Telescopic Drive Sealing Ring for Vehicle Flap Gap
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Solution Overview
Problem
Existing drive devices for vehicle flaps, such as tailgates, face issues with dirt and moisture ingress through the annular gap between the telescopically arranged housing and protective tubes, potentially damaging the linear drive and sealing ring, while maintaining a compact installation space is challenging.
Innovation Solution
A sealing ring with an outside diameter matching the inner tube is firmly arranged on the cylindrical surface of the inner tube, made of elastic material, and designed to radially close the annular gap with resilient pretension, featuring a conical taper at the end facing the gap to ensure secure sealing without increasing the device's diameter, and is resistant to environmental factors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sealing ring with larger outside diameter than the outer tube is used to close the annular gap, then sealing effectiveness is improved, but the installation space is increased
Solution Approach 1:
The sealing ring is designed with non-uniform cross-section where the first region (contacting the outer tube) has a smaller diameter than the second region (attached to inner tube). This local variation in geometry allows the seal to fit within the annular gap dimensions while maintaining sealing pressure against the outer tube surface.
Solution Approach 2:
Instead of making the sealing ring uniformly large to ensure contact with the outer tube, the invention inverts the approach by making the contact region smaller than the mounting region. The sealing ring is mounted on the inner tube with its larger diameter portion, but the smaller diameter first region extends into the annular gap to seal against the outer tube.
2Reliability
If the sealing ring has larger outer diameter than the outer tube to ensure sealing contact, then sealing reliability is improved, but frictional forces during extension increase
Solution Approach 1:
The sealing ring concentrates its sealing function in the first region with smaller diameter that contacts the outer tube, while the second region with larger diameter is isolated from the outer tube by the annular gap. This local differentiation ensures sealing contact where needed while eliminating unnecessary friction during extension movement.
3Reliability
If the sealing ring is made of elastic material with resilient pretension to close the annular gap, then sealing effectiveness is improved, but the risk of damage from tube end contact increases
Solution Approach 1:
The conical geometry of the first region creates a progressive contact interface with the outer tube. The taper angle is designed to guide the outer tube end away from the sealing ring's sensitive elastic sealing surface, distributing contact forces along the conical surface and preventing concentrated loads that could damage the elastic material.
Solution Approach 2:
The conical shape of the first region acts as a protective feature that prevents the outer tube end from directly impacting the sealing ring's sealing surface. The tapered geometry cushions and redirects forces before they reach the elastic sealing material, protecting it from damage during retraction and extension cycles.
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
Effectively prevents dirt and moisture ingress, reduces frictional forces during extension, and maintains the compact size of the drive device, ensuring the sealing ring's protection and longevity by minimizing wear and resisting environmental substances and temperatures.
Implementation Method 1
the sealing ring made of an elastic material is in contact with the inner wall of the outer tube with resilient pretension in the retracted position of the drive device
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
The invention relates to a drive device, in particular for a flap of a vehicle, comprising a housing tube (5) and a protective tube (6), which can be moved relative to each other axially in a telescopic manner, wherein the closed end of the housing tube (5) facing away from the protective tube (6) is arranged on a stationary base part or a movable component and the closed end of the protective tube facing away from the housing tube (5) is arranged on the movable component or the base part, and comprising a linear drive (9) arranged in the housing tube (5) and/or protective tube (6), by means of which linear drive the housing tube (5) and the protective tube (6) can be driven such as to be movable relative to each other in an axial manner. The protective tube (6) or housing tube (5) enclosed by the housing tube (5) or the protective tube (6) is enclosed at the radially circumferential outer cylindrical surface (15) thereof by a sealing ring (16, 16'), by means of which the annular gap (19) formed between the housing tube (5) and the protective tube (6) is closed in a sealing manner in the maximum retracted position of the housing tube (5) and protective tube (6) relative to each other.