Oil filter

Abstract: An oil filter comprising a housing opened at one end, a first separator unit in the housing for removing solid contaminants from the oil, a mount block for the housing and a second separator unit for removing gaseous contaminants. The first separator unit comprises a cylindrical filter element defining a central space therein, and the mount block is formed with a recess in which the second separator unit is disposed. The second separator unit includes a chamber arranged to generate a vortical flow of the oil introduced therein to thereby separate gas-rich oil which gathers in an axially central portion of the chamber, means for introducing the oil from the central space to the chamber, a first outlet member for leading the oil containing little gaseous contaminants and a second outlet member for discharging the gas-rich oil.

Description: The present invention relates to an oil filter to be incorporated in a lubricating system for an internal combustion engine or the like and, more particularly, to an oil filter of a type in which not only solid contaminants but also gaseous contaminants can be removed from the oil (See claims 1-19). The present invention also relates to a mounting means, provided with a separator for gaseous contaminants, for removably mounting a solid contaminant filter (see claim 20). The present invention finally relates to a unit for removing gaseous contaminants from oil (see claims 21-26). In machinery for construction, transportation and the like using lubricant, such as engines and various hydraulic devices, solid contaminants and gaseous contaminants have hitherto been removed from lubricant by separate devices and/or in different portions of the machinery. A device has thus been desired which can remove both of the solid and gaseous contaminants effectively and which can be installed in a limited space of the machinery. The inventors herein have proposed an integrated device in EP-A-0 342 308, which is part of the state of the art under EPC Article 54(3). The device disclosed therein comprises a first separator having a filter element for filtering lubricant which is pumped into a housing to thereby remove solid contaminants, and a second separator for removing gaseous contaminants from the filtered oil by utilizing a centrifugal force. i.e. Specifically, the second separator has a chamber adapted to generate a vortical flow of the lubricant introduced therein, whereby lubricant which is gas-lean, has little gaseous contaminants, and therefore has a larger specific gravity gathers in a peripheral area of the chamber while gas-rich lubricant having a smaller specific gravity gathers in a central area. A wall defining the chamber is provided with a plurality of pores through which the gas-removed lubricant flows out of the chamber. On the other hand, the gas-rich lubricant is discharged by a perforated pipe which extends into the chamber along its axis. In the above proposed device, both the first and second separators are arranged within a housing which is to be attached to a mount block in a lubricating system. The mount block should in turn be provided with various passages to supply the lubricant into the housing, lead the filtered and gas-removed lubricant to various parts to be lubricated, and to discharge the gas-rich lubricant into a tank for recirculation, and attachment of the housing involves connecting these passages to respective portions of the housing. However, the above device is not so constructed that it may easily be attached to the mount, and relatively complicated work will be needed for the attachment. This is particularly important because, as is well known in the art, the filter element is subjected to replacement due to its clogging during use of the device. For a conventional type oil filter adapted to remove only the solid contaminants, it is an usual practice to replace the oil filter as a whole, i.e. including a housing. Although such a practice has been found desirable, application thereof to the above proposed device would be a waste of the second separator which can be used semi-permanently. Further, there are many replacement units of the conventional oil filter available in the market, but those units can not be used for the above proposed device. GB-A-2 172 518 discloses an oil filter for removing entrained solid and gaseous contaminants from oil, comprising a solid contaminants filter unit removably mounted on a mounting means therefor, said mounting means providing the inlet and outlet means of the filter and providing therein means for removing gaseous contaminants from said oil. The present invention provides an oil filter as defined in the last preceding paragraph characterised in that (a) the mounting means comprises a mount block, (b) the inlet means directs oil to be filtered to the solid contaminants filter unit, (c) the means for removing gaseous contaminants comprises a separator unit disposed in a recess in the mount block for receiving filtered oil from said solid contaminants filter unit, said separator unit comprising a chamber adapted to generate a vortical flow of oil introduced therein for separating said oil into gas rich oil and gas lean oil, and (d) said outlet means comprise separate outlets for discharging gas rich oil and gas lean oil from said separator unit. Preferably said separator unit includes a cyclone, which may be funnel-shaped, secured in said recess for defining said chamber and having a plurality of pores formed through the wall thereof for the passage of gas-lean oil therethrough. Also, preferably said outlet for discharging gas-lean oil comprises an outlet passage extending in said mount block and opening in said recess. In the two embodiments of the invention described hereafter the filter unit is removably mounted on said mount block in a housing detachably secured thereto and comprises a cylindrical filter element having an outer periphery, an inner periphery and a central space defined within said inner periphery, and wherein means are provided for introducing oil from said central space to said chamber. In these embodiments a removal pipe extends into said chamber along the axis of said cyclone and has formed in the wall thereof a plurality of orifices for permitting gas-rich oil to flow thereinto, and said outlet for discharging gas-rich oil comprises an outlet passage formed in said mount block to communicate with said removal pipe. In one embodiment - which further comprises a base plate fixed to said housing at an open end thereof and having a surface defining a central opening, and a sleeve detachably secured to said surface of said base plate defining said central opening - said removal pipe comprises an extension of said sleeve and includes a threaded end portion engaged with said mount block. In the other embodiment - which further comprises a center bolt extending through said central space defined within said inner periphery of said filter element and said recess to engage with said mount block, thereby detachably securing said housing to said mount block - a removal passage is formed in said center bolt, orifices formed in a portion of said center bolt extending in said cyclone connect said chamber with said removal passage, and said outlet for discharging gas-rich oil comprises an outlet passage extending in said mount block to communicate with said removal passage. The invention also includes a mounting means for removably mounting a solid contaminants filter unit for forming an oil filter therewith, said mounting means providing therein means for removing gaseous contaminants from said oil and providing the inlet and outlet means of the filter, characterised in that (a) the mounting means comprises a mount block, (b) the inlet means is arranged for directing oil to be filtered to the solid contaminants filter unit when mounted on said mount block, (c) the means for removing gaseous contaminants comprises a separator unit disposed in a recess in the mount block for receiving filtered oil from said solid contaminants filter unit, said separator unit comprising a chamber adapted to generate a vortical flow of oil introduced therein for separating said oil into gas rich oil and gas lean oil and (d) said outlet means comprise separate outlets for discharging gas rich oil and gas lean oil from said separator unit. The invention further includes a unit for removing gaseous contaminants from oil in accordance with claims 21 - 26 of the claims hereafter. In order that the invention may be well understood, the two embodiments thereof referred to above, which are given by way of example only, will now be described with reference to the accompanying drawings, in which: FIG.1 is a longitudinally sectioned elevational view illustrating an oil filter according to an embodiment of the invention; and FIG.2 is a view similar to FIG.1 illustrating an oil filter according to another embodiment of the invention. Referring first to FIG.1 of the drawings, an oil filter according to a first embodiment of the invention has a housing 10 of substantially cylindrical shape having a lower open end and an upper closed end. A base plate or disk 12 is secured to an inner peripheral surface of the housing 10 at a position near its lower end and is fixedly supported by means of a ring member 14 of which outer edge is seamed with the lower edge of the housing 10. The base plate 12 is formed with a central opening defined by an upwardly projecting circular wall 16 which has a threaded inner surface 16a. An aperture 18 is provided in the base plate 12 radially outward of the opening, communicating with an inlet passage 22 formed in a mount block 20 to which the base plate 12 and therefore the housing 10 are attached. The mount block 20 is provided with a separately formed sleeve 24 which extends into the opening of the base plate 12 to threadedly engage with the inner surface 16a of circular wall 16. The ring member 14 is provided with a depression which is in tight contact with the upper surface of mount block 20 at a position radially outward the inlet passage 22 for preventing leakage of an oil. Arranged within the housing 10 is a separator unit A for separating solid contaminants from the oil circulating in a lubricating system of a machine. The separator unit A is of usual type and comprises a filter element 26, an upper end plate 28 and a lower end plate 30 both fixed to the element 26. The filter element 26 has a hollow cylindrical shape and is typically formed of a pleated sheet. A perforated plate 32 is attached to the inner periphery of element 26 in order to prevent the element from collapsing while allowing the oil to flow into the central space within the unit A. The upper end plate 28 extends radially inward to support a relief valve 33 and a spring 34 which is compressed between the top wall of housing 10 and the upper end plate 28, thereby holding the unit A in position. The relief valve 33 is adapted to open and provide a bypass passage for the oil when a pressure of oil is increased outside the filter element 26 due to a clogging thereof, so that the oil can flow through the valve 33 into the space defined within the element 26. On the other hand, the lower end plate 30 extends slightly beyond the perforated plate 32 where it is bent downwardly to secure a check valve 36 that is adapted to prevent a reverse flow of the oil from the housing 10 into the inlet passage 22. A second separation unit B is provided in the mount block 20 for removing gaseous contaminants from the oil that has passed through the first unit A. The second separator unit B includes a recess 38 which is formed in the center portion of mount block 20 and is closed by a cover plate 40 the upper surface of cover plate 40 being flush with the upper surface of mount block 20. The cover plate 40 has an opening through which the sleeve 24 extends into the housing 10. A funnel-shaped cyclone 42 is disposed in the recess 38 and is fixed at its upper edge to the wall defining the recess in a liquid-tight manner. The cyclone 42 defines in cooperation with an end plate 60 fixed thereto a chamber 44 adapted to generate a vortical flow of the oil introduced therein from inlets 61 formed in the end plate 60. The inlet 61 is formed by punch press to provide a guide wall or deflector 63 which extends in the circumferential direction of the 2nd plate 60 so that the oil can flow into the chamber 44 with a vortical pattern. A plurality of pores 46 are formed through the wall of cyclone 42 to connect the chamber 44 with a space 48 which is defined between the cyclone 42 and the wall of recess 38 and communicates with a first outlet passage 50 extending in the mount block 20. A removal pipe 52, which is an extension of the sleeve 24 with a reduced diameter, extends in the chamber 44 along its axial center to project downwardly through the lower open end of cyclone 42 that is closed by the pipe 52. The lower end of pipe 52 is threadedly fitted in a hole 54 formed in the mount block 20, thereby securing the base plate 12 to the block 20. The sleeve 24 has formed therein a vertical hole 56 opening into the space within the unit A and outlets 58 formed through the wall of sleeve at positions adjacent the lower end of vertical hole 56 and slightly above the upper edge of the cyclone 42. The upper portion of pipe 52 in the chamber 44 is formed with small orifices 62 through which a gas-rich oil flows into the pipe 52 as described later. The pipe 52 is connected via the blank space of hole 54 to a second outlet passage 64 which extends in the mount block 20 and is connected to, for example, an oil pan (not shown) for storing the oil. On the other hand, the first outlet passage 50 is connected to, for example, an engine (not shown) to be lubricated. When the oil is supplied by a pump (not shown) via the inlet passage 22, it flows into the housing 10 through the aperture 18 and the check valve 36. The oil then passes through the filter element 26 from outside to inside during which solid contaminants are removed from the oil. The thus filtered oil flows in the space within the perforated plate 32 and is introduced into the chamber 44 via the vertical hole 56 and outlets 58, the deflector 60 inducing the vortical flow. The oil flows downward in the chamber 44 with the vortical pattern, generating a centrifugal force which acts on the oil. Due to a difference in density, the oil containing gaseous contaminants, i.e. gas-rich oil, is separated and gathers near the axial center of the flow where it is introduced through the orifices 62 into the removal pipe 52 for discharge into the oil pan via the second outlet passage 64. On the other hand, the remaining oil, which is gas-lean, flows around the wall of cyclone 42 and passes through the pores 46 into the space 48 for circulation in the lubricating system via the first outlet passage 50. In this way, solid and gaseous contaminants can efficiently be separated and removed from the oil. When it becomes necessary to replace the filter element 26 for removing solid contaminants with a new element due to clogging after a long use, the housing 10 is rotated relative to the mount block 20 whereby the circular wall 16 of base plate 12 is released from the engagement with the sleeve 24. Thus, the housing 10 together with the separation unit A can be detached from the mount block 20 which retains the separation unit B. Thereafter, only the filter element 26 or the assembly of the housing 10, element 26 and base plate 12 need be replaced. If the latter is desired, the usual type of oil filter, that is available in the market, may be used without modification. There has been known and available in the market an oil filter of a so-called center bolt type in which a center bolt extends axially through the housing for attaching it to the mount block. One embodiment of the invention as applied to the oil filter of such a type is illustrated in FIG.2 in which those parts same as or corresponding to the parts in FIG.1 are designated by the same reference numeral but with an addition of "100". A housing 110 accommodating the first separation unit A rests on the peripheral edge of upper surface of a mount block 120 with interposing a gasket in the form of an O-ring 166 therebetween. The housing 110 is attached to the block 120 by means of a center bolt 168 which extends along a center axis of the housing and is threadedly engaged at its lower end with a hole 154 in the block 120. The upper end of center bolt 168 fitted in a gasket 184 penetrates the top wall of the housing 110 to provide an enlarged head 170 for fastening or loosening the bolt 168. As in the above embodiment, the unit A for separating solid contaminants comprises a filter element 126 and upper and lower end plates 128, 130. A gasket 186 is tightly fitted between the center bolt 168 and the upper end plate 128. Provided around the bolt 168 is a spring 134 which is compressed between the gaskets 184 and 186 for urging the unit A downwardly, whereby the lower end plate 130 abuts through a sealing member 188 against an end surface of a circular flange 172 to separate an inlet passage 122 from a recess 138. A funnel-shaped cyclone 142 is disposed within the recess 138 and fixed at its upper vertical edge to the inner surface of flange 172. The upper open end of cyclone 142 is closed by a dish-shaped cover member 174 which has a central opening for the center bolt 168 with an O-ring seal 176 fitted around the bolt and an aperture 178 formed through the bottom wall of cover member adjacent its outer end. Integrally provided with the cover member 174 is a cylindrical wall 180 extending downwardly from the bottom wall adjacent the aperture 178 to the slant surface of cyclone 142, defining a chamber 144 within the cyclone 142. A plurality of inlets 158 are formed in the cylindrical wall 180 and accompanied with deflectors 160 extending in a tangential direction of the wall 180 at the inlets 158, so that the oil flowing into the chamber 144 may generate a vortical pattern. The center bolt 168 extends through the chamber 144 along its axis and is loosely fitted in the lower end portion of the cyclone 142 with interposing an O-ring seal 182 therebetween. A plurality of orifices 162 are formed in the center bolt 168 to connect the chamber 144 with a removal passage 152 which extends centrally in the lower portion of bolt 168 and opens into the blank space of hole 154. The oil supplied into the housing 110 via the inlet passage 122 passes through the filter element 126 while separating solid contaminants, and is then introduced into the chamber 144 through the aperture 178 and the inlets 158. The vortical flow of the oil in the chamber 144 results in a separation of gas-rich oil which gathers around the center bolt 168 and is removed into the passage 152 via orifices 162. The gas-rich oil is finally discharged in an oil pan (not shown) through a second outlet passage 164 communicating with the passage 152. On the other hand, the gas-lean oil flows out of the cyclone 142 through pores 146 into a space 148 in the recess 138, and is led to a first outlet passage 150 connected to an engine. It will be understood that the housing 110 can be detached from the mount block 120 by disengaging the center bolt 168 from the hole 154.

Claims: An oil filter for removing entrained solid and gaseous contaminants from oil, comprising a solid contaminants filter unit (A) removably mounted on a mounting means (20, 120) therefor, said mounting means providing the inlet (22,122) and outlet means (50, 64, 150, 164) of the filter and providing therein means (B) for removing gaseous contaminants from said oil, characterised in that (a) the mounting means comprises a mount block (20, 120), (b) the inlet means (22, 122) directs oil to be filtered to the solid contaminants filter unit (A), (c) the means for removing gaseous contaminants comprises a separator unit (B) disposed in a recess (38, 138) in the mount block for receiving filtered oil from said solid contaminants filter unit, said separator unit (B) comprising a chamber (44, 144) adapted to generate a vortical flow of oil introduced therein for separating said oil into gas rich oil and gas lean oil, and (d) said outlet means comprise separate outlets (64, 50, 164, 150) for discharging gas rich oil and gas lean oil from said separator unit. An oil filter as claimed in claim 1, wherein said separator unit (B) includes a cyclone (42, 142) secured in said recess (38, 138) for defining said chamber (44, 144) and having a plurality of pores (46, 146) formed through the wall thereof for the passage of gas-lean oil therethrough. An oil filter as claimed in claim 2, wherein said cyclone (42, 142) is funnel-shaped. An oil filter as claimed in claim 2 or 3, wherein said outlet for discharging gas-lean oil comprises an outlet passage (50, 150) extending in said mount block and opening in said recess. An oil filter as claimed in claim 2, 3 or 4, wherein said filter unit (A) is removably mounted on said mount block (20, 120) in a housing detachably secured thereto and comprises a cylindrical filter element (26, 126) having an outer periphery, an inner periphery and a central space defined within said inner periphery, and wherein means are provided for introducing oil from said central space to said chamber (44, 144). An oil filter as claimed in claim 5, wherein an end plate (28, 128, 30, 130) is attached to each respective end of said filter element. An oil filter as claimed in claim 5 or 6, wherein a removal pipe (52, 152) extends into said chamber (44, 144) along the axis of said cyclone (42, 142) and has formed in the wall thereof a plurality of orifices (62, 162) for permitting gas-rich oil to flow thereinto, and said outlet for discharging gas-rich oil comprises an outlet passage (64, 164) formed in said mount block to communicate with said removal pipe. An oil filter as claimed in claim 7, further comprising a base plate (12) fixed to said housing (10) at an open end thereof and having a surface (16) defining a central opening, and a sleeve (24) detachably secured to said surface (16) of said base plate defining said central opening. An oil filter as claimed in claim 8, wherein said removal pipe (52) comprises an extension of said sleeve (24) and includes a threaded end portion engaged with said mount block (20). An oil filter as claimed in claim 8 or 9, wherein said means for introducing oil to said chamber (44) comprises a longitudinal hole (56) in said sleeve (24) opening in said central space and an outlet (58) formed through the wall of said sleeve to open in said recess (38) above said cyclone (42). An oil filter as claimed in claim 10, wherein an end plate (60) is attached to said cyclone (42) for closing the same, and wherein said oil introducing means further comprises an inlet (61) formed through said end plate (60). An oil filter as claimed in claim 11, wherein said oil introducing means further includes a deflector (63) adjacent said inlet (61) and extending along the circumferential direction of said end plate (60). An oil filter as claimed in any one of claims 8 to 12, wherein said base plate (12) has formed therein an aperture (18) communicating with said inlet passage (22) to allow oil to flow into said housing (10). An oil filter as claimed in any one of the preceding claims, further comprising a cover member (40) closing said recess (38). An oil filter as claimed in claim 5 or 6, further comprising a center bolt (168) extending through said central space defined within said inner periphery of said filter element (126) and said recess (138) to engage with said mount block (120), thereby detachably securing said housing (110) to said mount block. An oil filter as claimed in claim 15, wherein a removal passage (152) is formed in said center bolt (168), orifices (162) formed in a portion of said center bolt extending in said cyclone connect said chamber (144) with said removal passage (152), and said outlet for discharging gas-rich oil comprises an outlet passage (164) extending in said mount block (120) to communicate with said removal passage (152). An oil filter as claimed in claim 15 or 16, further including a cover member (174) attached to said cyclone (142) for closing the same. An oil filter as claimed in claim 17, wherein said means for introducing oil to said chamber (144) comprises an aperture (178) formed in said cover member (174), and an inlet (158) formed through a cylindrical wall (180) extending between said cover member (174) and the wall of said cyclone (142), whereby the oil flows into said chamber (144) through said aperture (178) and said inlet (158). An oil filter as claimed in claim 18, wherein said means for introducing oil further includes a guide plate (160) attached to said cylindrical wall (180) adjacent said inlet (158) and extending substantially along a tangent of said cylindrical wall at said inlet (158). A mounting means (20, 120) for removably mounting a solid contaminants filter unit (A) for forming an oil filter therewith, said mounting means providing therein means (B) for removing gaseous contaminants from said oil and providing the inlet (22, 122) and outlet (50, 64, 150, 164) means of the filter, characterised in that (a) the mounting means comprises a mount block (20, 120), (b) the inlet means (22, 122) is arranged for directing oil to be filtered to the solid contaminants filter unit (A) when mounted on said mount block, (c) the means for removing gaseous contaminants comprises a separator unit (B) disposed in a recess (38, 138) in the mount block for receiving filtered oil from said solid contaminants filter unit, said separator unit comprising a chamber (44, 144) adapted to generate a vortical flow of oil introduced therein for separating said oil into gas rich oil and gas lean oil and (d) said outlet means comprise separate outlets (64, 50, 164, 150) for discharging gas rich oil and gas lean oil from said separator unit. A unit for removing gaseous contaminants from oil, said unit comprising: a mount block (20, 120) adapted to support a device in an oil recirculating path, said mount block defining an internal cavity (38, 138); a separator assembly (B) disposed within said internal cavity of said mount block, said separator assembly having means (42, 142) for defining a separator chamber (44, 144), said mount block defining an inlet path to said chamber; means (61, 158) for causing centrifugal force to be exerted on the oil flowing in said separator chamber for separating the oil into a first oil part having higher oil density and a gas-rich second oil part having lower oil density so that said first oil part is concentrated in a first portion in said separator chamber and said second oil part is concentrated in a second portion of said separator chamber; a first discharge outlet (50, 150) communicated with said first portion of said separator chamber for discharging the first oil part therethrough; and a second discharge outlet (64, 164) communicated with said second portion of said separator chamber for discharging the second oil part therethrough. A unit as claimed in claim 22, wherein said means for causing centrifugal force to be exerted comprises a passage means (61, 158) for introducing the oil from said inlet path into said separator chamber (44, 144) in a tangential direction of said separator chamber. A unit as claimed in claim 21 or 22, wherein said first discharge outlet comprises a plurality of pores (46, 146) arranged adjacent said first portion of said separator chamber. A unit as claimed in claim 21, 22, or 23, wherein said second discharge outlet comprises a plurality of orifices (62, 162) arranged adjacent said second portion of said separator chamber. A unit as claimed in any one of claims 21 to 24, wherein said separator chamber (44, 144) has a configuration having circular cross section perpendicular to its axis, said first portion being located in the circumferential portion of said separator chamber and said second portion being located in the central portion of said separator chamber. A unit as claimed in any one of claims 21 to 25, wherein said separator chamber has a substantially conical configuration, its larger end diameter being at the end adjacent said inlet path.

Inventors: KUWAVARA RYUZI, YABUMOTO JUNSUKE, YANO HISASHI, KUWAVARA, RYUZI, YABUMOTO, JUNSUKE, YANO, HISASHI
Applicants: MITSUBISHI OIL CO, MITSUBISHI OIL COMPANY, LIMITED
Application year: 1989
Main classification: B01D35
IPC codes: B01D36, B01D19, F01M11, B01D35, B01D29, B01D27, F01M1