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Crank mechanism
| Fig. 3.5. Details of the cylinder block and crank mechanism: 1 - top compression ring; 2 - lower compression ring; 3 - oil ring; 4 - piston; 5 - the piston pin; 6 - a lock ring; 7 - rod; 8 - connecting rod bearings; 9 - a cover of the bottom head of a rod; 10 - an arm; 11 - the block of cylinders; 12 - a lining; 13 mounting crankshaft rear oil seal; 14 - rear oil seal; 15 - a flywheel; 16 - back cover of the cylinder; -probka Holes 17 for draining the coolant; 18 - centering sleeve; 19 - the crankshaft; 20 - third-liner with thrust bearing shoulders; 21 - Cover the crankshaft bearing; 22 - insert crankshaft bearing
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Composition mechanism (see. Fig. 3.5), such as a gasoline engine. The crankshaft is similar in design to the shaft of the petrol engine. The dimensional characteristics of the crankshaft shown in Table. 3.2.
Table 3.2 Parameters of the crankshaft Parameter | Size, mm | Diameter of radical necks: |
| 0 Group I | 52,967-52,975 | 1 th group | 52,959-52,967 | Group 2 | 52,951-52,958 | Diameter crankpins: |
| 0 Group I | 49,968-49,974 | 1 th group | 49,962-49,968 | Group 2 | 49,954-49,961 | Axial clearance: |
| nominal | 0,05-0,18 | maximum | 0.3 | Radial clearance: |
| nominal | 0,039-0,063 | maximum | 0,085 | Ovality necks, no more | 0.05 | The taper of the necks, no more | 0.05 |
Checking the technical condition of the crankshaft is similar checks crankshaft gasoline engine. Flywheel cast iron, has a ring gear, designed to start the engine starter motor is attached to the crankshaft flange bolts. The maximum allowable surface runout at the clutch disc of 0.15 mm. Pistons are cast from an aluminum alloy with a high content of silicon. The combustion chamber is formed in the piston crown. The connecting rods of steel, forged, I-section, with a straight connector of the bottom head. Main bearing shells, thin-walled aluminum alloy on a steel base. Dimensional groups of loose leaves of different paint (tab. 3.3). The width of the insert of the third main bearing 27,95 mm.
Table 3.3 Thickness indigenous liners Colour coding | Thickness | Yellow | 1,816-1,820 | Green | 1,820-1,824 | Brown | 1,824-1,828 | Black | 1,828-1,832 | Blue | 1,832-1,836 |
To replace worn inserts in parts come loose leaves of radical bearings of two repair sizes at the crankshaft journal, proshlifovanny 0.25 and 0.50 mm. Pistons repair sizes are manufactured with an increase of 0.25-0.50 mm outer diameter. Each piston has two compression and one oil ring. Gaps in the piston rings are shown in the Table. 3.4. Rings set labeled "TOP" upwards. Piston fingers are similar in construction and are installed as a gasoline engine, but have a larger diameter. Dimensional characteristics of connecting rod and piston group are presented in Table. 3.5. Technical condition is similar to checking for gasoline engines.
Table 3.4 The gaps in piston rings Ring | The gap in the castle, mm | The gap between the piston ring and the groove, mm | Top compression | 0,12-0,30 | 0,060-0,095 | Lower compression | 0,38-0,53 | 0,040-0,075 | Scraper | 0,30-0,55 | 0,030-0,070 |
Table 3.5 Parameters connecting rod and piston group Parameter | Size, mm | Bore: |
| 1 th group | 84,465-84,479 | Group 2 | 84,475-84,485 | Group 3 | 84,485-84,495 | Group 4 | 84,495-84,505 | 5th group | 84,505-84,519 | 1 oversize 0.25 | 84,715-84,765 | 2 oversize 0.50 | 84,965-85,015 | The gap in conjunction piston-cylinder | 0,025-0,045 | The diameter of the piston pin hole | 24,991-24,999 | The axial clearance of the connecting rod on the crankshaft, not more | 0.3 | The radial clearance of the bottom head of a rod | 0,031-0,051 | The diameter of the piston pin | 24,994-25,000 | Interference in conjunction piston and piston pin | 0,004 | Radial clearance in conjunction piston pin and connecting rod: | nominal | 0,025 | maximum | 0,044 |
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