Disconnect Plunger Cam Geometry for Reliable IDG Disengagement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Disconnect plungers in integrated drive generators face challenges in effectively disengaging from the input shaft under certain conditions, particularly due to the limitations of existing disconnect mechanisms used in gas turbine engines.
Innovation Solution
A disconnect plunger design with a specific cam surface geometry, including a cylindrical cam portion and a guide portion with defined ratios and dimensions, allows for efficient disengagement from the input shaft by utilizing a solenoid-actuated mechanism, ensuring reliable operation and replacement methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a disconnect plunger is spring biased to engage the disconnect shaft with the input shaft, then reliable engagement is achieved, but the plunger fails to effectively disengage under certain conditions
Solution Approach 1:
The patent modifies the geometric parameters of the cam surface, specifically defining precise ratios: the first radius to first distance ratio is between 0.230 and 0.250, and the second distance to first radius ratio is between 0.335 and 0.355. These parameter changes optimize the cam profile to ensure both reliable engagement through spring bias and effective disengagement when the solenoid is actuated, resolving the contradiction between engagement reliability and disengagement capability.
2Ease of operation
If a disconnect solenoid is used to hold the disconnect plunger against spring bias force, then controlled disengagement is achieved, but the mechanism complexity increases
Solution Approach 1:
The patent replaces a purely mechanical spring-biased disconnect mechanism with an electromechanical system by introducing a disconnect solenoid. The solenoid provides controlled actuation to overcome the spring bias force and achieve reliable disengagement, while the optimized cam surface geometry ensures smooth transition between engaged and disengaged states, managing the added complexity through precise geometric design.
3Productivity
If the cylindrical cam portion has specific radius and position ratios, then disengagement efficiency is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent defines specific parameter ranges for the cam surface geometry: the first radius to first distance ratio between 0.230 and 0.250, and the second distance to first radius ratio between 0.335 and 0.355. By providing acceptable ranges rather than single precise values, the design achieves optimal disengagement efficiency while accommodating normal manufacturing tolerances, balancing performance with manufacturability.
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 proposed design enhances the disconnect plunger's ability to disengage from the input shaft, improving operational control and reliability in integrated drive generators, particularly in gas turbine engines, by providing a precise and effective mechanism for disconnecting the rotational drive.
Implementation Method 1
A cam surface is formed on the second end, and has a cylindrical cam portion extending across the second end
Implementation Method 2
The disconnect shaft is spring biased into engagement with the input shaft
Implementation Method 3
a disconnect solenoid holds the disconnect plunger against this bias force
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A disconnect plunger (31) extends between a first end and a second end. A cam surface (32) is formed on the second end, and has a cylindrical cam portion (50) extending across the second end. The cylindrical cam portion has a location formed at a first radius about a point spaced beyond the second end relative to the first end. A first distance is defined from a second end facing surface of a cylindrical guide portion positioned intermediate the first and second end. A ratio of the first radius to the first distance is between .230 and .250. The point is spaced in a direction perpendicular to a center axis of the plunger body, and measured from the center axis by a second distance. A ratio of the second distance to the first radius is between .335 and .355. An integrated drive generator and a method of replacing a disconnect plunger are also disclosed.