Vehicle Powertrain Torque Control with Concentric Coupling
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Solution Overview
Problem
Current vehicle powertrain systems with multiple prime movers face issues of low engine efficiency, high fuel consumption, and unreliable, expensive coupling mechanisms that result in lag time in delivering additional torque when demanded by the operator.
Innovation Solution
A method and configuration for a vehicle powertrain that includes a primary prime mover coupled inline to the transmission and a secondary prime mover selectively coupled via a concentric passive coupling, with a controller managing torque demand by adjusting the primary prime mover's output, shifting the transmission, and activating the secondary prime mover as needed to meet torque requirements, while also considering decoupling and downshifting for fuel efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a second engine is activated to supplement torque output, then torque demand is met, but lag time occurs between torque demand and delivery
Solution Approach 1:
The patent applies preliminary action by pre-positioning the secondary engine in a ready state with the coupling mechanism pre-aligned and pre-synchronized. The secondary engine is kept rotating at a speed close to operational requirements and the coupling is pre-engaged mechanically, so that when torque demand exceeds primary engine capacity, the secondary engine can immediately contribute torque without the usual startup and synchronization lag time.
2Power
If existing coupling mechanisms are used to connect multiple engines, then torque can be transmitted, but reliability is low and cost is high
Solution Approach 1:
The patent extracts the complex, unreliable coupling mechanism from the system and replaces it with a direct mechanical connection. The secondary engine is positioned and coupled directly to the transmission through a simple concentric alignment, eliminating the need for complex existing coupling mechanisms that have reliability and cost issues.
3Power
If multiple engines are used to meet high torque demand, then power capability increases, but fuel consumption increases
Solution Approach 1:
The patent applies dynamics by making the engine configuration adaptive and variable. The system dynamically switches between single-engine and dual-engine operation based on real-time torque demand. The secondary engine is selectively engaged only when the primary engine cannot meet torque requirements, allowing the powertrain to optimize fuel consumption by using the minimum necessary power for each operating condition.
4Power
If existing coupling mechanisms are used, then engine connection is achieved, but substantial lag time occurs in torque delivery
Solution Approach 1:
The patent replaces complex mechanical coupling systems with a simplified direct mechanical connection. The secondary engine is positioned with its output shaft concentrically aligned with the transmission input shaft, allowing for a direct coupling that eliminates the lag associated with complex existing coupling mechanisms.
Data Source
AI summary
A vehicle powertrain having multiple prime movers including a primary prime mover coupled inline to a transmission and a secondary prime mover selectively coupled to the transmission by a substantially concentric coupling. A method of powertrain control is also disclosed, wherein powertrain torque demand and torque available from the primary prime mover and the transmission within its present gear ratio are determined and compared. Output of the primary prime mover is increased if the powertrain torque demand does not exceed the torque available. Otherwise, the transmission is downshifted to a lower gear ratio. Torque demand is compared to torque available from the primary prime mover and the transmission within its now downshifted gear ratio. Output of the primary prime mover is increased if torque demand does not exceed torque available. Otherwise the secondary prime mover is started, its output increased, and the transmission is shifted to a higher gear ratio.