A design method for a mechanical finger

Abstract

The present invention provides a design method for a mechanical finger, the mechanical finger includes three joints and two transmission mechanisms connecting the three joints in sequence, each joint includes a driving spur gear, a secondary driving spur gear and a driven spur gear, each transmission mechanism includes a plurality of transmission wheels arranged between the driving spur gears of two adjacent joints and meshing in sequence; the design method is used to design the number of teeth of each gear so that the rotation speeds of the three joints of the mechanical finger are the same or close. The design method of the mechanical finger makes the bending angles of the three joints of the mechanical finger the same or close at the same time, thereby improving the flexibility and grasping efficiency of the mechanical finger.

Description

Technical Field

[0001] The invention belongs to the technical field of manipulators, and in particular relates to a design method for a manipulator finger. Background Art

[0002] Robots are used to imitate human hands and play an important role in contemporary production and life, for example, they are used to grasp objects. However, when grasping objects, the robot hands and robot fingers in the prior art cannot contact the object to be grasped at the same time because the rotation speeds of the joints of the robot fingers are different, that is, the bending angles of the joints are different at the same time. It is necessary to wait until all the joints are in contact with the object before grasping can be achieved, which reduces the efficiency of the robot fingers; in order to make all joints rotate at the same speed in the prior art, a power device is often set separately for each joint, which increases the complexity of the robot hands and robot fingers, increases the size of the robot hands and robot fingers, and increases the cost. Summary of the invention

[0003] The technical purpose of the present invention is to provide a design method for a mechanical finger, aiming to drive the three joints of the mechanical finger when only one power device is provided, and make the bending angles of the three joints of the mechanical finger the same or close at the same time.

[0004] In order to solve the above technical problems, the present invention proposes a design method for a mechanical finger, which is used to design the number of teeth of each gear in the mechanical finger so that the rotation speeds of the first driven spur gear, the second driven spur gear and the third driven spur gear are the same or close to each other, thereby achieving the same or close rotation speeds of the three joints of the mechanical finger, that is, the same or close bending angles of the three joints at the same time. The design method comprises the following steps:

[0005] S1: According to the working conditions of the robot finger, the numbers of teeth of the first auxiliary spur gear and the first driven spur gear are selected so that the number of teeth of the first auxiliary spur gear is the minimum value under the working conditions, and the number of teeth of the first driven spur gear is the maximum value under the working conditions;

[0006] S2: Select the number of teeth of the first driving spur gear and the first transmission wheel according to equation 1, which is:

[0007] The number of teeth of the first active spur gear + the number of teeth of the first transmission wheel = the number of teeth of the first auxiliary spur gear + the number of teeth of the first driven spur gear;

[0008] S3: selecting any angle less than 180° as a reference angle, and calculating the angle of rotation of the first driving spur gear when the first driven spur gear rotates by the reference angle according to the number of teeth of the first driven spur gear, the first auxiliary driven spur gear and the first driving spur gear;

[0009] S4: Selecting the number of teeth of the second driving spur gear and the second transmission wheel so that the number of teeth of the second driving spur gear and the second transmission wheel are both between the number of teeth of the first auxiliary driving spur gear and the first driven spur gear, and calculating the rotation angle of the second driving spur gear when the first driven spur gear rotates by the reference angle;

[0010] S5: Select the number of teeth of the second auxiliary spur gear and the second driven spur gear so that the number of teeth of the two gears is between the number of teeth of the first auxiliary spur gear and the first driven spur gear, and the number of teeth of the two gears satisfies equation 2, and when the second driving spur gear rotates at the angle described in step S4, the angle of rotation of the second driven spur gear is the same as or close to the reference angle; equation 2 is:

[0011] The number of teeth of the second auxiliary spur gear + the number of teeth of the second driven spur gear = the number of teeth of the second driving spur gear + the number of teeth of the second transmission wheel;

[0012] S6: Select the number of teeth of the third driving spur gear, which is between the number of teeth of the first auxiliary driving spur gear and the first driven spur gear; calculate the angle of rotation of the third driving spur gear when the second driven spur gear rotates at the angle in step S5;

[0013] S7: Select the number of teeth of the third auxiliary spur gear and the third driven spur gear so that the number of teeth of both is between the number of teeth of the first auxiliary spur gear and the first driven spur gear, and when the third driving spur gear rotates at the angle described in step S6, the angle of rotation of the third driven spur gear is the same as or close to the reference angle.

[0014] Furthermore, the first active spur gear and the first transmission gear have the same number of teeth, and the equation 1 in step S2 is:

[0015] The number of teeth of the first driving spur gear = the number of teeth of the first transmission wheel = (the number of teeth of the first auxiliary driving spur gear + the number of teeth of the first driven spur gear) / 2.

[0016] Furthermore, the second driving spur gear has the same number of teeth as the first transmission gear, and the equation for calculating the rotation angle of the second driving spur gear in step S4 is:

[0017] The rotation angle of the second driving spur gear = the rotation angle of the first driving spur gear - the revolution angle of the second driving spur gear around the first driven spur gear = the rotation angle of the first driving spur gear - the reference angle.

[0018] Further, the second transmission wheel and the second active spur gear have the same number of teeth, and the equation 2 in step S5 is:

[0019] The number of teeth of the second auxiliary spur gear + the number of teeth of the second driven spur gear = the number of teeth of the second driving spur gear × 2 = the number of teeth of the second transmission wheel × 2.

[0020] Furthermore, the third driving spur gear has the same number of teeth as the second transmission gear.

[0021] Further, the number of teeth of the third auxiliary spur gear and the third driven spur gear satisfies the following equation:

[0022] The number of teeth of the third auxiliary spur gear + the number of teeth of the third driven spur gear = the number of teeth of the first auxiliary spur gear + the number of teeth of the first driven spur gear.

[0023] Furthermore, the reference angle is 60°-120°.

[0024] Through the above method, the rotation speeds of the first driven spur gear, the second driven spur gear and the third driven spur gear are the same or close, that is, at the same moment, the rotation angles of the first driven spur gear, the second driven spur gear and the third driven spur gear are the same or close, and the rotation angles of the first driven spur gear, the second driven spur gear and the third driven spur gear respectively correspond to the bending angles of the three joints of the robotic finger. Therefore, at the same moment, the bending angles of the three joints of the robotic finger are the same or close.

[0025] Compared with the prior art, the design method of the mechanical finger of the present invention has the beneficial effect that the bending angles of the three joints of the mechanical finger are the same or close at the same time, thereby improving the flexibility and grasping efficiency of the mechanical finger. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic diagram of the overall structure of a mechanical finger in an embodiment of the present invention;

[0027] Figure 2 is an exploded view of a mechanical finger in an embodiment of the present invention;

[0028] Figure 3 is a partial exploded view of the first joint in an embodiment of the present invention;

[0029] Figure 4 is a partial exploded view of the second joint in an embodiment of the present invention;

[0030] Figure 5 It is a flow chart of the design method of the present invention.

[0031] In the accompanying drawings, each reference numeral represents:

[0032] 2-driving assembly, 3-first joint, 4-first transmission mechanism, 5-second joint, 6-second transmission mechanism, 7-third joint, 11-fixing part, 12-first finger joint, 13-second finger joint, 14-third finger joint, 21-motor, 22-driving bevel gear, 23-driven bevel gear, 24-driven spur gear, 25-synchronizing pin shaft, 31-first driving spur gear, 32-first auxiliary driving spur gear, 33-first driven spur gear, 34-first annular pin, 35-first pin shaft, 41-first transmission wheel, 51-second driving spur gear, 52-second auxiliary driving spur gear, 53- The second driven spur gear, 54-the second annular pin, 61-the second transmission wheel, 71-the third driving spur gear, 72-the third auxiliary spur gear, 73-the third driven spur gear, 74-the third annular pin, 75-the square column pin, 76-the fourth driven spur gear, 111-the upper fixed plate, 112-the lower fixed plate, 121-the first upper clamping plate, 122-the first lower clamping plate, 131-the second upper clamping plate, 132-the second lower clamping plate, 141-the third upper clamping plate, 142-the third lower clamping plate, 341-the first protrusion, 541-the second protrusion, 1211-the first slot, 1311-the second slot. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0034] In the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "back", "bottom", "inner", "outer", "axial" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0035] Example:

[0036] In this embodiment, if Figure 1 and Figure 2 As shown in , the mechanical finger includes a fixing portion 11, a first finger joint 12, a second finger joint 13 and a third finger joint 14 arranged in sequence, and also includes:

[0037] A first joint 3, used to rotatably connect the first knuckle 12 to the fixing portion 11;

[0038] The second joint 5 is used to rotatably connect the second knuckle 13 to the first knuckle 12;

[0039] A third joint 7, used to rotatably connect the third finger joint 14 to the second finger joint 13;

[0040] A driving assembly 2 connected to the first joint 3 and used to drive the first knuckle 12 to rotate relative to the fixing portion 11;

[0041] A first transmission mechanism 4 is connected to the first joint 3 and the second joint 5 and transmits power, and is used to drive the second joint 13 to rotate relative to the first joint 12 when the first joint 12 rotates relative to the fixing part 11;

[0042] The second transmission mechanism 6 connects the second joint 5 and the third joint 7 and transmits the transmission, and is used to drive the third knuckle 14 to rotate relative to the second knuckle 13 when the second knuckle 13 rotates relative to the first knuckle 12 .

[0043] During operation, the driving assembly 2 provides power to drive the first joint 3 to move, so that the first finger joint 12 rotates relative to the fixed part 11, and the first joint of the mechanical finger is bent; at the same time, the first transmission mechanism 4 transmits between the first joint 3 and the second joint 5, drives the second joint 5 to move, and then the second finger joint 13 rotates relative to the first finger joint 12, and the second joint of the mechanical finger is bent; and the movement of the second joint 5 is transmitted to the third joint 7 through the second transmission mechanism 6, so that the third finger joint 14 rotates relative to the second finger joint 13, and the third joint of the mechanical finger is bent. Through the above scheme, only one power source is needed to realize the bending of three joints, which not only saves power but also makes the structure of the device simpler.

[0044] The following is a detailed description of each component.

[0045] like Figure 1 and Figure 2 As shown in the figure, the driving assembly 2 includes: a motor 21, a driving bevel gear 22, a driven bevel gear 23 and a driven spur gear 24; wherein, the output shaft of the motor 21 is coaxially connected to the driving bevel gear 22, and the driven bevel gear 23 is meshed with the driving bevel gear 22; the driven spur gear 24 is coaxially connected to the driven bevel gear 23; through this scheme, the driving bevel gear 22 rotates with the motor 21, and the driven bevel gear 23 is meshed with the driving bevel gear 22, changing the direction of rotation, and the driven spur gear 24 rotates with the driven bevel gear 23, and further transmits power to each knuckle of the mechanical finger.

[0046] Specifically, the driving bevel gear 22 and the output shaft of the motor 21 can be fixedly connected, such as by welding, or can be connected by a pin or key to achieve synchronous rotation. The driven spur gear 24 and the driven bevel gear 23 are connected by a synchronous pin shaft 25.

[0047] The fixing portion 11 includes an upper fixing plate 111 and a lower fixing plate 112. Figure 1 and Figure 2As shown in , the upper fixing plate 111 is located between the driven bevel gear 23 and the driven spur gear 24, the lower fixing plate 112 is located below the driven spur gear 24, and the upper fixing plate 111 and the lower fixing plate 112 are both rotatably connected to the synchronization pin 25, and when the synchronization pin 25 rotates, the upper fixing plate 111 and the lower fixing plate 112 remain stationary. On this basis, the upper fixing plate 111 and the lower fixing plate 112 can be further fixed by other means, such as being connected to the fixed part of the motor 21, and the connection can be a direct connection or an indirect connection, and can be achieved by various means such as welding, bonding, clamping, and bolting.

[0048] The first joint 3 includes a first driving spur gear 31, a first secondary driven spur gear 32 and a first driven spur gear 33; the first driving spur gear 31 is meshed with the driven spur gear 24 of the driving assembly 2, the first secondary driven spur gear 32 is coaxially connected with the first driving spur gear 31 and rotates synchronously, and both are rotatably connected to the fixed part 11; the first driven spur gear 33 is meshed with the first secondary driven spur gear 32, so that the first driven spur gear 33 rotates under the drive of the first driving spur gear 31; the first driven spur gear 33 is rotatably connected to the fixed part 11, and is connected to the first finger joint 12, so that the first finger joint 12 rotates synchronously with the first driven spur gear 33.

[0049] Specifically, Figure 1 and Figure 2 As shown in , the first driving spur gear 31 and the first auxiliary spur gear 32 are connected by a cylindrical pin, and the cylindrical pin passes through the upper fixing plate 111 and the lower fixing plate 112. The upper fixing plate 111 and the lower fixing plate 112 are respectively provided with a circular hole for the cylindrical pin to pass through, so as to realize the rotatable connection between the first driving spur gear 31 and the first auxiliary spur gear 32 and the fixed part 11. When the first driving spur gear 31 and the first auxiliary spur gear 32 rotate, the fixed part 11 remains stationary. Further, the size of the first auxiliary spur gear 32 is smaller than that of the first driving spur gear 31, and the lower part of the first auxiliary spur gear 32 is embedded in the first driving spur gear 31. The first driving spur gear 31 is correspondingly provided with a tooth groove to accommodate the lower part of the first auxiliary spur gear 32, so that the first auxiliary spur gear 32 rotates with the first driving spur gear 31.

[0050] Furthermore, if Figure 1 and Figure 2 As shown in the figure, the upper part of the first auxiliary spur gear 32 is meshed with the first driven spur gear 33. When the first auxiliary spur gear 32 rotates, the first driven spur gear 33 is driven to rotate. In addition, the diameter of the first driven spur gear 33 is larger than the diameter of the first auxiliary spur gear 32 to reduce the rotation speed.

[0051] The first finger joint 12 includes a first upper splint 121 and a first lower splint 122. Figure 1 and Figure 2 As shown in the figure, the first upper clamping plate 121 and the first lower clamping plate 122 are parallel to the upper fixing plate 111 and the lower fixing plate 112, and the first upper clamping plate 121 and the upper fixing plate 111 overlap at one end close to each other, and the first lower clamping plate 122 and the lower fixing plate 112 overlap at one end close to each other.

[0052] Figure 3 FIG. 3 shows the connection between the first driven spur gear 33 and the upper fixing plate 111, the lower fixing plate 112, the first upper clamping plate 121 and the first lower clamping plate 122. Figure 3 As shown in , the upper fixing plate 111, the first upper clamping plate 121, the first lower clamping plate 122 and the lower fixing plate 112 are arranged in sequence from top to bottom, and the first driven spur gear 33 is located between the first upper clamping plate 121 and the first lower clamping plate 122. The first driven spur gear 33 is rotatably connected to the upper fixing plate 111 and the lower fixing plate 112 through the first pin shaft 35, and the first pin shaft 35 passes through the overlapping part of the first upper clamping plate 121 and the upper fixing plate 111, and the overlapping part of the first lower clamping plate 122 and the lower fixing plate 112, connecting the first finger joint 12 and the fixing part 11. The first pin shaft 35 is a cylindrical pin, and the upper fixing plate 111 and the lower fixing plate 112 are provided with a circular hole at the place where the first pin shaft 35 passes. It can be understood that when the first pin shaft 35 rotates, the upper fixing plate 111 and the lower fixing plate 112 remain stationary. Similarly, a circular hole is formed in the first lower clamping plate 122 where the first pin shaft 35 passes through, and the first pin shaft 35 is rotatably connected to the first lower clamping plate 122 .

[0053] Furthermore, the first driven spur gear 33 is rotatably connected to the first pin shaft 35 through the first annular pin 34. The lower portion of the first annular pin 34 is embedded in the first driven spur gear 33 and is fixedly connected to the first driven spur gear 33. The fixed connection may be welding, key connection, etc. The first pin shaft 35 passes through the first annular pin 34 and can rotate relative to the first annular pin 34, thereby realizing the rotatable connection between the first driven spur gear 33 and the first pin shaft 35. Furthermore, the upper portion of the first annular pin 34 is clamped with the first upper clamping plate 121, so that the second upper clamping plate 121 and the first annular pin 34 are relatively fixed in the rotation direction of the first annular pin 34 (i.e., the rotation direction of the first driven spur gear 33), and the first upper clamping plate 121 can rotate with the first driven spur gear 33; specifically, as Figure 3 As shown in the figure, two protrusions 341 are provided on the upper part of the first annular pin 34, and a first groove 1211 for accommodating the upper part of the first annular pin 34 is opened on the first upper clamping plate 121. The shape of the first groove 1211 matches the shape of the upper part of the first annular pin 34, so that the upper part of the first annular pin 34 can be clamped into the first groove 1211. Through the cooperation between the first groove 1211 and the protrusion 341, the second upper clamping plate 121 and the first annular pin 34 are relatively fixed in the rotation direction of the first annular pin 34.

[0054] It can be understood from the above solution that when the first driven spur gear 33 rotates, the upper fixing plate 111 and the lower fixing plate 112 remain stationary, and the first upper clamping plate 121 rotates with the first driven spur gear 33 .

[0055] The first transmission mechanism 4 includes a plurality of first transmission wheels 41 arranged in sequence along the first finger joint 12 and rotatably connected to the first finger joint 12. The first transmission wheels 41 are spur gears. In this embodiment, there are three first transmission wheels 41. The three first transmission wheels 41 mesh in sequence. The first transmission wheel 41 near the first joint 3 meshes with the first driving spur gear 31. The first transmission wheel 41 is coaxial with the first driven spur gear 33 and rotatably connected. Figure 2 and Figure 3 As shown in , the first transmission wheel 41 close to the first joint 3 is located below the first driven spur gear 33, the first pin 35 passes through the first transmission wheel 41 and is rotatably connected to the first transmission wheel 41, and the first transmission wheel 41 rotates under the drive of the first driving spur gear 31. Figure 1 and Figure 2 As shown in , the other two first transmission wheels 41 are rotatably connected to the first upper clamping plate 121 and the first lower clamping plate 122 through the pin shaft. It can also be understood that when the first upper clamping plate 121 rotates with the first driven spur gear 33, the first lower clamping plate 122 also rotates accordingly, thereby realizing the rotation of the first finger joint 12 relative to the fixed part 11, that is, the bending of the first joint of the mechanical finger; at the same time, the two first transmission wheels 41 away from the first joint 3 are driven by the first upper clamping plate 121 and the first lower clamping plate 122, on the one hand, they revolve around the first driven spur gear 33, and the angular velocity of the revolution is the same as the angular velocity of the rotation of the first driven spur gear 33, and on the other hand, they rotate and transmit to the second joint 5 through the meshing of the gear teeth.

[0056] The second joint 5 includes a second driving spur gear 51, a second auxiliary spur gear 52 and a second driven spur gear 53; the second driving spur gear 51 is meshed with the first transmission wheel 41 adjacent to it, the second auxiliary spur gear 52 is coaxially connected with the second driving spur gear 51 and rotates synchronously, and both are rotatably connected to the first knuckle 12, the second driven spur gear 53 is meshed with the second auxiliary spur gear 52, and is rotatably connected to the first knuckle 12, and is connected to the second knuckle 13, so that the second knuckle 13 rotates synchronously with the second driven spur gear 53.

[0057] like Figure 1 and Figure 2As shown in, similar to the first joint 3, the second driving spur gear 51 and the second auxiliary spur gear 52 are rotated synchronously through the tooth grooves, and the second driving spur gear 51 and the second auxiliary spur gear 52 are rotatably connected to the first upper clamping plate 121 and the first lower clamping plate 122 through cylindrical pins, thereby realizing the rotatable connection between the second driving spur gear 51 and the second auxiliary spur gear 52 and the first knuckle 12; it can be understood that the second driving spur gear 51 and the second auxiliary spur gear 52 rotate on their own under the drive of the first transmission wheel 41 on the one hand, and revolve around the first driven spur gear 33 with the first upper clamping plate 121 and the first lower clamping plate 122 on the other hand, and the angular velocity of the revolution is the same as the angular velocity of the rotation of the first driven spur gear 33.

[0058] Likewise, if Figure 1 and Figure 2 As shown in , the upper portion of the second auxiliary spur gear 52 is meshed with the second driven spur gear 53. When the second auxiliary spur gear 52 rotates, the second driven spur gear 53 is driven to rotate. In addition, the diameter of the second driven spur gear 53 is larger than the diameter of the second auxiliary spur gear 52 to reduce the rotation speed.

[0059] The second finger joint 13 includes a second upper splint 131 and a second lower splint 132. Figure 1 and Figure 2 As shown in the figure, the second upper clamping plate 131 and the second lower clamping plate 132 are parallel to the first upper clamping plate 121 and the first lower clamping plate 122, and the second upper clamping plate 131 and the first upper clamping plate 121 overlap at one end close to each other, and the second lower clamping plate 132 and the first lower clamping plate 122 overlap at one end close to each other.

[0060] like Figure 4 As shown in FIG. 1 , the connection between the second driven spur gear 53 and the first upper clamping plate 121, the first lower clamping plate 122, the second upper clamping plate 131 and the second lower clamping plate 132 is as follows: Figure 3 It is similar to that shown in , and will not be repeated here. It should be noted that, in this embodiment, the second upper clamping plate 131 is located above the first upper clamping plate 121, and the second driven spur gear 53 is clamped with the second upper clamping plate 131 through the second annular pin 54, so that the second upper clamping plate 131 rotates synchronously with the second driven spur gear 53; in this embodiment, a second protrusion 541 is provided on the upper part of the second annular pin 54, and a second clamping groove 1311 is provided on the second upper clamping plate 131, and the second clamping groove 1311 cooperates with the second protrusion 541, so that the third upper clamping plate 131 and the second annular pin 54 are relatively fixed in the rotation direction of the second annular pin 54; in addition, a through groove is provided on the first upper clamping plate 121 for the second protrusion 541 to pass through during installation.

[0061] Similarly, the second driven spur gear 53 rotates on its own under the drive of the second auxiliary driven spur gear 52, and on the other hand, it revolves around the first driven spur gear 33 with the first upper clamping plate 121 and the first lower clamping plate 122, and the angular velocity of the revolution is the same as the angular velocity of the rotation of the first driven spur gear 33. The second upper clamping plate 131 rotates with the rotation of the second driven spur gear 53, and the first upper clamping plate 121 and the first lower clamping plate 122 do not rotate with the rotation of the second driven spur gear 53. Therefore, it can be understood that this solution realizes the rotation of the second finger joint 13 relative to the first finger joint 12, that is, the bending of the second joint of the mechanical finger.

[0062] The second transmission mechanism 6 includes a plurality of second transmission wheels 61 which are sequentially arranged along the second finger joint 13 and are rotatably connected to the second finger joint 13. The second transmission wheels 61 are spur gears. In the present embodiment, the number of the second transmission wheels 61 is three. In some embodiments, the number of the first transmission wheels 41 and the second transmission wheels 61 may not be three. The numbers of the two may be different, as long as the parity of the numbers of the two is the same. In the present embodiment, the three second transmission wheels 61 are meshed in sequence, and the second transmission wheel 61 close to the second joint 5 is meshed with the second driving spur gear 51, and the second transmission wheel 61 is coaxial with the second driven spur gear 53 and is rotatably connected. Figure 2 As shown in the figure, the position of the second transmission wheel 61 and the connection method with other components are similar to the position and connection method of the first transmission wheel 41, which will not be repeated here; similarly, the two second transmission wheels 61 away from the second joint 5, while rotating to transmit power to the third joint 7, also revolve around the second driven spur gear 53, and the angular velocity of the revolution is the same as the angular velocity of the rotation of the second driven spur gear 53.

[0063] The third joint 7 includes a third driving spur gear 71, a third auxiliary spur gear 72 and a third driven spur gear 73; the third driving spur gear 71 is meshed with the second transmission wheel 61 adjacent thereto, the third auxiliary spur gear 72 is coaxially connected with the third driving spur gear 71 and rotates synchronously, and both are rotatably connected to the second finger joint 13, the third driven spur gear 73 is meshed with the third auxiliary spur gear 72, and is rotatably connected to the second finger joint 13, and is connected to the third finger joint 14, so that the third finger joint 14 rotates synchronously with the second driven spur gear 53; similarly, the third driving spur gear 71 and the third auxiliary spur gear 72 rotate on their own under the drive of the second transmission wheel 61 on the one hand, and revolve around the second driven spur gear 53 with the second upper clamping plate 131 and the second lower clamping plate 132 on the other hand, and the angular velocity of the revolution is the same as the angular velocity of the rotation of the second driven spur gear 53.

[0064] like Figure 1 and Figure 2As shown in , similar to the first joint 3 and the second joint 5, the third active spur gear 71 and the third auxiliary spur gear 72 are rotatably connected to the second upper clamping plate 131 and the second lower clamping plate 132 through cylindrical pins, thereby realizing a rotatable connection with the second finger joint 13. Figure 2 As shown in the figure, different from the first joint 3 and the second joint 5, the third active spur gear 71 and the third auxiliary spur gear 72 realize coaxial rotation through a square column pin 75 sleeved on the outside of the cylindrical pin, and the third active spur gear 71 and the third auxiliary spur gear 72 are respectively provided with a corresponding slot for the square column pin 75 to pass through. In this embodiment, the slot is a square slot.

[0065] The third finger joint 14 includes a third upper splint 141 and a third lower splint 142. Figure 1 and Figure 2 As shown in the figure, the third upper clamping plate 141 and the third lower clamping plate 142 are parallel to the second upper clamping plate 131 and the second lower clamping plate 132, and the ends of the third upper clamping plate 141 and the second upper clamping plate 131 that are close to each other overlap, and the ends of the third lower clamping plate 142 and the second lower clamping plate 132 that are close to each other overlap; and the third upper clamping plate 141 is located below the second upper clamping plate 131, and the third lower clamping plate 142 is located above the second lower clamping plate 132.

[0066] like Figure 1 and Figure 2 As shown in FIG. 1 , the connection between the third driven spur gear 73 and the second upper clamping plate 131, the second lower clamping plate 132, the third upper clamping plate 141 and the third lower clamping plate 142 is as follows: Figure 3 It is similar to that shown in , and will not be repeated here. It should be noted that the third driven spur gear 73 is clamped with the third upper clamping plate 141 through the third annular pin 74, so that the third finger joint 14 rotates synchronously with the third driven spur gear 73. In addition, a fourth driven spur gear 76 is coaxially connected below the third driven spur gear 73, and the fourth driven spur gear 76 can support the third driven spur gear 73; in some embodiments, the fourth driven spur gear 76 may not be provided, for example, a clamping block may be provided below the third driven spur gear 73 to support the third driven spur gear 73, and the clamping block may be provided on the rotating shaft of the third driven spur gear 73.

[0067] Furthermore, in this embodiment, the sides of the third upper clamping plate 141 and the third lower clamping plate 142 are fixedly connected (not shown in the figure), and the fixed connection can be achieved by connecting the side plates so that the third upper clamping plate 141 and the third lower clamping plate 142 move synchronously.

[0068] Similarly, the third driven spur gear 73 rotates on its own under the drive of the third auxiliary driven spur gear 72, and on the other hand, it revolves around the second driven spur gear 53 with the second upper clamping plate 131 and the second lower clamping plate 132, and the angular velocity of the revolution is the same as the angular velocity of the rotation of the second driven spur gear 53; the third upper clamping plate 141 and the third lower clamping plate 142 rotate with the rotation of the third driven spur gear 73, and the second upper clamping plate 131 and the second lower clamping plate 132 do not rotate with the rotation of the third driven spur gear 73. Therefore, it can be understood that this solution realizes the rotation of the third finger joint 14 relative to the second finger joint 13, that is, the bending of the third joint of the mechanical finger.

[0069] In summary, the robotic finger of this embodiment can achieve bending of three joints with one power source.

[0070] In this embodiment, the first driving spur gear 31, the second driving spur gear 51, the third driving spur gear 71, the first transmission wheel 41 and the second transmission wheel 61 have the same size, and the module of all the spur gears is the same, which is 0.4; because the radius of the spur gear is proportional to the number of teeth when the module is the same, it can be understood that the first driving spur gear 31, the second driving spur gear 51, the third driving spur gear 71, the first transmission wheel 41 and the second transmission wheel 61 have the same number of teeth.

[0071] In this embodiment, by selecting the number of teeth of each spur gear, the rotation speeds of the first driven spur gear 33, the second driven spur gear 53 and the third driven spur gear 73 are the same or close, that is, at the same time, the rotation angles of the first driven spur gear 33, the second driven spur gear 53 and the third driven spur gear 73 are the same or close, and the rotation angles of the first driven spur gear 33, the second driven spur gear 53 and the third driven spur gear 73 correspond to the bending angles of the three joints of the robot finger, respectively. Therefore, this solution can achieve the same or close bending angles of the three joints of the robot finger at the same time. The following is a method for selecting the number of gear teeth, which includes the following steps:

[0072] S1: According to the working conditions of the robot finger, the number of teeth of the first auxiliary spur gear 32 and the first driven spur gear 33 are selected so that the number of teeth of the first auxiliary spur gear 32 is the minimum value under the working conditions, and the number of teeth of the first driven spur gear 33 is the maximum value under the working conditions;

[0073] The working conditions of the robot finger can be the size of the working space of the robot finger or the size of the force that the robot finger needs to withstand;

[0074] In this embodiment, based on the working conditions of the robot finger, the number of teeth of the first auxiliary spur gear 32 is selected to be 12, and the number of teeth of the first driven spur gear 33 is selected to be 42.

[0075] S2: Select the number of teeth of the first active spur gear 31 and the first transmission wheel 41 according to equation 1, which is:

[0076] The number of teeth of the first driving spur gear 31 + the number of teeth of the first transmission wheel 41 = the number of teeth of the first auxiliary driving spur gear 32 + the number of teeth of the first driven spur gear 33 .

[0077] At the first joint 3, the first driving spur gear 31 is meshed with the first transmission wheel 41, and the first auxiliary spur gear 32 is meshed with the first driven spur gear 33. At the same time, the first driving spur gear 31 is coaxially connected with the first auxiliary spur gear 32, and the first driven spur gear 33 is coaxially connected with the first transmission wheel 41. In addition, in this embodiment, the first driving spur gear 31 and the first transmission wheel 41 have the same size, and the modules of the spur gears are the same. Since the radius of the spur gear is proportional to the number of teeth when the modules are the same, it can be known that:

[0078] The number of teeth of the first driving spur gear 31 = the number of teeth of the first transmission wheel 41 = (the number of teeth of the first auxiliary driving spur gear 32 + the number of teeth of the first driven spur gear 33 ) / 2.

[0079] Therefore, the number of teeth of the first driving spur gear 31 and the first transmission wheel 41 are both 27.

[0080] S3: Select any angle less than 180° as a reference angle, and calculate the angle of rotation of the first driving spur gear 31 when the first driven spur gear 33 rotates by the reference angle according to the number of teeth of the first driven spur gear 33, the first auxiliary driven spur gear 32 and the first driving spur gear 31.

[0081] In this embodiment, for the convenience of calculation, 90° is selected as the reference angle. In some embodiments, the reference angle can be selected from 60° to 120°. In this embodiment, when the first driven spur gear 33 rotates 90°, that is, when the first finger joint 12 rotates 90° relative to the fixed portion 11, according to the gear ratio of the first auxiliary spur gear 32 and the first driven spur gear 33, the angle of rotation of the first auxiliary spur gear 32 and the first driving spur gear 31 is calculated to be 315°.

[0082] S4: Select the number of teeth of the second driving spur gear 51 and the second transmission wheel 61 so that the number of teeth of the two are between the number of teeth of the first auxiliary driving spur gear 32 and the first driven spur gear 33, and calculate the rotation angle of the second driving spur gear 51 when the first driven spur gear 33 rotates at the reference angle described in step S3.

[0083] In this embodiment, since the second driving spur gear 51 and the first transmission wheel 41 have the same number of teeth, the second driving spur gear 51 has 27 teeth.

[0084] It can be understood that when the first driving spur gear 31 rotates 315°, the first driving spur gear 31 is meshed with the first transmission wheel 41, and the first transmission wheel 41 coaxially connected to the first driven spur gear 33 also rotates 315°, and the next first transmission wheel 41 is driven by the first upper clamping plate 121 and the first lower clamping plate 122 to revolve 90° around the axle of the first driven spur gear 33, so the first transmission wheel 41 rotates 225°; similarly, through the meshing of the first transmission wheel 41 and the second driving spur gear 51, the second driving spur gear 51 and the second auxiliary spur gear 52 rotate 225°, and at the same time revolve 90° around the axle of the first driven spur gear 33.

[0085] That is, the equation for calculating the rotation angle of the second driving spur gear 51 is:

[0086] The rotation angle of the second driving spur gear 51 = the rotation angle of the first driving spur gear 31 − the revolution angle of the second driving spur gear 51 around the first driven spur gear 33 = the rotation angle of the first driving spur gear 31 − the reference angle.

[0087] S5: Select the number of teeth of the second auxiliary spur gear 52 and the second driven spur gear 53 so that the number of teeth of the two is between the number of teeth of the first auxiliary spur gear 32 and the first driven spur gear 33, and the number of teeth of the two satisfies equation 2, and when the second driving spur gear 51 rotates at the angle described in step S4, the angle of rotation of the second driven spur gear 53 is the same as or close to the reference angle; equation 2 is:

[0088] The number of teeth of the second auxiliary driven spur gear 52 + the number of teeth of the second driven spur gear 53 = the number of teeth of the second driving spur gear 51 + the number of teeth of the second transmission wheel 61 .

[0089] Equation 2 is the same as equation 1, and is derived based on the relationship between the gears at the second joint 5, that is, the second driving spur gear 51 is meshed with the second transmission wheel 61, and the second auxiliary spur gear 52 is meshed with the second driven spur gear 53. At the same time, the second driving spur gear 51 is coaxially connected with the second auxiliary spur gear 52, and the second driven spur gear 53 is coaxially connected with the second transmission wheel 61.

[0090] In this embodiment, the second transmission wheel 61 has the same number of teeth as the second active spur gear 51, which is also 27 teeth. Therefore, equation 2 is:

[0091] The number of teeth of the second auxiliary spur gear 52 + the number of teeth of the second driven spur gear 53 = the number of teeth of the second driving spur gear 51 × 2 = the number of teeth of the second transmission wheel 61 × 2 = 54.

[0092] Assuming that the number of teeth of the second auxiliary spur gear 52 is 13 and the number of teeth of the second driven spur gear 53 is 41, the second auxiliary spur gear 52 and the second driving spur gear 51 rotate synchronously. According to the tooth ratio of the second auxiliary spur gear 52 and the second driven spur gear 53, it is calculated that when the second driving spur gear 51 rotates 225°, the second driven spur gear 53 rotates 71.3°.

[0093] Similarly, when the number of teeth of the second auxiliary spur gear 52 is 14 and the number of teeth of the second driven spur gear 53 is 40, it is calculated that when the second driving spur gear 51 rotates 225°, the second driven spur gear 53 rotates 78.75°.

[0094] By analogy, it is finally obtained that when the number of teeth of the second auxiliary spur gear 52 is 16, the number of teeth of the second driven spur gear 53 is 38, and the second driving spur gear 51 rotates 225°, the second driven spur gear 53 rotates 94.7°, which is close to 90°. Therefore, when the number of teeth of the second auxiliary spur gear 52 is 16 and the number of teeth of the second driven spur gear 53 is 38, and when the first driven spur gear 33 rotates 90° (that is, the first knuckle 12 rotates 90° relative to the fixed part 11), the rotation angle of the second driven spur gear 53 (that is, the rotation angle of the second knuckle 13 relative to the first knuckle 12) is close to 90°.

[0095] Furthermore, through the meshing of the second driving spur gear 51 and the second transmission wheel 61, the second transmission wheel 61 coaxially connected to the second driven spur gear 53 also rotates 225°, and the next second transmission wheel 61, driven by the second upper clamping plate 131 and the second lower clamping plate 132, revolves 94.7° around the axle of the second driven spur gear 53, so the second transmission wheel 61 rotates 225°-94.7°=130.3°.

[0096] S6: Select the number of teeth of the third driving spur gear 71, which is between the number of teeth of the first auxiliary driving spur gear 32 and the first driven spur gear 33; calculate the rotation angle of the third driving spur gear 71 when the second driven spur gear 53 rotates at the angle described in step S5;

[0097] In this embodiment, the number of teeth of the third active spur gear 71 is selected to be equal to the number of teeth of the second transmission wheel 61, which is 27 teeth;

[0098] Similarly, when the first driven spur gear 33 rotates 90° and the second driven spur gear 53 rotates 94.7°, the third driving spur gear 71 revolves 94.7° around the second driven spur gear 53 driven by the second upper clamping plate 131 and the second lower clamping plate 132. At the same time, since the third driving spur gear 71 is meshed with the second transmission wheel 61 and has the same number of teeth, the third driving spur gear 71 rotates 130.3° under the drive of the second transmission wheel 61.

[0099] S7: Select the number of teeth of the third auxiliary spur gear 72 and the third driven spur gear 73 so that the number of teeth of the two is between the number of teeth of the first auxiliary spur gear 32 and the first driven spur gear 33, and when the third driving spur gear 71 rotates at the angle described in step S6, the angle of rotation of the third driven spur gear 73 is the same as or close to the reference angle.

[0100] In this embodiment, the number of teeth of the third auxiliary spur gear 72 and the third driven spur gear 73 satisfies the following equation:

[0101] The number of teeth of the third auxiliary spur gear 72 + the number of teeth of the third driven spur gear 73 = the number of teeth of the first auxiliary spur gear 32 + the number of teeth of the first driven spur gear 33 = 54;

[0102] Similarly, the number of teeth of the third auxiliary spur gear 72 and the third driven spur gear 73 is assumed, and finally it is obtained that when the number of teeth of the third auxiliary spur gear 72 is 22 and the number of teeth of the third driven spur gear 73 is 32, when the third driving spur gear 71 rotates 130.3°, the third driven spur gear 73 rotates 89.6°, which is close to 90°. Therefore, the number of teeth of the third auxiliary spur gear 72 is 22 and the number of teeth of the third driven spur gear 73 is 32.

[0103] In summary, in this embodiment, in order to make the bending angles of the three joints of the robot finger the same or close at the same time, the number of teeth of each gear is respectively:

[0104] The first driving spur gear 31, the second driving spur gear 51, the third driving spur gear 71, the first transmission wheel 41 and the second transmission wheel 61 all have 27 teeth;

[0105] The first auxiliary spur gear 32 has 12 teeth, and the first driven spur gear 33 has 42 teeth.

[0106] The number of teeth of the second auxiliary spur gear 52 is 16, and the number of teeth of the second driven spur gear 53 is 38;

[0107] The third auxiliary driven spur gear 72 has 22 teeth, and the third driven spur gear 73 has 32 teeth.

[0108] In some embodiments, the number of teeth of each gear can be adjusted accordingly as needed so that at the same time, the bending angles of the three joints of the robotic finger are different to match the shape of the object to be grasped, for example, the speeds of the three joints increase or decrease successively.

[0109] This embodiment also discloses a mechanical hand, which includes mechanical fingers, a palm skeleton and a mechanical thumb.

[0110] Similar to a mechanical finger, the mechanical thumb includes a fixed portion 11, a first joint 12 and a second joint 13 arranged in sequence, and also includes a first joint 3, a second joint 5, a driving assembly 2 and a first transmission mechanism 4. The structure and connection method of each component of the mechanical thumb are the same as those of the mechanical finger.

[0111] In this embodiment, the manipulator includes a mechanical thumb and four mechanical fingers. The palm frame, the mechanical thumb and each mechanical finger can be connected in any manner in the prior art, for example, a thumb fixing groove and a finger fixing groove are respectively provided at the connection between the palm frame, the mechanical thumb and the mechanical finger, the mechanical thumb is sleeved in the thumb fixing groove, and the mechanical finger is sleeved in the finger fixing groove.

[0112] This embodiment also discloses a robot, which includes the above-mentioned manipulator.

[0113] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for designing a mechanical finger, characterized in that: The design method comprises the following steps: S1: According to the working conditions of the robot finger, the number of teeth of the first auxiliary spur gear and the first driven spur gear are selected so that the number of teeth of the first auxiliary spur gear is the minimum value under the working conditions, and the number of teeth of the first driven spur gear is the maximum value under the working conditions; S2: Select the number of teeth of the first driving spur gear and the first transmission wheel according to equation 1, which is: The number of teeth of the first active spur gear + the number of teeth of the first transmission wheel = the number of teeth of the first auxiliary spur gear + the number of teeth of the first driven spur gear; S3: selecting any angle less than 180° as a reference angle, and calculating the angle of rotation of the first driving spur gear when the first driven spur gear rotates by the reference angle according to the number of teeth of the first driven spur gear, the first auxiliary driven spur gear and the first driving spur gear; S4: selecting the number of teeth of the second driving spur gear and the second transmission wheel so that the number of teeth of the second driving spur gear and the second transmission wheel are both between the number of teeth of the first auxiliary driving spur gear and the first driven spur gear, and calculating the rotation angle of the second driving spur gear when the first driven spur gear rotates by the reference angle; S5: Select the number of teeth of the second auxiliary spur gear and the second driven spur gear so that the number of teeth of the two gears is between the number of teeth of the first auxiliary spur gear and the first driven spur gear, and the number of teeth of the two gears satisfies equation 2, and when the second driving spur gear rotates at the angle described in step S4, the angle of rotation of the second driven spur gear is the same as or close to the reference angle; equation 2 is: The number of teeth of the second auxiliary spur gear + the number of teeth of the second driven spur gear = the number of teeth of the second driving spur gear + the number of teeth of the second transmission wheel; S6: Select the number of teeth of the third driving spur gear, which is between the number of teeth of the first auxiliary driving spur gear and the first driven spur gear; calculate the angle of rotation of the third driving spur gear when the second driven spur gear rotates at the angle in step S5; S7: Select the number of teeth of the third auxiliary spur gear and the third driven spur gear so that the number of teeth of the two is between the number of teeth of the first auxiliary spur gear and the first driven spur gear, and when the third driving spur gear rotates at the angle described in step S6, the angle of rotation of the third driven spur gear is the same as or close to the reference angle.

2. The design method according to claim 1, characterized in that: The first driving spur gear and the first transmission gear have the same number of teeth, and the equation 1 in step S2 is: The number of teeth of the first driving spur gear = the number of teeth of the first transmission wheel = (the number of teeth of the first auxiliary driving spur gear + the number of teeth of the first driven spur gear) / 2.

3. The design method according to claim 2, characterized in that: The number of teeth of the second active spur gear is equal to that of the first transmission gear. The equation for calculating the rotation angle of the second active spur gear in step S4 is: The rotation angle of the second driving spur gear = the rotation angle of the first driving spur gear - the revolution angle of the second driving spur gear around the first driven spur gear = the rotation angle of the first driving spur gear - the reference angle.

4. The design method according to claim 1, characterized in that: The second transmission wheel and the second driving spur gear have the same number of teeth, and the equation 2 in step S5 is: The number of teeth of the second auxiliary spur gear + the number of teeth of the second driven spur gear = the number of teeth of the second driving spur gear × 2 = the number of teeth of the second transmission wheel × 2.

5. The design method according to claim 1, characterized in that: The third driving spur gear has the same number of teeth as the second transmission gear.

6. The design method according to claim 1, characterized in that: The number of teeth of the third auxiliary spur gear and the third driven spur gear satisfies the following equation: The number of teeth of the third auxiliary spur gear + the number of teeth of the third driven spur gear = the number of teeth of the first auxiliary spur gear + the number of teeth of the first driven spur gear.

7. The design method according to claim 1, characterized in that: The reference angle is 60°-120°.

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