Vehicle Seat Fitting Locking Element Design
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Solution Overview
Problem
Existing vehicle seat fittings with eccentric epicyclic gear systems face issues with wobbling movements and inadequate locking mechanisms, particularly under dynamic conditions such as shaking or pushing, which can lead to spooling and loss of backlash control.
Innovation Solution
The design incorporates a locking element with radially inward-facing toothed segments that cooperate with the bearing bush's toothing, allowing for independent configuration of the toothed wheel and ring, and a ring-shaped locking element that provides enhanced security by locking the fitting even when not driven, using an eccentric epicyclic gear system to enable continuous adjustment of the backrest inclination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the locking element is positioned within the radius of the bearing bush and cooperates with the back side of the toothed wheel, then the structure is compact, but the toothed wheel and toothed ring cannot be configured independently and the locking security is reduced
Solution Approach 1:
The locking element is moved from a radial position within the bearing bush to an axial position beyond the collar. This dimensional relocation allows the locking element to engage with a separate toothing on the collar, enabling independent configuration of the toothed wheel and toothed ring while maintaining structural compactness through the axial arrangement of components.
2Reliability
If the bearing bush has sufficient width for proper bearing support, then the eccentric is properly supported, but the fitting part requires greater material strength and increased dimensions
Solution Approach 1:
The fitting is divided into functionally independent segments: the bearing bush is designed with sufficient width for proper eccentric support, while the collar with its separate toothing handles the locking function. This segmentation allows each component to be optimized for its specific function without compromising the other, enabling the bearing bush to have the necessary width for reliable bearing support.
3Device complexity
If the locking element engages with the toothed wheel, then the structure is simpler, but the locked state is not maintained when the fitting is not driven, allowing spooling under external influences
Solution Approach 1:
The locking element is pre-positioned to engage with the collar's toothing in a locked state before any driving action occurs. This preliminary locking action ensures that the fitting maintains its locked state even when not driven, preventing spooling under external influences such as shaking or pushing, while still allowing smooth engagement when driving forces are applied.
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
This configuration enhances security by maintaining a locked state without external influence and prevents wobbling movements, ensuring backlash-free operation and continuous adjustability of the backrest inclination.
Implementation Method 1
a toothed wheel is formed on a second fitting part which meshes with the toothed ring, as a result of which the two fitting parts are in gear connection with each other
Implementation Method 2
a circumferential eccentric, driven by a driver, for driving a relative rolling movement of the toothed wheel and the toothed ring
Implementation Method 3
The locking element which surrounds the bearing bush and/or the collar in a ring-shaped manner has at least one, particularly two, radially inward facing toothed segments for cooperating with the toothing of the bearing bush or the collar
Data Source
AI summary
A fitting (10) for a vehicle seat, in particular for a motor vehicle seat, includes a first fitting part (11), on which a ring gear (17) is formed, a second fitting part (12), on which a gear (16) is formed, which gear meshes with the ring gear (17), whereby the two fitting parts (11, 12) are in a transmission connection with each other, and a rotating eccentric (27, 35) for driving a relative rolling motion of the gear (16) and the ring gear (17). The eccentric is driven by a carrier (21), wherein the eccentric (27, 35) is rotatably supported in a collar (38), which is associated with one of the two fitting parts (11, 12), or in a bushing (28) sitting in said collar (38) in a rotationally fixed manner. A blocking element (50) for the eccentric (27, 35) is operative at least at times between the eccentric (27, 35) and the bushing (28). The bushing (28) has teeth (28a) pointing radially outward and the blocking element (50), which surrounds the bushing (28) annularly, has at least one, in particular two, tooth segments (58) pointing radially inward for interacting with the teeth (28a).