Bulkhead Drive Shaft Seal With Single-Bearing Flame-Resistant Layout
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Solution Overview
Problem
Existing mechanical seal systems for drive shafts extending through bulkheads are cumbersome, expensive, and lack flame resistance, making them unsuitable for compact installations and meeting modern safety regulations.
Innovation Solution
A compact mechanical seal system featuring a tubular element with an intermediate flange and dual mechanical seal devices, supported by a single hydrodynamic bearing, which includes a flushing circuit for lubrication and is constructed from non-inflammable materials to ensure effective sealing and flame resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple bearings are used to support the drive shaft, then the sealing effect is guaranteed, but the system becomes large, cumbersome, and expensive
Solution Approach 1:
The patent combines multiple sealing functions into a single mechanical seal device that integrates the sealing mechanism with the drive shaft support structure. The mechanical seal device incorporates stationary and rotary elements that work together to provide sealing without requiring separate bearing assemblies, thereby reducing overall system complexity while maintaining effective sealing.
Solution Approach 2:
The mechanical seal device serves multiple functions simultaneously: it supports the drive shaft, provides sealing against leakage, and enables rotational motion. This multi-functional design eliminates the need for separate bearings and sealing devices, reducing the number of components while achieving the same reliability goals.
2Reliability
If rubber material is used for the sealing device, then sealing is achieved, but flame and fire resistance is not guaranteed
Solution Approach 1:
The patent changes the material parameter of the sealing device from combustible rubber to non-combustible mechanical seal materials such as metals, ceramics, or graphite. This material substitution maintains the sealing function through precise mechanical contact between stationary and rotary elements while eliminating fire hazards, thus resolving the contradiction between sealing effectiveness and fire resistance.
3Device complexity
If a single bearing is used instead of multiple bearings, then the system becomes compact and cheaper, but sealing effectiveness may be compromised
Solution Approach 1:
The patent merges the bearing support function and sealing function into a single integrated mechanical seal device. The stationary part is coupled to the tubular element while the rotary part is integrally connected to the drive shaft, creating a unified component that performs both support and sealing functions simultaneously, eliminating the need for separate bearing assemblies.
Solution Approach 2:
The mechanical seal device is segmented into stationary and rotary parts with distinct functional zones. The stationary part provides structural support and sealing surface, while the rotary part follows the drive shaft rotation, allowing each segment to optimize its specific function within the integrated device.
4Reliability
If traditional sealing systems are used, then sealing is provided, but maintenance frequency is high due to lack of lubrication
Solution Approach 1:
The patent implements a self-lubrication system where the mechanical seal device incorporates lubrication channels that automatically deliver lubricant to the contact surfaces between stationary and rotary elements. This self-service lubrication mechanism reduces wear and friction without requiring external maintenance intervention, thereby extending service intervals and reducing maintenance frequency while maintaining reliable sealing.
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 solution provides a compact, cost-effective, and flame-resistant sealing system that reduces maintenance needs and ensures reliable operation by using a single hydrodynamic bearing and a flushing circuit for lubrication, while ensuring compliance with safety regulations.
Implementation Method 1
The intermediate element is a tubular element that supports said part of the drive shaft by means of a bearing. In a preferred embodiment the bearing is of the hydrodynamic type. Hydrodynamic bearings, or hydrodynamic sleeves, are composed of a single cylindrical piece wherein pressurized fluid flows and have very low coefficients of friction.
Implementation Method 2
There is provided a flushing circuit for a working fluid, which circuit comprises at least one duct, at least one pump and at least one tank. Thus the working fluid that is part of the hydrodynamic bearing wets also the inner part of seal devices by the interstice provided between such devices and the drive shaft, and particularly it wets the annular elements of each seal device while guaranteeing lubrication of flat contact faces thereof.
Data Source
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AI summary
Mechanical seal system for a drive shaft extending through an opening in a bulkhead (8), comprising an intermediate element (1) configured for housing part of the drive shaft; the intermediate element (1) is provided with an intermediate flange (10) having means fastening to the edge of said opening; the tubular element (1) has two opposite ends (11, 12) along the axis of rotation (R) of the drive shaft, each end (11, 12) being provided with a respective mechanical seal device (41, 42).