CZ2009539A3 - Piston pump, particularly blood pump - Google Patents

Abstract

The piston pump is formed by a body (1) adapted to be connected to a source of pumped liquid and equipped with standard control, control, sealing and sealing elements. A linear motor (2) with a single or double acting piston (21) is mounted in the body (1), where the working space (22) of the linear motor (2) is directly connected to the working chamber (11) of the sealing joint (23) filled fluid. The working chamber (11) is provided with a suction valve (12) and a discharge valve (13).

Description

Piston pump, in particular a blood pump

Technical field

The invention relates to a new design of a piston pump, in particular a pump used in medicine for pumping blood.

BACKGROUND OF THE INVENTION

It is currently used in medicine for pumping blood of various types of pumps, in particular piston or diaphragm pumps, in exceptional cases centrifugal pumps, where one possible construction of the pumping device is described in WO 01/89600.

In diaphragm pumps, the movement of the diaphragm is provided by an external energy source, for example a compressor, whereby a control rhythm initiates the desired rhythm of the diaphragm movement, ensuring pulse pumping of blood from a chamber equipped with a suction and discharge valve. Examples of constructions of this type of pumps are described, for example, in WO 00/76288, WO 01/13974, US 4,687,424, EP 880974. A disadvantage of these pumps is the overall design complexity of the devices requiring a compressor, a control valve and a control processor.

Diaphragm pumps are also known in which the movement of the diaphragm is ensured by mechanical transmission from the propulsion drive, kinematically by means of a linkage system directly connected to the diaphragm, and if the diaphragm is magnetized, it can also be moved by magnetic fields. Examples of such constructions are known, for example, from EP 531856, US 5,380,267, RU 2061503, CZ 280010 or CZ 276233. A common disadvantage of these solutions is the complex provision of gears from the drive mechanisms and the relatively low lifetime of the diaphragm, as there is a concentration at the point of its contact with the drive mount.

the stress of the material resulting in a failure of the diaphragm operating at high cyclic load.

In piston pumps, the movement of the piston is in most cases provided by an external drive, for example the crank mechanism described in DE 19919572 or the mechanisms disclosed in GB 1206156, GB 2074665, GB 1487053, CN 20105544. providing a high pressure seal in the working chamber against the atmosphere, which is structurally and fabrically demanding because it requires the use of special materials for individual components and the accuracy of their manufacture.

Currently, linear motors of different designs are used to drive both single-acting and double-acting pumps, and the piston may be provided with excitation springs to enhance the efficiency of the piston to tune the piston oscillations to the desired resonance. JP 63288162 discloses a double-acting pump driven by a linear motor housed in a separate dry housing, where the liquid pumping space is sealed by plugs, which in the case of pumping blood can cause its degradation. WO 93/09348 describes the construction of a pumping device with a linear motor immersed in oil, wherein the piston is actuated by a magnet. This is a technically demanding solution where the oils are used to cool the engine by means of the circulation flow. A linear motor pump whose piston is driven by a magnet is also known from the solution of US 2005/175489. Finally, a solution is known according to US 5693091, wherein the cylindrical casing of the pump is part of a linear motor, which affects the relatively large dimensions of the pump. The large diameter of the piston then causes greater transmission forces to the pump stator, which is disadvantageous for blood pumps. This solution also does not allow excitation of the piston to the resonance, thus increasing the demands on the linear motor power.

The aim of the proposed design is to present a piston pump design which minimizes these disadvantages, is relatively simple in design and ensures long-term operational reliability of the pumping system without the need for frequent inspection and maintenance.

3. Summary of the Invention

The object is achieved in practice by the invention of a piston pump, in particular a blood pump, comprising a body adapted to be connected to a source of the fluid to be pumped and equipped with standard controls, controls, controls and seals and members. A linear motor with a single-acting or double-acting piston is incorporated in the housing, the working space of the linear motor being directly connected to the working chamber of the body filled with the pumped liquid by means of a sealing gap, the working chamber being equipped with a suction valve and discharge valve.

In a preferred embodiment, the working space of a linear-acting single-acting piston engine is connected to a gas accumulator equipped with a control diaphragm dividing its interior into a gas chamber and a storage chamber.

In a possible embodiment, in a linear double-acting piston engine, the working chamber in the interior of the housing is formed symmetrically laterally, mirror-sidewise on both sides of the piston, each of which is provided with a suction valve and a discharge valve.

Finally, it is preferred that the inner surfaces of the working chamber of the housing, the working space of the linear motor and both gas storage chambers are non-wettable.

The pump according to the invention is structurally simple and thus less expensive to manufacture, which also affects the cost of acquisition. The basic advantage of the invention is that it is not necessary to provide the piston seal to the fluid to be pumped and that the actuator itself, i.e. the linear motor, is an integral part of the structure, so that complex transmission mechanisms are not required.

4 44 44 444444 «4 4 4 4 4 44

444 * 44 44 44 44

-4Description of figures in the attached drawings

Specific embodiments of the invention are schematically illustrated in the accompanying drawings, wherein Fig. 1 is a basic design of a single-acting pump, Fig. 2 is a diagram of an alternative embodiment of a single-acting pump with an excitation spring; alternative design of double acting pump with excitation springs.

DETAILED DESCRIPTION OF THE INVENTION

In the basic embodiment of FIG. 1, the pump consists of a housing 1, in which a linear motor 2 with a single-acting piston 21 is installed, where the working space 22 of the linear motor 2 is directly connected to the working chamber 11 of the housing 1 filled with the fluid to be pumped. blood. The working chamber 11 is equipped with a suction valve 12 and a discharge valve 13 connected to the suction and discharge lines of the pumping system (not shown). The working space 22 of the linear motor 2 is then connected to a gas accumulator 4, which is equipped with a control membrane 41 dividing its interior into a gas chamber 42 and a storage chamber 43. The pump is then equipped with standard controls, controls, controls and seals and embodiments that do not affect the nature of the solution and are therefore not shown and described. In order to minimize hydraulic losses, the inner surfaces of the working chamber 11 of the housing 1, the working space 22 of the linear motor 2 and the two chambers 42, 43 of the gas accumulator 4 are non-wettable.

During operation of the pump as the piston 21 moves into the working chamber, the pumped liquid moves in the same direction, while a small part flows through the sealing gap 23 into the working space 22 in front of the piston 21. At the same time the outlet φφ φ · 4 · ♦ · 9 9 9 9 · · 4 • 44 4 44 ♦ · · * 4 · · «4 ·>

Φ · · Φ4 «φΦφ

ΦΦΦ * ·· Φ »ΦΦ ΦΦ ΦΦ

Pumped fluids from the working chamber 11 via the open discharge valve 13 to the discharge line. The previously accumulated pumped liquid is sucked back from the storage chamber 43 of the gas accumulator 4 before the piston 21 of the linear motor 2. Upon reciprocating movement of the piston 21, the pumped liquid is sucked by the intake valve 12 into the working chamber 11 and at the same time the pumped liquid is discharged from the working space 22 of the linear motor 2 into the gas accumulator 4.

Due to the fact that the principle of operation of the linear motor 2 is based on the harmonic movement of the piston 21, the entire pump system can be tuned to resonance by selecting the appropriate parameters of the functional and control elements, the mass of the system being both piston 21 and working fluid and pumped fluid. the compressed gas in the gas chamber 43 represents the static rigidity of the system.

In an alternative embodiment of the single-acting piston pump 21 of FIG. 2, to increase the overall efficiency of the pumping system, the piston 21 is provided with an excitation spring 5 and tuned to the excitation frequency of the linear motor 2 so that the assembly operates at resonance.

In a further alternative embodiment of the pump according to FIG. 3, a linear motor 2 with a double-acting piston 21 in the central part is incorporated in its housing 1 when the working chamber 11 is symmetrically divided by the linear motor 2 into two laterally mirrored positioned parts. As the piston 21 moves, the fluid to be pumped out from adjacent parts of the working chamber 11 is sucked in and the fluid to be pumped into the opposing part. As the piston 21 reciprocates, the operation is mirrored. As in the case of a single-acting piston pump 21, in order to increase the overall efficiency of the pumping system, the piston 21 can be provided with excitation springs 5 at both ends as shown in Fig. 4 and tuned to the excitation frequency of the linear motor 2. works in resonance.

Industrial applicability

The linear motor piston pump according to the invention is suitable for use in particular in medicine for pumping blood. However, this is not the only possible field of application, but will also find application in other hydraulic systems.

Claims (4)

1. A piston pump, in particular a blood pump, comprising a housing (1) adapted to be connected to a source of the fluid to be pumped and having standard actuating, controlling, checking and sealing elements and members, characterized in that it is incorporated in the housing (1). a linear motor (2) with a single-acting or double-acting piston (21), wherein the working space (22) of the linear motor (2) is directly connected to the sealing chamber (23) with the working chamber (11) of the body (1) filled with pumped liquid; (11) is provided with a suction valve (12) and a discharge valve (13). Diaphragm pump according to claim 1, characterized in that the working space (22) of the linear motor (2) with a single-acting piston (21) is connected to a gas accumulator (4) equipped with a control diaphragm (41) dividing its an interior space for the gas chamber (42) and the storage chamber (43). Diaphragm pump according to claim 1, characterized in that, in a linear motor (2) with a double-acting piston (21), the working chamber (11) in the interior space of the housing (1) is symmetrically formed laterally mirrored on both sides of the piston (21). ), each of which is provided with a suction valve (12) and a discharge valve (13). Diaphragm pump according to one of Claims 1 to 3, characterized in that the inner surfaces of the working chamber (11) of the housing (1), of the working space (22) of the linear motor (2) and of the two chambers (42), ) of the gas accumulator (4) are non-wetting.