Reciprocating piston pumps for conveying media

Abstract

A reciprocating piston pump (1) for conveying a medium is described, the reciprocating piston pump having a pump module (2) and a drive device (3), wherein the pump module (2) has a cylinder head (6), a cylinder (7) and a reciprocating piston (8), wherein the reciprocating piston (8) has a reciprocating piston bottom (13) with a reciprocating piston bottom surface (14), wherein the cylinder head (6), the cylinder (7) and the reciprocating piston bottom (13) form a conveying space (35), wherein the reciprocating piston (8) is designed to convert a driving motion (32) into a conveying reciprocating motion (37), and wherein the cylinder head (6), the cylinder (7) and the reciprocating piston (8) are designed to convert the conveying reciprocating motion (37) into conveying the medium. The object of the present invention is to provide a reciprocating piston pump (1) with a medium separation structure, the object being achieved in the following manner: the reciprocating piston pump (1) has an auxiliary reciprocating piston (9), the auxiliary reciprocating piston (9) is arranged between the drive device (3) and the reciprocating piston (8) and has an auxiliary reciprocating piston bottom (17) with an auxiliary reciprocating piston bottom surface (18), the cylinder (7), the reciprocating piston (8) and the auxiliary reciprocating piston bottom (17) form a lubrication space (36), the cylinder (7), the reciprocating piston (8) and the auxiliary reciprocating piston (9) are constructed to convert the drive motion (32) into an auxiliary delivery reciprocating motion (33) of the auxiliary reciprocating piston (9) and convert the auxiliary delivery reciprocating motion into the delivery reciprocating motion (37) through a lubricating medium in the lubrication space, and the auxiliary reciprocating piston bottom surface (18) is smaller than the reciprocating piston bottom surface (14).

Description

Technical Field

[0001] The present invention relates to a reciprocating piston pump for conveying a medium. The reciprocating piston pump comprises at least one pump module and a drive device. The drive device is configured to drive the at least one pump module so that the at least one pump module conveys the medium during operation. Background Art

[0002] The reciprocating piston pump is used to supply power to equipment, wherein the power is transmitted via a medium that is pressurized by the reciprocating piston pump during delivery. During operation, the reciprocating piston pump generates a pressure in the medium exceeding 160 bar. For example, the reciprocating piston pump and the equipment to be supplied are connected to a hydraulic circuit for power transmission.

[0003] The at least one pump module includes a cylinder head, a cylinder, and a reciprocating piston, wherein the reciprocating piston includes a reciprocating piston base with a reciprocating piston bottom surface. The cylinder head, cylinder, and reciprocating piston base form a delivery space. In other words, the cylinder head, cylinder, and reciprocating piston base enclose the delivery space.

[0004] The reciprocating piston is configured to convert the drive motion of the drive device into a delivery reciprocating motion and a suction reciprocating motion of the reciprocating piston in the cylinder along the longitudinal axis. Therefore, the delivery volume is not constant: when the reciprocating piston approaches the cylinder head during the delivery reciprocating motion, the delivery volume decreases. Simultaneously, the pressure of the medium in the delivery volume increases. When the reciprocating piston moves away from the cylinder head during the suction reciprocating motion, the delivery volume increases. Simultaneously, the pressure of the medium in the delivery volume decreases.

[0005] Described cylinder head, cylinder and reciprocating piston are configured to be used for by the reduction of conveying space conveying reciprocating motion is converted into the output of medium from conveying space.Usually, they are also configured to by the increase of conveying space suction reciprocating motion is converted into the suction in the conveying space of medium.

[0006] The cylinder head may include, for example, a cylinder head control mechanism that ensures that the medium flows into the delivery space during the suction reciprocating motion and flows out of the delivery space during the delivery reciprocating motion. For this purpose, the cylinder head control mechanism may include, for example, an inlet valve and an outlet valve. The cylinder and reciprocating piston may be configured, for example, to seal tightly against each other, such that the pressure of the medium in the delivery space increases during the delivery reciprocating motion and decreases during the suction reciprocating motion.

[0007] The reciprocating piston pump is designed for conveying media with a lower viscosity than lubricating media. Examples of such media include HFA and HFC media, water-glycol mixtures, and water. Consequently, the reciprocating piston pump is also designed for conveying corrosive media. Furthermore, it is designed for conveying media containing particles, i.e., abrasive media.

[0008] Furthermore, the reciprocating piston pump is designed to generate pressures during the delivery of the reciprocating motion at which the medium is no longer suitable for lubricating the contact surfaces between the cylinder and the reciprocating piston and the bearings during the drive, for example, greater than 150 bar.

[0009] Due to the medium and pressure, these contact surfaces and bearings must be lubricated with a lubricating medium that is different from the medium, and a media separation must be achieved between the medium on the one hand and the lubricating medium on the other. This media separation must ensure that no medium leaks into the lubricating medium. Leakage of medium into the lubricating medium can lead to a deterioration in the lubricating properties of the lubricating medium, which in turn can no longer ensure lubrication of the contact surfaces and bearings and can damage them. However, a slight leakage of lubricating medium into the medium is tolerable.

[0010] Various implementations of media separation are known from the prior art.

[0011] The media separation is achieved by means of a stuffing box seal between the reciprocating piston and the cylinder. In order for the stuffing box seal to seal the cylinder and the reciprocating piston sufficiently tightly against each other, it must be saturated with the medium. However, ensuring saturation with the medium inevitably leads to leakage of the medium into the lubricating medium, so that the lubricating medium must be replaced at regular intervals depending on the medium concentration in the lubricating medium. A further disadvantage is that the sealing surface of the stuffing box seal is relatively large and requires a correspondingly high friction force, which must be applied by the drive. Furthermore, the sealing surface is uncontrollable.

[0012] In another implementation, elastomeric seals are used. To reduce wear on the elastomeric seals, they must be cooled. The medium is used for this purpose, but this requires minimal leakage past the elastomeric seals. Consequently, even with elastomeric seals, the medium can be squeezed into the lubricant. Furthermore, the frequency of the delivery and suction reciprocating motions is limited to a maximum frequency due to the viscoelastic properties of the elastomeric seals.

[0013] In another embodiment, the reciprocating piston and the delivery space are separated by a diaphragm. The delivery space is formed by the cylinder head, cylinder, and diaphragm. This embodiment ensures complete media separation, thus preventing leakage. The diaphragm follows the reciprocating piston's delivery and suction movements. However, the diaphragm rubs against the reciprocating piston and cylinder, causing wear and eventually requiring replacement. Summary of the Invention

[0014] The object of the present invention is to specify a reciprocating piston pump with a medium separation which at least reduces the disadvantages mentioned in the prior art.

[0015] 18. The pump of claim 17, wherein the at least one pump module comprises a cylinder head, a cylinder, and a reciprocating piston, wherein the reciprocating piston has a reciprocating piston bottom with a reciprocating piston bottom surface, wherein the cylinder head, the cylinder, and the reciprocating piston bottom surface form a delivery space, wherein the reciprocating piston is configured to: convert the driving motion of the drive device into a delivery reciprocating motion and a suction reciprocating motion of the reciprocating piston in the cylinder along a longitudinal axis, and wherein the cylinder head, the cylinder, and the reciprocating piston are configured to: convert the delivery reciprocating motion into an output of the medium from the delivery space by reducing the delivery space, and wherein the reciprocating piston pump has an auxiliary reciprocating piston, which is arranged between the drive device and the reciprocating piston and has an auxiliary reciprocating piston bottom surface. The bottom of the auxiliary reciprocating piston, the cylinder, the reciprocating piston and the bottom of the auxiliary reciprocating piston form a lubrication space for a lubricating medium, the lubricating medium is used to lubricate the contact surface between the cylinder on the one hand and the reciprocating piston and the auxiliary reciprocating piston on the other hand, the cylinder, the reciprocating piston and the auxiliary reciprocating piston are constructed to: convert the driving motion into an auxiliary delivery reciprocating motion and an auxiliary suction reciprocating motion of the auxiliary reciprocating piston in the cylinder along the longitudinal axis, and convert the auxiliary delivery reciprocating motion of the auxiliary reciprocating piston into the delivery reciprocating motion of the reciprocating piston through the lubricating medium in the lubrication space, and the bottom surface of the auxiliary reciprocating piston is smaller than the bottom surface of the reciprocating piston, so that the pressure of the lubricating medium in the lubrication space is greater than the pressure of the medium in the delivery space during the auxiliary delivery reciprocating motion.

[0016] As described above, the reciprocating piston pump includes an auxiliary reciprocating piston, which is arranged between the drive device and the reciprocating piston and has an auxiliary reciprocating piston bottom with an auxiliary reciprocating piston bottom surface.

[0017] The bottoms of the cylinder, reciprocating piston, and auxiliary reciprocating piston form a lubrication space for a lubricating medium, which is used to lubricate the contact surfaces between the cylinder on the one hand and the reciprocating piston and auxiliary reciprocating piston on the other hand. In other words, the bottoms of the cylinder, reciprocating piston, and auxiliary reciprocating piston enclose the lubrication space.

[0018] The cylinder, reciprocating piston and auxiliary reciprocating piston are constructed to convert the driving motion into auxiliary delivery reciprocating motion and auxiliary suction reciprocating motion of the auxiliary reciprocating piston along the longitudinal axis in the cylinder and to convert the auxiliary delivery reciprocating motion of the auxiliary reciprocating piston into the delivery reciprocating motion of the reciprocating piston through the lubricating medium in the lubrication space.

[0019] The lubrication space is formed not only by the cylinder but also by the reciprocating piston and the auxiliary reciprocating piston bottom, so that the lubricating medium is in direct contact with the cylinder. Due to the reciprocating piston's delivery and suction reciprocating motion and the auxiliary reciprocating piston's auxiliary delivery and suction reciprocating motion, both the reciprocating piston and the auxiliary reciprocating piston move through the section of the cylinder that was previously in direct contact with the lubricating medium, so that the contact surfaces between the cylinder and the reciprocating piston, on the one hand, and between the cylinder and the auxiliary reciprocating piston, on the other hand, are lubricated by the lubricating medium.

[0020] The auxiliary reciprocating piston bottom surface is smaller than the reciprocating piston bottom surface, so that during the auxiliary delivery reciprocating motion, the pressure of the lubricating medium in the lubrication space is greater than the pressure of the medium in the delivery space. In other words, the pressure in the lubricating medium is greater than the pressure in the medium because the auxiliary reciprocating piston bottom surface is smaller than the reciprocating piston bottom surface.

[0021] The pressure of the lubricating medium in the lubrication space is greater than the pressure of the medium in the delivery space, resulting in leakage only from the lubrication space into the delivery space, on the one hand, and toward the drive, on the other hand. Leakage toward the drive is not a problem, while leakage into the delivery space is tolerable. In any case, no medium is introduced into the lubricant, so the lubricating properties of the lubricant are not impaired.

[0022] Compared to the first two described implementations of media separation, there is no longer any leakage of the medium into the lubricant. Compared to the first implementation, the friction power is also reduced, and compared to the second implementation, the maximum frequency is higher. Compared to the third implementation of media separation, wear is reduced, and thus maintenance intervals are extended.

[0023] In one embodiment of the reciprocating piston pump, the cylinder has a cylinder inner circumference concentric with the longitudinal axis and having a cylinder radius, the reciprocating piston has a reciprocating piston outer circumference concentric with the longitudinal axis and having a reciprocating piston radius, and the auxiliary reciprocating piston has an auxiliary reciprocating piston outer circumference concentric with the longitudinal axis and having an auxiliary reciprocating piston radius. Furthermore, it is provided that both the reciprocating piston radius and the auxiliary reciprocating piston radius are matched to the cylinder radius.

[0024] For example, the cylinder radius has a first value in a first range along the longitudinal axis and a second value, which is smaller than the first value, in a second range along the longitudinal axis. The reciprocating piston radius then has a value that matches the first value, and the auxiliary reciprocating piston radius has a value that matches the second value. Here, the first range extends over the range of the reciprocating piston's delivery and suction reciprocating motions, and the second range extends over the range of the auxiliary reciprocating piston's auxiliary delivery and auxiliary suction reciprocating motions.

[0025] However, it is preferred that the reciprocating piston radius and the auxiliary reciprocating piston radius are equal. Then, the cylinder radius has the same value in the first and second intervals, and the reciprocating piston radius and the auxiliary reciprocating piston radius have values that match this value.

[0026] If the auxiliary delivery reciprocating motion of the auxiliary reciprocating piston is converted into the delivery reciprocating motion of the reciprocating piston by the lubricating medium in the lubrication space, the pressure in the lubricating medium in the lubrication space is higher than the pressure in the medium in the delivery space. This is achieved in the following manner, namely: the bottom surface of the auxiliary reciprocating piston is smaller than the bottom surface of the reciprocating piston. In another design, the reduction of the bottom surface of the auxiliary reciprocating piston relative to the bottom surface of the reciprocating piston is achieved in the following manner, namely: the reciprocating piston has a relief reciprocating piston and the auxiliary reciprocating piston has a relief cylinder matching the relief reciprocating piston in the bottom of the auxiliary reciprocating piston and the relief cylinder has a relief space and / or is connected to the relief space. Preferably, the relief reciprocating piston is a rod.

[0027] Since very small leaks are unavoidable between the cylinder on the one hand and the reciprocating piston and the auxiliary reciprocating piston on the other hand, the lubrication space is reduced, so that the piston distance between the reciprocating piston and the auxiliary reciprocating piston becomes smaller and the auxiliary delivery reciprocating movement is greater than the delivery reciprocating movement. The reduction in the piston distance causes the unloading piston to move towards the inside of the unloading cylinder. As a result, the pressure in the unloading space increases. The unloading space is formed, for example, by the unloading piston and the unloading cylinder. This pressure increase offsets the reduction of the auxiliary piston bottom surface relative to the piston bottom surface. It is therefore advantageous to select the unloading space to be as large as possible. The unloading space is preferably the surrounding environment, so that a pressure increase in the unloading space hardly occurs. For this purpose, the auxiliary reciprocating piston has a unloading line, which connects the unloading cylinder to the surrounding environment.

[0028] In a refinement of the aforementioned design, the pressure relief reciprocating piston and the unloading cylinder limit the piston distance along the longitudinal axis between the reciprocating piston and the auxiliary reciprocating piston to a maximum piston distance. Limiting this piston distance also limits the lubrication space to a maximum lubricant space. Without limiting the piston distance, there is a possibility that the reciprocating piston could strike the cylinder head during the delivery reciprocating motion, potentially damaging the reciprocating piston pump.

[0029] In another design, the reciprocating piston pump has a bearing and the bearing is arranged between the drive unit and the auxiliary reciprocating piston. In addition, the bearing is configured to convert the driving motion of the drive unit into the auxiliary delivery reciprocating motion and the auxiliary suction reciprocating motion of the auxiliary reciprocating piston.

[0030] In an improved version of the aforementioned design, it is provided that the drive device has a drive shaft. It is further provided that the drive shaft has a drive eccentric with an eccentric sliding surface and the auxiliary reciprocating piston has an auxiliary reciprocating piston sliding surface. Here, the eccentric sliding surface and the auxiliary reciprocating piston sliding surface form the bearing. In addition, the drive shaft and the auxiliary reciprocating piston are configured to convert the driving motion of the drive shaft in the form of rotation into an auxiliary delivery reciprocating motion and an auxiliary suction reciprocating motion via the bearing. A drive shaft without a drive eccentric is usually configured as a crankshaft having a crank journal, wherein the crank journal is rotatably arranged in the drive eccentric. The rotational motion of the drive eccentric is prevented by the eccentric shape of the eccentric sliding surface in combination with the auxiliary reciprocating piston sliding surface. An alternative to this is a drive shaft having an eccentric journal, wherein the eccentric journal is rotatably arranged in the drive eccentric.

[0031] The eccentric sliding surface and the auxiliary reciprocating piston sliding surface have a common contact surface, via which the rotation of the drive shaft is converted into an auxiliary conveying and auxiliary suction reciprocating motion. In this sense, the eccentric sliding surface and the auxiliary reciprocating piston sliding surface form the bearing. The common contact surface must be lubricated with a lubricating medium in order to reduce wear on the eccentric sliding surface and the auxiliary reciprocating piston sliding surface. The bearing is designed for a lubricating medium that is also suitable for the contact surface between the cylinder on the one hand and the reciprocating piston and the auxiliary reciprocating piston on the other hand.

[0032] If the reciprocating piston pump has the bearings described above, it should be ensured that the bearings are adequately supplied with lubricant. Therefore, in another embodiment, it is provided that the auxiliary reciprocating piston has an auxiliary reciprocating piston lubrication line, which connects the lubrication space and the auxiliary reciprocating piston sliding surface in order to supply lubricating medium to the bearings. The bearings are thus lubricated with a lubricating medium, which also lubricates the contact surfaces between the cylinder on the one hand and the reciprocating piston and the auxiliary reciprocating piston on the other hand. In this case, the lubricating medium is supplied to the bearings at the pressure that occurs in the delivery space during the reciprocating delivery motion. Preferably, the auxiliary reciprocating piston lubrication medium line is a channel in the auxiliary reciprocating piston. In this case, there is no separate lubricating medium line.

[0033] In a refinement of the aforementioned design, the auxiliary reciprocating piston lubrication line has at least one non-return valve. The non-return valve reduces the outflow of lubricating medium in the bearing. Without the non-return valve, such outflow would occur, for example, during a suction reciprocating movement.

[0034] In another embodiment, the reciprocating piston pump includes a longitudinal slide valve for controlling the delivery of lubricating medium into the lubrication space. The longitudinal slide valve has at least one cylinder opening in the cylinder for delivering lubricating medium into the lubrication space. Preferably, the at least one cylinder opening is a groove, a recess, and / or a bore. The valve function is inherently generated adjacent to the at least one opening in the cylinder, either by the reciprocating piston's delivery and suction reciprocating motion or by the auxiliary delivery and suction reciprocating motion of the auxiliary piston.

[0035] In a particularly preferred refinement of the aforementioned design, the auxiliary reciprocating piston lubrication line described above is additionally implemented. In this refinement, not only the contact surfaces between the cylinder on the one hand and the reciprocating piston and the auxiliary reciprocating piston on the other hand, but also the bearings are lubricated with a lubricating medium that can be supplied via a longitudinal slide valve.

[0036] In a refinement of the aforementioned design, provision is made for the at least one cylinder opening to release the supply of lubricating medium to the lubrication space when the reciprocating piston is in the region of a reversal point from the suction reciprocating motion to the delivery reciprocating motion. In the region of the reversal point, the pressure in the lubrication space is lowest, resulting in the most efficient supply of lubricating medium.

[0037] If the reciprocating piston pump has the bearings described above, it should be ensured that the bearings are adequately supplied with lubricant. As an alternative or supplement to the design described above with an auxiliary reciprocating piston lubrication line, the following design provides that the drive shaft has a drive device lubrication line. The drive device lubrication line therefore extends not only through the drive shaft itself but also through the drive eccentric of the drive shaft. In addition, the drive shaft has a rotary slide valve, which is used to control the supply of lubricating medium to the bearings. Here, the rotary slide valve has a drive shaft gap in the drive shaft over the angular range of rotation of the drive shaft, so that lubricating medium is only supplied to the bearings over this angular range. Preferably, the drive device lubrication line is a channel in the drive shaft and in the drive eccentric. In this case, there is no separate lubricating medium line. Here, the rotary slide valve is usually formed by the drive shaft gap and the drive device lubrication line in the eccentric. The rotary slide valve also ensures that lubricant is supplied to the contact surface between the drive shaft and the drive eccentric.

[0038] In a development of the aforementioned embodiment, it is provided that the drive lubrication line has at least one non-return valve, which reduces the outflow of lubricating medium present in the bearing.

[0039] In a particularly preferred development of the aforementioned design, the aforementioned auxiliary reciprocating piston lubrication line is additionally implemented. In this development, not only the bearings but also the contact surfaces between the cylinder on the one hand and the reciprocating piston and the auxiliary reciprocating piston on the other hand are lubricated with a lubricating medium that can be supplied via the drive lubrication line.

[0040] In another embodiment, the reciprocating piston pump includes a lubrication pump for supplying lubricating medium to at least one pump module and / or the drive. In this embodiment, the reciprocating piston pump is configured to convey lubricating medium from the lubrication pump to the longitudinal slide valve in an embodiment with the aforementioned longitudinal slide valve, and to convey lubricating medium from the lubrication pump to the drive lubrication line in an embodiment with the aforementioned drive lubrication line. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Specifically, a plurality of possible solutions for constructing and improving the reciprocating piston pump are given. For this, reference can be made not only to the preferred embodiments of the present invention, but also to the following description of the embodiments in conjunction with the accompanying drawings. In the accompanying drawings:

[0042] Figure 1 shows an abstract perspective sectional view of a first exemplary embodiment of a reciprocating piston pump,

[0043] Figure 2 shows an abstract perspective view of a cylinder of the first embodiment,

[0044] Figure 3 shows an abstract perspective view of the reciprocating piston of the first embodiment,

[0045] Figure 4a 、 4b Two different abstract perspective views showing the auxiliary reciprocating piston of the first embodiment,

[0046] Figure 5 shows an abstract perspective sectional view of a second embodiment of a reciprocating piston pump, and

[0047] Figure 6 A perspective view of a third embodiment of a reciprocating piston pump is shown. DETAILED DESCRIPTION

[0048] Figure 1 A first exemplary embodiment of a reciprocating piston pump 1 for conveying a medium is shown. The pump comprises a pump module 2 , a drive 3 , bearings 4 and a lubrication pump 5 .

[0049] The pump module 2 has a cylinder head 6, a cylinder 7, and a Figure 2 , reciprocating piston 8, see also Figure 3 and auxiliary reciprocating piston 9, see also Figure 4a 、 4b .

[0050] The cylinder 7 has a cylinder inner circumference 11 concentric with the longitudinal axis 10 and having a cylinder radius 12. The reciprocating piston 8 has a reciprocating piston bottom 13 with a reciprocating piston bottom surface 14 and a reciprocating piston outer circumference 15 concentric with the longitudinal axis 10 and having a reciprocating piston radius 16. The auxiliary reciprocating piston 9 is arranged between the drive device 3 and the reciprocating piston 8 and has an auxiliary reciprocating piston bottom 17 with an auxiliary reciprocating piston bottom surface 18, an auxiliary reciprocating piston outer circumference 19 concentric with the longitudinal axis 10 and having an auxiliary reciprocating piston radius 20, and an auxiliary reciprocating piston sliding surface 21. The reciprocating piston radius 16 and the auxiliary reciprocating piston radius 20 are equal and matched to the cylinder radius 12.

[0051] The reciprocating piston 8 has a relief reciprocating piston 22 and the auxiliary reciprocating piston 9 has a relief cylinder 23 in the auxiliary reciprocating piston bottom 17 that matches the relief reciprocating piston 22. The relief cylinder 23 is connected to the surrounding environment as a relief space via a relief line 24. The relief reciprocating piston 22 is a rod in this embodiment. The relief reciprocating piston 22 and the relief cylinder 23 limit the piston distance 25 along the longitudinal axis 10 between the reciprocating piston 8 and the auxiliary reciprocating piston 9 to a maximum piston distance. To this end, the relief reciprocating piston 22 has a ring 26 and the relief cylinder 23 has a groove 27 that matches the ring 26. The reciprocating piston 8 and the auxiliary reciprocating piston 9 can move relative to each other along the longitudinal axis 10 corresponding to the ring 26 and the groove 7.

[0052] The drive device 3 has a drive shaft 28, and the drive shaft 28 has a drive eccentric 29 with an eccentric sliding surface 30. The drive shaft 28 without the drive eccentric 29 is designed as a crankshaft with a crank journal 31, wherein the crank journal 31 is rotatably arranged in the drive eccentric 29. The rotational movement of the drive eccentric 29 is prevented by the eccentric shape of the eccentric sliding surface 30 in combination with the attached auxiliary reciprocating piston sliding surface 21.

[0053] The eccentric sliding surface 30 and the auxiliary reciprocating piston sliding surface 21 form the bearing 4. The bearing 4 is arranged between the drive device 3 and the auxiliary reciprocating piston 9. The drive shaft 28 with the drive eccentric 29 and the auxiliary reciprocating piston 9 are configured to convert the driving motion 32 in the form of rotation of the drive shaft 28 via the bearing 4 into an auxiliary delivery reciprocating motion 33 and an auxiliary suction reciprocating motion 34 of the auxiliary reciprocating piston 9 in the cylinder 7 along the longitudinal axis 10. Therefore, the bearing 4 is configured to convert the driving motion 32 into the auxiliary delivery reciprocating motion 33 and the auxiliary suction reciprocating motion 34.

[0054] The cylinder head 6, cylinder 7, and reciprocating piston base 9 form a delivery space 35. Furthermore, the cylinder 7, reciprocating piston 8, and auxiliary reciprocating piston base 17 form a lubrication space 36 for a lubricating medium, which is used to lubricate the contact surfaces between the cylinder 7, on the one hand, and the reciprocating piston 8 and auxiliary reciprocating piston 9, on the other hand. In this embodiment, the contact surfaces are, on the one hand, the cylinder inner circumference 11 and the reciprocating piston outer circumference 15, and, on the other hand, the cylinder inner circumference 11 and the auxiliary reciprocating piston outer circumference 19.

[0055] The cylinder 7, the reciprocating piston 8, and the auxiliary reciprocating piston 9 are configured to convert the drive motion 32 into an auxiliary delivery reciprocating motion 33 and an auxiliary suction reciprocating motion 34 of the auxiliary reciprocating piston 9 in the cylinder 7 along the longitudinal axis 10, and also to convert the auxiliary delivery reciprocating motion 33 of the auxiliary reciprocating piston 9 into a delivery reciprocating motion 37 of the reciprocating piston 8 in the cylinder 7 along the longitudinal axis 10 via the lubricating medium in the lubrication space 36. Furthermore, in the present embodiment, the cylinder 7, the reciprocating piston 8, and the auxiliary reciprocating piston 9 are configured to convert the auxiliary suction reciprocating motion 34 of the auxiliary piston 9 into a suction reciprocating motion 37 of the reciprocating piston 8 in the cylinder 7 along the longitudinal axis 10 via the lubricating medium in the lubrication space 36.

[0056] In this respect, the reciprocating piston 8 is designed to convert the drive movement 32 of the drive device 3 into a delivery reciprocating movement 37 and a suction reciprocating movement 38 of the reciprocating piston 8 in the cylinder 7 along the longitudinal axis 10 .

[0057] The cylinder head 6, cylinder 7 and reciprocating piston 8 are configured to convert the delivery reciprocating motion 37 of the reciprocating piston 8 into the discharge of the medium from the delivery space 35 by reducing the delivery space 35. To this end, the cylinder head 6 has a cylinder head control mechanism that ensures that the medium flows into the delivery space 35 during the suction reciprocating motion 38 and that the medium flows out of the delivery space 35 during the delivery reciprocating motion 37. The cylinder head control mechanism has an inlet valve and an outlet valve for this purpose. Not only the cylinder head control mechanism but also the inlet and outlet valves are not shown. In this embodiment, the cylinder head 6, cylinder 7 and reciprocating piston 8 are also configured to convert the suction reciprocating motion 38 into the suction of the medium into the delivery space 35 by increasing the delivery space 35.

[0058] The auxiliary reciprocating piston bottom surface 18 is smaller than the reciprocating piston bottom surface 14 because, compared to the reciprocating piston bottom surface 14, the auxiliary reciprocating piston bottom surface 18 lacks the cross-sectional area of the unloading cylinder 23. Therefore, during the auxiliary delivery reciprocating motion 33 of the auxiliary reciprocating piston 9, the pressure of the lubricant in the lubricant space 36 is greater than the pressure of the medium in the delivery space 35 generated by the delivery reciprocating motion 37 of the reciprocating piston 8.

[0059] The auxiliary reciprocating piston 9 has an auxiliary reciprocating piston lubrication line 39. This connects the lubrication chamber 36 and the auxiliary reciprocating piston sliding surface 21 to each other, thereby supplying lubricating medium to the bearing 4. The auxiliary reciprocating piston lubrication line 39 is a channel in the auxiliary reciprocating piston 9. The driving eccentric 29 preferably has an auxiliary lubrication line that connects the eccentric sliding surface 30 and the contact surface between the crank journal 31 and the driving eccentric 29, so that these contact surfaces are also supplied with lubricating medium during operation. However, this auxiliary lubrication line is not shown here.

[0060] The reciprocating piston pump 1 also has a longitudinal slide valve 40 for controlling the delivery of lubricating medium into the lubrication space 36. The longitudinal slide valve 40 has a cylinder opening 41 in the cylinder 7 for delivering lubricating medium into the lubrication space 36. The cylinder opening 41 is a bore. If the reciprocating piston 8 is in the region of the reversal point from the suction reciprocating motion 38 to the delivery reciprocating motion 37, the cylinder opening releases the delivery of lubricating medium into the lubrication space 36.

[0061] The lubrication pump 5 is configured to supply lubricating medium to the pump module 2 and the drive device 3, and the reciprocating piston pump 1 is configured to convey lubricating medium from the lubrication pump 5 to the longitudinal slide valve 40. During operation of the reciprocating piston pump 1, lubricating medium is supplied via the auxiliary reciprocating piston lubrication line 39 not only to the contact surfaces between the cylinder 7 on the one hand and the reciprocating piston 8 and the auxiliary reciprocating piston 9 on the other hand, but also to the bearing 4 for lubrication. The bearing 4 is supplied from the lubrication chamber 36 via the auxiliary reciprocating piston lubrication line 39.

[0062] Figure 5 A second embodiment of a reciprocating piston pump 1 for conveying a medium is shown. Only the differences from the first embodiment are described below. Otherwise, the explanations regarding the first embodiment apply analogously to the second embodiment.

[0063] In contrast to the first exemplary embodiment, the reciprocating piston pump 1 in the second exemplary embodiment does not have the described longitudinal slide valve 40. Instead, the drive shaft 28 has a drive lubrication line 42. The drive lubrication line 42 therefore extends not only through the drive shaft 28 itself but also through the drive eccentric 29. The portion of the drive lubrication line 42 in the drive eccentric 29 thus corresponds to the auxiliary lubrication line in the first exemplary embodiment.

[0064] The drive shaft 28 also has a rotary slide valve 43 for controlling the supply of lubricating medium to the bearing 4. The rotary slide valve 43 has a drive shaft recess 44 in the drive shaft 28 over the angular range of rotation of the drive shaft 28, so that lubricating medium is supplied to the bearing 4 only over this angular range. In this embodiment, the drive lubrication line 42 is a channel in the drive shaft 28 and in the drive eccentric 29. The rotary slide valve 43 is formed by the drive shaft recess 44 in the eccentric 29 and the drive lubrication line 42. The rotary slide valve 43 also ensures that lubricant is supplied to the contact surface between the drive shaft 28 and the drive eccentric 29.

[0065] The lubrication pump 5 is configured to supply lubricating medium to the pump module 2 and the drive 3 , and the reciprocating piston pump 1 is configured to convey lubricating medium from the lubrication pump 5 to a drive lubrication line 42 . During operation of the reciprocating piston pump 1 , lubricating medium is supplied to the bearing 4 and also to the contact surfaces between the cylinder 7 on the one hand and the reciprocating piston 8 and the auxiliary reciprocating piston 9 on the other hand, via the drive lubrication line 42 and the auxiliary reciprocating piston lubrication line 39 for lubrication. Lubricating medium is supplied from the drive lubrication line 42 via the auxiliary reciprocating piston lubrication line 39 and through the bearing 4 to the contact surfaces between the cylinder 7 on the one hand and the reciprocating piston 8 and the auxiliary reciprocating piston 9 on the other hand, as well as to the lubrication space 36 .

[0066] Figure 6 A third exemplary embodiment of a reciprocating piston pump 1 is shown. Compared to the first and second exemplary embodiments, the reciprocating piston pump has a plurality of pump modules 2. Otherwise, the reciprocating piston pump 1 is designed like the reciprocating piston pump described in the first or second exemplary embodiment.

[0067] Reference Signs List

[0068] 1 reciprocating piston pump

[0069] 2 pump modules

[0070] 3 drive device

[0071] 4 bearings

[0072] 5. Lubrication pump

[0073] 6-cylinder head

[0074] 7-cylinder

[0075] 8 reciprocating piston

[0076] 9 auxiliary reciprocating piston

[0077] 10 vertical axis

[0078] 11 cylinder inner surface

[0079] 12 cylinder radius

[0080] 13 Reciprocating piston bottom

[0081] 14 Reciprocating piston bottom

[0082] 15 Reciprocating piston outer surface

[0083] 16 Reciprocating piston radius

[0084] 17 Auxiliary reciprocating piston bottom

[0085] 18 Auxiliary reciprocating piston bottom surface

[0086] 19 Auxiliary reciprocating piston outer surface

[0087] 20 Auxiliary reciprocating piston radius

[0088] 21 Auxiliary reciprocating piston sliding surface

[0089] 22 Unloading reciprocating piston

[0090] 23 unloading cylinder

[0091] 24 unloading pipeline

[0092] 25 piston spacing

[0093] 26 rings

[0094] 27 slots

[0095] 28 drive shaft

[0096] 29 driving eccentric wheel

[0097] 30 eccentric wheel sliding surface

[0098] 31 crank journal

[0099] 32 drive motion

[0100] 33 Auxiliary conveying reciprocating motion

[0101] 34 auxiliary suction reciprocating motion

[0102] 35 conveying space

[0103] 36 lubrication space

[0104] 37 Conveying reciprocating motion

[0105] 38 Suction reciprocating motion

[0106] 39 auxiliary reciprocating piston lubrication line

[0107] 40 longitudinal slide valve

[0108] 41 cylinder opening

[0109] 42 Drive device lubrication pipeline

[0110] 43 Rotate the slide valve

[0111] 44 drive shaft clearance

Claims

1. A reciprocating piston pump (1) for conveying a medium, comprising at least one pump module (2) and a drive device (3), The at least one pump module (2) comprises a cylinder head (6), a cylinder (7) and a reciprocating piston (8), The reciprocating piston (8) has a reciprocating piston bottom (13) with a reciprocating piston bottom surface (14), The cylinder head (6), the cylinder (7) and the reciprocating piston bottom (13) form a conveying space (35), The reciprocating piston (8) is configured to convert the driving motion (32) of the driving device (3) into a delivery reciprocating motion (37) and a suction reciprocating motion (38) of the reciprocating piston (8) in the cylinder (7) along the longitudinal axis (10), and The cylinder head (6), the cylinder (7) and the reciprocating piston (8) are configured to convert the conveying reciprocating motion (37) into the discharge of the medium from the conveying space (35) by reducing the conveying space (35). It is characterized by: The reciprocating piston pump (1) has an auxiliary reciprocating piston (9), The auxiliary reciprocating piston (9) is arranged between the drive device (3) and the reciprocating piston (8) and has an auxiliary reciprocating piston bottom (17) with an auxiliary reciprocating piston bottom surface (18). The cylinder (7), the reciprocating piston (8) and the auxiliary reciprocating piston bottom (17) form a lubrication space (36) for a lubricating medium, the lubricating medium being used to lubricate the contact surfaces between the cylinder (7) on the one hand and the reciprocating piston (8) and the auxiliary reciprocating piston (9) on the other hand, The cylinder (7), the reciprocating piston (8) and the auxiliary reciprocating piston (9) are configured to: convert the driving motion (32) into an auxiliary delivery reciprocating motion (33) and an auxiliary suction reciprocating motion (34) of the auxiliary reciprocating piston (9) in the cylinder (7) along the longitudinal axis (10), and convert the auxiliary delivery reciprocating motion (33) of the auxiliary reciprocating piston (9) into a delivery reciprocating motion (37) of the reciprocating piston (8) via the lubricating medium in the lubrication space, and The auxiliary reciprocating piston bottom surface (18) is smaller than the reciprocating piston bottom surface (14), so that the pressure of the lubricating medium in the lubricating space (36) is greater than the pressure of the medium in the conveying space (35) during the auxiliary conveying reciprocating motion (33).

2. The reciprocating piston pump (1) according to claim 1, characterized in that The cylinder (7) has a cylinder inner circumference (11) which is concentric with the longitudinal axis (10) and has a cylinder radius (12). The reciprocating piston (8) has a reciprocating piston outer surface (15) which is concentric with the longitudinal axis (10) and has a reciprocating piston radius (16). The auxiliary reciprocating piston (9) has an auxiliary reciprocating piston outer peripheral surface (19) which is concentric with the longitudinal axis (10) and has an auxiliary reciprocating piston radius (20), and Both the reciprocating piston radius (16) and the auxiliary reciprocating piston radius (20) are adapted to the cylinder radius (12).

3. The reciprocating piston pump (1) according to claim 2, characterized in that The reciprocating piston radius (16) and the auxiliary reciprocating piston radius (20) are the same.

4. The reciprocating piston pump (1) according to any one of claims 1 to 3, characterized in that The reciprocating piston (8) has an unloading reciprocating piston (22), and the auxiliary reciprocating piston (9) has an unloading cylinder (23) matching the unloading reciprocating piston (22) in the auxiliary reciprocating piston bottom (17), and the unloading cylinder (23) has an unloading space and / or is connected to the unloading space.

5. The reciprocating piston pump (1) according to claim 4, characterized in that The unloading reciprocating piston (22) is a rod.

6. The reciprocating piston pump (1) according to claim 4, characterized in that The unloading reciprocating piston (22) and the unloading cylinder (23) limit the piston distance (25) between the reciprocating piston (8) and the auxiliary reciprocating piston (9) along the longitudinal axis (10) to a maximum piston distance.

7. The reciprocating piston pump (1) according to any one of claims 1 to 3, characterized in that The reciprocating piston pump (1) has a bearing (4), which is arranged between the drive device (3) and the auxiliary reciprocating piston (9) and is configured to convert the drive motion (32) into the auxiliary delivery reciprocating motion (33) and the auxiliary suction reciprocating motion (34).

8. The reciprocating piston pump (1) according to claim 7, characterized in that The drive device (3) has a drive shaft (28), the drive shaft (28) has a drive eccentric (29) with an eccentric sliding surface (30), the auxiliary reciprocating piston (9) has an auxiliary reciprocating piston sliding surface (21), the eccentric sliding surface (30) and the auxiliary reciprocating piston sliding surface (21) form the bearing (4), and the drive shaft (28) and the auxiliary reciprocating piston (9) are constructed to convert the driving motion (32) of the drive shaft (28) in the form of rotation into the auxiliary conveying reciprocating motion (33) and the auxiliary suction reciprocating motion (34) via the bearing (4).

9. The reciprocating piston pump (1) according to claim 8, characterized in that The auxiliary reciprocating piston (9) has an auxiliary reciprocating piston lubrication pipeline (39), which connects the lubrication space (36) and the auxiliary reciprocating piston sliding surface (21) to supply lubricating medium to the bearing (4).

10. The reciprocating piston pump (1) according to claim 9, characterized in that The auxiliary reciprocating piston lubrication line (39) is a passage in the auxiliary reciprocating piston (9).

11. The reciprocating piston pump (1) according to claim 9, characterized in that The auxiliary reciprocating piston lubrication line (39) has at least one check valve.

12. The reciprocating piston pump (1) according to any one of claims 1 to 3, characterized in that The reciprocating piston pump (1) has a longitudinal slide valve (40) for controlling the delivery of lubricating medium into the lubricating space (36), and the longitudinal slide valve (40) has at least one cylinder opening (41) in the cylinder (7) for delivering the lubricating medium into the lubricating space (36).

13. The reciprocating piston pump (1) according to claim 12, characterized in that The at least one cylinder opening (41) is a slot.

14. The reciprocating piston pump (1) according to claim 12, characterized in that If the reciprocating piston (8) is in the region of a reversal point from the suction reciprocating motion (38) to the delivery reciprocating motion (37), the at least one cylinder opening (41) releases the delivery of lubricating medium to the lubrication space (36).

15. The reciprocating piston pump (1) according to claim 8, characterized in that The drive shaft (28) has a drive lubrication line (42) and a rotary slide valve (43) for controlling the supply of lubricating medium to the bearing (4), wherein the rotary slide valve (43) has a drive shaft recess (44) in the drive shaft (28) over the angular range of rotation of the drive shaft (28), so that the lubricating medium is supplied to the bearing (4) only over the angular range.

16. The reciprocating piston pump (1) according to claim 15, characterized in that The drive lubrication line (42) is a channel in the drive shaft (28) and in the drive eccentric (29).

17. The reciprocating piston pump (1) according to claim 15, characterized in that The drive lubrication line (42) has at least one check valve.

18. The reciprocating piston pump (1) according to claim 12, characterized in that The reciprocating piston pump (1) has a lubrication pump (5) for supplying lubricating medium to the at least one pump module (2) and / or the drive device (3), and the reciprocating piston pump (1) is configured to convey the lubricating medium from the lubrication pump (5) to the longitudinal slide valve (40) and / or the drive device lubrication line (42).

19. The reciprocating piston pump (1) according to claim 12, characterized in that The at least one cylinder opening (41) is a notch.

20. The reciprocating piston pump (1) according to claim 12, characterized in that The at least one cylinder opening (41) is a drilled hole.

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