NSK Deep Groove Ball Bearings 6304DDU ,Single-Row D=20
| Bearing Numbers | Boundary Dimensions (mm) |
Basic Load Ratings (kN) |
Limiting Speeds (min-1) |
Factor f0 |
Mass (kg) approx. |
|||||
| d | D | B | r min. |
Cr | C0r | Grease | Oil | |||
| 6304DDU | 20 | 52 | 15 | 1.1 | 15.9 | 7.9 | 10000 | 12.4 | 0.145 | |
DESIGN, TYPES, AND FEATURES
SINGLE-ROW DEEP GROOVE BALL BEARINGS
Single-row deep groove ball bearings are classified into the types shown below.
The proper amount of good quality grease is packed in shielded and sealed ball bearings. A comparison of the features of each type is shown in Table 1.
Table 1 Features of Sealed Ball Bearings
| Type | Shielded (ZZ Type) |
Rubber Non-Contact Seal (VV Type) |
Rubber Contact Seal (DDU Type) |
| Torque | Low | Low | Higher than ZZ and VV types due to contact seal |
| Speed capability | Good | Good | Limited by contact seals |
| Grease-sealing effectiveness | Good | Better than ZZ type | Slightly better than VV type |
| Dust resistance | Good | Better than ZZ type (usable in moderately dusty environments) | Best (usable even in very dusty environments) |
| Water resistance | Not suitable | Not suitable | Good (usable even if fluid is splashed on bearing) |
| Operating temperature | –10 to +110 °C | –10 to +110 °C | –10 to +110 °C |
Note (1) The above temperature range applies to standard bearings. By using cold- or heat-resistant grease or changing the type of rubber, the operating temperature range can be extended.
□Formulation of Bearing Designations
Single-row deep groove ball bearings
| ①Bearing type | 6 : Single-row deep groove ball bearings |
| ②Dimension Series | 2 : 02 Series, 3 : 03 Series, 9 : 19 Series, 0 : 10 Series |
| ③Bore number | Less than 03, Bearing bore 00 : 10mm, 01 : 12mm, 02 : 15mm, 03 : 17mm Over 04, Bearing bore bore number X 5 (mm) |
| ④Seals/shields | ZZ : Shield on both sides, DDU: Rubber contact seal on both sides, VV: Rubber non-contact seal on both sides, Z: Shield on one side, DU: Rubber contact seal on one side V:Rubber non-contact seal on one side |
| ⑤Internal clearance | Omitted : CN clearance＊1, C3 : Clearance greater than CN, C4 : Clearance greater than C3, CM : For electric motors＊1 |
| ⑥NSKHPS designation | & : NSKHPSTM Bearings |
| ⑦Grease designation＊2 | NS7 : NS HI-LUBE |
＊1 CM clearance may be used instead of CN clearance (the reverse is not possible).
＊2 The grease designation is required when seals/shields are used on both sides.
NSKHPS™ Deep Groove Ball Bearings
Note (1) The above temperature range applies to standard bearings. By using
cold- or heat-resistant grease or changing the type of rubber, the operating temperature range can be extended.
Compared with conventional bearings:
● Improved reliability
Bearing life is 15% longer than conventional bearings thanks to optimization of the bearing’s internal design and improvement of processing technology. As a result, NSKHPS™ bearings contribute to reducing maintenance costs and facilitate the downscaling of related equipment.
● New product lineup
The standard dimensions are identical to standard size bearings. NSK has expanded the lineup of NSKHPS™ bearings by focusing on a wide range of sizes offering a high degree of versatility for various general-purpose applications.
