Variable Counterweight for Engine Vibration Mitigation

Solution Overview

Problem

Low cylinder count engines face significant challenges with noise vibration and harshness (NVH) issues due to high engine vibrations, which conventional vibration mitigation devices like dual mass flywheels and centrifugal pendulum vibration absorbers are unable to adequately address, limiting their deployment despite advantages such as reduced part count, lower cost, and higher efficiency.

Innovation Solution

A variable counterweight system comprising rotatable actuators and geometrically reconfigurable counterweights that adjust their center of gravity positions to counteract torque roll and engine vibrations, using a phaser system and linkages to vary the moment applied to mitigate NVH across different engine operating conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If conventional vibration mitigation devices (dual mass flywheels, centrifugal pendulum vibration absorbers) are used in low cylinder count engines, then device complexity is reduced and cost is lowered, but NVH performance deteriorates due to inadequate vibration mitigation

Engineering Contradiction:

Improvevibration mitigation device complexityVSAvoidengine vibration

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The counterweight system transitions from a fixed configuration to a dynamic, adjustable configuration. The counterweights can be repositioned along the crankshaft axis and rotated about their own axes, allowing the system to adapt to varying engine operating conditions and optimize vibration mitigation in real-time

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes physical parameters of the counterweights (position along the crankshaft axis, rotational angle about their own axes) to optimize vibration counterbalancing. By adjusting these parameters, the system can effectively counteract different vibration modes generated by low cylinder count engines under various operating conditions

Inventive Principle:

Principle #35Parameter changes

2Productivity

If low cylinder count engines are deployed, then part count is reduced and mechanical efficiency is improved, but NVH performance deteriorates due to high engine vibrations

Engineering Contradiction:

Improvemechanical efficiencyVSAvoidengine vibration

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The counterweight system transitions from a fixed configuration to a dynamic, adjustable configuration. The counterweights can be repositioned along the crankshaft axis and rotated about their own axes, allowing the system to adapt to varying engine operating conditions and optimize vibration mitigation in real-time

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes physical parameters of the counterweights (position along the crankshaft axis, rotational angle about their own axes) to optimize vibration counterbalancing. By adjusting these parameters, the system can effectively counteract different vibration modes generated by low cylinder count engines under various operating conditions

Inventive Principle:

Principle #35Parameter changes

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 system effectively reduces engine vibrations in low cylinder count engines and other configurations by dynamically adjusting the counterweight moments to match varying engine conditions, enhancing NVH mitigation and enabling wider deployment of these engines.

Implementation Method 1

a first counterweight rotatably coupled to the rotatable actuator to rotate about a first axis... a second counterweight rotatably coupled to the rotatable actuator to rotate about a second axis

Methodology Applied

Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

The first counterweight is configured to geometrically reconfigure so as to change a first counterweight center of gravity position with respect to the first counterweight

Methodology Applied

Scientific EffectMoment of inertia: Moment of Inertia

Data Source

PatentUS10794449B2Variable counterweight

Publication Date: 2020.10.06 CUMMINS INC

AI summary

Variable counterweight apparatuses, systems and methods. The variable counterweight system includes at least one rotatable actuator, a first variable counterweight assembly, and a second variable counterweight assembly. The first variable counterweight assembly is rotatably coupled to the rotatable actuator to rotate about a first axis. The first variable counterweight assembly is configured to geometrically reconfigure so as to change a first variable counterweight assembly center of gravity position with respect to the first variable counterweight assembly. The second variable counterweight assembly is rotatably coupled to the rotatable actuator to rotate about a second axis. The second variable counterweight assembly is configured to geometrically reconfigure so as to change a second variable counterweight assembly center of gravity position with respect to the second variable counterweight assembly.