Information
-
Patent Grant
-
6817846
-
Patent Number
6,817,846
-
Date Filed
Thursday, June 13, 200221 years ago
-
Date Issued
Tuesday, November 16, 200419 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Michael Best & Friedrich LLP
-
CPC
-
US Classifications
Field of Search
US
- 417 523
- 417 533
- 417 534
- 417 545
- 417 546
- 417 552
- 417 553
- 137 5121
-
International Classifications
-
Abstract
A gas compressor and method according to which a piston assembly reciprocates in a bore to draw the fluid to be compressed into the bore during movement of the piston unit in one direction and to compress the fluid during movement of the piston unit in the other direction.
Description
BACKGROUND
This invention relates, in general, to a fluid compressor, and, more particularly, to a compressor having improved discharge valves.
Many reciprocating compressor cylinders utilize a piston assembly that reciprocates in a cylinder formed in the compressor body, with outer heads closing off the ends of the cylinder. In these arrangements, the piston assembly often includes a discharge valve that controls the gas flow through its body structure into the cylinder and then compresses the fluid before permitting the compressed fluid to discharge through the outlet.
These type of valve assemblies utilize a plate valve which “lifts” off a valve seat in response to a pressure differential created from one side of the valve to the other side, to permit flow through the assembly. However, this flow area through the valve assembly is often limited in size, which compromises the efficiency of the compressor.
Therefore, what is needed is a compressor of the above type according to which the valve assemblies have a relatively large flow area and the compressor thus has an increased efficiency.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a partial sectional-partial elevational, view of a fluid compressor according to an embodiment of the present invention.
FIG. 2
is an enlarged sectional view of the piston assemblies of the compressor of FIG.
1
.
FIG. 3
is an exploded, isometric view of an outboard valve assembly utilized in a piston assembly of FIG.
2
.
FIG. 4
is an exploded, isometric view of an inboard valve assembly utilized in the piston assembly of FIG.
2
.
FIGS. 5
a-
5
h
are diagrammatic views depicting the operation of the compressor of FIG.
1
.
DETAILED DESCRIPTION
Referring to
FIG. 1
of the drawings the reference numeral
10
refers, in general, to a compressor for compressing a fluid, such as gas, according to an embodiment of the present invention. The compressor
10
includes a cylindrical housing
12
defining an internal cylindrical bore
14
and a radially extending outlet
15
that registers with the bore
14
.
An outer head
16
is formed at one end of the housing
12
, and a frame head
18
is mounted at the other end of the housing. A plurality of inlet chambers are formed through the head
16
with two being shown in FIG.
1
and referred to by the reference numerals
16
a
and
16
b
. The inlet chambers
16
a
and
16
b
, as well as the other inlet chambers in the head
16
, are interconnected and are in fluid communication with an inlet conduit
20
formed on the body member
12
.
The head
18
is identical to the head
16
and, as such, has a plurality of inlet chambers formed therein, two of which are shown in FIG.
1
and referred to by the reference numerals
18
a
and
18
b
. The inlet chambers
18
a
and
18
b
, as well as the other inlet chambers in the head
18
, are interconnected and are in fluid communication with an inlet conduit
22
formed on the body member
12
.
The inlet conduits
20
and
22
are adapted to receive a fluid to be compressed, such as a gas, and direct the gas into the heads
16
and
18
for discharge into the bore
14
as shown by the arrows in FIG.
1
.
A drive rod
24
extends through the center of the head
18
and into the bore
14
, and is mounted for reciprocal movement in a packing gland assembly
26
mounted in a chamber formed in the head
18
. The packing gland assembly
26
functions in a conventional manner to seal against compressed gas from leaking past the rod
24
. An end portion of the rod
24
projects from the bore
14
and through a collar
27
mounted to the face of the head
18
and, although not shown in the drawings, it is understood that it is connected to a conventional prime mover for reciprocating the rod in a right-to-left and in a left-to-right direction as viewed in
FIG. 1
, as shown by the double-headed arrow.
An outboard piston assembly
30
and an inboard piston assembly
32
are disposed in the bore
14
in a spaced relation. The rod extends through central openings in the piston assemblies
30
and
32
, and a jam nut
34
abuts the outboard face of the piston assembly
30
and is connected to the other end of the rod
24
in any conventional manner, such as by a plurality of bolts, or the like. A tubular spacer
36
extends between the piston assemblies
30
and
32
and is connected thereto in a manner to be described. Thus, when the above-mentioned reciprocal movement is imparted to the rod
24
, the piston assemblies
30
and
32
reciprocate in the bore
14
with the rod
24
, and function to draw the gas into the bore
14
and compress the gas before the gas is discharged through the outlet
15
, in a manner to be described.
as shown in
FIG. 2
, the outboard piston assembly
30
consists of an outboard valve assembly
40
and an inboard valve assembly
42
disposed in an abutting relationship. The jam nut
34
abuts the outboard face of the outboard valve assembly
40
, the inboard face of the outboard valve assembly abuts the outboard face of the inboard valve assembly
42
, and the inboard face of the inboard valve assembly is connected to the spacer
36
.
The outboard valve assembly
40
is shown in detail in
FIGS. 2 and 3
and consists of an annular valve seat
46
having an outer diameter less that the diameter of the inner wall of the body member
12
defining the bore
14
. A plurality of spaced bores
46
a
(
FIG. 2
) extend from the outboard face of the valve seat to a plurality of angularly and radially spaced, slots
46
b
(
FIG. 3
) formed in the inboard face of the seat. A reduced-diameter, annular stop
46
c
extends from the inboard face of the seat
46
and a relatively large central opening
46
d
is formed through the seat
46
for receiving the rod
24
(FIG.
2
).
An annular valve plate
48
, having a diameter slightly less than the diameter of the valve seat
46
, is provided and has a plurality of angularly and radially spaced, arcuate slots
48
a
formed therethrough. A relatively large central opening
48
b
is formed through the valve plate
48
for receiving the rod
24
(FIG.
2
). The valve plate
48
is adapted to move axially in the bore
14
relative to the valve seat
46
between a first position in which it engages the inboard face of the valve seat
46
and a second position in which it is spaced from the seat. In the first position, the non-slotted portion of the valve plate
48
blocks the slots
46
b
of the valve seat
46
to prevent gas flow through the valve seat, and in the second position gas can flow through the slots
46
b
and through the slots
48
a
of the valve plate.
An annular dampening plate
50
is disposed adjacent the valve plate
48
, is approximately the same diameter as the valve plate, and functions to decelerate movement of the valve plate under conditions to be described to prevent damage caused by impact inertia. To this end, the mass of the dampening plate
50
is normally greater than that of the valve plate
48
so that the plate
50
dampens movement of the plate
48
under conditions to be described. A plurality of angularly and radially spaced, arcuate slots
50
a
extend through the plate
50
and are in alignment with the slots
48
a
of the plate
48
. Six angularly-spaced through openings
50
b
are also provided in the plate
50
for reasons to be described, and a relatively large central opening
50
c
is formed through the plate
50
for receiving the rod
24
(FIG.
2
).
A valve guard
52
is disposed adjacent the dampening plate
50
and functions to provide a positive stopping point for the dampening plate
50
, also under conditions to be described. The valve guard
52
consists of a housing
54
having a tapered, or funnel-shaped, cross-section. A plate
56
is disposed in the housing
54
and has a plurality of through openings
56
a
and a relatively large central through opening
56
b
for receiving the rod
24
. As shown in
FIG. 2
, the outboard end portion of the housing
54
envelopes the outer circumferential portions of the valve plate
48
and the dampening plate
50
.
One end portion of a spring
58
extends into a pocket, or the like, (not shown) formed in the outboard face of the valve guard
52
. The spring
58
extends through an opening
50
b
in the dampening plate
50
and its other end engages the inboard face of the valve plate
48
. Although only one spring
58
is shown, it is understood that five other springs are provided which are identical to the spring
58
and which extend through the remaining five openings
50
b
in the plate
50
, respectively. The springs
58
function to urge the valve plate
48
into engagement with the valve seat
46
until forced away from the seat by differential fluid pressure, as will be described.
One end of a spring
60
also extends into a pocket, or the like, (not shown) formed in the outboard face of the valve guard
52
and its other end engages the inboard face of the dampening plate
50
. The spring
60
functions to urge the dampening plate
50
into engagement with the stop
46
c
and in a slightly spaced relation to the valve plate
48
until forced away from the stop by differential fluid pressure. Although only one spring
60
is shown in the drawing, it is understood that additional springs can be provided that are identical to the spring
60
and function in the same manner.
The springs
58
and
60
normally bias the valve plate
48
into a sealing position against the valve seat
46
, and the dampening plate
50
against the stop
46
c,
respectively.
An alignment pin
62
extends though corresponding aligned openings in the valve plate
48
and the dampening plate
50
for maintaining proper angular alignment of the plates. Two cap screws
64
a
and
64
b
extend through aligned openings in the valve seat
46
, through the center openings
48
b
and
50
c
in the plates
48
and
50
, respectively, and engage threaded bores in the valve guard
52
to maintain the valve assembly
40
in its assembled condition shown in FIG.
2
.
The inboard valve assembly
42
is shown in detail in
FIGS. 2 and 4
and consists of an annular valve seat
66
having an outer diameter slightly less that the diameter of the inner wall of the body member
12
(
FIG. 1
) defining the bore
14
. A plurality of spaced bores
66
a
(
FIG. 2
) extend from the outboard face of the valve seat
66
to a plurality of radially spaced, slots
66
b
(
FIG. 3
) formed in the inboard face of the seat. A plurality of angularly-spaced portals
66
c
are formed though the seat
66
, and a reduced-diameter annular stop
66
d
projects from the inboard face of the valve seat
66
.
A plurality of circumferential grooves
66
e
are formed in the outer surface of seat
66
and receive a corresponding number of seal rings
67
which engage the inner wall of the body member defining the bore
14
, to seal against the flow of compressed gas from the bore. A relatively large central opening
66
f
is formed through the seat
46
for receiving the rod
24
(FIG.
2
).
An annular valve plate
68
, is provided and has a plurality of angularly and radially spaced, arcuate slots
68
a
extending therethrough. The valve plate
68
is adapted to move in the bore
14
between a first position in which it engages the inboard face of the valve seat
66
, with the non-slotted portion of the plate blocking the slots
66
b
of the valve seat, and a second position in which it is spaced from the seat to permit the flow of gas through the slots in the valve seat and the slots
68
a
of the valve plate. A plurality of angularly-spaced portals
68
b
are formed though the plate
68
, and a relatively large central opening
68
c
is formed through the plate
68
for receiving the rod
24
(FIG.
2
).
An annular dampening plate
70
is disposed adjacent the valve plate
68
and functions to decelerate the valve plate under conditions to be described to prevent damage caused by impact inertia. To this end, the mass of the dampening plate
70
is greater than that of the valve plate
68
so that the plate
70
dampens movement of the plate
68
. A plurality of angularly and radially spaced, arcuate slots
70
a
, and a plurality of angularly spaced portals
70
b
extend through the plate
70
. The slots
70
a
register with the slots
68
a
of the valve plate
68
, and the portals
70
b
register with the portals
68
b
of the valve plate
68
. Six angularly-spaced openings
70
c
are provided through the plate
70
for reasons to be described, and a relatively large central opening
70
d
is formed through the plate
70
for receiving the rod
24
(FIG.
2
).
An annular guard plate
72
is disposed adjacent the dampening plate
70
and functions to provide a positive stopping point for the dampening plate
70
, also under conditions to be described. A plurality of angularly-spaced portals
72
a
extend through the guard plate
72
and register with the portals
70
b
of the dampening plate
70
, and a relatively large central opening
72
b
is formed through the guard plate
72
for receiving the rod
24
(FIG.
2
). The plate
72
also has a plurality of relatively small through openings
72
c,
for reasons to be described.
One end portion of a spring
74
extends into a pocket, or the like, (not shown) formed in the outboard face of the guard plate
72
. The spring
74
extends through an opening
70
c
in the dampening plate
70
and its other end engages the inboard face of the valve plate
68
. Although only one spring
74
is shown, it is understood that five other springs are provided which are identical to the spring
74
and which extend through the remaining five openings
70
c,
respectively. The springs
74
function to urge the valve plate
68
into engagement with the valve seat
66
until forced away from the seat by differential fluid pressure under conditions to be described.
One end of a spring
76
also extends into a pocket, or the like, (not shown) formed in the outboard face of the valve guard
72
and its other end engages the inboard face of the dampening plate
70
to urge the dampening plate into engagement with the stop
66
d
until forced away by differential fluid pressure. Although only one spring
76
is shown in the drawing, it is understood that additional springs can be provided that are identical to the springs
74
and
76
and function in the same manner.
An alignment pin
78
extends though corresponding aligned openings in the dampening plate
70
and the valve plate
68
for maintaining proper angular alignment of the plates. Two cap screws
80
a
and
80
b
extend through aligned openings in the valve seat
66
, through the center openings in the plates
68
and
70
, though the valve guard
72
and engage threaded bores in the spacer
24
(
FIG. 2
) to maintain the valve assembly
42
in its assembled condition shown in FIG.
2
.
As shown in
FIG. 2
, the outer diameter of the valve assembly
40
is considerably less than the outer diameter of the valve assembly
42
and the corresponding inner wall of the body member
12
defining the bore
14
. Thus, some of the gas from the head
16
passes around the outer surfaces of the valve assembly
40
and directly to the valve assembly
42
under conditions to be described.
The general operation of the valve assemblies
40
and
42
is as follows. When gas is admitted into the head
16
from the inlet conduit
20
, the gas passes through the inlet chambers in the head, including the chambers
16
a
and
16
b
, and into the outboard end portion of the bore
14
. As better shown in
FIG. 1
, a portion of this gas passes around the outer surface of the valve assembly
40
of the piston assembly
30
and to the valve assembly
42
which controls the flow of the gas in a manner to be described.
As better shown in
FIGS. 2 and 3
, the remaining portion of the gas passes through the bores
46
a
and the slots
46
b
in the valve seat
46
and exerts a pressure against the outboard face of the valve plate
48
. When this pressure exceeds the pressure acting on the inboard face of the valve seat
46
by the springs
58
, the valve plate
48
will be forced off the seating surface of the valve seat
46
and will move in a left-to-right direction as viewed in
FIG. 2
until it encounters the dampening plate
50
, and both plates then travel a short distance in unison until they come in contact with the plate
56
of the valve guard
52
.
This allows the passage of compressed gas through the openings
46
a
and the slots
46
b
in the valve seat
48
, and through the aligned slots
48
a
and
50
a
in the valve plate
48
and the dampening plate
50
, respectively, before passing through the openings
56
a
in the plate
56
. The tapered housing
54
of the valve guard functions to funnel, or direct the gas passing through the openings
56
a
towards the center, or axis of the valve assembly
42
so that the gas passes through the aligned portals
66
c
,
68
b
,
70
b
, and
72
a
(
FIG. 4
) of the valve seat
66
, the valve plate
68
, the dampening plate
70
, and the guard plate
72
, respectively, before the gas enters that portion of the bore
14
disposed between the piston assemblies
30
and
32
as shown in FIG.
1
.
The above-mentioned gas from the head
16
that passed around the outer surface of the valve assembly
40
of the piston assembly
30
passes directly to the valve assembly
42
. As better shown in
FIGS. 2 and 4
, this latter gas then passes through the bores
66
a
and the slots
66
b
in the valve seat
66
and exerts a pressure against the outboard face of the valve plate
68
. When this pressure exceeds the pressure acting on the inboard face of the valve seat
66
by the springs
74
, the valve plate
68
will be forced off the seating surface of the valve seat
66
and moved in a left-to-right direction, as viewed in FIG.
2
. This allows passage of compressed gas through the valve seat
66
and through the aligned slots in the valve plate
68
, the dampening plate
70
and the valve guard
72
before the gas enters the portion of the bore
14
extending between the piston assemblies
30
and
32
. Thus, this portion of the bore
14
receives two streams of gas from the piston assembly
30
, one that flows through both valve assemblies
40
and
42
, and one that flows only through the valve assembly
42
.
During the above operation, and as a non-limitative example, the valve plates
48
and
68
will move, or “lift”, for approximately 0.060″ until they come into contact with their corresponding dampening plates
50
and
70
, respectively. The plates
48
and
50
, as well as the plates
68
and
70
, will then move together approximately another 0.020″ while they decelerate and then come into contact with their respective valve guards
52
and
72
.
Referring to
FIG. 2
, the piston assembly
32
consists of two abutting valve assemblies
86
and
88
that are identical to the valve assemblies
40
and
42
, respectively, of the piston assembly
30
. The valve assemblies
86
and
88
face in the opposite direction than the valve assemblies
40
and
42
and the valve assembly
86
is positioned inboard of the valve assembly
88
. The valve assemblies
86
function in a manner identical to the functions of the valve assemblies
40
and
42
, respectively. Thus, some of the fluid introduced into the bore
14
from the inlet chambers formed in the head
18
, including the inlet chambers
18
a
and
18
b
, will pass into end portion of the bore
14
inboard of the valve assembly
86
. When the rod
24
, and therefore the valve assemblies
30
and
32
, move in a left-to-right direction, the pressure of the latter gas will exert a pressure on the valve plate associated with the valve assembly
86
to force it to move in a right-to-left position from its sealing position before the gas passes through the valve assembly
88
and into that portion of the bore between the piston assemblies
30
and
32
.
The remaining portion of the gas from the head
18
will pass around the outer surfaces of the valve assembly
86
and directly to the valve assembly
88
. This latter gas will exert a pressure on the valve plate associated with the valve assembly
88
to force it to move in a right-to-left position from its sealing position before the gas passes through the valve assembly
88
and into the latter portion of the bore
14
. Thus, the bore
14
also receives two streams of gas from the piston assembly
32
, one that flows through both valve assemblies
86
and
88
, and one that flows only through the valve assembly
88
.
The complete operation of the compressor
10
will be described in connection with
FIGS. 5A-5H
. As shown in
FIG. 5A
, the piston assemblies
30
and
32
divide the bore
14
into a section
14
a
between the head
16
and the piston assembly
30
, a section
14
b
between the piston assemblies
30
and
32
, and a section
14
c
between the piston assembly
32
and the head
18
. For the purposes of example, it will be assumed that as a result of a previous cycle of operation, a fluid, such as gas, or other product, has been drawn into the bore section
14
a
, and the rod
24
, and therefore the piston assemblies
30
and
32
, are in their extreme right position, as viewed in
FIG. 5
a
as a result of a previous cycle of the operation.
The gas is introduced, via the inlet conduit
22
, into the inlet chambers, including the chambers
18
a
and
18
b
, formed in the head
18
. The rod
24
, and therefore the piston assemblies
30
and
32
, are moved in a right-to-left direction, as shown by the solid arrow, from the position of
FIG. 5A
to the position of
FIG. 5B
, under the power of the above-mentioned prime mover. This movement draws gas from the head
18
into the bore section
14
c
and causes the gas that is present in the bore section
14
a
from the previous cycle to be compressed.
Further right-to-left movement of the rod
24
, and therefore the piston assemblies
30
and
32
, to the position of
FIG. 5C
causes additional gas to be drawn in the bore section
14
c
in the manner discussed above, and further increases the fluid pressure in the bore section
14
a
. Some of this compressed gas flows into the valve assembly
40
of the piston assembly
30
in the manner described above, and the right-to-left movement of the rod
24
continues until the pressure in the bore section
14
a
is great enough to move the valve plate
48
of the valve assembly
40
in a left-to-right direction off of its valve seat
46
. The above portion of the compressed gas thus flows through the valve assembly
40
in the manner described above and to the valve assembly
42
where it passes through the aligned openings
66
c,
68
b
,
70
b
, and
72
a
(
FIG. 4
) of the latter assembly and to the bore section
14
b
, as shown by the hollow arrows in FIG.
5
C. Thus, in this case the valving function of the valve seat
66
and the plate
68
are bypassed.
The other portion of the compressed gas in the bore section
14
a
passes around the valve assembly
40
and directly into the valve assembly
42
as also described above. When the gas pressure in the bore section
14
a
is great enough to move the valve plate
68
of the valve assembly
42
in a left-to-right direction off of its valve seat
46
, the latter portion of the compressed gas thus flows through the valve assembly
42
in the manner described above and into the bore section
14
c.
The compressed gas that flows into the bore section
14
b
in the two manners described above exits the body member
12
through the outlet
15
and is transferred from the compressor
10
via a pipe, or the like, connected to the outlet.
This right-to-left movement of the rod
24
and the piston assemblies
30
and
32
continues, causing further compression of the gas in the bore section
14
a
and passage of the compressed gas though the valve assemblies
40
and
42
of the piston assembly
30
. The gas in the bore section
14
a
discharges through the outlet
15
as described above until the rod
24
and the piston assemblies
30
and
32
reach the end position shown in FIG.
5
D.
Referring to
FIG. 5E
, gas is introduced, via the inlet conduit
20
into the inlet chambers, including the chambers
16
a
and
16
b
, formed in the head
16
. The rod
24
, and therefore the piston assemblies
30
and
32
, are moved in a left-to-right direction, as shown by the solid arrow, from the position of
FIG. 5E
to the position of
FIG. 5F
, under the power of the above-mentioned prime mover. This movement draws gas from the head
16
into the bore section
14
a
and causes the gas that is present in the bore section
14
c
as a result of the above operation to be compressed.
Further left-to-right movement of the rod
24
, and therefore the piston assemblies
30
and
32
, to the position of
FIG. 5G
causes additional gas to be drawn in the bore section
14
a
in the manner discussed above, and further increases the fluid pressure in the bore section
14
c.
Some of this compressed gas flows into the valve assembly
86
of the piston assembly
30
in the manner described above, and the left-to-right movement of the rod
24
continues until the pressure in the bore section
14
c
is great enough to move the valve plate of the valve assembly
86
in a right-to-left direction off of its valve seat. The above portion of the compressed gas thus flows through the valve assembly
86
in the manner described above and to the valve assembly
88
where it passes through the aligned openings of the latter assembly and to the bore section
14
b
, as shown by the hollow arrows in FIG.
5
G.
The other portion of the compressed gas in the bore section
14
c
passes by the valve assembly
86
and directly into the valve assembly
88
as also described above. When the gas pressure in the bore section
14
c
is great enough to move the valve plate of the valve assembly
88
in a right-to-left direction off of its valve seat
46
, the latter portion of the compressed gas thus flows through the valve assembly
88
in the manner described above.
The compressed gas that flows into the bore section
14
b
in the two manners described above exits the body member
12
through the outlet
15
and is transferred from the compressor
10
via a pipe, or the like, connected to the outlet.
This right-to-left movement of the rod
24
, and the piston assemblies
30
and
32
, continues, causing further compression of the gas in the bore section
14
c
and passage of the compressed gas though the piston assembly
32
and discharge of the gas through the outlet
15
as described above until the rod
24
and the piston assemblies reach the end position shown in FIG.
5
H.
The above cycle is then repeated and the compressor
10
thus functions to continuously receive gas via the inlet conduits
20
and
22
and discharge compressed gas from the outlet
15
.
Alternatives and Equivalents
It is understood that some of the components of the compressor
10
have been omitted in the interest of clarity. For example, although a dual acting system having two piston assemblies is disclosed above, it is understood that the present invention is equally applicable to a single acting system assembly in which only one piston assembly would be provided which would function in an identical manner to the piston assemblies
30
and
32
. Further, the present invention is not limited to the particular design of the valve assemblies
40
,
42
,
86
and
88
disclosed above, but rather other types of valve assemblies can be used, such as, for example, those disclosed in U.S. Pat. No. 5,011,383 or No. 5,015,158 (the disclosures of which are incorporated by reference) or those employing a series of rings or bullets. Still further, a plurality of inlet valves can be disposed in the inlet chambers defined in the heads
16
and
18
as disclosed in co-pending U.S. application Ser. No. 10/047,385 the disclosure of which is incorporated by reference. Moreover, another fluid, other than gas, can be compressed by the compressor
10
. Moreover, the number of openings extending through the valve seat
66
, the plates
68
and
70
, and the valve guard
72
can be varied; and the number of springs
58
,
60
,
74
, and
76
utilized in the above manner can be varied depending on the particular load conditions.
Those skilled in the art will readily appreciate that many other modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the following claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures.
Claims
- 1. A fluid compressor comprising:a body member defining an internal bore having an inlet at one end and an outlet; a first valve assembly disposed in the bore between the one end of the bore and the outlet; a second valve assembly disposed in the bore between the one end of the bore and the outlet in an axially spaced relation to the first valve assembly; the first and second valve assemblies being movable in a first direction in the bore to draw fluid through the inlet and into the bore; the first and second valve assemblies being adapted to move in a second direction in the bore to increase the fluid pressure in the bore; the first valve assembly being responsive to a predetermined fluid pressure acting on it for permitting the flow of a first portion of the fluid in the bore through the first valve assembly and to the second valve assembly; the second valve assembly defining a bypass passage for receiving the first portion of fluid from the first valve assembly and passing the first fluid portion to the outlet and defining at least one other passage through the second valve assembly; and the second valve assembly being responsive to a second portion of fluid in the bore exerting a predetermined fluid pressure on the second valve assembly for permitting the flow of the the second fluid portion through the at least one other passage and to the outlet.
- 2. The compressor of claim 1 wherein another inlet is disposed in the body member for introducing additional fluid into the other end of the bore, and further comprising a third valve assembly disposed in the bore in an axially spaced relation to the second valve assembly, a fourth valve assembly disposed in the bore in an axially spaced relation to the third valve assembly, means for moving the first, second, third and fourth valve assemblies in the first and second directions, whereby movement of the valve assemblies in the second direction draws the additional fluid from the other inlet into the other end portion of the bore so that a first portion of the additional fluid is directed to the fourth valve assembly and a second portion of the additional fluid is directed to the third valve assembly, wherein movement of the valve assemblies in the first direction increases the fluid pressure in the other end portion of the bore, the fourth valve assembly being responsive to a predetermined fluid pressure acting on it for permitting the flow of the first portion of the additional fluid through it and to the third valve assembly, and the third valve assembly defining a bypass passage for receiving the first portion of the additional fluid from the fourth valve assembly and passing it to the bore for passage to the outlet, the third valve assembly being responsive to the other portion of fluid exerting a predetermined fluid pressure on it for permitting the flow of fluid through it and to the bore for passage to the outlet.
- 3. The compressor of claim 2 wherein the second direction is opposite to the first direction.
- 4. The compressor of claim 2 wherein the means comprises a rod mounted for reciprocal movement in the bore and wherein the valve assemblies are attached to the rod for reciprocation therewith.
- 5. A method for compressing a fluid, comprising providing a bore having an inlet at one end and an outlet, disposing two valve assemblies in the bore between the one end of the bore and the outlet, moving the valve assemblies in the bore in a first direction to draw fluid through the inlet and into the bore, moving the valve assemblies in the bore in a second direction to increase the pressure in the bore, permitting the flow of a first portion of the fluid through the one valve assembly and to the other valve assembly in response to a predetermined fluid pressure acting on the one valve assembly, the first portion of the fluid bypassing the other valve assembly and passing to the outlet, and permitting the flow of another portion of the fluid through the other valve assembly and to the outlet in response to a predetermined fluid pressure acting on the other valve assembly.
US Referenced Citations (21)