Camshaft Adjuster Torque Fluctuation Energy Reduction

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Solution Overview

Problem

Conventional camshaft adjusters face inefficiencies in energy usage due to constant torque requirements, lacking the ability to automatically adjust and maintain energetically favorable positions, leading to higher energy expenditure.

Innovation Solution

An electrically driven camshaft adjuster with a three-shaft or four-shaft transmission system, utilizing an actuator with torque fluctuations dependent on the angular position of the adjusting shaft, combined with an elastic rolling bearing design that creates locking effects and fine positioning capabilities, allowing for automatic fixation and reduced energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If conventional camshaft adjusters use constant torque requirements, then the adjustment mechanism can maintain position, but energy consumption increases

Engineering Contradiction:

Improveenergy consumptionVSAvoidposition holding capability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent applies dynamics by making the torque requirement variable rather than constant. The adjusting transmission is designed so that torque requirements fluctuate periodically with the angular position of the adjusting shaft, creating preferential positions where minimal torque is needed to maintain position. This dynamic torque requirement reduces energy consumption while maintaining position holding capability through the periodic torque minima.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The adjusting transmission design enables the system to automatically seek and maintain preferential positions with minimal actuator intervention. The periodic torque fluctuations create natural stable positions where the transmission self-latches, allowing the actuator to remain largely de-energized while the camshaft adjuster maintains its position automatically.

Inventive Principle:

Principle #25Self-service

2Measurement precision

If the adjusting transmission uses a high reduction ratio, then positioning precision improves, but the complexity of the transmission increases

Engineering Contradiction:

Improvepositioning precisionVSAvoidtransmission complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The adjusting transmission is designed as a multi-functional mechanism that simultaneously achieves high reduction ratio (e.g., 1:250), low friction, and periodic torque characteristics. The double eccentric or double planetary transmission design integrates multiple functions into a single compact unit, avoiding the need for separate complex mechanisms for each function.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent replaces conventional mechanical positioning systems with an adjusting transmission that uses periodic torque minima and preferential positions to maintain positioning. Instead of relying on constant mechanical engagement or high friction, the system uses the inherent periodic torque characteristics of the eccentric or planetary transmission to create natural stable positions.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If the actuator is electrically driven, then control precision improves, but energy consumption increases compared to hydraulic systems

Engineering Contradiction:

Improvecontrol precisionVSAvoidenergy consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The system uses periodic action by designing the adjusting transmission to create periodic torque minima at specific angular positions of the adjusting shaft. The electric actuator only needs to operate intermittently to move the system between these preferential positions, rather than maintaining constant power output. During periods when the system is in a preferential position, the actuator remains de-energized, significantly reducing overall energy consumption.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent changes the torque parameter dynamically through the adjusting transmission design. The transmission converts constant actuator torque into variable output torque with periodic minima, allowing the electric actuator to operate at low power levels while still achieving precise positioning and maintaining it with minimal energy expenditure.

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 achieves an efficiency of over 50% by automatically locking the output shaft in preferential positions with minimal torque, significantly reducing energy requirements compared to conventional designs.

Implementation Method 1

at least one bearing ring, in particular an outer ring, of the rolling bearing is elastic and flexible

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Data Source

PatentUS9920660B2Camshaft adjuster and method for operating a camshaft adjuster

Publication Date: 2018.03.20 SCHAEFFLER TECHNOLOGIES AG & CO KG

AI summary

A method for operating a camshaft adjuster, which includes an adjusting transmission with an input shaft, an output shaft connected in a non-rotatable manner with a camshaft, and an adjusting shaft, whereby the adjusting shaft is driven by an actuator, characterized by the fact that the actuator drives the adjusting shaft by overcoming a torque that is dependent on its angular position.