BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding and appreciation of this invention, and many of its advantages, reference will be made to the following detailed description taken in conjunction with the accompanying drawings.
FIG. 1 depicts a partial cross sectional view of a reciprocating air compressor system of the prior art;
FIG. 2 depicts a magnified cross sectional view of inlet and outlet valves within the prior art compressor system of FIG. 1;
FIG. 3 depicts a magnified partial cross sectional view of a reservoir valve and bleed orifice of the prior art compressor system of FIG. 1;
FIG. 4 depicts a partial cross sectional view of a reciprocating air compressor system of the invention;
FIG. 5 depicts a magnified partial cross sectional view of the reciprocating air compressor system of FIG. 4 during an intake stroke of the piston;
FIG. 6 depicts a more highly magnified cross sectional view of the orifice pin and adjacent components depicted in FIG. 5;
FIG. 7 depicts a magnified partial cross sectional view of the reciprocating air compressor system of FIG. 4, the piston being located at a bottom dead center position;
FIG. 8 depicts a magnified partial cross sectional view of the reciprocating air compressor system of FIG. 4 during a compression stroke of the piston;
FIG. 9 depicts a magnified partial cross sectional view of the reciprocating air compressor system of FIG. 4, the piston being located at a top dead center position;
FIG. 10 is an exploded top perspective view of components of the compressor pump of FIG. 4;
FIG. 11 is an exploded bottom perspective view of the air compressor components depicted in FIG. 10;
FIG. 12 depicts a side cross sectional view of compressor pump used with a compressor system according to one embodiment of the invention;
FIG. 13 depicts a side cross sectional view of compressor pump used with a compressor system according to one embodiment of the invention;
FIG. 14 depicts a side cross sectional view of compressor pump used with a compressor system according to one embodiment of the invention;
FIG. 15 depicts a side cross sectional view of compressor pump used with a compressor system according to one embodiment of the invention;
FIG. 16 depicts a side cross sectional view of compressor pump used with a compressor system according to one embodiment of the invention;
FIG. 17A depicts a magnified, perspective exploded view of the outlet valve used with the compressor pump of FIG. 16;
FIG. 17B depicts a magnified, side cross sectional view of the outlet valve used with the compressor pump of FIG. 16, the outlet valve being in the closed position;
FIG. 17C depicts a magnified, side cross sectional view of the outlet valve used with the compressor pump of FIG. 16, the outlet valve being in the closed position;
FIG. 18A depicts a magnified, side cross sectional view of the inlet valve used with the compressor pump of FIG. 16, the inlet valve being in the closed position; and
FIG. 18B depicts a magnified, side cross sectional view of the inlet valve used with the compressor pump of FIG. 16, the outlet valve being in the closed position.
DETAILED DESCRIPTION
Referring again to the drawings, identical reference numerals and letters designate the same or corresponding parts throughout the several figures shown on the drawings. In some drawings, some specific embodiment variations in corresponding parts are denoted with the addition of lower case letters and/or prime indicators to reference numerals.
A reciprocating air compressor system 64a according to the invention is depicted in FIG. 4. The air compressor system 64a includes an air compressor pump 66a having a compression cylinder 68a and a piston 70 powered with an electric motor 72 that actuates the piston 70 using a belt 74, flywheel pulley 76, and crankshaft 78, connected to the piston 70 via a piston rod and pin assembly 79. The compressor pump 66a and electric motor 72 are mounted on an air reservoir 80.
Referring to FIGS. 5 and 7-9, which depicts a magnified partial cross sectional view of the compressor pump 66a during an intake stroke of the piston 70, each intake stroke causes air to be drawn from the atmosphere surrounding the compressor system 64a through an air filter 82a and head assembly 83a into a cylinder inlet chamber 84a. A reed valve serves as an inlet valve 86a allowing a unidirectional flow of air from the cylinder inlet chamber 84a to the compression cylinder 68a throughout the duration of each intake stroke.
An orifice 88a is positioned on a hollow orifice pin 90a to allow airflow between the cylinder inlet chamber 84a and compression cylinder 68a. FIG. 6 is a magnified cross sectional view of the orifice pin 90a and orifice 88a depicting the comparative sizing of the minimum cross sectional size of the orifice 88a with the orifice pin 90a and adjacent components.
Referring again to FIGS. 5 and 7-9, both the inlet valve 86a and orifice pin 90a/orifice 88a are positioned on a cylinder valve plate 92a that is located between the cylinder inlet chamber 84a and compression cylinder 68a. Air is therefore allowed to also pass through the cylinder valve plate 92a when passing through the inlet valve 86a and orifice 88a. As shown in FIG. 5, the inlet valve 86a assumes an open position during each intake stroke of the piston 86a, creating an inlet valve clearance 87a with the cylinder valve plate 92a through which air passes from the cylinder inlet chamber 84a and compression cylinder 68a during the intake stroke.
As best understood by comparing FIGS. 5 and 6, when the inlet valve 86a assumes the open position (shown in FIG. 5) during the intake stroke of the piston 70, the inlet valve clearance 87a of the open inlet valve 86a is sufficiently large to allow a substantial amount of air to enter the compression cylinder 68a. Further comparing FIGS. 5 and 6, the minimum cross sectional size of the orifice 88a is smaller than the inlet valve clearance 87a of the inlet valve 86a that is in the open position during the intake stroke. Thus, a smaller amount of air enters the compression cylinder 68a through the orifice 88a than through the inlet valve 86a during the intake stroke.
The size of the inlet valve clearance 87a and the corresponding amount of air that can be admitted during each intake stroke is dependent on the size and configuration of the inlet valve 86a. FIG. 10 depicts an exploded top perspective view of some components from the compressor pump 66a including the head assembly 83a, cylinder valve plate 92a, inlet valve 86a, and orifice pin 90a. As best understood with reference to FIG. 10, the inlet valve 86a includes a valve tab 94a disposing multiple reeds 96a in a fanlike configuration. The inlet valve 86a is constructed of a flexible material having a memory shape such as plastic or metal that enables the inlet valve 86a to be biased to the closed position. The orifice pin 90a fits through a spacer hole 97a of a spacer 98a, a tab hole 100a of the inlet valve 86a, and pin fastening hole 102a of the cylinder valve plate 92a to secure and position the inlet valve 86a to the valve plate 92a.
FIG. 11 depicts an exploded bottom perspective view of the air compressor components depicted in FIG. 10. As best understood with reference to FIG. 11, the inlet valve 86a fits within a valve recess 104a when attached to the cylinder valve plate 92a. A separate inlet hole 106a extending from the valve recess 104a through the cylinder valve plate 92a corresponds to each reed 96a of the inlet valve 86a. As best understood by comparing FIG. 5 with FIGS. 10 and 11, a feature of this embodiment of the invention is that the total inlet valve clearance of the inlet valve 86a is the combined total of the individual inlet valve clearances 87a of each reed 96a. Accordingly, the total amount of air that can be admitted through the inlet valve 86a into the compression cylinder 68a during each intake stroke of the piston 70 is the combined total amount of air that can be admitted past each reed 96a and corresponding inlet hole 106a during each intake stroke. Thus, the total amount of air that can be admitted through the inlet valve 86a is much greater, and often several orders of magnitude greater, than the amount of air that that can be admitted through the orifice 88a during each intake stroke. Although it will be appreciated that the ratio of the minimum cross sectional size of the orifice 88a to the total inlet valve clearance of the inlet valve 86a can vary greatly, all such ratios will allow for a total amount of air that can be admitted through the inlet valve 86a to be greater than the amount that can be admitted through the orifice 88a during each intake stroke of the piston 70. Such ratios are typically on the order of 1:2,000, and can commonly range from 1:1,000 to 1:4,000, though both larger and smaller ratios are within the contemplated scope of the invention.
Referring again to FIG. 5, an elastomeric o-ring check valve serves as a unidirectional outlet valve 108a. As best understood by comparing the side cross sectional view of FIG. 5 with the bottom perspective exploded view of FIG. 11, the outlet valve 108a is constructed around a hollow valve shaft 110a that is formed from a shaped recess of the head assembly 83a. Being hollow, the valve shaft 110a is open at the top to allow air from the surrounding environment to cool the outlet valve 108a and compressor pump interior with the assistance of cooling fins 112a. The valve shaft 110a extends through a cylinder outlet chamber 114a of the air compressor pump 66a to an outlet hole 116a through the cylinder valve plate 92a.
As best understood with a further comparison of FIGS. 5 and 6-9 with FIG. 11, the valve shaft 110a includes a cylindrically shaped non-tapered section 118a and an adjacent semi-conically shaped tapered section 120a, the tapered section 120a increasing in diameter in a direction that is away from the outlet hole 115a. An elastomeric sealing ring 122a is positioned in the cylinder outlet chamber 114a around the non-tapered section 118a to reciprocate between the cylinder valve plate 92a and the tapered section 120a. The sealing ring 122a is biased to a closed position (as shown in FIGS. 5, 7, and 9) by an elastomeric actuation ring 124a that is positioned in the cylinder outlet chamber 114a around the tapered section 118a of the valve shaft 110a. The actuation ring 124a has a memory shape that is generally smaller than the smallest diameter of the tapered section 120a, causing the actuation ring 124a to move in a direction along the tapered section 118a that is toward the outlet hole 116a, biasing the sealing ring 122a to the closed position.
The sealing ring 122a and actuation ring 124a are constructed from materials selected for having optimal properties for their respective functions and interactions. For example, one suitable combination is the use of a Teflon sealing ring 122a with a silicone elastomer actuation ring 124a. In such a combination, the Teflon material of the sealing ring 122a provides effective sealing and low frictional resistance to the operation of the outlet valve 108a while the silicone material of the actuation ring 124a is effective for providing elasticity, high-temperature resistance, and hardening resistance while retaining viscosity. Other possible actuation ring materials include nitrile elastomers and viton elastomers. Other possible sealing ring materials include viton elastomers, hard nitrate elastomers, brass, and stainless steel.
Although the invention is shown and described in FIGS. 4-5 and 7-11 with an outlet valve 108a having a separate sealing ring 122a and actuation ring 124a, it will be appreciated that some contemplated embodiments of the invention may include an outlet valve using a single elastomeric o-ring. In such embodiments, the single elastomeric o-ring will generally be constructed of a material that is suitable for performing both actuation and sealing functions of the outlet valve.
Referring again to FIGS. 4-11, when the sealing ring 122a, under the bias of the actuation ring 124a, assumes the closed position shown in FIGS. 5, 7, and 9, the sealing ring 122a makes sealing contact with the cylinder valve plate 92a to create a substantially leak free sealing closure of the outlet hole 116a, preventing the movement of air from the cylinder outlet chamber 114a back into the compression cylinder 86a.
As best understood by comparing FIGS. 4 with FIGS. 5 and 7-9, a discharge tube 126a connects the cylinder outlet chamber 114a to the air reservoir 80. Since the sealing closure of the outlet hole 116a by the sealing ring 122a in the closed position is substantially leak free, the sealing closure is sufficient to allow the outlet valve 108a to prevent air pressure from the discharge tube 126a and cylinder outlet chamber 114a from flowing back into the compression cylinder 68a. The sealing closure therefore enables the outlet valve 108a to maintain air pressure that is present within the outlet chamber 114a. Thus, when the piston 70 is not reciprocating in the compression cylinder 68a, the outlet valve 108a is also capable of preventing the loss of air pressure within the discharge tube 126a and air reservoir 80.
The ability of the outlet valve 108a to maintain air pressure in the outlet chamber 114a, discharge tube 126a, and air reservoir 80 eliminates the need for a separate reservoir check valve to preserve air pressure in the air reservoir 80 and further eliminates the need for a bleed orifice 54a to remove back pressure within the discharge tube 126a and outlet chamber 114a when the piston 70 is not reciprocating within the compression cylinder 68a. As depicted in FIG. 4, the discharge tube 124a and outlet chamber 114a are therefore constructed to be open to the air reservoir 80 via an open tube coupling 128a. Accordingly, an air pressure that is approximately the same as that present within the air reservoir 80 remains present within the discharge tube 124a and outlet chamber 114a when the sealing ring 122a is in the closed position, which is also the closed position of the outlet valve 108a.
It is usually desirable to remove backpressure that may remain in the compression cylinder 68a when the piston 70 is not reciprocating. Since the orifice 88a is much smaller than the inlet valve clearance 87a of the open inlet valve 86a, air passes through the orifice 88a at a much slower rate than through the inlet valve 86a during the intake stroke. However, given the typical length of intervals during which the piston 70 is not reciprocating within the compression cylinder 68a, the removal of such backpressure can normally proceed at a rate that is much slower than the rate at which air is compressed by the piston 70. Therefore, the orifice 88a can be used for the removal of backpressure from the compression cylinder 68a.
The advantages of using the orifice 88a to remove backpressure in conjunction with an outlet valve according to the invention are best understood by comparing FIGS. 5-9 with the prior art compressor system 20 of FIGS. 1-3. FIG. 5 depicts the air compressor pump 66a of FIG. 4 during an intake stroke of the piston 70. Air from the atmosphere surrounding the compressor pump 66a is drawn through the air filter 82 and cylinder inlet chamber 84a through the inlet valve clearance 87a of the inlet valve 86a. Although the cross sectional area of the inlet valve clearance 87a of the inlet valve 86a is much larger than the orifice 88a, and although most of the air drawn into the compression cylinder 68a during the intake stroke consequently enters through the inlet valve 86a, a comparatively small amount of air also enters the compression cylinder 68a through the orifice 88a during the intake stroke.
Since air is drawn into the compression cylinder 68a during the intake stroke, the outlet valve 108a assumes the closed position, with the sealing ring 122a moving into sealing contact with the cylinder valve plate 92a due to the bias of the actuation ring 124a and suction forces of the piston 70. The sealing contact between the sealing ring 122a and cylinder valve plate 92a in the closed position makes the outlet valve 108a substantially leak free. Thus, the outlet valve 108a is sufficient to prevent air from the discharge tube 125a and cylinder outlet chamber 114a from entering or reverting into the compression cylinder 68a during the intake stroke. This sealing effect substantially reduces inefficiencies of the compressor pump 66a that could otherwise be caused by reversion.
FIG. 7 depicts the compressor pump 66a with the piston 70 in a bottom dead center position between the intake and compression strokes. FIG. 7 also depicts the inlet valve 86a and outlet valve 108a in closed positions and can therefore also be considered to represent the compressor pump 66a when the piston 70 is not reciprocating within the compression cylinder 68a.
Consider the compressor pump 66a when the piston 70 is not reciprocating within the compression cylinder 68a. The sealing ring 122a moves to the closed position, as depicted in FIG, 7, to seal against the cylinder valve plate 92a and prevent the loss of air pressure within the air reservoir 80, discharge valve 126a, and cylinder outlet chamber 114a. The compressor system 64a of FIGS. 4-11 includes no orifice similar to the bleed orifice 54 of the prior art compressor system 20 of FIGS. 1-3 and therefore allows air pressure within the air reservoir 80 to be maintained in the air reservoir 80, discharge valve 126a, and cylinder outlet chamber 114a.
Backpressure remaining in the compression cylinder 68a is relieved through the orifice 88a into the cylinder inlet chamber 84a and surrounding environment without affecting the air pressure contained within the air reservoir 80, discharge valve 126a, and cylinder outlet chamber 114a. This release of backpressure occurs without the need for an additional check valve and bleed mechanism such as the reservoir check valve 52 and bleed orifice 54 in the prior compressor system 20 of FIGS. 1-3, reducing the overall number of components in the compressor system 64a of the invention in FIGS. 6-11.
Now consider FIG. 8, which depicts the compressor pump 66a during a compression stroke (upward in FIG. 8) of the piston 70. As the piston 70 moves upward and compresses air, the sealing ring 122a moves out of sealing contact with the cylinder valve plate 92a and against the bias of the actuation ring 124a to the open position of the outlet valve 108a (depicted in FIG. 8) to create an outlet valve clearance 130a that allows the compressed air to flow from the compression cylinder 68a through the outlet hole 116a of the valve plate 92a into the cylinder outlet chamber 114a and discharge tube 126a. The sealing ring 122a and outlet valve 108a remain in the open position at least until the piston 70 completes the compression stroke and reaches a top dead center position within the compression cylinder 68a as depicted in FIG. 9. Referring briefly to FIG. 9, once the compression stroke has been completed, the sealing ring 122a returns to the depicted closed position under the combined forces of the actuation ring 124a and any backpressure that may be present within the cylinder outlet chamber 114a.
Referring again to FIG. 8, the inlet valve 86a moves to a closed position during the compression stroke to prevent air from escaping through the inlet valve 86a back into the cylinder inlet chamber 84a. Some compressed air does escape through the orifice 88a during the compression stroke. However, as best understood by comparing FIG. 8 with the magnified cross sectional view of the orifice 88a and orifice pin 90a in FIG. 8, while the sealing ring 122a remains in the open position, the cross sectional size of the outlet valve clearance 130a is substantially larger than that of the orifice 88a. Due to this difference in cross sectional sizing, a much larger amount of air enters the cylinder outlet chamber 114a than the cylinder inlet chamber 84a during each intake stroke. As a result, the net air flow through the compressor pump 66a during a complete intake and compression stroke (reciprocation) of the piston 70 results in positive air compression through the cylinder outlet chamber 114a and discharge tube 126a to the air reservoir 80.
Although reciprocation of the piston 70 results in some air being lost through the orifice 88a during each compression stroke, the positioning of the orifice 88a between the cylinder inlet chamber 84a and compression cylinder 68a and the use of the substantially leak free outlet valve 108a allows for a substantial reduction in the overall amount of compressed air that is wasted. Rather than being bled continuously, air is lost from the compression cylinder 86a through the orifice 88a to the inlet chamber 84a only during each compression stroke. After a quantity of air is lost through the orifice 88a during each compression stroke, a roughly equal amount of air is drawn back through the orifice 88a from the cylinder inlet chamber 84a to the compression cylinder 68a during each subsequent intake stroke. Air is not lost through the orifice 88a during the intake strokes.
By limiting the loss of compressed air through the orifice 88a to compression strokes, the invention increases the overall efficiency of the compressor system 64a. For example, since the placement of the bleed orifice 54 in the prior art compressor system 20 of FIGS. 1-3 is positioned downstream of the compression cylinder 24 and outlet valve 46, the loss of compressed air from the discharge tube 50 through the bleed orifice 54 is constant while the piston 26 reciprocates within the compression cylinder 24. However, since the placement of the orifice 88a in the compressor system 64a of the invention of FIGS. 4-11 allows for the loss of compressed air through the orifice 88a only during compression strokes, the amount of compressed air lost during piston reciprocation in reduced to approximately 50% of the level lost by the prior art compressor system 64a depicted in FIGS. 1-3.
Referring to FIG. 9, the compressor pump 66a is depicted with the piston 70 in a top dead center position between the compression and intake strokes. FIG. 9 also depicts the inlet valve 86a and outlet valve 108a in closed positions and can therefore also be considered to represent the compressor pump 66a when the piston 70 is not reciprocating within the compression cylinder 68a. Once piston reciprocation has ended, the sealing contact of the sealing ring 118a with the cylinder valve plate 92a is sufficient to allow the outlet valve 108a to preserve air pressure within the cylinder outlet chamber 114a, discharge tube 126a, and air reservoir 80 until the piston 70 is again reciprocated or the air pressure contained within the reservoir 80 is consumed. However, it will be appreciated that other types of outlet valves can be similarly implemented within the intended scope of the invention and also allow for substantially leak free sealing of air pressure.
For example, FIG. 12 depicts a side cross sectional view of compressor pump 66b used with a compressor system 64b according to one embodiment of the invention in which a check valve is used as an outlet valve 108b. The outlet valve 108b extends downward from the head assembly 83b on a valve stanchion 132b toward the outlet hole 116b. A valve piston 134b is positioned to reciprocate (vertically in FIG. 12) along the valve stanchion 132b.
The valve piston 134b is constructed of a polymer, elastomer, rubber, or other material suitable for creating a sealing contact with the cylinder valve plate 92b. A valve spring 136b biases the valve piston 134b to a closed position that is also the closed position of the outlet valve 108b and depicted in FIG. 12. In the closed position, the valve piston 134b contacts the cylinder valve plate 92b over and around the outlet hole 116b to seal the outlet hole 116b and prevent air from moving from the cylinder outlet chamber 114b to the compression cylinder 68b.The material of the valve piston 134b allows the outlet valve 108b to be substantially leak free in the closed position and therefore prevents compressed air within the outlet chamber 114b, discharge tube 126b, and reservoir (not shown in FIG. 12) from flowing back into the compression cylinder 68b.
When the piston 70 reciprocates within the compression cylinder 68b, the valve piston 134b moves against the bias of the valve spring 136b away from sealing contact with the cylinder valve plate 92b to an open position (not shown) during each compression stroke. The open position results in an outlet valve clearance that allows air to exit the compression cylinder 68b through the outlet hole 116b. The inlet valve 86b closes to prevent air from exiting the compression cylinder 68b through the inlet hole 106b. Although some air escapes the compression cylinder 68b into the inlet chamber 84b through the orifice 88b, the cross sectional size of the outlet valve clearance of the outlet valve 108b is much larger than the orifice 88b, resulting in a net movement of compressed air into the outlet chamber 114b and discharge tube 126b. During subsequent intake strokes, the valve piston 134b moves back into the closed position and prevents backpressure from flowing back into the compression cylinder 68b while the inlet valve 86b opens to allow air to enter the compression cylinder 68b from the inlet chamber 84b.
It is contemplated that in some embodiments of the invention, orifices provided to relieve compression cylinder backpressure may be reconfigured or combined with other compressor components. For example, FIG. 13 depicts a side cross sectional view of a compressor pump 66c used with a compressor system 64c according to one embodiment of the invention in which orifices 88c extend through each reed 96c of the inlet valve 86c.
During each intake stroke of the piston 70, the inlet valve 86c opens to allow a valve clearance that is much larger than each orifice 88c, allowing a substantial amount of air to enter the compression cylinder 68c while the outlet valve 108c prevents backpressure in the outlet chamber 114c from flowing through the outlet hole 116c. During each compression stroke, the outlet valve 108c opens and the inlet valve 106c closes, though some compressed air escapes through the inlet hole 106c via each orifice 88c during the compression stroke. However, the cross sectional size of the orifice 88c is sufficient to allow the relief of backpressure from within the compression cylinder 68c during intervals when the piston 70 is not reciprocating. During such intervals, the outlet valve 108c continues to seal off backpressure in the outlet chamber 114c and discharge tube 126c and prevent the backpressure from entering the compression cylinder 68c.
FIG. 14 depicts a side cross sectional view of a compressor pump 66d used with a compressor system 64d according to one embodiment of the invention in which an orifice 88d is contained within an air passage that is an exterior orifice tube 138d that leads from the upstream cylinder inlet chamber 84d through the head assembly 83d to the exterior of the compressor pump 66d, then directly into the compression cylinder 68d.
During each intake stroke of the piston 70, the inlet valve 86d opens to allow a valve clearance that is much larger than the orifice 88d, allowing a substantial amount of air to enter the compression cylinder 68d while the outlet valve 108d prevents backpressure in the outlet chamber 114d from flowing through the outlet hole 116d. Some air from the inlet chamber 84d enters the compression cylinder 68d through the orifice tube 138d. During each compression stroke, the outlet valve 108d opens and the inlet valve 106d closes, though some compressed air escapes through the orifice tube 138d and orifice 88d back into the inlet chamber 84d. During intervals when the piston 70 is not reciprocating, the orifice tube 138d and orifice 88d relieve backpressure directly from the compression cylinder 68d into the inlet chamber 84d without first channeling air through the inlet hole 106d or through the cylinder valve plate 92d.
FIG. 15 depicts a side cross sectional view of a compressor pump 66e used with a compressor system 64e according to one embodiment of the invention in which an orifice 88e is contained within an air passage that is an exterior orifice tube 138e that leads directly from the upstream exterior of the compressor pump 66e to the compression cylinder 68e. During each intake stroke of the piston 70, the inlet valve 86e opens to allow a valve clearance that is much larger than the orifice 88e, allowing a substantial amount of air to enter the compression cylinder 68e while the outlet valve 108e prevents backpressure in the outlet chamber 114e from flowing through the outlet hole 116e. Some air from exterior of the compressor pump 66e enters the compression cylinder 68d through the orifice tube 138e. During each compression stroke, the outlet valve 108e opens and the inlet valve 106e closes, though some compressed air escapes through the orifice tube 138e and orifice 88e into the environment surrounding the compressor pump 66e. During intervals when the piston 70 is not reciprocating, the orifice 88e relieves backpressure directly from the compression cylinder 68e into the environment surrounding the compressor pump 66e without first channeling air through the cylinder valve plate 92e or into the inlet chamber 84c.
It will be further appreciated that outlet valves that are both metallic sealing check valves and substantially leak free can be implemented within the contemplated scope of the invention. It will also be appreciated that inlet valves that are substantially leak free can also be used. For example, FIG. 16 depicts a side cross sectional view of a compressor pump 66f used with a compressor system 64f according to one embodiment of the invention in which a metallic sealing check valve that is substantially leak free is used as an outlet valve 108f and positioned in the outlet hole 116f of the cylinder valve plate 92f.
A magnified, perspective exploded view of the outlet valve 108f is depicted in FIG. 17A. The outlet valve 108f includes a steel valve disk 140 having multiple radially-extending guides 142 and reliefs 144 and a center positioned spring seat 146 for engaging and positioning a valve spring 148. The valve spring 148 is positioned between the valve disk 140 and a steel spring retainer 150 having a plurality of air holes 152 arranged in a circular pattern and extending between the major planar surfaces through the spring retainer 150.
FIG. 17B depicts a magnified, side cross sectional view of the outlet valve 108f positioned within the outlet hole 116f of the cylinder valve plate 92f between the compression cylinder 68f and outlet chamber 114f. As best understood by comparing FIGS. 17A and B, the spring retainer 150 is positioned above the valve spring 148 and locked in place with a steel snap ring 154. The valve spring 148 biases the valve disk 140, which is positioned to reciprocate vertically within the outlet hole 116f, downward to a closed position against a steel valve seat 156 that extends from the cylinder valve plate 92f into the outlet hole 116f. The guides 142 center the valve disk 140 and the reliefs 144 provide spacing within the outlet hole 116f to allow air to flow past the valve disk 140 when in the open position.
Referring again to FIG. 16, a similar metallic sealing check valve that is also substantially leak free is used as an inlet valve 86f and positioned in the inlet hole 106f of the cylinder valve plate 92f. Consider the magnified cross sectional side view of the inlet valve 86f in FIG. 18A and compare the outlet valve 108f depicted in FIG. 17B. The inlet valve 86f differs from the outlet valve 108f in that the inlet valve 86f includes a valve disk 140f ′ that is biased upward to a closed position against the valve seat 156′. The inlet valve 86f includes a steel valve disk 140′ with a center positioned spring seat 146′, a valve spring 148′, a steel spring retainer 150′ having a plurality of air holes 152′, spring retainer 150′, and a steel snap ring 154′ that are similar to those of the outlet valve 108f but inverted to allow for the upward biasing of the valve disk 140′.
The compressor pump 66f also includes an orifice 88f positioned within an orifice tube 138f leading directly from the compression cylinder 68f to the environment surrounding the compressor pump 66f.
Operation of the compressor pump 66f is best understood by comparing FIGS. 16 with FIGS. 17A-C and 18A and B. During each intake stroke of the piston 70, the valve disk 140′ of the inlet valve 86f moves downward against the bias of the valve spring 148′ from the closed position depicted in FIG. 18A to the open position depicted in FIG. 18B. The open position of the valve disk 140′ is also the open position of the inlet valve 86f and results in the valve disk 140′ moving away from contact with the valve seat 156′. The open position of the inlet valve 86f leaves a valve clearance 87f between the valve disk 140′ and valve seat 156′ having a cross sectional size that is much larger than the orifice 88f, resulting in a much larger amount of air being drawn into the compression cylinder 68f through the inlet valve 86f than through the orifice 88f during the intake stroke. As air is drawn in from the cylinder inlet chamber 84f through the inlet valve 86f, it proceeds into the inlet hole 106f along a path indicated with air flow arrows 158′ through the valve clearance 87f′, around the reliefs 144′, and through air holes 152′ into the compression cylinder 68f.
During each intake stroke, the valve disk 140 of the outlet valve 108f remains in the closed position, as depicted in FIG. 17B, the valve disk 140 remaining in sealing contact with the valve seat 156. Both the valve seat 156 and valve disk 140 are typically constructed of steel. However, one or both of the valve seat 156 and valve disk 140 typically include a polished steel surface and also utilize oil carry over that may be present if the compressor system 64f is a lubricated system. The mating shapes of the valve seat 156 and valve disk 140 can also enhance the sealing characteristics of the outlet valve 108f. These features allow the outlet valve 108f to be substantially leak free in the closed position, enabling the outlet valve 108f to seal and prevent air pressure from the outlet chamber 83f and discharge tube 126f from flowing back into the compression cylinder 68f during the intake stroke.
During each compression stroke of the piston 70, the valve disk 140′ of the inlet valve 8f returns to the closed position under the combined force of air compression by the piston 70 and the bias of the valve spring 148′, as depicted in FIG. 18A. The closed position of the inlet valve 86f results in the valve disk 140′ moving into contact with the valve seat 156′, preventing compressed air from flowing into the inlet chamber 84f.
The compression forces of the piston 70 during the intake stroke also result in the valve disk 140 of the outlet valve 108f moving against the bias of the valve spring 148, as depicted in FIG. 17B, the valve disk 140 moving upward away from sealing contact with the valve seat 156. The open position of the outlet valve 108f also results in a valve clearance 87f between the valve disk 140 and valve seat 156, having a cross sectional size that is much larger than the orifice 88f. A much larger amount of air is therefore capable of exiting the compression cylinder 68f through the outlet valve 108f than through the orifice 88f during the compression stroke stroke. As air from the compression cylinder 68f enters the outlet valve 108f, the air flow proceeds along a path through the outlet hole 116f indicated with air flow arrows 158 through the valve clearance 87f, around the reliefs 144′, and through the air holes 152 into the outlet chamber 114f.
Those skilled in the art will recognize that the various features of this invention described above can be used in various combinations with other elements without departing from the scope of the invention. Thus, the appended claims are intended to be interpreted to cover such equivalent air compressor systems as do not depart from the spirit and scope of the invention.
Patent Application
20080063551
