TQOK series rolling mill bearings - Table List

Dec 02, 2021

The technical engineer of FV sorted out the old original Torringt* model and parameter table. If users are still using Torrington bearings and there is an urgent need for OEM to manufacture them, please contact FV's sales engineer.  The original Torringto* type TQOK bearing, with tapered bore for roll neck mounting, was developed for modern high speed rolling mill requirements. The TQOK bearingfeatures high capacity, compactness, and a mounting system that guarantees a positive inference fit on roll necks.  The tight-fitted twin cone mounting type TQOK provides extra mill rigidity and rolling accuracy by eliminating extraneous clearance. Rolling mill speeds in excess of 5,000 fpm are permissible.  Gauge uniformity is assured during the acceleration cycles of feeding the strip through the mill. The mill can be stopped and started without down time for screw adjustment.

The advantages of compactness of the TQOK design are numerous, but the chief advantage is the short lever arm required on the roll neck with reduction in neck bending stress. Conversely, more capacity can be obtained for any given space limit than with other bearing designs. These and other design features greatly improve rolling mill production and make the bearing ideal for back-up and work-roll mountings in 4-high and 2-high mills.

Type TQOK Design Features

Tapered Bore

The tapered bore design permits a positive interference fit between the bearing cones and roll neck. The tapered bore of 1" in 12" on diameter is referenced to the large end of the taper. The large end is mounted toward the mill roll thus achieving a stronger roll neck design.

Double Cone Design

Adapted from the proven TQO design, the double cone TQOK mounting achieves a positive interference fit. This provides maximum surface contact, prevents slippage and eliminates roll neck galling. No spacer is utilized between the matchground cones, minimizing bearing width and bringing the center of the bearing closer to the roll face for reduced neck bending stress.

Maximum Capacity

The tapered roller geometry of a cone on a cone, with the apex-on-center construction assures true rolling and minimum friction. The rollers are guided through the load zone by contact with the spherically ground integral guide rib. Only two center guide ribs are required with the TQOK construction, conserving bearing width and reducing the roll neck bending stress.

Combined Loads

A TQOK tapered roller bearing can sustain both radial and thrust loads, or any combination loading, without a separate thrust bearing package. Induced thrust resulting from radial loading is cancelled within the double cones and eliminates excessive loads on clamping and spacing members. Clamping must be included for the cups.

Minimum Friction

The coefficient of friction for starting and running is nearly the same. This minimizes roll slippage with resulting improvement of product quality, scrap reduction and longer roll life. The mill may be stopped and restarted without screwdown adjustment.

Bearing Assembly Interchangeability

The bearing bore is precision ground to a cone bore tolerance that is 1/4 that of commercial grade or class 4 tapered roller bearing. The cones are matchground to give continuity of the tapered bore accuracy and positive holding power for both cones. Such attention to high precision permits TQOK bearing assemblies to be interchanged on properly prepared roll necks.

Controlled Internal Clearance

An important TQOK design characteristic is its use of four single cups and three cup spacers. Running (diametral) clearance is controlled by spacer width. This eliminates regrinding of the mating cone faces when establishing the internal clearance at the mill.

Bearing Material

The use of vacuum degassed, ladle refined, low oxygen carburizing grade alloy steel on the TQOK rings and rollers results in a fine grain structure after heat treatment. Size stability is insured by using a sub-zero quench. These advantages are obtained:

• long fatigue life

• hard, wear-resistant rolling and raceway surfaces

• high impact resistance

• high fracture toughness

Lubrication Provisions

Circumferential lubrication grooves and radial holes are provided in the three cup spacers for grease, oil, or oil mist. Double cone bore lubrication grooves are modifications for the types TQO and TQSHL for improved rollneck lubrication.

Simplified Mounting

The Torrington TQOK design provides for unit assembly of the chock, bearing, seals and fillet spacer ring. This prevents bearing contamination and seal damage when the chock assembly is removed from the roll neck.

FV bearings can provide perfect OEM manufacturing.  Welcome users of steel mills all over the world to contact us.