Electric Excavator Swivel Frame Layout for Machine Balance
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Solution Overview
Problem
The existing configuration of hydraulic excavators, where a battery is located above the electric motor and hydraulic pump, results in a higher center of gravity due to the battery's weight, making it difficult to maintain balance, especially when using large-capacity batteries.
Innovation Solution
The electric work machine design includes a battery unit positioned on a swivel frame at the bottom of the upper swivel body, with the electric motor and hydraulic pump arranged side by side on the same frame, allowing for better weight distribution and balance.
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 positioned 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/pump) to a horizontal side-by-side arrangement on the swivel frame. This dimensional change allows all components to be positioned at a lower elevation while utilizing the lateral space of the upper swivel body, thereby maintaining compact space utilization while significantly lowering the center of gravity to improve machine balance
2Use of energy by moving object
If a large-capacity battery unit is used, then the electric motor can be driven with sufficient power, but the machine body becomes increasingly difficult to balance when the battery position is high or off-center
Solution Approach 1:
The patent applies local quality by positioning the heavy battery unit at a specific location on the swivel frame (side-by-side with motor and pump) rather than using a generic mounting position. This localized arrangement ensures the battery's weight contributes to lowering the overall center of gravity while maintaining optimal spatial relationships with other components, enabling large-capacity batteries to be used without compromising balance
3Area of stationary object
If the battery is positioned high in the upper swivel body, then space can be optimized, but the machine body balance deteriorates
Solution Approach 1:
The invention resolves this contradiction by changing the spatial arrangement from vertical (high position) to horizontal (side-by-side on swivel frame). This dimensional transformation allows the battery to occupy space efficiently within the upper swivel body footprint while maintaining a low center of gravity, thus optimizing space without sacrificing balance
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 configuration effectively maintains the balance of the machine body during operation, even with large-capacity batteries, by lowering the center of gravity and ensuring stable weight distribution.
Implementation Method 1
a battery unit (53) arranged in the upper swivel body (4) and storing electric power to drive the electric motor (61)
Implementation Method 2
an electric motor (61) arranged in the upper swivel body (4)
Implementation Method 3
a hydraulic pump (71) arranged in the upper swivel body (4) and driven by the electric motor (61), and a hydraulic actuator (73) driven by hydraulic oil supplied from the hydraulic pump (71)
Data Source
AI summary
A hydraulic excavator as an electric work machine comprises 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.