Steering Gear Floating Bearing to Limit Pinion Shaft Backlash
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Solution Overview
Problem
Power-assisted steering systems in motor vehicles experience backlash due to component tolerances, thermal expansion, and material wear, leading to unwanted noise during alternate steering, and existing solutions fail to adequately limit transverse movement of the pinion shaft while maintaining simplicity in design.
Innovation Solution
A steering gear design featuring a pinion shaft mounted in a fixed bearing for pivotability perpendicular to its longitudinal axis, with a floating bearing allowing radial mobility, and a preloaded spring element to increase distance between gearwheel and pinion axes, combined with a stop element to limit pivoting mobility and prevent transverse movement by contact surfaces designed for optimal interaction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the pinion shaft is made pivotable to eliminate backlash, then noise is reduced, but transverse movement of the pinion shaft occurs
Solution Approach 1:
The bearing support is divided into two distinct types: a fixed bearing at the drive side that prevents transverse movement, and a floating bearing at the free end that allows pivoting movement. This segmentation enables the pinion shaft to have both stability (no transverse movement) and mobility (pivoting capability) simultaneously, resolving the contradiction between noise reduction and transverse movement prevention.
2Object-generated harmful factors
If spring elements are added to press the pinion against the gearwheel, then backlash is eliminated, but device complexity increases
Solution Approach 1:
The spring element is integrated into the floating bearing assembly, combining the bearing function with the spring loading function in a single component. This merging eliminates the need for separate spring mounting structures and reduces overall device complexity while still achieving backlash elimination through the spring force.
Solution Approach 2:
The floating bearing assembly automatically provides spring loading to press the pinion against the gearwheel, eliminating backlash without requiring external adjustment or additional complex mechanisms. The spring element within the floating bearing self-regulates to maintain optimal contact between the pinion and gearwheel teeth.
3Stability of the object's composition
If the fixed bearing provides spring force, then pinion shaft stability is improved, but manufacturing precision requirements increase
Solution Approach 1:
The bearing functions are segmented into fixed bearing for stability and floating bearing for spring loading, allowing each component to be optimized independently. The fixed bearing focuses solely on providing stable support without transverse movement, while the floating bearing handles the spring force application, reducing the manufacturing precision requirements for each individual component.
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 effectively reduces backlash and noise, limits transverse movement, and maintains simplicity in design, ensuring reliable operation and reduced noise during alternate steering by utilizing a combination of fixed and floating bearings with a preloaded spring and strategically designed contact surfaces.
Implementation Method 1
a spring element which is preloaded in the direction which increases the distance between the axes of rotation of the gearwheel and pinion, in particular an elastically deformable pivot ring having an outer ring and an inner ring which are connected by at least one torsion web
Implementation Method 2
The pivoting sleeve comprises a bearing sleeve which receives the rolling bearing substantially without play, and an outer ring, which is held substantially without play in a receptacle of a housing of the steering gear, wherein the outer ring and the bearing sleeve are connected by a plurality of torsion webs, which are subject to torsion when the outer ring is rotated relative to the bearing sleeve
Data Source
AI summary
A steering gear for a steering system of a motor vehicle includes a housing, a gearwheel, a pinion meshing with the gearwheel, and a pinion shaft with the pinion. The pinion shaft is mounted on one side of the pinion in a floating bearing that includes a rotary bearing that receives the pinion shaft. The rotary bearing is connected to a stop element, which is simultaneously arranged displaceably and non-rotatably within a receiving space. The pivoting mobility of the pinion shaft guided by a fixed bearing, on the other side of the pinion, is limited by a stop between the stop element and a wall of the receiving space. The stop element and the receiving space are configured such that, only in the event of such a stop, pivoting mobility of the pinion shaft is blocked about an axis oriented perpendicular to the pivot axis.