SE541850C2

SE541850C2 - Power Take-off Arrangement, Powertrain, and Vehicle

Info

Publication number: SE541850C2
Application number: SE1750603A
Authority: SE
Inventors: Daniel Petersen; Lars Bergkvist
Original assignee: Scania Cv Ab
Priority date: 2017-05-16
Filing date: 2017-05-16
Publication date: 2019-12-27
Also published as: SE1750603A1; DE102018003792A1

Description

Power Take-off Arrangement, Powertrain, and Vehicle TECHNICAL FIELD The present invention relates to power take-off arrangement for a vehicle. The present invention further relates to a powertrain for a vehicle comprising a power take-off arrangement, and a vehicle comprising a powertrain.

BACKGROUND A power take-off arrangement, generally abbreviated as PTO, is an arrangement for taking power from a propulsion unit of a vehicle, such as a running engine, and transmitting it to a second unit such as an attached implement or a separate machine. Most PTO arrangements comprise an input shaft connected to a shaft of a powertrain of the vehicle, such as a lay shaft of a gearbox of the vehicle. Some PTO arrangements comprise a PTO unit in the form of a splined output shaft designed so that an input shaft of a second unit can be easily connected to the splined output shaft. As an alternative to the splined output shaft, or in addition thereto, a PTO arrangement may comprise a PTO unit in the form of a hydraulic pump, or similar. The hydraulic pump may be connected to, and drive, a temporarily attached hydraulic unit, and/or a hydraulic unit permanently arranged at the vehicle, such as a hydraulic unit configured to tilt a tipper body of a tipper truck, a crane, or the like. A common feature of the above described PTO arrangements is that they allow implements to draw energy from a power source of a vehicle, such as an engine.

A PTO unit is preferably disconnectable from the power source to ensure that parts of the PTO unit is stationary when the PTO unit not is in use. A PTO arrangement usually comprises a coupling device such as a dog clutch to be able to connect and disconnect the PTO unit to and from the power source. The connection and disconnection of a PTO unit may pose durability problems and reliability problems partly since rotating parts of conventional coupling device preferably should have the same, or similar, rotational speed prior to engagement.

Environmental concerns put increasing demands on vehicle manufacturers to produce energy efficient vehicles. Parasitic losses caused by various components of a vehicle may increase the total consumption of power.

In addition, generally, today’s consumer market requires high quality products which can be manufactured in a cost-efficient manner, while being reliable and durable. Further, in the vehicle industry, it is an advantage if components are designed so that they can be used in different kinds of vehicles and in vehicles having different specifications. However, this may pose problems since these vehicles usually have different requirements of the components.

SUMMARY It is an object of the present invention to overcome, or at least alleviate, at least some of the above-mentioned problems and drawbacks.

According to a first aspect of the invention, the object is achieved by a power take-off arrangement for a vehicle. The arrangement comprises a planetary gear comprising a sun gear, a ring gear and one or more planet gears supported by a carrier. The arrangement further comprises an input shaft connected to the carrier, a power take-off unit arranged to be driven by the ring gear, and an actuator arrangement configured to selectively brake or selectively drive the sun gear.

Thereby, an arrangement is provided in which power can be transferred from the input shaft to the power take-off unit simply by braking or driving the sun gear. As a result, a power takeoff arrangement is provided circumventing the need for a separate coupling device for engaging and disengaging power transfer to the power take-off unit. Instead, according to the arrangements provided, transfer of power from the input shaft to the power take-off unit will be disengaged when the actuator arrangement does not brake or drive the sun gear. This since the carrier and the sun gear will rotate upon rotation of the input shaft when the actuator arrangement does not brake or drive the sun gear. Transfer of power from the input shaft to the power take-off unit will be engaged when the actuator arrangement brakes or drives the sun gear. This since the braking or driving of the sun gear applies a torque onto the sun gear which causes the ring gear to rotate upon rotation of the carrier to which the input shaft is connected. In this manner, power is transferred from the input shaft to the power take-off unit when braking or driving the sun gear.

Accordingly, when the input shaft of the power take-off unit is connected to a shaft connected to a power source of a vehicle, such as a combustion engine of the vehicle, the power takeoff unit can be shifted between a disengaged state, in which no power is transferred to the power take-off unit, and an engaged state in which power is transferred to the power take-off unit, without having to turn of the power source, or hinder rotation of the shaft connected to the input shaft of the power take-off unit in another manner. Thereby, smooth and gradual transitions between the disengaged state and the engaged state can be obtained by selectively braking or selectively driving the sun gear.

Further, a reliable and durable arrangement is provided since the power take-off unit can be transitioned between the engaged state and the disengaged state in a smooth and gradual manner without using a coupling device.

Still further, an arrangement is provided in which different gear ratios between the input shaft and the power take-off unit can be obtained simply by applying different braking torques onto the sun gear, or by performing driving of the sun gear at different speeds and/or in different rotational directions. In addition, according to the embodiments of the arrangement in which the actuator arrangement is arranged selectively drive the sun gear, the power take-off unit can be driven by the actuator arrangement, even when a power source of the vehicle, such as a combustion engine, is turned off. Thus, according to such embodiments, power may be transferred from the actuator arrangement to the power take-off unit, via the sun gear, the planet gears of the carrier, and the ring gear. Power will be transferred from the sun gear to the ring gear, via the planet gears, since the carrier is at stand still when the power source of the vehicle is turned off in such embodiments.

Further, since the power take-off arrangement comprises a planetary gear, a compact power take-off arrangement is provided. Thus, conditions are provided for arranging the power takeoff unit between a power source of the vehicle and a transmission of the vehicle. The sun gear may easily be provided with a through hole for receiving a shaft connecting the power source and the transmission, wherein the shaft forms part of the input shaft of the power take-off unit.

In addition, in the disengaged state, the carrier, the planet gears and the sun gear are the only components moving. Thereby, low parasitixc losses are obtained when the power takeoff unit not is in use.

Accordingly, an arrangement is provided overcoming, or at least alleviating, at least some of the above-mentioned problems and drawbacks. As a result, the above-mentioned object is achieved.

According to the invention, the actuator arrangement comprises a brake arranged to selectively brake the sun gear. Thereby, a simple, reliable and durable arrangement is provided capable of transitioning the power take-off arrangement between the engaged state and the disengaged state in an efficient manner. Further, an arrangement is provided capable of performing gradual and smooth transitions between the engaged state and the disengaged state. Still further, an arrangement is provided capable of providing different gear ratios between the input shaft and the power take-off unit simply by applying different braking torques onto the sun gear.

Optionally, the arrangement further comprises a second gear set, wherein the power take-off unit is arranged to be driven by the ring gear via the second gear set. Thereby, a power takeoff arrangement is provided in which the gear ratio between the input shaft and the power take-off unit can be changed simply by changing the second gear set. Thus, due to these features, an arrangement is provided which can be adapted to different requirements of different vehicles in a simple and cost-efficient manner.

Optionally, the second gear set comprises a power take-off unit shaft connected to the power take-off unit, an intermediate shaft, a first gear, a second gear, and third gear, wherein the first and second gears, are arranged at the intermediate shaft, and wherein the third gear is arranged at the power take-off unit shaft, wherein the first gear is rotationally connected to the ring gear, and wherein the second gear is rotationally connected to the third gear.

Thereby, a power take-off arrangement is provided in which the gear ratio between the input shaft and the power take-off unit can be changed simply by changing the second gear and the third gear of the second gear set. Thus, due to these features, an arrangement is provided which can be adapted to different requirements of different vehicles in a simple and cost-efficient manner.

Optionally, the brake is a wet disc brake comprising a number of discs. Thereby, a still more reliable and durable arrangement is provided capable of transitioning the power take-off arrangement between the engaged state and the disengaged state in a gradual and smooth manner.

Optionally, the actuator arrangement comprises an electric machine arranged to selectively brake or drive the sun gear. Thereby, a reliable and durable arrangement is provided capable of transitioning the power take-off arrangement between the engaged state and the disengaged state. Further, an arrangement is provided capable of performing gradual and smooth transitions between the engaged state and the disengaged state. Still further, an arrangement is provided capable of providing different gear ratios between the input shaft and the power take-off unit simply by driving of the sun gear at different speeds, and/or in different rotational directions, and/or by applying different braking torques onto the sun gear, using the electric machine. In addition, an arrangement is provided which provides conditions for driving the power take-off unit with pure electric drive also when the power source of the vehicle is switched off.

Optionally, the arrangement further comprises a lubrication system configured to lubricate gears of the arrangement, wherein the lubrication system comprises a pump configured to pump lubricant to the gears, wherein the pump is arranged to be driven by the ring gear. Since the pump is arranged to be driven by the ring gear, an arrangement is provided in which the pump is actuated when the ring gear rotates, i.e. when power is transferred to the power take-off unit. Thus, an arrangement is provided in which the pump is driven only when lubrication of the gears is needed and which pump is at a standstill when lubrication not is needed. Thereby, parasitic losses from the arrangement are minimized in a simple and costefficient manner.

Optionally, the sun gear comprises a through hole, wherein the input shaft extends through the through hole. Thereby, a power take-off arrangement is provided being compact in size and in which the input shaft can be used to transfer power from one component to another component in addition to the transferring power to the power take-off unit. Examples of such components are a power source of the vehicle and a transmission of a vehicle. Further examples of such components are a first transmission member and a second transmission member.

Optionally, the power take-off arrangement is arranged to be positioned between a power source of the vehicle and a transmission of the vehicle. Thereby, a power take-off arrangement is provided being compact in size and in which the input shaft can be used to transfer power from the power source of the vehicle to the transmission of the vehicle in addition to the transferring power to the power take-off unit.

According to a second aspect of the invention, the object is achieved by a powertrain for a vehicle, wherein the powertrain comprises a power source and a transmission, wherein the power source is configured to provide motive power to the vehicle via the transmission, and wherein the powertrain comprises a power take-off arrangement according to some embodiments, wherein the input shaft of the power take-off arrangement is connected to a first shaft of the powertrain. Since the powertrain comprises a power take-off arrangement overcoming, or at least alleviating, at least some of the above-mentioned problems and drawbacks, a powertrain is provided overcoming, or at least alleviating, at least some of the above-mentioned problems and drawbacks.

As a result, the above-mentioned object is achieved.

Optionally, the power take-off arrangement is arranged between the power source and the transmission. Thereby, a compact powertrain is provided capable of performing gradual and smooth transitions between a disengaged state and an engaged state of the power take-off arrangement.

Optionally, the first shaft of the powertrain is arranged to transfer torque between the power source and the transmission, wherein the sun gear comprises a through hole and wherein the first shaft extends through the through hole. Thereby, a compact powertrain is provided capable of performing gradual and smooth transitions between a disengaged state and an engaged state of the power take-off arrangement.

Optionally, the input shaft of the power take-off arrangement forms part of the first shaft of the powertrain. Thereby, a compact powertrain is provided capable of performing gradual and smooth transitions between a disengaged state and an engaged state of the power takeoff arrangement. Further, a powertrain is provided in which the input shaft of the power takeoff arrangement forms part of the first shaft of the powertrain, and thus forms part of a component transferring power from the power source of the vehicle to the transmission of the vehicle.

According to a third aspect of the invention, the object is achieved by a vehicle comprising a powertrain according to some embodiments. Since the vehicle comprises a powertrain overcoming, or at least alleviating, at least some of the above-mentioned problems and drawbacks, a vehicle is provided overcoming, or at least alleviating, at least some of the above-mentioned problems and drawbacks.

Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS Various aspects of the invention, including its particular features and advantages, will be readily understood from the example embodiments discussed in the following detailed description and the accompanying drawings, in which: Fig. 1 schematically illustrates a power take-off arrangement, according to some embodiments, Fig. 2 schematically illustrates a power take-off arrangement, according to some further embodiments, Fig. 3 illustrates a powertrain for a vehicle, according to some embodiments, and Fig. 4 illustrates a vehicle, according to some embodiments, comprising the powertrain illustrated in Fig. 3.

DETAILED DESCRIPTION Aspects of the present invention will now be described more fully. Like numbers refer to like elements throughout. Well-known functions or constructions will not necessarily be described in detail for brevity and/or clarity.

Fig. 1 schematically illustrates a power take-off arrangement 1, according to some embodiments. The power take-off arrangement 1 comprises a planetary gear 5 comprising a sun gear 7, a ring gear 9 and a set of planet gears 11 supported by a carrier 13. In the illustrated embodiments, two planet gears 11 are visible of the set of four planet gears 11. The arrangement 1 may comprise another number of planet gears 11 than four, such as one, two, three, five, six, etc. Each planet gear 11 is rotationally connected to the carrier 13 in a respective rotational centre of each planet gear 11. According to the illustrated embodiments, the sun gear 7 comprises external cog teeth and the ring gear comprises internal cog teeth. The sun gear 7 and the ring gear 9 are concentrically arranged. Each planet gear 11 is arranged between cog teeth of the ring gear 9 and cog teeth of the sun gear 7. Further, each planet gear 11 comprises cog teeth intermeshing with the cog teeth of the sun gear 7, as well as cog teeth of the ring gear 9. Purely as an example, the ring gear 9 may comprise 98 cog teeth, each planet gear 11 may comprise 18 cog teeth and the sun gear 7 may comprise 62 cog teeth.

The arrangement 1 further comprises an input shaft 14 connected to the carrier 13. Further, the arrangement 1 comprises a power take-off unit 15 arranged to be driven by the ring gear 9. The power take-off unit 15 may comprise a splined output shaft, a hydraulic pump, or the like. The arrangement 1 further comprises an actuator arrangement 17. According to the illustrated embodiments, the actuator arrangement 17 comprises a brake 17 arranged to selectively brake the sun gear 7. Thereby, a power take-off arrangement 1 is provided capable of performing smooth and gradual transitions between a disengaged state of the power take-off unit 15 and an engaged state of the power take-off unit 15. That is, in the disengaged state when no braking torque is applied onto the sun gear 7 by the brake 17, the carrier 13 and the sun gear 7 rotates when the input shaft 14 is rotates. Since these and the planet gears 11 are the only parts moving in the disengaged state, low parasitic losses are obtained in the disengaged state. Thus, low parasitic losses are obtained when the power take-off unit 15 not is in use. The sun gear 7 will rotate at a higher rotational speed than the carrier 13. This since there is a gear ratio between the carrier 13 and the sun gear 7. As a result, the brake 17 can brake rotation of the sun gear 7 using a relative low braking torque which facilitates the provision of smooth and gradual transitions between the disengaged and the engaged state.

In a transition from the disengaged state to the engaged state, the brake is starting to apply a braking torque onto the sun gear 7. When a torque is applied onto the sun gear 7, torque is applied onto the ring gear 9. Accordingly, torque will be transferred from the input shaft 14 to the power take-off unit 15 when a torque is applied onto the sun gear 7. By regulating the amount of braking torque applied to the sun gear 7, the gear ratio between the input shaft 14 and the power take-off unit 15 can be regulated. That is, if some rotation of the sun gear 7 is allowed by the brake 17, less rotational movement will be transferred to the power take-off unit 15 via the ring gear 9. If no rotation of the sun gear is allowed by the brake 17, i.e. if the brake 17 brakes the sun gear 7 to a standstill, more rotational movement will be transferred to the power take-off unit 15 via the ring gear 9, than if some rotation of the sun gear 7 is allowed. Likewise, if the brake 17 is braking the sun gear 7 using a high braking torque, the power take-off unit 15 will be subjected to a quicker increase in rotational velocity than if the brake 17 is braking the sun gear 7 using a lower braking torque.

Thus, smooth and gradual transitions between the disengaged state and the engaged state, as well as different gear ratios, can be performed by applying braking torque onto the sun gear 7 using the brake 17. Further, transitions between the disengaged state and the engaged state can be performed without using a separate coupling device assigned for the task meaning that a robust, reliable and durable power take-off arrangement 1 is provided. In addition, since the power take-off unit 15 can be transitioned between the disengaged and engaged state simply by applying a braking torque onto the sun gear 7, the power take-off unit 15 can be transitioned between the disengaged and engaged state during rotation of the input shaft. Accordingly, a power take-off arrangement 1 is provided capable of transitioning between the disengaged and engaged state also when a power source, such as an internal combustion engine, is running.

Conventional coupling devices for power take-off arrangements usually operates by connecting two transmission members. In such coupling devices, two rotatable transmission members are to be connected meaning that they preferably should have the same rotational speed prior to engagement. If not so, the coupling device is subjected to considerable wear and tear and there is a risk that the coupling device will be damaged. However, according to the arrangement 1 provided, the power take-off unit 15 can be transitioned between the disengaged and engaged state simply by selectively braking the sun gear 7 using the brake 17.

Further, according to the illustrated embodiments, the brake 17 is a wet disc brake comprising a number of discs 31. The brake 17 may for example comprise a number of discs 31 ranging from 2 - 8 discs, or 3 - 5 discs. Thereby, a compact and efficient brake 17 is provided. Since the brake 17 is a wet disc brake, the discs 31 are configured to operate in a lubricated state. Due to these feature, even more smooth and gradual transitions between the disengaged state and the engaged state can be performed, and a robust, reliable and durable brake 17 is provided.

Fig. 2 schematically illustrates a power take-off arrangement 1, according to some further embodiments. The power take-off arrangement 1 illustrated in Fig. 2 comprises the same components, features and advantages as the power take-off arrangement 1 illustrated in Fig. 1, with the exception that the power take-off arrangement 1 illustrated in Fig. 2 comprises an actuator arrangement in the form of an electric machine 33 arranged to selectively brake or drive the sun gear 7.

In the disengaged state, the electric machine applies no torque onto the sun gear 7. Thereby, as described above, the carrier 13 and the sun gear 7 will rotate in the disengaged state and no power will thus be transferred from the input shaft 14 to the power take-off unit 15 via the ring gear 9.

When transitioning from the disengaged state to the engaged state, the electric machine 33 is starting to apply a torque onto the sun gear 7, e.g. a braking torque. When a torque is applied onto the sun gear 7, torque will be applied onto the ring gear 9 meaning that torque will be transferred from the input shaft 14 to the power take-off unit 15. The braking energy may be converted into electric energy by the electric machine 33, which for example may be utilized for charging one or more batteries, or used for another purpose. Thus, according to these embodiments, an arrangement 1 is provided circumventing the need for a coupling device, as well as circumventing the need for a friction brake. As a result, a still more reliable, durable, and energy efficient power take-off arrangement 1 is provided.

Still further, by regulating the amount of torque applied to the sun gear 7, the gear ratio between the input shaft 14 and the power take-off unit 15 can be regulated. That is, if some rotation of the sun gear is allowed by the electric machine 33, less rotational movement will be transferred to the power take-off unit 15 via the ring gear 9. If no rotation of the sun gear 7 is allowed by the electric machine 33, more rotational movement will be transferred to the power take-off unit 15 via the ring gear 9. Further, if torque is applied onto the sun gear 7 in an opposite direction in order to rotate the sun gear 7 in an opposite direction than during the disengaged state, still more rotational movement will be transferred to the power take-off unit 15 via the ring gear 9. Thus, the gear ratio between the input shaft 14 and the power take-off unit 15 can be regulated to a high degree by regulating the amount, and the rotational direction, of the torque applied onto the sun gear 7 by the electric machine 33.

Further, smooth and gradual transitions between the disengaged state and the engaged state can be performed by regulating the torque applied onto the sun gear 7 using the electric machine 33. Still further, transitions between the disengaged state and the engaged state can be performed without using a separate coupling device assigned for the task meaning that a robust, reliable and durable power take-off arrangement 1 is provided. In addition, since the power take-off unit 15 can be transitioned between the disengaged and engaged state simply by applying a torque onto the sun gear 7, the power take-off unit 15 can be transitioned between the disengaged and engaged state during rotation of the input shaft. Accordingly, a power take-off arrangement 1 is provided capable of transitioning between the disengaged and engaged state also when a power source, such as an internal combustion engine, is running.

Still further, an arrangement is provided capable of driving the power take-off unit 15 with pure electric drive also when the power source, such as an internal combustion engine, is switched off. This since a switched off power source, according to the illustrated embodiments, causes the input shaft 14 and the carrier 13 to stand still. Thereby, a torque applied onto the sun gear 7 will be transferred to the ring gear 9, and thus also the power take-off unit 15, via the one or more planet gears 11. According to further embodiments, the power take-off arrangement 1 may comprise a brake arrangement (not illustrated) configured to brake the input shaft 14 or the carrier 13, when the electric machine 33 is driving the sun gear 7 and when the power source of the vehicle is switched off. Thereby, rotation of the input shaft 14, and thus also the carrier 13, can be further hindered when the electric machine 33 is powering the power take-off unit 15 with a switched off power source.

As illustrated in Fig.1 and in Fig. 2, the arrangement 1 may comprise a second gear set 19, wherein the power take-off unit 15 is arranged to be driven by the ring gear 9 via the second gear set 19. Thereby, a power take-off arrangement 1 is provided in which the gear ratio between the input shaft 14 and the power take-off unit 15 can be changed simply by changing the second gear set 19.

According to the illustrated embodiments, the second gear set 19 comprises a power take-off unit shaft 21 connected to the power take-off unit 15. The second gear set 19 further comprises an intermediate shaft 23, a first gear 25, a second gear 27, and a third gear 29. The first and second gears 25, 27 are arranged at the intermediate shaft 23 and are rotationally connected to the intermediate shaft 23. The third gear 29 is arranged at the power take-off unit shaft 21 and is rotationally connected to the power take-off unit shaft 21. The first gear 25 is rotationally connected to the ring gear 9 by intermeshing with a portion 34 of the ring gear 9. According to the illustrated embodiments, the portion 34 of the ring gear 9 is an annular portion comprising external cog teeth arranged to intermesh with cog teeth of the first gear 25. The second gear 27 is rotationally connected to the third gear 29 by intermeshing with the third gear 29.

Accordingly, due to this arrangement, torque can be transferred from the ring gear 9 to the power take-off unit 15 via the first gear 25, the intermediate shaft 23, the second gear 27, the third gear 29 and the power take-off unit shaft 21. The gear ratio between the ring gear 9 and the power take-off unit 15, and thus also between the input shaft 14 and the power take-off unit 15, can be changed simply by changing the second and third gears 27, 29 to gears having a different circumference ratio and different ratio between their number of cog teeth. Thereby, an arrangement 1 is provided which can be adapted to requirements of different vehicles in a simple and cost-efficient manner. In addition, since the gear ratio between the ring gear 9 and the power take-off unit 15, and thus also between the input shaft 14 and the power take-off unit 15, can be changed simply by changing the second and third gears 27, 29, an arrangement 1 is provided in which a distance between the input shaft 14 and the power take-off unit shaft 21 can be kept the same also when using different sets of second and third gears 27, 29. That is, the size ratio of the second and third gears 27, 29 can be altered without affecting the distance between the intermediate shaft 23 and the power takeoff unit shaft 29, and thus without affecting the distance between the input shaft 14 and the power take-off unit shaft 21. Accordingly, an arrangement 1 is provided which can be adapted to requirements of different vehicles in a simple and cost-efficient manner.

According to the illustrated embodiments, the arrangement 1 further comprises a lubrication system 35 configured to lubricate gears 25, 27, 29 of the second gear set 19. The lubrication system 35 comprises a pump 37 configured to pump lubricant, such as oil, to the gears 25, 27, 29. As illustrated, the pump 37 is arranged to be driven by the ring gear 9. Thereby, the pump will be driven when the ring gear 9 is rotating. The ring gear 9 is rotating when power is transferred from the input shaft 14 to the power take-off unit 15 and the ring gear 9 is stationary when no power is transferred from the input shaft 14 to the power take-off unit 15. Accordingly, the pump 37 of the lubrication system 35 will pump lubricant to the gears 25, 27, 29 of the second gear set 19 only when needed. Thereby, parasitic losses of the lubrication system 35 are minimized. Thus, a reliable and energy efficient arrangement 1 is provided.

The lubrication system 35 may be arranged to lubricate further components of the arrangement 1 such as bearings and the power take-off unit 15. The lubrication system 35 may further comprise a lubricant reservoir in a housing of the planetary gear 5, ensuring lubrication of the sun gear 7, the planet gears 11, the carrier 13 and the cog teeth of the ring gear 9, when no power is transferred to the power take-off unit 15, i.e. when the arrangement is in the disengaged state. Such an lubrication reservoir may be configured to accommodate lubricant, such as oil, by an amount ensuring that the lubricant is reaching the sun gear 7, the planer gears 11, the carrier 13 and the cog teeth of the ring gear 9 upon rotation of the carrier 13, the planet gears 11 and the sun gear 7.

According to the embodiments illustrated in Fig. 1, as well as in Fig. 2, the sun gear 7 comprises a through hole 39, wherein the input shaft 14 extends through the through hole 39. According to the illustrated embodiments, the power take-off arrangement 1 is arranged to be positioned between a power source of the vehicle 3 and a transmission of the vehicle 3.

Fig. 3 illustrates a powertrain 47 for a vehicle 3, according to some embodiments. The powertrain 47 comprises a power source 43 and a transmission 45. The power source 43 is configured to provide motive power to the vehicle 3 via the transmission 45. The power source 43 may comprise a combustion engine, such as a diesel engine or an Otto engine configured to operate on gasoline, ethanol, or similar volatile fuel. As an alternative, or in addition thereto, the power source 43 may comprise one or more electric machines. The transmission 45 may comprise a clutch, a gear box, one or more shafts, and one or more differentials being arranged to transfer power from the power source 43 to one or more propulsion units, such as wheels of a vehicle. The powertrain 47 further comprises a power take-off arrangement 1. The power take-off arrangement 1 illustrated in Fig. 3 may comprise a power take-off arrangement 1 as illustrated in Fig. 1 or as illustrated in Fig 2. The input shaft 14 of the power take-off arrangement 1 is connected to a first shaft 41 of the powertrain 47.

According to the illustrated embodiments, the first shaft 41 of the powertrain 47 is arranged to transfer torque between the power source 43 and the transmission 45. The sun gear 7 of the power take-off unit 1 comprises a through hole 39, wherein the first shaft 41 extends through the through hole 39. As illustrated, the power take-off arrangement 1 is arranged between the power source 43 and the transmission 45.

Thus, according to these embodiments, the input shaft 14 of the power take-off arrangement 1 forms part of the first shaft 41 of the powertrain 47.

According to the illustrated embodiments, the power take-off arrangement 1 may be referred to as a sandwich power take-off arrangement.

Fig. 4 illustrates a vehicle 3 according to some embodiments comprising the powertrain 47 illustrated in Fig. 3. The power source 43 of the powertrain 47 is configured to provide motive power to the vehicle 3 via the transmission 45. The vehicle 3 illustrated in Fig. 4 is a truck. However, the powertrain 47, and thus also the power take-off arrangement 1, may be comprised in another type of manned or unmanned vehicle for land or water based propulsion such as a lorry, a bus, a construction vehicle, a tractor, a car, a ship, a boat, etc.

It is to be understood that the foregoing is illustrative of various example embodiments and that the invention is defined only by the appended claims. A person skilled in the art will realize that the example embodiments may be modified, and that different features of the example embodiments may be combined to create embodiments other than those described herein, without departing from the scope of the present invention, as defined by the appended claims. The actuator arrangement may for instance comprise a dog clutch configured to selectively brake the sun gear in order to allow transfer of power from the input shaft 14 to the power take-off unit 15. Thereby, a simple power take-off arrangement 1 is provided which can be manufactured in a cost-efficient manner. However, according to such embodiments, some of the above given advantages are not obtained such as the ability of the arrangement to perform smooth and gradual transitions between the disengaged state and the engaged state during rotation of the input shaft 14.

The term planetary gear used herein may also be referred to as planetary gearing, epicyclic gearing, epicyclic gear, or the like.

As used herein, the term "comprising" or "comprises" is open-ended, and includes one or more stated features, elements, steps, components or functions but does not preclude the presence or addition of one or more other features, elements, steps, components, functions or groups thereof. As an example, the power take-off arrangement 1 may comprise more than one power take-off unit 15, such as two, three, four, five power take-off units. Each of such power take-off units may be arranged to be driven by the ring gear 9, either directly or via one or more second gear sets.

In addition, according to some embodiments, the power take-off arrangement 1 may comprise an actuator arrangement in the form of a brake 17 arranged to selectively brake the sun gear 7, as well as an actuator arrangement in the form of an electric machine 33 arranged to selectively brake or drive the sun gear 7.

Further, the power take-off arrangement 1 may comprise a control unit, such as an electronic control unit, being arranged to control the actuator arrangement 17, 33.

Claims

1. A power take-off arrangement (1) for a vehicle (3), wherein the arrangement (1) comprises: - a planetary gear (5) comprising a sun gear (7), a ring gear (9) and one or more planet gears (11) supported by a carrier (13), - an input shaft (14) connected to the carrier (13), - a power take-off unit (15) arranged to be driven by the ring gear (9), and - an actuator arrangement (17, 33) configured to selectively brake or selectively drive the sun gear (7) characterized in that the actuator arrangement (17, 33) comprises a brake (17) arranged to selectively brake the sun gear (7).

2. The arrangement (1) according to claim 1, further comprising a second gear set (19), wherein the power take-off unit (15) is arranged to be driven by the ring gear (9) via the second gear set (19).

3. The arrangement (1) according to claim 2, wherein the second gear set (19) comprises a power take-off unit shaft (21) connected to the power take-off unit (15), an intermediate shaft (23), a first gear (25), a second gear (27), and third gear (29), wherein the first and second gears (25, 27) are arranged at the intermediate shaft (23), and wherein the third gear (29) is arranged at the power take-off unit shaft (21), wherein the first gear (25) is rotationally connected to the ring gear (9), and wherein the second gear (27) is rotationally connected to the third gear (29).

4. The arrangement (1) according to any one of the preceding claims, wherein the brake (17) is a wet disc brake comprising a number of discs (31).

5. The arrangement (1) according to any one of the preceding claims, wherein the actuator arrangement (17, 33) comprises an electric machine (33) arranged to selectively brake or drive the sun gear (7).

6. The arrangement (1) according to any one of the preceding claims, further comprising a lubrication system (35) configured to lubricate gears (25, 27, 29) of the arrangement (1), wherein the lubrication system (35) comprises a pump (37) configured to pump lubricant to the gears (25, 27, 29), wherein the pump (37) is arranged to be driven by the ring gear (9).

7. The arrangement (1) according to any one of the preceding claims, wherein the sun gear (7) comprises a through hole (39), wherein the input shaft (14) extends through the through hole (39).

8. The arrangement (1) according to any one of the preceding claims, wherein the power take-off arrangement (1) is arranged to be positioned between a power source (43) of the vehicle (3) and a transmission (45) of the vehicle (3).

9. A powertrain (47) for a vehicle (3), wherein the powertrain (47) comprises a power source (43) and a transmission (45), wherein the power source (43) is configured to provide motive power to the vehicle (3) via the transmission (45), and wherein the powertrain (47) comprises a power take-off arrangement (1) according to any one of the preceding claims, wherein the input shaft (14) of the power take-off arrangement (1) is connected to a shaft (41) of the powertrain (47).

10. The powertrain (47) according to claim 9, wherein the power take-off arrangement (1) is arranged between the power source (43) and the transmission (45).

11. The powertrain (47) according to claim 10, wherein the shaft (41) of the powertrain (47) is arranged to transfer torque between the power source (43) and the transmission (45), wherein the sun gear (7) comprises a through hole (39) and wherein the shaft (41) of the powertrain (47) extends through the through hole (39).

12. The powertrain (47) according to claim 11, wherein the input shaft (14) of the power take-off arrangement (1) forms part of the shaft (41) of the powertrain (47).

13. A vehicle (3) comprising a powertrain (47) according to any one of the claims 9 - 12.