Lubricating Oil Temperature Research Articles

高速円すいころ軸受の性能(第2報)

By the use of the method of circulating oiling in which lubricating oil is supplied and discharged from the back and the front of the bearings, the tapered roller bearings of 32211, 32216, and 32220 have been tested for their frictional moment and temperature rise under the following conditions. Rotational speed =3 000-15 000 rpm (dn 165000-1 100 000), thrust load =500-2 000 kgf, the amount of lubricating oil =0. 87-6. 96 kg/min, lubricating oil temperature =40-85°C. As the result, the following estimated formula is obtained.M=2. 7 × 10-3P ·dm0.65+1. 6 × 10-2ZB0.45 · Q0.4 · N0.4· dmM= frictional moment, kgf · cm, P= thrust load, kgf, dm=average bearing diameter, cm, ZB = oil viscosity at bearing temperature, cP, Q = the amount of lubricating oil, kg/min, N= rotational speed, rpm.θB-θI=7. 3 × 10-4 ZI0.3·P0.2·Q-0.4 · N0.85· dm.θB =bearing temperature, °C, θI = lubricating oil temperature, °C, ZI =lubricating oil viscosity, cP.

Synthesis of ammonia on iron, as investigated by the method of secondary ion-ion emission

The modification and testing of a compression ignition engine using diesel and vapourized ethanol as fuel has been carried out. Tests on the engine fuelled with diesel only were made, and the performance evaluated to form a basis for comparison for those of ethanol–diesel dual fuelling.Modifications were made in the introduction of the ethanol and air. A carburettor was used to vapourize aqueous ethanol into the engine. The effect of preheating the intake ethanol–air mixture was also investigated. Performance was evaluated in terms of engine horsepower, brake specific fuel consumption, brake thermal efficiency, the exhaust gas temperature, lubricating oil temperature and exhaust emissions. The vapourized ethanol partially reduced diesel fuel consumption but also increased total fuel delivery. Vapourization increased power output, thermal efficiency and exhaust emissions but lowered exhaust temperature and lubricating oil temperatures.

Crossed Helical Gears for High Speed Automotive Applications: Some Observations on the Problem of Failures, the Effects of the Changes of Design and Manufacturing Processes

The paper indicates that the problem has arisen in the last 10 years and is related to the increase in speed and output of automotive petrol and diesel engines. Failure incidence is furthermore associated with the change over from gear type to the cheaper multi-lobe constant displacement type lubricating oil pump. The latter have a very pronounced cycle of high torque pulses. A similar severe cyclic loading of the gear teeth is experienced when driving a distributor type diesel fuel injection pump. Changes of component design leading to reduced gear tooth loading are beneficial but cannot compensate for insufficient quality of surface finish of the tooth flanks. Failures of four distinctly different types of drives are illustrated and cause of failure analysed in detail. The part played by lubrication and oil additives is discussed. The author suggests that no drive will be successful unless the surface finish roughness of the tooth flanks is equal to or less than the oil film thickness generated. This film thickness diminishes rapidly with increase in sliding velocity and/or lubricating oil temperature. A relationship between tooth surface finish roughness and maximum safe tooth sliding velocity is demonstrated, based on the analysis of success and failure of 14 different engine types. The importance of obtaining a consistent quality of tooth flank surface finish is stressed and manufacturing methods of obtaining this are compared. The information on hobbing, shaving, grinding, lapping, buffing, phosphating, cutter blunting, shaving techniques for difficult abrasive and hard materials, detailed floor to floor production times etc. can be safely applied to gears of automotive proportions generally. The author gives a summary of his findings concerning successful and unsuccessful combinations of materials for worm-wormwheel as well as crossed-helical-gear drives. The stage by stage tooth flank surface finish improvement of an extremely successful crossed-helical-gear drive is followed through its different phases of production and demonstrated by photographic records.

Experiments for Lubricating oil Temperature in Plain Bearing

滑り輔受内において軸の囘轉方向に對する潤滑油の温度分布を實驗的に求め最後に實驗式を與えた.