Compact Gear Device for Industrial Robot Turning Section
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional turning portion structures of industrial robots have a high center of gravity due to the motor being positioned far from the reduction gear, leading to a less stable and more costly design with multiple crankshaft types.
Innovation Solution
A compact gear device with an input gear fixed to the motor's output shaft, an internal gear with inner teeth, external gears, a carrier, and a cylindrical gear that reduces the axial length, allowing the motor to be positioned closer to the gear device and reducing the number of components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the motor is positioned far from the reduction gear to transmit driving force to a particular crankshaft, then the driving force transmission is achieved, but the center of gravity of the rotating member becomes high
Solution Approach 1:
The patent merges the motor position with the reduction gear by having the motor rotate the input gear that is directly integrated into the reduction gear mechanism. This eliminates the need for separate driving force transmission paths to individual crankshafts, allowing the motor to be positioned closer to the center of the reduction gear and thereby lowering the center of gravity of the rotating member.
Solution Approach 2:
The input gear serves multiple functions: it is both the output element of the motor and the driving element for the reduction gear mechanism. This multi-functionality allows the motor to be directly coupled to the reduction gear without requiring additional transmission components, thus enabling compact positioning and lower center of gravity.
2Power
If the driving force is transmitted to a distal end portion of a crankshaft through gears or pulley, then the motor position is distanced from the reduction gear, but the mounting position of the motor to the rotating member is made high
Solution Approach 1:
The patent combines the motor output shaft with the input gear of the reduction gear, eliminating the need for intermediate transmission elements like gears or pulleys between the motor and crankshafts. This direct integration shortens the mounting position height and allows the motor to be positioned lower on the rotating member.
3Power
If the shape differs between the particular crankshaft and the remaining crankshafts, then the driving force transmission is achieved, but two kinds of crankshaft are required
Solution Approach 1:
The reduction gear mechanism provides universal driving force transmission to all crankshafts through the same mechanism type. The input gear drives the reduction gear which in turn drives all crankshafts uniformly, eliminating the need for different crankshaft shapes and reducing the number of component types required.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution results in a stable and cost-effective turning portion structure with a low center of gravity, achieved by compacting the gear device and optimizing the motor's position, thereby enhancing the robot's stability and reducing component count.
Implementation Method 1
a cylindrical gear which rotates by receiving the rotational driving force from the second transmitting member; and an external gear fixed to the crankshafts other than the particular crankshaft and adapted to mesh with the cylindrical gear
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A gear device includes: an input gear fixed to an output shaft of a motor; an internal gear; an external gear which rotates while revolving around a central axis of the internal gear while meshing with the internal gear; a carrier supported rotatably within the internal gear and adapted to rotate about the central axis of the internal gear in conjunction with the rotation of the external gear; a plurality of crankshafts which are rotatably supported by the carrier and are adapted to cause the external gear to revolve around the central axis of the internal gear; transmission gears each provided on a central portion of each of the crankshafts; and a cylindrical gear which meshes with the transmission gears of the crankshafts and to which rotation is transmitted from the input gear, wherein the cylindrical gear is located on a radially inner side of an imaginary line passing through a center of rotation of each crankshaft and is rotatably supported by the carrier, and wherein the input gear and the cylindrical gear mesh with each other in an axially central portion of the carrier.