Triumph TR6

Description

The rotor and sleeve assembly is made of steel and is supported inside the aluminum body by two ‘0’ ring seals. The body has an inlet and six outlets. Fuel in the supply line is maintained at a pressure of 100-110psi by the action of the fuel pump and the relief valve. Pressurized fuel enters the body through the nylon gauge strainer in the inlet. The space between the sleeve, the aluminum body and the two ‘0’ rings is filled with fuel at pressure 100-110psi. There are six outlets, one for each cylinder. All the outlets incorporate rubber ‘0’ type seals, to seal the pressurized fuel in the space between the sleeve and the rotor. The six outlet unions locate the sleeve in the aluminum body and are sealed to the sleeve by thick O-ring (bung) seals. Leakage fuel is collected in a chamber at the drive end, and is conveyed back to the fuel tank. A small quantity of the leakage fuel is used to lubricate the rubbing surface of the cam follower. It also lubricates the Oldham type coupling, which drives the rotor at half engine-speed.

Operation

The principle of shuttle metering is illustrated below and shows an arrangement suitable for a two-cylinder engine. An engine-driven rotor, having two radial ports leading to a bore in its centre, fits in a sleeve containing fuel inlet and outlet ports. The bore of the rotor contains a small shuttle capable of moving axially between two stops, one fixed and the other adjustable. As the rotor turns within the sleeve, the rotor port at the control stop end becomes coincident with the fuel inlet port in the sleeve. Fuel from the pump now enters at pressure and drives the shuttle towards the fixed stop. displacing fuel which is discharged through the rotor and sleeve ports at that end to an injector. A further 180 degrees of rotation of the rotor it will be coincident with the other fuel inlet and second injector port, the shuttle is then driven in the opposite direction, fuel now enters at the fixed stop end of the rotor, driving the shuttle towards the control stop and displacing an identical quantity of fuel to the second cylinder. In this way. the shuttle moves to and fro between the two stops as the rotor is driven round, and at each shuttle movement an accurately metered amount of fuel is displaced and injected into the appropriate cylinder. The quantity of fuel is the product of the area of the bore and the distance of shuttle travel. the latter being determined by the setting of the control stop. Hover the mouse pointer over the picture below to animate.

Fuel distributor animation