Structure of Single row Tapered Roller Bearing

This bearing can take radial load and   one direction axial load. Axial component force will come when bearing take   radial load, so we often need another bearing to balance this situation.    The capacity to take axial load decided by αangle, the larger α, the bigger axial load capacity. When radial load imposed to   single row TRB, internal axial load will come into being while the load   transferred from one raceway to another raceway. This must be taken into   account when calculating the equivalent load for a bearing configuration   consisting of two single bearings or a paired bearing. The standard single   row tapered roller bearing allows angular deviation of inner ring against   outer ring is limited to a few arc minute. A bearing with a modified contact   between roller and raceway allows inclination about 2 'to 4'. The internal   clearance of single row tapered roller bearing can only be obtained after   installation, which is determined by the adjustment of one bearing to another   bearing in the opposite direction. 

Dimension

Metric bearing:   single row TRB follows GB/T273.1-2003/ISO 355-1977

Imperial bearing:   dimension follows AFBMA 19-1974（ANSIB3.19-1975）

Clearance

The internal   clearance of single row tapered roller bearing can only be obtained after   installation, which is determined by the adjustment of one bearing to another   bearing in the opposite direction.

Permitted   misalignment

The standard   single row tapered roller bearing allows angular deviation of inner ring   against outer ring is limited to a few arc minute. A bearing with a modified   contact between roller and raceway allows inclination about 2 'to 4'.

Minimum load

In order to   ensure normal rotation, they must always take certain minimum load,   especially run at high speed or great acceleration or rapid change load   direction. In these cases, the inertia force between roller and cage plus the   friction from lubricant may play a harmful role in the rolling of bearing   configuration, and may cause destructive sliding between the roller and the   raceway.

The necessary   minimum radial load for standard tapered roller bearings can be estimated   according to the following formula.

Frm = 0,02 C

Frm = minimum   radial load，kN
  C = rated static load，kN（see   bearing specification）

A higher minimum   load may be required at low temperature start-up or when the lubricant   viscosity is high. The weight of the component supported by the bearing, plus   the external force, generally exceeds the necessary minimum load. If this is   not the case, the single row tapered roller bearing must bear additional   radial load, which can be obtained by applying preload.

Equivalent   dynamic load

For tapered   roller bearing  takes dynamic load
  When Fa/Fr ≤ e 时， P = Fr
  When Fa/Fr > e 时， P = 0,4 Fr + YFa
  Coefficient e and Y can be found from bearing specification. 

Equivalent static   load

For taper bearing   takes static load, 
  P0 = 0,5Fr + Y0Fa
  When P0 < Fr，should use P0 = Fr。Coefficient   Y0 can be found from bearing specification. 

Confirm axial   load

When a radial   load is applied to a single row tapered roller bearing, the load is   transmitted from one raceway to another, forming an angle with the bearing   axis, resulting in internal axial force in the bearing. This must be taken   into account when calculating the equivalent bearing load for paired bearing   configuration consisting of two single bearings and / or a series   configuration.

· Paired single tapered roller bearing

In a bearing   configuration in which the load capacity of a single tapered roller bearing   is not enough or the shaft must have certain positive or negative axial   clearance in both directions for axial positioning, the bearings listed in   the section of "single row tapered roller bearings" can be supplied   as matched bearing pairs, and the configuration methods are as follows:

1、Face to face

In the   face-to-face paired bearing alignment, a spacer is placed between two outer   rings, so manufacturing is relatively easy. In face-to-face configuration,   the load line converges on the axis of the bearing. The axial load acting on   two directions can be borne by one bearing in each direction. 

2、Back to back

In the   back-to-back configuration, a spacer is placed between the two inner rings   and between the two outer rings. The manufacturing process for this   configuration is more complex than that required for face-to-face bearing   sets. In the back-to-back configuration, the load line is separated from the   axis of the bearing, so the rigidity provided is relatively large, and it can   also bear the tilting moment. The axial load acting on two directions can be   borne by one bearing in each direction.