DE102023003152A1 - Housing part for a differential gear device - Google Patents

Abstract

The invention relates to a housing part (100) for a differential gear device of a drive device, with a housing body (10) with at least one receiving area (12, 14) for at least one part of a differential gear. The housing body (10) has a first housing part surface (16) which, during normal operation, faces the at least one part of the differential gear. The housing body (10) also has a second housing part surface (18) opposite the first housing part surface (16). The housing body (10) is made of solid material. The housing body (10) has at least one cooling channel (20) for guiding coolant, which runs between at least one first cooling channel connection (22) and at least one second cooling channel connection (24). The at least one cooling channel (20) is arranged as a hollow structure completely within the housing body (10).

Description

The invention relates to a housing part for a differential gear device of a drive device.

In differential gear systems such as rear axle drives of motor vehicles, the oil used as a lubricant can reach very high temperatures during operation. Oil-water heat exchangers are therefore usually used for the active water cooling of oil-bearing units. This requires a pump on the oil side that transports the oil through the oil-water heat exchanger. One disadvantage is the complex and costly integration of a pump into an existing gear concept, since for integration at least the pump itself, the cable set, the control of the pump and, above all, the installation space for it must be taken into account.

The EN 10 2021 207 527 A1 discloses a transmission for an integral differential, which comprises at least a first planetary gear set with a planet carrier fixed to the housing, on which several planetary gears rotatably mounted via respective planetary bearings are arranged, as well as a sun gear and a ring gear, each of which meshes with the planetary gears. A lubricant chamber for supplying the planetary bearings with lubricant is arranged at least partially around a rotation axis of the at least first planetary gear set. The lubricant chamber is spatially delimited by the planet carrier and a stationary housing part, wherein the planet carrier is arranged on the stationary housing part in a sealing manner to the lubricant chamber. The stationary housing part is a cover element of the transmission and has means for guiding a cooling medium on a side facing away from the lubricant chamber. For this purpose, the stationary housing part has a surface structure on the side facing away from the lubricant chamber, which is designed to enlarge a surface in contact with the cooling medium.

An object of the invention is to provide a housing part for a differential gear device of a drive device with improved heat dissipation.

The above-mentioned problem is solved with the features of the independent claim.

Favorable embodiments and advantages of the invention emerge from the further claims, the description and the drawing.

According to one aspect of the invention, a housing part for a differential gear device of a drive device is proposed, with a housing body with at least one receiving area for at least one part of a differential gear. The housing body has a first housing part surface which, during normal operation, faces the at least one part of the differential gear. The housing body also has a second housing part surface opposite the first housing part surface. The housing body is made of solid material. The housing body has at least one cooling channel for guiding coolant, which runs between at least one first cooling channel connection and at least one second cooling channel connection. The at least one cooling channel is arranged as a hollow structure completely within the housing body.

The part of the differential gear can be a ring gear which is accommodated in the receiving area of the housing body.

In the proposed housing part, for example, air fins attached to the housing part, which are usually used for air cooling, can be shortened in order to gain additional installation space. This installation space can be used as solid material to accommodate a cooling channel as a hollow structure completely in the housing part. The cooling channel can be operated with a cooling medium such as water.

In this way, an easy-to-implement active cooling of a differential gear device can be realized. This advantageously eliminates the need for an oil pump with cable set and control.

Active cooling can be combined with air cooling. In this way, the heat input into the cooling medium can be reduced.

Such a variant of a rear axle transmission with active cooling can conveniently be represented simply as a different cover of the transmission housing in the same installation space.

The housing part with an integrated cooling channel can be manufactured advantageously using additive manufacturing in the form of 3D printing of the housing part. This makes it possible to manufacture it from one piece. The housing body can be made from aluminum, for example.

The housing part can advantageously fulfil two functions as one component. The housing part serves a housing for the differential gear and it is also an integral cooler. This means that no additional housing part is required to close off any water cooling channels. This means that the housing part according to the invention stands out advantageously from the prior art, in which, for example, water cooling channels are formed by surface structures of two components screwed onto one another, whereby sealing devices are necessary.

According to an advantageous embodiment of the housing part, the at least one cooling channel can be designed in a meandering shape within the housing body. In this way, a cooling channel that is as long as possible can be advantageously implemented for high heat transfer, but with the smallest possible curvature of the cooling channel.

According to an advantageous embodiment of the housing part, the at least one cooling channel can be formed at least in part in one plane, wherein the at least one cooling channel can be arranged adjacent to the at least one receiving area and deflected out of the plane. Because the cooling channel runs at least in part in one plane, a lower pump output is required for the flow of the cooling medium. This enables more economical operation of the differential gears.

According to an advantageous embodiment of the housing part, the at least one cooling channel can be designed to match an inner contour of the at least one receiving area. In particular, the at least one cooling channel can surround the at least one receiving area at least in part. In this way, the heat transfer from the lubricant surrounding the gear part to the cooling medium can be further optimized, since the wall thicknesses for the heat transfer can be favorably reduced.

According to an advantageous embodiment of the housing part, the at least one first cooling channel connection and the at least one second cooling channel connection can be designed for the intended fluid connection to an engine cooling system. This allows the cooling system of the differential gear device to be operated favorably. Advantageously, no separate coolant pump is required for the flow of the cooling medium through the housing part.

According to an advantageous embodiment of the housing part, the first housing part surface can have a first surface structure which, during normal operation, is designed to protrude into an interior of the differential gear and which is designed to enlarge a surface in contact with a lubricant of the differential gear. The first housing part surface can, for example, comprise an oil sump side of the housing part in which the lubricating oil collects. Pins or ribs can be arranged there, for example, above the cooling channel arranged in the housing body. The pins can, for example, be arranged in two areas which lie on both sides of a recess as a receiving area for the ring gear of the differential gear. The orientation of the pins can advantageously be opposite to the direction of the recess.

According to an advantageous embodiment of the housing part, an extension region of the first surface structure can overlap with the at least one receiving region. In particular, the first surface structure can be arranged on opposite sides of the at least one receiving region. In this way, the largest possible surface can be available for the heat transfer from the heated lubricating oil through the housing body to the cooling medium. This allows the cooling of the lubricating oil to be significantly improved.

According to an advantageous embodiment of the housing part, the first surface structure can be designed as at least one of a honeycomb structure, a rib structure, or a pin fin structure. In this way, the first surface structure can be designed from a large number of structural elements that protrude into the housing interior or the space of the differential gear, such as so-called pin fins. This means that the largest possible surface area can be available for the heat transfer from the heated lubricating oil through the housing body to the cooling medium. This allows the cooling of the lubricating oil to be significantly improved.

According to an advantageous embodiment of the housing part, the second housing part surface can have a second surface structure, in particular a cooling fin structure, through which air can flow during normal operation. The housing part has the function of covering the differential gear from the environment. As a result, the second housing part surface can have cooling fins through which a wind flows and which provide additional cooling of the cooling medium. In this way, the cooling of the differential gear device can be designed to be particularly efficient.

According to an advantageous embodiment of the housing part, a spatial density of loops of the cooling channel in a region of the first and/or second surface structure can be increased This means that the heat from the heated lubricating oil can be absorbed particularly effectively from the receiving area. The cooling medium can also be cooled by the airstream, thus significantly improving the efficiency of the cooling system of the differential gear device.

Further advantages emerge from the following description of the drawings. The drawings show an embodiment of the invention. The drawings, the description and the claims contain numerous features in combination. The person skilled in the art will also expediently consider the features individually and combine them into further useful combinations.

• 1 eine isometrische Ansicht eines Gehäuseteils für eine Differentialgetriebeeinrichtung einer Antriebseinrichtung nach einem Ausführungsbeispiel der Erfindung;
• 2 eine Seitenansicht des Gehäuseteils nach 1;
• 3 eine teilgeschnittene Ansicht des Gehäuseteils in der Schnittebene A-A nach 2 mit einer Draufsicht auf eine erste Gehäuseteiloberfläche;
• 4 eine teilgeschnittene Ansicht des Gehäuseteils in einer weiteren Schnittebene mit einer Draufsicht auf die erste Gehäuseteiloberfläche;
• 5 eine teilgeschnittene Ansicht des Gehäuseteils in einer weiteren Schnittebene mit einer Draufsicht auf eine zweite Gehäuseteiloberfläche;
• 6 eine weitere Seitenansicht des Gehäuseteils; und
• 7 eine Schnittansicht des Gehäuseteils in der Schnittebene B-B nach 6.

Showing:

• 1 an isometric view of a housing part for a differential gear device of a drive device according to an embodiment of the invention;
• 2 a side view of the housing part after 1 ;
• 3 a partially sectioned view of the housing part in the section plane AA according to 2 with a plan view of a first housing part surface;
• 4 a partially sectioned view of the housing part in a further section plane with a plan view of the first housing part surface;
• 5 a partially sectioned view of the housing part in a further section plane with a plan view of a second housing part surface;
• 6 another side view of the housing part; and
• 7 a sectional view of the housing part in the section plane BB according to 6 .

In the figures, identical or similar components are numbered with identical reference symbols. The figures show only examples and are not to be understood as limiting.

1 shows an isometric view of a housing part 100 for a differential gear device of a drive device according to an embodiment of the invention. In 2 a side view of the housing part 100 is shown. The housing part 100 has the function of covering the differential gear from the environment.

The housing part 100 comprises a housing body 10 with a receiving area 12 for a ring gear and a receiving area for an input pinion of a differential gear. The housing body 10 has a first inner housing part surface 16, which faces the ring gear and the input pinion during normal operation. The housing body 10 also has a second outer housing part surface 18 opposite the first inner housing part surface 16. The housing body 10 is made of solid material, for example aluminum.

Two cooling channel connections 22, 24 are arranged on the housing body 10.

On a peripheral edge, the housing part 100 has screw domes 34 and a sealing contour 32, for example a groove for inserting a molded seal, for a reliable and tight connection with a counterpart of a housing of the differential gear device.

3 shows a partially sectioned view of the housing part 100 in the section plane AA according to 2 with a top view of the first housing part surface 16

As in 3 As can be seen, the housing body 10 has a cooling channel 20 for guiding coolant, which runs between the first cooling channel connection 22 and the second cooling channel connection 24. The cooling channel 20 is arranged as a hollow structure completely within the housing body 10 and is therefore shown in the sectional view in 3 only partially recognizable as a cut channel.

The cooling channel 20 is formed in a meandering shape within the housing body 10, which can be seen from the loops 26 of the cooling channel 20 running inside the housing body 10. In this way, a cooling channel 20 that is as long as possible can be implemented for a high heat transfer, but with the smallest possible curvature of the cooling channel 20.

In 4 is a partially sectioned view of the housing part 100 in a further sectional plane lying inside the housing part 100 with a plan view of the first housing part surface 16.

As in the 3 and 4 As can be seen, the cooling channel 20 is formed at least in some areas in one plane. The cooling channel 20 is only deflected out of the plane adjacent to the receiving areas 12, 14.

The two cooling channel connections 22, 24 can advantageously be fluidically connected to an engine cooling system.

As in the 1 to 4 As can also be seen, the first housing part surface 16 has a first surface structure 30 which, during normal operation, i.e. when the housing of the differential gear device is closed, projects into an interior space 28 of the differential gear. The surface structure 30, which in the exemplary embodiment is designed as so-called pin fins, serves to enlarge a surface in contact with a lubricant of the differential gear. The first surface structure 30 can also be designed as a honeycomb structure or a rib structure, for example.

The pin fins can, for example, be arranged in two areas as shown, which are located on both sides of a recess as a receiving area 12 for the ring gear of the differential gear. The orientation of the pin fins can advantageously be opposite to the direction of the recess.

This means that the largest possible surface area can be available for the heat transfer from the heated lubricating oil through the housing body 10 to the cooling medium. This significantly improves the cooling of the lubricating oil.

The first surface structure 30 can advantageously overlap with the receiving areas 12, 14 in its extension area. In the illustrated embodiment, the first surface structure 30 is arranged on opposite sides of the one receiving area 12.

5 shows a partially sectioned view of the housing part 100 in a further section plane with a plan view of the second housing part surface 18.

It can be seen that the second housing part surface 18 advantageously has a second surface structure 40, in particular a cooling fin structure 40, through which air, for example the airstream, can flow during normal operation. This can provide additional cooling of the cooling medium. In this way, the cooling of the differential gear device can be designed to be particularly efficient.

In 6 another side view of the housing part 100 with another marked cutting plane BB is shown. The corresponding sectional view in the cutting plane BB of the housing part 100 is shown in 7 shown.

It can be seen that the cooling channel 20 is designed to match an inner contour of the receiving areas 12, 14. In particular, the cooling channel 20 surrounds the receiving areas 12, 14 at least in some areas. In this way, the heat transfer from the lubricant surrounding the gear part to the cooling medium can be further optimized, since the wall thicknesses for the heat transfer can be favorably reduced.

Advantageously, a spatial density of loops 26 of the cooling channel 20 can be increased in an area of the first and/or second surface structure 40. This allows the heat of the heated lubricating oil from the receiving area 12, 14 to be absorbed particularly effectively. On the other hand, the cooling medium can be additionally cooled by the airstream, thus significantly improving the efficiency of the cooling system of the differential gear device.

List of reference symbols

10

Housing body

12

Recording area

14

Recording area

16

first housing part surface

18

second housing part surface

20

Cooling channel

22

first cooling channel connection

24

second cooling channel connection

26

Ribbon

28

inner space

30

first surface structure

32

Sealing contour

34

Screw dome

40

second surface structure

100

Housing part

QUOTES INCLUDED IN THE DESCRIPTION

This list of 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 accepts no liability for any errors or omissions.

Cited patent literature

• DE 102021207527 A1 [0003]

Claims (10)

Housing part (100) for a differential gear device of a drive device, with a housing body (10) with at least one receiving area (12, 14) for at least one part of a differential gear, wherein the housing body (10) has a first housing part surface (16) which, during normal operation, faces the at least one part of the differential gear, wherein the housing body (10) has a second housing part surface (18) opposite the first housing part surface (16), wherein the housing body (10) is formed from solid material, wherein the housing body (10) has at least one cooling channel (20) for guiding coolant, which runs between at least one first cooling channel connection (22) and at least one second cooling channel connection (24), wherein the at least one cooling channel (20) is arranged as a hollow structure completely within the housing body (10). Housing part after Claim 1 , characterized in that the at least one cooling channel (20) is formed in a meandering shape within the housing body (10). Housing part after Claim 1 or 2 , characterized in that the at least one cooling channel (20) is formed at least partially in a plane, wherein the at least one cooling channel (20) is arranged adjacent to the at least one receiving region (12, 14) deflected out of the plane. Housing part according to one of the preceding claims, characterized in that the at least one cooling channel (20) is designed to match an inner contour of the at least one receiving area (12, 14), wherein the at least one cooling channel (20) surrounds the at least one receiving area (12, 14) at least in regions. Housing part according to one of the preceding claims, characterized in that the at least one first cooling channel connection (22) and the at least one second cooling channel connection (24) are designed for the intended fluid connection to an engine cooling system. Housing part according to one of the preceding claims, characterized in that the first housing part surface (16) has a first surface structure (30) which, during normal operation, is designed to protrude into an interior space (28) of the differential gear, which is designed to enlarge a surface in contact with a lubricant of the differential gear. Housing part after Claim 6 , characterized in that an extension region of the first surface structure (30) overlaps with the at least one receiving region (12, 14). Housing part after Claim 6 or 7 , characterized in that the first surface structure (30) is formed as at least one of honeycomb structure, rib structure, pin fin structure. Housing part according to one of the preceding claims, characterized in that the second housing part surface (18) has a second surface structure (40), in particular a cooling fin structure (40), through which air can flow during normal operation. Housing part according to one of the Claims 6 until 9 , characterized in that a spatial density of loops (26) of the cooling channel (20) is increased in a region of the first and/or second surface structure (40).

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