Composite belt, use of a composite belt and belt drive of a self-propelled combine harvester

Description

[0001] The invention relates to a composite belt, comprising a cover layer and three ribs connected to the cover layer in a force-transmitting manner, each rib having the shape of a symmetrical trapezoid in cross section, each of which adjoins with its base a longer side of a rectangle, which in turn forms a cross section of the cover layer, and each rib having an elastomer material in a superstructure facing the base and in a substructure facing away from the base, and a plurality of tensile strands running parallel to one another and in the longitudinal direction of the composite belt between the superstructure and the substructure.

[0002] Furthermore, the invention relates to the use of such a composite belt in a belt drive of a self-propelled combine harvester, in particular in a belt drive driving a threshing drum.

[0003] Finally, the invention relates to a belt drive of a self-propelled combine harvester, in particular a belt drive driving a threshing drum.

[0004] The composite belts described above, also referred to as "composite V-belts" or "power belts," represent a combination of multiple (narrow) V-belts, with the individual V-belts arranged parallel to one another and connected to one another by the cover layer, also known as the belt backing. The advantage of composite V-belts over a corresponding number of individual belts is that they prevent twisting due to the lateral coupling, thus ensuring a completely even distribution of force across all individual ribs (corresponding to the individual belts). This results in low susceptibility to vibrations and shocks, as well as high breaking load and resilience, and a long service life. Such composite belts are particularly suitable for large pulley center distances, which also makes them ideal for use in large agricultural machinery, such as self-propelled combine harvesters.

[0005] DE 10 2013 103 450 A1 discloses a drive system for a self-propelled combine harvester designed as a belt drive, with composite belts with three ribs also being used in certain belt drives. Typically, the various rotationally driven devices, in particular the threshing and separating devices as well as a straw chopping device, are connected via various belt drives to an output of an internal combustion engine, usually a diesel engine. In the case of DE 10 2013 103 450, a first main belt drive is proposed, which includes the main drive pulley, a first intermediate gear stage, and a second intermediate gear stage.To ensure reliable drive of the residual grain separation device, the straw chopper, and high-performance harvesting attachments, it is proposed that the first reduction gear stage directly drive the residual grain separation device via a first belt drive and the straw chopper via a second belt drive. Furthermore, the second reduction gear stage should be connected to the drives of a harvesting attachment and a cleaning device. Improvements are needed in the known combine harvester and the belt drive system implemented therein with regard to the belt drives for driving the threshing drum and the quality of the composite belts used for the aforementioned belt drive.Further composite belts are known from the publications XP055562193 - "BELT DRIVE SYSTEMS, MAINTENANCE FREE, 35% REDUCED DRIVE COST, 67% REDUCED DRIVE WIDTH; 50% REDUCED DRIVE WEIGHT", XP055562231 - "GATES INDUSTRIAL POWER TRANSMISSION - A comprehensive product range" and US 3 948 113 A.

[0006] The invention is based on the object of proposing a composite belt for use in a belt drive of a drive system of a self-propelled combine harvester, which is characterized by high transmittable power and low manufacturing costs. Furthermore, a belt drive for driving a threshing drum of a self-propelled combine harvester is to be provided, which is characterized by high power density in a limited installation space and increased efficiency through high belt utilization.

[0007] Starting with a composite belt having the features of the preamble of claim 1, the problem is solved in conjunction with the characterizing features of this claim. Accordingly, the length of the composite belt is between 3,500 mm and 4,000 mm, the breaking load of the composite belt is 67,500 N, and the power that can be transmitted by the composite belt in continuous operation is at least 75 kW.

[0008] Such a belt draws on a well-known and proven principle of three-rib composite belts and therefore poses no particular problems in terms of manufacturability and production costs. Nevertheless, with its special length, the stated minimum belt breaking load, which corresponds to the breaking load of a single rib (corresponding to a single belt) of 22,500 N, and its minimum power that can be transmitted in continuous operation, it possesses a combination of features that allows for the realization of particularly space-saving and efficient belt drives for the threshing drum drive of a self-propelled combine harvester. The selected length enables a particularly advantageous arrangement of the axes of the individual pulleys or tension pulleys of the belt drive, as well as particularly large wrap angles, which allows for particularly high belt forces that can be transmitted reliably and without slippage, and the resulting torques.This results in a particularly high power density for a belt drive equipped with the composite belt according to the invention. Nevertheless, the composite belt according to the invention deliberately does not deviate excessively from known composite belts in order to largely continue to use existing manufacturing methods and the materials used for the individual components of the composite belt. Thus, with the composite belt according to the invention, there is no need to consistently use absolute "high-performance materials" or to resort to manufacturing processes with highly complex, potentially difficult-to-control processes or particularly complex steps.

[0009] Preferably, the maximum elongation of the composite belt after operation with a minimum continuous power transmitted by the composite belt of 75 kW and over a period of 200 hours is 1% of the length of the composite belt in new condition.

[0010] A length of the composite belt according to the invention between 3,700 mm and 3,900 mm is particularly advantageous, more preferably between 3,750 mm and 3,850 mm. A length of 3,790 mm is especially advantageous.

[0011] In order to transmit high belt forces with a comparatively small belt cross-sectional area, at least some of the tensile strands may contain filaments made at least partially of an aromatic polyamide, in particular high-strength aramid, and / or carbon. Such filaments possess particularly high tensile strength and, at the same time, high flexibility, enabling even small curvature radii when operating the composite belt according to the invention in a belt drive.

[0012] The present invention also relates to a belt drive for a self-propelled combine harvester, in particular a belt drive driving a threshing drum.

[0013] The belt drive according to the invention comprises a double pulley serving as the output, which is coupled to a threshing drum shaft, with the composite belt acting on a pulley of the double pulley having a larger diameter. Furthermore, the belt drive comprises a pulley serving as the drive, which is at least indirectly driven by an internal combustion engine, and a tensioning pulley arranged in a slack side, which is arranged entirely within an envelope of the belt drive—when viewed without the tensioning pulley.

[0014] This again results in a belt drive with outstanding power density and compactness. The composite belt used for this belt drive represents a tailor-made traction device that offers an excellent compromise between performance and durability on the one hand, and low manufacturing costs and the use of fundamentally known technology in the manufacturing process on the other.

[0015] The aforementioned belt drive is particularly advantageous if a wrap angle on the pulley of the double pulley having the larger diameter is greater than 250° and / or a wrap angle on the pulley driven by the internal combustion engine is greater than 200° and / or a wrap angle on the tensioning pulley is greater than 80°.

[0016] In this context, excellent compactness of the belt drive can be achieved if the distance of the axis of the tensioning pulley from a connecting line between the axis of the double belt pulley and the axis of the belt pulley driven by the internal combustion engine is less than 120 mm, preferably less than 100 mm.

[0017] The invention is explained in more detail below using an exemplary embodiment of both a composite belt and a belt drive. It shows: Fig. 1: a cross-section through a composite belt, Fig. 2: a side view in the direction of travel to the right of a self-propelled combine harvester showing a pre-acceleration drum drive and a threshing drum drive, and Fig. 3: the threshing drum drive according to Figure 4.

[0018] One in Figure 1The composite belt 1 (composite V-belt) shown in cross-section consists of a cover layer 2 with a flat, rectangular cross-section and a thickness 3 and a width 4. The thickness 3 is 13 ± 2 mm and the width 4 is 55 ± 2 mm. A surface 5 of the cover layer 2 forms a so-called back of the composite belt 1. A longitudinal direction of the composite belt runs perpendicular to the plane of the drawing.

[0019] The cover layer 4 forms a composite with three parallel ribs 6, each trapezoidal in cross-section, which extend from a surface 7 opposite the surface 5. Between the ribs 6 there are two equally trapezoidal grooves R. The trapezoids forming the cross-section of the ribs 6 each have a base 8 and a base side 9 running parallel thereto, opposite the base 8, which each delimits a surface 7 of the composite belt 1 opposite the surface 5. The respective legs 10 of the two trapezoids each enclose an angle 12 of 39 ± 3° with a straight line 11 running perpendicular to the surface 7.

[0020] The cover layer 2 consists of an elastomer material in the form of fabric-reinforced chloroprene.

[0021] The cross-section of the ribs 6 can be divided into a superstructure 13 facing the cover layer 2 and a substructure 14 extending from the base side 9 to the superstructure 13. The sum of the height of the superstructure 13 and the height of the substructure 14 thus corresponds to the total height 15 of the rib 6.

[0022] In each rib 6, between the superstructure 13 and the substructure 14, and half enclosed by these, there are tensile cords 16 arranged parallel to each other and extending within a plane aligned parallel to the surface 5 forming the back. In the present case, there are at least 6 tensile cords 16 per rib 6. Each tensile cord 16 consists of a multifilament thread with a diameter of 1.9 mm to 2.0 mm. The individual filaments forming the respective tensile cord 16 are made of aromatic polyamide, in particular high-strength aramid.

[0023] The base 14 of each rib 6 consists of an elastomer material in the form of fiber-reinforced chloroprene.

[0024] In addition, each rib 6 is provided on its outer sides with two sheaths 17, 18 made of a fabric. The outer sheath 17 forms, in cross-section, both the base 9 and the base 8, as well as the two legs 10 ("flanks" of the composite belt 1) of the trapezoid. The inner sheath 18 is located at a very short distance within the outer sheath 17.

[0025] The (stretched) length of the composite belt 1, which forms a closed ring, is 3,790 mm (for a threshing drum drive).

[0026] One in Figure 2The schematically illustrated self-propelled combine harvester 20 basically has a structure known from the prior art, but has a special design according to the invention, particularly with regard to the belt drives for driving a threshing drum and a pre-acceleration drum. Figure 2 The position of a belt drive 55 arranged on the right side in the direction of travel 21 for driving a threshing drum is illustrated. Figure 2 In addition, the position of a belt drive can be seen schematically, which serves to drive a pre-acceleration drum, but whose structure and function are not relevant in this case. Further details of the structure of the belt drive 55 can be found in Figure 3 :

[0027] In this case, the diameter of the two pulleys 23 and 24 is 350 mm each, and the diameter of the tension pulley is 173 mm. The wrap angle at pulley 23 is 228°, at pulley 24 it is 222°, and at the tension pulley it is 90°.

[0028] The distance between the axis 25 of pulley 23 and the axis 31 of pulley 24 is 685 mm. The distance between the axis 25 of pulley 23 and the axis 32 of tension pulley 28 is 325 mm. The distance between the axis 32 of tension pulley 28 and the axis 31 of tension pulley 24 is 326 mm. As previously stated, the length of the composite belt is 2,640 mm.

[0029] The belt drive 55 comprises a double pulley 56, which comprises a pulley 57 with a smaller diameter and a pulley 58 with a larger diameter and is designed as a one-piece composite component, so that the two pulleys 56, 57 are inseparable from one another. The two pulleys 56, 57, i.e., the double pulley 56, have a common hub 58, which accommodates a threshing drum shaft 59 rotatable about the axis 60. The composite belt 1 also runs around a pulley 61 with an axis 62, wherein the pulley 61 is drivable by means of an internal combustion engine via a main gear (not shown).

[0030] In addition, the composite belt 1 runs in a slack strand 66 of the belt drive 55 with its back-forming surface 5 around a tensioning roller 63, which is provided in the belt drive 55 with a tensioning device not described in detail but known in order to achieve a certain belt tension.

[0031] The running direction of the composite belt 1 or the direction of rotation of the pulley 61 or double pulley 56 is illustrated by the arrow 64.

[0032] In the belt drive 55, the wrap angle at the pulley 58 of the double pulley 56 is 250°, the wrap angle at the pulley 61 is 214°, and the wrap angle at the tension pulley 63 is 104°. The distance between the axis 60 of the double pulley 56 and the axis 62 of the pulley 61 is 875 mm. The distance between the axis 65 of the tension pulley 63 and the axis 62 of the pulley 61 is 286 mm, and the distance between the axis 65 of the tension pulley 63 and the axis 60 of the double pulley 56 is 600 mm. The length of the composite belt 1 of the belt drive 55 is 3,790 mm.

[0033] The distance A between the axis 65 of the tension pulley 63 and a connecting line V through the axis 62 of the pulley 61 and the axis 6 of the double pulley 56 is 66 mm. The tension pulley 63 lies entirely within an envelope curve H of the belt drive 55—viewed without the tension pulley 63. The envelope curve H consists of the sections of the two tangents to the double pulley 56 and the pulley 61, as well as the additional approximately semicircular sections of the composite belt 1 at the double pulley 56 and the pulley 61. List of reference symbols

[0034] 1Composite belt 2Cover layer 3Thickness 4Width 5Surface 6Rib 7Surface 8Base 9Base side 10Leg 11Straight 12Angle 13Superstructure 14Substructure 15Total height 16Tension cord 17Covering 18Covering 20Combine harvester 21Direction of travel 55Belt drive 56Double pulley 57Pulley 58Hub 59Threshing drum shaft 60Axle 61Pulley 62Axle 63Idler pulley 64Arrow 65Axle 66Slack side ADistance HHenvelope RRrille VConnecting line

Claims

1. A composite belt (1) comprising a cover layer (2) and three ribs (6) connected thereto in a force-transmitting manner, wherein in cross section, each rib (6) has the shape of a symmetrical trapezoid and respectively connects via a base (8) to a longer side of a rectangle which a cross section of the cover layer (2) forms, and wherein, in an upper structure (13) facing the base (8), each rib (6) has a plurality of tension cords (16) which are respectively parallel to each other and respectively extend in the longitudinal direction of the composite belt (1) in order to take up the longitudinal forces to be transmitted by the composite belt (1) and has an elastomeric material in a lower structure (14) facing away from the base (8), characterized in that the length of the composite belt (1) is between 3500 mm and 4000 mm, the breaking load of the composite belt (1) is 67500 N and the power which can be transmitted by the composite belt (1) in continuous operation is at least 75 kW.

2. The composite belt according to claim 1, characterized in that a maximum elongation of the composite belt (1) after an operation with a minimum continuous power of 75 kW transmitted by the composite belt (1) and over a time period of 200 hours is 1% of the original length of the composite belt (1).

3. The composite belt according to claim 1 or claim 2, characterized in that the length is between 3700 mm and 3900 mm, in particular 3750 mm or 3850 mm.

4. The composite belt according to one of claims 1 to 3, characterized in that at least a portion of the tension cords (16) contains filaments which consist at least in part of an aromatic polyamide, in particular high strength aramid, and / or carbon.

5. Use of a composite belt (1) according to one of claims 1 to 4 in a belt drive (55) of a self-propelled combine harvester (20), in particular in a belt drive (55) driving a threshing drum.

6. The use according to claim 5, characterized in that the belt drive (55) has a double belt pulley (56) serving as the output, which is coupled to a threshing drum shaft (59), wherein the composite belt (1) acts on a belt pulley (58) of the double belt pulley (56) which has a larger diameter, and furthermore has a belt pulley (41) acting as the drive, which can be driven at least indirectly by a combustion engine and has a tensioning roller (43) disposed in a slack side (46) which is disposed entirely within an envelope (H) of the belt drive (33) - considered without the tensioning roller (43) -, wherein the envelope (H) wraps around the belt pulley (37) of the double belt pulley (35) with the larger diameter.

7. The use according to claim 6, characterized in that a wrap angle at the belt pulley (36) of the double belt pulley (35) with the larger diameter is greater than 250° and / or a wrap angle at the belt pulley (41) which can be driven by means of the internal combustion engine is greater than 200° and / or a wrap angle at the tensioning roller (43) is greater than 80°.

8. The use according to claim 7, characterized in that a distance (A) of the axis (45) of the tensioning roller (43) from a straight connecting line (V) between the axis (40) of the double belt pulley (35) and the axis (42) of the belt pulley (41) for driving the pre-acceleration drum which can be driven by means of the combustion engine is less than 120 mm, preferably less than 100 mm, more preferably between 60 mm and 70 mm.

9. A belt drive for a self-propelled combine harvester (20), in particular a belt drive (22, 23) driving a threshing drum, characterized by a composite belt (1) in accordance with one of claims 1 to 4.