Window Regulator Pulley Snap-Fit Assembly for Shaft Retention
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Solution Overview
Problem
Existing window regulator assemblies in vehicles face high manufacturing and assembly costs due to complex component designs and processes, particularly in the fastening and assembly of pulley shafts and pulleys, which also compromise water tightness.
Innovation Solution
A pulley arrangement with a pulley interface featuring snap fit tabs that securely engage with the pulley shaft, providing axial retention and pre-tension to simplify assembly and ensure water tightness, using fewer components and eliminating the need for washers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a screw connection is used to fasten the pulley shaft and pulley, then the assembly is secure, but the assembly process becomes complex and expensive
Solution Approach 1:
The patent replaces the screw connection (threaded fastening system) with a snap-fit connection system. The snap-fit tabs engage with the pulley shaft through elastic deformation, eliminating the need for threads, screws, and associated fastening hardware. This substitution maintains secure assembly while dramatically simplifying the assembly process and reducing manufacturing complexity.
Solution Approach 2:
The pulley interface is segmented into multiple snap-fit tabs distributed around the circumference. Each tab independently engages with the pulley shaft, distributing the fastening function across multiple simple elements rather than relying on a single complex screw connection. This segmentation enables easier assembly while maintaining secure retention.
2Ease of manufacture
If a metal bracket with forming process is used, then the pulley can be mounted, but manufacturing costs increase due to high component complexity
Solution Approach 1:
The patent merges the pulley mounting function directly into the pulley interface structure itself. The snap-fit tabs are integrated as part of the pulley interface, eliminating the need for separate metal brackets and forming processes. This integration reduces component count and manufacturing complexity while maintaining the ability to securely mount the pulley.
Solution Approach 2:
The snap-fit tabs are designed as simple, inexpensive plastic elements that can be easily manufactured and replaced if needed. Rather than using expensive metal brackets with complex forming processes, the patent employs these simpler, cost-effective snap-fit elements that achieve the same mounting function with significantly reduced manufacturing costs.
3Reliability
If staking process is used to fasten the pulley shaft, then the connection is secure, but the process remains complex and washers are required
Solution Approach 1:
The patent replaces the staking process (which involves deforming metal to create permanent fastening) with an elastic snap-fit mechanism. The snap-fit tabs use controlled elastic deformation to engage with the pulley shaft, providing secure connection without requiring complex staking equipment or additional washers. This substitution maintains connection security while simplifying the fastening process.
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 manufacturing and assembly costs while ensuring reliable pulley shaft retention and water resistance through a simplified design with snap fit tabs, facilitating easy and cost-effective assembly.
Implementation Method 1
the snap fit tab is elastically in a radial direction
Implementation Method 2
one or more snap fit tabs are elastically engaged into the adjacent shaft section to establish an undercut in axial direction
Implementation Method 3
one or more snap fit tabs establish an axial pressing force onto the shaft end section
Implementation Method 4
The pressing force pushes the shaft end section away from the pulley (i.e. 'downwards') and thus creates a certain pre-tension that ensures water tightness
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
The invention relates to a window regulator assembly (1) of a vehicle, wherein the window regulator assembly (1) comprises a carrier element (2), wherein at least one pulley arrangement (3) for redirecting a cable (4) is mounted at the carrier element (2), wherein the pulley arrangement (3) comprises a pulley (5) which is arranged rotatable on a pulley shaft (6), which is mounted on the carrier element (2), wherein the pulley shaft (6) has a shaft end section (8) at one axial end, which shaft end section (8) is connected to the carrier element (2). To design such a window regulator assembly in such a way that fewer components are required and a simpler assembly process is possible, the invention suggests that the pulley arrangement (3) comprises a pulley interface (9) for receiving the pulley shaft (6), which is connected to the carrier element (2), wherein the pulley interface (9) comprises at least one snap fit tab (10, 10', 10") at an end section, wherein the snap fit tab (10, 10', 10") is elastically in a radial direction (r), wherein the shaft end section (8) is enlarged in diameter compared with an adjacent shaft section (11), wherein a snap fit tab (10, 10', 10") is elastically engaged into the adjacent shaft section (11) to establish an undercut in axial direction (a) and a snap fit tab (10, 10', 10") establishes an axial (a) pressing force onto the shaft end section (8).