Patent Description:
A combine harvester includes a main self-propelled body mounted on four wheels and comprising an engine to drive the self-propelled movement of the harvester, and further comprising a feeder at the front of the harvester, a threshing system, a cleaning arrangement, a grain tank and a crop residue spreading apparatus. A removable header is attached at the front of the harvester, the header comprising movable knives at the front of a header table, a reel for guiding crops towards the knives, and transportation means such as an auger or a set of draper belts, to move the cut crops towards the centre of the header where the crops enter the feeder.

The knives of the header are part of a single or double cutterbar, that further comprises stationary counterknives, wherein the movable knives undergo a reciprocating movement or a continuous movement relative to the counterknives, thereby cutting the crops at a given height above ground level.

The movement of a set of reciprocating knives is typically driven by a driveline that is coupled to a power shaft of the harvester, and that comprises a laterally placed gearbox near the back side of the header and a transmission near the front side of the header, where a rotating part of the transmission is converted into a reciprocating motion. In traditional harvester designs, the transmission may be a belt or chain transmission, and the conversion may be realized by a wobble box.

Alternative configurations have been developed, as illustrated for example in patent publication documents <CIT> and <CIT> wherein the driveline comprises a bevel gearbox, a telescopic rotatable shaft coupled at one end to the output axle of the gearbox, and a planetary gearbox coupled to the other end of the telescopic shaft. The telescopic shaft takes the place of the belt drive of the more traditional configuration, and the planetary gearbox takes the place of the wobble box. The fact that the shaft is telescopic enables moving the cutterbar forward and backward for varying the length of the header table.

In the configurations described in <CIT> and <CIT>, the joint that couples the telescopic shaft to the planetary gearbox is mounted inside a cup-shaped flywheel that is integral with the input axle of the planetary gearbox. This makes this joint however very difficult to access. Also, the flywheel can be rather heavy on larger machines, which can make it difficult to handle the flywheel during installation or maintenance.

Patent publication document <CIT> discloses a combine harvester wherein the forward-directed driveline from the combine is coupled to the transversely oriented header drive axle through a transverse gearbox that is mounted on a moveable cradle frame onto which the header is mounted. In addition, the housing of the gearbox or at least the portion of the housing comprising the input axle of the gearbox is rotatably arranged relative to the cradle frame, about a rotation axis oriented transversely to the combine's forward direction. A mechanical link is furthermore provided between the rotatable gearbox housing (portion) and the feeder housing, configured to control the orientation of the input axle of the transverse gearbox, so as to maintain the alignment of said input axle relative to the driveline of the combine.

Patent publication document <CIT> discloses a combine harvester including a feeder and a detachable header, the feeder comprising at least one or more rotatable cams and hooks, rotatable around a common axis, the cams being arranged to gradually lower the distance between the feeder and the header, by rotating the cams away from the header, the hooks being arranged to grip a bar or pin located on the header as the cams are being rotated away from the header, thereby securing the header to the feeder. The disclosure includes an example of a universal joint comprising two forks and a cross-piece, wherein one fork is integral with or fixed to a flange.

Patent publication document <CIT> discloses a straw chopper for a combine including a rotor mounted in a housing with blades for chopping the discharge material onto a material spreading assembly. The rotor is driven by a drive transmission from an output drive shaft of the drive system of the combine harvester including first a right angle gear box connected to the drive shaft, a second right angle gear box connected to the rotor and a single drive shaft communicating drive from the first gear box to the second gear box. The disclosure includes an example of a universal joint comprising two forks and a cross-piece, wherein one fork is integral with or fixed to a flange.

Patent publication document <CIT> discloses a crop harvesting machine including a mobile frame, a header movably suspended from the frame, a pair of upper and lower conditioner rolls rotatably mounted on the frame rearwardly of the header, and drive means for operating the conditioner rolls and the cutterbar and reel of the header. The drive means includes a gearbox assembly mounted on the frame and having rotary input drive transmission means and a transversely extending rotary output shaft drivingly coupled to the input means. The drive mechanism for operating the cutterbar includes a wobble box equipped with a flywheel.

Patent publication document <CIT> discloses a tractor drawn and powered agricultural machine, such as a mower-conditioner for hay-like crops, comprising a main frame having a pair of spaced apart side walls between which a sickle mower, a tine reel, a pair of conditioning rolls, a crop gathering hood and windrowing means, and a pair of transport wheel assemblies are mounted. Operating power from the tractor is supplied through a rotatable power take-off shaft and clutches to a transmission unit comprising enclosed gears which is mounted on the main frame outboard of one side wall. The transmission unit drives the sickle mower through a reciprocating pitman drive which includes a break-away bolt which breaks if the sickle-bar jams. The pitman drive also includes a flywheel to which one end of a pitman rod is pivotably connected.

The invention aims to solve the above-described problems and achieves this aim by a header comprising a driveline arrangement as described in the appended claims. The present invention is thus related to a combine header comprising a header frame and a set of knives at the front of the header configured to undergo a reciprocating transverse movement, i.e. transverse with respect to the forward direction of travel of the harvester when the header is coupled thereto. The header comprises a driveline for driving said reciprocating movement, the driveline including a transverse drive shaft at the back of the header frame, a bevel gearbox, a lateral drive shaft and a transmission in the vicinity of the knives and configured to directly drive the knife motion. The lateral drive shaft is coupled respectively to the bevel gearbox and the transmission by a first and second universal joint. The inlet axle of the transmission is integral with or fixed to a flywheel configured to stabilize the rotation of the lateral drive shaft. The second universal joint comprises two orthogonal forks coupled by a cross-piece. One of the forks is integral with or fixed to a flange that is attached to a surface of the flywheel that faces the lateral drive shaft. The flange is configured to contribute to the stabilizing function of the flywheel when the flange is attached to said surface In other words, the assembly of the flywheel and the flange forms an enlarged operational flywheel. Due to its function, the flywheel is an axisymmetric body with respect to the flywheel's rotation axis. As the flange contributes to the stabilizing function, the flange is also an axisymmetric body about said rotation axis. The flange may for example be bolted to the surface of the flywheel that faces the lateral drive shaft.

The attachment of the universal joint to the flywheel by way of the flange enables easy access to the universal joint as well as providing a construction wherein the weight of the flange contributes to the weight of the flywheel when the driveline is operational.

According to an embodiment, the flywheel has a base portion and an axisymmetric sidewall that is oriented towards the lateral drive shaft and/or towards the transmission. According to a preferred embodiment, the flywheel comprises a sidewall oriented towards the lateral drive shaft so as to form a cup-shaped interior space and the flange is a ring-shaped flange attached to the top surface of said sidewall, with the second universal joint at least partially located inside said cup-shaped inner space. Such a configuration is particularly advantageous in the case of a header provided with an extendable and retractable header table.

Preferred embodiments will now be described with reference to the drawings. The detailed description is not limiting the scope of the invention, which is defined only by the appended claims.

<FIG> illustrates a combine header <NUM> according to one exemplary embodiment of the invention. The construction of a combine header is well-known and the header is therefore not shown in its entirety. The header comprises a frame <NUM> having a back wall <NUM> and two side walls <NUM>, only one of which is shown in the image. The floor of the header is formed by an extendable and retractable header table <NUM>, at the front of which is mounted a cutterbar <NUM> comprising a row of stationary counterknives <NUM> and a set of movable cutter knives <NUM> configured to undergo a reciprocating movement relative to the counterknives <NUM>. The extension or retraction of the header table <NUM> (and thereby the cutterbar <NUM>) relative to the frame <NUM> may be actuated by multiple variable length actuators mounted underneath the header table <NUM> and not visible in the drawing, but known as such. The side wall <NUM> has a rear portion 4a that is part of the header frame <NUM>, and a front portion 4b that is integral with or fixed to the header table <NUM> so as to extend or retract together with said table <NUM> relative to the frame <NUM>.

A rotatable auger <NUM> is visible as well, configured to move crops towards the centre of the header <NUM>, where the crops enter the feeder section (not shown) of the harvester. A second auger with oppositely inclined auger blades is present on the other side (not shown) of the header <NUM>.

The driveline for driving the reciprocating movement of the knives <NUM> is now described in more detail. The terms 'inlet axle' and 'outlet axle' are defined within the present context as respective axles of gearboxes or other types of transmissions which are part of the driveline. The wording 'inlet' and 'outlet' are to be understood as referring to the direction of the power transfer along the driveline, starting at the back of the header where power is taken up from a power source, towards the front of the header, where power is consumed by the movement of the knives.

The driveline comprises a transverse drive shaft <NUM> mounted at the back of the header <NUM>. This shaft <NUM> is referred to as transverse in the sense that it is oriented transversally with respect to the header's forward direction of travel through a field of crops when the header <NUM> is mounted at the front of an operational combine harvester. The transverse shaft <NUM> is coupled at its first end (not shown) to a power shaft of the combine. At its second end, the transverse shaft <NUM> comprises a pair of sprockets <NUM> and <NUM>, which are the driving sprockets of a first and second chain drive. The first chain drive is configured to drive the rotation of the auger <NUM>, through a larger sprocket <NUM> coupled to the auger's rotation axle. The first chain drive further comprises a tensioning sprocket <NUM>. The first chain drive is not in fact part of the driveline for driving the knife movement, but it is driven by the same transverse shaft <NUM>. The auger <NUM> could be driven in another way, for example by a driveline that is completely separate from the knife movement's driveline.

The second chain drive comprises besides the sprocket <NUM>, a further sprocket <NUM> located above said sprocket <NUM>. Said upper sprocket <NUM> is coupled to the inlet axle of a bevel gearbox <NUM> mounted on a support bracket <NUM> that is fixed to the frame <NUM>. The bevel gearbox <NUM> comprises said inlet axle (not visible) and an outlet axle <NUM>, coupled to the first end of a lateral drive shaft <NUM> by a first universal joint <NUM>. The drive shaft <NUM> is termed 'lateral' in the sense that it is located at the side of the header frame <NUM> and oriented from the back area of the header <NUM> towards the front area of the header <NUM>, i.e. in the general direction of the header's forward movement through a field when it is coupled to an operational harvester.

The driveline for the knife movement may comprise further universal joints or other couplings upstream of the components described so far, i.e. between a power shaft of the harvester and the bevel gearbox <NUM>. Such upstream joints and couplings are not shown in detail and are not the subject of the present invention. In fact, this upstream part of the driveline may be in accordance with any currently known driveline design. Also the bevel gearbox <NUM> itself is a component that is known per se, and any suitable type of known bevel gearbox may be applied in the driveline of the invention, comprising a set of bevel gears configured to transform the rotation about a first axis to a rotation about a second axis oriented essentially perpendicularly to the first axis. According to alternative embodiments of the invention, the bevel gearbox <NUM> is coupled directly to the transverse drive shaft <NUM> instead of being coupled thereto via the chain drive comprising the sprockets <NUM> and <NUM>.

In the embodiment shown, the lateral drive shaft <NUM> is a telescopic drive shaft that can extend or retract in length when the header table <NUM> is extended or retracted. Such a telescopic drive shaft is known as such and any known type of telescopic drive shaft can be implemented in a header according to embodiments of the invention that include an extendable and retractable header table. The invention is however not limited to a header comprising an extendable header table, but applies also to header having a fixed header table. In that case, the lateral drive shaft <NUM> can be a standard (i.e. non-telescopic) drive shaft.

As stated, the first end of the lateral drive shaft <NUM> is coupled to the outlet axle <NUM> of the bevel gearbox <NUM> via the first universal joint <NUM>. The second end of the lateral drive shaft <NUM> is coupled to the inlet axle (not visible in <FIG>) of a planetary gearbox <NUM> mounted on a support bracket <NUM> in the vicinity of the cutterbar <NUM>, via a second universal joint <NUM>. The support bracket <NUM> is part of the extendable front portion 4b of the header sidewall <NUM>. The planetary gearbox <NUM> comprises an outlet axle (not visible) that is coupled to the knives <NUM> in order to actuate the reciprocating movement of the knives. The planetary gearbox <NUM> as such and the way in which it is coupled to the knives <NUM> may be in accordance with known configurations, and these aspects are therefore not described here in detail.

As seen in <FIG> and as will be shown in more detail later, a flywheel <NUM> is fixed to or integral with the inlet axle of the planetary gearbox <NUM>. The second universal joint <NUM> and the way in which it is coupled to the flywheel <NUM> forms the main focus of the present invention. A more detailed image of the second joint <NUM> and the manner in which it is coupled to the planetary gearbox <NUM> according to one particular embodiment is illustrated in the section view shown in <FIG>. In this section view, the internal rotatable components of the planetary gearbox <NUM> are not shown, and only the housing 30a of said gearbox is visible, as well as the bolts <NUM> by which this housing 30a is attached to the bracket <NUM> (not shown in <FIG>). The flywheel <NUM> comprises a hollow central axle <NUM> configured to receive therein the inlet axle (not shown in <FIG>) of the planetary gearbox <NUM>. Said inlet axle is fixed to the central axle <NUM> and thereby to the flywheel <NUM> as such. The flywheel <NUM> itself comprises a base portion 36a with the hollow axle <NUM> in the centre thereof, a sidewall comprising a first sidewall portion 36b rising up perpendicularly with respect to the base portion 36a in the general direction of the lateral drive shaft <NUM> and a second sidewall portion 36c oriented in the direction of the planetary gearbox <NUM>. For the sake of brevity, the first and second sidewall 'portions' 36b and 36c are hereafter referred to as first and second 'sidewalls' of the flywheel <NUM>. The flywheel's function is to stabilize the rotation of one or more rotating components of the driveline, in particular the lateral drive shaft <NUM>. Due to this stabilizing function, the flywheel <NUM> is an axisymmetric body with respect to its rotation axis 36d.

The base portion 36a and the first sidewall 36b are forming a cup shape with the base portion 36a defining the bottom of the cup and the first sidewall 36b defining the interior space of the cup. Side openings <NUM> are provided in the sidewall 36b, for the supply of lubricant to the interior of the cup shape. The second sidewall 36c forms an oppositely oriented cup shape. However in this particular embodiment, the second sidewall 36c is optional and could be omitted.

With reference to both <FIG> and <FIG>, it is seen that the second universal joint <NUM> comprises a first fork <NUM> and a second fork <NUM>, which are interconnected by a cross-shaped centre piece <NUM> and with the second fork <NUM> oriented at a right angle to the first fork <NUM>, the forks being pivotably coupled to the respective legs of the centre piece <NUM>. These elements are known elements of any universal joint. In the joint shown in <FIG> and <FIG> however, the second fork <NUM> is integral with a ring-shaped flange <NUM> that is removably fixed to the top surface <NUM> of the sidewall 36b of the flywheel <NUM>. In the particular case of the embodiment shown, the flange <NUM> is mounted flush against the top surface <NUM> of the sidewall 36b and secured thereto by screw connections <NUM>.

In <FIG>, the piece comprising the flange <NUM> and the second fork <NUM> of the universal joint <NUM> is shown in more detail. The flange has an inner circular circumference <NUM> and an outer circular circumference <NUM>. It is seen that the legs of the fork <NUM> are attached to the flange <NUM> in the vicinity of the inner circumference <NUM>. With reference to <FIG> and <FIG>, it is seen that the flange <NUM> has a first side plane <NUM> facing the flywheel <NUM> and a second side plane <NUM> facing the lateral drive shaft <NUM>. The fork <NUM> protrudes outward from the first side plane <NUM>, so that the joint <NUM> is essentially located inside the interior space of the cup defined by the base portion 36a and the sidewall 36b. It is to be understood that although in the embodiment shown, the second fork <NUM> is integral with the flange <NUM>, this flange itself is not a part of the universal joint <NUM>. The flange <NUM> further comprises a rim portion <NUM> along the inner circumference, which fits into a recess <NUM> along the inner circumference of the top of the sidewall 36b and that is helpful for aligning the flange <NUM> to the top surface <NUM> of the sidewall 36b. Said rim portion <NUM> is however optional and could be omitted.

The piece shown in <FIG> comprising both the flange <NUM> and the second fork <NUM> is preferably produced as an integrally cast or forged piece, but could also be obtained by producing the legs of the fork <NUM> and attaching them to the ring-shaped flange <NUM> by welding.

The configuration described so far has a number of advantages over the prior art. Through the flange <NUM>, the universal joint <NUM> is coupled to the top surface <NUM> of the flywheel's sidewall 36b and not to the base portion 36a of the flywheel, which facilitates removal and re-mounting operations performed during maintenance or repair, as the connection between the joint <NUM> and the flywheel <NUM> is more easily accessible. In addition, the weight of the flange <NUM> is added to the weight of the flywheel <NUM>, i.e. the 'operational' flywheel is mainly formed of the assembly of the flywheel <NUM> and the flange <NUM>. As a consequence, the dimensions of the flywheel <NUM> as such can be reduced without diminishing its stabilizing effect. The specific embodiment wherein the joint <NUM> (comprising the forks <NUM> and <NUM> but not the flange <NUM>) is mounted inside the flywheel <NUM> is moreover advantageous in that it maximizes the distance between the first and second joints <NUM> and <NUM>. This is particularly useful in the case of the header <NUM> shown in the drawings, i.e. a header provided with an extendable and retractable header table <NUM>. In this header type, it is important to obtain the highest possible extension length for a given header size. The higher the distance between the joints <NUM> and <NUM>, the higher the obtainable extension length without requiring more complex and expensive measures such as the use of a three-piece telescopic shaft or a header design with longer sidewalls <NUM>.

Nevertheless, the invention is not limited to the case where the joint <NUM> is located inside the cup-shape defined by the base portion 36a and the sidewall 36b of the flywheel <NUM>. The first two advantages, i.e. easy accessibility and reduction of the flywheel weight, are also obtained by a second embodiment illustrated in <FIG> and <FIG>, wherein the second joint <NUM> is located outside and adjacent to the flywheel <NUM>, while still being coupled to a ring-shaped flange <NUM> that is bolted to the top surface <NUM> of the flywheel's sidewall 36b. As seen in <FIG>, the second fork <NUM> of the joint is again integral with the flange <NUM> and attached to said flange <NUM> in the vicinity of the inner circumference <NUM>. The width W between the inner and outer circumferences <NUM> and <NUM> of the flange <NUM> is however larger in this case, as the first fork <NUM> is not required to enter into the interior of the cup-shape defined by the base portion 36a and the sidewall 36b of the flywheel <NUM>.

An equivalent to the configuration shown in <FIG> may include a closed disc-shaped flange instead of a ring-shaped flange, with the second fork <NUM> integral with or attached to the centre of the disc.

According to a variant of the embodiments wherein the universal joint <NUM> is adjacent the flywheel, the flywheel comprises only the base portion 36a and the second sidewall 36c, and the flange <NUM> or a closed disc-shaped flange is attached to the base portion 36a, at the side opposite the sidewall 36c.

In fact, the invention is not limited to a flywheel having either a single or double cup shape. In general terms, the flange <NUM> or <NUM> (or a closed disc-shape flange) is removably attached to a surface of the flywheel that faces the lateral drive shaft <NUM>. When the flange is a closed disc, the flywheel could even be a solid axisymmetric body.

A number of variations of the above-described embodiments are possible without departing from the scope of the independent claims.

The planetary gearbox <NUM> is just one example of a transmission that can be applied in a header according to the invention, and that is capable of transforming the rotation of the lateral drive shaft <NUM> into a reciprocating movement of the knives <NUM>. Another transmission that can be used in a header according to the invention is a wobble box.

The outer diameter of the flange <NUM> or <NUM> could be somewhat larger than the outer diameter of the flywheel <NUM> so that the outer circumference of the flange extends beyond the diameter of the flywheel <NUM>. Alternatively, the outer diameter of the flange <NUM> or <NUM> could be somewhat smaller than the outer diameter of the flywheel <NUM>, and the top surface <NUM> of the flywheel's sidewall 36b could be provided with a rim portion so that the flange <NUM> or <NUM> may be fitted into said rim portion for easy alignment of the flange to the flywheel.

The flange <NUM> or <NUM> is preferably directly attached to the surface <NUM> of the flywheel facing the lateral drive shaft <NUM>, i.e. lying flush against and in contact with said surface <NUM>, as illustrated in the drawings. There could however be an intermediate ring or an additional flange or a number of spacers in between the flange <NUM> or <NUM> and the surface <NUM> of the flywheel.

The flange <NUM> or <NUM> could be part of a larger piece that is attached to the flywheel <NUM>, such as for example a cup-shaped piece of which the flange <NUM> or <NUM> is the bottom portion and further comprising a sidewall that is placed over the flywheel <NUM>, for example overlapping the flywheel's sidewall 36b. Such a cup-shaped piece could then be attached to the flywheel by bolt connections through the flange <NUM> or <NUM> and/or by bolt connections through the overlapping sidewalls.

In the embodiment of <FIG>, the second universal joint <NUM> is preferably fully located inside the interior space of the cup-shape formed by the base portion 36a and the sidewall 36b of the flywheel, but the joint <NUM> could also be partially located in said interior space, if the fork <NUM> protrudes outward from the side plane <NUM> over a smaller distance than shown in the drawings, or if one or more spacers are added between the flange <NUM> and the top surface <NUM> of the flywheel's sidewall 36b.

In a header according to the invention, any of the embodiments described above can be present on both sides of header <NUM>, when the header is provided with a double cutterbar, i.e. a set of knives <NUM> on each side, the two sets spanning the complete width of the header <NUM>, each set of knives being actuated by respective drivelines arranged laterally on the two sides of the header. In this case, the inventive aspects described above are applicable to the driveline of each of the knife sets.

Claim 1:
A combine header (<NUM>) comprising a header frame (<NUM>) and a driveline for driving a reciprocating movement of a set of knives (<NUM>) mounted at the front of the header, the driveline comprising :
- a transverse drive shaft (<NUM>) at the back of the header,
- a bevel gearbox (<NUM>) having an inlet axle that is rotatably coupled to the transverse drive shaft (<NUM>), and an outlet axle (<NUM>),
- a lateral drive shaft (<NUM>) arranged laterally with respect to the header frame (<NUM>), the lateral drive shaft (<NUM>) having a first end and a second end,
- a transmission (<NUM>) having an inlet axle and an outlet axle, said outlet axle being coupled to the set of knives (<NUM>),
and wherein :
- the lateral drive shaft (<NUM>) is coupled at its first end to the outlet axle (<NUM>) of the bevel gearbox (<NUM>) via a first universal joint (<NUM>),
- the lateral drive shaft (<NUM>) is coupled at its second end to the inlet axle of the transmission (<NUM>) via a second universal joint (<NUM>),
- the driveline comprises a flywheel (<NUM>) that is rotatable about a central rotation axis (36d) and integral with or fixed to the inlet axle of the transmission (<NUM>), wherein the flywheel (<NUM>) is an axisymmetric body with respect to said central rotation axis (36d), the flywheel being configured to stabilize the rotation of the lateral drive shaft (<NUM>),
- the second universal joint (<NUM>) comprises a first fork (<NUM>) attached to the lateral drive shaft (<NUM>), a second fork (<NUM>) oriented orthogonally with respect to the first fork and attached to the inlet axle of the transmission (<NUM>) and a cross-piece (<NUM>), wherein the forks are pivotable relative to the legs of the cross-piece (<NUM>),
characterised in that the second fork (<NUM>) is attached to the inlet axle of the transmission (<NUM>) by being integral with or fixed to a flange (<NUM>,<NUM>) that is removably attached to a surface (<NUM>) of the flywheel (<NUM>) that faces the lateral drive shaft (<NUM>), and wherein said flange (<NUM>,<NUM>) is also an axisymmetric body with respect to the rotation axis of the flywheel, so that the flange is configured to contribute to the stabilizing function of the flywheel (<NUM>) when the flange is attached to said surface (<NUM>).