Composite Planetary Staking Pin Helical Lubrication
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Solution Overview
Problem
Existing planetary staking pins for automatic transmissions are complex and expensive due to the need for specialized formation techniques and materials to provide both softer axial ends for staking and a harder medial portion for rolling element support, while also requiring internal lubrication passages, making them difficult and costly to manufacture.
Innovation Solution
A composite planetary staking pin design featuring a bifurcated structure with a softer inner pin body and a harder outer sleeve, where the inner pin body is fixed to the planetary carrier via staking and the outer sleeve defines a helical lubricant flow path between the carrier and rolling elements, reducing manufacturing complexity and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single-piece staking pin with localized hardened portion and internal lubrication passages is used, then rolling element support and lubrication are provided, but manufacturing complexity and cost increase
Solution Approach 1:
The staking pin is divided into two separate components: an inner pin body and an outer sleeve. The inner pin body provides the hardened racing surface for rolling element support, while the outer sleeve contains the lubrication passage. This segmentation allows each component to be manufactured independently using simpler processes, reducing overall manufacturing complexity while maintaining the functional requirements.
Solution Approach 2:
The staking pin uses a composite structure combining two different materials with distinct properties. The inner pin body is made from a harder material suitable for rolling element support, while the outer sleeve is made from a softer material that is easier to stake and form. This composite approach allows optimization of each material for its specific function without the complexity of creating localized properties in a single piece.
2Ease of manufacture
If axial ends of the pin are made softer for staking, then axial fixation is facilitated, but the pin requires a harder medial portion for rolling element support
Solution Approach 1:
The pin is segmented into an inner pin body and outer sleeve, allowing each to have different material properties optimized for their specific functions. The inner pin body can be made from harder material for rolling element support, while the outer sleeve uses softer material for easier staking and formation.
Solution Approach 2:
The composite structure combines two materials with different hardness properties. The inner pin body uses a harder material to provide the racing surface for rolling elements, while the outer sleeve uses a softer, more formable material that facilitates staking operations. This eliminates the need for complex localized heat treatment or specialized formation techniques.
3Reliability
If internal lubrication passages are drilled into the pin body, then lubricant delivery to rolling elements is achieved, but manufacturing complexity increases
Solution Approach 1:
The lubrication function is separated from the structural pin body. The outer sleeve contains the lubrication passage and is designed as a separate component that can be manufactured independently. This segmentation allows the passage to be formed using simpler processes such as stamping or forming operations on the sleeve, rather than requiring complex drilling and tapping operations on the inner pin body.
Solution Approach 2:
The outer sleeve acts as an intermediary component that provides the lubrication passage. Instead of drilling passages directly into the inner pin body, the lubrication path is created through the outer sleeve, which serves as a mediator between the lubricant source and the rolling elements. This simplifies the manufacturing of both components.
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 composite design simplifies assembly, reduces material costs, and effectively supports rolling elements while providing adequate lubrication, enhancing the structural characteristics and operational efficiency of planetary transmissions without increasing complexity or expense.
Implementation Method 1
The outer sleeve defines a circumferentially extending helical channel. A lubricant flow path is defined by the channel between an inlet defined by the planetary carrier and an outlet to the rolling elements.
Implementation Method 2
The composite planetary staking pin is fixed to the planetary carrier via staking of the axial ends of the inner pin body.
Data Source
AI summary
A planetary transmission assembly including a composite planetary staking pin is disclosed. The composite planetary staking pin fixes a planetary gear to a planetary carrier, and the planetary gear is supported on the composite planetary staking pin by rolling elements. The composite planetary staking pin includes an inner pin body having axial ends with circular grooves. The composite planetary staking pin is fixed to the planetary carrier via staking of the axial ends of the inner pin body. An outer sleeve of the composite planetary staking pin is fixed to the inner pin body. The outer sleeve defines a circumferentially extending helical channel that provides a lubricant flow path between an inlet defined by the planetary carrier and an outlet to the rolling elements.