OIL PUMPS

NZ Truth, Issue 1208, 24 January 1929, Page 19

OIL PUMPS

Two of The Main Styles There are two main classes of oil circulating pumps, the rotary and the plunger type. The former consists of two gear wheels m mesh and carried m a very closely-fitting housing. THE wheels are driven from a shaft. The action is — oil is sucked into the pump at one side between the interstices of the teeth, carried round between the *gear wheels and casing, and forced out at the, other side, because it cannot pass between the teeth as they mesh.

- /This pump -is a- remarkably, efflei en i type, and ; long lasting. It has "neithei valves nor springs to break. As long as the clearance between the wheels of the casting remains Mttremely fine it will operate perfectly.

The plunger type of pump has more working parts, and therefore, is more vulnerable, but It is still an extremely efficient device. It consists of a small piston working m a cylinder. This piston is pushed downwards by a cam on "the camshaft. A strong spring ■raises the piston when the cam clears the face and oil is thereby, drawn m through: a valve controlled by a ball and spring. The cam then forces the piston down, and oil is. forced through the exit pipe. . .