Belt drive system with engagement and disengagement and 2 gears

Abstract

Belt drive system for driving a drive shaft (15a) of a unit (3) for a harvesting machine, which unit can be switched on and off and driven with two different transmission ratios, wherein the belt drive system has a pair of drive belts (11 and 14) driven by drive pulleys (8 and 9), which drive two driven pulleys (12 and 13) assigned to the drive shaft (15a) and designed with different diameters, wherein a positive-locking clutch (40) is arranged concentrically to the drive shaft (15a), wherein an internal toothing (21) of the clutch (40) permanently engages an external toothing (20) and is connected via this at least indirectly to the drive shaft (15a), and wherein optionally the first or second driven pulley (12, 13) can be drivingly connected to the drive shaft (15a) or both can be decoupled from the drive shaft (15a), thereby marked,that the clutch (40) has a longitudinally displaceable hollow cylindrical sliding sleeve (37) provided with an internal toothing (36) and at least one coupling toothing (38), and that the coupling toothing (38) selectively engages with a first driving toothing (41) provided on the first driven pulley (12), with a second driving toothing (42) of the second driven pulley (13), or with neither of the two driving toothings (41, 42), wherein the drive shaft (15a) is designed as a knife shaft (15) of a chopping unit (3) for a combine harvester, wherein the coupling toothing (38) is formed on the outer circumference of the sliding sleeve (37) and the driving toothing (41, 42) is formed within a hub (26, 29) of the at least one driven pulley (12, 13).

Description

[0001] The invention relates to a belt drive system for driving a drive shaft of a unit that can be switched on and off and driven with two different transmission ratios, preferably for a harvesting machine, wherein the belt drive system has a pair of drive belts driven by drive pulleys, which drive two driven pulleys that are assigned to the drive shaft and have different diameters, wherein a positive-locking clutch is arranged concentrically to the drive shaft, wherein an internal toothing of the clutch permanently engages an external toothing and is connected via this at least indirectly to the drive shaft and wherein optionally the first or the second driven pulley is drivingly connectable to the drive shaft or both are decoupled from the drive shaft.

[0002] Furthermore, the invention also relates to a belt drive system for driving a drive shaft of a unit that can be switched on and off, preferably for a harvesting machine, with a drive belt that drives a driven belt pulley assigned to the drive shaft, wherein the driven belt pulley can be selectively connected to the drive shaft or decoupled from the drive shaft via a positive-locking clutch arranged concentrically to the drive shaft, and wherein an internal toothing of the clutch permanently engages in a driving toothing that interacts at least indirectly with the drive shaft.

[0003] A belt drive system of the type specified in the respective preambles of patent claims 1 and 2 is known from WO 2014 / 085 466 A1. An output shaft driven by an internal combustion engine accommodates two drive pulleys of different diameters, which, via two drive belts designed as V-belts, drive two driven pulleys of likewise different diameters, which are freely rotatably mounted on a drive shaft of a chopping unit. The belt tension of the drive belts is adjusted via a manually adjustable belt tensioner. A clutch is arranged between the two driven pulleys, which has a disk-shaped, internally toothed coupling element, wherein the internal toothing engages with external toothing provided in sections on the drive shaft.The disc-shaped coupling element is guided axially movably on the drive shaft and has pins on both ends that protrude in the axial direction. In the two end positions of the displacement path performed by the coupling element, these pins each engage in recesses provided on the end of the two driven belt pulleys. In this way, either one or the other driven belt pulley is coupled to the drive shaft of the chopping unit, so that the drive system can be switched between two different transmission ratios. For this purpose, a handwheel that can be used as an operating handle is provided at the end of the drive shaft and engages an operating rod. This operating rod runs within a concentric longitudinal bore in the drive shaft to the disc-shaped coupling element and is connected to it via a cross pin.Consequently, the coupling element is moved from one engagement position to the other by pushing or pushing movements on the handwheel.

[0004] Further belt drive systems are known from US 2004 / 0 009 834 A1, US 9 107 345 B2, EP 0 343 461 A1, DE10 2011 114 627 A1 and JP H05- 164 208 A.

[0005] It is an object of the present invention to provide a belt drive system with a clutch which has structurally advantageous dimensions and can be provided with the belt drive systems without making changes to the drive shaft.

[0006] This problem is solved by the characterizing features of a belt drive system having the generic features specified in the preamble of patent claims 1 and 2. The patent claims dependent on these patent claims contain inventive developments of these solutions.

[0007] According to this, the clutch should have a longitudinally displaceable hollow cylindrical sliding sleeve provided with the internal toothing and at least one coupling toothing. The coupling toothing engages selectively with a first driving toothing provided on the first driven pulley, with a second driving toothing of the second driven pulley, or with neither of the two driving toothings. In this case, the belt drive system consequently has two gear stages, in which the drive shaft is driven with different gear ratios, and a neutral position in which the drive to the drive shaft is disengaged.The sliding sleeve according to the invention can be integrated with minimal structural modifications into an existing belt drive system, in which, for example, the driven pulleys were previously arranged in a rotationally fixed manner on the drive shaft of the unit and the transmission ratio was changed from one transmission stage to another by changing the drive belt. The sliding sleeve has small radial dimensions, so that the driving teeth on both driven pulleys can be provided in the area of ​​their hubs, preferably in the receiving bore of the respective hub. This design of the clutch with a sliding sleeve that alternately engages the two driven pulleys in a form-fitting manner also has the advantage that it can form the basis of a modular system.As explained below, the sliding sleeve can also be used solely to engage and disengage the drive shaft drive if the unit is not intended to be driven at different speeds. Since the coupling teeth must mesh with the respective driving teeth during the gear shifting process, this process can be simplified by a correspondingly high number of teeth in these teeth. This means that the corresponding driven pulley intended for a coupling process does not need to be manually turned until the teeth can mesh.

[0008] According to claim 1, the drive shaft is designed as a knife shaft of a chopping unit for a combine harvester.

[0009] In the alternative solution according to independent claim 2, the clutch can have a longitudinally displaceable hollow cylindrical sliding sleeve provided with internal toothing and a coupling toothing, wherein the coupling toothing can selectively engage with or be disengaged from a driving toothing of the driven pulley. In this case, the sliding sleeve can only assume two positions.

[0010] In contrast, the clutch according to WO 2014 / 085466 A1 has a disk with pins extending from each end face. These pins are designed to engage in recesses provided on the end faces of the two driven pulleys upon axial displacement of the disk. A rod system is provided for adjusting the position of the disk, which runs within the partially hollow drive shaft. Firstly, inserting the pins into the recesses is only possible after a complex manual adjustment of the driven pulley to the clutch disk, and secondly, the clutch has very large radial dimensions.

[0011] Furthermore, the drive shaft can be designed as a blade shaft for a chopping unit for a combine harvester. A corresponding chopping unit is mounted at the rear of the combine harvester and, using the blades mounted on the blade shaft and fixed counterblades, chops the straw emerging from the residual grain separation, threshed rapeseed stalks, or parts of corn plants that have passed through the threshing unit after the picking process into fine pieces.

[0012] If grain is harvested with the combine harvester, the straw emerging from the residual grain separation device can also be deposited unchopped as a swath on the stubble, so that this swath can then be picked up in a subsequent operation by a baler equipped with a pick-up. The straw chopper, which consists of a rotor with numerous rotating knives and a basket with fixed counter knives, can be switched on and off for this purpose and can be pivoted from a working position to a rest position in which the previously described swath formation of the straw can take place. In this rest position of the chopping unit, the chopping knives should not be driven if possible, as otherwise they could influence the swath formation despite the pivoting of the chopping unit or, in unfavorable positions, collide with the machine structure of the combine harvester and become damaged.In addition, switching off the chopping unit helps to increase machine efficiency.

[0013] By arranging the clutch according to the invention within the belt drive system of the chopping unit, the unit can be easily switched from one speed to another or switched off completely. This is done without complex assembly work. The chopping unit is driven at a correspondingly high speed when chopping straw and at a lower speed when chopping components of corn plants.

[0014] According to the invention, the coupling toothing is formed on the outer circumference of the sliding sleeve, and the driving toothing is formed within a hub of the at least one driven pulley. Consequently, the sliding sleeve is displaced by its axial displacement with its coupling toothing formed on the outer circumference into the driving toothing provided within the receiving bore of the hub of the respective driven pulley, so that the drive torque is transmitted from the driven pulley to the drive shaft. The individual teeth of the toothing can each have a chamfer or slope to facilitate mutual meshing regardless of position.

[0015] Furthermore, it is provided that an adjusting element engages the sliding sleeve, which interacts with an actuator that acts depending on specific parameters or with a manually operable adjusting device. A mechanically acting adjusting element can be provided. Alternatively, there are also options for adjusting the sliding sleeve hydraulically or electromagnetically. When using the belt drive system according to the invention to drive a knife shaft of a chopping unit, the data relating to the crop to be harvested and the other factors characterizing the harvesting process can be entered into a central control electronics unit, wherein the control electronics actuates the actuator that interacts with the sliding sleeve in such a way that the belt drive system is adjusted to the neutral position or one of the transmission ratios. At the start of the respective harvesting process, an automatic adjustment is then made to the clutch.It is also possible to convert both clutch variants from manual operation to a remote-controlled version implemented by an actuator. This can be achieved without any additional modification of the clutch itself. As already mentioned, this automated engagement and disengagement, as well as the speed change, can be carried out automatically based on predefined crop data, or manually remotely via the control terminal, depending on the harvester's equipment.

[0016] In a further embodiment of the invention, the adjusting element is to be designed as a rod assembly connected to one end face of the sliding sleeve. In this context, the rod assembly may have a driver at its end facing the sliding sleeve, which engages positively in a recess in the sliding sleeve. The driver is rotatably mounted.

[0017] Furthermore, it is provided that the hubs of the first driven pulley and the second driven pulley are axially adjacent to one another, with a radial clearance within the hub of the first driven pulley adjoining an internal toothing of the first pulley in the direction of an internal toothing of the second pulley. Thus, in all three positions of the first variant and in the two positions of the second variant, the sliding sleeve always occupies a position within the hub of one of the two driven pulleys. This results in an arrangement that is also very compact in the axial direction.

[0018] In addition, when the belt drive system is switched into three switching positions, a hollow cylindrical collar extends from each of the first and second driven belt pulleys, one collar being mounted radially on the other collar.

[0019] Finally, for the variant in which the drive of the drive shaft can be switched on and off, it is proposed that the sliding sleeve, in its neutral position, be movable against an axial stop in the area of ​​a hub of the second driven pulley. This creates a precise position for the sliding sleeve in its neutral position, in which the drive is switched off. According to this variant, the driven pulley is designed as a one-piece V-belt pulley and comprises two V-belt pulley sections with different diameters. By manually shifting the belt between the two V-belt pulley sections, two different speeds can be achieved.

[0020] For further explanation of the invention, reference is made to the drawing, which shows a simplified embodiment. Shown are: Fig. 1 is a schematic representation of a partial view of the rear of a self-propelled combine harvester, showing a drive of a chopping unit using a belt drive system according to the invention, Fig. 2 a half-section of a clutch arranged between a knife shaft and two driven pulleys, with which the drive of the knife shaft can be switched into two different gear ratios and an idle gear, and Fig. 3 a half-section of a clutch arranged between a knife shaft and a driven belt pulley, with which the drive of the knife shaft can be switched on or off.

[0021] In the Fig. 1, 1 denotes a self-propelled combine harvester, of which only a rear section with an exit 2 is visible in the side view. Below this exit 2, a chopping unit 3 is arranged, to which grain or rapeseed straw is fed during the grain or rapeseed harvest, and to which, during the corn harvest, the remains of the corn pods are fed from a residual grain separation device (not shown in detail). This chopping unit 3 chops the straw or the remains of the corn plant removed from the corn stalk into short pieces and, under certain circumstances, feeds these to a discharge device (also not shown). The chopping unit 3 is driven by a belt system, which is explained below.

[0022] An internal combustion engine 4 of the combine harvester 1 drives, by means of an output pulley 5 and a drive belt 6, a countershaft stage 7 comprising a first drive pulley 8 with a small diameter, a second drive pulley 9 with a larger diameter, and a third drive pulley 10 with the largest diameter. The first drive pulley 8 drives a first driven pulley 12 via a first drive belt 11, while a second driven pulley 13 is driven by the second drive pulley 9 via a second drive belt 14. The two driven pulleys 12 and 13 are assigned to a blade shaft 15 serving as a drive shaft 15a, which is mounted in a housing of the chopping unit 3. A belt tensioner 16 ensures sufficient belt tension on the two drive belts 11 and 14.The third drive pulley 10 drives the device for residual grain separation, which is formed, for example, by tray shakers, via a third drive belt 17 and a third driven pulley 18.

[0023] The Fig. Figure 2 shows a first embodiment of the invention, in which the blade shaft 15 can be driven via the belt drive system with two different gear ratios or decoupled from the drive. The blade shaft 15 is provided with a flange bearing 19, which serves to mount it in the housing of the chopping unit 3. Furthermore, the blade shaft 15 has an external toothing 20 in an area on its circumference, into which an internal toothing 21 of a bushing 22 engages. This bushing 22 is fixed in its axial direction to the blade shaft 15 via a collar 23 of the blade shaft 15 and via a fastening disc 24 and a fastening screw 25.

[0024] The driven pulley 12, which has a hub 26, is rotatably mounted on the bushing 22 by means of two radial roller bearings 27. For this purpose, the hub 26 has a first hollow cylindrical collar 28, which extends axially in one direction from the driven pulley 12 and accommodates the radial roller bearings 27 within its interior. The second driven pulley 13 has a hub 29, from which two hollow cylindrical bearing sections 30 and 31 extend. One bearing section 30 accommodates a radial roller bearing 32, with which the driven pulley 13 is mounted on the bushing 22. The further bearing section 31 extends towards the hub 26 of the driven pulley 12 and encloses the exterior of a radial roller bearing 33, which is fixed internally on a hollow cylindrical collar 34 of the hub 26. Thus, the second driven pulley 13 is rotatably mounted on the hub 26 of the driven pulley 12 via this radial rolling bearing 33.

[0025] Furthermore, the bushing 22 has an external toothing 35, into which an internal toothing 36 of a sliding sleeve 37 engages, so that the sliding sleeve 37 is guided longitudinally displaceably and rotationally fixed on the bushing 22. The sliding sleeve 37 is provided in a central area on its outer circumference with a coupling toothing 38, which extends according to the Fig. 2 is located in a radial clearance 39 of the hollow cylindrical collar 34 of the hub 26. Therefore, the clutch 40, consisting of the previously described components, is in a neutral position in which no torque is transmitted from the two driven pulleys 12 and 13 to the knife shaft 15.

[0026] The hubs 26 and 29 are each provided with a driving toothing 41 and 42, respectively, whereby the sliding sleeve 37 is displaced such that the coupling toothing 38 engages selectively with the driving toothing 41 or the driving toothing 42 to select one of the two transmission ratios. As a result, one of the two driven pulleys 12 or 13 is positively connected to the blade shaft 15. The driven pulley 12 should be engaged when components of, for example, corn plants are being chopped. The blade shaft 15 is driven via the driven pulley 13 when chopping straw. A rod 43 having a driver 44 at its end is provided for the axial displacement of the sliding sleeve 37. This driver 44 engages in a front-side recess 45 of the sliding sleeve 37 and is designed in such a way that the sliding sleeve 37 can be moved in both axial directions.This results in a decoupling of the rotational movement between the linkage 43 and the sliding sleeve 37. The linkage 43 can be actuated manually or via an actuator controlled by a central electronics or control device of the combine harvester 1.

[0027] Furthermore, in the Fig. 3 shows a clutch 46, with which a one-piece driven pulley 47, which has two pulleys 50, 51 with different pulley diameters, can be selectively coupled to or uncoupled from the blade shaft 15 provided with the bushing 22. In this case, the identically designed sliding sleeve 37, in its one position, is brought into engagement with the coupling toothing 38 in the driving toothing 41 of the hub 29. According to the Fig. 3, the clutch 46 is in the uncoupled state, i.e. the coupling toothing 38 of the sliding sleeve 37 assumes a position within a free space 48 of the hub 29, in which the driven pulley 13 can rotate freely relative to the blade shaft. The adjustment of the sliding sleeve 37 into its two positions is also carried out via the Fig. 2. When it reaches its disengaged position, the sliding sleeve 37 strikes the front end against a stop 49, which is designed as an annular shoulder in the hub 29. This disengaged position is provided when the chopping unit 3 is to be switched off during swathing of the straw. Due to the two different pulley diameters of the two pulleys 51, 52 of the driven pulley 47, a speed adjustment can be effected by manually shifting the belt from one pulley 50 to the other pulley 51. This arrangement also allows the chopping unit 3 to be operated at different speeds, optionally for maize or grain. This is achieved, however, by manually shifting the corresponding drive belt.

[0028] The two Fig. 2 and Fig.3 show that essentially the same components are used for belt drive systems that can be switched between two different gear ratios or a neutral position using a clutch 40, or that can be engaged or disengaged using a clutch 46. Thus, this arrangement is suitable for a modular system with which the belt drive system can be adapted to the respective requirements. Furthermore, the clutches 40 and 46 are designed with structurally advantageous dimensions. Reference symbol 1 self-propelled combine harvester 2 Exit 3 chopping unit 4 internal combustion engine 5 Output pulley 6 drive belts 7 Countershaft stage 8 first drive pulley 9 second drive pulley 10 third drive pulley 11 first drive belt 12 first driven pulley 13 second driven pulley 14 second drive belt 15 knife shaft 15a Drive shaft 16 belt tensioners 17 third drive belt 18 third driven pulley 19 flange bearings 20 external teeth of 15 21 internal gearing of 22 22 socket 23 bundles of 15 24 Mounting disc 25 fixing screw 26 hub of 12 27 double-row radial rolling bearing 28 hollow cylindrical collar of 26 29 hub of 13 30 hollow cylindrical bearing section 31 hollow cylindrical bearing section 32 radial rolling bearings 33 radial rolling bearings 34 hollow cylindrical collar of 26 35 external teeth of 22 36 internal gearing of 37 37 Sliding sleeve 38 coupling gearing 39 radial clearance of 34 40 clutch 41 driving teeth of 26 42 driving teeth of 29 43 rods 44 drivers 45 recess 46 clutch 47 Driven pulley 48 open space 49 stop 50 pulley 51 pulley

Claims

[1] Belt drive system for driving a drive shaft (15a) of a unit (3) for a harvesting machine, which unit can be switched on and off and driven with two different transmission ratios, wherein the belt drive system has a pair of drive belts (11 and 14) driven by drive pulleys (8 and 9), which drive two driven pulleys (12 and 13) assigned to the drive shaft (15a) and designed with different diameters, wherein a positive-locking clutch (40) is arranged concentrically to the drive shaft (15a), wherein an internal toothing (21) of the clutch (40) permanently engages an external toothing (20) and is connected via this at least indirectly to the drive shaft (15a), and wherein optionally the first or second driven pulley (12, 13) can be drivingly connected to the drive shaft (15a) or both can be decoupled from the drive shaft (15a). are, characterized bythat the clutch (40) has a longitudinally displaceable hollow cylindrical sliding sleeve (37) provided with an internal toothing (36) and at least one coupling toothing (38), and that the coupling toothing (38) selectively engages in a first driving toothing (41) provided on the first driven pulley (12), in a second driving toothing (42) of the second driven pulley (13) or in neither of the two driving toothings (41, 42), wherein the drive shaft (15a) is designed as a knife shaft (15) of a chopping unit (3) for a combine harvester, wherein the coupling toothing (38) is formed on the outer circumference of the sliding sleeve (37) and the driving toothing (41, 42) is formed within a hub (26, 29) of the at least one driven pulley (12, 13) is. [2] Belt drive system for driving a drive shaft (15a) of a switchable and switchable unit (3), preferably for a harvesting machine, with a drive belt which drives a driven pulley (47) assigned to the drive shaft (15a), wherein the driven pulley (47) can be selectively connected to the drive shaft (15a) or decoupled from the drive shaft (15a) via a positive-locking clutch (46) arranged concentrically to the drive shaft (15a), and wherein an internal toothing (21) of the clutch (46) permanently engages an external toothing (20) which interacts at least indirectly with the drive shaft (15a), characterized bythat the clutch (46) has a longitudinally displaceable hollow cylindrical sliding sleeve (37) provided with an internal toothing (36) and a coupling toothing (38), and that the coupling toothing (38) selectively engages with a driving toothing (42) of the driven belt pulley (47) or is disengaged therefrom, wherein the coupling toothing (38) is formed on the outer circumference of the sliding sleeve (37) and the driving toothing (41, 42) is formed within a hub (26, 29) of the at least one driven belt pulley (12, 13). [3] Belt drive system according to claim 2, characterized by that the drive shaft (15a) is designed as a knife shaft (15) of a chopping unit (3) for a combine harvester. [4] Belt drive system according to one of claims 1 or 2, characterized by that an adjusting element acts on the sliding sleeve (37) and interacts with an actuator or manually operable adjusting device acting as a function of certain parameters. [5] Belt drive system according to claim 4, characterized by that the adjusting element is designed as a rod (43) which is connected to an end face of the sliding sleeve (37). [6] Belt drive system according to claim 5, characterized by that the rod (43) has at its end facing the sliding sleeve (37) a driver (44) which engages positively in a recess (45) of the sliding sleeve (37). [7] Belt drive system according to claim 1 or 2, characterized by that the hubs (26 and 29) of the first driven pulley (12) and the second driven pulley (13) are axially adjacent to one another, wherein in the axial direction, a radial free space (39) located within the hub (26) of the first driven pulley (12) adjoins the driving toothing (41) of the first pulley (12) designed as an internal toothing in the direction of the driving toothing (42) of the second pulley (13) designed as an internal toothing. [8] Belt drive system according to claim 1, characterized by that a hollow cylindrical collar (28, 34) extends from each of the first and the second driven belt pulley (12 and 13), wherein one collar (34) is mounted radially on the other collar (28). [9] Belt drive system according to claim 2, characterized by that the sliding sleeve (37) is movable in its neutral position against an axial stop (49) in the region of a hub (29) of the driven belt pulley (47).

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