Injection pump for internal combustion engines

Claim 1

A fuel-injection pump for an internal combustion engine including a hollow casing, bearing means in said casing and an automatic hydraulic timing device rotatably supported by said bearing means, wherein said automatic device comprises in combination: a. a tubular cam-carrying body mounted for rotation directly in the pump casing; b. at least one pump-operating cam carried on the outer periphery of said tubular shaft; c. a driving shaft extending into said tubular body and being formed with a head arranged near one end of said body and mounted for rotation directly in said body and with a portion smaller in diameter than the inner bore of said body provided with an adapter for connection to a rotary drive input extending beyond the other end of said body; d. means acting directly between said tubular cam-carrying body and said driving shaft for preventing any relative axial displacement of said body and shaft; e. an annular support in the bore in said tubular body in proximity of said other end of said body and rotatably supporting the driving shaft near said adapter, said annular support defining, together with the tubular body the drive shaft and the respective head, an axially extending annular chamber; f. injection-timing means including an axially displaceable coupling member arranged in said annular chamber in the form of a sleeve provided with internal and external splined connections to the driving shaft and the tubular body respectively, at least one splined connection being helical; g. fluid pressure servocontrol means within said tubular body to vary the axial position of said sleeve, said servocontrol means including an annular piston mounted for sliding movement on the part of the driving shaft arranged between said sleeve and said annular support and bearing against the end of said sleeve facing said support to effect axial displacement thereof; h. a centrifugal governor, controlling the supply of pressure fluid to said servocontrol means dependently upon the rotary speed of the driving shaft, housed in the bore in the tubular body between the head of the drive shaft and a cover closing said one end of the tubular body.