A peristaltic pump and method

Abstract

According to the present disclosure there is provided a peristaltic pump (2) comprising: a housing (4) defining a pressing surface (10) and comprising suction and pressure ports (8a, 8b); a rotor assembly (12) rotatably mounted within the housing (4) and comprising a plurality of pressing members (18); and a compressible pump element 64 disposed between the rotor assembly (12) and the pressing surface (10); wherein the pump element (64) is provided with a pair of internal collars (72) which are retained by a flange (74) at either end of the pump element (64); wherein each internal collar (72) is detachably connected to an internal portion of one of the suction and discharge ports (8a, 8b). A method of installing or removing a pump element in a peristaltic pump is also provided.

Description

[0001] A PERISTALTIC PUMP AND METHOD

[0002] Field of Invention

[0003] The present disclosure relates to a peristaltic pump and method.

[0004] Background

[0005] In a peristaltic pump, the pumped product is completely contained within a tube or hose such that no moving parts come into contact with the product. Peristaltic pumps are therefore well suited to tough fluid handling applications such as the pumping of chemicals, slurries or sludge.

[0006] In a peristaltic pump, a compressible pump element (i.e. , a hose or tube) is squeezed between a pressing member (such as a roller or shoe) and a pressing surface (track) on an arc of a circle, creating a seal at the point of contact. As the pressing member advances along the pump element, the seal also advances. After the pressing member has passed, the pump element returns to its original shape, creating a partial vacuum which is filled by fluid drawn from a suction port.

[0007] Before the pressing member reaches the end of the pressing surface, a second pressing member compresses the pump element at the start of the pressing surface, isolating a packet of fluid between the compression points. As the first pressing member leaves the pressing surface, the second pressing member continues to advance, expelling the packet of fluid through a discharge port. At the same time, a new partial vacuum is created behind the second pressing member into which more fluid is drawn from the suction port.

[0008] In conventional pumps, it is common for the pump element to project from the pump housing through the suction and discharge ports where it is then retained by suitable end fittings which connect to the pump housing. The end fittings can then be used to connect the pump element to external suction and discharge lines. The end fittings are therefore responsible for sealing the pump element with the suction and discharge lines to avoid leakage of pumped fluid. The end fittings also seal the pump housing to prevent leakage of lubricating fluid held within the housing. As well as their sealingfunctions, the end fittings also fasten the pump element in position and thus provide strain relief against the movement of the rotor.

[0009] The pump element is a consumable part which needs to be replaced periodically. With conventional end fittings, the suction and discharge lines are first removed and then the drive unit of the pump is used to rotate the rotor in order to drive out the existing pump element and to pull in the new pump element.

[0010] It is desirable to provide a peristaltic pump which addresses some of the shortcomings of existing designs.

[0011] Summary

[0012] According to a first aspect, there is provided a peristaltic pump comprising:

[0013] a housing defining a pressing surface and comprising suction and pressure ports; a rotor assembly rotatably mounted within the housing and comprising a plurality of pressing members; and

[0014] a compressible pump element disposed between the rotor assembly and the pressing surface;

[0015] wherein the pump element is provided with a pair of internal collars which are retained by a flange at either end of the pump element;

[0016] wherein each internal collar is detachably connected to an internal portion of one of the suction and discharge ports.

[0017] Each of the suction and discharge ports may comprise an external portion for forming an external connection to suction and pressure lines.

[0018] The external connection to the suction and pressure lines may be independent of the connection of the internal collars to the internal portion of the suction and discharge ports, such that the pump element can be disconnected from the suction and discharge ports separately from the suction and pressure lines.

[0019] The peristaltic pump may further comprise an external collar which is received in the external portion of each of the suction and pressure ports.

[0020] Each external collar may be threaded.Each internal collar may be threaded.

[0021] Each internal collar may be threadedly engaged with the corresponding external collar to detachably connect the internal collars to the internal portions of the suction and discharge ports.

[0022] Each external collar may be rotatably mounted within the corresponding external portion such that it can be rotated to unscrew the internal collar.

[0023] Each external collar may be rotatably mounted within the corresponding external portion by a retaining plate which receives the external collar and is connected to the housing.

[0024] Each internal collar may comprise a non-circular portion which is received by a complementary non-circular portion of the internal portion of the suction and pressure ports to prevent the internal collar from rotating with the external collar.

[0025] Each external collar may receive an end fitting which is fluidical ly connected to the pump element.

[0026] The end fitting may have a flange which abuts against the corresponding flange of the pump element.

[0027] The pressing surface may follow a helical path which encircles the rotor assembly such that a front portion of the pressing surface adjacent the suction port overlaps a rear portion of the pressing surface adjacent the discharge port.

[0028] The front portion of the pressing surface may be formed as a removable component which is detachably connected to the housing.

[0029] The rotor assembly may have an engaged configuration in which the pressing members compress the pump element and a disengaged configuration in which the pressing members do not compress the pump element.The rotor assembly may comprise a base component and the pressing members may be detachably connected to the base component to allow the rotor assembly to transition between the engaged and disengaged configurations.

[0030] The rotor assembly may comprise a base component and the pressing members may be hingedly connected to the base component such that they are movable between an extended position and a retracted position so as to allow the rotor assembly to transition between the engaged and disengaged configurations.

[0031] The rotor assembly may comprise an actuator component which is rotatable relative to the base component between a first position and a second position. The actuator component may engage the pressing members such that, in the first position, the pressing members are in the extended position and, in the second position, the pressing members are in the retracted position.

[0032] The actuator component may comprise a plurality of lobe sections which engage the pressing members.

[0033] The lobe sections may engage a track formed in the pressing members which tapers from a first end to a second end.

[0034] A front surface of the actuator component may comprise a drive element for rotating the actuator component between the first and second positions.

[0035] The rotor assembly may further comprise a cover plate. One of the cover plate and the actuator component may comprise an arcuate slot and the other of the cover plate and the actuator component may comprise a pin which is received in the slot; wherein the pin is translatable along a length of the slot to allow the actuator component to rotate relative to the cover plate.

[0036] The pin may be at a first end of the slot when the rotor assembly is in the disengaged configuration and at a second end of the slot when the rotor assembly is in the engaged configuration.

[0037] The pump element may be a tube or hose.According to a second aspect, there is provided a method of installing or removing a pump element in a peristaltic pump, wherein the pump element is provided with a pair of internal collars which are retained by a flange at either end of the pump element, the method comprising:

[0038] connecting or disconnecting the internal collars to internal portions of suction and discharge ports of a housing of the pump; and

[0039] inserting the pump element or removing the pump element from between a rotor assembly and a pressing surface of the housing.

[0040] The method may further comprise, prior to inserting or removing the pump element, removing or retracting one or more pressing members of the rotor assembly.

[0041] The method may further comprise, prior to inserting or removing the pump element, removing a removable component from the housing which defines a front portion of the pressing surface.

[0042] The internal collars may be connected or disconnected to the internal portions of the suction and discharge ports by rotating an external collar.

[0043] The step of connecting or disconnecting the internal collars to the internal portions of the suction and discharge ports may be performed with external suction and discharge lines connected to the pump.

[0044] The peristaltic pump may include any of the features described above in relation to the first aspect.

[0045] The skilled person will appreciate that except where mutually exclusive, a feature described in relation to any one of the above aspects may be applied mutatis mutandis to any other aspect. Furthermore, except where mutually exclusive, any feature described herein may be applied to any aspect and / or combined with any other feature described herein.

[0046] Brief Description of the Drawings

[0047] Embodiments will now be described by way of example only, with reference to the Figures, in which:Figure 1 is front view of a peristaltic pump according to an embodiment of the invention;

[0048] Figure 2 is an exploded view of a rotor assembly of the peristaltic pump;

[0049] Figures 3 and 4 are perspective views of the rotor assembly in a disengaged configuration;

[0050] Figures 5 and 6 are front views of the rotor assembly in the disengaged configuration;

[0051] Figures 7 and 8 are perspective views of the rotor assembly in an engaged configuration;

[0052] Figures 9 and 10 are front views of the rotor assembly in the engaged configuration;

[0053] Figure 11 is a bottom view of the peristaltic pump;

[0054] Figure 12 is an exploded view of an external connection assembly;

[0055] Figures 13 to 15 show the external connection assembly during installation;

[0056] Figure 16 is a cross-sectional view of the external connection assembly after installation;

[0057] Figure 17 is a perspective view of the peristaltic pump with a pressing surface component removed;

[0058] Figure 18 shows a hose for the peristaltic pump;

[0059] Figure 19 is a cross-sectional view of the hose;

[0060] Figure 20 shows the hose before installation into the peristaltic pump;

[0061] Figure 21 is a close-up of a collar of the hose being inserted into the port;Figure 22 shows the peristaltic pump with the hose installed;

[0062] Figures 23 and 24 are cross-sectional views showing the hose during and after insertion of the collar into the port;

[0063] Figure 25 shows the peristaltic pump with the pressing surface component reinstalled;

[0064] Figure 26 is a front view of the peristaltic pump with the rotor assembly in the engaged configuration;

[0065] Figure 27 is a perspective view of a rotor assembly according to another embodiment;

[0066] Figure 28 is an exploded view of the rotor assembly of Figure 27;

[0067] Figures 29 and 30 show a hose being installed in a peristaltic pump having the rotor assembly of Figure 27.

[0068] Detailed Description

[0069] Figure 1 shows a peristaltic pump 2 according to an embodiment of the invention. The peristaltic pump 2 comprises a housing 4. The housing 4 defines a pump chamber 6 and suction and discharge ports 8a, 8b which open into the chamber 6. The pump chamber 6 is delimited by an inner surface of the housing 4 which at least partially forms a pressing surface 10. The pump chamber 6 and thus the pressing surface 10 are substantially circular in cross-section.

[0070] Although not shown, the housing 4 is provided with a cover which closes and seals the pump chamber 6.

[0071] A rotor assembly 12 is disposed within the housing 4. The rotor assembly 12 is connected to a drive unit (not shown) and is rotatably mounted within the pump chamber 6 so as to allow the rotor assembly 12 to rotate relative to the pressing surface 10.As shown in Figure 2, the rotor assembly 12 generally comprises a base component 14, an actuator component 16, a plurality (three, in this example) of pressing members 18 (i.e. , shoes), and a cover plate 20.

[0072] The base component 14 comprises a hub portion 22, a plate portion 24 and a plurality (three, in this example) of spacer portions 26.

[0073] The hub portion 22 has a generally cylindrical outer wall which extends from a first end to a closed second end. The hub portion 22 therefore forms a cavity which is open at a rear surface. The hub portion 22 is rotatably mounted to a corresponding hub portion provided on the housing 4. Specifically, the hub portion of the housing 4 is received in the cavity formed by the hub portion 22. Suitable bearings may be provided between the hub portions 22 to allow smooth rotation.

[0074] The plate portion 24 is provided at the first end of the cylindrical wall of the hub portion 22. The plate portion 24 is circular and so forms a rim which extends circumferentially around the hub portion 22. The spacer portions 26 project in an axial direction from the plate portion 24. The spacer portions 26 are spaced equally around the circumference of the plate portion 24 and are located at a perimeter of the plate portion 24.

[0075] The cover plate 20 is attached to the base component 14 via the spacer portions 26. The cover plate 20 is circular and has a diameter which substantially corresponds to that of the plate portion 24 of the base component 14. The cover plate 20 is arranged such that it is parallel to the plate portion 24 but spaced therefrom by the spacer portions 26.

[0076] Each of the pressing members 18 is supported by a post 28. The post 28 extends in an axial direction between the plate portion 24 and the cover plate 20. The pressing members 18 are pivotably (hingedly) connected to the base component 14 and the cover plate 20 by the posts 28.

[0077] The actuator component 16 is rotatably mounted to the base component 14.

[0078] Specifically, the actuator component 16 comprises a cylindrical body portion 32. A cavity is formed in a rear surface of the cylindrical body portion 32 which receives the hub portion 22 of the base component 14. The actuator component 16 comprises a drive element 30. The drive element 30 is located on a front surface of the actuatorcomponent 16 and is centred on the axis of rotation. In this example, the drive element 30 is a hexagonal head which can be engaged by a suitable wrench to rotate the actuator component 16 relative to the base component 14. However, it will be appreciated that other forms of drive element may be used which can be engaged by a suitable tool or by hand to cause rotation.

[0079] A plurality of lobe sections 34 project radially outward from the cylindrical body portion 32 of the actuator component 16. The lobe sections 34 are spaced equally around the circumference of the cylindrical body portion 32. The number of lobe sections 34 corresponds to the number of pressing members 18 (i.e. , three, in this example). Each of the lobe sections 34 comprises a front lobe portion 36a and a rear lobe portion 36b which are spaced from one another in an axial direction. The pressing members 18 each comprise a front track 38a and a rear track 38b which are separated from one another by a ridge 40. The front and rear tracks 38a, 38b are provided on a radially inner surface of the pressing member 18 and, in this example, are formed as grooves which extend along a length of the pressing member 18 from a first (proximal) end adjacent the post 28 to a second (distal) end spaced from the post 28. A depth of the front and rear tracks 38a, 38b tapers (i.e., reduces) from the first end to the second end.

[0080] Each of the lobe sections 34 engage one of the pressing members 18. In particular, the front lobe portion 36a is received by the front track 38a of the pressing member 18 and the rear lobe portion 36b is received by the rear track 38b with the ridge 40 disposed between the front and rear lobe portions 36a, 36b. In other examples, the pressing member 18 may have a single track which receives a single lobe portion. For example, the pressing member 18 may have a groove which runs along its length.

[0081] The front lobe portions 36a each comprise a pin 42 which projects in an axial direction. The cover plate 20 comprises a plurality of arcuate slots 44 (three, in this example) which each receive one of the pins 42.

[0082] Each pin 42 is arranged so as to move along the length of the respective slots 44 from a first end 46 to a second end 48. The movement of the pins 42 along the slots 44 therefore limit the rotation of the actuator component 16 relative to the cover plate 20 and base component 14.The cover plate 20 further comprises a central circular opening 50 which receives a circular boss 52 formed on the front of the actuator component 16. The engagement of the boss 52 in the opening positions the actuator component 16, whilst allowing rotation of the actuator component 16 relative to the cover plate 20.

[0083] The rotor assembly 12 has a disengaged (maintenance) configuration and an engaged (pumping) configuration. Specifically, in the disengaged configuration, the actuator component 16 is arranged such that the pins 42 are located at the first ends 46 of the slots 44, whereas in the engaged configuration, the actuator component 16 is arranged such that the pins 42 are located at the second ends 48 of the slots 44.

[0084] As shown in Figures 3 to 6, in the disengaged configuration, the lobe sections 34 engage the respective tracks 38a, 38b towards their first end. In this position, the depth of the tracks 38a, 38b is increased such that the pressing members 18 are able to move into a retracted position. In this position, an outer surface of the pressing members 18 is located at a reduced radius. For example, the outer surface of the pressing members 18 may be positioned at a radius which is substantially the same as the radius of the base component 14 and the cover plate 20 such that the pressing members 18 do not significantly project beyond the perimeter of the base component 14 and the cover plate 20 and are therefore concealed within the rotor assembly 12.

[0085] As shown in Figures 7 and 10, in the engaged configuration, the lobe sections 34 engage the respective tracks 38a, 38b towards their second end 48. In this position, the depth of the tracks 38a, 38b is decreased causing the pressing members 18 to pivot radially outwards about the posts 28 to an extended position. In this position, the pressing members 18 project beyond the perimeter of the base component 14 and the cover plate 20 (between adjacent spacer portions 26).

[0086] As can be seen in Figure 9, in the engaged configuration, the pressing members 18 may engaged the spacer portions 26 to prevent further outward movement of the pressing members 18. In this example, each pressing member 18 engages the adjacent pair of spacer portions 26 at both the first and second ends of the pressing member 18.

[0087] As shown in Figure 11, the suction and discharge ports 8a, 8b are provided on opposite sides of the housing 4 and are offset from one another in an axial direction.Each of the suction and discharge ports 8a, 8b is provided with an external connection assembly, as shown in Figure 12. The external connection assembly comprises an end (hose or pipe) fitting 50, an external collar 52 and a retaining plate 54.

[0088] The end fitting 50 comprises a cylindrical portion 55 which is provided with a flange 56 at one end. The cylindrical portion 55 of the end fitting 50 passes through the external collar 52 and is retained by the flange 56 which abuts against an internal shoulder 57 formed at the base of a receiving portion 63 (see Figure 16) of the collar 52. An inner surface of the receiving portion 63 comprises an internal thread, as will be described further below.

[0089] The end fitting 50 and external collar 52 are provided with hexagonal formations 59, 61 which can be gripped with suitable wrenches to rotate the external collar 52 relative to the end fitting 50, as will be described further below. It will be appreciated that other drive formations may be used which allow the end fitting 50 and external collar 52 to be grasped (either using a tool or by hand) and rotated relative to one another.

[0090] The external collar 52 is sized to be received within the port 8a, 8b. As shown in Figure 16, the external collar 52 is inserted in the port 8a, 8b until it is adjacent to an external surface of a lip 58 formed in the port 8a, 8b. The retaining plate 54 comprises an opening 60 which is sized such that the retaining plate 54 can be received over the external collar 52 (and the cylindrical portion 55 of the end fitting 50 which projects from the external collar 52) and abut against an external shoulder 62 of the external collar 52. The retaining plate 54 can then be bolted to the housing 4 to prevent the external collar 52 from being withdrawn from the port 8a, 8b. The external collar 52 is sized such that it does not necessarily abut against the external surface of the lip 58 and is therefore still able to rotate relative to the retaining plate 54, as will be described further below.

[0091] The end fittings 50 can be used to attach the pump to suction and discharge lines. The end fittings 50 may have any suitable structure to allow this. For example, the end fittings 50 may have barbs which are received within a tube or hose or may be joined to a rigid line using a bolted flange connection or the like.As described previously, the suction and discharge ports 8a, 8b are provided on opposite sides of the housing 4 and are offset from one another in an axial direction. Accordingly, the pump 2 utilises a pump element in the form of a hose 64 (or tube) which coils fully (360 degrees) around the rotor assembly 12 and thus follows a helical path which encircles the rotor assembly 12. Similarly, the pressing surface 10 follows a helical path which encircles the rotor assembly 12. Consequently, a front portion of the pressing surface 10 adjacent the suction port 8a (based on the helical path) overlaps a rear portion of the pressing surface 10 adjacent the discharge port 8b. As shown in Figure 17, the front portion of the pressing surface 10 is formed as a removable component 66. The outer surface of the removable component 66 is provided with a plurality of keys 68 which engage in corresponding keyways 70 formed in the inner surface of the housing 4. The keys 68 and keyways 70 run in an axial direction such that the removable component 66 can be slid into the housing 4 from the front in an axial direction. Once inserted, the pressing surface of the removable component 66 forms a continuation of the pressing surface 10 formed by the housing 4.

[0092] As shown in Figure 17, the removable component 66 can be removed to allow the hose 64 to be more easily inserted and removed from the housing 4.

[0093] As shown in Figures 18 and 19, each end of the hose 64 is provided with an internal collar 72 which abuts against a flange 74 formed at the end of the hose 64. The internal collar 72 comprises a cylindrical portion 76 and a flange 78. The internal collar 72 is arranged such that the flange 78 of the internal collar 72 is spaced from the flange 74 of the respective end of the hose 64 by the cylindrical portion 76. An outer surface of the cylindrical portion 76 is provided with a seal 80 in the form of an O-ring. The outer surface of the cylindrical portion 76 comprises an external thread.

[0094] As shown in Figure 20, the hose 64 is inserted into the pump 2 with the removable component 66 removed from the housing 4 and the rotor assembly 12 in the disengaged configuration. The pressing members 18 are therefore retracted providing spaced between the rotor assembly 12 and the pressing surface 10 to receive the hose 64.

[0095] With the hose 64 coiled around the rotor assembly 12, the ends of the hose 64 can then be coupled to the housing 4 by inserting the internal collars 72 into the suction and discharge ports 8a, 8b.As shown in Figures 23 and 24, the end of the hose 64 and the cylindrical portion 76 of the internal collar 72 is received within the receiving portion 63 of the external collar 52. As described previously, the outer surface of the cylindrical portion 76 of the internal collar 72 comprises an external thread and the inner surface of the receiving portion 63 of the external collar 52 comprises an internal thread. The cylindrical portion 76 of the internal collar 72 can therefore be drawn into the receiving portion 63 of the external collar 52 by rotating the external collar 52 using the hexagonal formation 61. The end fitting 50 can be prevented from rotating with the external collar 52 by grasping the hexagonal formation 59 of the end fitting 50 with a suitable wrench. Accordingly, the process lines connected to the end fittings 50 do not rotate with the external collar 52.

[0096] The rotation of the external collar 52 draws the cylindrical portion 76 of the internal collar 72 into the receiving portion 63 of the external collar 52 until the flange 78 of the internal collar 72 abuts against an internal surface of the lip 58. In this position, the seal 80 provided on the outer surface of the cylindrical portion 76 seals against the lip 58 and the flange 74 of the hose 64 abuts against the flange 56 of the end fitting 50 such that the hose 64 is in fluid communication with the end fitting 50. The hose 64 and end fitting 50 have the same bore diameter and so a continuous fluid pathway is formed which does not have any steps.

[0097] As shown in Figure 21, the flange 78 of the internal collar 72 is non-circular. In this example, the flange 78 comprises a pair of flat sides 79, although other geometries may be used. The port 8a, 8b comprises a seat 81 having a corresponding noncircular geometry such that the flange 78 is unable to rotate within the port 8a, 8b once the flange 78 has been received within the seat 81. Accordingly, this arrangement causes the internal collar 72 to translate when the external collar 52 is rotated, rather than rotating with the external collar 52. As such, the rotation of the external collar 52 may be used only when the non-circular geometry is engaged, with the internal collar 72 being rotated directly (e.g., by hand) over the rest of the movement.

[0098] As shown in Figure 25, with the internal collars 72 connected to the external collars 52, the removable component 66 can be replaced to complete the pressing surface 10. The rotor assembly 12 can then be transitioned from the disengaged configuration to the engaged configuration by rotating the actuator component 16 using the drive element 30 in an anticlockwise direction. This causes the pressing members 18 toproject from the perimeter of the base component 14 and the cover plate 20 and thus compress the hose 64 against the pressing surface 10.

[0099] The cover can then be placed on the housing 4 in order to close and seal the pump chamber 6. The housing 4 or cover may be provided with a fill port to allow the pump chamber 6 to be filled with a lubricant.

[0100] The pump 2 can then be operated in a conventional manner. In particular, the rotor assembly 12 is rotated by the drive unit so as to pump a pumped product (fluid) from the suction port 8a to the discharge port 8b via the hose 64.

[0101] In addition to allowing the hose 64 to be changed, the disengaged configuration of the rotor assembly 12 may be used to allow the hose 64 to be flushed / cleaned (i.e., as part of a Cl P procedure).

[0102] It will be appreciated that the operations described above in relation to the installation of the hose 64 can be reversed in order to remove the hose 64 for replacement with a new hose.

[0103] It will be appreciated that in other examples, the range of rotation of the actuator component 16 may be restricted in other ways. In particular, the range of rotation may be restricted using only a single slot and pin or via suitable formations on the opening 50 and boss 52.

[0104] A biasing element may be provided which biases the pressing members 18 towards the retracted position. For example, a torsion spring may be provided at the pivot to bias each pressing member 18 to the retracted position. Other suitable biasing elements and arrangements may be used.

[0105] In other examples, the outer surface of the external collar 52 may comprise an external thread and the port 8a, 8b may comprise an internal thread such that the external collar 52 is screwed into the port 8a, 8b. Alternatively, the external collar 52 may be retained in the port 8a, 8b in other manners. In other examples, the internal and external collars may be screwed into a threaded port instead of into one another.Figure 27 shows a rotor assembly 112 according to another embodiment of the invention.

[0106] The rotor assembly 112 differs from the rotor assembly 12 described previously in that the pressing members 118 are removable, rather than retractable. In particular, the rotor assembly 112 comprises a base component 114 and a plurality of pressing members 118 which are removably attached to the base component 114.

[0107] As shown in Figure 28, the base component 114 comprises a central portion 182 and an outer rim 184 which extends around the perimeter of the central portion 182. An outer surface of the rim 184 defines a plurality of mounting portions 186. The mounting portions comprise locating features which, in this example, are in the form of a pair of slots 188 which extend axially (partway) into the rim 184 and a retaining tab 190 which extends along the rim 184 between the slots 188.

[0108] Each of the pressing members 118 is provided with complementary locating features which engage with the locating features of the base component 114. Specifically, an inner surface of the pressing member 118 which faces the mounting portion 186 is provided with a pair of ridges 192 which extend axially into the pressing member 118 and a groove 194 which extends along the pressing member 118 between the ridges 192.

[0109] Each pressing member 118 is affixed to the base component 114 by passing a bolt through a bore 194 which extends through the outer rim 184 of the base component 114 and into a corresponding threaded hole 196 provided in the pressing member 118. The bore 194 is accessible from the front of the rotor assembly 112 such that the pressing members 118 can be connected and disconnected without removing the rotor assembly 112 from the pump. The ridges 192 engage in the slots 188 and the tab 190 engages in the groove 194 in order to locate the pressing member 118 and prevent movement of the pressing member 118 relative to the base component 114 during use.

[0110] The rotor assembly 112 is therefore able to transition between an engaged configuration and a disengaged configuration by attaching and detaching the pressing members 118 from the base component 114.As shown in Figure 29, the hose 64 is inserted into the pump 2 with the removable component 66 removed from the housing 4 and with the pressing members 118 removed from the base component 114 to provide space between the rotor assembly 112 and the pressing surface 10 to receive the hose 64.

[0111] As shown in Figure 30, once the hose 64 has been installed, the removable component 66 can be replaced to complete the pressing surface 10 and the rotor assembly 112 can then be transitioned from the disengaged configuration to the engaged configuration by reattaching the pressing members 118 to the base component 114.

[0112] Although the rotor assemblies 12, 112 have been described as being convertible between engaged and disengaged configurations to allow the hose to be removed and inserted more easily, it will be appreciated that the hose connection arrangement may be used with a rotor assembly which does not have such functionality. With such an arrangement, the rotor assembly as a whole may be removed from the pump to allow the hose to be removed and replaced or the hose may be removed and replaced with the rotor assembly in situ. Further, in other examples, only some (i.e. , one or more) of the pressing members may be retracted or removed to allow the hose to be removed and inserted.

[0113] In other examples, there may be only two or more than three pressing members.

[0114] Although the pressing members have been described as shoes, in other examples they may take other forms. For example, the pressing members may be rollers.

[0115] The arrangement of the present invention allows the hose 64 to be removed and replaced without needing to disconnect the suction and discharges lines from the pump. Further, the hose 64 can be replaced without any power to the drive unit. The hose 64 can therefore be replaced under a lockout-tagout (LOTO) procedure, thereby improving safety.

[0116] It will be understood that the invention is not limited to the embodiments described and various modifications and improvements can be made without departing from the concepts described herein. Except where mutually exclusive, any of the features may be employed separately or in combination with any other features and the disclosure extends to and includes all combinations and sub-combinations of one or more features described herein.

Claims

CLAIMS1. A peristaltic pump comprising:a housing defining a pressing surface and comprising suction and pressure ports; a rotor assembly rotatably mounted within the housing and comprising a plurality of pressing members; anda compressible pump element disposed between the rotor assembly and the pressing surface;wherein the pump element is provided with a pair of internal collars which are retained by a flange at either end of the pump element;wherein each internal collar is detachably connected to an internal portion of one of the suction and discharge ports.

2. A peristaltic pump as claimed in claim 1, wherein each of the suction and discharge ports comprise an external portion for forming an external connection to suction and pressure lines.

3. A peristaltic pump as claimed in claim 2, wherein the external connection to the suction and pressure lines is independent of the connection of the internal collars to the internal portion of the suction and discharge ports, such that the pump element can be disconnected from the suction and discharge ports separately from the suction and pressure lines.

4. A peristaltic pump as claimed in claim 2 or 3, further comprising an external collar which is received in the external portion of each of the suction and pressure ports.

5. A peristaltic pump as claimed in claim 4, wherein each external collar is threaded.

6. A peristaltic pump as claimed in claim 5, wherein each internal collar is threaded.

7. A peristaltic pump as claimed in claim 6, wherein each internal collar is threadedly engaged with the corresponding external collar to detachably connect the internal collars to the internal portions of the suction and discharge ports.

8. A peristaltic pump as claimed in claim 7, wherein each external collar is rotatably mounted within the corresponding external portion such that it can be rotated to unscrew the internal collar.

9. A peristaltic pump as claimed in claim 8, wherein each external collar is rotatably mounted within the corresponding external portion by a retaining plate which receives the external collar and is connected to the housing.

10. A peristaltic pump as claimed in claim 8 or 9, wherein each internal collar comprises a non-circular portion which is received by a complementary non-circular portion of the internal portion of the suction and pressure ports to prevent the internal collar from rotating with the external collar.

11. A peristaltic pump as claimed in any one of claims 4 to 9, wherein each external collar receives an end fitting which is fluidically connected to the pump element.

12. A peristaltic pump as claimed in claim 11 , wherein the end fitting has a flange which abuts against the corresponding flange of the pump element.

13. A peristaltic pump as claimed in any one of the preceding claims, wherein the pressing surface follows a helical path which encircles the rotor assembly such that a front portion of the pressing surface adjacent the suction port overlaps a rear portion of the pressing surface adjacent the discharge port.

14. A peristaltic pump as claimed in claim 13, wherein the front portion of the pressing surface is formed as a removable component which is detachably connected to the housing.

15. A peristaltic pump as claimed in any one of the preceding claims, wherein the rotor assembly has an engaged configuration in which the pressing members compress the pump element and a disengaged configuration in which the pressing members do not compress the pump element.

16. A peristaltic pump as claimed in claim 15, wherein the rotor assembly comprises a base component and the pressing members are detachably connected to the base19component to allow the rotor assembly to transition between the engaged and disengaged configurations.

17. A peristaltic pump as claimed in claim 15, wherein the rotor assembly comprises a base component and the pressing members are hingedly connected to the base component such that they are movable between an extended position and a retracted position so as to allow the rotor assembly to transition between the engaged and disengaged configurations.

18. A peristaltic pump as claimed in claim 17, wherein the rotor assembly comprises an actuator component which is rotatable relative to the base component between a first position and a second position; wherein the actuator component engages the pressing members such that, in the first position, the pressing members are in the extended position and, in the second position, the pressing members are in the retracted position.

19. A peristaltic pump as claimed in claim 18, wherein the actuator component comprises a plurality of lobe sections which engage the pressing members.

20. A peristaltic pump as claimed in claim 19, wherein the lobe sections engage a track formed in the pressing members which tapers from a first end to a second end.

21. A peristaltic pump as claimed in any one of claims 18 to 20, wherein a front surface of the actuator component comprises a drive element for rotating the actuator component between the first and second positions.

22. A peristaltic pump as claimed in any one of claims 18 to 21, wherein the rotor assembly further comprises a cover plate; wherein one of the cover plate and the actuator component comprises an arcuate slot and the other of the cover plate and the actuator component comprises a pin which is received in the slot; wherein the pin is translatable along a length of the slot to allow the actuator component to rotate relative to the cover plate.

23. A peristaltic pump as claimed in claim 22, wherein the pin is at a first end of the slot when the rotor assembly is in the disengaged configuration and is at a second end of the slot when the rotor assembly is in the engaged configuration.2024. A peristaltic pump as claimed in any one of the preceding claims, wherein the pump element is a tube or hose.

25. A method of installing or removing a pump element in a peristaltic pump, wherein the pump element is provided with a pair of internal collars which are retained by a flange at either end of the pump element, the method comprising:connecting or disconnecting the internal collars to internal portions of suction and discharge ports of a housing of the pump; andinserting the pump element or removing the pump element from between a rotor assembly and a pressing surface of the housing.

26. A method as claimed in claim 25, further comprising, prior to inserting or removing the pump element, removing or retracting one or more pressing members of the rotor assembly.

27. A method as claimed in claim 25 or 26, further comprising, prior to inserting or removing the pump element, removing a removable component from the housing which defines a front portion of the pressing surface.

28. A method as claimed in any one of claims 25 to 27, wherein the internal collars are connected or disconnected to the internal portions of the suction and discharge ports by rotating an external collar.

29. A method as claimed in any one of claims 25 to 28, wherein the step of connecting or disconnecting the internal collars to the internal portions of the suction and discharge ports is performed with external suction and discharge lines connected to the pump.

30. A method as claimed in any one of claims 25 to 29, wherein the peristaltic pump is as claimed in any one of claims 1 to 24.

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