taper roller bearings
taper roller bearings
Author :Admin | Publish Date:2012-08-03 13:29:18
"Taper roller bearings" are bearings that can take large axial forces (i.e., they are good thrust bearings) as well as being able to sustain large radial forces.Tapered roller bearings are separable and have the following components: outer ring, inner ring, and roller assembly (containing the rollers and a cage). The non-separable inner ring and roller assembly is called the cone, and the outer ring is called the cup. Internal clearance is established during mounting by the axial position of the cone relative to the cup.
Tapered roller bearings were a breakthrough at the end of the 19th century because bearings used in wheel axles had not changed much since ancient times. They relied on bearings enclosed in a case that held lubricants. These were called journal bearings and depended on lubricants to function. Without proper lubrication[2], these bearings would fail due to excessive heat caused by friction. Timken was able to significantly reduce the friction on his bearings by using a cup and cone design incorporating tapered bearings which actually rolled, which reduced the load placed on the bearings by distributing the weight and load evenly across the cups, cones, and bearings.
In many applications tapered roller bearings are used in back-to-back pairs so that axial forces can be supported equally in either direction.Pairs of tapered roller bearings are used in car and vehicle wheel bearings where they must cope simultaneously with large vertical (radial) and horizontal (axial) forces. Applications for tapered roller bearings are commonly used for moderate speed, heavy duty applications where durability is required. Common real world applications are in agriculture, construction and mining equipment, axle systems, gear box, engine motors and reducers.
Tapered roller bearings have tapered inner and outer ring raceways between which tapered rollers are arranged. The projection lines of all the tapered surfaces meet at a common point on the bearing axis. Their design makes tapered roller bearings particularly suitable for the accommodation of combined (radial and axial) loads. The axial load carrying capacity of the bearings is largely determined by the contact angle(fig); the larger, the higher the axial load carrying capacity (fig). An indication of the angle size is given by the calculation factor e; the larger the value of e, the larger the contact angle and the greater the suitability of the bearing for carrying axial loads.
Tapered roller bearings are generally separable, i.e. the cone, consisting of the inner ring with roller and cage assembly, can be mounted separately from the cup (outer ring).
SKF tapered roller bearings have the logarithmic contact profile that provides optimum stress distribution over the roller/raceway contacts. The special design of the sliding surfaces of the guide flange and large roller ends considerably promote lubricant film formation in the roller end/flange contacts. The resulting benefits include increased operational reliability and reduced sensitivity to misalignment.
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