Integrated seal, oil circuit, oil distributor ring with integrated seal, and e-axle

Abstract

The invention relates to an oil distributor ring (1) for terminating a flow of fluid, which is able to be guided through cooling channels (2) in a stator (3) or rotor (15), in fluidtight fashion, wherein the oil distributor ring (1) has at least one connection face (7) intended to rest against an end face (5) of a stator (3) or of a housing / rotor (15) or of a housing with interposition of a seal (8), wherein the seal (8) is an integral part of the oil distributor ring (1). The invention also relates to a stator (3) or rotor (15) and to an electrical machine (4) and to a E-axle in which such an electrical machine (4) is used.

Description

[0001] Integrated seal oil circuit, oil distribution ring with integrated seal and e-axle

[0002] The invention relates to an oil distribution ring for fluid-tight sealing of a fluid flow that can be guided through cooling channels of a stator or a rotor, wherein the oil distribution ring has at least one connection surface that is intended to bear against an end face of a stator or a rotor or a housing with a seal interposed therebetween.

[0003] US 2015 / 0 369242 A1 and DE 10 2013 201 384 A1, for example, represent this prior art. These documents disclose, for example, an internal gear pump for a slip-controlled hydraulic vehicle brake system. The disclosure therein proposes rotatably supporting a pump shaft on one side of a pinion and a ring gear of the internal gear pump in an axial disc, which laterally seals the pinion and the ring gear. A pivot bearing with a sealing arrangement is known from US 2019 / 0 323 551 A1 and the parallel DE 10 2019205 525 A1. The disclosure therein relates to a pivot bearing comprising a first ring and a second ring, wherein the rings are in relative rotation about a rotational axis, and at least one row of rolling elements arranged between the rings.The pivot bearing is further provided with a sealing device comprising at least one seal having an annular shoulder secured to the first ring and a sealing lip in sliding frictional contact with the second ring, and a deflector secured to a side surface of the second ring and a cover member at least partially radially surrounding the sealing lip.

[0004] However, the invention is specifically directed at the field of electric axles for motor vehicles, with the goal of optimizing the oil circuit and its components from a technical and economic perspective. Existing solutions to date have been complex to install, costly, and not entirely satisfactory. O-rings, flat gaskets, sealing washers, liquid gaskets, sealing plates, and metal bead seals have so far failed to deliver success.

[0005] In particular, electric motors with winding head lubrication systems that rely on a nozzle shield and use metal bead seals are unsatisfactory. Actuators / oil pumps in 4-in-1 electric axes that rely on O-rings are also unsatisfactory.

[0006] It is therefore the object of the present invention to provide an improvement from a technical and economic point of view and to facilitate assembly.

[0007] This is achieved according to the invention in a generic oil distribution ring by the seal being an integral / single-material / non-separate component of the oil distribution ring. This means that a "sealing cord" is formed in one piece from the material of the oil distribution ring. The technical necessity of a sealed oil circuit is now also met, particularly in e-mobility, in a cost-effective, easy-to-install, and sufficiently functional manner. It can be used in open, closed, and combined oil circuits. The requirement for a seal to connect housings and lines, sometimes only for certain sections of the oil circuit, is met. The sealing solution can be specifically tailored to the specific pressure conditions, the operating temperature range, and the type of oil used. An additional assembly step for inserting a seal is avoided.

[0008] One could also say that the inventive solution consists in integrating a seal into the housing / component. This avoids additional assembly work and makes matching / selection of the additional sealing material obsolete. A geometry, for example a sealing lip, is formed directly from the base material on the flange of the component. This is pressed against the component to be connected during assembly and held under prestress. Depending on the application, the resulting geometry can exhibit purely elastic or elasto-plastic deformation. The size, shape, and material must be matched to the specific application. In principle, various materials can be used, including those from which the housings and cables are made. Metals, plastics, and composites are conceivable.

[0009] In the specific case of stator cooling, the oil is guided through the axial channels of the stacks / sheet metal plates / stamped discs / stator laminations / rotor laminations to provide a cooling jacket. To distribute and convey the coolant, in particular a fluid, preferably a liquid, such as oil, especially hydraulic oil, an oil distribution ring and a motor cover are required, both of which should / must be sealed against the stator lamination stack. For this purpose, several sealing lips are now provided directly on the oil distribution ring, which are axially preloaded during assembly. These seal the various pockets and channels in the axial direction against both the housing (die-cast aluminum) and the stator (steel). Transferring this solution to the rotor is conceivable.It is also conceivable that the oil distribution ring is an integral / single-material / non-separate component of the housing and thus the seal is an integral / single-material / non-separate component of the housing.

[0010] The oil distribution ring with the integrated sealing lip is manufactured from plastic using an injection-molded process. Especially with large diameters, as is common in traction machines, the additional sealing function can be easily integrated into the actual component, as a sufficiently large and stable base body is already present to accommodate the sealing lip. Ribbing or a support structure supports the even distribution of force across the entire circumference of the surface to be sealed, ensuring consistent preload of the sealing lip even with a reduced number of force application points. Of particular note is the bolted stator with six screws.

[0011] It is suitable for use in electric axles, hybrids, and combustion engines with an oil circuit. Advantageous embodiments are claimed in the subclaims and are explained in more detail below.

[0012] It is advantageous if the oil distribution ring has a first connection surface for contact with the stator / rotor and a second connection surface for contact with the housing, and both the first and second connection surfaces have an integral / single-material / non-separate seal. This effectively prevents leakage.

[0013] In order to facilitate the introduction of preload, it has proven advantageous if the seal is designed as an axially protruding sealing lip.

[0014] An advantageous embodiment is characterized in that the sealing lip has a spherical / concave / axially protruding outer contour.

[0015] Particularly circular segment-like base areas / cross-sections of the sealing lip or elliptical / partially elliptical cross-sections are suitable.

[0016] In order to ensure functionality even after disassembly and reassembly, it has proven advantageous if the oil distribution ring has a base body made of such a material that a purely elastic or elasto-plastic deformation occurs on the seal during assembly.

[0017] To keep costs low, it has proven beneficial to use particularly suitable materials. It is advantageous if the base body consists of metal, plastic, and / or a composite material, or is constructed predominantly, partially, or entirely of these materials. PA, PP, and similar plastics are particularly suitable.

[0018] If the base body has ribbing, it can be designed to be sufficiently rigid. The invention also relates to a stator or rotor for an electric motor, comprising a plurality of stacks / sheet metal plates / stamped discs / stator laminations or a main body / solid material base body, in which fluid channels for conducting a cooling fluid such as oil are present, wherein an oil distribution ring according to the invention is sealingly mounted on the fluid channels. This means that a separate seal is unnecessary.

[0019] The invention also relates to an electric motor with a stator or a rotor of the type according to the invention, which is operatively connected to its counterpart, i.e. a rotor or a stator.

[0020] Finally, the invention also relates to an electric axle of a land-based motor vehicle with such a motor, in particular a 4-in-1 electric axle.

[0021] The invention is explained in more detail below with the aid of a drawing. It shows:

[0022] Fig. 1 shows a first embodiment of an inventive

[0023] Oil distribution ring in use in an electric motor, namely on a stator, in a partially shown longitudinal section,

[0024] Fig. 2 is an enlargement of area II from Fig. 1 ,

[0025] Fig. 3 is an enlargement of area III from Fig. 2,

[0026] Figs. 4 and 5 different perspective views of the oil distribution ring of Figs. 1 to 3,

[0027] Fig. 6 a stator with windings forming winding heads, wherein in the stator

[0028] Cooling channels are provided which are to be covered by the oil distribution ring of Figs. 1 to 5, and Fig. 7 is a partial representation of a longitudinal section through an electric motor according to the invention with an oil distribution ring of Figs. 1 to 5.

[0029] The figures are merely schematic and serve only to clarify the invention. The same elements are designated by the same reference numerals.

[0030] Fig. 1 shows an oil distribution ring 1 according to the invention. It has a cover-like shape. It can also be designed as an integral component of the engine cover. It interacts with cooling channels 2 in a stator 3 of an electric motor 4.

[0031] Fig. 2 clearly shows how the oil distribution ring 1 rests on an end face 5, formed by stacks of the stator 3, against a connecting surface 7 of the oil distribution ring 1. At the heart of the invention is an integral seal 8 formed on the connecting surface 7. The seal 8 ultimately forms a "sealing cord" around a cooling channel 2. An enlargement can be seen in Fig. 3. The seal 8 has a spherical, polygonal or roof-shaped contour / cross-section. The seal 8 thus forms a sealing lip, the state of which is shown before assembly. The height is between 45% and 55%, preferably 50% of the width. The height is referenced with the reference numeral 9, whereas the width is referenced with the reference numeral 10.

[0032] The oil distribution ring 1 typically has an inlet 11 and an outlet 12, as well as different compartments 13, which are divided by the seal 8. Reference is made to Figs. 4 to 5.

[0033] A stator 3 with a plurality of stacks 6, comprising a plurality of cooling channels 2 and a winding 14 arranged radially within them, is shown in Fig. 6. The oil distribution ring 1 is not yet mounted here.

[0034] In Fig. 7, however, the oil distribution ring 1 is mounted. The rotor is referenced there with the reference numeral 15.

[0035] List of reference symbols

[0036] Oil distribution ring

[0037] Cooling channel I Fluid channel

[0038] stator

[0039] E-machine / E-motor

[0040] frontal surface

[0041] Stack

[0042] Connection surface

[0043] seal

[0044] Height

[0045] Width

[0046] inlet

[0047] Outlet

[0048] compartment

[0049] winding

[0050] rotor

Claims

Patent claims 1 . Oil distribution ring (1 ) for fluid-tight sealing of a fluid flow that can be guided through cooling channels (2) of a stator (3) or a rotor (15), wherein the oil distribution ring (1 ) has at least one connection surface (7) which is intended to bear against an end face (5) of a stator (3) or a rotor (15) or a housing with the interposition of a seal (8), characterized in that the seal (8) is an integral component of the oil distribution ring (1 ).

2. Oil distribution ring (1) according to claim 1, characterized in that the oil distribution ring has a first connection surface (7) for contact with the stator (3) or the rotor (15) and a second connection surface (7) for contact with the housing, and both the first connection surface (7) and the second connection surface (7) have an integral seal (8).

3. Oil distribution ring (1) according to claim 1 or 2, characterized in that the seal (8) is designed as an axially projecting sealing lip.

4. Oil distribution ring (1) according to claim 3, characterized in that the sealing lip has a spherical / concave outer contour.

5. Oil distribution ring (1) according to one of claims 1 to 4, characterized in that the oil distribution ring (1) has a base body made of such a material that a purely elastic or elasto-plastic deformation occurs on the seal (8) during assembly.

6. Oil distribution ring (1) according to claim 5, characterized in that the base body comprises or is constructed from metal, plastic and / or a composite material.

7. Oil distribution ring (1) according to claim 5 or 6, characterized in that the base body has ribbing.

8. Stator (3) or rotor (15) for an electric motor (4), with a plurality of stacks (6) in which fluid channels / cooling channels (2) for guiding a cooling liquid are present, wherein an oil distribution ring (1) according to one of the preceding claims is sealingly placed on the fluid channels / cooling channels (2).

9. Electric motor (4) with a stator (3) and / or a rotor (15) according to claim 8, which is operatively connected to a rotor (15) or a stator (3).

10. Electric axle of a land-based motor vehicle, comprising an electric motor (4) according to claim 9.

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