Research into the pressure capability and friction torque of a rotary lip seal lubricated by ferrofluid

•Lubricating lip seals with ferrofluid to enhance performance in challenging conditions.•Development of an innovative hybrid seal that combines a standard lip seal with ferrofluid technology.•Fluid spring-like properties of ferrofluid, which improve pressure capability compared to non-lubricated seals. Lip seals are commonly used in various applications, particularly in dry conditions where maintaining a continuous lubricant supply can be challenging. A promising solution for this issue is local lubrication utilizing a controllable fluid, such as ferrofluid. This study explores a hybrid seal that integrates a standard lip seal with a ferrofluid seal. The standard lip seal was modified by adding components that create a magnetic field gradient in the contact zone. The objective of this research was to examine the basic operating parameters of the hybrid seal. Numerical simulations were conducted to analyze how different geometric dimensions affect the magnetic field distribution. Additionally, experimental studies were carried out to measure frictional torque, temperature, and pressure capabilities. Both spring-loaded and non-spring configurations of the lip seal were tested under both lubricated and dry friction conditions. The results indicated that increasing the volume of ferrofluid and using ferrofluid with higher saturation magnetization lead to a reduction in friction torque. Ferrofluid has demonstrated properties similar to a fluid spring, which enhances pressure capability compared to seals that are not lubricated.