Micro-motion mechanism for industrial robot wrist
Technical Field
The invention relates to the field of industrial robots, in particular to a micro-motion mechanism for a wrist of an industrial robot.
Background
Industrial robots are multi-joint manipulators or multi-degree-of-freedom machine devices oriented to the industrial field, can automatically execute work, and are machines which realize various functions by means of self power and control capacity. The robot can accept human command and operate according to a preset program, and modern industrial robots can also perform actions according to a principle formulated by artificial intelligence technology. The six-degree-of-freedom serial industrial robot is a common industrial robot at present, generally consists of a machine base, a waist part, a large arm, a small arm and a wrist part in sequence, and the precision required by transmission from the machine base to the wrist part is higher and higher, particularly the transmission precision of the wrist part has great influence on the positioning of the final industrial robot. At present, the machine base, the waist, the big arm, the small arm and the wrist are driven by chains, the open chain driving is adopted, and driving errors are accumulated along with the increase of the length of a driving chain, so that the whole driving precision of the robot is low.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a micro-motion mechanism for a wrist of an industrial robot, which has high transmission precision, small structural volume and convenient replacement.
The purpose of the invention can be realized by the following technical scheme: a micro-motion mechanism for a wrist of an industrial robot comprises an input gear, an output gear and a transmission gear meshed with the input gear and the output gear, wherein a sheet is fixed at the meshing position of the transmission gear, the input gear and the output gear, the outline of the sheet and the outline of the meshing position of the transmission gear are distributed in a coaxial and same-diameter mode, and the outline of the sheet is provided with a tooth part and meshed with the input gear and the output gear. According to the invention, the thin sheet is additionally arranged at the meshing part of the transmission gear, the input gear and the output gear, so that the abrasion degree of the tooth part of the transmission gear can be reduced, and the transmission gear can be meshed better.
The tooth part of the sheet is the same as the tooth space of the transmission gear, and the tooth part of the sheet is staggered with the tooth of the transmission gear. Because the shaft in the robot does not always rotate towards a certain direction, but needs to rotate forwards and backwards, if the two gear axes cannot be completely installed according to the numerical value calculated theoretically during assembly, return errors occur when the transmission shaft of the robot rotates backwards, so that the accuracy is reduced, and the situation is overcome, the two gear axes are required to be completely the same as the numerical value calculated theoretically, and the requirement on the manufacturing process is too high. The invention can effectively eliminate return error by staggering the thin sheet and the teeth of the transmission gear, namely adopting a double-gear gap adjusting structure and respectively meshing with the teeth of the input gear or the output gear.
Preferably, the distance between the tooth part of the sheet and the tooth of the transmission gear is 1/6-1/4 of the tooth space.
One end of the transmission gear is fan-shaped and is meshed with the input gear, the middle of the transmission gear is of a hollow structure, the output gear is located in the hollow structure, and one end, far away from the input gear, of the hollow structure is meshed with the output gear.
The fan-shaped annular sheet is fixedly arranged at the bottom of one fan-shaped end in the transmission gear through a plurality of screws and is coaxially distributed with the fan-shaped end in the transmission gear in the same diameter.
The circular sheet is fixedly arranged at the bottom of the meshing part of the transmission gear and the output gear through a screw and is coaxially and radially distributed with the contour of the meshing part of the transmission gear and the output gear.
The circle center of the circular slice is superposed with the axis of the rotating shaft of the whole transmission gear.
Compared with the prior art, the invention has the beneficial effects that:
(1) and a small number of anti-backlash gears with high transmission precision are used, so that the structural volume of the wrist is reduced, and the overall transmission precision of the robot is improved.
(2) The transmission gear has small abrasion.
Drawings
FIG. 1 is a schematic bottom view of the present invention;
FIG. 2 is a side view of the structure of FIG. 1;
FIG. 3 is a schematic view of the structure of the junction of two gears when the gear axes are exactly the same as the theoretically calculated values;
FIG. 4 is a schematic structural diagram of a conventional joint;
fig. 5 shows a dual gear backlash adjustment structure according to the present invention.
Wherein, 1 is an input gear, 2 is a sector annular sheet, 3 is a transmission gear, 4 is an output gear, 5 is a circular sheet, 6 is a screw, 7 is a gasket, and 8 is a hollow structure.
Detailed Description
The following examples are given for the detailed implementation and specific operation of the present invention, but the scope of the present invention is not limited to the following examples.
Example 1
A micro-motion mechanism for a wrist of an industrial robot is structurally shown in figures 1 and 2 and comprises an input gear 1, an output gear 4 and a transmission gear 3 meshed with the input gear 1 and the output gear 4, wherein a sheet is fixed at the meshing position of the transmission gear 3, the input gear 1 and the output gear 4, the outline of the sheet and the outline of the meshing position of the transmission gear 3 are coaxially distributed in the same diameter, and the outline of the sheet is provided with a tooth part and meshed with the input gear 1 and the output gear 4. According to the invention, the thin sheet is additionally arranged at the meshing part of the transmission gear 3, the input gear 1 and the output gear 4, so that the abrasion degree of the tooth part of the transmission gear 3 can be reduced, and the transmission gear can be meshed better.
The teeth of the sheet are spaced from the teeth of the drive gear 3 by the same distance, and the teeth of the sheet are offset from the teeth of the drive gear 3. Wherein, the staggered distance between the tooth part of the sheet and the tooth of the transmission gear 3 is 1/6-1/4 of the tooth distance. Because the shaft in the robot does not always rotate in a certain direction, but needs to rotate forwards and backwards, if the two gear axes can be ensured to be completely installed according to the numerical value calculated theoretically during assembly, as shown in fig. 3, the transmission is accurate, but the two gear axes cannot be completely installed according to the numerical value calculated theoretically due to the existing preparation technology and the abrasion generated in the operation process, return stroke errors can be generated when the transmission shaft of the robot rotates backwards, as shown in fig. 4, the accuracy is reduced, and in the structure, the return stroke errors can be effectively eliminated by staggering the thin sheets and the teeth of the transmission gear, namely, adopting a double-gear gap adjusting structure and respectively meshing with the teeth of the input gear or the output gear, as shown in fig. 5.
One end of the transmission gear 3 is fan-shaped and is meshed with the input gear 1, the middle part of the transmission gear 3 is a hollow structure 8, the output gear 4 is positioned in the hollow structure 8, and one end, far away from the input gear 1, of the hollow structure 8 is meshed with the output gear 4.
The fan-shaped annular sheet 2 is fixedly arranged at the bottom of the fan-shaped end in the transmission gear 3 through three screws 6 and a gasket 7 and is coaxially and radially distributed with the fan-shaped end in the transmission gear 3.
The circular sheet 5 is fixedly arranged at the bottom of the meshing part of the transmission gear 3 and the output gear 4 through a screw 6 and a gasket 7 and is coaxially and radially distributed with the contour of the meshing part of the transmission gear 3 and the output gear 4. The circle center of the circular slice 5 is coincided with the axis of the rotating shaft of the whole transmission gear 3.