Ball and Roller Bearings

!Deep Groove Ball Bearings2. Standard cage typesAs shown in Table 2, pressed cages are generally used indeep groove ball bearings. Machined cages are howeverused for large bearings and high-speed bearings.Table 2 Standard cage for deep groove ball bearingsBearing series67686916060626364Pressed cages6700 67066800 68346900 693416001160526000 60526200 62446300 63446403 64163. Other bearing types3. 1 Bearings with snap ringsMachined cages6836 686006936 6950016056 160726056 6084Some bearings accommodate a snap ring which isattached along the outer diameter of the outer ring. By usingsnap rings, positioning in the axial direction is possible andhousing installation is simplified. In addition to open type,shielded and sealed types are also manufactured. ConsultNTN Engineering.3. 2 Expansion compensating bearings(creep prevention bearings)The boundary dimensions of expansion compensating deepgroove ball bearings are the same as for standard bearings,but formed high polymer material with a high expansion rateis provided in the grooves on the outer circumference of theouter ring (see Diagram 1) .Due to the extremely small difference of thermal expansionattained between the fitted surfaces of the high polymerequipped outer ring and the light alloy bearing housing, agood interference fit can be achieved with stableperformance across a wide temperature range. Anotheradvantage is a large reduction in the occurrence of outer ringcreeping.(1) Allowable loadMaximum allowable load Cp (refer to the table of boundarydimensions) has been determined in accordance with outerring strength; therefore, it is necessary to select a bearingwith a maximum allowable load greater than the largestanticipated bearing load.(2) Housing and bearing fitTable 3 shows the recommended fits for bearings withlight metal alloy housings.In cases where the bearing is going to be interference fitwith the housing, it is very important not to damage the highpolymer material. Therefore it is essential that the lip of thehousing diameter be given a 10˚–15˚ chamfer as shown inDiagram 2.Furthermore, as shown in Diagram 2, it is also advisable toapply the interference fit using a press in order not force thebearing into the housing in a misaligned position. (Diagram 2)(3) Radial internal clearanceRegulations for radial internal clearance are the same asthose for standard deep groove ball bearings. For standardfit and application conditions, a C3 clearance is used withTable 3 Recommended fits for outer ring and housing boreConditionsLoad type, etc.Rotating outer ring loadRotating inner ring load;light loadDirection indeterminate load;ordinary loadRotating outer ring load;heavy loadDirection indeterminate load;shock loadHousing materialAl alloyMg alloyOther light alloysAl alloyMg alloyOther light alloysSuitablebearingDeep grooveball bearingCylindricalroller bearingThickwalledtypedeep grooveball bearingHousing boretolerance classH6N6High polymer material0.5mm1015Diagram 1. Expansion compensating bearingsDiagram 2. Fitting method and housing inner diameter chamferB-6