30304 Bearing

Tapered roller bearings are separable, consisting of the inner ring with roller and cage assembly, can be mounted separately from the cup (outer ring). The modified contact line between rollers and raceway contacts reduce the stress concentration. Tapered roller bearings take large radial loads and axial loads.

They only have axial loads for carrying capacity in one direction; therefore, another one logarithmic tapered roller bearings should be mounted to support the opposite axial loads. The most consumed tapered roller bearings are single-row tapered roller bearings. In recent years, small-sized double row tapered roller bearings has also been used in the cars front wheel hubs. And four-row tapered roller bearings are adopted in large-size cold and hot rolling mills as well as other heavy machinery.

Single-row tapered roller bearings have an outer ring, and an inner ring assembly consisting of an inner ring and a group of tapered rollers embraced by the basket-shaped cage. The outer ring(cup) is separable from the inner ring assembly. According to standardized dimensions of tapered roller bearing specified by ISO, the outer ring or inner ring assembly of any tapered roller bearing with standardized dimension could make international exchange with the outer ring or inner ring assembly of the same series. That is to say, besides external dimensions, tolerances shall be in accordance with the provisions of the ISO492 (GB307), the cone angle of the inner ring assembly and cone diameter of assembly must also comply with the relevant provisions of the exchange.

Generally, when cone angle of outer ring raceway of single-row tapered roller bearings is from 10°to 19°, they could withstand axial loads and radial loads spontaneously. The big the cone angle, the larger the axial loads carrying capacity. Large-sized tapered roller bearings with post code plus B, the cone angle is from 25° to 29°, they carry large axial loads. In addition, single-row tapered roller bearings have the ability to adjust clearance during installation. The inner ring (or outer ring) of double row tapered roller bearings is a whole part. The small end face between two inner rings (or outer rings) is similar, there is one middle spacer ring between two inner rings, and the clearance is adjusted by thickness of spacer ring, which can also be used for adjusting the pre-interference of double row tapered roller bearings.

1. Single-row Tapered Roller Bearings (30000 series)

Note: Carry radial loads based joint loads of radial loads and axial joint loads. Bearings with big cone angle withstand radial loads based radial loads and axial joint loads, generating added axial force under radial loads. Therefore, they are arranged in pairs to take radial loads. The external axial force shall be larger than additional axial force for exclusive use. 313 series bearings has big contact angle (from 27° to 30°), for taking large axial loads. Contact angle of other series of bearings is from 10° to 18°.

2. Double Row Tapered Roller Bearings (35000 series)

Note: This type of bearings has an outer ring and two inner rings, between which spacer ring is arranged. The clearance is adjusted by changing thickness of spacer ring. The bearings are capable of taking both radial and axial loads in two directions. The axial deflection in two directions of shaft and housing could be limited among bearing clearance range.

3. Four Row Tapered Roller Bearings (330000 series)

Note: This type of bearings has spacer rings for adjusting clearance in both inner rings and outer rings. Similar to the performance of double row tapered roller bearings, they have large load carrying capability and low limit speed. They are mainly used in heavy machinery, such as rolling mills etc.