Subframe Integration for Electric Lawn Mower Transaxles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electric lawn mowers have complex and inefficient wiring, heavy electric components that complicate manufacturing and balance, and increased costs due to the separate mounting of transaxles, motor drivers, and batteries.
Innovation Solution
The design includes a subframe that supports transaxles, motor drivers, and a battery, allowing for easier assembly and reduced wiring by connecting these components to a main frame, optimizing weight balance and space usage, with the battery positioned between the mower deck and drive wheels to enhance efficiency and reduce labor and costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If electric components (motors, batteries, controller) are separately mounted onto the vehicle body frame, then the lawn mower can be assembled, but manufacturing labor and processes increase significantly
Solution Approach 1:
The patent combines multiple electric components (transaxles with motors, motor drivers, controller, and battery) onto a single sub-frame structure. This merging of components reduces the number of separate mounting operations from multiple individual component installations to a single sub-frame attachment, directly addressing the manufacturing time loss while maintaining assembly simplicity.
2Reliability
If wirings are extended to connect electric components, then all components can be connected, but wiring complexity increases and power transmission efficiency decreases
Solution Approach 1:
By consolidating all electric components onto one sub-frame, the patent dramatically reduces wiring lengths and eliminates the need for complex wiring routes. The controller, motor drivers, and transaxles are positioned in close proximity, allowing for short, direct electrical connections that maintain reliability while minimizing wiring complexity and improving power transmission efficiency.
3Ease of manufacture
If heavy electric components are positioned without considering weight balance, then assembly is simplified, but the lawn mower achieves required weight balance
Solution Approach 1:
The sub-frame integrates all heavy electric components (batteries, motors, controller) into a single assembled unit before attachment to the main vehicle body. This allows the weight distribution to be pre-calculated and pre-balanced during sub-frame assembly, maintaining assembly simplicity while ensuring the lawn mower achieves the required weight balance for stable operation.
Data Source
AI summary
An electric lawn mower includes a main frame, a mower deck supported by the main frame, a castor supported by the main frame, a sub frame, a pair of transaxles, and a pair of motor drivers. Each of the transaxles includes a transaxle housing, an electric motor disposed in the transaxle housing, a single axle supported by the transaxle housing, and a drive wheel fixed on the axle outside of the transaxle housing. The motor drivers supply electric power to the respective motors of the respective transaxles. The sub frame, supporting the transaxles and the motor drivers, is connected to the main frame.