Peristaltic Pump Tire Sidewall Air Maintenance
Solution Overview
Problem
Tire pressure in pneumatic tires naturally decreases over time due to air diffusion, leading to underinflation, which affects fuel economy, tire life, and vehicle handling, and existing solutions require driver intervention for maintenance.
Innovation Solution
A peristaltic pump assembly integrated into the tire, featuring an annular air passageway that closes and opens segmentally as the tire rotates, with inlet and outlet check valves to maintain pressure by pumping air into the tire cavity, ensuring air flow only into the tire and not out, and a pressure relief valve to prevent overpressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If a peristaltic pump assembly with check valves is integrated into the tire, then tire pressure is automatically maintained without driver intervention, but the device complexity increases
Solution Approach 1:
The tire pressure maintenance system operates autonomously using the tire's own rotation to drive the peristaltic pump, eliminating the need for external power sources or driver intervention. The system self-regulates pressure through integrated check valves that automatically prevent backflow and maintain inflation without requiring external control mechanisms.
Solution Approach 2:
The peristaltic pump assembly is integrated directly into the tire structure, combining the pumping mechanism, check valves, and air passageways into a unified system that utilizes the tire's existing rotational motion and structural components, thereby reducing overall system complexity while maintaining automation functionality.
2Reliability
If the air passageway is continuously pumped to maintain pressure, then tire inflation is maintained, but energy is consumed through rolling resistance
Solution Approach 1:
The peristaltic pump operates periodically during tire rotation rather than continuously, with the air passageway being compressed and expanded in cyclic segments as the tire rotates. This periodic pumping action maintains tire pressure while minimizing energy consumption by only activating during necessary phases of the rotation cycle, reducing overall rolling resistance.
3Reliability
If check valves are used to ensure unidirectional air flow, then air is pumped into the tire but not out, but the valve complexity increases
Solution Approach 1:
The check valve functionality is extracted and integrated directly into the air passageway structure itself, rather than being separate components. The outlet check valve is positioned at the discharge end of the air passageway to prevent backflow into the pump mechanism, simplifying the overall valve system while maintaining reliable unidirectional air flow control.
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 system maintains tire pressure at a desired level without driver intervention, enhancing fuel efficiency, tire longevity, and vehicle performance by continuously replenishing air and preventing overinflation.
Implementation Method 1
an elongate substantially annular air passageway enclosed within a bending region of the sidewalls, the air passageway operatively closing and opening, segment by segment, as the bending region of the sidewalls passes adjacent a rolling tire footprint to pump air along the air passageway
Implementation Method 2
The inlet control valve includes two inlet check valves for ensuring air flow only into, and not out of, the inlet control valve, the air passageway, a corresponding plain tee inlet structure, and the tire cavity
Implementation Method 3
the outlet tee structure includes two outlet check valves for ensuring air flow only into, and not out of, the tire cavity
Implementation Method 4
A pressure relief valve is provided for relieving a volume equal to a last segment volume of the air passageway plus a volume of the outlet tee structure
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
An air maintenance tire and pump assembly is disclosed. The assembly comprises a tire having a tire cavity, first and second sidewalls extending from first and second tire bead regions, respectively, to a tire tread region; an elongate substantially annular air passageway enclosed within a bending region of the sidewalls, the air passageway operatively closing and opening, segment by segment, as the bending region of the sidewalls passes adjacent a rolling tire footprint to pump air along the air passageway; an air inlet port assembly coupled to, and in air flow communication with, the air passageway, the air inlet port assembly being operable to channel inlet air from outside of the tire into the air passageway, the air inlet port assembly including an inlet control valve and an outlet tee structure preferably positioned 180° opposite the inlet control valve in the air passageway for moving air into the tire cavity, the inlet control valve including two inlet check valves for ensuring air flow only into, and not out of, the inlet control valve, the air passageway, a corresponding plain tee inlet structure, and the tire cavity; and a pressure relief valve for relieving a volume equal to a last segment volume of the air passageway plus a volume of the outlet tee structure.