Calculation and design of cylindrical gearbox

Contents

Introduction

Regulatory References

1 Kinematic analysis of mechanism

2 Material selection and definition of allowable stresses

2.1 Selection of materials and definition of permissible stresses for the first (high-speed) toothed pair

2.2 Selection of materials and determination of permissible stresses for the second (slow-moving) gear pair

3 Design calculation of the mechanism

3.1 Design calculation of high-speed transmission

3.2 Design calculation of low-speed transmission

4 Calculation of open transmission

5 Design calculation of shafts

6 Sketched layout

6.1 Shaft Design

6.2 Preselection of bearings

6.3 Selection of transmission and bearing lubrication method

6.4 Selection of bearing unit covers and seals

6.5 Graphic part of gearbox sketch layout

7 Determination of internal force factors in sections of slow-moving shaft

8 Check of bearings for durability

9 Selection of keys and their strength check

10 Selection of couplings

11 Selection of gearbox parts fits

12 Conclusion

13 List of sources used

Paper

Course design: 56 p., 10 Fig., 11 Table, 4 sources, illustrative part - 1 sheet of A1 format, 1 sheet of A3 format and 1 sheet of A4 format.

REDUCTION GEAR, SHAFT, UNDERCARRIAGE, BOLT, WASHER, GEAR CLUTCH, GEAR WHEEL, ELECTRIC MOTOR, KEY, FIT, HOUSING, ROTATION SPEED, TORQUE

The object of the course project is the mechanical drive of the ball mill.

Purpose: selection of electric motor calculation and selection of optimal dimensions of reduction gear, determination of torque, selection and check of bearings for durability, selection of keys and check for crushing and cutting, execution of sketched arrangement of reduction gear, selection of coupling according to torque, selection of method of lubrication of bearings and gears, selection of materials for manufacture of gear pairs.

Introduction

In any mechanism, each part has its own significance, due to which it works. The gearbox is the main element that reduces angular velocity, increasing torque, which allows you to transfer less power to the corresponding part. The gearbox is a set of gears and gears that are in the crankcase, which allows you to protect all parts from any damage, including dirt, and also provides the necessary lubrication.

The manufacturing of the gear box is a complex process, during which, in accordance with the transmitted load, it is necessary to select materials for toothed ones, calculate the structural dimensions of the shafts and the housing, put bearings capable of withstanding this load, choose a lubrication method for toothed pairs and bearings, and make appropriate covers. All these calculations are given in this course project. The reduction gear is made strictly according to the drawing made in advance and the technical characteristics indicated on it.

Before machining, all parts are rengenocontrol to detect microcracks, shrinkage shells, loosening. Machining is carried out on the plane of the connector, perimeter and mating surfaces. on milling machines. Subsequently, these surfaces are used as technological bases for subsequent processing. Cover and body pre-treated at joints are connected by process bolts and are coordinated relative to each other by two pins, holes for which are drilled and cut together in body and cover.

Machining of holes, seats for bearings of gear wheels and attachment surface of engine housing, feedback sensor is performed on coordinate boring machines. In order to ensure the required accuracy in alignment and perpendicular to the axes of the gear wheels, the treatment of the cover and body is carried out jointly after their assembly. After machining, the parts of the gearbox housing are sent to the coating shop, where they are anodized.

Thus, performing all the actions correctly, following the technical requirements, the output will be a gearbox of excellent quality, which will last a long time if the operating rules are observed and maintenance is carried out on time.

Conclusion

During the work on the course project, methods for calculating typical parts of general-purpose machines were mastered and fixed and the 4A90L4Y3 engine was selected, the main skills of designing the reduction gear box and its parts were obtained.

Design calculation of cylindrical spur gear is made according to criterion of contact strength of teeth surface. After determining the dimensions of the gears, check calculations were made according to the criterion of contact and bending endurance. All strength conditions are met. The dimensions of the structural elements of the gears, the shape and dimensions of the elements of the gearbox housing were determined and agreed with standards.

Fatigue strength calculation was performed for the most dangerous sections of shafts. Methods for lubrication of gears and bearings are selected.

The resulting drive design fully meets the modern requirements for these mechanisms.