MX2007004851A - Air compressor oil recirculation system - Google Patents

Abstract

An apparatus for removing oil from air in an air compressor that has a piston reciprocable in a cylinder to compress the air, includes an oil removal chamber associated with the compressor. An unloader valve has an unactuated condition and an actuated condition disabling flow of compressed air out of the compressor and establishing fluid communication between the cylinder and the oil removal chamber. The apparatus may include an oil discharge port for draining oil from the oil removal chamber to a location away from the cylinder, and/or a filter element in the oil removal chamber.

Description

AIR COMPRESSOR OIL RECIRCULATION SYSTEM Background of the Invention Technical Field The present invention relates to compressed air systems. In particular, the present invention relates to an air compressor using lubricating oil and to a method and apparatus for reducing oil migration from the compressor to the compressed air outlet. Description of the Previous Branch Air compressors that use lubricating oil are commonly used in, for example, heavy vehicle air brake systems. The compressor uses motor oil or other oil for internal lubrication. Some of this oil can undesirably migrate to the air brake system through the compressed air outlet of the compressor, a result sometimes referred to as air passage and oil transport. For example, in a known compressor, when the compressor is in the unloaded mode, the swept volume of the cylinder is open to a small chamber at the head of the compressor where the air is compressed and expanded. The oil is collected in this chamber or drained back into the cylinder and is taken to the air stream when the compressor charges. Compendium of the Invention The invention in one aspect relates to removing oil from the air in an air compressor having a reciprocable piston in a cylinder for compressing the air. In one embodiment, an apparatus includes an oil removal chamber associated with the compressor, and a discharging valve having an unactuated condition and having an actuated condition that incapacitates the flow of compressed air out of the compressor and establishes communication from the compressor. fluid between the cylinder and the oil removal chamber. In one embodiment, an apparatus may include an oil discharge port for draining the oil from the oil removal chamber to a location away from the cylinder, for example the crankcase, and / or a filter element in the oil removal chamber. oil. In another embodiment, a method for removing the oil can be provided. BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other features of the present invention will become apparent to an expert in the field to which the present invention relates after consideration of the following description of the invention with reference to the accompanying drawings, in which: Figure 1 is a schematic illustration of portions of a compressed air supply system for a vehicle, including a compressor and a system oil recirculation, in accordance with one embodiment of the invention; Figure 2 is a schematic illustration of the compressor and oil recirculation system of Figure 1; Figure 3 is a schematic illustration of an oil recirculation system which is another embodiment of the invention; and Figure 4 is a schematic illustration of an oil recirculation system which is still another embodiment of the invention. Detailed Description of the Invention The present invention relates to compressed air systems. In particular, the present invention relates to an air compressor using lubrication oil and to a method and apparatus for preventing oil migration from the compressor to the compressed air outlet. The present invention is applicable to air systems of different constructions. As representative of the invention, Figure 1 illustrates schematically an air system 10 which is a first embodiment of the invention. The system 10 includes a compressor 12 for compressing inlet air from an inlet line 14. The compressed air from the compressor 12 flows through a discharge line 16 to a reservoir 18. The reservoir 18 It is connected to various system devices as shown schematically in 20, such as the vehicle brake chambers, which use compressed air to operate. A regulator 22 is operative to control the operation (loading and unloading) of the compressor 12, in response to the pressure perceived on a line 26 from the reservoir 18, through a control line 24. Figure 2 shows schematically the compressor 12 and an apparatus 60 for removing oil from the compressed air outlet of the compressor, which is a first embodiment of the invention. The compressor 14 includes a block 32 and a cylinder head 34. The cylinder head 34 includes portions not shown that include an inlet passage connected to an inlet port, and a discharge passage connected to a discharge port. The inlet passage and the discharge passage are connected in fluid communication with the swept volume of a cylinder 36 in block 32. A piston 38 is reciprocable in cylinder 36, during rotation of a crank 40, to compress the air which flows between the entrance gate and the discharge gate. The compressor 12 has a discharge valve 50 that is normally closed. When the discharge valve 50 closes, it blocks the flow of air out of the cylinder 36 through a discharge passage 52, so that the air in the cylinder 36 can be compressed by the piston 38. The compressor 12 has a discharge port 54 for receiving an air pressure discharge signal through the control line 24, to open (actuate) the valve 50 download. When the discharge valve 50 is actuated, in conjunction with the operation of the discharge valve interrupting system, air can flow out of the cylinder 36 through the discharge passage 52, thereby rendering the flow of compressed air out of the air compressor of the vehicle braking system even when the piston 38 continues to reciprocate. The discharge port 24 also communicates with a discharge port interruption valve to close the discharge port when in the unloaded mode. The compressor 12, including the piston. 38 and cylinder 36, is lubricated by a lubricant (not shown) from a source, such as motor oil from the oil lubrication system 10. Typically a small amount of the lubricating oil flows out of the cylinder 36 (migrates) towards the compressed air outlet of the compressor 12. The system 10 includes an apparatus 60 for removing oil from the air in the system. In the illustrated embodiments, the apparatus 60 is shown as associated with the compressor 12; in other embodiments, the apparatus 60 could be positioned or associated elsewhere in the system 10.

The € 0 device includes a discharge mode unloading chamber or 62 oil removal chamber. The chamber 62 is a volume defined by the chamber walls 64. The chamber 62 is in fluid communication with the discharge passage 52 when the discharge valve 50 is opened as shown in Figure 2. The chamber walls 64 can be formed as one piece with the compressor block 32, as shown in FIG. shown in Figure 2. Alternatively, the chamber walls 64 can be formed separately from the cylinder block 32. A port or drain passage 66 at the bottom of the chamber 62 communicates with the compressor crankcase 68. A condensate oil drain valve 70 is positioned between the oil removal chamber 62 and the compressor crankcase 68. The valve 70 is controlled by an air pressure discharge signal from the regulator 22 through the control line 24. In the embodiment shown in Figure 2, a filter element 74 is placed in the chamber 62. The filter element 74 may be any element suitable for filtering or coalescing the oil in the air. An aluminum filter regenerates ivo is an example. When the pressure in the reservoir 18 is sufficiently high that additional supply of compressed air is not needed for the devices, 20, the The compressor discharge valve 12 is closed, and the air pressure is applied to the discharge port 54, by opening (operating) the discharge valve 50. The air that would otherwise be compressed in the cylinder 36 and delivered outside the discharge port is not compressed as such. Instead, the air from the cylinder 36, in the upstream piston stroke, is delivered to the oil removal chamber 2 through the discharge passage 52, which is open due to the opening of the discharge valve 50. The air flows into the oil removal chamber 62. As the air expands into the oil removal chamber 62, it cools. Some of the oil in the air condenses out and collects in the chamber 62. The chamber 62 is preferably maintained at a lower temperature than the cylinder 36, being external to the cylinder. This can help in the condensation of the oil. In addition, the oil in the air can be filtered, that is, physically captured by the filter element 74. In the downward stroke of the piston 38, the air in the chamber 62 expands back to the cylinder 36. This process is repeated with each cycle of the piston 38. When the compressor 12 is thus in the unloaded mode, the pressure in the 62 Chamber of oil removal cycles constantly, at the frequency of operation of the compressor, from an atmosphere to around 4-6 atmospheres In this way, at least a portion of the oil is removed from the air that is discharged from the cylinder 36 in the upward stroke of the piston. This can reduce or minimize the amount of oil migrating into the air flowing in the downstream portions of the system 10. When the compressor 12 is in the discharged mode, the discharge valve 50 is closed and the compressed air delivery outside the discharge porthole. During the loaded cycle, the oil that was trapped in the filter 7, as well as the oil collected in the chamber 62 can be drained back to the crankcase 68. Specifically, when the compressor 12 is loaded, the discharge valve 50 closes and the drain valve 70 opens. The oil collected in the chamber 62 is allowed to drain from the chamber to the compressor crankcase 68. Figures 3 and 4 illustrate the oil removal apparatus 60 which are other embodiments of the invention. The features or alternatives shown in these embodiments can be replaced by or combined with, in any appropriate combination, features of Figure 2. Figure 3 illustrates an oil removal apparatus 60a associated with a compressor 12a. The parts of the apparatus 60a and the compressor 12a, which are the same as :, or similar to the parts of the apparatus 60 and compressor 12 receive the same reference numerals with the suffix "a" attached. In the embodiment of Figure 3, the oil removal chamber 62a is defined by the walls 64a that are formed separately from the compressor block 32a. In addition, the chamber walls 64a are spaced apart from the cylinder block 32a to define a space or space 8 of air therebetween. This air space 80 helps to cool the chamber 62a. In addition, the chamber walls 64a are provided with cooling fins 82 to help promote cooling of the chamber 62a. The greater temperature differential between the chamber 62a and the cylinder 36a can help to increase the oil removal. The apparatus 60a also includes an oil drain passage 66a that does not connect the chamber 62a to the crankcase 68a. Instead, the oil drain passage 66a opens to a port 84 on the outside of the compressor 12a. An oil line (not shown) can be connected to port 84 to deliver oil back to the lubrication system from which came, for example, the engine lubrication system. Figure 4 illustrates an oil removal apparatus 60b with a compressor 12b. The parts of the apparatus 60b and the compressor 12b which are the same as, or similar to the parts of the apparatus 60 and the compressor 12, receive the same reference numbers with the suffix "b" linked. In the embodiment of Figure 4, the oil removal chamber 62b is defined by the walls 64b that are formed separating the compressor block 2b, and the walls 64b are spaced from the cylinder block 32b. Water at least partly surrounds the walls 64b of the chamber The water jacket 86 may be connected to the cooling system of the compressor 12 itself. The water jacket 86 helps to cool the chamber 62b.The water jacket 86 is an example of A cooling system that can be used From the above description of the invention, those skilled in the art will perceive improvements, changes and modifications in the invention These improvements, changes and modifications within the experience in the field are intended to be included within the scope of the appended claims.

Claims (39)

1. CLAIMS 1. - An apparatus for removing air oil in an air compressor having a reciprocable piston in a cylinder for compressing the air, the apparatus comprising: an oil removal chamber associated with the compressor; a discharge valve having an unactuated condition and having an actuated condition that incapacitates the flow of compressed air out of the compressor and which establishes fluid communication between the cylinder and the oil removal chamber; and an oil discharge port to drain oil from the oil removal chamber to a location away from the cylinder.
2. 2. - An apparatus according to claim 1, which includes a filter element in the oil removal chamber.
3. 3. - An apparatus according to claim 1, wherein the oil discharge port drains the oil away from the compressor.
4. 4. - An apparatus according to claim 1, wherein the oil discharge port drains the oil towards a compressor crankcase.
5. 5. - An apparatus according to claim 4, which includes a drain valve of oil in the oil discharge port, the oil drain valve being controlled by an air pressure signal.
6. 6. - An apparatus according to claim 5, wherein the oil drain valve is controlled by the same air pressure signal as the discharge valve, the oil drain valve being open when the discharge valve It is closed, and the oil drain valve is closed when the discharge valve is open.
7. 7. - An apparatus according to claim 1, including chamber walls that define the oil removal chamber and connected with the compressor to make the oil removal chamber integral with the compressor.
8. 8. - An apparatus according to claim 7, including an air space between the compressor and the chamber walls to help cool the chamber.
9. 9. - An apparatus according to claim 8, which includes cooling fins on the chamber walls to help cool the chamber.
10. 10. - An apparatus according to claim 7, including a water jacket between the compressor and the chamber walls to help cool the camera .
11. 11. - An apparatus according to claim 7, wherein the chamber walls are formed with a cylinder block of the compressor.
12. 12. - An apparatus for removing air oil in an air compressor having a reciprocable piston in a cylinder for compressing the air and having a charged mode and an unloaded mode, the apparatus comprising: an oil removal chamber that is it can selectively place in fluid communication with the cylinder; a means to place the compressor in the unloaded mode; means for establishing fluid communication between the oil removal chamber and the cylinder when the compressor is in the unloaded mode; and a drainage drift to drain oil from the chamber to a location away from the cylinder.
13. 13. The apparatus according to claim 12, further including a filter means in the chamber for filtering air oil in the chamber.
14. 14. - The apparatus according to claim 12, wherein the drainage means is operative to drain oil from the chamber towards the compressor crankcase.
15. 15. - The apparatus according to claim 12, wherein the draining means is operative to drain the oil from the chamber to a location away from the compressor.
16. 16. The apparatus according to claim 12, wherein the drain means includes an oil drain valve and wherein the means for placing the compressor in an unloaded mode comprises a discharge valve that is connected to the drain valve. operates by the same control signal as the oil drain valve.
17. 17. The apparatus according to claim 12, comprising means for cooling the oil removal chamber.
18. The apparatus according to claim 17, wherein the means for cooling comprises a water jacket.
19. 19. The apparatus according to claim 17, in. wherein the cooling means comprises fins in the chamber walls of the chamber.
20. 20. A compressor for a vehicle air system, comprising; a block that defines a cylinder; a reciprocable piston in the cylinder; a discharge mechanism for selectively placing the compressor in an unloaded mode; Y a discharged delivery chamber connected in fluid communication with the cylinder, by the unloading mechanism, to receive air from the cylinder when the compressor is in discharged mode, the chamber having a discharge port to drain oil from the chamber to a location away from the cylinder.
21. 21. - A compressor according to claim 20, having a crankcase and comprising an oil return passage between the delivery chamber and the cartridge.
22. 22. A compressor according to claim 21, further including a drain valve in the oil return passage to selectively control the drainage of oil from the oil removal chamber to the crankcase.
23. 23. - A compressor according to claim 20, comprising an oil retort passage to return oil from the delivery chamber to the compressor oil source.
24. 24. - A compressor according to claim 20, further comprising a filter in the chamber for filtering oil from the air flowing into the chamber.
25. 25. - A compressor according to claim 20, including an air space of insulation between the chamber and the cylinder block to promote cooling.
26. 26. - A compressor according to claim 20, wherein the chamber has cooling fins.
27. 27. - A compressor according to claim 20, wherein the chamber is integrated towards the cylinder block of the compressor.
28. 28. - A compressor according to claim 3, wherein the compressor has a liquid cooling system that includes a water jacket around the chamber to promote cooling of the chamber.
29. 29.- A method to remove air oil in an air compressor that has a reciprocable piston in a cylinder to compress the air, the method comprising the steps of: unloading the compressor; remove the oil from the air in the compressor when the compressor is discharged; and drain the removed oil to a location away from the cylinder.
30. 30. A method according to claim 29, wherein the step of removing oil comprises removing oil with a filter that is arranged in an air removal chamber.
31. 31. - A method according to claim 29, wherein the step of draining oil comprises draining oil to a crankcase of the compressor.
32. 32. - A method according to claim 29, wherein the step of draining oil comprises draining oil to a remote location of the compressor.
33. 33. - A vehicle air system comprising: a compressor having a reciprocable piston in a cylinder for compressing air and having a discharge mechanism; a tank connected to the compressor by a discharge line; system devices, such as vehicle brake chambers, which use compressed air to operate; an operating regulator for controlling the compressor discharge mechanism in response to perceived pressure in the compressor reservoir including a discharged delivery chamber connected in fluid communication with the cylinder, by the discharge mechanism, to receive air from the cylinder When the compressor is in the unloaded mode, the chamber having a discharge port to drain oil from the chamber to a location away from the cylinder
34. 34. - A system according to claim 33, wherein the compressor has a crankcase and an oil return passage between the delivery chamber and the crankcase.
35. 35. A compressor according to claim 34, further including a drain valve in the oil return passage to selectively control the oil drain from the oil removal chamber to the crankcase.
36. 36. A compressor according to claim 33, further comprising a filter in the chamber for filtering oil from the air flowing into the chamber.
37. 37. - An apparatus for removing air oil in an air compressor having a reciprocable piston in a cylinder for compressing the air, the apparatus comprising: an oil removal chamber with the compressor; a filter element in the oil removal chamber; and a discharge valve having an unactuated condition and having an actuated condition that incapacitates the flow of compressed air away from the compressor and which establishes fluid communication between the cylinder and the oil removal chamber.
38. 38. - An apparatus in accordance with the claim 37, wherein the filter element is a regenerative aluminum filter.
39. 39. The apparatus according to claim 37, further including an oil discharge port for draining oil from the oil removal chamber to a location away from the cylinder. 40. - An apparatus according to claim 39, wherein the oil discharge port drains the oil away from the compressor. 40.- An apparatus according to claim 39, wherein the oil discharge port drains the oil away from the compressor. 41. - An apparatus according to claim 39, wherein the oil discharge port drains oil to a compressor housing. 42. - An apparatus according to claim 41, including an oil drain valve in the oil discharge port, the oil drain valve being controlled by the same air pressure signal as the discharge valve, The oil drain valve is open when the discharge valve is closed, and the oil drain valve is closed when the discharge valve is open. SUMMARY OF THE INVENTION An apparatus for removing air oil in an air compressor having a reciprocable piston in a cylinder for compressing the air, includes an oil removal chamber associated with the compressor. A discharge valve has a non-driven condition and an actuated condition that incapacitates the flow of compressed air out of the compressor and that establishes fluid communication between the cylinder and the oil removal chamber. The apparatus may include an oil discharge port to drain oil from the oil removal chamber to a location away from the cylinder; and / or a filter element in the oil removal chamber.