| 摘要 |
An oil pump is disclosed for a motor-driven apparatus and in particular for lubricating the cutting chain of a chain saw. The oil pump has a pump piston that is rotatable about its longitudinal axis and has a control cam for its axial reciprocation, which as it revolves comes into contact engagement with a control bolt. A control slide upon which a biasing force is exerted is associated with the pump piston. The stroke of the pump piston is limited during normal operation by means of the control slide. If an increased amount of lubricating oil is required, the limitation on the piston stroke effected by the control slide is overcome by moving the control slide away from the pump piston counter to its biasing force, so that the pump piston can move through its maximum total stroke as predetermined by the control cam. |
