638ZZ Bearing 8*28*9 mm ( 4 PCS ) 638Z Miniature 638 ZZ Ball Bearings | Спорт и развлечения

638ZZ Bearing 8*28*9 mm ( 4 PCS ) 638Z Miniature 638 ZZ Ball Bearings | Спорт и развлечения

What is a Ball Bearing?

The Function of Ball Bearings
From small and large motors to car axles to electric fans and hard disc drives (HDDs), ball bearings are used in a wide array of machines for rotary motion. Ball bearings support rotary parts and reduce friction to facilitate the smooth operation of machines.

Ball Bearing Components
Ball bearings are comprised of four major parts: a large ring (outer ring), a small ring (inner ring), balls between the rings (steel balls), and a cage to prevent the balls from hitting each other. The modern structure dates back to around 1500, when Leonardo da Vinci invented ball bearings to reduce friction against the axles of horsedrawn carts. For more than 500 years, the ball bearing has been defined by this simple structure.

Miniature Ball Bearings are a type of rolling-element bearing that uses balls to maintainthe separation between the moving parts of the bearing. The purpose of a ball bearing is to reduce rotational friction and support radial and axial loads. Radial Ball bearings can support moderate radial loads and moderate axial loads (parallel to the shaft). They can operate at high speeds . Ball bearings with shields or seals for protection can be lubricated to last for the operating life. Sometimes ball bearings are also called "deep groove ball bearings."

TECHNICAL SPECS

Item: 638ZZ Ball Bearing
Type: Deep Groove Ball Bearing
Material: 52100 Chrome Steel
Closures: 2 Shield
Grade: ABEC-1
Size: 8mm x 28mm x 9mm
Inner Diameter: 8mm
Outer Diameter: 28mm
Width: 9mm
Dynamic load rating Cr: 4,160 N
Static load rating Cor: 1,780 N
Chamfer: 0.3 mm
Quantity: 1 lot = 4 Pcs Bearings

BEARING DETAILS

DIMENSION LIST

F A Q

1. Why do the bearings I received have shaking?

The clearance of the bearing is related to the play.
The default is the standard C0 clearance, which is usually 3-18um.
The corresponding principle is shown in the figure below.
If you don't need to shake, please choose C2 small clearance bearing.
If you have any questions, please contact us before purchasing.

2. What is the accuracy of ABEC-1?

ABEC is the American ANSI standard.
The corresponding German DIN standard and international ISO standard are as follows:

3. Do you provide logistics tracking information?

Yes, all our products provide full logistics tracking.
And the products you buy are all new.
We will buy transportation insurance for you.
If the product is damaged or lost during transportation, you can get paid.