SKF C 2214 KTN9 CARB Toroidal Roller Bearing, 70 mm

A CARB bearing that handles misalignment and axial shaft growth in one bearing

The SKF C 2214 KTN9 is a CARB toroidal roller bearing with a 1:12 tapered bore, a 70 mm nominal bore, 125 mm outside diameter and 31 mm width. CARB bearings have a single row of long, slightly barrel-shaped rollers on torus-shaped raceways. They are non-locating and accommodate radial load only, but unlike a spherical roller bearing they also let the shaft move axially inside the bearing, and unlike a cylindrical roller bearing they tolerate angular misalignment.

That combination is why CARB bearings are fitted at the free end of a shaft, in place of a non-locating spherical roller bearing. With a CARB in that position there are no internally induced axial forces, so the other bearing carries less load, runs cooler and the lubricant lasts longer, according to the SKF brochure. The bearing has the same boundary dimensions as the corresponding spherical roller bearing size, so it can replace one without changing the housing.

Technical specifications

Designation and sleeve mounting

In C 2214 KTN9, the letter C identifies the CARB type, 22 is the dimension series and 14 gives the 70 mm bore. K is the 1:12 tapered bore, and the SKF brochure lists a glass fibre reinforced polyamide cage, window-type and roller centred, under the suffix TN; the product page shows TN9. The product tables in the brochure list this bearing with adapter sleeve H 314 E or withdrawal sleeve AH 314 G.

Permissible axial displacement is printed as s1 of up to 9.6 mm, and the misalignment factor k1 of 0.1 and the internal clearance factor k2 of 0.13 are used in the SKF bearing selection method. A full complement version, C 2214 V, has a higher dynamic rating of 212 kN but a limiting speed of only 2 400 r/min, so the caged KTN9 is the choice for higher speeds.

Mounting notes and what to confirm

The minimum housing shoulder diameter is 107 mm and the maximum is 116 mm. Ca is printed as at least 0.4 mm, and SKF states that a negative value would be theoretical. Because a CARB bearing needs freedom to move, the shaft must not be fixed axially at the CARB end, and the mounting dimensions must allow the axial displacement shown in the table.

Before ordering, confirm bore type, clearance class (the SKF listings show C3 and C4 versions of some CARB sizes), the sleeve you will use and the lubricant. See Electric Motors for other bearings on this site, and the SKF TKBA 40 belt alignment tool for checking drive alignment after the bearing is fitted.

Documents and quotation

The attached SKF CARB toroidal roller bearings brochure describes the design, cages, sealed variants and product tables, including this bearing with its sleeves. The values in the table come from the SKF product page for C 2214 KTN9. Seven Star LLC, an independent supplier in Muscat, will quote on the designation and quantity.