Brushless DC Motor in Winch Drum for Reliability

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Solution Overview

Problem

Brush DC motors in winches are prone to wear, sparking, and limited speed due to brushes, and are vulnerable to contaminants in non-ideal conditions, while existing brushless DC motors do not fully address the need for a sealed and efficient solution for portable winches.

Innovation Solution

A brushless DC motor is integrated within the winch drum with a fixed shaft and rotating housing, utilizing a sealed design to prevent contaminant ingress, where the permanent magnets are on the rotor and electromagnets are on the stator, with electrical wiring passing through the shaft for external power connection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a brush DC motor is used in a winch, then the motor can provide sufficient power, but the brushes wear out, cause sparking, limit maximum speed, and increase vulnerability to contaminants

Engineering Contradiction:

Improvemotor reliabilityVSAvoidbrush structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent removes the brushes and commutator from the motor design, extracting the problematic components that caused wear, sparking, and reliability issues. This is achieved by using a brushless DC motor where the rotor contains permanent magnets and the stator contains electromagnets, eliminating the need for sliding contact components.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical brush-commutator system with an electronic control system using power transistors and computer control. The commutation function previously performed mechanically by brushes is now achieved through electronic switching of the stator electromagnets based on rotor position feedback.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Temperature

If the motor is exposed to the external environment, then it is easier to access and cool, but contaminants can ingress and damage the motor

Engineering Contradiction:

Improvemotor coolingVSAvoidcontaminant ingress

Core Design Contradiction:

TemperatureVSObject-affected harmful factors

Solution Approach 1:

The patent combines the motor housing with the winch drum, merging two separate components into one integrated unit. The drum serves as both the winding mechanism and the protective enclosure for the motor, eliminating the need for separate housing while providing both mechanical function and environmental protection.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent nests the motor completely within the drum structure, with the motor housing contained inside the drum cavity. This nested arrangement allows the drum to act as an outer protective shell while the motor operates in a protected internal environment, with only essential components like the shaft extending outward.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Reliability

If an in-runner brushless DC motor is used, then the permanent magnets are on the rotor, but the shaft must rotate which complicates the winding mechanism

Engineering Contradiction:

Improvebrushless motor performanceVSAvoidshaft rotation complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent inverts the traditional motor configuration by using an out-runner brushless DC motor where the permanent magnets are on the outer rotor and the stator is in the center. This inversion allows the shaft to remain stationary while the outer rotor rotates, simplifying the connection to the drum and eliminating the need for rotating electrical connections.

Inventive Principle:

Principle #13The other way round (Inversion)

4Speed

If brushes are used to control rotor speed, then speed control is possible, but the brushes wear out and limit maximum speed

Engineering Contradiction:

Improverotor speed controlVSAvoidbrush service life

Core Design Contradiction:

SpeedVSDuration of action of moving object

Solution Approach 1:

The patent replaces the mechanical brush-based speed control system with an electronic control system using power transistors and microprocessor control. Speed is controlled by varying the frequency and duty cycle of the electrical signals to the stator electromagnets, eliminating wear and allowing for precise, unlimited speed control within motor capabilities.

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 design provides precise speed control, reduced noise, increased efficiency, and protection from contaminants, ensuring reliable operation in harsh environments.

Implementation Method 1

The armature contains an electromagnet which creates a magnetic field when electrical current is provided. The magnetic field attracts and repels the permanent magnets of the stator.

Methodology Applied

Scientific EffectMagnetic field attraction and repulsion: Magnetic Field

Implementation Method 2

In a brushless motor, the permanent magnets are mounted on the rotor and the electromagnets are positioned on the stator. The rotor is kept spinning by alternating the polarity of the electromagnets.

Methodology Applied

Scientific EffectElectromagnetism: Electromagnet

Data Source

PatentUS9556008B2Winch with drum-encased brushless DC motor

Publication Date: 2017.01.31 MOTOWINCH GROUP LLC

AI summary

A winch having a brushless DC motor, the brushless DC motor having a fixed, non-rotating shaft and a rotating housing; and a rotating drum mounted to the rotating housing, wherein the rotating housing is fully encased within the rotating drum.