NACHI 0-7 Inch Series O Thrust Ball Bearing 22.225x42.069x15.875 mm

The NACHI 0-7 is a single-direction thrust ball bearing from the inch series O (catalogue designation O-7) with a flat back-face housing washer. It measures 22.225 x 42.069 x 15.875 mm (bore x outer diameter x height) and carries a basic dynamic axial load rating of 21,900 N and a basic static axial load rating of 37,500 N. Limiting speed is 3,800 rpm on grease and 5,800 rpm on oil, and the mass is 0.1 kg.

A thrust ball bearing is a shaft washer, a housing washer and a ball and cage assembly running in a groove in each washer. It carries axial load in one direction only and cannot carry any radial load, and it is not suited to high speed running.

Where this product is used

• Vertical shaft pumps, gearboxes and drives
• Screw jacks, lifting screws and clamps
• Turntables, rotary tables and swivel joints
• Machine tool tailstocks and spindle thrust positions
• Low speed, axial load positions in general machinery

Features

• Single-direction thrust ball bearing: carries axial load in one direction only, with a ball and cage assembly running in a groove in each of the shaft washer and the housing washer
• Carries axial load only and cannot carry any radial load, so a separate bearing has to locate the shaft radially
• Flat back-face housing washer for a flat housing shoulder; it does not permit any angular misalignment between shaft and housing
• Not suited to high speed running, because centrifugal force throws the lubricant out; limiting speeds for grease and oil are listed
• Basic dynamic axial load rating 21.9 kN and static 37.5 kN; limiting speed 3,800 rpm on grease, 5,800 rpm on oil

Key specifications

Selecting the right option

Ca is the basic dynamic axial load rating, used for life calculations on a rotating bearing, and Coa is the static rating. Check the axial load against both and apply a suitable safety factor.

This is a single-direction bearing. Where axial load acts in both directions, a double-direction thrust ball bearing is needed.

Fitting and use

Axial loads only. The bearing cannot carry any radial load, so the shaft needs a separate bearing to locate it radially. The flat back-face housing washer needs a flat, square seat and does not permit any angular misalignment between shaft and housing.

On a horizontal shaft a minimum axial load must be applied so the balls roll rather than skid. The minimum axial load Fa min (N) is the larger of K x n² and Coa / 1000, where K is the minimum axial factor for the bearing (x 10⁻⁶) and n is the speed in rpm. On a vertical shaft the weight of the shaft often exceeds this, and an opposing external axial load reduces the load that acts on the bearing. For this size Coa / 1000 is 37.5 N and K is 7.76 x 10⁻⁶.

The shaft washer is smaller in outside diameter than the housing washer (d1 against D in the table), so no clearance step is needed in the housing bore for the shaft washer. Fit the shaft washer (the one with the smaller bore) to the shaft and the housing washer in the housing.

Related products

More from the NACHI thrust ball range: NACHI inch series O thrust ball bearings, 15.875 to 57.15 mm bore (10 sizes), NACHI single-direction thrust ball bearings, 511 / 512 / 513 series, 10 to 120 mm bore (46 sizes) and NACHI 0-10 thrust ball bearing, 31.75 x 53.181 x 18.256 mm. For heavier axial loads, or where some radial load or shaft misalignment has to be accommodated, see the NACHI spherical roller thrust bearings (60 to 140 mm bore).