EP3987159A1

EP3987159A1 - Pump stage assembly, external gear pump, use of a pump stage assembly and vehicle transmission

Info

Publication number: EP3987159A1
Application number: EP20734138.9A
Authority: EP
Inventors: Christian Böhm
Original assignee: Vitesco Technologies GmbH
Current assignee: Vitesco Technologies GmbH
Priority date: 2019-06-18
Filing date: 2020-06-17
Publication date: 2022-04-27
Also published as: US20220356941A1; DE102019208845A1; US11867281B2; WO2020254449A1; CN114008371A

Abstract

Proposed is a pump stage assembly (2) for supplying lubricating oil to at least one consumer, comprising: - at least two pump suction stages (4, 6) and - at least one pump pressure stage (8), said pump suction stages and said pump pressure stage being arranged at a distance relative to each other in a pump housing PG and having a common drive shaft (56), wherein the pump suction stages (4, 6) are formed by a first assembly ZA₁ of at least three intermeshing external gears (12, 14, 16) which lie on a first plane, and the pump pressure stage (8) is formed by a second assembly ZA₂ of two intermeshing external gears (18, 20) which lie on a second plane. As a result, a first delivery volume flow can be drawn in from a first region of a dry sump (24) by means of a first pump suction stage (4), and a second delivery volume flow can be drawn in from a second region of the dry sump (24) by means of a second pump suction stage (6). The two delivery volume flows intermix in the pump housing PG before they reach an oil reservoir (26).

Description

description

Pump stage arrangement, external gear pump, use of a pump stage arrangement and vehicle transmission

The present invention relates to a pump stage arrangement for supplying lubricating oil to at least one consumer. The present invention also relates to a use of such a pump stage arrangement for supplying lubricating oil to an at least one or two-stage transmission for driving a vehicle, in particular an electric vehicle and a vehicle transmission.

In vehicles, so-called wet sump lubrication systems or dry sump lubrication systems are used to lubricate combustion engines and gearboxes.

Dry sump lubrication is mostly only used in sports cars, off-road vehicles and motorcycles. In doing so, it ensures lubrication even when cornering or driving at an angle by preventing lubricating oil from flowing away from an area of an intake port of an oil pump due to high centrifugal forces or corresponding inclines. This is ensured by the fact that in addition to an oil pan, which as such - unlike wet sump lubrication - is kept dry, a separate oil tank is also used, which as such stores the lubricating oil. With regard to the kept dry oil pan, one also speaks of an oil sump - also called a dry sump - from which a lubricating oil-air mixture is usually sucked.

With a lower volume of such an oil pan, dry sump lubrication gives you more ground clearance, so that e.g. an engine can be installed deeper, which in turn goes hand in hand with a lower center of gravity and from which the aforementioned sports cars or off-road vehicles benefit.

A dry sump lubrication system comprises one or more pump suction stages for delivering the lubricating oil from the oil sump into the oil tank and one or more pump pressure stages for delivering the lubricating oil from the oil tank to a consumer. The delivery volume of the pump pressure stages is always lower than the delivery volume of the pump suction stages. An object of one embodiment of the present invention is to improve a dry sump lubrication system.

This object is achieved by a pump stage arrangement with the features of claim 1. Claims 14, 15, 17 provide a multi-acting external gear pump with such a pump stage arrangement, a use of such a pump stage arrangement for supplying lubricating oil to at least one or two-stage transmission for driving a vehicle, in particular a special electric vehicle or a vehicle transmission with such Pump stage arrangement under protection. Advantageous embodiments of the invention are the subject of the dependent claims.

A pump stage arrangement for supplying lubricating oil to at least one consumer is proposed. The pump stage arrangement includes:

- At least two pump suction stages for sucking in a lubricating oil from a first oil container functioning as a dry sump and for conveying the lubricating oil into a second oil container functioning as an oil tank as well

- At least one pump pressure stage for sucking in the lubricating oil from the second oil container and for delivering it to the consumer.

The pump suction stages and the pump pressure stage are arranged at a distance from one another in a pump housing and have a common drive shaft.

The pump suction stages are formed by a first arrangement of at least three intermeshing external gears which lie in a first plane. The pump pressure stage, on the other hand, is formed by a second arrangement of two intermeshing external gear wheels, the first plane and the second plane being parallel to one another.

A first delivery volume flow can be drawn in from a first area of the first oil container by means of a first pump suction stage - via a first inlet - and via a second inlet using a second pump suction stage

- A second delivery volume can be drawn in from a second area of the first oil container. The two delivery volume flows mix in the pump housing before they reach the second oil tank via one outlet each. It is further proposed to arrange at least two of the respective tooth centers of the first external gear arrangement and the respective tooth centers of the second external gear arrangement in a common, third plane which intersects the pump housing in a longitudinal direction and which as such is orthogonal to the aforementioned first and second plane lies.

The proposed pump stage arrangement advantageously enables a dry sump system to be implemented with only five external gears. The proposed pump stage arrangement represents a very compact pump solution. The number of rotating components is kept to a minimum, which in turn is associated with a reduction in friction loss. This also saves weight.

In principle, these external gear arrangements can be expanded accordingly as required.

According to one embodiment of the present invention, in addition to at least two pump suction stages, at least two pump pressure stages are provided, which are formed by the second arrangement of at least three intermeshing external gears, the at least two of the respective tooth centers of the first external gear arrangement and at least two of the respective tooth centers of the second external gear arrangement are arranged in the common plane.

A first delivery volume flow can be drawn in from the second oil container or the oil tank by means of a first pump pressure stage - via a first inlet - and a second delivery volume flow can be drawn in by means of a second pump pressure stage - via a second inlet. The two delivery volume flows mix in the pump housing before they reach the respective consumer via an outlet each.

This proposed embodiment advantageously enables a dry sump system to be implemented with only six external gears. This version also represents a very compact pump solution in which the number of rotating components is kept to a minimum. According to a further, particularly advantageous embodiment of the present inven tion, the respective tooth centers of all gears of the first external gear arrangement and the respective tooth centers of all gears of the second external gear arrangement are arranged in said plane. This enables an even more compact pump solution overall.

It is further proposed that the first oil container and / or the second oil container form / form an oil reservoir inside an at least one or two-stage transmission for driving a vehicle, in particular an electric vehicle.

According to a further embodiment of the present invention, the pump stage arrangement is designed as part of a plug-in pump solution for arrangement on an at least one or two-stage transmission for driving a vehicle, in particular an electric vehicle, the plug-in pump solution being flanged to a housing of the transmission and in the housing protrudes. The plug-in pump solution can advantageously be designed as a substantially cylindrical body, the pump housing forming the cylindrical body being at least partially or expediently at least largely injection-molded from a plastic.

According to a further embodiment of the present invention, a hydraulic connection of the pump suction stages and / or the at least one pump pressure stage to the transmission oil reservoir is carried out radially to the respective section of the pump housing. This enables an even more compact pump solution. A hydraulic connection to the pressure side of the at least one pump pressure stage can be provided at the end of the pump housing protruding into the gear housing.

According to a further embodiment of the present invention, a hydraulic connection to the suction side of the pump suction stages can be provided on the end face on the end of the pump housing protruding into the transmission housing.

According to a further embodiment of the present invention, a hydraulic connection to the pressure side of the pump suction stages and to the suction side of the at least one pump pressure stage can be provided on the end of the pump housing protruding into the gear housing. According to a further embodiment of the present invention, the common drive shaft can be driven by an electric motor and / or mechanically.

It is also proposed a multi-acting external gear pump with a pump stage arrangement of the type described above.

Furthermore, a use of the above-described pump stage arrangement for supplying lubricating oil to an at least one or two-stage transmission for driving a vehicle, in particular an electric vehicle, is proposed.

In addition, it is proposed that the pump stage arrangement also be used for cooling an electric motor driving the electric vehicle.

In addition, vehicle transmission for driving a vehicle, in particular an electric vehicle, is proposed, the vehicle transmission having a pump stage arrangement of the type described above.

Further advantageous developments of the present invention emerge from the dependent claims and the following description of preferred embodiments. To show schematically:

1 shows a first gear wheel arrangement forming two pump suction stages

ZAi and a combined two pump pressure stages forming the second gear arrangement ZA2,

Fig. 1a shows the first gear arrangement ZA1 shown in Fig. 1 in an enlarged representation,

Fig. 2 shows a pump housing PG with the two gear arrangements shown in Fig. 1 ZAi, ZA2,

3 shows a pump plug-in solution in a first embodiment,

4 shows a pump plug-in solution in a second embodiment,

5 shows a pump plug-in solution in a third embodiment,

Fig. 6 shows a representation of gear trainings and 7 shows a representation of conveying flows.

1 illustrates a proposed pump stage arrangement 2 as part of a multiple-acting external gear pump which, on the one hand, is used to supply lubricating oil to an at least one or two-stage vehicle transmission Vi for driving an electric vehicle and, on the other hand, for cooling an electric motor V2 driving the electric vehicle is used, which as such forms a drive unit with the vehicle transmission V1.

The pump stage arrangement 2 comprises two pump suction stages 4, 6 for sucking in a lubricating oil from a first oil container 24 - functioning as a dry sump - and for conveying the lubricating oil into a second oil container 26 - the actual oil container or oil tank - and two pump pressure stages 8 , 10 for sucking in the lubricating oil from the second oil container 26 and for conveying it to the two consumers V1, V2.

The pump stage arrangement 2 is part of an - at least essentially cylindrical - plug-in pump solution, which as such is flanged to a housing 62, 64 of the vehicle transmission, the plug-in pump solution protruding into the housing 62, 64 (see FIGS. 3, 4, Fig. 5). The pump housing PG forming the cylindrical body is advantageously injection-molded from a plastic.

The pump suction stages 4, 6 and the pump pressure stages 8, 10 are arranged at a distance from one another in the pump housing PG and have a common drive shaft 56. This drive shaft 56 is in the context of the embodiments proposed here by an electric motor (electric motor) M driven ben. In principle, however, the plug-in pump solutions proposed here can also be driven purely mechanically.

The pump suction stages 4, 6 are formed by a first arrangement ZA1 of three intermeshing external gears 12, 14, 16, whereas the pump pressure stages 8, 10 are formed by a second arrangement ZA2 of three intermeshing external gears 18, 20, 22 are formed. The external gear arrangement ZAi lies in a first plane and the external gear arrangement ZA2 lies in a second plane parallel thereto. Fig. 2 illustrates a pump housing PG with a housing part 50 in which both the two external gear arrangements ZA-i, ZA2 and the drive shaft 56 and two axles 58, 60 are added. The drive shaft 56 extends through the gears 12, 18 and drives them, whereas the axis 58 through the driven gears 14, 20 and the axis 60 through the driven gears 16, 22 extends. With an appropriate design, shafts 58, 60 can also be provided instead of axes 58, 60. The housing part 50 is joined to a first housing cover 52 and a second housing cover 54 (see FIG. 2). The pump housing PG, 50, 52, 54 is also combined with the aforementioned electric motor M, which drives the drive shaft 56 on which the two driving gears 12, 18 are arranged.

The respective tooth centers ZM1, ZM2, ZM3 of all gears of the first external gear arrangement ZA1 as well as the respective tooth centers ZM4, ZM5, ZMb of all gears of the second external gear arrangement ZA2 are arranged in a common, third plane E - E, which the pump housing PG in a longitudinal direction or longitudinal extension X - X intersects (cf. FIG. 2). The plane E - E is orthogonal to the aforementioned first and second plane of the respective external gear arrangement ZA1, ZA2.

Via two suction lines 28, 30, which each protrude into one of two areas 24i, 24M of the dry sump 24 divided by a wall W, the lubricating oil or - and this is the normal case - just one, depending on the fill level

Lube oil-air mixture sucked in. The wall W dividing the dry sump 24 helps to evacuate the dry sump 24, because it is important to keep the dry sump 24 as dry or empty as possible in every vehicle position.

The suction line 30 leads to a first pump suction stage suction connection SEi of the first pump suction stage 4 formed by the two gears 12, 14, whereas the suction line 28 leads to a second pump suction stage suction connection SEn of the two gears 12, 16 ge formed second pump suction stage 6 leads. A line 32 leads from a first pump suction stage pressure connection SAi, also formed by the two gears 12, 14, into the oil tank 26. A line 34 also leads from a second pump suction stage pressure connection SAn, also formed by the two gears 12, 16 into the oil tank 26 (see. Fig. 1 a). As an alternative to this, the line 32 can also open into the line 34, which as such then opens into the oil tank (cf. FIG. 1). Via a suction line 36, the lubricating oil is then on the one hand via a first pump pressure stage suction connection DEi (see suction line 38, which branches off from the suction line 36 and leads to the pump pressure stage suction connection DEi) and a first pump pressure stage pressure connection DAi the first pump pressure stage 8 - which are each formed by the two gears 18, 20 - and a line 42 is conveyed to the vehicle transmission Vi. On the other hand, that will

Lubricating oil also via a second pump pressure stage suction connection DEn and a second pump pressure stage pressure connection DAn of the second pump pressure stage 10 - which are each formed by the two gears 18, 22 - and a line 42 to the electric motor V2 promoted.

In a proposed first embodiment of the plug-in pump solution (see FIG. 3), an oil tank 26 is formed in the interior of the transmission housing 62, 64. A single or two pump pressure stages DS is / are arranged between an electric motor M arranged on the transmission wall side and two pump suction stages SS. The hydraulic connection of the suction side of the pump pressure stage (s) DS (see suction ADS) on the one hand and the pressure side (see output ASD) of the pump suction stage SS on the other hand to the oil tank 26 are each carried out radially to the respective section of the pump housing PG. The pump pressure stage (s) DS is / are accordingly sealed circumferentially with respect to the pump suction stage SS (cf. seal D1). A hydraulic connection of the pump plug-in solution to a dry sump 24 separated therefrom, on the one hand, and to the two aforementioned consumers, on the other hand, is provided on the front side of the pump end protruding into the transmission housing 62, 64 (see suction Assi, suction Ass2 of the respective suction stage SS and output ADDI , Output ADD2 of the respective pressure level DS).

Alternatively, in a proposed second embodiment of the pump plug-in solution (see FIG. 4), a dry sump 24 is formed in the interior of the gear housing 62, 64. Two pump suction stages SS are arranged between an electric motor M arranged on the drive wall side and two pump pressure stages DS. The hydraulic connection of the two pump suction stages SS (cf. suction Assi, suction Ass2) to the dry sump 24 is designed in each case radially to the pump housing PG. The pump pressure stages DS are accordingly sealed circumferentially with respect to the pump suction stages SS (cf. seal Dl). A hydraulic connection of the pump plug-in solution to an oil tank 26 separated therefrom on the one hand and to the two aforementioned users Vi, V2, on the other hand, is provided at the end of the pump end protruding into the transmission housing 62, 64 (see pressure-side output ASD of the pump suction stage SS, suction ADS of the pump pressure stage DS, pressure-side outputs ADDI, output ADD2 of the Pum pen pressure levels DS).

In a proposed third embodiment of the plug-in pump solution (see FIG. 5), however, both an oil tank 26 and a dry sump 24i, 24M divided by a wall W are formed in the interior of the gear housing 62, 64. The oil tank 26 is also sealed against the dry sump 24 accordingly (see FIG. Seal Dl). Two pump suction stages SS are arranged between an electric motor M arranged on the transmission wall side and two pump pressure stages DS. The hydraulic connection of the two pump suction stages SS (see suction Assi, suction Ass2 of the pump suction stages SS) to the dry sump 24i, 24M on the one hand and the two pump pressure stages DS to the oil tank 26 on the other (suction ADAI, suction ADA2 of the pump Pressure stages DS) are designed radially to the pump housing PG. The hydraulic connection of the pressure-side output ASD of the two pump suction stages SS also leads radially to the pump housing PG in the oil tank 26. The pump pressure stages DS are accordingly circumferentially sealed with respect to the pump suction stages SS (see seal Dl). A hydraulic connection of the pump plug-in solution to the two aforementioned consumers V1, V2 is provided on the front side at the pump end protruding into the gear housing 62, 64 (see output ADDI, output ADD2 of the pump pressure stages DS).

It is common to all of these embodiments that engine electronics ME are arranged outside the transmission housing 62, 64 (cf. FIGS. 3, 4, 5; in each case to the right of the flange). On the one hand, this enables simple electrical contacting of the electric motor or the motor electronics ME and, on the other hand, a corresponding heat exchange between the motor electronics ME and the environment.

6 illustrates an embodiment of three external gears that form two pump suction stages or pump pressure stages and mesh with one another, the middle gear being preferably the rubbed gear. All three gears of this external gear arrangement have the same cross-sectional geometry, ie also the same number of teeth. The two outer gears also have the same center distance to the middle gear. Only the right gear has, for example, one opposite the other two gears shorter longitudinal extension. In principle, however, these center distances can also be different. The number of teeth of the two outer external gears can also be set differently than the inner external gear.

7 schematically and by way of example illustrates a division and

Mixing of delivery flows as they appear on the one hand with regard to the two pump suction stages (cf. ZAi) and on the other hand with regard to the two pump pressure stages (cf. ZA ₂ ) within the pump housing PG. While the two pump suction stages promote an air flow or oil-air flow from the dry sump 24i, 24M (area 24i, area 24M) into the oil tank 26, the two pump pressure stages promote an oil flow from the oil tank 26 to the respective consumers V ₁ , V ₂ . The individual thicknesses of the arrows illustrate qualitatively a corresponding delivery volume flow. In principle, the respective inflows and outflows with respect to the individual pump stages can be determined as required, namely via a corresponding external gear design (cf. the individual, different gear lengths in FIG. 7).

The plug-in pump solutions described in the context of this disclosure each enable a very compact pump solution that is suitable for the described flange-mounting on the vehicle transmission V ₁ . The number of rotating components is kept to a minimum, which in turn is associated with a reduction in friction loss. This also saves weight.

With the plug-in pump solutions described, a dry sump system with only six external gears each is implemented.

It should also be pointed out that the exemplary designs are only examples that are not intended to limit the scope of protection, the applications and the structure in any way. Rather, the preceding description provides a person skilled in the art with guidelines for the implementation of at least one exemplary embodiment, with various changes, in particular with regard to the function and arrangement of the described components, being able to be made without leaving the scope of protection as he did results from the claims and these equivalent combinations of features. List of reference symbols:

Claims

1. Pump stage arrangement (2) for supplying lubricating oil to at least one consumer, comprising: at least two pump suction stages (4, 6) for sucking in lubricating oil from a first oil container (24) functioning as a dry sump and for conveying the lubricating oil into a second functioning as an oil tank Ölbe container (26) and at least one pump pressure stage (8) for sucking in the lubricating oil from the second oil container (26) and for delivery to the consumer, the pump suction stages (4, 6) and the pump pressure stage (8) zuei are arranged spaced apart in a pump housing (PG) and have a common drive shaft (56), the pump suction stages (4, 6) being formed by a first arrangement (ZAi) of at least three intermeshing external gears (12, 14, 16) are, which lie in a first plane, and wherein the pump pressure stage (8) by a second arrangement (ZA2) of two meshing the external gears (18, 20) is formed in a second plane lie, wherein the first plane and the second plane are parallel to each other, wherein by means of a first pump suction stage (4, 12, 14) - via a first input (SEi; Suction) - from a first area of the first Ölbehäl age (24) a first delivery volume flow can be sucked in and by means of a second pump suction stage (6, 12, 16) - via a second input (SEn; suction) - from a second area of the first Oil container (24), a second delivery volume flow can be sucked in, the two delivery volume flows mix in the pump housing (PG) before they reach the second Ölbe container (26) via an output (SAi, SAn).

2. Pump stage arrangement (2) according to claim 1, wherein at least two of the respective tooth centers (ZM1, ZM2, ZM3) of the first external gear arrangement (ZAi) and the respective tooth centers (ZM4, ZM5) of the second external gear arrangement (ZA2) in a common plane ( E - E) are arranged on which the pump housing (PG) in a longitudinal direction (X - X) and which as such is orthogonal to the first and second planes.

3. Pump stage arrangement (2) according to claim 2, wherein at least two pump pressure stages (8, 10) are provided, which are formed by the second to order (ZA2) of at least three meshing external gears (18, 20, 22), The at least two tooth centers (ZMi, ZM2, ZM3) of the first external gear arrangement (ZA1) and at least two of the respective tooth centers (ZM4, ZM5, ZMb) of the second external gear arrangement (ZA2) are arranged in the common plane (E - E).

4. Pump stage arrangement (2) according to claim 2 or 3, wherein the respective tooth centers (ZM1, ZM2, ZM3) of all gears (12, 14, 16) of the first external gear arrangement (ZA1) and the respective tooth centers (ZM4, ZM5) of all gears ( 18, 20, 22) of the second external gear arrangement (ZA2) are arranged in the plane (E - E).

5. Pump stage arrangement (2) according to one of claims 1 to 4, wherein the first oil container (24) and / or the second oil container (26) has an oil reservoir inside an at least one or two-stage transmission (62, 64) for driving a Vehicle, in particular an electric vehicle forms / form.

6. Pump stage arrangement (2) according to one of the preceding claims, wherein the pump stage arrangement (2) is designed as part of a plug-in pump solution for arrangement on an at least one or two-stage transmission for driving a vehicle, in particular an electric vehicle, the plug-in pump solution on a Housing (62, 64) of the transmission is flanged and protrudes into the housing (62, 64).

7. Pump stage arrangement (2) according to claim 6, wherein the plug-in pump solution is designed as a substantially cylindrical body.

8. Pump stage arrangement (2) according to claim 7, wherein a hydraulic connection of the pump suction stages (4, 6) and / or the at least one pump pressure stage (8, 10) to the oil reservoir is carried out radially to the respective section of the pump housing (PG) .

9. Pump stage arrangement (2) according to claim 8, further comprising a hydraulic cal connection to the pressure side of the at least one pump pressure stage (8, 1 0, ADD-I, ADD2) at the end of the end of the into the transmission housing (62, 64) protrude Pump housing (PG) is provided.

10. Pump stage arrangement (2) according to claim 9, wherein a hydraulic cal connection to the suction side of the pump suction stages (4, 6, Assi, Ass2) is provided at the end of the end of the pump housing (PG) protruding into the gear housing (62, 64) .

11. Pump stage arrangement (2) according to claim 9, further comprising a hydraulic cal connection to the pressure side of the pump suction stages (4, 6, ASD) and to the suction side of the at least one pump pressure stage (8, 10, ADS) on the end face in the transmission housing (62, 64) protruding end of the Pumpenge housing (PG) is provided.

12. Pump stage arrangement (2) according to one of the preceding claims, wherein the first oil container (24) is divided into at least two areas (24i, 24M) by means of at least one wall (W).

13. Pump stage arrangement (2) according to one of the preceding claims, wherein the common drive shaft (30) is driven by an electric motor and / or me mechanically.

14. Multiple-acting external gear pump with a pump stage arrangement (2) according to one of the preceding claims 1 to 13.

15. Use of a pump stage arrangement (2) according to one of the preceding claims 1 to 13 for supplying lubricating oil to an at least one or two-stage transmission for driving a vehicle, in particular an electric vehicle.

16. Use of a pump stage arrangement (2) according to claim 15, wherein the pump stage arrangement (2) is also used for cooling an electric motor driving the electric vehicle.

17. Vehicle transmission for driving a vehicle, in particular an electric vehicle, the vehicle transmission having a pump stage arrangement (2) according to one of the preceding claims 1 to 13.