Electric Oil Pump Shift Control for Friction Clutch Slip
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle transmission systems with friction clutches require complex configurations and multiple components for effective shift control, leading to increased costs and reduced marketability.
Innovation Solution
A shift control method that directly connects an electric oil pump to the friction clutch, using a controller to set target RPMs and adjust driving power to minimize slip and reduce the need for separate solenoid valves, thereby simplifying the control of the friction clutch and reducing the number of required components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a friction clutch is used for shift control in transmission, then shifting operation can be achieved, but the configuration becomes complex and requires multiple components
Solution Approach 1:
The patent combines the electric oil pump and friction clutch into a directly connected integrated system, eliminating the need for separate solenoid valves and complex hydraulic control circuits. The EOP directly generates hydraulic pressure to engage/disengage the friction clutch, merging multiple components (pump, valves, circuits) into a simplified direct connection architecture.
Solution Approach 2:
The patent extracts and eliminates unnecessary intermediate components (solenoid valves, complex hydraulic circuits) from the traditional friction clutch control system. By using a directly connected EOP system, the design removes extraneous elements while retaining the core shifting function, achieving simplification through selective extraction of essential components only.
2Reliability
If multiple components are used for friction clutch control, then shift control can be achieved, but the number of parts increases and assembling efficiency decreases
Solution Approach 1:
The patent merges the hydraulic pressure generation function directly into the EOP unit that connects to the friction clutch, combining multiple previously separate components (pressure pump, control valves, hydraulic circuits) into a single integrated system. This reduction in part count directly improves assembling efficiency while maintaining reliable shift control through the unified design.
3Ease of operation
If traditional hydraulic control system is used for friction clutch, then shifting can be controlled, but the system requires separate solenoid valves and complex circuits
Solution Approach 1:
The patent extracts and removes the solenoid valve component and complex hydraulic control circuits from the traditional system. By using a directly connected EOP system with electronic control, the design eliminates these intermediate elements while maintaining effective friction clutch control through direct electronic-hydraulic integration.
Solution Approach 2:
The patent replaces the traditional mechanical-hydraulic control system (with solenoid valves and complex circuits) with an electronically controlled EOP system. The electronic control unit directly manages the EOP to generate hydraulic pressure, substituting the complex mechanical-hydraulic control architecture with a simpler electronic control approach that directly actuates the friction clutch.
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 method allows for smoother and more efficient shifting operations by directly controlling hydraulic pressure on the friction clutch, reducing the number of parts needed and improving assembling efficiency and cost-effectiveness, thus enhancing the marketability of vehicles.
Implementation Method 1
an electric oil pump (EOP) directly connected to a friction clutch
Implementation Method 2
controlling hydraulic pressure on the friction clutch
Implementation Method 3
increase a friction force of the friction clutch such that a slip of the friction clutch is smaller than a predetermined reference slip
Data Source
AI summary
A shift control method of a transmission including an electric oil pump (EOP) directly connected to a friction clutch for a vehicle may include: when a shift is initiated, setting, by a controller, a predetermined first target RPM for controlling the EOP; determining, by the controller, a target current based on the first target RPM; maintaining, by the controller, the first target RPM until an EOP driving current reaches the target current; when the EOP driving current is greater than or equal to the target current, linearly reducing, by the controller, an RPM of the EOP from a predetermined second target RPM to a third target RPM; and increasing, by the controller, an EOP driving power to increase a friction force of the friction clutch such that a slip of the friction clutch is smaller than a predetermined reference slip.