CA2961235A1

CA2961235A1 - Peristaltic pump with a rotary actuator and a transfer tube

Info

Publication number: CA2961235A1
Application number: CA2961235A
Authority: CA
Inventors: Ralf Hannibal
Original assignee: Individual
Current assignee: Individual
Priority date: 2017-03-17
Filing date: 2017-03-17
Publication date: 2018-09-17

Abstract

Peristaltic pump with a rotary actuator 14 and a transfer tube 5, having a cylindrical pump housing 2 and the openings 4 and 12 are arranged in a bottom. The openings 4 and 12 are alternately used as outlet and inlet, controlled by the transfer tube 5 and in dependence on the swivel direction of the pump head 7. The roller or the sliding shoe 8 constantly flattens the pump hose and in this way, forms an annular space, which is distinguished into a suction and compression chamber. Due to the constant contact of the roller or the sliding shoe 8, a sudden space enlargement is prevented according to the invention.

Description

Peristaltic pump with a rotary actuator and a transfer tube Specification The invention concerns a peristaltic pump, especially one with a cylindrical pump housing, in whose interior there is arranged a hose lying against the cylinder wall, which is connected at its ends to openings in the bottom or the cylinder wall of the pump housing and/or led at its ends through openings in the bottom or the cylinder wall of the pump housing, and with a pump head, which flattens the hose by a roller or a sliding shoe.
Pumps for liquids, especially thick materials such as concrete or mortar, must have the largest possible clear cross section in order to keep the flow resistance low. This requires relatively large cross sections for openings in the suction and compression chamber. Valves are somewhat of a hindrance here and cross section changes must be avoided.
High density solids pumps are known primarily in the form of piston pumps.
They are subjected to relatively great wear and are very costly to manufacture. The piston rods of the cylinders additionally need to be cooled in a water tank. Oil and water may form an emulsion in this case. The water needs to be disposed of.
Peristaltic pumps with a pump head rotating steadily in one direction are also used. But since the roller or the sliding shoe leaves the hose during the delivery stroke, an enlarged space necessarily results, causing an intense pulsation.
When the roller or the sliding shoe returns, the hose is flattened and a constricted space necessarily results, which likewise causes a strong pulsation. Strong pulsation means a turbulent delivery and great wear caused by this. As a result, when the pressure is large, the hose has a short service life. As a rule, two oppositely situated rollers or sliding shoes are used, so that the time from lift-off of the roller to set-down of the roller (idle time) is shortened.
The straightening out of the pump hose after the flattening process is a problem, which can be somewhat remedied by special hose materials or a partial vacuum in the housing.
Peristaltic pumps of the kind mentioned above are generally known, e.g., from DE 69700070 T2. The pump described here always rotates in only one direction during the delivery and it comprises several rollers or sliding shoes. A short reversal of direction of rotation occurs only for the shut-down process, in order to lift the rollers off from the hose by means of a special mechanism and prevent its permanent deformation.
DE 10 2004 031 137 A 1 likewise describes a pump rotating in only one direction during delivery, comprising an arrangement for relieving the hose of the loading by the rollers to prevent a lasting deformation of the hose.

2 DE 31 48 683 AI describes a peristaltic pump, but without a cylindrical housing, in which the pump head is driven in reverse, but a delivery of a medium present in the hose occurs only in one of the two directions. In the opposite direction, the roller or the sliding shoe is lifted off from the hose, so that the pump head does not describe the same circular trajectory in both directions, but rather different trajectories.
The problem which the invention proposes to solve is to create a pump, especially a high-density solids pump, which has large cross sections, less pulsation, less wear, especially for the pump hose, and which is favorable in its manufacture.
This problem is solved according to the invention in that the peristaltic pump, especially of the kind mentioned at the outset, comprises a rotary actuator, by which the pump head can swivel in circular manner alternately back and forth as far as the openings.
Preferably, the roller or the sliding shoe of the pump head flattens the pump hose constantly during the delivery and the suction and does not leave it. The roller or the sliding shoe remains constantly in contact with the hose.
By such a contact is meant not only a simple touching of the hose, but rather the flattening of the hose for purposes of the delivery.
Again preferably, the openings or the associated hose ends each serve alternately as inlet and outlet. The action of the respective opening or the respective hose end as inlet or outlet is preferably determined by the position, especially the working position of a transfer tube, especially in combination with the direction of rotation of the pump head.
The pump head swivels in circular manner in both directions on the same trajectory, e.g., at first from left to right, or clockwise, and flattens the pump hose by a roller or a sliding shoe.
In this way, the medium in the hose is delivered to one of the openings, e.g., to the right here. Preferably, the pump head has precisely a single roller or a single sliding shoe for the flattening of the hose. This single roller or single sliding shoe is always situated during the pump operation in an angle range which is subtended by the mentioned openings or hose ends.
Unlike with conventional peristaltic pumps with rollers turning in only one direction, this roller or sliding shoe thus does not in its movement sweep across the circumferential position at which the respective openings are situated.
The preferably mechanically or hydraulically driven transfer tube swivels in dependence on the direction of rotation and also preferably in dependence on the position of the pump head.
It can have a swivel axis parallel to the swivel axis of the pump head, which is driven by a rotary actuator on or in the pump housing.
The pump thus delivers in the one direction between opening 1 and opening 2 and in the second direction between opening 2 and opening 1. By means of the transfer tube, the delivery in a delivery hose connected to a connection piece of the swiveling transfer tube is rectified in that this delivery hose ¨ depending on the desired

3 delivery direction ¨ is connected by the transfer tube each time to one of the two openings and this connection is resy-nchronized in dependence on the direction of rotation of the pump head, especially also the position of the pump head, e.g., preferably when the pump head has reached its particular reversal point on its movement trajectory. Thus, the delivery in both possible rotating directions of the pump head always occurs in the same direction within the delivery hose which is connected to the transfer tube, and the desired direction is preferably reversible, in particular, the dependency of the transfer tube position on the rotational direction of the pump head can be reversed.
For example, if it is desired to deliver a medium away from the pump, the transfer tube will always be adjusted so that the opening to which the roller or the sliding shoe moves is connected across the transfer tube to the delivery hose. On the other hand, if the pump is required to suction a medium out from the delivery hose, that opening or that hose end [sentence left incomplete in the original]
Thus, the position of the transfer tube and the swivel direction determines whether the pump is suctioning or delivering at the end of the delivery hose.
The two fixed openings provided in one of the bottoms of the cylindrical housing or the hose ends connected to them serve, as described, alternately as inlet and outlet. The openings can also be positioned structurally in another location, e.g., at/in the cylinder wall of the pump housing.
In one preferred embodiment, the openings can be formed by the mouths of pipes, e.g., pipes bent at 90 degrees, onto which the hose ends are shoved. In this way, the hose lies entirely inside the housing. The hose is thus led at its ends indirectly, i.e., by means of the preferably bent pipes, through the openings in the bottom or the cylinder wall of the pump housing. Such pipes, especially pipes bent at 90 degrees, can be led loosely through the particular opening. Thanks to the bending of the pipe from the circumferential direction to the radial or axial direction relative to the housing and the extension of the hose in the circumferential direction of the housing, a fixed connection is obtained between pipe or hose end and opening. A pipe, especially one bent at 90 degrees, can also be firmly connected to a respective opening in the housing, e.g., by a welded connection or a screw/pin connection.
It can also be provided in one embodiment that the hose itself is led through the openings, i.e., directly at or by its ends.
The pump head, which flattens the hose by a roller or a sliding shoe, swivels alternately back and forth, each time up to the openings, the hose ends or the (bent) pipes connected to them.
Whether the opening acts as an inlet or outlet is determined by the position of the transfer tube and the rotation direction of the pump head.
Preferably, the pump head is connected to a central rotation shaft, which emerges from one of the bottoms of the housing, preferably exiting in the middle and being connected outside the pump housing to a rotary drive unit serving as the drive. Such a drive can be a hydraulic or electric drive. The design as a hydraulic drive especially

4 has the advantage that such a pump can also be mounted as an accessory device on a vehicle, such as farm machinery, and be operated by its hydraulics.
The rotary angle of the pump head is preferably limited at most up to the inlet or outlet opening in the bottom or the pipe pieces, preferably the bent pipe pieces, on which the hose is shoved, or depending on the installation position of the transfer tube. The function of inlet and outlet is exchanged during each stroke, preferably when the pump head runs through its reversal point, or dead center.
The mechanical or hydraulic driven transfer tube in a furthermore preferred embodiment is controlled by the position of the pump head. For this, a position detection can be present at each end position, controlling a change in direction of swiveling of the transfer tube and the pump head.
On the transfer tube preferably located on the housing, but on the outside of the housing, there is arranged a coupling, such as a threaded coupling, which provides a connection for a delivery line and each time alternately makes one of the two openings the outlet or, upon reversal, the inlet.
A flexible delivery hose can be connected to the connection as the delivery line, delivering the material to a suitable position.
When the hose is flattened, a restraightening into the original condition at the suction side is very important so that the material can be suctioned.
This is accomplished by a special hose material or by a partial vacuum in the pump housing. But this is only possible to a limited extent.
In one possible modification, in the peristaltic pump with rotary actuator and transfer tube it is possible to place in the pump hose, on either side left and right of the flattening site, a shape-stable body such as a ball, which has roughly the internal diameter of the hose, i.e., it is somewhat smaller so that it can be moved in the hose. The body then moves in dependence on the pump head, or the roller of the sliding shoe. By the suctioning of the ball, the pump hose is mechanically straightened on the inside and the suctioning is greatly improved.
In another embodiment, two shape-stable bodies, such as rotatable rollers, can be arranged on the outside at two axially opposite sides next to the hose, so that the hose again assumes its original shape after the flattening process. This can occur, for example, in that the bodies press the hose, which is broadened at the flattening site, back into its original open hose shape from the outside. Such bodies can be secured, for example, on both sides of the pump head with a distance from the flattening roller or the sliding shoe and move along with it.
On each side of the flattening roller or the sliding shoe there are preferably arranged two such bodies, which enclose the pump hose and have a spacing from each other in the axial direction, corresponding to the outer diameter of the hose, especially so that a hose broadened by the flattening is pressed back to its diameter in the axial direction. Insofar as the bodies are designed as rollers, these have a respective axis of rotation which lies radially. The terms -axial" and "radial" are used here in regard to the axis of rotation of the pump motor or the center axis of the cylindrical pump housing.
The level of the material being delivered is always preferably above the level of the mentioned openings, which significantly facilitates the suctioning. The walls of a material container can be arranged around the two openings, and preferably the pump housing wall which comprises these openings forms a lower floor of the material container. Thus, material is always above the openings and can be suctioned.
On account of the swivel movement of the pump head and the continual switching between inlet and outlet, at the same time as the constant contact of the roller or the sliding shoe with the pump hose, the peristaltic pump according to the invention with a rotary actuator and a transfer tube runs extremely low in vibration and free of jolting. The service life of the pump hose is thereby increased.
In order to facilitate the mounting of the new pump hose when it is necessary to replace the pump hose, the invention provides an arrangement as the mounting unit, whereby a pump hose, especially one having an angular extension of less than 360 degrees between its ends, is placed on a ring, especially a closed ring, and secured on it, especially at least in the region of its ends, e.g., by belts or other ties. When it is necessary to replace the pump hose, this mounting unit after removing the old hose can be placed in the pump housing and then the ring is removed. Thus, the installer is freed from the very strenuous labor of bending the stiff hose with large diameter in order to adapt it to the pump housing.
The invention can also provide the using of hose pieces as the pump hose which already have an imprinted curvature, corresponding at least substantially to the pump housing diameter.
Such hose pieces can be fabricated, e.g., by arranging the material of the hose, especially fabric layers and rubber material, on a production mandrel curved at least into a partial circle.
Preferably, the production mandrel in its at least partial circular curvature has an outer diameter which corresponds at least substantially to the diameter of the pump housing at the inner wall against which the pump hose rests during operation, minus the wall thickness of the hose. The material arranged on the curved production mandrel is then vulcanized into the finished hose, then having this precise curvature and being able to be installed virtually free of stress inside the pump housing. The curved production mandrel has a preferably circular cross section, corresponding in its diameter to the later internal diameter of the finished pump hose.
The invention can provide that a torque greater than 10.000 Newton-meters can be generated with the drive motor of the pump head. The drive motor can drive the pump head across a planetary gearing.

Furthermore, the pump hose can have a rated width larger than 50 mm, preferably larger than 75 mm, even more preferably larger than 100 mm. The pump hose can have a wall thickness greater than 20 mm, especially one with at least 4 fabric inlays.
The pump housing can have an outer diameter larger than 500 mm, preferably larger than 800 mm, even more preferably larger than 1000 mm.
In the following, preferred sample embodiments of the invention shall be explained more closely with the aid of the enclosed drawings.
Fig. 1: shows a view into the pump housing after removing one of the bottoms;
Fig. 2: is a perspective view of the pump housing with the swivel motor;
Fig. 3: is a top view of the pump housing seen from the drive side;
Fig. 4: shows a view with pump housing and mounted material container;
Fig. 5: shows the inside (section) of the pump hose with the two bodies; in this case, two balls;
Fig. 6: shows an embodiment in which rollers are used for straightening out the flattened hose, enclosing the hose in pair on both sides of the pump head;
Fig. 7: shows a mounting unit of pump hose and ring, maintaining the hose in curved shape.
A pump housing 1 comprises substantially a cylindrical wall 2 and a circular bottom 3. In the bottom 3 are situated the openings 4 which serve as inlet and outlet, depending on the position of the transfer tube 5.
In Fig. 1, a driving core 6 is situated inside the pump housing 1, which in combination with the pump head 7 moves the roller or the sliding shoe 8 in circular manner, swiveling in the pump housing 1. In this process, the roller or the sliding shoe 8 flattens the pump hose 9, since this lies against the wall of the pump housing 2 and forms a partitioned annular space.
The pump hose 9 lies against the cylinder wall 2 and is connected to pipe ends 10 and 11, whose outer mouths form the opening 4 or pass into the opening 12 across the transfer tube.
Moreover, a roller or sliding shoe 8 extends between the driving core 6 and the cylindrical wall 2, flattening the pump hose 9 in back and forth manner and forming a suction or compression chamber depending on the direction of rotation; in dependence on the position of the transfer tube 5.
The roller or the sliding shoe 8 always remains in contact with the pump hose 9 and forms a separation point between the suction and compression chamber; this is determined by the position of the transfer tube 5 and the rotation direction of the pump head 7.
In the bottom 3 there are two openings 4 and 12 with a circular cross section.
The opening 4 or 12 freed up by the transfer tube 5 serve as the material inlet during normal operation.

In Fig. 2 moreover the opening 4 is visible from the outside of the bottom 3, while the other opening 12 is concealed by a connection piece 13; or by the transfer tube 5. At this connection piece the material emerges, for the most part into a flexible hose, which serves as a discharge line for the thick material emerging from the Opening 12. The transfer tube is shown here in a position in which the connection piece 13 is standing above the left opening in the figure. Upon reversal of direction of the pump head 7, the transfer tube 5 will then be swiveled over the right opening 4.
The swivel axis of the transfer tube 5, looking radially, lies between the swivel axis of the pump head 7 and the openings 4/12 and it has a circumferential position lying between the openings 4/12.
A reversed pump mode can also be realized, in which the function of the openings 12 and 4 is interchanged;
now, the thick material is suctioned in through the opening covered by the transfer tube 5, which normally serves as a discharge line for the thick material, and the material emerges through the opening not covered. This is accomplished by a changing of the dependency of the transfer tube position on the rotation direction of the pump head 7. Thus, by inverting the dependency, the pump operation can be reversed.
Fig. 3 is a top view of the side of the pump housing with the swivel motor 14 of the pump head facing the observer. One can also see the arrangement of the transfer tube 5 and the openings 4 and 12.
The pins 16 serve as a pivot point of the pump housing 2, and in this way, the pump housing or the entire unit can be swiveled by hand. The cleaning and maintenance of the pump is always done in a user-friendly position.
In this way, a complete emptying and cleaning of the pump is possible, with no additional cleaning openings.
In Fig. 4 one sees the peristaltic pump with rotary actuator and a transfer tube with a mounted material container 15. This allows the pump to be flange-mounted on a machine or to be used without container as a submerged pump. The material container here is semicircular in cross section with a central indentation, surrounding the drive 14. The material container can also extend for an angle range of more than 180 degrees, e.g., it can be a complete circle extending for 360 degrees.
In Fig. 5 one sees the pump hose 9 in cross section; one recognizes here the balls 17 to the right and left of the roller 8, which serve to straighten out the flattened hose once more from the inside.
On the other hand. Fig. 6 shows a design in which a pair of two rollers 18 each is arranged on either side of the sliding shoe or roller 8 of the pump head 7 for straightening out the flattened hose from the outside. The rollers 18 have radially directed axes of rotation and are arranged axially opposite each other, preferably with a spacing corresponding to the outer diameter of the hose.
Fig. 7 shows a mounting unit, formed from a ring 19, on which a pump hose 9 is placed on the outside and secured on the ring 19 with belts 20 at least at the hose ends. Thanks to the ring 19, the hose 9 is held in a curvature which corresponds to the curvature which the hose 9 must have inside the pump housing. When such a mounting unit is used, the installer does not need to place the hose in the required curvature by himself. Such a mounting unit can be installed in its entirety in the pump housing for a hose replacement, after which the belts are loosened and removed.
For the swiveling of the pump head, a hydraulic swivel motor or a gear motor would be the best variant, since it is compact and theoretically can work in the medium. Large forces can likewise be achieved. This also allows the peristaltic pump with a rotary actuator and a transfer tube to work in water, for example.
For smaller peristaltic pumps with rotary actuator and a transfer tube, electric drives are also possible, of course.

Claims

claims

1) Peristaltic pump with a cylindrical pump housing (1), in whose interior there is arranged a hose lying (9) against the cylinder wall (2), which is connected at its ends to openings (4, 12) in the bottom or the cylinder wall of the pump housing (1) or led at its ends through openings in the bottom or the cylinder wall of the pump housing, and with a pump head (7), which flattens the hose (9) by a roller or a sliding shoe (8), characterized in that a) it comprises a rotary actuator (14), by which the pump head (7) can swivel in circular manner alternately back and forth as far as the openings (4, 12), while the roller or the sliding shoe (8) of the pump head (7) constantly flattens the pump hose (9) during the delivery and the suction and does not leave it, and b) the openings (4. 12) serve alternately as inlet and outlet, this being determined in particular by the position of a transfer tube (5) and further preferably also by the rotational direction of the pump head (7).

2) Peristaltic pump according to claim 1, characterized in that the transfer tube (5) is controlled by the position of the pump head (7).

3) Peristaltic pump according to claim 2, characterized in that a position detection is provided at the end positions, by which a change in the direction of swivel of the transfer tube (5) and the pump head (7) is controlled.

4) Peristaltic pump according to one of the preceding claims, characterized in that the transfer tube (5) is electrically, hydraulically or mechanically driven.

5) Peristaltic pump according to one of the preceding claims, characterized in that the transfer tube (5) is arranged on the cylindrical pump housing (1), especially on its bottom or on an external container outside of the pump housing (1).

6) Peristaltic pump according to one of the preceding claims, characterized in that the transfer tube (5) has a connection piece (13) especially on which a flexible delivery hose can be connected, while the connection piece (13) is coupled to one of the openings (4, 12) in the two end positions of the transfer tube (5) which can swivel between them.

7) Peristaltic pump according to one of the preceding claims, characterized in that at least one shape-stable body, especially an internal ball (17) or external rollers (18), is placed in or on the outside of the pump hose (9) next to the flattening site.

8) Peristaltic pump according to one of the preceding claims, characterized in that the pump housing (1) is mounted beneath a material holder (15), in particular forming its bottom.

9) Peristaltic pump according to one of the preceding claims, characterized in that the pump housing (1) is mounted so that it can swivel about an axis perpendicular to the axis of rotation of the pump head (7), in particular the pump housing (1) has bolts (16) arranged opposite each other on the swivel axis, which stick out from the housing (1) and the housing (1) is mounted via the bolts (16).

10) Peristaltic pump according to one of the preceding claims, characterized in that the drive motor (14) is a hydraulic motor.

11) Peristaltic pump according to one of the preceding claims, characterized in that it forms a submerged pump, in particular being designed as a closed system for this.

12) Peristaltic pump according to one of the preceding claims, characterized in that it is designed as a device mounted on a vehicle, in particular, it comprises at least one mechanical interface for this, preferably also a hydraulic interface with the vehicle.

13) Peristaltic pump according to one of the preceding claims, characterized in that the bearing surface of the pump hose (9) inside the housing (1) is lined with a rubber or polyurethane layer, especially to increase the life of the hose (9).

14) Peristaltic pump according to one of the preceding claims, characterized in that the pump hose (9) is laid in a circle in the pump housing (1) and does not leave the pump housing (1), in particular the hose ends lying in the pump housing (1) are each connected to pipe pieces (10, 11), preferably pipe pieces (10, 11) bent at 90 degrees, which pass through a housing wall and form the openings (4, 12) with switchable function.

15) Peristaltic pump according to one of the preceding claims, characterized in that a torque greater than 10,000 Newton-meters can be generated with the drive motor (14) of the pump head (7).

16) Peristaltic pump according to one of the preceding claims, characterized in that the pump hose (9) has a rated width larger than 50 mm, preferably larger than 75 mm, even more preferably larger than 100 mm.

17) Peristaltic pump according to one of the preceding claims, characterized in that the pump hose (9) has a wall thickness greater than 20 mm, especially one with at least 4 fabric inlays.

18) Peristaltic pump according to one of the preceding claims, characterized in that the drive motor (14) drives the pump head (7) across a planetary gearing.

19) Peristaltic pump according to one of the preceding claims, characterized in that the pump housing (1) has an outer diameter larger than 500 mm, preferably larger than 800 mm, even more preferably larger than 1000 mm.

20) Mounting unit for use with a peristaltic pump according to one of the preceding claims, characterized in that the pump hose (9) is previously mounted on a ring (19) and in this way, is given a curvature which corresponds at least substantially to the curvature which the pump hose (9) has inside the pump housing.

21) Method for production of a pump hose (9) for a peristaltic pump according to one of the preceding claims 1 to 19, characterized in that the material of the pump hose, especially fabric layers and rubber material, is arranged on a production mandrel which is bent at least partially in a circle and has preferably a circular cross section shape, after which the material arranged on the bent production mandrel is processed into the finished hose, especially by vulcanization, and it then has a curvature such that it can be placed at least substantially free of stress inside the pump housing.

22) Method according to claim 21, characterized in that the production mandrel in its at least partial circular curvature has an outer diameter which corresponds at least substantially to the diameter of the pump housing at the inner wall against which the finished pump hose rests during operation, minus the wall thickness of the hose.