The plain bearing is a famous thrust bearing consisting of a flat cage assembly with a needle, cylindrical roller or steel ball and a flat washer.The plane bearing is divided into the plane bearing with needle and the plane bearing with ball.
The role of aircraft bearings
Needle and cylindrical rollers are supported and guided by a flat cage.
When used with different series of DF flat bearing washers, many different combinations are available for bearing configurations.
Advantages of flat bearings
Because high precision cylindrical roller (needle roller) is used to increase the contact length, the bearing can achieve high bearing capacity and high stiffness in a very small space.
Another advantage is that if the surface of adjacent parts is suitable for the raceway surface, the gasket can be eliminated and the design is compact.DF flat needle roller bearing and cylindrical roller bearing cylindrical roller surface are modified surface, can reduce the edge stress, improve the service life.
Plane bearing main components
Plain roller and cage assembly are the main components of plain roller bearings.The needle is held and guided by the radiation bag.The cage section has a specific shape and consists of hardened steel strips.The small size cage is made of industrial plastic.
High precision needle diameter grouping tolerance of 0.002mm to ensure uniform load distribution.The flat needle and cage assembly is guided by a shaft, allowing for relatively low circumferential speeds even at high speeds.
If the surfaces of adjacent parts are designed to eliminate the raceway surfaces of the gaskets, special space-saving support can be obtained.If this solution cannot be implemented, the use of thin-walled steel as a series of gaskets can also make the design compact under fully supported conditions.
Flat bearing product series
The bearing is composed of a flat cylindrical roller and cage assembly, bearing housing positioning ring GS and shaft positioning WS.The 893 series, 874 series and 894 series cylindrical roller bearings can bear high loads.
The cage can be made of high quality steel plate, industrial plastic, light metal and brass.
Principle of flat bearing installation
Plane bearing mainly bears axial load in assembly and is widely used.Although the plane bearing installation operation is relatively simple, but the actual maintenance often still have errors, that is, the bearing tight ring and loose ring installation position is not correct, resulting in the bearing lost function, journal wear fast.As shown in the figure, the tight ring is installed on the end face of the stationary part, that is, assembly error.The inner ring of the compact ring is matched with the transition of the journal. When the shaft rotates, it drives the compact ring and causes friction with the end face of the fixed part.When the axial force is (Fa), the friction torque is greater than the inside diameter torque.This results in forced rotation of the fastening ring and the assembly surface of the shaft, exacerbating journal wear.
The following points should be noted when installing flat bearings:
(1) distinguish the compact ring from the loose ring of the bearing (the difference of the bore diameter is from o. 1 to o. 3mm, as judged by the diameter of the bearing).
(2) distinguish the rest of the machine (that is, the parts that do not move, mainly refers to the assembly).
(3) in any case, the loose ring of the bearing shall be fixed on the end face of the stationary part.