FITRUN would like to share with you the basic knowledge of ball bearing manufacturing, mainly on the manufacturing process. We split the contents into 6 blocks as below.
I. Bearing Manufacturing Basic Process
First all of, we would like to show you the basic process of bearing manufacturing. As we know, there are usually 3 main parts compose of the bearings, they are: bearing rings, rollers and cages. So the following are the main manufacturing processes for these 3 components:
1. Bearing Ring (Outer and Inner)
Material → Forging → Turning → Heat Treatment → Grinding → Assemble
2. Roller
Material → Turning → Heat Treatment → Grinding → Assemble
3. Cage (Brass Cage)
Material → Casting → Turning → Milling → Deburring → Assemble
II. Bearing Material
And in the 2nd blocks, we are talking about the material for bearing ring, roller and cage. For more details of bearing steel information, please check the bearing steel composition and model interchange of different standards.
Bearing Ring & Roller
Here below are the materials and their performance for bearing ring and roller:
Common material: high-carbon chromium bearing steel: Gcr15 (52100), Gcr15SiMn (1.3520)
Other material: carburized bearing steel, abrasion and corrosive resistance bearing steel, heat resistance bearing steel
Material Performance Requirements:
a) High surface load capacity
b) Good abrasion resistance
c) High elastic limit
d) Good hardness
e) Toughness
f) Good size stability
g) Good rust resistance
h) Good processing performance
Bearing Cage
a) Non-ferrous metal:
Brass HPb59-1, bronze QAL10-3-1.5, Aluminum alloy LY11CZ
b) Ferrous Metal:
Quality carbon steel thin plate
c) Non-metal:
Engineering nylon, phenolic adhesive
III. Forging
Forging process comes at the 3rd block. Forging is the preliminary processing of bearing ring making, it’s also named blank processing.
The main purposes of bearing ring forging processing are:
1. To obtain the semi-finished ring which is similar with the bearing, so as to enhance the efficient of metal material and reduce the mechanical machining work, and at last to save the cost of production.
2. To eliminate the inner defect of metal, improve metal organized system, so as to make the metal be with proper streamline distribution and with good compactness, and at last to enhance the life span of bearings.
There are 3 ways of forging:
Hot forging — metal is heated to be above the crystallization temperature. This is the widely used method.
Cold forging —metal is forged in the room temperature. This type of forging is barely used.
Warm forging — metal is forged in the temperature between hot forging and cold forging. This method is still not so matured.
Bearing Ring Forging Process
IV. Turning
The 4th block is turning process. Turning is for semi-finished bearing ring and roller, it’s also called forming process.
The main purposes of turning:
1. To make the bearing ring and roller be the same shape with the finished products.
2. To create good condition for the coming grinding processing.
There are 2 ways of turning process:
a) Integrated Processing: to finish all the turning procedure in one machine. This is suitable for small quantity production.
b) Distributed Processing: to finish only one turning procedure in one machine. This is suitable for large quantity production.
Bearing Ring Turning Process
Roller Turning Process
Usually, the equipments used are specially for bearing processing, and are arranged according to the distributed procedure follow.
V. Heat Treatment
Heat treatment is the key processing procedure to enhance the bearing inner quality.
The main purposes of heat treatment:
1. To change the material structure through treat treatment so as to enhance its mechanical performance.
2. To enhance the bearing inner quality (abrasive resistance, toughness, etc), so as to enhance the bearing life span.
Bearing ring and roller heat treatment process
VI. Grinding
Grinding is the final processing of bearing ring and roller, it is called finished product processing.
The main purposes of grinding process:
1. To make the bearing ring and roller be in accordance with the design requirements in size and shape precision.
2. To prepare qualified rings and rollers for bearing assembly.
Normally, it’s processed by distributed procedure; or the machines can be connected to integrate into a production line by material loading and unloading equipments so as to enhance the production efficient.
Bearing Ring Grinding Process
Roller Grinding Process
VII. Bearing Assembly
And here, we come to the final process – assembly. Bearing assembly is the final process of bearing manufacturing; it has very important effect to the bearing performance.
The main purposes of bearing assembly:
1. To assemble the finished components (out rings, inner rings, rollers and cages) into finished bearings.
2. To assemble the finished components into a variety of precisions, clearances and special requirements of bearings according to different technological requirements.
Bearing Assembly Process
Above is the simple presentation of bearing manufacture basic knowledge. Hope you have had a preliminary knowledge of bearing manufacture.
Bearing manufacture has many processing procedures and requires high machining precision even though the bearing is just common standard component. In order to produce high quality and high precision bearing products to meet customers’ requirements, in addition to above work mentioned, as a ball bearing manufacturer we still have a lot of work to do.
For the video version of this knowledge sharing, please click Ball Bearing Manufacturing Process. We welcome your comments or questions, please contact us.