Bushing processing process

Contents

Assigning a Part

Part Processability Analysis

Calculating Dimension Chains

linear circuits

diametral chains

Purpose of Cutting Modes

current operation

grinding operation

long-term operation

Rationing of operations

Justification of the developed process design of the part

List of used literature

Purpose of the part and its operating conditions in the article

Part: bushing.

Bearing bushing is intended for installation of ball or roller bearing with demixing package into NLG housing.

Bearing bushing is pressed into housing by diameter.

The demixing pack is also installed in diameter and is fixed with a key.

Part Processability Analysis

The bushing part is quite specific: the largest diameter is 166 mm, the linear size is 86.4 mm. The manufacturing process consists of 20 different operations .

All dimensions of the part are standardized according to the normal number series, allowable deviations are assigned according to GOST. The presence of unified elements and part parameters reduces the required range of cutting and measuring tools.

The sleeve is a body of rotation, which determines the widespread use in the manufacture of the part of turning-screw machines - 1K625, 1K62.

Grinding is carried out on in-grinding and round grinding machines. A small number of machines are used in the manufacture of the part.

The configuration of the part mainly allows the use of standard machine tools. It was necessary to design special devices only for heat treatment operations, as a result of which the cost of the part increases.

Let's consider the surfaces of the part, to which high requirements of manufacturing accuracy and mutual arrangement are presented:

The surface of the left end is made according to the 6th accuracy quota with Ra 0.16;

Non-perpendicular of projection relative to outer diameter not more than 0.01 mm;

End run-out of projection relative to outer diameter is not more than 0.03 mm;

End run of inner left end relative to inner hole is not more than 0.02 mm.

Justification of developed part processing process

The annual production program of the bushing part is 200 pieces, which corresponds to the average production.

Preparation - a forging, preparation material - srednelegirovanny chrome-nickel steel 10X11H23TMPBP, hardness of HRC 3342, without preliminary heat treatment.

Based on the working drawing of the part, we determine that the technological process of the part includes 4 stages: draft, finish, final, finish.

In general, the process consists of:

- rough turning and milling of surfaces according to JT12 and JT11;

- finishing turn as per JT10 and JT19;

- rough, finished, medium accuracy according to JT9, JT8;

- fine grinding according to JT6;

At the end of the draft stage, some treated surfaces are winded to protect these surfaces from subsequent cementation. Next, heat treatment is quenching.

To reduce distortions, internal stresses arising after rough treatment are relieved - this is thermal treatment - tempering.

To protect against corrosion, to ensure the lapping properties of the part during assembly at the end of the process, a silver operation is provided.

When assigning bases, we use the principle of combining the source and installation bases.

As the installation base, we select the surface of the part that has the greatest extent and regular geometric shape.

If possible, we reduce the range of equipment, cutting and measuring tools used.

We envisage mechanization of machine tools.