Door Drive Coupling Mechanism for Manual and Motorized Operation

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Solution Overview

Problem

Existing door drives for refrigerators and freezers lack efficient mechanisms for moving doors between open and closed positions, particularly in terms of energy efficiency and manual operation, often requiring additional actuators and increasing complexity and cost.

Innovation Solution

A door drive system utilizing a drive motor, drive shaft, clutch, and threaded spindle, where the clutch's actuation areas convert relative rotation into translational movement, allowing the door to be moved between open and closed positions using a single drive motor and eliminating the need for additional actuators by decoupling and coupling mechanisms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single drive motor is used to move the door, then device complexity and cost are reduced, but the ability to enable/disable torque transmission during manual operation becomes more challenging

Engineering Contradiction:
Improvenumber of actuatorsVSAvoidmanual door operation
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The clutch element is designed to be dynamically switchable between coupled and decoupled states. During automatic operation, the clutch couples the threaded spindle to the actuating element for motor-driven movement. During manual operation, the clutch decouples them, allowing the door to be moved freely without motor interference. This dynamic state change enables a single motor to serve both automatic and manual operation modes.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The clutch element acts as an intermediary between the threaded spindle and the actuating element. It selectively transmits or blocks torque based on operational needs. When coupled, it transmits motor torque to drive the door; when decoupled, it allows manual operation without motor resistance. This intermediary mechanism resolves the contradiction by enabling a single motor to accommodate both automated and manual operation modes.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If actuation areas are designed to convert relative rotation into translational movement, then coupling and decoupling efficiency is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improvecoupling/decoupling efficiencyVSAvoidactuating area alignment
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The actuating areas are designed with curved or inclined surfaces that guide the coupling and decoupling motion. The curved geometry naturally guides the clutch element between positions while accommodating minor manufacturing variations. This curvature provides self-aligning characteristics that reduce the impact of manufacturing precision limitations while maintaining efficient torque transmission during coupling.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Ease of operation

If the clutch element is translationally movable between coupled and decoupled positions, then ease of operation is improved, but device complexity increases

Engineering Contradiction:
Improvedoor movement controlVSAvoidclutch mechanism structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The clutch element combines multiple functions into a single component: it serves as both the torque transmission interface and the positional indicator. The same element that couples or decouples the torque path also provides mechanical feedback about the operational state. This merging reduces the number of separate components needed while maintaining ease of operation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The clutch element is designed as a multi-functional component that performs torque transmission, positional indication, and operational state signaling simultaneously. This universal design approach enables improved ease of operation without proportionally increasing device complexity, as one component fulfills multiple roles in the system.

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

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 enables efficient, energy-saving door operation with reduced parts, weight, and cost, allowing for both motor-driven and manual door movement with enhanced mobility and simplified design.

Implementation Method 1

The threaded spindle (24) has a first thread (28), in particular in the form of an external thread. A screw element is provided, for example, which has a second thread corresponding to the first thread and designed, for example, as an internal thread. By means of the first and second threads, the relative rotation between the threaded spindle (24) and the screw element is converted into a translational movement of the screw element

Methodology Applied
Scientific EffectScrew mechanism: Screw

Implementation Method 2

By means of the actuating areas, a relative rotation between the actuating element and the coupling element, which can be effected or brought about by rotating the drive shaft, is converted into a translational movement of the coupling element from the decoupling position to the coupling position along the actuating axis of rotation

Methodology Applied
Scientific EffectFriction-based actuation: Friction

Data Source

PatentEP3767061B1Door drive for a door, especially of a piece of furniture or a device, method for operating such a door drive and device comprising at least one such door drive
Publication Date: 2022.05.04 APPARATEBAU GRONBACH SRL
  • EP3767061B1 patent drawingFigure 1~2
  • EP3767061B1 patent drawingFigure 3
  • EP3767061B1 patent drawingFigure 4

AI summary

The invention relates to a door drive (10) for a door, comprising a drive motor (12), a drive shaft (14) that can be driven by the drive motor (12) and is thereby rotatable, a coupling (22), and a threaded spindle (24) that can be driven by the drive shaft (14) via the coupling (22) and is thereby rotatable, wherein the coupling (22) comprises: - a drive element (30), - an actuating element (32) that can be driven by the drive shaft (14) by rotating the drive shaft (14) and is thereby rotatable about an actuating axis of rotation (34) and has at least one first actuating area (36), and - a coupling element (38) that has at least one second actuating area (40) corresponding to the first actuating area (36) and is located along the actuating axis of rotation (34) relative to the drive element (30) between at least one decoupling position (E) in which the coupling element (38) is disengaged from the drive element (30). is decoupled,and is translationally movable in at least one coupling position (K) in which the coupling element (38) is coupled to the drive element (30), wherein, by means of the actuating areas (38, 40), a relative rotation between the actuating element (32) and the coupling element (38) effected by rotating the drive shaft (12) can be converted into a translational movement of the coupling element (38) from the decoupling position (E) to the coupling position (K) along the actuating axis of rotation (34), relative to the drive element (30), relative to the actuating element (32) and in the direction of the drive element (30).