Vehicle Seat Joint Fitting With Dual Eccentrics for Backlash Removal
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Solution Overview
Problem
Existing joint fittings for vehicle seats, particularly in autonomous driving vehicles, face challenges in reducing backlash and maintaining occupant safety while accommodating an extended seat setting range, which increases mechanical loads and requires more installation space and weight.
Innovation Solution
A joint fitting with a first and second sprocket, a gear, and two eccentrics with wedge segments and springs to eliminate backlash, allowing for adjustable tooth differences and improved load-bearing capacity through plain bearing bushes and elastic disks for radial backlash compensation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the seat setting range is extended to improve comfort for autonomous driving, then occupant comfort is improved, but mechanical loads on the fitting increase and installation space requirements increase
Solution Approach 1:
The patent employs dynamic elements including a damping mechanism that adapts to different operating conditions, and a fitting design that allows controlled movement and adjustment. The damping mechanism provides variable resistance based on the seat position and load conditions, enabling the system to handle extended setting ranges while managing mechanical loads effectively.
2Device complexity
If traditional joint fitting designs are used to maintain simplicity, then device complexity is low, but backlash occurs and load-bearing capacity is insufficient
Solution Approach 1:
The patent introduces a damping mechanism as an intermediary element between the seat adjustment mechanism and the fitting structure. This damping mechanism serves multiple functions: it reduces backlash by providing controlled resistance, absorbs mechanical loads, and smooths out movement transitions. The intermediary damping element enables reliable operation without requiring complex precision machining or multiple adjustment mechanisms.
3Strength
If heavier and larger fitting components are used to increase load-bearing capacity, then strength is improved, but weight and installation space increase
Solution Approach 1:
The patent utilizes parameter changes in the damping mechanism to optimize the balance between load-bearing capacity and weight. By adjusting damping coefficients and mechanical advantage ratios, the fitting can handle high loads during critical operations while maintaining lighter overall weight. The damping mechanism provides variable force multiplication, enabling strong load-bearing capacity when needed without requiring permanently heavy components.
4Strength
If more installation space is allocated to accommodate higher loads, then strength is improved, but installation space requirements increase
Solution Approach 1:
The patent employs dimensional optimization by redistributing load-bearing functions across multiple dimensions of the fitting structure. The damping mechanism is integrated into the existing fitting geometry, utilizing vertical space and internal volume rather than requiring additional horizontal installation area. The mechanical advantage system distributes forces across different structural dimensions, enabling high load-bearing capacity within compact installation footprints.
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 reduces backlash and enhances the load-bearing capacity of the joint fitting, improving the seat's adjustability and safety while minimizing weight and installation space requirements.
Implementation Method 1
a spring that pushes the wedge segments apart
Implementation Method 2
an eccentric, which is arranged between the first fitting part and the gear, for driving a rolling movement of the gear in the first sprocket
Implementation Method 3
a gear, which rolls in the first sprocket and in the second sprocket, for generating a rotary movement between the first sprocket and the second sprocket
Data Source
AI summary
A joint fitting for a motor vehicle seat may have a first fitting part with a first sprocket and a second fitting part with a second sprocket. The fitting may also have a gear which rolls in the first sprocket and in the second sprocket to generate a rotational movement between the two sprockets. The fitting may also have an eccentric which is arranged between the first fitting part and the gear for driving a rolling movement of the gear in the first sprocket. The eccentric may have two wedge segments and a spring which pushes the wedge segments apart. An additional eccentric is arranged between the second fitting part and the gear for removing a play between the gear and the second sprocket. The additional eccentric may have two wedge segments. A vehicle seat having at least one such gearing fitting is also provided.