Gearbox Output Seal Floating Design
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Solution Overview
Problem
Existing gearbox seal designs face challenges in providing a simple, mechanically robust, and reliable sealing system that effectively prevents lubricant leakage while ensuring predictable life expectancy.
Innovation Solution
A seal assembly featuring a rotating ring secured to a shaft with a contact face abutting a stationary seal, incorporating a floating seal portion with a spring for mechanical biasing and radially located pins to prevent rotation, along with cooling holes for heat removal, and materials like silicon carbide and diamond for reduced friction and increased hardness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a stationary seal with rotating ring is used to prevent lubricant leakage, then sealing effectiveness is improved, but mechanical robustness and reliability deteriorate due to complex design requirements
Solution Approach 1:
The seal portion is designed to float and move axially within the retainer, transitioning from a static seal design to a dynamic one. The spring provides continuous axial force to maintain sealing contact between the seal face and rotating ring, while allowing the seal to adapt to dimensional variations and wear. This dynamic configuration improves sealing reliability without requiring complex adjustment mechanisms.
Solution Approach 2:
The floating seal design allows the seal to self-adjust its position axially within the retainer based on operating conditions, wear, and dimensional variations. The spring automatically maintains contact force between the seal face and rotating ring, eliminating the need for external adjustment mechanisms or complex control systems, thereby improving reliability while keeping the design relatively simple.
2Strength
If a floating seal portion with spring biasing is implemented, then mechanical robustness and load distribution are improved, but device complexity increases due to additional components
Solution Approach 1:
The seal portion is designed to float axially within the retainer rather than being fixed, allowing it to dynamically adjust its position based on operating conditions. The spring provides continuous axial force to maintain proper contact pressure between the seal face and rotating ring. This dynamic configuration distributes mechanical loads more uniformly across the sealing interface, improving robustness while adding only minimal complexity through the spring mechanism.
3Reliability
If pins and recesses are added to prevent rotation of floating seal portion, then reliability is improved, but manufacturing complexity increases
Solution Approach 1:
The pin and recess configuration creates an asymmetric mechanical constraint system that prevents rotation of the floating seal portion. The pin fits into a specifically shaped recess with non-circular geometry, allowing only axial movement while blocking rotational motion. This asymmetric design provides reliable rotational constraint through a simple geometric feature that can be manufactured using conventional machining processes, adding minimal manufacturing complexity.
4Temperature
If cooling holes are incorporated into the seal assembly, then heat management is improved, but device complexity and leakage risk increase
Solution Approach 1:
The rotating ring is designed with a porous or perforated structure containing multiple cooling holes that allow lubricant to flow through and remove heat from the sealing interface. This porous configuration provides effective heat management by utilizing the existing lubricant circulation system, rather than requiring separate cooling channels or external cooling mechanisms. The holes are integrated into the rotating ring geometry, adding minimal structural complexity while significantly improving thermal management.
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 solution enhances the mechanical robustness and reliability of the seal, effectively prevents lubricant leakage, and extends the life expectancy by ensuring uniform mechanical load distribution and optimal pressure balance, while also improving heat management through cooling holes.
Implementation Method 1
a spring positioned within the channel and inward of an inner end of the floating seal portion, and biasing the floating seal portion outwardly
Implementation Method 2
cooling holes for heat removal
Implementation Method 3
materials like silicon carbide and diamond for reduced friction and increased hardness
Data Source
Figure 1~2
Figure 3~4
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AI summary
A seal assembly for use in a gearbox has a rotating ring to be secured to a shaft, and having a contact face. The contact face abuts a stationary seal. The stationary seal has a retainer with a channel extending to a bottom. A floating seal portion is positioned within the retainer, with a spring positioned inward of an inner end of the floating seal portion, and biasing the floating seal portion outwardly. There is an inner bore of the retainer which is spaced from an outer periphery of the floating seal portion. One of the inner bore and the outer periphery presides with the plurality of radially located pins. The other of the inner bore and the outer periphery is formed with the plurality of recesses. The pins are received in the recesses, to prevent rotation of the floating seal portion within the retainer.