Single-row tapered roller bearing

Single-row tapered roller bearing

In tapered roller bearings, the three lines elongated from the axis of the rollers and the two generatrices of the cone and cup raceways are designed to interact at one point on the bearing axis, so as to enable the rollers to make a pure rolling motion between the grooves.

Tapered roller bearings are therefore particularly suitable to take combined loads consisting of high radial loads and one direction axial loads. The larger the contact angle is, the more the axial load carrying capacity is. Even if a single row tapered roller bearing is used to carry a radial load only, an axial component must be induced from the bearing which is generally counteracted by the second one in an opposed pair.

Structure features

HRB tapered roller bearings are divided into three row types: single row, double row and four row.

HRB tapered roller bearings have the modification of main parameters, in this case the number and effective length of the rollers are increased and the line contact between the tapered rollers and raceways is modified to yield a uniform stress distribution and help on lubricant film good at roller motion conditions. And hence the load carrying capacity and life of the current bearings would be higher than that of the earlier products as the same type and size.

HRB double row tapered roller bearings can carry the combined loads which are composed of radial loads and axial loads in double directions. Between the two cones there is a spacer which can adjust the axial clearance of these bearings by way of changing the spacer thickness to moderate the stress distribution. These bearings are consequently suitable for low and medium speed applications.

Dimensions

HRB single row tapered roller bearings both in metric and inch dimensions are utilized widely. The boundary dimensions of the metric bearings conform to ISO-355-1977, which those of the bearings with prefix F-J conform to AFBMA standard 19.1. The boundary dimensions of the inch bearings listed comply with AFBMA standard 19 (1974).

Angular misalignment

HRB single row tapered roller bearings are admitted to have the maximum error angular alignment of 3′of radian, in this case the concentricity of the bearing bore to the housing bore must be excellent by assembling. If not, bearing life would be shortened.

Tolerances

For tapered roller bearings, all the outer rings or the inner rings with cage and roller assembly which must have the same bearing designation are fully interchangeable. After replaced, the bearing width will have a required tolerance.

Metric bearing

HRB basic tapered roller bearings in metric dimensions have normal class tolerances. The products are also supplied with P6X, P6, P5, P4 and P2 class tolerances, in which the bearings higher than P5 class are mainly used for machine tool spindles. Their chamfer tolerances comply with ISO-582-1979. F-J series bearings are made to P6X class tolerance, with chamfer tolerance in conformity to the inch bearing chamfer tolerance.

Inch bearings

HRB basic tapered roller bearings in inch dimensions are produced to normal class tolerances. On customer’s demand, the products with CL2, CL3, CL0 and CL00 class tolerances are provided as well.

Internal clearance

For single row tapered roller bearings, the internal clearance can only be determined when the mounting is made and the adjustment of the bearing against a second one is finished. The radial internal clearance in HRB double row tapered roller bearings is given in the following table.

Estimated values for axial internal clearance converse from values for radial internal clearance.

△a=△r × 1.5/e or △a=△r × cota
Where
△a: axial internal clearance
△r: radial internal clearance
e: factor (see the bearing tables)
α: contact angle

Cages

HRB tapered roller bearings have pressed steel cages of good quality, but in which the large size bearings are often mated with machined brass cages. For some specific applications, moulded nylon 66 cages are adopted as well.

HRB Metric Single row tapered roller bearings catalog