RU2769063C2 - Volumetric pump - Google Patents

Abstract

FIELD: medical equipment.

SUBSTANCE: invention relates to medical equipment, namely to volumetric pumps. Volumetric pump (1) for pumping media through flexible hose (2) is made with the possibility of being closed by means of door (3) by case (4). It contains displacing device (5) for applying pressure force to flexible hose (2), support section (6), on which flexible hose (2) is located, and relatively to which it is supported by pressure force applied by displacing device (5), and adjustable device (7) for prestressing, by means of which displacing device (5) and/or support section (6) are installed with adjustable compliance or prestressed relatively to each other to provide the adjustment of pressure force applied to or having the possibility of being applied to hose (2). At the same time, displacing device (5), support section (6) and device (7) for prestressing in a closed state of case (4) are located inside it, and device (7) for prestressing in a closed state of case (4) has the possibility of outside adjustment without the need for opening case (4).

EFFECT: obtaining a volumetric pump.

10 cl, 6 dwg

Description

The present invention relates to a volumetric pump for transferring media through a flexible hose with a housing that can be closed by means of a door or a cover, with a displacement device for applying pressure to the flexible hose, with a support section on which the flexible hose is located and on which the flexible hose, loaded with pressing force by means of the displacement device, rests. hose, and with an adjustable prestressing device, by means of which a displacing device (e.g. vane peristalsis or a pump rotor) and/or a support with adjustable compliance is installed and, if necessary, prestressed to allow adjustment of the clamping force that is applied or can be applied to the hose.

Infusion hose pumps (peristaltic pinch roller pumps) are known from the prior art. They are used, for example, to pump the active agent at a defined delivery rate from the active agent reservoir via an infusion hose to the patient respectively. Infusion hose pumps are typically designed as volumetric pumps that externally expel volume into the infusion hose. This has the advantage that the displacing device (sliding peristalsis/pump rotor) remains unaffected by the media present in the hose or does not come into contact with these media. With these types of pumps, the downforce peristalsis makes an important contribution to pumping accuracy. As a result, it is necessary to fine-tune this clamping force, for example to adjust it to the different elasticity of different hoses (single-use product). There is a need to further improve the long-standing need among the competent circles for the pumping accuracy and resistance to pressure surges of infusion hose pumps in order to be able, for example, to dispense medicines in even more precise dosages.

In addition, with known solutions, there is a risk of an uncontrolled failure of the clamping force adjusting device, for example as a result of a broken spring. In such a case, this leads to the lifting of the peristaltic gate from its respective support, whereby an uncontrolled amount of active substance could enter or exit the patients.

Therefore, it is an object of the present invention to provide means and ways by which the pumping accuracy of a positive displacement pump can be improved.

The above problem is solved by means of a device with features of paragraph 1 of the claims. Preferred improvements are the subject of dependent claims.

The positive displacement pump according to the invention for conveying media through a flexible hose has the following features/components:

housing closed by means of a door/flap door/lid,

a displacement device, in particular a vane peristalsis or a pump rotor, for introducing/applying (moving along the hose) a pressing force against the flexible hose,

a support section (counter support) on which the flexible hose is located and on which it rests due to the pressing pressure introduced / applied by means of the displacing device, and

adjustable pretensioning device, by means of which the displacement device and/or the support section with adjustable compliance are installed and, if necessary, prestressed, whereby it is possible to adjust the introduced/applied or to be introduced/applied (by means of the displacement device) to the clamping force hose.

In this case, according to the invention, the displacing device, the support section and the device for prestressing in the closed state of the housing are located inside it, and the device for prestressing can be adjusted from the outside in the closed state of the housing, without the need to open the housing for this. In other words, the displacement pump according to the invention is designed so that by means of a displacement device (sliding peristalsis/pump rotor), by compressing a certain hose volume with a predetermined, adjusted/applied by means of a pretensioning device, the pressing force is to pump a certain amount of liquid/active substance/infusion agent. solution. In this case, the individual components of the displacing means (pump mechanics) are structurally coordinated with each other and with the housing in such a way that the pressing force of the displacing device generated by the prestressing device can be adjusted/adjusted from the outside and without dismantling or opening the housing.

With known solutions, it is quite possible to adjust the pressing force of the displacing device (peristalsis), however, this requires opening, respectively, dismantling of the pump (pump housing). In this case, due to the reassembly of the pump and the resulting tolerances, there are inaccuracies or deviations, and therefore the pumping accuracy achievable in this way is limited. Therefore, the inventive system described above provides not only ergonomic advantages for the user, but also better pumping accuracy, since the pressure force of the prestressing device can be adjusted with the housing closed and dimensional deviations/tolerances are compensated for when reassembling the pump.

According to one preferred aspect of the invention, the prestressing device can be designed to be purely mechanically aligned. Preferably, the pretensioning device may have an adjustment spring, i. e. a spring element whose preload force can be adjusted by moving the actuating element.

According to one preferred embodiment, the displacing device may have a plurality of peristaltic gates which are mounted for linear movement, for example, in a stationary gate housing (in the direction of movement) and driven by an eccentric shaft with several (angularly offset) eccentrics. In other words, the displacing device can be made in the form of a gate peristalsis. In such vane peristalsis, the vanes are preferably driven by an eccentric shaft in such a way that they displace one after the other in a wave motion to displace a certain volume in the flexible hose in the direction of pumping. The valve housing can be either a separate inner housing that is located inside the housing (pump), or be an integrated section of the housing (pump), on which peristaltic gates are mounted with the possibility of linear displacement. Preferably, the peristaltic gates arranged in this manner have a single degree of freedom in the direction of movement. The eccentric shaft can preferably be rotatably mounted and can be driven, preferably by a motor.

However, it is also fundamentally possible to equip a (peristaltic with pinch rollers) pump with a pump rotor, around the perimeter of which several pressure rollers located at an angular distance from each other are installed, and the flexible hose is laid in an arcuate manner around the pump rotor and is applied to an also arcuately made around the flexible hose (around the pump rotor) to the supporting section, as it were, in the form of a hose guide.

According to one preferred aspect, the vane housing/rotor housing can be fixed relative to the housing (pump) to provide precise guidance of the peristaltic vanes/pinch rollers. In the prior art, in order to apply an adjustable clamping force, often the entire gate housing/rotor housing is prestressed towards the bearing area. However, the resulting mobility of the peristaltic gate/pressure roller support is reflected in inaccurate pumping.

According to one preferred embodiment, the eccentric shaft or the rotor shaft of the pump can be mounted resiliently relative to the gate housing. Here, preferably, the pretensioning device can prestress the eccentric shaft/rotor shaft of the pump directly or indirectly towards the bearing section, so as to generate a pressing force.

According to another preferred aspect of the invention, the eccentric shaft (gate peristalsis) can be rotatably/rotatably mounted by means of a pendulum arm on the (stationary relative to the housing) gate housing. In this case, the eccentric shaft itself, in this embodiment, is rotatably mounted on the pendulum arm.

According to one preferred embodiment, the prestressing device can act transversely to the direction of travel, in particular in a direction perpendicular to the direction of travel and perpendicular to the orientation of the hose laid in the housing. This is due to the fact that the housings of positive displacement pumps in the direction of travel as well as in the direction of the hose, due to the space required in these directions, generally have larger dimensions/edge lengths than perpendicular to these two directions (most often the vertical direction) . That is, by said orientation of the prestressing device perpendicular to the direction of movement as well as the direction of the hose, the distance of the prestressing device to the outer surface of the housing can be reduced in order to facilitate its adjustment from the outside. Particularly preferably, the eccentric shaft can be mounted on a pendulum lever pivotable relative to the gate body and the pretensioning device, for example via the cantilever arm of the pendulum lever, can apply a torque transversely to the direction of movement to the pendulum lever, which opposes the applied pressure. by the force of the sliding gate peristalsis to the torque on the pendulum lever.

According to one preferred embodiment, the prestressing device may have:

adjusting screw;

a spring element that is axially displaceable and substantially concentric on the adjusting screw; and

a spring holder that is axially displaceable and substantially concentric on the adjusting screw and configured to hold the axial end of the spring element in a certain axial position relative to the adjusting screw.

According to an even more preferred aspect of the invention, the spring holder can be connected to the adjusting screw, in particular via a self-locking threaded pair, in such a way that it can be displaced in an axial direction forcibly due to the pivotal movement of the adjusting screw. Thus, the pretensioning device can be configured in such a way that the pressing force can be adjusted by means of a simple rotational movement. The self-braking design of the threaded pair can prevent undesired adjustment/movement of the spring holder, for example due to prestressing.

According to one preferred embodiment, the spring holder can be mounted on the body or body of the gate, in particular by form-fitting, linearly displaceable and non-rotatable.

According to one preferred embodiment, the adjusting screw can be rotatably mounted on the body and/or body of the gate and/or the pendulum arm. Even more preferably, the adjusting screw has circumferential locking means by which the adjusting screw can be locked in several predetermined angular steps relative to the body.

According to one even more preferred aspect of the invention, the spring element may be in the form of a compression spring. Even more preferably, the spring element may be in the form of a wave spring. Thus, the structural space in the axial direction of the spring element can be saved. Even more preferably, the spring element/wave spring can be designed/formed in such a way that it cannot rotate relative to itself after breakage and retains the accumulated force. If the auxiliary support spring breaks, an uncontrolled flow immediately occurs in both directions (depending on the pressure level). The use of a wave spring is safe in this place, since if one coil is damaged, the spring force is practically preserved.

According to one preferred embodiment, the positive displacement pump may have a through hole or recess in the housing and/or valve body, which is formed respectively - in particular concentric with - the prestressing device, in order to allow access to it. It is advantageous if the through hole/recess is sealed by means of a sealing device to prevent contamination from entering the interior of the housing.

In the following, the invention is explained in more detail on the basis of preferred embodiments with reference to the appended figures. The figures are only a schematic description (nature) and are solely for the purposes of understanding the invention. Like elements are provided with like reference numerals.

Shown:

1 is a schematic sectional view of a displacement pump according to the invention according to one preferred embodiment of the invention;

2 is a detail view of a positive displacement pump displacement device according to said preferred embodiment;

Fig. 3 is a rear perspective view of a positive displacement pump displacement device according to the indicated embodiment;

4 is a detailed view of an adjustable prestressing device according to one preferred embodiment;

Fig.5 diagram of the balance of force in the displacing device; and

Fig. 6 is a schematic view of one other preferred embodiment of the positive displacement pump according to the invention in the radial type.

It is known in medical technology to use volumetric pumps. In this type of pump, the downforce of the peristalsis makes a significant contribution to pumping accuracy. Therefore, it is required to adjust the clamping force of peristalsis as accurately as possible. In the case of known pumps, such an adjustment of the pressing force of the peristalsis is possible only in the disassembled, respectively, open state of the pump housing. Due to the tolerances arising from the reassembly of the pump, due to installation work, for deviations from the specified position of the individual components relative to each other, the achievable adjustment accuracy of such pumps is limited. Therefore, the object of the present invention is to provide pumping mechanics with higher alignment accuracy. This is achieved, in particular, by the fact that the individual components of the pump are structurally designed relative to each other so that the adjustment of the pressing force of the peristalsis can be carried out in the closed state of the pump housing (without dismantling the pump).

Figure 1 shows a positive displacement pump 1 for pumping media through a flexible hose 2 according to one preferred embodiment of the invention. More specifically, it is an infusion hose pump that can supply or deliver to the patient the active substance from the active substance reservoir (not shown) with a predetermined capacity (delivery rate) through the infusion line. To this end, the volumetric pump 1 essentially has a housing 4 closed by a door 3. During operation, a flexible hose 2 is located between the door 3 and the housing 4. In this system, the hose 2 is provided between the displacing device 5 located in the housing 4 and the support (counter-support) section formed by the door 3 6, the support section 6 supporting the pressing force generated by the displacing device.

Depicted in figure 2 and 3 displacement device 5 positive displacement pump 1 is made in the form of mechanics with slide peristalsis. As such, it has several (here 12) peristaltic gates 8, which are mounted for linear movement in the gate housing 9. The gates 8 are driven by an eccentric shaft 10, which has a number of eccentrics 10.1 corresponding to the number of gates 8, which are located respectively in response to the gate 8. The eccentrics 10.1 of the depicted eccentric shaft 10 are respectively offset by 30 ° relative to the neighboring, respectively, neighboring eccentrics 10.1, so that - when the rotation of the eccentric shaft 10 driven by the motor 11 is forcibly guided by means of the eccentrics 10.1 in their linear movement, the gate valves 8 in an essentially sinusoidal displacement movement carry out pumping of one volume in the direction of pumping.

The gate housing 9 is fixedly located on the pump housing 4 in order to ensure the most accurate guidance of the gates 8. In the illustrated example, the gate housing 9 is made as a separate housing (inner housing), which is preferably fixed to the pump housing 4 (outer frame). In the illustrated example, the gate body 9 is fixed to the body 4 by means of pressed pins. However, all fixing methods used by those skilled in the art are acceptable, for example by means of other fixing means, such as screws, form-fitting or press-fitting or welding. The body 9 of the gate can also be formed as a section of the body 4 that is integral in material.

Therefore, both the valve body 9 and the support section 6 are fixed in the displacement pump shown relative to the pump body 4 . Therefore, the adjustable clamping force of the peristaltic gates 8 relative to the support section 6 is realized by installing an eccentric shaft 10. For this, the eccentric shaft is installed relatively movable relative to the remaining components of the displacing device 5. 9.2 pendulum lever gate housings 9.1. In order to generate an adjustable pressing force, the pendulum arm 9.1 is prestressed by means of an adjustable pretensioning device 7 in such a way that the eccentric shaft 10, which is rotatably mounted on the pendulum arm 9.1, exerts pressure in the direction of the support section 6 (cf. FIG. 1). Correspondingly, the slide gates 8 forced by the eccentric shaft 10 are subjected to a force load in response to the prestressing force from the prestressing device 7 .

In order to ensure that the force introduced into the peristaltic mechanics by means of the pretensioning device 7 can be adjusted, the prestressing device 7 in the illustrated preferred embodiment is designed as a spring adjustment (in this case in three parts). The spring adjustment in the depicted displacing device 5 is made in the form of an adjustable, compressively loaded spring, which is clamped between the cantilever arm 9.4 of the gate body 9 and the cantilever arm 9.5 of the pendulum lever 9.1 in order to prestress the eccentric shaft in the direction of the support section.

As can best be borrowed from FIGS. 2 and 3, the prestressing device is here essentially transverse to the direction of movement of the peristaltic gates 8. Therefore, the prestressing device 7 generates a torque about the axis of rotation of the hinge 9.2 of the gate body, around which it is able to rotate pendulum lever 9.1, which is opposed to the torque created by the support force of the peristaltic gates 8. The perpendicular orientation of the direction of prestressing and the direction of movement of the peristaltic gates 8 relative to each other has the advantage that the distance to the pump housing 4 in the transverse direction relative to the direction of movement is shorter than in the direction of movement or in the direction of the hose. This consists in the fact that the positive displacement pump housing most often has the shape of a rectangular parallelepiped and has a shorter rib length across the direction of travel and the direction of the hose (most often the vertical direction). In other words, by means of such a design, the accessibility of the device to be adjusted 7 for prestressing outside the housing 4 can be improved, since a shorter distance has to be overcome.

In order to allow repositioning of the prestressing device 7 in the assembled state of the housing 4, the shown pump is provided with a through hole 12 through the housing 4 and through the cantilever arm 9.4 of the valve body 9, relative to which the prestressing device 7 is concentrically located and through which the device 7 for prestress. As can be inferred from FIG. 4, the access to the spring adjustment in the illustrated example is sealed by a sealing device 13 (which here has a screw plug and an O-ring) to prevent dirt particles from entering the sludge transmission. In addition, next to the passage shown in FIG. 4 to the pretensioning device 7 to be adjusted, markings 14 are provided on the outside of the pump housing 4, which indicate to the user the direction of rotation corresponding to the increase or decrease in the peristaltic pressing force.

In the preferred embodiment shown here, the three-part pretensioning device 7, designed as a spring adjustment, consists of an adjusting screw 7.1, a spring element (wave spring) 7.2 and a spring holder 7.3 (retaining ring). The adjusting screw, as can be seen in figure 3, is rotatably mounted on the cantilever arm 9.4 of the gate housing 9 and on the cantilever arm 9.5 of the pendulum lever 9.1. The holder 7.2 of the spring through the internal thread interacts with the external thread of the adjusting screw 7.1 and therefore, during the rotational movement of the adjusting screw 7.1, it moves relative to it in the axial direction. To do this, the holder 7.2 of the spring additionally interacts with the body 9 of the gate with positive locking in such a way that it (the holder) is fixed from rotation, respectively, joint rotation with the adjusting screw 7.1 and at the same time is installed with the possibility of axial movement relative to the body of the gate. This is solved in the example shown by the fact that the holder 7.3 of the spring forms an integral fork section, which receives the rib 9.3 of the body 9 of the gate with positive locking. The thrust surfaces 9.6 on the gate housing 9 limit the possible compression of the spring element 7.2.

The spring element 7.2 is preferably positioned so that its axial ends form a butt joint with the spring holder 7.3 and the cantilever arm 9.4 of the pendulum arm 9.1. Thus, the spring element 7.2 can pre-stress the eccentric shaft 10 mounted on the pendulum lever 9.1 in the direction of the support section 6. Turning the adjusting screw 7.1 starts the axial movement of the spring holder 7.3, as a result of which the spring element 7.2 is flattened, respectively, unclenched. Therefore, the adjustment of the prestressing force applied to the pendulum arm 9.1 is ensured by simply turning the adjusting screw 7.1, which is accessible through the through hole/recess 12.

The spring element 7.2 in the illustrated preferred embodiment is in the form of a wave spring. On the one hand, this has the advantage that wave springs need relatively little structural space in the axial direction to apply the same force as many other types of springs. In addition, the wave spring - in contrast to traditional (helical) compression springs - can be designed in such a way that, if the spring element 7.2 breaks in place, the two fractured parts cannot rotate relative to each other. This is an advantage in particular for the present medical use, since in this way, even if the spring element 7.2 fails, the prestressing force accumulated therein can be reliably retained. If this were not the case, then the failure of the spring element 7.2 could lead to fluctuations in performance and thus to uncontrolled administration of drugs.

The internal thread of the spring holder 7.3 and the external thread of the adjusting screw 7.1 in the example shown are made in the form of a self-locking thread (for example, in the form of a trapezoidal thread) to prevent that the axial position of the spring holder 7.3 is changed due to the prestressing force, respectively, to ensure that the set user downforce is saved.

The adjusting screw 7.2 is provided with a circumferential, crown-shaped locking means 15 which interacts with a corresponding locking portion 16 (for example, a triangular-shaped locking tongue) of the gate body 9 to prevent unwanted adjustment of the adjusting screw 7.1 (in addition to the self-braking thread). In addition, the locking means 15, 16 provides the user with improved tactile (haptic) and acoustic feedback during the passage of the angular pitch, when he adjusts the downforce through the device 7 for prestressing.

5 shows a schematic representation of the balance of forces within the depicted displacement device 5. The eccentric shaft 10 presses the gate 8 towards the flexible hose 2 to cause displacement. The gate is held by a fixed support section 6, as a result of which a counteracting (returning) force F _R arises, which acts on the eccentric shaft 10 and thus also on the cantilever arm 9.1 (on which the eccentric shaft 10 is rotatably mounted). As a result, a torque occurs on the hinge 9.2 of the valve body, on which the pendulum lever 9.1 is rotatably mounted. Oriented perpendicularly to the main body of the pendulum arm 9.1, the cantilever arm 9.5 experiences a prestressing force F _V by means of a spring element 7.2, which is oriented perpendicular to the reaction force F _R and counteracts the torque generated by the reaction force F _R .

FIG. 6 shows an alternative embodiment of the positive displacement pump 1 according to the invention, which in this case is designed not as a vane peristaltic pump, but as a radial peristaltic pump (hose peristaltic pump). According to the embodiment described above, the radial peristaltic pump 1 also has a housing 4 closed by a door 3. In the housing 4, an insertion recess is provided with a substantially arcuate outer edge, which constitutes a support section 6. The displacing device 5 in the embodiment shown in FIG. made in the form of a pump rotor 5, which is rotatably mounted in the housing 4 and has several (here three) pressure rollers or support shoes 5.1. The pump rotor 5 is positioned within the recess in such a way that, in combination with the circular arc-shaped edge (i.e. with the support section 6), it forms an arcuate gap into which the flexible hose 2 is inserted or can be inserted. As the pump rotor 5 rotates, the hose 2 by means of pressure rollers/support shoes 5.1 experiences a pressure force moving in the axial direction of the hose (in the circumferential direction of the pump rotor 5), which flattens the hose 2 in relation to the support section 6 to a predetermined degree and thus moves/pumps the volume in the pumping direction. The radial positive displacement pump 1 also has an adjustable clamping force. To this end, in the illustrated example, the pump 1 has two separate adjustment springs 7, with which the bearing section 6 and the pump rotor 5 are respectively prestressed relative to each other (to each other). According to the invention, both adjusting springs 7 in the housing 4 (for example, in the through hole in it) are located in such a way that they can be adjusted from the outside, without having to open the door 3 or dismantle the housing 4. The support section 6 in the illustrated example is installed with the possibility of movement relative to the rest of the housing 4 to provide its pre-stress to the rotor 5 of the pump. Preferably, said prestressing force of the prestressing device 7, which applies the prestressing force to the pump rotor 5 and thus presses it in the direction of the bearing section 6, is introduced into the rotor axis 5.2. It goes without saying that it is quite sufficient for the implementation of the invention to provide one single prestressing device 7, which either the pump rotor 5 or the support section 6 prestresses in the direction of the respective other component 5, 6.

In summary, the positive displacement pump 1 according to the invention can be adapted by means of various design measures (such as, for example, orientation of the direction of travel perpendicular to each other or prestressing or the use of an axial pressure-loading wave spring) so that the pressure force of the displacing device (peristaltic mechanics) can be adjusted from the outside and without dismantling the housing 4. For the user, this means that the clamping force could be adjusted even without having to remove the hose 2 (disposable).

LIST OF REFERENCES

1 displacement pump

2 flexible hose

3 door/pump cover

4 building

5 displacing device

5.1 pressure rollers/support shoes

5.2 rotor axis

6 support section

7 adjustable prestressing device

7.1 adjusting screw

7.2 spring element

7.3 spring holder

8 gate

9 valve body

9.1 pendulum lever

9.2 valve body hinge

9.3 rib

9.4 cantilever arm of gate body

9.5 cantilever swing arm

9.6 thrust surfaces

10 eccentric shaft

10.1 eccentric (eccentric cam)

11 motor

12 through hole

13 sealing device

14 marking

15 retainer

16 stop section

Claims (19)

1. Positive displacement pump (1) for pumping media through a flexible hose (2) with - made with the possibility of closing by means of a door or cover (3) body (4); - a displacing device (5) for introducing/applying a clamping force to the flexible hose (2); - a support section (6) on which the flexible hose (2) is located and on which the flexible hose (2) is supported in relation to the pressing force applied by means of the displacing device (5); and - an adjustable prestressing device (7), by means of which the displacing device (5) and/or the support section (6) are prestressed at least in separate sections with an adjustable prestressing force or are prestressed relative to each other in order to allow adjustment of the applied or capable of applying clamping force to the hose (2), characterized in that the displacing device (5), the support section (6) and the device (7) for prestressing in the closed state of the body (4) are located inside it so that the device (7) for prestressing in the closed state of the body (4) can be adjusted from the outside without having to open the housing (4) for this. 2. Displacement pump (1) according to claim 1, characterized in that the pretensioning device (7) is in the form of a purely mechanical spring adjustment means (7.1, 7.1, 7.3) which is accessible from the outside of the housing (4). 3. Displacement pump (1) according to claim 1 or 2, characterized in that the displacing device (5) has peristaltic gates (8), which are mounted for linear movement in the fixed housing (9) of the gate in the direction of movement and are driven by means of an eccentric shaft (10), which is pliantly mounted relative to the gate body (9) by means of a prestressing device (7). 4. Displacement pump (1) according to one of claims 1 to 3, characterized in that the prestressing device (7) introduces a prestressing force into the displacing device (5) via the eccentric shaft (10). 5. Displacement pump (1) according to claim 3 or 4, characterized in that the prestressing device (7) is designed in such a way that the prestressing force applied by means of it is oriented transversely to the direction of movement of the peristaltic gates (8). 6. Displacement pump (1) according to one of claims 1 to 5, characterized in that the device (7) for prestressing has adjusting screw (7.1); a spring element (7.2) which is axially movable and substantially concentric on the adjusting screw (7.1); and a spring holder (7.3) which is axially movable and essentially concentric on the adjusting screw (7.1) and for this purpose designed to hold the axial end of the spring element (7.2) in a certain axial position relative to the adjusting screw (7.1). 7. Displacement pump (1) according to claim 6, characterized in that the spring holder (7.3) is connected to the adjusting screw (7.1) in such a way that, due to the rotational movement of the adjusting screw (7.1), it is displaced with a forced direction in the axial direction. 8. Displacement pump (1) according to claim 6 or 7, characterized in that the adjusting screw (7.1) is rotatably mounted on the housing (4) and/or on the housing (9) of the gate and has a locking means (15), by means of which the adjusting screw (7.1) has the possibility of locking in predetermined angular steps relative to the body (4) and/or body (9) of the gate. 9. Displacement pump (1) according to one of claims 6 to 8, characterized in that the spring element is made in the form of a wave spring and is made in its geometry in such a way that it cannot turn after a breakdown. 10. Displacement pump (1) according to one of the previous claims, characterized by a through hole (12) or a recess in the body (4) and/or body (9) of the gate, which is made in response to the device (7) for prestressing to provide access to him.

Images