Ring Gear Axial Radial Cooling Passages
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In transmission assemblies, particularly those with planetary gear sets, it is challenging to deliver cooling fluid to certain components due to tight packaging, which can lead to inadequate heat dissipation and increased stress on gear teeth from radial through bores.
Innovation Solution
A ring gear configuration with axial and radial flow passages that extend through the gear body without intersecting the toothed periphery, allowing for efficient coolant distribution without penetrating the gear teeth, and an annular groove for coolant collection to enhance lubrication and heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If radial through bores are used to route coolant fluid through the ring gear, then coolant delivery to internal components is improved, but stress risers occur in the gear teeth areas
Solution Approach 1:
The patent transitions from radial through-bores (one-dimensional path) to a combination of axial and radial flow passages (two-dimensional path). The axial flow passages extend from the inner diameter toward the outer diameter without breaking the tooth profiles, while radial flow passages extend from the outer diameter to intersect with axial passages, creating a multi-dimensional coolant distribution network that avoids stress risers.
Solution Approach 2:
The coolant flow path is segmented into two distinct sections: axial flow passages and radial flow passages. This segmentation allows the coolant to travel through different routes within the ring gear body, with axial passages avoiding the tooth root areas and radial passages providing additional cooling paths without intersecting tooth profiles, thereby eliminating stress concentration points.
2Volume of moving object
If tight packaging of planetary gear sets is implemented, then space efficiency is improved, but coolant routing to certain components becomes difficult
Solution Approach 1:
The ring gear structure serves multiple functions simultaneously: it transmits mechanical power through its toothed periphery and provides integrated coolant distribution through embedded axial and radial flow passages. This multi-functionality allows the same component to fulfill both mechanical and thermal management roles, enabling tight packaging without compromising coolant access to internal components.
Solution Approach 2:
The coolant flow passages are nested within the ring gear body itself, with axial passages embedded in the gear thickness and radial passages extending from the outer surface to intersect with axial passages. This nested configuration allows coolant routing to be integrated into the existing ring gear structure without adding external cooling components, thereby maintaining compact packaging while ensuring adequate coolant delivery.
3Strength
If radial through bores are closely clocked to tooth root, then stress risers are reduced, but manufacturing precision requirements increase
Solution Approach 1:
The harmful radial through-bores that caused stress risers are extracted and replaced with axial flow passages that do not intersect the tooth profiles. The axial passages extend from the inner diameter toward the outer diameter without breaking the tooth continuity, eliminating the need for precise clocking to tooth roots. Radial flow passages are then added from the outer surface to intersect with axial passages, providing coolant access without creating stress concentration points.
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 design improves thermal performance by ensuring thorough coolant distribution, reduces localized stresses, and prolongs the operational lifespan of transmission components while simplifying manufacturing by avoiding precise location of radial through bores.
Implementation Method 1
An axial flow passage section extends axially through the gear body from the annular groove without intersecting the first and second annular sides. A radial flow passage section extends radially into the gear body from the second annular side to the axial flow passage section.
Implementation Method 2
Transmission assemblies of various kinds for various work vehicles may include gears and associated components arranged to contact a fluid to dissipate heat and ease engagement of mating parts.
Data Source
AI summary
A ring gear for a planetary gear set has an annular gear body with a first annular side and a second annular side concentric about a center axis. The first annular side defines a toothed periphery. The gear body may include an annular groove in the first annular side proximate a first axial side of the gear body. An axial flow passage section may extend axially into the gear body from the annular groove without intersecting the first and second annular sides. A radial flow passage section extends radially into the gear body from the second annular side to the axial flow passage section.