GB2506280A

GB2506280A - Pumping apparatus with printed circuit and switching device

Info

Publication number: GB2506280A
Application number: GB1317504.7A
Authority: GB
Inventors: John Peter Rickaby; Alan Rodney Henderson
Original assignee: Salamander Pumped Shower Systems Ltd
Current assignee: Salamander Pumped Shower Systems Ltd
Priority date: 2008-11-17
Filing date: 2008-11-17
Publication date: 2014-03-26
Anticipated expiration: 2028-11-17
Also published as: GB2506280B; GB0820990D0; GB2465392B; GB2465392A; GB201317504D0

Abstract

Pumping apparatus, in particular for a shower pump, a printed circuit board (PCB) 40 is contained within the housing for controlling the motor. The PCB incorporates a switching device 43, 44 which is actuatable by a fluid flow and/or pressure operated device 41, 42 in the outlet 26, 27. Preferably the pump comprises a motor 10 which is mounted via at least a first backplate assembly 13, 14 for delivering rotational energy through a shaft 15, and at least a first pump assembly having a first impeller 16, 17 which is rotatable in a first pumping chamber 20, 21 to deliver fluid under pressure to an outlet 26, 27. The switching device may be a reed switch and the fluid flow and or pressure operated device is a float comprising a magnet. In a preferred arrangement the apparatus comprises two pumps and the PCB is arranged to extend between the two outlets.

Description

Improvements in pumping apparatus This invention relates to pumping apparatus.

The invention provides pumping apparatus comprising an electric motor and a fluid pump in which the motor and pump arc coupled together and mounted in an integral housing assembly, wherein the housing assembly contains a printed circuit board (PCB) with control circuitry for operating the motor, the pump has at least one outlet for delivery of fluid, and the PCB has a switching device connected into its circuitry which is arranged to be adjacent to a fluid flow and/or pressure operated device in said outlet.

By way of example, embodiments of the invention will now be described with reference to the accompanying drawings, in which: Figure 1 is an exploded view of pumping apparatus according to the present invention, and Figure 2 is a cross-sectional view of the pumping apparatus of Figure 1.

The pumping apparatus seen in the drawings comprises an electric motor 10 having a stator 11 and rotor 12. The motor 10 is mounted via its stator 11 to first and second backplate assemblies 13,14. The backplate assemblies 13,14 are bolted together from the two axial ends of the motor 10.

The motor 10 has a shaft 15 which is driven to rotate by the rotor 12. The shaft 15 protrudes beyond each backplate assembly 13,14 and has first and second impellers 16,17 keyed or otherwise coupled onto its respective end sections for rotation therewith.

First and second casings 18,19 are bolted onto the outer faces of respective backplatc assemblies 13,14. The casings 18,19 and their respective backplate assemblies 13,14 together define pumping chambers 20,2 1 in which respective impellers 16,17 rotate. The joints between the casings 18,19 and their respective backplate assemblies 13,14 are provided with suitable seals 22,23 to keep each pumping chamber 20,21 fluid tight. Also, a suitable rotational seal is provided around the motor shaft 15 where it enters through each respective backplate assembly 13,14.

Each easing 18,19 is formed with a fluid inlet 24,25 and a fluid outlet 26,27 for its respective pumping chamber 20,21. The two inlets 24,25 are arranged in line with the rotational axis of the motor 10. The two outlets 26,27 are arranged to lie in parallel, perpendicular to the motor axis.

The outer face of each backplate assembly 13,14 here has a specially moulded formation: these extend into the interior of respective pumping chambers 20,21 and defme in each a volute scroll form 28,29. The volute scroll forms 28,29 define the fluid flow path within their respective pumping chambers 20,21 and thus serve to create the rise in fluid pressure in operation of the respective impellers 16,17, in known manner. It will be noted that in the arrangement here, the respective impellers 16,17, casings 18,19 and volutc scroll forms 28,29 are each essentially minor images of the other.

The various components of the motor and pump arrangement described above are mounted within a housing assembly 30. The housing assembly 30 comprises a number of sections. There is a central section 31, to either side of which are bolted end sections 32,33. The end sections 32,33 comprise feet 34,35 on which the whole apparatus stands. The feet include resilient pads 50,51 of rubber or the like to help dampen vibration and noise, in use. The end sections 32,33 are closed off by respective cover plates 36,37.

Because of the symmetry of the design here, the same cover plate 36,37 can be used at either end of the apparatus. The various sections of the housing assembly 30 are connected together with suitable sealing means in order to protect the motor by preventing ingress of water or dirt etc. Power is supplied to the motor 10 by an electric cable (not shown) which enters into the housing assembly 30 via a grommet 38 in the central section 31. A fan 39 is mounted on the motor shaft 15 to help keep the windings of the motor 10 cool in operation. Finning 52,53 is incorporated into the design of the end sections 32,33 of the housing assembly 30 to assist with heat dissipation from the apparatus in use. The finning 52,53 is situated adjacent vents 54,55, which arc provided to allow circulation of air into and out of the interior of the housing 30 under the action of the motor fan 39.

In order to reduce to a minimum the need for a wiring harness inside the housing assembly 30, a printed circuit board (PCB) 40 is provided.

The PCB 40 contains all the necessary circuitry for controlling operation of the motor 10. The PCB 40 is mounted on top of the motor stator 11 and between the two backplate assemblies 13,14.

The design of the PCB 40 here offers a further advantage. The PCB 40 is arranged to extend between the two casings 18,19, specifically, with its ends lying adjacent to the outlets 26,27 of respective pumping chambers 20,21. In each of these outlets 26,27 a float 41,42 is arranged. The floats 41,42 are each movable between two end positions: a lower end position, to which the float will fall under gravity when there is no flow of fluid through the pumping chamber, and upper end position, to which the float will be caused to move by action of the fluid flow in operation. Each float 41,42 contains a magnet and at each end of the PCB 40 a reed switch 43,44 is mounted. The reed switches 43,44 are thus caused to be activated by the rising and falling of their respective floats 4 1,42, depending on the state of fluid flow through the apparatus. The reed switches 43,44 are connected to the circuitry in the PCB 40 and thus form an integral part of the control system for operation of the apparatus.

The above arrangement uses detection of fluid flow in the outlets 24,25 to control operation of the apparatus. It would be possible instead, or additionally, to usc dctcction of fluid prcssurc in the outlets 24,25.

The pumping apparatus described above could be used in many different applications. In one arrangement, for example, one of the pumping assemblies could be connected to a cold water supply, whilst the other is connected to a hot water supply. This would make the apparatus particularly suitable for use in a shower pump arrangement.

In any given application, it is possible that there may be a demand from time to time for supply of fluid from one of the pumping chambers, but not the other. Because of the nature of the direct coupling of the impellers, both will be operable in their pumping chambers, whether or not fluid is actually being delivered from them. To avoid the possibility that this could cause overheating of the fluid in a pumping chamber that is not delivering fluid, the apparatus may include provision for allowing a release of fluid from the pumping chambers. A suitable such provision could take the form of a small bleed connection between the outlet from each pumping chamber.

It will be understood that instead of having two pumping chambers as described above, the apparatus could readily be modified to comprise just one pumping chamber.

Claims

CLAIMS1. Pumping apparatus comprising an c!cctric motor and a fluid pump in which the motor and pump are coupled together and mounted in an integral housing asscmbly, whcrcin thc housing asscmbly contains a printcd circuit board (PCB) with control circuitry for opcrating thc motor, thc pump has at least one outlet for delivery of fluid, and the PCB has a switching device connected into its circuitry which is arranged to be adjacent to a fluid flow and/or prcssurc opcratcd device in said outlet.
2. Pumping apparatus as claimed in claim 1 wherein the apparatus comprises two pumps which are arranged to be coupled to the motor to either end thereof each pump has a fluid outlet and the PCB is arranged to extend between the outlets with a switching device arrangcd to be adjacent to a respective fluid flow and/or pressure operated device in cach outlet.
3. Pumping apparatus as claimed in claim I or claim 2 wherein the or cach switching device is a reed switch, and thc fluid flow and/or prcssurc operated device is a float comprising a magnet arranged in its respective out'et.
4. Pumping apparatus as claimed in any preceding claim wherein the motor is mounted via a baekplatc assembly and the pump has a pumping chamber in which an impeller is rotatable to deliver fluid under pressure, wherein the backplate assembly is arranged to form -of the boundaries of the pumping chamber.
5. Pumping apparatus as claimed in claim 4 and further comprising a second pump having an impdllcr which is rotatable in a second pumping chamber to deliver fluid under pressure, wherein a second backplate assembly is arranged to form part of the boundaries of the second pumping chamber.
6. Pumping apparatus as claimed in claim 5 wherein the impellers of the first and second pumps are arranged each at either end of a shaft driven by said motor and are mounted directly onto said shaft
7. Pumping apparaws as claimed in claim 5 or claim 6 wherein the motor is mounted by and between said first and second backplatc assemblies.
8. Pumping apparatus as claimed in any one of claims 4 to 7 wherein the or each backplate assembly comprises a volute scroll form that extends into the or each respective pumping chamber.
9. Pumping apparatus as claimed in any one of claims 4 to 8 wherein the or each pumping chamber comprises a fluid inlet which is in line with the axis of rotation of the motor.
10. Pumping apparatus as claimed in any one of claims 4 to 9 wherein thc or each pumping chamber has a fluid outlet which lies perpendicular to the axis of mtation of the motor.
11. Pumping apparatus substantially as hcrcin dcscribcd with reference to the accompanying drawings.