Oil pan for a drive unit

Abstract

An oil pan for a drive unit is proposed, comprising an electrical machine, a gearing, and an oil circuit, wherein the oil pan encloses an oil chamber which is integrated into the oil circuit via an oil return duct and a suction duct. An improved oil chamber cover is now proposed, by means of which the oil pan is closed so that the oil chamber is formed, wherein the oil chamber cover comprises a duct via which oil can be conducted from the oil chamber to the suction duct.

Description

[0001] Oil pan for a drive unit

[0002] The invention relates to an oil pan for a drive unit with an electric motor, a gearbox and an oil circuit.

[0003] Drive units consisting of an electric motor and a transmission are well-known and commonly used in motor vehicles. An oil circuit is provided for cooling the electric motor and the transmission.

[0004] From CN115 467 969 A, a drive unit is known that comprises an electric motor, a gearbox, and an oil circuit. The oil pan of the oil circuit is located below the gearbox. The oil circuit runs through the oil pan and the oil filter integrated within the oil pan, which is integrated into the oil pan for ease of maintenance.

[0005] The purpose of the invention is to provide an improved oil pan.

[0006] The problem is solved according to the invention by an embodiment according to the independent claim. Further advantageous embodiments of the present invention are found in the dependent claims.

[0007] An oil pan for a drive unit comprising an electric motor, a gearbox and an oil circuit is proposed, wherein the oil pan encloses an oil chamber which is integrated into the oil circuit via an oil return channel and a suction channel.

[0008] An improved oil sump cover is proposed, which seals the oil pan, thus creating an oil sump. This cover incorporates a channel through which oil can be directed from the sump to the suction port. The channel in the oil sump cover separates the oil drawn from the oil in the sump by a pump. The oil flowing through the channel can be cooled just before entering the suction port. This allows the heat energy in the oil to be dissipated effectively, keeping the outgoing oil separate from the remaining oil in the sump.

[0009] Preferably, the channel may have an intake area with an intake opening in the middle of the oil chamber cover and the cross-section of the channel tapers towards the intake channel, resulting in improved flow into the intake channel.

[0010] Alternatively, the channel can be divided into two sections, with each channel having its own intake port. Ribs in the oil reservoir cover can also be arranged to create a meandering, forced flow of oil within the chamber, thus improving pre-cooling.

[0011] Furthermore, screens can be provided in front of each intake opening to trap dirt particles.

[0012] Preferably, the intake area can be designed as a trough, in which a magnetic catching device and / or an oil drain screw can be provided.

[0013] The invention will be explained below with the aid of figures. The figures show, in detail:

[0014] Fig. 1: Sectional view of drive unit

[0015] Fig. 2: Oil compartment cover

[0016] Fig. 3: Alternative oil chamber cover with ribs

[0017] Figure 1 shows a drive unit 1 comprising an electric machine 18 and a gearbox 13. The gearbox 13 and the electric machine 18 are arranged in a housing and are cooled and lubricated via a common oil circuit.

[0018] The electric motor 18, the gearbox 13, and the actual oil circuit are not shown in detail here and are only described in general terms below. The gearbox 13 can be a planetary gear set or a spur gear set with a fixed ratio; however, switchable gearboxes can also be used at this location.

[0019] The oil circuit is only roughly indicated as follows: pump 10 pumps the oil from oil chamber 2 towards the lubrication and / or cooling points. The oil circuit also includes a heat exchanger located downstream of pump 10 (in the direction of flow) and an oil filter (both not shown). Channels are provided downstream of the oil filter through which the oil is distributed. These channels can be integrated into the housing, or they can be pipe or hose connections. The oil returns to oil chamber 2, as shown, via various channels in the oil pan 12 and the gearbox housing 15.

[0020] The invention relates to the design of the oil pan 12, which is arranged below the housing 19 in relation to the installation position of the drive unit. The oil pan 12 encloses an oil chamber 2, and the oil pan 12 is closed by means of an oil chamber cover 3.

[0021] When the drive unit 1 is at rest, the oil pan 12 is filled with oil, and when the drive unit 1 is in operation, the oil is pumped from the oil pan 12 into the oil circuit by means of the pump 10. The oil flow is drawn in via the channel 5, which is shown in more detail in Figures 2 and 3.

[0022] Figures 2 and 3 show two different versions of the oil chamber cover 3 with the integrated channel 5. The channel 5 is a suction channel cast directly into the oil chamber cover 3, with the inlets to the channel 5 located at its lowest point. This ensures that air intake is prevented during operation in all predetermined operating positions of the drive unit. Alternatively, the channel could also be designed as a separate pipe or in a two-part construction. Oil drawn off via the suction port 6 passes through the channel 5 into the suction channel 4 leading to the oil pump 10. The oil chamber cover is designed as a cooling surface, thus achieving a significant cooling effect via the oil chamber cover 3.

[0023] Channel 5 separates the flowing oil from the total oil volume in oil chamber 2, ensuring particularly effective cooling of the flowing oil. Targeted heat transfer to the ambient air occurs via the external cooling fins located on the outside of the lid.

[0024] Channel 5 in the oil pan tapers towards the pump to achieve a continuous reduction in cross-section and optimal flow (minimizing pressure loss).

[0025] As can be seen in Figure 3, the channel 5 can also have two separate suction inlets 5. Furthermore, 3 ribs 8 are provided on the inside of the tank lid to influence the oil flow within the oil chamber 2, ensuring that the oil follows a defined path across the inner surface of the oil pan and that heat is dissipated to the external convection ribs via the ribs and the bottom of the oil pan. Additionally, screens can be provided in front of the suction inlet 6 to prevent the intake of particles.

[0026] A magnetic oil drain plug is screwed in centrally below the intake, so that metallic particles are caught that must not reach the pump.

[0027] Reference symbol list

[0028] 1 geared motor unit

[0029] 2 Oil room

[0030] 3 Oil compartment lids

[0031] 4 Suction channel to the oil pump

[0032] 5-channel

[0033] 6 Suction mouth

[0034] 7 Oil drain plug

[0035] 8 separating element

[0036] 9 Engine cover

[0037] 10 Oil pump

[0038] 11 Oil return channel

[0039] 12 Oil pan

[0040] 13 gearboxes

[0041] 14 Planetary Set

[0042] 15 Gearbox housings

[0043] 16 Rotor

[0044] 17 Stator

[0045] 18 electric machine

[0046] 19" enclosure

[0047] 20 Intake area

Claims

- 6 - Patent claims 1. Oil pan (12) for a drive unit comprising an electric motor, a transmission and an oil circuit, wherein the oil pan (12) encloses an oil chamber (2) which is connected to the oil circuit via an oil return channel (12) and a suction channel (4), characterized in that an oil chamber cover (3) is provided by means of which the oil pan (12) is closed, so that the oil chamber (2) is formed, wherein the oil chamber cover comprises a channel (5) through which oil can be conveyed from the oil chamber (2) to the suction channel (4).

2. Oil pan (12) according to claim 1, characterized in that the channel (5) has a suction area (20) with a suction opening (6) in the center of the oil space cover (3) and the cross-section of the channel (5) tapers towards the suction channel (4).

3. Oil pan (12) according to claim 1, characterized in that the channel (5) is divided into two parts and each channel is assigned an intake port (6).

4. Oil pan (12) according to claim 1 , characterized in that sieves are provided in front of each suction opening (6).

5. Oil pan (12) according to claim 1, characterized in that the intake area (20) is designed as a recess, wherein a magnetic catching device and / or an oil drain screw (7) is arranged in the recess.

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