EP2642122B1 - Pump power unit - Google Patents

Description

The invention relates to a pump unit according to the preamble of patent claim 1.

Such a pump unit A ( Fig. 1 and 2 ) is manufactured and distributed by the applicant and is used for installation, for example in portable tool units, such as torque wrenches for high torque torques for installation of wind turbines, which in a version with a non-starting single-phase AC under oil motor 7 in a valve combination V outside the housing, a pressure switch DW is included, which can be omitted in designs (not shown) with a starting against pressure three-phase under oil engine. The housing, which is often installed in horizontal operating position, consists of an externally ribbed pipe section 1, mounted thereon housing covers 2, 4, and an optionally provided cooling fan 3 on a housing cover 2. The housing has ( Fig. 2 ) two separate pressure outlets (pressures P1 and P3 of the pumps 5, 6) for the separately supplied to the outside flows to which the valve combination is connected with two ports in which a pressure line to the pressure outlet (pressure P) of the valve combination, a return line to a return port 8 of the housing and at least one pilot line for the closing control side of a pressure switch DW as multiple blocks passing through channels are included. The valve combination V contains, in addition to the system pressure limiting valve DB, a low-pressure reversing valve U to the return line 9, a check valve R, optionally a pressure switch DW with assigned diaphragm B and optionally a secondary pressure limiting valve SD. At least one directional valve W is attached to the block structure of the valve combination V. From this construction results for a certain performance specification of the pump unit relatively high weight, which basically and especially for the portable tool unit in which the pump unit is installed, represents a significant disadvantage. Unfavorable is also the case on the outside of the housing relatively high and expansive construction of the valve combination and the directional control valve, which leads under operating vibrations to significant local loads for the housing where the valve combination is mounted on the two pressure outlets on the housing outer wall.

A similar pump unit with a two-circuit pump system is known from EP 2 330 304 A , Again, the valve combination is mounted outside on the housing.

Further prior art is contained in EP 2 241 753 A . WO 2008/055147 A2 . US 2006/255657 A1 . US 4,651,380 A. and EP 1 731 762 A ,

The invention has for its object to provide a pump unit of the type mentioned with reduced for a given performance specification weight.

The stated object is achieved with the features of claim 1.

By incorporating at least the low pressure switching valve and the check valve into the housing interior, so to speak under oil, in a more compact arrangement with shorter flow paths and easy mounting options and by a reduced oil absorption volume in the housing by the incorporated components, the pump unit is considerably easier, and is also the structure externally mounted components less bulky. Since the delivery flows of the pumps are already combined inside the housing and only a single pressure outlet of the housing is required, this restructuring also contributes to the weight saving compared to the known construction and an external sealing area is saved. The weight savings can be further increased if a smaller sub-oil engine with high or increased power density is used. With a pump unit with a single-phase AC under-oil engine and a pressure switch, more than one third of the weight can be saved compared with a known pump unit of the same performance specification.

In an expedient embodiment of the pump unit with an AC under oil engine, which does not start reliably against pressure, the pressure switch is installed to the return line, but with an associated aperture together with the low pressure switching valve and the check valve inside the housing and in a very compact overall arrangement in the housing , which further saves weight. If a three-phase oil sub engine is used instead of an AC sub oil engine, the structural conditions for integrating the pressure switch and its diaphragm can optionally be retained without, however, installing the pressure switch and the diaphragm. The flow channels provided for their functions can be closed by plugs.

Suitably, the low pressure switching valve, the check valve, and optionally the pressure switch are arranged with their diaphragm in a common, very compact valve block which is mounted inside the housing to pump elements of both pumps, wherein the pump elements are installed on a housing inner wall structure. This equipment components are grouped in this way in a confined space, resulting in a noticeable weight savings, and only a small volume of oil is occupied.

Suitably, the valve block, which receives the equipment components inside the housing, has only a single outlet which passes through the housing inner wall structure the pressure outlet of the housing is connected, which indirectly contributes to weight savings, because housing channels are shortened and eliminated and only an outer sealing area is needed.

Suitably, the valve block has an approximately trapezoidal outline, which can be snuggled into a space-saving manner in an approximately circular inner cross-section of the housing. This valve block can be made extremely compact, and contains in a confined space all incorporated inside the housing valve components.

In an expedient embodiment, a plurality of high-pressure and low-pressure pump elements of the two pumps are installed in the circumferential direction about a drive shaft of the sub-oil engine alternately and substantially in the same radial plane of the housing on the housing inner wall structure. In order to achieve a high degree of uniformity in the promotion, three high-pressure pump elements and three low-pressure pump elements are expedient, which are connected to each other via a high-pressure or a low-pressure pressure collecting ring, which summarizes the flow rates. This concept is favorable for mounting the valve block, which, preferably, is mounted on collecting plates of the low-pressure pressure collecting ring, which thus also take on the additional task of placing the valve block. This design saves considerable space, especially in the direction of the drive shaft axis.

In view of a compact construction inside the housing despite the incorporation of the equipment components, it is expedient for the high-pressure pressure collecting ring to have a body which is mounted under a high-pressure pump element and has a connection extension through which the outlet of the valve block communicates with the pressure outlet of the housing is connected. This takes place, preferably, via a pressure tube pressed into the connection extension of the body and through the drilled-out housing inner wall structure. In this way, the single outlet of the valve block is connected in a short path to the pressure outlet of the housing.

The pump unit can be designed for a standing or a horizontal operating position, depending on the selected operating position suction hoses are performed on at least some of the high pressure and / or low pressure pump elements to a dependent depending on the use position deep sump inside the housing. Especially in portable tool units such a pump unit is usually installed in horizontal operating position.

For the pump unit is recommended a construction in which the housing has an externally ribbed pipe section with the internally molded housing inner wall structure both for fixing the lower oil motor and for mounting the pump, e.g. a light metal cast body, which is closed at both ends by attached housing cover. For continuous operation of the pump set or for the thermal relief of the oil stored in the housing, it may be expedient if a housing cover carries a cooling fan, such as an electric cooling fan.

Advantageously, external parts of the valve combination are mounted with the directional control valve on the single pressure outlet of the housing to the housing outer wall, in particular the system pressure relief valve, and a secondary pressure relief valve, wherein the directional control valve can be mounted either on the system pressure relief valve or the secondary pressure relief valve.

A weight-saving design is given when the diaphragm, the check valve, the low-pressure switching valve and the optionally provided pressure switch have in each case in valve blocks running in the valve block connected inside the valve inserts used. This is convenient to install and also saves costs, since highly loaded or specially machined or tempered valve inserts made of high-quality steel or tool steel are housed in the block bores of the valve block made of plain steel.

A compact housing of the internally incorporated components of the valve combination is possible when a connection of the valve block with an outlet of the high-pressure pressure collecting ring and the single outlet of the valve block are connected to an inlet of the body of the high-pressure pressure collecting ring via a respective inserted pressure tube, and if the Valve block with an inlet to the check valve sealed directly above an outlet, preferably in a collecting plate, the low-pressure pressure collecting ring is mounted. In this way, the valve block with a minimum volume of material, since the port, the outlet and the inlet can be placed directly in at least one outer side of the valve block.

Fig. 1 und 2

eine Seitenansicht und ein zugehöriges Blockschaltbild eines Pumpenaggregats des Standes der Technik,

Fig. 3

eine Seitenansicht eines Pumpenaggregats gemäß der Erfindung, in einer Blickrichtung analog zu Fig. 1,

Fig. 4

das Pumpenaggregat gemäß der Erfindung und Fig. 3 als Blockschaltbild,

Fig. 5

eine Seitenansicht des erfindungsgemäßen Pumpenaggregats, wobei außenliegende Ausstattungskomponenten weggelassen sind,

Fig. 6

einen Querschnitt in der Schnittebene VI - VI in Fig. 5 des erfindungsgemäßen Pumpenaggregats,

Fig. 7

eine Montagephase des erfindungsgemäßen Pumpenaggregats bei abgenommenem unteren Gehäusedeckel,

Fig. 8

eine weitere Montagephase bei abgenommenem unterem Gehäusedeckel, jeweils in Blickrichtung von unten in Fig. 6,

Fig. 9

einen in Fig. 8 bereits montierten, hier losgelöst gezeigten Ventilblock mit eingegliederten Ausstattungskomponenten, in einer Seitenansicht und größerem Maßstab,

Fig. 10

einen Schnitt des Ventilblocks in der Schnittebene X - X in Fig. 9,

Fig. 11

einen Schnitt des Ventilblocks in der Schnittebene XI - XI in Fig. 9,

Fig. 12

einen Schnitt des Ventilblocks in der Schnittebene XII - XII in Fig. 9,

Fig. 13

einen Schnitt des Ventilblocks in der Schnittebene XIII - XIII in Fig. 9,

Fig. 14

eine schematische Draufsicht eines Hochdruck-Drucksammelrings, der in den Fig. 6, 7 und 8 in montiertem Zustand angedeutet ist, und

Fig. 15

eine Seitenansicht des Hochdruck-Drucksammelrings von Fig. 14 in Blickrichtung von links in Fig. 14.

With reference to the drawings, embodiments of the subject invention will be explained. Show it:

Fig. 1 and 2

a side view and an associated block diagram of a pump unit of the prior art,

Fig. 3

a side view of a pump unit according to the invention, in a viewing direction analogous to Fig. 1 .

Fig. 4

the pump unit according to the invention and Fig. 3 as a block diagram,

Fig. 5

a side view of the pump unit according to the invention, wherein external equipment components are omitted,

Fig. 6

a cross section in the section plane VI - VI in Fig. 5 the pump unit according to the invention,

Fig. 7

an assembly phase of the pump unit according to the invention with the lower housing cover removed,

Fig. 8

another assembly phase with removed lower housing cover, respectively as viewed from below in Fig. 6 .

Fig. 9

one in Fig. 8 already mounted, here detached valve block with integrated equipment components, in a side view and larger scale,

Fig. 10

a section of the valve block in the sectional plane X - X in Fig. 9 .

Fig. 11

a section of the valve block in the sectional plane XI - XI in Fig. 9 .

Fig. 12

a section of the valve block in the sectional plane XII - XII in Fig. 9 .

Fig. 13

a section of the valve block in the sectional plane XIII - XIII in Fig. 9 .

Fig. 14

a schematic plan view of a high-pressure pressure collecting ring, in the Fig. 6 . 7 and 8 is indicated in the assembled state, and

Fig. 15

a side view of the high-pressure pressure collecting ring of Fig. 14 in view from the left in Fig. 14 ,

For in the explanation of the prior art according to Fig. 1 and 2 Reference numerals used functionally identical equipment components also appear in the embodiments of the pump unit A of the invention which relates to the invention Fig. 3 to 15 on.

Already the comparison between the Fig. 1 and 3 shows that the housing 1, 2, 3, 4 of the pump unit A according to the invention for the given performance specification same external dimensions Like the well-known pump unit A in Fig. 1 , However, of the valve combination V, in the known pump unit A in Fig. 1 outside the low-pressure switching valve U, the check valve R, the system pressure limiting valve DB, the pressure switch DW with associated diaphragm B and the optional secondary pressure relief valve SD comprises in Fig. 3 , outside only the system pressure limiting valve DB, the optional provided secondary pressure relief valve SD of the valve combination V and the at least one directional control valve W in the pump unit A according to the invention mounted externally, with fastening screws 15 on a single pressure outlet 13 of the housing.

The housing comprises the pipe section 1, the housing cover 2, 4 and optionally the example electric cooling fan 3. The pipe section 1 may be a light metal or light metal alloy casting. In the Fig. 3 no longer mounted outside equipment components of the valve combination V, as for example with reference to Fig. 8 . 6 and 9 seen housed inside the housing, as well as from the block diagram of the pump unit A according to the invention Fig. 4 is apparent.

The pump set A in Fig. 4 is to scale different from the pump unit A of the prior art in Fig. 2 However, like this contains in the oil-filled housing 1, 2, 3, 4, the high-pressure pump 5 (discharge pressure P1), the low-pressure pump 6 (discharge pressure P3) and this common electric sub-oil engine 7, here for example a single-phase AC motor, to start the pressure switch DW should have. Furthermore, the housing has the return connection 8, through which the return line 9 extends from the valve combination V and the directional control valve W into the housing interior.

The pump unit A according to the invention ( Fig. 4 ) has only a single pressure outlet 13 (delivery pressure P ') to the valve combination V on the housing. The pressure outlet 13 comprises a ( Fig. 6 ) Pressure tube 23, which leads from a single outlet 14 of an inner valve block 10 to the pressure outlet 13, via which the valve combination V is mounted externally on the housing. The valve block 10 includes the baffle B, the check valve R, the low pressure switching valve U and the optional pressure switch DW. The delivery outlet of the high pressure pump 5 is connected at 11 to the valve block 10, for example by means of a pressure tube 38 (delivery pressure P1 of the high pressure pump 5), while the delivery outlet of the low pressure pump 6 is connected to an inlet 12 in the valve block 10 (delivery pressure P3 of the low pressure pump 6).

The low-pressure switching valve U is biased by a spring 37 in the reverse direction, and is connected via a pilot line 41 with an aperture 42 therein in the open direction applied. The pressure switch DW, if present, is biased by a spring 35 in the direction of control to the return line 9 by a spring 35 and in up and Zusteuerrichtungen also via pilot lines 31, 31 'acted upon, which are formed as housing channels in the valve block 10.

For an embodiment of the pump unit A in accordance with the invention Fig. 4 equipped with a three-phase under oil motor 7, which does not necessarily need the pressure switch DW, the housing channels in the valve block 10 may be closed by plugs 40, or, alternatively, an even more compact valve block 10 may be used, which the pressure switch DW (and does not contain the diaphragm B) (not shown).

The housing channels in the valve block 10 in Fig. 4 (Pilot control line 31, a branch line via the check valve R, the pilot line 41, and a connecting line 32 via the pressure switch DW to the return channel 9 branches off from a pressure line in the valve block 10 from the inlet 11 to the outlet 14 and via the pressure tube 23 to the pressure outlet 13th The low-pressure change-over valve U is contained in a working line guided from the second inlet 12 of the valve block 10 to the return line 9, to which the connecting line guided via the check valve R is connected to the single outlet 14 of the valve block 10, a further pressure tube 39 can be installed (see also Fig. 6 ).

Fig. 5 shows the pump unit A of the invention in a side view with omitted valve combination V. On both sides of the single pressure outlet 13 (pressure P ') are bores 15' for the in Fig. 3 placed fastening screws 15 shown. In this area, for example, the return port 8 may be located in the housing outer wall.

The sectional view in Fig. 6 (Section VI - VI in Fig. 5 ) shows the internal structure of the housing 1, 2, 4, 3 in detail. The pipe section of the housing 1 has a molded-in inner wall structure 16, which serves for mounting a stator of the sub-oil motor 7, the drive shaft 24 through an unspecified highlighted bearing in the inner wall structure 16 to a drive eccentric 25 for the high pressure and low pressure pumps 5, 6 leads.

The high-pressure pump 5 consists in the embodiment shown, for example, three offset by 120 ° about the drive shaft axis offset piston pump elements 5 ', which are mounted on a high-pressure pressure collecting ring 19 and with this on the inner wall structure 16. In the embodiment shown, the low-pressure pump 6 likewise comprises, for example, three low-pressure piston pump elements 6 'which are grouped around the drive shaft axis 24 by 120 ° and mounted, for example, via spacers with fastening screws 17 on the housing inner wall structure 16, so that they are in the circumferential direction regularly alternating high-pressure pump elements 5 'and low-pressure pump elements 6'. On the low-pressure pump elements 6 ', a low-pressure pressure collecting ring 26 is mounted, on which directly the valve block 10 can be mounted, with the same fastening screws 17 Fig. 7, 8 and 14, 15 directed.

To the second inlet 12 of the valve block 10 (opening 29), a pressure valve of the left low pressure pump element 6 'passes through a collecting plate 27 of the low pressure pressure collecting ring 26. The three collecting plates 27 of the low pressure pressure collecting ring 26 are connected to each other via pipe sections 28, so that all three low-pressure pump elements 6 'together in the second inlet 12 promote.

From the high-pressure pressure collecting ring 19 is in Fig. 6 one based FIGS. 14 and 15 illustrated body 20 via pipe sections 21 with two further bodies 22, 22 '( Fig. 14 ) of the high-pressure collecting ring. A pressure tube 39 connects the single outlet 14 of the valve block 10 to the body 20. Another pressure tube 38 (pressure P1) connects the inlet 11 of the valve block 10 with another body 22 '(FIG. Fig. 14 The valve block 10 contains the check valve R, the diaphragm B, the low-pressure changeover valve U, and the optionally required pressure switch DW in an extremely compact arrangement and connected according to in Fig. 4 indicated housing channels in the valve block 10. At least some of the high-pressure and / or low-pressure pump elements 5 ', 6' are connected via suction hoses 18 with a depending on the operating position of the pump unit A (vertical or horizontal) low-lying oil sump (return line 9). The body 20 of the high-pressure pressure collecting ring 19, which is connected via the pressure tube 39 to the single outlet 14 of the valve block 10, connects this flow path via the pressure tube 23 inserted through the drilled housing inner wall structure 16 with the single pressure outlet 13 of the housing (supplied pressure P ').

Fig. 7 illustrates a mounting phase of the pump assembly A, in which initially the high-pressure pump elements 5 'and the low-pressure pump elements 6' and the suction hoses 18, the in Fig. 7 non-visible high-pressure pressure collecting ring 19 and the low-pressure collecting ring 26 with the pipe sections 28 and the collecting plates 27 are mounted on the low pressure pump elements 6 'on the housing inner wall structure 16. In the body 22 'of the high-pressure pressure collecting ring 19 is a port exposed to the inlet 11 of the valve block 10 (FIG. Fig. 6 ), while in the body 20 of the high-pressure pressure collecting ring 19 under another high-pressure pump element 5 'an inlet 14' is exposed, which is aligned with the single outlet 14 of the valve block 10 to be mounted. Finally, in a collecting plate 27 on a low-pressure pump element 6 '(in Fig. 7 left) an opening 29 'free (discharge pressure P3 of the low pressure pump 6), which is aligned with the second inlet 12 of the valve block 10 to be mounted. At 14 'and 11 are in or after the in Fig. 7 assembly phase shown in Fig. 6 indicated pressure pipes 39, 38 used.

In Fig. 8 the valve block 10 is installed under the suction hoses 18 and fixed with the same fastening screws 17, which also fix two of the low-pressure pump elements 6 'on the housing inner wall structure 16. The pressure pipes 38, 39 (indicated by dashed lines), make pressure-tight connections between the valve block 10 and the bodies 22 ', 20 of the high-pressure pressure collecting ring 19 ago.

Fig. 9 is a side view of the valve block 10, which may have an approximately trapezoidal outline, and according to Fig. 8 is nestled in the largely round inner cross-section of the housing. Fig. 9 shows the valve block outside, in which the only outlet 14 (pressure P '), in which the pressure tube 39 is introduced, the inlet 11, in which the pressure tube 38 is introduced (pressure P1), and the area 12 with the opening 29th lie to the check valve R. Further clarified Fig. 9 the grouping of the diaphragm B, the pressure switch DW, the low-pressure switching valve U and the check valve R in the valve block 10th

The corresponding sectional view in Fig. 10 (Section plane X - X in Fig. 9 ) shows a baffle insert 30 in a block bore, to which the inlet 11 is connected, branches off from the upstream of the baffle insert 30, the control line 31 to the closing control side of the pressure switch DW, and from the downstream of the baffle insert 30, the connecting line 32 branches off, via the pressure switch DW leads to the return channel 9. Some of the block holes are in Fig. 10 closed by screw plugs.

Fig. 11 shows in section (section plane XI - XI in Fig. 9 ) the pressure switch DW, which includes a seat valve cone 33 in a block bore, which cooperates with a valve seat 34 of a sleeve insert and is acted upon by the spring 35 in the opening direction. At the closing control side at the larger end diameter of the seat poppet 33, the control line 31 is connected, while the control line 31 'branches off from the connecting line 32 and leads to the opening control side in the region of the spring 35 of the seat poppet 33.

Fig. 12 shows in section (section plane XII - XII in Fig. 9 ) the low-pressure switching valve U with a valve spool 36 in a block bore of the valve block 10. The valve spool 36 is acted upon in the blocking position shown by the spring 37 and separates a housing channel 43 of the return line 9. In Aufsteuerrichtung the valve spool 36 ( Fig. 12 up) is the valve spool 36, the diaphragm (or nozzle) 42 from the control channel 41 is applied, which branches off from the coming of the diaphragm B connecting line 32.

Fig. 13 shows in section (section plane XIII - XIII in Fig. 9 ) the check valve R with a seat 44 forming Einschraubeinsatz and a mushroom-shaped valve member 45 which separates the connection line 32 from the low pressure switching valve U leading channel 43 in a block bore. The block bore has the opening 29 (pressure P3) with the in Fig. 7 shown opening 29 'is aligned.

Fig. 14 schematically illustrates the high-pressure pressure collecting ring 19 with the three bodies 20, 22 and 22 ', which are connected to each other via the pipe sections 21. The body 20 has on one side a connection extension 47 in which a bore 46 for pressing in the pressure tube 23 is formed, which is connected via a channel 48 to a connection 39 "in which the pressure tube 39 is seated High-pressure pressure collecting ring 19 has a connection 38 ", in which the pressure tube 38 is seated, and which communicates with the pipe section 21.

Function of the Pump Unit A of FIGS. 3 to 15:

After switching on the sub-oil engine 7 promote both pumps 5, 6 together, with their flow rates through the check valve R in the in Fig. 4 shown shutoff position of the low pressure switching valve U are combined and first flow through the standing in the passage position pressure switch DW in the return line 9, so that the lower oil motor 7 is able to start easily in the case of a single-phase AC motor. As soon as the lower oil engine 7 has started and a sufficient pressure gradient arises at the diaphragm B, the pressure switch DW is brought into the blocking position via the control line 31 so that when the check valve R is open, the pumped pressure medium (pressure P ') is present at the single pressure outlet 13 of the housing , As soon as the diaphragm 42 and the control line 41 is a sufficiently high, defined by the spring 37 pressure, the low-pressure switching valve U is controlled, so that the flow rate (delivery pressure P3) of the low-pressure pump 6 low resistance is promoted in the return line 9, and only the high-pressure pump 5 at then kept closed check valve R to the single pressure outlet 13 promotes (pressure P ') until finally the desired maximum pressure (limited by the system pressure relief valve DB) of, for example, 700 bar is reached, which is processable at the pressure port P from the directional control valve W. For example, the secondary pressure is limited by the secondary pressure relief valve SD to 100 bar at the consumer port A '.

The summed flow rates of both pumps 5, 6 are used, for example, for a fast idle stroke, while the flow is used only the high-pressure pump 5 to build up the required high maximum pressure of, for example, about 700 bar, after the backlash is passed.

If the lower oil motor 7 is designed as a three-phase motor, which can also start against pressure, then the pressure switch DW can be omitted or passivated.

If the lower oil motor 7 is switched off, and drops due to consumption of the pressure in the pressure line leading to the pressure line 13 from far, the low pressure switching valve U goes back into the shut-off position shown and the pressure switch DW returns to its shown passage position, so that relieves the system pressure is.

Claims (12)

1. Pump aggregate (1) for supplying at least one directional control valve (W), the pump aggregate comprising a housing (1, 2, 4) containing a high-pressure pump (5) and a low-pressure pump (6), and an oil-immersed electric motor (7) common for both pumps (5, 6) and oil and a return line port (8) connected to a return line (9), and a valve arrangement (V) mounted between separated discharge outlet ports of the pumps (5, 6) and a pressure port (P), said valve arrangement (V) comprising at least one low-pressure change-over valve (U), which can be switched open to the return line (9) depending from pressure, a check valve (R) combining the discharge flows of both pumps (5, 6) until the low-pressure change-over valve (U) is switched open, and a system pressure-limiting valve (DB), characterised in that at least the low-pressure change-over valve (U) and the check valve (R) of the valve combination (V) are arranged in the interior of the housing (1, 2, 4) and are circuited in such a way that the discharge flows of both pumps (5, 6) are combinable in the housing interior into a single pressure outlet port (P', 13) of the housing, to which pressure outlet port at least the system pressure-limiting valve (DB) mounted on the exterior of the housing is connected.
2. Pump aggregate according to Claim 1, characterised in that in the case of an oil-immersed alternating current motor (7) commonly driving both pumps (5, 6) the valve combination (V) comprises a pressure shunting switch (DW) connectable to the return line (9) and an aperture (B) assigned to the pressure shunting switch, and that the pressure shunting switch (DW), the aperture (B), the low-pressure change-over valve (U) and the check valve (R) are all arranged in the interior of the housing (1, 2, 4).
3. Pump aggregate according to Claim 1 or 2, characterised in that the low-pressure change-over valve (U), the check valve (R), and optionally the pressure shunting switch (DW) with its aperture (B) are arranged in a common valve block (10), which is mounted in the interior of the housing on pump elements (5', 6') of both pumps (5, 6) which pump elements are installed on a housing interior wall structure (16).
4. Pump aggregate according to Claim 3, characterised in that the valve block (10) has a single outlet port (14) that is connected through the housing interior wall structure (16) to the pressure outlet port (13, P') of the housing (1, 2, 4).
5. Pump aggregate according to Claim 3, characterised in that the valve block (10) has an approximately trapezoidal contour that can be nestled into an approximately circular interior cross-section of the housing (1, 2, 4).
6. Pump aggregate according to Claim 3, characterised in that a plurality of high-pressure and low-pressure pump elements (5', 6'), preferably three of each kind, respectively connected to one another via a high-pressure and a low-pressure pressure collector ring (26, 19), are alternatingly installed at the housing interior wall structure (16) in circumferential direction around a drive shaft (24) of the oil-immersed motor (7) and in essentially the same radial plane of the housing and that, preferably, the valve block (10) is mounted on collector plates (27) provided in the low-pressure pressure collector ring (26).
7. Pump aggregate according to Claims 4 to 6, characterised in that the high-pressure pressure collector ring (19) contains a body (20) mounted underneath one of the high-pressure pump elements (5'), the body (20) comprising a connection protrusion (47) and through which body the single outlet port (14) of the valve block (10) is connected to the pressure outlet port (13, P') of the housing (1, 2, 4), preferably via a pressure resistant pipe (23) press-fit into the connection protrusion (47) of the body (20) and through a bore penetrating the housing interior wall structure (16).
8. Pump aggregate according to Claim 1, characterised in that depending on a predetermined upright or recumbent operating position of the pump aggregate (A), suction hoses (18) connected to at least some high-pressure and / or low-pressure pump elements (5', 6'), extend to a low-lying oil sump in the housing (1, 2, 4), the low position of the oil sump depending on the respective operation position during use.
9. Pump aggregate according to Claim 1, characterised in that the housing (1, 2, 4) is an externally ribbed pipe section with the moulded-in housing interior wall structure (16) both for fixing in place the oil-immersed motor (7) and the pumps (5, 6), the pipe section bearing housing cover lids (2, 4) affixed on both pipe section ends, wherein preferably, one housing cover lid (2) bears a cooling fan (3).
10. Pump aggregate according to Claim 1, characterised in that the sole externally arranged parts of the valve combination (V) are directional control valves (W) mounted to the housing exterior wall on top of the single pressure outlet port (13) of the housing, particularly the system pressure-limiting valve (DB) and, preferably, a secondary pressure-limiting valve (SD), to which the directional control valve (W) is affixed.
11. Pump aggregate according to at least one of the preceding claims, characterised in that the aperture (B), the check valve (R), the low-pressure change-over valve (U), and the pressure shunting switch (DW) each have valve inserts (30, 33, 36, 45) inserted into bores of the valve block (10), the bores being interconnected via channels formed in the interior of the valve block (10).
12. Pump aggregate according to at least one of the preceding claims, characterised in that a connection port (38') of the valve block (10) is connected to an opening (38") of the high-pressure pressure collector ring (19) by an inserted pressure pipe (38), that the single outlet port (14) of the valve block (10) is connected to an opening (39") of the body (20) of the high-pressure pressure collector ring (19), by an inserted pressure pipe (39), and that the valve block (10) connected via an opening (29) to the check valve (2) is mounted with the opening (29) in a sealed manner directly on top of an outlet (29') of the low-pressure pressure collector ring (26), preferably above an outlet (29') provided in a collector plate (27) of the low-pressure collector ring (26).

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