Page 40 - NSK_CAT_E1102m_A7-141

FITS AND INTERNAL CLEARANCES

Table 9.2 Fits of Radial Bearings with Shafts Table 9.4 Fits of Radial Bearings with Housings

Shaft Diameter (mm) Load Conditions Examples Tolerances for Axial Displacement Remarks
Housing Bores of Outer Ring
Load Conditions Examples Cylindrical Roller Spherical Roller Tolerance Remarks Automotive Wheel Hubs
Ball Brgs Brgs, Tapered Brgs of Shaft Heavy Loads on Bearing in (Roller Bearings) P7
Roller Brgs Thin-Walled Housing or Crane Travelling Wheels N7
Heavy Shock Loads Automotive Wheel Hubs M7
Radial Bearings with Cylindrical Bores Rotating Normal or Heavy (Ball Bearings)
Outer Ring Loads Vibrating Screens K7
Easy axial Wheels on Use g5 and h5 where Impossible —
displacement of accuracy is required. Load Light or Variable Conveyor Rollers JS7 (J7)
Rotating inner ring on shaft Stationary g6 In case of large Loads Rope Sheaves H7
Outer bearings, f6 can be Tension Pulleys H8
desirable. Axles All Shaft Diameters h6 used to allow easy axial Solid G7
Ring Load movement. Housings Traction Motors
Easy axial Tension Pulleys js5 JS6 (J6)
displacement of js6(j6) Heavy Shock Loads
inner ring on shaft K6
unnecessary Rope Sheaves k6
m6 M6 or N6
Light Loads Electrical Home <18 — — Direction of Normal or Heavy Pumps Generally If axial displacement of
Appliances Pumps, 18 to 100 <40 — Load Loads Crankshaft Main H6 Impossible the outer ring is not
or Variable Blowers, Transport 100 to 200 40 to 140 — Bearings required.
Vehicles, Precision 140 to 200 — Indeterminate Medium and Large Possible
Loads Machinery, — Motors(1) Axial displacement of
(<0.06Cr(1)) Machine Tools Normal or Light outer ring is
Loads General Bearing necessary.
Applications,
<18 — — js5 or js6 (j5 or j6) Railway Axleboxes
18 to 100 <40 <40
General Bearing 100 to 140 40 to 100 40 to 65 k5 or k6 Solid or Loads of All kinds Plummer Blocks
140 to 200 100 to 140 65 to 100 m5 or m6 Split
Applications, 200 to 280 140 to 200 100 to 140 k6 and m6 can be Paper Dryers
200 to 400 140 to 280 m6 used for single-row Housings
Rotating Inner Medium and — 280 to 500 n6 tapered roller Normal or Light Grinding Spindle Rear Easily —
Large Motors(3), — — over 500 p6 bearings and single- Loads Ball Bearings possible
Ring Load or Turbines, Pumps, — — r6 row angular contact High Speed Centrifugal
Direction of Normal Loads Engine Main ball bearings Rotating High Temperature Rise Compessor Free
(0.06 to 0.13Cr(1)) Bearings, instead of k5 and Inner Ring of Inner Ring Through Bearings
Load Gears, m5. Shaft
Load Grinding Spindle Front
Indeterminate Ball Bearings
High Speed Centrifugal
Woodworking Compressor Fixed Possible —
Bearings
Machines Accurate Running
Desirable under Cylindrical Roller
r7 Normal or Light Bearings for Machine
Direction of Loads Tool Main Spindle
Heavy Loads Railway Axleboxes, — 50 to 140 50 to 100 n6 Load Generally For heavy loads,
Industrial Vehicles, — 140 to 200 100 to 140 More than CN Solid Housing Indeterminate Electrical Home Impossible interference fit tighter
or Shock Loads Traction Motors, — over 200 140 to 200 Appliances than K is used.
(>0.13Cr(1)) Construction — 200 to 500 p6 bearing internal Impossible When high accuracy is
Equipment, — required, very strict
Crushers r6 clearance is Accurate Running and Easily tolerances should be
necessary. High Rigidity Desirable Possible used for fitting.
under Variable Loads
r7 —
Minimum noise is
Axial Loads Only All Shaft Diameters js6 (j6) — Rotating required.
Inner Ring
Radial Bearings with Tapered Bores and Sleeves
Load

All Types of Loading General bearing All Shaft Diameters h9/IT5(2) IT5 and IT7 mean that Note (1) Refer to Tables 9.13.1 and 9.13.2 for the recommended fits of housing bores of deep groove ball bearings and
Applications, h10/IT7(2) the deviation of the shaft cylindrical roller bearings for electric motors.
Railway Axleboxes from its true geometric
Transmission Shafts, form, e. g. roundness and Remarks 1. This table is applicable to cast iron and steel housings. For housings made of light alloys, the interference should
Woodworking cylindricity should be be tighter than those in this table.
Spindles within the tolerances of
IT5 and IT7 respectively. 2. Refer to the introductory section of the bearing dimension tables (blue pages) for special fits such as drawn cup
needle roller bearings.
Notes (1) Cr represents the basic load rating of the bearing.
(2) Refer to Appendix Table 11 on page C22 for the values of standard tolerance grades IT. Table 9.5 Fits of Thrust Bearings with Housings
(3) Refer to Tables 9.13.1 and 9.13.2 for the recommended fits of shafts used in electric motors for deep groove ball
bearings with bore diameters ranging from 10 mm to 160 mm, and for cylindrical roller bearings with bore diameters
ranging from 24 mm to 200 mm.

Remarks This table is applicable only to solid steel shafts.

Table 9.3 Fits of Thrust Bearings with Shafts Load Conditions Bearing Types Tolerances for Remarks
Axial Loads Only Housing Bores
Load Conditions Examples Shaft Diameter (mm) Tolerance Remarks Thrust Ball For General Applications
of Shaft — Bearings Clearance over 0.25mm When precision is required
All Shaft Diameters H8
h6 or Spherical Thrust
Central Axial Load Only Main Shafts All Shaft Diameters js6 (j6) Roller Bearings Outer ring has radial When radial loads are sustained by
of Lathes <200 Steep Angle
js6 (j6) Tapered Roller clearance. other bearings.
Cone Crushers 200 to 400 Bearings
Combined Stationary Inner over 400 k6
Radial and Ring Load Paper Pulp Combined Stationary Outer Ring Loads Spherical Thrust H7 or JS7 (J7) —
Axial Loads Refiners, m6 Radial Roller Bearings
(Spherical Rotating Inner Ring Plastic Rotating Outer Ring Loads or K7 Normal Loads
Thrust Roller Load or Direction Extruders n6 and Axial Direction of Load Indeterminate M7 Relatively Heavy Radial Loads
Bearings) Loads
of Load
Indeterminate

A 84 A 85