Mechanical Seal Elastomer Isolation and Stress Mitigation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Mechanical sealing devices in pumps face issues where stresses from the connection between the holder element and housing are transferred to the seal surface, causing non-planar states and leakage, and elastomer elements come into contact with the sealed medium, which is undesirable in hygienic applications.
Innovation Solution
The mechanical sealing device features an elastomer element with an annular flange extending into a groove, and a holder element with locking means to secure the elastomer between the outer and inner surfaces, preventing medium contact and allowing slight radial movements to mitigate stress transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an elastomer element is provided between the outer peripheral surface of the first seal element and the inner surface of the first holder element to remedy stress transfer, then the sealing performance is improved, but the elastomer element comes into contact with the liquid to be pumped which is undesirable for hygienic reasons
Solution Approach 1:
The holder element is divided into two distinct parts: a first holder element that contacts the liquid and a second holder element that does not. The elastomer element is positioned between these two holder elements, creating a segmentation that isolates the elastomer from the liquid while maintaining its stress-absorbing function. This resolves the contradiction by allowing the elastomer to improve sealing performance without contacting the liquid.
Solution Approach 2:
The first holder element acts as an intermediary component between the liquid and the elastomer element. It transmits mechanical stresses from the liquid-contacting region to the elastomer without allowing direct contact between the elastomer and liquid. This intermediary structure enables the elastomer to perform its stress-absorbing function while preventing harmful contact with the liquid.
2Object-affected harmful factors
If the opposite backing surface of the first seal element abuts tightly the support surface of the first holder element to prevent medium contact with elastomer, then hygiene is improved, but stress transfer to the seal surface may occur
Solution Approach 1:
The holder element is segmented into a first holder element (liquid-contacting) and a second holder element (non-contacting). The elastomer element is positioned between these segments, allowing tight abutment surfaces to prevent medium contact while the elastomer absorbs stresses independently, preventing stress transfer to the seal surface.
Solution Approach 2:
The first holder element serves as an intermediary that provides a tight abutment surface to prevent medium contact with the elastomer, while simultaneously transmitting stresses to the elastomer element which absorbs them, thereby preventing stress transfer to the seal surface.
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
This configuration ensures tight abutment between the seal and holder surfaces, preventing medium leakage and reducing stress transfer, while keeping the elastomer element isolated from the sealed medium, enhancing the sealing performance and hygiene in applications like medical and food industries.
Implementation Method 1
the elastomer element permits the first seal element to perform slight movements along a radial plane, so that any possible transfer of stresses from the connection of the first holder element to any component, for instance an external component such as a housing, may be reduced or prevented
Implementation Method 2
the opposite backing surface of the first seal element abuts tightly or sealingly the support surface of the first holder element, any medium to be sealed is efficiently prevented form reaching the elastomer element
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A mechanical sealing device and a pump comprising a mechanical sealing device are described. The sealing device comprises a first seal element (11) and a first holder element (12) holding the first seal element. The first seal element (11) forms a first seal surface (13), an opposite backing surface (14) and an outer peripheral surface (15). The first holder element has a support surface (16) and an inner surface (17). A second seal element (21), forming a second seal surface (22), is rotating in relation to the first seal element around an axis (x) of rotation so that the first seal surface (13) abuts sealingly the second seal surface (22) in a radial plane. An elastomer element (30) is provided between the outer peripheral surface (15) and the inner surface. The opposite backing surface abuts tightly the support surface.