6-36. TRANSMISSION OIL PUMP.
1. Oil pressure to operate the forward and reverse clutches of the torqmatic marine gear is provided by a
positive displacement rotor type oil pump mounted on the rear face of the flywheel housing and driven by the blower
drive shaft through two coupling hubs and a coupling.
2. The pump has a constant flow control valve incorporated with the pressure relief valve, forming a constant
flow and relief valve assembly. At all engine speeds, the oil flow is approximately 6 gpm.
3. The pump has a constant flow control valve incorporated with the pressure relief valve, forming a constant
flow and relief valve assembly. This valve assembly of the pump, controls the amount of oil pumped through the
hydraulic system regardless of engine speed. At all engine speeds, the oil flow is approximately 6 g.p.m. By controlling
the oil flow, the operating pressure will be more constant resulting in a smooth and positive reversing action. The flow
control valve is sensitive only to engine speed and operates independently of the pressure relief valve section of the
assembly which controls the pressure within the complete hydraulic system.
4. As illustrated below an inner rotor (1), locked to a shaft (2) by a drive pin revolves inside an outer rotor (3),
the bore of which is eccentric to the shaft and the inner rotor.
5. The outer periphery of the inner rotor and the inner periphery of the outer rotor are such that, when one
lobe of the inner rotor is in full engagement with a cavity of the outer rotor, the former can revolve inside the latter
without interference Since the inner rotor has six lobes compared to seven cavities in the outer rotor, the outer rotor
revolves inside the housing at six-sevenths of the speed of the inner rotor.
6. The outer rotor (3) rides in a replaceable bushing (4) pressed into the pip body. The shaft (2) rides in two
replaceable bushings - one (5) in the pump body, the other (6) in the pump cover. Bearing alignment for the rotor shaft
and true travel of the rotor in the housing are assured by the use of two dowel pins in addition to four bolts which rigidly
secure the cover to pump body.
7. Two single lip oil seals in the pump body and a single lip oil seal in the pump cover are located outside the
two oil pump shaft bushings to prevent oil leaks along the shaft.