Worm Gear Steering Reducer With Damping Sleeve for Play Control
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Solution Overview
Problem
Existing electric power steering systems suffer from parasitic play between the toothed wheel and the helical spline due to wear and thermal variations, leading to noise and vibrations, and require complex mounting and non-compact designs.
Innovation Solution
A power steering reduction device with a support, worm screw, and toothed wheel, featuring rotational guiding means with a damping sleeve and centering means to minimize play and deformations, ensuring constant contact and easy assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional reduction device with worm screw and toothed wheel is used, then the assist torque can be transmitted to the steering column, but parasitic play develops between the toothed wheel and helical spline due to wear and temperature variations, generating noise and vibrations
Solution Approach 1:
The invention applies preliminary anti-action by pre-tensioning the worm screw through a tensioning device that applies a constant axial force. This pre-tensioning compensates for wear and thermal expansion before they can create parasitic play, thereby preventing noise and vibrations before they occur.
Solution Approach 2:
The invention changes the parameter of axial force applied to the worm screw by introducing a tensioning device that maintains a constant pre-tensioning force. This parameter change ensures continuous contact between the toothed wheel and helical spline, eliminating parasitic play while maintaining compact design.
2Reliability
If a pushing mechanism with prestressed spring and sliding piece is used to reduce play, then the parasitic play between worm screw and toothed wheel is reduced, but the housing requires complex shapes and good surface conditions, impacting compactness and increasing manufacturing complexity
Solution Approach 1:
The invention extracts the complex pushing mechanism with sliding pieces and prestressed springs from the housing design. Instead, it uses a simpler tensioning device that applies axial force directly to the worm screw, thereby reducing play without requiring complex housing shapes or high-precision surface finishes.
Solution Approach 2:
The tensioning device serves multiple functions: it reduces parasitic play, compensates for wear, maintains continuous contact, and does so without requiring complex housing modifications. This multi-functionality simplifies the overall device complexity while maintaining reliability.
3Reliability
If a pushing mechanism with multiple components is installed to reduce play, then the contact between worm screw and toothed wheel is improved, but the mounting process becomes complex requiring installation of sliding pieces, springs, and abutments
Solution Approach 1:
The invention segments the tensioning function from the housing structure, using a separate, modular tensioning device that can be independently installed and adjusted. This segmentation simplifies the mounting process by eliminating the need to install multiple interconnected components like sliding pieces, springs, and abutments within the housing.
Solution Approach 2:
The tensioning device is designed to be self-contained and self-adjusting, requiring minimal installation steps. It automatically maintains the necessary pre-tensioning force on the worm screw without requiring complex assembly procedures or multiple adjustment steps, thereby improving ease of manufacture.
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 parasitic play and vibrations, maintains compactness, and simplifies mounting, while being cost-effective and easy to produce.
Implementation Method 1
the second rotational guiding means comprising a damping sleeve and a rotational guiding device
Implementation Method 2
the second rotational guiding means comprising a damping sleeve and a rotational guiding device
Data Source
AI summary
Reducer device having electric power steering, including a support member, an endless screw, a toothed wheel that meshes with a helical spline arranged on the endless screw, the endless screw including a first end capable of being rotated, and a second end receiving a first rotation-guiding means and a second rotation-guiding means, respectively, causing the endless screw to pivot relative to the support member, the second rotation-guiding means including a damping sleeve and a rotation-guiding device, the sleeve surrounding the rotation-guiding device, the second rotation-guiding means including a centering means including a press-fitting part inserted into the rotation-guiding device, and an attachment part rigidly connected to the support member.