Rolling body cage for a telescopic rail or a linear guide

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Solution Overview

Problem

Conventional linear guides and telescopic rails experience noise issues due to the impact of rail elements on end stops, which are not adequately dampened, leading to disruptive resonance and perceived noise.

Innovation Solution

A rolling element cage with a connecting bridge surrounded by a softer plastic damping element on its end faces, which reduces the impact noise by absorbing the contact between the rail elements and the end stops, maintaining the stop position precision within tolerances.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional rigid end stops are used to limit travel, then the stop position precision is maintained, but impact noise increases due to direct contact between rail elements and end stops

Engineering Contradiction:
Improvestop position precisionVSAvoidimpact noise
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

A damping element made of softer plastic is introduced as an intermediary between the rigid end stop and the rolling element cage. This mediator absorbs impact energy and reduces noise while maintaining the stop position precision through its controlled deformation properties.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The hardness parameter of the damping element is specifically selected (Shore A 40-90) to optimize the balance between noise damping and positional accuracy. This parameter change allows the material to deform under impact while maintaining sufficient rigidity for precise stopping.

Inventive Principle:
Principle #35Parameter changes

2Object-generated harmful factors

If a softer damping element is introduced to reduce impact noise, then noise is dampened, but the complexity of the device increases

Engineering Contradiction:
Improveimpact noiseVSAvoiddevice complexity
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The damping element is integrated with the connecting bridge of the rolling element cage to form a combined structure. This merging reduces the number of separate components and simplifies assembly while maintaining the noise damping function.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The solution uses composite construction by combining the softer damping material with the rigid plastic of the connecting bridge. This composite approach allows each material to perform its optimal function while maintaining overall structural integrity.

Inventive Principle:
Principle #40Composite materials

3Object-generated harmful factors

If the damping element is made softer to absorb more impact energy, then noise reduction improves, but the stop position accuracy may deteriorate

Engineering Contradiction:
Improveimpact noiseVSAvoidstop position accuracy
Core Design Contradiction:
Object-generated harmful factorsVSMeasurement precision

Solution Approach 1:

The Shore hardness of the damping element is precisely controlled within the range of 40-90 Shore A. This parameter optimization ensures the material is soft enough to dampen noise effectively but rigid enough to maintain accurate stop positioning within tolerance ranges.

Inventive Principle:
Principle #35Parameter changes

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 damping element effectively reduces noise by absorbing the impact, ensuring the stop position accuracy and extending the service life of the rail systems while maintaining ease of use.

Implementation Method 1

the connecting bridge is surrounded on at least two opposing end faces by a damping element made of a second plastic, wherein the second plastic is softer than the first plastic and wherein the second plastic has a Shore hardness in a range of 40 Shore A to 90 Shore A

Methodology Applied
Scientific EffectImpact absorption: Damping

Data Source

PatentEP3565982B1Rolling body cage for a telescopic rail or a linear guide
Publication Date: 2021.03.24 ACCURIDE INTERNATIONAL GMBH
  • EP3565982B1 patent drawingFigure 1
  • EP3565982B1 patent drawingFigure 2
  • EP3565982B1 patent drawingFigure 3

AI summary

The present invention relates to a rolling body cage for a linear guide or a telescopic rail with rail elements which can be moved with respect to one another, wherein the rolling body cage has at least one bottom section which extends in a longitudinal direction of the rolling body cage, side wall sections which are arranged in parallel, extend on opposite sides of the bottom section substantially perpendicularly from the latter, and in which rolling body holding recesses are provided for receiving and holding rolling bodies between the raceways of rail elements, and a connecting bridge at at least a first end of the rolling body cage, which connecting bridge extends between the side wall sections and substantially perpendicularly with respect to the latter, wherein the bottom section, the side wall sections and the connecting bridge are produced in one piece from a first plastic. It has proved that both the bearing of the inner rail against the rolling body cage and the bearing of the rolling body cage against the end stop of the outer rail can generate noise which is perceived as annoying. It is therefore a problem of the present invention to further reduce said stop noises. In order to solve said problem, it is proposed according to the invention to provide a rolling body cage of the type mentioned at the outset, in the case of which rolling body cage the connecting bridge is surrounded on two opposite end surfaces by a damping element made from a second plastic, wherein the second plastic is softer than the first plastic.