Scavenging Pump for Automatic Transmission Coolant Pooling
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Solution Overview
Problem
Current automatic transmission systems face issues with coolant delivery from the electric motor, as it tends to pool in the bell housing, disrupting fluid circulation and affecting gear engagement in hybrid vehicles.
Innovation Solution
A scavenging pump system is integrated within the automatic transmission, connected to the main transmission fluid pump and torque converter, which collects pooled electric motor coolant from the bell housing and recirculates it back to the transmission sump through a fluid return passage, ensuring continuous fluid circulation and efficient gear engagement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If coolant is delivered to the electric motor, then cooling effect is improved, but coolant pools in the bell housing disrupting fluid circulation
Solution Approach 1:
The patent divides the fluid circulation system into separate pathways: one for transmission fluid and another for coolant. The scavenging pump is specifically dedicated to removing pooled coolant from the bell housing, while the main pump handles transmission fluid. This segmentation prevents coolant from interfering with transmission fluid circulation.
Solution Approach 2:
The scavenging pump acts as an intermediary device between the bell housing and the sump. It intercepts pooled coolant before it can disrupt the main fluid circulation system and redirects it back to the sump, thereby mediating between the cooling function and the fluid circulation reliability.
2Reliability
If a scavenging pump is added to remove pooled coolant, then fluid circulation reliability is improved, but device complexity increases
Solution Approach 1:
The scavenging pump is mechanically integrated with the main transmission pump shaft, allowing both pumps to be driven by a single power source. This merging reduces the need for separate drive mechanisms and simplifies the overall system architecture despite adding functional capability.
Solution Approach 2:
The main pump shaft serves dual purposes: driving both the main transmission pump and the scavenging pump. This multi-functionality reduces the number of independent components needed in the system, offsetting the complexity added by the scavenging pump itself.
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 scavenging pump effectively addresses coolant pooling issues by ensuring consistent fluid delivery to the transmission, enhancing the performance and reliability of automatic transmissions in hybrid vehicles by maintaining optimal fluid circulation and gear engagement.
Implementation Method 1
a scavenging pump arranged in the sump portion and fluidically connected to the fluid return passage
Data Source
AI summary
An automatic transmission includes a transmission housing having a sump portion, a main transmission fluid pump arranged at the sump portion, and a recess having a fluid return passage. A torque converter mounted in the recess and a scavenging pump arranged in the sump portion and fluidically connected to the fluid return passage.