DE102022202914A1 - Gearbox for a drive device - Google Patents

Abstract

The invention relates to a transmission (4) for a drive device (2) of an at least partially electrically driven vehicle (1), comprising a transmission input shaft (6) with a first gear (Z1), an intermediate shaft (5) with a second gear (Z2) and a third gear (Z3) arranged axially adjacent thereto, and a differential input shaft (8) of a differential (7) with a fourth gear (Z4), the first and second gears (Z1, Z2) having a first gear ratio (9) and that The third and fourth gears (Z3, Z4) form a second gear ratio (10), the transmission input shaft (6) or the intermediate shaft (5) or the differential input shaft (8) being mounted in an axially fixed manner and the other two shafts (5, 6, 8) are floatingly mounted, with a first pressure comb (DK1) and a second pressure comb (DK2) being effectively formed between the gears (Z1, Z2) of the first gear ratio stage (9), with between the gears (Z3, Z4) of the second gear ratio stage (10 ) a third pressure comb (DK3) and a fourth pressure comb (DK4) are designed to be effective.

Description

The invention relates to a transmission for a drive device for an at least partially electrically driven vehicle. The invention further relates to a drive device with such a transmission and to an at least partially electrically driven vehicle with such a drive device.

Electric axle drives with a one-piece rotor shaft, which can be formed in one piece with the transmission input shaft, and a one-piece intermediate shaft are known from the prior art, the intermediate shaft being operatively connected to a differential, which divides the drive power between two output shafts. The intermediate shaft is arranged axially parallel in the power flow between the rotor shaft and the differential, with the drive power of an electric machine being transmitted to the respective output shaft via the rotor shaft, the intermediate shaft and the differential. The one-piece rotor shaft is statically overdeterminedly mounted via a first, second and third bearing element. The second bearing element, which is arranged axially between the pinion and the electrical machine, is a fixed bearing which, due to assembly, has a comparatively large diameter, in particular larger than the pinion. The first and third bearing elements of known axle drives are floating bearings with a spring-loaded outer ring. The intermediate shaft, which is also one-piece, is mounted on a fourth and fifth bearing element, each of which is an angular contact ball bearing. The differential divides the drive power between two output shafts, with each of the output shafts being mounted with a preloaded tapered roller bearing relative to a housing.

From the DE 102014207431 A1 a gear with at least one pressure comb is also known, the gear having an axis of rotation. A toothing extends along a circumferential direction of the gear, with the pressure comb being arranged axially next to the toothing. The gear consists of at least 80% weight. made of a base material, the pressure comb being formed in one piece with the base material.

The object of the present invention is to propose an efficient, quiet and space-saving transmission for a drive device. In particular, losses should be reduced. This task is achieved with a transmission according to independent claims 1. Advantageous refinements result from the dependent claims.

A transmission according to the invention for a drive device of an at least partially electrically driven vehicle comprises a transmission input shaft with a first gear, an intermediate shaft with a second gear and a third gear arranged axially adjacent thereto, and a differential input shaft of a differential with a fourth gear, the first and second Gear forms a first gear ratio and the third and fourth gears form a second gear ratio, the transmission input shaft or the intermediate shaft or the differential input shaft being mounted in an axially fixed manner and the other two shafts being mounted in a floating manner, with a first pressure comb and a second pressure comb between the gears of the first gear ratio are effectively designed, wherein the first pressure comb comprises a first pressure disk which is arranged in a rotationally fixed manner on one of the gears of the first transmission stage and is axially supported thereon, wherein the first pressure disk has a first counter surface which is designed to be in traction or thrust operation of the transmission to come into contact with a second counter-surface formed on the other of the two gears of the first transmission stage for absorbing gearing axial forces, a third pressure comb and a fourth pressure comb being effectively formed between the gears of the second transmission stage, the third pressure comb comprising a second pressure disk, which is arranged in a rotationally fixed manner on one of the gears of the second gear ratio and is axially supported thereon, the second pressure disk having a third counter-surface which is designed to, in the pulling or pushing operation of the transmission, with a fourth one formed on the other of the two gears of the second gear ratio Counter surface to come into contact to absorb gear axial forces.

The transmission input shaft is designed to be at least indirectly connected in a rotationally fixed manner to a rotor shaft of an electric machine. The transmission input shaft is designed in particular to be axially displaceable against the rotor shaft and coupled to it in a spring-loaded manner. Alternatively, the transmission input shaft can be connected to the rotor shaft via an articulated shaft coupling. The rotor shaft and the transmission input shaft are arranged coaxially to one another and axially parallel to the output shafts of the transmission, the intermediate shaft and the differential input shaft.

The drive power from the electric machine is introduced into the differential via the differential input shaft. The differential input shaft is preferably a shaft of the differential which is connected in a rotationally fixed manner to the fourth gear. The differential input shaft can be designed as a differential basket of the differential, which contains the interacting differentials absorbs profitable elements. The output shafts are designed to transmit the drive power divided by the differential to wheels that are effectively connected to drive the vehicle. The output shafts are preferably arranged radially within the differential input shaft and passed axially through the differential input shaft.

An axially parallel arrangement of the shafts is to be understood as meaning a substantially parallel arrangement of the longitudinal axes of the shafts, in which even a slight deviation from an exactly parallel arrangement of the components of the drive device or the axes of the shafts to one another is still an axially parallel arrangement and therefore falls within the protected area the invention falls. In other words, for example, the rotor shaft and the transmission input shaft or the intermediate shaft and the differential input shaft can also be arranged slightly inclined to one another.

The rotor shaft of the electric machine serves as an output shaft in rotor or traction operation. The rotor shaft is at least indirectly connected in a rotationally fixed manner to the transmission input shaft, with the first gear being arranged in a rotationally fixed manner on the transmission input shaft. The transmission input shaft is therefore to be understood as a pinion shaft.

When the electric machine is in traction, for example, electrical energy is fed into the electric machine from an energy storage device, in particular a battery, which, as a result of the current supply, causes the rotor or the rotor shaft to rotate, the drive power being provided for the rotational drive of the first gear. The output shafts of the drive device each function as the output shaft of the differential and are connected to the differential input shaft in a driving manner. The differential is designed, for example, as a bevel gear differential or the like.

In generator operation of the electric machine or in overrun mode of the transmission, the respective output shaft of the transmission functions at least indirectly as an input shaft of the drive device or of the transmission, whereas the transmission input shaft is operated accordingly as an output shaft of the transmission. The rotor shaft serves as the input shaft of the electrical machine in overrun mode. The vehicle's drive power is fed into the electric machine via the transmission, so that electrical energy can be generated with the electric machine and fed into a battery for storage. In generator operation, the drive power is introduced, for example, from one or more rotating wheels of the vehicle via the transmission into the electric machine.

The term “at least indirectly” means that two components are connected to one another via at least one further component that is arranged between the two components or are directly and therefore directly connected to one another. Therefore, further components can be arranged between shafts or gears, which are operatively connected to the shaft or gear.

An “active connection” or “drive-effective connection” is understood to be a connection between two torque-carrying parts that allows torque or power to be transmitted between these parts. In particular, both parts are mounted so that they can rotate accordingly. Connections that have a driving effect include those that do not have a gear ratio or intermediate components, as well as those that have a gear ratio or intermediate components. For example, further shafts and/or gears can be arranged to have a driving effect between two shafts or two gears.

A connection means that the two elements to be connected are permanently connected to one another in a rotationally fixed manner. Alternatively, but if necessary, they can be connected to one another in a rotationally fixed manner. In the present case, a non-rotatable connection means that the elements connected in this way rotate at a speed that is proportional to one another. A non-rotatable connection in the sense of this invention cannot be switched.

For the purposes of the invention, a shaft, be it a rotor shaft, an output shaft, a transmission input shaft, an intermediate shaft or the like, is to be understood as meaning a rotatable component of the drive device for transmitting torque, via which associated components of the drive device are connected to one another in a rotationally fixed manner.

The rotor shaft is mounted on a housing of the electrical machine via a fixed bearing. Thanks to the two-part design, the gearbox input and rotor shaft combination is statically supported. As a result, the bearing elements of the transmission input shaft can be designed with a smaller diameter that is optimal in terms of service life, whereby the assembly does not have to be carried out via the teeth of the first gear because of the shafts that are only subsequently coupled to one another or because of the split input shaft.

Pressure combs are arranged on the gears of the transmission to absorb gear axial forces. The pressure combs are intended to absorb the axial gearing forces directly at the tooth mesh so that they do not over the shafts and the fixed bearings must be inserted into the housing walls. As a result, floating bearings can be realized for two of the three elements from the group of transmission input shaft, intermediate shaft and differential input shaft and the bearing elements that support the shafts can be made slimmer, in particular smaller. This in turn can reduce transmission losses. According to a first exemplary embodiment, the differential input shaft is mounted in an axially fixed manner via a fixed bearing, with the transmission input shaft and the intermediate shaft being mounted in a floating manner. According to a second exemplary embodiment, the transmission input shaft is mounted in an axially fixed manner via a fixed bearing, with the differential input shaft and the intermediate shaft being mounted in a floating manner. According to a third exemplary embodiment, the intermediate shaft is mounted in an axially fixed manner via a fixed bearing, with the differential input shaft and the transmission input shaft being mounted in a floating manner.

The gear axial forces result from the magnetic field of the electric machine, with all gear axial forces in pulling and pushing operation being absorbed directly on the gear rims of the pinion and the gears by the pressure combs. The pressure combs therefore absorb axial forces and introduce acoustic stimuli from the teeth directly into the housing. The transmission proposed here allows a drive to be designed very efficiently and quietly.

The respective transmission stage is preferably designed as a pair of spur gears with helical gears, the second gear of the first transmission stage and the third gear of the second transmission stage being arranged axially adjacent, in particular axially spaced from one another, on the intermediate shaft in a rotationally fixed manner. The first transmission stage forms a first pair of helical spur gears. The second transmission stage forms a second pair of helical spur gears.

By forming, on the one hand, an easy-to-produce pressure washer with a counter-running surface molded onto it and, on the other hand, a counter-running surface formed on the respective gear, the additional effort for producing the pressure combs can be minimized, because the pressure combs, with the exception of the pressure washers, are manufactured integrally on existing elements of the transmission. With a gear designed in this way, the efficiency of the gear can be increased. In particular, a low-noise axle drive can be achieved. This allows the range of an at least partially electrically powered vehicle to be increased with the same battery capacity.

The first pressure washer with the first counter surface can be arranged in a rotationally fixed manner on the first gear, which is arranged in a rotationally fixed manner on the transmission input shaft, and can be axially supported thereon, the second counter surface correspondingly being formed on the second gear, in particular integrally formed thereon. The first gear on the transmission input shaft is to be understood as the pinion of the transmission. The first pressure comb is therefore formed on the first gear and the second pressure comb on the second gear. Alternatively, the first pressure washer can be arranged in a rotationally fixed manner with the first counter-running surface on the second gear, which is arranged in a rotationally fixed manner on the intermediate shaft, and can be axially supported thereon, the second counter-running surface being correspondingly formed on the first gear, in particular integrally formed thereon. In this case, the first pressure comb is formed on the second gear and the second pressure comb on the first gear. Axial forces that result from the helical gearing between the pinion or the first gear and the second gear of the first transmission stage are supported either via the first pressure comb or the second pressure comb, depending on the direction of the power flow.

The second pressure washer with the third counter surface can be arranged in a rotationally fixed manner on the third gear, which is arranged in a rotationally fixed manner on the intermediate shaft, and can be axially supported thereon, the fourth counter surface being correspondingly formed on the fourth gear, in particular integrally formed thereon. The third pressure comb is therefore formed on the third gear and the fourth pressure comb on the fourth gear. Alternatively, the second pressure washer can be arranged in a rotationally fixed manner with the third counter surface on the fourth gear, which is arranged in a rotationally fixed manner on the differential input shaft, and can be axially supported thereon, the fourth counter surface being correspondingly formed on the third gear, in particular integrally formed thereon. In this case, the third pressure comb is formed on the fourth gear and the fourth pressure comb is formed on the third gear. Axial forces that result from the helical gearing between the third gear and the fourth gear of the second transmission stage are supported either via the third pressure comb or the fourth pressure comb, depending on the direction of the power flow.

The respective pressure washer is a separate component and is preferably annular, in particular annular disk-shaped. The respective pressure washer is designed to be axially short. The separate pressure washers are intended to place the pressure point of the pressure combs on the radius that corresponds to the operating pitch circle of the teeth of the respective gear. The advantage of this measure is to reduce differential speeds in the contact zone of the pressure comb avoid and thus achieve the best possible efficiency of the printing combs.

Preferably, the second counter surface is formed on a substantially radially extending first receiving section of the respective gear of the first transmission stage, with a fifth counter surface being formed on an end face of the first receiving section opposite the second counter surface, which is designed to form the second pressure chamber in pushing or pulling operation of the transmission, to come into contact with a sixth counter-surface for absorbing gearing axial forces, the sixth counter-surface being supported at least indirectly axially on that shaft on which the respective gear with the first pressure disk arranged thereon in a rotationally fixed manner is arranged in a rotationally fixed manner. In other words, the second counter surface and the fifth counter surface are integrally formed on opposite end faces on the first receiving section of the respective gear of the first transmission stage. The first pressure comb is formed by the first and second counter surfaces. The second pressure comb is formed by the fifth and sixth counter surfaces. If the first pressure washer is arranged in a rotationally fixed manner on the first gear and is axially supported, the sixth counter surface is at least indirectly axially supported on the transmission input shaft. In particular, the sixth counter surface is integrally formed on the transmission input shaft. If the first pressure washer is arranged in a rotationally fixed manner on the second gear and is axially supported, the sixth counter surface is at least indirectly axially supported on the intermediate shaft. The first receiving section is preferably arranged axially between the first counter-surface on the first thrust washer and the sixth counter-surface.

According to one exemplary embodiment, the transmission comprises a parking lock wheel which is connected in a rotationally fixed manner to the first gear, with the sixth counter surface being formed on the parking lock wheel to form the first pressure chamber. In other words, the parking lock wheel is arranged in a rotationally fixed manner together with the first gear on the transmission input shaft. The parking lock wheel is particularly pressed onto the transmission input shaft. When pulling or pushing, the respective gear wheel with the receiving section is supported axially on the parking lock wheel to transmit the toothing axial forces. It is also conceivable to arrange the parking lock wheel in a rotationally fixed manner on the intermediate shaft or on the differential input shaft. The mode of operation can be analogous to the transmission input shaft.

If the first pressure comb with the first and second counter-running surfaces transmits gearing axial forces in a pulling operation, the second pressure comb with the fifth and sixth counter-running surfaces is intended to transmit gearing axial forces in a pushing operation, or vice versa.

The fourth counter surface is preferably formed on a substantially radially extending second receiving section of the respective gear of the second transmission stage, with a seventh counter surface being formed on an end face of the second receiving section opposite the fourth counter surface, which is designed to form the fourth pressure chamber Push or pull operation of the transmission to come into contact with an eighth counter surface for absorbing gearing axial forces, the eighth counter surface being supported at least indirectly axially on the shaft on which the respective gear with the second pressure disk arranged thereon in a rotationally fixed manner is arranged in a rotationally fixed manner. In other words, the fourth counter surface and the seventh counter surface are integrally formed on opposite end faces on the second receiving section of the respective gear of the second transmission stage. The third pressure comb is formed by the third and fourth counter surfaces. The fourth pressure comb is formed by the seventh and eighth counter surfaces. If the second pressure washer is arranged in a rotationally fixed manner on the third gear and is axially supported, the eighth counter surface is at least indirectly axially supported on the intermediate shaft. If the second pressure washer is arranged in a rotationally fixed manner on the fourth gear and is axially supported, the eighth counter surface is at least indirectly axially supported on the differential input shaft. The second receiving section is preferably arranged axially between the third counter-surface on the second thrust washer and the eighth counter-surface. The eighth counter surface can be formed on a section of the intermediate shaft. Alternatively, the eighth counter surface can be integrally formed on the second gear, so that the fourth gear with the second receiving section can come into axial contact with the second gear for transmitting gear axial forces in push or pull operation of the transmission.

The counter-running surfaces of the respective pressure comb each function as a contact surface, with two counter-running surfaces forming a pair of counter-running surfaces of the respective pressure comb, with the counter-running surfaces of the respective counter-running surface pair coming into contact with one another depending on the operating state of the transmission. The operating state is to be understood as the traction operation and the overrun operation of the transmission.

Depending on the arrangement and design of the first and second pressure chambers the third pressure comb with the third and fourth counter-running surfaces can be designed to also transmit toothing axial forces in pulling operation, wherein the fourth pressure comb with the seventh and eighth counter-running surfaces can be designed to transmit toothing axial forces in pushing operation, or vice versa. In any case, one of the pressure combs between the transmission input shaft and the intermediate shaft and one of the pressure combs between the intermediate shaft and the differential input shaft transmit gearing axial forces during traction operation, with the other pressure comb between the transmission input shaft and the intermediate shaft and the other pressure comb between the intermediate shaft and Gear axial forces are transmitted to the differential input shaft. In other words, the transmission has two traction pressure combs and two thrust pressure combs.

The respective receiving section is formed on the gear rim of the respective gear and is preferably arranged at a distance from the gear rim in order to ensure a uniform production of the teeth of the respective gear. However, the distance is chosen to be as small as possible in order to save axial length. The toothing of the gears can be produced, for example, using a so-called scudding process or using power honing.

Preferably, the first pressure washer is arranged in a circumferential first groove on the outer circumference of the respective gear of the first transmission stage, which has the first receiving section, the first groove being formed axially between the first receiving section and a ring gear of the respective gear of the first transmission stage. The axial distance between the first receiving section and the ring gear of the respective gear of the first transmission stage is determined via the axial extent of the groove. The first groove is designed in such a way that, depending on the operating state, the first receiving section can move axially between the first pressure disk with the first counter-running surface and the sixth counter-running surface in order to transmit gearing axial forces via the associated second or fifth counter-running surface in accordance with the operating state.

The second pressure washer is preferably arranged in a circumferential second groove on the outer circumference of the respective gear of the second transmission stage, which has the second receiving section, the second groove being formed axially between the second receiving section and a ring gear of the respective gear of the second transmission stage. The axial distance between the second receiving section and the ring gear of the respective gear of the second transmission stage is determined via the axial extent of the groove. The second groove is designed in such a way that, depending on the operating state, the second receiving section can move axially between the second pressure disk with the third counter-running surface and the eighth counter-running surface in order to transmit gearing axial forces via the associated fourth or seventh counter-running surface in accordance with the operating state.

The respective pressure comb or the respective receiving section can be machined at a comparatively small distance from the toothing end face of the respective gear, since the manufacturing processes mentioned, for example hard scudding or power honing, require no or only a very small tool run-out. The manufacturing processes can be used in the soft or hardened state of the respective gear.

The first and third pressure combs each form a tensile pressure comb, with the respective pressure comb absorbing or transmitting axial forces during the tensile operation of the drive device. In contrast, the second and fourth pressure combs each form a thrust pressure comb, with the respective pressure comb absorbing or transmitting axial forces during the thrusting operation of the drive device. This minimizes additional effort for efficient pressure combs through the integral design of the pressure combs, although this does not come at the expense of the efficiency of the pressure comb in pulling or pushing operation. The first and second printing combs form a first pair of printing combs, with the third and fourth printing combs forming a second pair of printing combs. Three counter-running surfaces of the respective pair of pressure combs are integrally formed on existing gears of the transmission stages, with only one of the four counter-running surfaces being formed on the separate pressure disk.

It has proven to be advantageous if one of the two counter-surfaces of the respective pressure comb has a spherical shape and the other of the two counter-surfaces of the same pressure comb has a conical shape. A spherical shape is to be understood as meaning a substantially convex shape of the respective mating surface. This avoids the formation of a pressure line when contacting the mating surfaces, which would have an unfavorable effect on the friction losses. Rather, during operation of the transmission, a pressure ellipse is generated over the circumference, with the mating surfaces only rolling against one another at a pressure point. This increases the efficiency of the transmission due to comparatively small friction surfaces. The pressure point is preferably exactly on the operating circle of the meshing gears. This ensures that only those parts of the pressure ellipse produce sliding friction losses that are located radially away from the pressure point. Sliding friction components are therefore minimized.

Preferably, the first parking lock wheel has an at least partially circumferential first channel structure, which is arranged and designed to supply the second pressure comb with coolant and/or lubricant. Preferably, the first pressure disk has an at least partially circumferential second channel structure, which is arranged and designed to supply the first pressure comb with coolant and/or lubricant. Furthermore, the second pressure disk preferably has an at least partially circumferential third channel structure, which is arranged and designed to supply the third pressure comb with coolant and/or lubricant. During operation of the gearbox, lubricant and/or coolant collects in the respective channel structure due to centrifugal forces, which enters the contact surface between the mating surfaces of the respective pair of mating surfaces when the channel structure overflows during operation of the gearbox. This further reduces sliding losses and ensures continuous lubrication and/or cooling. The channel structure is to be understood as an at least partially circumferential recess on the respective component.

Preferably, the transmission input shaft is rotatably mounted via a first bearing element and a second bearing element, the intermediate shaft being rotatably mounted via a third bearing element and a fourth bearing element, the differential input shaft being rotatably mounted via a fifth bearing element and a sixth bearing element, one of the bearing elements being a is an axial guide bearing and the other five bearing elements are a cylindrical roller bearing. The bearing elements are designed to support the respective shaft on the housing. The bearing elements can all be arranged in the main housing of the transmission. However, individual bearing elements can be integrated into cover elements of the housing. It is also conceivable to design the main housing in several parts.

For the transmission to function effectively, it is sufficient if one of the six bearing elements is an axial guide bearing. According to one embodiment, the fifth bearing element is the axial guide bearing. The entire shaft assembly is held in an axial position relative to the housing by the axial guide bearing or the fifth bearing element as a fixed bearing. An axial displacement of the respective floating shafts is prevented by the pressure combs. In one exemplary embodiment, the intermediate shaft and the transmission input shaft are mounted in a floating manner, with the differential input shaft being mounted in an axially fixed manner by means of the fifth bearing element. The first, second, third, fourth or sixth bearing element can also be the axial guide bearing or the fixed bearing instead of the fifth bearing element, with the other five bearing elements correspondingly forming the floating bearing for floating storage. According to the bearing element designed as a fixed bearing, either the transmission input shaft, the intermediate shaft or the differential input shaft is mounted axially fixed and the other two shafts are mounted floating.

Furthermore, a seventh bearing element can be provided, which is designed to support the rotor shaft relative to the housing. The seventh bearing element can also be integrated in the main housing or on a cover. The seventh bearing element is designed in particular as a fixed bearing or axial guide bearing.

The differential input shaft, the intermediate shaft and the transmission input shaft are axially guided via the axial guide bearing, with the gearing axial forces being simultaneously absorbed via the pressure combs. The axial forces to be absorbed by the guide bearing are comparatively low. In other words, the guide bearing takes over the axial guidance of the differential input shaft, the intermediate shaft and the transmission input shaft with the exception of the rotor shaft, which can be mounted on the housing via a separate bearing, in particular an axial guide bearing.

Preferably, the respective fixed bearing or the axial guide bearing is a deep groove ball bearing with a spring-loaded outer ring. The remaining bearing elements can be designed as cylindrical roller bearings that only transmit radial forces. Bearing elements designed as deep groove ball bearings each have a minimum size for reasons of service life. The storage of the respective floating shaft is more efficient thanks to the higher load-bearing cylindrical roller bearings, since cylindrical roller bearings can be made smaller compared to other bearing variants, such as deep groove ball bearings, with the same service life.

Preferably, at least one pin is formed on the respective pressure disk, which engages in a tooth gap of one of the gears of the respective transmission stage to prevent rotation. A plurality of pins distributed over the circumference can also be arranged on one end face of the respective pressure washer in order to provide anti-twist protection.

According to a further aspect of the invention, a drive device according to the invention comprises an electric machine with a rotor shaft and a transmission according to the above statements according to the first aspect of the invention. Preferably, the transmission input shaft is at least indirectly connected in a rotationally fixed manner to a rotor shaft of an electric machine. The rotor shaft can be mounted in an axially immovable, rotatable manner by means of an axial guide bearing. The transmission input shaft is axially displaceable against the rotor shaft and is coupled to it in a spring-loaded manner. Alternatively, the transmission input shaft can be connected to the rotor shaft of the electric machine via an articulated shaft coupling.

The term “axially displaceable and spring-loaded coupled to one another” means that the rotor shaft and the transmission input shaft are connected to one another in a rotationally fixed manner via such a coupling, which enables an axial displacement of the rotor shaft relative to the transmission input shaft, and/or vice versa. In addition, the respective axially displaceable shaft is axially prestressed against the other shaft by the coupling in order to be able to start two fixed bearings with a minimum axial load from the no-load state. This coupling of the transmission input shaft with the rotor shaft to the input shaft must be able to transmit gearing axial forces, resulting from the magnetic field of the electric machine, in both directions to the first bearing element, i.e. to the fixed bearing, as well as torques. The differential input, intermediate shaft and transmission input shaft bearings can thereby be designed efficiently, since there are no axial tensions in the bearing elements in any operating state of the drive device.

For example, the coupling is designed as a cylinder-piston connection with a spring element, with a receptacle being arranged on the rotor shaft in which a piston attached to the transmission input shaft is guided axially on the one hand and, on the other hand, between a prestressed spring element arranged between the rotor shaft and the transmission input shaft is axially prestressed. The cylinder-piston connection with the spring element can also be arranged the other way around.

The drive device according to the invention can be used in purely electrically driven vehicles as well as in hybrid-driven vehicles, which can be driven partly electrically and partly by means of a separate internal combustion engine. The drive device is preferably arranged transversely to the vehicle's longitudinal axis, so that the rotor shaft, the intermediate shaft as well as the differential input shaft and the output shafts are arranged transversely to the vehicle's longitudinal axis or parallel to the vehicle's transverse axis. Depending on the design and number of driven axles, the vehicle can also include two or more such drive devices, whereby one axle, several axles or all axles of the vehicle can be equipped with the respective drive device according to the invention and can therefore be designed to be drivable. The vehicle is preferably a motor vehicle, in particular an automobile (e.g. a passenger car weighing less than 3.5 t), bus or truck (bus and truck e.g. weighing over 3.5 t ).

According to a further aspect of the invention, a vehicle comprises at least one transmission according to the first aspect of the invention or at least one drive device according to the second aspect of the invention.

The above definitions and statements on technical effects, advantages and advantageous embodiments of the transmission according to the invention also apply mutatis mutandis to the drive device according to the invention and to the at least partially electrically driven vehicle according to the invention.

It is understood that features of the solutions described above or in the claims and/or figures can also be combined if necessary in order to be able to cumulatively implement the advantages and effects that can be achieved in the present case.

• 1 eine schematische Draufsicht eines Fahrzeugs mit einer erfindungsgemäßen Antriebsvorrichtung gemäß einer bevorzugten Ausführungsform,
• 2 eine stark schematische Ansicht der erfindungsgemäßen Antriebsvorrichtung gemäß 1,
• 3 eine schematische Längsschnittdarstellung eines erfindungsgemäßen Getriebes der Antriebsvorrichtung nach 2,
• 4 eine schematische Längsschnittdarstellung einer ersten Übersetzungsstufe des erfindungsgemäßen Getriebes gemäß 3,
• 5 eine detaillierte Darstellung eines ersten Druckkammpaares an der ersten Übersetzungsstufe des erfindungsgemäßen Getriebes gemäß 4,
• 6 eine schematische Längsschnittdarstellung einer zweiten Übersetzungsstufe des erfindungsgemäßen Getriebes gemäß 3, und
• 7 eine detaillierte Darstellung eines zweiten Druckkammpaares an der zweiten Übersetzungsstufe des erfindungsgemäßen Getriebes gemäß 6.

An exemplary embodiment of the invention is explained in more detail below with reference to the schematic drawings, with the same or similar elements being provided with the same reference numerals. This shows

• 1 a schematic top view of a vehicle with a drive device according to the invention according to a preferred embodiment,
• 2 a highly schematic view of the drive device according to the invention 1 ,
• 3 a schematic longitudinal sectional representation of a transmission according to the invention of the drive device 2 ,
• 4 a schematic longitudinal sectional representation of a first gear ratio of the transmission according to the invention 3 ,
• 5 a detailed representation of a first pair of pressure combs on the first gear ratio of the transmission according to the invention 4 ,
• 6 a schematic longitudinal sectional representation of a second gear ratio of the transmission according to the invention 3 , and
• 7 a detailed representation of a second pair of pressure combs on the second gear ratio of the transmission according to the invention 6 .

1 shows an electrically driven vehicle 1 with two axles 31, 32 of a drive device 2 according to the invention according to a preferred embodiment. The drive device 2 is in 2 shown in a very simplified manner and arranged in a driving manner on the first axle 31, in this case the rear axle of the vehicle 1 as an example. The drive device 2 generates a drive power, which is divided in the manner described below between two output shafts 23, 24, which in turn are connected to a respective wheel 33 of the vehicle 1 in a driving manner.

The drive device 2 includes 2 an electric machine 3, which generates drive power in rotor or traction operation and transmits it via a gear 4 to a differential 7, which is operatively connected to the output shafts 23, 24. The electrical machine 3 is connected electrically and in terms of control technology to power electronics (not shown here), the power electronics and the electrical machine 3 being connected to an energy storage unit (also not shown here). In a reverse power flow or in generator operation or overrun operation, the energy storage can be fed with electrical energy. The energy storage can be, for example, a battery or the like. By means of the electrical machine 3, electrical energy can be generated in generator mode, stored and made available to supply the electrical machine 3 again.

The electrical machine 3 has a stator 25 with a rotor 26 which is arranged radially within the stator 25 and can be driven in rotation, the rotor 26 being connected in a rotationally fixed manner to a rotor shaft 22. The rotor shaft 22 is connected in a rotationally fixed manner to a transmission input shaft 6 via a coupling 27 and is arranged coaxially therewith. The coupling is designed to couple the transmission input shaft 6 and the rotor shaft 22 to one another in an axially displaceable and spring-loaded manner.

After 2 and 3 In addition to the transmission input shaft 6, the transmission 4 includes an intermediate shaft 5 and a differential input shaft 8 of the differential 7. The transmission input shaft 6, the intermediate shaft 5 and the differential input shaft 8 are arranged axially parallel to one another. The transmission input shaft 6 and the intermediate shaft 5 are operatively connected to one another via a first gear ratio 9, the intermediate shaft 5 and the differential input shaft 8 being operatively connected to one another via a second gear ratio 10. The first gear ratio 9 has a first gear Z1 which is connected in a rotationally fixed manner to the transmission input shaft 6 and a second gear Z2 which is connected in a rotationally fixed manner to the intermediate shaft 5. The second transmission stage 10 has a third gear Z3, which is connected in a rotationally fixed manner to the intermediate shaft 5, and a fourth gear Z4, which is connected in a rotationally fixed manner to the differential input shaft 8. The second and third gears Z2, Z3 are arranged axially spaced from one another on the intermediate shaft 5. It is conceivable to design the transmission 4 with more than two gear ratios, that is, with more than one intermediate shaft 5. This allows a transmission ratio of the drive to be adjusted. On the transmission input shaft 6, a parking lock wheel P is also arranged in a rotationally fixed manner to implement a parking lock function - not described in detail here.

In the present case, the differential 7 is designed as a bevel gear differential and has a differential input shaft 8 which is connected in a rotationally fixed manner to the fourth gear Z4. The differential input shaft 8, together with the third gear 28, forms a differential gear of the differential 7. Drive power from the transmission 4 is introduced into the differential 7 via the differential input shaft 8 and distributed to the output shafts 23, 24. The structure of the differential 7 is not described in more detail below. It should only be noted that the differential input shaft 8 is operatively connected to first bevel gears, which are in tooth engagement with second bevel gears, which are each connected in a rotationally fixed manner to an associated output shaft 23, 24.

In this exemplary embodiment, the transmission input shaft 6 and the intermediate shaft 5 are mounted floating relative to a housing 28 of the drive device 2 via respective bearing elements L1 - L4 designed as cylindrical roller bearings. In contrast, the differential input shaft 8 is mounted in an axially fixed manner, namely via a fifth bearing element L5 designed as a deep groove ball bearing and a sixth bearing element L6 designed as a cylindrical roller bearing. The deep groove ball bearing transmits radial and axial forces into the housing 28. The cylindrical roller bearings only transmit radial forces and are to be understood as floating bearings. The rotor shaft 22 is after 2 combined with 3 also rotatably mounted relative to the housing 28 by a seventh bearing element L7 designed as a deep groove ball bearing.

After 4 A first pressure comb DK1 and a second pressure comb DK2 are effectively formed between the gears Z1, Z2 of the first transmission stage 9, which are based on 5 be explained in more detail. Accordingly, the first pressure comb DK1 comprises a first pressure disk 11, which is non-rotatable on the first gear Z1 of the first transmission stage 9 is arranged and axially supported thereon. The rotation-proof arrangement is achieved by means of a pin 21, which engages in a tooth gap in a toothing 29 of the first gear Z1 of the first transmission stage 9 to prevent rotation. The first thrust washer 11 has a first counter surface G1, which is designed to come into contact with a second counter surface G2 formed on the second gear Z2 of the first gear ratio stage 9 in order to absorb gearing axial forces during pulling operation of the transmission 4.

The second counter surface G2 is formed on a substantially radially extending first receiving section 13 of the second gear Z2 of the first transmission stage 9. On an end face of the first receiving section 13 opposite the second counter surface G2, a fifth counter surface G5 is formed, which is designed to come into contact with a sixth counter surface G6 for absorbing gearing axial forces to form the second pressure chamber DK2 during overrun operation of the transmission 4. The sixth counter surface G6 is supported at least indirectly axially on that shaft 5, 6 on which the respective gear Z1 with the first pressure disk 11 arranged in a rotationally fixed manner thereon is arranged in a rotationally fixed manner. In the present case, the sixth counter surface G6 is integrally formed on the parking lock wheel P to form the second pressure chamber DK2.

The first pressure washer 11 is arranged in a circumferential first groove 15 on the outer circumference of the second gear Z2 of the first transmission stage 9, on which the first receiving section 13 is arranged. The first groove 15 is formed axially between the first receiving section 13 and a first ring gear 17 of the second gear Z2. The first pressure disk 11 therefore projects radially into the first groove 15.

When changing between pulling and pushing operation, the second gear Z2 can move axially to a limited extent between the first pressure disk 11 and the parking lock wheel P. The axial mobility of the second gear Z2 with the intermediate shaft 5 is determined, among other things, by the width of the first groove 15. In pulling operation, the first and second counter-running surfaces G1, G2 come into contact with one another for the transmission of gearing axial forces, while in pushing operation the fifth and sixth counter-running surfaces G5, G6 come into contact with one another for transmitting gearing axial forces. Conversely, it can also be provided that the first and second counter-running surfaces G1, G2 come into contact with one another in pushing operation for gearing axial force transmission, with the fifth and sixth counter-running surfaces G5, G6 coming into contact with one another in pulling operation for gearing axial force transmission.

In the present case, the parking lock wheel P has a fully circumferential first channel structure R1, which is arranged and designed to supply at least the second pressure comb DK2 with coolant and/or lubricant. Furthermore, the first pressure disk 11 has a fully circumferential second channel structure R2, which is arranged and designed to supply at least the first pressure comb DK1 with coolant and/or lubricant. Coolant or lubricant can thus continuously reach the contact surface of the mating surfaces G1, G2 or G5, G6 that roll against one another. Corresponding guide channels 30 are provided on the transmission input shaft 6, through which coolant or lubricant can reach the corresponding channel structures R1, R2 due to centrifugal forces.

After 6 a third pressure comb DK3 and a fourth pressure comb DK4 are effectively formed between the gears Z3, Z4 of the second transmission stage 10, which are based on 7 be explained in more detail. Accordingly, the third pressure comb DK3 comprises a second pressure disk 12, which is arranged in a rotationally fixed manner on the third gear Z3 of the second transmission stage 10 and is axially supported thereon. The rotation-proof arrangement is achieved by means of a pin 21, which engages in a tooth gap in a toothing 30 of the third gear Z3 of the second transmission stage 10 to prevent rotation. The second pressure washer 12 has a third counter surface G3, which is designed to come into contact with a fourth counter surface G4 formed on the fourth gear Z4 of the second transmission stage 10 in order to absorb gearing axial forces during pulling operation of the transmission 4.

The fourth counter surface G4 is formed on a substantially radially extending second receiving section 14 of the fourth gear Z4 of the second transmission stage 10. On an end face of the second receiving section 14 opposite the fourth counter surface G4, a seventh counter surface G7 is formed, which is designed to come into contact with an eighth counter surface G8 for absorbing gear axial forces to form the fourth pressure chamber DK4 during overrun operation of the transmission 4. The eighth counter surface G8 is at least indirectly supported axially on that shaft 5, 8 on which the respective gear Z3 with the second pressure disk 12 arranged in a rotationally fixed manner thereon is arranged in a rotationally fixed manner. In the present case, the eighth counter surface G8 is integrally formed on the front side of the second gear Z2 to form the fourth pressure chamber DK4.

The second pressure washer 12 is arranged in a circumferential second groove 16 on the outer circumference of the fourth gear Z4 of the second transmission stage 10, on which the second receiving section 14 is arranged. The second groove 16 is formed axially between the second receiving section 14 and a second ring gear 18 of the fourth gear Z4 of the second transmission stage 10. The second pressure washer 12 therefore projects radially into the second groove 16.

When changing between pulling and pushing operation, the fourth gear Z4 can move axially to a limited extent between the second pressure disk 12 and the second gear Z2. The axial mobility of the fourth gear Z4 with the differential input shaft 8 is determined, among other things, by the width of the second groove 16. In pulling operation, the third and fourth counter surfaces G3, G4 come into contact with one another for the transmission of gearing axial forces, while in pushing operation the seventh and eighth counter surfaces G7, G8 come into contact with one another for transmission of toothing axial forces. Conversely, it can also be provided that the third and fourth counter-running surfaces G3, G4 come into contact with one another in pushing operation for gearing axial force transmission, with the seventh and eighth counter-running surfaces G7, G8 coming into contact with one another for gearing axial force transmission in pulling operation.

In the present case, the first and third pressure combs DK1, DK3 each form a tensile pressure comb, which absorb or transmit tooth axial forces during the tensile operation of the drive device 2. In contrast, the second and fourth pressure combs DK2, DK4 each form a thrust pressure comb, which absorb or transmit tooth axial forces during the thrust operation of the drive device 2. The assignment of the pressure combs DK1 - DK4 can, as mentioned above, vary depending on the design of the transmission 4 or be adjusted as desired.

In the present exemplary embodiment, the first counter surface G1 on the first thrust washer 11, the sixth counter surface G6 on the parking lock wheel P, the third counter surface G4 on the second thrust disk 12 and the eighth counter surface G8 on the second gear Z2 have a spherical shape, whereas the others Counter-contact surfaces G2, G3, G5, G7 have a substantially conical shape. However, this can be customized as desired. In any case, one mating surface of each pair of mating surfaces G1 with G2 or G3 with G4 or G5 with G6 or G7 with G8 is crowned and the other mating surface of the same pair of mating surfaces G1 with G2 or G3 with G4 or G5 with G6 or G7 with G8 conical design. The surfaces of the counter-running surfaces G1 - G8 are designed in such a way that a contact point or pressure point between the counter-running surfaces G1 - G8 that are in contact with one another lies exactly on a respective operating pitch circle BK of the teeth that are in mesh with one another. The operating circuits are in 5 or. 7 indicated.

In the present case, the second pressure disk 12 has a fully circumferential third channel structure R3, which is arranged and designed to supply at least the third pressure comb DK3 with coolant and/or lubricant. Furthermore, the second gear Z2 has a fully circumferential fourth channel structure R4 in the area of the fourth pressure chamber DK4, which is arranged and designed to supply at least the fourth pressure chamber DK4 with coolant and/or lubricant. Coolant or lubricant can thus continuously reach the contact surface of the mating surfaces G3, G4 or G7, G8 that roll against one another. Corresponding guide channels 30 are provided on the intermediate shaft 5, through which coolant or lubricant can reach the corresponding channel structures R3, R4 by means of centrifugal forces.

The invention is not limited to the embodiment shown here. Other embodiments or variations will become apparent to those skilled in the art upon use of the present invention and upon careful analysis of the drawings, description and claims. In particular, the arrangement of the respective pressure washer 11, 12 and the respective receiving section 13, 14 on the respective gear Z1 - Z4 can be swapped or adapted to the requirements of the transmission 4.

Reference symbols

1

vehicle

2

Drive device

3

Electric machine

4

transmission

5

Intermediate shaft

6

Transmission input shaft

7

differential

8th

Differential input shaft

9

First translation stage

10

Second translation stage

11

First pressure washer

12

Second pressure washer

13

First recording section

14

Second recording section

15

First groove

16

Second groove

17

First sprocket

18

Second sprocket

19

First translation stage

20

Second translation stage

21

Cones

22

Rotor shaft

23

First output shaft

24

Second output shaft

25

stator

26

rotor

27

coupling

28

Housing

29

Teeth of the first gear

30

Guide channel

31

First axis

32

Second axis

33

wheel

BK

Operating circulation circuit

DK1

First print comb

DK2

Second pressure comb

DK3

Third pressure comb

DK4

Fourth pressure comb

G1

First counter surface

G2

Second counter surface

G3

Third counter surface

G4

Fourth counter surface

G5

Fifth counter surface

G6

Sixth counter surface

G7

Seventh counter surface

G8

Eighth counter surface

L1

First bearing element

L2

Second bearing element

L3

Third bearing element

L4

Fourth bearing element

L5

Fifth bearing element

L6

Sixth bearing element

L7

Seventh bearing element

P

Parking lock wheel

R1

First gutter structure

R2

Second gutter structure

R3

Third gutter structure

R4

Fourth gutter structure

Z1

First gear

Z2

Second gear

Z3

Third gear

Z4

Fourth gear

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102014207431 A1 [0003]

Claims (14)

Transmission (4) for a drive device (2) of an at least partially electrically driven vehicle (1), comprising a transmission input shaft (6) with a first gear (Z1), an intermediate shaft (5) with a second gear (Z2) and an axially adjacent one arranged for this third gear (Z3), and a differential input shaft (8) of a differential (7) with a fourth gear (Z4), the first and second gears (Z1, Z2) having a first gear ratio (9) and the third and fourth gears (Z3, Z4) form a second transmission stage (10), the transmission input shaft (6) or the intermediate shaft (5) or the differential input shaft (8) being mounted in an axially fixed manner and the other two shafts (5, 6, 8) being mounted in a floating manner, wherein a first pressure comb (DK1) and a second pressure comb (DK2) are effectively formed between the gears (Z1, Z2) of the first transmission stage (9), the first pressure comb (DK1) comprising a first pressure disk (11) which is non-rotatable one of the gears (Z1, Z2) of the first transmission stage (9) is arranged and axially supported thereon, the first pressure disk (11) having a first counter surface (G1) which is designed to be in traction or thrust operation of the transmission (4 ) to come into contact with a second counter surface (G2) formed on the other of the two gears (Z2, Z1) of the first gear ratio stage (9) to absorb gearing axial forces, wherein a third pressure comb (DK3) and a fourth pressure comb (DK4) are effectively formed between the gears (Z3, Z4) of the second transmission stage (10), the third pressure comb (DK3) comprising a second pressure disk (12) which is non-rotatable one of the gears (Z3, Z4) of the second transmission stage (10) is arranged and axially supported thereon, the second pressure washer (12) having a third counter surface (G3) which is designed to be in the pulling or pushing mode of the transmission (4 ) to come into contact with a fourth counter-surface (G4) formed on the other of the two gears (Z4, Z3) of the second transmission stage (10) for absorbing gearing axial forces. Gearbox (4) after Claim 1 , wherein the second counter surface (G2) is formed on a substantially radially extending first receiving section (13) of the respective gear (Z1, Z2) of the first transmission stage (9), on an end face of the first opposite the second counter surface (G2). A fifth counter surface (G5) is formed on the receiving section (13), which is designed to come into contact with a sixth counter surface (G6) to absorb gearing axial forces in order to form the second pressure chamber (DK2) in push or pull operation of the transmission (4). occur, the sixth counter surface (G6) being supported at least indirectly axially on that shaft (5, 6) on which the respective gear (Z1, Z2) with the first pressure disk (11) arranged in a rotationally fixed manner thereon is arranged in a rotationally fixed manner. Gearbox (4) after Claim 1 or 2 , wherein the fourth counter surface (G4) is formed on a substantially radially extending second receiving section (14) of the respective gear (Z3, Z4) of the second transmission stage (10), on an end face of the second one opposite the fourth counter surface (G4). A seventh counter surface (G7) is formed on the receiving section (14), which is designed to come into contact with an eighth counter surface (G8) for absorbing gearing axial forces to form the fourth pressure chamber (DK4) in push or pull operation of the transmission (4). occur, the eighth counter surface (G8) being supported at least indirectly axially on that shaft (5, 8) on which the respective gear (Z3, Z4) with the second pressure disk (12) arranged in a rotationally fixed manner thereon is arranged in a rotationally fixed manner. Transmission (4) according to one of the preceding claims, wherein the first pressure washer (11) is arranged in a circumferential first groove (15) on the outer circumference of the respective gear (Z1, Z2) of the first transmission stage (9), which has the first receiving section (13 ), wherein the first groove (15) is formed axially between the first receiving section (13) and a first ring gear (17) of the respective gear (Z1, Z2) of the first transmission stage (9). Transmission (4) according to one of the preceding claims, wherein the second pressure washer (12) is arranged in a circumferential second groove (16) on the outer circumference of the respective gear (Z3, Z4) of the second transmission stage (10), which has the second receiving section (14 ), wherein the second groove (16) is formed axially between the second receiving section (14) and a second ring gear (18) of the respective gear (Z3, Z4) of the second transmission stage (10). Gearbox (4) according to one of the preceding claims, wherein one of the two counter-running surfaces (G1 - G8) of the respective pressure chamber (DK1 - DK4) has a spherical shape and the other of the two counter-running surfaces (G1 - G8) of the same pressure chamber (DK1 - DK4) has a conical shape. Gearbox (4) according to one of the Claims 2 until 6 , further comprising a parking lock wheel (P), which is non-rotatably connected to the first gear (Z1). is, wherein the sixth counter surface (G6) is formed on the parking lock wheel (P) to form the second pressure chamber (DK2). Gearbox (4) after Claim 7 , wherein the parking lock wheel (P) has an at least partially circumferential first channel structure (R1), which is arranged and designed to supply at least the second pressure comb (DK2) with coolant and / or lubricant. Transmission (4) according to one of the preceding claims, wherein the first pressure disk (11) has an at least partially circumferential second channel structure (R2), which is arranged and designed to supply at least the first pressure comb (DK1) with coolant and/or lubricant . Transmission (4) according to one of the preceding claims, wherein the second pressure disk (12) has an at least partially circumferential third channel structure (R3) which is arranged and designed to supply at least the third pressure comb (DK3) with coolant and/or lubricant . Transmission (4) according to one of the preceding claims, wherein the transmission input shaft (6) is rotatably mounted via a first bearing element (L1) and a second bearing element (L2), the intermediate shaft (5) via a third bearing element (L3) and a fourth Bearing element (L4) is rotatably mounted, the differential input shaft (8) being rotatably mounted via a fifth bearing element (L5) and a sixth bearing element (L6), one of the bearing elements (L1 - L6) being an axial guide bearing and the other five Bearing elements (L1 - L6) are a cylindrical roller bearing. Gearbox (4) according to one of the preceding claims, wherein at least one pin (21) is formed on the respective pressure disk (11, 12), which is inserted into a tooth gap of one of the gears (Z1 - Z4) of the respective transmission stage (9, 10) to prevent rotation ) intervenes. Drive device (2), comprising an electric machine (3) with a rotor shaft (22) and a gearbox (4) according to one of the preceding claims. Drive device (2). Claim 13 , wherein the transmission input shaft (6) is at least indirectly connected in a rotationally fixed manner to a rotor shaft (8) of an electric machine (3).

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