Engine Rocker Arm Roller Assembly Stepped Axle Design
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Solution Overview
Problem
The existing rocker arm and roller assemblies in engines are complex and costly to manufacture due to tight tolerances and the need for precise press-fitting of multiple components, which can lead to seizing issues and engine failure if not assembled correctly.
Innovation Solution
A rocker arm assembly with a stepped-profile axle press-fit into the rocker arm, eliminating the need for internal pins, races, and bushings, and using bronze for the axle and steel for the roller for improved durability and rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a complicated assembly of components (internal pin, inner race, bushing, roller) is used to mount the roller, then the roller can rotate, but the assembly and manufacture become complicated with tight tolerances and press-fitting requirements
Solution Approach 1:
The patent combines multiple separate components (internal pin, inner race, bushing, and roller) into a single integrated roller assembly. The roller is directly mounted to the rocker arm without requiring separate races and bushings, eliminating the need for complex press-fitting operations and reducing the number of parts while maintaining rotational reliability
Solution Approach 2:
The patent removes unnecessary components from the traditional roller assembly. By eliminating the inner race and bushing that were required in conventional designs, the invention simplifies the assembly while still achieving the desired roller rotation function through direct mounting of the roller to the rocker arm
2Manufacturing precision
If tight tolerances and press-fitting are used for bushing and inner race assembly, then proper fit is achieved, but manufacturing difficulty and cost increase
Solution Approach 1:
By merging the bushing and inner race functions into a single integrated roller component, the patent eliminates the need for precision press-fitting operations. The roller is directly mounted to the rocker arm with simplified tolerances, significantly reducing manufacturing difficulty and cost while maintaining the necessary fit precision
3Reliability
If lead tin overlay is applied to the assembly, then durability is improved, but complexity and cost of assembly increase
Solution Approach 1:
The patent eliminates the lead tin overlay process from the assembly by redesigning the roller and rocker arm interface. The simplified direct-mount design achieves sufficient durability without requiring additional overlay processes, reducing both complexity and cost while maintaining reliability
4Reliability
If multiple components with tight tolerances are assembled, then proper function is achieved, but manufacturing cost increases
Solution Approach 1:
The patent merges multiple high-tolerance components into a single roller assembly that can be manufactured and installed more economically. By eliminating the need for precision press-fitting of separate races and bushings, the invention maintains proper valve train function while significantly reducing manufacturing cost
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 design simplifies manufacturing, reduces costs, and ensures consistent rotatability of the roller, enhancing engine operation and durability by using fewer parts and avoiding the need for lead tin overlays.
Implementation Method 1
using bronze for the axle and steel for the roller for improved durability and rotation
Data Source
AI summary
An engine rocker arm and roller assembly is disclosed which may include a rocker arm having a first end and a second end, with a rocker arm being adapted to pivot about a pivot aperture therein. The engine rocker arm and roller assembly may further include an axle mounted in the second end with the axle being made of bronze and having a stepped profile. The roller may be rotatively mounted to the axle.