DE102019130716A1 - Liquid pump - Google Patents

Abstract

A liquid pump (10), in particular an oil pump for supplying a clutch actuator, a gear actuator, a lubrication system and / or a cooling system of a drive train, is described, which has an electric drive unit (18) with a stator (22) and a drive unit ( 22) arranged rotor (24). The rotor (24) is accommodated in a rotor space (26) which is separated from the stator (22) in a liquid-tight manner. Furthermore, at least one coolant flow path (28) is provided for cooling the electric drive unit (18), which starts from a liquid outlet (16) of the liquid pump (10) and opens into a liquid inlet (14) of the liquid pump (10). The coolant flow path (28) runs at least in sections through the rotor space (26).

Description

The invention relates to a liquid pump, in particular an oil pump for supplying a clutch actuator, a gear actuator, a lubrication system and / or a cooling system of a drive train, with an electric drive unit comprising a stator and a rotor arranged within the stator, the rotor in a rotor space is added, which is liquid-tight separated from the stator.

Such liquid pumps are known from the prior art and are often installed in motor vehicles, in particular in automobiles.

For example, the EP 3 179 106 A1 a known liquid pump.

The liquid pumps must meet partially contradicting requirements. On the one hand, a compact design of liquid pumps is generally required in this context. This is due to the fact that a compact structure usually saves material and thus inexpensive liquid pumps can be provided. In addition, this requirement is due to the limited space in the engine compartment of a motor vehicle, in which such liquid pumps are usually arranged. On the other hand, it must be possible to operate liquid pumps in a broad temperature range, particularly in the field of motor vehicles.

It is the object of the invention to provide a liquid pump which solves the above-mentioned conflict and is both compact in construction and can at the same time be used in a wide temperature field.

The object is achieved by a liquid pump of the type mentioned at the outset, in which at least one coolant flow path for cooling the electric drive unit starts from a liquid outlet of the liquid pump and opens into a liquid inlet of the liquid pump, the coolant flow path running at least in sections through the rotor space. The drive unit can therefore be cooled by means of the coolant flowing along the coolant flow path. With a compact design of the liquid pump, the waste heat generated in the drive unit can consequently be reliably dissipated. This is all the more true if the liquid pump is arranged in a comparatively warm environment, for example in an engine compartment of a motor vehicle. Since the liquid flow path branches off from the liquid outlet and flows into the liquid inlet, that liquid which is conveyed by means of the liquid pump is used as a coolant at the same time. The liquid pump can thus be constructed simply and inexpensively. In particular, no coolant circuit separate from the liquid to be conveyed is necessary. In this context, the liquid inlet is understood to mean all the lines carrying the liquid to be conveyed up to the suction connection of the actual pump unit. In an analogous manner, the liquid outlet is understood to mean all the lines carrying the liquid to be conveyed which branch off from the pressure outlet of the pump unit. The liquid inlet thus relates to the suction side of the liquid pump and the liquid outlet to the pressure side. The fact that the coolant flow path runs at least in sections through the rotor space means that the rotor comes into contact with the coolant. This means that large amounts of waste heat can be reliably dissipated. On the other hand, the structure of the liquid pump is simplified in this way.

The liquid pump is in particular a lubricating oil pump, a coolant pump, an additional oil pump or an actuator pump.

In one variant, the coolant flow path runs at least in sections between the rotor and the stator. The coolant flow path is therefore arranged in the broadest sense in the gap of the electrical machine formed by the rotor and the stator. At this point, the waste heat generated in the drive unit can be dissipated particularly efficiently.

In this case, the coolant flow path can run at least in sections in a wall section of a rotor pot separating the rotor space and the stator in a liquid-tight manner. A rotor pot is to be understood here as a component which has an essentially cylinder jacket-shaped wall section, which can also be referred to as a pot wall, and a base section or pot bottom axially closing the cylinder jacket-shaped wall section. Such a rotor pot separates so-called wet areas, i.e. those that come into contact with the liquid to be pumped, and dry areas, i.e. those that do not come into contact with the liquid to be pumped, within the drive unit. The rotor is in a wet area and the stator in a dry area. Since the coolant flow path runs in a wall section of the rotor pot, it only takes up an extremely small amount of space. As a result, an associated liquid pump can be made compact.

In other words, the sections of the coolant flow path provided in the wall section run between the rotor and the stator.

According to a preferred embodiment, the rotor is also designed in the shape of a pot.

Furthermore, it can be provided that the wall section has a radial projection with respect to an axis of rotation of the drive unit and the coolant flow path runs within a coolant channel arranged in the radial projection, in particular wherein the radial projection and the coolant channel run essentially over an entire axial length of the rotor pot. In this way, coolant channels can be arranged particularly easily within the liquid pump. Since they essentially run through the core area of the drive unit, the resulting waste heat can be reliably dissipated.

In this context, the term coolant flow path must also be distinguished from the term coolant channel. While a coolant flow path describes only an area in which coolant can flow, a coolant channel defines a geometrically determined area in which a coolant flow path can form. In other words, a coolant channel relates to a certain geometric expression of a component of the liquid pump, whereas a coolant flow path is based on the at least theoretically conceivable presence of a coolant flow.

According to one embodiment, the coolant channel is open on a radial inside of the wall section in the direction of the rotor space, in particular open over the entire axial length of the rotor pot. Thus, in particular over the entire axial length of the rotor pot, coolant can flow from the coolant channel into the interior of the rotor space. As a result, the rotor in particular can be wetted by coolant over its entire axial length, whereby it is cooled in an efficient manner.

The radial projection is advantageously positioned circumferentially between two stator segments with respect to the axis of rotation of the drive unit. A status segment can be understood to mean, among other things, a stator pole or a stator winding. Such stator segments are arranged essentially uniformly on the circumference of the stator. Since the radial projection, which can include a coolant channel, engages between these stator segments, it can cool the stator in an efficient manner. In addition, such a structure of the liquid pump saves space.

According to a further variant, the coolant flow path runs at least in sections with respect to an axis of rotation of the drive unit radially outside the stator. In contrast to the variant described above, the coolant flow path now does not run in the region of the gap in the electrical machine formed from the rotor and stator. In comparison to this variant, the gap in the electrical machine can thus be selected to be particularly small, which increases the performance of the electrical machine. Since the coolant flow path surrounds the drive unit on the outside, efficient heat dissipation can nevertheless be ensured.

The coolant flow path can run at least in sections in a pump housing or a stator housing. For this purpose, coolant channels are provided in the pump housing or in the stator housing. Only a small amount of installation space is therefore required for the coolant channels, so that the liquid pump can be constructed in a compact manner overall.

A plurality of coolant flow paths can also be provided, each of which starts from the liquid outlet and opens into the liquid inlet. On the one hand, a high volume flow of coolant can be used for cooling the liquid pump via the plurality of coolant flow paths. This makes the cooling particularly effective. In addition, the coolant flow paths can be arranged locally distributed within the liquid pump, so that it is evenly cooled.

Each of the coolant flow paths then preferably has a first flow path section, which extends in terms of flow between the liquid outlet and the rotor space, in particular wherein the first flow path sections are arranged circumferentially distributed with respect to the axis of rotation of the drive unit, and / or each of the coolant flow paths has a second flow path section, which extends in terms of flow between the rotor space and the liquid inlet, in particular wherein the second flow path sections are arranged circumferentially distributed with respect to the axis of rotation of the drive unit. Along each coolant flow path, the coolant thus flows first through a first flow path section, then through the rotor space and finally through a second flow path section. First and second flow path sections assigned to one another can be arranged diametrically opposite one another. This results in uniform cooling of the drive unit.

According to a particularly preferred embodiment, a total of four coolant flow paths are provided. If the liquid pump is viewed along a rotor axis, two of the first flow path sections can lie in the region of a 9:00 o'clock position. The associated second flow path sections are then preferably at a 3:00 o'clock position. Two more of the first flow path sections are, for example, at a 12:00 o'clock position and the associated second flow path sections are in the region of a 6:00 o'clock position.

In an alternative, the rotor space is a common flow path section of all coolant flow paths. This means that the coolant is introduced into the rotor space regardless of the first flow path section via which it was branched off from the liquid outlet. In the same way, starting from the rotor space, coolant is conducted via all second flow path sections to the liquid inlet.

In addition, a control unit can be provided for controlling the drive unit, and all coolant flow paths can be coupled to the control unit in a thermally conductive manner. In this way, the control unit is also effectively cooled. In particular, the control unit is arranged in the area of a bottom of the rotor pot. The common flow path section thus serves in particular to cool the control unit.

In this case, the control unit is preferably arranged at an end of the rotor space facing away from a pump unit. This means that the control unit, in particular, is also arranged opposite a liquid inlet and a liquid outlet.

The liquid pump is preferably a gear pump, in particular a gerotor pump. Gerotor pumps are also known as gerotor pumps and represent a type of gear pump that is particularly powerful and at the same time compact in design.

• - 1 eine erfindungsgemäße Flüssigkeitspumpe in einer perspektivischen Außenansicht,
• - 2 eine erfindungsgemäße Flüssigkeitspumpe gemäß einer ersten Ausführungsform in einer Schnittdarstellung entlang der Ebene II-II aus 3,
• - 3 die Flüssigkeitspumpe aus 2 in einer Schnittdarstellung entlang der Ebene III-III aus 2, und
• - 4 eine erfindungsgemäße Flüssigkeitspumpe gemäß einer zweiten Ausführungsform in einer der 2 entsprechende Schnittdarstellung.

The invention is explained below with reference to various exemplary embodiments which are shown in the accompanying drawings. Show it:

• - 1 a liquid pump according to the invention in a perspective external view,
• - 2 a liquid pump according to the invention according to a first embodiment in a sectional view along the plane II-II 3 ,
• - 3 the liquid pump off 2 in a sectional view along the plane III-III 2 , and
• - 4th a liquid pump according to the invention according to a second embodiment in one of the 2 corresponding sectional view.

1 shows a liquid pump 10 , which is designed in the illustrated embodiment as an oil pump to supply a clutch actuator.

At the same time is the liquid pump 10 also suitable for supplying a gear actuator, a cooling system and / or a lubrication system of a drive train with oil.

The liquid pump 10 is designed as a gerotor pump. So it includes a pumping unit 12th that works on the principle of a gerotor pump.

By means of the pumping unit 12th is via a liquid inlet 14th the liquid pump 10 provided liquid into a liquid outlet 16 the liquid pump 10 promoted. The liquid is pressurized, which is why the liquid inlet 14th also as the suction side and the liquid outlet 16 can be referred to as the print side.

The pumping unit 12th is by means of an electric drive unit 18th driven by means of a control unit 20th is controlled.

Here is the electric drive unit 18th between the pumping unit 12th and the control unit 20th arranged.

The electric drive unit 18th has a stator 22nd and a rotor 24 on, with the rotor 24 in a rotor space 26th is added inside the stator 22nd lies. One therefore speaks of an inner rotor.

The liquid pump 10 is also provided with at least one coolant flow path 28 provided that the cooling of the electric drive unit 18th as well as the cooling of the control unit 20th serves.

Furthermore, by means of the coolant flow path 28 a sensor unit that has a magnet cooled 29 having on one of the control unit 20th facing end of a rotor shaft is provided.

The coolant flow path is in all of the embodiments explained separately below 28 from the liquid outlet 16 and flows into the liquid inlet 14th . Thereby are under the liquid inlet 14th all the pump unit on the suction side 12th to understand with liquid supply lines and under the liquid outlet 16 all within the liquid pump 10 running lines leading from the pumping unit 12th lead away.

Those within the coolant flow path 28 present coolant flow is shown in the figures by means of arrows (see 2 and 4th ).

The coolant flow path also runs 28 always at least in sections through the rotor space 26th , the liquid-tight for this from the stator 22nd is separated.

That means the rotor 24 is in contact with the coolant, but not the stator 22nd . In other words is the rotor 24 in a "wet" area of the liquid pump 10 arranged and the stator 22nd in a "dry" area.

Inside the rotor space 26th is also the magnet 29 arranged, which is therefore also in the "wet" area.

As the coolant flow path 28 from the liquid outlet 16 goes out, the means of the liquid pump 10 pumped liquid is used as a coolant at the same time.

In the 2 and 3 is a first embodiment of the liquid pump 10 shown in detail.

In this embodiment, there are a plurality of coolant flow paths 28 provided (see in particular 3 ).

Any coolant flow path 28 comprises a first flow path section 28a , the flow between the liquid outlet 16 and the rotor space 26th extends.

The individual first flow path sections 28a are with respect to an axis of rotation 30th the electric drive unit 18th arranged distributed circumferentially.

In the direction of flow to the first flow path sections 28a then the rotor space 26th a common flow path section 28b of all coolant flow paths 28 represent.

In addition, each has a coolant flow path 28 a second flow path section 28c on, the flow between the rotor space 26th and the liquid inlet 14th extends. Here are the second flow path sections 28c again with respect to the axis of rotation 30th arranged distributed circumferentially.

In the illustrated first embodiment (see 3 ) are mutually associated first flow path sections 28a and second flow path section 28c arranged diametrically opposite.

The coolant flowing along one of the coolant flow paths 28 flows, so it first passes through the first flow path section 28a , then through the rotor space 26th formed common flow path section 28b and thereafter the second flow path section 28c .

In the first embodiment of the liquid pump 10 are the coolant flow paths 28 , more precisely the first flow path sections 28a and the second flow path sections 28c , within coolant channels 32a , 32c formed, each within a radial projection 34 trained wall section 36 one the rotor space 26th and the stator 22nd liquid-tight separating rotor pot 37 are trained.

In other words, the coolant flow path runs 28 at least in sections between the rotor 24 and the stator 22nd , so within one between the rotor 24 and the stator 22nd formed gap.

Around the rotor 24 The coolant channels are responsible for cooling effectively 32a , 32c on their radial inner sides in the direction of the rotor space 26th open (see 3 ). The rotor 24 is therefore wetted with coolant on its periphery, among other things.

Here are the coolant channels 32a , 32c essentially over the entire axial extent of the rotor pot 37 open on the radial inner sides.

To this end, each of the radial projections comprises 34 when it is along the axis of rotation 30th is considered, one of the respective coolant channel 32a , 32c comprehensive line section 34a along the axis of rotation 30th has a substantially circular cross-section and is substantially parallel to the axis of rotation 30th runs, and one the line section 34a with the rotor space 26th connecting web section 34b with a substantially rectangular cross-section. The web section 34b is hollow on the inside or points to the axis of rotation 30th radially extending lines, which the respective coolant channel 32a , 32c fluidically with the rotor space 26th connect.

A diameter of the line section can be 34a be greater than a circumferential width of the web portion 34b .

In addition, the radial projections are 34 with respect to the axis of rotation 30th extensively each between two stator segments 22a arranged. This is how the stator becomes too 22nd effectively cooled. For the sake of clarity, in 3 just some of the stator segments 22a provided with a reference number.

Also, all are coolant flow paths 28 thermally conductive with the control unit 20th coupled. This applies in particular to the common flow path sections 28b that are inside the rotor space 26th run away.

The control unit 20th includes a printed circuit board 20a .

A second embodiment of the liquid pump 10 is in 4th shown. In the following, only the differences from the first embodiment will be discussed. In addition, the above explanations apply.

The second embodiment essentially differs in this respect from the first embodiment of the liquid pump 10 that the coolant flow path 28 not between the rotor 24 and the stator 22nd runs, but outside of the stator 22nd .

The coolant flow path 28 runs in the embodiment shown in the outside of the stator 22nd lying sections in a stator housing 38 .

In the second embodiment as well, there are a plurality of coolant flow paths 28 provided, this again dividing into circumferentially distributed first flow path sections 28a , a common flow path section 28b going through the rotor space 26th and second flow path sections 28c structure.

More precisely, the first flow path sections therefore run 28a and the second flow path sections 28c in the stator housing 38 .

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

• EP 3179106 A1 [0003]

Claims (13)

Fluid pump (10), in particular an oil pump for supplying a clutch actuator, a gear actuator, a lubrication system and / or a cooling system of a drive train, with an electric drive unit (18) which has a stator (22) and a rotor ( 24), the rotor (24) being accommodated in a rotor space (26) which is separated from the stator (22) in a liquid-tight manner, characterized in that at least one coolant flow path (28) for cooling the electric drive unit (18) from a liquid outlet (16) of the liquid pump (10) and opens into a liquid inlet (14) of the liquid pump (10), the coolant flow path (28) running at least in sections through the rotor space (26). Liquid pump (10) Claim 1 , characterized in that the coolant flow path (28) runs at least in sections between the rotor (24) and the stator (22). Liquid pump (10) Claim 2 , characterized in that the coolant flow path (28) runs at least in sections in a wall section (36) of a rotor pot (37) which separates the rotor space (26) and the stator (22) in a liquid-tight manner. Liquid pump (10) Claim 3 , characterized in that the wall section (36) has a radial projection (34) with respect to an axis of rotation (30) of the drive unit (18) and the coolant flow path (28) runs within a coolant channel (32) arranged in the radial projection (34), in particular wherein the The radial projection (34) and the coolant channel (32) run essentially over an entire axial length of the rotor pot (37). Liquid pump (10) Claim 4 , characterized in that the coolant channel (32) is open on a radial inside of the wall section (36) in the direction of the rotor space (26), in particular is open over the entire axial length of the rotor pot (37). Liquid pump (10) Claim 4 or 5 , characterized in that the radial projection (34) is positioned circumferentially between two stator segments (22a) with respect to the axis of rotation (30) of the drive unit (18). Liquid pump (10) Claim 1 , characterized in that the coolant flow path (28) extends at least in sections with respect to an axis of rotation (30) of the drive unit (18) radially outside the stator (22). Liquid pump (10) Claim 7 , characterized in that the coolant flow path (28) runs at least in sections in a pump housing or a stator housing (38). Liquid pump (10) according to one of the preceding claims, characterized in that a plurality of coolant flow paths (28) are provided, each of which starts from the liquid outlet (16) and opens into the liquid inlet (14). Liquid pump (10) Claim 9 , characterized in that each of the coolant flow paths (28) has a first flow path section (28a) which extends in terms of flow between the liquid outlet (16) and the rotor space (26), in particular wherein the first flow path sections (28a) with respect to the axis of rotation (30) the drive unit (18) are arranged circumferentially distributed, and / or that each of the coolant flow paths (28) has a second flow path section (28c) which extends in terms of flow between the rotor space (26) and the liquid inlet (14), in particular wherein the second flow path sections (28c) are arranged distributed circumferentially with respect to the axis of rotation (30) of the drive unit (18). Liquid pump (10) Claim 9 or 10 , characterized in that the rotor space (26) is a common flow path section (28b) of all coolant flow paths (28). Liquid pump (10) according to one of the preceding claims, characterized in that a control unit (20) is provided for controlling the drive unit (18) and all coolant flow paths (28) are coupled to the control unit (20) in a thermally conductive manner. Liquid pump (10) according to one of the preceding claims, characterized in that the liquid pump (10) is a gear pump, in particular a toothed ring pump.

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