Mechanical Seal Drive With Cushioning for Variable-Speed Rotation
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Solution Overview
Problem
Existing mechanical seal drive mechanisms for rotating components at variable angular speeds suffer from backlash, wear, and damage due to clearance and jerk, leading to increased manufacturing complexity and cost, and are not suitable for high-pressure applications.
Innovation Solution
A seal arrangement with a cushioning member between the retainer and seal face to dampen rotary driving forces, providing a robust drive mechanism that reduces backlash and wear, allowing for variable angular speeds and axial movement, using complementary drive flats and O-rings for torque transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mechanical seal drive mechanism is used for rotating components at variable angular speeds, then torque transmission is achieved, but backlash and wear occur due to clearance between components
Solution Approach 1:
A cushioning member is disposed between the retainer and the seal face to dampen the rotary driving force before it reaches the seal face. This beforehand cushioning reduces jerk and backlash during variable angular speed operation, preventing damage and wear while maintaining reliable sealing performance
2Adaptability or versatility
If a drive mechanism with clearance between retainer and seal face is used, then axial movement is permitted, but jerk and damage occur during variable speed operation
Solution Approach 1:
The cushioning member is positioned in advance between the retainer and seal face to provide damping during variable speed operation. This allows axial movement capability to be maintained while the cushioning member prevents jerk and damage by absorbing shock loads during acceleration and deceleration phases
3Power
If a robust drive mechanism is designed to handle variable angular speeds, then torque transmission is improved, but manufacturing complexity and cost increase
Solution Approach 1:
A cushioning member is introduced as an intermediary element between the retainer and seal face. This simple intermediary component dampens rotary driving forces and reduces jerk during variable speed operation, providing robust torque transmission capability without significantly increasing manufacturing complexity
Solution Approach 2:
The cushioning member changes the physical parameters of force transmission by introducing damping characteristics. This allows the drive mechanism to handle variable angular speeds robustly while maintaining simple manufacturing, as the cushioning member can be made from standard elastomeric materials with appropriate durometer ratings
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 seal arrangement effectively reduces damage and wear, simplifies manufacturing and assembly, and maintains sealing performance under variable angular speeds and axial movements, suitable for high-pressure applications.
Implementation Method 1
a first cushioning member disposed between the first seal face and the first retainer, wherein the first cushioning member is configured to dampen the rotary driving force provided by the first retainer to the first seal face
Implementation Method 2
The thin film, sometimes referred to as a fluid film, generates hydrostatic forces (e.g. forces which are present regardless of whether the mating ring is stationary or rotating) and hydrodynamic forces
Implementation Method 3
The thin film, sometimes referred to as a fluid film, generates hydrostatic forces (e.g. forces which are present regardless of whether the mating ring is stationary or rotating) and hydrodynamic forces (e.g. forces which are present only when the mating ring rotates)
Implementation Method 4
Grooves may be provided on the mating ring (e.g. logarithmic spiral grooves) which are involved in generating the hydrodynamic forces, for example, when the mating ring rotates, the grooves may shear fluid flow towards the central longitudinal axis of the mating ring which increases the pressure of the fluid flow
Implementation Method 5
The thin fluid film also prevents wear of the mating ring and primary ring
Data Source
AI summary
The present invention relates to seal arrangements for rotating components, in particular, for rotating components which are driven at variable angular speeds. An aspect of the disclosure provides a seal arrangement for an apparatus comprising: a housing; and, a rotatable component disposed within the housing; wherein the rotatable component is configured to rotate at a variable angular speed about a rotational axis, the seal arrangement comprising: a first seal assembly (500) configured to be disposed on the rotatable component of the apparatus and to rotate around the rotational axis, the first seal assembly comprising: a first retainer (510); a first seal face (516); wherein: the first seal face is disposed within the first retainer; and, the first retainer is configured to provide a rotary driving force to the first seal face to thereby rotationally drive the first seal face; a first cushioning member (530) disposed between the first seal face and the first retainer, wherein the first cushioning member is configured to dampen the rotary driving force provided by the first retainer to the first seal face; a second seal assembly configured to be disposed on the housing: a second retainer (611); a second seal face (618); wherein: the second seal face configured to be disposed within the second retainer; wherein the first seal face is disposed in contact with the second seal face to thereby seal against egress of fluid between the first seal face and the second seal face.