MOTION & CONTROL™ Needle Roller Bearings

NSK NEEDLE BEARING TECHNICAL INFORMATION Cage & Needle Roller Assemblies Drawn Cup Needle Roller Bearings Solid Needle Roller Bearings Inner Rings for Needle Roller Bearings Thrust Bearings FJT FJTT FJLT FJLTT FJHTT MFJT MFJLT Roller Followers FYCRS FYCJS YCRS Needle Rollers Spherical Plain Bearings Needle Roller Bearings for Universal Joints Drawn Cup Roller Clutches Oil Seals for Needle Roller Bearings Example Figures and Appendices

Newly Revised & Updated NSK Needle Roller Bearing Catalog Welcome to the latest edition of the NSK Needle Roller Bearing catalog (Catalog No. E1419c). Our new catalog has been revised and updated to better meet the needs of our customers. NSK needle roller bearings enjoy a favorable reputation and are well accepted in the industrial machinery marketplace. NSK will continue to meet the future needs of industry by further developing automation-related products that are more compact, lightweight, consume less energy, and offer extended maintenance-free performance. This newly revised NSK needle...

MOTION & CONTROL Needle Roller Bearings

TECHNICAL INFORMATION BEARING TABLES EXAMPLE FIGURES

1. Bearing Types and Features Needle roller bearings are a type of roller bearings and are classified as either radial or thrust depending on the direction of the load they support. Needle roller bearings include bearings whose rollers slightly exceed the size range of needle rollers as stipulated by ISO. Needle roller bearings include drawn cup and solid radial bearings, as well as application-specific cam followers, roller followers. Thrust bearings include thrust needle bearings. Although not classified as a rolling bearing, there is also a spherical sliding bearing that supports radial and...

1.3 Solid Needle Roller Bearings 1. The bearing ring can sustain high shock loads because it is precisely ground after being heat treated. 2. Providing high load capacity, many rollers are held in the outer ring by strong integrated ribs. 3. The unique single-piece cage is also excellent for high speeds as the cage accurately guides the rollers at the roller pitch diameter at both ends of the rollers. 4. Considerable space is allotted for lubricant and lubricant life is long. 5. The cage is surface treated, increasing wear resistance and rigidity. 6. Appropriate crowning is applied to the rollers...

1.7 Spherical Plain Bearings 1. Since the structure is composed simply of an inner ring with spherical outside and an outer ring with a spherical bore, this bearing is ideal for applications where the inner and outer rings are misaligned. 2. Carefully selected high-carbon chromium bearing steel is used, and high load capacity is achieved thanks to ideal hardening. 3. Bearings with single-cut outer rings are not separable even without snap rings. 4. Bearings with double-cut outer rings are assembled by a wire snap ring into a single body. 5. The lubrication grooves and lubrication holes provided...

2. Bearing Life and Basic Load Rating Average Life Rating Life Failure Probability Fig. 2.1 Failure Probability and Bearing Life 2.2 Basic Dynamic Load Rating The basic load rating is defined as the constant load applied on bearings with stationary outer rings that the inner rings or shafts can endure for a rating life of one million revolutions (106 rev). The basic load rating of radial bearings is defined as a central radial load of constant direction and magnitude, while the basic load rating of thrust bearings is defined as an axial load of constant magnitude in the same direction as the...

2.3.1 Temperature Adjustment for Basic Dynamic Load Rating If rolling bearings are used at high temperature, the hardness of the bearing steel decreases. Consequently, the basic load rating, which depends on the physical properties of the material, also decreases. Therefore, the basic load rating should be adjusted for higher temperatures using the following equation. rapid reduction in the fatigue life of the bearing. When hardness is lower than HRC58, it is necessary to correct the basic dynamic load rating by multiplying it by the hardness factor, fH, shown in Fig. 2.3. 2.3.3 Correction of...

3. Bearing Loads 2.4.2 Permissible Static Load Factor The permissible static equivalent load on bearings varies depending on the basic static load rating and also the application and operating conditions. The permissible static load factor, fs, is a safety factor that is applied to the basic static load rating, and it is defined by the ratio in Equation 2.10. The generally recommended values of fs are listed in Table 2.3. Conforming to the modification of the static load rating, the values of fs were revised, especially for bearings for which the values of C0 were increased, please keep this...

calculate the actual load, Kb, in the case of a belt transmission, the effective transmitting power is multiplied by the belt factor, fb, which represents the belt tension. Values of fb for different types of belts are shown in Table 3.2. Kb In the case of a chain transmission, the values corresponding to fb should be 1.25 to 1.5. In addition to the theoretical load calculated above, vibration and shock (which depend on how accurately the gear is finished) should be included by multiplying the theoretically calculated load by the gear factor, fg. The values of fg should generally be those in...

4. Bearing Selection 4.1 Bearing Types It is important to select the needle roller bearing that is most suited to the particular application. One must fully understand the structure and characteristics of a selected bearing to determine whether it is appropriate for a given application. When selecting needle bearings, the following factors should be considered: (1) Amount, direction and condition of bearing load (2) Rotating speed and which ring is rotating (3) Required bearing life (4) Ambient temperature of bearing (5) Accuracy of bearings (6) Degree of friction (7) Noise (8) Vertical shaft...