Field of invention

The present invention relates to a hydraulic wheel drive assembly for agriculture machine to increase the efficiency with which the agriculture machines operate, thereby reducing the amount of fuel used. In particular, the major benefits are the torque is high, less friction loss and high safety when machine is in overloaded condition.

Background of invention Designers of hydraulic systems and assemblies for agricultural machines face some difficult challenges. This is especially true for high horsepower tractors with not only steering and brake functions, but where a great variety of hydraulic implements will be connected and towed. With the operating parameters of a farmer's collection of cross-branded, specialty implements unknown to a tractor designer, the hydraulic system may be either inefficient due to over-sizing and over design or it might fail to perform adequately if under-designed.

Self-propelled row crop harvesters, as well as fruit and vegetable harvesters now approach the size of many pulling tractors with engines larger than 500 hp. Some forage corn harvesters have engines with more than 1,000 hp. For some of these machines, the only reason to start the engine is to power hydraulic pumps. Others split the mechanical functions between a direct drive gearbox and a hydraulic system. System design must balance the challenge of evenly distributing hydraulic flow to all of the sub-circuits, while retaining the capability of bringing all of the hydraulic power to bear on motor functions for quick travel between growing areas.

Hydraulics has been absolutely integral to farming since the invention of fluid power. Where industrial hydraulics replaced mechanical machinery, agricultural hydraulics replaced man and beast, saving both warm bodies from injury and increasing productivity exponentially. Because a tractor could and would be anywhere in the hundreds or thousands of acres around a farm, access to any type of electric power was non-existent.

Earlier hydraulic technology had fixed pressure and flow. Depending on the situation it was sometimes possible to change the settings, but this required human intervention.

There is a well-known conventional hydrostatic transaxle including a motor casing incorporating a hydraulic motor for driving an axle drivingly connected to a pair of left and right steerable drive wheels, wherein a pair of left and right steerable wheel support units are attached onto opposite outer ends of the motor casing so as to steerably support the respective steerable drive wheels. In each of the steerable wheel support units, a steerable casing supporting each of the steerable drive wheels is steerably (i.e., horizontally rotatably) connected to the motor casing. Such a conventional hydrostatic transaxle is provided to various four- wheel drive working vehicles, e.g., an agriculture tractor, a riding lawn mower and construction machinery. In the above-mentioned conventional hydrostatic transaxle, the tie rod requires a considerably large space (hereinafter, the space is referred to as "tie-rod arrangement space") near the hydrostatic transaxle so as to be spanned between the left and right steerable casings, so that a space for arranging another member or device near the hydrostatic transaxle may be narrowed depending on where the tie rod is disposed.

JP 2005-35402A, for example, supposes the tie rod to be disposed (on the fore-and-aft proximate side of the hydrostatic transaxle) opposite to a pressure fluid pipe (on the fore-and-aft distal side of the hydrostatic transaxle) with respect to the hydrostatic transaxle so as to prevent the tie rod from interfering with the pressure fluid pipe. However, the tie rod still requires a laterally long tie-rod arrangement space near the hydrostatic transaxle so as to space other members and devices, such as another pressure fluid pipe (for supplying fluid to the hydraulic motor or for lubricating the hydrostatic transaxle) and/or a mechanical power transmission component (e.g., a propeller shaft), from the hydrostatic transaxle into the outside of the tie-rod arrangement space.

JP 10-211883 A describes a steering system of a farm working vehicle, comprising an intermediate shaft and an arm shaft supported in parallel with a shaft transmitting a steering wheel rotation in a gearbox to be installed in front of a traveling car body. A symmetrical pair of tie rods are connected to an arm clamped tight to a lower and of the arm shaft, and thereby a symmetrical pair of wheels arc steered by a rotation of the arm.

With the advance of recent hydraulic technology, numerous forms of hydrostatic drive systems have been developed for all types of vehicles in either two or four-wheel drive systems. Parallel type drive circuits have some inherent advantages wherein a single pump source supplies two or more wheel motors through a parallel rather than series flow path. In a parallel drive system, differential motor drive speed, inherent in all turning vehicles, creates no problems since the individual wheel motors are independently driven through a parallel flow path.

The basic disadvantage of a parallel flow system is that if one wheel motor loses traction and begins to spin, it will absorb all of the flow capacity of the system, robbing any torque from the remaining wheels. One system to solve this spin-out problem has been a valve and corresponding circuitry which shifts the flow from a parallel path to a series path locking all wheels together while the machine is in a spin-out condition. This system has its disadvantages in that it is manual in operation and more importantly, that it has a maximum efficiency of fifty percent tractive effort as compared with the parallel system.

Another prior art method is a parallel circuit with individual flow restrictors or flow limiters in the lines to each of the motors as illustrated in U.S. Pat. No. 3,736,732. This type of system is inefficient since one wheel can accept one-half of the total system flow before the flow limiter means begins to function. The most important disadvantage of a flow limiter system of this type is that it cannot have a free-wheeling closed loop circuit when it is desired to disengage the auxiliary drive system and run the vehicle at higher speeds. In the above mentioned patent, to disengage the auxiliary drive system, it is necessary to include a mechanical clutch and brake on each individual wheel which is very complex and expensive. Another method of disengaging the auxiliary drive system on the steerable wheels is to stop the vehicle and mechanically disconnect the gear reduction hubs on the individual wheels which obviously do not lend itself to an environment wherein the two-wheel to four-wheeled mode is frequently changed.

The common challenge across the entire spectrum of agricultural machinery is to create a hydraulic system that is energy efficient, easy to operate and maintain, and of course reliable. Partial automation is an absolute minimum necessity for large-scale machines where the operator's attention can be drawn in so many directions.

Hence, it is needed to the coupling of the power of hydraulics using hydraulic wheel drive assemblies for agriculture machine with the precision of electronics opens up all kinds of exciting possibilities.

Object of Invention The main object of a hydraulic wheel drive assembly for agriculture machine according to present invention is to overcome the problem associated with conventional agriculture machines by providing hydraulic wheel drive assembly for agriculture machine.

Another object of the present invention is to increase individual and overall efficiency and productivity with which the agriculture machine operates and reducing the amount of fuel used. Another object of the present invention is to provide hydraulic drive assembly to eliminate mechanical gear drives for accurate power transmission and reduces transmission loss.

Further object of the present invention is to provide hydraulic drive assembly with flexible design of hydraulic drive assembly to adapt to any agriculture machine is possible and quite simple.

Yet, another object of present invention is to provide hydraulic drive assembly to reduce friction losses and eliminate mechanical components.

These and other objects will be apparent based on the disclosure herein.

Summary of invention

The present relates to a hydraulic wheel drive assembly for agriculture machine to increase the efficiency with which the agriculture machines operate, thereby reducing the amount of fuel used. The present invention comprises a vehicle body, a chassis assembly, a hydraulic assembly and a wheel drive assembly. The hydraulic assembly comprises the hydraulic assembly comprises a power transmission unit consists of a hydraulic system operatively connected through an engine is mounted at a rear side of the chassis, a variable pump and a gear pump is operatively connected with the engine for transmitting the power to the wheel drive assembly, the gear pump is operatively connected with the steering wheel for smooth steering operation of the steering wheel, a manifold block is operatively connected with the variable pump and gear pump to convert the machine from 4WD to 2WD of vise-versa, a front and rear steering cylinder is drivably connected with the manifold block and is mounted below the chassis to control the directions of the front and rear wheels, an oil tank is fixed below the right side of the chassis to provide a hydraulic operation of the whole hydraulic wheel drive assembly, a fuel tank is fixed blow the chassis to carry the fuel for running the wheel drive assembly, a battery is placed beside the engine inside the engine cover to run the engine, an oil cooler is placed near the engine inside the engine cover for cooling the oil of the oil tank.

The hydraulic wheel drive assembly for agriculture machine of present invention provides multiple benefits to the end users which are described in the following pages of specification.

Brief description of drawings

Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the present embodiment when taken in conjunction with the accompanying drawings.

Fig. 1 illustrates a side view of a hydraulic wheel drive assembly for agriculture machine according to the present invention.

Fig. 2 illustrates a perspective view of a hydraulic wheel drive assembly for agriculture machine according to the present invention. Fig. 3 illustrates a bottom view of a hydraulic wheel drive assembly for agriculture machine according to the present invention. Fig. 4 illustrates an exploded view of front and rear fabricated height extension of a hydraulic wheel drive assembly for agriculture machine according to the present invention.

Fig. 5 illustrates an exploded view of the variable pump and gear pump of a hydraulic wheel drive assembly for agriculture machine according to the present invention.

Fig. 6 illustrates an exploded view of an engine of a hydraulic wheel drive assembly for agriculture machine according to the present invention

Detailed Description of Invention Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of the construction and arrangement of parts illustrated in the accompany drawings. The invention is capable of other embodiment, as depicted in different figures as described above and of being practiced or carried out in a variety of ways. It is to be understood that the phraseology and terminology employed herein is for the purpose of description and not of limitation.

It is to be also understood that the term "comprises" and grammatical equivalents thereof are used herein to mean that other components, ingredients, steps, etc. are optionally present. For example, an article "comprising" (or "which comprises") components A, B, and C can consist of (i.e., contain only) components A, B, and C, or can contain not only components A, B, and C but also contain one or more other components. It is to be understood that here in the present invention a hydraulic wheel drive assembly is installed or assembles in the agriculture heighted boom sprayer. Here, the present invention is not limited to agriculture boom sprayer, but it is used or installed or assembled in the any agriculture machines.

As shown in Fig. 1 and Fig. 2, it shows a side view of a hydraulic wheel drive assembly for agriculture machine according to present invention. The machine comprises a chassis assembly (C), a vehicle body (B) supported on the chassis assembly (C), a hydraulic assembly (H) (not shown) and a wheel drive assembly (W) located below the chassis assembly (C).

The vehicle body (B) comprises a cabin (1) fixed over the chassis assembly (c) and accommodated control panel for controlling the operation of the machine, a driver seat (17) fixed inside the cabin (1), a engine cover (18) fixed at rear side of the vehicle body (B) to cover the engine from rust & dirt from atmosphere. The control panel includes a steering wheel (24) is mounted on a front fabricated axle (2), a forward and reverse handle (25) is fixed beside the steering wheel (24) providing forward and reverse direction to the front and rear wheels (5, 5a, 8, 8a) through the hydraulic motors (6, 7), a break pedal (27) (not shown) is fixed at down side into the cabin (1) and an accelerator lever (28) is fixed beside the break pedal (27).

As shown in Fig. 3 and Fig. 4, the chassis assembly (C) comprises a chassis (9) and it corresponds to the wheel drive assembly (W) and hydraulic assembly (H). The wheel drive assembly (W) consisting of a front fabricated axle (2) and a rear fabricated axle (16) is mounted below the chassis (9) to provide a supportive structure of the chassis (9), front wheels (5, 5a) connected at opposite ends of the front fabricated axle (2) through a respective front fabricated height extension (4) and a hydraulic motor (6), rear wheels (8, 8a) connected at opposite ends of the rear fabricated axle (16) through a respective rear fabricated height extension (22) and a hydraulic motor (7), each front and rear fabricated height extension (4, 22) is provided with connecting member (M, Ml). Now as shown in Fig. 2 and 4, one end of each front fabricated height extension (4) is connected with a respective front hydraulic steering cylinder (15) at connecting member (M) and second end of each front fabricated height extension (4) is connected with the respective front wheels (5, 5a) through the hydraulic motor (6). Likewise, one end of each rear fabricated height extension (22) is connected with a respective rear hydraulic steering cylinder (14) at connecting member (Ml) and second end of each rear fabricated height extension (22) is connected with the respective rear wheels (8, 8a) through the hydraulic motor (7).

As shown in Fig. 3, Fig. 5 and Fig. 6, it shows the hydraulic assembly (H) comprises a power transmission unit consists of a hydraulic system operatively connected through an engine (19) is mounted at a rear side of the chassis (9), a variable pump (10) and a gear pump (11) is operatively connected with the engine (19) for transmitting the power to the wheel drive assembly (W), the gear pump (11) is operatively connected with the steering wheel (24) for smooth steering operation of the steering wheel (24), a manifold block (29) is operatively connected with the variable pump (10) and gear pump (11) to convert the machine from 4WD to 2WD of vise-versa, a front and rear steering cylinder (15, 14) is drivably connected with the manifold block (29) and is mounted below the chassis (9) to control the directions of the front and rear wheels (5, 5a, 8, 8a), an oil tank (12) is fixed below the right side of the chassis (9) to provide a hydraulic operation of the whole hydraulic assembly (H), a fuel tank (13) is fixed blow the chassis (9) to carry the fuel for running the engine (19), a battery (20) is placed beside the engine (19) inside the engine cover (18) to start the engine (19), an oil cooler (20) is placed near the engine (19) inside the engine cover (18) for cooling the oil of the oil tank (13). Operation of a hydraulic wheel drive assembly (W) is started with the starting of engine (19). Said hydraulic system powered by the engine (19) and the generated power extracted via variable pump (10) through a gear pump (11). This extracted power received by the manifold block (29) and transmits the converted hydraulic power to the front and rear steering cylinder (15, 14). This variable pump (10) provides hydraulic pressures to the hydraulic motors (6, 7). These hydraulic motors (6, 7) runs the front and rear wheels (5, 5a, 8, 8a) of the agriculture machine according to the direction given by the forward and reverse handle (25). The control panel controls the agriculture machine through the steering wheel (24) and the speed of the hydraulic wheel drive assembly of the agriculture machine is adjusted by an accelerator lever (28).

The present invention has less rotating parts as compare to mechanical drives. Hence, it makes the present invention easier to fabricated whole hydraulic wheel drive assembly for the all agriculture machines. The present invention provides high torque and reduced the friction losses due to elimination of mechanical components. The agriculture machine according to present invention needs less maintenance and no need of greasing & oiling of the components. Moreover, the agriculture machine is overloaded or peak loaded, there is no chances of damages in the hydraulic wheel drive assembly, while in the mechanical drives, there may chance of damage rotating component at peak load.

The present invention has beneficial advantages that the hydraulic motors are mounted on the wheels of the agriculture machines which make break mechanism easy as compare to existing brake mechanism. The present invention decreases complexity as it eliminates mechanical gear drives and reduced the cost of the agriculture machine. Further the present invention provides more accurate hydraulic power transmission and reduced the power transmission losses as compare to mechanical drives.

The invention has been explained in relation to specific embodiment. It is inferred that the foregoing description is only illustrative of the present invention and it is not intended that the invention be limited or restrictive thereto. Many other specific embodiments of the present invention will be apparent to one skilled in the art from the foregoing disclosure.

All substitution, alterations and modification of the present invention which come within the scope of the following claims are to which the present invention is readily susceptible without departing from the spirit of the invention. The scope of the invention should therefore be determined not with reference to the above description but should be determined with reference to appended claims along with full scope of equivalents to which such claims are entitled.

List of Reference Numerals

B Vehicle body

C Chassis assembly

H Hydraulic assembly

W Wheel drive assembly

M, Ml Connecting member

1 Cabin

2 Front fabricated axle

4 Front fabricated height extension

5, 5a Front wheel

6, 7 Hydraulic motor

8, 8a Rear wheel

9 Chassis

10 Variable Pump

11 Gear Pump

12 Oil Tank

13 Fuel Tank

14 Rear hydraulic steering cylinder

15 Front hydraulic steering cylinder

16 Rear fabricated axle

17 Driver seat 18 Engine cover

19 Engine

20 Battery

21 Oil cooler 22 Rear fabricated height extension

24 Steering wheel

25 Forward & Reverse handle

27 Brake pedal

28 Accelerator lever 29 Manifold block