Influence of the Lubrication Oil Temperature on the Disengaging Dynamic Characteristics of a Cu-Based Wet Multi-Disc Clutch

Clutch disengaging dynamic characteristics, including the disengaging duration and the variations of friction pair gaps and friction torque, are crucial to the shifting control of an automatic transmission. In the present paper, the influence of lubrication oil (ATF) temperature on disengaging dynamic characteristics is investigated through a comprehensive numerical model for the clutch disengaging process, which considers the hydrodynamic lubrication, the asperity contact, the heat transfer, the spline resistance, and the impact between the piston and clutch hub. Moreover, the non-uniformity coefficient (NUC) is proposed to characterize the disengaging uniformity of friction pairs. As the ATF temperature increases from 60 °C to 140 °C, the clutch disengaging duration shortens remarkably (shortened by 55.1%); besides, the NUC sees a decreasing trend before a slight increase. When the ATF temperature is 80 °C, the distribution of friction pair gaps is most uniform. During the disengaging process, the increase of ATF temperature not only accelerates the change of the lubrication status between friction pairs but also contributes to the decrease of contact torque and hydrodynamic torque. This research demonstrates for the first time, evidence for clutch disengaging dynamic characteristics with the consideration of ATF temperature.

Isolation and Study of Biodegradation Capability of Hydrocarbonoclastic Bacteria from Industrial Waste Lubrication Oil Contaminated Sites

A research was carried out on Isolation and study of biodegradation capability of hydrocarbonoclastic bacteria from industrial waste lubricant oil contaminated sites. 12 different bacterial cultures are isolated from the soil samples collected from liquid effluent dump site of black galaxy granite, chimakurthy, prakasam Dist, and auto motive lubrication oil replacement garages, Auto Nagar, Vijayawada. Among the 12isolates 10 isolates were found to have capability of degrading used industrial lubrication oil VG 320 collected from NSL textiles LTD, Guntur. Among the isolates tested the isolate no BG4 obtained from liquid effluent dump site gave the maximum biodegradation potential of 18.78mm2followed by BG7 of 15.36, BG1 of 14.07and BG8 of 10.56 mm2 and the isolate no AL1 from automotive lubrication oil replacement garage soil sample found to be 9.03mm2 degradation potential. These isolates were identified based on physical and biochemical characters as Pseudomonas, Bacillus, Proteus, Flavobacterium and Enterococcussps respectively. For the future, our study will be focused on several data like the species of isolates, the optimal activity of isolates to degrade several Industrial lubricant oils.

Combustion and Oxidation of Lube Oils at Gas Turbine Conditions: Experimental Methods

Because of the high temperatures involved, undesirable ignition events can happen during gas turbine operation, often necessitating expensive down time and repairs. The ignition events are frequently linked to the lubricant, a flammable mixture of large hydrocarbons with a very low vapor pressure. To understand better the role of the lubricant in such ignition events, increased understanding of the fundamental thermal and oxidation characteristics of such oils is needed. To this end, a suite of different tests has been set up and demonstrated at the TEES Turbomachinery Laboratory at Texas A&M University (TAMU) to study various aspects of lubrication oil breakdown and oxidation at elevated temperatures, mostly those related to their coking and ignition behaviors. Five types of tests have been implemented: ignition delay time measurements using a shock tube; hot surface ignition (HSI); autoignition temperature (AIT) determination; thermal cook-off under controlled heating; and a high-temperature coking experiment. Such tests can be used both for fundamental understanding of how lube oils burn and for comparing the reactivity of various types and grades of oil. Each technique at TAMU is briefly described in this paper as they pertain to gas turbine lube oils, and sample results are presented for a common lubrication oil, Mobil DTE 732. For this oil, the HSI tests produced a lowest temperature without ignition of 510°C, and in shock-tube measurements, lower-temperature ignition kinetics are observed below about 1300 K, even at 1 atm. Typical AIT values for oils have been found to be around 370°C but do vary amongst brands, types, and level of degradation. The measured temperatures for the exothermic and boiling events were measured as 166±2 °C and 277±4 °C using the cook-off rig.

Review on PLC Based Crankshaft Oil Hole Checking Automation

Crankshaft oil hole checking automation is nothing but the machine used to check the lubrication oil holes on crankshaft. Because of manufacturing inaccuracies or errors there may have chances of blocked or undrilled or semi drill lubrication holes on crankshaft. And due to these inaccuracies or errors no proper lubrication is provided to the complete engine and engine cease may occur. While driving a vehicle this engine cease is occurred then it can causes severe accidents and person may losses his/her life. To avoid this problem this automation is specifically design to check all lubrication hole presence on crankshaft with the help of sensors and actuators and controlled by Programmable Logic Controller (PLC). If all pokayoke sensors are giving desired signal then machine display will show all hole presence with green light and ok job counter, else any of hole is missing or blocked or hole length is improper display will show not ok signal for respective hole and job is not ok with red light indicator and buzzer. This helps to detect the problem at the stage of manufacturing before assembly results in increased productivity and stoppage of severe accidents.

Evaluation of Flushed Oil with Respect to New Oil

<p><i>The paper address the tests required to be conducted for lubrication oil. It investigates the change of properties of new oil after it is being used for flushing. The recommendations of changing flushed oil or keeping it made on different analysis and studies, however, if the oil properties are not changing, then using the flushed oil is recommended as the new oil will not be as clean as flushed oil. The paper listed several oil cleaning methods and highlighted several causes which could result on bearing failure. The bearing lifetime was discussed and how the impact of different parameter could impact the bearing life span if it is generating additional forces, for example, due to the increase of friction force which contribute to the equivalent dynamic bearing load. </i></p>

Challenges in the Design of Propulsion Shafting

Shafting system in a ship is probably its most critical component. Problems in the propulsion shafting, connecting engine with propeller may let the vessel dead in the water. This study focuses on three components of the shafting system which are well known to cause problems. These are the aft stern tube bearing, the coupling bolts and the sealing arrangement which prevents the ingress of sea water or the leakage of lubrication oil to the sea. A variety of issues related to these “weak” links of the shafting system is analyzed, based on actual cases of damage.

Evaluation of Flushed Oil with Respect to New Oil

<p><i>The paper address the tests required to be conducted for lubrication oil. It investigates the change of properties of new oil after it is being used for flushing. The recommendations of changing flushed oil or keeping it made on different analysis and studies, however, if the oil properties are not changing, then using the flushed oil is recommended as the new oil will not be as clean as flushed oil. The paper listed several oil cleaning methods and highlighted several causes which could result on bearing failure. The bearing lifetime was discussed and how the impact of different parameter could impact the bearing life span if it is generating additional forces, for example, due to the increase of friction force which contribute to the equivalent dynamic bearing load. </i></p>