NTN Develops World's Thinnest
"Low Cross-Sectional Height Thrust Needle Roller Bearings"
NTN Bearing Corporation has developed the world's thinnest "low cross-sectional height thrust needle roller bearing", making it possible to compact component designs for applications such as automotive automatic transmissions.
In recent years, in order to prevent automotive automatic transmissions from becoming larger due to the increases in engine output and the number of speeds, the components used within them have become more compact. This requires the thrust needle roller bearings used to be more compact in the axial direction, or in other words, to have smaller cross-sectional heights.
In general, thrust needle bearings are comprised of rollers, a cage, and races. If the cross-section is reduced while retaining the conventional design, the steel cage interferes with the rollers. If the steel cage plate is made thinner to compensate for this, the strength of the cage decreases. Therefore, 2 mm was the previous limit to the roller diameter of the smallest cross-sectional height thrust bearings.
To solve this problem NTN has developed a "low cross-sectional height thrust needle roller bearing" that can have cross section heights as low as 1 mm (roller diameters of 1 mm). In order for the cage not to interfere at smaller cross-section heights, the design of the cage pocket pillar has been improved. The improvements ensure adequate cage strength while making it possible to have cross-sections of 1 to 2 mm.
The development of this product not only makes more compact transmissions possible, but also makes it possible to reduce friction by introducing roller bearings into applications where space constraints have previously rendered the use of roller bearings impossible.
[Features]
The world's thinnest 1-mm cross-section for thrust needle roller bearings that use steel cages
Low Cross-Sectional Height Thrust Needle Bearings
• World's thinnest Attains 1mm cross-section
• Secures adequate cage strength
|
|
NW type
(using low cross-sectional height cage; 1.5mm diameter rollers)
|
FW type
(using ultra-low cross-sectional cage; 1.0mm diameter rollers)
|
(conventional product)
W type
(using conventional cage)
|
(Newly Developed product)
NW type (using low cross-sectional height cage)
- Attains a smaller cross section and increased cage strength with the same cage plate thickness as the W type cage.
|
(Newly Developed product)
FW type (using ultra-low cross-sectional cage)
- Attains a far smaller cross section and increased cage strength with increased cage plate thickness.
|
| Roller diameter: 2.0 mm | Roller diameter: 1.5 mm | Roller diameter: 1.0 mm |
| Cage plate thickness: 0.4 mm | Cage plate thickness: 0.4 mm | Cage plate thickness: 0.7mm |
(Cage strength)
1.0
|
(Cage strength:
compared to W type)
1.3
Reduced moment load at stress concentration location through smaller cross section
|
(Cage strength:
compared to W type)
3.0
Reduced moment load at stress concentration location through increased plate thickness and smaller cross section
|
|
