Hybrid implement drive

FIELD

[0001] The present disclosure generally relates to implements to be used with work vehicles. More specifically, the present disclosure is concerned with a hybrid drive for such implements.

BACKGROUND

[0002] The present disclosure generally relates to implements that are conventionally attached to the PTO (Power Take-Off) connection of an agricultural or industrial vehicle, i.e. a work vehicle, the vehicle comprising a prime mover, generally in the form of Internal Combustion Engine (ICE) and ground drive wheels driven by a main or traction drive transmission.

[0003] The prime mover of work vehicle is generally sized according to the maximal power that the vehicle may require, plus a safety margin. For work vehicles including a PTO, the power that may be transferred from the prime mover to the PTO is part of that calculation. Accordingly, prime movers of work vehicles are routinely oversized to take the PTO output power into account, and that leads to prime movers that therefore often work outside of their most efficient zones when the PTO is not used.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004] In the appended drawings:

[0005] Figure 1 is a block diagram view of a work vehicle provided with a hybrid implement drive provided between the PTO and the implement; [0006] Figure 2 is a block diagram of the hybrid implement drive of the work vehicle of Figure 1 , according to a first illustrative embodiment;

[0007] Figure 3 is a block diagram of the hybrid implement drive of the work vehicle of Figure 1 , according to a second illustrative embodiment; and

[0008] Figure 4 is a block diagram similar to Figure 1 but illustrating a third embodiment where the hybrid implement drive is part of the implement.

DETAILED DESCRIPTION

[0009] An object is generally to provide a hybrid implement drive.

[0010] More specifically, according to an illustrative embodiment, there is provided a hybrid implement drive provided with an input connectable to an output shaft of a prime mover and a hybrid output connectable to the input shaft of an implement, the hybrid implement drive comprising: a hybrid driveline interconnecting the input and the hybrid output of the hybrid implement drive; the hybrid driveline including a transmission provided with an input and an output; a secondary power generator provided with an output connected to the hybrid driveline; and a controller so associated with the secondary power generator as to selectively allow power developed by the secondary power generator to be combined with power developed by the prime mover.

[0011] The use of the word “a” or “an” when used in conjunction with the term “comprising” in the claims and/or the specification may mean “one”, but it is also consistent with the meaning of “one or more”, “at least one”, and “one or more than one”. Similarly, the word “another” may mean at least a second or more.

[0012] As used in this specification and claim(s), the words

“comprising” (and any form of comprising, such as “comprise” and “comprises”), “having” (and any form of having, such as “have” and “has”), “including” (and any form of including, such as “include” and “includes”) or “containing” (and any form of containing, such as “contain” and “contains”), are inclusive or open-ended and do not exclude additional, unrecited elements or process steps.

[0013] The term “about” is used to indicate that a value includes an inherent variation of error for the device or the method being employed to determine the value.

[0014] It is to be noted that the expression “prime mover” is to be construed herein and in the appended claims as an internal combustion engine a turbine engine, an electric traction motor or any other mechanical power production element or assembly.

[0015] It is to be noted that while the expression “CVT”, standing for

Continuously Variable Transmission is to be construed, herein and in the appended claims as any type of Continuously variable transmission including, amongst others dual-cavity full toroidal CVT, half-toroidal CVT; single cavity toroidal CVT, Variable-diameter pulley CVT, Magnetic CVT, Ratcheting CVT, hydrostatic CVT, Cone CVT and planetary CVT. It is also to be noted that the term “CVT” is also to be construed, herein and in the appended claims, as a CVT provided with further elements allowing it to operate as an IVT, standing for Infinitely Variable Transmission, a subset of CVT designs in which the range of ratios of output shaft speed to input shaft speed includes a zero ratio. [0016] The expressions “connected” and “coupled” are interchangeable and should be construed herein and in the appended claims broadly so as to include any cooperative or passive association between mechanical parts or components. For example, such parts may be assembled together by direct coupling or connection, or indirectly coupled or connected using further parts in between. The coupling and connection can also be remote, using for example a magnetic field or else.

[0017] The expression “input”, without reference to a specific component such as a shaft, should be construed herein and in the appended claims, as including any movable part of an object, an assembly, a system or a mechanism that is used to receive a mechanical work from same or from another assembly, system or mechanism. Similarly, the expression “output” should be construed as including a similar part that is used to transfer a mechanical work.

[0018] The term “implement” should be construed herein and in the appended claims as any element, tool or device connected to the PTO shaft to be driven thereby. Here are some non-limiting examples of implements: bailers, feed mixers, spreaders, disc mowers, rotary rakes, aerators, rotary mowers, sprayers, and concrete mixer.

[0019] Other objects, advantages and features of the hybrid implement drive will become more apparent upon reading of the following non- restrictive description of illustrative embodiments thereof, given by way of example only with reference to the accompanying drawings.

[0020] Generally stated, the illustrative embodiments describe a hybrid implement drive, that may be integrated with an implement, provided between the PTO of a work vehicle and an implement. The hybrid implement drive includes a mechanical power input and a secondary power generator, for example in the form of an electric motor, that may supplement or replace the mechanical power input.

[0021] Figure 1 of the appended drawings schematically illustrates a work vehicle drivetrain 10, a hybrid implement drive 12 provided between a PTO shaft 14 and an implement 16.

[0022] The work vehicle drivetrain 10 includes a prime mover, in the form of an Internal Combustion Engine (ICE) 18, having an output shaft connected to the input of a drive transmission 20. The output of the drive transmission 20 is conventionally connected to the wheels 22 of the vehicle. The drivetrain 10 also includes the PTO shaft 14 allowing implements to be driven by the ICE 18.

[0023] Of course, one skilled in the art will understand that the drivetrain 10 is schematically illustrated in Figure 1 and that other elements of the drivetrain 10, interesting and/or required for the operation of the vehicle, such as clutches, differentials and the like are not illustrated since they are not relevant to the present disclosure.

[0024] Turning now to Figure 2 of the appended drawings, the hybrid implement drive 12 will be described.

[0025] The hybrid implement drive 12 includes a PTO mechanical input 24, an electrical input 26 and a hybrid PTO output 28 connectable to an implement. [0026] The electrical input 26 is connectable to an electrical source, for example an AC outlet or an external DC power source (both not shown). One skilled in the art is believed in a position to design the required electric circuits (not shown) depending on the type of electrical source considered.

[0027] The hybrid implement drive 12 includes a hybrid driveline 30 interconnecting the PTO mechanical input 24 and the hybrid PTO output 28.

[0028] The hybrid driveline 30 includes an intermediate shaft 31 interconnecting the PTO mechanical input 24 and a clutch 32. The output of the clutch 32 is connected to the input of a Continually Variable Transmission (CVT) 34, the output of which defines the hybrid PTO output 28.

[0029] A gear train 36 includes a first gear 38 rotating with the intermediate shaft 31 and a second gear 40 meshed with the first gear 38. The second gear 40 is mounted to the shaft of a secondary power generator, shown herein in the form of an electric motor 42.

[0030] A motor controller 44 controls and powers the motor 42 and is powered either by a battery 46 or from the electrical input 26, as will be described hereinbelow. Accordingly, the controller 44 includes an electrical input and a battery input.

[0031] As will be apparent to one skilled in the art, since the PTO of a work vehicle conventionally has a constant rotational speed (often 1000 RPM), the gear train 36 is so sized that the natural rotational speed of the electric motor 42 is brought to the constant rotational speed of the PTO. [0032] Of course, as will be clear to one skilled in the art, the user of the work vehicle has direct or indirect control on the operation of the clutch 32, the CVT 34 and the motor controller 44.

[0033] In operation, since both the PTO input 24 and the output of the electric motor 42 rotate at the same speed, thanks to the gear train 36, they can be energized at the same time to deliver more power to the implement 16 via the CVT 34.

[0034] Depending on the type and power output of the electric motor

42, and of the power requirement of the specific implement 16, it could be possible for the motor 42 alone to drive the implement. Of course, the PTO of the work vehicle could be disconnected from the PTO input 24 in this instance.

[0035] Of course, for the power to reach the implement through the

CVT 34, the clutch 32 has to be engaged.

[0036] As show in Figure 2, the motor controller 44, and therefore the motor 42, can be powered by either a battery 46 or a grid connection from the electrical input 26. Accordingly, if the electric motor 42 is powerful enough to drive the specific implement attached, it is possible to operate the implement without a PTO connection.

[0037] One skilled in the art will understand that the motor controller

44 can also have battery charging features. For example, if the motor controller 44 senses that the electrical input connection 26 is connected to the utility grid and that the battery 46 is not fully charged, it can charge the battery. [0038] Similarly, if there is no need to energize the implement, the clutch 32 can be disengaged and the motor 42 can be used as a generator to recharge the battery from the PTO shaft rotation. In another case, if only the power from the PTO is desired and/or required to operate the implement, the clutch can be engaged and the excess power from the PTO can be used to recharge the battery 46 via the motor 42 working as a generator.

[0039] Turning now to Figure 3 of the appended drawings, a hybrid implement drive 12’ according to a second illustrative embodiment will be described. Since the hybrid implement drive 12’ is very similar to the hybrid implement drive 12 of Figure 2, and for concision purpose, only the differences therebetween will be described.

[0040] Generally stated, the main difference between the drive 12’ and the drive 12 of Figure 2 is the connection of the electric motor 42’ downstream from the CVT 34. Indeed as can be seen from this Figure, in the hybrid driveline 30’, the input of the CVT 34 is directly connected to the PTO input and the output of the CVT 34 is connected to the gear train 36 and to the clutch 32.

[0041] Since the CVT 34 has a variable output speed, the speed of the motor 42’ must also be variable, which was not necessary the case for motor 42 of Figure 2. As shown in Figure 3, one will also note that the CVT 34 supplies output speed data to the controller 44’ so that the speed of the motor 42’ can be matched.

[0042] The operation of the drive 12’ is similar to the operation of the drive 12 and will therefore not be repeated herein. [0043] One skilled in the art will understand that CVTs, are often provided with integrated output clutches (not shown). Should this be the case, the gear 38 could be mounted to the CVT upstream from this clutch and clutch 32 could be omitted.

[0044] Finally, turning to Figure 4 of the appended drawings one skilled in the art will understand that while the hybrid implement drive has been shown and described above as a separate element from either the work vehicle and the implement 16, the hybrid implement drive could be integrated to any one of the work vehicle and the implement. Figure 4 shows a hybrid drive 12” integrated with an implement 16”.

[0045] Should the hybrid implement drive be integrated with either a work vehicle or an implement, the motor controller 44 or 44’ could be integrated with a main controller of the vehicle or implement.

[0046] One skilled in the art will understand that should the implement be provided with an input clutch, or if a clutch such as 32 is not required since a permanent connection is desired between the PTO in 24 and the hybrid PTO output 28, the clutch 32 could be omitted. The clutch 32 is therefore considered optional.

[0047] Similarly, should the goal of the hybrid implement drive be solely to be able to operate the implement through a utility grid, the battery 46 could be omitted. The battery 46 is therefore considered optional.

[0048] While the electric motor has been illustrated as being connected to the intermediate shaft via a simple gearset arrangement, it would be possible to use a planetary gear train instead to thereby allow further speed ranges.

[0049] Similarly, depending on the technology used in the secondary power generator, supplemental mechanical elements could be interesting. For example, a clutch (not shown) could be provided between the motor 42 and the gear train 36 to disconnect the motor 42 when it is not used.

[0050] One skilled in the art will also understand that having a CVT in the hybrid implement drive allows the implement to be operated at variable speeds.

[0051] It is to be understood that the hybrid implement drive is not limited in its application to the details of construction and parts illustrated in the accompanying drawings and described hereinabove. The hybrid implement drive is capable of other embodiments and of being practiced in various ways. It is also to be understood that the phraseology or terminology used herein is for the purpose of description and not limitation. Hence, although the hybrid implement drive has been described hereinabove by way of illustrative embodiments thereof, it can be modified, without departing from the spirit, scope and nature thereof.