Cylindrical-Gear Gearing with Partial Encapsulation
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Solution Overview
Problem
High-speed spur gears experience power losses due to turbulence of the air-oil mixture in transmission housings, and existing solutions that aim to minimize pressure to reduce losses are costly and complex, differing from the requirements for gear pumps where tight encapsulation is necessary for pressure creation rather than lubrication.
Innovation Solution
A spur gear design with an enveloping wall that encloses the gears in the circumferential direction, featuring annular gaps that merge concentrically with the axes of rotation, allowing for partial encapsulation that reduces power loss while being easy to implement and retrofit, and made from materials like bent sheet metal for reduced roughness and manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If tight encapsulation with extensive sealing is provided to minimize pressure and reduce power losses, then power losses are reduced, but device complexity and manufacturing costs increase significantly
Solution Approach 1:
The patent applies partial encapsulation instead of complete tight sealing. The shell wall encloses the spur gears only in the circumferential direction, leaving the axial ends open. This partial action reduces power losses by minimizing turbulence in the critical meshing area while avoiding the complexity of extensive sealing around the entire gear assembly.
Solution Approach 2:
The transmission housing is segmented into multiple functional zones: an enclosed zone with the shell wall for reducing power losses, and open zones at the axial ends for lubrication and cooling. This segmentation allows different regions to serve different purposes without requiring complete sealing throughout the entire housing.
2Loss of energy
If powerful vacuum pumps are used to generate strong vacuum for optimizing power loss reduction, then power losses are minimized, but energy consumption and costs increase
Solution Approach 1:
Instead of creating a complete vacuum throughout the entire transmission housing, the patent uses partial encapsulation to create a localized low-pressure zone only where the gears mesh. This reduces power losses effectively while avoiding the high energy consumption associated with powering strong vacuum pumps for complete encapsulation.
3Loss of energy
If complete encapsulation is provided to reduce power losses, then power losses are reduced, but lubrication effectiveness deteriorates due to restricted oil flow
Solution Approach 1:
The shell wall provides partial encapsulation that reduces power losses in the meshing area while leaving the axial ends open. This allows lubricating oil to flow freely into and out of the gear mesh zone, maintaining effective lubrication while still achieving the benefit of reduced turbulence and power losses in the enclosed region.
4Loss of energy
If tight sealing is implemented to create negative pressure for power loss reduction, then power losses are reduced, but manufacturing costs increase due to expensive sealing components
Solution Approach 1:
The patent implements partial encapsulation with a shell wall that requires minimal sealing - only at the circumferential interface between the shell wall and housing. This avoids the need for expensive sealing components around the entire gear assembly, significantly reducing manufacturing costs while still achieving power loss reduction in the critical meshing area.
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 effectively reduces power losses, minimizes wear, and is cost-effective by allowing for partial encapsulation that prevents unwanted oil escape and entry, maintaining efficient lubrication without the need for extensive sealing or expensive vacuum systems.
Implementation Method 1
undesirable losses occur due to the turbulence of the air-oil mixture in the interior of the transmission housing
Implementation Method 2
generate a negative pressure in the area of the outer diameter of the spur gears or in the area of their toothing, which reduces losses
Data Source
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AI summary
The invention relates to a cylindrical-gear gearing, comprising at least two toothed cylindrical gears, the sets of teeth of which mesh with each other and which can be rotated by means of respective axes of rotation; comprising an enveloping wall, which surrounds the two cylindrical gears in the peripheral direction and in the direction of the axes of rotation; wherein the enveloping wall has an inner contour that is adapted to the outside diameters of the cylindrical gears in such a way that two annular gaps transitioning into each other result between the enveloping wall and the cylindrical gears, wherein each annular gap is arranged at least substantially concentrically to a corresponding axis of rotation. The cylindrical-gear gearing according to the invention is characterized in that the enveloping wall is formed by a multi-part housing closed along a joint, wherein the joint extends partially or completely substantially within a plane in which one of the two axes of rotation or the two axes of rotation extend.