DE102020125000A1 - In-line piston pump - Google Patents

Abstract

The present invention relates to an in-line piston pump, comprising a drive shaft for driving the pump, at least two pistons which are operatively connected to the drive shaft and which are arranged along a drive shaft axis and are each arranged to be movable to and fro in a piston chamber, a base housing part for receiving the drive shaft and for inserting the at least two pistons into corresponding receiving recesses, and a cover housing part for attachment to the basic housing part. The invention is also characterized in that the contact area generated when the cover housing part is attached to the base housing part runs in a surface, preferably in a plane, which exposes the piston space of a respective one of the at least two pistons.

Description

The present invention relates to an in-line piston pump, which is preferably a hydraulic positive displacement pump of in-line piston design. This comprises at least two displacement units which are arranged one behind the other in the direction of the drive shaft axis.

Such pumps are required in a large number of applications, for example for circulating a coolant circuit in a vehicle, for supplying a fan motor, for oil circulation in an internal combustion engine. Such pumps are also required for use in small devices, e.g. a mini excavator.

The DE 197 08 597 discloses a suction throttled feed pump and shows the use of a suction throttle for a series piston pump.

The WO 2010 130 495 A1 discloses an in-line piston pump whose drive shaft is designed as a crankshaft.

In-line piston pumps with a camshaft are also known from the prior art.

The aim of the present invention is to provide an in-line piston pump which is as inexpensive as possible and offers extensive flexibility for installation and, in addition, offers the highest possible power density.

This is achieved with the in-line piston pump, which has all the features of claim 1. Such a pump has an advantageously constructed structure and is designed to optimize installation space. Advantageous refinements are set out in the dependent claims.

The in-line piston pump according to the invention comprises a drive shaft for driving the at least two pistons which are operatively connected to the drive shaft, which pistons are arranged along a drive shaft axis and are each arranged to be movable back and forth in a piston chamber, a base housing part for receiving the drive shaft and for inserting the at least two pistons in corresponding receiving recesses, for example piston bores and a cover housing part for attachment to the basic housing part. The pump is characterized in that the contact area generated when the cover housing part is attached to the base housing part runs in a surface, preferably in a plane, which exposes the piston space of a respective one of the at least two pistons.

The pump can be installed particularly easily, since the necessary components, such as pistons and valves, etc., can be inserted in a simple manner through the section of the preferably flat contact surface of the base housing part and the cover housing part.

It can be provided that the contact area is designed so that when the base housing part and cover housing part are separated, the pistons and at least one pressure valve, preferably in the form of high-pressure check valves, can be inserted into the basic housing part and at least one suction valve can be inserted into the cover housing part .

According to a further modification, it can be provided that the drive shaft is designed as a camshaft with single or multiple cams, as a crankshaft or an eccentric shaft.

According to a further optional development of the invention, it can be provided that the drive shaft axis runs parallel to a plane formed by the contact area.

It is preferably provided that the pump is furthermore provided with at least one suction valve which is arranged in the cover housing part and preferably does not protrude beyond the contact area in an installed state.

The suction valve and the piston of a respective displacement unit can have an identical longitudinal axis.

According to a further modification, it can be provided that the respective longitudinal direction of the bores for receiving the at least one suction valve runs preferably perpendicular to a plane formed by the contact area.

This facilitates the introduction of the at least one suction valve into the respective bore provided for this purpose.

Furthermore, it can be provided that the cover housing part comprises several suction valves arranged in parallel next to one another. The suction valves can be present in pairs with a corresponding piston in the in-line piston pump, the base housing part having corresponding receiving recesses for the pistons.

The invention also includes the possibility that at least one high-pressure check valve is provided, which is arranged in the basic housing part and preferably does not protrude beyond the contact area in an installed state. The high-pressure check valves can be present in pairs with a corresponding piston in the in-line piston pump,

A displacement unit comprises a piston and two valves, which are preferably designed as check valves. The valve located at the inlet of a displacement unit is referred to in the following text as a suction valve and the term high-pressure check valve is used below for the valve located at the outlet of the displacement unit.

A suction valve is in fluid connection with a space that can be changed in volume by the piston, which is called the oil compression space, and ensures that during a piston stroke that leads to an increase in this space, fluid from the suction side of the in-line piston pump due to the negative pressure can flow into this space and no pressurized fluid flows back to the suction side during the compression stroke of the piston.

A high-pressure check valve is in fluid connection with a space that can be changed in volume by the piston, i.e. the oil compression space and ensures that (i) the compressed fluid can flow off in the direction of the high-pressure outlet during a compression stroke of the piston of the same displacement unit; (ii) during a piston stroke that leads to an enlargement of this space, no fluid can flow into this space from the high-pressure side of the in-line piston pump and (iii) during the compression stroke of a piston in another displacement unit, no pressurized fluid flows back into the displacement unit under consideration .

The longitudinal axis of the piston and the longitudinal axis of a high-pressure check valve of a respective displacement unit are preferably arranged on a plane which is preferably pierced perpendicularly by the drive shaft axis.

In addition, it can be provided according to the invention that the basic housing part comprises a plurality of high-pressure check valves arranged in parallel next to one another. The side of the high-pressure check valve facing away from the oil compression chamber preferably represents a common high-pressure channel of the in-line piston pump, via which fluid conveyed by the displacement unit in question is discharged to a high-pressure connection.

According to a further modification, it can be provided that the respective longitudinal directions of the piston chambers for receiving the pistons run perpendicular to a plane formed by the contact area and preferably extend radially from the drive shaft axis.

According to the invention it can also be provided that the piston has a pin which, when installed, exceeds the surface formed by the contact area and preferably protrudes into the recess that houses the suction valve of the same displacement unit and preferably into the spring chamber of the centering element The pressure spring of the suction valve protrudes.

The pump according to the invention can furthermore be provided with a device which is used to regulate or control the pump, which is preferably arranged in the cover housing part.

This device for regulating or controlling the in-line piston pump can, for example, be a suction throttle valve which is preferably arranged such that its longitudinal axis is arranged parallel to the drive shaft axis.

This could regulate the flow of the fluid to be pumped.

According to the invention it can be provided that the pump comprises three separable housing parts, preferably only three separable housing parts, namely the basic housing part, the cover housing part and a mounting flange part.

It is preferably provided that the basic housing part comprises an outlet that can be used for a high pressure connection, the high pressure check valves, the drive shaft, at least one drive shaft bearing and the receiving recesses, the wall surfaces of which are the respective guides of the pistons or whose wall surfaces accommodate the bushings of the pistons and the Cover housing part comprises a suction connection and the suction valves, and the mounting flange part is used to lead the drive shaft out of an interior of the pump.

According to an advantageous embodiment, the drive shaft is centered and supported by the mounting flange part, which can be inserted in a housing opening in the base housing part so that it is sealed so that the drive shaft can be mounted from this side through the housing opening of the base housing part provided for the mounting flange part.

Furthermore, it can be provided that the basic housing part has at least two perforated fastening tabs which are aligned with a pair of several pairs of corresponding fastening holes in the mounting flange part, so that There are several mounting options for the base housing part rotated around the drive shaft on the mounting flange part, ie different mounting angles of the mounting flange part are possible.

Furthermore, according to an advantageous modification of the invention, it can be provided that the base housing part has, in addition to the opening which can be reduced in size by the mounting flange part, through which one end section of the drive shaft is led out of the base housing part, a further opening through which the other end section of the drive shaft is accessible and the cover part provided for closing the latter opening can be fastened to the basic housing part.

Furthermore, according to an advantageous modification of the invention, it can be provided that the base housing part and the cover part are designed so that when the cover part is dismantled, the drive shaft opening of the base housing part is large enough to allow the drive shaft to be installed and removed via this opening.

In a further development of this modification it can be provided that the mounting flange part is made in one piece with the basic housing part.

Furthermore, according to an advantageous modification of the invention, it can be provided that the basic housing part and the cover part are designed so that, when the cover part is dismantled, two basic housing parts of an in-line piston pump can be connected back to back and in an oil-tight manner and a space enclosed by the two housings Is available, which enables the drive shafts of both in-line piston pumps to be interlocked.

According to the invention it can also be provided that the basic housing part is designed such that the drive shaft protrudes on two sides of the basic housing part, so that tandem operation of the pump is possible without making changes to the basic housing part.

According to the invention, the pump can be designed in such a way that the fluid is fed to the suction valves via a common suction channel, which preferably runs parallel to the drive shaft axis.

According to an optional modification of the invention it can be provided that a suction connection is arranged in such a way that it is arranged as coaxially as possible to the suction channel to the suction channel and is preferably an extension of the common suction channel or is arranged in a bore that is preferably at a right angle to it Suction channel meets.

It can also be provided according to the invention that the high-pressure, pumped fluid is guided from the high-pressure check valves to the high-pressure connection via a common high-pressure channel which is preferably arranged parallel to the drive shaft axis

Furthermore, it can be provided according to the invention that in each displacement unit the central axis of the receiving recess for the piston and that of the recess for the high-pressure check valve in an angular range between 10 ° and 70 °, preferably between 15 ° and 60 °, preferably between 15 ° and 50 ° and very particularly preferably between 25 ° and 45 °.

According to a further modification of the invention it can be provided that sealing elements are inserted into recesses in the base housing part and / or recesses in the cover housing part.

Furthermore, it can be provided according to the invention that sealing elements, for example in the form of a sealing system, are inserted into recesses in the base housing part and / or recesses in the cover housing part.

These sealing elements prevent the undesired escape of fluid to be pumped from the contact area of the base housing part and the cover housing part. For example, a correspondingly shaped sealing washer can be arranged here in the intermediate area of the two housing components to be placed on top of one another. For this purpose, recesses can be provided on the base housing part and / or on the cover housing part, into which the sealing washer can be inserted.

It can further be provided that an in-line piston pump according to the invention has several openings which can be used as a high-pressure connection. It is therefore possible to use one of these openings as a high-pressure connection, whereas the other of these openings must be closed in a high-pressure-tight manner.

As an alternative or in addition, it can be provided that an in-line piston pump according to the invention has a plurality of openings which can be used as a suction connection. It is therefore possible to use one of these openings as a suction connection, whereas the other of these openings must be closed in a pressure-tight manner.

According to an optional modification of the invention, it can be provided that the volume flows of a fluid to be pumped generated by a respective piston are not complete downstream or are not combined with one another at all, but are led out of the in-line piston pump via at least two separate high-pressure outlets.

Normally, if several high-pressure outlets are present, these are fluidically connected to one another downstream of the displacement units. However, it can be advantageous for the consumers to be connected to the multiple high-pressure outlets if the two consumers are hydraulically separated from one another on their high-pressure side. There is also the possibility of supplying volume flows already separated from one another from several high-pressure connections to separate hydraulic consumers and / or high-pressure inputs of a switching valve as partial volume flows, which at its output can either output one of these partial volume flows or total volume flows based on these partial volume flows. The selection of those partial volume flows that are part of the total volume flow can be predetermined via remote control on the switching valve.

Therefore, in the in-line piston pump according to the invention, at least one channel separator is provided which fluidically separates the relevant outlets from one another in the high-pressure channel. Thus, the several hydraulic consumers connected to the high pressure outlets have displacer units exclusively assigned to them, whose output volume flow respectively. whose hydraulic output cannot be used otherwise. In the case of a supply of separated partial volume flows to a switching valve, its multiple high pressure inlets are each generated by exclusively assigned displacement units volume flows.
Furthermore, according to an advantageous modification of the invention, it can be provided that the volume flows of a fluid to be pumped generated by a respective displacement unit are converted downstream by the optional provision of at least one channel separator which is inserted into the high-pressure channel.

Such channel separators can, if necessary, only be inserted when the in-line piston pump is assembled, so that their flexibility of use is high.

According to the invention it can be provided that the at least two pistons have different diameters. By providing several different diameters, the needs of different consumers that are connected to different high-pressure outlets of the in-line piston pump can be taken into account. The bores accommodating these pistons can be adapted to the respective piston diameter or those bores which have a larger diameter can each be provided with a cylinder liner that matches the piston diameter.

As an alternative or in addition to the use of such channel separators, a series piston pump according to the invention can have flow paths that are separated from the inlet into the displacement units, i.e. hermetically separated from one another, up to the respective high pressure outlets with regard to the direction of flow of the fluid to be pumped. Through the combination of a channel separation on the high pressure side of a series piston pump and a separate supply of these partial volume flows to such a switching valve, which is designed to provide an output volume flow that is variable in that it is made up of the possibility of different sums that accumulate from the said partial volume flows can be, there is - even with a constant speed of the drive shaft and a constant setting of the device via which the volume flow of the fluid to be pumped to the at least one displacement unit are set - the possibility of a variable output volume flow. In this case, the variability is limited to the choice between certain discrete values and does not allow a continuous setting of a volume flow; but with a comparably low cost. After all, such a setting of a volume flow is possible even if the in-line piston pump is operated at a constant speed or can only be operated at a constant speed and does not require actuation of the said device or even the presence of such a device is not necessary, via which the volume flow of the fluid to be pumped that can be supplied on the suction side is set.

According to a further optional modification, provision can be made for a switching valve to be provided which optionally combines the at least two separate high-pressure outlets from the in-line piston pump and outputs the volume flow generated by the combination at a collective output or an optional one of the two partial volume flows supplied on the input side.

A very variable volume flow can thus be generated, the variability of which is further increased by the volume flows of the at least two different high-pressure outlets of the pump being different due to different piston diameters of the associated displacement unit. It is clear to the person skilled in the art that the present invention is not limited to two high-pressure outputs and corresponding inputs on the switching valve.

In addition, it can be provided according to the invention that the inflow for several or all displacement units is routed jointly via a suction throttle valve, a suction throttle valve is provided for a displacement unit or a suction throttle valve is provided for a subgroup of the displacement units of a series piston pump.

According to an optional modification of the invention, it can be provided that at least one bore extending from the contact area extends through the base housing part to the drive shaft chamber ( B6 , B6 ' , B6 " ) and at least one bore (starting from the contact area) through the cover housing part to the suction side ( B8 , B8 ' , B8 " ) and results in a fluid connection which is used at least for a partial fluid drainage of the drive shaft chamber, with at least one pressure limiting valve preferably being located in each such fluid connection and particularly preferably along the course of the bore located in the main housing part ( B6 , B6 ' , B6 " ) is arranged.

It can also be provided that at least one further sealing element is arranged along the contact area, which the at least one contact area 37 of the holes occurring in pairs ( B6 ) With ( B8 ) or ( B6 ' ) With ( B8 " ) or ( B6 " ) With ( B8 " ), which represent the fluid connection between the drive shaft chamber and the suction side, and encloses several of the sealing elements and preferably all sealing elements.

The invention also relates to a method for controlling and regulating a series piston pump, in particular the output volume flow, the power and the torque, the series piston pump having at least two separate high-pressure outputs and thus being able to deliver at least two separate volume flows, each in separate high-pressure inlets a switching valve can be fed. It is provided that the controllable switching valve provides an output volume flow in relation to this, has one of the possible summations of the input volume flows in relation to the size and is variable within the scope of these degrees of freedom.

In a further training, the latter method uses a switching valve to control and regulate the output volume flow, the power or the torque of the in-line piston pump according to the invention, which can be set remotely, preferably via an actuator integrated in the switching valve, which in turn receives a control signal from a control unit. In a preferred variant, the control device receives at least one additional piece of information about another unit, respectively. an input signal from this unit, which supplies mechanical power to the in-line piston pump according to the invention and / or draws hydraulic power from the in-line piston pump. As an alternative or in addition to this preferred variant, at least one operating variable of the in-line piston pump is fed to the control unit.

• 1: eine schematische Schnittdarstellung der erfindungsgemäßen Reihenkolbenpumpe quer zur Triebwellenachse,
• 2: eine schematische Schnittdarstellung der erfindungsgemäßen Reihenkolbenpumpe entlang der Triebwellenachse,
• 3: eine Perspektivansicht der erfindungsgemäßen Reihenkolbenpumpe,
• 4: eine schematische Schnittdarstellung der erfindungsgemäßen Reihenkolbenpumpe durch das Deckelgehäuse, bei der die darin angeordnete Saugdrossel freiliegt,
• 5: eine Perspektivansicht eines Zentrierelements der Reihenkolbenpumpe,
• 6: eine schematische Schnittdarstellung einer weiteren Ausführungsform der erfindungsgemäßen Reihenkolbenpumpe quer zur Triebwellenachse,
• 7: eine schematische Schnittdarstellung einer weiteren Ausführungsform der erfindungsgemäßen Reihenkolbenpumpe quer zur Triebwellenachse,
• 8: eine schematische Schnittdarstellung einer weiteren Ausführungsform der erfindungsgemäßen Reihenkolbenpumpe quer zur Triebwellenachse,
• 9: eine schematische Schnittdarstellung einer weiteren Ausführungsform der erfindungsgemäßen Reihenkolbenpumpe quer zur Triebwellenachse, und
• 10: eine schematische Schnittdarstellung einer weiteren Ausführungsform der erfindungsgemäßen Reihenkolbenpumpe quer zur Triebwellenachse, und
• 11 eine schematische Darstellung einer erfindungsgemässen Reihenkolbenpumpe mit zwei fluidisch voneinander getrennten Hochdrucksanschlüssen ,
• 12 eine schematische Darstellung einer erfindungsgemässen Vorrichtung, bei der über ein Schaltventil ein variabler Volumenstrom erzeugt wird,
• 13 eine schematische Darstellung einer Abdichtung zwischen dem Grund- und Deckelgehäuseteil, die mittels Zusatzaufwand eine erhöhte Sicherheit aufweist.

Further features, details and advantages can be seen from the following description of the figures. Show:

• 1 : a schematic sectional view of the in-line piston pump according to the invention transversely to the drive shaft axis,
• 2 : a schematic sectional view of the in-line piston pump according to the invention along the drive shaft axis,
• 3rd : a perspective view of the in-line piston pump according to the invention,
• 4th : a schematic sectional view of the in-line piston pump according to the invention through the cover housing, in which the suction throttle arranged therein is exposed,
• 5 : a perspective view of a centering element of the in-line piston pump,
• 6th : a schematic sectional view of a further embodiment of the in-line piston pump according to the invention transversely to the drive shaft axis,
• 7th : a schematic sectional view of a further embodiment of the in-line piston pump according to the invention transversely to the drive shaft axis,
• 8th : a schematic sectional view of a further embodiment of the in-line piston pump according to the invention transversely to the drive shaft axis,
• 9 : a schematic sectional view of a further embodiment of the in-line piston pump according to the invention transversely to the drive shaft axis, and
• 10 : a schematic sectional view of a further embodiment of the in-line piston pump according to the invention transversely to the drive shaft axis, and
• 11 a schematic representation of an in-line piston pump according to the invention with two fluidically separated high-pressure connections,
• 12th a schematic representation of a device according to the invention, in which a variable volume flow is generated via a switching valve,
• 13th a schematic representation of a seal between the base and cover housing part, which has increased security by means of additional expenditure.

1 shows a sectional view of the in-line piston pump according to the invention 1 .

One recognizes a displacement unit, which is a piston 3rd comprises, which is to be pumped via a first check valve, which acts as a suction valve 11 is referred to, fluid introduced into an oil compression chamber is compressed and via a second check valve, which is called the high-pressure check valve 10 is referred to, promotes. There are several displacement units in the direction of the drive shaft axis 4th arranged one behind the other. Every piston 3rd stands with the drive shaft 2 in an operative connection and is arranged in such a way that its longitudinal axis is as radial as possible to the drive shaft axis 4th is aligned. The in-line piston pump 1 preferably comprises three housing parts 6th , 8th , 13th . The lower housing part, which is the basic housing part in the following text 6th is called, houses the part of the drive shaft located inside the pump 2 who have favourited pistons 3rd and the high pressure check valves 10 on the high pressure side (outlet valves) of the respective displacement units. An oil compression chamber comprises the entire volume in a displacement unit, which is filled with the fluid to be conveyed with the delimitation that both the suction valve 11 as well as the high pressure check valve 10 this displacement unit are closed.

The upper housing part, which is also the cover housing part 8th includes the suction valves 11 (Inlet valves). The two housing parts 6th , 8th boundaries over a flat and preferably over a flat contact area 9 to each other.

For example, based on a specific drive speed, the volume flow of the in-line piston pump 1 pumped fluids with one unit 12th can be adjusted by the suction-side inflow of the fluid to the in-line piston pump 1 is limited. The in-line piston pump 1 has an advantageous structure and is designed to optimize installation space.

How to continue the 1 what can be seen is the piston 3rd movable to and fro in a piston chamber 5 added, the parts in the cover housing part 8th and the basic housing part 6th is arranged. The piston 3rd has a centrally arranged pin in the exemplary embodiment 31 on, which is in the cover housing part 8th protrudes. The up and down movement of the piston 3rd occurs due to the rotation of the cam 27 provided drive shaft 2 and the one on the piston 3rd supporting spring 32 .

The mounting flange part is also next 13th to recognize with which the in-line piston pump 1 can be attached to an element not shown.

The workflow of the in-line piston pump 1 is as follows. First it flows through the suction valve 11 a fluid to be pumped into the oil compression chamber, as the piston 3rd moved on the way from top to bottom dead center. The one on the piston 3rd supported spring 32 makes the piston move 3rd towards the bottom dead center, so that there is a continuous operative connection between the pistons 3rd and the drive shaft 2 is guaranteed. The piston movement leads to an enlargement of the oil compression chamber and thus to a negative pressure, so that the suction valve 11 into its open position against the biasing force of the spring 16 is transferred, which means that the fluid to be pumped penetrates or is sucked into the oil compression chamber. The high pressure non-return valve is located during this process 10 its locked position.

When the piston moves 3rd The pressure in the oil compression chamber rises from bottom to top dead center, the suction valve closes and the fluid under high pressure flows through the high pressure check valve which is then opened 10 to the high pressure side of the in-line piston pump 1 from.

2 shows a sectional view of the embodiment under consideration in the longitudinal direction of the drive shaft 2 from which one can see the arrangement of the displacement units. Multiple pistons 3rd , their respective longitudinal axes 71 as radial as possible to the longitudinal axis of the drive shaft 4th are aligned, are in the longitudinal direction of the drive shaft 2 arranged one behind the other and each act with a specifically shaped section of the drive shaft 2 together, so that there is approximately a continuous delivery of the fluid.

It can be seen that the three displacement units shown, which are geometrically arranged one behind the other, adjoin a common suction channel upstream 40 are connected, of which the fluid to be conveyed via a respective suction valve 11 is promoted in the associated oil compression chamber. When the piston moves 3rd From the bottom dead center to the top dead center, no fluid reaches the suction channel from the relevant oil compression chamber 40 because the suction valve plunger 111 about the by the pen 16 acting force is pushed into its closed position.

The frictional connection of the spring 16 with the suction valve plunger 111 as well as the frictional connection of the spring 32 with the piston 3rd is made possible by the fact that the two springs 16 , 32 to a centering element 15th support, which is rigidly arranged in the recess through which the piston chamber 5 is formed. Accordingly, it creates the support of the springs 16 , 32 on the centering element 15th the prerequisite for the pressing of the piston 3rd about the pen 32 on the cam of the drive shaft 2 and pressing the suction valve stem 111 on its contact surface to close the suction valve 11 in the absence of negative pressure in the oil compression chamber via the spring 16 is possible.

The centering element 15th can be completely in the cover housing part 8th be plugged in and through the basic housing part 6th be fixed in it.

One further recognizes in the 2 the presence of a to the base housing part 6th attached mounting flange part 13th which is the drive shaft 2 centered and has that opening over which the outside of the basic housing part 6th located end portion of the drive shaft 2 is led directly to the outside. In the embodiment shown, the drive shaft 2 from the basic housing part 6th removed and installed if the mounting flange part 3rd Will get removed. An accessibility of the drive shaft 2 is here only about the mounting flange part 3rd given.

The invention includes a further training in which an accessibility of the drive shaft 2 alternatively or in addition to the mounting flange part 13th remote cover side of the cylindrically shaped housing section of the basic housing part 6th is possible (not shown in the figures). This can be done by a subsequent modification or a corresponding construction of the basic housing part 6th be provided, which already takes this aspect into account. Appropriate preparation can be achieved in that the basic housing part is attached to said cover side 6th can be closed and opened via a cover designed as a separate component. If the opening area on the basic housing part 6th , which can be closed by this cover is correspondingly large, the drive shaft can 2 also through this opening in the basic housing part 6th can be installed and removed. In a further training based on this, the mounting flange part 13th on the front of the in-line piston pump 1 , on which the drive shaft toothing for driving the in-line piston pump 1 is in one piece with the basic housing part 6th be connected. The basic housing part 6th in such an embodiment, which is closed with said cover, can be designed in such a way that a second in-line piston pump arranged in the opposite direction 1 with the first in-line piston pump 1 Can be screwed back to back and a non-rotatable coupling of both drive shafts 2 is possible via a corresponding toothing, the shape of the base housing part 6th takes place in such a way that the drive shaft toothing is also carried out by the two basic housing parts fastened to one another 6th is covered. With such a structure, the two drive shaft chambers of the two in-line piston pumps built together form 1 a common volume. The contact area of the two basic housing parts 6th is closed by a sealing system.

3rd Figure 3 shows a perspective view of the pump 1 , by means of which one can recognize the three-part housing structure. The cover housing part 8th is on the basic housing part 6th put on, which in turn in connection with the mounting flange part 13th stands.

The high pressure connection 20th the in-line piston pump 1 can be attached to one of the mounting flange part 13th opposite side on the basic housing part 6th be arranged.

According to an alternative configuration, the mounting flange part 13th in relation to the embodiment of 3rd but also on the same side as the high pressure connection 20th be arranged, in which case the drive shaft section on the drive side is preferably formed in one piece with the base housing part 6th formed opening and centering area is guided to the outside and the mounting flange part 13th in one on the basic housing part 6th installed state the output-side part of the drive shaft 2 covers and in a dismantled state this end portion of the drive shaft 2 exposed so that the connection with the drive shaft of the other component to be attached is possible. The component to be added on, which is meant here, can be a structurally identical in-line piston pump or a different type of hydraulic pump or an electrical machine, etc.

4th shows a plan view of one in the cover housing part 8th arranged cutting plane 91 showing the piston bore and valve piston 124 of the suction throttle valve. Along the exposed flow path from the suction port 18th you can see the annular space through which the fluid to the suction channel 40 got. You can also see the three feed bores above the one when the suction valve is open 11 the fluid from the suction channel 40 in the piston chamber 5 can arrive. Between a feed hole and the suction channel 40 there is a fluid connection that occurs when the suction throttle valve is open 11 to the suction connection 18th continues. Depending on its position, the suction throttle valve can influence the flow rate of the fluid to be conveyed into the suction channel.

The suction connection 18th does not have to be on a side wall of the cover housing part as shown 8th Be arranged, but can also be on another surface side, for example. On the top. It is also possible for several openings to exist, one of which as Suction connection 18th is used and all other of these openings are closed. This opening is preferably located or these openings are located on the side wall and / or the top of the housing part 8th .

5 Figure 3 is a perspective view of the centering element 15th , which is an inner ring element 153 and an outer ring element 152 comprises, wherein the inner ring member 153 and the outer ring member 152 are arranged coaxially to one another. The two ring elements 152 , 153 come with a connecting bridge 158 connected, the inner ring element 153 in its interior an inwardly directed flange area 154 has on which the spring 16 for the suction valve stem 111 sits on. The central recess 155 can with the appropriate hub through a pin 31 of the piston 3rd be pierced.

It should also be noted that the drive shaft 2 can alternatively be designed as a crankshaft or eccentric shaft, in which case the piston 3rd are in an indirect operative connection to it. Unless the drive shaft 2 is designed as a camshaft, a direct operative connection is preferred for reasons of cost. A direct connection means that the face of a piston 3rd directly their opposite cams 27 touched. On the piston 3rd For example, a roller, less preferably a ball bearing or possibly also a sliding element, via which rolling or sliding takes place on the rotating cam, can be attached. Then lies between the piston 3rd and the drive shaft 2 an indirect operative connection.

The fluid can in particular be oil, respectively. Trade hydraulic oil. For better readability, the terms oil pressure, oil flow, oil quantity, oil temperature, oil quality, oil storage tank, oil dead volume, oil compression, etc. are used in the following explanations for the terms combined with regard to the fluid. This is by no means intended to mean a restriction to the fluid oil.

Each displacer unit has an inlet valve, preferably designed as a check valve, on the inlet side, which acts as a suction valve 11 is called a piston 3rd and as the outlet valve, a check valve on the high pressure side, which is referred to as a high pressure check valve. The in-line piston pump shown in the figures as an exemplary embodiment 1 has three displacement units and is equipped with a drive shaft designed as a camshaft 2 equipped, which has double cams (cf. 1 ). The three displacement units convey fluid - this can be oil - to a common high-pressure connection 20th the in-line piston pump 1 .

About a feather 32 is achieved that the piston 3rd is also supported in suction mode on the cam opposite it. Since it is a double cam in the exemplary embodiment, complete rotation of the drive shaft takes place 2 two lifting and lowering operations of the piston 3rd . If in the course of the camshaft rotation there is a piston under consideration 3rd Moving from TDC (top dead center) in the direction of BDC (bottom dead center), the increase in volume of the oil compression chamber of the displacement unit under consideration results in a negative pressure. Due to the higher oil pressure on the suction side, the suction valve opens 11 , whereby an oil flow leaving the oil storage tank and flowing in the direction of the oil compression chamber of the displacement unit under consideration begins. After BDC (bottom dead center) has been exceeded, the volume of the oil compression chamber is reduced as the piston continues to plunge further 3rd into its receiving recess 7th . The rise in pressure of the amount of oil enclosed in the oil compression chamber, which begins in the displacement unit under consideration, leads to the suction valve closing 11 . After a further increase in pressure, the high-pressure check valve opens 10 of the displacer unit under consideration. The two check valves of a respective displacement unit also ensure that different displacement units do not interfere with one another in order to prevent the fluid brought to the high pressure level by one displacement unit from reaching the suction side via an adjacent displacement unit.

The use of an eccentric or crankshaft would also result in the analogous interrelationships between the piston movement and the switching states of the two check valves of a displacement unit.

The components for the suction valve that are inserted in the housing 11 and the piston 3rd of a displacement unit preferably all have an imaginary common longitudinal axis 71 on, the radial on the drive shaft axis 4th is aligned (cf. 2 ).

These are the following components: A piston 3rd , a feather 32 , a suction valve valve stem 111 , a feather 16 and a centering element 15th . The longitudinal axis 71 is also the longitudinal axis of the piston chamber 5 forming recess and the adjoining receiving recess 7th for the piston 5 . Said recesses extend over the housing parts 6th , 8th in which the named components are housed.

The suction valve stem 111 can resemble the shape of a thimble. The piston 3rd can along its outer surface in the receiving recess 7th be performed and is preferred as a hollow piston executed. In a particularly preferred embodiment, it has in that of the drive shaft 2 remote side a central pin 31 whose length exceeds that of the piston wall. This lies inside the piston 3rd an annulus in front of which part of the spring is located 32 is located. The lower end of the annulus terminates on the inner bottom of the piston 3rd on which one end of the pen is 32 supports. The area of the spring facing away from it 32 protrudes beyond the open top of this annulus. The end of the pen there 32 rests on the centering element 15th from. An embodiment of such a centering element that can be seen in its details 15th is in 5 and is explained in the following text. When the spring 32 is compressed to its minimum length, which is possible in its installed state, it may be that this is almost completely in the annular space of the piston 3rd is located. The cross-sectional area of this annular space must be dimensioned correspondingly large to accommodate the movement of the spring 32 not to disturb, but should otherwise be as small as possible in order to limit the dead oil volume as much as possible.

The shaft-shaped section of the suction valve plunger 111 has an inner diameter that is equal to the outer diameter of the inner wall 153 of the centering element 15th is matched, whereby a guide of the suction valve plunger 111 he follows. On the inside of the inner wall 153 of the centering element 15th if there is a paragraph or a support surface 158 on which the spring is located 16 can support. The opposite end of the spring 16 is supported on the bottom of the blind hole in the suction valve stem 111 from. The spring constant of the spring 16 is much smaller than that of the spring 32 . The feather 16 must be compressed to a corresponding extent in relation to the pressure level prevailing in the oil storage tank by the flow cross-section at the suction valve, even with the only slight negative pressure that results when the volume of the oil compression chamber is increased 11 to release. As mentioned earlier, the spring needs to be 32 ensure that the punch surface of the piston 3rd is also pressed on the cam contour in the BDC position.

The piston moves when the in-line piston machine is in operation 3rd and the suction valve stem 111 in the direction of the imaginary longitudinal axis 71 .

In a preferred embodiment, the pin is 31 of the piston 3rd designed in such a way that in the TDC position it takes up as large a proportion of the remaining blind hole volume of the suction valve stem as possible 111 fills in (cf. 1 ). Because one near the bottom of the blind hole in the suction valve stem 111 The pin end located on it supports the quick closing of the suction valve 11 when the piston 3rd Moving from UT in the direction of OT. It also reduces the pin 31 filled dead oil volume, in the oil compression chamber contributes to an increased oil compression.

On the stem of the high pressure check valve 10 three forces act (cf. 1 ). This plunger offers a support surface for the high pressure channel 17th the in-line piston pump 1 located fluid. In the same direction, ie in the blocking direction of the high pressure check valve 10 the restoring force of its spring acts. As soon as the oil pressure in the oil compression chamber under consideration is high enough, it is in the flow direction of the high pressure check valve 10 acting force large enough to open it. As long as the high pressure check valve 10 is open, this displacement unit provides hydraulic power via the high-pressure channel 17th to the high pressure connection 20th the in-line piston pump 1 is delivered, ready.

The stem guide on the high pressure check valve 10 takes place in the same way as with the suction valve 11 . Different than for those in the housing 8th built-in suction valves 11 must for the exemplary embodiment for the high pressure check valves 10 in the housing 6th each an additional component according to 1 be installed so that the high pressure check valves 10 are high-pressure tight in the blocking direction.

For each displacement unit there is a section plane through which a central longitudinal section through the piston exists 3rd at the same time a central longitudinal section through the suction valve 11 and also a central longitudinal section through the high pressure check valve 10 is exposed. This cutting plane and the axis of the drive shaft 2 are preferably perpendicular to each other.

The central axis of the receiving recess are located in each displacement unit 7th for the piston 3rd and that of the hole for the high pressure check valve 10 in an angular range between 10 ° and 70 °, preferably between 15 ° and 60 ° to one another. An angle range between 15 ° and 45 ° and very particularly preferably between 25 ° and 45 ° is particularly preferred.

Sharp angles allow the in-line piston pump to be narrowly spaced 1 and to a certain extent an increase in the power density of the in-line piston pump 1 and - which is possibly decisive for the mountability of the in-line piston pump 1 on a specific drive arrangement, for example on a power take-off of an internal combustion engine or on a multi-circuit unit - but require a stronger deflection of the oil outflow of the fluid brought to the high pressure level. Therefore, particularly acute angles are unfavorable, since the strong deflection too leads to high pressure losses. Particularly acute angles are also unfavorable because the height of the in-line piston pump is different 1 elevated.

The ones in the valves 10 , 11 existing centering elements make a significant contribution to ensuring that the design of the in-line piston pump shown as an exemplary embodiment 1 can be kept simple.

Also in the 5 embodiment of a centering element shown in perspective 15th has a comparatively simple structure. The bottom has the shape of a circular disc, the two kidney-shaped openings and a centrally placed circular opening 155 having. Furthermore, the centering element 15th two wall areas 153 , 152 in the form of concentric circles. As can be seen, such a centering element 15th can be manufactured from a round material largely as a turned part using a single clamping process. Only the kidney-shaped openings have to be made in some other way, for example by milling.

In the exemplary embodiment, there are two centering elements per displacement unit 15th (one per valve 10 , 11 ) used. In its generic design, this can be done in the area of the suction valve 11 used centering element 15th be designed in the same way as that in the high-pressure check valve 10 used centering element 15th . However, because of the required space limitation in the area of the high pressure check valve 10 preferably a smaller sized centering element 15th used than in the area of the suction valve 11 , since smaller flow cross-sections in the suction area, ie in the low pressure area, are much less noticeable than in the high pressure area.

The two kidney-shaped areas in the on the 5 illustrated perspective view of a centering element 15th are each part of the flow cross-section and represent a local constriction along the flow path. As can easily be seen, the outer diameter of the centering element is reduced 15th while maintaining all other dimensions that are independent of this, a decrease in the two kidney-shaped flow cross-sections.

The housing preferably consists of an in-line piston pump according to the invention 1 from a basic housing part 6th and a cover housing part 8th and a third mounting flange part 13th (see. 2 ).

The basic housing part 6th can approximately have the shape of two composite geometric base bodies, namely that of a cylinder and that of a cuboid. In this configuration, the drive shaft is located 2 and their storage - in the exemplary embodiment, the rear drive shaft bearing 49 - In the interior of the cylindrical sub-area, whereas the internal volume of the cuboid sub-area contains the pistons 3rd and the high pressure check valves 10 , the high pressure channel 17th and the high pressure connection 20th the in-line piston pump 1 houses.

The cover housing part 8th can approximately have the shape of a cuboid. The suction connection is located on it 18th and in the inner volume of the cover housing part 8th the suction valves are located 11 . It can also be part of the facility 12th that are used to regulate or control the in-line piston pump 1 serves, in the cover housing part 8th be housed. Such a device is preferably involved 12th around a suction throttle valve. That in the 4th The exemplary embodiment shown only shows a preferred embodiment of the valve piston 124 which is used for the suction throttle and is inserted in its bore. Suction throttle valves are generally known to those skilled in the art.

The housing parts 6th and 8th touch each other directly via a flat contact area 9 or touch each other indirectly via sealing elements 19th . It is preferably a flat system that lies on a plane E1, which is particularly preferably parallel to the drive shaft axis 2 runs. In the context of the mathematical description, a vector along the longitudinal axis is very particularly preferred 71 a normal vector to plane E1. As mentioned, it is the longitudinal axis 71 around the longitudinal axis of the cob 3rd and / or the suction valve 11 .

In a first variant of the pump housing, the cylindrical section of the base housing part 6th on the side on which the drive shaft 2 is led to the outside, no cover surface (cf. 2 ).

The closing of the pump housing there is the responsibility of the mounting flange part 13th designated component, which, as indicated by its designation, is flange-shaped and attached to the basic housing part 6th is grown and preferably flat on the end face of the cylinder wall of the basic housing part 6th rests.

On their exit side from the basic housing part 6th becomes the drive shaft 2 through the mounting flange part 13th centered and guided to the outside via the longitudinal opening located therein and is in this length range via an in the mounting flange part 13th inserted front drive shaft bearing 48 stored (cf. 2 ).

With the basic housing part 6th the closed cover side of the cylindrical partial area is shaped in such a way that the built-in drive shaft 2 preferably via a rear drive shaft bearing attached directly to it 49 is recorded. Plus the front drive shaft position fastened in the mounting flange part 48 are at least in such in-line piston pumps 1 with a comparatively small number of pistons, no further drive shaft bearings are provided. Rolling or sliding bearings can be used as drive shaft bearings. Those sliding bearings which can absorb radial and axial forces and are referred to as flange bearings are preferred.

By tapering the diameter at the longitudinal ends of the drive shaft accordingly 2 , can be stored in a simple manner with axial fixation by a front drive shaft bearing 48 , which prefers mounting flange part 13th is attached, and by a rear drive shaft bearing 49 , which is the preferred base housing part 6th is attached, can be achieved.

The seal between the mounting flange part 13th and the basic housing part 6th takes place with a seal B. , e.g. an O-ring. The seal between the mounting flange part 13th and the drive shaft 2 takes place with a seal A. , e.g. by means of a sealing ring with a sealing lip (cf. 2 ).

The basic housing part 6th has a plurality of protruding perforated tabs on the open end face of its cylindrical sub-area, which preferably end flush with the cylinder wall on a plane that serves as the support surface of the mounting flange part 13th is provided.

The cuboid area of the basic housing part 6th is preferably designed in such a way that it encloses only the smallest possible circumference of the cylindrical area. The hole pattern of the said tabs can already be in the form of prepared holes during the manufacture of the mounting flange part 13th be incorporated into it, especially if the mounting flange part 13th is manufactured as a cast part.

In an advantageous embodiment, the said hole pattern can be multiple times on the circumference of the mounting flange part 13th be applied. In this way it becomes an in-line piston pump 1 provided, which can be installed in other than the originally / mainly intended installation position without a lot of additional effort. The in-line piston pump 1 is by adapting a single component, namely by modifying the mounting flange part 13th , which can also have the equivalent, which can also have the equivalent of another flange type, adaptable to different installation situations, whereas all other components of the in-line piston pump 1 can be kept unchanged. (For example, instead of the embodiment shown in the figures, in which the mounting flange part 13th an SAE A. Flange corresponds to the mounting flange part 13th according to an SAE B. Flange.)

For the basic housing part 6th It can be advantageous if its cylindrical housing area in the end area of its closed longitudinal end is geometrically wider than the bearing of the drive shaft 2 requires. If such additional installation space is available, the corresponding cover surface at the longitudinal end of the housing part can be used 6th can be removed and a further in-line piston pump can be added, ie a tandem arrangement of two in-line piston pumps is shown. The modification to the basic housing part 6th relates to the addition of a further in-line piston pump 1 . The coupling of the drive units of both hydraulic pumps can take place, for example, via a drive shaft toothing. Instead of an identical in-line piston pump 1 Of course, a rotary drive of a completely differently constructed hydraulic pump, an air compressor or an electric machine, etc. can also be represented.

If the pump housing is constructed as described above, it is used for the mounting flange part 13th preferably aluminum or an alloy containing aluminum is used.

In a further variant, which is not set out in any figure, the entire flange area of the in-line piston pump is located 1 directly on the basic housing part 6th which restricts the flexibility to be able to adapt to different installation space conditions, but it does so if the mounting flange part is omitted 13th as an additional separate component and without increasing the cost of manufacturing the basic housing part 6th a simple structure of a tandem arrangement of two in-line piston pumps 1 enables. In such a design, the mounting flange is on the side of the in-line piston pump 1 is on which the drive shaft 2 is guided to the outside, integrally connected to the basic housing part. The centering of the drive shaft 2 , the inclusion of the front drive shaft bearing 48 and the seal B. is thus located in the basic housing part 6th . The seal B. can be omitted. The installation and removal of the drive shaft 2 is via an opening of the drive shaft chamber, which is opposite to the side of the base housing part 6th located over which the drive shaft 2 is led to the outside. With built-in drive shaft 2 this opening is closed by a lid-shaped attachment. The basic housing part is preferred 6th designed in such a way that this is arranged in the opposite direction with another Basic housing part 6th Can be screwed back to back. In this way, it becomes a tandem arrangement of two in-line piston pumps 1 implemented, the two drive shaft chambers form a common volume, which preferably also covers the drive shaft toothing. The contact area of the two basic housing parts 6th is closed by a sealing system.

Of course, it would be conceivable that the in-line piston pump according to the invention 1 in a third variant, for which likewise no figure exists, does not have a completely separate housing, but part of its casing is already part of another housing, ie the in-line piston pump according to the invention 1 would be used as a built-in pump. Apart from the changes directly affected by this, the other features described are also considered advantageous here; in particular the retention of what is described in the following paragraph.

The separation point between the lower housing part is preferred 6th and the upper housing part 8th set so that the suction valves 11 as completely as possible in the upper part of the housing 8th are located, whereas the actual piston is 3rd as well as the high pressure check valves 10 as completely as possible in the lower housing part 6th are located. For the reasons mentioned above, the protrudes from the piston 3rd located pin 31 in the housing part 8th into it. Such an arrangement offers the advantage that the named components or assemblies are easily accessible for assembly / disassembly and with good accessibility to their respective installation end positions in the housing parts 6th and 8th can be brought or can be easily taken out of it.

The separation point between the basic housing part is preferred 6th and the cover housing part 8th set in such a way that the suction valves 11 as completely as possible in the cover housing part 8th are, whereas the receiving recesses 7th The piston 3rd in the basic housing part 6th and the high pressure check valves are located 10 as completely as possible in the basic housing part 6th or are as completely as possible in the cover housing part 8th are located (not shown in the figures). For the reasons mentioned above, the protrudes from the piston 3rd located pin 31 in the cover housing part 8th into it. Such an arrangement offers the advantage that the named components or assemblies are easily accessible for assembly / disassembly and with good accessibility to their respective installation end positions in the housing parts 6th and 8th can be brought or can be easily taken out of it.

The separation point between the basic housing part is particularly preferred 6th and the cover housing part 8th set in such a way that the suction valves 11 completely in the cover housing part 8th are, whereas the receiving recesses 7th The piston 3rd completely in the basic housing part 6th and the high pressure check valves are located 10 either completely in the basic housing part 6th or completely in the cover housing part 8th are located (not shown in the figures). If the drilling walls of the receiving recesses 7th , ie the contact surfaces of the piston walls only in the main housing part 6th are located, the finishing of these contact surfaces is clearly limited to this housing part. The said division of the housing parts 6th and 8th also offers the advantage that the contact surface for the upper side of the suction valve stem 111 directly into the cover housing part 8th can be incorporated, although the requirements for dimensional accuracy and surface quality on the aforementioned contact surfaces are high, so that the suction valves 11 are high-pressure-tight in the blocking direction. If a corresponding special drill is available, this contact surface can be used in one operation together with the preparation of the recess in which the centering element 15th assembled.

When assembling or dismantling an in-line piston pump according to the invention 1 the two housing parts 6th and 8th positioned in such a way that in each case their surface is that in relation to the assembled in-line piston pump 1 on the contact area, which is preferably designed as level E1 9 is located, is exposed and coming from this side is the assembly or disassembly of the suction valves 11 , The piston 3rd and the high pressure check valves 10 can be made. Thanks to such a housing structure, good assembly accessibility is achieved with the corresponding consequential advantages.

Instead of sealing all the separation points between the housing parts 6th and 8th through discrete sealing elements 19th , is preferred in the flat contact area 9 between the housing parts 6th and 8th inserted such a sealing system, which has a plurality of individual seals or at least one individual seal and at least one further structural element with which additional functions that are related to the sealing has. The structural elements can be seal support elements and control elements for visual and / or haptic control of the installation position and / or installation orientation. The individual seals and structural elements are preferably applied to a seal carrier which, when the in-line piston pump is installed 1 is installed as a whole. The sealing system can also contain positioning elements that allow incorrect installation impossible or at least let it be seen from the outside.

The in-line piston pump 1 can use at least one as a suction connection 18th Have usable bore, which is preferably located on the cover housing part 8th is located. A suction connection 18th can like on the 4th shown, be arranged such that the oil connection is preferably perpendicular to the suction channel 40 meets through one of a longitudinal side wall or from diametrically to the main housing part 6th located wall outgoing hole. Located in the cover housing part 8th An institution 12th , which is preferably designed as a suction throttle valve, are the suction channel 40 and the openings, one of which is to accommodate the suction port 18th are usable and are used to accommodate the facility 12th preferably arranged in such a relative position to one another that the on the suction channel 40 matching bore of the suction connection 18th as perpendicular as possible from the borehole to accommodate the facility 12th meets (cf. 4th ). To achieve greater flexibility for the attachment or installation of the in-line piston pump 1 , additional openings can be provided as a suction connection 18th can be used, creating a certain flexibility for actually acting as a suction connection 18th used opening exists. Such a possibility would be, for example, the arrangement of a further opening, the axis of which is parallel to the respective piston movement directions of the in-line piston pump 1 is executed. Obviously, one of these openings is then used as a suction connection 18th used and the other openings must be sealed

The in-line piston pump 1 has at least one bore that serves as a high pressure connection 20th is usable, this preferably being on that housing part 6th or 8th which is the high pressure check valve 10 houses. A placement of a high pressure connection that can be implemented with little effort 20th is the continuation of the 1 to be recognized high pressure channel 17th to the outside, as in 3rd recognizable. An alternative or additional placement of a suitable opening is one of the longitudinal side wall of the housing part 6th outgoing bore pointing to the high pressure channel 17th meets and preferably as perpendicularly as possible on the high pressure channel 17th meets.

Unnecessary openings for further suction and high pressure connections 20th , 18th can or must be sealed pressure-tight. The option of one of different openings as a suction connection 18th being able to choose makes it easier to adapt the in-line piston pump 1 to different accessibility and space conditions. Likewise, the option of choosing one of different openings as a high pressure connection makes it easier 20th to be able to use the adaptation of the in-line piston pump 1 to different accessibility and space conditions.

For draining the oil leakage from the drive shaft chamber, ie the cylindrical area of the base housing part 6th , in which the drive shaft 2 is located, can be from there to the suction side, ie into the inner volume of the housing cover 8th extend an oil connection, this oil connection preferably running within the housing walls. This has the advantage that the leakage does not first have to be conveyed back to the oil storage tank, but directly to the suction side of the in-line piston pump 1 got. With regard to the direction of flow of the fluid to be pumped, the oil leakage for discharging this said oil leakage preferably ends upstream to the device 12th . In order to avoid the drive shaft chamber from being sucked dry with the corresponding consequential damage, the oil connection used as a leakage line can be equipped with a pressure relief valve.

To discharge the leakage from the mounting flange part 13th there are preferably several oil connections which are arranged in such a way that leakage discharge is ensured regardless of the mounting angle of the in-line piston engine. Explanation: The basic housing is located at the preferred mounting bracket 6th below the cover housing part 8th . Due to the structural space conditions, however, it may also be necessary for the cover housing part 8th below the basic housing part 6th is located.

6th shows a schematic sectional illustration of a further embodiment of the in-line piston pump according to the invention 1 transverse to the drive shaft axis 4th .

In contrast to the version described above, there is now an increased flow cross-section between the piston within such a displacement unit 3rd and the high pressure check valve 10 in front. Due to the improved geometry of the oil connection, which is used by the fluid compressed to high pressure, namely from the outlet of the piston chamber 5 to the high pressure check valve 10 , there is less deflection and / or less turbulence of the fluid to be pumped, so that an overall improved efficiency of the in-line piston pump 1 can be achieved.

The one with the double arrow at the narrow point between the piston chamber 5 and the high pressure check valve 10 The section marked is expanded so that the flow section there, which in its correspondence was also the constriction in the exemplary embodiment described above, is enlarged in its cross section. For this purpose, it can be provided that with respect to the Main flow direction a wall rounding in the flow path of the fluid from the piston chamber 5 towards the high pressure check valve 10 deflects less strongly than was the case with the embodiment described above.

In addition, it can be provided that the flow path is between the piston chamber 5 and the high pressure check valve 10 is arranged such that the piston 3rd even in its TDC position does not protrude into this flow path.

The angle marked with 'alpha' describes the angle between the longitudinal axes of the piston 3rd and the high pressure check valve 10 . If you enlarge this - as in the 6th to recognize - this causes a decrease in turbulence and a decrease in pressure loss along the distance from the piston chamber 5 to the high pressure check valve 10 extending flow path, since the deflection of the high pressure channel 17th leading to compressed fluids is less severe. This increases the efficiency of the in-line piston pump 1 .

7th shows a sectional view of a further embodiment of the in-line piston pump according to the invention 100 transverse to the drive shaft axis 4th , where the high pressure check valve 10 , the high pressure channel 17 ' and the high pressure connections 120 , 120 ' in the housing cover part 81 are located.

In contrast to the previous variants, the at least one high-pressure check valve is located in this exemplary embodiment 10 in the cover housing part 81 . The same then also applies to an associated high-pressure channel 17 ' and the at least one high pressure connection 120 , 120 ' . There is still the possibility of a high pressure connection 120 in the side wall and a high pressure connection 120 ' on the top resp. in the to the basic housing part 6th diametrical side of the cover housing part 8th . As explained above, this exemplary embodiment also involves openings, one of which is a high-pressure connection 120 , 120 ' , whereas the other is closed pressure-tight. In the section shown, the 7th are each one of the possible high pressure connections 120 , 120 ' to be assigned high-pressure bores only near the outer surface of the cover housing part 81 exposed, meanwhile the respective continuation of these oil connections to the high pressure channel 17 ' is not exposed, these oil connections from the as possible high pressure connections 120 , 120 ' provided openings to the high pressure channel 17 ' already in the casting blank of the cover housing part 81 can be prepared.

When using the high-pressure outlet on the top 120 ' there is a slight deflection of the high pressure channel 17 ' inflowing fluids, so that this high-pressure outlet 120 'should advantageously be used.

When using the other high pressure outlet 120 the fluid flowing in from the high-pressure channel is deflected by approx. 90 °, so that a renewed deflection again leads to a slight loss of effectiveness.

It can preferably be provided that in the basic housing part 61 a certain hollow volume is located, which is used to increase the flow cross-section of the high pressure and the high pressure check valve 10 urgent fluid is provided. However, the aspect to be taken into account here is that such an enlarged recess ultimately leads to an enlargement of the oil compression chamber, whereby the other geometrical mass, in particular the stroke and diameter of the piston, is retained 3rd , the achievable high pressure is reduced.

Above the suction channel 40 you can see the face of the suction throttle valve. The (thinner) second length section faces the viewing side 122 of the valve piston 124. Its second length section is also exposed 122 , which has the annular space (not visible in section), although this is in a different plane in relation to the viewing direction.

The suction connection 18 " is located, unlike the previous exemplary embodiments, on that outside of the cover housing which is at a smaller distance from the suction throttle valve. Due to the design, there is a 90 ° deflection of the fluid from the suction connection 18 " into the suction channel 40 via the suction throttle valve. With the suction valve open 11 reaches the fluid passing through the suction throttle arrives via the suction channel 40 in the piston chamber 5 . With regard to this section of the flow path, there is no difference from the two previous exemplary embodiments.

Furthermore, the geometric arrangement of the drive shaft is the same 2 , the piston 3rd , its receiving recess 7th , the suction valve 11 and its arrangement relative to the flow channel in the previous exemplary embodiments, which also applies to all other exemplary embodiments considered below. The high pressure check valve 10 as such it can be identical to that of the other exemplary embodiments, but in the exemplary embodiment according to FIG 7th another installation location. This requires a geometric adaptation of the sealing elements 19 ' . As well

The differences between the exemplary embodiment lead to a change in the contact area 19 ' . However, they form part of the basic housing 61 and cover housing part 81 also in this (cf. 7th ) as in all other exemplary embodiments shown below, contact area 19 ' which is preferably designed to be flat and the contact area 19 ″ is particularly preferably located on one plane.

The longitudinal axes of the piston 3rd and the high pressure check valve 10 form a comparatively acute angle. The pump has a comparatively small pump width but a slightly increased pump height.

The installation of the at least one high pressure check valve 10 and the presence of the high pressure channel 17 ' and the at least one high pressure connection 120 , 120 ' in the cover housing part 81 the advantage that the creation of an oil connection with the one provided control surface of the valve piston 124 with that of the in-line piston pump 100 self-generated high pressure can be implemented comparatively easily. The exemplary embodiment points out that of the high pressure connection 120 the line drawn in as far as the longitudinal axis of the valve piston 124, which can be an oil connection as the center of the bore, on the one hand to the control pressure bore 23 as well. The one from the high pressure connection 120 The section extending up to the high pressure channel would clearly be drilled with a comparatively large diameter and the second section extending from the high pressure channel to the control surface, which corresponds to the control pressure bore 23, would be continued with a comparatively small diameter. Through a corresponding relative arrangement of the high pressure connection 120 and the suction throttle valve and the arrangement of the control surface provided for it on the valve piston 124, it is also possible to create the high-pressure oil connection to the said control surface, which is located far inside the cover housing, with a single bore. In contrast to the previous exemplary embodiments, there is therefore no passage through the contact area to create the last-mentioned oil connection 9 ' required. As a result, at least one corresponding hole in the basic housing part 61 and a corresponding high pressure seal in the contact area 9 ' can be saved.

As is known to those skilled in the art, there must always be a certain minimum amount of fluid in the drive shaft chamber so that the components moving in it relative to one another (drive shaft 2 with the front and rear drive shaft bearings 48 , 49 as well as the drive shaft 2 with the faces of the pistons 3rd to avoid. In the course of use, oil leaks along the between the piston walls and the receiving recesses 7th into the drive shaft chamber. Since, in turn, an excessive oil filling of the drive shaft chamber leads to increased splash losses, a corresponding oil drain is provided. Instead of being returned to the oil storage tank, there is emptying to the suction side of the in-line piston pump 100 intended. Such an oil connection is indicated by the two dashed lines B6 and B8 shown. Through a hole in each of the basic housing part 61 and the cover housing part 61 , which is a contact area 37 form, the component of the much larger contact area 39 ' is.

8th shows a schematic sectional illustration of a further embodiment of the in-line piston pump according to the invention 200 transverse to the drive shaft axis 4th , in which not only the suction throttle valve 11 above the suction channel 40 but also the suction inlet 18 ' . As a result, a further reduction in the overall width can be achieved, but this requires additional space in terms of overall height; at least locally. Apart from the flow around the opening area of the tapered area, valve piston 124 of the suction throttle valve takes place in the flow path of the fluid from the suction inlet 18 ' to the suction channel 40 no diversion. All other relationships find their correspondence in the previously explained exemplary embodiment.

9 shows a schematic sectional illustration of a further embodiment of the in-line piston pump according to the invention 300 transverse to the drive shaft axis 4th . The cut establishes, among other things, a high pressure connection 120 , the high pressure channel 17 ' and (thinner) second length section 122 of the valve piston 124 of the suction throttle valve free. The suction connection is also shown in this section 18 " and which lead to the suction channel 40 extending oil connection exposed and the position of the suction throttle valve due to the drawn (thinner) second section 122 his valve piston 124 can be seen. Actually, this second section should be 122 on the central longitudinal axis of the oil connection between the suction connection 18 " and the suction channel 40 are located, but it can also be seen from the view shown here that the control pressure bore 23 has a single one from the suction connection 120 attached hole can be made.

In contrast to the two previous exemplary embodiments, the one between the longitudinal axes of the engine piston 3rd and the high pressure check valve 10 formed angles kept larger.

The hole required to drain the drive shaft chamber B6 " is through one on the basic housing part 63 existing rib area 65 out, which is only used to cover this hole. In the longitudinal direction of the in-line piston pump 300 exhibits the rib area 65 consequently only a small expansion. Otherwise the basic housing part is covered 63 a much smaller angular range of the mounting flange part 13th which is possible because the high pressure is attached to the base housing part 63 Possible via four screws, the fourth screw going through the rib area 65 is covered. A part of the for receiving this fourth screw on the cylindrical housing area of the basic housing part 63 protrudes behind the rib area 65 emerged.

10 shows a schematic sectional illustration of a further embodiment of the in-line piston pump according to the invention 400 transverse to the drive shaft axis 4th , in which not only the suction throttle valve, as in the visibility of the (thinner) second length section 122 of the valve piston 124 can be seen, but also the suction inlet 18 " above the suction channel 40 is located. As a result, a further reduction in the overall width can be achieved, but this requires additional space in terms of overall height; at least locally. Apart from the flow around the opening area of the tapered area, the first length section of the valve piston 124 of the suction throttle valve takes place in the flow path of the fluid from the suction inlet 18 ' to the suction channel 40 no diversion. These two advantages are offset by the disadvantage that to create the oil connection of the drive shaft chamber at least one further bore in the housing cover part 64 must be introduced.

In contrast to the previous exemplary embodiment, the basic housing part 64 no rib area. This makes the attachment of the mounting flange part 13th visible with the fourth screw. All other relationships find their correspondence in the previously explained exemplary embodiment.

11 shows a schematic representation of an in-line piston pump according to the invention 10 with two fluidically separated high pressure outlets 120 * , 120 ** .

It is provided here that the high pressure channel 17th in two high pressure channels 17 * , 17 ** can be separated, which in turn can be hermetically sealed from each other. Each of these high pressure channels 17 * , 17 ** the fluid placed under high pressure by at least one displacement unit can be supplied in each case, the high pressure channels 17 * , 17 ** are connected to different displacer units. The partial volume flows originating from the individual displacement units or on the high-pressure side, displacing unit groups separated from one another V1 , V2 , V3 , V4 are not all fluidically connected to one another downstream of the displacement units, but are instead by a channel separator 171 Fluidically separated from each other, which is a segmentation of the high pressure channel 17th in the high pressure channels 17 * , 17 ** causes.

From each of such segments, that is, the high pressure channel 17 * , 17 ** there is at least one opening that serves as a high-pressure connection 120 * , 120 ** can be used.

It can also be provided that the piston 3rd , 3 ' , 3 "with different diameters can be used so that different requirements of the consumers to be connected can be taken into account.

12th shows a schematic representation in which to the high pressure outlets 120 * , 120 ** , 120 *** the in-line piston pump 1 with different piston diameters 3rd , 3 ' , 3 "a switching valve 72 is connected, the separate high pressure outlets 120 * , 120 ** , 120 *** the in-line piston pump 1 can connect with each other in different constellations. So can the volume flow Q any combination of the individual output volume flows of the high pressure outlets 120 * , 120 ** , 120 *** represent, so that a very high variability of the volume flow can be achieved.

The switching valve 72 also via telecontrol 73 to be controlled. Essentially, the three high pressure inlets are used 92 , 93, 94 of the valve 72 with a respective one of the high pressure outlets 120 * , 120 ** , 120 *** the in-line piston pump 1 fluidically connected and inside the switching valve 72 combined with each other and on the high pressure collection outlet 95 given.

13th shows a schematic representation of a seal between the base and cover housing part, which has an increased security by means of additional expenditure, which with correspondingly particularly high demands on the oil tightness, such as in food production, in which an in-line piston pump according to the invention is also used 1 can be used is required.

It can never be completely ruled out that the sealing elements 19th , 19 ' , 19 "there is perfect oil-tightness, especially since the contact area 9 , 9 ' .9 "against that of the in-line piston pump 1 generated high pressure level must be sealed. If necessary via a sealing element 19th , 19 ' .19 "leaking oil would enter the contact area 9 , 9 ' .9 "existing gap volume and with a correspondingly large for the restricted volume conditions there Finally, drain the accumulation from the in-line piston pump.

To prevent such an ingress of oil, it is provided that on the contact area 9 , 9 ' , 9 "a further seal is provided that includes all sealing elements 19th , 19 ' , 19 ". This is preferably done by a single sealing element, which additionally encompasses the mentioned contact area 37 with encloses.

In the time intervals in which at least one displacement unit is in suction mode, the contact area prevails 37 a negative pressure that ensures that the sealing elements may be applied 19th , 19 ' , 19 "overcoming leakage oil is discharged to the suction side together with the fluid to be diverted from the drive shaft chamber.

Since it is advantageous for the measure presented if, in relation to the order of magnitude of the present device, the negative pressure in terms of amount in the contact area 37 is high, the required throttling of the oil connection under consideration is preferably within the bore located in the base housing part B6 , B6 ' , B6 " intended.

List of reference symbols

1

In-line piston pump

2

Drive shaft

3

piston

3 '

piston

3 ''

piston

3 '' '

piston

4th

Drive shaft axis

5

Piston chambers

5 '

Piston chambers

6th

Basic housing part

6 '

Basic housing part

7th

Receiving recess

7 '

Receiving recess

7 ''

Receiving recess

8th

Cover housing part

9

Contact area

9 '

Contact area

9 ''

Contact area

10

High pressure check valve

11

Suction valve

12th

Facility

13th

Mounting flange part

14th

Recess

15th

Centering element

16

feather

17th

High pressure channel

17 '

High pressure channel

17 *

High pressure channel

17 **

High pressure channel

17 ***

High pressure channel

18th

Suction connection

18 '

Suction connection

18 ''

Suction connection

19th

Sealing element

19 '

Sealing element

19 ''

Sealing element

20th

High pressure connection

29

Sealing element

27

cam

31

Pin code

32

feather

37

Contact area

39

Sealing element

39 '

Sealing element

39 ''

Sealing element

40

Suction channel

48

front drive shaft bearing

49

front drive shaft bearing

61

Basic housing part

63

Basic housing part

64

Basic housing part

65

Rib area

71

Longitudinal axis

72

Switching valve

73

Telecontrol

81

Cover housing part

82

Cover housing part

83

Cover housing part

84

Cover housing part

91

Cutting plane

92

High pressure inlet

93

High pressure inlet

94

High pressure inlet

95

High pressure outlet

100

In-line piston pump

111

Suction valve stem

120

High pressure outlet

120 '

High pressure outlet

120 *

High pressure outlet

120 **

High pressure outlet

120 ***

High pressure outlet

121

Part of the valve piston with the large diameter

122

Part of the valve piston with the small diameter

152

outer ring element

153

inner ring element

154

Flange area

155

central recess

158

Connecting bridge

171

Duct separator

200

In-line piston pump

300

In-line piston pump

400

In-line piston pump

A.

poetry

B.

poetry

B6

drilling

B6 '

drilling

B6 ''

drilling

B8

drilling

B8 '

drilling

B8 ''

drilling

B12

drilling

Q1

Volume flow

Q2

Volume flow

Q3

Volume flow

Q

Sum of different volume flows

V1

Partial volume flow

V2

Partial volume flow

V3

Partial volume flow

V4

Partial volume flow

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 19708597 [0003]
• WO 2010130495 A1 [0004]

Claims (34)

In-line piston pump (1, 100, 200, 300, 400), comprising: a drive shaft (2) for driving the in-line piston pump (1, 100, 200, 300, 400), at least two pistons ( 3, 3 '), which are arranged along a drive shaft axis (4) and are each arranged to be movable to and fro in a piston chamber (5, 5', 51, 53), a base housing part (6, 61, 63, 64) for receiving the Drive shaft (2) and for inserting the at least two pistons (3, 3 ') into corresponding receiving recesses (7, 7'), and a cover housing part (8, 81, 82, 83, 84) for attachment to the basic housing part (6, 61 , 63, 64), characterized in that the contact area (9, 9 ', 9 ") produced when the cover housing part (8, 81, 82, 83, 84) is attached to the base housing part (6, 61, 63, 64) in a surface, preferably in a plane, which exposes the piston chamber (5, 5 ', 51, 53) of a respective one of the at least two pistons (3, 3'). In-line piston pump (1,100, 200, 300, 400) according to Claim 1 , the contact area (9, 9 ', 9 ") being designed in such a way that when the base housing part (6, 61, 63, 64) and cover housing part (8, 81, 82, 83, 84) are separated from one another, the pistons (3 , 3 ') in the basic housing part (6,61,63,64) and inserting at least one pressure valve (10), preferably in the form of high-pressure check valves, into the basic housing part (6) or the cover housing part (81, 82, 83, 84) and at least one suction valve (11) can be inserted into the cover housing part (8, 81, 82, 83, 84). Pump (1, 100, 200, 300, 400) according to one of the preceding claims, wherein the drive shaft (2) is designed as a camshaft with single or multiple cams, as a crankshaft or an eccentric shaft. In-line piston pump (1, 100, 200, 300, 400) according to one of the preceding claims, wherein the drive shaft axis (4) runs parallel to a plane formed by the contact area (9, 9 ', 9 "). In-line piston pump (1, 100, 200, 300, 400) according to one of the preceding claims, further comprising at least one suction valve (11) which is arranged in the cover housing part (8, 81, 82, 83, 84), and preferably in an installed state does not protrude beyond the contact area (9, 9 ', 9 "). In-line piston pump (1, 100, 200, 300, 400) according to Claim 5 , wherein the suction valve (11) and the piston (3, 3 ') of a respective displacement unit have an identical longitudinal axis (71). In-line piston pump (1, 100, 200, 300, 400) according to one of the preceding Claims 5 or 6th , wherein the respective longitudinal direction of the bores for receiving the at least one suction valve (11) runs perpendicular to a plane formed by the contact area (9, 9 ', 9 "). In-line piston pump (1, 100, 200, 300, 400) according to one of the preceding Claims 5 - 7th , wherein the cover housing part (8, 81, 82, 83, 84) comprises several suction valves (11) arranged in parallel next to one another. In-line piston pump (1, 100, 200, 300, 400) according to one of the preceding claims, further with at least one high-pressure check valve (10) which is arranged in the base housing part (6) or cover housing part (8, 81, 82, 83, 84) , and preferably does not protrude beyond the contact area (9, 9 ', 9 ") in an installed state. In-line piston pump (1, 100, 200, 300, 400) according to Claim 9 , the longitudinal axis of the piston (3, 3 ') and the longitudinal axis of a high-pressure check valve (10) of a respective displacement unit being located on a plane which is preferably pierced perpendicularly by the drive shaft axis (4). In-line piston pump (1, 100, 200, 300, 400) according to one of the preceding Claims 9 or 10 , wherein the basic housing part (6) or the cover housing part (81, 82, 83, 84) comprises a plurality of high-pressure non-return valves (10), preferably arranged in parallel next to one another. In-line piston pump (1, 100, 200, 300, 400) according to one of the preceding claims, wherein the longitudinal axis of the pistons (3, 3 ') preferably run perpendicular to a plane formed by the contact area (9, 9', 9 ") and preferably depart radially from the drive shaft axis (4). In-line piston pump (1, 100, 200, 300, 400) according to one of the preceding claims, wherein the piston (3, 3 ') has a pin (31) which, in the installed state, has the contact area (9, 9', 9 " ) and preferably protrudes into the recess (14) which houses the suction valve (11) of the same displacement unit and preferably protrudes into the spring chamber of the compression spring (16) of the suction valve (11) acting on a centering unit (15). In-line piston pump (1, 100, 200, 300, 400) according to one of the preceding claims, further comprising a device (12) which is used to regulate or control the in-line piston pump (1, 100, 200, 300, 400), which is preferably in the Lid housing part (8, 81, 82, 83, 84) is arranged. In-line piston pump (1, 100, 200, 300, 400) according to Claim 14 , whereby this device (12) for regulating or controlling the in-line piston pump (1, 100, 200, 300, 400) is a suction throttle valve which is preferably arranged so that its longitudinal axis is arranged parallel to the drive shaft axis (4) and particularly preferably the longitudinal axis of the suction throttle valve is arranged perpendicular to at least one central axis (71) of a displacement unit. In-line piston pump (1, 100, 200, 300, 400) according to one of the preceding claims, wherein the in-line piston pump (1, 100, 200, 300, 400) comprises three separable housing parts (6, 8, 13), preferably only three separable from one another Housing parts, namely the base housing part (6, 61, 63, 64), the cover housing part (8, 81, 82, 83, 84) and a mounting flange part (13). In-line piston pump (1) Claim 16 , the basic housing part (6) comprising at least one outlet (20) that can be used as a high pressure connection, the high pressure check valves (10), the drive shaft (2), at least one drive shaft bearing and the receiving recesses (7, 7 '), the wall surfaces of which contain the respective guides the pistons (3, 3 ') are or their wall surfaces accommodate the bushings of the pistons (3, 3'), the cover housing part (8) comprises at least one suction connection (18) and the suction valves (11), and the mounting flange part (13) serves to lead the drive shaft (2) out of an interior of the in-line piston pump (1). In-line piston pump (100, 200, 300, 400) Claim 16 , the basic housing part (61, 63, 64) comprising the drive shaft (2), at least one drive shaft bearing and the receiving recesses (7, 7 '), the wall surfaces of which are the respective guides of the pistons (3, 3') or the wall surfaces of which are Hold the bushings of the pistons (3, 3 '), the cover housing part (81, 82, 83, 84) at least one suction connection (18, 18', 18 ") and the suction valves (11) and at least one outlet (120) that can be used for a high-pressure connection , 120 '), and the mounting flange part (13) serves to lead the drive shaft (2) out of an interior of the in-line piston pump (100, 200, 300, 400). In-line piston pump (1, 100, 200, 300, 400) according to one of the preceding Claims 16 to 18th , wherein the drive shaft (2) is mounted on the mounting flange part (13), which can be inserted sealingly into a housing opening of the base housing part (6, 61, 63, 64) so that the drive shaft (2) from this side through the for the mounting flange part (13) provided housing opening of the basic housing part (6, 61, 63, 64) can be mounted. In-line piston pump (1, 100, 200, 300, 400) according to one of the preceding Claims 16 - 18th , the basic housing part (6, 61, 63, 64) having at least two perforated fastening lugs which are aligned with a pair of several pairs of corresponding fastening holes in the mounting flange part (13), so that several fastening options for the basic housing part rotated around the drive shaft (2) (6, 61, 63, 64) exist on the mounting flange part (13). In-line piston pump (1, 100, 200, 300, 400) according to one of the preceding Claims 16 , 18th and / or 19, the basic housing part (6, 61, 63, 64) and the mounting flange part (13) being designed as a one-piece basic housing (6 ', 61', 63 ', 64') in which the front drive shaft bearing (48 ) and through which the drive shaft (2) is led out of the interior of the in-line piston pump (1, 100, 200, 300, 400) and the base housing has an opening on the opposite side that enables the drive shaft 2 to be installed and removed and a cover part, which is preferably screwed to the base housing and in which the drive shaft is guided over the rear drive shaft bearing (49), is sealingly centered in the opening. In-line piston pump (1, 100, 200, 300, 400) according to one of the preceding claims, wherein the fluid is fed to several suction valves (11) via a common suction channel 40, preferably parallel to the drive shaft axis (4). In-line piston pump (1, 100, 200, 300, 400) according to one of the preceding claims, at least one suction connection (18, 18 ') being arranged in such a way that it is an extension of the common suction channel (40) or is arranged in a bore, which preferably meets this suction channel (40) at a right angle. In-line piston pump (1, 100, 200, 300, 400) according to one of the preceding claims, wherein the high-pressure, pumped fluid from the high-pressure check valves (10) to the high-pressure connection (20, 120, 120 ') via a common, preferably parallel to the drive shaft axis (4) extending high pressure channel (17, 17 ') is guided. In-line piston pump (1, 100, 200, 300, 400) according to one of the preceding claims, wherein in each displacement unit the central axis (71) of the receiving recess (7, 7 ') for the piston (3, 3'), and that of the recess for the high pressure check valve (10) in an angular range between 10 ° and 70 °, preferably between 15 ° and 60 °, more preferably between 15 ° and 50 ° and very particularly preferably between 25 ° and 45 °. In-line piston pump (1, 100, 200, 300, 400) according to one of the preceding claims, wherein sealing elements (19, 19 ', 19 "), for example in the form of a sealing system in recesses of the basic housing part (6, 61, 63, 64) and / or recesses of the cover housing part (8, 81, 82, 83, 84) are inserted. Series piston pump (1, 100, 200, 300, 400) according to one of the preceding claims, wherein the flow of a fluid to be pumped generated by a respective piston (3, 3 ') is not completely combined with one another downstream, but rather via at least two separate high-pressure outlets ( 120 *, 120 **) from the in-line piston pump (1, 100, 200, 300, 400). In-line piston pump (1, 100, 200, 300, 400) according to one of the preceding claims, wherein the at least two pistons (3, 3 ') have different diameters. In-line piston pump (1, 100, 200, 300, 400) according to one of the preceding claims, wherein the inflow for several or all displacement units is routed jointly via a suction throttle valve (11), a suction throttle valve for a displacement unit or in each case a suction throttle valve (11) for one Subgroup of the displacement units of an in-line piston pump (1, 100, 200, 300, 400) is provided. Series piston pump (1, 100, 200, 300, 400) according to one of the preceding claims, wherein at least one of the contact area (9, 9 ', 9 ") extending through the base housing part (6, 61, 63, 64) to the drive shaft chamber is continuous Bore (B6, B6 ', B6 ") extends and at least one bore (B8, B8") extending from the contact area (9, 9', 9 ") extends through the cover housing part (8, 81, 82, 83, 84) to the suction side ', B8 ") and results in a fluid connection which is used at least for a partial fluid emptying of the drive shaft chamber, with at least one pressure relief valve preferably located in each such fluid connection and particularly preferably along the in the base housing part (6, 61, 63, 64) located course of the bore (B6, B6 ', B6 ") is arranged In-line piston pump (1, 100, 200, 300, 400) according to Claim 30 , wherein at least one further sealing element (39, 39 ', 39 ") is arranged along the contact area (9, 9', 9"), which connects the at least one contact area 37 of the bores (B6) occurring in pairs with (B8) or (B6 ') with (B8 ") or (B6") with (B8 "), which represent the fluid connection between the drive shaft chamber and the suction side, and several of the sealing elements (9, 9', 9") and preferably all of the sealing elements (9, 9 ', 9 "). In-line piston pump (1, 100, 200, 300, 400) according to Claim 27 wherein the flow of a fluid to be pumped generated by a respective piston (3, 3 ') is converted downstream by the optional provision of at least one channel separator (171) which is inserted into the high-pressure channel (17 *, 17 **). In-line piston pump (1) according to one of the preceding claims, developed with the features of Claim 27 , whereby a switching valve (72) is provided which optionally combines the at least two separate high-pressure outlets (120 *, 120 **) from the in-line piston pump (1) with one another or not and the volume flow (Q) generated by the combination at a collective outlet (95 ) outputs. Method for controlling and regulating an output volume flow of a series piston pump (1) according to one of the preceding claims, wherein: the output volume flow can be varied as a function of a speed of the drive shaft (2) and / or an opening degree of the device (12) and / or via a switching valve (72).

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