Electromechanical Spring Seat Control for Vehicle Suspension

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Solution Overview

Problem

Existing vehicle suspension systems with mechanical spring portions rely on hydraulic control, which is inefficient and difficult to integrate, especially for low-frequency suspension deflections below the wheel hop frequency.

Innovation Solution

The method involves electromechanically controlling the spring seat position using an electric motor and mechanical gear assemblies or screw and ball nut systems, eliminating the need for fluid pressure and simplifying integration by determining frequency content to adjust spring stiffness accordingly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If hydraulic control is used to control spring seat position, then the suspension system can adjust spring stiffness, but the system complexity increases due to hydraulic components (cylinders, valves, hoses, filters)

Engineering Contradiction:

Improvespring stiffness adjustment capabilityVSAvoidhydraulic system complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent replaces the hydraulic control system with an electromechanical system consisting of an electric motor and a lead screw mechanism. The electric motor drives the lead screw to move the spring seat, eliminating the need for hydraulic cylinders, valves, hoses, and filters while maintaining the capability to adjust spring stiffness.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent extracts and removes the hydraulic components (cylinders, valves, hoses, filters) from the suspension system, retaining only the essential function of spring seat position control through a simplified electromechanical actuation system.

Inventive Principle:

Principle #2Taking out (Extraction)

2Ease of operation

If hydraulic components are used, then spring seat position can be controlled, but packaging and integration become more difficult

Engineering Contradiction:

Improvespring seat position controlVSAvoidpackaging space requirements

Core Design Contradiction:

Ease of operationVSVolume of moving object

Solution Approach 1:

The compact electromechanical actuator with lead screw mechanism occupies significantly less space than the equivalent hydraulic system, including cylinders, hoses, and associated components, thereby improving packaging and integration into the vehicle suspension system.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Speed

If hydraulic control is used for low-frequency suspension deflection, then the system can respond to body motions, but the hydraulic system requires additional components (accumulator, pump, proportional valve)

Engineering Contradiction:

Improveresponse to low-frequency suspension deflectionVSAvoidhydraulic control components

Core Design Contradiction:

SpeedVSDevice complexity

Solution Approach 1:

The patent replaces the complex hydraulic control system with an electromechanical system that uses an electric motor and lead screw mechanism to control spring seat position in response to low-frequency suspension deflection, eliminating the need for accumulators, pumps, and proportional valves while maintaining responsive control capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 approach enhances ride quality and road isolation while reducing the complexity of hydraulic systems, providing easier packaging and integration by controlling spring seat position effectively without fluid pressure, thus improving vehicle handling and suspension performance.

Implementation Method 1

The screw and ball nut assembly is operatively connected to the spring seat to control spring seat position and is adapted to be driven by an electric motor

Methodology Applied

Scientific EffectScrew mechanism: Screw

Implementation Method 2

screw and ball nut assembly

Methodology Applied

Scientific EffectRolling contact: Ball Bearing

Data Source

PatentUS7665585B2Vehicle suspension system and method for operating

Publication Date: 2010.02.23 BWI CO LTD SA

AI summary

A vehicle suspension system includes a mechanical spring portion adapted to undergo suspension deflection, a spring seat contacting and supporting the mechanical spring portion, and a mechanical gear assembly which is operatively connected to the spring seat to control spring seat position and which is adapted to be driven by an electric motor. A method for operating a vehicle suspension system undergoing suspension deflection, wherein the vehicle suspension system includes a mechanical spring portion having a spring seat with a movable spring seat position, includes determining a frequency content of the suspension deflection. The method also includes electromechanically controlling the spring seat position in response to suspension deflection when the determined frequency content is in a low-frequency range below a wheel hop frequency.