Control for hydraulic machine having adjustable blades

Claim 2

In a hydraulic machine having a runner fixedly secured to a runner shaft for rotation therewith and blades pivotally mounted in the runner for angular adjustment about their pivot axes, a control system for adjusting said blades comprising, in combination, a hydraulic servo, including a cylinder and a piston slidable in said cylinder, rotatable coaxially with said runner; means connecting one of said cylinder and said piston to said blades for adjusting said blades, the other of said cylinder and said piston being fixed to said runner shaft; a pilot valve controlling supply of hydraulic fluid under pressure to said servo to effect relative movement of said cylinder and said piston to adjust said blades; said pilot valve including a casing and a valve spool slidable in said casing coaxially with said runner; said casing being incorporated in said one of said cylinder and said piston for rotation coaxially with said runner; said valve spool being non-rotatable; respective passage means connecting the interior of said casing to said cylinder on respective opposite sides of said piston; said valve spool having a passage extending therethrough and selectively connectable to either of said passage means responsive to relative axial displacement of said valve spool and said casing; an oil supply line connected to said valve spool in communication with the passage therethrough; drive means connected to said valve spool and operable to effect relative axial movement of said casing and said valve spool to control supply of oil to opposite sides of said piston; and means connected to the axially outer end of said valve spool and serving to balance the weight of said valve spool.

Claim 3

A control system, as claimed in claim 1, in which said valve spool is formed with bearing means spaced axially outwardly from each of said lands and engaged with said casing.

Claim 4

A control system, as claimed in claim 2, in which each of said bearing means defines axially extending passages for flow of oil for lubrication of said pilot valve.

Claim 5

A control system, as claimed in claim 2, in which said bearing means comprises respective bearing collars each disposed axially outwardly of a respective land; each collar being formed with passages extending therethrough parallel to the axis of said valve spool for flow of oil for lubrication of said pilot valve.

Claim 6

A control system, as claimed in claim 2, in which said bearing means comprises respective sets of circumferentially spaced radially extending ribs on said valve spool, each set of ribs being disposed axially outwardly of a respective land.

Claim 7

A control system, as claimed in claim 5, in which each of said fins is chamfered at the leading edge thereof.

Claim 8

In a hydraulic machine having a runner fixedly secured to a runner shaft for rotation therewith and blades pivotally mounted in the runner for angular adjustment about their pivot axes, a control system for adjusting said blades comprising, in combination, a hydraulic servo, including a cylinder and a piston slidable in said cylinder, rotatable coaxially with said runner; means connecting one of said cylinder and said piston to said blades for adjusting said blades, the other of said cylinder and said piston being fixed to said runner shaft; a pilot valve controlling supply of hydraulic fluid under pressure to said servo to effect relative movement of said cylinder and said piston to adjust said blades; said pilot valve including a casing and a valve spool slidable in said casing coaxially with said runner; said casing being incorporated in said one of said cylinder and said piston for rotation coaxially with said runner; said valve spool being non-rotatable; respective passage means connecting the interior of said casing to said cylinder on respective opposite sides of said piston; said valve spool having a passage extending therethrough and selectively connectable to either of said passage means responsive to relative axial displacement of said valve spool and said casing; an oil supply line connected to said valve spool in communication with the passage therethrough; drive means connected to said valve spool and operable to effective relative axial movement of said casing and said valve spool to control supply of oil to opposite sides of said piston; and a counterweight connected to the axially outer end of said valve spool and serving to balance the weight of said valve spool.

Claim 9

In a hydraulic machine having a runner fixedly secured to a runner shaft for rotation therewith and blades pivotally mounted in the runner for angular adjustment about their pivot axes, a control system for adjusting said blades comprising, in combination, a hydraulic servo, including a cylinder and a piston slidable in said cylinder, rotatable coaxially with said runner; means connecting one of said cylinder and said piston to said blades for adjusting said blades, the other of said cylinder and said piston being fixed to said runner shaft; a pilot valve controlling supply of hydraulic fluid under pressure to said servo to effect relative movement of said cylinder and said piston to adjust said blades; said pilot valve including a casing and a valve spool slidable in said casing coaxially with said runner; said casing being incorporated in said one of said cylinder and said piston for rotation coaxially with said runner; said valve spool being non-rotatable; respective passage means connecting the interior of said casing to said cylinder on respective opposite sides of said piston; said valve spool having a passage extending therethrough and selectively connectable to either of said passage means responsive to relative axial displacement of said valve spool and said casing; an oil supply line connected to said valve spool in communication with the passage therethrough; drive means connected to said valve spool and operable to effective relative axial movement of said casing and said valve spool to control supply of oil to opposite sides of said piston; and a counterweight connected to the axially outer end of said valve spool and serving to balance the weight of said valve spool.

Claim 10

In a hydraulic machine having a runner fixedly secured to a runner shaft for rotation therewith and blades pivotally mounted in the runner for angular adjustment about their pivot axes, a control system for adjusting said blades comprising, in combination, a hydraulic servo, including a cylinder and a piston slidable in said cylinder, rotatable coaxially with said runner; means connecting one of said cylinder and said piston to said blades for adjusting said blades, the other of said cylinder and said piston being fixed to said runner shaft; a pilot valve controlling supply of hydraulic fluid under pressure to said servo to effect relative movement of said cylinder and said piston to adjust said blades; said pilot valve including a casing and a valve spool slidable in said casing coaxially with said runner; said casing being incorporated in said one of said cylinder and said piston for rotation coaxially with said runner; said valve spool being non-rotatable; respective passage means connecting the interior of said casing to said cylinder on respective opposite sides of said piston; said valve spool having a passage extending therethrough and selectively connectable to either of said passage means responsive to relative axial displacement of said valve spool and said casing; an oil supply line connected to said valve spool in communication with the passage therethrough; drive means connected to said valve spool and operable to effect relative axial movement of said casinG and said valve spool to control supply of oil to opposite sides of said piston; and a lifting spring connected to the axially outer end of said valve spool and serving to balance the weight of said valve spool.

Claim 11

In a hydraulic machine having a runner fixedly secured to a runner shaft for rotation therewith and blades pivotally mounted in the runner for angular adjustment about their pivot axes, a control system for adjusting said blades comprising, in combination, a hydraulic servo, including a cylinder and a piston slidable in said cylinder, rotatable coaxially with said runner; means connecting one of said cylinder and said piston to said blades for adjusting said blades, the other of said cylinder and said piston being fixed to said runner shaft; a pilot valve controlling supply of hydraulic fluid under pressure to said servo to effect relative movement of said cylinder and said piston to adjust said blades; said pilot valve including a casing and a valve spool slidable in said casing coaxially with said runner; said casing being incorporated in said one of said cylinder and said piston for rotation coaxially with said runner; said valve spool being non-rotatable; respective passage means connecting the interior of said casing to said cylinder on respective opposite sides of said piston; said valve spool having a passage extending therethrough and selectively connectable to either of said passage means responsive to relative axial displacement of said valve spool and said casing; an oil supply line connected to said valve spool in communication with the passage therethrough; drive means connected to said valve spool and operable to effect relative axial movement of said casinG and said valve spool to control supply of oil to opposite sides of said piston; and a lifting spring connected to the axially outer end of said valve spool and serving to balance the weight of said valve spool.