EP3259479B1

EP3259479B1 - A self-lubricating pump arrangement

Info

Publication number: EP3259479B1
Application number: EP16751803.4A
Authority: EP
Inventors: David Gehlert; Matthew Smith; Nesimi Ertugrul
Original assignee: Intelligent Electric Motor Solutions Pty Ltd
Current assignee: Intelligent Electric Motor Solutions Pty Ltd
Priority date: 2015-02-19
Filing date: 2016-02-18
Publication date: 2021-03-31
Anticipated expiration: 2036-02-18
Also published as: ES2877430T3; EP3259479A4; EP3259479A1; AU2016222258B2; WO2016131080A1; AU2016222258A1; CN107429699A

Description

FIELD OF THE INVENTION

This invention relates to a pump arrangement utilising an impeller rotationally controlled by a motorised drive shaft for carrying out the pumping operation and more particularly to a new and improved bearing bush arrangement to rotationally constrain but allow free rotational movement of the motorised shaft when fluid is being pumped.

BACKGROUND ART DISCUSSION

In general the bearing bush and the sealing arrangement around the motorised shaft of the pump which may also include mechanical type seals and the associated bearing lubrication system, are designed for the most part to constrain the mounted drive shaft against radial movement but at the same time allow free rotation of this motorised drive shaft whilst fluid is being pumped.
By the inherent nature of constraining against radial movement of the motorised drive shaft of the pump whilst allowing free rotation of the motorised drive shaft during pumping fluid the associated bearing bush and/or mechanical seal arrangements with the applicable bearing lubrication system regularly require maintenance where the worn bearing bushes would have to be replaced and the mechanical seals accessed to check on the state of the lubricant.
While any maintenance is a good thing as it provides a means of preventing breakdown and also increasing longevity of pump componentry it also brings its own challenges such as significant costs and operational considerations for the ongoing requirement to continually inspect and maintain both the bearing bush and/or the sealing arrangements about the motorised drive shaft of the pump.
Also pump construction requiring mechanical seals and conventional bearing lubrication systems brings design complexity to the pump making the pump more expensive to manufacture, places potential restrictions on efficiency as tooling and access to mechanical seals for repair need to be considered, as such pumps regularly are required to be disassembled in order for adequate inspections to take place for the appropriate maintenance of the conventional bearing bushes and/or sealing arrangements to be checked.
Further, bearings and seals are major components in pumps that regularly fail and rely upon periodic maintenance hence it would be advantageous to be avoid such conventional arrangements for bearing and seals and rely upon more seal less design that is not prone to failure and/or regular maintenance.
Accordingly it would be advantageous to be able to provide for a pump that utilises an impeller under the rotational control of a motorised drive shaft that, rather than having to rely upon self-sacrificing bearing bushes and/or lubricated mechanical seals that would be adapted to constrain the motorised drive shaft against radial movement but permit free rotation of the motorised drive shaft during pumping could alternatively inherently rely upon a self-lubricating system configured into the arrangement that could avoid the necessity for any regular replaceable bushes and/or a bearing lubrication system that would need periodic inspection and maintenance.
It is known patent number US3635499 disclosing a flam-arresting vent valve.
It is an object of this invention to provide such a self-lubricating pump arrangement that will substantially ameliorate or eliminate some of the problems referred to above.
Further objects and advantages of the invention will become apparent from a complete reading of this specification.

SUMMARY OF THE INVENTION

In one form of the invention there is provided a self-lubricating pump arrangement, said self-lubricating pump arrangement including:

a main housing block, said main housing block having a fluid suction opening at a first distal end and a fluid discharge opening at a second distal end;
a stator supported therein said main housing block;
a rotor configured within a stator, wherein electrical inductive communication between the rotor and the stator rotationally drives a drive shaft longitudinally extending out from said rotor;
an impeller member rotationally operative by said drive shaft, wherein the impeller member includes a first face including one or more openings wherein each opening is adapted to take fluid from the fluid suction opening of the main housing body when the drive shaft is rotatably driven and wherein a series of internal vanes within the impeller member are configured to radially exit said fluid from a side of the impeller member;
a fluid flow guide arrangement adapted to take the radial exiting fluid flow from the side of the impeller member and guide said fluid along a hollow chamber or slot towards and out there from the fluid discharge opening at the second distal end of the main housing block;
said impeller member further characterised by including a second face wherein the series of internal vanes of the impeller member are configured there in between said first face and second face, said second face of the impeller member having a plurality of apertures to which fluid is passable there into to so as to engage the series of internal vanes configured within the impeller member;
one bearing bush configured to support said drive shaft during rotation of said drive shaft when said drive shaft is being driven;
said bearing bush including a series of open grooves along said bearing bush length to which fluid is passable there along whilst rotation of said drive shaft when said drive shaft is being driven;
a re-directed fluid guide arrangement adapted to take a portion of the exiting fluid flow and redirect said portion of the exiting fluid flow into the series of open grooves of the bearing bush and through the plurality of apertures on the second face of the impeller member thereby allowing the portion of the exiting fluid flow to re-join fluid taken from the fluid suction side.

An advantage of such an arrangement is that by utilising a portion of the exiting fluid being discharged out through the pump arrangement and redirecting it back up internally through the main housing block is that this redirected fluid can be guided up into the grooves of the bearing bush thereby implementing a self-lubricating mechanism of the fluid such that while the bearing bush is mounted so as to support radial movement of the drive shaft, the drive shaft is free to rotate during pumping as the fluid flow along the grooves provides for a lubrication system.
Advantageously this lubrication system does not form part of any mechanical seal and therefore does not require periodic inspection or regular maintenance, simplifying design, construction costs, efficiency and the appropriate fittings necessary in order to achieve the requisite pumping operation.
As the redirected fluid flow creates a lubrication system between the bearing bush and the drive shaft, there is no self-sacrificing of the bush itself as frictional contact between the drive shaft and the bush from a frictional point of view while fluid pumping is minimum as that portion of the exiting fluid flow re-directed through the re-directed fluid guide arrangement provides the necessary lubrication.
Uniquely, the impeller member includes not only the conventional opening or openings on the first face (suction side) in order to take fluid flow from the fluid suction opening of the main housing block, but also includes on the opposing second face a plurality of openings which are able to accept the redirected fluid that is passing up through the grooves within the mounted bearing bush so as to again join the main flow as it radially exits through the series of vanes of the impeller member.
In preference the main housing is made up of two joinable half sections.
In preference the self-lubricating pump arrangement further includes a sub-assembly, wherein the sub-assembly is supportable within the two joinable half sections of the main housing block.
In preference the sub-assembly supportable within the two joinable half sections of the main housing block includes at least two sections adapted to be fastenable together to encapsulate the stator and the rotor.
In preference the hollow chamber is defined by spacing between an internal side of the two joinable half sections of the main housing block and an external side of the sub-assembly.
In preference the sub-assembly includes a first half section and a second half section, wherein the first half section and the second half section are adapted to be fastenable together to encapsulate the stator and the rotor.
In preference the first half section includes a top surface configured to allow the impeller member to be restable thereon.
In preference the top surface of the first half section includes a series of guide baffles that form part of the fluid flow guide arrangement.
In preference the bearing bush includes an upper flange.
In preference the top surface of the first half section includes a central circular slot having a depressed collared skirt adapted for the upper flange of the bearing bush to be positionable therein.
In preference the generally circular impeller member has a corresponding central slot such that the drivable shaft is adapted to pass through the mounted bearing bush mounted within the front cylindrical portion of the vertical fluid flow guide arrangement to be insertable through the central slot of the impeller member with a fastening arrangement adapted then to secure the impeller member to the drivable shaft such that electrical inductive communication between the rotor and the stator provides for rotational motorised movement of the drive shaft wherein rotational movement of the drive shaft translates to rotational movement of the impeller member to provide pumping operability.
In preference the second half section of the sub-assembly includes a central slot at one end adapted to receive the portion of re-directed exiting fluid flow.
In preference the central slot includes a filter.
In preference the first half section and the second half section of sub-assembly are configured to come together in a mating snap fit or frictional engagement in order to encapsulate the stator and the rotor.
In preference the first half section and the second half section of the sub-assembly that encapsulates the stator and the rotor include external tab extensions assist in mounting the sub-assembly within the main housing block.
In preference the main housing block includes two halves that can be joined together to enclosed all componentry of the pump arrangement other than an external electrical power source.
As is to be appreciated the wound stator, rotor and any other circuitry or components associated with the electrical inductive operation of the pump are fully encapsulated in appropriate insulating material.

BRIEF DESCRIPTION OF THE DRAWINGS

In order now to understand the invention in greater detail a preferred embodiment will be presented with the assistance of the following illustrations and accompanying text.

Figure 1 is an exploded perspective view of the self-lubricating pump arrangement in a preferred embodiment of the invention.
Figure 2 is a cross-sectional view of the self-lubricating pump arrangement in a preferred embodiment of the invention illustrating in addition main fluid flow from suction through to discharge as well as the back and/or self-lubrication fluid flow.
Figure 3a is a bottom view of the mountable bearing bush and Figure 3b is a general perspective view of the mountable bearing bush of the self-lubricating pump arrangement in a preferred embodiment of the invention.
Figure 4 is an underside perspective view of the impeller member of the self-lubricating pump arrangement in a preferred embodiment of the invention.

DETAILED DESCRIPTION OF THE ILLUSTRATIONS

Referring to the drawings now in greater detail wherein provided is a self-lubricating pump arrangement (10).
The self-lubricating pump arrangement (10) includes a main housing block made up of two joinable halves (12) and (14) which as best seen in Figure 2 are joinable together to encapsulate the remaining components and elements of the self-lubricating arrangement (10).
Mounted internally within the two joinable halves (12) and (14) of main housing block is the sub-assembly of the vertical fluid flow guide arrangement which in itself is made up in the preferred embodiment of two generally cylindrical half portions (16) and (18) which again as best seen in Figure 2 are able to be snap fitted together in order to encapsulate and contain therein the wound stator (26) and the rotor (24) positionable within the wound stator (26).
The sub-assembly of the vertical fluid flow guide arrangement made up of the two halves (16) and (18) also encapsulates the printed circuit-board (33) and the related electrical and electronic componentry which work in combination with the insulated power connection shown as (60) in Figure 2 to provide the requisite electrical inductive communication between the rotor (24) configured within the stator (26) such that induced rotation of the rotor (24) results in corresponding rotation of the drive shaft (28) extending out from the rotor (24).
When the sub-assembly portions (16) and (18) of the vertical fluid guide arrangement encapsulate the rotor (24) and stator (26) as well as the associated electrical and electronic componentry (33), the drive shaft (28) is appropriately constrained against radial movement by virtue of the mounted bearing bush (22) which as best seen in Figure 2 is able to rest within the defined slot (66) of the half portion (18) wherein a depressed collared ring shown as (67) allows the flange (75) of the bearing bush (22) to be positionable therein.
The drive shaft (28) is able to pass through the defined opening (66) and where the distal end (7) of the drive shaft (28) is able to engage a fastener (30) by virtue of the corresponding slot (91) passing through the impeller member (20) so as to secure the impeller member (20) to the drive shaft (28). Support ring (32) also assist in positioning the impeller (20) within the main housing block.
The impeller member (20) is mounted to the drive shaft (28) such that it is positioned to take fluid from the fluid suction opening (51) of the half section (14) of the main housing block whereupon rotation of the impeller member (20) as the drive shaft (28) is sent into driven rotation by the electrically induced communication between the rotor (24) and the wound stator (26) fluid may be sucked through the opening (92) of the impeller member (20) upon the upper face (87) of the impeller member (20) wherein once the fluid passes through the opening (92) it is then able to engage the series of internal vanes (46) so that fluid shown by way of the thicker arrows (57) in Figure 2 is able to be sucked in through the opening (92) of the impeller member (20) to radially exit through the side (94) of the impeller (20) and wherein baffles (25) that include a section (27) on the top surface (23) of the sub-assembly end portion (18) are configured to take fluid radially exiting from the side (94) of the impeller member (20) so as to guide this exiting fluid across the top surface (23) and down the longitudinal side section (29) of the baffles (25).
As shown in Figure 2 once the sub-assembly (16) and (18) has encapsulated the motor elements of the pump and rotation of the drive shaft (28) commences, as discussed above the main flow of fluid (57) during operational pumping is designed to suck fluid from the opening (51) to direct it through the opening (92) of the impeller member (20) where it can engage the circulating internal vanes (46) to increase velocity of the radially exiting fluid so as to then be guided down the internal chamber (44) between the main housing block halves (12) and (14) and the enclosed sub-assembly (16) and (18) which is housing the motorised pump componentry. Wherein the fluid, again shown by way of arrows (57) is able to exit the main housing block (12) and (14) through the fluid discharge opening (53).
Importantly however in this invention, not only is there the main fluid flow as represented by the thicker arrows (57) shown in Figure 2, there is also the establishment of a redirected flow of a portion of this main flow (57) as illustrated by the series of thinner represented arrows referenced as (80a) through to (80g).
This redirected flow represented as (80a) from the main flow at (57a) by virtue of the contoured profiling (99) of the bottom section of the end portion (16) of the encapsulating sub-assembly for the motorised components of the pump.
The defined slot (40) which includes at the main opening filter (42) allows a redirected flow shown by way of arrow (80b) to be introduced into the encapsulated hollow spacing (101) of the confines of the end portion (16) of the sub-assembly enclosing the motor of the pump arrangement.
As introduced above, the actual electrical and electronic componentry of the printed circuit-board (33), rotor (24) and wound stator (26) are all appropriately insulated such that the introduction of the self lubrication fluid (80b) entering the hollow chamber (101) does not have any adverse effect on the integrity of operation of the electrical and electronic componentry for the pump arrangement.
The redirected lubrication flow (80b) is directed into opening (54) shown by way of the arrow (80c) and as best seen when reviewing Figure 2 but also Figures 3a and 3b, as the bearing bush (22) along its main longitudinal column (70) includes a series of appropriately aligned open internal grooves (71), (72) and (73), this allows the redirected lubrication flow to pass up through these internal groove openings (71), (72) and (73) such that when the bearing bush (22) constrains the radial movement of the drive shaft (28) it still allows for free lubricated rotational movement of the drive shaft when fluid is being pumped due to the unique arrangement of redirecting a small portion of the main fluid flow (57) back into the sub assembly (16) and (18) so that it acts as a lubrication thereby preventing the bearing bush from being sacrificially slowly disintegrated which would generally be the case with a conventional bearing bush which slowly withers away during the slight frictional contact as the drive shaft is constrained against radial movement but allowed for the most part to freely rotate in order to operate the impeller member (20) accordingly.
Once the fluid (80d) and (80e) makes its way up the internal side (77) of the bearing bush (22) by virtue of the open internal grooves (71), (72) and (73) this redirected flow is then able to engage the openings (90) on the underside (89) of the impeller member (20) to enter the impeller member (20) shown by way of arrow (80f, 80g) so as then to again join the main flow (57) to be subsequently discharged accordingly from the main housing block.
Advantageously the redirected lubricating fluid flow is able to absorb heat generated by the motorised componentry encapsulated within the sub-assembly made up of the two halves (16) and (18) where once it enters the impeller member (20) and re-joins the main flow can then be discharged the heat out through the fluid discharge opening (53) of the main housing block half of the self-lubricating pump arrangement (10).
It needs to be recognised that the preferred embodiment described above and referred to in relation to Figure 1 through to Figure 4 show a restrictive preferred embodiment and should not be considered as limiting the general scope of the invention that is solely defined by the appended claims.
For example the bearing bush (22) shows three internal groove openings (71), (72) and (73) wherein there can be a variety of arrangements for balanced flow of the re-directed fluid there along the internal side (77) of the bearing bush in order to establish the requisite self-lubricating system.
Also the sub-assembly which is made up of the half portions (16) and (18) can further include brackets or external tabs and the like which will allow the sub-assembly to be conveniently mounted and enclosed therein the main housing block when the two external joinable halves (12) and (14) of the main housing block are brought together as seen in Figure 2.
Accordingly, not only is an inherent self-lubricating pump arrangement provided for by this invention, this invention also is designed to allow convenient assembly and disassembly of the pump arrangement in order to inspect and maintain any ongoing maintenance and the like that may be required during ongoing operation of the self-lubricating pump arrangement.

Claims

A self-lubricating pump arrangement (10), said self-lubricating pump arrangement (10) including:
a main housing block (12, 14), said main housing block (12, 14) having a fluid suction opening at a first distal end (51) and a fluid discharge opening at a second distal end (53);

a stator supported (26) therein said main housing block (12, 14);

a rotor (24) configured within a stator (26), wherein electrical inductive communication between the rotor (24) and the stator (26) rotationally drives a drive shaft (28) longitudinally extending out from said rotor (24);

an impeller member (20) rotationally operative by said drive shaft (28), wherein the impeller member (20) includes a first face (87) including one or more openings (92) wherein each opening (92) is adapted to take fluid from the fluid suction opening of the main housing body (12, 14) when the drive shaft (28) is rotatably driven and wherein a series of internal vanes (46) within the impeller member (20) are configured to radially exit said fluid from a side (94) of the impeller member (20);

a fluid flow guide arrangement (16, 18) adapted to take the radial exiting fluid flow from the side (94) of the impeller member (20) and guide said fluid along a hollow chamber (101) or slot towards and out there from the fluid discharge opening at the second distal end (53) of the main housing block (12, 14);

said impeller member (20) further including a second face (89)

wherein the series of internal vanes (46) of the impeller member (20) are configured there in between said first face (87) and second face (89), said second face (89) of the impeller member (20) having a plurality of apertures (90) to which fluid is passable there into so as to engage the series of internal vanes (46) configured within the impeller member (20);

wherein said arrangement further comprises:
one bearing bush (22) configured to support said drive shaft (28) during rotation of said drive shaft (28) when said drive shaft (28) is being driven;

said bearing bush (22) including a series of open grooves (71, 72, 73) along said bearing bush (22) length to which fluid is passable there along whilst rotation of said drive shaft (28) when said drive shaft (28) is being driven;

a re-directed fluid guide arrangement adapted to take a portion of the exiting fluid flow and redirect said portion of the exiting fluid flow into the series of open grooves (71, 72, 73) of the bearing bush (22) and through the plurality of apertures (90) on the second face (89) of the impeller member (20) thereby allowing the portion of the exiting fluid flow to re-join fluid taken from the fluid suction side.
The self-lubricating pump arrangement of claim 1 wherein the main housing is made up of two joinable half sections (12, 14).
The self-lubricating pump arrangement of claim 2 further including a sub-assembly (16, 18), wherein the sub-assembly is supportable within the two joinable half sections of the main housing block (12, 14).
The self-lubricating pump arrangement of claim 3 wherein the sub-assembly (16, 18) supportable within the two joinable half sections of the main housing block (12, 14) includes at least two sections adapted to be fastenable together to encapsulate the stator (26) and the rotor (24).
The self-lubricating pump arrangement of claim 4 wherein the hollow chamber is defined by spacing between an internal side of the two joinable half sections of the main housing block (12, 14) and an external side of the sub-assembly (16, 18).
The self-lubricating pump arrangement of claim 5 wherein the sub-assembly (16, 18) includes a first half section and a second half section, wherein the first half section (18) and the second half section (16) are adapted to be fastenable together to encapsulate the stator (26) and the rotor (24).
The self-lubricating pump arrangement of claim 6 wherein the first half section (18) includes a top surface (23) configured to allow the impeller member (20) to be restable thereon.
The self-lubricating pump arrangement of claim 7 wherein the top surface (23) of the first half section (18) includes a series of guide baffles (25) that form part of the fluid flow guide arrangement.
The self-lubricating pump arrangement of claim 1 wherein the bearing bush (22) includes an upper flange (75).
The self-lubricating pump arrangement of claim 8 and 9 wherein the top surface (23) of the joinable first half section (18) includes a central circular slot (91) having a depressed collared skirt adapted for the upper flange (75) of the bearing bush (22) to be positionable therein.
The self-lubricating pump arrangement of claim 10 wherein the second half section (16) of the sub-assembly includes a central slot (40) at one end adapted to receive the portion of re-directed exiting fluid flow.
The self-lubricating pump arrangement of claim 11 wherein the central slot (40) includes a filter (42).
The self-lubricating pump arrangement of any one of claims 6 to 12 wherein the first half section (18) and the second half section (16) of sub-assembly are configured to come together in a mating snap fit or frictional engagement in order to encapsulate the stator (26) and the rotor (24).
The self-lubricating pump arrangement of any one of claims 6 to 13 wherein the first half section (18) and the second half section (16) of the sub-assembly that encapsulates the stator (26) and the rotor (24) include external tab extensions adapted to assist mounting the sub-assembly within the main housing block (12, 14).