Sliding bearing clearance is usually?

Sliding bearing clearance is usually? 2019 - 05 - 19 sliding bearing clearance generally is 0. 01 to zero. 02 mm. The scope of sliding bearing clearance is according to the site of use to determine the accuracy, such as: grinding machine and the precision of lathe main bearing of dividing head to cooperate for H7 / g6, agricultural machinery for H11 / d11 with bearing fit precision. Sliding bearing clearance has two kinds of radial clearance and axial clearance. Radial clearance is divided into top clearance and side clearance; Axial clearance is also called axial momentum. Sliding bearing to have certain radial clearance, has the following purposes, first, the radial clearance was the least realize the connection between shaft and bearing conditions; Second, the radial clearance is the assurance of running accuracy control shaft. Of course, the smaller the radial clearance, axial movement of the higher precision, but can't reduce the radial clearance, the radial clearance is too small, not only difficult to form oil film, and may cause the tile burning accident holding shaft; Third, the radial clearance is the important condition of formation fluid lubrication, especially the dynamic pressure bearing, lubricating oil film formed mainly by wedge between shaft and bearing clearance. Radial clearance end clearance and side clearance, twice the value of the former is about the latter. This is the interval between two wedge formed between the journal and bearing oil film needed. Should have certain axial clearance, it refers to the axis of the dynamic clearance, divide again thrust clearance and expansion gap. Thrust clearance is for thrust bearing, is to allow some axial channeling move and leave a gap. Expansion gap is for bearings with radial load, in order to ensure the shaft free expansion and leave a gap. Machines in operation with the size of the gap in the precision, the smaller the radial clearance, precision is high, but the gap narrowed to a certain degree cannot guarantee the fluid lubrication. Clearance is too large, will have to beat in the rotation, also can't form stable oil film lubrication. So the radial clearance value cannot optional provisions, shall comply with the requirements of technical documents machine. Radial clearance of sliding bearing is very important, too big too small, are extremely harmful. Clearance is too large, the lubricating oil film bearing is difficult to form, ensure that the liquid lubricant, and will reduce the accuracy of machine running, especially can produce violent vibration and noise, serious can cause accidents; Gap is too small, lubricating oil film is difficult to form, also have high fever, serious when can happen accident. Sliding bearing axial clearance, be reserved in order to make the shaft in temperature changes have a free room for expansion. Generally speaking, in order to improve the running accuracy of shaft, the axial clearance is advisable. But not too small, axial clearance is too small, may be produced with a high temperature occurs while the bite phenomenon, even damage the bearings, accident.