WO2019092028A1

WO2019092028A1 - Driving propulsion assembly for a machine

Info

Publication number: WO2019092028A1
Application number: PCT/EP2018/080487
Authority: WO
Inventors: Stefan Frank; Robert Naether; Alexander Baar; Martin Wegscheider
Original assignee: Robert Bosch Gmbh
Priority date: 2017-11-07
Filing date: 2018-11-07
Publication date: 2019-05-16
Also published as: DE102017219756A1

Abstract

The invention relates to a driving propulsion assembly (1) for a machine (12) having at least one first and one second axle (2, 3), wherein: the at least one first and second axle (2, 3) have at least one wheel (4a, 4b, 4c, 4d) at each of the distal ends thereof; the at least one first and second axle (2, 3) or the wheels (4a, 4b, 4c, 4d) are each connected to a propulsion unit (5a, 5b, 5c, 5d); an associated transmission unit (6a, 6b, 6c, 6d) is arranged in the power flow in each case between the at least one first and second axle (2, 3) or the wheels (4a, 4b, 4c, 4d) and the propulsion unit (5a, 5b, 5c, 5d); each transmission unit (6a, 6b, 6c, 6d) comprises a transmission (7a, 7b, 7c, 7d) having a plurality of switching stages (8a, 8b, 9a, 9b); the transmissions (7a, 7b, 7c, 7d) can be shifted in a temporally offset manner relative to one another by means of an associated control unit (10) to carry out a shifting process of the driving propulsion assembly (1) between the axles (2, 3) without interrupting the traction force. The invention also relates to a method for carrying out a shifting process in such a driving propulsion assembly (1). The invention also relates to a machine (12) and to a computer program product.

Description

description

title

The invention relates to a traction drive assembly for a work machine having at least a first and a second axis having at their distal ends a respective wheel, wherein the axes or the wheels are connected to a respective associated drive unit, wherein in the power flow between the Axes or the wheels and the respective drive unit, a respective gear unit is arranged, wherein the respective gear unit comprises a respective transmission with a plurality of switching stages. Furthermore, the invention relates to a method for performing a switching operation in such a traction drive assembly. In addition, the invention also relates to a work machine and a computer program product. State of the art

From DE 102010036142 AI a traction drive assembly with a drive motor and a transmission device shows that includes a gearbox with a plurality of shift stages each having a fixed gear ratio and a variable gate with continuously variable transmission ratio. The variator and arranged between the drive motor and the variator, releasable coupling are connected upstream of a first switching stage of the gearbox and a second switching stage of the gearbox is connected directly to the input side or with the interposition of at least one further translation stage with the drive motor.

Based on the above-mentioned prior art, the present invention seeks to further develop a traction drive assembly for a work machine, and in particular perform switching operations of traction drive assembly traction interruption-free. The task is solved by the counterpart Stand of the patent claim 1. Preferred embodiments are given in the dependent claims.

Disclosure of the invention

A traction drive arrangement according to the invention has at least one first and one second axle, which has at least one respective wheel at its distal ends, wherein the at least one first and second axle or the wheels are connected to a respective associated drive unit, wherein in the power flow between the at least one first and the second axle or the wheels and the respective drive unit, a respective associated transmission unit is arranged, each gear unit comprises a respective transmission with a plurality of shift stages, wherein the gearbox by means of an associated control unit are staggered with respect to each other to a switching operation of the traction drive assembly between the Axles traction uninterruptible perform. In other words, the working machine has a final drive or a single-wheel drive. The first axis is preferably the front axle, the second axis preferably the rear axle of the working machine. If the working machine is operated axially, then each axle has a separate drive unit and a respective gear unit with a respective associated transmission. The gear unit is connected to the drive unit via a drive shaft and connected to the respective wheel via a respective output shaft.

Preferably, a respective differential is arranged in the power flow between the respective gear unit and the respective wheels, which is intended to drive two wheels such that they can rotate, for example during cornering of the work machine with different speeds, but with the same propulsion power. In other words, the differential is connected via an output shaft with the gear unit and is preferably located between the two wheels, wherein the output shaft of the gear unit is also the drive of the differential. Since each axis of the work machine preferably has two wheels connected to one another via the axle, the differential thus has two power take-offs. Thus, the differential is designed as axle differential. If the working machine is driven by individual wheels, each wheel at the distal end of the at least first and second axles has a separate drive unit and a respective gear unit with a respective associated manual transmission. Analogous to the final drive, each gear unit is connected to the drive unit via a drive shaft and to the respective wheel via a respective output shaft.

The drive units can be designed, for example, as an electric motor. All drive units can be supplied centrally by a power supply unit with electrical energy. Alternatively, the drive units can also be designed as a thermal motor, wherein the drive units are designed such that a switching axis, as described below, at least briefly can undertake a takeover of the drive of the machine.

The respective gearbox integrated in the transmission unit has at least two switching stages, preferably three or more switching stages, wherein each switching stage preferably has a fixed gear ratio. All gearboxes have an identical number of shift stages, wherein the gear ratios of the switching stages of the first axis differ from the gear ratios of the switching stages of the second axis. The first axis thus achieves a switching time during an acceleration process of the work machine due to the higher transmission ratio compared to the second axis at an earlier point in time.

If the gearboxes of the first axis reach the aforementioned switching time, a switching operation of the respective gearbox takes place in the next higher gear stage. The control of the switching operation is preferably carried out by the control unit. In other words, the first axis is a switching axis during the switching process. The second axis is in this case a non-switching axis, wherein the non-switching second axis assumes a tensile force portion of the switching first axis at least briefly during the switching operation. In a normal driving operation of the working machine, the drive torques, that is, the traction components are taken over in half by the first axis and half by the second axis. During switching, the non-switching axis then takes over half of it the currently switching axis. In other words, the non-switching axis provides 100% of the drive power for the duration of the shift.

The second axis of the work machine switches due to a lower gear ratio at a later time than the first axis. In other words, the second axis at this moment is the switching axis and the first axis is the non-switching axis. During the switching operation of the gearbox of the second axis, the first axis takes over at least briefly the Zugkraftanteil the second axis. The switching operation of the traction drive assembly is thus off-axis, wherein the switching operation of the first axis is always performed at a different time than the switching operation of the second axis. It is advantageous that a drop in the tensile force of the traction drive assembly is avoided by the acquisition of the tensile component of the respective non-switching axis. Thus, the acceleration process for a work machine driver is unchanged and without noticeable traction losses, the speed range of the machine is thereby optimally utilized. Furthermore, by such a configuration of the traction drive assembly to wear-prone components, such as clutches and / or synchronization units are dispensed with.

According to a first preferred embodiment, the switching stages of the first and second gear units of the first and second wheels, a first gear ratio and the switching stages of the third and fourth gear unit of the third and fourth gear on a second gear ratio, wherein the first and second gear ratio are sized unequal. In other words, the gear ratios of the first switching stages of both axes differ from each other, so that each axis with the associated gearboxes switches at a different time from the first to a second switching stage or vice versa. Furthermore, the gear ratios of the second shift stages of the two axles differ from one another, so that each axle with the associated shift transmissions advances from the second to a third shift stage at a different time or switches back from the second to a first shift stage. The same applies to an embodiment of the manual transmission with four or more switching stages. In other words, thus takes place in a work machine with independent wheel drive traction interruption-free and off-axis shifting both in advance and when switching back the manual transmission.

According to a second preferred embodiment, the switching stages of the first gear unit of the first axis, a first gear ratio and the

Shift stages of the second gear unit of the second axis to a second gear ratio, wherein the first gear ratio and the second gear ratio of the two gear units are sized unequal size. In other words, in this case of the final drive, the transmission ratio of the first shift stage of the first axle to the gear ratio of the first one differ

Switching stage of the second axis, so that the switching operation of the first axis in relation to the switching operation of the second axis is offset and at a time offset time.

According to a method according to the invention for carrying out a switching operation of a traction drive assembly of the type described above, the manual transmissions are controlled by a control unit in such a way that they are shifted in time with respect to one another in order to carry out an off-axis switching operation of the traction drive assembly from a first to at least one second switching stage without traction interruption. Preferably, the switching operation of the respective gearbox from a first switching stage in at least one second switching stage is carried out speed-dependent and / or speed-dependent. In other words, the shift operation can be viewed on the one hand from the viewpoint of the driving speed of the working machine. On the other hand, the switching operation can be considered from the viewpoint of the rotational speed of the respective drive unit.

The respective gearboxes are designed by a suitable choice of the respective gear ratio such that a switching operation of the at least one gearbox of a respective axis at a certain driving speed of the driven machine, wherein due to the different ratios of the shift stages of the switching operation of the respective axes is carried out at a different driving speed , Thus, in the case of a final drive, the respective first shift mechanism of the first axle shifts during an acceleration process because of the higher transmission ratio of the respective shift stage. at a first driving speed in the next higher switching stage and during a deceleration process of the machine at the first driving speed in the next lower switching stage. The second second-speed transmission shifts to the next higher gearshift stage during an acceleration operation at a second vehicle speed and to the next lower shift stage during a deceleration operation of the work machine at the second vehicle speed due to the lower gear ratio of the respective shift stage relative to the first axle. The second driving speed is greater than the first driving speed. Since the second driving speed is reached at a later time than the first driving speed of the working machine, the switching operation between the first and second axis is delayed.

If the shift is considered as a function of the rotational speed of the respective drive unit, the respective transmission is such that a switching operation at a certain switching speed of the drive unit, ie at a switching time of the respective drive unit, wherein the at least one gearbox of the respective axis the switching operation due to different transmission ratios at a time offset. The switching speed, in which the respective switching operation of the respective gearbox is performed, is preferably below a limit speed of the respective drive unit to ensure a long life of the traction drive assembly and to increase the safety of the traction drive assembly.

Thus, in the case of a final drive, the respective first transmission of the first axis shifts at a first time in the next higher switching stage due to the higher compared to the second axis ratio during an acceleration process at the switching speed of the drive unit. The respective second second-speed transmission shifts to a second time in the next higher switching stage due to the lower compared to the first axis ratio during the acceleration process at the switching speed of the drive unit. In this case, the second time is later than the first time, wherein the switching speed of both drive units is identical. Consequently, the switching operation of the manual transmission is offset and offset in time. Similarly, the second second-speed transmission shifts during a deceleration Process at the switching speed of the drive unit first in the next lower switching stage. The first transmission of the first axis subsequently switches during a deceleration process at the switching speed of the drive unit at a later time in the next lower switching stage.

A single-wheel drive can be performed analogously to the axle drive described above, wherein the gearbox of the wheels of the respective axis perform the switching operation either at a certain, different driving speed of the machine or at the switching speed of the respective drive unit.

In particular, the traction drive assembly according to the invention is used in a work machine. By a working machine, for example, a wheel loader is to be understood, which is provided according to its type and its particular, firmly connected to the vehicle devices for loosening and conveying material. In addition, such traction drive assembly can be used in agricultural vehicles, passenger cars or trucks.

Brief description of the drawing

In the following, two exemplary embodiments of the invention will be explained in more detail with reference to FIGS. This shows

Fig. 1 is a greatly simplified schematic representation of an inventive

Traveling drive arrangement according to a first embodiment,

Fig. 2 is a greatly simplified schematic representation of the invention

Travel drive assembly according to a second embodiment, and

3 shows an exemplary speed curve of the drive units of the traction drive arrangement according to FIG. 1.

Detailed description of the drawing According to FIG. 1, a first exemplary embodiment of a traction drive arrangement 1 for a work machine 12 is shown, wherein the working machine 12 is currently driven in the axial direction. The traction drive assembly 1 comprises a first and a second

Axle 2, 3, wherein the two axes 2, 3 at their distal ends a respective wheel 4a, 4b, 4c, 4d have. The first axis 2 is in this case the front axle and the second axle 3, the rear axle of the working machine 12. The first and second

Wheel 4a, 4b are connected to the first axle 2 and the third and fourth wheels 4c, 4d are connected to the second axle 3. Each of the axles 2, 3 is further connected to a respective drive unit 5a, 5b, wherein a respective gear unit 6a, 6b is arranged in the power flow between the axles 2, 3 and the respective drive unit 5a, 5b. The two gear units 6a, 6b comprise a respective one

Manual transmission 7a, 7b with a plurality of switching stages 8a, 9a, wherein the

Manual transmission 7a, 7b by means of an associated control unit 10 are staggered in time to each other to perform a switching operation of the traction drive assembly 1 zugkraftunterbrechungsfrei. Further, in the power flow between the respective gear unit 6a, 6b of the axles 2, 3 and the respective ones

Wheels 4a, 4b, 4c, 4d a respective differential IIa, IIb arranged.

The first drive unit 5a is operatively connected to the first transmission unit 6a via a first drive shaft 16a, wherein the first transmission unit 6a is connected to the first differential IIa via a driving shaft (not shown here). The first differential IIa is further operatively connected to the first wheel 4a via a first output shaft 17a and to the second wheel 4b via a second output shaft 17b, thereby driving the first and second wheels 4a, 4b. The second drive unit 5b is operatively connected to the second gear unit 6b via a second drive shaft 16b, wherein the second gear unit 6b is connected to the second differential IIb via a driving shaft (not shown here). The second differential IIb is further operatively connected to the third wheel 4c via a third output shaft 17c and to the fourth wheel 4d via a fourth output shaft 17d, thereby driving the third and fourth wheels 4a, 4b.

2, a second embodiment of a traction drive assembly 1 for a work machine 12 is shown, wherein the working machine 12 in the present case is single wheel driven. The traction drive assembly 1 comprises a first and a second Axle 2, 3, wherein the two axes 2, 3 at their distal ends a respective wheel 4a, 4b, 4c, 4d have. The first and second wheels 4a, 4b are connected to the first axle 2 and the third and fourth wheels are connected to the second axle 3. Each of the wheels 4a, 4b, 4c, 4d is further connected to a respective drive unit 5a, 5b, 5c, 5c, wherein in the power flow between the wheels 4a, 4b, 4c, 4d and the respective drive unit 5a, 5b, 5c, 5d respective gear unit 6a, 6b, 6c, 6d is arranged. Each of the gear units 6a, 6b, 6c, 6d comprises a respective shift transmission 7a, 7b, 7c, 7d with a plurality of shift stages 8a, 9a, wherein the shift gears 7a, 7b of the first axle 2 have the same number of shift stages 8a, 9a and the manual transmission 7c, 7d of the second axis 3 have the same number of switching stages 8a, 9a. The manual transmissions 7a, 7b, 7c, 7d can be shifted in time relative to one another by means of an associated control unit 10 in order to interrupt a switching operation of the traction drive assembly 1 without traction interruption

perform, wherein the manual transmission 7a, 7b of the first axis 2 are switched together and the manual transmission 7c, 7d of the second axis 3 are switched together.

The first drive unit 5a is operatively connected to the first gear unit 6a via a drive shaft (not shown), wherein the first gear unit 6a is operatively connected to the first wheel 4a via an output shaft (not shown here) and thus drives the first wheel 4a. The second drive unit 5b is operatively connected to the second gear unit 6b via a drive shaft 6b, wherein the second gear unit 6b is actively connected to the second wheel 4b via an output shaft (not shown here) and thus drives the second wheel 4b. The third drive unit 5c is operatively connected to the third gear unit 6c via a drive shaft 6c, wherein the third gear unit 6c is operatively connected to the third wheel 4c via an output shaft (not shown here) and thus drives the third wheel 4c. The fourth drive unit 5d is operatively connected to the fourth gear unit 6d via a drive shaft 6d, wherein the fourth gear unit 6d is operatively connected to the fourth wheel 4d via an output shaft (not shown here) and thus drives the fourth wheel 4d.

With reference to FIG. 3, the method for carrying out a switching operation of the traction drive assembly 1 during an acceleration process by means of a slide explained. The left-hand ordinate describes the rotational speed 13 in revolutions per minute for the rotational speed curves 19a, 19b of the drive units 5a, 5b shown in FIG. FIG. 3 shows a first speed curve 19a for the first drive unit 5a of the first axle 2 and a second speed curve 19b for the second drive unit 5b of the second axle 3 as a function of time 15 for a typical axle-driven drive assembly 1 according to FIG. 1. The right-hand ordinate describes the travel speed 14 in kilometers per hour for the vehicle speed curve 21 of the work machine 12 shown in FIG. 1 during an acceleration process.

In the present case, the first shift transmission 7a of the first axle 2 has a first and a second shift stage 8a, 9a, and the second shift gear 7b of the second axle 3 likewise has a first and second shift stage 8b, 9b. In other words, the gearboxes 7a, 7b of the respective axles 2, 3 have two respective switching stages 8a, 8b, 9a, 9b. Even with a design of the transmission 7a, 7b with three o or more switching stages, the described method can be used analogously, since a switching operation of a first to a second switching stage is independent of the number of manual transmission and / or the switching stages. Thus, the method is also applicable for single wheel drives analog.

The shift stages 8a, 9a of the first shift transmission 7a have a first transmission ratio and the shift stages 8b, 9b of the second shift transmission 7b have a second transmission ratio. The first gear ratio is in this case designed to be higher than the second gear ratio, so that a first switching operation 18a of the first axis 2 from the first switching stage 8a in the second switching stage 9a at an earlier time than a second switching operation 18b in the second axis 3 of the first switching stage 8b in the second switching stage 9b. In other words, the second axis 3 during the first switching operation 18a is a non-switching axis and the first axis 2 is a switching axis. The time of the respective axis 2, 3 is referred to below switching time 23a, 23b. During the first shift operation 18a, the second axle 3 takes over the tensile force of the first axle 2 for a short time, namely for the time duration of the first shift operation 18a, so that the first shift operation 18a for the work machine operator is traction interruption-free and thus not substantially noticeable. During the second shift Operation 18b takes over the first axis 2 briefly, namely for the duration of the second shift operation 18b, the tensile force of the second axis 3, so that the second shift operation 18b for the work machine driver also traction interruption-free and thus not substantially noticeable.

The switching operations 18a, 18b are performed depending on the speed. In other words, the switching operations 18a, 18b of the gearboxes 7a, 7b take place in each case at a switching speed 22 which is below a limit speed 20 of the drive units 5a, 5b. During the acceleration process of the work machine 12, the first drive unit 5a according to the first speed curve 19a reaches the shift speed 22 due to the higher first gear ratio of the respective shift stage 8a to a first shift timing 23a. The second drive unit 5b reaches the shift speed according to the second speed curve 19b due to the lower second gear ratio of the respective shift stage 8b to a second shift time point 23b, the second shift time point 23b being behind the first shift time point 23a. After reaching the respective switching time 23a, 23b, the respective drive unit 5a, 5b switched torque-free, that is, the respective axis 2, 3 generates no drive torque. During the first switching operation 18a, the second drive unit 5b compensates for the traction power drop of the first drive unit 5a and during the second shift operation 18b the first drive unit 5a briefly compensates for the traction power drop of the second drive unit 5b, the acceleration process of the work machine 12 continuing unchanged in both switching operations 18a, 18b , This shows the driving speed curve 21. After completion of the first or second switching operation 18a, 18b, the respective drive unit 5a, 5b again acted upon by a drive torque to take over the traction component again. A deceleration process of the working machine 12 takes place in the reverse order to the described acceleration process.

The shift operation can also be considered from the point of view of the travel speed of the work machine 12. Thus, the switching operation of the traction drive assembly 1 is dependent on driving speed. In this case, the respective switching operation 18a, 18b is performed by reaching a switching speed 24a, 24b of the working machine 12 defined by the control unit 10. Furthermore, during the acceleration The first shift transmission 7a at the first shift speed 24a is shifted from the first to the second shift stage 8a, 9a due to the higher first gear ratio of the respective shift stage 8a, and the second shift gear 7b at the second shift speed 24b due to the lower second gear

Gear ratio of the respective switching stage 8b from the first to the second

Switching stage 8b, 9b connected, wherein the switching operations 18a, 18b are analogous to the speed-dependent switching operation. A delay process of

Work machine 12 takes place in reverse order to the described acceleration process. Thus, the driving speed of the working machine 12 is coupled to the rotational speed of the respective drive units 5a, 5b.

Claims

claims

A drive assembly (1) for a work machine (12) having at least a first and a second axis (2, 3) having at least one respective wheel (4a, 4b, 4c, 4d) at their distal ends, the at least one the first and second axles (2, 3) or the wheels (4a, 4b, 4c, 4d) are connected to a respective associated drive unit (5a, 5b, 5c, 5d), wherein in the power flow between the at least one first and second axle ( 2, 3) or the wheels (4a, 4b, 4c, 4d) and the respective drive unit (5a, 5b, 5c, 5d) a respective associated gear unit (6a, 6b, 6c, 6d) is arranged, each gear unit (6a , 6b, 6c, 6d) comprises a respective shift transmission (7a, 7b, 7c, 7d) having a plurality of shift stages (8a, 8b, 9a, 9b),

characterized in that the gearboxes (7a, 7b, 7c, 7d) by means of an associated control unit (10) are staggered in time to each other to perform a switching operation of the traction drive assembly (1) between the axles (2, 3) traction uninterruptible.

2. Travel drive arrangement (1) according to claim 1,

characterized in that the switching stages (8a, 9a) of the first and second gear units (6a, 6b) of the first and second wheels (4a, 4b) have a first gear ratio and the gear stages of the third and fourth gear units (6c, 6d) of the third and fourth gears fourth gear (4c, 4d) have a second gear ratio, wherein the first and second gear ratio are sized unequal.

3. Travel drive arrangement (1) according to claim 1,

characterized in that the switching stages (8a, 9a) of the first gear unit (6a) of the first axis (2) has a first gear ratio and the switching stages (8b, 9b) of the second gear unit (6b) of the second axis (3) has a second gear ratio wherein the first gear ratio and the second transmission ratio of the two gear units (6a, 6b) are sized unequal size.

4. traction drive assembly (1) according to claim 5

characterized in that a respective differential (IIa, IIb) is arranged in the power flow between the respective gear unit (6a, 6b) of the axles (2, 3) and the respective wheels (4a, 4b, 4c, 4d).

5. Work machine (12), comprising a traction drive arrangement (1) according to one of claims 1 to 4.

6. A method for performing a switching operation of a traction drive assembly (1) according to one of claims 1 to 4, wherein the transmission (7a, 7b, 7c, 7d) are controlled in such a coordinated manner by a control unit (10) that they are switched in time offset from each other in order to carry out an off-axis shift operation of the traction drive assembly (1) from a first to at least one second shift stage (8a, 9a) without traction interruption.

7. The method according to claim 6,

characterized in that the switching operation of the respective

Gearbox (7a, 7b, 7c, 7d) from a first switching stage (8) in at least one second switching stage (9) is carried out as a function of driving speed and / or speed dependent.

8. Computer program product with program code means for performing the method according to any one of claims 6 and 7, when the computer program product on a control unit (10) of a traction drive assembly (1) according to one of claims 1 to 4 runs or stored on a computer-readable medium.