Brake Drum Recovery Process

Paper

The course project in its volume contains 3 sheets of the graphic part and an explanatory note with a volume of 31 sheets.

Keywords: REPAIR; WEAR AND TEAR; DEFECT; RESTORATION; SHAFT.

In the course design, technological processes for defect detection and restoration of the slave drum were developed, the following were made: selection and justification of methods for defect detection; Selecting and justifying the use of different methods for restoring a part development of the part recovery route; calculation and selection of process modes and time standards for basic recovery operations.

Introduction

The Republic of Belarus operates several thousand items of agricultural machinery, which is characterized by structural complexity, energy saturation and versatility. Machines are subject to high requirements for reliability and technical readiness to perform work in the optimal agrotechnical time frame. The processes of use, maintenance and repair of machines are regulated by the organizational and technical documentation, among which the "Machine Maintenance and Repair System" occupies a special place.

The efficient use of machines and equipment is ensured by a high level of their maintenance and repair, the availability of the necessary number of spare parts. The balanced provision of spare parts of repair enterprises and the field of operation of machines and equipment, as shown by technical and economic calculations, is advisable to carry out taking into account the periodic resumption of operability of parts restored by modern methods.

A significant role in improving the efficiency of the use of the machine and tractor fleet is played by its high-quality and timely maintenance and repair using modern technical means. The cost of maintaining the operability of machines used in agriculture in some cases exceeds the cost of their manufacture by 4... 5 times. The reduction of these costs ensures the use of technical diagnostics as the information basis of the maintenance and repair process management system.

The restoration of machine parts ensures the saving of high-quality metal, fuel, energy and labor resources, as well as the rational use of natural resources and environmental protection. To restore the operability of worn-out parts, 5-8 times less process operations are required compared to manufacturing.

Analysis of design, working conditions and defects

Details

The assembly unit "Driven drum" consists of two parts, the driven drum itself, and a bushing pressed into it.

On the main part there are: a toothed rim for transmitting motion from one rotating part, the other; holes for supply of lubricant to friction surfaces; screw threaded holes; bushing press hole.

The bushing, in turn, can be characterized by the presence of seats for bearings, grooves for installing the locking ring.

In parts of this type, defects most often appear on mounting surfaces for bearings and threaded surfaces. Bearing surfaces are restored at wear of more than 0.0170.060 mm; surfaces of fixed joints (places under hubs with key slots, etc.) due to additional parts - at wear of more than 0.040.13 mm; surfaces of movable joints - wear and tear of more than 0.41.3 mm; for seals - more than 0.150.20 mm. Keyways are restored when wear is more than 0.0650.095 mm wide; splined surfaces - with wear of more than 0.20.5 mm.

Of the total recoverable surfaces of parts of this type, 46% wear up to 0.3 mm; 27% - from 0.3 to 0.6 mm; 19% - from 0.6 to 1.2 mm and 8% - more than 1.2 mm.

The main requirement to be fulfilled when restoring this part and parts of the same type is to ensure the dimensions and roughness of the surfaces to be restored, their hardness, the continuity of the coating, the adhesion strength of the applied layers to the base metal, as well as symmetry, coaxiality, radial and end beating of the treated surfaces, parallelism of the side surfaces of the teeth of the splined surfaces and key slots of the shaft axis or forming the base surfaces.

In this course work, it is necessary to develop a technology for restoring the driven drum, the possible defects of which are wear of the surface for bearings, wear or tear of the thread, wear of the spline in thickness. The shaft recovery technology will be developed taking into account the recommended standard technological routes, as well as the recommendations of the industry standard.

Design of resource-saving technology for cleaning parts

2.1 Technical requirements for cleaning of parts and quality control of cleaning

The part entering the repair carries various contaminants on its surfaces. Complete cleaning of them determines the culture of production, the objectivity of sorting and control of parts, the quality of restoration and post-repair operating time. Well-cleaned repair facilities are easier to disassemble and less damaged. Poor-quality cleaning of parts reduces the post-repair operating time of the part on 20... 30%.

The allowable contamination of surfaces depends on the class of their roughness. For example, on surfaces with roughness of the 9th class, residual contamination of 2.5 g/m2 is permissible, and on surfaces with roughness of the 4th class - 12.5 g/m2.

The main requirements for the cleaning process are technical (define the requirements for surface cleanliness and the method of residual contamination control).

The following purification methods are distinguished:

macro cleaning - removal of contaminants to the level of surface roughness.

micro-cleaning - removal of contaminants from micro-irregularities of the surface.

It precedes the assembly and painting of parts. activation - used when applying galvanic coatings by bleeding the upper layer to remove oxides and bare the metal.

Cleaning quality control:

for macro cleaning - visual, weight, fluorescent,

gauze or cotton.

for micro-cleaning - activation, water wetting method, fluorescent.