Cageless Six-Roller Bearing Geometry for Compact Planetary Gears
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing full complement roller bearings struggle to handle high radial loads efficiently while maintaining compactness and ease of manufacture, particularly for compact planetary gears with diameters less than 100 mm.
Innovation Solution
A full complement roller bearing design featuring exactly six roller bodies with the same outer diameter as the inner bearing body, an inner bore diameter 0.05% to 1% larger than three times the outer diameter, and a lubricant reservoir in the inner bearing body to reduce friction and optimize load distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the roller bearing is designed without a cage to increase the number of rolling elements, then the load capacity increases, but the friction between adjacent rolling elements increases and manufacturing complexity increases
Solution Approach 1:
The patent applies different surface finishes to different regions of adjacent rolling elements. Specifically, one rolling element has a first surface finish on its first surface that contacts the second rolling element, while the second rolling element has a second surface finish on its second surface that contacts the first rolling element. This local differentiation of surface properties reduces friction and wear at the contact points between rolling elements, allowing the cageless design to maintain high load capacity without excessive friction.
2Volume of moving object
If the roller bearing is designed without a cage to improve compactness, then the overall size decreases, but the risk of rolling elements blocking each other increases
Solution Approach 1:
The patent pre-establishes optimal geometric relationships between the rolling elements before the bearing operates. Specifically, the rolling elements are arranged with precise spacing and orientation such that their centers form a regular polygon, and the diameter of the circle passing through their centers is predetermined based on the rolling element diameter. This preliminary geometric configuration ensures that during operation, the rolling elements maintain proper spacing and cannot block each other, even in the compact cageless design.
3Strength
If the outer diameter of rolling elements is increased to improve load capacity, then the radial load support increases, but the bearing outer diameter increases and compactness is lost
Solution Approach 1:
The patent transitions from a single-dimensional approach (increasing rolling element diameter) to a multi-dimensional solution by optimizing the spatial arrangement of rolling elements. The rolling elements are positioned with their centers forming a regular polygon, and the spacing is predetermined based on geometric relationships. This allows the bearing to achieve high load capacity through optimal distribution of multiple rolling elements in space, rather than relying on a single large rolling element, thus maintaining compact outer dimensions while supporting high radial loads.
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 design achieves high efficiency and compactness, effectively supports high radial loads, and simplifies manufacturing, making it suitable for compact planetary gears with improved lubrication and reduced wear.
Implementation Method 1
A lubricant or oil is introduced into the roller bearing to reduce friction
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
The present invention relates to a full complement rolling bearing comprising several rolling elements, an inner bearing body in the form of a shaft or axle with a cylindrical outer diameter, and an outer bearing body arranged concentrically thereto with an inner bore. All rolling elements have the same outer diameter and are arranged between the inner and outer bearing bodies such that the rolling elements roll on the outer diameter of the inner bearing body and on the inner bore of the outer bearing body, thereby enabling the outer bearing body to rotate relative to the inner bearing body. The full complement rolling bearing is also cageless.According to the invention, the rolling bearing has exactly six rolling elements, wherein the outer diameter of the rolling elements corresponds essentially to the outer diameter of the inner bearing body, and wherein a diameter of the inner bore of the outer bearing body is slightly larger than three times the outer diameter of the inner bearing body.