Development of a Novel Underground Mine Reconnaissance Robot

<p>Despite advancements in safety technology, underground mining disasters kill hundreds of people each year. Typically after a disaster, a manned response team will enter the hazardous mine to ascertain its condition and rescue any survivors. A robotic entry platform could significantly reduce the risk to the response teams and the time taken to recover any survivors. However, existing mine search and rescue robots have had limited success in past disasters. Two primary aspects caused the failure of the existing platforms; poor rough terrain ability and lack of ingress protection for the harsh mine environment. HADES, a novel underground mine reconnaissance robot is developed to address these issues. A lightweight yet robust chassis is manufactured from fibreglass. To allow HADES to operate in the potentially explosive atmosphere, the chassis is protected with a positive pressure gas system, designed to meet the ANZ60079.29 standard. This chassis is sealed against the mine environment with a series of O-rings and lip seals. Whegs are used as the primary locomotion method and are driven with a planetary gearbox and a brushless DC motor. To further improve a rough terrain capability of the locomotion system the rear arm of the chassis is mounted on an actuated pivot, increasing the rough terrain capability of HADES. To ensure the operator can successfully assess and navigate the mine, HADES carries a comprehensive set of environmental and navigation sensors. The internal electronics and locomotion systems are powered with six Li-Po batteries that achieve an operating time of six hours and an expected range of 25 km. HADES is 780x800x400 mm and is mostly sealed to the IP68 standard. The locomotion system is robust and can traverse the majority of the terrain expected in an underground mine. Loss of traction is the only problem encountered with the Wheg design. However, this can be easily fixed by changing the tip shape of the Wheg.</p>

Development of a Novel Underground Mine Reconnaissance Robot

<p>Despite advancements in safety technology, underground mining disasters kill hundreds of people each year. Typically after a disaster, a manned response team will enter the hazardous mine to ascertain its condition and rescue any survivors. A robotic entry platform could significantly reduce the risk to the response teams and the time taken to recover any survivors. However, existing mine search and rescue robots have had limited success in past disasters. Two primary aspects caused the failure of the existing platforms; poor rough terrain ability and lack of ingress protection for the harsh mine environment. HADES, a novel underground mine reconnaissance robot is developed to address these issues. A lightweight yet robust chassis is manufactured from fibreglass. To allow HADES to operate in the potentially explosive atmosphere, the chassis is protected with a positive pressure gas system, designed to meet the ANZ60079.29 standard. This chassis is sealed against the mine environment with a series of O-rings and lip seals. Whegs are used as the primary locomotion method and are driven with a planetary gearbox and a brushless DC motor. To further improve a rough terrain capability of the locomotion system the rear arm of the chassis is mounted on an actuated pivot, increasing the rough terrain capability of HADES. To ensure the operator can successfully assess and navigate the mine, HADES carries a comprehensive set of environmental and navigation sensors. The internal electronics and locomotion systems are powered with six Li-Po batteries that achieve an operating time of six hours and an expected range of 25 km. HADES is 780x800x400 mm and is mostly sealed to the IP68 standard. The locomotion system is robust and can traverse the majority of the terrain expected in an underground mine. Loss of traction is the only problem encountered with the Wheg design. However, this can be easily fixed by changing the tip shape of the Wheg.</p>

Research into the lubrication of a rotary lip seal using ferrofluid

The paper presents the results of research into a hybrid seal which is a combination of standard rotary lip seals and a magnetic fluid seal. To maintain the magnetic fluid in the friction zone region, either a specially shaped pole piece was used or the shaft was modified accordingly. The research study concerns the allowable operating pressure and lubrication conditions in short-term and durability tests after which shaft wear was also assessed. Magnetic fluids with different rheological and magnetic properties were considered. The test results showed that the long-term operation of a hybrid seal is possible. The requirements, however, are the appropriate value of the magnetic field and dynamic viscosity of the magnetic fluid.

How to measure the radial load of radial lip seals

The radial load of a radial lip seal indicates how strongly the sealing lip is pressed on the shaft. The radial load significantly affects the function of the seal. The German standard DIN 3761-9 describes the measurement of the radial load according to the split-shaft method but leaves room for interpretation. During the revision of the standard, a parameter study was conducted at the University of Stuttgart. This study analyses the influence of the measurement device, the mandrels and the measuring procedure on the results. Based on the study results, recommendations are derived and summarized in a best-practice guideline, which should enable an appropriate and reproducible measurement of the radial load.

Stern tube seals operation: A practical approach

Stern tube seals are a key component of the propulsion system of a ship. The purpose of these sealing rings is to ensure a reliable sealing condition, preventing the spillage of lubricant to the environment. The research on these large rotary seals is limited due to their complex accessibility: stern tube seals are located below the seawater level on a moving ship. A dynamic setup replicating the operating conditions of a stern tube seal is presented together with a novel arrangement for monitoring the flow rate across the seal. The frictional torque, the operating temperature, and the lubricant migration across the seal are measured under various shaft velocities and pressure differences. The existing theory for rotary lip seals is reviewed for the stern tube seal application. From the results it is deduced that the stern tube seals tested operate within the elastohydrodynamic regime with film thicknesses in the sub-micrometer range.

Measurement of the Crankshaft Seals Friction Losses in a Modern Passenger Car Diesel Engine

This paper presents results of experimental investigations on the friction losses of the crankshaft radial lip seals of a modern four-cylinder diesel engine for passenger car applications. A two stage strip-test has been conducted on a motored engine test bed to obtain the friction torque of the radial lip seals. For the experimental investigations with the crankshaft seals removed from the engine, a special sealing apparatus has been designed and built. A wide range of tests have been performed covering the full speed range of the engine at lubricant temperatures of 70 ℃, 90 ℃, and 110 ℃. The results show a dependency on crankshaft speed and engine media supply temperature but also revealed the presence of constant plateaus of friction torque over engine speed.