Electric axle drive device for an electric vehicle

Abstract

The invention relates to an electric axle drive device (1) for an electric vehicle comprising: - a housing (2) for separating a gearbox from the environment, - wherein the housing (2) comprises a receiving area (3) for receiving a ring gear (4), - a ring gear (4) as part of a transmission, - wherein the ring gear (4) is arranged in the receiving area (3), - a damping device (5) for damping audible and / or perceptible vibrations of a transmission, - wherein the damping device (5) is arranged between the ring gear (4) and the housing (2), - wherein the ring gear (4) is mounted in the damping device (5) such that the ring gear (4) and the damping device (5) have a positive fit, and / or - wherein the damping device (5) is attached to the receiving area (3) in such a way that the receiving area (3) and the damping device (5) form a positive fit.

Description

[0001] The invention relates to an electric axle drive device for an electric vehicle.

[0002] Known electric axle drive systems for electric vehicles typically comprise a housing and a gearbox with a ring gear. The ring gear is connected to the housing. The meshing of other gears, or a gear with the ring gear, creates vibrations in interaction with the housing, which can lead to noise.

[0003] Such vibrations are also referred to as "noise, vibration, harshness" (abbreviated to NVH). The term NVH refers to the audible or perceptible vibrations in motor vehicles or machinery. Roughness refers to the transition range, both audible and perceptible, between 20 Hz and 100 Hz.

[0004] DE 10 2018 131 837 A1 shows a transmission arrangement which is suitable and / or designed for an electric drive for a vehicle. The transmission arrangement forms, in particular, part of the drive train of the vehicle. In particular, a drive torque is transmitted or supported by the transmission arrangement. The vehicle can be, in particular, a passenger car, truck, bus, etc., or even a two-wheeler or three-wheeler. The electric drive can form the exclusive drive of the vehicle, so that the vehicle is designed as an electric vehicle. In alternative embodiments, the vehicle can also be designed as a hybrid vehicle, so that in addition to the electric drive, another drive, such as a drive with an internal combustion engine, is provided.In particular, the electric drive can be designed as an electric axle, wherein the electric axle has two output shafts that are operatively connected to two driven wheels of the vehicle. In particular, the electric axle is arranged between the two driven wheels of the vehicle, wherein the two output shafts are positioned coaxially to each other.

[0005] Against this background, it is the object of the present invention to provide an electric axle drive device for an electric vehicle which can be produced cost-effectively and with reduced material consumption and which ensures improved damping of vibrations.

[0006] This problem is solved by the features of the independent patent claims. Further advantageous developments are the subject of the dependent claims.

[0007] The present invention comprises an electric axle drive device for an electric vehicle.

[0008] The electric axle drive device or axle drive unit has a housing for isolating a transmission from the environment. For example, a coolant can be shielded using the housing to prevent potential environmental pollution and to ensure continuous cooling of the electric axle drive unit. The housing includes a receiving area for accommodating a ring gear. This allows a ring gear to be connected to the housing.

[0009] Furthermore, the axle drive device has a ring gear as part of a transmission. The ring gear is arranged in the receiving area.

[0010] The axle drive device also includes a damping device for dampening audible and / or tangible vibrations of a transmission. The damping device is located between the ring gear and the housing, thus reducing vibrations.

[0011] The ring gear is mounted and / or pressed into the damping device in such a way that the ring gear and the damping device have a positive connection. This design feature makes it possible to achieve improved vibration damping while simultaneously transmitting torque between the ring gear and the damping device.

[0012] Alternatively or additionally, the damping device is mounted and / or pressed into the receiving area in such a way that the receiving area and the damping device form a positive connection. This design measure enables improved vibration damping and, at the same time, torque transmission between the housing and the damping device.

[0013] Furthermore, the ring gear and the damping device can have a press fit, and / or the receiving area and the damping device can have a press fit. A press fit increases the friction between the ring gear and the damping device, or between the housing and the damping device. This can improve the transmission of torque.

[0014] In addition, the ring gear and the damping device can form a frictional and positive engagement. Alternatively or additionally, the receiving area and the damping device can form a frictional and positive engagement. A frictional and positive engagement improves torque transmission.

[0015] Furthermore, the ring gear can be knurled on the outside. The ring gear can also be formed on the outside or on its radially outer side as part of a knurled connection for a frictional and positive connection with the damping device. Thus, for example, when the ring gear is pressed into the damping device, the knurled connection can cut into the damping device. This creates a positive connection.

[0016] Furthermore, the receiving area can be knurled on the inside. The receiving area can also be designed on the inside or on its radially inner side as part of a knurled connection for a frictional and positive connection with the damping device. In this way, for example, when the damping device is pressed into the receiving area, the knurled connection can cut into the damping device. This creates a positive connection.

[0017] Using the aforementioned knurled connection and / or press-fitting, the mechanical transfer path for structure-borne sound can be further optimized, thus damping vibrations. By reducing the amplitudes of the free modes of the ring gear, structure-borne sound peaks can be reduced frequency-dependently. This allows for additional damping across a significantly broader frequency spectrum.

[0018] The recording area can also have an L-shape in the half section.

[0019] Furthermore, the receiving area can be provided with a hollow cylindrical section, with which the movement of the ring gear in the radial direction can be limited. The hollow cylindrical section can form a type of sleeve that limits radial movements.

[0020] Furthermore, the hollow cylindrical section can have an outer or a radially outer surface, which can be cylindrical or cylindrical in shape.

[0021] In addition, it is possible for the hollow cylindrical section to have an inner or radially inner lateral surface, which can be frustoconical in shape, whereby the inner lateral surface can be formed in a funnel-shaped manner.

[0022] Alternatively, the hollow cylindrical section may have an inner or a radially inner lateral surface, which may be cylindrical or cylindrical in shape.

[0023] In addition, the receiving area can have a toothing formed on an inner or radially inner surface of the hollow cylindrical section. The toothing can be formed as part of a knurled connection for a frictional and positive connection with the damping device.

[0024] Furthermore, the toothing can have a chamfer angle between 5 and 110 degrees. The chamfer angle can be the angle between an axis of symmetry of the receiving area, which can be oriented in the same direction as the axial direction, and a chamfer of the toothing.

[0025] The receiving area can also have a stop against which the ring gear can be clamped or pre-tensioned in the axial direction. This allows the axial movement of the ring gear relative to the housing to be limited.

[0026] The receiving area may have an annular portion which may have a shape similar to an annular disc, which forms the stop and / or which may be arranged on an end face and / or on an end of the hollow cylindrical portion.

[0027] Furthermore, it is possible for the receiving area to have a further section or a third section which has an inner or a radially inner lateral surface which can be cylindrical or cylindrically or frustoconically shaped.

[0028] In addition, the receiving area can be geometrically complementary to the outer or radially outer surface of the damping device, or to the damping device itself or its first damping section. This design allows for a positive fit. Thus, the housing and the damping device can be easily joined together to prevent vibrations.

[0029] According to the invention, the ring gear or at least a portion of the ring gear has the shape of a truncated cone and / or the ring gear or at least a portion of the ring gear can have an obliquely extending outer side in cross section to an axis of symmetry of the ring gear, which is oriented in the same way as the axial direction.

[0030] Furthermore, it is possible for the ring gear to have at least two sections, one of which has an outer surface or a radially outer surface, which may be cylindrical or cylindrical in shape. It is also conceivable for the ring gear to have at least two sections, one of which has an outer surface or a radially outer surface, which may be frustoconical in shape.

[0031] The truncated cone shape of the ring gear or the truncated cone shape of a section of the ring gear can be geometrically complementary to a truncated cone-shaped recess in the damping device of the axle drive. This allows a simple positive connection between the ring gear and the damping device to be achieved.

[0032] The ring gear can also have a cylindrical recess in the middle.

[0033] Furthermore, the ring gear can be in contact with the damping device on the outside and / or in the radial direction, essentially with its entire outer surface in the radial direction. This allows for optimal torque transmission.

[0034] In this description, “essentially over its entire surface” can be understood to mean that the ring gear rests against the damping device with its entire outer surface, or the entire surface lying on the outside in the radial direction. In this description, “essentially over its entire surface” can also be understood to mean that the ring gear rests completely or entirely against the damping device with its outer surface, or surface lying on the outside in the radial direction. In this case, “essentially over its entire surface” can also be understood to mean that the aforementioned formulations include a deviation of + / - 15%, i.e. that, for example, only 85% of the outer surface, or surface lying on the outside in the radial direction, of the ring gear rests against the damping device.

[0035] In addition, the ring gear can have an inner, or radially inner, surface and an outer, or radially outer, surface, as well as two end faces. Thus, the ring gear can be modeled after a hollow cylinder.

[0036] The ring gear can also have a first set of teeth formed on the inner circumferential surface. The first set of teeth can be designed as a gear. This provides an interface to one or more gears for transmitting torque.

[0037] In addition, the ring gear can have a second toothing formed on the outer surface. The second toothing can be formed as part of a knurled connection for a frictional and positive connection with the damping device.

[0038] Furthermore, the second gearing can have a chamfer angle between 5 and 110 degrees. The chamfer angle can be the angle between the cone axis or an axis of symmetry of the ring gear, which is oriented in the same direction as the axial direction, and a chamfer of the second gearing.

[0039] Furthermore, it can be provided that the ring gear is geometrically complementary to the damping device or to its first damping section.

[0040] The damping device can be designed in one piece or in one part.

[0041] According to the invention, the damping device has a shape similar to a cylinder or similar to a hollow cylinder and / or an obliquely running inner side in cross section to an axis of symmetry of the damping device, which is oriented in the same way to the axial direction.

[0042] The damping device can have a truncated cone-shaped recess in the center, so that the damping device has a shape similar to a circular ring.

[0043] Furthermore, the frustoconical recess can be geometrically complementary to the truncated cone shape of the ring gear. This allows a simple, positive connection between the ring gear and the damping device to be achieved.

[0044] The damping device can also be designed to complement the geometry of the housing or its first section. This makes it easy to achieve a positive fit between the housing and the damping device.

[0045] The damping device can also have an inner or radially inner lateral surface and an outer or radially outer lateral surface as well as two end faces.

[0046] In addition, the damping device can have an inner or a radially inner lateral surface which encloses a truncated cone, whereby the inner lateral surface can be formed in a funnel-shaped manner.

[0047] Furthermore, the damping device can have an outer surface, or a surface located radially outward, which can be cylindrical or cylindrically shaped. Alternatively, the damping device can have an outer surface, or a surface located radially outward, which can be frustoconical, whereby the outer surface can be formed with a funnel-shaped taper.

[0048] The outer surface of the damping device can be arranged on the hollow cylindrical section of the receiving area and / or in the receiving area.

[0049] The inner surface of the damping device can be arranged on the outer surface of the ring gear.

[0050] The damping device can also be made of plastic. Furthermore, the damping device can be designed as a plastic ring.

[0051] Furthermore, the damping device can be in contact with both the ring gear and the housing.

[0052] Furthermore, the axle drive device can have a securing device for securing the damping device and / or the ring gear in the receiving area of ​​the housing.

[0053] The securing device can tension the front side of the damping device and / or the ring gear in the direction of the stop of the receiving area.

[0054] The securing device can be designed as a retaining ring and / or as a circular disc element that can be inserted into a groove in the housing. The securing device can also be attached to the housing by means of screws or rivets.

[0055] The axis of symmetry can be an axis for which rotations by any angle map the object onto itself. In other words, the axis of symmetry can also be referred to as the axis of a solid of revolution. The axis of symmetry can also form an axis of rotation.

[0056] In summary, it can be stated that with the help of the presented invention for an electric axle drive device for an electric vehicle, it is possible, for example, for a knurled connection of the ring gear to cut into the damping device when a ring gear is pressed into the damping device. This allows a positive connection to be created.

[0057] Furthermore, it is possible that, for example, when the damping device is pressed into the receiving area, the knurled connection of the receiving area cuts into the damping device. This can also create a positive fit.

[0058] The conical design of the ring gear and the damping device allows for an improved frictional connection between the two to be created.

[0059] The invention is explained in more detail below using an exemplary embodiment in conjunction with the accompanying drawings. The drawings schematically show: Fig. 1 is a plan view of a part of an electric axle drive device for an electric vehicle; and Fig. 2 a sectional view along the line AA of Fig. 1.

[0060] In the following description, the same reference symbols are used for the same items.

[0061] Fig. 1 shows a plan view of a part of an electric axle drive device 1 for an electric vehicle, wherein in Fig. 2 a sectional view along the line AA of Fig. 1 is shown.

[0062] For the sake of simplicity and brevity, the following are the Fig. 1 and Fig. 2 described together.

[0063] Both figures show an electric axle drive device 1 for an electric vehicle.

[0064] The electric axle drive device 1 or the axle drive device 1 comprises a housing 2 for separating a transmission from the environment, wherein the housing 2 has a receiving area 3 for receiving a ring gear 4.

[0065] Furthermore, the axle drive device 1 has a ring gear 4 as part of a transmission, which is arranged in the receiving area 3.

[0066] In addition, the axle drive device 1 has a damping device 5 for damping audible and / or perceptible vibrations of a transmission. The damping device 5 is arranged between the ring gear 4 and the housing 2.

[0067] Strictly speaking, the ring gear 4 is mounted in the damping device 5 in such a way that the ring gear 4 and the damping device 5 form a positive connection. Furthermore, the damping device 5 is mounted in the receiving area 3 in such a way that the receiving area 3 and the damping device 5 form a positive connection.

[0068] In other words, the ring gear 4 and the damping device 5 have a press fit and form a frictional and positive connection. The receiving area 3 and the damping device 5 also have a press fit, which also form a frictional and positive connection.

[0069] For this purpose, the ring gear 4 is knurled on the outside or the ring gear 4 is designed on the outside or on its radially outer side as part of a knurled connection for a frictional and positive connection with the damping device 5.

[0070] The same applies to the receiving area 3. This is knurled on the inside and is designed on the inside or on its radially inner side as part of a knurled connection for a frictional and positive connection with the damping device 5.

[0071] According to the Fig. 1 and Fig. 2, the receiving area 3 has a hollow cylindrical section 6, with which a movement of the ring gear 4 in the radial direction R can be limited. The receiving area 3 has a toothing 7, formed on an inner or, in the radial direction R, inner surface of the hollow cylindrical section 6.

[0072] The toothing 7 is designed as part of a knurled connection for a frictional and positive connection with the damping device 5 and has a chamfer angle between 5 and 110 degrees. The chamfer angle is the angle between an axis of symmetry S of the receiving area 3, which is oriented in the same direction as the axial direction A, and a chamfer of the toothing 7.

[0073] Furthermore, Fig. 2, that the receiving area 3 has a stop 8 against which the ring gear 4 can be clamped or pre-tensioned in the axial direction A.

[0074] The receiving area 3 has a circular section 9, which forms the stop 8 and is arranged at one end of the hollow cylindrical section 6. The receiving area 3 is geometrically complementary to the outer or radially outer surface of the damping device 5.

[0075] According to Fig. 2, the ring gear 4 has the shape of a truncated cone, or the ring gear 4 has a cross-sectionally inclined outer side relative to an axis of symmetry S of the ring gear 4, which is oriented in the same direction as the axial direction A. The truncated cone shape of the ring gear 4 is geometrically complementary to a truncated cone-shaped recess of the damping device 5 of the axle drive device 1. In addition, Fig. 2, that the ring gear 4 has a cylindrical recess in the middle.

[0076] Furthermore, Fig. 2 shows that the ring gear 4 rests on the outside or in the radial direction R essentially over its entire surface on the damping device 5, e.g. with the entire outer surface lying in the radial direction on the damping device 5.

[0077] The ring gear 4 has an inner or in the radial direction R inner surface and an outer or in the radial direction R outer surface as well as two end faces.

[0078] In addition, the ring gear 4 has a first toothing 10 formed on the inner circumferential surface, which is designed as a gear.

[0079] Furthermore, the ring gear 4 has a second toothing 11, formed on the outer circumferential surface, which is designed as part of a knurled connection for a frictional and positive connection with the damping device 5.

[0080] The second toothing 11 comprises a chamfer angle between 5 and 110 degrees, wherein the chamfer angle is the angle between the cone axis or an axis of symmetry S of the ring gear 4, which is oriented in the same way to the axial direction A, and a chamfer of the second toothing 11.

[0081] As in the Fig. 1 and Fig. 2, the damping device 5 has a shape similar to a hollow cylinder or the damping device 5 has an obliquely running inner side in cross section to an axis of symmetry S of the damping device 5, which is oriented in the same way to the axial direction A.

[0082] The damping device 5 has a truncated cone-shaped recess in its center, so that the damping device 5 has a shape similar to a circular ring. The truncated cone-shaped recess 14 is geometrically complementary to the truncated cone shape of the ring gear 4.

[0083] The damping device 5 also has an inner or, in the radial direction R, inner lateral surface and an outer or, in the radial direction R, outer lateral surface as well as two end faces.

[0084] The outer surface of the damping device 5 is arranged on the hollow cylindrical section 6 of the receiving area 3, with the inner surface of the damping device 5 being arranged on the outer surface of the ring gear 4. Thus, the damping device 5 is in contact with both the ring gear 4 and the housing 2.

[0085] Specifically, the damping device 5 comprises plastic as its material or the damping device 5 is designed as a plastic ring.

[0086] Furthermore, Fig. 2, that the axle drive device 1 has a securing device 12 for securing the damping device 5 and the ring gear 4 in the receiving area 3 of the housing 2.

[0087] The securing device 12 tensions the front side of the damping device 5 and the ring gear 4 in the direction of the stop 8 of the receiving area 3.

[0088] The securing device 12 is designed as a securing ring or as a circular disc element which is inserted into a groove in the housing 2.

[0089] With the presented design of an electric axle drive device 1 for an electric vehicle, it is possible, for example, when pressing the ring gear 4 into the damping device 5, for the knurled connection of the ring gear 4 to cut into the damping device 5. This allows a positive connection to be created.

[0090] Furthermore, it is possible that, for example, when pressing the damping device 5 into the receiving area 3, the knurled connection of the receiving area 3 cuts into the damping device 5. This also creates a positive connection.

[0091] The conical design of the ring gear 4 and the damping device 5 allows for improved frictional engagement between the two. List of reference symbols 1 axle drive device 2 housings 3 Recording area 4 ring gear 5 Damping device 6 hollow cylindrical section 7 Gearing 8 stop 9 circular section 10 first gearing 11 second gearing 12 Safety device A axial direction R radial direction S axis of symmetry

Claims

[1] Electric axle drive device (1) for an electric vehicle comprising: - a housing (2) for isolating a gearbox from the environment, - wherein the housing (2) comprises a receiving area (3) for receiving a ring gear (4), - a ring gear (4) as part of a transmission, - wherein the ring gear (4) is arranged in the receiving area (3), - a damping device (5) for damping audible and / or perceptible vibrations of a transmission, - wherein the damping device (5) is arranged between the ring gear (4) and the housing (2), - the ring gear (4) is mounted in the damping device (5) in such a way that the ring gear (4) and the damping device (5) have a positive connection, and / or that - the damping device (5) is mounted in the receiving area (3) in such a way that the receiving area (3) and the damping device (5) form a positive connection, characterized by , that - the ring gear (4) or at least a portion of the ring gear (4) has the shape of a truncated cone, and / or - wherein the ring gear (4) or at least a portion of the ring gear (4) has an obliquely extending outer side in cross-section to an axis of symmetry (S) of the ring gear (4), which is oriented in the same direction as the axial direction (A), - wherein the truncated cone shape of the ring gear (4) or the truncated cone shape of a section of the ring gear (4) is geometrically complementary to a truncated cone-shaped recess of the damping device (5) of the axle drive device (1), - wherein the ring gear (4) has an inner circumferential surface and an outer circumferential surface as well as two end faces, - wherein the ring gear (4) has a second toothing (11) formed on the outer surface, - wherein the second toothing (11) is designed as part of a knurled connection for a frictional and positive connection with the damping device (5). [2] Axle drive device according to claim 1, - wherein the ring gear (4) and the damping device (5) have a press fit, and / or - wherein the receiving area (3) and the damping device (5) have a press fit. [3] Axle drive device according to claim 1 or 2, - wherein the ring gear (4) and the damping device (5) form a frictional and positive connection, and / or - wherein the receiving area (3) and the damping device (5) form a frictional and positive connection. [4] Axle drive device according to one of the preceding claims, - wherein the ring gear (4) is knurled on the outside and / or - wherein the receiving area (3) is knurled on the inside. [5] Axle drive device according to one of the preceding claims, - wherein the receiving area (3) has a hollow cylindrical section (6) with which a movement of the ring gear (4) in the radial direction (R) can be limited, - wherein the receiving area (3) has a toothing (7) formed on an inner or in the radial direction (R) inner surface of the hollow cylindrical section (6), and - wherein the toothing (7) is designed as part of a knurled connection for a frictional and positive connection with the damping device (5). [6] Axle drive device according to one of the preceding claims, - wherein the receiving area (3) is geometrically complementary to the outer or radially outer surface of the damping device (5). [7] Axle drive device according to the preamble of claim 1, - wherein the damping device (5) has a shape similar to a hollow cylinder, - wherein the damping device (5) has a truncated cone-shaped recess in the center, so that the damping device (5) has a shape similar to a circular ring, - wherein the damping device (5) has an inner surface and an outer surface as well as two end faces, - wherein the outer surface of the damping device (5) is arranged on the hollow cylindrical section (6) of the receiving area (3), and - wherein the inner circumferential surface of the damping device (5) is arranged on the outer circumferential surface of the ring gear (4). [8] Axle drive device according to one of the preceding claims, - a securing device (12) for securing the damping device (5) and / or the ring gear (4) in the receiving area (3) of the housing (2).

Images