Integrated Drive Unit Housing for Low-Loss Planetary Support

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing drive units for vehicles are cumbersome and inefficient due to high mechanical losses and structural complexity, requiring numerous components for stability and torque transmission, which complicates assembly and increases weight and volume.

Innovation Solution

A compact drive unit design incorporating a housing with a stator, rotor, planetary gear set, and interfacing means, including support bearings, which reduces power-flow losses and simplifies the structure by integrating all components within a single housing, with the rotor supported via a gear shaft, eliminating the need for intermediate walls and reducing the number of components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If multiple bearings and intermediate walls are used to ensure structural stability, then the drive unit becomes more stable, but the device complexity and number of components increases

Engineering Contradiction:
Improvestructural stabilityVSAvoidnumber of components
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent merges the motor housing and gear set housing into a single integrated housing structure. The housing contains both the stator and the planetary gear set, eliminating the need for separate housings and intermediate connection walls. This reduces the number of components while maintaining structural stability through the unified design.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single housing serves multiple functions: it contains the stator, supports the rotor, houses the planetary gear set, and provides structural stability. The housing acts as both a protective enclosure and a structural framework, reducing the need for additional components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Strength

If intermediate walls are made thicker to ensure resistance and solidity, then the housing becomes more stable, but the drive unit volume and weight increase

Engineering Contradiction:
Improvehousing resistanceVSAvoiddrive unit volume
Core Design Contradiction:
StrengthVSVolume of moving object

Solution Approach 1:

By merging the motor housing and gear set housing into one unified structure, the patent eliminates intermediate walls entirely. The single housing is optimized to provide necessary strength without requiring thick intermediate sections, thereby reducing overall volume and weight while maintaining structural integrity.

Inventive Principle:
Principle #5Merging (Combining)

3Stability of the object's composition

If multiple bearings are used to support rotor and gear set, then the mechanical stability improves, but the bearing churning losses and power-flow losses increase

Engineering Contradiction:
Improvemechanical stabilityVSAvoidbearing churning losses
Core Design Contradiction:
Stability of the object's compositionVSLoss of energy

Solution Approach 1:

The patent reduces the number of bearings by integrating the housing structure and using fewer support points. The single housing provides structural support that reduces reliance on multiple bearings, thereby minimizing bearing churning losses and improving power-flow efficiency while maintaining mechanical stability.

Inventive Principle:
Principle #5Merging (Combining)

4Reliability

If more components are added to guarantee stability, then the structural reliability improves, but the assembly process becomes more difficult and time-consuming

Engineering Contradiction:
Improvestructural reliabilityVSAvoidassembly process
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The integrated housing design reduces the total number of components that need to be assembled. By combining the motor housing and gear set housing into one piece, the assembly process is simplified, requiring fewer assembly steps and reducing manufacturing complexity while maintaining structural reliability.

Inventive Principle:
Principle #5Merging (Combining)

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 enhances efficiency by minimizing bearing churning and load losses, results in a lighter, more durable, and simpler structure with reduced volume and weight, while facilitating easier assembly and improved stability.

Implementation Method 1

bearings that couple the moving portions of the assembly with the static ones to reduce to a minimum the mechanical losses between the various components involved and the consequent power loss

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

The planetary gear set, also placed inside the housing, comprises a ring gear, a plurality of planet gears and a planet carrier. The ring gear is fixed to the housing, the planet gears are in meshing engagement between the sun gear and the ring gear

Methodology Applied
Scientific EffectGear meshing: Gear

Data Source

PatentEP4387060A1Drive unit
Publication Date: 2024.06.19 RIMAC TECH LLC
  • EP4387060A1 patent drawingFigure 1
  • EP4387060A1 patent drawingFigure 2A
  • EP4387060A1 patent drawingFigure 2B

AI summary

A drive unit (1) comprises a housing (2), a stator (3), a rotor (4), a planetary gear set (5) and interfacing means. The rotor (4) comprises a rotor shaft (7) rotatable around a rotation axis (X) and a sun gear (8) coupled to said rotor shaft (7). The planetary gear set (5) comprises a ring gear (9) fixed to said housing (2), a plurality of planet gears (10) in meshing engagement between the sun gear (8) and the ring gear (9), and a planet carrier (11) supporting them. Furthermore, the planet carrier (11) comprises an axial protrusion developing along the rotation axis (X) and defining a gear shaft (12) concentric to the rotor shaft (7). The interfacing means interface the rotor (4) with the planetary gear set (5) and comprise at least one support bearing (14) interposed between the rotor shaft (7) and the gear shaft (12).