Patent Application
20150337823
The present invention relates in general to the field of gas compressors. Compressors are known in the art. However, such compressors do not operate without a lubricant by utilizing a graphite piston in a glass cylinder. The present invention provides embodiments of compressors with several advantages over the prior art including improved transportability, reduced size, reduced power consumption, operation with little or no lubrication, and increased operational life.
This application hereby incorporates by reference U.S. Publication Numbers 2011-0309721; 2012-0038245; 2013-0234562; 2013-0234561, U.S. patents:
U.S. Pat. No. 7,564,171
U.S. Pat. No. 6,717,332;
U.S. Pat. No. 6,548,938;
U.S. Pat. No. 6,737,788;
U.S. Pat. No. 6,836,056;
U.S. Pat. No. 6,879,087;
U.S. Pat. No. 6,759,790;
U.S. Pat. No. 7,132,781;
U.S. Pat. No. 7,126,259;
U.S. Pat. No. 6,870,305;
U.S. Pat. No. 6,975,061;
U.S. Pat. Nos. 7,368,856; and 6,924,586. All incorporated patents, patent applications and patent publications are incorporated in their entirety.
Embodiments of the present invention provide a compressor with a glass cylinder having a hollow interior. A graphite piston is situated within the glass cylinder, with a connecting rod attached to the graphite piston. A cylinder head seals one end of the glass cylinder and has at least one exhaust valve in operable connection with the hollow interior of the glass cylinder. At least one inlet valve is in operable connection with the hollow interior of the glass cylinder. In certain embodiments, the inlet valves are mounted within the cylinder head. In other embodiments, the inlet valves are mounted on the graphite piston. Inlet and exhaust valves may also be situated in connection with lines connected to the compressor where a simpler cylinder head design is desirable.
Upon the connecting rod moving the graphite piston toward the cylinder head, material within the hollow interior of the glass cylinder is compressed. When a sufficient pressure is attained, a portion of the material is expelled out the exhaust valve. Upon the connecting rod moving the graphite piston away from the cylinder head, pressure within the glass cylinder is reduced and the exhaust valve substantially prevents backflow. The reduced pressure, however, allows material to be drawn into the hollow interior of the glass cylinder through the inlet valve. Repeated transverse movement of the graphite piston thereby serves to provide a supply of compressed material through the exhaust valve. Due to the low coefficient of friction between the graphite piston (and in some embodiments a low friction ring) and the glass cylinder, the need for lubrication is reduced or eliminated.
Other features in the invention will become apparent from the attached drawings, which illustrate certain embodiments of the apparatus of this invention, wherein
While the following describes embodiments of this invention, it is understood that this description is to be considered only as illustrative of the principles of the invention and is not to be limitative thereof, as numerous other variations, all within the scope of the invention, will readily occur to others.
The term “adapted” shall mean sized, shaped, configured, dimensioned, oriented and arranged as appropriate. Herein, it will also be understood that in the figures, different embodiments may comprise the same or similar components. Where the same components are used in different embodiments, the same reference number may be used. Where components in different embodiments have a comparable structure, but are not necessarily common or identical parts, a similar number is used, but with a differing initial first digit, but common second and third digits. For example, and without limitation, cylinder heads 140, 240, 540, and 640 are examples of similar structures adapted for use in different embodiments of compressors 100, 200, 500, 600 of the present invention, but need not be interchangeable parts.
The various embodiments of the present invention for gas compression may be applicable to various operations used in numerous industries. For example, certain compressor embodiments may be utilized to pump air through a nitrogen filter in order to provide nitrogen. The nitrogen may be used for many purposes, including food refrigeration and preservation. In one embodiment, nitrogen may be fed to a vegetable drawer.
Embodiments may be utilized to compress refrigerant for a personal cooling device. Such an embodiment may be adapted for a soldier. An evaporator may be carried near the compressor in a neck pad or vest in contact with the soldier's body.
Certain embodiments may be utilized to pump air through a filter in order to scavenge oxygen. The generated oxygen may be provided to a person for health reasons or to assist in high-altitude activities, such as skiing. Other embodiments may be used to inflate bladders in vehicle seats or to drive tools and machines.
Embodiments of the compressor may be used with an electric motor or an actuator, which may operate at resonance. A brushless DC motor may be preferred for embodiments that need to operate at slower speeds. Such motors may be suitable for use with compressors having passive valves, such a reed valves. Resonant Piezo drive systems may operate at higher frequencies and may optionally use actively actuated valves. A brushless DC motor may be lower cost alternative. Additionally, other DC or AC motors can be used for such applications, such as conventional brushed motors.
An embodiment of the present invention comprises a compressor assembly that utilizes a glass cylinder with a graphite piston. The glass cylinder preferably comprises borosilicate glass such as Pyrex, but may also be formed of tempered glass, or other variations of glass materials known in the art that have thermal characteristics similar to those of Pyrex. An advantage of such an assembly is that the compressor may operate with minimal or zero lubricant, such as oil or grease. The lack of a lubricant in the compressor avoids contamination of the compressed gases. Contaminants into the air stream of lubricated compressors may include excessive oil vapor and carbon monoxide. Such impurities in the exiting gases may be harmful, especially if the gases are expected to be inhaled, and may require filtering before use.
Another advantage of the disclosed invention is the small size and light weight of the compressor. Accordingly, embodiments may be easily carried by a user. Transportability may be a critical feature for compressors that are intended to be carried by ill, weak or elder users that require an oxygen supply. Such compressors provide mobility without the burden of transporting heavy oxygen tanks. The compact size of certain embodiments allows the compressors to be used by skiers and soldiers.
Yet another advantage includes the low energy consumption of the compressor. Embodiments used with actuators may also operate at resonance to provide additional efficiencies.
Cylinder head 140 seals against on end of glass cylinder 110 with upper seal 146 (shown in
Cylinder head 140 has at least one outlet 160 through which compressed material may pass when compressor 100 is in operation. In the illustrated embodiment, inlet 150 and second inlet 152 are in operable connection with the hollow interior of glass cylinder 110 and enable material to flow into glass cylinder 110 when connecting rod 130 urges graphite piston 120 away from cylinder head 140. Whereas two inlets are shown in the illustrated embodiment, alternate embodiments of the present invention may include a single inlet or a plurality of inlets as needed to achieve the necessary flow characteristics for a given application.
Lower seal 170 partially seals glass cylinder 110 but allows connecting rod 130 to move freely during compressor operation. Where fully sealed operation is required (such as when compressing caustic materials) a bellows (not illustrated) can be used to provide a movable seal between connecting rod 130 and glass cylinder 110.
Cylinder head 140 may be formed of any material capable of withstanding the pressure and thermal constraints of the desired compressor application. Without limitation, steel, aluminum, brass and stainless steel are examples of suitable materials.
Referring to
Referring to
While a variety of valves may be used, including both passive valves and actuated valves, the illustrated embodiment shows inlet valve 151, second inlet valve 153, and exhaust valve 161 as passive reed valves. Upon connecting rod 130 moving graphite piston 120 toward cylinder head 140, pressure is asserted on material within glass cylinder 110. When such pressure reaches a point higher than the back pressure at outlet 160, and the difference is sufficient to operate exhaust valve 161, exhaust valve 161 opens and a portion of the material is expelled out exhaust valve 161. Upon connecting rod 130 moving graphite piston 120 away from cylinder head 140, pressure within glass cylinder 110 is reduced. Exhaust valve 161 then closes to prevent back flow from outlet 160. Inlet valve 151 and second inlet valve 153 open to allow additional material to be drawn in through inlet 150 and second inlet 152. When graphite piston 120 reverses, the increase in pressure closes inlet valve 151 and second inlet valve 153 and opens exhaust valve 161 as discussed above.
As has been noted, the location, configuration and number of inlets and exhausts can be varied according the needs of a particular application. In certain embodiments it may also be convenient to locate inlet and/or exhaust valves in lines connected to the compressor as opposed to in the cylinder head or piston assembly, as will be apparent to those of skill in the art.
Graphite piston 220 is secured by piston T-Nut 225. Inlet valve 251 is mounted in piston T-Nut 225. Inlet 250 allows material to flow through graphite piston 220 and through inlet valve 251 into the hollow interior of glass cylinder 210.
It can further be seen in this figure how clamping plate 241 may be adapted to compress cylinder head 240 against glass cylinder 210 through the use of clamping fasteners 242 which may attach to a base (not illustrated) to allow clamping pressure to be exerted. Thus it is seen that clamping plate 241 may clamp against cylinder head 240 in this embodiment. Other embodiments may also conveniently include an integral extension (not illustrated on
It will be understood by those of skill in the art that in the embodiments so far described, graphite pistons 120 and 220 form a suitable seal with glass cylinders 110 and 210 respectively. This may be accomplished by adapting graphite pistons 120 and 220 to have an outside diameter substantially equal to the inside diameter glass cylinder 110 and 210 respectively. The natural low friction properties of the graphite and the glass will then allow graphite pistons 120 and 220 to move transversely during operation, even with a seal tight enough to allow a significant degree of compression. Graphite and borosilicate glass are preferred materials both because of their coefficients of friction and because their thermal characteristics are such that an operable seal can be maintained during compressor operation.
It should be noted, however, that it is not necessary to have tight tolerances between the graphite piston and glass cylinder. Referring to
Compressor 500 thus comprises cylinder head 540, glass cylinder 510, graphite piston 520 and low friction ring 521. Connecting rod 530 is operably connected to graphite piston 520 as has been previously described, and extends into housing 580. When assembled, lower seal 570 forms a seal against housing 580.
Compressor 500 also incorporates a means of generating transverse motion of graphite piston 530 comprising motor 585, eccentric 587, and shaft retainer 588. Motor 585 may be any motor, but is preferably an electric motor and more specifically is preferably a brushless DC motor. Motor 585 engages eccentric 587 substantially in the center of eccentric 587. Eccentric 587 comprises offset eccentric shaft 589 which is adapted to engage connecting rod bearing 531, which is retained by shaft retainer 588. As eccentric 587 rotates, offset eccentric shaft 589 imparts a substantially linear motion to graphite piston 520 through connecting rod 530.
For certain high speed applications, it may be desirable to operate smart material actuator 685 at resonance. As is further described in incorporated U.S. Published application number 2012-0038245, resonant operation can be achieved using a control circuit (not illustrated) capable of operating smart material actuator 685 at a resonant frequency and adjusting the electric potential applied to smart material device 690 when resonance is achieved to prevent over-extension of webs 691. The result is a high frequency operation with reduced power consumption. It should be noted, however, that the configuration of base 680 can affect the resonant characteristics of the system. Accordingly different base and/or mounting means (not illustrated) may be used to achieve the desired resonant properties as is further discussed in the incorporated references and in particular in U.S. Published application number 2012-0038245.
As will be understood by those in the art, a variety of means of generating motion are thus adaptable for use in compressors according to the present invention. Examples include electric motors (both AC, DC, brushless, and with brushes), chemically fueled motors (including for example internal combustion engines), hydraulic or pneumatic motors, actuators (both mechanically amplified and otherwise), and even manual operation. Any such means of generating the desired transverse motion may be selected based on the constraints of the compressor application.
It will be apparent to those of ordinary skill in the art, the volume and rate of flow may be adjusted by adjusting the size of the compressor components (whereby larger pistons, chambers and ports allow for increased flow and smaller pistons, chambers and ports allow for decreased flow), changing the stroke length of the pistons (whereby longer stroke lengths create greater flow and lower stroke lengths create lesser flow), and/or by changing the pump speed (whereby faster speeds increase flow while lower speeds decrease flow). As will also be apparent, the tolerances may vary depending on the material to be compressed, with thicker gasses having larger molecular sizes allowing for looser tolerances than thinner gasses with small molecular sizes.
For all of the actuator-driven embodiments described, and embodiments utilizing actuated valves, it will be understood by those of skill in the art that a control mechanism, device or means (not illustrated) is necessary to ensure that the various actuators activate and deactivate at the proper times. Such means will be an electronic control circuit (not shown) of any of the suitable types known to those of ordinary skill in the art. Flow and back pressure sensors (not shown) may also be incorporated such that the control circuit can increase or decrease speed or volume as required to maintain a predetermined flow speed. While the specific control means will vary according to the type of actuator used, such means are well understood in the art for each type of applicable actuator. Additional information on controllers may be found in the incorporated references.
Other variations and embodiments will be apparent to those of ordinary skill in the art, all of which are within the scope of the present invention, which is limited only by the claims.
This application is a non-provisional application based upon, and claims benefit of, U.S. Provisional Application No. 61/723,815, filed Nov. 8, 2012, which is hereby incorporated by reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2013/069164 | 11/8/2013 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 61723815 | Nov 2012 | US |
