Electric Scooter Power Module Lubricant Leakage Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electric scooters face issues with lubricant leakage from the transmission device into the motor due to the design of the integrated power module, where the lubricant can flow into the motor through the shaft, often leading to motor damage, and existing solutions like oil seals are difficult to detect until damage occurs.
Innovation Solution
The integrated power module incorporates a motor unit with a sealed motor room and a transmission unit featuring a lubricant room with a spiral slot on the motor shaft, a holder with a chamber, and an O-ring to prevent lubricant flow into the motor by using a spiraling direction that matches the motor shaft's rotation, ensuring lubricant remains within the lubricant room.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an oil seal is provided on the motor shaft to prevent lubricant leakage, then lubricant leakage is prevented, but the oil seal is difficult to detect and maintain as it is received within the integrated power module
Solution Approach 1:
The power module is divided into separate functional units: the motor unit with motor shaft and the transmission unit with transmission gears. The oil seal is specifically positioned at the interface between these units, allowing it to be accessed and maintained independently while still providing effective sealing.
Solution Approach 2:
The oil seal acts as an intermediary component between the motor unit and transmission unit. It is strategically placed to prevent lubricant from the transmission unit from migrating to the motor unit, while its external positioning allows it to serve as a detectable and maintainable barrier.
2Power
If the motor shaft extends into the transmission device to connect gears, then power transmission is enabled, but lubricant can flow into the motor along the shaft
Solution Approach 1:
The harmful element (lubricant) is prevented from reaching the motor by extracting it at the interface boundary. The oil seal is positioned to intercept and contain the lubricant within the transmission unit, preventing its migration into the motor unit while allowing the motor shaft to extend for power transmission.
Solution Approach 2:
The oil seal provides preliminary protection by preventing lubricant from reaching the motor shaft in the first place. It acts as a preemptive barrier that stops the harmful flow before it can contaminate the motor, rather than attempting to clean or protect the motor after contamination occurs.
3Reliability
If a grease blocking member is mounted onto the shaft in addition to an oil seal, then grease leakage is prevented, but device complexity increases
Solution Approach 1:
The oil seal is designed to perform multiple functions simultaneously: it seals against lubricant leakage, prevents grease migration, and provides a detectable indicator of transmission unit health. By positioning it externally rather than internally on the shaft, it achieves these functions without adding complex multi-component assemblies.
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 design effectively prevents lubricant from entering the motor unit, reducing the risk of motor damage and allowing for easier detection of seal issues before they cause harm, thereby enhancing the reliability and maintenance of the electric scooter's power module.
Implementation Method 1
A spiral slot, a portion of which is received in the holder and the rest portion of which is received in the lubricant room, is provided on the motor shaft. A spiraling direction of the spiral slot from an end in the holder to an opposite end in the lubricant room is the same as a rotating direction of the motor shaft. The lubricant in the holder will be forced to flow to the lubricant room when the motor shaft is rotating
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An integrated power module of an electric scooter includes a motor unit (10) and a transmission unit (12). The motor unit (10) includes a motor case (14), in which a stator (18), a rotor (20), and a motor shaft (22) are provided. A board (24) is fixed to an end of the motor case (14), and a holder (32) is fixed to the board (24). The transmission unit (12) has a lid (56) connected to the board (24) to form a lubricant chamber (42). The motor shaft (22) passes through the holder (32) to the lubricant chamber (42). The transmission unit (12) further includes a transmission shaft (68), which is connected to the motor shaft (22) through a pair of meshed gears (74, 76). The motor shaft (22) is provided with a spiral slot (78) to force lubricant in the holder (32) flowing to the lubricant room (58) instead of flowing to the motor unit (10) when the motor shaft (22) is rotating.