Browsing by Author "Olbrich, Christoph"

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Open Access
Influence of protection lips on the frictional torque of rotary shaft seals
(2024) Olbrich, Christoph; Feldmeth, Simon; Bauer, Frank
Rotary shaft seals are used to seal rotating machine parts. In most cases one single sealing lip (main lip) contacts the shaft and separates the fluid on one side from the environment on the other side. To prevent the entry of other fluids and or particles, seals with additional protection lips are used (two lips), especially in heavily contaminated environments. When the protection lip contacts the shaft, a vacuum can form between the main lip and the protection lip, leading to increased contact pressure and friction. The increased frictional torque generates more heat and leads to overheating in the contact area between the lip and the shaft. Test runs conducted on a friction torque test bench with various seal configurations confirm that the two lips influence each other. Higher frictional torques and contact temperatures occur, when the volume between the lips isn't vented. This shows the importance of venting.
Open Access
Multiphase conjugate heat transfer analyses on the assembly situation of rotary shaft seals
(2023) Hannss, Jacqueline; Grün, Jeremias; Olbrich, Christoph; Feldmeth, Simon; Bauer, Frank
Rotary shaft seals prevent the exchange of fluid at shaft passages. Their function and service life depend decisively on the temperature in the contact area between the sealing edge and the shaft. Since the temperature depends on both the generation of frictional heat in the contact area and the heat transfer to the surrounding sealing system, the design of the sealing system is crucial. Within the scope of this work, multiphase conjugate heat-transfer analyses were performed considering different assembly situations. The computed results were presented and contrasted to experimental data. This resulted in a valid model for predicting the temperature in the sealing system, which provided insight into the influence of the sealing surroundings on the contact temperature.
Open Access
Using multiphase conjugate heat transfer analyses to predict the contact temperature of rotary shaft seals
(2024) Hannss, Jacqueline; Grün, Jeremias; Olbrich, Christoph; Feldmeth, Simon; Bauer, Frank
Rotary shaft seals are used to seal shaft passages and prevent the exchange of fluids. The performance and service life of rotary shaft seals is strongly dependent on the temperature in the contact area between the sealing edge and the rotating shaft. Multiphase conjugate heat-transfer analyses covering different assembly scenarios, for example additional bearings or different shaft geometries, were performed in the software Ansys CFX 2021 R2. A model for predicting the maximum temperature in the sealing contact and for determining the heat dissipation from the sealing contact to the surrounding geometry was developed. This model provides the ability to predict the influence of the design of the surrounding sealing system on the contact temperature. Thus, the surrounding geometry of rotary shaft seals can be optimally designed to reduce the contact temperature between the sealing ring and the shaft as much as possible in order to achieve a longer service life.