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
  • F04D13/00—Pumping installations or systems
  • F04D13/02—Units comprising pumps and their driving means
  • F04D13/021—Units comprising pumps and their driving means containing a coupling
  • F04D13/024—Units comprising pumps and their driving means containing a coupling a magnetic coupling
  • F04D13/027—Details of the magnetic circuit
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D13/00—Pumping installations or systems
  • F04D13/02—Units comprising pumps and their driving means
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D13/00—Pumping installations or systems
  • F04D13/02—Units comprising pumps and their driving means
  • F04D13/021—Units comprising pumps and their driving means containing a coupling
  • F04D13/024—Units comprising pumps and their driving means containing a coupling a magnetic coupling
  • F04D13/025—Details of the can separating the pump and drive area
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D13/00—Pumping installations or systems
  • F04D13/02—Units comprising pumps and their driving means
  • F04D13/021—Units comprising pumps and their driving means containing a coupling
  • F04D13/024—Units comprising pumps and their driving means containing a coupling a magnetic coupling
  • F04D13/026—Details of the bearings

Definitions

• This invention relates to improvements to rotary pumps, and in particular coolant pumps for combustion engines.
• sealing faces may film over with deposits from chemicals held in solution - a situation familiar to the industry known as filming which subsequently leads to sealing breakdown and coolant leakage.
• the faces may fail prematurely and leak due to excessive shaft run-out.
• the faces may also fail due to vibration transmitted from ailing bearings which have been overloaded by over zealous tightening of the drive belt. Additionally the faces may wear out prematurely due to scoring caused by hard particles in the pumped medium.
• a mechanical seal consists of two polished radial surfaces running adjacent to each other. Since the pressure of the pumped medium at the seal is different from the pressure of the air outside the seal a pressure gradient is set up across the seal faces between which slow leaking or weeping is apt to occur. It is therefore evident that a slightly weeping mechanical seal is not always indicative of a failed seal. However, a common misconception is that any signs of weeping indicates a failed seal. A perfectly serviceable coolant pump assembly is thus often needlessly replaced.
• a sealless pump which employs a magnetic coupling comprising a driving and a driven magnetic member which couple with one another through a static, hermetically sealed container or containment shroud. Accordingly, the static container prevents leakage since it is a non-moving part.
• the disadvantage with conventional magnetic couplings is that they are bulky. Because of an ever- in creasing need to reduce the space occupied by the internal combustion engine in its engine compartment, is has not been feasible to accommodate a known magnetic coupling between the pulley or the gear drive system and the coolant pump.
• An object of the invention is to provide a sealless coolant pump of the type described comprising a magnetic coupling suitable for use with an internal combustion engine.
• One aspect of the invention provides a sealless coolant pump comprising a pulley assembly having a pulley for co-operation with a drive belt and a driving magnetic member, a pump body housing a driven pump member attached to a driven magnetic member, which co-operates with the driving magnetic member through a static container attached to the pump body, wherein the pulley assembly and driven pump member are rotatable about a common axis, and the pulley, driving magnetic member, and driven magnetic member are substantially radially aligned or superpositioned with respect to said common axis.
• a sealless coolant pump having a reduced axial length is thereby provided compared to known pumps.
• the driving magnetic member can be radially outward of the driven magnetic member.
• the driving magnetic member can be radially inward of the driven magnetic member.
• the pulley assembly can comprise an annulus for carrying the driving magnetic member.
• the annulus can carry part of a bearing for co-operating with part of the bearing carried by the static container.
• the static container comprises a centrally protruding portion which operably carries a bearing for co-operating with the pulley assembly.
• the driven pump member can comprise a shaft which is rotatable about the common axis which shaft protrudes axially in to said centrally protruding portion of the static container.
• a second aspect of the invention provides a sealless coolant pump comprising a pulley assembly having a pulley for co-operating with a drive belt and a driving magnetic member, a pump body housing a driven pump member attached to a driven magnetic member which co-operates with the driving magnetic member through a static container attached to the pump body, wherein the driving magnetic member and driven magnetic member are substantially radially aligned and the driving magnetic member is radially inward with respect to the driven magnetic member.
• this configuration enables the pulley assembly to comprise a bearing which co-operates with the static container and a pump shaft assembly attached to the driven pump member.
• a sealless coolant pump comprising a pump body housing a driven pump member attached to a driven magnetic member and a shaft assembly rotatable about a rotation axis, a pulley assembly comprising a pulley and driving magnetic member which co-operates with the driven magnetic member through a static container attached to the pump body, wherein the driving magnetic member and driven magnetic member are substantially radially aligned with respect to the rotation axis but the pulley is axially displaced therefrom, the pulley assembly comprising a bearing which co-operates with the pump shaft assembly and wherein the static container encloses the whole of the shaft assembly and the driven magnetic member.
• the pulley can be axially outermost from the pump.
• a further aspect of the invention relates to sealless coolant pump comprising a pump impeller such as the pump disclosed in European Patent specification EP-A-0331288 to Concentric Pumps Limited.
• the sealless coolant pump comprising a pump body housing a driven impeller pump member attached to a shaft assembly and a driven magnetic member, and a pulley assembly comprising a driving magnetic member for co-operating with the driven magnetic member through a static container attached to the pump body, the pump further comprising a radially inward fluid inlet region and radially outward fluid outlet, an axial or thrust, bearing for co-operating with the shaft assembly, and a duct for communicating fluid from the outlet region to a position proximal the thrust bearing.
• FIGURE 1 is a schematic sectional side elevation view of a pump according to the invention.
• FIGURE 2 is a schematic sectional side elevation view of a second embodiment of a pump according to the invention.
• FIGURE 3 is a schematic sectional side elevation view of a third embodiment of a pump according to the invention.
• FIGURE 4 is a sectional side elevation view of a fourth embodiment of a pump according to the invention.
• a pump 10 comprising a pump body 12 and pulley assembly 14.
• the pulley assembly and pump body are separated by a static container 16 which hermetically seals the pump body to prevent loss or leakage of fluid in this region.
• the container 16 is attached to body 12 by bolts which clamp an annular ring against the container 16 and body 12.
• Pulley assembly 14 comprises a pulley or pulley ring 18 which in use is engaged by a belt B which drives the pulley.
• the assembly further comprises an annular flange 20 which provides an annular bore radially inward of the pulley 18.
• Flange 20 carries a driving magnetic member 22 which can consist of an annular series of spaced bar magnets.
• the pulley bore engages a bearing 24 for example of the double row angular contact ball bearing type.
• a spacer 25 can be used to position pulley assembly 14 with respect to container 16 and pump body 12.
• the pump body 12 houses a driven member 26 comprising impeller blades 28.
• the driven member carries a driven magnetic member 30 which also can comprise an annular series of spaced bar magnets. Preferably, there is a 50% overlap between the bar magnets of the driven and driving magnetic members.
• the driven magnetic member 30 is carried on an axial extension 32 which can comprise a series of radial apertures to enable fluid communication around the pump body for lubrication purposes.
• the driven member 26 is attached to a shaft assembly 34 which comprises a hollow shaft 35 having first and second journal ends 36 and 38.
• First journal end 36 is journalled in a bearing 40 which abuts an axial spacer 42.
• Second journal end 38 is journalled in a bearing 44 which together with journal end 38 abuts an axial bearing 46 which acts as a thrust bearing for hollow shaft 35.
• the pump body 12 also defines a fluid inlet region 38 and fluid outlet region 50.
• belt B drives pulley assembly 14 about rotational axis A which causes the driving magnetic member 22 also to rotate and transfer kinetic energy to driven pump member 26 due to magnetic coupling with driven magnetic member 30. This causes rotation of blades 28 which drive fluid from inlet region 48 to outlet region 50 thereby providing a pressure differential between these regions.
• Fluid passes from the pump 10 through an outlet (not shown) for example for communication with an internal combustion engine. Fluid can be supplied to an inlet (not shown) from a radiator within a vehicle having such an internal combustion engine.
• pump 10 has a reduced axial extent compared to known sealless coolant pumps, due to the positioning of the pulley substantially radially in line with magnetic members 22 and 30.
• bearing 24 provides a dynamically stable system since it compresses container 16 on to bearing 40.
• bearing 40 can comprise a ceramic material such as silicon carbide which is strong in compression.
• driven magnetic member 30 can comprise an induced magnetic drive coupling comprising a ring of axially placed copper rods suitably embedded in an appropriate matrix.
• a pump 110 according to the invention wherein components which are in common with those shown in Figure 1 are given the same two digits reference number prefixed with the number 1.
• a static hermetic seal is provided by container 116 which can for example be made of a non-magnetic stainless steel.
• the container comprises a series of folded regions as shown in Figure 1.
• the driving magnetic member 122 is radially outside the driven magnetic member 130 with respect to the rotation axis A.
• Bearing 124 is carried on the outside radial face of angular flange 120 for co-operating with housing 116 and extension 132.
• pulley 218 comprises an annular flange 220 at approximately the same radial position with respect to axis A and therefore axially displaced with respect to pulley 218.
• bearing 224 Radially inward of pulley 218 is bearing 224 which co-operates with housing 216 and bearings proximal a first journal end 236 of shaft assembly 234.
• magnetic driving member 222 Axially displaced from pulley 218 is magnetic driving member 222 which co-operates with driven magnetic member 230 carried on extension 232 attached to shaft assembly 234.
• Beneficially housing 216 encloses the moving driven parts of the pump and in this embodiment shaft 234 protrudes beyond the co-operating magnetic members to enable pulley 218 to engage housing 216 and effectively shaft 235 via a series of bearings thereby providing a dynamically stable pump in which significant radial forces are applied to pulley 218 by belt B. Also, a diametrically compact pump is provided which can use a smaller pulley than other embodiments.
• a pump 310 comprises many features in common with those shown in Figure 1 in relation to pump 10. Components in common with pump 10 are given the same two digit reference numbers prefixed with the number 3.
• pump 310 further comprises a duct 352 which passes through pump body 312 between the outlet region 350 and a position proximal the thrust bearing 346.
• Body 312 also comprises an end plate 354 which locates thrust bearing 346 at the end of shaft 335.
• the duct 352 can comprise a bore in body 312 as well as a tube passing away from and back to plate 354.
• shaft 335 can comprise a central bore 356 which only passes from end 336 to a point beyond driven member 326 where a cross bore 358 communicates the lubricating medium with region 348.
• the lubricant supplied to the thrust bearing 346 is therefore derived from duct 352.
• fluid is drawn from the relatively high pressure region of outlet region 350 to a relatively low pressure region proximal the assembly shaft 334 thereby to lubricate the contact between journal end 238 and thrust bearing 346.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)
• Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
• Details And Applications Of Rotary Liquid Pumps (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Publications (1)

Family

ID=10817913

Family Applications (1)

Country Status (11)

Cited By (6)

Families Citing this family (3)

Citations (8)

Family Cites Families (8)

• 1997
  • 1997-08-23 GB GBGB9717866.9A patent/GB9717866D0/en active Pending
• 1998
  • 1998-08-20 BR BR9811991-5A patent/BR9811991A/pt not_active Application Discontinuation
  • 1998-08-20 ZA ZA987530A patent/ZA987530B/xx unknown
  • 1998-08-20 CN CN98809457A patent/CN1271408A/zh active Pending
  • 1998-08-20 JP JP2000507939A patent/JP2001514360A/ja active Pending
  • 1998-08-20 CA CA002301560A patent/CA2301560A1/en not_active Abandoned
  • 1998-08-20 KR KR1020007001799A patent/KR20010023173A/ko not_active Application Discontinuation
  • 1998-08-20 WO PCT/GB1998/002500 patent/WO1999010655A1/en not_active Application Discontinuation
  • 1998-08-20 EP EP98939761A patent/EP1005614A1/en not_active Withdrawn
  • 1998-08-20 AU AU88165/98A patent/AU8816598A/en not_active Abandoned
  • 1998-08-20 GB GB9818082A patent/GB2332928A/en not_active Withdrawn
  • 1998-08-21 AR ARP980104149A patent/AR016853A1/es unknown

Patent Citations (8)

Non-Patent Citations (2)

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