Continuously Variable Transmission Assembly via Segmented Carriers
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Solution Overview
Problem
Existing continuously variable ratio transmission units (variators) face complexities in assembly, require intricate housing design for hydraulic fluid supply, and have size issues that complicate installation in motor vehicles.
Innovation Solution
The variator design includes a housing with sub-assemblies and actuators mounted on carriers that can be easily assembled by advancing the carriers along specific axes, allowing for a compact shape suitable for vehicle installation and simplified fluid supply through integrated channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hydraulic actuators are mounted directly in the housing with intricate fluid supply passages, then the variator can function properly, but the housing fabrication becomes complex and time-consuming
Solution Approach 1:
The housing is divided into multiple separate parts (first housing part, second housing part, third housing part) that can be manufactured independently with simpler geometry, then assembled together. This segmentation eliminates the need for complex internal fluid passages in each part while maintaining the required hydraulic functionality through external or simplified internal passages in the assembled structure.
2Ease of operation
If roller control actuators are accommodated with laterally projecting lobes in the housing, then the actuators can be mounted, but the variator width increases creating installation difficulties
Solution Approach 1:
Instead of accommodating actuators by projecting lobes laterally (increasing width in one dimension), the housing parts are designed to integrate actuators within the main body volume by utilizing the third dimension (height/length along the variator axis). The actuators are positioned within the housing assembly rather than projecting outward, reducing the overall width footprint.
3Productivity
If multiple components are assembled inside a single housing, then the variator can be constructed, but the assembly process becomes time-consuming and difficult to automate
Solution Approach 1:
The variator is divided into modular housing parts (first, second, third housing parts) that can be prepared separately and then assembled in a standardized sequence. This segmentation allows for pre-assembly of sub-components and facilitates automated assembly line processes, reducing overall assembly time and complexity.
Solution Approach 2:
Housing parts are designed with pre-formed features (bores, passages, mounting surfaces) that are prepared in advance during manufacturing. This preliminary preparation of housing components allows for faster final assembly, as components can be directly installed without complex on-site fabrication or adjustment.
4Ease of operation
If the housing is designed with integrated fluid supply passages, then hydraulic fluid can reach actuators, but the machining complexity increases
Solution Approach 1:
Fluid supply passages are distributed across multiple housing parts rather than being carved through a single complex housing structure. Each housing part contains simplified passages that connect to form the complete fluid supply network when assembled, reducing machining complexity while ensuring proper fluid delivery to all actuators.
Data Source
AI summary
A continuously variable ratio transmission unit having a housing (116) and input (102, 106) and output (100) discs paired to define first and second toroidal cavities. The discs (100, 102, 106) are mounted to the housing for rotation about a common axis. First (110) and second (112) rollers—or more typically first and second sets of rollers—are respectively arranged in the first and second cavities and serve to transmit drive between the input and output discs. First (130) and second (148, 150, 152) actuators act on the respective rollers. The first actuator is coupled to a first carrier part (126) which can be mated with the housing introducing it to the housing along a direction generally parallel to the variator axis. The second actuator is coupled to a second carrier part (146) which can be mated with the housing by introducing the second carrier part to the housing along a direction non-parallel to the variator axis.