Pump apparatus

Abstract

A pump apparatus includes a pump chamber having a fluid inlet and a fluid outlet and a flexible impeller mounted for rotation within the pump chamber. The flexible impeller includes a plurality of radially extending vanes to contact a curved wall of the pump chamber, such that separate pump cavities are defined between adjacent vanes and the pump chamber wall. The fluid inlet and the fluid outlet are defined in the second end wall so that the curved pump chamber wall is uninterrupted.

Claims

1. A pump apparatus comprising a pump chamber having a fluid inlet and a fluid outlet; and a flexible impeller mounted for rotation within the pump chamber, wherein the pump chamber is defined by a curved wall, the curved wall including a first wall portion having a first radius and a second wall portion having a second radius, wherein the second radius is greater than the first radius; the flexible impeller includes a plurality of radially extending vanes, wherein the plurality of radially extending vanes contact the curved wall of the pump chamber such that separate pump cavities are defined between adjacent vanes and the pump chamber wall; the flexible impeller is driven to rotate by a drive shaft; the drive shaft passes through a first end wall which closes one side of the pump chamber and a distal end of the drive shaft rotates within a bearing defined by a second end wall which closes the opposite side of the pump chamber, wherein the drive shaft is drivable by a motor; and wherein the fluid inlet and the fluid outlet are defined in the second end wall.

2. The pump apparatus according to claim 1, wherein the curved wall of the pump chamber is defined by a sleeve.

3. The pump apparatus according to claim 2, wherein the sleeve defines an outer wall having a circular cross-section and the sleeve is located within a pump body.

4. The pump apparatus according to claim 3, wherein a sealing element is provided between the sleeve and each of the first and second end walls.

5. The pump apparatus according to claim 1, wherein the pump apparatus further includes a connector which connects the pump apparatus to a motor.

6. The pump apparatus according to claim 5, wherein the connector defines the first end wall.

7. The pump apparatus according to claim 1, wherein the proximal end of the drive shaft includes a first part of a two-part coupling.

8. A combination of a pump apparatus according to claim 1 and an electric motor, wherein a rotary drive output from the electric motor is coupled to the drive shaft of the pump apparatus.

9. The combination according to claim 8, wherein one of the drive output from the electric motor and the drive shaft includes a first part of a two-part connector and the other of the drive output from the electric motor and the drive shaft includes a second part of the two-part connector.

10. A combination according to claim 9, wherein the first part of the two-part connector includes a rib and the second part of the two-part connector includes a channel having sloped sides such that the two-part connector is self-aligning.

11. A combination according to claim 10, wherein the first part of the two-part connector includes two or more ribs and the second part of the two-part connector includes a corresponding number of complementary channels.

12. A combination according to claim 11, wherein the pump apparatus is coupled to the electric motor via a connector.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

(2) FIG. 1 is an exploded perspective view of a combination of a pump apparatus according to the first aspect of the invention with an electric motor;

(3) FIG. 2 is a sectional view through the combination shown in FIG. 1 in its assembled configuration;

(4) FIG. 3 is an exploded perspective view of a pump body according to the third aspect of the invention; and

(5) FIG. 4 is an exploded perspective view of a pump receiver according to the third aspect of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(6) For the avoidance of doubt, the skilled person will appreciate that in this specification, the terms “up”, “down”, “front”, “rear”, “upper”, “lower”, “width”, “above”, “below”, etc. refer to the orientation of the components of the invention when installed for normal use as shown in the Figures.

(7) FIG. 1 shows a combination 2 of a pump apparatus 4 and an electric motor 6. The pump apparatus 4 includes a pump body 8 within which is located a sleeve 10 that defines a pump chamber. O-ring seals 12, 14 provide a fluid tight seal between the sleeve 10 and end walls of the pump apparatus 4 (discussed below).

(8) A flexible impeller 16 is located within the sleeve 10. The flexible impeller 16 includes eight flexible vanes 18, the ends of which wipe against the inwardly facing wall of the sleeve 10 in use. Such an arrangement defines eight pump cavities within the pump chamber, wherein each pump cavity is defined by an adjacent pair of the vanes 18 and the inwardly facing wall of the sleeve 10.

(9) The flexible impeller 16 includes an insert element (not shown) at its core which defines a hexagonal shaped central channel. A drive shaft 20, which has a corresponding hexagonal shaped portion is located within the central channel, such that the flexible impeller 16 is rotationally locked to the drive shaft 20.

(10) While the outwardly facing wall of the sleeve 10 has a circular cross-sectional shape, the inwardly facing wall has a first portion 11 which has a first radius and a second portion 13 which has a second, greater radius. This has the effect of providing the inwardly facing wall with a “flattened” portion (i.e. the second portion 13). As the flexible impeller 16 is driven to rotate by the drive shaft 20, the volume of the pump cavities decrease as they pass the “flattened” portion of the sleeve 10 (i.e. the second portion 13 of the inwardly facing wall of the sleeve). This decrease in pump cavity volume forces the fluid from the pump cavities.

(11) The pump chamber defined by the sleeve 10 is closed at one end by an end plate 22. The end plate defines a fluid inlet port 24 which is aligned with the first portion of the sleeve 10 and a fluid outlet port 26 which is aligned with the second portion of the sleeve 10.

(12) The end plate 22 further defines a bearing portion 28, which is shown in more detail in FIG. 2. A distal end 30 of the drive shaft 20 is located within the bearing portion 28 and is rotatably supported by the bearing portion 28.

(13) The opposite end of the pump chamber is closed by a closure portion 34 of a connector element 36. The connector element defines therein a cavity 38 and includes a mating surface 40, opposite to the closure portion 34, which permits the mating of the connector element 36 to the electric motor 6.

(14) The drive shaft 20 extends through a channel 42 defined through the closure portion 34 of the connector element 36 and a proximal end 32 of the drive shaft 20 terminates in the cavity 38 defined by the connector element 36. A dynamic seal 44 and a support bearing 46 are coupled to the proximal portion 32 of the drive shaft 20. The dynamic seal 44 prevents fluid from within the pump chamber leaking through the closure portion 34 and the support bearing 46 supports the proximal end 32 of the drive shaft as it is rotated by the electric motor 6.

(15) A first part 48 of a two-part connector is secured to the proximal end 32 of the drive shaft 20. The first part 48 of the two-part connector is engaged by a second part 50 of the two-part connector which is carried by an output shaft 52 of the electric motor 6.

(16) FIG. 3 shows a flexible impeller pump 104 which is similar to that described above in connection with FIGS. 1 and 2.

(17) The pump 104 includes a pump body 108 within which is located a sleeve 110. The sleeve 110 has the same physical features as the sleeve 10 described above, but is formed from PTFE, which is a softer material, and as such, the pump 104 does not require O-ring seals to prevent fluid from within the pump chamber defined by the sleeve 110 leaking between the sleeve 110 and end plates 122, 134. A fluid-tight seal is formed between the sleeve 110 and the end plates 122, 134.

(18) A flexible impeller 116, which is identical to the flexible impeller 16 described above, is located within the sleeve 110 and the flexible impeller is driven to rotate by a drive shaft 120 which is similar to the drive shaft 20 described above.

(19) One end of the pump chamber defined by the sleeve 110 is closed by the end plate 122. Again, the end plate 122 is identical to the end plate 22 described above and it includes a fluid inlet port 124, a fluid outlet port 126 and a bearing portion (not shown in FIG. 3) which is shaped and configured to rotationally support a distal end 130 of the drive shaft 120.

(20) A proximal end 132 of the drive shaft 120 also includes a dynamic seal 144 and a support bearing 146.

(21) The pump 104 differs from that shown in FIGS. 1 and 2 in that the pump body 108 includes an alignment tab 160 and that the opposite end of the pump chamber is closed by the second end plate 134.

(22) The drive shaft 120 passes through a channel 142 defined by the second end plate 134. In this embodiment, the support bearing 146 is located within the channel 142.

(23) The proximal end 132 of the drive shaft 120 carries a first part 148 of a two part connector, which is discussed in more detail below.

(24) On the opposite side of the second end plate (i.e. facing away from the pump chamber) is carried a first array of four permanent neodymium magnets 162.

(25) FIG. 4 shows a pump receiver 202 for magnetically receiving the pump 104 shown in FIG. 3.

(26) The pump receiver 202 comprises a mounting plate 204 to which is fixed a bearing plate 206 and a pump receiving element 208.

(27) The bearing plate 206 defines therethrough a channel within which is located a pair of support bearings 210a, 210b which rotationally support an auxiliary drive shaft 212. The auxiliary drive shaft passes through the channel defined by the bearing plate 206 and carries at its first end a second part 214 of the two-part connector which is spaced from the bearing plate by a cylindrical spacer 216.

(28) The first part 148 of the two-part connector includes three radial ribs 149 arranged about a central axis. The ribs include sloped sides. The second part 214 of the two-part connector defines three channels 215 which correspond to the ribs 149 of the first part 148 and which also include sloped sides. The arrangement of the first and second parts 148, 214 of the two-part connector results in a self-aligning connector, as the ribs 149 will align themselves with the corresponding channels 215 as the first part 148 is moved towards the second part 214. The drive shaft 120 will be urged to rotate by the engagement of the sloped sides of the ribs 149 with the sloped sides of the channels 215 until the ribs 149 are aligned perfectly with the corresponding channels 215.

(29) At its second end, the auxiliary drive shaft 212 carries a drive input connector 218 which may be connected to an output shaft of an electric motor (not shown).

(30) Located between the bearing plate 206 and the pump receiving element 208 is a rotatable collar 220 which is rotatably coupled to the pump receiving element 208 such that it can rotate through an arc defined between stops (not shown). A first stop defines a first angular orientation of the rotatable collar 220 and a second stop defined a second angular orientation of the rotatable collar. The rotatable collar 220 further includes a manually operable tab 221.

(31) Sandwiched between the rotatable collar 220 and a securing ring 222 is a second array of four permanent neodymium magnets 224.

(32) The pump receiving element 208 includes a cylindrical body portion 226 which is open at one end to define an aperture which is configured to receive therein the pump body 108. The cylindrical body portion 226 defines therein a locating slot 228 which is sized and configured to receive therein the alignment tab 160 of the pump body 108. This ensures that the pump body 108 has a predetermined orientation relative to the pump receiving element 208 when the pump body is located within the cylindrical body portion 226.

(33) In use, the rotatable collar 220 is arranged in its first orientation and the pump body 108 is located within the cylindrical body portion 226 with the alignment tab 160 located within the locating slot 228. With the rotatable collar 220 in its first orientation and the pump body correctly aligned within the pump receiving element 208, the first array of magnets 162 aligns with the second array of magnets 224 and a magnetic attraction force is generated between each of the magnets 162 and 224. In this arrangement, the removal of the pump 104 from the receiver 202 is resisted.

(34) As the pump 104 is drawn into the receiver 202 by the magnetic attraction, the first part 148 of the two-part connector aligns automatically with the second part 214 of the two-part connector as discussed above. Thus, the drive shaft 120 is operatively coupled to the auxiliary drive shaft 212 and the drive shaft 120 may be driven by an electric motor when the auxiliary drive shaft 212 is coupled to an electric motor.

(35) In order to detach the pump 104 from the receiver 202, the collar 220 is rotated to its second orientation via the tab 221. In this orientation, a first pair of the first magnets 162 are moved from alignment with a first pair of the second magnets 224 to alignment with a second pair of the second magnets 224. This results in the second pair of first magnets 162 and the first pair of the second magnets 224 no longer being in alignment with corresponding magnets. Furthermore, as the poles of the first pair of first magnets 162 and the second pair of second magnets are the same, a magnetic repulsive force urges the pump 104 away from the receiver 202.