Variable Displacement Pump Control for Transmission Thermal Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Automatic transmissions equipped with fixed displacement pumps often experience inefficiencies due to oversupply of hydraulic fluid, leading to increased fuel consumption, especially at higher vehicle speeds, and can result in overheating and reduced driving comfort due to inadequate thermal management.
Innovation Solution
A method utilizing a variable displacement hydraulic pump that adjusts its delivery volume based on current hydraulic fluid requirements and temperature, allowing partial flow through a heat exchanger to optimize efficiency and prevent overheating, with adjustments made according to temperature thresholds and heat exchanger output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed displacement pump is designed for maximum delivery capacity to avoid undersupplied operating states, then the transmission can be reliably supplied with hydraulic fluid across the entire operating range, but the pump delivers excessive hydraulic fluid volume at higher speeds, reducing transmission efficiency and increasing fuel consumption
Solution Approach 1:
The patent applies a variable displacement pump instead of a fixed displacement pump, allowing the pump's delivery volume to be dynamically adjusted based on actual hydraulic fluid requirements. The pump control unit varies the displacement volume according to operating conditions (speed, temperature, hydraulic demand), enabling the system to maintain reliable supply across all operating ranges while avoiding excessive delivery at higher speeds, thus resolving the contradiction between reliability and energy efficiency.
2Loss of energy
If a variable displacement pump is used to adapt delivery volume to hydraulic fluid volume requirements, then transmission efficiency is improved, but the transmission components may overheat due to insufficient hydraulic fluid flow for thermal management
Solution Approach 1:
The patent implements a feedback control mechanism where the pump control unit continuously monitors transmission operating parameters including temperature. Based on this feedback, the control unit adjusts the pump's delivery volume to ensure adequate hydraulic fluid flow for thermal management while maintaining efficiency. The system balances hydraulic supply requirements with cooling requirements, preventing overheating even when operating at high efficiency points with reduced pump delivery.
3Use of energy by moving object
If the pump delivery volume is reduced to improve efficiency at higher speeds, then fuel consumption decreases, but the transmission may experience inadequate lubrication and temperature control
Solution Approach 1:
The variable displacement pump dynamically adjusts its delivery volume based on real-time monitoring of transmission operating conditions. The pump control unit calculates the actual hydraulic fluid requirements for both actuation and thermal management, then sets the pump delivery accordingly. This dynamic adaptation ensures that the minimum necessary fluid flow is maintained for reliable lubrication and temperature control, while avoiding excessive delivery that would waste energy and increase fuel consumption.
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
This approach enhances transmission efficiency, prevents thermal damage, and ensures rapid attainment of optimal operating temperatures, improving driving comfort and reducing fuel consumption by dynamically adapting hydraulic fluid supply to match operational demands.
Implementation Method 1
a heat exchanger, in order for it to be possible for a hydraulic fluid volume flow guided via a cooler to be set to the desired extent
Data Source
AI summary
A method for operating a transmission (3) with a hydraulic system comprising a variable capacity hydraulic pump, the method comprising determining during operation, a current hydraulic fluid volume requirement for actuating the transmission (3) and for temperature controlling and lubricating components of the transmission (3); setting the delivery volume of the hydraulic pump in a manner dependent on the currently determined hydraulic fluid volume requirement of the transmission (3), the delivery volume of the hydraulic pump, provided for temperature controlling and lubricating the components, being guided at least partially through a heat exchanger; wherein the delivery volume of the hydraulic pump is varied in a manner dependent on a temperature of the hydraulic fluid to an extent which sets that part of the delivery volume flow of the hydraulic pump which is to be guided via the heat exchanger.