Bearing configuration and the basic pattern of the supporting structure ( Illustrated)

Configuration in the form of bearing, bearing configuration form is two symmetric arrangement, the centripetal bearing can withstand pure axial radial load, also can bear radial load and axial load combination of shaft, bearing configuration forms are mainly divided into three kinds, respectively is: back to back, face to face and series. 1, back to back load center outside the bearing axis. Characteristics and applications: pivot between span is larger, the cantilever length is smaller, so the cantilever end larger rigidity, when the axial thermal elongation, bearing clearance, bearing not jammed. For back to back arrangement of tapered roller bearing structure, its clearance changes are as follows: ( 1) Outer raceway cone tip overlap ( Figure a) Axial expansion as well as the radial expansion, basic balance, preset clearance remain the same, 2) Outer raceway cone tip cross ( Figure b) , radial expansion quantity is greater than the axial expansion amount, smaller clearance ( 3) Outer raceway cone tip do not intersect, C) , the axial expansion quantity is greater than the radial expansion, increase work clearance. Installation, if the preload when axial thermal elongation, preloaded quantity will reduce 2, face to face load center under the center line of the bearing. Characteristic and application: simple structure, convenient installation, when the axial thermal elongation, bearing clearance is reduced, easy to cause bearing jammed, so it is important to pay special attention to the bearing clearance adjustment. 3, series: load center in the same side bearing the centerline. Characteristics and applications: suitable for large axial load, multiple bearing is held jointly. 2, 1, both ends fixed bearing structure bearing: refers to the two bearing end limit the axial displacement in the direction of a bearing. Characteristic and application: 1) Under pure radial load and axial load of smaller shaft joint load. Generally USES the centripetal fixed supported on both ends of the type of bearing, and in one of the supported end, the bearing outer ring and shell adopts loose fit between hole, leave appropriate gap between outer ring and end cover, at the same time to adapt to the axial thermal elongation. 2) Under radial and axial load combination axle. Use type angular contact bearings more face to face or back to back up both ends fixed bearing arrangement. This support can be adjusted by a bearing ring axial positioning, the bearing clearance or preload required quantity, so the rotation and is especially suitable for high precision machinery. 2 swimming, fixed support: refers to the axis of a bearing end bearing and the shaft and shell hole position is relatively fixed, in order to realize the axial positioning, on the other side bearing and the shaft or housing can move relatively. Characteristics and applications: high precision, strong adaptability to various working conditions, so in all sorts of machine tool spindle, high working temperature of the worm shaft and large span long axis bearing is widely used in the shaft axial positioning accuracy depends on the fixed end bearing axial clearance. So with a diagonal contact ball bearing or fixed end of tapered roller bearing axial positioning accuracy, such as with a set of deep groove ball bearing high end bearing usually choose: ( 1) The radial load and some axial load - — Deep groove ball bearings; ( 2) The radial load and two-way axial load - — Diagonal contact ball bearing or tapered roller bearing; ( 3) By the radial load and axial load respectively - — The centripetal bearing and thrust bearing combination, or a different type of angular contact bearings portfolio. 3, swimming on both ends of the bearing: refers to the two supporting the bearing to the shaft is not accurate axial positioning. Characteristics and applications: figure a, in the work, even in a bad state of fever, bearing will not be stuck; Figure b, used in the location of axis has been restricted by other parts, such as the herringbone gear bearing; Figure c almost all don't need to adjust the bearing, both for swimming. Angular contact ball bearing is unfavorable for travelling support.