Special vertical drilling machine 2C150

Contents

Introduction

Technical characteristics of the 2C machine

Defining Processing Modes

Kinematic calculation of the main motion drive

Dynamic calculation of the speed box

Geometrical calculation of gears

Design calculation of V-belt transmission

Selection of bearings by dynamic lifting capacity

Development of speed box design

List of literature used

Appendix A

Introduction

Machine tool builders face enormous challenges in increasing the production of metal cutting machines and blacksmithing machines; providing advanced development of production of machine tools with numerical program control, development of production of heavy, unique and high-precision machines; significant increase in the production of special machines and automatic lines, organization of production of parts of complex automatic lines for large-scale and mass production industries; creation of sets of high-performance metalworking equipment controlled by electronic computing machines, for organization of sections and workshops on the basis of this equipment in industries with small-scale and serial production of products; development and production of equipment for automating assembly of mass products in mechanical engineering; organization of serial production of automatic manipulators with software control, which allow to mechanize and automate heavy physical and monotonous operations.

The designs of the machines created should be promising, i.e. meet the requirements of tomorrow. When developing a new machine, it is necessary to lay down in the project a certain margin of excellence and novelty of the solutions of its main elements compared to the already known ones. No wonder the word design itself comes from the Latin "proektus" - thrown forward. When creating a new machine, we should strive to reduce the design and development time of its production .

The designer designing a modern machine must make optimal technical decisions both on its individual elements and on the machine as a whole.

When designing a machine, the designer needs to determine the optimal dimensions of its individual units and elements and choose the optimal design solutions. Newly created machines should be socially expedient, technically and aesthetically perfect, economical. A very important requirement is patentability and patent purity. All these tasks can be successfully solved only with the correct organization of the work of the staff of the design bureau, everyday hanging of the knowledge of designers, taking into account in the design process the modern requirements for machine tools and modern directions of machine tool development. The pace of development of machine tools, compact and high-quality machines is largely determined by the industrial development of any country and characterizes the level of its machine building.

Modern metal cutting machines are very advanced machines that include a large number of mechanisms and use mechanical, electrical, hydraulic and other methods of movement and cycle control.

In terms of design and purpose, it is difficult to find more diverse machines than metal cutting machines. They process all kinds of parts - from gears and levers for watches and devices to huge parts, the dimensions of which reach tens of meters, for turbines, rolling machines and ships. Therefore, the dimensions of the machines are very different.

On machines, parts made of steels and cast iron are processed, and special heat-resistant alloys, light, hard, etc. are also used.

High performance of modern machines is ensured due to speed, power and wide automation. For example, the spindles of in-grinding machines make up to 150 thousand revolutions per minute. In modern heavy machines, the power of only the main engine reaches 150 kW, and several dozen electric motors are installed on just one machine. Automation of machine tools has reached a high level. There are, for example, automatic lines consisting of hundreds of complex machines and including control and assembly operations. In design, various mechanisms using hydraulics, electrics and pneumatics are used to give the machine the required qualities and functions.

Along with the development and improvement of existing processing methods in recent years, machines have appeared on the basis of fundamentally new technological processes. Such processes include electroerosion treatment, laser treatment, ultrasonic treatment, etc.

Thus, metal cutting machines include a wider group of machine tools that process not only metals but also other materials. To perform such a variety of technological tasks, it is necessary to use the latest advances in engineering thought.

Thus, the main task of the designer is to find the optimal version of the technical solution for the design of a metal cutting machine and its individual elements.

In this course work, it is necessary to design a metal cutting machine of the boring-boring group, according to the given diameters of the workpieces to be treated and the material of the cutting tool.

7 Selection of bearings by dynamic load capacity

In general-purpose speed and feed boxes, rolling bearings are used as shaft supports, since they better perceive various loads in a wide range of speeds and with frequent starts and stops.

When the assembly is subjected to only a radial load, for example, when the shaft transmits torque using spur gears, radial bearings are used. In case of axial loads from helical and conical wheels radial-thrust bearings are used.

For rotating shafts and spindles of metal cutting machines, rolling bearings of the following accuracy classes are used in order of increasing their accuracy 0.6, 5, 4.3, 2. In the mechanisms of metal cutting machines, various rolling bearings of accuracy class 0 are used. Roller bearings of increased accuracy classes are used in supports of spindle assemblies.

Standard sizes of bearings having the required durability at these loads are selected according to operability coefficient C, which characterizes load-carrying capacity and durability of the selected bearing. The value of factor C is specified by the manufacturer.

8 Development of speed box design

8.1 Gearbox control system

Machine control mechanisms are designed to start and stop individual mechanisms and the entire machine, to include the required speeds and feeds, fast inlets and taps of the mechanisms, as well as to perform all functions to change the nature of the tool and workpiece movement that are required for the implementation of the technological process.

The more complex the machine cycle, the higher its performance, the higher the requirements for control mechanisms.

Machine control systems can be divided into manual and automatic. During manual control, all cycle switches are performed by the operator using handles (levers), handwheels, pedals and control buttons.

There are control systems for many handles and one handle, different positions of each correspond to separate switches. In systems with the so-called preselection of speeds, the switching time is minimal, since the setting of the required speed is carried out in advance - during the previous technological operation and then it is only necessary to turn on this speed.

The simplest is a multi-loop control system. In this case, for each switch, an appropriate control is provided - handle, pedal, wheel.

The transfer links from the handle to the driven link can be very diverse.

For example, to move the gear blocks of the speed and feed boxes, a rack is used that translates the fork.

In case of small axial movements, a swinging fork or lever is used, and two handles can be placed on the same axis to improve the arrangement of control handles.

The use of multi-beam systems is only useful in machines with a small number of switchable mechanisms and relatively rare switching. As the number of handles increases, the serviceability is degraded, and the time required for switching is increased.

8.2 Description of speed box design

The design and location of the speed box assembly in the machines are very diverse. In drilling, turning, grinding and other machines, the speed box is made in the form of an independent unit. Such an arrangement of one of the most important components of the machine is simple and convenient from the point of view of its manufacture, especially with in-line production methods. The gearbox is a multi-gearbox assembly with stepwise speed adjustments. Speed switching is carried out using mobile gear blocks, the gear is simple in design, provides high efficiency, but does not allow switching speeds on the go. The speed range is located along a geometric row with the denominator A = 1.58 .

8.3 Lubrication of speed box

Lubrication of mainly rubbing surfaces of machines is one of the main methods of increasing their durability and increasing the efficiency of the machine, as well as reducing noise and vibration. The lubricant layer eliminates direct contact between the two surfaces, thereby not only significantly reducing friction forces, but also creating conditions for troubleshooting and avoiding sharp wear of the surfaces.

Liquid friction, in which the friction surfaces are completely separated by the lubrication layer, is most desirable to reduce wear. Liquid friction can be achieved by circulating lubrication. Oil from crankcase or tank is supplied by pump to lubrication points via pipeline through nozzles. It is possible to supply oil from a centralized lubrication system serving several units.

We accept industrial oil N30A (GOST 2079975).

During operation of lubrication systems, lubrication filtration is of great importance.

8.4 Maintenance Safety

The first condition for rational operation of machines is compliance with safety conditions when working on the machine. Modern machines are powerful high-speed machines, often removing a large number of chips per unit time. The possibility of injuries when the worker enters the area of ​ ​ action of the mechanisms, in case of breakdowns of rapidly rotating parts of the machine, in case of damage by flying hot and sharp chips, in case of stress and other reasons obliges to use special devices and mechanisms that ensure safe operation on the machine.