Drum rotating device for laundry care apparatus

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Solution Overview

Problem

Existing drum driving devices in laundry care apparatuses face challenges in smoothly transitioning between different rotational forces and speeds due to limitations in clutch engagement, leading to increased size, noise, vibration, and limited control over clutch displacement.

Innovation Solution

A drum rotating device with a clutch mechanism that allows for gear shifting during operation by using inclined surfaces on clutch and coupling gears for precise alignment, coupled with a drive module that moves the clutch rectilinearly, enabling smooth engagement and synchronization with the rotor without the need for elastic members, thus reducing noise and vibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a clutch mechanism is used to change gears during drum operation, then gear shifting becomes possible during rotation, but large vibrations and noise are generated due to difficulty in coupling the clutch and motor while rotating

Engineering Contradiction:
Improvegear shifting capability during operationVSAvoidvibration and noise
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The clutch is pre-positioned adjacent to the motor before rotation begins. The inclined surfaces of the clutch gear and coupling gear are designed to guide engagement before full rotational speed is reached, allowing the clutch to be coupled to the motor while minimizing vibration and noise during the coupling process

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If separate mover and stator are installed surrounding the planetary gear assembly to drive the clutch, then the clutch can be driven independently, but the overall size of the drum driving device increases

Engineering Contradiction:
Improveindependent clutch controlVSAvoidoverall device size
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

The motor's rotor serves dual functions: it directly drives the drum through the planetary gear assembly and simultaneously drives the clutch through the coupling gear. This integration eliminates the need for separate movers and stators, reducing the overall device size while maintaining independent clutch control capability

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The motor is designed to perform multiple functions: it acts as both the primary drive for the drum and the drive mechanism for the clutch. The coupling gear on the rotor enables the motor to control both the planetary gear assembly and the clutch mechanism, making the motor a universal drive component

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If a lever unit is used to move the clutch while rotating, then the clutch can be actuated during drum rotation, but space for lever rotation must be secured inside the motor driving device, increasing its size

Engineering Contradiction:
Improveclutch actuation during rotationVSAvoidmotor driving device size
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The lever unit is completely removed from the design. Instead, the clutch is actuated directly through the axial movement of the clutch gear along the inclined surface, which is driven by the rotating coupling gear on the motor rotor. This eliminates the need for internal lever rotation space within the motor driving device

Inventive Principle:
Principle #2Taking out (Extraction)

4Stability of the object's composition

If an elastic member such as a spring is used to constrain clutch displacement, then the clutch can be restrained, but when external force greater than elastic force is applied, the displacement changes, causing vibration, noise, and part wear

Engineering Contradiction:
Improveclutch displacement constraintVSAvoidclutch displacement control under external force
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The elastic member (spring) is replaced with a rigid mechanical constraint system. The clutch gear's axial position is constrained by the inclined surface geometry and the engagement with the coupling gear, creating a deterministic displacement constraint that does not deform under external force, thereby eliminating vibration, noise, and wear associated with elastic member failure

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

The solution enables quick and stable mode conversion with reduced noise and vibration, allows for precise control of clutch displacement, and miniaturizes the device by eliminating the need for additional space for elastic members, improving assembly and maintainability.

Implementation Method 1

the clutch gear and the coupling gear may include inclined surfaces that induce the clutch gear and the coupling gear to slide and engage correctly with each other

Methodology Applied
Scientific EffectInclined surface geometry: Inclined Plane

Data Source

PatentEP4650506A1Drum rotating device for laundry care apparatus
Publication Date: 2025.11.19 LG ELECTRONICS INC
  • EP4650506A1 patent drawingFigure 1~2
  • EP4650506A1 patent drawingFigure 3
  • EP4650506A1 patent drawingFigure 4

AI summary

Proposed are a drum rotating device and a laundry care apparatus including the same. The drum rotating device includes a drum shaft (80) coupled to the drum (30), a motor (200) including a stator (220) and a rotor (230) that rotates relative to the stator (220). A gear assembly (300) transmits rotational force of the rotor (230) to the drum shaft (80). A clutch (410) is connected to the gear assembly (300), and is selectively coupled to the rotor (230) to be rotated together therewith. An actuator (400) is connected to the clutch (410). The actuator (400) includes drive gears that move the clutch (410) rectilinearly in an axial direction of the drum shaft (80). In this case, the clutch and the rotor include a clutch gear and a coupling gear, respectively, which protrude to face each other in the axial direction and are coupled to each other.