Gearbox

The most typical type of bearing, these are used in a wide range of fields. They include grease-enclosed sealed and shield bearings for ease of use.

Other types include bearings with a locating snap-ring to facilitate positioning when mounting the outer ring, expansion compensating bearings that absorb variations in bearing fitting surface dimensions due to housing temperature, and TAB bearings that are resistant to contamination in lubricating oil.

In these ball bearings, the direct line that connects the inner ring, balls, and outer ring has a given angle in the radial direction (the contact angle).

This angle is generally designed with three kinds of contact angle.

These bearings can bear axial loads, but because of the contact angle cannot be used singly and must be used in pairs or combinations.

These are angular contact ball bearings with the inner ring divided into two. When the outer ring and inner ring are pushed in the radial direction, the balls make contact with the inner ring and outer ring at four points. One bearing is able to bear an axial load from both directions, and can be used in a two-point contact state under a general pure axial load or under a composite load with large axial load.

These have a structure that arranges single row angular contact ball bearings as back-to-back duplex (DB) bearings, uniting both the inner ring and outer ring.

They are able to bear radial loads and bi-directional axial loads, with ability to bear moment loads as well.

Both seal-type and shield-type bearings are available, with rated loads differing from open types.

These ball bearings have a spherical surface with a point at which the center of the outer ring track surface matches the center of the bearing, and the inner ring has a two-row track groove.

The balls, cage, and inner ring are able to tilt freely to a degree with respect to the outer ring, and rotate. As such, misalignment caused by processing errors in the axis or housing, or by mounting of the bearing, is automatically corrected.

However, as the capacity to bear axial loads is not so great, the bearings are not suited to locations with large axial loads.

The bearings are often used in applications such as drive shafts, as mounting and un-mounting are easy if an adapter is used for bearings with tapered bore calibers.

These bearings have balls enclosed in a cage between the shaft raceway washer that corresponds to the inner ring, and the housing raceway washer that corresponds to the outer ring. They can bear only single-direction axial loads.

These use rollers as the rolling elements and have a high load capacity. The rollers are guided by the ribs of the inner or outer ring. The inner and outer rings can be separated to facilitate assembly, and both can be fitted tightly.

On types with no ribs, either the inner or the outer ring can move freely in the axial direction, making cylindrical roller bearings ideal for use in free side bearings that absorb shaft expansion.

On types with ribs, the bearing can bear a slight axial load between the roller end surfaces and the ribs. Cylindrical roller bearings include the HT type that modifies the shape of roller end surfaces and ribs to increase axial load capacity, and the E type that has a special internal design to increase radial load capacity. The E type is standard for small-diameter sizes.

These are used in the printing cylinders of printing machinery, rolling mill rolls, and the main shafts of machine tools, where thin-walled bearings are required. In the main shafts of machine tools, the radial inner clearance is adjusted by pushing the tapered shaft into the inner ring of the tapered bore.

These bearings use small needle rollers, 6mm or less in diameter with a width 3 to 10 times diameter, as rolling elements. As such, they feature low cross-section height, high load capacity relative to dimensions, and high rigidity due to the number of elements, and are suited to wobbling or pivoting motion.

Tapered roller bearings are designed so the inner and outer ring raceway and the apex of the tapered rollers intersect at one point on the bearing centerline. For this reason, the rollers are pushed against the inner ring rib and roll guided by the rib, receiving the loads from the inner ring raceway surface and the outer ring raceway surface as a combined load on the raceway surface.

Component force is produced in the axial direction when a radial load is applied, so the bearings must be used in pairs. The inner ring with rollers and outer ring separate, facilitating mounting with clearance or preload. However, assembled clearance is hard to manage and calls for attention. Tapered roller bearings are capable of supporting large loads, both axial and radial.

These have outward-facing types (for double-row outer ring use) and inward-facing types (for double-row inner ring use). As the inner clearance is adjusted to a set value, the bearings must be used in combination with components of the same product number, as marked.

In addition to duplex bearings that combine a pair of single row tapered roller bearings, there are also four-row tapered roller bearings composed of two double-row inner rings, one double-row outer ring, and two single-row outer rings. Four-row tapered outer bearings are used in high-load applications such as rolling mill roll necks.

These bearings have an outer ring with a spherical track surface, and an inner ring that encloses two rows of barrel-shaped rolling elements.

Various types exist that differ by internal design, including bearings with a tapered bore inner caliber. The bearings are easily mounted on the shaft with an adapter or un-mounting sleeve, and are used in many industrial machines for their high load capacity. Potential troubles include one row bearing no load when axial load is large, calling for attention to usage conditions.

These bearings use cylindrical rollers and have single-row, double-row, and three-row types for larger load capacities.

They support axial loads only, are suited to high loads, and have high axial rigidity.

These include bearings using machined parts and bearings using pressed steel plate parts for the raceway washer, with the latter type having the smallest cross-sectional height and high load-bearing capacity.

These bearings have a self-aligning nature that uses barrel-shaped rolling elements, with a spherical surface on which the raceway surface of the housing raceway washer (outer ring) is centered on the guide sleeve. They can bear high axial loads.

As there are many sliding surfaces such as the roller end surfaces and the cage, oil lubrication must be used even in low-speed operation.

Components used to transmit rotational motion so both axes rotate at a constant velocity regardless of the angle between the input and output shaft, and torque is transmitted smoothly (bearings used here).