Drive device, in particular for an electric vehicle
Patent Information
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- MERCEDES BENZ GROUP AG
- Filing Date
- 2017-07-15
- Publication Date
- 2026-07-23
AI Technical Summary
Existing drive devices for electric vehicles lack a compact, efficient, and flexible transmission system that allows for multiple gear ratios without the need for additional components, such as final drives or spur gear differentials, while also supporting forward and reverse operation.
A drive device with a multi-stage transmission system featuring three interconnected planetary gear stages, two switching units, and a coaxial arrangement that enables switching between two forward gears, including a creep gear for trailer operation, using a design that integrates the electric motor directly with the axle drive, eliminating the need for a final drive and reducing drag losses.
The solution provides a compact, efficient, and flexible drive system that optimizes gear efficiency, reduces drag losses, and allows for both forward and reverse operation, while utilizing a compact design that integrates the electric motor with the axle drive, eliminating the need for additional components.
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
[0001] The invention relates to a drive device for a motor vehicle, in particular an electric vehicle or a motor vehicle with at least one purely electrically driven drive axle.
[0002] From WO 2015 / 169837 A1, a drive device for an electric vehicle is already known, which has an electric motor, an axle drive and a gearbox arranged between the electric motor and the axle drive.
[0003] The invention is based in particular on the objective of providing a further developed, especially load-shiftable, drive device for an electric vehicle. This is achieved according to the invention by the features of claim 1. Further embodiments are described in the dependent claims.
[0004] The invention relates to a drive device, in particular for an electric vehicle, with at least one electric motor, with at least one axle drive and a multi-stage transmission arranged between the electric motor and the axle drive, structurally designed for switching two forward gears, which has three operatively interconnected planetary gear stages, each with a sun gear, a ring gear and a planet carrier, two switching units, each with two coupling elements that can be connected to each other in a rotationally fixed manner, a transmission input element for the rotationally fixed connection of the electric motor and a transmission output element for the rotationally fixed connection of the axle drive, wherein the transmission input element is permanently and rotationally fixedly connected to the sun gear of the first planetary gear stage.the transmission output element is permanently and rotationally fixedly connected to the planet carrier of the third planetary gear stage, and the planet carrier of the first planetary gear stage and the sun gear of the third planetary gear stage are permanently and rotationally fixedly connected to each other.
[0005] It is proposed that the ring gear of the second planetary gear stage and the planet carrier of the third planetary gear stage be permanently and rotationally fixed to one another. This design allows for a compact drive unit for an electric vehicle, enabling advantageous connection of the electric motor to the axle drive. In particular, a coaxial arrangement can be achieved. The multi-stage transmission allows for different forward gear ratios, which can be used to advantageously convert the drive torque delivered by the electric motor. This allows the speed of the electric motor to be reduced, particularly advantageously at high speeds. Furthermore, one gear, especially first gear, can enable extended creeping and even trailer operation.Reverse gears can be omitted by designing the electric motor for reversing the direction of rotation. The drive gears can therefore preferably be used for both forward and reverse travel. Furthermore, a particularly efficient and compact design can be achieved. Additional gear sets are unnecessary, and no further final drive is required. Low relative speeds can also be maintained in the planetary gears. Additionally, the design allows for optimal stacking and space utilization. Moreover, since the overall gear ratio is preferably achieved through the multi-stage transmission, a favorable gear efficiency can be attained in the main drive range. The gear efficiency is particularly high because no further output gear ratio is required.In particular, no additional gear losses arise from a spur gear differential. The gear ratios of the forward transmission and / or the axle drive can be at least partially adapted to the specific configuration of the electric vehicle. A flexible drive system can be provided. Furthermore, particularly advantageously, low rotational speeds can be achieved in the drive system, thereby keeping drag losses to a minimum.
[0006] In this context, a "drive device with at least one electric motor, at least one axle drive, and a multi-stage transmission arranged between the electric motor and the axle drive" is understood to mean, in particular, a drive device that comprises only electric motors for generating drive torque. Specifically, it is understood to mean a drive device independent of an internal combustion engine. In this context, a "multi-stage transmission" is understood to mean, in particular, a transmission arranged between the electric motor and the axle drive for shifting the differently geared forward gears.The term "planetary gear stage" is further defined, in particular, as a gear stage characterized by a tooth mesh between a sun gear and a planet gear guided by a planet carrier, and / or a tooth mesh between a planet gear guided by a planet carrier and a ring gear. In principle, the planetary gear stages can be manufactured, at least partially, as a single unit. In particular, it is conceivable that two of the planetary gear stages may have a common ring gear and separate sun gears, or a common sun gear and separate ring gears. The term "axle drive" is defined, in particular, as a functional connection between the transmission output element of the multi-stage transmission and at least one drive wheel of the motor vehicle.The axle drive can have fundamentally different configurations, designed for a permanent and / or switchable connection between the transmission output element and at least one drive wheel. For example, the axle drive can be designed for a direct, permanent, rotationally fixed connection between the transmission output element and the drive wheel; that is, the axle drive can essentially consist solely of a drive shaft connecting the transmission output element and the drive wheel. Alternatively, the axle drive can also include a differential designed to connect two drive wheels in parallel to the transmission output element. Preferably, a spur gear stage between the transmission output element and the differential is omitted; that is, the differential has an input element that is rotationally fixed to the transmission output element.The term "gearbox input element" refers in particular to a gearbox element that is designed, at least structurally, for a rotationally fixed connection to a rotor of the electric motor. The term "gearbox output element" refers in particular to a gearbox element that is designed, at least structurally, for a rotationally fixed connection to an axle drive. The term "gearbox element" refers in particular to a configuration designed for a permanent, rotationally fixed connection between the sun gears, planet carriers, ring gears, and / or coupling elements.
[0007] The term "constructive" is understood to mean, in particular, that a corresponding design is provided in the design, but that in a possible embodiment, the functional use of the design may be dispensed with. In this context, "constructively designed for shifting a gear" is understood to mean, in particular, that a corresponding gear can be mechanically formed by means of the shifting units and planetary gear stages, regardless of whether the gear shifting is omitted within a shifting strategy or not. For example, in one embodiment, the shifting units may be designed to shift more forward gears than it might be practical to shift within an operating strategy for the multi-stage transmission.
[0008] The planetary gear stages are referred to below as "first planetary gear stage," "second planetary gear stage," and "third planetary gear stage." The designations "first," "second," and "third" planetary gear stage are primarily intended to define an axial arrangement, although the axial sequence of the planetary gear stages may deviate from the numbering. In principle, a modified arrangement of the planetary gear stages and / or a stacked arrangement, in which the planetary gear stages are at least partially radially nested, is conceivable. In particular, various kinematically equivalent gear structures can be realized by a spatial rearrangement of the switching units, by a modified arrangement of gear elements, and / or by interchanging the sun gears, planet gears, and / or ring gears.The term "kinematically equivalent transmission structures" refers to transmission structures that have the same number of shift units and identical shift patterns for shifting the forward and reverse gears.
[0009] Furthermore, it is proposed that the first switching unit be designed to mount the ring gear of the third planetary gear stage to the housing. It is further proposed that the first switching unit be designed to mount the planet carrier of the second planetary gear stage to the housing. It is further proposed that the second switching unit be designed to mount the ring gear of the first planetary gear stage to the housing. It is further proposed that the second switching unit be designed to mount the sun gear of the second planetary gear stage to the housing. This allows for particularly advantageous low relative speeds in the open-running switching units. Preferably, it is conceivable that at least one of the switching units be designed as a claw switching unit or freewheel to further reduce losses.Furthermore, advantageously small speed differences can be provided, thus enabling simple synchronization. In addition, easy access to the switching units can be ensured.
[0010] The term "switching unit" shall be understood to mean, in particular, a unit with exactly two coupling elements rotatable relative to each other and designed to form a rotationally fixed connection. A switching unit can optionally be designed as a clutch or a brake. A switching unit designed as a "clutch" shall be understood to mean, in particular, a switching unit arranged in a power flow between two planetary gear stages and designed to connect its two rotatably arranged coupling elements, which are independently rotatable in an open state, in a rotationally fixed connection when closed.A switching unit designed as a "brake" is understood to mean, in particular, a switching unit that is operatively arranged between one of the planetary gear stages and a gearbox housing and that is designed to connect its rotatable coupling element, which is rotatable independently of the gearbox housing in an open state, to its coupling element that is rotationally fixed to the gearbox housing in a closed state. "Rotationally fixed connection" is understood to mean, in particular, a connection in which a power flow is transmitted over a complete revolution with an unchanged torque, an unchanged direction of rotation, and / or an unchanged rotational speed.
[0011] In this context, the term "shifting unit" specifically excludes any clutch located upstream or downstream of a gear set formed by planetary gear stages. A "clutch upstream of the gear set" refers specifically to a clutch located in a power flow between the electric motor and the transmission input element in at least one gear, such as a disconnect clutch or a starting clutch. A "clutch downstream of the gear set" refers specifically to a clutch unit located in a power flow between the transmission output element and an axle drive in at least one gear, such as an all-wheel-drive clutch. In principle, the shiftability of a multi-stage transmission can be improved by a clutch unit located upstream or downstream of the gear set.
[0012] Preferably, some of the switching units are designed with a positive locking mechanism. This minimizes drag losses, thereby advantageously reducing power loss within the multi-stage transmission. A "positive locking switching unit" is understood to be, in particular, a switching unit that has teeth and / or claws for connecting its coupling elements or for attaching its coupling element, which interlock to create a rotationally fixed connection, whereby the transmission of power flow in a fully closed state occurs at least primarily through a positive locking mechanism. The switching units can, in principle, be designed with either friction locking or positive locking. A "friction locking switching unit" is understood to be, in particular, a switching unit that has teeth and / or claws for connecting its coupling elements or for attaching its coupling element.The coupling element has at least two friction partners that frictionally engage to create a rotationally fixed connection, whereby the transmission of power in a fully closed state occurs at least primarily through friction. A frictionally designed clutch unit is preferably a multi-plate clutch unit, and a frictionally designed brake unit is preferably a multi-plate brake unit. A positive-locking clutch unit is preferably a dog clutch unit, and a positive-locking brake unit is preferably a dog brake unit. A positive-locking switching unit is advantageously switchable via a sliding sleeve. The positive-locking switching units are preferably designed without synchronization, but can, in principle, also include synchronization.
[0013] Preferably, the multi-stage transmission includes actuators for the automated switching of the shifting units. However, it is also possible to design at least some of the shifting units to be at least partially self-shifting. A self-shifting clutch unit or brake unit is preferably designed as a freewheel. Furthermore, the configuration of the planetary gear stages with single or double planetary gear sets can also differ from the illustrated embodiment. For example, it is possible to replace a single planetary gear set with a double planetary gear set in a kinematically equivalent manner, whereby, in order to achieve the same kinematic operation, the stationary gear ratio of the planetary gear stage must also be adjusted.In particular, when using a double planetary gear set, the connection between a sun gear and a planet carrier, a ring gear and a planet carrier, or a sun gear and a ring gear can generally be exchanged, whereby, for a kinematically identical mode of operation, the stationary gear ratio of the planetary gear stage must also be adjusted.
[0014] Furthermore, it is proposed that the ring gear of the first planetary gear stage and the sun gear of the second planetary gear stage be permanently and rotationally fixed to one another or be capable of being rotationally fixed to one another. It is further proposed that the planet carrier of the second planetary gear stage and the ring gear of the third planetary gear stage be permanently and rotationally fixed to one another. It is also proposed that the axle drive comprise at least one axle shaft that passes through the transmission input element, the transmission output element, and / or the electric motor. Such a design allows for a compact drive unit for an electric vehicle, enabling advantageous integration of the electric motor with the axle drive.
[0015] The terms "axial" and "radial" in the following refer specifically to the main axis of rotation of the multi-stage transmission, such that the term "axial" specifically denotes a direction that runs parallel or coaxial to the main axis of rotation. Furthermore, the term "radial" specifically denotes a direction that runs perpendicular to the main axis of rotation. A "transmission-side arrangement" is understood to mean, in particular, that the aforementioned component is arranged on a side of the other component that faces the transmission input element and / or the electric motor.The term "transmission-side arrangement" shall be understood in particular to mean that the aforementioned component is arranged on a side of the further component which is facing away from the transmission input element and / or the electric motor, even if the further component is arranged in an axial direction after the transmission output element, for example because the transmission output element is arranged between two planetary gear stages.
[0016] Further advantages will become apparent from the following description of the figures. The figures illustrate two exemplary embodiments of the invention. The figures, the description of the figures, and the claims contain numerous features in combination. A person skilled in the art will expediently consider the features individually and combine them into meaningful further combinations.
[0017] This shows: Fig.1 a motor vehicle with a drive device comprising an electric motor and a multi-stage transmission, Fig. 2 a gear diagram of the multi-stage transmission, Fig. 3 a shift diagram for the multi-stage transmission and Fig. 4 a gear diagram of an alternative multi-stage transmission with stacked planetary gear stages.
[0018] Fig. Figure 1 shows a motor vehicle with a drive device. Fig.Figure 1 shows an electric vehicle with a drive unit. The drive unit is designed for electric propulsion of the vehicle. The vehicle can, in principle, be configured as a purely electric vehicle. The drive unit is intended solely for electric propulsion. It is also conceivable that the drive unit could be combined with a second drive unit for internal combustion engine propulsion. For example, the proposed drive unit designed for electric propulsion could act on a first drive axle of the vehicle, while the drive unit designed for internal combustion engine propulsion could act on a second drive axle.If the proposed drive device is combined with an internal combustion engine drive device, it is also conceivable that the motor vehicle has an additional summing and / or selection transmission that is connected downstream of the two drive devices and that is intended to connect both drive devices to a single drive axle.
[0019] The drive device includes an electric motor. 10a , an axle drive 11a and one between the electric motor 10a and the axle drive 11a arranged multi-stage gearbox 12a (cf.) Fig. 2) The electric motor 10a It can be a permanent magnet synchronous machine or a permanent magnet asynchronous machine. The multi-stage gearbox 12a is designed for switching between two forward gears V1a , V2a planned. The multi-stage transmission 12ais designed to switch between exactly two differently geared forward gears V1a , V2a planned. The multi-stage transmission 12a features three planetary gear stages P1a , P2a , P3a up. The multi-stage transmission 12a It has exactly three interconnected planetary gear stages. P1a , P2a , P3a up. The multi-stage transmission 12a has a main axis of rotation to which the first planetary gear stage is connected P1a , the second planetary gear stage P2a and the third planetary gear stage P3a are arranged coaxially. The planetary gear stages P1a , P2a , P3a each feature a sun wheel P11a , P21a , P31a , a hollow gear P13a , P23a , P33a and a planetary gear carrier P12a , P22a , P32a up. The multi-stage transmission 12aIt is designed to have exactly two differently geared forward gears. V1a , V2a to shift gears. A number of the forward gears actually used V1a , V2a may be restricted depending on an operating strategy, for example electronically by a correspondingly programmed control unit.
[0020] The multi-stage transmission 12a has two switching units S1a , S2a up. The multi-stage transmission 12a has exactly two switching units S1a , S2a on, which are used to shift the forward gears V1a , V2a are planned. The multi-stage transmission 12a a gearbox housing 15a that the planetary gear stages P1a , P2a , P3a and the switching units S1a , S2a records. The switching units S1a , S2aare effectively within a range defined by the planetary gear stages P1a , P2a , P3a arranged in a formed gear set, i.e., the switching units S1a , S2a are designed to create different functional connections between the planetary gear stages P1a , P2a , P3a among themselves and the gearbox housing 15a to produce the switching units S1a , S2a Each has two coupling elements that can be connected to each other in a rotationally fixed manner. S11a , S12a , S21a , S22a on.
[0021] The in Fig. The circuit diagram shown in section 3 illustrates how closing the switching units S1a , S2a the forward gears V1a , V2a to be shifted. The forward gears V1a , V2a are each activated by closing one of the two switching units S1a , S2ashifted. A power shift between the two forward gears. V1a , V2a This is particularly possible whenever at most one of the switching units is involved in a switching operation. S1a , S2a is closed and / or at most one of the switching units S1a , S2a is opened, i.e., when a power flow from one of the switching units S1a , S2a to another of the switching units S1a , S2a is transferred or when a switching state is only one of the switching units S1a , S2a is changed. The two forward gears V1a , V2a are fully load-switchable with each other.
[0022] The first forward gear V1a is designed as a creeper and / or heavy-duty gear. The first forward gear V1a It should enable trailer operation. Furthermore, the first forward gear is... V1adesigned for creeping operations to power the electric motor 10a or to protect power electronics from overheating. The second forward gear V2a It is intended for normal operation. Preferably, the forward gears can be used. V1a , V2a depending on the direction of rotation of the electric motor 10a It can be used for both forward and reverse travel.
[0023] The multi-stage transmission 12a connects the electric motor 10a with the axle drive 11a of the motor vehicle. By means of the multi-stage transmission. 12a Can a gear ratio between the electric motor 10a and the axle drive 11a be changed. The multi-stage transmission 12a a transmission input element 13a up. The transmission input element 13a It serves to securely attach the electric motor. 10a The transmission input element 13ais intended to be used by the electric motor 10a output drive torque into the multi-stage gearbox 12a to initiate. The electric motor 10a comprises a rotor which, in the illustrated embodiment, is permanently fixed to the gearbox input element in a rotationally fixed manner. 13a is connected. The transmission input element 13a It can be designed in different ways, such as a shaft or a flange.
[0024] Furthermore, the multi-stage transmission 12a a transmission output element 14a up. The transmission output element 14a It serves for the rotationally fixed connection of the axle drive. 11a The transmission output element 14a is intended to generate a drive torque from the multi-stage gearbox 12a to divert. The axle drive 11a features a transfer case whose input is permanently rotationally fixed to the transmission output element 14ais connected. The transmission output element 14a Different modules can be connected downstream, by means of which the output from the multi-stage gearbox can be modified. 12a The output torque can be distributed to the drive wheels, such as in an all-wheel drive module that distributes the drive torque to two different drive axles. The transmission output element 14a It can be designed in different ways, such as a shaft, a spur gear, or a pinion. In particular, it is also conceivable that the transmission output element... 14a It is permanently and non-rotatably connected to an axle shaft and / or a drive wheel. For example, the motor vehicle may have two of these drive devices, each acting directly on a drive wheel of the motor vehicle.
[0025] The transmission input element 13a and the transmission output element 14aare arranged coaxially to the main axis of rotation. The gearbox input element 13a defines a [something] for the electric motor 10a Facing side. For the transmission output element 14a Fundamentally different arrangements are conceivable in the axial direction. In the multi-stage gearbox shown, 12a are the planetary gear stages P1a , P2a , P3a between the transmission input element 13a and the transmission output element 14a arranged P1a , P2a , P3a possible, where the transmission output element 14a between two of the planetary gear stages P1a , P2a , P3a is arranged. The planetary gear stages P1a , P2a , P3a are arranged one behind the other in the axial direction. For the redesign of the multi-stage transmission. 12a Is it possible to determine the sequence of the planetary gear stages? P1a , P2a , P3a to change along the main axis of rotation. The multi-stage gearbox 12a It has three levels in which the planetary gear stages P1a , P2a , P3a are arranged. A numbering of the levels corresponds to a sequence of levels, which are subsequently applied to the transmission input element. 13a is related. The first level has a smaller distance to the electric motor. 10a on as the third level.
[0026] The first planetary gear stage P1a is arranged along the main axis of rotation in the first plane. The first planetary gear stage P1a features a single planetary gear set and includes the sun gear P11a , the hollow gear P13a and the planetary gear carrier P12a. The planetary gear carrier P12a planetary gears P14a on a circular path. The planetary gears P14a combing with the sun wheel P11a and with the ring gear P13aThe planetary gears P14a are rotatable on the planetary gear carrier P12a stored.
[0027] The second planetary gear stage P2a is arranged along the main axis of rotation in the second plane. The second planetary gear stage P2a is along the main axis of rotation on one of the transmission input elements 13a far side of the first planetary gear stage P1a arranged. The second planetary gear stage P2a features a single planetary gear set and includes the sun gear P21a , the hollow gear P23a and the planetary gear carrier P22a The planetary gear carrier P22a planetary gears P24a on a circular path. The planetary gears P24a combing with the sun wheel P21a and with the ring gear P23a The planetary gears P24a are rotatable on the planetary gear carrier P22a stored.
[0028] The third planetary gear stage P3ais arranged along the main axis of rotation in the third plane. The third planetary gear stage P3a is along the main axis of rotation on one of the transmission input elements 13a far side of the second planetary gear stage P2a arranged. The third planetary gear stage P3a features a single planetary gear set and includes the sun gear P31a , the hollow gear P33a and the planetary gear carrier P32a The planetary gear carrier P32a planetary gears P34a on a circular path. The planetary gears P34a combing with the sun wheel P31a and with the ring gear P33a The planetary gears P34a are rotatable on the planetary gear carrier P32a stored.
[0029] The two switching units S1a , S2a are designed as brakes. The switching units S1a , S2a Each has a rotatably mounted coupling element. S11a, S21a and a housing-mounted coupling element S12a , S22a up. The switching units S1a , S2a are each designed to have their rotatably mounted coupling element S11a , S21a rotationally fixed to the gearbox housing 15a to connect. Each of the rotatably mounted coupling elements S11a , S21a the switching units S1a , S2a is with at least one of the sun wheels P11a , P21a , P31a , one of the planetary gear carriers P12a , P22a , P32a and / or one of the hollow gears P13a , P23a , P33a The coupling elements are permanently and rotationally fixed to the housing. S12a , S22a the switching units S1a , S2a are permanently rotationally fixed to the gearbox housing 15a connected. Furthermore, it would be conceivable that the first switching unit S1aFor further loss reduction, it is designed as a claw switching unit. The claw switching unit can be designed with or without a synchronizing unit for further loss reduction.
[0030] To connect the planetary gear stages P1a , P2a , P3a among themselves and with the coupling elements S11a , S12a , S21a , S22a The multi-stage transmission includes 12a a plurality of gear elements 16a , 17a , 18a The gear elements 16a , 17a , 18a are designed to transmit torques and / or rotary movements within the system via the planetary gear stages P1a , P2a , P3a to support and / or transmit the designed gear set. Each of the gear elements 16a , 17a , 18a connects at least two of the sun wheels P11a , P21a , P31a , planetary gear carrier P12a , P22a , P32a , hollow gears P13a , P23a , P33a , and / or coupling elements S11a , S12a , S21a , S22a , S31a , S32a permanently rotationally fixed to each other or at least supports one of the sun wheels P11a , P21a , P31a , planetary gear carrier P12a , P22a , P32a and / or hollow gears P13a , P23a , P33a permanently against the gearbox housing 15a away.
[0031] The transmission input element 13a forms a transmission input shaft that connects to the transmission input element 13a and the sun wheel P11a the first planetary gear stage P1a connects them in a rotationally fixed manner. The gear input element 13a The formed gearbox input shaft is connected to the sun gear on the input side. P11a connected. The transmission input element 13a is permanently rotationally fixed to the sun wheel P11athe first planetary gear stage P1a tied together.
[0032] The transmission output element 14a forms a transmission output shaft that connects to the transmission output element 14a and the planetary gear carrier P32a the third planetary gear stage P3a permanently and rotationally fixedly connected. The gearbox output element 14a is permanently rotationally fixed to the planetary gear carrier P32a the third planetary gear stage P3a connected. Furthermore, the ring gear P23a the second planetary gear stage P2a and the planetary gear carrier P32a the third planetary gear stage P3a The gearbox output element is permanently and rotationally fixed together. 14a is thus via the planetary gear carrier P32a the third planetary gear stage P3a permanently rotationally fixed to the ring gear P23a the second planetary gear stage P2a connected. The one through the transmission output element 14aThe designed transmission output shaft serves as a planetary gear carrier P32a through the third planetary gear stage P3a led through to the hollow gear P23a the second planetary gear stage P2a .
[0033] The planetary gear carrier P22a the second planetary gear stage P2a and the ring gear P33a the third planetary gear stage P3a are permanently and rotationally fixed to each other. The first gear element 16a forms an intermediate shaft that supports the planetary gear carrier P22a the second planetary gear stage P2a , the first coupling element S11a the first switching unit S1a and the ring gear P33a the third planetary gear stage P3a permanently and rotationally fixedly connected to each other. The gear element 16a The intermediate shaft, in particular, encloses the second planetary gear stage. P2a The first switching unit S1a is intended to be the ring gear P33a the third planetary gear stage P3a to be mounted securely to the housing. Furthermore, the first switching unit S1a intended to be the planetary gear carrier P22a the second planetary gear stage P2a to be permanently mounted to the housing. The first coupling element S11a the first switching unit S1a is permanently rotationally fixed to the first gear element 16a and thus also with the planetary gear carrier P22a the second planetary gear stage P2a and the ring gear P33a the third planetary gear stage P3a tied together.
[0034] The planetary gear carrier P12a the first planetary gear stage P1a and the sun wheel P31a the third planetary gear stage P3a are permanently and rotationally fixed to each other. The second gear element 17a forms an intermediate shaft that supports the planetary gear carrier P12a the first planetary gear stage P1a and the sun wheel P31athe third planetary gear stage P3a permanently and rotationally fixedly connected to each other. The gear element 17a The formed intermediate shaft passes through the second planetary gear stage P2a .
[0035] The ring gear P13a the first planetary gear stage P1a and the sun wheel P21a the second planetary gear stage P2a are permanently and rotationally fixed to each other, or at least can be rotationally fixed to each other. The ring gear P13a the first planetary gear stage P1a and the sun wheel P21a the second planetary gear stage P2a are permanently and rotationally fixed to each other. Furthermore, the second switching unit S2a intended to be the hollow gear P13a the first planetary gear stage P1a to be mounted securely to the housing. Furthermore, the second switching unit S2a intended to be the sun wheel P22a the second planetary gear stage P2ato be fixed to the housing. The third gear element 18a forms an intermediate shaft that connects to the ring gear P13a the first planetary gear stage P1a , the first coupling element S21a the second switching unit S2a and the sun wheel P21a the second planetary gear stage P2a permanently and rotationally fixedly connected to each other. The gear element 19a The intermediate shaft is positioned between the planetary gear stages. P1a , P2a guided radially inwards.
[0036] The first switching unit S1a is at the level of the second planetary gear stage P2a arranged. By the first coupling element S11a the first switching unit S1a to the first transmission element designed as an intermediate shaft 16a is connected, a position of the switching unit can be determined. S1a The second switching unit can generally be varied along the main axis of rotation. S2a is at the level of the first planetary gear stage P1a arranged. In principle, a different spatial arrangement of the switching units is also possible. S1a , S2a , S3a possible.
[0037] The switching units S1a , S2a are externally mounted, i.e., an actuator supply for the switching units S1a , S2a This can be implemented without routing operating lines, using a rotatably mounted component. The switching units S1a , S2a are hydraulically operated.
[0038] In the described configuration, the axle drive 11a the differential gear, whose outputs are coaxial to the main axis of rotation of the multi-stage transmission 12a are arranged. In the described configuration, the axle drive comprises 11aFurthermore, two axle shafts are provided for driving the drive wheels of a drive axle. In an advantageous embodiment, the axle drive features 11a a main axis of rotation that is coaxial with the main axis of rotation of the multi-stage gearbox 12a is arranged. Preferably, one of the axle shafts passes through at least the transmission input element. 13a and the electric motor 10a The axle drive 11a has an axle shaft that connects to the transmission input element 13a , the transmission output element 14a and the electric motor 10a pervasive. In particular, it is possible to control the axle drive. 11a at least partially into the multi-stage transmission 12a to integrate. A nesting of the multi-stage gearbox. 12a and the axle drive 11a depends in particular on the position of the differential gear along the main axis of rotation of the multi-stage transmission. 12aoff. Is the differential gear between the transmission input element 13a and the transmission output element 14a Arranged, one of the axle shafts passes through the transmission input element. 13a and the electric motor 10a , while the other axle shaft drives the transmission output element 14a permeated. Is the differential gear of the axle drive 11a Arranged on the transmission output side, preferably one of the axle shafts passes through the transmission output element. 14a , the transmission input element 13a and the electric motor 10a . Also in a configuration in which the axle drive 11a If it is intended for a direct connection of only one drive wheel, it is conceivable to use the gearbox output element 14a in the form of an internal shaft through the transmission input element 13a and the electric motor 10a to pass through, whereby the electric motor 10abetween the drive wheel and the multi-stage gearbox 12a is arranged.
[0039] In the Fig. Figure 4 shows a further embodiment of the invention. The following descriptions are essentially limited to the differences between the embodiments, whereby with regard to components, features and functions that remain the same, reference is made to the description of the embodiment of Figure 4. Fig. 1 to Fig. 3 can be referenced. To distinguish the embodiments, the letter a in the reference numerals of the embodiment is in the Fig. 1 to Fig. 3 by the letter b in the reference numerals of the embodiment of the Fig. 4 replaced. With regard to identically designated components, in particular with regard to components with the same reference numerals, reference can generally also be made to the drawings and / or the description of the embodiment of the Fig. 1 to Fig. 3 are referred.
[0040] Fig. Figure 4 shows, as a second embodiment, a gear diagram of a multi-stage gearbox. 12b for a drive device with an electric motor and an axle drive. The multi-stage gearbox 12b The design is at least intended for the switching of two forward gears. The transmission scheme is structurally identical to that of the preceding embodiment.
[0041] The multi-stage transmission 12b includes a transmission input element 13b for the rotationally fixed connection of the electric motor and a gearbox output element 14b for the rotationally fixed connection of the axle drive. The multi-stage gearbox also includes 12b a gear set with a first planetary gear stage P1b , a second planetary gear stage P2b and a third planetary gear stage P3b , each of which is a sun wheel P11b , P21b , P31b , a hollow gear P13b , P23b , P33b and a planetary gear carrier P12b , P22b , P32b , which planetary gears P14b , P24b , P34b in a circular path around the corresponding sun wheel P11b , P21b , P31b leads to, exhibit. Furthermore, the multi-stage transmission includes 12b two switching units S1b , S2b , each of which has two coupling elements S11b , S12b , S21b , S22b exhibit. For the transmission of power flows between the planetary gear stages. P1b , P2b , P3b and / or for support against a gearbox housing 15b The multi-stage transmission includes 12b a plurality of gear elements 16b , 17b , 18b .
[0042] The multi-stage transmission 12b differs particularly in the arrangement of the planetary gear stages P1b , P2b , P3b from the previous embodiment. The multi-stage transmission 12b It has two levels in which the planetary gear stages P1b , P2b , P3b are arranged. The planetary gear stages P1b , P2b are arranged in a stacked fashion. The planetary gear stage P3b is located on the second level.
[0043] The first planetary gear stage P1b is radial within the second planetary gear stage P2b arranged. The ring gear P13b the first planetary gear stage P1b and the sun wheel P21b the second planetary gear stage P2b can be manufactured as a single piece. The switching units S1b , S2b are on the input side of the planetary gear stages P1b , P2b arranged. The switching units S1b , S2b are designed to be external.
[0044] The multi-stage transmission 12bIt exhibits particularly good stackability, which offers significant potential for space optimization. Furthermore, it would also be conceivable, for example, to stack the second planetary gear stage. P2b to be designed as a double planetary gear set. It would be conceivable that the ring gear P23b the second planetary gear stage P2b permanently rotationally fixed to the ring gear P333b the third planetary gear stage P3b is connected. The planetary gear carrier P24b the second planetary gear stage P2b could thereby be permanently rotationally fixed to the planetary wheel carrier P34b the second planetary gear stage P3b be connected. Furthermore, it would also be conceivable, for example, to connect the second planetary gear stage. P2b and the third planetary gear stage P3b to be performed together as a Ravigneaux set. Furthermore, the multi-stage gearbox could 12b are arranged stacked, with the first planetary gear stage P1b and the Ravigneaux set from the second planetary gear stage P2b and the third planetary gear stage P3b They are arranged in stacked positions. The first planetary gear stage P1b The first shifting unit could be arranged radially within the Ravigneaux set. It could be designed to fix the ring gear of the Ravigneaux set to the housing. The transmission output element, on the other hand, could be permanently and rotationally fixed to the planet carrier of the Ravigneaux set. The ring gear P13b the first planetary gear stage P1b and the first sun wheel of the Ravigneaux set can be made in one piece. Reference symbol list 10 Electric motor 11 axle drive 12 multi-stage gearboxes 13 Gearbox input element 14 Gearbox output element 15 Gearbox housings 16 Gear element 17 Gear element 18 Gear element P1 planetary gear stage P11 Sun wheel P12 Planetary gear carrier P13 Ring gear P14 planetary gears P2 planetary gear stage P21 Sun wheel P22 Planetary gear carrier P23 ring gear P24 planetary gears P3 planetary gear stage P31 Sun wheel P32 Planetary gear carrier P33 ring gear P34 planetary gears S1 switching unit S11 coupling element S12 coupling element S2 switching unit S21 coupling element S22 coupling element V1 forward gear V2 forward gear QUOTES INCLUDED IN THE DESCRIPTION
[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. 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
[0000] WO 2015 / 169837 A1
[0002]
Claims
[1] Drive device, in particular for an electric vehicle, comprising at least one electric motor (10a), at least one axle drive (11a) and a multi-stage transmission (12a; 12b) arranged between the electric motor (10a) and the axle drive (11a), comprising three interconnected planetary gear stages (P1a, P2a, P3a; P1b, P2b, P3b) each with a sun gear (P11a, P21a, P31a; P11b, P21b, P31b), a ring gear (P13a, P23a, P33a; P13b, P23b, P33b) and a planet carrier (P12a, P22a, P32a; P12b, P22b, P32b), two switching units (S1a, S2a; S1a, S2a) each with two rotationally fixed connecting coupling elements (S11a, S12a, S21a, S22a; S11b, S12b, S21b, S22b), a gear input element (13a; 13b) for rotationally fixed connection of the electric motor (10a) and a gear output element (14a; 14b) for rotationally fixed connection of the axle drive (11a), wherein the gear input element (13a; 13b) is permanently rotationally fixed to the sun gear (P11a;P11b) of the first planetary gear stage (P1a; P1b), the transmission output element (14a; 14b) is permanently non-rotatably connected to the planet carrier (P32a; P32b) of the third planetary gear stage (P3a; P3b), and the planet carrier (P12a; P12b) of the first planetary gear stage (P1a; P1b) and the sun gear (P31a; P31b) of the third planetary gear stage (P3a; P3b) are permanently non-rotatably connected to each other; characterized by , that the ring gear (P23a; P23b) of the second planet gear stage (P2a; P2b) and the planet gear carrier (P32a; P32b) of the third planet gear stage (P3a; P3b) are permanently connected to each other in a rotationally fixed manner. [2] Drive device according to claim 1, characterized by , that the ring gear (P13a; P13b) of the first planetary gear stage (P1a; P1b) and the sun gear (P21a; P21b) of the second planetary gear stage (P2a; P2b) are permanently connected to each other in a rotationally fixed manner or can be connected to each other in a rotationally fixed manner. [3] Drive device according to one of the preceding claims, characterized by , that the first switching unit (S1a; S1b) is intended to fix the ring gear (P33a; P33b) of the third planetary gear stage (P3a; P3b) to the housing. [4] Drive device according to one of the preceding claims, characterized by , that the planet carrier (P22a; P22b) of the second planet gear stage (P2a; P2b) and the ring gear (P33a; P33b) of the third planet gear stage (P3a; P3b) are permanently connected to each other in a rotationally fixed manner. [5] Drive device according to one of the preceding claims, characterized by , that the second switching unit (S2a; S2b) is intended to fix the ring gear (P13a; P13b) of the first planetary gear stage (P1a; P1b) to the housing. [6] Drive device according to one of the preceding claims, characterized by , that the axle drive (11a) has at least one axle shaft that passes through the transmission input element (13a; 13b), the transmission output element (14a; 14b) and / or the electric motor (10a). [7] Drive device according to one of the preceding claims, characterized by , that the first switching unit (S1a; S1b) is intended to mount the planet carrier (P22a; P22b) of the second planet stage (P2a; P2b) in a housing-fixed manner. [8] Drive device according to one of the preceding claims, characterized by , that the second switching unit (S2a; S2b) is intended to mount the sun gear (P22a; P22b) of the second planetary gear stage (P2a; P2b) in a housing-fixed manner. [9] Electric vehicle with a drive device according to any of the preceding claims.