Thrust Tapered Roller Bearing

Configuration of bolt-fixed bearings for rolling mills:

Thrust tapered roller bearings are one of the structural types of thrust roller bearings. They are mainly composed of shaft rings, housing rings, tapered rollers and cages, and are divided into single-direction and double-direction types. The large end of the tapered rollers is spherical, and the rolling elements and raceway generatrix intersect at the axis to achieve pure rolling motion. The separate structure is easy to install. This bearing can withstand heavy axial loads, is not sensitive to impact loads and has high rigidity. It is often used in bolt-fixed configurations for rolling mills, crane hooks and oil drilling rig swivels. The design adopts logarithmic contact generatrix to optimize stress distribution. The limiting speed is higher than that of thrust cylindrical roller bearings. The external dimensions are mostly non-standard. The current standard that can be referenced is GB/T 4663-1994 [1]. The product includes a full complement roller structure, which is fixed by bolts to form a special configuration. The tolerance is in accordance with GB/T307.4 standard. WJZW and other manufacturers produce double-direction tapered roller bearings that can be used in conjunction with multi-row cylindrical roller bearings. The spherical raceway design compensates for angular displacement of the roll journal.

Features: This type of bearing is used in bolt-fixed bearing configurations for rolling mills. WJZW thrust tapered roller bearings have logarithmic contact profiles between the raceways and rollers, ensuring optimal stress distribution within the bearing and thus extending its lifespan.

Structure: Because the rolling elements in thrust tapered roller bearings are tapered rollers, structurally, the rolling generatrices and the raceway generatrices of the washers all converge at a single point on the bearing’s axis. Therefore, the rolling surfaces can achieve pure rolling motion, resulting in a higher limiting speed than thrust cylindrical roller bearings.

Due to the limited production volume of thrust tapered roller bearings, most of the models produced by various manufacturers are non-standard in size. Standard size series are produced in smaller quantities, therefore, there is currently no national standard for the dimensions of this type of bearing. The available standard is GB/T 4663-1994. [1]

Design and Installation: The WJZW thrust tapered roller bearing with cage is a separable design, allowing for easy separate installation of the two washers, rollers, and cage thrust assembly. The full roll bolt-set bearing is secured together by special positioning components, and the washers have threaded holes for lifting bolts to simplify operation.

The following describes:

I. Small One-Way Thrust Tapered Roller Bearings are almost exclusively used in steering knuckle bearing configurations in commercial vehicles. These bearings have full rolls and are secured with a thin steel cover. Most of these bearings are fitted with wear-resistant, oil-resistant nitrile rubber (NBR) friction seals. These bearings are lubricated for life with multi-purpose grease and require no maintenance. Various designs are available, differing only in the design of the bearing housing race and bearing cover.

Larger one-way bearing washers are manufactured differently; some bearing washers are identical in size to the bearing housing race, while others have different designs.

Washers with identical sizes to the bearing housing race all have a tapered raceway and a locating flange. This type of bearing is often used in applications requiring high axial loads, such as on drilling equipment turntables or crane hooks. This bearing features a cage and is positioned by two washers.

Other bearing designs have shaft washers with tapered raceways and locating flanges, while the bearing housing races are flat. Therefore, this design can tolerate slight eccentricity of the shaft relative to the housing bore without adversely affecting bearing performance. Except for a few sizes with full-length rollers, these bearings have a cage concentric with the rollers.

II. Double-direction thrust tapered roller bearings are primarily used in rolling mills alongside multi-row cylindrical roller bearings. This type of bearing with flat shaft washers is more popular because it can tolerate slight eccentricity of the shaft relative to the housing bore, as well as slight variations in radial internal clearance used in radial bearings. A spacer sleeve is positioned between the two bearing housing races. The spacer sleeve is sized to allow the roll bearing housing screws to be fully tightened, and the bearing does not require special springs for adjustment.

Double-direction tapered roller thrust bearing with tapered raceways on both the shaft and bearing housing races. Generally, this type of thrust tapered roller bearing has a higher axial load capacity than bearings with flat bearing housings and can provide some radial positioning of the shaft. If the load capacity of this type of bearing is insufficient considering the required service life, a double-row tapered roller bearing with a large contact angle designed by TDIS can be used; see “Double-row Tapered Roller Bearings”.

Since double-direction thrust tapered roller bearings are typically installed with a loose fit on the roll journal and roll bearing housing, most bearing housings have one or two locating grooves. This allows the use of keys or similar methods embedded in the locating grooves to prevent the housing from rotating on the shaft.

III. This type of thrust tapered roller bearing must be able to withstand extremely high axial loads and allow angular displacement of the threaded shaft relative to the support. Therefore, this type of bearing is usually full roll, with large-diameter and extra-long rollers. To withstand misalignment of the roll bearing housing without adversely affecting bearing performance, this type of bearing has a spherical housing ring. This housing ring can be either the shaft housing ring or the bearing housing ring.

In bearings with a spherical bearing housing and a corresponding concave spherical threaded shaft or pressure baffle, a necessary misalignment occurs on the roller assembly between the spherical bearing housing and the corresponding pressure baffle. WJZW also supplies the aforementioned pressure baffles.

When the bearing housing ring is spherical, the misalignment is borne by the roller assembly between the bearing housing ring and the pressure baffle. The pressure baffle for this type of bearing is usually supplied with the bearing.

WJZW manufactures a variety of screw-set bearing designs; these bearings are custom-made to meet the specific requirements of particular applications.