CA1130169A - Fluid supply system - Google Patents
Fluid supply systemInfo
- Publication number
- CA1130169A CA1130169A CA337,346A CA337346A CA1130169A CA 1130169 A CA1130169 A CA 1130169A CA 337346 A CA337346 A CA 337346A CA 1130169 A CA1130169 A CA 1130169A
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- Canada
- Prior art keywords
- fluid
- passage
- main
- bore
- secondary fluid
- Prior art date
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Abstract
FLUID SUPPLY SYSTEM
Abstract of the D closure A fluid supply system includes a pump body having a main bore connectible through inlet check valves to draw secondary fluid from a first fluid reservoir and through outlet check valves to supply it to a secondary fluid function upon recipro-cation of a free piston in the main bore. The free piston in-cludes a pair of coaxial driving pistons on either side which extend into main passages which are alternately connected to a pressurized primary fluid source to cause reciprocation of the free piston. A first spool valve which responds to the comple-tion of a free piston stroke activates a second spool valve which changes the primary fluid source connections to the driving pistons.
Abstract of the D closure A fluid supply system includes a pump body having a main bore connectible through inlet check valves to draw secondary fluid from a first fluid reservoir and through outlet check valves to supply it to a secondary fluid function upon recipro-cation of a free piston in the main bore. The free piston in-cludes a pair of coaxial driving pistons on either side which extend into main passages which are alternately connected to a pressurized primary fluid source to cause reciprocation of the free piston. A first spool valve which responds to the comple-tion of a free piston stroke activates a second spool valve which changes the primary fluid source connections to the driving pistons.
Description
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FLUID SI~PPLY SYSTEM
The present invention relates generally to secondary fluid supply pumps and more particularly to a hydraulically driven, pressure compensated, self-priming, low-pressure freon supply pump, In the past, cornplex and expensive pumps were required to obtain pressure compensated, self-priming, two fluid operation and attempts to make direct pressure-operated reciprocating piston pumps were frustrated by the incompressibility of hydraulic fluid which would prevent totally bi-stable operation of the free piston.
Summary of the invention The present invention provides a simpler primary fluid driven, pressure compensated, self-priming, secondary fluid supply system.
The above and addi-tional advantages of the present invention will become apparent to those skilled in the art from a reading of the following detailed description when taken in conjunction :
with the accompanying drawing.
` 20 Brief Descri~tion of the Drawing The drawing is a schematic, partially in section, incorporat-ing the preferred embodiment of the present invention.
Description of the Preferred Embodiment :
Referring now to the drawing, therein is shown a fluid `- supply system 10 including a primary fluid pump 12 drawing primary fluid from a first fluid reservoir 14 and pressurizing it to supply a primary fluid inlet 16 in a pump body 18. In the pre- i~
ferred embodiment, the primary fluid is hydraulic oil.
; The pump body 18 further contains a reservoir passage 20 which is connected so as to allow the drawing of a secondary ~
fluid from a second fluid reservoir 21 and a secondary fluid `
outlet passage 22 which is connected so as to allow the supplying ;~ '`'' , ~3~
1 of the secondary fluid to a conventional secondary fluid function, generally designated 24, which, with freon as the secondary fluid, would be an air conditioning system.
Referring back to the primary fluid inlet 16 and utilizing a convention wherein the right and left hand sides of the pump body 18 are respectively on the right and left hand sides of the viewer, the primary fluid inlet 16 is medially connected to first and second bores 26 and 28 in first and second five-way valves 30 and 32, respectively.
The first bore 26 has ports immediately adjacent to the left and right of the primary fluid inlet 16 which are respectively connected to right and left pilot passages 34 and 36 and which, in turn, are directly connected to the right and left ends, respectively, of the second bore 28. Right and left relief passages 38 and 40 are respectively connected to the right and left ends of the first bore 26 as well as the right and left ends respectively of the second bore 28. The relief passages are interconnected and relieve to the first reservoir 14.
A cylindrical main bore 42 is provided in the pump body 18 and is connected to right and left inlet check valves 44 and 46 ; which allow the flow of fluid from the second reservoir 21 and the reservoir passage 20 into the main bore 42. The right and left inlet check valves 44 and 46 are respectively adjacent to right and left outlet check valves 48 and 50 which allow the passage of secondary fluid from the main bore 42 into the second-ary fluid outlet passage 22.
Coaxial with the main bore 42 are portions of right and left main passages 52 a:nd 54 which are connected to the second bore 28 respectively to thle right and left of the primary fluid inlet 16.
Further connected to the right and left main passages 52 and 54 are right and l~eft control passages 56 and 58 which are con-nected to the right and left ends respectively of the first bore .
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1 26. The ri~ht and left relief passages 38 and 40 are respec-tively connected to the right and left main passages 52 and 54 between the right and left control passages 56 and 58.
The first valve 30 includes a first spool 60 which has right and left lands 62 and 64 and right and left pilot pistons 66 and 68 which are slidable in coaxial portions of the right and left control passages 56 and 58, respect1vely. The first spool 60 is '.
shiftable from a right position (~as shown) in which the primary fluid inlet 16 is connected to the left pilot passage 36 and the left relief passage 40 is connected to the right pilot passage 34 to a second position in which the first spool 60 connects the : primary fluid inlet 16 to the right pilot passage 34 and the right relief passage 38 to the left pilot passage 36.
The second valve 32 includes a second spool 70 which has right and left lands 72 and 74 and right and left pilot pistons 76 and 78 which extend into coaxial portions of the right and left pilot passages 34 and 36, respectively. The second spool 70 is movable between a right position ~as shown) in which the primary fluid inlet 16 is connected to the right main passage 52 and the left relief passage 40 is connected to the left main passage 54 to a left position in which the primary fluid inlet 16 is connected to the left main passage 54 and the right relief passage 38 is connected to the right main passage 52.
The main bore 42 is part of a secondary fluid pump 80 which includes a free piston 82 which is sealingly slidable in the main bore 42. The free piston 82 includes right and left driving pistons 84 and 86 which extend into the coaxial portions of the ~ -right and left main passages 52 and 54, respectively. Between --the coaxial portions of the right and left main passages 52 and 54 and the main bore 42 are right and left seal assemblies 85 and 87 which respectively encircle the right and left driving pistons 84 and 86 to prevent the mixing of the primary and secondary - . - .... . .. . . . . :
1 fluids. The right and left seal assemblies are respectively relieved to the right and le~t relief passages 38 and 40 by passages 89 and 91. The right and left driving pistons 84 and 86 are respectively provided with reliefs 88 and 90. The free piston 82 is movable from a right position where it abuts a stop 92 to a left position where it abuts a stop 94.
In operation, the fluid supply system 10 may be started at any position of the free piston 82 upon application of pressurized primary fluid from the primary fluid pump 12 to the primary fluid inlet 16 because the first and second valves 30 and 32 ensure bi-stable operation.
Starting from the position shown in the drawing, pressurized fluid in the primary fluid inlet 16 is supplied to the left pilot passage 36 by the first valve 30 which causes the second valve 32 to cause pressurized fluid from the primary fluid inlet 16 to pressurize the right main passage 52. Pressurization of the right main passage 52 causes the right driving piston 84 to start moving the free piston 82 to the left.
Leftward movement of the free piston 82 causes the left inlet check valve 44 to open to draw secondary fluid into the main bore 42. Simultaneously, the outlet check valve 50 is opened to allow secondary fluid in the main bore 42 to exit to the secondary fluid function 24. As would be evident to those skilled in the art, with proper sealing between the free piston 82 and the main bore 42, the secondary fluid pump 80 will be self-priming.
With the free piston 82 moving to the left, it will be noted in this position that the left control passage 58, the left main passage 54, and the right pilot passage 34 are all connected to the left relief passage 40 and thence to the first reservoir 14.
Also, it will be seen that the right control passage 56 is connec-ted by the relief 88 to the first reservoir 14.
- 1:L3~6~3t 1 As the free piston 82 continues to the left, the right driving piston 84 will allow fluid communication be-tween the pressurized right main passage 52 and the right control passage 56. However, since the left driving piston 86 will block the left control passage 58, movement of the first spool 60 will be prevented and subsequently movement of the second spool 70 will also be prevented.
When the free piston 82 reaches a position proximate the second stop 94, the left control passage 58 will be placed in fluid communication with the left relief passage 40 via the relief 90. At this point, the pressurized primary fluid in the right control passage 56 from the right main passage 52 acting on the right pilot piston 66 will cause the first spool 60 to shift to its left position while the free piston 82 continues towards the position in which it abuts the second stop 94. When the ~-first spool 60 of the first valve 30 reaches the left position, pressurized primary fluid from the primary fluid inlet 16 is supplied to the right pilot passage 34 to cause a shift in the second valve 32 of the second spool 70 to its left position also.
As would be evident to those skilled in the art, with the free piston 82 and the first and second valves 30 and 32 in their left positions, the second half of a cycle similar to the above -~
described first part of the cycle begins. Secondary fluid is ' drawn through the left inlet check valve 46 from the second reservoir 21 and pumped from the main bore 42 through the outlet ,- check valve 48 to the secondary fluid function 24.
It should be noted that the above fluid system 10 would by nature be pressure compensated. The free piston 82 and the right and left driving p:istons 84 and 86 would have forces acting in `~
opposition and the resulting forces would accelerate the mass of these pistons thus increasing the output of the pump when the pressure drops. The mass of the system would come to equilibrium -~3~
1 at some pressure that produced a zero resultant force. As would be evident to those skilled in the art, flow restriction losses inside the system 10, itself, would form part of the pressure load on the free piston 82 and there would be a limiting avail-able acceleration force corresponding to zero pressure at the secondary fluid outlet passage 22. Naturally, the fluid system 10 should be designed such that acce:Leration of the pistons take a small portion of the cycle. This can be accomplishea by in-creasing the displacement of the free piston 82, reducing the mass of the pistons and spools, and minimizing flow restrictions.
While the invention has been described in conjunction with a - specific embodiment, it is to be understood that many alterna-tives, modifications and variations will be apparent to those skilled in the art in light of the aforegoing description. For example, one pair of check valves 46 and 50 could be connected to one fluid circuit and the second pair of check valves 44 and 48 could be connected to another different fluid circuit with the free piston 82 being driven by a third fluid circuit containing a different fluid from the other two fluids. Accordingly, it is intended to embrace all such alternatives, modifications, and variations which fall within the spirit and scope of the appended claims.
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FLUID SI~PPLY SYSTEM
The present invention relates generally to secondary fluid supply pumps and more particularly to a hydraulically driven, pressure compensated, self-priming, low-pressure freon supply pump, In the past, cornplex and expensive pumps were required to obtain pressure compensated, self-priming, two fluid operation and attempts to make direct pressure-operated reciprocating piston pumps were frustrated by the incompressibility of hydraulic fluid which would prevent totally bi-stable operation of the free piston.
Summary of the invention The present invention provides a simpler primary fluid driven, pressure compensated, self-priming, secondary fluid supply system.
The above and addi-tional advantages of the present invention will become apparent to those skilled in the art from a reading of the following detailed description when taken in conjunction :
with the accompanying drawing.
` 20 Brief Descri~tion of the Drawing The drawing is a schematic, partially in section, incorporat-ing the preferred embodiment of the present invention.
Description of the Preferred Embodiment :
Referring now to the drawing, therein is shown a fluid `- supply system 10 including a primary fluid pump 12 drawing primary fluid from a first fluid reservoir 14 and pressurizing it to supply a primary fluid inlet 16 in a pump body 18. In the pre- i~
ferred embodiment, the primary fluid is hydraulic oil.
; The pump body 18 further contains a reservoir passage 20 which is connected so as to allow the drawing of a secondary ~
fluid from a second fluid reservoir 21 and a secondary fluid `
outlet passage 22 which is connected so as to allow the supplying ;~ '`'' , ~3~
1 of the secondary fluid to a conventional secondary fluid function, generally designated 24, which, with freon as the secondary fluid, would be an air conditioning system.
Referring back to the primary fluid inlet 16 and utilizing a convention wherein the right and left hand sides of the pump body 18 are respectively on the right and left hand sides of the viewer, the primary fluid inlet 16 is medially connected to first and second bores 26 and 28 in first and second five-way valves 30 and 32, respectively.
The first bore 26 has ports immediately adjacent to the left and right of the primary fluid inlet 16 which are respectively connected to right and left pilot passages 34 and 36 and which, in turn, are directly connected to the right and left ends, respectively, of the second bore 28. Right and left relief passages 38 and 40 are respectively connected to the right and left ends of the first bore 26 as well as the right and left ends respectively of the second bore 28. The relief passages are interconnected and relieve to the first reservoir 14.
A cylindrical main bore 42 is provided in the pump body 18 and is connected to right and left inlet check valves 44 and 46 ; which allow the flow of fluid from the second reservoir 21 and the reservoir passage 20 into the main bore 42. The right and left inlet check valves 44 and 46 are respectively adjacent to right and left outlet check valves 48 and 50 which allow the passage of secondary fluid from the main bore 42 into the second-ary fluid outlet passage 22.
Coaxial with the main bore 42 are portions of right and left main passages 52 a:nd 54 which are connected to the second bore 28 respectively to thle right and left of the primary fluid inlet 16.
Further connected to the right and left main passages 52 and 54 are right and l~eft control passages 56 and 58 which are con-nected to the right and left ends respectively of the first bore .
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1 26. The ri~ht and left relief passages 38 and 40 are respec-tively connected to the right and left main passages 52 and 54 between the right and left control passages 56 and 58.
The first valve 30 includes a first spool 60 which has right and left lands 62 and 64 and right and left pilot pistons 66 and 68 which are slidable in coaxial portions of the right and left control passages 56 and 58, respect1vely. The first spool 60 is '.
shiftable from a right position (~as shown) in which the primary fluid inlet 16 is connected to the left pilot passage 36 and the left relief passage 40 is connected to the right pilot passage 34 to a second position in which the first spool 60 connects the : primary fluid inlet 16 to the right pilot passage 34 and the right relief passage 38 to the left pilot passage 36.
The second valve 32 includes a second spool 70 which has right and left lands 72 and 74 and right and left pilot pistons 76 and 78 which extend into coaxial portions of the right and left pilot passages 34 and 36, respectively. The second spool 70 is movable between a right position ~as shown) in which the primary fluid inlet 16 is connected to the right main passage 52 and the left relief passage 40 is connected to the left main passage 54 to a left position in which the primary fluid inlet 16 is connected to the left main passage 54 and the right relief passage 38 is connected to the right main passage 52.
The main bore 42 is part of a secondary fluid pump 80 which includes a free piston 82 which is sealingly slidable in the main bore 42. The free piston 82 includes right and left driving pistons 84 and 86 which extend into the coaxial portions of the ~ -right and left main passages 52 and 54, respectively. Between --the coaxial portions of the right and left main passages 52 and 54 and the main bore 42 are right and left seal assemblies 85 and 87 which respectively encircle the right and left driving pistons 84 and 86 to prevent the mixing of the primary and secondary - . - .... . .. . . . . :
1 fluids. The right and left seal assemblies are respectively relieved to the right and le~t relief passages 38 and 40 by passages 89 and 91. The right and left driving pistons 84 and 86 are respectively provided with reliefs 88 and 90. The free piston 82 is movable from a right position where it abuts a stop 92 to a left position where it abuts a stop 94.
In operation, the fluid supply system 10 may be started at any position of the free piston 82 upon application of pressurized primary fluid from the primary fluid pump 12 to the primary fluid inlet 16 because the first and second valves 30 and 32 ensure bi-stable operation.
Starting from the position shown in the drawing, pressurized fluid in the primary fluid inlet 16 is supplied to the left pilot passage 36 by the first valve 30 which causes the second valve 32 to cause pressurized fluid from the primary fluid inlet 16 to pressurize the right main passage 52. Pressurization of the right main passage 52 causes the right driving piston 84 to start moving the free piston 82 to the left.
Leftward movement of the free piston 82 causes the left inlet check valve 44 to open to draw secondary fluid into the main bore 42. Simultaneously, the outlet check valve 50 is opened to allow secondary fluid in the main bore 42 to exit to the secondary fluid function 24. As would be evident to those skilled in the art, with proper sealing between the free piston 82 and the main bore 42, the secondary fluid pump 80 will be self-priming.
With the free piston 82 moving to the left, it will be noted in this position that the left control passage 58, the left main passage 54, and the right pilot passage 34 are all connected to the left relief passage 40 and thence to the first reservoir 14.
Also, it will be seen that the right control passage 56 is connec-ted by the relief 88 to the first reservoir 14.
- 1:L3~6~3t 1 As the free piston 82 continues to the left, the right driving piston 84 will allow fluid communication be-tween the pressurized right main passage 52 and the right control passage 56. However, since the left driving piston 86 will block the left control passage 58, movement of the first spool 60 will be prevented and subsequently movement of the second spool 70 will also be prevented.
When the free piston 82 reaches a position proximate the second stop 94, the left control passage 58 will be placed in fluid communication with the left relief passage 40 via the relief 90. At this point, the pressurized primary fluid in the right control passage 56 from the right main passage 52 acting on the right pilot piston 66 will cause the first spool 60 to shift to its left position while the free piston 82 continues towards the position in which it abuts the second stop 94. When the ~-first spool 60 of the first valve 30 reaches the left position, pressurized primary fluid from the primary fluid inlet 16 is supplied to the right pilot passage 34 to cause a shift in the second valve 32 of the second spool 70 to its left position also.
As would be evident to those skilled in the art, with the free piston 82 and the first and second valves 30 and 32 in their left positions, the second half of a cycle similar to the above -~
described first part of the cycle begins. Secondary fluid is ' drawn through the left inlet check valve 46 from the second reservoir 21 and pumped from the main bore 42 through the outlet ,- check valve 48 to the secondary fluid function 24.
It should be noted that the above fluid system 10 would by nature be pressure compensated. The free piston 82 and the right and left driving p:istons 84 and 86 would have forces acting in `~
opposition and the resulting forces would accelerate the mass of these pistons thus increasing the output of the pump when the pressure drops. The mass of the system would come to equilibrium -~3~
1 at some pressure that produced a zero resultant force. As would be evident to those skilled in the art, flow restriction losses inside the system 10, itself, would form part of the pressure load on the free piston 82 and there would be a limiting avail-able acceleration force corresponding to zero pressure at the secondary fluid outlet passage 22. Naturally, the fluid system 10 should be designed such that acce:Leration of the pistons take a small portion of the cycle. This can be accomplishea by in-creasing the displacement of the free piston 82, reducing the mass of the pistons and spools, and minimizing flow restrictions.
While the invention has been described in conjunction with a - specific embodiment, it is to be understood that many alterna-tives, modifications and variations will be apparent to those skilled in the art in light of the aforegoing description. For example, one pair of check valves 46 and 50 could be connected to one fluid circuit and the second pair of check valves 44 and 48 could be connected to another different fluid circuit with the free piston 82 being driven by a third fluid circuit containing a different fluid from the other two fluids. Accordingly, it is intended to embrace all such alternatives, modifications, and variations which fall within the spirit and scope of the appended claims.
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Claims (6)
1. A secondary fluid supply system connectible to a fluid source of primary fluid, a fluid reservoir of secondary fluid, and a secondary fluid function, said secondary fluid supply system comprising:
a) a secondary fluid pump;
b) a cylinder enclosed in said secondary fluid pump having first and second check means, said first check means disposed proximate an end of said cylinder for fluidly connecting said fluid reservoir to said cylinder, and said second check means disposed proximate said end of said cylinder for fluidly connect-ing said cylinder to said secondary fluid pressure function;
c) free piston means disposed in said cylinder movable between first and second positions therein to draw secondary fluid from said fluid reservoir through said first check means and to supply secondary fluid to said secondary fluid pressure function through said second check means, said free piston means having first and second driving means operatively connected thereto respectively responsive to connection to said fluid source to move said free piston means between said first and second positions, said fluid pump including first and second :
sealing means respectively operatively associated with said first and second driving means for sealing said primary fluid connected thereto from said secondary fluid in said cylinder; and d) first and second interconnected valve means connecting said fluid source to said first and second driving means, said first valve means responsive respectively to the connection of said primary fluid from said fluid source to said first and second driving means to said free piston means in the respective second and first positions for causing said second valve means to respectively connect said primary fluid from said fluid source to said second and first driving means.
a) a secondary fluid pump;
b) a cylinder enclosed in said secondary fluid pump having first and second check means, said first check means disposed proximate an end of said cylinder for fluidly connecting said fluid reservoir to said cylinder, and said second check means disposed proximate said end of said cylinder for fluidly connect-ing said cylinder to said secondary fluid pressure function;
c) free piston means disposed in said cylinder movable between first and second positions therein to draw secondary fluid from said fluid reservoir through said first check means and to supply secondary fluid to said secondary fluid pressure function through said second check means, said free piston means having first and second driving means operatively connected thereto respectively responsive to connection to said fluid source to move said free piston means between said first and second positions, said fluid pump including first and second :
sealing means respectively operatively associated with said first and second driving means for sealing said primary fluid connected thereto from said secondary fluid in said cylinder; and d) first and second interconnected valve means connecting said fluid source to said first and second driving means, said first valve means responsive respectively to the connection of said primary fluid from said fluid source to said first and second driving means to said free piston means in the respective second and first positions for causing said second valve means to respectively connect said primary fluid from said fluid source to said second and first driving means.
2. A secondary fluid supply system connectible to a fluid source of a primary fluid, a fluid reservoir of a secondary fluid, and a secondary fluid function, said secondary fluid supply system comprising:
a) a secondary fluid pump;
b) a cylinder enclosed in said secondary fluid pump having first and second check means, said first check means disposed at opposite ends of said cylinder for connection to said fluid reservoir to allow entrance of secondary fluid to said cylinder therefrom, and said second check means disposed at said opposite ends of said cylinder for connection to said secondary fluid pressure function to allow exit of secondary fluid from said cylinder thereto;
c) free piston means disposed in said cylinder movable between first and second positions therein to draw secondary fluid from said fluid reservoir through said first check means and to supply secondary fluid to said secondary fluid pressure function through said second check means, said free piston means having first and second driving means operatively connected thereto respectively responsive to connection to said fluid source to move said free piston means between said first and second positions, said fluid pump including first and second sealing means respectively operatively associated with said first and second driving means for sealing said primary fluid connected thereto from said secondary fluid in said cylinder; and d) first and second interconnected valve means connecting said fluid source to said first and second driving means, said first valve means responsive respectively to the connection of said primary fluid source to said first and second driving means and said free piston means in the respective second and first positions to cause said second valve means to respectively connect said primary fluid from said fluid source to said second and first driving means.
a) a secondary fluid pump;
b) a cylinder enclosed in said secondary fluid pump having first and second check means, said first check means disposed at opposite ends of said cylinder for connection to said fluid reservoir to allow entrance of secondary fluid to said cylinder therefrom, and said second check means disposed at said opposite ends of said cylinder for connection to said secondary fluid pressure function to allow exit of secondary fluid from said cylinder thereto;
c) free piston means disposed in said cylinder movable between first and second positions therein to draw secondary fluid from said fluid reservoir through said first check means and to supply secondary fluid to said secondary fluid pressure function through said second check means, said free piston means having first and second driving means operatively connected thereto respectively responsive to connection to said fluid source to move said free piston means between said first and second positions, said fluid pump including first and second sealing means respectively operatively associated with said first and second driving means for sealing said primary fluid connected thereto from said secondary fluid in said cylinder; and d) first and second interconnected valve means connecting said fluid source to said first and second driving means, said first valve means responsive respectively to the connection of said primary fluid source to said first and second driving means and said free piston means in the respective second and first positions to cause said second valve means to respectively connect said primary fluid from said fluid source to said second and first driving means.
3. A secondary fluid supply system connectible to a source of primary fluid, a first fluid reservoir of primary fluid, a second fluid reservoir of secondary fluid, and a secondary fluid function, said secondary fluid supply system comprising:
a) a pump body;
b) a main bore enclosed within said pump body having first and second ends;
c) first and second bores enclosed within said pump body having respective first and second ends;
d) an inlet into said pump body connecting said source of primary fluid to said first and second bores between said respec-tive first and second ends thereof;
e) first and second pilot passages enclosed within said pump body respectively connecting said first bore proximate said first end to said second end of said second bore, and said first bore proximate said second end to said first end of said second bore;
f) first and second main passages enclosed within said pump body respectively connecting said second bore proximate said first end to said first end of said main bore, and connecting said second bore proximate said second end to said second end of said main bore;
g) first and second control passages enclosed within said pump body respectively connecting said first and second ends of said first bore to said first and second main passages approxi-mately at said ends of said main bore;
h) first and second relief passages enclosed within said pump body respectively connecting said first ends of said first and second bores to said first main passage between said first control passage and said first end of said main bore and said second ends of said first and second bores to said second main passage between said second control passage and said second end of said main bore;
i) a secondary fluid reservoir passage enclosed within said pump body connecting said second fluid reservoir to both said first and second ends of said main bore;
j) a secondary fluid passage enclosed within said pump body connecting said secondary fluid pressure function to both said first and second ends of said main bore;
k) first and second reservoir check valve means respec-tively disposed in said reservoir passage proximate said first and second ends of said main bore for preventing secondary fluid from flowing from said main bore into said reservoir passage;
l) third and fourth check valve means respectively dis-posed in said secondary fluid pressure function passage proximate said first and second ends of said main bore for preventing secondary fluid from flowing from said secondary fluid pressure function into said main bore;
m) first spool means positioned within said first bore and extending into both said first and second control passages, said first spool means movable in response to primary fluid in said second control passage to connect said primary fluid from said source to said second pilot passage and said second relief passage to said first pilot passage and in said first control passage to connect said primary fluid from said source to said first pilot passage and said second relief passage to said second pilot passage;
n) second spool means positioned within said second bore and extending into both said first and second pilot passages, said second spool means movable in response to primary fluid in said second pilot passage to connect said source to said first main passage and said second relief passage to said second main passage and to primary fluid in said first pilot passage to connect said source to sald second main passage and said first relief passage to said first main passage; and o) free piston means positioned within said main bore and extending into said first and second main passages, said free piston means for responding to high pressure primary fluid in said first main passage to move from a first position connecting said first and second control passages to said first fluid reservoir and said second bore through a series of positions drawing fluid from said reservoir through said first reservoir check valve means and supplying fluid from said main bore through said second outlet check valve means while respectively blocking said first and second control passages from said first and second main passages to a second position respectively connecting said first and second control passages to said second bore and said first fluid reservoir, said free piston means responsive to primary fluid in said second main passage to move from said second posit-on through a series of positions drawing fluid from said reservoir through said second reservoir check valve means and supplying fluid from said main bore through said first outlet check valve means to said first position.
a) a pump body;
b) a main bore enclosed within said pump body having first and second ends;
c) first and second bores enclosed within said pump body having respective first and second ends;
d) an inlet into said pump body connecting said source of primary fluid to said first and second bores between said respec-tive first and second ends thereof;
e) first and second pilot passages enclosed within said pump body respectively connecting said first bore proximate said first end to said second end of said second bore, and said first bore proximate said second end to said first end of said second bore;
f) first and second main passages enclosed within said pump body respectively connecting said second bore proximate said first end to said first end of said main bore, and connecting said second bore proximate said second end to said second end of said main bore;
g) first and second control passages enclosed within said pump body respectively connecting said first and second ends of said first bore to said first and second main passages approxi-mately at said ends of said main bore;
h) first and second relief passages enclosed within said pump body respectively connecting said first ends of said first and second bores to said first main passage between said first control passage and said first end of said main bore and said second ends of said first and second bores to said second main passage between said second control passage and said second end of said main bore;
i) a secondary fluid reservoir passage enclosed within said pump body connecting said second fluid reservoir to both said first and second ends of said main bore;
j) a secondary fluid passage enclosed within said pump body connecting said secondary fluid pressure function to both said first and second ends of said main bore;
k) first and second reservoir check valve means respec-tively disposed in said reservoir passage proximate said first and second ends of said main bore for preventing secondary fluid from flowing from said main bore into said reservoir passage;
l) third and fourth check valve means respectively dis-posed in said secondary fluid pressure function passage proximate said first and second ends of said main bore for preventing secondary fluid from flowing from said secondary fluid pressure function into said main bore;
m) first spool means positioned within said first bore and extending into both said first and second control passages, said first spool means movable in response to primary fluid in said second control passage to connect said primary fluid from said source to said second pilot passage and said second relief passage to said first pilot passage and in said first control passage to connect said primary fluid from said source to said first pilot passage and said second relief passage to said second pilot passage;
n) second spool means positioned within said second bore and extending into both said first and second pilot passages, said second spool means movable in response to primary fluid in said second pilot passage to connect said source to said first main passage and said second relief passage to said second main passage and to primary fluid in said first pilot passage to connect said source to sald second main passage and said first relief passage to said first main passage; and o) free piston means positioned within said main bore and extending into said first and second main passages, said free piston means for responding to high pressure primary fluid in said first main passage to move from a first position connecting said first and second control passages to said first fluid reservoir and said second bore through a series of positions drawing fluid from said reservoir through said first reservoir check valve means and supplying fluid from said main bore through said second outlet check valve means while respectively blocking said first and second control passages from said first and second main passages to a second position respectively connecting said first and second control passages to said second bore and said first fluid reservoir, said free piston means responsive to primary fluid in said second main passage to move from said second posit-on through a series of positions drawing fluid from said reservoir through said second reservoir check valve means and supplying fluid from said main bore through said first outlet check valve means to said first position.
4. The secondary fluid supply system of claim 3 wherein first and second sealing means are positioned between said first and second main passages and said first and second ends of said main bore respectively for sealing said primary fluid from said secondary fluid.
5. A secondary fluid supply system connectible to a primary fluid pump, a first fluid reservoir of primary fluid, a second fluid reservoir of secondary fluid, and a secondary fluid function, said secondary fluid supply system comprising:
a) a pump body;
b) a cylindrical main bore enclosed within said pump body having first and second ends;
c) first and second bores enclosed within said pump body having respective first and second ends;
d) a primary fluid inlet into said pump body connecting said primary fluid pump to said first and second bores medially between said respective first and second ends thereof;
e) first and second pilot passages enclosed within said pump body respectively connecting said first bore between said primary fluid inlet and said second relief passage to said first end of said second bore and said first bore between said primary fluid inlet and said first relief passage to said second end of said second bore;
f) first and second main passages enclosed within said pump body respectively connecting said second bore between said primary fluid inlet and said first relief passage to said first end of said main bore and said second bore between said primary fluid inlet and said second relief passage to said second end of said main bore;
g) first and second control passages enclosed within said pump body respectively connecting said first and second ends of said first bore to said first and second main passages respec-tively proximate said first and second ends of said main bore;
h) first and second relief passages enclosed within said pump body respectively connecting said first ends of said first and second bores to a first main passage between a first control passage and said first end of said main bore and said second ends of said first and second bores to a second main passage between a second control passage and said second end of said main bore;
i) a reservoir passage enclosed within said pump body connectible to said second fluid reservoir;
j) a secondary fluid outlet passage enclosed within said pump body connectible to said secondary fluid function;
k) first and second reservoir check valves respectively connecting said reservoir passage to said first and second ends of said main bore and allowing secondary fluid into said main bore;
l) third and fourth check valves respectively connecting said secondary fluid outlet passage to said first and second ends of said main bore and allowing secondary fluid out of said main bore;
m) a first spool slidably positioned within said first bore and having first and second ends, said first spool having first and second pilot pistons respectively extending from said first and second ends and respectively extending into said first and second control passages to move said first spool to a first position when said first and second control passages are respec-tively connected to said primary fluid pump and said main bore and to a second position when said first and second control passages are respectively connected to said second ends of said first and second bores to a second main passage between a second control passage and said second end of said main bore;
n) second spool means positioned within said second bore and extending into both said first and second pilot passages, said second spool means movable in response to primary fluid in said second pilot passage to connect said source to said first main passage and said second relief passage to said second main passage and to primary fluid in said first pilot passage to connect said source to said second main passage and said first relief passage to said first main passage; and o) free piston means positioned within said main bore and extending into said first and second main passages, said free piston means for responding to high pressure primary fluid in said first main passage to move from a first position connecting said first and second control passages to said first fluid reser-voir and said second bore through a series of positions drawing fluid from said reservoir through said first reservoir check valve means and supplying fluid from said main bore through said second outlet check valve means while respectively blocking said first and second control passages from said first and second main passages to a second position respectively connecting said first and second control passages to said second bore and said first fluid reservoir, said free piston means responsive to primary fluid in said second main passage to move from said second posi-tion through a series of positions drawing fluid from said reser-voir through said second reservoir check valve means and supply-ing fluid from said main bore through said first outlet check valve means to said first position.
a) a pump body;
b) a cylindrical main bore enclosed within said pump body having first and second ends;
c) first and second bores enclosed within said pump body having respective first and second ends;
d) a primary fluid inlet into said pump body connecting said primary fluid pump to said first and second bores medially between said respective first and second ends thereof;
e) first and second pilot passages enclosed within said pump body respectively connecting said first bore between said primary fluid inlet and said second relief passage to said first end of said second bore and said first bore between said primary fluid inlet and said first relief passage to said second end of said second bore;
f) first and second main passages enclosed within said pump body respectively connecting said second bore between said primary fluid inlet and said first relief passage to said first end of said main bore and said second bore between said primary fluid inlet and said second relief passage to said second end of said main bore;
g) first and second control passages enclosed within said pump body respectively connecting said first and second ends of said first bore to said first and second main passages respec-tively proximate said first and second ends of said main bore;
h) first and second relief passages enclosed within said pump body respectively connecting said first ends of said first and second bores to a first main passage between a first control passage and said first end of said main bore and said second ends of said first and second bores to a second main passage between a second control passage and said second end of said main bore;
i) a reservoir passage enclosed within said pump body connectible to said second fluid reservoir;
j) a secondary fluid outlet passage enclosed within said pump body connectible to said secondary fluid function;
k) first and second reservoir check valves respectively connecting said reservoir passage to said first and second ends of said main bore and allowing secondary fluid into said main bore;
l) third and fourth check valves respectively connecting said secondary fluid outlet passage to said first and second ends of said main bore and allowing secondary fluid out of said main bore;
m) a first spool slidably positioned within said first bore and having first and second ends, said first spool having first and second pilot pistons respectively extending from said first and second ends and respectively extending into said first and second control passages to move said first spool to a first position when said first and second control passages are respec-tively connected to said primary fluid pump and said main bore and to a second position when said first and second control passages are respectively connected to said second ends of said first and second bores to a second main passage between a second control passage and said second end of said main bore;
n) second spool means positioned within said second bore and extending into both said first and second pilot passages, said second spool means movable in response to primary fluid in said second pilot passage to connect said source to said first main passage and said second relief passage to said second main passage and to primary fluid in said first pilot passage to connect said source to said second main passage and said first relief passage to said first main passage; and o) free piston means positioned within said main bore and extending into said first and second main passages, said free piston means for responding to high pressure primary fluid in said first main passage to move from a first position connecting said first and second control passages to said first fluid reser-voir and said second bore through a series of positions drawing fluid from said reservoir through said first reservoir check valve means and supplying fluid from said main bore through said second outlet check valve means while respectively blocking said first and second control passages from said first and second main passages to a second position respectively connecting said first and second control passages to said second bore and said first fluid reservoir, said free piston means responsive to primary fluid in said second main passage to move from said second posi-tion through a series of positions drawing fluid from said reser-voir through said second reservoir check valve means and supply-ing fluid from said main bore through said first outlet check valve means to said first position.
6. The secondary fluid supply system of claim 5 wherein first and second sealing means are positioned between said first and second main passages and said first and second ends of said main bore respectively for sealingly encircling said first and second driving pistons.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US95106778A | 1978-10-13 | 1978-10-13 | |
| US951,067 | 1978-10-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1130169A true CA1130169A (en) | 1982-08-24 |
Family
ID=25491212
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA337,346A Expired CA1130169A (en) | 1978-10-13 | 1979-10-10 | Fluid supply system |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1130169A (en) |
-
1979
- 1979-10-10 CA CA337,346A patent/CA1130169A/en not_active Expired
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| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |