EP0645543A1 - Low noise cooling system - Google Patents

Low noise cooling system Download PDF

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Publication number
EP0645543A1
EP0645543A1 EP94112831A EP94112831A EP0645543A1 EP 0645543 A1 EP0645543 A1 EP 0645543A1 EP 94112831 A EP94112831 A EP 94112831A EP 94112831 A EP94112831 A EP 94112831A EP 0645543 A1 EP0645543 A1 EP 0645543A1
Authority
EP
European Patent Office
Prior art keywords
fan
cooling system
fan shroud
central axis
shroud
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
EP94112831A
Other languages
German (de)
English (en)
French (fr)
Inventor
Jim K. Carroll
Paul A. Dicke
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Caterpillar Inc
Original Assignee
Caterpillar Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Caterpillar Inc filed Critical Caterpillar Inc
Publication of EP0645543A1 publication Critical patent/EP0645543A1/en
Ceased legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/40—Casings; Connections of working fluid
    • F04D29/52—Casings; Connections of working fluid for axial pumps
    • F04D29/54—Fluid-guiding means, e.g. diffusers
    • F04D29/541—Specially adapted for elastic fluid pumps
    • F04D29/545—Ducts
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
    • F01P5/00—Pumping cooling-air or liquid coolants
    • F01P5/02—Pumping cooling-air; Arrangements of cooling-air pumps, e.g. fans or blowers
    • F01P5/06—Guiding or ducting air to, or from, ducted fans

Definitions

  • This invention relates generally to a low noise fan and shroud arrangement for use with an engine cooling system.
  • noise is the noise emitted by its cooling system.
  • noise is a function of a variety of factors, including the type and position of the fan, the design of the fan shroud, and the type, size and position of the radiator core.
  • U.S. Patent No. 3,903,960 One example of a noise suppressing fan shroud is the fan shroud entrance structure disclosed in U.S. Patent No. 3,903,960 to Beck et al.
  • the fan of U.S. Patent No. 3,903,960 is typical of other prior art fan structures in that it immediately tapers between a circular shape corresponding to that of the cylindrical discharge throat section and a rectangular shape corresponding to that of the radiator.
  • asymmetrical discharge separation and turbulence of cooling flow exiting the cylindrical discharge throat section, and its associated noise, is produced.
  • U.S. Patent No. 5,024,267 to Yamaguchi et al. discloses a fan shroud having a box-shaped main body covering one of the surfaces of a heat exchanger and a cylindrical portion penetrating through the main body.
  • a fan is disposed in the cylindrical portion and extends partially into the box-shaped main body.
  • the main body includes an enlarged portion disposed adjacent to and corresponding to the protruding portion of the cylindrical portion to create a high static pressure region between the fan and radiator in an attempt to increase axial flow and reduce noise.
  • some recirculation and turbulence, and its associated noise, at the fan discharge is still likely to occur as a result of the influence of the asymmetrical box-shaped main body.
  • U.S. Patent No. 3,872,916 to Beck discloses a radially diverging shroud exit section which immediately tapers between a circular shape corresponding to that of the cylindrical discharge throat section and a rectangular shape corresponding to that of the radiator. As a result of such an asymmetrical inlet, inlet distortion and downstream turbulence of cooling flow through the fan is produced.
  • Such a cooling system should be adaptable to both blower-type and suction-type fan arrangements as well as axial flow and mixed flow fans.
  • a cooling system should provide a defined flow path to reduce inlet distortion, separation, recirculation and turbulence of cooling flow through the fan.
  • such a cooling system should also be compact in view of vehicle space restrictions and should provide improved cooling characteristics.
  • a cooling system for use with an internal combustion engine comprising a fan defining a central axis for the cooling system, the fan having an overall diameter and a projected axial chord width associated therewith, a heat exchanger asymmetrical in shape about the central axis, a fan shroud disposed about the fan, the fan shroud defining a flow path for directing cooling flow axially across the heat exchanger.
  • the fan shroud includes a radially converging inlet portion, a radially diverging outlet portion and a cylindrical transition portion disposed between the inlet and the outlet portions, which inlet and outlet portions are axisymmetrical in shape about the central axis.
  • the fan shroud is mounted stationary about the fan defining a predetermined small radial running clearance therewith, the fan shroud including a radially converging inlet portion and a cylindrical transition portion, the radially converging inlet portion being axisymmetrical in shape about the central axis, and a box-shaped plenum sealingly connected between the stationary fan shroud and the heat exchanger, the box-shaped plenum extending between the stationary fan shroud and the heat exchanger and defining an abrupt transition with the fan shroud between the asymmetrically shaped heat exchanger and the axisymmetrical shaped fan shroud.
  • the improvement comprising the fan shroud including a radially converging inlet portion axisymmetrical in shape about the central axis and a radially diverging outlet portion axisymmetrical in shape about the central axis.
  • Fig. 1 is a side cross-sectional view of a cooling system including a fan, fan shroud and heat exchanger arranged in a suction mode according to one embodiment of the present invention.
  • Fig. 2 is a perspective view of the cooling system of Fig. 1.
  • Fig. 3 is a partial side cross-sectional view of the fan shroud mounting arrangement of Fig. 1.
  • Fig. 4 is a partial side cross-sectional view of a first alternate fan shroud mounting arrangement for the cooling system of Fig. 1.
  • Fig. 5 is a partial side cross-sectional view of a second alternate fan shroud mounting arrangement for the cooling system of Fig. 1.
  • Fig. 6 is a partial side cross-sectional view of a cooling system including a fan shroud and heat exchanger arranged in a suction mode according to a second embodiment of the present invention.
  • Fig. 7 is a partial side cross-sectional view of a first alternate fan shroud mounting arrangement for the cooling system of Fig. 6.
  • Fig. 8 is a partial side cross-sectional view of a second alternate shroud mounting arrangement for the cooling system of Fig. 6.
  • Fig. 9 is a partial side cross-sectional view of a cooling system including a fan, fan shroud and heat exchanger arranged in a blower mode according to a third embodiment of the present invention.
  • Fig. 10 is a partial side cross-sectional view of a cooling system including a rotating fan and shroud assembly and heat exchanger arranged in a suction mode according to a fourth embodiment of the present invention.
  • Fig. 11 is a partial side cross-sectional view of a cooling system including a rotating fan and shroud assembly and heat exchanger arranged in a blower mode according to a fifth embodiment of the present invention.
  • Fig. 12 is a partial side cross-sectional view of a cooling system including a mixed flow fan, fan shroud and heat exchanger arranged in a suction mode according to a sixth embodiment of the present invention.
  • fan structures Prior to the present invention, fan structures have focused primarily on improving flow characteristics of cooling flow entering the fan. As such, various radiused fan inlet structures have evolved in an attempt to reduce turbulence of cooling flow entering the fan.
  • the overall design of the fan structure and of fan spacing relationships relative to the fan structure is equally important to achieving a cooling system having reduced noise characteristics.
  • the present invention provides a fan structure and optimized fan spacing relationships which yield an efficient cooling system having reduced operating noise levels.
  • Cooling system 20 for a vehicle 22 is shown. Cooling system 20 is mounted and driven separate from engine 24 of vehicle 22 to reduce noise produced by the vehicle. Cooling system 20 includes a rotating bladed fan 26 hydraulically driven by a motor 27. Motor 27 derives hydraulic power from engine 24. Fan 26 is rotatably mounted independent of engine 24 within a cooling compartment 28 and is separated from the engine by a noise barrier 29. Fan 26 is mounted downstream of a radiator 30 and oil cooler 31 to induce flow from inlets 32 of compartment 28 thereacross as shown by the direction of the arrows.
  • fan 26 is mounted in close running radial clearance within a stationary fan shroud 34.
  • Fan 26 defines a central axis 38 for cooling system 20 and rotates thereabout to define a swept region generally cylindrical in shape.
  • a plenum 36 Disposed between fan shroud 34 and radiator 30 is a plenum 36.
  • Plenum 36 seals between fan shroud 34 and radiator 30 and provides an optimally sized and spaced transition duct that, together with the fan shroud, minimizes inlet distortion and large scale turbulence of cooling air entering the fan.
  • cooling system 20 is shown in perspective view to better illustrate the axisymmetric flow path defined by the fan shroud and the asymmetric flow path defined by the plenum.
  • Fan shroud 34 is generally circular in shape corresponding to fan 26 and is concentric about central axis 38.
  • plenum 36 is rectangular in shape corresponding to radiator 30 and is asymmetric throughout its length along central axis 38. Rather than tapering between a rectangular shape corresponding to that of the radiator and a circular shape corresponding to that of the fan shroud, plenum 36 is box-shaped throughout its length to define an abrupt transition at its junction with the fan shroud.
  • cooling system 20 is shown in greater detail. As previously stated, because fan 26 is disposed downstream of radiator 30, cooling system 20 operates in a suction mode to induce cooling flow across the radiator. Flow exiting the radiator enters box-shaped plenum 36 and is drawn into the fan shroud 34 where it transitions from the asymmetric rectangular flow path of the radiator to an axisymmetric flow path.
  • box-shaped plenum 36 is drawn into the fan shroud 34 where it transitions from the asymmetric rectangular flow path of the radiator to an axisymmetric flow path.
  • Fan shroud 34 includes a radially converging inlet portion 40, a cylindrical transition portion 42 and a radially diverging outlet portion 44.
  • Inlet portion 40 and outlet portion 44 each are shaped axisymmetric about central axis 38 and, further, are preferably substantially symmetric with one another about an imaginary plane, such as plane 49, constructed perpendicular to central axis 38.
  • the radially converging axisymmetric shape of inlet portion 40 uniformly accelerates flow into the fan to reduce inlet distortion and minimize turbulence intensity.
  • the transition portion 42 permits the fan to be mounted at low running clearances with the fan shroud, thereby reducing recirculation and turbulence across the leading edge of the fan blades.
  • the radially diverging axisymmetric shape of outlet portion 44 uniformly decelerates or diffuses flow exiting the fan to maintain minimal recirculation and turbulence across the fan blades.
  • inlet and outlet portions 40 and 44 are axisymmetrically shaped about respectively, are axisymmetrically shaped about central axis 38 each having a preferred constant radius of curvature R related to the overall fan diameter D.
  • the radius of curvature of the inlet portion can be preferably greater than or equal to the radius of curvature of the exit portion, in the preferred embodiment the inlet and outlet portion radii of curvature are substantially equal to provide upstream and downstream flow path symmetry.
  • the radius of curvature R is desirably in the range of about 6 percent to about 10 percent of the overall fan diameter D and, in the specific preferred embodiment of Fig. 3, is approximately 8 percent of the overall fan diameter D.
  • transition portion 42 relative to fan 26 to reduce recirculation across the fan blades.
  • the axial length L of transition portion 42 is desirably in the range of about 40 percent to about 75 percent of the projected axial chord width W of fan 26 and, in the specific preferred embodiment of Fig. 3, is approximately 50 percent of the projected axial width W.
  • leading edge 48 of fan 26 is aligned with a plane 49 constructed normal to central axis 38 and passing through the junction of inlet portion 40 with transition portion 42. As a result, a predetermined projected chord width portion P of fan 26 extends into outlet portion 44.
  • the predetermined projected chord width portion P is directly related to the axial length L of transition portion 42 and is desirably in the range of about 60 percent to about 25 percent of the projected axial chord width W of fan 26 and, in the specific preferred embodiment of Fig. 3, is approximately 50 percent of the projected axial width W.
  • radial clearance T is in the range of about 0.1 percent to about 1.0 percent of the overall fan diameter D and, in one specific embodiment, is approximately 0.5 percent of the overall fan diameter D.
  • fan shroud 34 is optimally spaced from exit surface 50 a distance E of about 1.5 percent to about 10 percent of the overall fan diameter D and, in the specific preferred embodiment of Fig. 3, is approximately 2 percent of the overall fan diameter D.
  • plenum 36 can be sealingly connected further downstream to encompass varying portions of fan shroud 34.
  • box-shaped plenum 36 is mounted to fan shroud 34 at transition portion 42 encompassing inlet portion 40, while in Fig. 5 plenum 36 is mounted to the exit of outlet portion 44 encompassing the entire fan shroud 34.
  • the radius of the inlet bell-mouth can be increased to further reduce separation and turbulence while still maintaining a compact shroud and plenum assembly. Further, an additional noise barrier is provided radially outward of fan shroud 34, also tending to shield noise levels produced during fan operation.
  • axisymmetric fan shroud 60 is disposed downstream of a box-shaped plenum similar to fan shroud 34 of Fig. 1. As such, there exists similar desired spacing relationships tending to reduce noise produced by the fan. However, the preferred axial length and axial placement for fan shroud 60 relative to fan 26 differs somewhat from the axial length and axial placement disclosed for fan shroud 34.
  • the axial length L' of transition portion 61 is desirably in the range of about 65 percent to about 85 percent of the projected axial chord width W of fan 26 and, in the specific preferred embodiment of Fig. 3, is approximately 80 percent of the projected axial width W.
  • Leading edge 48 of fan 26 is similarly aligned with a plane 62 constructed normal to central axis 38 and passing through the junction of inlet portion 63 with transition portion 61. As a result, a predetermined projected chord width portion P' of fan 26 extends beyond fan shroud 60.
  • the predetermined projected chord width portion P' is related to the axial length L' of transition portion 61 and is desirably in the range of about 35 percent to about 15 percent of the projected axial chord width W of fan 26 and, in the specific preferred embodiment of Fig. 6, is 20 percent of the projected axial width W.
  • other fan mounting arrangements contemplated for fan shroud 60 include plenum 36 being sealingly connected to transition portion 61 and encompassing inlet portion 63 (Fig. 7) and plenum 36 being sealingly connected to the exit of transition portion 61 and encompassing the entire fan shroud 60 (Fig. 8).
  • the present invention is also adaptable to blower-type cooling systems by mounting the fan and fan shroud upstream of the radiator and maintaining the leading edge of the fan aligned with the junction of the inlet and transition portions of the fan shroud.
  • cooling system 70 is shown including a similar fan shroud 74 and fan 76 to that of cooling system 20, except fan shroud 74 and fan 76 are disposed upstream of radiator 80 to blow or force air across radiator 80.
  • the present invention is also adaptable to shrouded fan assemblies mounted both in a suction mode downstream of the radiator (Fig. 10) and in a blower mode upstream of the radiator (Fig. 11).
  • a labyrinth seal 82 is provided between the plenum and fan shroud similar to that disclosed in U.S. Patent No. 5,183,382 issued to a common inventor on 02 February 1993.
  • fan shroud 84 is shaped and aligned relative to fan 86 similar to that of cooling system 20, except that shroud 84 is attached to fan 86 to define a fan and shroud assembly.
  • plenum 88 is sealingly connected between a radiator 89 and the inlet portion 91 of fan shroud 84. As such, plenum 88 defines the stationary portion of the labyrinth seal 82, while inlet portion 91 of fan shroud 84 defines the rotating portion of labyrinth seal 82.
  • fan shroud 90 is shown adapted for use with a mixed flow fan 92 in a mixed flow cooling system 93. Similar to fan shroud 34 of cooling system 20, fan shroud 90 includes an axisymmetric radially converging inlet portion 94 and an axisymmetric radially diverging outlet portion 96. However, to provide close radial running clearance with mixed flow fan 92, transition portion 98 has a radially diverging shape corresponding to the blade contours of fan 92.
  • the preferred spacing relationships for cooling system 93 are substantially the same as those for cooling system 20, except that the overall fan diameter refers to the mean fan diameter of fan 92.
  • an engine cooling system includes a fan shroud optimally configured to reduce noise generated by separation, recirculation and turbulence of cooling flow. Further, the fan, fan shroud and heat exchanger are optimally arranged relative to one another to reduce operating noise levels. Still other related objects and advantages of the present invention are apparent from the drawings and written description. For example, the present invention is also adaptable to provide a higher performance cooling flow system. For a given allowable operating noise level, the fan speed may be higher with the present invention over that of prior art cooling systems.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
EP94112831A 1993-08-31 1994-08-17 Low noise cooling system Ceased EP0645543A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US11443393A 1993-08-31 1993-08-31
US114433 1993-08-31

Publications (1)

Publication Number Publication Date
EP0645543A1 true EP0645543A1 (en) 1995-03-29

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ID=22355175

Family Applications (1)

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EP94112831A Ceased EP0645543A1 (en) 1993-08-31 1994-08-17 Low noise cooling system

Country Status (2)

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EP (1) EP0645543A1 (ja)
JP (1) JPH0777044A (ja)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19745816B4 (de) * 1996-10-17 2006-08-17 Scania Cv Ab Lüfterring
WO2008022739A1 (de) * 2006-08-19 2008-02-28 Daimler Ag Luftführungsanordnung zum kühlen eines verbrennungsmotors
DE102007007231A1 (de) * 2007-02-14 2008-08-21 Behr Gmbh & Co. Kg Kühlsystem für ein Kraftfahrzeug
WO2009099384A1 (en) * 2008-02-04 2009-08-13 Scania Cv Ab Method and arrangement for control of cooling and an engine
ITCO20100063A1 (it) * 2010-11-16 2012-05-17 Nuovo Pignone Spa Flangia di ingresso anti-distorsione per un compressore centrifugo ad ingresso radiale e metodo
EP2796725A1 (en) * 2013-04-22 2014-10-29 Lennox Industries Inc. Fan systems
US9551356B2 (en) 2013-10-04 2017-01-24 Caterpillar Inc. Double bell mouth shroud

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3023433B2 (ja) * 1995-04-10 2000-03-21 日立建機株式会社 熱交換器の冷却装置
JPH10115222A (ja) 1996-10-11 1998-05-06 Hitachi Constr Mach Co Ltd エンジン冷却装置
WO2005098213A1 (ja) * 2004-04-05 2005-10-20 Komatsu Ltd. 冷却装置
JP4655902B2 (ja) * 2005-11-24 2011-03-23 株式会社デンソー クーリングモジュール
US8282349B2 (en) * 2008-03-07 2012-10-09 General Electric Company Steam turbine rotor and method of assembling the same
JP6320773B2 (ja) * 2014-01-31 2018-05-09 本田技研工業株式会社 鞍乗型車両用内燃機関の冷却装置
CN108590851B (zh) * 2018-05-30 2023-12-01 隆鑫通用动力股份有限公司 导风罩及其发电机
JP7412917B2 (ja) * 2019-07-31 2024-01-15 株式会社中村自工 車両用冷却装置

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1370283A (en) * 1918-05-27 1921-03-01 Carling Turbine Blower Co Fan-casing
US3872916A (en) * 1973-04-05 1975-03-25 Int Harvester Co Fan shroud exit structure
US3903960A (en) * 1973-12-26 1975-09-09 Int Harvester Co Fan shroud entrance structure
DE3737391A1 (de) * 1987-11-04 1989-05-18 Kloeckner Humboldt Deutz Ag Luftleitvorrichtung fuer eine kuehler-luefter-anordnung
WO1991006779A1 (en) * 1989-11-01 1991-05-16 Scoates William D Shroud assembly for axial flow fans
US5024267A (en) * 1989-06-28 1991-06-18 Aisin Kako Kabushiki Kaisha Cooling apparatus for heat exchanger
EP0445804A1 (en) * 1990-03-07 1991-09-11 Nippondenso Co., Ltd. Fan apparatus
US5183382A (en) * 1991-09-03 1993-02-02 Caterpillar Inc. Low noise rotating fan and shroud assembly
EP0543694A1 (fr) * 1991-11-07 1993-05-26 Ecia - Equipements Et Composants Pour L'industrie Automobile Carénage perfectionné pour ventilateur et son application à un groupe motoventilateur d'automobile

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1370283A (en) * 1918-05-27 1921-03-01 Carling Turbine Blower Co Fan-casing
US3872916A (en) * 1973-04-05 1975-03-25 Int Harvester Co Fan shroud exit structure
US3903960A (en) * 1973-12-26 1975-09-09 Int Harvester Co Fan shroud entrance structure
DE3737391A1 (de) * 1987-11-04 1989-05-18 Kloeckner Humboldt Deutz Ag Luftleitvorrichtung fuer eine kuehler-luefter-anordnung
US5024267A (en) * 1989-06-28 1991-06-18 Aisin Kako Kabushiki Kaisha Cooling apparatus for heat exchanger
WO1991006779A1 (en) * 1989-11-01 1991-05-16 Scoates William D Shroud assembly for axial flow fans
EP0445804A1 (en) * 1990-03-07 1991-09-11 Nippondenso Co., Ltd. Fan apparatus
US5183382A (en) * 1991-09-03 1993-02-02 Caterpillar Inc. Low noise rotating fan and shroud assembly
EP0543694A1 (fr) * 1991-11-07 1993-05-26 Ecia - Equipements Et Composants Pour L'industrie Automobile Carénage perfectionné pour ventilateur et son application à un groupe motoventilateur d'automobile

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19745816B4 (de) * 1996-10-17 2006-08-17 Scania Cv Ab Lüfterring
WO2008022739A1 (de) * 2006-08-19 2008-02-28 Daimler Ag Luftführungsanordnung zum kühlen eines verbrennungsmotors
DE102007007231A1 (de) * 2007-02-14 2008-08-21 Behr Gmbh & Co. Kg Kühlsystem für ein Kraftfahrzeug
WO2009099384A1 (en) * 2008-02-04 2009-08-13 Scania Cv Ab Method and arrangement for control of cooling and an engine
US8408169B2 (en) 2008-02-04 2013-04-02 Scania Cv Ab Method and arrangement for control of cooling and an engine
ITCO20100063A1 (it) * 2010-11-16 2012-05-17 Nuovo Pignone Spa Flangia di ingresso anti-distorsione per un compressore centrifugo ad ingresso radiale e metodo
EP2796725A1 (en) * 2013-04-22 2014-10-29 Lennox Industries Inc. Fan systems
US9618010B2 (en) 2013-04-22 2017-04-11 Lennox Industries Inc. Fan systems
US10533577B2 (en) 2013-04-22 2020-01-14 Lennox Industries Inc. Fan systems
US9551356B2 (en) 2013-10-04 2017-01-24 Caterpillar Inc. Double bell mouth shroud

Also Published As

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