Design features of NTN deep groove ball bearing
NTN deep groove ball bearings are very widely used. A deep groove is formed on the inner and outer ring of the bearing enabling the bearing to sustain radial and axial loads in either direction as well as the complex loads which result from the combination of these forces. Deep groove ball bearings are suitable for high speed applications.
When two or more NTN deep groove ball bearings are used in combination and mounted adjacent to each other a duplex set (D2) should be used. Duplex bearings (D2) utilize controlled tolerances to more evenly distribute the loading between the individual bearing rows which improves the overall performance of the assembly.
In addition to unsealed and unlubricated “open” bearings, NTN provides deep groove ball bearings that are pre-lubricated with grease and enclosed by seals or shields.
Table below shows the construction and special characteristics of various sealed deep groove ball bearings.
| Types and codes | Shielded type | Sealed type | |||
|---|---|---|---|---|---|
| Non-contact type ZZ | Non-contact type LLB | Contact type LLU | Low torque type LLH | ||
| Construction |  |  |  |  | |
| Metal shield plate is affixed to the outside ring; the inner ring incorporates a V-groove and labyrinth clearance. | The outer ring incorporates synthetic rubber molded to a steel plate; seal edge is aligned with V-groove along inner ring surface with labyrinth clearance. | The outer ring incorporates synthetic rubber molded to a steel plate; seal edge contacts V-groove along inner ring surface. | Basic construction is the same as LLU type, but a specially designed lip on the edge of the seal prevents foreign matter penetration; low torque construction. | ||
| Performance comparison | Torque | Small | Small | Higher | Medium |
| Dust proofing | Good | Better than ZZ type | Excellent | Much better than LLB type | |
| Water proofing | Poor | Poor | Very good | Good | |
| High speed capacity | Same as open type | Same as open type | Limited by contact seals | Much better than LLU type | |
| Allowable temp. range | Depends on lubricant | -20 to 120°C | -20 to 110°C | -20 to 120°C | |
Standard cage type
Pressed cages are generally used for most deep groove ball bearings. Larger size deep groove ball bearings, and bearings operating at high rotational speeds often utilize a machined cage.
| Bearing series | Pressed cage | Machined brass cage |
|---|---|---|
 |  | |
| 67 | 6700 ~ 6706 | - |
| 68 | 6800 ~ 6834 | 6836 ~ 68/600 |
| 69 | 6900 ~ 6934 | 6936 ~ 69/500 |
| 160 | 16001 ~ 16052 | 16056 ~ 16072 |
| 60 | 6000 ~ 6052 | 6056 ~ 6084 |
| 62 | 6200 ~ 6244 | - |
| 63 | 6300 ~ 6344 | - |
| 64 | 6403 ~ 6416 | - |
Other NTN deep groove ball bearings
Bearings with snap rings
A snap ring grove or snap ring groove with snap ring combination are optional enhancements for the outside diameter of most deep groove ball bearings. Snap rings allow for simpler axial positioning and installation in the housing. Snap rings can be utilized with both open type and sealed or shielded deep groove ball bearings.
Expansion compensating bearings (creep prevention bearings)
NTN offers the innovative Expansion Compensating (EC) feature to help with bearing retention when mounted in light alloy housings which is often a problem at elevated temperatures due to property differences between the bearing steel and the housing.
AC bearings (creep prevention bearings)
NTN Offers the AC type bearing which performs a similar function to the EC bearing. AC bearings have the same outside diameter dimensions as standard bearings with the addition of two O-rings located in circumferential grooves on the outside diameter of the outer ring. While the EC bearing is more beneficial when using a light alloy housing at elevated temperatures, AC bearings are suitable for applications where a “tight fit” is not possible but outer ring creeping exists under rotating load on the outer ring.