What material is used for bushing

Bushings with parts material for 45 steel.

Selection of blanks: according to the parts material is 45 steel, the type of production for the middle batch production, the parts of the diameter of the size of the large differences in the parts, parts of thin-walled, low stiffness, easy to deformation, high machining accuracy requirements, parts need to be quenched, etc. Factors such as the bar and the forging of a choice between the drop-forged parts.

Benchmark analysis, the main positioning reference should be Φ20.5 hole center

Installation program, processing of the big end and the inner hole, can be used directly three-jaw chuck clamping; rough processing of small end can be used to clamp the big end of the anti-jaw, semi-finish, finish machining of the small end, should be equipped with the mandrel to Φ20.5 hole positioning axial clamping of the workpiece.

When machining the holes, the indexing head can be mounted to raise the spindle up 90? and the direct indexing method is used to ensure that the 3 × Φ6 in the circumference of the parts in the even position. For the four screw holes at the big end, a special fixture is used for mounting: the big end face and Φ20.5 holes are used as the main positioning reference, the holes are anti-rotation, and the workpiece is axially clamped.

Surface machining method of the parts, Φ20.5 bore, precision grinding to achieve the accuracy and roughness requirements; the outer circle and its step surface by grinding; the rest of the rotary surface to meet the requirements of semi-finish turning; hole in the vertical milling.

Heat treatment arrangement, because the surface of the die forging parts have hard skin, will accelerate tool wear and passivation, in order to improve the machinability, die forging blanks after annealing treatment, soften the hard skin; parts of the final treatment for the quenching, due to the parts of the wall thickness of the small, easy to deform, coupled with the parts of the machining of the high precision requirements, in order to maximize the control of quenching deformation in the rough machining of the parts of the quenching process is arranged for the pre-treatment of the quenching process.

Extended information

Common causes of failure:

Shaft sleeve in the long-term operation process, the journal surface by the expansion sleeve of the extrusion pressure and the role of the composite mechanical force will lead to permanent deformation of the diameter or shrinkage of 0.1mm ~ 0.3mm. which leads to the mechanical expansion with the strength of the required tightening force can not reach the required tightening force The gap between the bushing and the spindle causes wear of the bushing.

Latest repair methods:

Because of the large value of the components, the traditional repair method is more expensive, with the development of foreign polymer composite materials and other advanced technologies, some repair fast and low-cost repair methods are favored. Domestic also introduced such methods, the more mature Fuselan 2211F material, etc..

The material has a traditional method is incomparable to the comprehensive mechanical properties, excellent adhesion and temperature and corrosion resistance, the maximum compressive strength of up to 1200kg/cm2, adhesion (overlap shear tensile test) in the smooth surface of the steel for 225 kg/cm2. so can be used for large-scale repair of wear and tear of the bushing parts. And the equipment does not require extensive disassembly, for enterprises to save a lot of manpower and material resources.

References:

Baidu Encyclopedia-Bushings