Peristaltic Pump

Abstract

The present invention relates to a peristaltic pump including planetary rollers (6) configured to revolve around a rotor driving the planetary rollers, wherein the rotor is configured to push the planetary rollers against a flexible tube such that the flexible tube is squeezed between the planetary rollers and a wall of a pump housing. In order to facilitate the assembly and/or reduce the manufacturing cost and/or reduce the operating noise, a contact surface between the rotor and the planetary rollers is toothless.

Claims

1. A peristaltic pump comprising planetary rollers configured to revolve around a rotor driving the planetary rollers, wherein the rotor is configured to push the planetary rollers against a flexible tube such that the flexible tube is squeezed between the planetary rollers and a wall of a pump housing, and a toothless contact surface between the rotor and the planetary rollers.

2. The peristaltic pump according to claim 1, wherein the contact surface is formed by an elastic material.

3. The peristaltic pump according to claim 1, further comprising a rotatable support having supporting arms that are arranged inside the planetary rollers.

4. The peristaltic pump according to claim 3, wherein the supporting arms are arranged eccentrically inside the planetary rollers.

5. The peristaltic pump according to claim 3, wherein the support is loosely connected to the rotor via the planetary rollers.

6. The peristaltic pump according to claim 3, wherein the support comprises two parts that sandwich the planetary rollers inbetween.

7. The peristaltic pump according to claim 3, wherein the support comprises two separable rings, at least one of the rings comprising axially projecting ring segments forming at least partially the supporting arms, wherein opposite end faces of the projecting ring segments (52) in a circumferential direction of the rings are convex.

8. The peristaltic pump according to claim 1, further comprising a flexible sleeve provided between the rotor and the planetary rollers and having the contact surface.

9. The peristaltic pump according to claim 8, wherein the flexible sleeve has a Shore A hardness of between 40 and 100.

10. The peristaltic pump comprising planetary rollers configured to revolve around a rotor driving the planetary rollers, wherein the rotor is configured to push the planetary rollers against a flexible tube such that the flexible tube is squeezed between the planetary rollers and a wall of a pump housing, further comprising a drive unit with a drive shaft, and a contactless coupling between the drive shaft and the rotor (8) for transferring torque from the drive shaft to the rotor.

11. The peristaltic pump according to claim 1, further comprising a first sensor element revolving around the rotor at the same speed as the planetary rollers, and a stationary second sensor element configured to detect the revolution of the first sensor element.

12. The peristaltic pump according to claim 11, wherein the first sensor element is provided in a receptacle of a supporting arm.

13. The peristaltic pump according to claim 1, wherein the rotor comprises a conical section and a cylindrical section, the cylindrical section having the contact surface, and wherein the rotor is axially displaceable from a storage position, in which the conical section or a section with reduced diameter contacts the planetary rollers such that the flexible tube is not squeezed between the planetary rollers and the wall of the pump housing, into an operating position, in which the cylindrical section contacts the planetary rollers such that the planetary rollers are pushed against the flexible tube and the flexible tube is squeezed between the planetary rollers and the wall of the pump housing.

14. The peristaltic pump according to claim 13, wherein an edge of the conical section next to the cylindrical section has a larger diameter than the cylindrical section.

15. The peristaltic pump according to claim 13, wherein the pump housing has an aperture in which the rotor is axially displaceable from the storage position into the operating position, and wherein the pump housing is provided with an inlet port and an outlet port that are connectable inside the pump housing via the flexible tube.

16. The peristaltic pump according to claim 6, wherein the two parts of the support are releasably connected to each other.

17. The peristaltic pump according to claim 8, wherein the flexible sleeve has a Shore A hardness of between 60 and 80.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0026] FIG. 1 is a cross-sectional view including a perspective portion at the right side,

[0027] FIG. 2 is a perspective top view of the pump housing without top cover,

[0028] FIG. 3a is a perspective side view of the pump housing showing the rotor in the storage position,

[0029] FIG. 3b corresponds to FIG. 3a without top cover,

[0030] FIG. 4a is a perspective side view of the pump housing showing the rotor in the operating position,

[0031] FIG. 4b corresponds to FIG. 4a without top cover,

[0032] FIG. 5 is an exploded view of the support, the planetary rollers, and the first sensor element,

[0033] FIG. 6 is a longitudinal view, and

[0034] FIG. 7 shows components of the pump housing and in the pump housing according to detail D in FIG. 6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] In FIG. 1, an embodiment of a peristaltic pump according to the present invention is shown in a cross-sectional view. The peristaltic pump 2 comprises a pump housing 4 accommodating planetary rollers 6, a rotor 8, a flexible tube 10 and a support 12. In the embodiment, there are four planetary rollers 6 that are configured to revolve around the rotor 8 that drives the planetary rollers 6. The rotor 8 is configured to push the planetary rollers 6 against the flexible tube 10 such that the flexible tube 10 is squeezed between the planetary rollers 6 and a wall 14 of the pump housing 4. The rotor 8 comprises a sun roller 16 that carries a flexible sleeve 18. The flexible sleeve 18 has a toothless outer peripheral surface, which is in physical contact with the planetary rollers 6 to transmit torque onto the planetary rollers 6 and which forms a contact surface 20 between the planetary rollers 6 and the rotor 8.

[0036] The support 12 has four supporting arms 22, each supporting arm 22 being provided inside one planetary roller 6, and a rigid base 24 connecting the supporting arms 22, wherein the supporting arms 22 are equally spaced in a circumferential direction of the support 12, the circumferential direction of the support 12 corresponding to a rolling direction of the planetary rollers 6 indicated by an arrow with reference sign R.

[0037] The supporting arms 22 secure a substantially unchanging circumferential distance between the planetary rollers 6. That is, the support 12 prevents that one of the planetary rollers 6 falls behind or runs on ahead which could end in a collision and/or blockage of two planetary rollers 6. The supporting arms 22 are arranged eccentrically inside the planetary rollers 6 and opposing end faces 58 of the supporting arms 22 in a circumferential direction are convex. This allows the planetary rollers 6 to turn even though there is physical contact between the planetary rollers 6 and the support 12.

[0038] The support 12 is loosely connected to the rotor 8 via the planetary rollers 6. That is, at least one of the planetary rollers 6, which are driven by the rotor 8, acts as a driver for the support 12 through physical contact with the respective supporting arm 22 provided inside the planetary roller 6.

[0039] FIG. 2 shows the pump housing 4 of the embodiment in a perspective top view. The pump housing 4 is provided with an inlet port 26 and an outlet port 28 that are connected inside the pump housing 4 via the flexible tube 10. The sun roller 16 accommodates rotor magnets 30 that are alternatingly oriented and belong to a contactless coupling that will explained later in connection with FIG. 6.

[0040] FIGS. 3a and 3b show the pump housing 4 of the embodiment in a perspective side view, wherein the rotor 8 is in a storage position. In the storage position, a portion of the sun roller 16 having a reduced diameter contacts the planetary rollers 6, such that the flexible tube 10 is not squeezed between the planetary rollers 6 and the wall 14 of the pump housing 4. This prolongs the lifetime of the flexible tube 10 before the peristaltic pump 2 is put into operation and/or when the peristaltic pump 2 is not used. The storage position will also allow sterilization of the flexible tube 10 prior to use of the peristaltic pump.

[0041] FIGS. 4a and 4b show the pump housing 4 of the embodiment in a perspective side view, wherein the rotor 8 is in an operating position. In the operating position, the contact surface 20 contacts the planetary rollers 6 such that the planetary rollers 6 are pushed against the flexible tube 10 and the flexible tube 10 is squeezed between the planetary rollers 6 and the wall 14 of the pump housing 4. The diameters of the wall 14, the planetary rollers 6 and the sun roller 16 are configured accordingly. The storage position of the rotor 8 is turned into the operating position by axial displacement of the rotor 8 towards the planetary rollers 6.

[0042] The pump housing 4 is essentially disc-shaped and has an aperture 34 at its front face 36, in which the rotor 8 is axially displaceable from the storage position into the operating position. The front face 36 and a rear face 70 of the pump housing 4 each have an essentially circular portion 38 and an essentially three-cornered portion 40 that are integrally connected, the essentially three-cornered portion 40 having the inlet port 26 and the outlet port 28.

[0043] The pump housing 4 has a base plate 42 providing the rear face 70 and a top cover 44 providing the front face 36, wherein the base plate 42 comprises outer lugs 46 and the top cover 44 comprises corresponding outer latches 48, such that the base plate 42 and the top cover 44 are releasably connectable.

[0044] A circumferential wall of the pump housing 4 between the front face 36 and the rear face is provided by the top cover 44 and surrounds the flexible tube 10. The circumferential wall corresponds to the wall 14 of the pump housing 4.

[0045] As shown in FIG. 5, the support 12 (see FIG. 2) comprises two separable rings 50. Each ring 50 comprises four axially projecting ring segments 52, two inner lugs 54 and two inner latches 56, the projecting ring segments 52 being alternately provided with an inner lug 54 or an inner latch 56, wherein the inner lugs 54 of one ring 50 match with the inner lugs 56 of the other ring 50. The projecting ring segments 52 are equally spaced in the circumferential direction. By joining the rings 50, the projecting ring segments 52 form the supporting arms 22. Accordingly, opposite end faces 58 of the projecting ring segments 52 in a circumferential direction of the rings 50 are convex. One of the two rings 50 has two receptacles 60, the receptacles 60 being formed by two projecting ring segments 52 arranged diametrically and comprising the inner latches 56. Sensor magnets 62 are arranged in the receptacles 60 as a first sensor element 64.

[0046] FIG. 6 shows the embodiment in a longitudinal view, wherein the left side in FIG. 6 corresponds to a portion that is cut away in FIG. 1. The pump housing 4 is held by a casing 66 that is connected with a container 68 having a reservoir for the fluid that is to be supplied to or suctioned from a human or animal body. The container 68 is displayed in FIG. 1 perspectively and arranged at the rear face 70 of the pump housing 4. A drive unit with a motor providing the drive energy for the rotor 8 is arranged at the front face 36 of the pump housing 4, the drive unit and the pump housing 4 being separated by a stationary sealing wall 72. The drive unit comprises a drive shaft 74 that carries a turret 76, the drive shaft 74 being rotatably supported via a rolling bearing 78.

[0047] The turret 76 is provided with drive magnets 80, which are arranged in alternating orientation in the circumferential direction and face the rotor magnets 30 at the other side of the sealing wall 72. When the drive magnets 80 turn, the rotor magnets 30 follow. That is, the drive magnets and the rotor magnets 30 form a magnetic coupling, which is a contactless coupling.

[0048] A hall sensor is provided as a second sensor element 82, the second sensor element 82 being fixed to the sealing wall 72, wherein the second sensor element 82 and the sensor magnets 62 of the first sensor element 64 essentially have the same radial distance from an axis of rotation A. Thus, the second sensor element 82 is configured to detect the sensor magnets 62 when they pass at the other side of the sealing wall 72. The signals of the second sensor element 82 are evaluated to determine the velocity of the support 12, which corresponds to the rotational speed of the planetary rollers 6 around the rotor 8, in order to check whether said velocity matches the transmission ratio of the rotation of the drive shaft 74.

[0049] As shown in FIG. 7, the sun roller 16 has a central hole 84 receivingfrom one enda pin 86, which is integrally connected with the base plate 42 of the pump housing 4, andfrom the opposite enda connector 87 of a cap 88, wherein the connector 87 forms a shaft of a bearing sleeve for the sun roller 16. The pin 86 comprises locking projections 90 that, when the sun roller 16 is pushed into the operating position, lock an axial position of the cap 88 and the sun roller 16. Further, the locking projections 90 prevent rotation of the connector 87. The cap 88 closes the aperture 34 when the rotor 8 is in the operating position.

LIST OF REFERENCE SIGNS

[0050] 2 peristaltic pump [0051] 4 pump housing [0052] 6 planetary roller [0053] 8 rotor [0054] 10 flexible tube [0055] 12 support [0056] 14 wall of the pump housing [0057] 16 sun roller [0058] 18 flexible sleeve [0059] 20 contact surface [0060] 22 supporting arm [0061] 24 rigid base [0062] 26 inlet port [0063] 28 outlet port [0064] 30 rotor magnet [0065] 32 conical section [0066] 34 aperture [0067] 36 front face [0068] 38 circular portion [0069] 40 three-cornered portion [0070] 42 base plate [0071] 44 top cover [0072] 46 outer lug [0073] 48 outer latch [0074] 50 ring [0075] 52 projecting ring segment [0076] 54 inner lug [0077] 56 inner latch [0078] 58 opposite end face [0079] 60 receptacle [0080] 62 sensor magnet [0081] 64 first sensor element [0082] 66 casing [0083] 68 container [0084] 70 rear face [0085] 72 sealing wall [0086] 74 drive shaft [0087] 76 turret [0088] 78 bearing [0089] 80 drive magnets [0090] 82 second sensor element [0091] 84 central hole [0092] 86 pin [0093] 87 connector [0094] 88 cap [0095] 90 locking projection [0096] A axis of rotation [0097] R rolling direction