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Pic. 5. Engine lubrication system.
1. Oil supply channel to the main bearing of the crankshaft; 2. Oil supply channel from the main bearing to the connecting rod; 3. Oil sump; 4. Crankshaft; 5. Oil level indicator; 6. Oil filter; 7. Bypass valve; 8. Filter element; 9. Anti-drainage valve; 10. Oil pump; 11. Oil supply channel from the pump to the filter; 12. Horizontal channel for supplying oil to the oil line; 13. Channel in the cylinder block for supplying oil to the oil pump drive gear support and ignition distributor; 14. Front crankshaft oil seal; 15. Channel in the neck of the crankshaft; 16. Oil supply channel from the oil line to the main bearing and to the oil pump drive shaft and ignition distributor; 17. Oil pump drive shaft and ignition distributor; 18. Hole in the sprocket for chain lubrication; 19. Camshaft sprocket; 20. Main channel in the camshaft; 21. Annular groove on the middle bearing neck of the camshaft; 22. Channel in the camshaft cam; 23. Oil filler cap; 24. Channel in the camshaft bearing journal; 25. Camshaft bearing housing; 26. An inclined channel in the cylinder head for supplying oil to the gas distribution mechanism; 27. Vertical channel in the cylinder block for supplying oil to the gas distribution mechanism; 28. Main channel in the cylinder block; 29. Sensor control lamp and oil pressure gauge; 30. Exhaust manifold for crankcase ventilation; 31. Flame arrester; 32. Exhaust hose; 33. Oil separator cover; 34. Oil separator; 35. Oil separator drain pipe; 36. Spool on the axis of the throttle valve of the primary chamber of the carburetor; 37. Calibrated hole; 38. Inlet pipe; 39. Throttle valve; 40. Carburetor; 41. Crankcase suction hose into the throttle space of the carburetor; 42. Air filter; I. Scheme of crankcase ventilation; II. The operation of the spool device of the carburetor; III. At a low frequency of rotation of the engine crankshaft; IV. At an average engine speed.
1. Oil supply channel to the main bearing of the crankshaft; 2. Oil supply channel from the main bearing to the connecting rod; 3. Oil sump; 4. Crankshaft; 5. Oil level indicator; 6. Oil filter; 7. Bypass valve; 8. Filter element; 9. Anti-drainage valve; 10. Oil pump; 11. Oil supply channel from the pump to the filter; 12. Horizontal channel for supplying oil to the oil line; 13. Channel in the cylinder block for supplying oil to the oil pump drive gear support and ignition distributor; 14. Front crankshaft oil seal; 15. Channel in the neck of the crankshaft; 16. Oil supply channel from the oil line to the main bearing and to the oil pump drive shaft and ignition distributor; 17. Oil pump drive shaft and ignition distributor; 18. Hole in the sprocket for chain lubrication; 19. Camshaft sprocket; 20. Main channel in the camshaft; 21. Annular groove on the middle bearing neck of the camshaft; 22. Channel in the camshaft cam; 23. Oil filler cap; 24. Channel in the camshaft bearing journal; 25. Camshaft bearing housing; 26. An inclined channel in the cylinder head for supplying oil to the gas distribution mechanism; 27. Vertical channel in the cylinder block for supplying oil to the gas distribution mechanism; 28. Main channel in the cylinder block; 29. Sensor control lamp and oil pressure gauge; 30. Exhaust manifold for crankcase ventilation; 31. Flame arrester; 32. Exhaust hose; 33. Oil separator cover; 34. Oil separator; 35. Oil separator drain pipe; 36. Spool on the axis of the throttle valve of the primary chamber of the carburetor; 37. Calibrated hole; 38. Inlet pipe; 39. Throttle valve; 40. Carburetor; 41. Crankcase suction hose into the throttle space of the carburetor; 42. Air filter; I. Scheme of crankcase ventilation; II. The operation of the spool device of the carburetor; III. At a low frequency of rotation of the engine crankshaft; IV. At an average engine speed.
The engine lubrication system is combined: under pressure and splashing.
Under pressure, the main and connecting rod bearings, camshaft bearings, gear bushings and the oil pump drive shaft and ignition distributor are lubricated.
Oil flowing from the gaps and splashed by moving parts lubricates the cylinder walls, pistons with piston rings, piston pins in the piston bosses, the timing chain, the valve lever bearings, and the valve stems in their guide bushings.
The capacity of the lubrication system is 3.75 liters. The oil level is controlled by the marks on the pointer 5. Normal oil pressure is 0.35-0.45 MPa (3.5-4.5 kgf/cm2) at a crankshaft speed of 5600 rpm. The minimum pressure must be at least 0.08 MPa (0.8 kgf/cm2)
The lubrication system includes: an oil pump 10, a suction pipe with a filter mesh attached to the pump housing, a full-flow oil filter 6 mounted on the left front side of the engine; oil pressure reducing valve built into the intake pipe, sensors 29 for the pointer and oil pressure warning lamp.
The circulation of oil during engine operation is as follows. The oil pump 10, driven by a pair of gears with helical teeth, sucks oil from the crankcase through the filter mesh of the intake pipe and delivers it through channel 11 to the full-flow filter 6. The filtered oil through channel 12 enters the longitudinal main channel 28, passing along the block on the left side, and from there through channels 16 drilled in the partitions of the cylinder block, it is supplied to the main bearings of the crankshaft. Oil is supplied to the central support of the camshaft through channels drilled in the cylinder block 27, in the cylinder head 26 and in the camshaft bearing housing. The cylinder head gasket has a copper-lined hole through which oil passes from channel 27 of the block to channel 26 of the head.
The 1st, 2nd, 4th and 5th main bearing shells each have two holes through which oil enters the annular grooves on the inner surfaces of the bearing shells. From the grooves, part of the oil goes to lubricate the main bearings, and the other part through channels 2 drilled in the necks and cheeks of the crankshaft to the connecting rod bearings, and from them, through the holes in the lower heads of the connecting rods, a jet of oil enters the cylinder mirrors at the moment the bearing hole coincides with channel in the crankpin. Since 1990, connecting rods have been manufactured without a hole in the lower head, and oil from it is not supplied to the cylinder walls.
The oil that has passed to the central bearing of the camshaft through the annular groove 21 in the bearing journal enters the main channel 20 of the camshaft, and from the channel through the holes in the cams and bearing journals to the working surfaces of the cams, levers and shaft bearings.
Oil from the first bearing of the roller 17 of the oil pump drive and the ignition distributor flows through a channel drilled in the roller itself to the second bearing. Oil is supplied to the gear hub of the oil pump drive and the ignition distributor through a separate channel 13 from the cavity in front of the oil filter. The remaining parts are lubricated by splashing and gravity.
Oil pump
Oil pump (see fig. 4) - gear type, installed inside the crankcase and attached to the cylinder block with two bolts. The drive gear of the pump is fixed on the roller, and the driven gear rotates freely on the axis pressed into the pump housing. The oil enters the pump through the oil intake pipe, passing through the filter mesh. A pressure reducing valve is built into the body of the oil receiver. When the pressure in the lubrication system rises above the permissible level, the oil is squeezed out by the pressure reducing valve, and the excess oil is bypassed from the pressure cavity into the oil receiver cavity. The pressure at which the pressure reducing valve operates is provided by a spring of appropriate elasticity, set at the factory. This pressure is not adjustable.
Oil filter
The oil filter is screwed onto the fitting and pressed against the annular shoulder on the cylinder block. The tightness of the connection is ensured by a rubber gasket installed between the filter cover and the block shoulder. The filter has an anti-drainage valve 9, which prevents oil from draining from the system when the engine is stopped, and a bypass valve 7, which is activated when the filter element is clogged and bypasses oil in addition to the filter into the main channel 28. The oil is filtered by a paper element 8.
Crankcase ventilation
Crankcase ventilation is closed, forced type, does not allow pressure increase in the crankcase due to the penetration of exhaust gases into it. Crankcase gases are sucked into the manifold 30 of the air filter 42 through the oil separator 34, the exhaust hose 32 with a flame arrester 31. From the manifold 30 gases can go in two ways: directly into the air filter 42, as well as through the hose 41, the spool 36 on the throttle axis in the throttle space of the carburetor.
With an increase in the speed of the crankshaft when the throttle valve is opened, the spool 36 rotates and opens an additional path for crankcase gases through a groove in the spool.