Door Drive Cam Disc Roller Mechanism Reducing Friction

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Solution Overview

Problem

Existing motor-operated drives for doors and windows face challenges such as complex structural connections, high friction due to numerous bearing points, and inefficient energy transmission, leading to increased manufacturing costs and the need for larger, more expensive drive motors.

Innovation Solution

A drive system featuring a swivel lever with a rotatable roller that transmits force between a cam disk and an energy storage unit, where the energy storage unit is arranged on opposite sides of the pivot lever, reducing friction by minimizing bearing points and allowing direct force transmission, enabling a compact and efficient design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a cage and tie rod are used to connect the cam disc to the compression spring, then the drive power can be transmitted, but the structural connection becomes complex and space is consumed

Engineering Contradiction:
Improvedrive power transmissionVSAvoidstructural connection complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the cage and tie rod from the drive mechanism. Instead of using these complex intermediate components, the cam disc directly acts on the roller, which is pivotally connected to the pivot lever, which in turn directly acts on the compression spring. This extraction of unnecessary components simplifies the structural connection while maintaining drive power transmission capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention merges multiple functions into fewer components. The pivot lever serves both as a lever arm for the roller and as a direct connector to the compression spring, eliminating the need for separate cage and tie rod components. This merging reduces structural complexity while preserving the essential drive function.

Inventive Principle:
Principle #5Merging (Combining)

2Shape

If the center axis of the output shaft is not aligned with the compression spring, then the cam disc can be positioned, but bending moments act on the cage and tie rod requiring complex design

Engineering Contradiction:
Improvecam disc positioningVSAvoidbending force resistance
Core Design Contradiction:
ShapeVSStrength

Solution Approach 1:

The invention removes the cage and tie rod that were subjected to bending moments. By establishing direct action between the cam disc and the pivot lever through the roller, and direct connection between the pivot lever and compression spring, the design eliminates the intermediate components that required complex bending force resistance design.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of trying to strengthen the cage and tie rod to resist bending moments, the invention inverts the approach by eliminating these components entirely and creating a direct action mechanism where forces are transmitted through pivoting connections rather than bending-prone linkages.

Inventive Principle:
Principle #13The other way round (Inversion)

3Reliability

If numerous bearings are used in the cage and tie rod connection, then the components can be supported, but friction increases and drive efficiency decreases

Engineering Contradiction:
Improvecomponent supportVSAvoidfriction losses
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The invention extracts and removes the numerous bearings from the drive mechanism by eliminating the cage and tie rod assembly. The simplified direct-action mechanism requires minimal bearing points, dramatically reducing friction losses while maintaining reliable component support through the essential pivot connections.

Inventive Principle:
Principle #2Taking out (Extraction)

4Strength

If the cage, piston bearings, and tie rod connections are designed to be robust, then the drive can handle loads, but manufacturing costs increase

Engineering Contradiction:
Improveload handling capabilityVSAvoidmanufacturing cost
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The invention removes the expensive-to-manufacture cage, piston bearings, and complex tie rod connections. The simplified mechanism with direct cam disc-to-roller-to-pivot lever-to-spring action requires fewer precision-machined parts, reducing manufacturing complexity and cost while maintaining adequate load handling capability through the essential load-bearing components.

Inventive Principle:
Principle #2Taking out (Extraction)

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 results in a more powerful, cost-effective, and compact drive system with reduced friction losses, allowing for efficient operation and cost-effective manufacturing.

Implementation Method 1

a roller (22) which rolls on an outer peripheral surface (16a) of the cam disc (16)

Methodology Applied
Scientific EffectRolling: Roller

Implementation Method 2

an energy storage device (32) having a longitudinal axis (30), in particular designed as a compression spring

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4314459B1Drive for a door or window
Publication Date: 2024.08.28 GEZE GMBH
  • EP4314459B1 patent drawingFigure 1
  • EP4314459B1 patent drawingFigure 2
  • EP4314459B1 patent drawingFigure 3A~3B

AI summary

The application relates to a drive for a door or a window, comprising a housing, an output shaft mounted rotatably on the housing and comprising a cam disc, an electric motor comprising a transmission for driving the output shaft from a closed position in an opening direction in order to open the door or the window, a roller rolling over the rotating cam disc during operation, a pivot lever, which is hinged to the housing so as to be pivotable about a pivot axis, the roller being arranged rotatably on the pivot lever, and an energy storage unit for driving the output shaft from an open position in a closing direction in order to close the door or the window, the energy storage unit comprising an energy store having a longitudinal axis and movable first abutment facing the roller, and a second abutment, which faces away from the roller, on which abutments the energy store is supported, the roller acting in a force-transmitting manner between the cam disc and the movable first abutment of the energy storage unit, the cam disc and the energy storage unit being arranged on mutually opposed sides with respect to the pivot lever, and the movable first abutment of the energy storage unit being coupled rotatably and non-displaceably to the pivot lever at a coupling point and thus being guided on a circular path by the pivot lever.