while the automobile wheel shafts and reducer gears use rolling bearings?
The lubrication of the crankshaft of an internal combustion engine is pressure type. It has lubricating grooves on its bearings, which can further lubricate the crankshaft. But the automobile wheel shaft and the reduction gearbox gear's rotational speed is low, therefore uses the rolling bearing. Still wantThe bearing capacity of rolling bearing is strong.
The reason is very simple, in general requirements under the condition of rolling bearing performance than the sliding bearing a lot of excellent, so generally use rolling bearing, why crankshaft sliding bearing, the rolling bearing is forced, because there is no way to go above can be mounted to the crankshaft, the crankshaft is curved to bend to. The rolling bearing is impossible to install crankshaft inside the spindle neck, unless it is a single cylinder crankshaft. If you want to install the crankshaft rolling bearing must be decomposed, become assembled crankshaft can be assembled by a rolling bearing, but generally can only be used on a single cylinder engine crankshaft, such as motorcycle crankshaft, rolling bearing is used, then V type double cylinder cylinder can also be used for rolling bearings, twin cylinder in-line with rolling bearing assembly of the crankshaft, which is generally small gasoline engine for motorcycles. But the car is generally at least 3 cylinder, 4 cylinder common assembled crankshaft will do, can not guarantee the accuracy and performance of the crankshaft, can only do the crankshaft, then rolling bearing will not be installed, can only be installed because of sliding bearing, sliding bearing can be split, very easy to install on the crankshaft.Finally, if appropriate lubrication, the performance of sliding bearing is rolling bearing can not be compared in many aspects, such as the crankshaft in this place, good design would cause to become dynamic pressure bearing sliding bearing. High efficiency and high speed and high carrying capacity will be achieved. In other words, high speed crankshaft is better than sliding bearing in performance.
The crankshaft is easy to produce axial movement, often need correction of axial clearance so sliding bearings, gears and gear box has basically not axial (produces radial runout), so the gear box are generally used in high quality of rolling bearing!
The main sliding bearing sleeve is two pieces, can be installed on the crankshaft, the roller bearings can not be installed on the crankshaft. The utility model has the advantages of simple structure, low cost, easy lubrication, convenient installation, easy sealing, low noise and high precision. As long as the material pass, wear little. In addition, for a precision problem, nor is it suitable for other bearings.As for other places, both work speed, noise, work conditions, rotation accuracy, withstand shock, vibration ability, maintenance is not the same. The sliding bearing has the characteristics of high bearing capacity, good seismic resistance, low noise, long service life, etc. the rolling bearing has the characteristics of shock, vibration, noise and sealing. Rolling bearings are standard parts, easy to change. Plain bearings consume nonferrous metals.
