Binary Hydraulic Pump for Transmission Fuel Economy
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Solution Overview
Problem
Hydraulic systems in vehicle transmissions face challenges in meeting peak demands while minimizing fuel consumption and packaging constraints, particularly in rear wheel-drive vehicles where space is limited, and existing pumps suffer from inefficiencies and increased torque requirements.
Innovation Solution
A binary fixed displacement hydraulic pump with two discharge ports, allowing for full or partial output, is designed to operate efficiently in both front and rear wheel-drive vehicles, with an optional auxiliary pump for hybrid systems, enabling faster response times and reduced power consumption by controlling output based on engine speed and transmission conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pump operates at full displacement to meet peak hydraulic demands, then sufficient hydraulic pressure and flow are provided, but fuel economy deteriorates due to increased torque and horsepower requirements
Solution Approach 1:
The pump employs a binary control mechanism that dynamically switches between full displacement mode (using both discharge ports) and partial displacement mode (using only the first discharge port). This dynamic operation allows the pump to adapt its output to actual hydraulic demands, operating at full capacity during peak demands and reducing to partial capacity during steady-state operation, thereby improving fuel economy while maintaining reliability
Solution Approach 2:
The pump is designed to operate at partial displacement (partial action) during normal steady-state conditions by closing the second discharge port, and only switches to full displacement (excessive action) when peak hydraulic demands occur. This partial operation during most of the time significantly reduces torque and horsepower requirements while still meeting the hydraulic needs of the transmission
2Use of energy by moving object
If a variable displacement vane pump is used to reduce energy consumption, then fuel economy improves, but response time deteriorates due to the delay associated with moving a slide
Solution Approach 1:
The invention extracts and eliminates the slide mechanism from the pump design. By using a binary fixed displacement pump with a simple on/off control mechanism for the second discharge port, the patent removes the complex variable displacement mechanism that causes response delays, achieving both fast response time and improved fuel economy
Solution Approach 2:
The patent replaces the mechanical slide-based variable displacement mechanism with a binary fixed displacement system controlled by a simpler mechanism (such as a valve or clutch). This substitution eliminates the inherent delay of moving a slide while maintaining the ability to switch between full and partial output modes
3Adaptability or versatility
If an off-axis pump is used to improve packaging flexibility, then packaging options increase, but the pump size must be larger to handle hydraulic requirements in rear wheel-drive vehicles with limited tunnel space
Solution Approach 1:
The pump is segmented into two independent discharge ports, allowing the second port to be selectively activated or deactivated. This segmentation enables the pump to deliver full hydraulic capacity when both ports are open while occupying less space than a traditionally sized pump would need to provide the same peak capacity, since it can operate at partial capacity during normal conditions
Data Source
AI summary
A fixed displacement binary pump is provided for a powertrain on a vehicle. A hydraulic system is operatively connected with first and second discharge ports of the pump and is operable to alternately permit fluid flow through both discharge ports (i.e., full displacement or volumetric output of the pump) or permit flow through only the first discharge port (i.e., partial displacement or volumetric output of the pump). The pump may be packaged in a front support of the transmission. An auxiliary pump may be provided that is operable to supplement the output of the binary pump or to be used when the binary pump is off. A method of operating the binary pump and auxiliary pump is provided.