gear 6 is changed to the state in which only the driven gear 7 located above is meshed with the driving gear 6. The bottom end of the connecting shaft 12 abuts against different abutting surfaces, corresponding to the meshing of different driven gears 7 with the driving gear 6. The meshing driven gear 7 driven by the driving gear 6 rotates to control the rotation of the auxiliary arm 4. Therefore, the piezoelectric ceramic sheet 8 can be used to make the bottom end of the connecting shaft 12 located on abutting surfaces at different heights, thereby realizing the rotation of the mechanical arm in three degrees of freedom controlled by a single motor. A group of piezoelectric ceramic components can simultaneously control the meshing or separation of the two driven gears 7 with the driving gear 6, reducing the overall volume.

[0023] The implementation modes of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned one implementation mode, and all other embodiments obtained by those skilled in the art without making any creative work are within the scope of protection of the present invention.

Claims

1. A single-motor multi-degree-of-freedom mechanical limb structure controlled by piezoelectric ceramics, comprising a driving motor, a mounting seat (1), a main arm (3), a secondary arm (4), a universal joint (5), a driving gear (6) and four driven gears (7), wherein the main arm (3) and the secondary arm (4) are rotationally connected via the universal joint (5), the driving motor is connected to the mounting seat (1) and drives the main arm (3) and the driving gear (6) to rotate, and the four driven gears (7) are respectively used to drive the secondary arm (4) to rotate in four directions, characterized in that: The invention also comprises two groups of piezoelectric ceramic components and a bracket, each group of the piezoelectric ceramic components comprises a piezoelectric ceramic sheet (8), a connecting plate element (9), a ratchet (10), a conversion element (11), a connecting shaft (12) and a reset element, the axes of the driving gear (6) and each of the driven gears (7) are vertically arranged, the connecting shaft (12) is vertically arranged and vertically slidably connected to the bracket, the connecting shaft (12) is rotatably connected to two upper and lower coaxially arranged driven gears (7), the conversion element (11) is rotatably connected to the bracket and rotatably connected to the driven gears (7), and the conversion element (11) is rotatably connected to the bracket and rotatably connected to the driven gears (7) The moving axis is arranged vertically, and a plurality of abutment surfaces are evenly distributed along the circumferential direction at the top end of the conversion element (11), and the plurality of abutment surfaces sequentially include a first abutment surface (14), a second abutment surface (15) and a third abutment surface (16) in a clockwise or counterclockwise direction. The heights of the first abutment surface (14), the second abutment surface (15) and the third abutment surface (16) are successively increased, and adjacent abutment surfaces are connected by arc surfaces (17). The bottom end of the connecting shaft (12) abuts against one of the abutment surfaces, and the ratchet (1 0) is connected to the bottom end of the conversion element (11), the middle part of the connecting plate element (9) is rotatably connected to the bracket, the piezoelectric ceramic sheet (8) is connected to the bracket, the upper end of the connecting plate element (9) is connected to the ratchet (10), and the lower end of the connecting plate element (9) is connected to the piezoelectric ceramic sheet (8). Each time the piezoelectric ceramic sheet (8) is energized, the connecting plate element (9) is driven to rotate and the connecting plate element (9) is driven to rotate the ratchet (10) by one tooth groove. The number of teeth of the ratchet (10) is the same as the total number of the abutment surfaces. When the When the bottom end of the connecting shaft (12) abuts against the first abutting surface (14), the two driven gears (7) are separated from the driving gear (6); when the bottom end of the connecting shaft (12) abuts against the second abutting surface (15), the driven gear (7) located above is meshed with the driving gear (6); when the bottom end of the connecting shaft (12) abuts against the third abutting surface (16), the driven gear (7) located below is meshed with the driving gear (6); the reset member is used to drive the connecting plate element (9) to reset.

2. The single-motor multi-degree-of-freedom mechanical limb structure controlled by piezoelectric ceramics according to claim 1, characterized in that: The connecting shaft (12) comprises a main shaft (121) and a secondary shaft (122); the bottom end of the main shaft (121) abuts against the abutment surface; the secondary shaft (122) is connected to the main shaft (121); and the two driven gears (7) are rotatably connected to the secondary shaft (122).

3. The single-motor multi-degree-of-freedom mechanical limb structure controlled by piezoelectric ceramics according to claim 1, characterized in that: It also includes a first spring arranged vertically, wherein the first spring is compressed between the top end of the connecting shaft (12) and the bracket.

4. The single-motor multi-degree-of-freedom mechanical limb structure controlled by piezoelectric ceramics according to claim 1, characterized in that: The upper end of the connecting plate element (9) is connected to a first cone angle (18), and the lower end of the connecting plate element (9) is connected to a second cone angle (19); the first cone angle (18) abuts against the ratchet (10), and the second cone angle (19) abuts against the piezoelectric ceramic sheet (8).

5. The single-motor multi-degree-of-freedom mechanical limb structure controlled by piezoelectric ceramics according to claim 1, characterized in that: The reset member is a second spring arranged horizontally, one end of the second spring abuts against the upper part of the connecting plate element (9), and the other end of the second spring abuts against the bracket.

6. The single-motor multi-degree-of-freedom mechanical limb structure controlled by piezoelectric ceramics according to claim 5, characterized in that: A protrusion (20) is provided on the upper side wall of the connecting plate element (9), a groove (21) is provided in the protrusion (20), and one end of the second spring abuts against the groove (21).

7. The single-motor multi-degree-of-freedom mechanical limb structure controlled by piezoelectric ceramics according to claim 1, characterized in that: The top of the conversion element (11) is provided with six abutment surfaces, and the six abutment surfaces are, in a clockwise or counterclockwise direction, the first first abutment surface (14), the first second abutment surface (15), the first third abutment surface (16), the second first abutment surface (14), the second second abutment surface (15) and the second third abutment surface (16), and the ratchet wheel (10) has six teeth.

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