Exercise Machine Dual-Preload Dampener to Reduce Actuator Backlash

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Solution Overview

Problem

Exercise machines experience actuator backlash due to reversing loads during striding exercises, leading to undesirable noise and unbalanced user feedback.

Innovation Solution

Incorporation of a dampener system that applies a preload force on the actuator to dampen reversing loads, using a dual preload dampener system with tension and compression forces to reduce backlash.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If an actuator is used to adjust the rocker arm position for incline adjustment, then the exercise machine can provide variable incline settings, but actuator backlash occurs during reversing loads causing noise and unbalanced user feedback

Engineering Contradiction:

Improveincline adjustment capabilityVSAvoidactuator backlash noise

Core Design Contradiction:

Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The dampener applies a preload force to the actuator before reversing loads occur, maintaining constant contact between actuator components and eliminating backlash before it can cause noise or vibration during direction changes

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The dampener acts as an intermediary element between the actuator and the reversing loads from the rocker arm, absorbing and dampening the impact of reversing loads to prevent them from causing actuator backlash and noise

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If a single preload force is applied to the actuator, then backlash reduction is achieved, but the dampener cannot effectively handle both tension and compression reversing loads

Engineering Contradiction:

Improvebacklash reductionVSAvoidhandling of tension and compression loads

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The dampener system is segmented into two independent springs: a compression spring to handle compressive reversing loads and a tension spring to handle tensile reversing loads. This segmentation allows each spring to be optimized for its specific load type, ensuring effective backlash reduction across all operating conditions

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system changes the physical state of the dampening mechanism by using two different spring types (compression and tension) to handle different load directions. This parameter change enables the dampener to adapt to both tensile and compressive reversing loads effectively

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 dampener system effectively reduces actuator backlash, minimizing noise and ensuring a smooth, balanced user experience across varying incline configurations.

Implementation Method 1

The dampener may comprise a spring configured to apply the preload force. The spring may comprise an elastomer.

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS20250262505A1Exercise machines having dampener for reducing actuator backlash

Publication Date: 2025.08.21 LIFE FITNESS LLC

AI summary

An exercise machine has a frame, a rocker arm operable to perform a striding exercise motion relative to the frame, an actuator coupling the rocker arm to the frame, the actuator being configured to adjust a position of the rocker arm relative to the frame to adjust an incline of the striding exercise motion, and a dampener configured to apply a preload force on the actuator to dampen reversing loads from the rocker arm and reduce backlash in the actuator.