Hydraulic pump unit for driving and controlling hydraulic tool components

Abstract

Hydraulic pump unit (30) with at least one pump element (7) in a first subchamber (2) which is at least partially filled with a first fluid, a fluid connection for the first fluid, namely an outflow (32) and an inflow (33), to a hydraulic tool (18), an electric motor (31), having a stator (25) and a rotor (12) connected to a motor shaft (11), in a second sub-chamber (3) which is at least partially filled with a second fluid, and the electric motor (31) drives the at least one pump element (7) by means of the motor shaft (11), and a housing (26), wherein the first fluid is cooled by means of a first cooling circuit (10), both the first sub-chamber (2) and the second sub-chamber (3) are arranged within the housing (26), characterized in that the first sub-chamber (2) is separated from the second sub-chamber (3) by a separator (24) and the separator (24) serves as a fluid seal between the first sub-chamber (2) and the second sub-chamber (3), and the fluid in both the first sub-chamber (2) and the second sub-chamber (3) can be drained by means of a single screw plug (6).

Description

[0001] The invention relates to a hydraulic pump unit, in particular a hydraulic pump unit for driving and controlling hydraulic tool components.

[0002] Hydraulic pump units are known in the art. Such units comprise an electric motor and at least one pump element driven by the motor via a motor shaft. In the prior art, hydraulic pump units are designed so that the motor and the pump element are located in the pressure fluid reservoir. This design is chosen to achieve improved cooling of the motor winding.

[0003] This device has the following disadvantages, among others: With this design, the motor dissipates its waste heat directly into the surrounding pressure medium in the reservoir, which is then pumped to the consumer, e.g., a hydraulic tool component, by means of the pump elements. This causes the tool to be heated by the motor's waste heat. This is particularly disadvantageous if the tool has no thermal insulation - which is usually the case - and is held by a person. Furthermore, the prior art does not allow switching from a liquid-cooled version of the motor to an air-cooled version, which would be expedient depending on the ambient temperature and to save weight.

[0004] DE 10 2013 002 187 A1 shows a generic hydraulic pump unit with the features of the preamble of patent claim 1. Further prior art is discussed in DE 103 31 191 A1, DE 101 17 373 A1 and DE 200 07 554 U1.

[0005] Based on this prior art, it is the object of the present invention to at least partially overcome or improve the disadvantages of the prior art.

[0006] This object is achieved by a device according to claim 1. Preferred embodiments and modifications are the subject of the dependent claims. In the following, the terms hydraulic pump unit, hydraulic unit, and unit are used synonymously.

[0007] A hydraulic pump unit according to the invention has at least one pump element in a first subchamber that is at least partially filled with a first fluid, preferably a hydraulic fluid. Furthermore, the pump unit has a fluid connection for the first fluid, namely an outflow and an inflow, to a hydraulic tool. The pump unit also has an electric motor with a stator and a rotor that is connected to a motor shaft. The rotor is arranged in a second subchamber that is at least partially filled with a second fluid. The electric motor has a motor shaft, by means of which the electric motor drives the at least one pump element. The pump unit also has a housing.

[0008] In the pump unit according to the invention, both the first sub-chamber and the second sub-chamber are arranged within the housing, the first sub-chamber is separated from the second sub-chamber by a separator, and the first fluid is cooled by means of a first cooling circuit.

[0009] Because both the first and second subchambers are located within the housing, the pump unit can be designed to be particularly compact yet robust. Furthermore, it is easy to transport.

[0010] Even though both the first sub-chamber and the second sub-chamber are arranged within the housing, the first sub-chamber is structurally, fluid-dynamically and / or thermally separated from the second sub-chamber by a separator. In the pump unit according to the invention, the coolant medium in the motor volume cannot communicate with the medium in the reservoir. In this way, each sub-chamber can be optimally cooled according to requirements. The requirements depend, for example, on the temperature requirements at the place of use. For example, the temperature requirements for use in an air-conditioned environment, e.g. in a factory hall, differ significantly from the requirements for outdoor use near the equator or, in turn, from the requirements for outdoor use in polar regions.

[0011] It may also be the case that different fluids are to be used for different applications or different requirements. Reasons for this may be that the requirements, e.g. with regard to corrosion resistance or environmental compatibility, for the motor of the unit and for the hydraulic tool and / or its supply line diverge. The use of different fluids is possible with a device according to the invention because the fluids in the first and second sub-chambers do not communicate. It may therefore be necessary to use highly efficient, but environmentally harmful, engine coolants in the second sub-chamber for motor cooling. However, the use of these fluids as hydraulic fluid is not permitted, since leakage losses to the environment can occur in the tool circuit. With the unit according to the invention, operation with two completely different fluids is also possible.

[0012] Furthermore, with the unit according to the invention, it is not only possible to optimally design a specific series according to a specific range of requirements, but even a single pump unit can be adapted to a wide variety of different requirements in a very simple manner.

[0013] The first fluid is cooled by a first cooling circuit; as mentioned above, this occurs without affecting the cooling of the engine and, in particular, independently of the fluid used for engine cooling. As a result, the fluid volume in the second subchamber is maintained, regardless of the pressure fluid discharge in the first subchamber.

[0014] In one embodiment, the second fluid is a gas, in particular air.

[0015] Using air or another gas to cool the engine has the advantage of reducing the weight of the entire hydraulic unit, making it easier to transport.

[0016] If gases are preferably used for motor cooling, it is advisable to use motors that are suitable for higher winding temperatures or have lower power losses, such as synchronous motors.

[0017] In one embodiment, the second fluid is a liquid, in particular a hydraulic fluid, and particularly preferably optionally a gas, in particular air, or a liquid, in particular a hydraulic fluid.

[0018] If the second fluid is either a gas or a liquid, then a device according to the invention is particularly flexible in use and multifunctional. This is because one and the same hydraulic unit can be easily modified – even during use – to optimally meet a specific range of requirements. For example, the unit can be air-cooled for outdoor use in a cold environment and then – after a simple conversion – used in a hot factory environment with liquid cooling.

[0019] In the case of liquid cooling, the engine is essentially completely immersed in the engine coolant, so the likelihood of engine overheating is significantly reduced even under very high ambient temperatures.

[0020] In one embodiment, the first fluid is the same liquid as the second fluid.

[0021] For certain applications, it is possible or necessary to use the same fluid for motor cooling and for operating the hydraulic tools. This is possible with a hydraulic unit according to the invention. Many advantages of the present invention are retained in this case, such as the separate optimization of the cooling circuits for the first and second subchambers, and the fact that the removal of hydraulic fluid in the tool circuit—e.g., due to leakage—has no effect on the motor circuit.

[0022] According to the invention, the liquid can be drained in both the first sub-chamber and the second sub-chamber by means of a single screw plug.

[0023] The screw plug is preferably designed as a double-sealing screw plug, i.e., with a double sealing seat geometry. This seals the first subchamber from the environment, while also sealing the second subchamber from the environment. The screw plug can be located, for example, on the pump block.

[0024] During maintenance, it may be advisable to drain the pressure fluid and the engine coolant using a common screw plug. This is particularly advantageous because the user is often unfamiliar with the internal structure of the unit and could therefore simply overlook the need to change a fluid. Using the screw plug according to the invention eliminates this misoperation.

[0025] In one embodiment, the first sub-space and the second sub-space can each be ventilated and / or ventilated individually, ie separately from the other sub-space.

[0026] This is particularly advantageous when different fluids are present in the first subspace and the second subspace.

[0027] In one embodiment, the pump element is arranged, preferably fastened, to a pump block, wherein the pump block closes off the first sub-chamber from the environment.

[0028] This involves implementing several design solutions in a single component. Firstly, at least one pump element is arranged on a pump block. Preferably, the pump element (or elements) are attached to the pump block, for example, by means of screws. Secondly, the pump block serves as the A-end bearing plate for the motor shaft of the electric motor.

[0029] This allows for simple and precise alignment of the pump elements relative to the motor shaft. Furthermore, the pump block is designed to seal off the first compartment from the environment.

[0030] The pump block can be fastened to the A-end shield-side end of the housing using fastening elements - e.g. screws. In the prior art, the A-end shield is guided past the housing using screws that are approximately the length of the housing and is screwed to the B-end shield-side end using a thread. This leads to disadvantages with regard to assembly and maintainability of the unit. With a device according to the invention, assembly is simplified and the maintainability of the pump unit is improved by the pump block being used as the A-end shield and being fastened to the A-end shield-side end of the housing. This means that short fastening means can be used compared to the prior art, which are much easier for a fitter to handle.To ensure good sealing of the first compartment while maintaining a cost-effective design and ease of assembly, the motor-pump housing can be sealed tightly to the pump block using an O-ring inserted into a groove. The motor cover (B-end shield) can also be sealed in this way.

[0031] The front-mounted pump block should preferably be designed so that there are no screw plugs in the first and second compartments to avoid the risk of invisible leakage.

[0032] The fastening elements could comprise bores and / or the bores could be arranged in bore ribs of the cooling profile, wherein the bore ribs preferably have a rectangular cross-section to improve the stability of the fastening. Advantageously, the fastening means can be designed as screws and the bores as threads, thus enabling a particularly simple yet secure fastening between the housing and the pump block.

[0033] In one embodiment, a sensor is arranged in the first sub-chamber, which sensor detects when the level of the first fluid in the first sub-chamber falls below a predetermined level.

[0034] This significantly improves the operational reliability of the unit. Preferably, the sensor is arranged in the first subchamber such that a drop in the pressure medium level can be detected in at least two operating positions, preventing air from being sucked in by the pump elements. In response to the detection of a drop below a predetermined level, the hydraulic unit can be shut down and / or an alarm can be triggered, and the user can be prompted to fill the first subchamber with pressure medium—in practice, via the reservoir.

[0035] In one embodiment, a cooler is arranged within the first cooling circuit and / or within the second cooling circuit.

[0036] This embodiment is preferably selected in the case of high ambient temperatures. A pressure medium cooler is arranged within the first cooling circuit in the virtually pressure-free return line. This cooler is preferably located near the air inlet of the motor fan, so that cooling air flows through it. Particularly preferably, it is mounted perpendicular to the motor shaft and circumferentially adjacent to the fan's intake area to ensure maximum cooling air flow. This motor fan can be driven by the pump motor shaft or designed as a separate electric fan; alternatively or additionally, it can be designed as a separate electric fan.

[0037] Alternatively or additionally, a cooler can be arranged within the second cooling circuit. This is preferably chosen for liquid-cooled engine versions.

[0038] In one embodiment, a separate inlet opening and outlet opening for the first and second fluids, respectively, is arranged on at least one of the coolers.

[0039] This has the advantage that the first and second fluids can be drained or changed separately.

[0040] In one embodiment, a fan is arranged on the housing, and / or the housing has cooling fins, which are preferably, at least partially, T-shaped or L-shaped.

[0041] This creates a larger cooling surface compared to the bare housing wall, thus improving the cooling of the first and / or second subchamber. Cooling can be further improved by arranging a fan on the housing, specifically in such a way that the cooling air flows along the housing.

[0042] In one embodiment, a return line is arranged at the first subchamber, which is connected to the first subchamber at a first end and a second end. A reservoir is arranged within the return line to supply the first subchamber with pressure fluid in the event of a pressure fluid discharge. The pressure fluid discharge can be caused by actuation of the hydraulic tools, which can lead to dynamic fluctuations in the hydraulic fluid. These fluctuations can be quickly compensated for by the reservoir in the return line. The pressure fluid discharge can also be caused by leakage.

[0043] In one embodiment, the return line is part of the first cooling circuit.

[0044] This type of design solves both the problem of pressure fluid discharge and the problem of cooling. This has the advantage that the hydraulic unit can be constructed more simply and with fewer components.

[0045] In one embodiment, the reservoir is arranged above the first cooling circuit and has a fluid filling opening with a closure lid on its upper side.

[0046] The reservoir can be located entirely above or partially above the first cooling circuit. This is primarily determined by design considerations. For example, the reservoir can be designed larger so that its underside has a curve that at least partially encompasses the housing and also has cavities on the sides of the housing, meaning that these cavities are no longer located entirely above the first cooling circuit or above the housing. The user must observe a maximum oil level mark in the reservoir to ensure that no pressurized fluid can escape through the filler opening during operation.

[0047] Furthermore, an additional fill level marker or electronic fill level monitoring device is provided in the first subchamber to ensure proper filling of the pressure medium in the reservoir. The device thus functions even with a statically empty return line down to a minimum pressure fluid level above the intake opening of the pump elements, which are preferably located as low as possible in the reservoir.

[0048] To ensure the pump unit is sealed in all transport positions, the reservoir is equipped with a filler opening with a cap, which preferably includes a check valve and a pressure relief valve that only opens at a pressure at least 1.5 times the static pressure of the maximum fluid level. Air is drawn in unimpeded through the cap by a check valve that is open in the suction direction.

[0049] To enable the pump unit to be transported and operated in two different positions, regardless of the electric motor type, the fluid filler opening is preferably positioned at the top, corresponding to the vertical operating position. This means that the fluid filler opening is positioned on the housing in such a way that the pump unit can be operated in both a vertical and a horizontal position. The open design thus ensures that at least 90% of the motor winding is covered by the motor coolant in the vertical operating position.

[0050] In one embodiment, the reservoir contains a filter and / or cooling elements.

[0051] The reservoir is relatively large, especially in relation to the housing volume. The reservoir is typically shallow rather than tall. This size and design allows it to contain a filter and / or cooling elements. In the case of cooling elements, the size of the reservoir ensures effective cooling of the first fluid. In the case of the filter, the size of the filter ensures that the pressure medium flows through the filter with very little resistance. In addition - and to further enhance this effect - the return line is preferably designed with a relatively large cross-section. The filter element filters out solids from the coolant, for example, and defoams the pressure medium.

[0052] In one embodiment, a further filter element is arranged in the fluid filling opening of the reservoir, which is preferably arranged directly below the closure lid.

[0053] The fluid filler opening is a small tube that is closed at the top by the cover and extends into the reservoir. The aforementioned filter element can be arranged in this tube. This filter element preferably prevents contaminants, especially coarse contaminants, from entering the reservoir when hydraulic fluid is added.

[0054] In one embodiment, the separator can be used for high temperatures, in particular up to 175 °C, preferably up to 150 °C. Furthermore, it has a low thermal conductivity, in particular less than 0.5 W / (m^K), preferably less than 0.25 W / (m^K).

[0055] This design allows the separator to withstand even high temperatures that can occur when the pump unit is subjected to intensive use.

[0056] Furthermore, the low thermal conductivity ensures that the first sub-chamber - and thus also the first cooling circuit - is actually thermally independent of the second sub-chamber, and thus the engine temperature has no or only very little influence on the temperature of the hydraulic fluid.

[0057] In one embodiment, the separator serves as a fluid seal between the first sub-chamber and the second sub-chamber, in particular in that the separator is made at least partially of a material that can be deformed under pressure, preferably of polyvinylidene fluoride (PVDF). As a result, the first sub-chamber is not only structurally, fluidically and thermally separated from the second sub-chamber by a separator, but the selected material also simplifies the seal between the first sub-chamber and the second sub-chamber. The seal on the housing therefore does not require any additional sealing elements, such as O-rings. The separator either has its own sealing seat relative to the motor shaft or it accommodates a corresponding sealing element.

[0058] In one embodiment, the first sub-chamber is in fluid communication with an additional reservoir.

[0059] This design with a reservoir and an additional reservoir allows for response to different sized pendulum volumes, so that many different hydraulic tools can be connected to the unit.

[0060] The design could be such that the first subchamber, in which the pump elements are located, is fluidly connected to an auxiliary reservoir, preferably approximately at the height of the motor shaft, so that a reduction in the pressure medium in the first subchamber can be compensated by an external supply of pressure medium from the auxiliary reservoir. The connection to the auxiliary reservoir is located on the front and / or long side of the pump block. Alternatively, this auxiliary reservoir could simply be located next to the pump as a container and, with a connecting line communicating with the connection on the reservoir via the pump block, effectively compensate for pressure medium fluctuations in the reservoir.

[0061] In the event of a particularly high pressure medium requirement, a mounting surface for an additional reservoir is provided on the pump block (A-end shield). This surface preferably communicates with the first subchamber above the intake openings of the uppermost pump element and is also equipped with a vent opening at the same height as the filler and vent screw of the filter and filler unit. The fact that the structure is located above the intake lines of the pump elements has the advantage that such an additional reservoir contains no unusable volume, thus minimizing weight. With this arrangement of the components, it is also possible to seal the circulating volume airtight in order to keep the water level in the filler and filter unit constant under all operating conditions.

[0062] In one embodiment, the additional reservoir is arranged laterally of the housing and the closure cover of the additional reservoir is arranged at the same height, relative to the motor shaft, as the closure cover of the reservoir.

[0063] This arrangement of the additional reservoir has the advantage that there is no structural collision with the reservoir and that both the reservoir and the additional reservoir can be operated in several positions.

[0064] In one embodiment, a further pump is arranged on the pump block, outside the housing, preferably on the front side.

[0065] This makes it possible, for example, to operate another hydraulic tool. This has the advantage of expanding the pump unit's application range.

[0066] The invention is explained below using a preferred embodiment. It should be noted that this example encompasses modifications and additions that would immediately become apparent to those skilled in the art. Furthermore, this preferred embodiment does not represent a limitation of the invention, in the sense that modifications and additions are within the scope of the present invention.

[0067] Showing: Fig. 1: a schematic representation of a pump unit according to the invention in lateral section, without frame; Fig. 2: a schematic representation of a pump unit according to the invention in front view, without frame.

[0068] Fig. 1 shows a hydraulic pump unit 30 with a first subchamber 2, which is at least partially filled with a first fluid, preferably with a hydraulic fluid. A pump element 7, which is fastened to a pump block 4, is arranged in the first fluid. The pump block 4 also serves as an A-end bearing plate for a motor shaft 11. At the same time, the pump block 4 closes off the first subchamber 2 from the environment. The front-mounted pump block 4 is designed such that there are no screw plugs in the first and second subchambers in order to avoid the risk of invisible leakage. An outflow 32 and an inflow 33 are arranged on the pump block 4, which conduct the hydraulic fluid from the first subchamber 2 to a hydraulic tool 18 and away from it, respectively.

[0069] The first subchamber 2 is separated from a second subchamber 3 by a separator 24. An electric motor 31 is arranged in the second subchamber 3, which has a stator 25 and a rotor 12. The rotor 12 is connected to the motor shaft 11. The motor shaft 11 is guided through the separator 24. This passage of the motor shaft 11 is sealed by a sealing seat 29 located between the separator 24 and the motor shaft 11. In this way, the electric motor 31 drives the pump element 7 via the motor shaft 11.

[0070] The pump unit 30 has a housing 26. Both the first subchamber 2 and the second subchamber 3 are arranged within the housing 26.

[0071] A screw plug or fluid drain plug 6 is arranged horizontally on the pump block 4 at the lowest point of the first subchamber 2. This screw plug 6 has a sealing seat on the pump block 4 and a sealing seat 8 on the separator 24. This double-sealing screw plug 6 seals off the first subchamber 2 from the environment, and the second subchamber 3 from the environment. This screw plug 6 allows the first fluid in the first subchamber 2 and the second fluid in the second subchamber 3 to be drained simultaneously.

[0072] To the right of the motor cover 23, which also serves as the B-end shield, is a fan 13, which is also driven by the electric motor 31 via the motor shaft 11. The fan 13 is protected by a fan cover 16. The fan 13 could also be driven by a separate motor.

[0073] A second cooling circuit 5 or engine cooling circuit is connected to the second subchamber 3. A radiator 14 is arranged within the second cooling circuit 5. The diagram shows that the fan 13 can be arranged in such a way, ie, in front of the fan cover 16, that it can also cool the radiator 14.

[0074] The pump unit 30 also has a first cooling circuit 10. Through this, the hydraulic fluid is guided out of the first sub-chamber 2 via the first end 34 and fed back to the first sub-chamber 2 via the second end 35. The first cooling circuit 10 is completely separate from the second cooling circuit 5. A cooler 15 is arranged within the first cooling circuit 10. The hydraulic fluid reaches the filter and filling unit or reservoir 1 via the return line 28. The reservoir 1 is part of the first cooling circuit 10. The reservoir 1 contains a filter and / or cooling elements. It is also clearly visible in this schematic representation that the reservoir 1 is designed to be relatively large, so that in the case of cooling elements, effective cooling of the first fluid is ensured by the size of the reservoir.If the reservoir 1 contains a filter, it can be designed to be large enough to ensure—due to the size of the filter—a very low-resistance flow of the pressure medium through the filter. Furthermore, a filling device with a closure cap 20 and a filling filter 17 is arranged at the top of the reservoir 1. A screw plug 9 is arranged at the bottom of the reservoir 1, by means of which fluid can be introduced from the reservoir 1 into the second subchamber 3. This, of course, only makes sense in cases where the first fluid and the second fluid are the same liquid.

[0075] In addition, a connection to an additional reservoir 19 is schematically shown. The connection is located above the highest pump element 7. The additional reservoir 19 is filled directly from the first subchamber 2 when the pressure medium level is again greater than the amount of pressure medium removed by the tool 18 due to a larger return flow of pressure medium, caused by the interaction of the tool 18 via the return line 27, 28.

[0076] Fig.2 shows the hydraulic pump unit 30 in a front view, with the reservoir 1 shown partially cut away. The round housing 26 of the pump unit is clearly visible. Cooling fins are arranged at the bottom, which are L-shaped; these could also be T-shaped. An outflow 32 and an inflow 33 are arranged on the pump block 4. The first cooling circuit 10 leads from the housing 26 into the reservoir 1, via the cooler 15 and the return line 28. Within the reservoir 1, in the cutaway area, the pressure medium filter 21 is clearly visible. The closure cap 20 is arranged on top of the reservoir 1 and is at the same height as the closure cap 22 of the additional reservoir 19. The additional reservoir 19 is arranged to the side of the housing 26. List of reference symbols 1 filter and filling unit, reservoir 2 first subspace 3 second subspace 4 Pump block (A-bearing shield) 5 second cooling circuit 6 Plug screw, fluid drain screw 7 Pump element 8 Sealing seat on the separator 9 Plug screw (engine compartment) 10 first cooling circuit 11 Motor shaft 12 Rotor 13 fans 14 Cooler, second circuit 15 cooler, first circuit 16 Fan cover 17 Filling filter 18 Hydraulic tools 19 Additional reservoir 20 closure caps 21 pressure medium filter 22 Cover cap (additional reservoir) 23 Engine cover (B-end shield) 24 Separator 25 Stator 26 housings 27 Filter and filling element (return line) 28 Return line 29 Sealing seat (between separator and motor shaft) 30 Hydraulic pump unit 31 electric motor 32 Outflow / backflow from / to the first sub-chamber 33 Return / outflow to / from the first sub-chamber 34 first end of the return line (28) 35 second end of the return line (28)

Claims

[1] Hydraulic pump unit (30) with at least one pump element (7) in a first subchamber (2) which is at least partially filled with a first fluid, a fluid connection for the first fluid, namely an outflow (32) and an inflow (33), to a hydraulic tool (18), an electric motor (31), having a stator (25) and a rotor (12) connected to a motor shaft (11), in a second sub-chamber (3) which is at least partially filled with a second fluid, and the electric motor (31) drives the at least one pump element (7) by means of the motor shaft (11), and a housing (26), wherein the first fluid is cooled by means of a first cooling circuit (10), both the first sub-chamber (2) and the second sub-chamber (3) are arranged within the housing (26), characterized by , that the first sub-chamber (2) is separated from the second sub-chamber (3) by a separator (24) and the separator (24) serves as a fluid seal between the first sub-chamber (2) and the second sub-chamber (3), and the fluid in both the first sub-chamber (2) and the second sub-chamber (3) can be drained by means of a single screw plug (6). [2] Hydraulic pump unit (30) according to claim 1, wherein the second fluid is a gas [3] Hydraulic pump unit (30) according to claim 1, wherein the second fluid is a liquid. [4] Hydraulic pump unit (30) according to claim 3, wherein the first fluid is the same liquid as the second fluid. [5] Hydraulic pump unit (30) according to one of the preceding claims, wherein the first sub-chamber (2) and the second sub-chamber (3) are each ventilated and / or vented individually, ie separately from the other sub-chamber. [6] Hydraulic pump unit (30) according to one of the preceding claims, wherein the pump element (7) is arranged on a pump block (4), wherein the pump block (4) closes off the first sub-chamber (2) from the environment. [7] Hydraulic pump unit (30) according to one of the preceding claims, wherein a sensor is arranged in the first sub-chamber (2) which detects when the level of the first fluid in the first sub-chamber (2) falls below a predetermined level. [8] Hydraulic pump unit (30) according to one of the preceding claims, wherein a cooler (14, 15) is arranged within the first cooling circuit (10) and / or within a second cooling circuit (5). [9] Hydraulic pump unit (30) according to claim 8, wherein a separate inlet opening and outlet opening for the first and second fluids, respectively, is arranged on at least one of the coolers (14, 15). [10] Hydraulic pump unit (30) according to one of the preceding claims, wherein a fan (13) is arranged on the housing (26) and / or the housing (26) has cooling fins. [11] Hydraulic pump unit (30) according to one of the preceding claims, wherein a return line (28) is connected to the first sub-chamber (2) at a first end (34) and at a second end (35) and a reservoir (1) is arranged within the return line (28) in order to supply the first sub-chamber (2) with pressure medium in the event of a pressure medium discharge. [12] Hydraulic pump unit (30) according to claim 11, wherein the return line (28) is part of the first cooling circuit (10). [13] Hydraulic pump unit (30) according to claim 11 or 12, wherein the reservoir (1) is arranged above the first cooling circuit (10) and has on its upper side a fluid filling opening with a closure cap (20). [14] Hydraulic pump unit (30) according to claims 11 to 13, wherein the reservoir (1) contains a filter and / or cooling elements. [15] Hydraulic pump unit (30) according to claim 13 to 14, wherein a further filter element (17) is arranged in the fluid filling opening of the reservoir (1). [16] Hydraulic pump unit (30) according to one of the preceding claims, wherein the separator (24) is usable for high temperatures up to 175 °C and has a low thermal conductivity of less than 0.5 W / (m^K). [17] Hydraulic pump unit (30) according to one of the preceding claims, wherein the first sub-chamber (2) is in fluid communication with an additional reservoir (19). [18] Hydraulic pump unit (30) according to claim 17 as far as it is based on claim 13, wherein the additional reservoir (19) is arranged laterally of the housing (26) and a closure cover (22) of the additional reservoir (19) is arranged at the same height, relative to the motor shaft (11), as the closure cover (20) of the reservoir (1). [19] Hydraulic pump unit (30) according to claim 6 and one of the preceding claims as far as related to claim 6, wherein a further pump is arranged on the pump block (4) outside the housing (26).

Images