Steering Gear Pinion Locking Screw with Elastic Ratchet Levers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for securing units in housings, such as pinions in steering gears, face issues due to different coefficients of thermal expansion leading to reduced securing effectiveness over time, play, and frictional wear, and require complex assembly processes involving thread sealants.
Innovation Solution
A cost-effective and easy-to-assemble device featuring a locking screw with radially distributed locking levers and lugs that engage with a toothing geometry in the housing, ensuring play-free fixation and secure locking, even with varying thermal expansion coefficients.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a screw connection with frictional connection or adhesive connection is used to secure a unit in a housing, then the securing effect is initially achieved, but over service life the securing effectiveness reduces due to different coefficients of thermal expansion leading to play and frictional wear
Solution Approach 1:
The locking lever is designed to be elastically deformable, allowing it to dynamically adapt to thermal expansion differences between materials. The locking lever can elastically deform to accommodate dimensional changes while maintaining continuous engagement with the toothing geometry, preventing play and maintaining securing effectiveness throughout service life despite thermal cycling between components with different expansion coefficients
Solution Approach 2:
The securing connection is segmented into discrete toothing elements and locking lever engagement points rather than a continuous friction-based connection. This segmentation allows each element to independently accommodate thermal expansion while maintaining overall connection integrity, preventing the cumulative play that develops in continuous friction or adhesive connections over time
2Object-affected harmful factors
If a thread sealant is used to seal against external media, then sealing is achieved, but the manufacturing and assembly process becomes more complex
Solution Approach 1:
The sealing function is extracted from the thread connection area and relocated to a dedicated sealing ring positioned elsewhere in the assembly. This allows the thread connection to be simple and dry (without sealant), while the sealing ring provides the required seal against external media, thereby simplifying the manufacturing and assembly process by eliminating sealant application steps
Solution Approach 2:
A sealing ring is introduced as an intermediary component between the internal and external environments. This sealing ring mediates the sealing function, allowing the main thread connection to remain simple while the intermediary sealing element provides protection against external media, thus reducing overall device complexity
3Reliability
If a locking mechanism with locking lever and toothing geometry is used to achieve play-free fixation, then securing effectiveness over service life is improved, but the device complexity increases
Solution Approach 1:
The locking lever is merged with the securing element (screw or clip), eliminating the need for separate locking components. The toothing geometry is integrated directly into the housing structure rather than being a separate part. This merging reduces the number of discrete components and assembly steps while maintaining the play-free fixation function throughout service life
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 provides a secure, play-free fixation over the service life, reducing frictional wear and acoustic issues while simplifying the assembly process by using a plastic locking screw with a sealing ring and self-locking external thread, effectively managing thermal expansion and axial forces.
Implementation Method 1
at least one locking lever (9) which is connected via its one end (9a) to the securing element (5) and whose other end (9b) is supported in a deflection-free manner on the inner wall of the bore (2a)
Implementation Method 2
which is provided with a sealing ring (6) in order to seal against external media
Implementation Method 3
the securing element is designed as a securing screw (5) which is connected via an external thread (8) to an internal thread of the bore (2a) of the housing (2)
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The invention relates to a device for securing a unit in a housing (2), in particular a locating bearing (3) of a pinion (1) in a steering gear of a motor vehicle, having a securing element which is inserted into a bore (2a) in the housing (2). The securing element (5) is provided with at least one ratchet lever (9), wherein the at least one ratchet lever (9) latches into toothing gaps (14) of a toothing geometry (13) in the bore (2a) of the housing (2) via a latching lug (12) which is arranged at the free end of the ratchet lever, or wherein at least one latching lug is arranged in the bore (2a), which latching lug latches into toothing gaps of a toothing geometry in the securing element.