US20180010593A1

US20180010593A1 - Air compressor pump with condensing chamber

Info

Publication number: US20180010593A1
Application number: US15/610,023
Authority: US
Inventors: Mark W. Wood; James P. Nichols, Jr.; Kurt R. Beckman; Thomas B. Sharp
Original assignee: Mat Industries LLC
Current assignee: Mat Industries LLC
Priority date: 2016-07-06
Filing date: 2017-05-31
Publication date: 2018-01-11

Abstract

An air compressor pump is provided, including a crankcase with an opening and a crankshaft extending out of the opening; a cover disposed over the opening in the crankcase; and a condensing chamber formed between the crankcase and the cover.

Description

RELATED APPLICATION

The present application claims priority under 35 US 119 from U.S. Provisional application No. 62/358,973, filed Jul. 6, 2016.

BACKGROUND

This disclosure relates generally to a pump for an air compressor, and more particularly to a belt driven oil-lubricated pump for an air compressor.
Air compressors are commonplace in home and commercial workshops. In general, an air compressor is a machine that decreases the volume and increases the pressure of a quantity of air by mechanical means. Air thus compressed possesses great potential energy, because when the external pressure is removed, the air expands rapidly. The controlled expansive force of compressed air is used in many ways and provides the motive force for air motors and tools, including pneumatic hammers, air drills, sandblasting machines, paint sprayers, and others.
A conventional air compressor includes a storage tank for compressed air, and a prime mover mounted on the compressor tank for compressing the air flowing into the compressor tank. The prime mover may be a gas engine or an electric motor, but many conventional models utilize electric power.
The basic components of an electric air compressor are an electric motor, a pump, a pressure switch, and a tank. The electric motor powers the pump which compresses the air and discharges it into the tank. For conventional air compressors, compressed air from the pump is discharged through a tube and a check valve into the tank. The check valve prevents air from flowing out of the tank back through the tube when the compressor pump is not in operation. Compressed air is stored in the tank.
The pump associated with such air compressors typically includes a crankcase and a crankshaft extending out of the crankcase. The crankshaft is driven by the electric motor. To seal the crankcase, a cover is mounted on the side of the crankcase through which the crankshaft extends. The cover typically supports the crankshaft and is made out of cast iron or other similar material.
Additionally, in pumps that are oil lubricated, the cover functions as a heat exchanger. More specifically, a fly wheel is usually disposed on the crankshaft and used to blow air onto an outer surface of the cover. Within the crankcase, some oil vapor in the hot pressurized air may contact with an inner surface of the cover and be condensed back into liquid oil. In order to allow hot air from within the cover to be vented, the cover typically includes a breather or other venting structure.
In use, as hot air leaves the crankcase, through the breather in the cover for example, some oil vapor is often vented to the atmosphere along with the hot air. This loss of oil vapor in the hot air vented to the atmosphere increases the oil consumption of the compressor pump as the pump continually loses oil in the vented hot air. Additionally, the oil vapor in the hot air that has been vented has a tendency to condense on the outside surface of the compressor pump, creating a dirty and undesirable appearance.
Thus, there is a need for developing a compressor pump which effectively and efficiently condenses oil vapor within the crankcase, lowering the amount of oil lost via the exiting hot air and, thereby decreasing the oil consumption of the compressor pump.

SUMMARY

The present disclosure is directed to a compressor pump having a condensing chamber which allows oil vapor to be condensed and retained within the crankcase. An important feature of the present condensing chamber is that the condensing chamber is formed by a baffle shaped as an annular ring disposed between a crankcase and a crankcase cover. This configuration provides a seal between the crankcase and the crankcase cover. Additionally, the baffle provides improved alignment between the front and rear crankshaft bearings. Furthermore, this configuration allows for oil vapor to enter the condensing chamber and controls the flow of same. The baffle also facilitates the return of liquid oil to the crankcase after the oil has been condensed in the condensing chamber. In the preferred embodiment, the baffle is made of elastomeric material, but is also contemplated as being made of plastic or metal. Finally, it is thought that the baffle additionally functions as a thermal barrier between the hot crankcase interior and the cooler inner cavity of the condensing chamber. In other words, the present elastomeric baffle is constructed and arranged so that it insulates and forms a barrier between the condensing chamber which has cool air circulating across it, and the internal sump of the crankcase which has a mixture of hot oil, oil vapor and air.
Another important feature of the present compressor pump is that the cover for the crankcase includes ribs that protrude into the condensing chamber. It is believed to be particular advantageous if the ribs also extend outward from the outer surface of the cover. As described in greater detail below, such a configuration is believed to maximize cooling efficiency and condensation of the oil vapor back to a liquid.
Additional aspects, embodiments, and details of the present disclosure, all of which may be combinable in any manner, are set forth in the following detailed description of the disclosure.

DETAILED DESCRIPTION OF THE DRAWINGS

One or more exemplary embodiments of the present disclosure will be described below in conjunction with the following drawing figures, in which:

FIG. 1A shows a front and side perspective view of the present air compressor pump;

FIG. 1B shows a rear and side perspective view of the present air compressor pump;

FIG. 2 shows a side and front partially-exploded, perspective view of the present air compressor pump;

FIG. 3 shows a side cutaway view of the present air compressor pump;

FIG. 4 shows a rear and side perspective view of the internal crankcase for the present air compressor pump; and,

FIG. 5 shows a rear and side partially-exploded, perspective view of the internal crankcase for the present air compressor pump.

DETAILED DESCRIPTION

With these general principles in mind, one or more embodiments of the present disclosure will be described with the understanding that the following detailed description is not intended to be limiting.
As shown in FIGS. 1A and 1B, an air compressor pump generally designated 10 includes a crankcase 12, a cylinder 14, disposed on top of the crankcase 12, and a head 16, disposed on top of the cylinder 14. A valve plate 15 is optionally disposed between the cylinder 14 and the head 16. A crankshaft 18 extends out an aperture 20 (see FIG. 2) in the crankcase 12.
The air compressor pump 10 is typically part of an air compressor that includes a tank (not shown), for example a 20-gallon cylindrical tank. Additionally, the air compressor includes a motor (not shown), typically an electric motor that can be powered via a typical AC wall outlet. However, other motors or power sources such as gasoline engines are contemplated. The particular sizes, shape, or configuration of the tank or motor is not believed to be important for the understanding of the present disclosure. Exemplary air compressors are described in, for example, U.S. Pat. No. 7,789,102 the entirety of which is incorporated herein by reference.
Returning to FIGS. 1A and 1B, a cover 22 is disposed over the aperture 20 (FIG. 2) and is preferably secured with fasteners 24 or the like. As can be seen, the crankshaft 18 passes through the center of the cover 22. As will be discussed in more detail below, an outer surface 26 of the cover 22 includes a plurality of ribs 28, or projections, extending away from the outer surface 26 of the cover 22. In a preferred embodiment, while other materials known in the art are contemplated, the cover 22 is made of aluminum to increase the heat transfer or heat exchange proprieties of the cover 22. A vent aperture 30 is disposed in, and passes through the cover 22.
Turning to FIG. 2, disposed between the cover 22 and the crankcase 12 is a baffle 32, preferably configured as an annular ring. Additionally, a front crankshaft bearing 34 and crankshaft seal 35 are preferably disposed in a cylindrical housing 36 formed in the center of the cover 22. In the preferred embodiment, the baffle 32 is made of an elastomeric, rubber-like material. A variety of conventional durable, flexible, oil-resistant materials are considered suitable for the baffle 32. In addition, it is contemplated that the baffle 32 is made of suitable plastics or metals.
The baffle 32 includes a center opening 38 that is preferably sized to allow the front crankshaft bearing 34 and crankshaft seal 35 to pass therethrough. In the preferred embodiment, the diameter of the center opening 38 is dimensioned to maintain a sealing contact with a generally cylindrical, inwardly projecting formation 22 a on the cover 22 (FIG. 5). The baffle 32 includes a planar portion 33 having an outer perimeter and a wall 37 extending away and generally normally from the planar portion 33 along the outer perimeter. An inner surface of the wall 37 is optionally notched or grooved. The baffle 32 also includes a positioning aperture 40 and a condensing chamber aperture 42 both disposed in the planar portion 33.
With reference to FIGS. 3 to 5, the positioning aperture 40 of the baffle 32 receives a post 44 in an inner surface 46 of the cover 22. This facilitates the positioning and orientating of the baffle 32 in relation to the cover 22 to create a condensing chamber 48. The condensing chamber aperture 42 allows for fluid communication between the crankcase 12 and the condensing chamber 48.
Preferably, the positioning aperture 40 and the condensing chamber aperture 42 are disposed on opposite sides along the circumference (i.e., 180 degrees apart along the circumference) of the baffle 32. For example, the positioning aperture 40 is preferably disposed proximate the top (relative to orientation in FIGS. 3 to 5) of the baffle 32 and the condensing chamber aperture 42 is disposed proximate the bottom (relative to orientation in FIGS. 3 to 5) of the baffle 32. It is contemplated in such a configuration that the vent aperture 30 in the cover 22 is disposed proximate the top (relative to orientation in FIGS. 3 to 5) of the cover 22 (similar in position to the positioning aperture 40). This will create a long path for the hot air from the condensing chamber aperture 42 to the vent aperture 30 in the cover 22 to allow for more oil vapor in the hot air to be condensed.
The diameter of the positioning aperture 40 and the condensing chamber aperture 42 is contemplated as varying to suit the application. In certain exemplary embodiments, the positioning aperture 40 and the condensing chamber aperture 42 each have a diameter of 6.0 mm Preferably, the condensing chamber aperture 42 is sized to allow liquid to flow out of the condensing chamber 48 and into the crankcase 12 at the same time that hot air is flowing out of the crankcase 12 and into the condensing chamber 48.
Turning to FIG. 5, the cover 22 preferably also includes ribs 50 or projections extending into the condensing chamber 48. The ribs 50 increase the heat exchange between the hot vapors inside of the condensing chamber 48 and the cooler air outside of the cover 22. Preferably, the ribs 50 inside of the condensing chamber are each aligned with one of the ribs 28 on the outer surface 26 of the cover 22 to increase the heat transfer.
In operation, as the crankshaft 18 is rotated by a motor (not shown), pistons 52 a, 52 b will move in and out of the cylinder 14 compressing air, as is known, which can be discharged to and stored in the tank (not shown). The movement of the pistons 52 a, 52 b and/or the rotation of the crankshaft 18 will also generate heat within the crankcase 12. As operation continues, the heat will vaporize oil 54, creating oil vapor in the hot air within the crankcase 12. The hot air, with the oil vapor, passes through the condensing chamber aperture 42 and into the condensing chamber 48.
A fly wheel (not shown) is typically disposed on the crankshaft 18 proximate the cover 22 and will force relatively cool air towards the outer surface 26 of the cover 22. Within the condensing chamber 48, the hot air with the oil vapor contacts the inner surface 46 of the cover 22 and/or the ribs 50 (if present), causing heat to be absorb therefrom. The heat will be transferred to the ribs 28 on the outer surface 26 of the cover 22 and may be absorbed by cool air from the flywheel, discussed above. Inside of the condensing chamber 48, after heat is removed from the oil vapor, the oil vapor condenses into liquid oil. The liquid oil in the condensing chamber 48 passes through the condensing chamber aperture 42 and into the crankcase 12. Hot air in the condensing chamber 48, which is lean in oil vapor, is preferably vented to the atmosphere from the condensing chamber 48 through the vent aperture 30.
In the preferred embodiment, the baffle 32 additionally functions as a thermal barrier between the hot crankcase interior and the cooler inner cavity of the condensing chamber 48. In other words, the present baffle is constructed and arranged so that it insulates and forms a barrier between the condensing chamber 48, which has cool air circulating across it, and the internal sump of the crankcase 12 which has a mixture of hot oil, oil vapor and air.
Compared to existing air compressors pumps, the hot air exiting an air compressor pump according to the embodiments of the present disclosure will have less oil vapor in the vented hot air. This will decrease the loss of oil for the air compressor and accordingly decrease the consumption of same. Also, the exterior surface of the air compressor pump will not accumulate oil as quickly. Furthermore, the use of the present condensing chamber allows for a simpler venting structure, i.e., an aperture or the like, as opposed to breather or other such device typically used in conventional devices. The aperture also allows for the crankcase to vent even if the air compressor pump is not in operation, for example while the air compressor pump is being filled with oil. Additionally, the air compressor pump with the cover allows for easier construction and assembly of the air compressor pump.
While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the disclosure in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the disclosure, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the disclosure.

Claims

What is claimed is:

1. An air compressor pump comprising:

a crankcase with an opening and a crankshaft extending out of the opening;

a cover disposed over the opening in the crankcase; and

a condensing chamber formed between the crankcase and the cover.

2. The air compressor pump of claim 1 further comprising:

one or more ribs disposed on an outer surface of the cover, or an inner surface of the cover, or both.

3. The air compressor pump of claim 1 further comprising:

a baffle disposed between the crankcase and the cover, disposed for defining the condensing chamber.

4. The air compressor pump of claim 3 further comprising:

a positioning aperture and a condensing chamber aperture both being disposed in the baffle.

5. The air compressor pump of claim 3 further comprising:

a vent aperture disposed in the cover.

6. The air compressor pump of claim 3, wherein said baffle is constructed and arranged to form a thermal barrier between the condensing chamber, which has relatively cool air circulating across it, and the internal sump of the crankcase, which has a mixture of hot oil, oil vapor and air.

7. The air compressor pump of claim 3, wherein said baffle is made of elastomeric material.