Design of cylindrical single-stage reduction gear box

Contents

Contents

Introduction

1. Description of the kinematic diagram of the mechanical drive of the belt conveyor

2. Justification of electric motor selection

3. Kinematic and power calculation of the belt conveyor mechanical drive

4. Fitting of clutch for mechanical drive

5. Calculation of V-belt transmission

6. Calculation of closed cylindrical helical gear

Conclusion

List of literature used

Application. Drawings and diagrams

Terms of reference for the development of the mechanical drive of the belt conveyor:

Design the mechanical drive of the belt conveyor. Maximum tractive force on conveyor F = 8 kN. Belt speed V = 0.5 m/s. Diameter of belt conveyor drum D = 250 mm. The load of the conveyor is calm, the work on it is two-shift. The mechanical drive shall include an electric motor, belt transmission, reduction gear and chain transmission. Inclination of the line connecting the center of the drum and transmission to the horizon [theta] = 30 °.

Drive life 21· 103 h. Non-reversible load, constant. During start-up the short-term (peak) load is 1.8 times the rated load.

Introduction

The mechanical energy used to drive the machine tool is the rotational energy of the motor shaft. Rotational motion is most common in mechanisms and machines, as it has the following advantages:

1. Provides continuous and uniform motion with small friction losses.

2. It allows to have simple and compact design of transfer mechanism.

Purpose of transmissions. All modern motors for reducing size and cost are high-speed with a very narrow range of changes in angular speeds. Directly, the high-speed shaft of the engine is rarely connected to the shaft of the machine (fans, etc.). In the absolute majority of cases, the mode of operation of the gun machine does not coincide with the mode of operation of the engine, so the transfer of mechanical energy from the engine to the working body of the machine is carried out using various gears.

Mechanical gears, or just gears, are mechanisms that transfer the operation of the engine to the executive body of the machine. By transferring mechanical energy, transmissions can simultaneously perform the following functions:

lower and increase angular velocities, respectively, increasing or decreasing torques;

Convert one type of motion to another (rotary and return, uniform to discontinuous, etc.)

adjust the angular speeds of the machine working member; reverse the movement (forward and reverse); distribute engine operation among several machine actuators.

In modern mechanical engineering, mechanical, pneumatic, hydraulic and electrical transmissions are used.

Depending on the principle of operation, all mechanical transmissions are divided into two groups:

1) friction transmissions - friction and belt;

2) gears - toothed, worm, chain.

All friction transmissions have increased wear of working surfaces, since in them slippage of one link relative to another is inevitable.

Depending on the connection method of the master and slave links, there are :

a) direct contact transmissions - friction, toothed, worm;

b) flexible communication transmissions - belt, chain. The flexible link transmissions allow considerable distances between the drive and driven shafts.

In the terms of reference for heading work, it is set to develop a mechanical drive, which consists of an engine and mechanical gears.

Conclusion

As a result of the course project for the development of the mechanical drive of the belt conveyor, the following actions were performed:

kinematic scheme is described;

motor selection is justified;

kinematic and power calculation of the belt conveyor mechanical drive was performed;

a clutch for a mechanical drive is selected;

V-belt gear and closed cylindrical helical gear are designed.