DESC:FIELD OF THE INVENTION:
This invention relates to the field of mechanical engineering and agricultural engineering.

Particularly, this invention relates to a rotary rake machine with a hydraulic power transmission and tine arm torque control.

BACKGROUND OF THE INVENTION:
Agriculture, as a significant contributor to employment and livelihood creation, continues to be the mainstay, of India’s rural economy. Hence, it is imperative to focus on increase in production, productivity, and profitability in agriculture by improving intensity of farm mechanization in the country. Though farm mechanization has improved state of agriculture in certain parts of the country, it is crucial to take concrete steps to propel farmers in large numbers towards adoption of efficient, cost effective and scalable mechanization technologies.

Farm mechanization, in India, is still in its nascent stages and during the last two decades has been able to achieve a meager growth of less than 5%. The sector faces critical challenges in terms of large share of small and marginal farmers, declining land holding sizes, high cost of farm machinery and equipment.

Another Important aspect is environmental Impact created by the agricultural waste/residue burning. According to Environmental research & Public Health and Aerosol and Air Quality research study around 93Mt of agriculture residue is burnt in open fields in India of which Sugarcane trash alone contributes to 20% and rice straw contributes to 40%.

Agricultural waste can be beneficial in various agro-based applications and other industrial processing. However, the cost of collection, processing and transportation can be much higher than the revenue generated. Also, the time available between harvesting and next crop cycle is less which necessitates the use of machines to do this work.

Post harvesting phase consists of Harvest handling and Crop residue management.

Harvest handling / processing includes handling of the harvest, storage, processing, packaging etc. and there is significant research is carried out in this area. Similarly, crop residue management consists of collecting, compacting, and processing so that it can be used in paper factory, Dairy farm, packaging industry, Mushroom farming, grape wine yards and Brick Kiln-Briquetting. This new area is generating additional opportunity for farmers to generate income and reduce the Environmental Impact.

One of the machines used for harvesting and crop residue management activities is a rotary rake machine.

Case New Holland popularly known as CNH was one of the first introduced raker machines in 2015 which is imported from Italy followed by John Deere, Kuhn and Shaktiman. Most of these machines either imported or majority of the parts are imported and assembled here without altering the design.

Most prior art machines exhibited major component failures; their components failed within 900 hours of operation i.e. within one season of 3-4 month period considering 8 hours shift. The failures were predominantly from the rotating group. The failure was preliminary attributed to tine arm or tines getting stuck or seen sudden load which leading to subsequent component failure.

During their research, the inventors found out that major failures, captured from field survey in Maharashtra and Karnataka, were:
(a) Pinion Failure;
(b) Gear Failure;
(c) Connecting rod failure;
(d) Cam failure refer;
(e) Cover failure refer.

Therefore, there is a need for an improved machine that solves the aforementioned problems.

OBJECTS OF THE INVENTION:
An object of the invention is to reduce mechanical downtime of rotary rake machines caused by sudden loading of tine arms.

Another object of the invention is to provide a mechanism which allows peak load adjustment through hydraulic pressure modulation.

Yet another object of the invention is to provide a mechanism which works well with plain surface and material with relatively low density such as alfalfa hay, paddy, or wheat trash.

Still another object of the invention is to provide a mechanism which works well with uneven / raised bed-type surfaces.

SUMMARY OF THE INVENTION:
According to this invention, there is provided a hydraulic power transmission and tine arm torque control system, for controlling a rake machine, said control system comprising:
- a hydraulic pump and a motor configured to drive a gear through an associated pinion wherein, flow to said motor being received through a pump connected to a tractor or driven by a PTO shaft connected to said tractor;
- a relief valve, associated in connection with said motor and said pump, such that pressure setting of said relief valve deciding maximum torque capability of an associated machine; and
- a flow control valve, associated in connection with said motor and said pump, configured to adjust speed of said pump correlative to field of operation.

In at least an embodiment, said pump being configured to operate at 2160 rpm, with 4:1 gear ratio, and with PTP input at 540 rpm.

In at least an embodiment, said PTO shaft transmits torque and speed to a gear through a pinion arrangement which, in turn, rotates rake arms.

In at least an embodiment, said sleeve is placed into said cage with a spring such that it pushes said sleeve against said cage in order to form an assembly, said assembly being screwed into said spacer having female threads such that a spherical part of said sleeve slides into a tine arm hole, said spring force pushes said sleeve against said hole which keeps said tine arm and said profile tube held together.

In at least an embodiment, a rotating group consisting, essentially of said pinion, said gear, said casing, received power from a PTO in order to angularly displace said pinion which, in turn, angularly displaces a helical gear and said casing, said angular displacement motion being transferred to a connecting rod connected by a cam profile which gives desired motion to said connecting rod, said connecting rod, in turn, angularly displaces said tine and tine arm; thereby, collecting trash.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Figure 1 illustrates a general arrangement of raker / rake and power transmission; and
Figure 2 illustrates the portion where the system of this invention is implemented.

The invention will now be described in relation to the accompanying drawings, in which:
Figure 3 illustrates a hydraulic power transmitting architecture according to this invention;
Figure 4 illustrates a spring-loaded spherical ball type torque limiter; and
Figure 5 and Figure 6 shows external and internal construction of the machine.

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
FIGURE 1 illustrates a general arrangement of raker / rake and power transmission.

Rakes can be divided into three groups:
a) Finger-Wheel Rakes;
b) Parallel Bar Rakes;
c) Rotary Rakes.

This invention relates to Rotary Rakes.

According to this invention, there is provided a hydraulic power transmission and tine arm torque control.

FIGURE 2 illustrates a portion where the system of this invention is implemented.
FIGURE 3 illustrates a hydraulic power transmitting architecture according to this invention.
FIGURE 4 illustrates spring-loaded spherical ball type torque limiter.

In at least an embodiment, a hydraulic pump and a motor is provided which drives a gear (12a) through an associated pinion (12b). Flow to the motor (14) can be received either through a hitch pump of a tractor or through a separate pump (16) driven by a PTO shaft. The pump (16) and motor (14) combination, selected, is such that it gives the same speed as that of current mechanism. In at least a non-limiting exemplary embodiment, as seen in Figure 3:
• Gear Pump running at 2160 rpm
• 4:1 Gear Ratio
• PTO input @ 540 rpm

One of the advantages, of this architecture, is that load on the system / machine can be controlled by controlling system pressure through a relief valve (18) as shown in the Figure 3 of the accompanying drawings. Pressure setting of the relief valve (18) decides maximum torque capability of the machine. A flow control valve can be included in a circuit to adjust speed of the pump to suit field, of operation, requirements.

The pump (16) is driven by the PTO through gear box. Flow from the pump (16) is used to drive the gear motor (14). The motor shaft transmits torque and speed to the gear (12a) through pinion (12b) arrangement which, in turn, rotates the rake arms. During overload situations, torque requirement increases; however, the motor (14) does not generate higher torque since the torque is controlled using the relief valve (18). In this situation, the motor (14) slips; thereby, protecting the gear (12a), pinion (12b), and other mechanical components of the rake.

FIGURE 4 depicts a system that provides protection against sudden loads on tines. The design consists of a sleeve (22) (with front spherical shape) and a spring (24) contained within a cage (26) which can be screwed into a spacer (28). The spring (24) retains the sleeve (22) in its position which, in turn, fixes the tine arm. Tune arm torque control: The idea includes sleeve with front spherical shape, cage and spacer. The sleeve (22) is placed into the cage (26) with spring (24) such that it pushes sleeve (22) against cage (26). This assembly is screwed into the spacer (28) having female threads such that the spherical part of sleeve (22) slides into the tine arm hole. The spring (26) force pushes the sleeve (22) against the hole which keeps the tine arm (23) and profile tube (21) held together. When torque exceeds the predetermined set value, the sleeve (22) lifts against spring (24) and tine safely rotates without damage. The arrangement can be reset before next operation. The torque from the tine arm can be modulated with spring force.

When torque on the tine arm exceeds a set limit, force Fy (Resultant force Fr is split into Fx and Fy) lifts the sleeve (22) from its position and the tine arm slips from its position – thereby, protecting the tines and subsequent components along the load path.

FIGURE 5 and FIGURE 6 shows external and internal construction of the machine.

The machine has 2 groups mainly:
a. Rotating group; and
b. Non-rotating group.

Machine frames, generally, are made from tubular structures welded together supported with two, three, or four wheels. These wheels provide support to the rotating group, serves as transport trailed machine unit, but also for tracing ground as reference to adjust the height of the fingers in relation to ground surface.

REFERENCE NUMERAL PART / ITEM
1 THREE-POINT LINKAGE
2 LOWER LINK
3 RIGHT HAND GUARD
4 TINE
5 TINE ARM
6 LIGHTING BRACKET
7 GEARBOX
8 CRANK
9 DRAWBAR
10 RATCHET
11 CARDAN SHAFT PROTECTION
12 CARDAN SUPPORT
13 PARKING SUPPORT
14 LEFT HAND GUARD
15 WHEEL UNIT
16 TELESCOPING TUBE
17 SWATHING DEFLECTOR
18 ANTI-SNAKING KIT
19 TRAVERSE

In at least an embodiment, the rotating group consists of pinion (19), gear (2), casing (1).
In at least an embodiment, the non-rotating group consists of cover (4), shaft (27), cam (31), cover (27).
Power is supplied, to this machine, from a tractor PTO; this power is transmitted to the rotating group through a pinion (19) which, in turn, angularly displaces a helical gear (3) and casing (1). With this angular displacement, a connecting rod (34) follows a cam profile which gives desired motion to the connecting rod (34). The connecting rod (34), in turn, angularly displaces the tine and tine arm; thereby, collecting trash.

The current invention’s idea solves the failure of gear pinion and tine arm due to spike loading of the tines. This is identified as the major issue during field visits the downtime associated with this is estimated to be 40-56 hours. The invention, presented here, significantly reduces this failure mode.

TECHNICAL ADVANTAGES:
This invention provides an alternative architecture for transmitting power from a PTO shaft to a rake.
This invention provides a mechanism to control torque and speed through relief and flow controls.
This invention provides a mechanism to limit maximum torque in its associated rake machine.
This invention provides a mechanism to connect tine arm with profile tube to limit maximum torque in the rake machine.
This invention provides a mechanism to vary safe operating torque by varying spring force of the detent mechanism.
This invention provides a mechanism to handles time varying loads for the rake machine.
This invention works well with raised bed plantations such as sugarcane in addition to existing plain surface and material with relatively low density such as alfalfa hay, paddy, or wheat trash.
In the prior art, there was no overload protection built in; as a result, frequent failures were seen in applications subjected to time-varying loads due to uneven surfaces. The uneven surfaces are results of different crop bed preparation: e.g. paddy and wheat will have flat bed whereas sugarcane have raises bed arrangement. These problems are addressed by the current invention.
In the prior art, due to sudden loads, the weakest link in a load path would be damaged; the prior art failures include, tine arm, tines, profile tube, cam, gear and pinion or sometimes the casting parts as well; all of this is addressed by the current invention since it protect gear, pinion, tine arm and profile tube due to sudden load on the tines.

The TECHNICAL ADVANCEMENT of this invention lies in providing a hydraulic power transmission architecture which is provided to reduce mechanical downtime of a rotary rake machine caused by sudden loading of its tine arms. The hydraulic components are adjusted such that during peak load the motor is stalled by the limiting pressure of the relief valve.

While this detailed description has disclosed certain specific embodiments for illustrative purposes, various modifications will be apparent to those skilled in the art which do not constitute departures from the spirit and scope of the invention as defined in the following claims, and it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

Dated this 28th day of June, 2023

CHIRAG TANNA
of INK IDEE
APPLICANT’S PATENT AGENT
REGN. NO. IN/PA – 1785

,CLAIMS:WE CLAIM,

1. A hydraulic power transmission and tine arm torque control system, for controlling a rake machine, said control system comprising:
- a hydraulic pump (16) and a motor (14) configured to drive a gear (12a) through an associated pinion (12b) wherein, flow to said motor (14) being received through a pump (16) connected to a tractor or driven by a PTO shaft connected to said tractor;
- a relief valve (18), associated in connection with said motor (14) and said pump (16), such that pressure setting of said relief valve (18) deciding maximum torque capability of an associated machine; and
- a flow control valve, associated in connection with said motor (14) and said pump (16), configured to adjust speed of said pump (16) correlative to field of operation.

2. The control system as claimed in claim 1 wherein, said pump (16) being configured to operate at 2160 rpm, with 4:1 gear ratio, and with PTP input at 540 rpm.

3. The control system as claimed in claim 1 wherein, said PTO shaft transmits torque and speed to a gear (12a) through a pinion (12b) arrangement which, in turn, rotates rake arms.

4. The control system as claimed in claim 1 wherein, said sleeve (22) is placed into said cage (26) with a spring (24) such that it pushes said sleeve (22) against said cage (26) in order to form an assembly, said assembly being screwed into said spacer (28) having female threads such that a spherical part of said sleeve (22) slides into a tine arm hole, said spring (26) force pushes said sleeve (22) against said hole which keeps said tine arm (23) and said profile tube (21) held together.

5. The control system as claimed in claim 1 wherein, a rotating group consisting, essentially of said pinion (19), said gear (12a), said casing (14), received power from a PTO in order to angularly displace said pinion which, in turn, angularly displaces a helical gear (3) and said casing (14), said angular displacement motion being transferred to a connecting rod (34) connected by a cam profile which gives desired motion to said connecting rod (34), said connecting rod (34), in turn, angularly displaces said tine and tine arm; thereby, collecting trash.