Proportional directional control unit

Claim 2

A hydraulic servo device for proportioning fluid under pressure, comprising: manually operably means movable to positions represenTing the desired quantity of fluid to be delivered, servo valve means positioned by said manually operable means, said servo valve means having supply port means, first load port means and second load port means, a relatively stationary internally toothed outer gear member, a carrier member rotatable about an axis, at least one planet gear rotatably supported on said carrier having an axis spaced from the axis of said carrier member, said planet gear having external teeth interengaging the internal teeth on said outer gear and defining therewith expanding and contracting tooth spaces upon relative rotation of said gears, first port means in said carrier member continuously communicating with one of said spaces, and second port means in said carrier member continuously communicating with the other of said spaces, said supply port means being selectively connectable with said first and second port means in said carrier member so that as the servo valve means ports fluid to one of the carrier port means the carrier will follow movement of the servo valve means, said first load port means being selectively connectable with one of said port means in said carrier member, said second load port means being selectively connectable with the other port means in said carrier member.

Claim 3

A hydraulic servo device for proportioning fluid under pressure, comprising: manually operable means movable to positions representing the desired quantity of fluid to be delivered, servo valve means positioned by said manually operable means, said servo valve means having supply port means, first load port means and second load port means, a relatively stationary internally toothed outer gear member, a carrier member rotatable about an axis, at least one planet gear rotatably supported on said carrier having an axis spaced from the axis of said carrier member, said planet gear having external teeth interengaging the internal teeth on said outer gear and defining therewith expanding and contracting tooth spaces upon relative rotation of said gears, first port means in said carrier member continuously communicating with one of said spaces, and second port means in said carrier member continuously communicating with the other of said supply port means being selectively connectable with said first and second port means in said carrier member so that as the servo valve means ports fluid to one of the carrier port means the carrier will follow movement of the servo valve means, said first load port means being selectively connectable with one of said port means in said carrier member, said second load port means being selectively connectable with the other port means in said carrier member, said carrier member having a centrally disposed bore therein, said bore having a first port opening communicating with said first port means and a second port opening communicating with said second port means, said servo valve means including a cylindrical member rotatably supported for limited rotating movement in said bore, said supply port means and said first and second load port means being defined in said cylindrical member and being selectively communicable with said first and second openings.

Claim 4

A hydraulic servo device for proportioning fluid under pressure, comprising: manually operable means movable to positions representing the desired quantity of fluid to be delivered, servo valve means positioned by said manually operable means, said servo valve means having supply port means, first load port means and second load port means, a relatively stationary internally toothed outer gear member, a carrier member rotatable about an axis, at least one planet gear rotatably supported on said carrier having an axis spaced from the axis of said carrier member, said planet gear having external teeth interengaging the internal teeth on said outer gear and defining therewith expanding and contracting tooth spaces upon relative rotation of said gears, first port means in said carrier member continuously communicating with one of said spaces, and second port means in said carrier member continuously communicating with the other of said supply port means being selectively connectable with said first and second port means in said carrier member so that as the servo valve means ports fluid to one of the carrier port means the carrier will follow movement of the servo valve means, said first load port means being selectively connectable with one of said port means in said carrier member, said second load port means being selectively connectable with the other port means in said carrier member, said carrier member having a centrally disposed bore therein, said bore having a first port opening communicating with said first port means and a second port opening communicating with said second port means, said servo valve means including a cylindrical member rotatably supported for limited rotating movement in said bore, said supply port means and said first and second load port means being defined in said cylindrical member and being selectively communicable with said first and second openings.

Claim 5

A hydraulic servo device as defined in claim 2, wherein said supply port means and said first and second load port means lie in a plane transverse to said cylindrical servo valve member.

Claim 6

A hydraulic servo device as defined in claim 1, including a plurality of gears rotatably supported on said carrier member and having external teeth interengaging the teeth on said outer gear.

Claim 7

A hydraulic servo device as defined in claim 1, wherein said first and second load port means are adapted to be connected to drive a load in either direction of movement, said servo valve member being movable to a neutral position where said supply port means is out of communication with said first and second port means in said carrier member, said first and second load port means in said valve means being positioned so that they at least parTially communicate with said first and second port means in the carrier member when the valve means is in the neutral position.

Claim 8

A hydraulic servo device as defined in claim 1, wherein each of said supply port means, said first load port means and said second load port means has a port opening at the periphery of the valve means, said valve means including a cylindrical valve member, and means for balancing the force of fluid pressure on the valve member in each of said port openings.

Claim 9

A hydraulic servo device as defined in claim 6, wherein said balancing means includes a pocket in the periphery of the valve member opposite each of said port openings, and means providing communication between the port openings and the oppositely disposed pocket.

Claim 10

A fluid-proportioning device, comprising: manually operable means movable to positions representing the desired quantity of fluid to be delivered, servo valve means positioned by said manually operable means, said servo valve means having supply port means, first load port means and second load port means, a servo device supplied fluid by said servo valve including first and second fluid pressure chambers, said servo device having first and second ports when pressurized causing rotation of said servo device, said supply port means being selectively connectable with said servo device first and second port means so that as the servo valve means ports fluid to one of the carrier port means the carrier will follow movement of the servo valve means, said servo device first and second port means also being selectively connectable with the first and second load port means, said servo valve being movable to a neutral position when said supply port means is out of communication with said first and second port means of the servo device, said first and second load port means having at least partial communication with said first and second servo device port means in said neutral position whereby the servo device is responsive to load variations when the servo valve means is in the neutral position.

Claim 11

A fluid-proportioning device, comprising: manually operable means movable to positions representing the desired quantity of fluid to be delivered, servo valve means positioned by said manually operable means, said servo valve means having supply port means, first load port means and second load port means, a servo device supplied fluid by said servo valve including first and second fluid pressure chambers, said servo device having first and second ports when pressurized causing rotation of said servo device, said supply port means being selectively connectable with said servo device first and second port means so that as the servo valve means ports fluid to one of the carrier port means the carrier will follow movement of the servo valve means, said servo device first and second port means also being selectively connectable with the first and second load port means, said servo valve being movable to a neutral position when said supply port means is out of communication with said first and second port means of the servo device, said first and second load port means having at least partial communication with said first and second servo device port means in said neutral position whereby the servo device is responsive to load variations when the servo valve means is in the neutral position.

Claim 12

A fluid-proportioning device as defined in claim 8, including a pump for supplying fluid under pressure to said supply port means, a fluid actuator, first conduit means connecting one of said load port means with one side of said actuator, second conduit means connecting the other of said load port means to the other side of said actuator.

Claim 13

A hydraulic servo device as defined in claim 1, wherein said carrier member has a return port between said first and second port means, said supply port being communicable with said return port when the servo valve means is in a neutral position.

Claim 14

A fluid-proportioning device, comprising: manually operable means movable to positions representing the desired quantity of fluid to be delivered, servo valve means positioned by said manually operable means, said servo valve means having supply port means, first load port means and second load port means, a servo device supplied fluid by said servo valve including first and second fluid pressure chambers, said servo device having first and second ports when pressurized causing rotation of said servo device, said supply port means being selectively connectable with said servo device first and second port means so that as the servo valve means ports fluid to one of the carrier port means the carrier will follow movement of the servo valve means, said servo device first and second port means also being selectively connectable with the first and second load port means, said servo valve being movable to a neutral position when said supply port means is out of communication with said first and second port means of the servo device, return port means in said servo device between said first and second ports, said supply port means communicating with said return port means when the servo valve means is in a neutral position so that fluid under pressure in said supply port means may flow through said return port means.

Claim 15

A fluid-proportioning device, comprising: manually operable means movable to positions representing the desired quantity of fluid to be delivered, servo valve means positioned by said manually operable means, said servo valve means having supply port means, first load port means and second load port means, a servo device supplied fluid by said servo valve including first and second fluid pressure chambers, said servo device having first and second ports when pressurized causing rotation of said servo device, said supply port means being selectively connectable with said servo device first and second port means so that as the servo valve means ports fluid to one of the carrier port means the carrier will follow movement of the servo valve means, said servo device first and second port means also being selectively connectable with the first and second load port means, said servo valve being movable to a neutral position when said supply port means is out of communication with said first and second port means of the servo device, return port means in said servo device between said first and second ports, said supply port means communicating with said return port means when the servo valve means is in a neutral position so that fluid under pressure in said supply port means may flow through said return port means.