To simplify, consider it 100 mm, and travel up from 100 to a location midway between the 3,000 and 5,000 rpm lines in Figure 2. The bearing's mean diameter would be 105 mm. (Courtesy of SKF)įor another example, if a bearing was mounted on a 70-mm shaft rotating at 3,600 rpm, we might assume that the bearing's outside diameter (OD) is twice its inner diameter (ID), or 140 mm. 3 A bearing with a mean diameter of 390 mm at a shaft speed of 500 r/min will require v 1= 13.2 cSt. Required minimum (rated) viscosity v 1 as a function of bearing dimension and shaft speed. Oil overheating may be an additional concern.įigure 2. Oil rings, if used, would probably slow down and malfunction in such viscous oils. But that is unrealistically thick for most process pump bearings. The MRC Engineer's Handbook states, "In general, the oil viscosity should be about 100 Saybolt Universal Seconds (SUS) at the operating temperature." 1 If for some reason a bearing was operating at 210 degrees F, Figure 1 would call for a lubricant with an International Organization for Standardization (ISO) viscosity grade (VG) somewhere between 220 and 320. Whatever the user chooses, he or she must guard against using the thinnest oil found on the market to avoid the problem of inadequate oil film strength and thickness. They can use a jet of oil (oil spray) or convey the oil mixed with compressed air in the form of an oil fog-also called oil mist. Users can heat the oil or avoid oil rings and other risk-inducing lube application methods by using smarter means. Thick oils are more viscous and may not readily flow into the bearings. Figure 1 illustrates where these motor oils fit in comparison to the industrial oil designations used today. But thinner oils, perhaps SAE 10, can help prepare a vehicle for winter driving. For the most part, the oil works smoothly regardless of the vehicle and the temperature.Some will know from their experience with automobiles that thicker oils, such as Society of Automotive Engineers (SAE) 30, are more appropriate for warm summer months. Second, the oil also covers a diverse range of possible temperatures but is ideal for warmer temperatures. First, it works surprisingly well with a broad selection of vehicles with different engine types. 5W30 Motor Oilĥw30 is one of the two most commonly used types of motor oils for various reasons. The number prior to the alphabet W shows the ‘cold’ viscosity rating of the oil whereas the number after the alphabet W shows the ‘hot’ viscosity rating. The idea of this motor oil is simple: use physics and science to stop the base oil from becoming too runny and thin when the engine heats up. Single grade oils become too thin when they come into contact with the heat produced by the car’s engine, and this is where multi-grade oil comes in. 5W ViscosityĥW viscosity grade calls for the lubricant to properly flow at lower temperatures as compared to, for instance, oil with 20W viscosity, hence you should use it when the weather is cold. It is recommended that you keep 5W motor oil on hand before the first gust of cold strikes. Keep in mind that high-quality motor oil lasts longer and you will have to schedule an oil change for later as compared to using any generic brand. There is no dearth of motor oils that deliver high performance and withstand extreme temperatures, dirty climates, and aggressive driving. Thinner motor oil flows more smoothly and quickly when the engine is cold, which is why you should not use anything less than 5W-30 in the summer. To keep your motor up and running at all times, you should stick to the mechanic’s or manufacturer’s recommendations regarding motor oil. All vehicles have a particular oil viscosities/weight, and you can usually find this information on the top of the crankcase, usually on top of the oil cap. Thus, if you live in colder environments or freezing temperatures, you should use thin grade oil, such as the 5w30. The higher the initial number, the thicker or viscous the oil is. The thickness or viscosity determines how well the oil will flow through the engine. Oil is the lifeblood of any motor, but you cannot get away with using just any motor oil because its thickness plays a great role in its efficiency.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |