Coursework for the design of a cylindrical two-stage gearbox

Contents

Introduction. ______________________________________________________________

Source data. ______________________________________________________

1. Kinematic calculation. _______________________________________________

2. Calculation of cylindrical two-stage reduction gear box _____________________

3.Excise design. _____________________________________________

4. Construction of gear parts. ______________________________________

5. Calculation of key connections. _________________________________________

6. Calculation of shafts for static strength and fatigue resistance. __________

7. Calculation of rolling bearings for the assigned service life. _________________________

8.Selection of lubricants and lubrication system. ______________________

9.Construction of housing parts ____________________________________

10. Selection of elastic coupling ______________________________________________

11. Frame Design _______________________________________________

List of literature used. ______________________________________

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 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. One of the areas of solving these problems is improving the design training of students of higher technical educational institutions.

The implementation of this course project completes the general technical cycle of student training. This is our first independent creative engineering work, during which we actively use knowledge from a number of disciplines passed: material resistance, metal technology, interchangeability, etc.

The objects of course design are usually drives of various machines and mechanisms (for example, belt and chain conveyors, individual, test stands), using most parts and assemblies of general engineering applications. Engineering is a creative task. It is known that each design problem has several solutions. It is important to compare competing options according to certain criteria and choose one of them - optimal for these specific conditions.

Design recommendations are accompanied by an analysis of the working conditions, machining, and assembly of subassemblies and parts. When performing a course project, we must successively go from choosing a mechanism scheme through the multivariability of design solutions to its implementation in detailed drawings; getting involved in engineering creativity, learning from previous experience, learns to anticipate new ideas in the creation of machines that are reliable and durable, economical to manufacture and operate, convenient and safe to maintain.

In my task there is a gear cylinder gear, a clutch (open gear).

II Selection of lubricants and lubrication system

To reduce friction power losses and wear intensity of friction surfaces, as well as to prevent them from jamming, gouging, corrosion and better heat removal, the friction surfaces of the parts must have reliable lubrication.

Lubrication system - immersion. A distinctive feature is the immersion of the worm so that the initial cylinder is completely immersed in an oil bath.

The choice of lubricant is based on the experience of the machines. The principle of assigning the oil grade is as follows: the higher the circumferential speed of the wheel, the lower the viscosity of the oil, the higher the contact pressures in the teeth, the greater the viscosity of the oil. Therefore, the required viscosity of the oil is determined depending on the contact voltage and the circumferential speed of the wheels. Circumferential velocity is determined in advance, then required kinematic viscosity and oil grade are found by speed and contact stresses.

According to Tables 11.1 and 11.2 (P.F. Dunaev, O.P. Lelilikov) oil is selected

I-G-A-32as per GOST 17479.4-87

And - industrial oil

D - for hydraulic systems

A - oil without additives

32 - kinematic viscosity class

The bearings of the reduction gear are lubricated with the same oil, since we have a crankcase lubrication system.

XI Frame Design

The frame configuration and size determine the type and dimensions of the gearbox and motor. The frame is conveniently constructed of two longitudinally arranged channels and three to four transverse channels welded to them. Channels are arranged by flanges outside. This arrangement is suitable for bolting the assemblies to the frame. The channel type is selected based on the diameter of the foundation bolt. Since the diameter of the gearbox attachment bolt to the frame d = 20 (mm), we accept the diameter of the foundation bolt D = 36 (mm) (see [1] p.336). According to Table 17.1 (see [1] p.266) the diameter of the hole in the frame d1 = 18... 20 (mm). Considering the above, according to GOST 824072 (see [4] p.473) we select channel No. 20. The number of bolts attaching the frame to the floor is selected based on the length of the frame. As per instructions [1] p.336 we accept number of bolts z = 4. To ensure the coaxiality of the input shaft of the reduction gear box and the electric motor, it is necessary to add two equal angles 20 × 50 GOST 50 to channel No. 8509. The size of the weld leg is selected based on the smallest thickness of the frame parts. Such a part is an edge. T.O. seam leg 3 (mm). Manual arc welding as per GOST 526480.