A measure of INA bearing surface treatment technology has te

2011-11-18 17:51    Author:admin   Click:

1.INA bearing surface deformation strengthening

INA bearing by mechanical method to make the surface layer of metal plastic deformation, thereby forming a high hardness and strength of the hardened layer, the surface strengthening method called surface deformation strengthening, also known as hardening. Includes shot peening, sandblasting, cold extrusion, rolling, cold rolling and impact, explosion hardening. The characteristics of these methods are : to strengthen the horizon dislocation density increased, the subgrain structure refinement, so that the hardness and strength, the surface roughness decreases, can significantly improve the part's surface fatigue strength and reducing the fatigue notch sensitivity. This enhancement method has the advantages of simple process, significant effect, hardened layer and the substrate does not have clear boundaries, structural coherence, not easy in use shedding. Many of the methods have been applied in bearing industry: rolling the impingement surface strengthening is this kind of method application in precision rolling, has become a new ring machining and strengthening methods.

2.INA bearing  surface heat treatment

INA bearing using solid phase transformation, through the rapid heating method for parts of the surface layer for quenching treatment known as a surface heat treatment, commonly known as surface quenching. Flame quenching, high (medium ) frequency induction heating quenching, laser heating or electron beam heating quenching. The method is characterized by: surface local hardening, little deformation of the workpiece; fast heating speed, high production efficiency; the heating time is short, the surface oxidation and decarbonization of very minor. The method is particularly to improve under impact load of large and oversize bearing parts wear resistance and fatigue strength effect.

3.INA bearing chemical heat treatment

Use some elements of the solid-state diffusion into metal surface layer, to change the chemical composition, in order to achieve the surface strengthening method called chemical heat treatment, also known as diffusion heat treatment. Includes boronizing, alloying, carburizing and carbonitriding, nitriding and nitrocarburizing, sulfide and carbon sulfonitriding, chromizing, aluminizing and chromium aluminum silicon infiltration, graphite layer and so on, a wide variety, with different characteristics. The infiltration of elements or into the base metal to form a solid solution, or with other metal elements combine and form a compound. In conclusion the infiltration of elements which can change the chemical composition of the surface layer, and can obtain different phase structure. Carburizing bearing steel parts processing technology and needle roller bearing sleeve surface nitridation processing are of this class of strengthening method.

4.INA bearing surface metallurgical

Use of workpiece surface layer of metal to the melting and solidification, to produce the expected composition or tissue surface strengthening technique called surface metallurgical. Including surface autolysis alloy or composite powder coating, surface melt crystalline or amorphous treatment, surface alloying method. Is characterized by high energy density by rapid heating, the surface of the metal layer or coating on metal surface alloying material is melted, then on their own cooling solidification to obtain special structure or of the specific properties of strengthened layer. This special structure may be the refinement of crystal structure, it is perhaps the supersaturated metastable phase, phase, or even non crystal structure, which depends on surface metallurgy process parameter and method. Rolling bearing industry in miniature bearing working surface made laser heating intensive research, good results.

5.INA bearing surface film reinforcement

INA bearing applied physics or chemical method, in the surface of the metal coating on the substrate material performance of different reinforcement layer, called the surface film reinforcement. It includes electroplating, electroless plating (chrome, nickel, copper, silver and so on ) and the composite plating, brush plating and conversion treatment, including in recent years the rapid development of high and new technology: such as CVD, PVD, P-CVD vapor deposition film strengthening method and ion implantation surface strengthening technology ( also called atomic Metallurgical Technology ) and so on. Their common feature is can be formed in the work surface specific properties of the films, to strengthen the surface wear resistance, fatigue resistance, corrosion resistance and self-lubricating properties. Such as ion implantation technology to strengthen the working surface of the bearing, can make the bearing working surface wear resistance, corrosion resistance, and the contact fatigue resistance are improved, so that the service life of the bearing be multiplied.

1, separable bearing ( precision )

This is a ring can be detached and installed INA bearing, when the two races, the tight fit the very obvious advantages.

Separable bearing consists of four point contact ball bearing, double half ring of the double row angular contact ball bearings, cylindrical roller bearings, tapered roller bearings, thrust ball bearings, thrust cylindrical roller bearing and thrust roller bearing.

Here also introduce a non-separable bearing type: ), can not be separated bearings are: deep groove ball bearings, single row angular contact ball bearings, self-aligning ball bearings, drum-shaped roller bearings and spherical roller bearing.

2, precision

In most cases applied general size and rotation accuracy of rolling bearing is enough. When required to be higher, bearings require higher precision grade,

3, no neutral compensation

Do not appear in the processing of neutral axis neck mating surface or bearing seat surface, especially with the surface processing is not installed in a card to complete the. The use of the bearing seat can also arise when misalignment, ( for example: flange bearing or bearing seat ). Because the work load so that the shaft is bent and deformed, thereby causing the bearing inner and outer ring is tilted, also will appear the same misalignment.

A self-aligning bearing can be right and tilt compensation, for example: self-aligning ball bearings, roller bearings, drum-shaped centripetal and thrust roller bearings. This type of bearing has a concave spherical outer ring raceway, the rolling body and inner ring in rotary. These bearings to compensate for shaft center deflection angle depends on the ability of their own type, size and load condition.

Outside the spherical bearing and the thrust ball bearing with race has a spherical bearing surface: installed in the concave spherical washer can be adjusted while compensating deflection angle in the.

4, speed

Single row bearing friction is very low, it can achieve a maximum speed. This type of bearings can only bear the radial load of deep groove ball bearings and can bear the load of the angular contact ball bearing.

Improved bearing size precision, precision of rotation and fitting parts, precision, using the lubricating and cooling mode, using a special form of the holder can improve bearing allowable speed.

Low noise operation

In small motors, office equipment and household appliances such as general requirements to 's running noise.

5, a conical hole

With a conical bore of bearing can be mounted directly onto the tapered shaft neck ( for example: high precision in the structure of single row and double row cylindrical roller bearings). Installation of the bearings can be adjusted for a given radial clearance.

Most with the conical hole of the self-aligning ball bearings, cylindrical roller bearings and spherical roller bearings can be through an adapter sleeve mounted to the cylindrical shaft neck. This type of bearing is particularly easy to install and disassemble.

6, stiffness

The stiffness of the bearing is usually to produce certain elastic deformation of bearing the force required to. Machine tool spindle and the pinion shaft bearing are required to have high rigidity. As a result of roller and raceway contact condition is different, roller bearing stiffness than ball bearings of high rigidity.

7, the friction

In addition to being heating and cooling, internal friction on the working temperature of the bearing is also great decision function. Low friction bearings are: bear radial load of deep groove ball bearings, single row angular contact ball bearings and cylindrical roller bearings with a cage. Contact type sealed bearings, cylindrical roller bearings and thrust roller bearings will have a larger friction force.

8, bearing radial load

Mainly bear radial load bearing for radial bearings. This type of bearing 's nominal contact angle A0 < = 450. Ulnar rain the same roller bearing ratio of ball bearing can be subject to radial load more.

N type and NU type cylindrical roller bearings can only bear radial load, other types of centripetal INA bearings can bear radial load, but also can bear the axial load.

9, the bearing axial load

Main bearing the axial load bearing the general for the thrust bearing, its nominal contact corner A0 > 450. Thrust bearing and thrust angular contact ball bearings under different structures can be subjected to one or two directions of the axial force. When subjected to stress and selection of very high thrust cylindrical roller bearing and thrust roller bearing.

Spherical thrust roller bearing and thrust angle contact ball bearing can bear the axial load and radial load, the other thrust bearings can only bear the axial load.

10, bearing its own length compensation

The supporting shaft and bearing usually adopts the fixed bearing and floating bearing combination structure. Floating bearing shaft length error and compensation of thermal expansion.

NU type and N type cylindrical roller bearing is the ideal floating bearing, the bearing itself can be conducted on length compensation. Bearing inner and outer ring can be tightly matched.