Seal Equipped Bearing Assembly Reducing Sealing Torque
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing seal equipped bearing assemblies in automotive transmissions face high sealing torque, leading to mechanical loss and increased fuel consumption, as they struggle to prevent foreign matter ingress while minimizing torque.
Innovation Solution
A seal equipped bearing assembly with a contact seal and a gap formation facilitating element, such as a minute projection or high friction paint, that transitions from contact to non-contact mode due to frictional wear, reducing sealing torque and preventing foreign matter ingress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If contact type sealing members are used to seal the bearing space, then foreign matter ingress is prevented, but sealing torque becomes considerably high causing mechanical loss
Solution Approach 1:
The patent applies shot peening treatment to the sealing lip surface, changing the surface parameters by creating compressive stress layers and increasing surface roughness. This modifies the contact characteristics between the sealing lip and bearing ring, allowing the seal to maintain reliability while reducing sealing torque through altered surface interaction properties
Solution Approach 2:
The patent replaces the traditional smooth contact surface with a shot-peened surface that utilizes mechanical deformation and surface irregularities to achieve sealing. The shot peening process substitutes a simple geometric contact with a complex surface morphology that reduces contact pressure and torque while maintaining seal integrity
2Loss of energy
If surface roughness is reduced to lower sealing torque, then torque reduction is limited, but if non-contact seal is used, torque reduces to zero yet foreign matter ingress cannot be prevented
Solution Approach 1:
The patent optimizes the surface roughness parameters through shot peening, creating a specific Ra value range that balances sealing torque reduction with foreign matter prevention. The controlled surface irregularities provide sufficient contact for sealing while minimizing friction and torque
Solution Approach 2:
The shot peened surface layer acts as a sacrificial element that wears in during initial operation to achieve optimal sealing characteristics. The surface morphology evolves from the shot-peened state to a stabilized wear-in state, providing a cost-effective way to achieve low torque operation
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 effectively reduces sealing torque to near zero within minutes of operation, preventing foreign matter ingress and allowing the use of lower viscosity lubricant, thereby reducing fuel consumption and ensuring reliable sealability.
Implementation Method 1
a gap formation facilitating element (friction facilitation treated element) is defined in a seal contact face of such other of the raceway rings, with which the sealing lip contacts, the gap formation facilitating element being, when used under a condition of the bearing assembly being rotated, operable to render the sealing member to be a non-contact seal
Data Source
AI summary
A seal equipped bearing assembly includes a plurality of rolling elements interposed between opposite raceway surfaces defined in respective raceway rings; a sealing member to seal a bearing space delimited between the raceway rings; and a gap formation facilitating element defined in a seal contact face in the other of the raceway rings, the gap formation facilitating element being a projection provided in a circumferential portion of the seal contact face in the raceway ring. The gap formation facilitating element is configured to render the sealing member to be a non-contact seal or to contact so that the contact pressure is approximately zero when the bearing assembly is in a rotating state. The sealing member is provided with a suction preventing device for preventing the sealing member from being sucked onto the other of the raceway rings.