Rotary fluid pressure device and pressure relief system therefor

Claim 2

A rotary fluid pressure device, comprising: a. a housing having a fluid inlet port and a fluid outlet port and defining at least a first surface therein; b. an internally-toothed member and an externallytoothed member eccentrically disposed within said internally-toothed member for relative orbital and rotational movement therebetween, the teeth of said members interengaging to define a plurality of expanding and contracting volume chambers during said relative movement; c. valve means; d. means connecting said valve means for synchronous movement with one of said movements of said toothed members, said valve means being operable upon said synchronous movement to connect one of said ports in fluid communication with said expanding volume chambers and the other of said ports in fluid communication with said contracting volume chambers; e. said toothed members having first axial end faces abuttingly engaging said first housing surface, said housing surface and one of said first axial end faces cooperating to define a first sealing land radially adjacent said volume chambers and at least one area of relieved pressure, including a fluidicly continuous groove, said sealing land being disposed radially between said volume chambers and said area of relieved pressure; f. said area of relieved pressure being at least about as wide in a radial direction as said sealing land; and g. passage means disposed within said housing for connecting said relieved area in open communication with one of said ports to reduce the area subjected to fluid pressure tending to separate said faces from said surface during operation of said device.

Claim 3

The device of claim 1 wherein said sealing land has a generally constant width and is substantially continuous circumferentially about said first housing surface.

Claim 4

The device of claim 1 including a plurality of circumferentially spaced apart areas of relieved pressure, the total of said relieved areas being relatively greater than the area of said sealing land.

Claim 5

The device of claim 1 wherein said fluidicly continuous groove comprises a seal ring groove and sealing means disposed therein, said sealing land being disposed radially between said volume chambers and said seal ring groove.

Claim 6

The device of claim 1 including a generally circular seal ring groove disposed generally concentric with said fluidicly continuous groove.

Claim 7

The device of claim 1 wherein: a. said housing defines a second surface therein, said first and second surfaces being substantially parallel and oppositely disposed about said toothed members; and b. said toothed members having second axial end faces abuttingly engaging said second housing surface, said housing surface and one of said axial end faces cooperating to define a second sealing land radially adjacent said volume chambers and at least one second area of relieved pressure, said second sealing land being disposed radially between said volume chambers and said second relieved area.

Claim 8

The device of claim 6 wherein said first and second relieved areas are in open communication.

Claim 9

A rotary fluid pressure device, comprising: a. a housing having a fluid inlet port and a fluid outlet port; b. an internally-toothed member having first and second axial end faces thereon and an externally-toothed member eccentrically disposed within said internallytoothed member for orbital and rotational movement relatiVe thereto, the teeth of said members interengaging to define a plurality of expanding contracting volume chambers during said relative movement; c. valve means operable between said inlet port and said outlet port for selectively porting fluid to and from said volume chambers as said chambers alternately expand and contract in response to said relative movement; d. means connecting said valve means for synchronous movement with one of said movements of said toothed members; e. a first plate member having an axial end face in engagement with said first axial end face of said internally-toothed member over a major portion thereof; f. said plate member end face and said first axial end face cooperating to define a first sealing land disposed radially outward from and adjacent to said volume chambers and at least one area of relieved pressure including a fluidicly continuous groove disposed radially outward from and adjacent to said sealing land; g. said area of relieved pressure being at least about as wide in a radial direction as said sealing land; and h. passage means disposed within said housing for venting said relieved area to reduce the pressure therein, to thereby reduce the force tending to separate said end faces during pressurization of said volume chambers.

Claim 10

A rotary fluid pressure device, comprising: a. a housing having a fluid inlet port and a fluid outlet port; b. an internally-toothed member having first and second axial end faces thereon and an externally-toothed member eccentrically disposed within said internallytoothed member for orbital and rotational movement relatiVe thereto, the teeth of said members interengaging to define a plurality of expanding contracting volume chambers during said relative movement; c. valve means operable between said inlet port and said outlet port for selectively porting fluid to and from said volume chambers as said chambers alternately expand and contract in response to said relative movement; d. means connecting said valve means for synchronous movement with one of said movements of said toothed members; e. a first plate member having an axial end face in engagement with said first axial end face of said internally-toothed member over a major portion thereof; f. said plate member end face and said first axial end face cooperating to define a first sealing land disposed radially outward from and adjacent to said volume chambers and at least one area of relieved pressure including a fluidicly continuous groove disposed radially outward from and adjacent to said sealing land; g. said area of relieved pressure being at least about as wide in a radial direction as said sealing land; and h. passage means disposed within said housing for venting said relieved area to reduce the pressure therein, to thereby reduce the force tending to separate said end faces during pressurization of said volume chambers.

Claim 11

The device of claim 8 wherein said fluidicly continuous groove comprises a seal ring groove and sealing means disposed therein.

Claim 12

The device of claim 8 including a generally circular seal ring groove, said fluidicly continuous groove being generally circular and disposed concentric with said seal ring groove.

Claim 13

The device of claim 8 including a plurality of said area of relieved pressure, each of said areas being disposed radially outward from and adjacent to one of said volume chambers and disposed circumferentially between adjacent teeth of said internally-toothed member.

Claim 14

The device of claim 11 wherein the total of said relieved areas is relatively greater than the area of said sealing land to minimize the area over which leakage of pressurized fluid can exert a force tending to separate said engaging end faces.

Claim 15

The device of claim 12 wherein said sealing land has a generally constant width and is substantially continuous circumferentially about said internally-toothed member.

Claim 16

The device of claim 8 including: a. a second plate member having an axial end face in engagement with said second axial end face of said internally-toothed member over a major portion thereof; b. said second plate member end face and said second axial end face cooperating to define a second sealing land disposed radially outward from and adjacent to said volume chambers and at least one second area of relieved pressure radially outward from and adjacent to said sealing land; and c. said relieved area being in fluid communication with said passage means.

Claim 17

The device of claim 14 wherein a plurality of fluid passage means extend axially through said internally-toothed member interconnecting said first and second areas of relieved pressure in fluid communication.

Claim 18

The device of claim 15 including a plurality of tie bolts received in axially-extending bores for urging said internally-toothed member and said first and second plate members toward tight fluid sealing engagement.

Claim 19

The device of claim 16 wherein said fluid passage means comprises a clearance between each of said axially-extending bores and said tie bolt received therein.

Claim 20

A hydraulic motor, comprising: a. a housing having a high pressure fluid port and a low pressure fluid port; b. an internally-toothed member having first and second axial end faces thereon and an externally-toothed member eccentrically disposed within said internally-toothed member for orbital and rotational movement relative thereto, the teeth of said toothed members interengaging to define a plurality of expanding and contracting volume chambers during said relative movement; c. valve means including a rotatable valve member connected for synchronous movement with one of said movements of said externallytoothed member to provide fluid communication between said expanding volume chambers and one of said fluid ports and between said contracting volume chambers and the other of said fluid ports in response to said relative movement; d. a valve port plate disposed between said valve member and said toothed members, said port plate having an axial end face in engagement with said first axial end of said internally-toothed member over a major portion thereof, said end faces defining a generally circular first seal ring groove therebetween; e. said port plate end face and said first axial end face cooperating to define a first plurality of pressure relief areas disposed radially between said volume chambers and said seal ring groove and being in fluid communication with said seal ring groove and said low pressure fluid port; and f. said port plate end face and said first axial end face defining a first fluid sealing land disposed radially between said volume chambers and said pressure relief areas to reduce the area subjected to pressure resulting from a pressure drop caused by fluid leaking from said high pressure in said volume chambers to said low pressure in said pressure relief areas across said sealing land in a radially outward direction, said first fluid sealing land being relatively narrower in a radial direction than said pressure relief areas.

Claim 21

A hydraulic motor, comprising: a. a housing having a high pressure fluid port and a low pressure fluid port; b. an internally-toothed member having first and second axial end faces thereon and an externally-toothed member eccentrically disposed within said internally-toothed member for orbital and rotational movement relative thereto, the teeth of said toothed members interengaging to define a plurality of expanding and contracting volume chambers during said relative movement; c. valve means including a rotatable valve member connected for synchronous movement with one of said movements of said externallytoothed member to provide fluid communication between said expanding volume chambers and one of said fluid ports and between said contracting volume chambers and the other of said fluid ports in response to said relative movement; d. a valve port plate disposed between said valve member and said toothed members, said port plate having an axial end face in engagement with said first axial end of said internally-toothed member over a major portion thereof, said end faces defining a generally circular first seal ring groove therebetween; e. said port plate end face and said first axial end face cooperating to define a first plurality of pressure relief areas disposed radially between said volume chambers and said seal ring groove and being in fluid communication with said seal ring groove and said low pressure fluid port; and f. said port plate end face and said first axial end face defining a first fluid sealing land disposed radially between said volume chambers and said pressure relief areas to reduce the area subjected to pressure resulting from a pressure drop caused by fluid leaking from said high pressure in said volume chambers to said low pressure in said pressure relief areas across said sealing land in a radially outward direction, said first fluid sealing land being relatively narrower in a radial direction than said pressure relief areas.

Claim 22

The hydraulic motor of claim 18 including: a. a wear plate having an axial end face in engagement with said second axial end face of said internallytoothed member over a major portion thereof, said end faces defining a generally circular second seal ring groove therebetween; b. said wear plate end face and said second axial end face cooperating to define a second plurality of pressure relief areas disposed radially between said volume chambers and said second seal ring groove and being in fluid communication with said seal ring groove, said first plurality of pressure relief areas and said low pressure fluid port; and c. said wear plate end face and said second axial end face defining a second fluid sealing land disposed radially between said volume chambers and said second plurality of pressure relief areas.

Claim 23

The hydraulic motor of claim 18 wherein each of said plurality of pressure relief areas is disposed radially outward from and adjacent to one of said volume chambers and is disposed circumferentially between adjacent teeth of said internally-toothed member.

Claim 24

The hydraulic motor of claim 18 wherein said internally-toothed member is maintained in fixed, sealing engagement with said valve port plate by means of a plurality of tie bolts extending axially at least through said internallytoothed member and said port plate.

Claim 25

The hydraulic motor of claim 18 wherein the total of said plurality of pressure relief areas is relatively greater than the area of said fluid sealing land to substantially reduce the area over which pressurized fluid between said engaging end faces exerts a force tending to separate said end faces.

Claim 26

A fluid servo-control device, comprising: a. a housing having a fluid inlet port, a pair of fluid outlet ports and a fluid exhaust port; b. an internally-toothed member having first and second axial end faces thereon and an externally-toothed member eccentrically disposed within said internally-toothed member for orbital and rotational movement relative thereto to define a plurality of expanding and contracting fluid volume metering chambers during said relative movement; c. valve means including a rotary input valve member and a follow-up valve member, said follow-up valve member being connected for synchronous movement with one of said movements of said externally-toothed member for selectively porting fluid from said inlet port to said expanding metering chambers and from said contracting metering Chambers to one of said outlet ports in response to rotation of said input valve member; d. a port plate disposed between said internally-toothed member and said valve means, said port plate having an axial end face in engagement with said first axial end face of said internally-toothed member over a major portion thereof, said end faces defining a generally circular first seal ring groove therebetween; e. said port plate end face and said first axial end face cooperating to define a first fluidically continuous pressure relief groove disposed radially between said metering chambers and said seal ring groove and being in fluid communication with said seal ring groove and said fluid exhaust port; and f. said port plate end face and said first axial end face defining a first fluid sealing land disposed radially between said metering chambers and said pressure relief groove to reduce the area subjected to pressure resulting from a pressure drop caused by fluid leaking from said metering chambers to said pressure relief groove across said sealing land in a radially outward direction, said pressure relief groove being approximately as wide in a radial direction as said first fluid sealing land over at least a substantial circumferential portion of said pressure relief groove.

Claim 27

A fluid servo-control device, comprising: a. a housing having a fluid inlet port, a pair of fluid outlet ports and a fluid exhaust port; b. an internally-toothed member having first and second axial end faces thereon and an externally-toothed member eccentrically disposed within said internally-toothed member for orbital and rotational movement relative thereto to define a plurality of expanding and contracting fluid volume metering chambers during said relative movement; c. valve means including a rotary input valve member and a follow-up valve member, said follow-up valve member being connected for synchronous movement with one of said movements of said externally-toothed member for selectively porting fluid from said inlet port to said expanding metering chambers and from said contracting metering Chambers to one of said outlet ports in response to rotation of said input valve member; d. a port plate disposed between said internally-toothed member and said valve means, said port plate having an axial end face in engagement with said first axial end face of said internally-toothed member over a major portion thereof, said end faces defining a generally circular first seal ring groove therebetween; e. said port plate end face and said first axial end face cooperating to define a first fluidically continuous pressure relief groove disposed radially between said metering chambers and said seal ring groove and being in fluid communication with said seal ring groove and said fluid exhaust port; and f. said port plate end face and said first axial end face defining a first fluid sealing land disposed radially between said metering chambers and said pressure relief groove to reduce the area subjected to pressure resulting from a pressure drop caused by fluid leaking from said metering chambers to said pressure relief groove across said sealing land in a radially outward direction, said pressure relief groove being approximately as wide in a radial direction as said first fluid sealing land over at least a substantial circumferential portion of said pressure relief groove.

Claim 28

The control device of claim 23 including: a. an endcap member having an axial end face in engagement with said second axial end face of said internallytoothed member over a major portion thereof, said end faces defining a generally circular second seal ring groove therebetween; b. said endcap member end face and said second axial end face cooperating to define a second fluidically continuous pressure relief groove disposed radially between said metering chambers and said second seal ring groove, and being in fluid communication with said second seal ring groove, said first pressure relief groove and said fluid exhaust port; and c. said endcap member end face and said second axial end face defining a second fluid sealing land disposed radially between said metering chambers and said second pressure relief groove.

Claim 29

The control device of claim 23 wherein said internally-toothed member is maintained in fixed, sealing engagement with said port plate by means of a plurality of tie bolts extending axially at least through said internally-toothed member and said port plate.

Claim 30

The control device of claim 23 wherein said externally-toothed member has an axial end face, substantially planar with said first axial end face of said internally-toothed member, and said externally-toothed member end face and said port plate end face cooperate to define a pressure relief area in fluid communication with said fluid exhaust port to reduce the area subjected to leakage pressure tending to separate said externally-toothed member and said wear plate.

Claim 31

The control device of claim 23 wherein said fluid sealing land is contoured to follow substantially the outer periphery of said metering chambers.