Part Repair Process

Job for Course Project

1) To develop the process of restoring the Shaft Master part with serial number according to catalog 5512185B, which is part of the gearbox of the tracked tractor TDT55A. It is necessary to eliminate defect No. 1 .

Source Data:

• Part sketch (repair drawing) (Fig. 1.1)

• Defect map (Fig. 1.2)

• Diagram for assembly (disassembly) of the part into the unit (Fig. 1.3)

2) Develop the design of the accessory and the original parts included in it for the repair of the drive shaft.

3) Design a production site or workplace for restoration and repair of forest machinery parts.

Source Data:

• Annual scope of work carried out on site N = 10000 pcs.

Introduction

The constant need for repair production in the provision of spare parts is a serious factor in reducing the technical readiness of the tractor fleet. The expansion of the production of new spare parts is associated with an increase in material and labor costs. Therefore, an alternative is the secondary use of worn parts restored during machine repair.

Choosing a rational technological process for restoring worn-out surfaces of parts of logging machines is an urgent task, the solution of which depends on the composition of equipment of sections and workshops of repair enterprises, and ultimately on the effectiveness of the applied technological processes for restoring parts and the life of overhauled units and machines.

The experience of advanced auto-tractor plants shows an increased level of technological preparation of production, especially since plants carry out not only the production of logging equipment, but also perform branded repairs of units by industrial methods. Under these conditions, the cost of design error and recovery process selection increases.

The purpose of this course project is to develop a rational process of restoring one of the possible defects of the part "drive shaft" (serial number of catalog 5512185B) of the gearbox.

1. Analysis of operating conditions and main structural and technological features of the part

The part presented in this course design is part of the disc brake of the gearbox used for smooth, impact-free engagement of gearbox gears during gearshift. In this regard, the "drive shaft" part undergoes large alternating loads during operation, and is also designed for bending and torsion.

To lubricate the rubbing surfaces of the part, plastic lubricants are used, which are a mixture of liquid mineral oils with a thickener. As a thickener, solid products of oil processing (paraffin, ceresin, petrolatum) and various metal oils are used. In this case, US-1 or US-2 universal lubricant (universal medium-melting tank with fat-based thickener) or TS14 transmission oil can be used.

It can be seen from the operating conditions that the part rotates with frequent stops. From this, it can be concluded that the "drive shaft" part operates at high speeds and loads in high temperature mode and is a responsible part of its mechanism (gearbox), and therefore needs a high-quality restoration process.

The part has a brand of material Steel ZOHGT GOST 454371 and the hardness of the teeth is HRC 56... 62 and, in addition, the hardness of the core of HRC 35... 45.