[3] LUBRICATING SYSTEM

The lubricating system within this engine consists of an oil strainer, oil pump, relief valve, oil filter cartridge and oil switch

The oil pump draws in lubricating oil from the oil pan through the oil strainer. The oil flows down to the filter cartridge, where it is further filtered.

Then the oil is force-fed to the crankshaft, connecting rods, id Ie gear, camshaft and rocker arm shaft and lubricates each part.

So m e pa rt o f oi I, s pI a s he d by t he crankshaft or Ieaki ng and droppi ng from gaps of each part, lubricates these parts: pistons, cylinders, small ends of connecting rods, tappets, push rods, inlet and exhaust valves.

(1) Rocker Arm Shaft

(2) Rocker Arm

(3) Governor Gear

(4) Idle Gear 2

(5) !dle Gear 1

(6) Oil Switch

(7) Oil Pump

(8) Oil Strainer

(9) Relief Valve

(10) Oil Filter

(J I ) Crankshaft

(12) Piston

(\ 3) Camshaft

(1) Oil Pump

The oil pump in this engine is a trochoid pump, which is included in gear case and driven directly by the crankshaft.

Inside the pump body, the 10 lobe inner rotor is eccentrically engaged with the 11 lobe outer rotor, When the inner rotor is rotated by the crankshaft, the outer rotor al so rotates sam e di rect i o n. According to the rotation, volume of each space, generated between the i nner and oute r rotor, changes and act as the pump.

(1) Pump Gear

{2) Crankshaft

(3) Oil Pump

C09SF007

(4) Pump Cover

(S) Inner Rotor

(6) Outer Rotor

C095F00B

» (A) (B)

OF4JF110

(A) Aii Flow (Air Bleeding)

(B) Fuel Flow

(1) Injection Pump

C095F010

(2) Governor

The fuel is sucked by the feed pump (5) to feed from the fuel tank (1) into the injection pump (2) throu gh the fuel fi I ter (3). The n, th e fu el i s distributed by the injection pump to the injection nozzles to time to the injection of each cylinder of the engine, and i njec ted into the com busti on chamber.

Air bleeding of the fuel system is done without manual operation. Simply fill the fuel tank and turn on the cock of the fuel fi I1er, and air wiII be auRoma tically removed from the fuel system. This eliminates the need of any other special operation for a air bleeding.

()) Fuel TarJk

(2) lnjection Pump

(3) Fuel Filter

(4) Cock

(S) Feed Pump

(6) Injection NozzIe

Employed as an injection pump is a Bosch fVlD-type mini injection pump with com pa ct, Iig htvveig ht design and enhanced reliability. The injection pump, as shown in the figure, is composed of a plunger (S), tappet {6), control rack (3), delivery valve (2), etc.

A damping valve is provided inside the delivery valve holder (1), allovvi ng stable injection witliout cavitation or secondary injection throughout all stages from idling to full operation.

(1) Delivery Valve Holder

(2) Delivery Valve

(3) ContrOl Rack

(3) Cylinder

(S) Plunger

(6) Tappet

With centrifugal mechanical weight system, this governor works in the whole range of speeds It keeps the engi ne speed and c ontrol s Lhe eng ine output.

This governor provides the governor shaft, which rotates two times as the fuel camsha ft, performing quick response to the load IIuctuation.

(1) Fork Lever2

(2) Work Neue r 1

{3) Fly Weight

(4) Governor Sleeve

(S) Governor Shaft

(6) Torque Spring

(7) Start Spring

(8) Governor Swmg J

(9) Govenor Sping 2

W AtStart

When the engine is started, more fuel is required than in running. At starting, fork lever 1 (4) is pulled Teftward by the start spring (12), because fly weights

(7) have no centri fugal force. Control rack ( 11) moves to a position for over limit discharging of fuel to assure easy starting.

(1) Speed Control Lever

(2) Governor Spring 1

(3) Governor Spring 2

(4) Fork Lever 1

(5) Governor Shaft

(6) Governor Sleeve

M At Idling

(7) Fly Weight

(8) Fork Lever 2

(9) Idle Limit Spring

(10) Control Rack Pin

(11) Control Rack

(12) Start Spring

When speed control lever is set at idling position after the engine is started, high speed governor spring 1 does not work at all and also low speed governor sp ring 2 does on I y a I itt I e a ct i o n. Therefore, governor sleeve is pushed leftward by a centrifugal force of fly weights. Fork lever 1 and control rack are moved rightward by the sleeve and then idling limit spring is compressed by control rack. As a result, the control rack is kept at a position where a centrifugal force of fly weights and forces of start spring, governor spring 2 and idling limit spring are balanced, providing stable idling.

0343C11?

M At Middle/High Speed Running

-rhe engine speed is controlled when the tension of governor springs 1 and 2, which are pulled by the speed control lever, and the centrifugal force of fly weights are balanced. When the speed is reduced with load increased, the centrifugal force of fl y weights becomes smal ie r th an I he te nsion of governor springs 1 and 2. As a result, the control rack is moved leftward and fuel inj ecti on amount is increased to produce an engine torque required for theload.

M AtHigh Speed Running with Overload

When an overload i s appl i ed to th e e ngin e running at a high speed, the centri fugal force of fly weights become small as the speed is reduced, and fork lever 2 (4) ispulled leftward by governor springs 1 and 2, inc reasing fuel injecti on. Fork I ever 2 becomes ineffective to increase fuel injection when it is stopped by maximum output limit screw (5). After that when the force of torque spring (3) becomes larger than the centrifugal forCe of J‘ly weights, fork lever 1 (2) moves leftward to increase fuel injection, driving the engine continuously with a high torque.

(1) control Rack

(2) Fork I ever 1

(3) Torque

(3) Injection Nozzle

(4) Fcrk Lever 2

(5) Maximum output Limit Screw

This nozzle is throttle-type. Fuel fed from the pump is pressurized to push the needle valve (5) up and the luel is then injected. The needle valve is pressed by thenozzle spring (7) through the push rod (3). Fuel over flow is passed from nozzle holder center through the fuel overflow pipe (1) to the fuel tank. The injection pressure is provided 13.7 to 14.7 MPa ( 140 to 150 kgf/cm2 , 1991 tO 2133 psi). Injection pressure can be control Ied by i nsert i ng shims between nozzle hol der bod y (2) and adj usti ng washers (8). the pressure increases approx. 981 kPa ( 13 kgf/cm2 , \ 85 psi) when inserted a 0.1 mm (0.0039 in.) shim. lnjec tion nozzle is also precision finished as is the injection pump, treat it carefully and protect from water and dust.

(J) Overflow Pipe

(2) Nozzle Holder

(3) Push Rod

(4) Re taming Nut

(S) Needle Valve

(6) Nozzle Body

(7) Spring

(8) Adjusting Washer

(9) injection Pipe