Dual-Motor Pull Rope Reel Layout for Shake-Canceling Fitness Resistance

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Solution Overview

Problem

Traditional pull fitness devices are heavy, occupy a large area, and lack adjustable pull force, making them inconvenient for users with limited space and time for exercise.

Innovation Solution

A fitness device using two motors to drive a pull rope reel, equipped with a control system to adjust the pull force, offsetting shakes and vibrations, and featuring a stable, reliable structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional force-adjustable pull fitness devices are used, then pull force can be adjusted, but the device becomes heavy and occupies large area

Engineering Contradiction:
Improvepull force adjustabilityVSAvoiddevice weight
Core Design Contradiction:
Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The patent replaces traditional mechanical force-adjustment mechanisms with an electromagnetic motor system controlled by electronic circuits. The motor-driven reel system with electronic control achieves variable pull force without the heavy mechanical components of traditional adjustable resistance devices, thus reducing overall device weight while maintaining force adjustability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the control parameter from mechanical adjustment to electronic control. By using a motor with variable speed control and electronic feedback, the pull force can be adjusted by changing motor rotation speed and torque parameters, eliminating the need for heavy mechanical adjustment mechanisms while providing continuous variable resistance.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If single motor is used to drive pull rope, then device structure is simple, but shakes and vibrations occur during exercise

Engineering Contradiction:
Improvemotor configurationVSAvoidexercise stability
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

The patent uses two motors positioned asymmetrically on opposite sides of the reel axis, driving the reel in opposite directions. This asymmetric configuration creates balanced counteracting forces that cancel out vibrations and shakes during operation, improving exercise stability while maintaining relatively simple device structure.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The two motors function as counterbalancing elements, with one motor's rotational force compensating for the vibrations and shakes generated by the other motor during pull exercise. This counterweight principle eliminates the instability issues of single-motor systems without significantly increasing device complexity.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

3Force

If high power motor is used to provide sufficient pull force, then exercise effectiveness is improved, but motor load increases and service life decreases

Engineering Contradiction:
Improvepull forceVSAvoidmotor service life
Core Design Contradiction:
ForceVSDuration of action of stationary object

Solution Approach 1:

The patent uses two motors providing partial pull force each, rather than one motor providing excessive force. This distributes the mechanical load, reducing stress and heat generation on each motor, thereby extending service life while maintaining sufficient total pull force for effective exercise.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The control system implements periodic duty cycles, adjusting motor operation intensity based on exercise phase and user feedback. The motors operate at variable power levels rather than constant high power, reducing cumulative thermal load and extending motor service life while maintaining exercise effectiveness through controlled intermittent high-force output.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP4368259B1Dual-motor-based shaking cancellation fitness device
Publication Date: 2025.12.03 DONGGUAN DIRECT DRIVE TECH LTD
  • EP4368259B1 patent drawingFigure 1
  • EP4368259B1 patent drawingFigure 2
  • EP4368259B1 patent drawingFigure 3

AI summary

The invention relates to the technical field of smart fitness, in particular to a fitness device using two motors for offsetting shake. The fitness device comprises a box, two support frames symmetrically mounted in the box, two driving motors mounted on the two support frames and arranged opposite to each other, a pull rope reel connected to the two driving motors, a fitness pull rope wound around the pull rope reel and extending out of the box, and a control system electrically connected to and used for controlling the driving motors. The control system comprises a main controller, a power module, a communication module, a driving circuit and a sampling module, the power module is electrically connected to the main controller and the communication module, the communication module is electrically connected to the main controller, the sampling module is electrically connected to the driving motors and the main controller, and the driving circuit is electrically connected to the power module, the main controller and the driving motors. The two symmetrical driving motors are used to drive the pull rope reel to drive the fitness pull rope, such that shakes and vibrations generated during exercise can be offset, the load of each motor is reduced, and the stability is improved.