Rolling Body Cage With Soft-Plastic Bridge Damping for Rail Noise
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Solution Overview
Problem
Conventional linear guides and telescopic rails experience annoying noise due to abutment of rail elements and rolling body cages, despite the use of connecting bridges to dampen noise at end abutments.
Innovation Solution
A rolling body cage with a connecting bridge surrounded by a damping element made of a softer second plastic, which reduces noise by damping the impact of the cage against both the outer and inner rails, while maintaining the required precision of the abutment position through specific Shore hardness and thickness of the damping material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a connecting bridge is used to dampen noise at end abutments, then noise from direct rail contact is reduced, but annoying abutment noise still occurs due to impact between the rolling body cage and rail elements
Solution Approach 1:
A damping element made of softer plastic material is introduced as an intermediary between the connecting bridge and the rail elements. This damping element absorbs impact energy during abutment, reducing noise while the connecting bridge maintains the precise abutment position. The softer material deforms under impact, preventing direct hard contact between the cage and rails.
Solution Approach 2:
The solution uses composite material construction with two different plastics: a harder first plastic for the connecting bridge structure that maintains precision, and a softer second plastic for the damping element that reduces noise. This composite approach allows simultaneous achievement of positional precision and noise reduction.
2Object-affected harmful factors
If a softer damping material is used to reduce noise, then acoustic damping improves, but the precision of the abutment position may be compromised
Solution Approach 1:
The connecting bridge is segmented into two functional parts: a structural component made of harder plastic that defines the abutment position, and a damping element made of softer plastic that reduces noise. This segmentation allows each part to optimize its specific function without compromising the other.
Solution Approach 2:
Different plastic materials with different hardness properties are applied to different locations of the connecting bridge. The harder plastic is used where structural precision is needed, while the softer plastic is used where noise damping is required. This local differentiation of material properties resolves the contradiction between precision and noise reduction.
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 effectively reduces noise at abutment points by using a softer plastic damping element, ensuring adequate acoustic damping without compromising the precision of the abutment position, thus minimizing direct contact between rail elements and the harder plastic material.
Implementation Method 1
the connecting bridge is surrounded at least on two mutually opposite end faces by a damping element of a second plastic, wherein the second plastic is softer than the first plastic
Implementation Method 2
a damping element of a second plastic, wherein the second plastic is softer than the first plastic
Data Source
AI summary
The present invention concerns a rolling body cage for a linear guide or telescopic rail having rail elements which are displaceable relative to each other, wherein the rolling body cage has at least one bottom portion extending in a longitudinal direction of the rolling body cage, side wall portions which are arranged parallel and which extend on mutually opposite sides of the bottom portion substantially perpendicularly therefrom and in which there are provided rolling body holding recesses for receiving and holding rolling bodies between the raceways of rail elements and at at least a first end of the rolling body cage a connecting bridge which extends between the side wall portions substantially perpendicularly thereto, wherein the bottom portion, the side wall portions and the connecting bridge are produced in one piece from a first plastic. It has been found that both abutment of the inner rail against the rolling body cage and also abutment of the rolling body cage against the end abutment of the outer rail can generate noise which is perceived to be annoying. Therefore an object of the present invention is to further reduce those abutment noises. To attain that object it is proposed according to the invention that a rolling body cage of the kind set forth in the opening part of this specification is provided, in which the connecting bridge at least on two mutually opposite end faces is surrounded by a damping element comprising a second plastic, wherein the second plastic is softer than the first plastic.