Spindle Nut Linear Drive Bellows Venting for Cooling and Sealing

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Solution Overview

Problem

Existing linear drives lack effective protection and cooling mechanisms, leading to potential damage from heat generation and environmental contamination.

Innovation Solution

A linear drive design featuring a spindle nut and spindle rotatably mounted in a bearing plate, with bellows surrounding the spindle to create a hermetically sealed air space for pressure equalization and heat dissipation, allowing for improved cooling and protection through a continuous air duct and strategically placed recesses for air passage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the linear drive is hermetically sealed with bellows surrounding the spindle, then protection against environmental contamination is improved, but heat dissipation becomes problematic due to enclosed air spaces

Engineering Contradiction:
Improveprotection against environmental contaminationVSAvoidheat dissipation
Core Design Contradiction:
Object-affected harmful factorsVSTemperature

Solution Approach 1:

The patent employs bellows as flexible protective shells that enclose the spindle and motor shaft, creating hermetically sealed air spaces that protect against environmental contamination while allowing for the integration of cooling channels within the bearing plate structure

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The bearing plate serves as an intermediary component that houses continuous cooling channels, mediating between the hermetically sealed bellows and the heat-generating components (motor and spindle nut) by facilitating heat transfer through the enclosed air spaces

Inventive Principle:
Principle #24Intermediary (Mediator)

2Temperature

If cooling channels are integrated into the bearing plate, then heat dissipation is improved, but the structural complexity of the bearing plate increases

Engineering Contradiction:
Improveheat dissipationVSAvoidstructural complexity of bearing plate
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent merges the bearing plate with integrated cooling channels, combining the structural support function with the thermal management function into a single unified component, thereby improving heat dissipation without proportionally increasing overall system complexity

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The bearing plate is designed as a multi-functional component that simultaneously provides mechanical support for the spindle and motor, houses cooling channels for thermal management, and facilitates pressure equalization between air spaces, thereby achieving multiple functions without requiring separate dedicated components

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

3Length of moving object

If the spindle nut is driven by a coaxially arranged motor spaced apart via belt drive, then compact design in axial direction is achieved, but installation space in transverse direction increases

Engineering Contradiction:
Improveaxial lengthVSAvoidtransverse installation space
Core Design Contradiction:
Length of moving objectVSArea of stationary object

Solution Approach 1:

The patent positions the motor coaxially with the spindle but spaced apart in the axial direction, utilizing the axial dimension for motor placement rather than occupying transverse space, thereby achieving a compact transverse footprint while maintaining functional separation through the belt drive mechanism

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 design achieves enhanced protection and cooling by efficiently dissipating heat generated during operation, maintaining a hermetically sealed environment, and extending the service life by reducing tension and preventing contamination.

Implementation Method 1

the bearing plate has a continuous recess for equalizing air pressure between the air space surrounded by the first bellows and the air space surrounded by the second bellows

Methodology Applied
Scientific EffectPressure equalization: Pressure Gradient

Implementation Method 2

the heat generated during rotational movement can be at least partially dissipated by the airflow that equalizes pressure

Methodology Applied
Scientific EffectHeat dissipation: Convection

Data Source

PatentEP3464944B1Linear drive having a spindle nut, which is rotatably mounted in a bearing plate, and a spindle
Publication Date: 2021.03.17 SEW EURODRIVE GMBH & CO KG
  • EP3464944B1 patent drawingFigure 1
  • EP3464944B1 patent drawingFigure 2
  • EP3464944B1 patent drawingFigure 3

AI summary

Linear drive having a spindle nut, which is rotatably mounted in a bearing plate, and a spindle, in particular wherein the spindle is in operative connection with the spindle nut, in particular is screwed into the spindle nut, wherein the spindle is guided through the spindle nut, and/or the spindle projects from the bearing plate on both sides, wherein a first bellows at least partially encloses a first region of the spindle and a second bellows at least partially encloses a second region of the spindle, in particular wherein the first region and the second region are spaced apart from one another, in particular wherein at least the bearing plate is interposed, wherein the bearing plate has a continuous aperture for air pressure equalization between the air space enclosed by the first bellows and the air space enclosed by the second bellows.