DE102019207925A1 - Power take-off gear and agricultural work machine - Google Patents

Abstract

The invention relates to a power take-off transmission (1) for a motor vehicle, comprising a drive shaft (2) and an output shaft (3), with a number of idle drive gears (5, 6) and at least one of the number of idle drive gears (5) on the drive shaft (2) , 6) associated switching element (7) are arranged, wherein by actuation of at least one of the number of idler gears (5, 6) associated switching element (7) each individual idler gear (5, 6) can be driven or coupled to the drive shaft (2) from the first drive shaft (2) is drivably separable, with a number of idle output gears (9, 10) and at least one switching element (11) assigned to the number of idle output gears (9, 10) being arranged on the output shaft (3), whereby by means of a Actuation of the at least one of the number of idler output gears (9, 10) assigned switching element (11) each a single idle output gear (9, 10) can be driven to be coupled to the output shaft (3) or vo n the output shaft (3) can be separated in terms of drive, and one idler gear (5, 6) in each case meshes with an idler gear (9, 10). The power take-off gear (1) according to the invention is characterized in that the power take-off gear (1) also comprises a multiple spur gear (14) which meshes with at least two idle output gears (9, 10). The invention also relates to a corresponding agricultural work machine.

Description

The invention relates to a power take-off gear according to the preamble of claim 1 and an agricultural machine.

In the prior art, in particular for agricultural work machines, power take-off shafts are known which enable the drive of drivable work devices that can be coupled to the work machines. Examples of such drivable implements are mowers, straw balers or fertilizer spreaders. The known power take-off shaft transmissions often have several switchable gear steps, which set a speed of a drive unit of the work machine and an output speed of the power take-off shaft in an adjustable ratio.

In this context, the DE 10 2011 084 623 A1 a power take-off gear in the form of a power take-off gear, in which a drive shaft can be coupled to an off-axis output shaft via one of several intermediate gear stages, each defining an associated gear ratio. The gear ratios are each assigned to one of two sub-transmissions, each sub-transmission having an input shaft which can be coupled non-rotatably to the drive shaft via a powershift element. In addition, the input shafts are arranged coaxially to one another and the powershift elements are combined in a double clutch, so that the power take-off transmission is designed as a whole in the manner of a double clutch transmission. A change between the individual gear ratios that can be represented can then be carried out under load by preselecting an adjacent gear ratio in the respective other sub-gear when the drive shaft and output shaft are coupled via a gear ratio of one sub-transmission and the change then takes place by switching between the powershift elements.

The known power take-off shafts or power take-off gears are, however, disadvantageous in that they are designed to be comparatively complex.

It is an object of the present invention to propose an improved power take-off transmission.

This object is achieved according to the invention by the power take-off gear according to claim 1. Advantageous refinements and developments of the invention emerge from the dependent claims.

The invention relates to a power take-off transmission for a motor vehicle, comprising a drive shaft and an output shaft, a number of idler gears and at least one shift element assigned to the number of idler gears being arranged on the drive shaft, whereby by actuation of the at least one shift element assigned to the number of idler gears is arranged a single idler gear can be coupled to the drive shaft or be separated from the first drive shaft, with a number of idler gears and at least one shift element assigned to the number of idler gears being arranged on the output shaft, whereby by actuating the at least one shift element assigned to the number of idler gears in each case a single output idler gear can be coupled to the output shaft or can be separated from the output shaft in terms of drive, and in each case one idler gear with one output drive ad is engaged. The power take-off gear according to the invention is characterized in that the power take-off gear further comprises a multiple spur gear which meshes with at least two idle output gears.

According to the invention, a power take-off transmission is therefore proposed which comprises a drive shaft and an output shaft, a number of idle drive gears being arranged on the drive shaft and a number of idle output gears being arranged on the output shaft. The power take-off gearbox preferably comprises a single drive shaft and a single output shaft. One idler gear is in engagement with one idler gear. In addition, at least one shift element assigned to the number of idler gears is provided on the drive shaft and at least one shift element assigned to the number of idler gears is provided on the output shaft. When the at least one switching element assigned to the number of idler gears is actuated, depending on the type of actuation, an individual idler gear is drive-coupled to the drive shaft, i.e. connected to the drive shaft in a rotationally fixed manner, or separated from the drive shaft in a driving manner, so that there is no longer a non-rotatable connection between the individual idler gear and the drive shaft. Functionally, the shift element thus represents a clutch for the transmission of a rotary movement from the drive shaft to the individual drive wheel or vice versa. In an analogous manner, an individual output idler gear is coupled to the output shaft or separated from it when the at least one of the number of idler gears assigned switching element is actuated. The different gear stages of the power take-off transmission can thus be selected by appropriate actuation of the respectively assigned shift elements. If all switching elements are actuated to the effect that at least If no idler gear is coupled to the drive shaft and, if necessary, no idler gear is coupled to the output shaft, an uncoupled neutral state or idling is shown. Finally, the power take-off gear according to the invention comprises a multiple spur gear which meshes with at least two idle output gears of the number of idle output gears. The multiple spur gear preferably consists of exactly as many individual spur gears as the power take-off gear includes idle output gears; the number of individual spur gears of the multiple spur gear thus corresponds identically to the number of idle output gears. If the power take-off gear comprises, for example, three idle output gears, that is, if the number of idle output gears is three, then the multiple spur gear also consists of three single spur gears. The multiple spur gear is advantageously a plurality of single spur gears welded to one another or otherwise non-rotatably connected to one another. In particular, the multiple spur gear is not a single spur gear arranged on a separate shaft. The multiple spur gear used according to the invention represents a simple and inexpensive alternative to single spur gears arranged on a shaft. In addition, when using a multiple spur gear, no additional switching elements are required to couple one or more individual spur gears of the multiple spur gear to continue the load flow with a shaft or again from to separate this, since the individual spur gears of the multiple spur gear are naturally non-rotatably connected to one another. This in turn reduces the costs, the weight and the space required for the power take-off gear.

It is preferably provided that the drive shaft and the output shaft as well as an axis of rotation of the multiple spur gear are arranged parallel to one another.

It is preferably provided that the shift element assigned to the number of idler gears is designed as a power shift clutch. Likewise preferably, the at least one shift element assigned to the number of idle output gears is also designed as a power shiftable clutch. In this case, the torque transmission to the drive shaft or to the output shaft does not have to be interrupted for the actuation of the corresponding switching element or the corresponding switching elements. A power-shiftable clutch enables shifting from an engaged gear to a gear to be shifted, whereby a synchronization of the speeds of the shifted elements can take place via a so-called "grinding", whereby an essentially jerk-free shifting can be guaranteed.

It is particularly preferably provided that the drive shaft is permanently coupled to a drive unit, i.e. that the drive shaft is permanently driven. However, via the shifting element assigned to the number of idler gears, it is possible to drively decouple all idler gears from the drive shaft, so that a load flow from the drive shaft to the output shaft is nevertheless interrupted. It is also possible to use the switching element assigned to the number of idle output gears to drively separate all idle output gears from the output shaft, so that a load flow from the drive shaft to the output shaft can also be interrupted in this way.

According to a preferred embodiment of the invention, it is provided that in each case a drive idler gear and a single spur gear of the multiple spur gear are in engagement with a common output idler gear. This leads to the advantage that a large number of shiftable gear stages of the power take-off gear can be produced in a comparatively simple and cost-effective manner by using comparatively few idler gears or a few idler gears. Furthermore, this leads to a reduction in the required installation space and the required weight. For example, a total of only six gears, that is to say a total of six idler gears, idler output gears and individual spur gears of the multiple spur gear, are necessary to represent four shiftable gear stages. The power take-off gears known in the prior art, on the other hand, require eight wheels to represent four shiftable gear stages.

According to a further preferred embodiment of the invention it is provided that a main switching element for interrupting a torque transmission to the drive shaft is arranged on the drive shaft. The power take-off transmission can thus be completely separated from a torque supply. Accordingly, losses due to friction in the power take-off gear can be avoided if the power take-off gear is not required and is not in operation. Thus, the efficiency of a drive train of a vehicle that includes the power take-off transmission can be improved.

It is particularly preferred that the at least one shift element assigned to the number of idler gears is designed as a non-power shift clutch. Likewise, the at least one shift element assigned to the number of idle output gears is also preferably designed as a non-power shift clutch. During a switching process, ie when one of the two switching elements is actuated, one is then advantageously by means of the main switching element Torque transmission to the drive shaft interrupted in order to enable the actuation of the corresponding switching element or the corresponding switching elements. In this case, the main switching element is preferably designed to be power-shiftable.

According to a further preferred embodiment of the invention, it is provided that the shift element assigned to the number of idler gears and the shift element assigned to the number of idler gears are each designed as a sliding sleeve with a sleeve carrier and / or each designed as an electrohydraulically actuated multi-plate clutch. Such a training method has proven to be equally suitable as it is inexpensive in terms of production. The embodiment as an electrohydraulically actuated multi-plate clutch is particularly suitable for a shift element designed as a power shift element.

According to a further preferred embodiment of the invention it is provided that two idler gears are arranged on the drive shaft, that two idler gears are arranged on the output shaft and that the multiple spur gear is designed as a double spur gear. This embodiment enables the representation of two torque transmission branches from the drive shaft via the double spur gear to the output shaft and two further torque transmission branches from the drive shaft directly to the output shaft. When only six gears are used, i.e. a total of six idler gears, idle output gears and individual spur gears of the multiple spur gear, the representation of four gear stages is possible.

According to a particularly preferred embodiment of the invention, it is provided that ratios of pitch circle diameters of the two meshing idler gears and idle output gears as well as the two idle output gears and individual spur gears of the double spur gear that are in engagement with one another are designed such that an output speed of the power take-off gear is normalized Input speed corresponds to a standardized PTO stage. This has the advantage that the output shaft can be used to drive attachments that can be driven to the power take-off gear, e.g. Mowers, hay balers and planting machines, which are often designed to be driven with a standardized input speed. Different standardized power take-off shaft stages are known to the person skilled in the art, each of which indicates a specific speed of the output shaft at a specific engine speed. Via the power take-off gear, the speed of the output shaft is nevertheless proportional to the engine speed and changes accordingly with the engine speed in accordance with a change in the engine speed. Known PTO stages are e.g. "540", "540E", "1000" or "1000E".

According to a further particularly preferred embodiment of the invention, it is provided that the shifting element assigned to the two idle drive gears is arranged between the two first idle drive gears and / or that the shifting element assigned to the two idle output gears is arranged between the two idle output gears. This enables a simple coupling or disconnection of a drive connection between the drive shaft and the respective idler gear or between the output shaft and the idler gear and has proven particularly suitable in the operation of the power take-off gear according to the invention.

According to a further preferred embodiment of the invention, it is provided that an end piece of the output shaft is designed as a power take-off shaft stub. This enables attachments to be connected and operated in a simple manner.

According to a further preferred embodiment of the invention, it is provided that the drive shaft can be drivably coupled to a drive unit of the motor vehicle in such a way that a speed of the drive shaft is identical to an output speed of the drive unit. Typically, when driving attachments, the output speed of the drive unit is then switched to an operating mode for driving the power take-off shaft. This favors the drive of attachments.

The invention further relates to an agricultural work machine, comprising a power take-off gear according to the invention. The use of the power take-off gear according to the invention in the agricultural work machine leads to the advantages already described in connection with the power take-off gear according to the invention.

• 1 schematisch eine mögliche Ausbildungsform eines erfindungsgemäßen Nebenabtriebsgetriebes.

It shows:

• 1 schematically a possible embodiment of a power take-off gear according to the invention.

The same objects, functional units and comparable components are denoted by the same reference symbols in all the figures. These objects, functional units and comparable components are identical in terms of their technical features, unless the description explicitly or implicitly states otherwise.

1 shows schematically a possible embodiment of a power take-off gear according to the invention 1 , which is a drive shaft 2 , an output shaft 3 and one as a double spur gear 4th trained multiple spur gear 4th includes. On the drive shaft 2 are, for example, two idler gears 5 and 6th arranged over a switching element 7th , which is also on the drive shaft 2 is arranged to drive with the drive shaft 2 can be coupled or separated from it. The switching element 7th is the idler gears 5 and 6th assigned and can represent, for example, three different states, namely a drive coupling of the idler gear 5 with the drive shaft 2 , a drive coupling of the idler gear 6th with the drive shaft 2 and an uncoupled state in which neither the idler gear 5 nor the idler gear 6th with the drive shaft 2 is coupled. The switching element 7th is not designed to be load-shiftable. Also on the drive shaft 2 is a main switching element 8th arranged, by means of which a load flow from an in 1 Drive unit not shown, for example according to an internal combustion engine, on the drive shaft 2 can be interrupted so that the load flow by means of the switching element 7th from the drive shaft 2 on the idler gear 5 or that can be switched to. As soon as one of the two idler gears 5 or. 6th with the first drive shaft 2 was drive-coupled, can be via the main switching element 8th the load flow to the drive shaft can be restored. The main switching element 8th is designed, for example, power shiftable.

On the output shaft 3 are two idler gears 9 and 10 arranged by means of an actuation of the switching element 11 each with the output shaft 3 be drive-coupled or are drive-separated from this. As can be seen, the idler gear is stationary 5 with the idler gear 9 engaged. The idler gear 6th stands with the idler gear 10 engaged. The switching element 11 is the output gears 9 and 10 assigned and not designed to be power shiftable. Also the switching element 11 can represent, for example, three different states, namely a drive-related coupling of the idler gear 9 with the output shaft 3 , a drive coupling of the idler gear 10 with the output shaft 3 and an uncoupled state in which neither the idler gear 9 nor the idler gear 10 with the output shaft 3 is coupled. An axial end piece of the output shaft is a flange 12 the output shaft, via which the drive of an in 1 attachment is not shown in full. Only one with the flange can be seen in FIG 12 connected PTO stub 13 .

The double spur gear 4th consists of two single spur gears 14 ' and 14 " , which are welded to one another according to the example. The single spur gear 14 ' stands with the idler gear 10 engaged while the single spur gear 14 " with the idler gear 9 is engaged.

This in 1 PTO shown 1 enables the representation of a total of four torque transmission branches from the drive shaft 2 on the output shaft 3 and thus from four switchable gear steps. A first torque transmission branch runs from the drive shaft 2 via the idler gear 6th and the idler gear 10 on the output shaft 3 . A second torque transmission branch runs from the drive shaft 2 via the idler gear 5 and the idler gear 9 on the output shaft 3 . A third torque transmission branch runs from the drive shaft 2 via the idler gear 6th and the idler gear 10 to the single spur gear 14 ' of the double spur gear 14th . From there, the third torque transmission branch continues to the single spur gear 14 " and via the idler gear 9 finally on the output shaft 3 . Finally, a third torque transmission branch runs from the drive shaft 2 via the idler gear 5 and the idler gear 9 to the single spur gear 14 " of the double spur gear 14th . From there the fourth torque transmission branch continues to the single spur gear 14 ' and via the idler gear 10 finally on the output shaft 3 .

List of reference symbols

1

Power take-off gear

2

drive shaft

3

Output shaft

4th

Multiple spur gear, double spur gear

5

Idler gear

6th

Idler gear

7th

Switching element

8th

Main switching element

9

Output idler gear

10

Output idler gear

11

Switching element

12

Output shaft flange

13

PTO stub

14th

Output idler gear

14 '

Single spur gear

14 "

Single spur gear

QUOTES INCLUDED IN THE DESCRIPTION

This list of the 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.

Patent literature cited

• DE 102011084623 A1 [0003]

Claims (10)

Power take-off gear (1) for a motor vehicle, comprising a drive shaft (2) and an output shaft (3), with a number of idler gears (5, 6) and at least one associated with the number of idler gears (5, 6) on the drive shaft (2) Switching element (7) are arranged, whereby by actuation of the at least one of the number of idler gears (5, 6) assigned switching element (7) an individual idler gear (5, 6) can be driven to the drive shaft (2) or from the first drive shaft (2) can be separated by drive, a number of idle output gears (9, 10) and at least one switching element (11) assigned to the number of idle output gears (9, 10) being arranged on the output shaft (3), whereby by actuating the at least one the number of idle output gears (9, 10) assigned switching element (11) each have an individual idle output gear (9, 10) drivably coupled to the output shaft (3) or from the output shaft (3) tri can also be separated and one idler gear (5, 6) each engages with one idler output gear (9, 10), characterized in that the power take-off gear (1) further comprises a multiple spur gear (14) which is equipped with at least two idle output gears (9 , 10) is engaged. Power take-off gear (1) Claim 1 , characterized in that one idler gear (5, 6) and one single spur gear (14 ', 14 ") of the multiple spur gear (14) are in engagement with a common idle output gear (9, 10). Power take-off gear (1) according to at least one of the Claims 1 and 2 , characterized in that a main switching element (8) for interrupting a torque transmission to the drive shaft (2) is arranged on the drive shaft (2). Power take-off gear (1) according to at least one of the Claims 1 to 3 , characterized in that the shift element (7) assigned to the number of idler gears (5, 6) and the shift element (11) assigned to the number of idler gears (9, 10) are each designed as a sliding sleeve with a sleeve carrier and / or as an electro-hydraulically actuatable Multi-disc clutch are formed. Power take-off gear (1) according to at least one of the Claims 1 to 4th , characterized in that two idler gears (5, 6) are arranged on the drive shaft (2), that two idler gears (9, 10) are arranged on the output shaft (3) and that the multiple spur gear (14) is designed as a double spur gear (14) is. Power take-off gear (1) Claim 5 , characterized in that ratios of pitch circle diameters of the two meshing idler gears (5, 6) and idle output gears (9, 10) and the two idle output gears (9, 10) and individual spur gears (14 ', 14 " ) of the double spur gear (14) are designed such that an output speed of the power take-off gear (1) corresponds to a normalized power take-off stage at a normalized input speed. Power take-off gear (1) according to at least one of the Claims 5 and 6th , characterized in that the shift element (7) assigned to the two idler gears (5, 6) is arranged between the two first idler gears (5, 6) and / or that the shift element (11) assigned to the two idler gears (9, 10) is between the two idle output gears (9, 10) is arranged. Power take-off gear (1) according to at least one of the Claims 1 to 7th , characterized in that an end piece of the output shaft (3) is designed as a power take-off shaft stub (16). Power take-off gear (1) according to at least one of the Claims 1 to 8th , characterized in that the drive shaft (2) is drivably coupled to a drive unit of the motor vehicle in such a way that a speed of the drive shaft (2) is identical to an output speed of the drive unit. Agricultural work machine, comprising a power take-off gear (1) according to at least one of Claims 1 to 9 .

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