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Bearing type selection: Bearing is generally based on the use of complementary products to bear the load conditions and NSK Bearings choice. Therefore, we must understand the user's actual load with selected bearing is the same, if the bearing is not up to the requirements, the model re-election as soon as possible, but unless special products, in the choice of models is generally not a problem.
Bearing clearance choice: buy bearings are generally only tell what type, level, rarely bearing clearance requirements, companies must require the use of NSK bearings condition in which the bearing speed, temperature, tolerances are directly related to the bearing Select the gap. Generally 3500 rev / min speed high-speed motor, the motor using the following CM clearance, if necessary, a relatively large gap. Bearing clearance in the assembly will rise, because the gap to reduce the amount of noise reduction caused by the large hole and cylindrical narrowing = × 60% (except aluminum bearing housing). This bearing assembly before clearance is 0.01mm, 0.01mm when the General Assembly for the degree of interference, bearing 0.004 mm clearance after assembly. In theory, the zero gap in life bearing noise and achieve the best state, but in actual operation, taking into account issues such as temperature rise, NSK bearing after assembly 0.002 mm -0.004 mm better clearance.
A, strict chemical requirements
General bearing steel is mainly carbon chromium bearing steel, the carbon content of about 1%, with 1.5% of chromium, and contains a small amount of manganese, silicon element eutectoid steel. The strict control of the chemical composition of the steel bearing the content can be met by the heat treatment step bearing performance and hardness.
B, strict dimensional accuracy requirements
Rolling steel requires high dimensional accuracy, it is because most NSK bearing part go through the pressure forming. In order to save raw materials and improve labor productivity, most of the bearing rings must forging, cold heading or after the ball is rolled shape, small size of the roller is formed by cold forging. If the steel is not high dimensional accuracy, we can not accurately calculate cutting size and weight, and thus can not guarantee the quality of products bearing parts, are likely to cause damage to the equipment manufacturer.
C, particularly stringent purity requirements
Steel purity refers to the number of impurities contained in the steel, the higher the purity, the non-metallic inclusions in steel less. Bearing steel oxides, silicates and other harmful impurities early fatigue spalling of the bearing, NSK reduced bearing life has a great relationship. Harmful impurities, especially brittle, since the process from the metal substrate is easily peeled off, seriously affect the bearing surface quality after finishing.
D, strict low magnification and microscopic (high power) organizational requirements
Bearing Steel low magnification refers to the general loose, center porosity and flat analysis, microscopic (high power) organizations, including organizations of steel annealing, carbide mesh, ribbon and liquid analysis and so on. Carbide liquation hard and brittle, brittle inclusions with the same dangers. Carbide reduce the impact toughness, and to organize uneven quenching easily deformed and cracking. Carbide strip annealing and quenching and tempering influence organizations and contact fatigue strength.
E, the external and internal defects particularly stringent requirements
Bearing steels, external defects including cracks, slag, burrs, scarring, scale, etc., internal defects including shrinkage, bubbles, white spots, severe osteoporosis and segregation. For the processing of these defects bearings, NSK bearing performance and life have a great impact, bearing data specification clearly states allowed these deficiencies.
Bearing Sealed choice: bearing lubrication oil lubrication and can be divided into greased. NSK bearings generally use grease lubricated bearings generally use rubber seal or seal in the form of dust. Shield, high temperature or environmental good parts, seals and sealing contact with non-contact seals contact seals dustproof performance is good but starting torque, starting torque, suitable for non-small seals, but no contact is good sealing performance.
| Product Model | Inside Diameter | Outside Diameter | Thickness |
| 7034A NSK | 170 | 260 | 42 |
| 7934C NSK | 170 | 230 | 28 |