We can provide free samples . Please contact Email for any inquiries

Rolling Basics

The basic structure of the first section of the rolling bearing
Sliding bearings developed on the basis of the rolling bearing , its working principle is based on rolling friction instead of sliding friction , usually consisting of two rings , a set of rolling elements and a cage consisting of highly versatile , standardization, serialization degree is high mechanical basic parts . Due to a variety of mechanical work with different conditions, the load capacity of rolling bearings , and other aspects of the structure and performance have raised a variety of different requirements. For this reason, there is a wide range of rolling bearings need structure. However , the basic structure is composed of inner and outer rings , rolling elements and cage formed.

The role of the various parts in the bearing are:
For radial bearings , the inner ring is usually a tight fit with the shaft , and run together with the shaft , the outer ring is usually the case with the bearing or mechanical transition fit into the hole , play supporting role . However, in some cases , also the outer ring running, which support a fixed inner ring or inner ring, outer ring are simultaneously operated . For thrust bearings, shaft , said shaft ring tight fit and move together , and bearing or mechanical shell holes into the match and play the supporting role in the transition of said seat. Rolling element ( ball, roller or needle ) means normally kept in a bearing bracket arranged evenly between the two rings for rolling movement , its shape, size and number of the load directly affects the performance and capacity of the bearing . Except evenly spaced cage can open rolling outside , but also from the guide and improve the bearing rolling elements rotating internal lubrication performance and so on.

Classification Section of rolling bearings

1 . By Rolling structural type classification , divided into:
( 1 ) . Press the bearings can bear the load direction or different nominal contact angle is divided into:
1 ) . Radial bearings ---- mainly used to bear radial load bearing , its nominal contact angle from 0-45 . Nominal contact angle is different, is divided into: radial contact bearings ---- nominal contact angle is 0 bearing to the heart ; radial angular contact bearings ---- nominal contact angle greater than the centripetal 0-45 bearings.
2 ) . Thrust bearings ---- mainly used for axial load bearing , its nominal contact angle greater than 45-90 . Nominal contact angle is divided into different : axial contact bearings ---- nominal contact angle of 90 thrust bearings ; thrust angular contact bearings ---- nominal contact angle greater than 45 but less than 90 of the thrust bearing .
( 2 ) . By category bearing rolling elements , divided into:
1 ) . ---- Rolling ball bearings for the ball ;
2 ) . Roller Bearing ---- rolling of the roller . Roller Bearing press roller types are divided into: cylindrical roller bearings ---- rolling body is cylindrical roller bearings, cylindrical roller than the length and diameter of less than or equal to 3 ; needle bearing ---- rolling body is needle bearings, needle length and diameter ratio greater than 3 , but the diameter is less than or equal to 5mm; tapered roller bearings ---- rolling body is tapered roller bearings ; Spherical roller bearings - - rolling body is spherical roller bearings.
( 3 ) . Can press aligning bearing work , divided into:
1 ) . Spherical Bearings ---- raceway is spherical shape , and can adapt to the two raceways angular deviation between the axis and bearing angular motion ;
2 ) . Non- aligning bearing ( rigid bearing ) ---- Can impedance between the axis line roller bearing angular offset .
( 4 ) . Rolling bearing according to the number of columns , divided into:
1 ) . ---- With a single row bearings rolling element bearings ;
2 ) . ---- Double row bearings with two rows of rolling element bearings ;
3 ) . Multi-row bearings ---- with more than two rolling element bearings, such as three , four bearings.
( 5 ) . Bearing their ability to separate parts , divided into:
1 ) . Separable bearings ---- bearings with separable parts ;
2 ) . Can not be separated after the final bearing ---- bearings supporting freedom rings are not arbitrarily separated bearings.
( 6 ) . Bearing their structural shapes ( if no slot loading , within or without , and the structure of the outer shape of the ring , ribs , and even whether the cage , etc. ) can also be divided into a variety of structural types.

2 . Rolling classified by size , bearing their outer diameter size is divided into:

1 ) . Miniature Bearings ---- nominal diameter size range of 26mm or less bearing ;
2 ) . Small bearings ---- nominal diameter size range of 28-55mm bearings ;
3 ) . Small and medium size bearings ---- nominal diameter range of 60-115mm bearings ;
4 ) . Large bearing ---- nominal diameter size range of 120-190mm of bearings ;
5 ) . Large bearing ---- nominal diameter size range of 200-430mm of bearings ;
6 ) . Large bearings ---- nominal diameter size range of 440mm or more bearings.

Section basic production process of rolling bearings

Due to the different types, structure type, tolerance level , technical requirements, and bulk materials such as rolling bearings , the basic production process is not the same.
A variety of bearing the main parts of the process :
1 . Ferrule process : the bearing inner and outer rings of the processing of raw materials or blank forms depending differ , which processes the car before processing can be divided into the following three types , the whole process is: bar or tube feeding ( subject to some bar forging and annealing , normalizing ) ---- car ---- grinding heat treatment processing ---- ---- lapping or polishing ---- Part final inspection ---- rust ---- storage ---- ( to be fit suit with >
2 . Ball machining process : Ball processing depending on the state of the same raw materials differ , which processes setback before the cut or ball of light can be divided into the following three , before the heat treatment process can be divided into the following two kinds , the whole process is: cold red bar or wire ( red zone and need some bar annealed cold punch ) ---- setback cut , coarse , soft grinding or ball of light ---- Heat Treatment - --- hard grinding mill ---- ---- ---- lapping or polishing final inspection group ---- rust , packaging ---- warehousing < suit to be combined with > .
3 . Roller process : Roller processing depending on the raw materials vary , including heat treatment process can be divided into the following two before , the whole process is: bar car after processing or cold heading wire and string annulus Polishing ---- heat treatment ---- string soft spots ---- coarse outer diameter ---- roughing end face ---- end face grinding ---- finely grind the outer diameter of the outer end ---- Trail ---- grouped ---- rust final inspection , packing ---- storage (to be co- suit with > .
4 . Cage process : holding frame depending on the process design of the structure and materials can be divided into the following categories:
( 1 ) . → cutting → ??punching sheet metal stamping → ??→ → shaping and finishing pickling or shot or string light rust → → final inspection , packing → ??warehousing (to be combined with packages )
( 2 ) . Solid cage machining process : physical frame to keep working , according to raw materials or a bad hair differ , of which the first process can be divided into the following four cars rough type, the whole process are: bar, tube feeding , forgings , castings ---- car inside diameter , outside diameter , face, chamfer ---- drilling ( or broaching , boring ) ---- pickling ---- final inspection ---- rust , packaging ---- warehousing < pending suit together with > .

Second, the rolling bearing assembly :
Rolling bearing parts such as the inner and outer rings , rolling elements and cage , etc., after passing inspection , assembly plant for assembly into its process is as follows :
Parts demagnetization , cleaning → ??inner and outer roll < ditch > channel size grouping together sets of sorting → ??→ → Check clearance riveting cage → → demagnetization final inspection , cleaning → ??rust , into finished products packaging → ??( packing, shipping > .

IV characteristics of rolling bearings

Rolling compared with the sliding bearing has the following advantages:

1 . Rolling coefficient of friction than plain bearings , high transmission efficiency . Average coefficient of friction 0.08-0.12 sliding bearing , a rolling bearing and the friction coefficient is only 0.001-0.005 ;
2 . Rolling has achieved standardization, serialization , universal, suitable for mass production and supply , use and maintenance is very convenient ;
3 . Rolling bearing steel manufacturing , and after heat treatment, therefore , bearing not only has high mechanical properties and long life , and can save manufacturing plain bearings used in more expensive non-ferrous metals ;
4 . Internal bearing clearance is very small, high precision machining of the parts and, therefore, high running accuracy . At the same time , can increase the rigidity of the bearing by the preload method . This precision machinery is very important ;
5. Some of rolling bearings can support radial load and axial load , so you can simplify the bearing support structure ;
6. Due to the high rolling bearing transmission efficiency, less heat , and therefore can reduce oil consumption , lubrication maintenance relatively easy ;
7 . Rolling can be easily applied to any spatial orientation axis.

Rolling also has some drawbacks , mainly:
1 . Rolling load bearing capacity than the same volume of the sliding bearing is much smaller , and therefore , a large radial dimension of the rolling bearing . So, in the case of heavy load to bear and requirements of small radial size , compact structure requires the occasion < as crankshaft bearings ) , the use of sliding bearings ;
2 . Rolling vibration and noise is large, especially in the use of the latter is particularly significant. Therefore , the requirements for high precision , without Xu Youzhen moving occasion , Rolling difficult competent , generally used in sliding bearings better.
3 . Rolling metal shavings and other foreign matter are particularly sensitive to foreign material enters the bearing will produce greater vibration and noise intermittently , will cause early damage. In addition , bearing impurities due to the metal clip is also easy possibility of early damage occurred. Even early damage does not occur , the life of rolling bearings have certain limits. In short, the life of rolling bearings shorter than the sliding bearings .

However, Rolling and plain bearings compared to the advantages and disadvantages, each occupy a certain applicable occasions. Therefore , the two can not completely replace each other , and each to a certain direction, to expand their fields. However , due to the outstanding advantages of rolling bearings , quite latecomers trend. Currently, the rolling bearing has developed into a major type of mechanical support , the application more widely .