Description:FORM 2
THE PATENT ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)

HYDRAULIC CONTROLLED ROTARY TILLER TRANSMISSION SYSTEM AND METHOD OF OPERATING THE SYSTEM THEREOF

1. APPLICANT
(a) Name : Tractors & Farm Equipment Limited
(b) Nationality : India
(c) Address : No. 861, Annasalai, Chennai - 600002, Tamil nadu, India.

2. PREAMBLE TO THE DESCRIPTION

COMPLETE SPECIFICATION
The following specification particularly describes the invention and the manner in which it is to be performed.

HYDRAULIC CONTROLLED ROTARY TILLER TRANSMISSION SYSTEM AND METHOD OF OPERATING THE SYSTEM THEREOF

FIELD OF THE INVENTION
The present invention relates to a hydraulic controlled rotary tiller transmission system in agricultural vehicles. Particularly the invention relates to a rotary tiller transmission system having hydrostatic variable displacement pump and hydraulic motor drive that will achieve multiple/infinite speed to cut different types of soil with respect to the field requirements. Furthermore, the invention also relates to a method for operating the system of rotary tiller transmission system.
BACKGROUND OF THE INVENTION
Rotary tiller is an agricultural implement to prepare the seed bed. Fundamentally, rotary tiller is used to turn the soil and pulverize it, thereby aerating the soil. For different types of soil/land preparation different blade speeds are required depending on the application and soil variations. Currently the speed variations in rotary tiller are achieved by replacing different mechanical gear pairs manually to achieve the desired speed ratios.
CN205389333U discloses a hydraulic drive rotary cultivator, which is mainly composed of a rotary blade roller shaft, a hydraulic motor and a hydraulic motor box, plough, a side plate, a mud cover, a supporting rod, a hydraulic oil port, frame, cross board, roller shaft disc, an engine, a hydraulic oil tank, a hydraulic lifting system and a hydraulic driving system. directly connected with the roller shaft, the hydraulic transmission simplifies the transmission link, and the hydraulic lifting system uses hydraulic synchronous loop of the flow distributing and collecting valve, two hydraulic synchronous speed hydraulic motor plate hydraulic motor installed in the rotary cultivator. The hydraulic driving system adopts variable pump-quantitative motor form, it can be adjusted by control variable hydraulic swash plate angle of the variable plunger pump, so as to realize the rotary speed control by changing the variable plunger pump displacement, and the system can realize the step-less speed regulation in large range. The hydraulic driving system uses the slippage pump is a variable pump. The utility model has simple structure, power-mass ratio is high, operation is convenient, and work is safe and reliable and can realize step-less speed regulation and so on.
JP2000219056A provide a hydraulic continuously variable transmission arranged with one variable displacement pump and two parallel hydraulic motors interconnected to the side face of one center section so that an operating mechanism for the hydraulic continuously variable transmission can be simply constructed. solution: When a first hydraulic motor and a second hydraulic motor are of a variable displacement type, both swash plates are simultaneously controlled and, when one is of a fixed displacement type, the other variable displacement hydraulic motor is controlled. The first hydraulic motor and the second hydraulic motor are covered with a housing. A variable displacement hydraulic pump, the first hydraulic motor and the second hydraulic motor are covered with a housing. The first hydraulic motor and the second hydraulic motor are associated with a gear.
CN101025233B disclose the load control structure of work vehicle. Load control structure of work vehicle, comprising: an operation position detecting mechanism for detecting the operating position of the shifting gears operating assemble; detecting the load detecting mechanism of engine load, detecting a variable capacity pump operation position of the swash plate of the swash plate position detecting mechanism; pump for step-less the slanting plate of operating the alterable capacity pump for operation mechanism; the swash plate switching operation with variable capacity motor to at least two shift positions comprising a high speed position and the low speed position for the motor operation mechanism, operation mechanism for control pump and control mechanism for the motor operation mechanism of action; the control mechanism comprises an automatic pump swash plate control mechanism, according to the detected detecting control pump and a swash plate position detecting mechanism of the load detecting mechanism by the movement of the operating mechanism, so that the engine load is larger, can be inclined down operating degree of larger, variable capacity pump motor swash plate control mechanism for controlling motor operating mechanism of action, so as to switch to one of the at least two shift positions on the swash plate of the variable capacity motor.
DE102006000784B4 discloses a hydraulic power control system for a work machine comprising: a hydraulic power output device selected from the group consisting of a hydraulic motor and a hydraulic work implement actuator a variable displacement hydraulic pump configured to deliver hydraulic fluid to the hydraulic power output device; at least one pressure sensor configured to measure the pressure of the hydraulic fluid at a location between the hydraulic pump and the hydraulic power output device; at least one temperature sensor configured to measure a temperature of the hydraulic fluid in the system; and a control device which is configured to control a displacement of the hydraulic pump based on a pressure measurement of the at least one pressure sensor and based on a temperature measurement of the at least one temperature sensor , wherein the control device is configured to reduce the displacement of the hydraulic pump when the pressure measurement of the at least one pressure sensor exceeds a predetermined pressure limit.
All the above cited prior art documents disclose a Hydraulic output device / machine with rotary tiller transmission or device used for the purpose of agriculture but none of the device provide all the components as disclosed in the present invention and the arrangement of the components in the system. Moreover none of the prior arts discloses the type of rotary tiller with hydraulic pump, a hydraulic motor which helps in achieving N no. of speed & torque while running a particular application.
Therefore this new invention rotary tillers are subjected not only to various types of soil such as red soil, black soil, etc. but also to these soil under various conditions like wet, dry, etc.
Moreover, the land preparation varies with the type of the crop that is being planted /sowed, which further add the complexity of the land preparation, thereby demanding for uniqueness in soil preparation.
Hence, Rotary tiller cannot operate effectively in a single speed/torque owing to the aforementioned variations of soil textures, its conditions & the diversity in the cropping.
Gear drive mechanism is prevailing over the rotary tiller for speed variation. Also, it should be noted that the speed variation can only be achieved by replacing the existing gear pair with another set that needs to be procured as additionally to achieve the desired speed ratio.
This gear changing is method is a time consuming activity, but also requires certain tools to replace the existing gear pairs, it also resulting the implement & also the tractor downtime.
Therefore in the present invention to overcome the aforesaid shortfalls of fixed gear ratios by providing step less & variable speeds in rotary tiller transmission using hydrostatic variable displacement pump and hydraulic motor drive. Thus achieving multiple speeds to cater to different soil and field requirements.

OBJECTIVES OF THE INVENTION
The principal objective of the present invention is to provide a hydraulic controlled rotary tiller transmission system to achieve multiple speed ranges to cut different soil and field requirements.
Another objective of the present invention is to provide a hydraulic controlled rotary tiller transmission system that enables easy speed shift with a single control lever by operator or user.
Another objective of the present invention is to provide a hydraulic tiller transmission system which gives increased productivity, fuel efficiency, and versatility to various soil, crops and land conditions.
Yet another objective of the present invention is to provide a hydraulic system in which step up or step down the speed of rotary tiller without changing the engine RPM.
Yet another objective of the present invention is to provide a method of operating the hydraulic controlled rotary tiller transmission system with increased productivity.
Another object of the present invention is to provide a hydraulic controlled rotary tiller transmission system with increased productivity and zero downtime for speed change.

SUMMARY OF THE INVENTION
Accordingly the present invention relates to a Hydraulic controlled variable step less speed rotary tiller transmission, comprising:
Input drive from engine driven hydraulic pump (1), Steering unit (2) ,steering cylinder LH(3), Steering Cylinder RH (4) , Oil Cooler (5),Bypass Check Valve (6) ,Hydraulic Filter (7) ,Speed Control Valve (8) , Direction Control Valve(9), Variable Displacement Servo Piston Pump (10), High Pressure Relief Valve (11) , PTO Drive (12) , Hand Lever(13) , Hydraulic Shuttle Valve (14) , Dual Stage displacement Hydraulic Motor (15) , Sequence valve (16) , Hydraulic Tank (17). In the present invention replacement of rotary tiller mechanical gearbox with variable displacement pump and hydraulic motor that provides:
• Step less / infinite speed at rotary tiller blades.
• Step up or step down the speed of rotary tiller without changing the engine RPM.
• Increased productivity & Fuel efficiency.
• Versatility to various soil, crops and land conditions
The mechanical means of achieving the required speeds and torque is replaced by a variable displacement servo piston pump and dual stage hydraulic motor. The hydraulic pump is driven through tractor PTO and the pump displacement is controlled by operator through a hydraulic control valve. This variable flow and pressure drives the hydraulic motor to achieve multiple speeds and torque at the rotary tiller blades.
The Present invention hydrostatic transmission provides variable step less speed in rotary tiller without changing engine rpm. And the speeds of the rotary tiller can be changed without stopping the vehicle, i.e., on the go speed shift. Thus this present invention of hydraulic actuated hydrostatic pump and motor drive transmission system can cater to different speed, soil, crop and field conditions.
In one of the embodiment of the present invention a hydraulic controlled rotary tiller transmission system for an agricultural vehicle, comprising:
Input drive from engine driven hydraulic pump (01);
steering Unit (02) comprising a steering cylinder for LH and RH (3,4), and Steering Cylinder RH (4);
Oil Cooler (5);
a filter (07),
a variable displacement piston pump (10);
a PTO Drive (12);
a hand lever (13);
dual stage hydraulic motor (15);one or more valves (06, 08, 09,11,14, 16); and
Hydraulic Tank (17),
wherein the system is configured to achieve variable step less speed in rotary tiller comprising step up or step down the speed of the rotary tiller without changing engine rpm by the hydraulic pump (01) driven through PTO (12) and the pump displacement is controlled by operator through a hydraulic control valve (08), variable flow and pressure drives the hydraulic motor to achieve multiple speeds and torque at the rotary tiller blades (22), wherein a variable speed range is achieved based on nature of the soil when the vehicle is in moving condition, without halting the vehicle.
In another embodiment of the present invention the hydraulic controlled rotary tiller transmission system for an agriculture vehicle, wherein the said valves is bypass check valve (6), speed control valve (8), Direction control valve (9) , High Pressure Relief valve (11), Hydraulic Shuttle Valve (14) , and Sequence valve (16).
In another embodiment of the present invention the hydraulic controlled rotary tiller transmission system for an agricultural vehicle, wherein the hydraulic pump is a variable displacement piston pump (10).
In another embodiment of the present invention the hydraulic controlled rotary tiller transmission system for an agricultural vehicle, wherein the motor (15) is a two-step fixed displacement motor.
In another embodiment of the present invention the hydraulic controlled rotary tiller transmission system for an agriculture vehicle, wherein the gear pump (01) is driven by the engine drive through a gear and the gear pump (01) outlet is connected to steering unit (2).
In another embodiment of the present invention the hydraulic controlled rotary tiller transmission system for an agriculture vehicle, wherein the said system uses the steering excess flow connected to oil cooler (5) to reduce the oil temperature.
In another embodiment of the present invention the hydraulic controlled rotary tiller transmission system for an agriculture vehicle, wherein oil cooler (5) is connected in line with the bypass check valve (6) that is used as a safety to prevent the oil cooler (5) from any damages due to pressure deviation in the system.
In another embodiment of the present invention, the hydraulic controlled rotary tiller transmission system for an agriculture vehicle, wherein the speed control valve (8) is to control the inlet flow & speed of the rotary tiller transmission system which is connected to a direction control valve (9).
In another embodiment of the present invention, the hydraulic controlled rotary tiller transmission system for an agriculture vehicle, wherein, the direction control valve (9) is connected to variable displacement servo piston pump (10) and will decide the variable displacement piston pump (10) rotation & control the direction of the hydraulic flow.
In another embodiment of the present invention the hydraulic controlled rotary tiller transmission system for an agricultural vehicle, wherein the variable displacement piston pump (10) is associated with the input from the drive of the PTO (12), whose speed is controlled by the engine speed (01) and the dual stage hydraulic motor (15) in a closed loop unit.
In another embodiment of the present invention the hydraulic controlled rotary tiller transmission system for an agricultural vehicle, wherein the hand lever (13) is configured such that the operator controls the angle of the swash plate that in turn controls the output speed.
In another embodiment of the present invention the hydraulic controlled rotary tiller transmission system for an agricultural vehicle, wherein the hydraulic motor (15) is configured to provide high torque low speed, or low torque high speed based on the soil nature.
In another embodiment of the present invention the hydraulic controlled rotary tiller transmission system for an agriculture vehicle, wherein the hydraulic flow of the variable displacement piston pump (10) is controlled by the speed control valve (8) and the pressure of the variable displacement piston pump (10) is controlled through a high pressure relief valve (11).

In another embodiment of the present invention the hydraulic controlled rotary tiller transmission system for an agriculture vehicle, wherein the high pressure relief valve (11) is connected to the variable displacement servo piston pump (10) pressure line.
In another embodiment of the present invention the hydraulic controlled rotary tiller transmission system for an agriculture vehicle, wherein the variable displacement servo piston pump (10) is connected to hydraulic shuttle valve (14) & dual stage displacement hydraulic motor (15) and the hydraulic shuttle valve (14) is there to control the hydraulic oil flow direction.
In another embodiment of the present invention the hydraulic controlled rotary tiller transmission system for an agriculture vehicle, wherein the hydraulic shuttle valve (14) is connected to sequence valve (16), which is for maintaining pressure & flow in the dual stage displacement hydraulic motor (15).
In another embodiment of the present invention the hydraulic controlled rotary tiller transmission system for an agriculture vehicle, wherein the excess flow of speed control valve (8), variable displacement servo piston pump (10), dual stage displacement hydraulic motor (15) and sequence valve is dump to hydraulic tank (17).
In another embodiment of the present invention the method of operating the system comprises the step of;
mounting a hydraulic pump (01) on an input PTO (12) shaft of an agricultural vehicle;
input from an oil tank (5a) of a tractor, via a charge pump (5) to the variable displacement piston pump (2);
the variable displacement piston pump is associated with the input from the drive of the PTO (12) and the dual stage hydraulic motor (4) in a closed loop unit;
Based on the soil nature, change of the swash plate angel by the operator via the driver speed control (03) lever, controls corresponding displacement of the swash plate, in turn controls the output speed, and
wherein based on the dual stage displacement hydraulic motor (15) direction of rotation, the hydraulic shuttle valve (14) is used to control the hydraulic oil flow direction, a sequence valve (16) is connected to the hydraulic shuttle valve (14), the sequence valve (16) is used for maintain the pressure & flow in the Dual Stage displacement hydraulic motor (15).
BRIEF DESCRIPTION OF THE DIAGRAMS / FIGURES
Figure 1 illustrates the whole hydraulic controlled rotary tiller transmission system having all the arranged components in the claimed system;
Figure 2 illustrates a Block Diagram of hydraulic controlled rotary tiller transmission system according to embodiments of the present invention;
Figure 3 illustrates the existing Drivetrain architecture of rotary tiller transmission system;
Figure 4 represents the present invention variable speed rotary tiller architecture.

DETAILED DESCRIPTION OF THE INVENTION
The present invention as embodied by “Hydraulic controlled speed rotary tiller transmission system and method of operating the system thereof”, succinctly fulfils the above-mentioned need(s) in the art. The present invention has objective(s) arising as a result of the above-mentioned need(s), said objective(s) being enumerated below. In as much as the objective(s) of the present invention are enumerated, it will be obvious to a person skilled in the art that the enumerated objective(s) are not exhaustive of the present invention in its entirety, and are enclosed solely for the purpose of illustration. Further, the present invention encloses within its scope and purview, any structural alternative (s) and/or any functional equivalent(s) even though such structural alternative (s) and/or any functional equivalent(s) are not mentioned explicitly herein or elsewhere, in the present disclosure. The present invention therefore encompasses also, any improvisation(s)/modification(s) applied to the structural alternative (s)/functional alternative(s) within its scope and purview. The present invention may be embodied in other specific form(s) without departing from the spirit or essential attributes thereof.
Throughout this specification, the use of the word "comprise" and variations such as "comprises" and "comprising" may imply the inclusion of an element or elements not specifically recited.
Rotary tiller is a crucial implement for the land preparation, which is the primary and initial activity of an agricultural process. It is an agricultural implement to prepare the seed bed. Fundamentally, rotary tiller are used to turn the soil and pulverize it, thereby aerating the soil.
Rotary tillers are normally used in the agriculture applications, in the primary or secondary cultivations. Rotary tiller is currently used in all type of tractors as a mechanical drive, in which rotary tiller is connected to the rear end of the tractor via a PTO and being drive by PTO, used for soil preparation . Currently all the rotary tiller available in the market as mechanically transmission and with respect to different soil conditions to achieve the different speed in view of increasing the torque or pulverize of the soil, gears is to be changes means change in the gear box and need to work in the same application. In the existing rotary tiller to change the speed, input from the tractor rear PTO shaft having couple of drop gears are there to increase the torque input to the rotary tiller. And all these gears are fixed gears, by which fixed set of RPM is achieved in the output blades. As shown in figure 3, the existing drive train architecture, where the input from PTO is 540rpm/800 Nm and first speed reduction is variable, final speed reduction is permanent, output to blades received is approx. 160 to 250 rpm.
In figure 4 represents the variable speed rotary tiller architecture, in which the hydraulic pump directly mounted on the input from PTO-304Nm/ 540 rpm. Hydraulic pump drives the hydraulic motor & this hydraulic pump is variable displacement hydraulic pump which is like a swash plate arrangement where the flow & the pressure can be varied. Speed changing technique by adjusting the swash plate angle through cable mechanism, which is placed near driver seat, so the control lies with the driver of the vehicle the present invention system is easy reversing – no need of reversing vehicle while stuck with the mud
The present invention relates to a hydraulic controlled rotary tiller transmission system and method of operating the system thereof, wherein the system comprises of ; input drive from engine driven hydraulic pump (1) ,Steering unit (2) , Steering cylinder LH (3) , Steering cylinder RH (4), oil cooler (5) , Bypass Check Valve (6), Hydraulic Filter (7), speed control valve (8), Direction control valve (9), Variable displacement servo piston pump (10), High pressure Relief Valve (11), PTO Drive (12), Hand Lever (13), Hydraulic Shuttle Valve (14), Dual Stage displacement Hydraulic motor (15), Sequence Valve (16) ,Hydraulic Tank (17) as represented in figure 1.
According to figure 1, the Gear Pump (1) is driven by the engine drive through a gear. The Gear pump (1) outlet is connected to Steering unit (2), the gear pump hydraulic power is used for the hydraulic power steering operations. The Steering unit (2) is used to Steer the tractor either LH (3) or RH (4) based on the direction of the steering wheel rotation. The steering excess flow is used by hydraulic controlled rotary tiller transmission system.The steering excess flow is connected to Oil cooler (5) to reduce the oil temperature. The bypass check valve (6) is connected in line with the Oil Cooler (5) & it’s used as a safety to prevent the Oil Cooler (5) from any damages due to pressure deviation in the system.
The Hydraulic Filter (7) is used in the Steering excess flow to reduce the oil contamination. The Speed control valve (8) is used to control the inlet flow & Speed of the rotary tiller transmission system. The Speed control valve (8) is connected to a Direction control valve (9). The Direction control valve (9) is connected to VDS (variable displacement servo) piston pump (10). The Direction control valve (9) will decide the VDS piston pump (10) rotation & control the direction of the hydraulic flow. A Hand lever (13) is used as a direction input to the Direction control valve (9). The VDS piston pump (10) is driven by the PTO drive (12).The PTO drive (12) speed is controlled by the engine speed .The Speed control valve (8) is used to control the hydraulic flow of the VDS piston pump (10).The VDS piston pump (10) pressure is controlled through a High pressure relief valve (11).The High pressure relief valve (11) is connected to the VDS piston pump (10) pressure line .The VDS piston pump (10) is connected to Hydraulic shuttle valve (14) & Dual Stage displacement hydraulic motor (15). Based on the Dual stage displacement hydraulic motor (15) direction of rotation, the Hydraulic shuttle valve (14) is used to control the hydraulic oil flow direction. A Sequence valve (16) is connected to the Hydraulic shuttle valve (14).The sequence valve (16) is used for maintain the pressure & flow in the Dual Stage displacement hydraulic motor (15).The Dual Stage displacement hydraulic motor (15) is control the rotary tiller transmission system. The excess flow of Speed Control Valve (8), VDS piston pump (10), Dual stage displacement Hydraulic motor (15) & Sequence valve (16) is dump to Hydraulic tank (17).
And Figure 2 represents the block diagram of the step less speed hydraulic variable rotary tiller drivetrain system, wherein step 1 is input from PTO (12) goes to variable displacement pump (10) via driver control lever (13) through high pressure line to dual stage hydraulic motor (15). And then output drive to RT gear train (24), final speed is reduced (26) and goes to drive to rotary tiller blades (22). Oil and power source is provided by the oil tank and charge pump (18) which goes through oil filter to variable displacement piston pump (2).
Table 1 represents the existing rotary tiller speed and torque at blades.

PTO SHAFT
RPM Input
torque
from
PTO shaft
@540
RPM First
Reduction
(Change Gear) Ratio Bevel
Gear
ration Final
reduction Rotor
final
ration Rotor
0/P
Torque
(Nm) Rotor
O/P
Rpm

540
212.94 14 19 1.36 1.77 1.43 3.43 730 157
Pair 1 19 14 0.74 1.86 397 290

Table 2(a,b) represents the variable/ finalized speed rotary tiller speed and torque at blades which shows the minimum and maximum speed, & torque.
Table 2a Variable speed Rotary tilller speed and torque at blades
Variable speed rotary tiller speed and torque mapping
PTO shaft
RPM Input torque from PTO HST
Ratio
Min
Range HST
Ratio
Max
Range HST Speed
Min Range
(Rpm) HST Speed
Max Range
(Rpm) HST Torque
Min
Range
(Nm) HST Torque
Max
Range
(Nm) Final reduction Rotor fixed gear pari Rotor final ratio
Min
range Rotor final ratio
Max
range Rotor
Torque Min Range (Nm) Rotor
Torque Max Range (Nm) Rotor Rpm Min Range Rotor Rpm Max Range
2106 54.6 5.09 9.35 225.2406 413.752 277.914 510.51 1.42 7.27 13.35 397.02 729.3 157.7 289.6

Table 2(b) Finalized Variable Speed Rotary Tiller
Finalized Variable Speed Rotary Tiller

Finalized design- Motor output desired 278Nm at 415 Rpm
PTO input- 54.6 Nm at 2106 Rpm 511 Nm at 225 Rpm
S.No Pump cc/rev Input
Rpm Pump flow in lpm Input power in kw
Input torque loaded in Nm Motor size in cc/rev Motor rpm System pressure in bar Motor output torque in Nm Max rated Nm of motor Max rated rpm of motor
1 37 2000 70 13 64 155 431 115 270 380 450
2 37 2000 70 13 64 305 219 115 531 765 225

In the present invention replacement of rotary tiller mechanical gearbox with variable displacement pump and hydraulic motor that provides:
Step less / infinite speed at rotary tiller blades;
Step up or step down the speed of rotary tiller without changing the engine RPM;
Increased productivity & Fuel efficiency;
Versatility to various soil, crops and land conditions.
The mechanical means of achieving speeds and torque is replaced by a variable displacement servo piston pump and dual stage hydraulic motor. The hydraulic pump is driven through tractor PTO and the pump displacement is controlled by operator through a hydraulic control valve. This variable flow and pressure drives the hydraulic motor to achieve multiple speeds and torque at the rotary tiller blades.
This new hydrostatic transmission provides variable step less speed in rotary tiller without changing engine rpm. And the speeds of the rotary tiller can be changed without stopping the vehicle, i.e., on the go speed shift. Thus this new invention of hydraulic actuated hydrostatic pump and motor drive transmission system can cater to different speed, soil, crop and field conditions.
WORKING EXAMPLE
In reference to the drawing 1, a tractor transmission system schematic is depicted. The Gear Pump (1) is driven by the engine drive through a gear. The Gear pump (1) outlet is connected to Steering unit (2), the gear pump hydraulic power is used for the hydraulic power steering operations.
The steering unit (2) is used to Steer the tractor either LH (3) or RH (4) based on the direction of the steering wheel rotation.
The steering excess flow is used by hydraulic controlled rotary tiller transmission system.
The steering excess flow is connected to oil cooler (5) to reduce the oil temperature
The bypass check valve (6) is connected in line with the oil cooler (5) & it’s used as a safety to prevent the oil cooler (5) from any damages due to pressure deviation in the system
A hydraulic filter (7) is used in the Steering excess flow to reduce the oil contamination. A Speed control valve (8) is used to control the inlet flow & Speed of the rotary tiller transmission system. The Speed control valve (8) is connected to a Direction control valve (9). The Direction control valve (9) is connected to VDS piston pump (10), and it will decide the VDS piston pump (10) rotation & control the direction of the hydraulic flow. A Hand lever (13) is used as a direction input to the Direction control valve (9). The VDS piston pump (10) is driven by the PTO drive (12). The PTO drive (12) speed is controlled by the engine speed. The Speed control valve (8) is used to control the hydraulic flow of the VDS piston pump (10). The VDS piston pump (10) pressure is controlled through a High pressure relief valve (11). The High pressure relief valve (11) is connected to the VDS piston pump (10) pressure line. The VDS piston pump (10) is connected to Hydraulic shuttle valve (14) & Dual Stage displacement hydraulic motor (15). Based on the Dual stage displacement hydraulic motor (15) direction of rotation, the Hydraulic shuttle valve (14) is used to control the hydraulic oil flow direction, a Sequence valve (16) is connected to the Hydraulic shuttle valve (14).The sequence valve (16) is used for maintain the pressure & flow in the Dual Stage displacement hydraulic motor (15). The Dual Stage displacement hydraulic motor (15) is control the rotary tiller transmission system. The excess flow of Speed Control Valve (8), VDS piston pump (10), Dual stage displacement Hydraulic motor (15) & Sequence valve (16) is dump to Hydraulic tank (17).

Table 3 Variable speed rotary tiller specification according to embodiments of the present invention.
VARIABLE SPEED ROTARY TILLER SPECIFICATION
Pump Type
Servo piston PUMP
Motor Type Two Stage motor
Shifting System Cable operated
Rotary Tiller speed range RPM 158 ~290
Rotary Tiller Torque range Nm 398~730
Oil type 10W30
Filtration 15 micron
Charge pump Size 11cc
Charge pump pressure 20 bar
System Pressure Range 120 bar
Pump Size 37cc
Pump Flow @ RPM 70 lmp @2000
Motor Size 155 &305 cc/rev
Motor Rated RPM Range 219~431
Motor Rated Torque Range 270~531

ADVANTAGES OF THE PRESENT INVENTION
1. The present invention provides a hydraulic controlled speed rotary tiller transmission system which can be used for all types of soil and land preparation by achieving infinite and multiple speed ranges.
2. The system provided by the present invention having easy speed shift with a single control lever by operator.
3. The system provided by the present invention having increased tractor fuel efficiency.
4. The system provided by the present invention gives increased productivity.
5. The present invention provides a system having zero downtime for speed change.
6. The present invention provides a system in which transformation from “changing gear pairs” to multi speed shift on the go in rotary tiller applications.
7. The present invention provides a hydraulic system which is versatility to various crops / soil, field applications.
It will be apparent to a person skilled in the art that the above description is for illustrative purposes only and should not be considered as limiting. Various modifications, additions, alterations, and improvements without deviating from the spirit and the scope of the invention may be made by a person skilled in the art.
, Claims:We Claim:
1. A hydraulic controlled rotary tiller transmission system for an agricultural vehicle, comprising:
Input drive from engine driven hydraulic pump (01);
steering Unit (02) comprising a steering cylinder for LH and RH (3,4), and Steering Cylinder RH (4);
Oil Cooler (5);
a filter (07),
a variable displacement piston pump (10);
a PTO Drive (12);
a hand lever (13);
dual stage hydraulic motor (15);one or more valves (06, 08, 09,11,14, 16); and
Hydraulic Tank (17),
wherein the system is configured to achieve variable step less speed in rotary tiller comprising step up or step down the speed of the rotary tiller without changing engine rpm by the hydraulic pump (01) driven through PTO (12) and the pump displacement is controlled by operator through a hydraulic control valve (08), variable flow and pressure drives the hydraulic motor to achieve multiple speeds and torque at the rotary tiller blades (22), wherein a variable speed range is achieved based on nature of the soil when the vehicle is in moving condition, without halting the vehicle.

2. The hydraulic controlled rotary tiller transmission system for an agriculture vehicle as claimed in claim 1 , wherein the said valves is bypass check valve (6), speed control valve (8), Direction control valve (9) , High Pressure Relief valve (11), Hydraulic Shuttle Valve (14) , and Sequence valve (16).

3. The hydraulic controlled rotary tiller transmission system for an agricultural vehicle as claimed in claim 1, wherein the hydraulic pump is a variable displacement piston pump (10).

4. The hydraulic controlled rotary tiller transmission system for an agricultural vehicle as claimed in claim 1, wherein the motor (15) is a two-step fixed displacement motor.

5. The hydraulic controlled rotary tiller transmission system for an agriculture vehicle as claimed in claim 1 wherein the gear pump (01) is driven by the engine drive through a gear and the gear pump (01) outlet is connected to steering unit (2).

6. The hydraulic controlled rotary tiller transmission system for an agriculture vehicle as claimed in claim 1, wherein the said system uses the steering excess flow connected to oil cooler (5) to reduce the oil temperature.

7. The hydraulic controlled rotary tiller transmission system for an agriculture vehicle as claimed in claim 4, wherein oil cooler (5) is connected in line with the bypass check valve (6) that is used as a safety to prevent the oil cooler (5) from any damages due to pressure deviation in the system.

8. The hydraulic controlled rotary tiller transmission system for an agriculture vehicle as claimed in claim 2, wherein the speed control valve (8) is to control the inlet flow & speed of the rotary tiller transmission system which is connected to a direction control valve (9).

9. The hydraulic controlled rotary tiller transmission system for an agriculture vehicle as claimed in claim 2, wherein, the direction control valve (9) is connected to variable displacement servo piston pump (10) and will decide the variable displacement piston pump (10) rotation & control the direction of the hydraulic flow.

10. The hydraulic controlled rotary tiller transmission system for an agricultural vehicle as claimed in claim 1, wherein the variable displacement piston pump (10) is associated with the input from the drive of the PTO (12), whose speed is controlled by the engine speed (01) and the dual stage hydraulic motor (15) in a closed loop unit.

11. The hydraulic controlled rotary tiller transmission system for an agricultural vehicle as claimed in claim 1, wherein the hand lever (13) is configured such that the operator controls the angle of the swash plate that in turn controls the output speed.

12. The hydraulic controlled rotary tiller transmission system for an agricultural vehicle as claimed in claim 1, wherein the hydraulic motor (15) is configured to provide high torque low speed, or low torque high speed based on the soil nature.

13. The hydraulic controlled rotary tiller transmission system for an agriculture vehicle as claimed in claim 1, wherein the hydraulic flow of the variable displacement piston pump (10) is controlled by the speed control valve (8) and the pressure of the variable displacement piston pump (10) is controlled through a high pressure relief valve (11).

14. The hydraulic controlled rotary tiller transmission system for an agriculture vehicle as claimed in claim 11, wherein the high pressure relief valve (11) is connected to the variable displacement servo piston pump (10) pressure line.

15. The hydraulic controlled rotary tiller transmission system for an agriculture vehicle as claimed in claim 1, wherein the variable displacement servo piston pump (10) is connected to hydraulic shuttle valve (14) & dual stage displacement hydraulic motor (15) and the hydraulic shuttle valve (14) is there to control the hydraulic oil flow direction.

16. The hydraulic controlled rotary tiller transmission system for an agriculture vehicle as claimed in claim 13, wherein the hydraulic shuttle valve (14) is connected to sequence valve (16), which is for maintaining pressure & flow in the dual stage displacement hydraulic motor (15).

17. The hydraulic controlled rotary tiller transmission system for an agriculture vehicle as claimed in claim 1 wherein the excess flow of speed control valve (8), variable displacement servo piston pump (10), dual stage displacement hydraulic motor (15) and sequence valve is dump to hydraulic tank (17).

18. The method of operating the system as claimed in claim 1 comprises the step of;
mounting a hydraulic pump (01) on an input PTO (12) shaft of an agricultural vehicle;
input from an oil tank (5a) of a tractor, via a charge pump (5) to the variable displacement piston pump (2);
the variable displacement piston pump is associated with the input from the drive of the PTO (12) and the dual stage hydraulic motor (4) in a closed loop unit;
Based on the soil nature, change of the swash plate angel by the operator via the driver speed control (03) lever, controls corresponding displacement of the swash plate, in turn controls the output speed, and
wherein based on the dual stage displacement hydraulic motor (15) direction of rotation, the hydraulic shuttle valve (14) is used to control the hydraulic oil flow direction, a sequence valve (16) is connected to the hydraulic shuttle valve (14), the sequence valve (16) is used for maintain the pressure & flow in the Dual Stage displacement hydraulic motor (15).

Dated this 30th day of September, 2022