Exercises

Abstract

Completion of the above exercises by students of education contributes.

5.1 General Recommendations

Completion of the above exercises by students of education contributes to the development of the following competencies:

• 1. Ability to abstract thinking, analysis, and synthesis.

• 2. Knowledge and understanding of the subject area and understanding of professional activity.

• 3 Ability to work in a team.

Depending on the number of students in the academic group, the teacher forms teams of 2–4 people each. Each team, in agreement with the teacher, receives a task, the object of which is an assembly product. The general task for each team is:

• (a) formulation of the structure and functional purpose (principle of action) of the given assembly product;

• (b) designing an assembly 3D model of a given product;

• (c) designing of animation of assembly and disassembly of product components;

• (d) designing the assembly drawing of the product with the indication of all the necessary information following the current standards:

  • (1) image of the assembly unit (views, sections, cross-sections, remote elements), which gives a complete understanding of the design, arrangement, and relationship of the component parts, data for assembly, and control of the functioning of the assembly unit;

  • (2) overall dimensions and dimensions for reference;

  • (3) dimensions and accuracy of installation and connecting elements;

  • (4) dimensions, limit deviations, and surface roughness, which must be performed or controlled according to this assembly drawing;

  • (5) other technical requirements;

  • (6) technical characteristics (if necessary);

  • (7) numbering of all component parts of the product following the items specified in the specification.

Each team member, in agreement with the teacher, receives an individual task, the object of which is a separate part of the assembly product (a part or a series of parts). The task for each team member is:

• (e) formulation of the functional purpose of the specified part (parts);

• (f) designing a 3D model of a given part (parts);

• (g) designing the working drawing of the specified part (parts) with the indication of all the necessary information following the current standards:

  • (1) image of the part (views, sections, cross-sections, remote elements), which gives a complete understanding of the design, placement, and interconnection of surfaces, data for manufacturing, and quality control;

  • (2) dimensions: overall, connecting, dimensions of individual elements of the part, dimensions for reference;

  • (3) size tolerances;

  • (4) roughness of the part surfaces;

  • (5) tolerances on the shape and geometric relationship of surfaces;

  • (6) technical requirements that should be ensured during the manufacturing of the part (heat treatment, coating, etc.);

  • (7) additional data necessary for the manufacturing and control of the part;

  • (8) special requirements for jointly processed parts;

  • (9) the part material.

5.2 Exercise 1—Roller Shock Absorber

Brief Description of the Product. The roller shock absorber is used to guide the workpieces moved during rolling and absorb shock loads (Fig. 5.1).

Fig. 5.1

Roller shock absorber (assembly view)

Fig. 5.2

Roller shock absorber (exploded view)

Fig. 5.3

Roller shock absorber (drawing)

The beat when feeding the workpiece is transmitted from roller 6 (Fig. 5.2) on the spring 7 shock absorber through rod 4. Fork 10 is installed at the end of the rod, which can only move in the axial direction, for which there is a guide key 18. The initial force of pressing the spring on the roller is adjusted using the screw nut 16. To the rubbing surfaces of the roller parts through the channels of the center shaft 8 is lubricated.

Cylinder 2 is attached to body 1 with six pins 17 and nuts 15. The six bottom holes in the body are for attaching the roller shock absorber to the frame or bed of the unit.

The list of components of the roller shock absorber (Fig. 5.3) is specified in Table 5.1.

Table 5.1 Parts list

5.3 Exercise 2—Hydraulic Crane

Brief Description of the Product. The plug-type hydraulic crane (Fig. 5.4) is intended for switching the fuel supplied from the main and additional tanks to the fuel pump.

Fig. 5.4

Hydraulic crane (assembly view)

Fig. 5.5

Hydraulic crane (exploded view)

Fig. 5.6

Hydraulic crane (drawing)

The crane consists of a cast iron body 1 (Fig. 5.5), on which there are two mounts for fixturing; plug 2 for overlapping holes; packing nut 3 and handle 4, with the help of which the plug is turned.

The list of components of the hydraulic crane (Fig. 5.6) is specified in Table 5.2.

Table 5.2 Parts list

5.4 Exercise 3—Puller

Brief Description of the Product. The puller (Fig. 5.7) is used when dismantling the hub of the car. The bolts 2 (Fig. 5.8) are screwed into the corresponding sockets of the hub, and the heel moves by rotating the lead screw 3. At the same time, it rests against the axle shaft and squeezes the last one out of the hub.

Fig. 5.7

Puller (assembly view)

Fig. 5.8

Puller (exploded view)

The list of components of the puller (Fig. 5.9) is specified in Table 5.3.

Fig. 5.9

Puller (drawing)

Table 5.3 Parts list

5.5 Exercise 4—Carriage

Brief Description of the Product. The carriage of the overhead conveyor (Fig. 5.10) is used to move goods along a monorail (or I-beam) and is used in warehouses, farms, and workshops. It is also an integral part of the undercarriage (electric hoist), which is supplied with a manual or machine drive.

Fig. 5.10

Carriage (assembly view)

The carriage consists of a suspension bar and two symmetrical roller parts (Fig. 5.11). Roller 2 (carriage wheel) is mounted on center pin 5 on ball bearings. The center pin is fixed in bracket 1. The suspension is rigidly fixed between the planes of the brackets.

Fig. 5.11

Carriage (exploded view)

The list of components of the carriage (Fig. 5.12) is specified in Table 5.4.

Fig. 5.12

Carriage (drawing)

Table 5.4 Parts list

5.6 Exercise 5—Wheel

Brief Description of the Product. The wheel (Fig. 5.13) is used in a trolley designed for transporting workpieces and finished products in a machine workshop.

Fig. 5.13

Wheel (assembly view)

In two holes of bracket 1, fixed center pin 3 (Fig. 5.14). In body 2, two ball bearings 14 are pressed, which are clamped by cover 4 and spacer bush 6. In covers 4 and 5, there are grooves for sealing rings 12 and 13, which prevent dust from entering the bearings. On the cylindrical surface of the body, bandage 7 is tensioned, which is pressed by cover 4. The wheel is attached to the base of the cart with four bolts.

Fig. 5.14

Wheel (exploded view)

The list of components of the wheel (5.15) is specified in Table 5.5.

Fig. 5.15

Wheel (drawing)

Table 5.5 Parts list

5.7 Exercise 6—Traveling Wheel

Brief Description of the Product. The traveling wheel (Fig. 5.16) of the under-crane trolley serves as a support for it and guides the trolley along the rail.

Fig. 5.16

Traveling wheel (assembly view)

The wheel is mounted on two roller bearings 12 (Fig. 5.17) on the center pin 5, fixed by the center pin holder 4 in the carriage frame.

Fig. 5.17

Traveling wheel (exploded view)

In the wheel hub, the bearings are fixed with two covers 3 and a spacer sleeve 2. The covers have a stuffing box that protects the bearing from contamination. Bearings are periodically lubricated with a lubricator 11.

The list of components of the traveling wheel (Fig. 5.18) is specified in Table 5.6.

Fig. 5.18

Traveling wheel (drawing)

Table 5.6 Parts list

5.8 Exercise 7—Gear Pump

Brief Description of the Product. Gear pumps (Fig. 5.19) are used to supply fluid under pressure up to 0.03 Pa. They are used to supply liquid, lubricants, and fuel. High-pressure gear pumps (0.06–0.07 Pa) are used to a limited extent and are manufactured with great care. Gear pumps are simple in design and have a small number of parts but are sensitive to fluid contamination, so an inlet filter should be used.

Fig. 5.19

Gear pump (assembly view)

The pump work gears 4 (Fig. 5.20) rotate in opposite directions. The gear teeth, disengaging, create a reduced pressure, as a result of which the lubricant enters the suction zone and, in the cavities between the gear teeth, is transferred (along the periphery) to the discharge zone, where it is displaced by the teeth, which enter into an engagement. An increased pressure is created in the discharge zone, under the influence of which the lubricant enters the pipeline. The pump is made on plain bearings with a cast-iron body 1 and cover 5; it has a check valve 10 at pressure.

Fig. 5.20

Gear pump (exploded view)

The list of components of the gear pump (Fig. 5.21) is specified in Table 5.7.

Fig. 5.21

Gear pump (drawing)

Table 5.7 Parts list

5.9 Exercise 8—Gear Pump

Brief Description of the Product. The car's gear pump (Fig. 5.22) is used to supply lubricant to the rubbing parts of the engine. The pump is installed in the engine body and mounted on the fourth main bearing cap using a bracket integral to the pump body.

Fig. 5.22

Gear pump (assembly view)

The pump is driven by the engine camshaft gear through an intermediate shaft. When the leading shaft 2 (Fig. 5.23) rotates, the lubricant from the oil pan (through the oil receiver) enters the suction zone and, in the gashes between the teeth of the gear wheels 6, rotating in opposite directions, is transferred (distilled) to the discharge zone. Lubricant is forced out of the gashes by the meshing teeth and accumulates in the discharge zone. As a result, the pressure increases, and the lubricant is sent to the coarse filter. From the filter, it enters the lubrication line.

Fig. 5.23

Gear pump (exploded view)

The list of components of the gear pump (Fig. 5.24) is specified in Table 5.8.

Fig. 5.24

Gear pump (drawing)

Table 5.8 Parts list

5.10 Exercise 9—Clip

Brief Description of the Product. The clip (Fig. 5.25) is used in load-lifting mechanisms. The hoisting mechanism cable (not shown in the figure) envelops block 3 (Fig. 5.26), where a replaceable sleeve 8 is pressed. Block 3 rotates on pin 6. Inside the center pin, some channels are filled with grease through a hole closed by screw 11. Pin 6 is supported by fork 1, connected by pin 7 to suspension 2, and rotating around this pin. A lifting hook is screwed into the threaded hole of suspension 2 (not shown in the figure).

Fig. 5.25

Clip (assembly view)

Fig. 5.26

Clip (exploded view)

The list of components of the clip (Fig. 5.27) is specified in Table 5.9.

Fig. 5.27

Clip (drawing)

Table 5.9 Parts list

5.11 Exercise 10—Spool Pneumatic Apparatus

Brief Description of the Product. The spool pneumatic apparatus (Fig. 5.28) is designed to disconnect the working chamber from the supply line and communicate this chamber with the atmosphere when the input lever is deflected at a given angle.

Fig. 5.28

Spool pneumatic apparatus (assembly view)

When the lever is returned to its original position, the spool separates the chamber from the atmosphere and connects it to the line. Lubricant is supplied to the rubbing surfaces of the spool valve using piston 8 (Fig. 5.29).

Fig. 5.29

Spool pneumatic apparatus (exploded view)

The list of components of the spool pneumatic apparatus (Fig. 5.30) is specified in Table 5.10.

Fig. 5.30

Spool pneumatic apparatus (drawing)

Table 5.10 Parts list

5.12 Exercise 11—Valve Pneumatic Apparatus

Brief Description of the Product. The air valve (Fig. 5.31) of the brake cock is used to supply compressed air from the air cylinder to the brake chambers. It consists of body 6, valve 1, valve seat 2, push-rod 4, and spring 5 (Fig. 5.32).

Fig. 5.31

Valve pneumatic apparatus (assembly view)

Fig. 5.32

Valve pneumatic apparatus (exploded view)

The air valve opens when the brake pedal is pressed. Compressed air from the cylinder enters the brake chambers. When the brake pedal is released, the spring lifts the push-rod and closes the valve. It cuts off the compressed air supply to the brake chambers.

The list of components of the valve pneumatic apparatus (Fig. 5.33) is specified in Table 5.11.

Fig. 5.33

Valve pneumatic apparatus (drawing)

Table 5.11 Parts list

5.13 Exercise 12—Pneumatic Reducing Valve

Brief Description of the Product. The pneumatic reducing valve (Fig. 5.34) is designed to regulate—limit and maintain a constant pressure of the working medium in the pipeline.

Fig. 5.34

Pneumatic reducing valve (assembly view)

The allowable pressure in the outlet branch is limited by plunger 3 (Fig. 5.35), which closes the pipeline when the pressure rises above the prescribed one and is regulated by pressing cover 2 on spring 4.

Fig. 5.35

Pneumatic reducing valve (exploded view)

The list of components of the pneumatic reducing valve (Fig. 5.36) is specified in Table 5.12.

Fig. 5.36

Pneumatic reducing valve (drawing)

Table 5.12 Parts list

5.14 Exercise 13—Pneumatic Cylinder

Brief Description of the Product. Pneumatic cylinders (Figs. 5.37 and 5.38) are used as a power link in fixtures and drive mechanisms of clamping devices. They use compressed air. Pneumatic cylinders provide remote adjustment and control of the clamping force and are characterized by fast action. The large piston area (with a diameter of 80 mm) allows you to get significant forces at low pressure.

Fig. 5.37

Pneumatic cylinder (assembly view)

Fig. 5.38

Pneumatic cylinder (exploded view)

The list of components of the pneumatic cylinder (Fig. 5.39) is specified in Table 5.13.

Fig. 5.39

Pneumatic cylinder (drawing)

Table 5.13 Parts list

5.15 Exercise 14—Sliding V-Block

Brief Description of the Product. The sliding V-block (Fig. 5.40) serves as a fixed support when machining parts with a diameter of 40–200 mm on drilling, boring, milling, and planning machines. It consists of body 1 (Fig. 5.41), which is fixed relative to the tool with keys (the key is not shown in the drawing) and fixed with machine tool bolts. Prismatic jaw members 2 and 3 are moved along the body guides by rotating screw 4 (with right and left threads).

Fig. 5.40

Sliding V-block (assembly view)

Fig. 5.41

Sliding V-block (exploded view)

The list of components of the sliding V-block (Fig. 5.42) is specified in Table 5.14.

Fig. 5.42

Sliding V-block (drawing)

Table 5.14 Parts list

5.16 Exercise 15—Milling Fixture

Brief Description of the Product. The fixture (Fig. 5.43) is used to quickly and accurately set the workpiece in the desired position concerning the cutting tool (milling cutter). The fixture is installed on the movable table of the horizontal milling machine and is attached to it with two bolts (the bolts are not shown in the drawing) included in the grooves of plate 1 (Fig. 5.44).

Fig. 5.43

Milling fixture (assembly view)

Fig. 5.44

Milling fixture (exploded view)

The workpiece of the “lever” type (shown in the drawing as a solid thin line) is placed on the support plane of the slider 2. The position of the workpiece is fixed with pin 4, on which it is clamped with a clamp 5 on one side and a V-block 3 moved by a screw 6 on the other side. The slider is fixed in the desired position with screws 9.

The list of components of the milling fixture (Fig. 5.45) is specified in Table 5.15.

Fig. 5.45

Milling fixture (drawing)

Table 5.15 Parts list

5.17 Exercise 16—Locking Device

Brief Description of the Product. The end locking device (Fig. 5.46) is designed to connect the ends of the hoses when bypassing compressed air from one container to another.

Fig. 5.46

Locking device (assembly view)

When connecting the ends of the hoses with a union nut 7 (Fig. 5.47), the balls 10 are squeezed out from the valve seat and the body, thereby opening the air passage. When the ends of the hoses are separated, the balls under the action of the spring 6 and air pressure tightly close the outlet openings of both ends.

Fig. 5.47

Locking device (exploded view)

The list of components of the locking device (Fig. 5.48) is specified in Table 5.16.

Fig. 5.48

Locking device (drawing)

Table 5.16 Parts list

5.18 Exercise 17—Roller

Brief Description of the Product. This roller (Fig. 5.49) design is installed on the metal structures of the lifting transport mechanism and serves to guide the steel cable.

Fig. 5.49

Roller (assembly view)

The cable enters the groove of roller 3 (Fig. 5.50) and bends around the roller at a certain angle. The roller rotates freely on pin 5, which is fixed in the lugs of fork 2 by plate 7, which is included in the pin slot. Plate 7 is connected to fork 2 with two screws 10. To reduce friction during the rotation of the roller, an oiler is installed in the threaded hole of pin 5, from which lubricant flows through the cylindrical channels to the friction surfaces. Fork 2 is connected to bearing slide 4 with bolts 9 and nuts 12. Bearing slide 4 with fork 2 is fixtured with bolts 8 and nuts 11 on bracket 1. Bolts 8 and 9 can move along the grooves of parts 1 and 2, which is necessary when adjusting the position of the roller.

Fig. 5.50

Roller (exploded view)

The list of components of the roller (Fig. 5.51) is specified in Table 5.17.

Fig. 5.51

Roller (drawing)

Table 5.17 Parts list

5.19 Exercise 18—Tension Roller

Brief Description of the Product. The tension roller (Fig. 5.52) is designed for tensioning belts in V-belt drives.

Fig. 5.52

Tension roller (assembly view)

The base of the roller is frame 1 (Fig. 5.53), fixed with 12 bolts at the installation site. Two ball bearings 14 are installed on the cylindrical part of slider 3, on which roller 2 rotates freely. The slider moves in the guide grooves of the frame by screw 9. When the screw rotates, nut 7 acts on the slider through spring 10.

Fig. 5.53

Tension roller (exploded view)

The list of components of the tension roller (Fig. 5.54) is specified in Table 5.18.

Fig. 5.54

Tension roller (drawing)

Table 5.18 Parts list

5.20 Exercise 19—Supporting Roller

Brief Description of the Product. The rollers (Fig. 5.55) are installed on the sheet rolling mill on both sides to support the rolled sheets while feeding and receiving them from the rolls.

Fig. 5.55

Supporting roller (assembly view)

Fig. 5.56

Supporting roller (exploded view)

Fig. 5.57

Supporting roller (drawing)

Table 5.19 Parts list

The roller is driven by an electric motor. Shaft 7 (Fig. 5.56) is supported by rolling bearings 14. The bearings are lubricated with grease coming from oilers pressed into the holes of the covers 3. The roller bodies 1 are bolted to the frame of the rolling mill.

The list of components of the supporting roller (Fig. 5.57) is specified in Table 5.19.

5.21 Exercise 20—Adjustable Roller

Brief Description of the Product. The roller device (Fig. 5.58) is used when transporting sheet material, which rolls over rollers.

Fig. 5.58

Adjustable roller (assembly view)

Fig. 5.59

Adjustable roller (exploded view)

Fig. 5.60

Adjustable roller (drawing)

Table 5.20 Parts list

Body 1 (Fig. 5.59) is attached to the machine's frame with four bolts (the frame and bolts are not shown in the drawing).

When screw 7 is rotated, wedge 4 will slide along the inclined plane of the body. As a result, the supporting block 2 with roller 3 will rise or fall. After installing the roller at the desired level, the supporting block is fixed with bolts 8 and nuts 11. The roller rotates on center pin 5, which is fixed on the supporting block with screws 9.

To the rubbing surfaces of the roller and the pin through the holes and special grooves in the axle comes thick grease from the oiler. The oiler is pressing into the center pin hole 5 (not shown in the drawing).

The list of components of the adjustable roller (Fig. 5.60) is specified in Table 5.20.