The limit of the contact angle of bearing for idler is 120 degrees. When the bearing for idler is worn to this contact angle, the liquid lubrication will be destroyed. Therefore, the smaller the pressure condition of bearing for idler, the smaller the contact angle is. From the analysis of friction theory, when the contact angle is 60 degrees, the minimum friction torque, therefore suggested that the speed is higher than that of 500r/min bearing for idler, the contact angle of 60 degrees, the speed is lower than 500r/min bearing for idler, the contact angle of 90 degrees can be used, also can use 60 degrees.
Bearing for idler is surface contact, so it is necessary to maintain a certain oil film between the contact surfaces, so the following problems should be paid attention to in the design.
1, it is necessary to make the oil film enter the friction surface smoothly.
2, the oil should enter the bearing for idler from the non bearing area.
3, do not open the full ring oil tank in the middle of bearing for idler.
4, such as oil tiles, seam opening oil ditch.
5, it is necessary to make the oil ring fully reliable.
6, the filling hole not blocked.
7, do not form an oil non flow zone.
8, prevent the sharp edge and angle of cutting oil film.