Steering Column Gear Wheel With Molded Threaded Insert
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Solution Overview
Problem
The existing gear wheels for motor vehicle steering columns require high manufacturing and assembly costs due to the need for separate production and precise fitting of threaded elements, which can lead to deformation and reduced durability, especially under high load conditions such as crashes.
Innovation Solution
A gear wheel design where the threaded element is injection-molded as a plastic part directly onto the core element during manufacturing, forming an integrated and durable connection, with a metallic core element providing additional support and a crash support section to enhance resilience.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a threaded element is manufactured separately and joined to the core element, then the gear wheel can be assembled, but the production cost increases and the joint may deform or misalign reducing durability
Solution Approach 1:
The patent combines the threaded element and core element into a single integrated component. The threaded element is injection-molded directly onto the core element, eliminating the need for separate manufacturing and assembly operations. This merging reduces production costs by removing multiple manufacturing steps and quality control requirements for joints, while simultaneously improving reliability by eliminating potential weak points at connection interfaces where deformation or misalignment could occur under load.
Solution Approach 2:
The patent employs composite construction by integrating a threaded element made of one material (e.g., plastic or metal) with a core element made of potentially different material properties. The threaded element is molded directly onto the core element, creating a composite structure that leverages the advantages of different materials while ensuring a strong, integrated connection without requiring separate assembly operations. This composite approach reduces both manufacturing complexity and joint-related reliability issues.
2Productivity
If a separate threaded element is assembled into the core element, then the gear wheel can be manufactured, but additional assembly work and time are required
Solution Approach 1:
The patent merges the manufacturing of the threaded element and core element into a single injection molding operation. The threaded element is molded directly onto the core element in one continuous process, eliminating separate assembly steps. This significantly improves manufacturing productivity by reducing the number of operations, handling requirements, and quality inspection steps, while also simplifying the overall device complexity by removing the need for separate components and their associated assembly procedures.
Solution Approach 2:
The patent applies preliminary action by pre-forming the threaded element with its threading already integrated onto the core element during the injection molding process. This preliminary formation of the complete assembly in one step eliminates the need for subsequent assembly operations, thereby improving productivity and reducing assembly process complexity. The threaded element is prepared and attached simultaneously rather than in separate sequential steps.
3Ease of manufacture
If the threaded element is made of plastic injection molded onto the core element, then manufacturing cost and assembly effort are reduced, but load capacity must be sufficient under crash conditions
Solution Approach 1:
The patent uses composite material construction where a plastic threaded element is injection-molded directly onto a core element. The plastic material provides corrosion resistance and manufacturing advantages, while the core element (which can be metallic) provides structural strength and load-bearing capacity. This composite approach maintains ease of manufacture through injection molding while ensuring sufficient load capacity under crash conditions by leveraging the strength properties of the core element.
Solution Approach 2:
The patent applies local quality by using different materials in different regions of the gear wheel assembly. The threaded element is made of plastic for ease of molding and corrosion resistance, while the core element can be made of a stronger material for load-bearing applications. This localized material selection optimizes both manufacturing ease and structural strength where needed, allowing the plastic threaded element to be molded directly onto the core element without compromising load capacity under crash conditions.
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 approach reduces manufacturing and assembly costs while increasing the durability and load capacity of the gear wheel, ensuring reliable operation even under crash conditions by providing a positive-locking and form-fitting connection between the plastic threaded element and the metallic core element.
Implementation Method 1
the threaded element is made of plastic as a plastic injection molded part, which is injection-molded onto the core element on an inner wall of the through-opening
Data Source
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AI summary
The invention relates to a gear wheel for an adjustment drive mechanism (2) which has a ring gear (30), which is attached coaxially circumferentially to the outside of a core element (31), which has an axial passage opening (311), in which a threaded element (33) is fitted, the latter having an axially continuous internal thread (32) having at least one thread tooth (321) running around helically. According to the invention, the threaded element (33) is formed from a plastic as an injection moulded plastic part, which is moulded onto the core element (31) on an inner wall of the passage opening (311).