Cable Drum Drive Assembly With Hollow Shaft Shock Damping

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Solution Overview

Problem

Existing drive arrangements with a shaft, cable drum, and gear motor are not compact and robust, and they do not effectively dampen shock loads transmitted via rods.

Innovation Solution

A drive arrangement with a geared motor having a hollow output shaft, bearings in a gearbox housing, and damping rings made of softer materials like plastic or rubber, connected via screws to a torque arm, which presses damping rings against a gearbox housing, allowing direct connection of the cable drum to the output shaft without an adapter, and using a parallel-shaft gearbox with a rotor shaft aligned parallel to the shaft.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a direct drive with bearingless motor is used, then device complexity is reduced, but shock load damping capability is insufficient

Engineering Contradiction:
Improvedevice complexityVSAvoidshock load damping capability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent incorporates damping rings made of elastomeric material between the torque arm and gearbox housing before shock loads occur. These damping rings are pre-positioned to absorb and dissipate shock loads through hysteresis damping, protecting the gear motor from sudden impacts without requiring complex active control systems.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent uses composite construction by combining rigid components (torque arm, gearbox housing) with elastomeric damping rings. This composite approach allows the rigid parts to provide structural support while the elastomeric material provides shock absorption, achieving both mechanical strength and vibration damping in a single integrated solution.

Inventive Principle:
Principle #40Composite materials

2Adaptability or versatility

If adapters or couplings are used to connect cable drum to output shaft, then alignment flexibility is improved, but compactness is reduced

Engineering Contradiction:
Improvealignment flexibilityVSAvoidcompactness
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The patent merges the cable drum mounting function directly with the gearbox output shaft by using a hollow output shaft design. The cable drum is mounted directly on the hollow output shaft, eliminating the need for separate adapters or couplings. This integration reduces the number of parts while maintaining alignment flexibility through the hollow shaft's inherent design.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements nesting by placing the hollow output shaft inside the gearbox housing structure. The hollow shaft allows the cable drum to be positioned concentrically within the gearbox assembly, creating a nested configuration that maximizes compactness while maintaining proper alignment between components.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Strength

If harder materials are used for torque arm and housing, then structural strength is improved, but shock load damping is reduced

Engineering Contradiction:
Improvestructural strengthVSAvoidshock load damping
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent applies local quality by using different materials in different locations: rigid materials (steel, aluminum) for the torque arm and gearbox housing where structural strength is needed, and elastomeric material for the damping rings where shock absorption is required. This localized material selection allows each component to optimize its function without compromising overall system performance.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent creates a composite structure by combining rigid structural components with elastomeric damping elements. The rigid parts provide the necessary mechanical strength and load-bearing capacity, while the elastomeric damping rings provide shock absorption and vibration isolation, achieving both strength and damping in the same assembly.

Inventive Principle:
Principle #40Composite materials

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 provides a compact, robust drive assembly that effectively dampens shock loads, eliminating the need for adapters and ensuring the gear motor is protected from shocks, thus enhancing durability and efficiency.

Implementation Method 1

the damping rings are made of a material that is softer and/or has greater elasticity and/or is more easily deformable than the material from which the torque arm and/or the housing part are made

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

shock loads, which are transmitted via the rods to the holding device, can be dampened by the gear motor

Methodology Applied
Scientific EffectDamping: Damping

Data Source

PatentEP4341194B1Drive assembly comprising a shaft, a cable drum, a holding means, and a gear motor
Publication Date: 2025.07.02 SEW EURODRIVE GMBH & CO KG
  • EP4341194B1 patent drawingFigure 1
  • EP4341194B1 patent drawingFigure 2
  • EP4341194B1 patent drawingFigure 3

AI summary

The invention relates to a drive assembly comprising a shaft, a cable drum, a holding means, and a gear motor. The gear motor has a gearing mechanism which is driven by an electric motor of the gear motor and the output shaft of which is designed as a hollow shaft, wherein bearings are received in a housing part of the gearing mechanism in order to rotatably support the output shaft. The shaft is rotatably supported by means of bearings in the holding means, and the cable drum is rotationally fixed to the shaft. A torque support is connected to the holding means, and at least one screw which passes through a recess of the torque support is screwed into a threaded bore of the housing part of the gearing mechanism or into a threaded bore of a part lying against the housing part of the gearing mechanism. The screw head of the screw pushes a first damping ring onto the torque support, and the torque support thus pushes a second damping ring to the housing part of the gearing mechanism.