is a small reference application for smartphones and tablets based on Android. It presents qualifications (all tolerance values provided by the standard) for part sizes from 1 to 500 mm. The reference book is intended for specialists in the field of mechanical engineering, designing or manufacturing machine parts and various equipment.
The application serves as an analogue of reference data on the normalization of the dimensions of products given in GOST or in other technical documentation. The table of qualifications in it contains rows with smaller size ranges and columns with designations of existing tolerances. At the same time, only a small part of it is displayed on the device screen, and to find the necessary values, you need to scroll it up, down or sideways. At the same time, columns and rows with designations remain anchored to the edges of the window. To make it easier to find the places where they intersect, the backgrounds of neighboring cells are slightly contrasted with each other.
The application is distributed completely free of charge and does not contain advertising inserts. Searching for data in it is no more difficult than in a traditional paper reference. The table is designed in pleasant blue tones, with a clear and easy to read black font. As disadvantages of the directory, some users note the lack of search and the possibility of grouping columns. However, the application can be extremely useful for owners of outdated devices with not the best hardware - it launches quickly and is undemanding to resources.
Designed in accordance with the standard curriculum subject"Tolerances, landings and technical measurements". The Unified System of Tolerances and Fits is considered in detail, the basic standards for tolerances and fits of rolling bearings, keyed, splined and threaded connections, gears and gears, parts on plastics are imposed. Means of technical measurements of linear and angular dimensions are given, a method for their selection is given. The basic concepts of dimensional chains are considered. Designed for students of educational institutions implementing educational programs vocational education.
PREFACE.
The content of the subject "Tolerances, landings and technical measurements" includes the volume compulsory knowledge which must be mastered by a specialist and which he must be able to use without resorting additionally to reference books and textbooks. The peculiarity of the subject lies in the fact that it is necessary to remember a large amount of concepts, definitions, formulations, without which it is impossible to learn the material. The purpose of studying this subject is to acquire the knowledge necessary for right choice tolerances and fits, measurement of controlled parameters, a reasonable choice of measuring instruments and methods of control, as well as the correct use of indications of controlled parameters on the drawing.
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Download the book Tolerances, landings and technical measurements, Zavistovsky V.E., Zavistovsky S.E., 2016 - fileskachat.com, fast and free download.
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Lecturer R.A. Tsikunova
Section topic. Lesson topic. |
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1. Introduction. Product quality in mechanical engineering |
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1.1 Product quality indicators |
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1.2 Interchangeability and its types |
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2. Basic concepts of sizes, tolerances and fits |
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2.1 Terms and definitions. |
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2.2 Graphic representation of tolerances and landings. |
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2.3 Concepts about conjugations. |
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2.4 Free sizes. |
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3. Basic principles for building a unified system of tolerances and landings |
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3.1 Unified system of tolerances and landings (ESDP). |
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3.2 Principles of construction of the ESDP. |
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3.3 Shaft system and hole system. |
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3.4 Deciphering the designations of tolerances and landings. |
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3.5 Tables of limit deviations in the ESDP. |
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3.6 Thematic test |
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4. Deviations and tolerance of shapes and surfaces |
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4.1 Deviations and tolerances of the shape of surfaces |
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4.2 Deviations and tolerance of the location of surfaces. |
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4.3 Conventions deviations and shape tolerance in the drawings |
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4.4 Methods and means of control and measurement of deviations from the shape and location of surfaces. |
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4.5 Roughness parameters. Designation on the drawings |
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4.6 Designation on drawings |
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5. Tolerances and fits of rolling bearings |
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5.1 Purpose and classification of rolling bearings |
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5.2 Fittings of rolling bearings. |
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6. Tolerances for keyed and splined connections |
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6.1 Purpose and types of keyed and splined connections. |
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6.2 Landings of keyed connections. Centering splines. |
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7. Tolerances and means of measuring angles and smooth cones. |
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7.1 The concept of normal cones and angles |
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7.2 Smooth conical joints. |
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Practical work No. 1 Measuring the magnitude of angles |
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8. Tolerances of threaded surfaces and connections. |
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8.1 General classification of threads. |
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8.2 Means and methods of control and measurement of threaded connections. |
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9. Tolerances of gears and gears |
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9.1 The main elements of the gear and transmission. |
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9.4 Inspection and measurement of gears. |
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ABOUT mandatory test No. 1 |
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10. Technical measurements. |
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10.1 Metrology. Units of physical quantities. |
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10.2 Metrological indicators of measuring instruments. |
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10.3 Types and methods of measurements |
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10.4 Mechanical measuring instruments. |
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Practical work №2. Measurement of the magnitude of radial and end runout. |
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11.1 The concept of a dimensional chain, the closing link. |
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11.2 Calculation of dimensional chains |
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Total |
Lecturer R.A. Tsikunova
"Tolerances, landings and technical measurements"
The plan for studying the subject is divided into sections. When studying the sections, you need to know the following questions.
1. Introduction. Product quality in mechanical engineering.
Product quality in mechanical engineering. Product quality indicators.
The concept of the inevitability of errors in the manufacture of parts and assembly. Types of errors: errors in size, shape and location of surfaces; surface roughness.
1.2 Basic information about interchangeability and its types. Standardization, unification, normalization.
2 Basic concepts of dimensions, tolerances and fits.
2.1 The concept and definition of the main types of dimensions and deviations: nominal, actual, limit dimensions; upper limit deviation, lower limit deviation, actual deviation.
Designation of nominal dimensions and maximum deviations in the drawings. Size conditions.
2.2 Approval. Tolerance field. Schemes for the location of tolerance fields.
2.3 Mating and non-mating surfaces, male and female. The concepts of "hole" and "shaft"; "landing", "clearance", "preload". Types of landings: landings with a guaranteed gap, landings with a guaranteed interference fit, transitional landings. Landing conditions. Landing parameters. Rules for calculating landings.
2.4 Limit deviations of dimensions with unspecified tolerances (free dimensions).
3. Basic principles for building a unified system of tolerances and landings.
3.1 Unified system of tolerances and landings (ESDP) Purpose of the ESDP.
3.2 Principles of construction of the ESDP. The concepts of intervals of nominal sizes, the main deviation, qualifications in the ESDP. Rules for the formation of tolerance fields.
3.3 Shaft system and hole system. Tolerance fields of holes and shafts in ESDP.
3.4 Symbols of tolerance fields and fits in the shaft system and the hole system.
3.5 Tables of limit deviations in the ESDP. Use of tables.
4. Deviations and tolerances of the shape and location of surfaces. Surface roughness.
4.1 Concepts: form, element, nominal element, real element, adjoining element.
The concept of deviations and tolerances of the shape of flat and cylindrical parts. Symbols for deviations and tolerances of the form in the drawings.
Methods and means of control and measurement of form deviations.
4.2 The concept of deviations and tolerances for the location of surfaces.
4.3 Symbols and rules for setting deviations in the shape and location of surfaces in the drawings.
4.4 Basic methods and means of controlling deviations and tolerances of the location of surfaces.
Total deviations and tolerances of the shape and location of surfaces; radial and end beating. Methods for measuring their values, tools and devices used.
4.5 The concept and definition of surface roughness. Surface roughness parameters.
4.6 Designation of surface roughness in the drawings. Surface roughness control by comparison with roughness samples. Measurement of surface roughness using a profilograph and profilometer.
5. Tolerances and landings of rolling bearings.
5.1 Purpose and classification of rolling bearings.
5.2 Marking of rolling bearings. Fittings of rolling bearings.
6. Tolerances for keyed and splined connections.
6.1 Purpose and types of keyed and splined connections, their normalized parameters.
6.2 Tolerances and fits of keys in the grooves of the bushing and shaft. landing groups. Designation of keyed connections in the drawings. Methods for centering spline joints. Landings and layouts of tolerance fields of the main elements of spline joints when various methods centering. Designation of tolerances and landings of splined joints in the drawings.
7. Tolerances and means of measuring angles and smooth cones.
7.1 General concept of normal angles and taper. Units of measurement of angles and tolerances for angular dimensions in mechanical engineering. Degrees of accuracy of angular dimensions. Taper as the main parameter of a conical connection.
7.2 Smooth conical joints; their main elements; tolerances and landings.
The designation of the taper in the drawings. Control of angles and cones with gauges. General information about means of measuring cones and angles: angular measures, angular templates, squares, goniometers with vernier, machine-building levels.
8. Tolerances of threaded surfaces and connections.
8.1 General classification of threads. Basic elements of metric thread. Nominal dimensions and thread profiles. Fundamentals of thread interchangeability.
Tolerances and fits of metric threads. Degrees of thread accuracy. Designation on the drawings of tolerance fields and the degree of accuracy of the thread.
8.2 General information about the means and methods for monitoring and measuring threaded surfaces. Gauges for checking the thread of bolts and nuts, gauges working and control. Thread templates. Measuring the average diameter of an external thread using the three-wire method. Micrometers with inserts.
9. Tolerances of gears and gears.
9.1 The main elements of the gear and transmission. Classification of gears. Performance requirements for gears.
Tolerances of gears and gears. Degrees of accuracy of gears. Side clearance in the gear train, guaranteed side clearance rates. Accuracy standards for gears; the norm of kinematic accuracy, smoothness of operation and contact of gear teeth.
9.2 General information about the methods and means of monitoring and measuring the parameters of gears and gears. Features of standardization of accuracy standards for bevel and worm gears.
The designation of the accuracy of gears and gears in the drawings.
10. Technical measurements
10.1 Fundamentals of technical measurements. Metrology as a scientific basis for technical measurements.
10.2 Basic metrological characteristics of measuring instruments.
10.3 Types and methods of measurements. Measurement errors.
10.4 Mechanical means of measuring linear quantities - plane-parallel end blocks of length, caliper tools, micrometric tools, gauges.
11. Basic concepts of dimensional chains
11.1 The concept of a dimensional chain, the closing link. Types of dimensional chains.
11.2 Rules for calculating the dimensional chain for maximum and minimum.
Questions for self-control.
1. What is meant by product quality in mechanical engineering? Name the indicators of product quality.
2. Name and describe the types of errors
3. Name the main types of interchangeability.
4. Give a definition of the main types of dimensions and deviations: nominal, actual, limit dimensions; upper limit deviation, lower limit deviation, actual deviation.
5. How is the designation of nominal dimensions and maximum deviations in the drawings?
6. What is a tolerance, a tolerance field? How are tolerance field layouts produced?
7. Give a definition of mating and non-mating surfaces, covered and covering surfaces.
8. Define the concepts of "hole" and "shaft"; "landing", "clearance", "preload".
9. Name the types of landings and give their definition.
10. What are the conditions for the formation of landings? Landing parameters. Rules for calculating landings.
11. What is the essence and purpose of the unified system of tolerances and landings (ESDP)?
12. Name the principles of building the ESDP.
13 Define the concepts of intervals of nominal sizes, the main deviation, qualifications in the ESDP.
14. What are the rules for the formation of tolerance fields?
15. Define the terms shaft system and hole system.
16. How are tolerance fields for holes and shafts formed in ESDP? Symbols of tolerance fields and landings in the shaft system and the hole system.
17. Define the concepts: form, element, nominal element, real element, adjacent element.
18. Give a definition of what is the deviation and tolerance of the shape of flat and cylindrical parts. 19. How are the deviations and tolerances of the form indicated in the drawings?
20. Name the methods and means of control and measurement of form deviations.
21 Define what is the deviation and tolerance of the location of surfaces.
22. How are the deviations and tolerance of the location of surfaces in the drawings indicated?
23. Name the main methods and means of controlling deviations and tolerances for the location of surfaces.
24. Give a definition of what the total deviations and tolerances of the shape and location of surfaces are; radial and end beating. What are the methods for measuring their values, the tools and devices used.
25. Give a definition of surface roughness. Name the parameters of surface roughness.
26. How is the surface roughness indicated in the drawings?
27. How is surface roughness controlled?
28. What is the purpose and classification of rolling bearings?
29. How are rolling bearings marked?
30. Name the landings for the installation of rolling bearings.
31. Name the purpose and types of keyed and splined connections, their normalized parameters.
32. Name the tolerances and fit of the keys in the grooves of the bushing and shaft. landing groups.
33. How is the designation of keyed connections in the drawings?
34. Name the methods for centering splined joints.
35. Show landings and layouts of tolerance fields for the main elements of splined joints with various centering methods.
36. How is the designation of tolerances and landings of splined joints in the drawings?
37. Give general concept about normal angles and taper.
38. What are the units of measurement of angles and tolerances for angular dimensions in mechanical engineering. Degrees of accuracy of angular dimensions.
39. What are the main elements of smooth conical joints? Tolerances and fit of conical joints.
40. How is the designation of taper in the drawings?
41. What measuring instruments are used to control angles and cones?
42. Name general classification threads.
43. What are the main elements of a metric thread?
44. Name the tolerances and fit of the metric thread. Degrees of thread accuracy. How is the designation on the drawings of the tolerance fields and the degree of accuracy of the thread?
45. What methods and means are used to control metric threads?
46. Name the main elements of the gear and transmission. How are gears classified?
47. Name the degrees of accuracy of gears. What is backlash in a gear train, guaranteed backlash standards, gears accuracy standards?
48. Name the methods and means of monitoring and measuring the parameters of gears and gears.
49. What are the features of the standardization of accuracy standards for bevel and worm gears?
50 How is the designation of the accuracy of gears and gears in the drawings.
51. What is metrology?
52. Name the main metrological characteristics of measuring instruments. Types and methods of measurements. Measurement errors.
GuidelinesGuidelines on the implementation of electronic distance learning systems in the activities of educational institutions of the Russian Federation table of contents (2)
GuidelinesBearings serve as supports for shafts and rotating axes. Rolling bearings are standard assembly units of increased accuracy, which are manufactured at specialized bearing factories using special equipment of increased accuracy. The industry of the CIS countries produces bearings with an outer diameter from 1.5 to 2600 mm. Bearings Ǿ20…200 mm are produced in large series. The bearings have complete external interchangeability in the connecting surfaces, determined by the outer diameter of the outer ring and the inner diameter of the inner ring, and incomplete internal interchangeability between the rolling elements and rings. Lecture 7 Bearing rings and rolling elements are selected by a selective method. Complete external interchangeability allows quick mounting and replacement of worn rolling bearings while maintaining good quality.
Accuracy of geometric parameters of rolling bearings Determined by deviations for the following parameters: Width of the inner and outer rings B; Width of the outer ring C, if the inner ring has a different width; Nominal diameters of the bore of the inner ring and the seating surface of the outer ring (d, D); Average bore diameters of the inner and outer rings (dm, Dm); dm=(dmax+dmin)/2, Dm=(Dmax+Dmin)/2, dmax, Dmax and dmin, Dmin are the largest and smallest diameters of the bearing rings seating surfaces.
Radial runout of the raceway of the inner ring relative to its hole Ri; Radial runout of the outer ring raceway relative to its outer cylindrical surface of the hole Ra; Mounting height of a single-row tapered roller bearing T; Inconstancy of the ring width Up. form accuracy and relative position surfaces of bearing rings and their roughness; the accuracy of the shape and dimensions of the rolling elements in one bearing and the roughness of their surfaces; rotational accuracy, characterized by radial and axial runout of the raceways and the ends of the rings.
Tolerance fields (GOST) for the housing and shaft and tolerance fields for the outer and inner rings of the bearing (GOST)
Influence of the accuracy class of a rolling bearing on the choice of fits For bearings of accuracy classes 0 and 6, the recommended set of tolerance fields for seating surfaces is the same. For higher accuracy classes of rolling bearings, the set of tolerance fields for seating surfaces changes somewhat, in particular, tolerance fields of more accurate qualifications are used.
The influence of the type of loading of the bearing rings on the choice of fits The inner rings of the bearings rotate with the shaft, the outer rings installed in the housing are stationary. The radial load P is constant in magnitude and does not change its position relative to the housing. I scheme
Scheme II Influence of the type of loading of the bearing rings on the choice of landings The outer rings of the bearings rotate together with the gear wheel. The inner rings of the bearings, mounted on the axle, remain motionless relative to the housing. The radial load P is constant in magnitude and does not change its position relative to the body
Scheme III Influence of the type of loading of the bearing rings on the choice of fits The inner rings of the bearings rotate with the shaft, the outer rings installed in the housing are stationary. Two radial loads act on the rings, one is constant in magnitude and direction P, the other is centrifugal Pc, rotating with the shaft. The resultant of the forces P and Rc performs a periodic oscillatory motion, symmetrical with respect to the direction of the force P.
