Two-Way Oil Sump Structure for EV Reducer Churning Loss Reduction

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Solution Overview

Problem

Conventional oil sumps in electric vehicle reducers have insufficient oil collecting efficiency due to the limited directionality of oil collection, leading to significant oil churning losses and reduced working efficiency.

Innovation Solution

A two-way oil-collecting reducer design featuring an oil sump with a radial sump opening and a circumferential sump opening, allowing lubricating oil to be collected from both radial and circumferential directions, thereby enhancing oil collection efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a conventional oil sump with a single-direction opening is used, then the structure is simple, but the oil collecting efficiency is insufficient

Engineering Contradiction:
Improvestructure simplicityVSAvoidoil collecting efficiency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The oil sump opening is segmented into two distinct directions: a radial sump opening facing upward to collect oil from the output gear, and a circumferential sump opening facing the output gear to collect oil from the intermediate gear set. This segmentation allows the oil sump to collect lubricating oil from multiple directions simultaneously, significantly improving oil collecting efficiency while maintaining reasonable structural complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from a single-direction (one-dimensional) oil collection approach to a multi-directional (two-dimensional) oil collection system. By adding both radial and circumferential opening directions, the oil sump can collect oil from different spatial dimensions, effectively increasing the oil collection area and efficiency without proportionally increasing structural complexity

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Ease of manufacture

If the oil sump only collects oil from one direction, then the manufacturing is simple, but the oil churning loss is large

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidoil churning loss
Core Design Contradiction:
Ease of manufactureVSLoss of energy

Solution Approach 1:

The oil sump opening is divided into radial and circumferential segments, each oriented to collect oil from specific gear components. The radial opening collects oil thrown by the output gear from above, while the circumferential opening collects oil from the intermediate gear set, ensuring comprehensive oil collection and reducing oil churning loss

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different portions of the oil sump opening are oriented in different directions to match the local oil throwing patterns of specific gear components. The radial opening is positioned to receive oil from the output gear area, while the circumferential opening receives oil from the intermediate gear set area, optimizing oil collection at each location

Inventive Principle:
Principle #3Local quality

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

The two-way oil-collecting design significantly reduces oil churning losses and improves the efficiency of the reducer by ensuring more effective lubrication and cooling of the gear train components.

Implementation Method 1

When a gear wheel works and rotates, lubricating oil in the reducer is churned and thrown into the oil sump from above the oil sump

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP4563847A1Two-way oil-collecting reducer and electric vehicle
Publication Date: 2025.06.04 HUAWEI DIGITAL POWER TECH CO LTD
  • EP4563847A1 patent drawingFigure 1
  • EP4563847A1 patent drawingFigure 2
  • EP4563847A1 patent drawingFigure 3

AI summary

This application provides a two-way oil-collecting reducer and an electric vehicle. The reducer includes an input gear, an intermediate gear set, an output gear, and an oil sump, the input gear is configured to drive, via the intermediate gear set, the output gear to rotate forward or reversely, a rotation direction of the intermediate gear set is opposite to a rotation direction of the output gear, and the oil sump includes a radial sump opening and a circumferential sump opening. An orientation of the radial sump opening is away from the intermediate gear set along a radial direction of the intermediate gear set. An orientation of the circumferential sump opening faces the output gear along a circumferential direction of the intermediate gear set. The radial sump opening is connected to the circumferential sump opening. The radial sump opening and the circumferential sump opening are formed at the oil sump, so that the oil sump can collect lubricating oil churned by a gear train when the input gear drives, via the intermediate gear set, the output gear to rotate forward or reversely, to increase an amount of lubricating oil collected by the oil sump, reduce an oil churning loss of the gear train, and improve efficiency of the reducer.