Drive Unit Mounting Using Steering Rack Mass Damping

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing drive unit mounting systems in vehicles fail to effectively absorb and isolate vibrations from the drive unit, leading to increased noise, vibration, and harshness (NVH) in the vehicle, and also complicate manufacturing with excessive parts and complexity.

Innovation Solution

The proposed solution involves an assembly that includes mounts extending from the drive unit, each carrying an isolator that secures to a frame rail or steering rack, allowing the steering rack to function as a mass damper and absorb vibrations. This configuration reduces the number of parts and manufacturing complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional mounting systems are used to secure the drive unit, then the drive unit can be firmly mounted, but vibration isolation performance is insufficient and NVH performance deteriorates

Engineering Contradiction:

Improvemounting stabilityVSAvoidvibration and noise

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces isolators as intermediary elements between the drive unit mounts and the steering rack. These isolators act as mediators that decouple the direct mechanical connection, allowing the drive unit to be firmly mounted while simultaneously isolating vibrations and improving NVH performance.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The isolators are pre-installed on the mounts before assembly with the steering rack. This beforehand cushioning approach ensures that vibration isolation is built into the mounting system from the outset, preventing vibration transmission before it can affect the steering rack and surrounding components.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Object-affected harmful factors

If additional vibration isolation components are added to the mounting system, then vibration isolation performance improves, but device complexity and manufacturing cost increase

Engineering Contradiction:

Improvevibration isolationVSAvoidnumber of parts

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent makes the steering rack serve multiple functions: it acts as both the steering mechanism and a mass damper for vibration isolation. By utilizing the existing steering rack structure for dual purposes, the system achieves improved vibration isolation without adding separate dedicated vibration control components, thereby avoiding increased device complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The steering rack utilizes its own mass to provide vibration damping benefits. Instead of requiring external active vibration control systems, the system leverages the inherent properties of the steering rack itself to absorb and dampen vibrations, achieving effective vibration isolation through self-service rather than additional complex components.

Inventive Principle:

Principle #25Self-service

3Object-affected harmful factors

If the steering rack is used as a mass damper to absorb vibrations, then vibration amplitude is reduced, but the steering rack structure must withstand additional dynamic loads

Engineering Contradiction:

Improvevibration amplitudeVSAvoidstructural load capacity

Core Design Contradiction:

Object-affected harmful factorsVSStrength

Solution Approach 1:

The isolators are installed beforehand on the mounts to cushion and attenuate vibrations before they reach the steering rack. This beforehand cushioning protects the steering rack structure from excessive dynamic loads by reducing the amplitude of vibrations that the rack must withstand, while still allowing it to function as a mass damper.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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 solution effectively reduces the amplitude of vibrations from the drive unit, enhances NVH performance, and simplifies manufacturing by utilizing existing vehicle components and reducing the number of parts required.

Implementation Method 1

The isolator may be configured to reduce an amplitude of vibration of the drive unit

Methodology Applied

Scientific EffectVibration isolation: Damping

Implementation Method 2

the steering rack may function as a mass damper to absorb vibration from the drive unit

Methodology Applied

Scientific EffectMass damping: Damping

Implementation Method 3

The first isolator may include a first rubber bushing. The second isolator may include a second rubber bushing

Methodology Applied

Scientific EffectViscoelastic damping: Viscoelasticity

Data Source

PatentUS12286157B1Integrated mounting for drive units and steering racks

Publication Date: 2025.04.29 RIVIAN HOLDINGS LLC

AI summary

A drive unit includes mounts coupled to an existing structure (e.g., steering rack) in a vehicle. The steering rack may provide mass damping to the drive unit during operation, thus providing NVH performance. The mounts may include an isolator designed to provide isolation for a component from vibration generated by the drive unit. Alternatively, a steering rack housing may carry isolators, and the mounts may couple to the isolators in the steering rack housing. Using an existing structure in the vehicle, the number of components and manufacturing complexity may be reduced.