Planetary Internal Gear Reinforcement for High-Speed Meshing Stability
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Solution Overview
Problem
High-speed rotation of internal gears in planetary gear mechanisms leads to deformation due to centrifugal forces, causing defects when meshing with planetary gears.
Innovation Solution
Incorporating a reinforcing member with higher specific strength, formed in an annular shape, fixed to the outer peripheral surface of the internal gear to suppress deformation caused by centrifugal forces, allowing stable operation at high speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the internal gear is made to rotate at high speed to increase output speed, then the speed increasing ratio is improved, but centrifugal force deforms the internal gear causing meshing defects
Solution Approach 1:
The internal gear is segmented into multiple independent reinforcing members (annular ribs) that are radially protruding from the inner peripheral surface. These segmented reinforcing structures distribute the centrifugal force across multiple points, preventing overall deformation while maintaining the gear's ability to rotate at high speeds without meshing defects
Solution Approach 2:
Reinforcing members are strategically positioned at specific locations where deformation is most likely to occur during high-speed rotation. The annular ribs are arranged to provide localized structural support exactly where needed to maintain meshing stability, rather than uniformly strengthening the entire gear structure
2Stability of the object's composition
If the internal gear is reinforced to suppress deformation, then meshing stability is improved, but the gear structure becomes more complex
Solution Approach 1:
The reinforcing members are integrated directly into the internal gear structure as annular ribs protruding from the gear body, rather than being separate attachment components. This merging of reinforcement functions into the gear's existing structure provides deformation suppression without adding external complexity or requiring additional assembly steps
Solution Approach 2:
The internal gear is constructed using composite structure combining the gear material with radially protruding annular reinforcing members made of material having higher modulus of elasticity. This composite approach provides enhanced stiffness and deformation resistance while maintaining a relatively simple overall gear geometry and manufacturing process
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
Effectively suppresses deformation of the internal gear, maintaining a stable meshing state with planetary gears regardless of rotation speed, enabling the planetary gear mechanism to respond to high-speed rotation.
Implementation Method 1
deformation caused by a centrifugal force of an internal gear
Data Source
AI summary
A planetary gear mechanism includes a sun gear rotatable about an axis, a first shaft that is fixed to the sun gear and is rotatable integrally with the sun gear, a plurality of planetary gears that mesh with the sun gear and are rotatable about a center line thereof parallel to the axis, an internal gear that includes internal teeth facing inside in a radial direction to mesh with the planetary gears and is rotatable about the axis, a second shaft that extends in the axial direction to be connected to the internal gear and rotates about the axis together with the internal gear, and a reinforcing member that is fixed to an outer peripheral surface of the internal gear and is formed in an annular shape of a material having a higher specific strength than that of a material forming the internal gear.