Internal Planetary Gear Layout for Smaller Inner Pin Holes
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Solution Overview
Problem
Existing internal-meshing planetary gear devices face challenges in miniaturization due to the difficulty in reducing the size of inner pin holes, which restricts the miniaturization of the planetary gear and the entire gear device.
Innovation Solution
The proposed internal-meshing planetary gear device includes a bearing member, an internally toothed gear, a planetary gear, multiple inner pins, and multiple sets of rolling bearings. The inner pins are held in a self-rotatable state by rolling bearings, allowing them to self-rotate without the need for inner rollers, thus reducing frictional resistance and enabling miniaturization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If inner rollers are used to reduce frictional resistance, then frictional loss is reduced, but device complexity increases due to additional components
Solution Approach 1:
The invention extracts and eliminates the inner rollers from the planetary gear structure, allowing the inner pins to self-rotate directly within the inner pin holes. This removal of unnecessary components reduces device complexity while maintaining the friction-reduction function through the self-rotation mechanism.
Solution Approach 2:
The inner pins are designed to self-rotate within the inner pin holes without requiring additional inner rollers. The self-rotation capability of the inner pins themselves provides the friction-reduction function, making the system self-sufficient and eliminating the need for separate friction-reducing components.
2Volume of moving object
If inner pin holes are reduced in size for miniaturization, then planetary gear size is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The invention changes the functional parameters of the inner pin holes by allowing the inner pins to self-rotate, transforming the interaction from sliding friction to rolling friction. This parameter change enables smaller inner pin hole dimensions while maintaining acceptable manufacturing precision, as the self-rotation mechanism is more tolerant of dimensional variations.
3Measurement precision
If multiple sets of rolling bearings are added to hold inner pins, then centering precision is improved, but device complexity increases
Solution Approach 1:
The rolling bearings serve multiple functions: they hold the inner pins in proper position, provide precise centering, support radial and axial loads, and enable smooth rotation. By making the rolling bearings multi-functional, the invention achieves improved centering precision without proportionally increasing device complexity, as a single component performs multiple critical functions.
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
This configuration allows for the miniaturization of the gear device by eliminating the need for inner rollers, reducing frictional losses, and improving centering precision of the inner pins, thereby enhancing the transmission efficiency and reducing vibration.
Implementation Method 1
Multiple sets of rolling bearings are arranged on an inner side of the planetary gear respectively. Each of the multiple inner pins is held on each corresponding set of rolling bearings in a self-rotatable state.
Data Source
AI summary
An internally engaged planetary gear device includes a bearing member, an internally toothed gear, a planetary gear, a plurality of inner pins, and a plurality of rolling bearings. When respectively inserted into a plurality of inner pin holes formed in the planetary gear, the plurality of inner pins are configured to rotate relative to the internally toothed gear while revolving in the inner pin holes. The plurality of rolling bearings are configured to hold respective inner pins of the plurality of inner pins at two sides in a direction parallel to a rotation axis Ax1 with respect to the planetary gear. Each inner pin of the plurality of inner pins is configured to be held on each rolling bearing in a state capable of rotation.