Gearbox Design and Screw Conveyor Layout

Contents

1. Description of kinematic diagram of the drive

2. Energy-kinematic calculation

2.1. Electric motor selection

2.2. Electric motor parameter tables

2.3 Determination of power, speed and torques at specified points

3. Gearbox Gear Calculation

3.1 Calculation of wedge-belt transmission

3.2 Calculation of conical high-speed stage

3.3 Calculation of the cylindrical slow-moving stage

4. Orientation calculation and design of shafts

5. Calculating, Matching, and Designing Gear Parts

6. Calculation and design of housing elements

7. Sketched Layout

8. Shaft check calculations for static and fatigue strength

9. Selection and inspection of bearings

10. Check of input and output shafts

11. Check calculation of keys

12. Selection of couplings

13. Gear lubrication (method, type, volume)

14. Gearbox assembly

15. Frame (Plate) Design

Bibliographic list

Appendix A

Appendix: Specifications

Introduction

Mechanical engineering has a leading role among other sectors of the economy, since machines perform the main production processes. Therefore, the technical level of many industries largely determines the level of development of engineering.

Improving operational and quality indicators, reducing the time of development and implementation of new machines, improving their reliability and durability are the main tasks of machine builders. The basis of design is no less important for an engineer, as well as the basis of technology for a design engineer. One of the areas of solving these problems is improving design training.

Depending on the complexity and overall dimensions, machines are divided into a number of parts, which consist of separate parts - products made of a material uniform in name and brand, without the use of assembly operations. Distinguish between parts of general and special-purpose vehicles. General-purpose parts include rivets, nut bolts, shafts, axles, gear and friction wheels, pulleys, sprockets, couplings, bearings, springs, housings and many others. In a wide variety of machines, such parts of the same type perform the same functions, which allows you to distinguish their study into an independent field of science - machine parts. Special-purpose parts, such as piston, valve, spindle, lemech, are found only in certain types of machines. The parts form assembly units - articles, the components of which are to be connected to each other at the manufacturer by assembly operations.

The project is a set of technical documents related to the product intended for manufacture or modernization and containing drawings, calculations, description with fundamental justification, layouts, etc. During the design process, the engineer solves a number of complex and diverse tasks. To do this, the designer must be able to perform kinematic, power, strength and other calculations; of the plurality of shapes that can be given to the part, of the plurality of materials having numerous and varied properties, he must choose those that allow the best use of these properties to increase the efficiency and reliability of the product.

A drive is a device that drives a machine or mechanisms of units and assemblies.

Gearbox Gear Calculation

When designing, the optimal parameters of the product should be selected that best satisfy various, often contradictory requirements: lowest weight, overall, cost; highest efficiency; required rigidity, reliability.

The use of computer programs for calculating transmissions expands the amount of information used, allows you to make calculations with the selection of values ​ ​ (variation) of the most significant parameters: the method of thermal treatment or the materials used, the distribution of the total gear ratio between stages, etc.

3.1 Calculation of V-belt transmission

We will use the REMZ.EXE. program to calculate the belt gear. To simplify the design of the gear box, we will accept the maximum number of belts equal to 3.

After analyzing the results of the calculation, we choose rational options. In this case, the option (axial distance 141 mm) is suitable. Calculation is in Appendix A.

3.2 Calculation of conical high-speed stage

Calculation is carried out on the computer using KONPER.OUT program. Initial data are torque on the wheel shaft, rotation speed, required gear ratio, service life, loading cyclogram, minimum and maximum angle of teeth inclination. When calculating, we also enter the properties of the gear and wheel materials, a total of 3 pairs of materials for 3 transmission options.

Selection and inspection of bearings

Bearings are selected by dynamic lifting capacity at rotation speed. During the construction of the drive or gearbox layout, the bearings have already been preselected by shaft diameter. Therefore, the calculations given are limited to checking the selected bearing and refining its type, diameter and series according to the program PODSCH.EXE The initial data for the calculation of bearings are: bearing installation diagram, required life, safety factor, temperature factor, ring rotation factor, load cyclogram. Appendix B.

Check of input and output shafts

During the work, calculations were made on the basis of which we can argue the suitability of the designed shafts for working in a gear box.

Calculations are given in Appendix C.

Gear lubrication (method, type, volume)

To reduce friction power losses, reduce the wear rate of friction surfaces, their cooling and cleaning from wear products, as well as to protect against jamming, gouging, corrosion, reliable lubrication of friction surfaces must be provided.

A crankcase system is widely used to lubricate the gears. Oil is poured into the gear box housing so that wheel rims are immersed in it. When rotating, the wheels entrain the oil, spraying it inside the body. Oil enters the inner walls of the housing, from where it flows into its lower part. A suspension of oil particles and air is formed inside the housing, which covers the surface of the parts located inside the housing.

Collars as per GOST 875279 are used to prevent oil leakage through shaft supports. They are installed in through covers of bearings of inlet and outlet shafts. Surface of shaft under cuff is hardened, ground and polished.

Gearbox assembly

Assembly consists in connection of all units to each other by means of bolts. Bearing sockets are closed with embedded covers, which do not require threaded fixation. Reduction gear case and cover are connected by bolts tightening at bosses and flanges.

Before connecting the cover to the housing, it is necessary to cover the surface of the housing flange with a thin layer of sealant. After filling of oil check the reducer for tightness.

Frame (Plate) Design

These elements are supporting structures and serve for connection into a single unit of a machine or separate mechanisms, in this case - drive units. They perceive and transmit to the foundation the loads acting on the machine and ensure the correct location of the units during operation.

In addition to strength, support structures must be rigid, since the latter determines the vibration resistance of the machine.

When developing the design of plates or frames, the operational, technological and economic requirements for the machine are taken into account.

The length and width (L and B) are specified along the drawn drive contour. We assign the height of the plate based on the condition of sufficient rigidity based on the design practice of similar structures:, where L is the length of the plate; We round these values according to GOST 663669 according to row Ra40. H = 220 mm .

After H calculation we select the nearest larger channel size (GOST 824089).

Choose Profile # 22

Under the main view is a top view. It shows the holes in the legs of the electric motor and reduction gear, the coordinates of their location, which we take from the catalog of motors and from the drawing of the reduction gear.