Electric Excavator Upper Body Layout for Low Center of Gravity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The conventional arrangement of a battery above an electric motor and hydraulic pump in hydraulic excavators raises the center of gravity, making it difficult to maintain balance, especially with large-capacity batteries positioned high or off-center.
Innovation Solution
The battery unit is placed on a swivel frame in the upper swivel body alongside the electric motor and hydraulic pump, allowing them to be arranged side by side, which lowers the center of gravity and balances the weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the battery is located above the electric motor and hydraulic pump in the upper swivel body, then the battery can be arranged in a compact space, but the center of gravity becomes higher making it difficult to maintain balance
Solution Approach 1:
The patent transitions from a vertical stacking arrangement (battery above motor and pump) to a horizontal side-by-side arrangement on the swivel frame. This dimensional change allows all components to be positioned at a lower height level, reducing the center of gravity while maintaining compact arrangement within the upper swivel body space.
2Use of energy by moving object
If a large-capacity battery unit is used, then the electric power storage is increased, but the weight increases making balance maintenance more difficult
Solution Approach 1:
The patent accommodates large-capacity battery units by arranging them horizontally side-by-side with the electric motor and hydraulic pump on the swivel frame, rather than stacking them vertically. This horizontal arrangement distributes the increased weight across a wider base area at a lower height, maintaining better balance despite the increased power storage capacity.
Data Source
AI summary
A hydraulic excavator as an electric work machine includes a lower traveling body, an upper swivel body located above the lower traveling body and provided to be swivelable with respect to the lower traveling body, an electric motor arranged in the upper swivel body, a hydraulic pump arranged in the upper swivel body and driven by the electric motor, a battery unit arranged in the upper swivel body and storing electric power to drive the electric motor, and a hydraulic actuator driven by hydraulic oil supplied from the hydraulic pump. The upper swivel body has a swivel frame at a bottom portion thereof. The battery unit is arranged on the swivel frame. The electric motor and the hydraulic pump are arranged on the swivel frame, side by side in a left-right direction of the upper swivel body.