Coursework on Machine Parts: "Design of Chain Conveyor Drive"

Contents

TABLE OF CONTENTS

INTRODUCTION

1 MOTOR SELECTION AND KINEMATIC CALCULATION OF DRIVE

1.1 Selection of electric motor (power and speed)

1.2 Sketch of motor with dimensions

1.3 Determination of total gear ratio and distribution between gear box and belt

1.4 Determination of power, angular speed, frequency of rotation, the moment on drive shafts

2 GEARBOX GEAR CALCULATION

4 DESIGN CALCULATION OF SHAFTS AND PURPOSE OF GEARBOX SKETCH LAYOUT

5 CALCULATION OF GEARBOX SHAFTS FOR STATIC STRENGTH

5.1 Calculation of low-speed shaft

5.2 Calculation of high-speed shaft

6 UPDATED CALCULATION OF GEARBOX SHAFTS

6.1 Test calculation of low-speed shaft for endurance

6.2 Test calculation of high-speed shaft for endurance

7 DURABILITY CHECK OF GEARBOX ROLLING BEARINGS

7.1 Durability check for low-speed shaft

7.2 Durability check for high-speed shaft

8 CHECK OF STRENGTH OF KEY AND SPLINED (TOOTHED) CONNECTIONS OF REDUCTION GEAR SHAFTS

8.1 Selection and calculation of key connection under gear wheel

8.2 Selection and calculation of the key connection under the toothed coupling

8.3 Selection and calculation of splined (toothed) connection at output end of shaft

8.4 Selection and calculation of splined (toothed) connection of half-couplings

8.5 Calculation of bolted connections

9 CALCULATION OF BUILT-IN SAFETY CLUTCH AND SELECTION OF STANDARD CLUTCH

9.1 Calculation of safety friction cone coupling

9.2 Calculation of compression spring

9.3 Selection of coupling (gear) as per GOST

10 DETERMINATION OF DESIGN DIMENSIONS OF GEARS AND GEARBOX HOUSING

10.1 Gear Design

10.2 Design dimensions of V-belt pulley

10.3 Gearbox Housing Design

CONCLUSION

BIBLIOGRAPHIC LIST

APPENDIX A Kinematic diagram of chain conveyor drive

APPENDIX B Safety Coupling Assembly Drawing

APPENDIX TO Gearbox general view drawing

APPENDIX D Low-speed shaft drawing

APPENDIX E Gear Drawing

INTRODUCTION

The drive is a set of devices designed to drive machines and mechanisms. The drive performs work on turning one type of energy into another and transfers this energy to the executive mechanism.

Drives of various types are used everywhere, from machine tools in heavy industry to various home appliances.

The purpose of the course design is to design and calculate the chain conveyor drive according to the proposed specification, which defines the main parameters of the working tool, the requirements for the drive, the life of the drive, the conditions under which the drive will operate, the load schedule and the starting moment multiplicity.

During the design, the most optimal kinematic diagram of the drive is determined, which corresponds to the specification as much as possible. Within the framework of this project, the electric motor is selected (calculation of its power and test for starting), the design of a cylindrical single-stage reduction gear (closed cylindrical gear train), the development of a V-belt transmission transmitting torque from the electric motor to the reduction gear box and a safety clutch protecting the drive from destruction during overloads.

The objectives of the project are to calculate the above-mentioned drive units satisfying the conditions of failure-free operation of the drive during the time specified in the terms of reference.

10.3 Gearbox Housing Design

The gearbox housing is used for arrangement and coordination of transmission parts, their protection from contamination, organization of lubrication system, as well as perception of forces arising in engagement of the gearbox pair, bearings and open transmission. The most common method of manufacturing cases is casting from gray cast iron. This gearbox adopts the design of a split housing consisting of a cover (upper part of the housing) and a base (lower part).

The overall dimensions of the housing are determined by the dimensions of the reduction pair located inside, taking into account the wall thicknesses and equal to 367x225x312 mm

The thickness of the walls of the housing δ and cover δ1 are accepted in section 4, item 2.

5 flanges are used in the designed gearbox housing:

1) The foundation flange of the housing base is designed to attach the reduction gear box to the foundation frame (plate). Attachment points are located at the most possible distance L1 from each other (L1 = 333 mm). The reducer is attached to the frame (plate) by four M14 bolts located in the housing niches. Niche height: h01 = 60 mm.

2) Flange of bearing boss of cover and housing base is used for connection of cover and base of detachable housings. Bearing tightening screws M12 (4 pieces) are located closer to the bearing hole at a distance L2 from each other (L2 = 143 mm). Flange height h2 = 35 mm.

3) The connecting flange of the cover and the base of the housing is designed to connect the cover of the housing with the base along the entire outline of the connector. Connecting screws M10 (4 pieces) are located at a distance L3 = 333 mm.

4) The flange of the bearing assembly cover is designed to close the bearing assembly opening. This gearbox has cut-in covers.

5) Flange for inspection window cover is used for attachment of oil indicator cover for oil level control. It is attached by two screws M5 at a distance L5 = 50 mm from each other.

Gearbox housing parts and elements:

1) The inspection panel is used for control of gearbox assembly and inspection during operation. It is located on the upper cover of the housing, which also allows it to be used for filling oil. The hatch is closed with a cover aligned with the perfume intended to communicate the internal cavity of the reducer with the external environment in order to prevent pressure increase inside the housing due to oil heating. The cover is attached to the housing with screws with a secret head. In order not to get dust inside the body, a gasket is installed under the cover.

2) Locating pins are used to fix the relative position of the body cover and the base in subsequent assemblies. 2 conical pins with diameter d = 8 mm and length l = 40 mm are used.

3) Push screws are designed to ensure that the glued cover and the base of the housing are disconnected during disassembly. This gearbox uses 2 M10 screws.

4) Eyes are intended for lifting and transportation of cover of housing and assembled reduction gear box. Eyes are cast together with cover of reduction gear box housing.

5) Hole for oil indicator and drain plug. Both holes are located nearby on one side of the base of the housing in a place accessible for control and use. The lower edge of the drain hole is located at the bottom level and is made with a slope of 1... 2 ° towards the hole. The oil indicator hole is located at a height sufficient to accurately measure the upper and lower oil levels. When installing the oil indicator, a sealing gasket made of paronite is used.

10.4 Lubrication selection. Lubricating device

Lubrication of gears and bearings is used to protect against corrosion, reduce friction coefficient, reduce wear, remove heat and wear products from friction surfaces, reduce noise and vibrations.

For general-purpose reducers, continuous lubrication with liquid oil by a crankcase method is used (dipping into an oil bath). This method is used for gears at circumferential speeds from 0.3 to 12.5 m/s.

The oil grade is selected depending on the calculated values of contact stresses in the teeth αH and the actual circumferential speed of the wheels V as per [3, Table 10.29] using the data from section 2, p.3, 11

We choose the variety: I-G-S-100 (industrial for hydraulic systems with antioxidant additives, kinematic viscosity class - 100).

For single-stage gearboxes with dip lubrication, the volume of the oil bath is determined on the basis of 0.4... 0.8 l per 1 kW of transmitted power [3, c.255]. For this reducer we accept oil volume equal to 2.5 l

Bearing lubrication device is described in Section 4, Item 6.

CONCLUSION

As a result of the course project, a chain conveyor drive was developed. The 4A112M4UZ electric motor was selected and checked by the required power and starting torque. A V-belt transmission consisting of four V-belts was calculated, checked according to the condition of durability of the belts. Further, a cylindrical single-stage reduction gear was designed, the engagement of which was checked for fatigue by contact stresses. Check calculations of gearbox shafts for static strength and endurance were made. Verification calculations of bearing units for static and dynamic lifting capacity were also carried out. A safety friction cone clutch built into the V-belt pulley was designed. A chain coupling for connecting the slow-moving shaft of the reduction gear and the drive sprocket of the conveyor is also selected according to GOST.

Based on the calculations, assembly drawings of the reduction gear and coupling were compiled, as well as working drawings of the slow-moving shaft and gear wheel, as well as a general drive diagram.

The objectives and objectives of the project have been achieved. According to calculations, the drive is fully operational and can ensure failure-free operation during a given service life.