AU2004100794A4

AU2004100794A4 - Pumps for spa baths and pools

Info

Publication number: AU2004100794A4
Application number: AU2004100794A
Authority: AU
Inventors: Desmond John Berry
Original assignee: EDGETEC SYSTEMS Pty Ltd
Current assignee: EDGETEC SYSTEMS Pty Ltd
Priority date: 2004-09-21
Filing date: 2004-09-21
Publication date: 2004-11-11
Anticipated expiration: 2012-09-21
Also published as: CN100587275C; CN1752463A

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION INNOVATION PATENT Applicant(s): EDGETEC SYSTEMS PTY LTD Invention Title: PUMPS FOR SPA BATHS AND POOLS The following statement is a full description of this invention, including the best method of performing it known to me/us: 2 PUMPS FOR SPA BATHS AND POOLS This invention relates to pumps for spa baths and pools and more particularly relates to pumps that include means to heat the water flowing through the pumps.

Conventional spa baths and spa pools utilise an electrically driven pump to propel a mixture of water and air under pressure through adjustable nozzles into the bath or pool. A problem with assemblies of this kind is that there tends to be a substantial loss of heat which means that it is difficult to maintain the temperature of the water at a desired level.

Pumps for spa baths and pools usually incorporate an electric motor that drives an impeller that is located in a water chamber. It is usual for the water chamber to be fed via a water inlet and for the pressurised water to leave the pump via a water outlet. The water inlet and outlets are often placed close to one another with their axes parallel and this can cause difficulties in fitting the pump in tight configurations.

It is these issues that have brought about the present invention.

According to one aspect of the present invention there is provided a pump for a spa bath or pool comprising an electric motor having an output shaft projecting through an end plate assembly of a water chamber and being coupled to an impeller housed within the chamber, the end plate assembly including a heat sink incorporating an electrically powered heating element, whereby a face of the heat sink is arranged to be in contact with water in the chamber and the heating element is positioned on an opposite face of the heat sink out of contact with the water.

\\melb-file\home$\nicolab\keep\peci\53905 .innovation.doc 20/09/04 3 In accordance with a still further aspect of the present invention there is provided a pump for a spa bath or pool comprising an electric motor having an outlet shaft that projects through an end plate of the motor, the end plate housing a bearing about which the shaft rotates, the output shaft extending through an end face of a water chamber and being coupled to an impeller that is located within the chamber, the end plate of the electric motor being physically coupled to and in positive contact with the end face; the end face having internal water passageways whereby heat from the electric motor is conducted via the end plate into the end face and into the water within the passageways in the end face.

Preferably, the end face is constructed of plastics containing thermal conductive additives. In a preferred embodiment the end plate of the motor is provided with an annular recess around the adjacent bearing housing whereby the end face has an annular projection that locates within the recess so that the heat of the bearing and excess hear of the electric motor winding are transmitted to the annular projection.

Embodiments of the present invention will now be described of way of example only with reference to the accompanying drawings in which: Figure 1 is a side elevational view of a pump for use with spa baths and spa pools, Figure 2 is an end elevational view of the pump, Figure 3 is a cross sectional view of the pump taken along the lines of A-A of Figure 2, Figure 4 is a perspective view of the exterior of an end plate of the motor, Figure 5 is a perspective view of a heat sink that is adapted to fit within the end plate of the motor, Figure 6 is a perspective view of the heat sink \\melb_files\homeS\nicolab\keep\Speci\53905 .innovation.doc 20/09/04 4 viewed from the opposite side of Figure Figure 7 is an end elevation view of a water chamber of a pump in accordance with another embodiment Figure 8 is a cross sectional view taken along the lines B-B of Figure 7, Figure 9 is a perspective view of a heater assembly that forms part of the water chamber, and Figure 10 is a section through the assembly.

As shown in Figures 1 and 2, a pump 10 for a spa bath or pool has an outer cylindrical casing that is essentially split into four components, namely an electric motor casing 11, having mounted at one end a fan casing 12, and at the other end a water chamber casing 13. A capacitor casing 14 is mounted above the motor and houses the electrical componentry and circuitry that drives the motor. The fan casing 12 houses a fan 15 that is driven by a rearwardly extending output shaft 16 that is coupled to the rotor 17 of the motor 20. The rotor 17 also includes a forwardly projecting output shaft 25 and both shafts 16 and 25 are mounted to rotate about bearing assemblies 26 and 27. The bearing assemblies 26 and 27 are respectively mounted in end plates 28 and 29. The water chamber housing 13 includes a main body 30 with a front face 31 and an end face 32 that is sealingly engaged with the end plate 29 of the motor. As shown in Figure 3 the motor 20 has the rotor 17 mounted to be rotatable about a laminated stator 18 which in turn is surrounded by copper windings 19.

As shown in Figures 1 and 2, the front face of the water chamber 13 has an inlet aperture 33 that is surrounded by an externally threaded sleeve 34.

Positioned above and parallel to the inlet aperture 33 is an outlet aperture 35 that is also surrounded by an externally threaded sleeve 36. The top of the main body of the water chamber is provided with a second water \\melbfiles\home$\nicolab\keep\Speci\53905.innovation.doc 20/09/04 5 outlet aperture 37 that is in turn surrounded by an externally threaded sleeve 38. The two outlet apertures and 37 are mounted with their axis perpendicular to one another and the provision of two outlets improves the versatility of the mounting position of the pump and does away with the need to incorporate T-pieces into the plumbing. It is understood that users of the pump may utilise both outlet apertures 35, 37 or may blank off one aperture by screwing on a closed end cap (not shown) onto the threaded flange. The fact that one outlet aperture is in the end wall of the chamber 13 and the other 37 is in the side wall improves the versatility of coupling the pump to associated plumbing and does away with the need for cumbersome T-pieces.

As shown in Figure 3, the forward end of the output shaft 25 is threadedly coupled to the center of a vaned impeller 40. A shaft seal assembly 41 sits between the impeller 40 and the end face 32 of the water chamber and ensures that the impeller 40 is a free running fit on the output shaft 25 within the water chamber. The seal assembly 41 also incorporates a seal 42 that prevents escape of water from the water chamber past the rotating shaft. The interior of the water chamber is an appropriately profiled plenum chamber 45 which directs the incoming water from the inlet aperture 33 to the vaned rotor 40 to be accelerated and expelled out of either or both of the outlet apertures 35 and 37.

The interface between the end plate 29 of the motor casing 11 and the end face 32 of the water chamber 13 is specifically designed so that the end face of the water chamber 32 operates as a heat sink to draw heat from the bearing 27 on the output shaft 25 and draw excess heat from motor windings 19 of the electric motor 20 and transfer that heat to the water that circulates within the water chamber. As shown in detail in Figures 4 to 6, the \\melb-files\home$\nicolab\keep\Speci\53905 .innovation.doc 20/09/04 6 end plate 29 of the motor housing 11 has a central aperture 50 through which the output shaft 25 extends.

The central aperture 50 is positioned centrally of an annular recess 51 which houses the outer race of the bearing 27 so that the periphery of the outer race of the bearing is in direct physical contact with the annular wall of the recess 51. The end plate 29 has a peripheral flange 52 that is adapted to be in parallel abutting contact with the outer wall of the water chamber casing 13 as shown in Figure 3. The end plate has a annular wall 53 that joins the recess 51 to the peripheral flange 52.

The end face 32 of the water casing 13 is shown from both sides in Figures 5 and 6. The outer surface of the end face 32 is shown in Figure 5 and this includes a central housing 55 that supports the shaft seal assembly 41 through which the output shaft 25 of the motor extends.

A broken annular land 56 is adapted to be in parallel abutting contact with the annular wall 53 on the front of the end plate 29 of the motor. As shown in Figure 6, the opposite side of the annular land 56 includes a water passageway 57 that is separated by a plurality of baffles 58. The broken portion 59 of the annular land 56 is positioned at the base of the assembly as shown in Figure 3 and allows escape of any water that might leak from the water housing 13 past the shaft seal 42 of the motor to drain out of the pump 10 through a small aperture in the base of the join between the motor housing 11 and water chamber 13. As shown in Figure 3, the end face 32 of the water chamber is a substantial body that acts as a heat sink conducting heat from the end plate of the electric motor into the end face of the water chamber. A flinger washer 61 is mounted on the shaft 25 between the end face 32 and end plate 29 to direct any water that leaks past the seal 42 radially and passing to the drainage hole As shown in Figure 3, the end face 32 is quite \\melbf iles\homeS \nicolab\keep\Speci\53905.innovation.doc 20/09/04 7 thick and preferably moulded in plastics that is impregnated with a heat conductive additive that substantially increases the thermal conductivity of the unit. The water chambers 57 on the forward side of the end face 32 house circulating water in the water chamber to draw the heat from the heat sink (and face 32) into the water and in this manner a substantial proportion of the heat generated by the electric motor through the bearing 27 on the output shaft 25 and windings 19 is absorbed through the end plate 29 of the motor and the end face 32 of the water chamber that both act as heat sinks.

In this manner, the bearing 27 on the working side of the motor 20 is kept to preferred operating temperatures and the heat that would otherwise be lost is absorbed by the water that is being pumped into the spa or bath. The fan 15 at the front end of the motor serves to cool the remainder of the motor and ensures that the motor can run notwithstanding no flow of water in the chamber 13. No flow condition relates to low motor current which leads to low temperature rise in motor. Operation at full flow equals high motor current and high temperature rise in motor. The interface and interfitting relationship between the end plate 29 of the motor 20 and the end face 32 of the water chamber 13 have been deliberately designed to ensure that both act as heat sinks conducting heat away from the bearing 27 and motor windings 19, cooling the motor.

In the embodiment of Figures 7 to 10, the interior of the end face 32 of the water chamber 13 supports a heater assembly 100 comprising a stainless steel plate 101 with a peripheral lip 102 that seals to the interior of the water chamber 13 via an O-ring (not shown). The radially inner end 103 of the stainless steel plate engages and is in sealed engagement with the shaft seal assembly 41. The outer side of the plate 101 is \\melb_files\home$\nicolab\keep\Speci\53905.innovation. doc 20/09/04 8 bonded to an aluminium annular heat sink 104 that in turn supports an arcuate electric element 105 housed in a sheath 109 of wedge shaped cross section.

The element sheath 109 shown in Figures 9 and does not form a closed annulus and the electric heating element 105 ends in terminals 106 and 107 that are provided at the gap at opposite ends of the sheath 109.

The terminals 106, 107 are adapted to be coupled to a source of mains electricity so that a substantial voltage and current can be transferred to the heating element to generate a considerable heating force which is transmitted into the water chamber 13 via the element sheath 109 and aluminium heat sink 104, and stainless steel plate 101.

The electric element is designed to run at 700watts though it is understood that it could run at 3KW.

The rear of the heating element 105 is spaced from the end face 32 of the water chamber 13 to provide an air gap therebetween to reduce the amount of heat that is conducted towards the electric motor Also shown in Figure 8 is a thermostat 110 that cuts off electric power to the heater 100 at a certain temperature and a pressure sensor 111 that also cuts off power to the heater 100 should water not flow within the water chamber 13.

The passage of water driven by the impeller past the interior surface of the stainless steel plate will rapidly draw heat from the electric element to heat up the water and avoid overheating of the space between the end face 52 of the water chamber 13 and end plate 29 of the motor 20 and thus reduce the likelihood of bearing damage caused by overheating.

In this manner the pump not only has means to \\melbfiles\homeS\nicolab\keep\Speci\53905 innovationdoc 20/09/04 9 pressurise the water through the water chamber by rotating the impeller but includes an electric element that through conduction heats the water within the chamber to compensate for any other heat loss that would occur as the spa is operational. As the water is driven under pressure by the pump through the water chamber it is also heated through the electric element.

Although not shown in the drawings is it understood that the embodiments of Figures 1 to 6 and 7 to could be combined so that the end face 32 of the water chamber 13 and the endplate 29 of the motor 20 could be designed as heat sinks to take heat from the bearing 27 whilst the water chamber could also include an electric heating element associated with the end face 32 but outside the wet portion of the water chamber to heat the heat sink of the end face so that heat can be conducted into the water via the end face.

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Claims

2. The pump according to claim 1 wherein the heat sink comprises a stainless steel plate adapted to be in sealed contact with the wall of the chamber and a block of heat conductive material supporting an electric element being secured to the rear face of the plate.
3. The pump according to claim 2 wherein the end plate assembly includes a thermostat to cutoff electrical power to the heating element when a predetermined temperature is reached.
4. The pump according to any one of the proceeding claims wherein the end plate assembly includes a pressure sensitive switch that turns off power to the heating element when no water is flowing in the water chamber.
5. A pump for a spa bath or pool according to claim 1, substantially as described herein with reference to and as illustrated in Figures i, 2 and 6 to 9 of the accompanying drawings.
6. A pump for a spa bath or pool comprising an electric motor having an outlet shaft that projects through an end plate of the motor, the end plate housing a \\melb-files\home$\nicoab\keep\Speci\53905.innovation.doc 20/09/04 11 bearing about which the shaft rotates, the output shaft extending through an end face of a water chamber and being coupled to an impeller that is located within the chamber, the end plate of the electric motor being physically coupled to and in positive contact with the end face; the end face having internal water passageways whereby heat from the electric motor is conducted via the end plate into the end face and into the water within the passageways in the end face.
7. The pump according to claim 6 wherein the end face is constructed of plastics containing thermal conductive additives.
8. The pump according to either claim 6 or claim 7 wherein the end plate of the motor is provided with an annular recess around the adjacent bearing housing whereby the end face has an annular projection that locates within the recess so that the heat of the bearing is transmitted to the annular projection.
9. The pump according to any one of claims 6 to 8 wherein the end face includes an electric heating element positioned between the end face of the water chamber and the end plate of the motor. A pump for a spa bath or pool according to any one of claims 6 to 9 substantially as described herein with reference to and as illustrated in the accompanying drawings. Dated this 20th day of September 2004 EDGETEC SYSTEMS PTY LTD By their Patent Attorneys GRIFFITH HACK Fellows Institute of Patent and Trade Mark Attorneys of Australia \\melbfiles\ome$\nicolab\keep\Speci\539s 5innovationdoc 20/09/04