Electric Vehicle Oil Pump Control for Startup Lubrication
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Solution Overview
Problem
Electric vehicles with electric motors face damage to the driving power transmission mechanism due to the lack of lubrication oil during long stops, as the mechanical oil pump is deactivated during vehicle stoppage, leading to insufficient oil feeding when the vehicle is restarted.
Innovation Solution
Incorporating an electric oil pump that is mechanically activated by the electric motor to feed oil to the driving power transmission mechanism, with a controller managing its operation to initiate lubrication before the electric motor starts, especially after long stops, and adjusting for the discharge characteristics of the mechanical oil pump to prevent damage and optimize oil distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a mechanical oil pump activated by the electric motor is used to feed oil to the driving power transmission mechanism, then the structure is simple and cost-effective, but the oil pump is deactivated during vehicle stoppage causing insufficient lubrication at startup
Solution Approach 1:
The controller activates the electric oil pump before the electric motor starts (when the ignition switch is turned on but the motor hasn't begun rotating yet), allowing lubrication oil to be supplied to the driving power transmission mechanism in advance. This preliminary action ensures that the gear teeth are already lubricated when maximum torque is transmitted at motor startup, preventing damage while keeping the overall system simple.
2Reliability
If the electric oil pump operates continuously to ensure sufficient lubrication, then lubrication reliability is improved, but energy consumption increases
Solution Approach 1:
The electric oil pump operates periodically rather than continuously - it activates when the ignition switch is turned on (before motor startup) and when the motor rotational speed is low (below a predetermined threshold). When the motor reaches normal operating speed, the mechanical oil pump takes over and the electric oil pump stops. This periodic operation ensures adequate lubrication while minimizing energy consumption.
3Quantity of substance
If the mechanical oil pump operates at high speed to ensure sufficient oil supply, then lubrication is improved, but pump drive loss increases
Solution Approach 1:
The electric oil pump acts as an intermediary to supplement the mechanical oil pump's output when the motor rotational speed is low. The controller monitors the motor rotational speed and activates the electric oil pump when speed is below a predetermined threshold, ensuring sufficient total oil supply without requiring the mechanical oil pump to operate at excessively high speeds, thereby reducing pump drive loss.
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
Prevents damage to the driving power transmission mechanism by ensuring lubrication is maintained during startup, reduces pump drive loss at high speeds, and ensures sufficient oil feeding at low speeds, thereby extending the vehicle's operational lifespan.
Implementation Method 1
an electric oil pump that feeds the oil to the driving power transmission mechanism
Implementation Method 2
a mechanical oil pump that is mechanically activated by the electric motor to feed oil to the driving power transmission mechanism
Implementation Method 3
lubrication oil in the driving power transmission mechanism... teeth surfaces of the gears which are in mesh are damaged
Data Source
AI summary
An electric vehicle such as an electric motorcycle includes a driving motor which activates a wheel via a driving power transmission mechanism (e.g., transmission), a mechanical oil pump which is mechanically activated by the driving motor to feed oil to the driving power transmission mechanism, and an electric oil pump which feeds the oil to the driving power transmission mechanism. A controller causes the electric oil pump to initiate its operation before the driving motor in a deactivated state initiates its operation under a specified condition, thus preventing a situation in which there is no lubrication oil in the driving power transmission mechanism during starting.