Course Project "Belt Conveyor Drive Design"

Contents

Contents

I. Purpose and scope of the drive

II.Technical characteristic of the drive

III. Kinematic diagram

IV. Calculations confirming the operability and reliability of the structure

V. Description of organization of works using the developed drive

VI.Level of standardization and unification

VII. List of literature used

VIII DZ No. 2 (Annex 1)

I. Purpose and

scope of the drive

At the moment, there is a wide variety of kinematic schemes of reduction gears, their shapes and structures.

Reduction gears are divided into cylindrical (axes of drive and driven shafts are parallel), conical (axes of shafts intersect), worm (axes of shafts intersect in space). There are also combined reduction gears, representing a combination of toothed (cylindrical and conical) and worm gears.

Gears.

In most cases, the gearing serves to transmit rotational motion. In some mechanisms, this transmission is used to convert rotational motion into translational motion.

Gear gears are the most common type of gear in modern machine building and instrument making; they are used in wide ranges of speeds (up to 100 m/s), capacities (up to tens of thousands of kilowatts).

The main advantages of gears compared to other gears:

- processability, constant gear ratio;

- high load capacity;

- high efficiency (up to 0.970.99 for one pair of wheels);

- small overall dimensions compared to other types of gears under equal conditions;

- high reliability in operation, easy maintenance;

- relatively small loads on shafts and supports.

The disadvantages of gears include:

- impossibility of stepless change of gear ratio;

- high requirements for manufacturing and installation accuracy;

- noise at high speeds; poor damping properties;

- bulkiness at large distances between axes of driving and driven shafts;

- the need for special equipment and tools for cutting teeth;

- gearing does not protect the machine from possible dangerous overloads.

Cylindrical gears.

A gear train with parallel axes, whose wheels have cylindrical surfaces along the diameter of the protrusions, is called a cylindrical one.

The spur gear consists of two or more pairs of spur gears (Fig. 30). This transfer is easiest to manufacture. It is used in both open and closed versions.

Geared wheels with internal engagement.

With severe limitations on dimensions, in planetary mechanisms, in gear pumps with internal engagement, in the drive of the tank turret, wheels with a toothed rim cut from the inside are used. Drive and driven wheels are rotated in one direction. In such a transmission, there is less friction loss, that is, higher efficiency.

Application of cylindrical gears.

invention relates to machine building and can be used to reduce weight of workpieces and weight of gear gears, reduce energy consumption and tool at cutting and increase efficiency at low and medium speeds.

Advantages of cylindrical transmission:

1) small dimensions;

2) high efficiency;

3) high reliability and durability;

4) constant transmission ratio;

5) the possibility of changing the law of movement;

6) possibility of use in a wide range of speeds and capacities.

Disadvantages of cylindrical transmission:

1) production of gears requires a high production culture,

and this is expensive ;

2) absence of self-protection function from overload;

3) increased noise in operation ;

4) impossibility of step-free adjustment of gear ratio.

Classification of cylindrical gears:

. Cylindrical gears are spur, oblique and chevron.

Spur-shaped cylindrical gears are easy to manufacture, but when they work, high noise occurs, they create vibration and because of this wear out faster.

Helical cylindrical transmissions have good smooth operation, low noise and good performance. A significant drawback is that axial forces arise, due to which you have to make a more rigid design of the gearbox housing.

Chevron cylindrical gears have extremely high smoothness of operation. The gears of these gears are double helical gears, but they have a larger tooth angle than the helical gears. The cost of making chevron gears is high, they require specialized machines and high qualification of workers.

V. Description of organization of works using the developed drive

Belt conveyor is the most common type of continuous transport machine. The main purpose of belt conveyors is to move a variety of bulk and piece cargoes in horizontal and gentle directions. At the same time as transporting goods, they can distribute them to given points, store them, accumulating them in specified places, move them according to technological operations and provide the necessary rhythm of the production process.

Scope of Application

Belt conveyors have become widespread in all industries and are the main units of mechanization of transport in foundries, on fuel supplies of power plants, underground and ground transportation of coal and rock in the coal mining industry, ore, coke and fluxes in metallurgy, building materials and minerals in quarries, grain in granaries, sand and stone on the construction of channels and hydraulic stations, etc.

Principle of operation

Belt conveyors are characterized by continuous movement of bulk or piece loads along a given route without stops for loading or unloading. The conveyable bulk is arranged in a continuous layer on the belt or in separate portions. The unit weights are also moved in a continuous flow in a predetermined sequence one after the other. At the same time, working and reverse movements of the load-carrying element of the machine occur simultaneously. The belt is moved by the friction force between the drive drum and the belt, which occurs when sufficient pre-tension of the traction member is provided.

Belt Conveyor Classification

According to location on the ground, conveyors are divided into stationary and mobile, mobile and portable, rearranged and surface, floating on pontoons.

By design and purpose, general-purpose conveyors and special ones are distinguished: underground, for the food, flour, cereal and feed processing industries and in-line production in the instrument-making, radio and light industries.

According to the belt type, conveyors come with a rubberized, steel all-rolled and wire belt.

Advantages and disadvantages of belt conveyors

The main advantages include:

1) large performance range;

2) significant length of movement;

3) small cost;

4) insignificant energy intensity;

5) variety of conveyor circuits.

Disadvantages of belt conveyor:

1) inability to rotate in a horizontal plane;

2) presence of open rotating parts;

3) dusting during transportation of bulk cargoes.

VI.Level of standardization and unification

When developing this drive, standard assembly units were used, such as:

On reduction gear box

To connect the bearing cover to the gearbox housing (perfume cover and wheel cover)

1.1.Screw M66gX16.109.30XGSA GOST 11738-84

Screws with cylindrical head and hexagonal recess for wrench with thread diameter from 3 to 36 mm.

It is used to connect structural elements in mechanical engineering, instrument making and other industrial, industrial and construction industries together with nuts, washers of appropriate sizes.

1.2. VintM86gH20.109.30HGSA GOST 11738-84

Screws with cylindrical head and hexagonal recess for wrench with thread diameter from 3 to 36 mm.

It is used to connect structural elements in mechanical engineering, instrument making and other industrial, industrial and construction industries together with nuts, washers of appropriate sizes.

2.1. Cuff 145 x 651/3 GOST 8752-79

Used everywhere, for this case worn on a slow-moving shaft.

Reinforced single-edge cuffs with spring according to GOST 875279 are designed to seal shafts in various industries.

Cuffs work in mineral oils, diesel fuel, water with an excessive pressure up to 0.05 MPas (0.5 kgfs/cm2), speed up to 20 m/s and temperature from 60 to +170os depending on group of rubber.

2.2. Cuff 140 x 601 GOST 8752-79

Reinforced single-edge cuffs with spring according to GOST 875279 are designed to seal shafts in various industries.

Cuffs work in mineral oils, diesel fuel, water with an excessive pressure up to 0.05 MPas (0.5 kgfs/cm2), speed up to 20 m/s and temperature from 60 to +170os depending on group of rubber.

3.1. Bearing 308 GOST 8338-75

It is installed on a high-speed shaft.

Ball radial bearings are single-row. Direction of perceived loads is radial and axial in both directions. Axial - up to 70% of unused permissible radial load. They can operate under axial loads at a high speed.

3.2. Bearing 309 GOST8338-75

Installed on slow-moving shaft

Ball radial bearings are single-row. Direction of perceived loads is radial and axial in both directions. Axial - up to 70% of unused permissible radial load. They can operate under axial loads at a high speed.

4.1. Washer 6BrKMc31 GOST 6402-70

Washers GOST 640270 spring (grover) are used in construction, machine building as locking elements of the connection. Hardness of steel spring washers: 41.5-49.5 HRC.

Steel brands: 65G, 70, 3X13.

4.2. Washer 8 BrKMc31 GOST 6402-70

Washers GOST 640270 spring (grover) are used in construction, machine building as locking elements of the connection.

Hardness of steel spring washers: 41.5-49.5 HRC.

Steel brands: 65G, 70, 3X13.

On drive shaft

1. Bolt of M14 x 85 GOST 7798-70

For attachment of bearing cover

Bolt with hexagonal head of accuracy class C, metric thread size from M6 to M48, length from 8 to 300 mm. Galvanized bolts GOST 779870 are used for connection and attachment of parts, assemblies, structures in mechanical engineering and construction.

2. Nut M14 GOST 591670

Hexagonal nut low, accuracy class B, thread diameter from M1 to M48 mm. The thread complies with GOST 24705. Nuts GOST 591670 are used for connection and attachment of parts and structures together with bolts and washers of corresponding diameters.

3. Bolt M148gx115.109.3XGSA GOST 15589-70

For attachment of bearing cover

Bolt with hexagonal head of accuracy class C, metric thread size from M6 to M48, length from 8 to 300 mm. Galvanized bolts GOST 1558970 are used for connection and attachment of parts, assemblies, structures in mechanical engineering and construction.

4. Cuff 145 x 651 GOST 8752-79

Installed between bearing housing and bushing

Reinforced single-edge cuffs with spring according to GOST 875279 are designed to seal shafts in various industries.

Cuffs work in mineral oils, diesel fuel, water with an excessive pressure up to 0.05 MPas (0.5 kgfs/cm2), speed up to 20 m/s and temperature from 60 to +170os depending on group of rubber.

5. Bearing 1309 GOST 5720-75

Spherical two-row self-aligning bearing for support of drive shaft.

6.Shayba 70190631 GOST 1473-69

The washer is spring-loaded to create a larger area of ​ ​ the support surface, reduce damage to the surface of the part, prevent self-screwing of the fastening part, as well as to seal the connection.

7. Shponka18 h11 h70 GOST 23360-78

Prismatic key for coupling with drive shaft

8. Bolt of M6 x 8 GOST 7798-70

Mounting bolt with square head and stepped end with sphere of accuracy classes A and B.

9. Spline of 20х12х56 GOST 23360-78

10. Wire 1,2 Np30HGSA GOST 10543-98

Steel surfacing wire.

On the clutch

For connection of two clamps of half-couplings

Bolt M12 x 38 GOST 7798-75

Bolt with a six-sided head: • GOST 779875 (Steel: 20, 35, 40H, 09G2S, 20H13, 14H17N2, 12H18N10T) Bolts in accordance with GOST 779870 are most often used in mechanical engineering, the industry and construction as connection details

2. M12 screw x 14 GOST 17475-80

Screw is used to connect parts, with or without internal thread

Mounting screws with straight spline for screwdriver and flat end from M2 to M24

3. GOST 1478-75 M12x25.5.6 screw

GOST 147875 - set screw with cylindrical end with spline. Screw GOST 147875 is used in instrument making, mechanical engineering and other industrial and industrial industries together with nuts, washers of corresponding sizes.

Screw GOST 1478 75 is made of carbon steel, stainless steel A2 and A4, brass.