| Cr | 24700 N | Basic dynamic load rating, radial |
| C0r | 38000 N | Basic static load rating, radial |
| Cur | 5200 N | Fatigue load limit, radial |
| Fw | 25 mm | Inner diameter of needle roller complement |
| nG | 17500 1/min | Limiting speed |
| Ew | 31 mm | Outside diameter of needle roller complement |
| nu03d1r | 9400 1/min | Reference speed |
| Bc | 21 mm | Width |
| Tmax | 140 u00b0C | Operating temperature max. |
| Tmin | -30 u00b0C | Operating temperature min. |
INA Bearing K25X31X21 Category: INA Bearing > Roller Bearings > Needle Roller Bearings INA needle roller bearings are bearings with cylindrical rollers that are small in diameter relative to their length. The modified roller/raceway profile prevents stress peaks to extend bearing service life.
INA supplies needle roller bearings in many different designs, series and in a wide range of sizes, which makes them appropriate for a wide variety of operating conditions and applications. INA machined needle roller bearings NK and NKI are successful machine elements for the design of radially,compact bearing arrangements with very high load carrying capacity. They consist of machined bearing rings and needle roller and cage assemblies with cages made from either plastic or deep drawn steel strip. Bearings of series NKI have an inner ring while series NK is supplied without an inner ring.
INA Bearing K25X31X21, Bearings without an inner ring are most suitable if the shaft can be hardened and ground.
The material for the plastic cages is heat-stabilized, glass fibre-reinforced poly-amide 66. This material has high strength and elasticity. Cage friction is low due to the positive sliding characteristics of the plastic on lubricated steel surfaces and the low roughness of the cage surface. This leads to reduced heat generation within the bearing. Since the material density is lower than that of steel cages, the mass inertia forces of the cage are lower. Poly-amide cages have good emergency running characteristics, can be produced in the functionally correct form by the injection moulding process and are resistant to organic solvents and diluted alkaline cleaning agents. They also run with very little noise. New sizes with plastic cage
INA Bearing K25X31X21, INA needle roller bearings NK were previously produced up to enveloping circle diameter Fw= 10 mm with plastic cages, while needle roller bearings NKI were produced up to a bore diameter of 7 mm with plastic cages. In order to further exploit the advantages of these cages, addition all sizes now have plastic cages. The cages are designed to accommodate more olling elements than steel cages. Since more olling elements in the same space give higher load carrying capacity, the new bearings have higher load capacities than comparable bearings with a conventional steel cage. The new series: have proven, high performance plastic cages have higher basic dynamic and static load ratings than the previous designs allow smaller bearing arrangements, if necessary, under the same load have little running noise allow very economical bearing arrangements.
