A damping tablet pressing multi-degree-of-freedom thumb mechanism

Abstract

This invention provides a multi-degree-of-freedom thumb mechanism with a damping pressure plate, comprising: a thumb body, the thumb body including a first finger segment, a second finger segment, and a third finger segment connected in sequence; a first driving part, the first driving part driving the first finger segment to bend and extend; a second driving part, the second driving part driving the second finger segment to bend and extend; a third driving part, the third driving part driving the third finger segment to rotate, thereby causing the first finger segment and the second finger segment to rotate; a base, the base integrating the first driving part, the second driving part, and the third driving part at the end of the third finger segment; and a damping pressure plate, the damping pressure plate being installed on the third driving part to counteract the looseness caused by backlash in the third driving part. The thumb mechanism of this invention has multiple degrees of freedom; by adding a damping pressure plate to the third driving part, backlash is counteracted, thereby ensuring gripping and operational accuracy.

Description

Technical Field

[0001] This invention relates to the field of robotic arms, and more specifically, to a multi-degree-of-freedom thumb mechanism with damping pressure plate. Background Technology

[0002] Robotic fingers, as a key component of robot end effectors, play a crucial role in improving the overall performance of robot systems due to their grasping ability, operational precision, and reliability. Especially for dexterous robotic hands aiming to simulate human hand functions, despite continuous technological advancements, current robotic hands are often limited by their relatively low dexterity, making them ill-suited for complex and varied tasks.

[0003] It is worth noting that while increasing the degrees of freedom of a single finger improves finger dexterity, it also increases the complexity of the drive mechanism, leading to a larger overall size of the robotic hand. This increased size not only raises manufacturing costs but may also limit the robotic hand's application in confined spaces or specific environments, thus restricting the breadth of its practical applications.

[0004] In addition, the drive unit usually has backlash problems caused by gear transmission, which can cause the fingers to become loose, which is not conducive to gripping and operation accuracy. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a multi-degree-of-freedom thumb mechanism with damping pressure plate.

[0006] According to one aspect of the present invention, a multi-degree-of-freedom thumb mechanism with damping pressure plate is provided, comprising:

[0007] The thumb body comprises a first finger segment, a second finger segment, and a third finger segment connected in sequence;

[0008] A first driving unit drives the first finger segment to bend and extend;

[0009] The second driving part drives the second finger segment to bend and extend;

[0010] The third driving unit drives the third finger segment to rotate, thereby causing the first finger segment and the second finger segment to rotate.

[0011] A base that integrates the first driving part, the second driving part, and the third driving part at the end of the third finger segment;

[0012] A damping plate is installed on the third drive unit to counteract the looseness caused by the back clearance of the third drive unit.

[0013] Preferably, the first drive unit and the second drive unit are coaxially designed to achieve independent control of the first finger segment and the second finger segment, specifically:

[0014] The first driving unit includes:

[0015] A first motor is fixed to the lower surface of the base;

[0016] A first worm gear is disposed on the upper surface of the base and connected to the output shaft of the first motor;

[0017] A first turbine, which meshes with a first worm gear;

[0018] A first rotating shaft is inserted into the first turbine;

[0019] The first winch is sleeved on the first rotating shaft;

[0020] The first steel wire rope is coiled on the first winch and extends outward until it connects with the first finger segment;

[0021] The second drive unit includes:

[0022] The second motor is fixed to the lower surface of the base;

[0023] The second worm gear is disposed on the upper surface of the base and is connected to the output shaft of the second motor;

[0024] The second turbine is sleeved on the first rotating shaft and meshes with the second worm.

[0025] The second winch is disposed at the end of the first shaft and adjacent to the first winch;

[0026] The second steel wire rope is coiled on the second winch and extends outward until it connects with the second finger segment.

[0027] Preferably, the first finger segment and the second finger segment are hinged together by a first motion axis; the second finger segment and the third finger segment are hinged together by a second motion axis.

[0028] A guide wheel is installed in each of the third and second finger segments;

[0029] The first steel wire rope runs along each of the guide wheels, passes around the first motion axis, and connects to the first finger segment, directly driving the first finger segment to rotate; the second steel wire rope runs along the guide wheels and is connected to the second motion axis through a bushing.

[0030] Preferably, the first turbine and the first shaft are concentrically mounted via a transition bushing, and the first turbine and the first winch are designed as an integrated unit.

[0031] The second turbine is fixed to the first shaft, and the second winch is fixed to the first shaft.

[0032] Preferably, when the first motor is started, it drives the first worm gear to rotate, which in turn drives the first turbine to rotate and the first winch to rotate simultaneously in the transition bushing, thereby driving the first steel wire rope, while the first rotating shaft remains unaffected and maintains its original state.

[0033] The second motor starts, driving the second worm gear to rotate, which in turn drives the second turbine, the first shaft and the second winch to rotate together, thus moving the second wire rope.

[0034] Preferably, the third driving unit includes:

[0035] The third drive shaft is connected to the third finger segment and maintains the same axial direction as it;

[0036] The third worm gear, the third turbine being fixed to the end of the third drive shaft;

[0037] A third motor is fixed to the lower surface of the base;

[0038] The third worm gear is disposed on the upper surface of the base, connected to the output shaft of the third motor, and meshes with the third turbine.

[0039] Preferably, the third drive shaft is a hollow shaft, and the first steel wire rope and the second steel wire rope pass through the third drive shaft;

[0040] When the first finger segment, the second finger segment, and the third finger segment move synchronously, the third driving part does not affect the first steel wire rope and the second steel wire rope.

[0041] Preferably, the third drive shaft is made of a self-lubricating material, which includes POM, PPS, or POM or PPS sprayed onto a metal material.

[0042] Preferably, the damping plate provides rotational damping for the third drive shaft to counteract the looseness caused by the backlash of the third worm and the third turbine;

[0043] The damping pressure plate includes:

[0044] Two fixing ears are provided in parallel to each other; the entire damping plate is fixed to the base by means of the fixing ears.

[0045] The first arch plate spans between the two fixed lugs;

[0046] The second arch piece spans between the two fixed lugs, is parallel to the first arch piece and has a gap between them;

[0047] The third arch piece is parallel to the second arch piece and maintains a gap; one end of the third arch piece is fixed to the fixing lug, and the other end is suspended.

[0048] The first arch plate, the second arch plate, the third arch plate, and the clearance fit between them are pressed against the surface of the third drive shaft.

[0049] Preferably, the inner surface of the third arch plate is provided with protrusions; the protrusions press against the surface of the third drive shaft.

[0050] Compared with the prior art, the embodiments of the present invention have at least one of the following beneficial effects:

[0051] The multi-degree-of-freedom thumb mechanism with damping pressure plate in this embodiment of the invention has multiple degrees of freedom; by adding a damping pressure plate to the third drive part, the backlash phenomenon is offset, thereby ensuring the gripping and operation accuracy.

[0052] The multi-degree-of-freedom thumb mechanism with damping pressure plate in this embodiment of the invention adopts a coaxial design for the first and second drive parts, which improves the flexibility of the fingers and increases the drive power device while avoiding an increase in the overall size of the robot hand.

[0053] The multi-degree-of-freedom thumb mechanism with damping pressure plate in this embodiment of the invention uses multiple steel wires and worm gears for drive. Through clever arrangement, the finger's gripping ability, operation ability, reliability and flexibility are improved. Attached Figure Description

[0054] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0055] Figure 1 This is a schematic diagram of the structure of a multi-degree-of-freedom thumb mechanism with damping pressure plate in one embodiment of the present invention;

[0056] Figure 2 This is a side view of a multi-degree-of-freedom thumb mechanism with damping pressure plate according to an embodiment of the present invention;

[0057] Figure 3 This is a cross-sectional view showing the connection relationship between the first driving unit and the second driving unit in a preferred embodiment of the present invention.

[0058] Figure 4This is a diagram showing the connection relationship between the second turbine and the first shaft in a preferred embodiment of the present invention;

[0059] Figure 5 This is an overall cross-sectional view of the multi-degree-of-freedom thumb mechanism in a preferred embodiment of the present invention;

[0060] Figure 6 To and Figure 5 A corresponding overall sectional view from another perspective;

[0061] Figure 7 This is a schematic diagram of the damping pressure plate structure in a preferred embodiment of the present invention.

[0062] In the diagram, 1-first finger segment, 2-second finger segment, 3-third drive shaft, 4-third worm gear, 5-second worm gear, 6-second turbine, 7-first shaft, 8-first turbine, 9-first winch, 10-second winch, 11-first worm gear, 12-first motor, 13-third turbine, 14-third motor, 15-third finger segment, 16-base, 17-second motor, 18-outer shell, 19-damping pressure plate, 191-fixed lug, 192-first arch plate, 193-second arch plate, 194-third arch plate, 195-protrusion. Detailed Implementation

[0063] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0064] In one embodiment of the present invention, a multi-degree-of-freedom thumb mechanism with a damping pressure plate is provided, comprising a thumb body, a first driving part, a second driving part, a third driving part, a base, and a damping pressure plate.

[0065] The thumb body includes a first finger segment 1, a second finger segment 2, and a third finger segment 15 connected in sequence; a first driving part drives the first finger segment 1 to bend and extend; a second driving part drives the second finger segment 2 to bend and extend; a third driving part drives the third finger segment 15 to rotate, thereby causing the first finger segment 1 and the second finger segment 2 to rotate; a base 16 integrates the first driving part, the second driving part, and the third driving part at the end of the third finger segment 15; a damping plate 19 is installed on the third driving part to counteract the looseness caused by the back gap of the third driving part.

[0066] The multi-degree-of-freedom thumb mechanism with damping pressure plate in this embodiment has multiple degrees of freedom; by adding damping to the third drive unit, the backlash phenomenon is offset, thereby ensuring the gripping and operation accuracy.

[0067] Each finger segment is controlled by a drive unit, which increases the overall size of the robotic arm. In a preferred embodiment of the present invention, a coaxial design of the first and second drive units is proposed to save design space. Specifically, the first drive unit includes a first motor 12, a first worm gear 11, a first turbine 8, a first winch 9, and a first wire rope. The first motor 12 is fixed to the lower surface of the base 16, with its output shaft extending upwards. The first worm gear 11 is sleeved outside the output shaft. The first turbine 8 meshes with the first worm gear 11. A first rotating shaft 7 is inserted into the first turbine 8. The first winch 9 is mounted on the first rotating shaft 7. The first wire rope is coiled on the first winch 9, extending outwards until it connects to the first finger segment 1.

[0068] Similarly, the second drive unit includes a second motor 17, a second worm gear 5, a second turbine 6, a second winch 10, and a second wire rope. The second drive unit is coaxial with the first drive unit, primarily in two aspects: the turbines of both drive units are coaxial, and the winches of both drive units are coaxial, thus ensuring a compact arrangement of the two ropes. Specifically, the second motor 17 is fixed to the lower surface of the base 16, with its output shaft extending upwards. The second worm gear 5 is sleeved outside the output shaft. The second turbine 6 meshes with the second worm gear 5. The second worm gear 6 is sleeved outside the first rotating shaft 7. The second winch 10 is located at the end of the first rotating shaft 7 and is adjacent to the first winch 9. The second wire rope is coiled on the second winch and extends outwards until it connects with the second finger segment.

[0069] To achieve more flexible and precise control of the wire rope over the first or second finger segment, in a preferred embodiment, such as... Figure 5 , Figure 6 As shown, the first finger segment 1 and the second finger segment 2 are hinged together by a first motion shaft; the second finger segment 2 and the third finger segment 15 are hinged together by a second motion shaft. Bushings are installed outside the first and second motion shafts, and a right guide wheel is installed inside the third finger segment, and a left guide wheel is installed inside the second finger segment.

[0070] The first steel wire rope extends outward from the first winch, passes around the right guide wheel, the second motion shaft, the left guide wheel, and the first motion shaft, and is fixedly connected to the first finger segment; the first steel wire rope directly drives the first finger segment to rotate around the first motion shaft.

[0071] The second steel wire rope extends outward from the first winch, passes around the right guide wheel, and is fixed to the bushing of the second motion shaft.

[0072] It should be noted that the second steel wire rope starts from one side of the right guide wheel and wraps around to the same side of the second motion shaft; the first steel wire rope starts from one side of the right guide wheel and wraps around to the other side of the second motion shaft. Therefore, from... Figure 5 and Figure 6The first steel wire rope is S-shaped at the second motion shaft and the right guide wheel, while the second steel wire rope is semi-elliptical at the second motion shaft and the right guide wheel.

[0073] Normally, the rotation of the second drive unit affects the first drive unit. This is a coupling effect. When the second drive unit rotates, the first drive motor operates relative to it, ensuring that the rotation of the second drive unit does not affect the first drive unit. Through this structural design, when the second drive unit drives the second finger segment to retract, the first drive unit needs to relax the first finger segment to counteract the effect of the second drive. When the second drive unit drives the second finger segment to relax, the first drive unit needs to retract the first finger segment to counteract the effect of the second drive.

[0074] To further achieve flexible control over the first and second finger segments, in a preferred embodiment, as follows: Figure 3 and Figure 4 As shown, a transition sleeve is installed between the first turbine 8 and the first rotating shaft 7 to achieve concentric installation, so that the first turbine 8 does not drive the first rotating shaft 7 while rotating. The first winch 9 is fixed to the first turbine 8, which can be an integrated design.

[0075] The second turbine 6 is fixed to the first shaft 7, and the second winch 10 is fixed to the first shaft 7. The second turbine 6 and the first shaft are connected by a T-shaped connection, and the first shaft 7 and the second winch 10 are connected by a D-shaped shaft. This design can transmit torque.

[0076] Based on the structural design in the above embodiments, in a preferred embodiment of the present invention, the first drive unit and the second drive unit are operated. Specifically, the first motor 12 is started, its output shaft rotates, which drives the first worm gear 11 to rotate, and the transmission causes the first turbine 8 to rotate, which drives the first winch 9 to rotate, thereby causing the first wire rope to move.

[0077] The second motor 17 starts, and its output shaft rotates, which drives the second worm gear 5 to rotate. This transmission causes the second turbine 6 to rotate, which in turn drives the first rotating shaft 7 and the second winch 10 to rotate simultaneously, thereby causing the second wire rope to move.

[0078] In some specific embodiments, an additional housing 18 is also installed, which mainly provides a fixing function for the first rotating shaft 7, the first turbine 8, and the second turbine 6.

[0079] The degree of freedom of the third finger segment differs from that of the first and second finger segments. To enable the first, second, and third finger segments to move synchronously as a whole, a preferred embodiment of the present invention provides a preferred method for the third drive unit. Specifically, the third drive unit includes a third drive shaft 3, a third motor 14, a third worm gear 4, and a third turbine 13. The third drive shaft 3 is connected to the third finger segment 15. The direction of the third drive shaft 3 is perpendicular to the directions of the first and second motion axes, i.e., the third motion shaft 3 and the third finger segment are coaxial. The third turbine 13 is located at the end of the third drive shaft. The third motor 14 is also located on the lower surface of the base 16, and its output shaft is also connected to the third worm gear 4, which meshes with the third turbine 13.

[0080] When the third finger segment needs to rotate, the third motor 14 is started, which drives the third worm gear 4 to rotate. The transmission causes the third turbine 13 to rotate, which drives the third drive shaft 3 to rotate, thereby causing the third finger segment to rotate, that is, the entire thumb body to rotate synchronously.

[0081] In a preferred embodiment, the third drive shaft 3 is configured as a hollow shaft, through which the first steel wire rope and the second steel wire rope pass, ensuring that when the third drive shaft 13 drives the three finger segments to move together, the impact on the spatial position of the first steel wire rope and the second steel wire rope is reduced.

[0082] The above embodiments employ multiple steel wires and worm gears for drive. Through clever arrangement, the finger gripping ability, operation ability, reliability, and flexibility are improved.

[0083] Typically, the third drive shaft will experience overall loosening of the third finger segment due to the backlash in the third turbine and third worm gear transmission. Therefore, in a preferred embodiment, the third drive shaft 3 uses a self-lubricating material, including POM (Polyoxymethylene, a high-performance thermoplastic), PPS (Polyphenylene Sulfide, a semi-crystalline high-temperature thermoplastic polymer), or POM or PPS sprayed onto a metal material.

[0084] Furthermore, in a preferred embodiment, the third drive shaft 3 employs a damping plate to provide rotational shaft damping, thereby counteracting the backlash of the third turbine and the third worm gear.

[0085] Specifically, such as Figure 7As shown, the damping plate 19 includes an integrally formed fixing lug 191, a first arch plate 192, a second arch plate 193, and a fourth arch plate 194. The two fixing lugs 191 are parallel; the entire damping plate is fixed to the base 16 via the fixing lugs 191. The first arch plate 192 spans between the two fixing lugs 191. The second arch plate 192 spans between the two fixing lugs, parallel to the first arch plate 192 with a gap. The third arch plate 194 is parallel to the second arch plate 193 and maintains a gap. One end of the third arch plate 194 is fixed to the fixing lug 191, and the other end is suspended; the purpose of this suspension is to maintain the arch plate's elasticity while pressing against the drive shaft. The first arch plate, second arch plate, third arch plate, and the gap between them fit together and press against the surface of the third drive shaft. The elastic deformation of the arch plates presses against the drive shaft, providing a damping effect. Because the rotating shaft is damped, in actual operation, the looseness caused by the back gap can be eliminated.

[0086] Preferably, in some other embodiments, the inner surface of the third arch plate 194 is provided with a protrusion 195; the protrusion 195 is press-fitted against the surface of the third drive shaft. The entire third arch plate is press-fitted against the rotating shaft, which is not conducive to adjusting the damping magnitude; the protrusion can provide available damping.

[0087] The above embodiment, by installing a damping plate on the surface of the third drive shaft, compensates for the backlash phenomenon and provides control precision for the thumb.

[0088] Similarly, the first and second worm gears also have backlash. In some embodiments, tension springs are used for the first and second finger segments to address the backlash issue.

[0089] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention. The above preferred features can be used in any combination without conflict.

Claims

1. A multi-degree-of-freedom thumb mechanism with damping pressure plate, characterized in that, include: The thumb body comprises a first finger segment, a second finger segment, and a third finger segment connected in sequence; A first driving unit drives the first finger segment to bend and extend; The second driving part drives the second finger segment to bend and extend; The third driving unit drives the third finger segment to rotate, thereby causing the first finger segment and the second finger segment to rotate. A base that integrates the first driving part, the second driving part, and the third driving part at the end of the third finger segment; A damping plate is installed on the third drive unit to counteract the looseness caused by the back clearance of the third drive unit; The third drive unit includes: The third drive shaft is connected to the third finger segment and maintains the same axial direction as it; The third worm gear is fixed to the end of the third drive shaft; A third motor is fixed to the lower surface of the base; The third worm gear is disposed on the upper surface of the base, connected to the output shaft of the third motor, and meshes with the third worm wheel; The damping plate provides rotational damping for the third drive shaft, counteracting the looseness caused by the backlash of the third worm and the third worm wheel; The damping pressure plate includes: Two fixing ears are provided in parallel to each other; the entire damping plate is fixed to the base by means of the fixing ears. The first arch plate spans between the two fixed lugs; The second arch piece spans between the two fixed lugs, is parallel to the first arch piece and has a gap between them; The third arch piece is parallel to the second arch piece and maintains a gap; one end of the third arch piece is fixed to the fixing lug, and the other end is suspended. The first arch plate, the second arch plate, the third arch plate, and the clearance fit between them are pressed against the surface of the third drive shaft.

2. The multi-degree-of-freedom thumb mechanism with damping pressure plate according to claim 1, characterized in that, The first drive unit and the second drive unit adopt a coaxial design to achieve independent control of the first finger segment and the second finger segment, specifically: The first driving unit includes: A first motor is fixed to the lower surface of the base; A first worm gear is disposed on the upper surface of the base and connected to the output shaft of the first motor; A first turbine, which meshes with a first worm gear; A first rotating shaft is inserted into the first turbine; The first winch is sleeved on the first rotating shaft; The first steel wire rope is coiled on the first winch and extends outward until it connects with the first finger segment; The second drive unit includes: The second motor is fixed to the lower surface of the base; The second worm gear is disposed on the upper surface of the base and is connected to the output shaft of the second motor; The second turbine is sleeved on the first rotating shaft and meshes with the second worm. The second winch is disposed at the end of the first shaft and adjacent to the first winch; The second steel wire rope is coiled on the second winch and extends outward until it connects with the second finger segment.

3. The multi-degree-of-freedom thumb mechanism with damping pressing plate according to claim 2, characterized in that, The first finger segment and the second finger segment are hinged together by a first motion axis; the second finger segment and the third finger segment are hinged together by a second motion axis. A guide wheel is installed in each of the third and second finger segments; The first steel wire rope runs along each of the guide wheels, passes around the first motion axis, and connects to the first finger segment, directly driving the first finger segment to rotate; the second steel wire rope runs along the guide wheels and is connected to the second motion axis through a bushing.

4. The multi-degree-of-freedom thumb mechanism with damping pressing plate according to claim 3, characterized in that, The first turbine and the first shaft are concentrically mounted via a transition bushing, and the first turbine and the first winch are designed as an integrated unit. The second turbine is fixed to the first shaft, and the second winch is fixed to the first shaft.

5. A multi-degree-of-freedom thumb mechanism with damping pressure plate according to claim 4, characterized in that, When the first motor starts, it drives the first worm gear to rotate, which in turn drives the first turbine to rotate and the first winch to rotate simultaneously in the transition bushing, which in turn drives the first steel wire rope. The first rotating shaft remains unaffected and maintains its original state. The second motor starts, driving the second worm gear to rotate, which in turn drives the second turbine, the first shaft and the second winch to rotate together, thus moving the second wire rope.

6. The multi-degree-of-freedom thumb mechanism with damping pressing plate according to claim 2, characterized in that, The third drive shaft is a hollow shaft, and the first steel wire rope and the second steel wire rope pass through the third drive shaft; When the first finger segment, the second finger segment, and the third finger segment move synchronously, the third driving part does not affect the first steel wire rope and the second steel wire rope.

7. A multi-degree-of-freedom thumb mechanism with damping pressure plate according to claim 1, characterized in that, The third drive shaft uses a self-lubricating material, which includes POM, PPS, or POM or PPS sprayed onto a metal material.

8. The multi-degree-of-freedom thumb mechanism with damping pressure plate according to claim 1, characterized in that, The inner surface of the third arch plate is provided with protrusions; the protrusions press against the surface of the third drive shaft.

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